1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
31 and force_fit_type_double.
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type_double takes a constant, an overflowable flag and a
43 prior overflow indicator. It forces the value to fit the type and
46 Note: Since the folders get called on non-gimple code as well as
47 gimple code, we need to handle GIMPLE tuples as well as their
48 corresponding tree equivalents. */
52 #include "coretypes.h"
57 #include "fixed-value.h"
66 #include "langhooks.h"
70 /* Nonzero if we are folding constants inside an initializer; zero
72 int folding_initializer = 0;
74 /* The following constants represent a bit based encoding of GCC's
75 comparison operators. This encoding simplifies transformations
76 on relational comparison operators, such as AND and OR. */
77 enum comparison_code {
96 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
97 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
98 static bool negate_mathfn_p (enum built_in_function);
99 static bool negate_expr_p (tree);
100 static tree negate_expr (tree);
101 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
102 static tree associate_trees (tree, tree, enum tree_code, tree);
103 static tree const_binop (enum tree_code, tree, tree, int);
104 static enum comparison_code comparison_to_compcode (enum tree_code);
105 static enum tree_code compcode_to_comparison (enum comparison_code);
106 static int operand_equal_for_comparison_p (tree, tree, tree);
107 static int twoval_comparison_p (tree, tree *, tree *, int *);
108 static tree eval_subst (tree, tree, tree, tree, tree);
109 static tree pedantic_omit_one_operand (tree, tree, tree);
110 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
111 static tree make_bit_field_ref (tree, tree, HOST_WIDE_INT, HOST_WIDE_INT, int);
112 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
113 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
114 enum machine_mode *, int *, int *,
116 static int all_ones_mask_p (const_tree, int);
117 static tree sign_bit_p (tree, const_tree);
118 static int simple_operand_p (const_tree);
119 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
120 static tree range_predecessor (tree);
121 static tree range_successor (tree);
122 static tree make_range (tree, int *, tree *, tree *, bool *);
123 static tree build_range_check (tree, tree, int, tree, tree);
124 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
126 static tree fold_range_test (enum tree_code, tree, tree, tree);
127 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
128 static tree unextend (tree, int, int, tree);
129 static tree fold_truthop (enum tree_code, tree, tree, tree);
130 static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
131 static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
132 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
133 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
136 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
138 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
139 static tree fold_div_compare (enum tree_code, tree, tree, tree);
140 static bool reorder_operands_p (const_tree, const_tree);
141 static tree fold_negate_const (tree, tree);
142 static tree fold_not_const (tree, tree);
143 static tree fold_relational_const (enum tree_code, tree, tree, tree);
144 static tree fold_convert_const (enum tree_code, tree, tree);
147 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
148 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
149 and SUM1. Then this yields nonzero if overflow occurred during the
152 Overflow occurs if A and B have the same sign, but A and SUM differ in
153 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
155 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
157 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
158 We do that by representing the two-word integer in 4 words, with only
159 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
160 number. The value of the word is LOWPART + HIGHPART * BASE. */
163 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
164 #define HIGHPART(x) \
165 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
166 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
168 /* Unpack a two-word integer into 4 words.
169 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
170 WORDS points to the array of HOST_WIDE_INTs. */
173 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
175 words[0] = LOWPART (low);
176 words[1] = HIGHPART (low);
177 words[2] = LOWPART (hi);
178 words[3] = HIGHPART (hi);
181 /* Pack an array of 4 words into a two-word integer.
182 WORDS points to the array of words.
183 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
186 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
189 *low = words[0] + words[1] * BASE;
190 *hi = words[2] + words[3] * BASE;
193 /* Force the double-word integer L1, H1 to be within the range of the
194 integer type TYPE. Stores the properly truncated and sign-extended
195 double-word integer in *LV, *HV. Returns true if the operation
196 overflows, that is, argument and result are different. */
199 fit_double_type (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
200 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, const_tree type)
202 unsigned HOST_WIDE_INT low0 = l1;
203 HOST_WIDE_INT high0 = h1;
205 int sign_extended_type;
207 if (POINTER_TYPE_P (type)
208 || TREE_CODE (type) == OFFSET_TYPE)
211 prec = TYPE_PRECISION (type);
213 /* Size types *are* sign extended. */
214 sign_extended_type = (!TYPE_UNSIGNED (type)
215 || (TREE_CODE (type) == INTEGER_TYPE
216 && TYPE_IS_SIZETYPE (type)));
218 /* First clear all bits that are beyond the type's precision. */
219 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
221 else if (prec > HOST_BITS_PER_WIDE_INT)
222 h1 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
226 if (prec < HOST_BITS_PER_WIDE_INT)
227 l1 &= ~((HOST_WIDE_INT) (-1) << prec);
230 /* Then do sign extension if necessary. */
231 if (!sign_extended_type)
232 /* No sign extension */;
233 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
234 /* Correct width already. */;
235 else if (prec > HOST_BITS_PER_WIDE_INT)
237 /* Sign extend top half? */
238 if (h1 & ((unsigned HOST_WIDE_INT)1
239 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
240 h1 |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
242 else if (prec == HOST_BITS_PER_WIDE_INT)
244 if ((HOST_WIDE_INT)l1 < 0)
249 /* Sign extend bottom half? */
250 if (l1 & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
253 l1 |= (HOST_WIDE_INT)(-1) << prec;
260 /* If the value didn't fit, signal overflow. */
261 return l1 != low0 || h1 != high0;
264 /* We force the double-int HIGH:LOW to the range of the type TYPE by
265 sign or zero extending it.
266 OVERFLOWABLE indicates if we are interested
267 in overflow of the value, when >0 we are only interested in signed
268 overflow, for <0 we are interested in any overflow. OVERFLOWED
269 indicates whether overflow has already occurred. CONST_OVERFLOWED
270 indicates whether constant overflow has already occurred. We force
271 T's value to be within range of T's type (by setting to 0 or 1 all
272 the bits outside the type's range). We set TREE_OVERFLOWED if,
273 OVERFLOWED is nonzero,
274 or OVERFLOWABLE is >0 and signed overflow occurs
275 or OVERFLOWABLE is <0 and any overflow occurs
276 We return a new tree node for the extended double-int. The node
277 is shared if no overflow flags are set. */
280 force_fit_type_double (tree type, unsigned HOST_WIDE_INT low,
281 HOST_WIDE_INT high, int overflowable,
284 int sign_extended_type;
287 /* Size types *are* sign extended. */
288 sign_extended_type = (!TYPE_UNSIGNED (type)
289 || (TREE_CODE (type) == INTEGER_TYPE
290 && TYPE_IS_SIZETYPE (type)));
292 overflow = fit_double_type (low, high, &low, &high, type);
294 /* If we need to set overflow flags, return a new unshared node. */
295 if (overflowed || overflow)
299 || (overflowable > 0 && sign_extended_type))
301 tree t = make_node (INTEGER_CST);
302 TREE_INT_CST_LOW (t) = low;
303 TREE_INT_CST_HIGH (t) = high;
304 TREE_TYPE (t) = type;
305 TREE_OVERFLOW (t) = 1;
310 /* Else build a shared node. */
311 return build_int_cst_wide (type, low, high);
314 /* Add two doubleword integers with doubleword result.
315 Return nonzero if the operation overflows according to UNSIGNED_P.
316 Each argument is given as two `HOST_WIDE_INT' pieces.
317 One argument is L1 and H1; the other, L2 and H2.
318 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
321 add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
322 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
323 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
326 unsigned HOST_WIDE_INT l;
330 h = h1 + h2 + (l < l1);
336 return (unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1;
338 return OVERFLOW_SUM_SIGN (h1, h2, h);
341 /* Negate a doubleword integer with doubleword result.
342 Return nonzero if the operation overflows, assuming it's signed.
343 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
344 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
347 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
348 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
354 return (*hv & h1) < 0;
364 /* Multiply two doubleword integers with doubleword result.
365 Return nonzero if the operation overflows according to UNSIGNED_P.
366 Each argument is given as two `HOST_WIDE_INT' pieces.
367 One argument is L1 and H1; the other, L2 and H2.
368 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
371 mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
372 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
373 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
376 HOST_WIDE_INT arg1[4];
377 HOST_WIDE_INT arg2[4];
378 HOST_WIDE_INT prod[4 * 2];
379 unsigned HOST_WIDE_INT carry;
381 unsigned HOST_WIDE_INT toplow, neglow;
382 HOST_WIDE_INT tophigh, neghigh;
384 encode (arg1, l1, h1);
385 encode (arg2, l2, h2);
387 memset (prod, 0, sizeof prod);
389 for (i = 0; i < 4; i++)
392 for (j = 0; j < 4; j++)
395 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
396 carry += arg1[i] * arg2[j];
397 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
399 prod[k] = LOWPART (carry);
400 carry = HIGHPART (carry);
405 decode (prod, lv, hv);
406 decode (prod + 4, &toplow, &tophigh);
408 /* Unsigned overflow is immediate. */
410 return (toplow | tophigh) != 0;
412 /* Check for signed overflow by calculating the signed representation of the
413 top half of the result; it should agree with the low half's sign bit. */
416 neg_double (l2, h2, &neglow, &neghigh);
417 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
421 neg_double (l1, h1, &neglow, &neghigh);
422 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
424 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
427 /* Shift the doubleword integer in L1, H1 left by COUNT places
428 keeping only PREC bits of result.
429 Shift right if COUNT is negative.
430 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
431 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
434 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
435 HOST_WIDE_INT count, unsigned int prec,
436 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
438 unsigned HOST_WIDE_INT signmask;
442 rshift_double (l1, h1, -count, prec, lv, hv, arith);
446 if (SHIFT_COUNT_TRUNCATED)
449 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
451 /* Shifting by the host word size is undefined according to the
452 ANSI standard, so we must handle this as a special case. */
456 else if (count >= HOST_BITS_PER_WIDE_INT)
458 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
463 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
464 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
468 /* Sign extend all bits that are beyond the precision. */
470 signmask = -((prec > HOST_BITS_PER_WIDE_INT
471 ? ((unsigned HOST_WIDE_INT) *hv
472 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
473 : (*lv >> (prec - 1))) & 1);
475 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
477 else if (prec >= HOST_BITS_PER_WIDE_INT)
479 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
480 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
485 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
486 *lv |= signmask << prec;
490 /* Shift the doubleword integer in L1, H1 right by COUNT places
491 keeping only PREC bits of result. COUNT must be positive.
492 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
493 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
496 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
497 HOST_WIDE_INT count, unsigned int prec,
498 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
501 unsigned HOST_WIDE_INT signmask;
504 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
507 if (SHIFT_COUNT_TRUNCATED)
510 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
512 /* Shifting by the host word size is undefined according to the
513 ANSI standard, so we must handle this as a special case. */
517 else if (count >= HOST_BITS_PER_WIDE_INT)
520 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
524 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
526 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
529 /* Zero / sign extend all bits that are beyond the precision. */
531 if (count >= (HOST_WIDE_INT)prec)
536 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
538 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
540 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
541 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
546 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
547 *lv |= signmask << (prec - count);
551 /* Rotate the doubleword integer in L1, H1 left by COUNT places
552 keeping only PREC bits of result.
553 Rotate right if COUNT is negative.
554 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
557 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
558 HOST_WIDE_INT count, unsigned int prec,
559 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
561 unsigned HOST_WIDE_INT s1l, s2l;
562 HOST_WIDE_INT s1h, s2h;
568 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
569 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
574 /* Rotate the doubleword integer in L1, H1 left by COUNT places
575 keeping only PREC bits of result. COUNT must be positive.
576 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
579 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
580 HOST_WIDE_INT count, unsigned int prec,
581 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
583 unsigned HOST_WIDE_INT s1l, s2l;
584 HOST_WIDE_INT s1h, s2h;
590 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
591 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
596 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
597 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
598 CODE is a tree code for a kind of division, one of
599 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
601 It controls how the quotient is rounded to an integer.
602 Return nonzero if the operation overflows.
603 UNS nonzero says do unsigned division. */
606 div_and_round_double (enum tree_code code, int uns,
607 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
608 HOST_WIDE_INT hnum_orig,
609 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
610 HOST_WIDE_INT hden_orig,
611 unsigned HOST_WIDE_INT *lquo,
612 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
616 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
617 HOST_WIDE_INT den[4], quo[4];
619 unsigned HOST_WIDE_INT work;
620 unsigned HOST_WIDE_INT carry = 0;
621 unsigned HOST_WIDE_INT lnum = lnum_orig;
622 HOST_WIDE_INT hnum = hnum_orig;
623 unsigned HOST_WIDE_INT lden = lden_orig;
624 HOST_WIDE_INT hden = hden_orig;
627 if (hden == 0 && lden == 0)
628 overflow = 1, lden = 1;
630 /* Calculate quotient sign and convert operands to unsigned. */
636 /* (minimum integer) / (-1) is the only overflow case. */
637 if (neg_double (lnum, hnum, &lnum, &hnum)
638 && ((HOST_WIDE_INT) lden & hden) == -1)
644 neg_double (lden, hden, &lden, &hden);
648 if (hnum == 0 && hden == 0)
649 { /* single precision */
651 /* This unsigned division rounds toward zero. */
657 { /* trivial case: dividend < divisor */
658 /* hden != 0 already checked. */
665 memset (quo, 0, sizeof quo);
667 memset (num, 0, sizeof num); /* to zero 9th element */
668 memset (den, 0, sizeof den);
670 encode (num, lnum, hnum);
671 encode (den, lden, hden);
673 /* Special code for when the divisor < BASE. */
674 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
676 /* hnum != 0 already checked. */
677 for (i = 4 - 1; i >= 0; i--)
679 work = num[i] + carry * BASE;
680 quo[i] = work / lden;
686 /* Full double precision division,
687 with thanks to Don Knuth's "Seminumerical Algorithms". */
688 int num_hi_sig, den_hi_sig;
689 unsigned HOST_WIDE_INT quo_est, scale;
691 /* Find the highest nonzero divisor digit. */
692 for (i = 4 - 1;; i--)
699 /* Insure that the first digit of the divisor is at least BASE/2.
700 This is required by the quotient digit estimation algorithm. */
702 scale = BASE / (den[den_hi_sig] + 1);
704 { /* scale divisor and dividend */
706 for (i = 0; i <= 4 - 1; i++)
708 work = (num[i] * scale) + carry;
709 num[i] = LOWPART (work);
710 carry = HIGHPART (work);
715 for (i = 0; i <= 4 - 1; i++)
717 work = (den[i] * scale) + carry;
718 den[i] = LOWPART (work);
719 carry = HIGHPART (work);
720 if (den[i] != 0) den_hi_sig = i;
727 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
729 /* Guess the next quotient digit, quo_est, by dividing the first
730 two remaining dividend digits by the high order quotient digit.
731 quo_est is never low and is at most 2 high. */
732 unsigned HOST_WIDE_INT tmp;
734 num_hi_sig = i + den_hi_sig + 1;
735 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
736 if (num[num_hi_sig] != den[den_hi_sig])
737 quo_est = work / den[den_hi_sig];
741 /* Refine quo_est so it's usually correct, and at most one high. */
742 tmp = work - quo_est * den[den_hi_sig];
744 && (den[den_hi_sig - 1] * quo_est
745 > (tmp * BASE + num[num_hi_sig - 2])))
748 /* Try QUO_EST as the quotient digit, by multiplying the
749 divisor by QUO_EST and subtracting from the remaining dividend.
750 Keep in mind that QUO_EST is the I - 1st digit. */
753 for (j = 0; j <= den_hi_sig; j++)
755 work = quo_est * den[j] + carry;
756 carry = HIGHPART (work);
757 work = num[i + j] - LOWPART (work);
758 num[i + j] = LOWPART (work);
759 carry += HIGHPART (work) != 0;
762 /* If quo_est was high by one, then num[i] went negative and
763 we need to correct things. */
764 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
767 carry = 0; /* add divisor back in */
768 for (j = 0; j <= den_hi_sig; j++)
770 work = num[i + j] + den[j] + carry;
771 carry = HIGHPART (work);
772 num[i + j] = LOWPART (work);
775 num [num_hi_sig] += carry;
778 /* Store the quotient digit. */
783 decode (quo, lquo, hquo);
786 /* If result is negative, make it so. */
788 neg_double (*lquo, *hquo, lquo, hquo);
790 /* Compute trial remainder: rem = num - (quo * den) */
791 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
792 neg_double (*lrem, *hrem, lrem, hrem);
793 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
798 case TRUNC_MOD_EXPR: /* round toward zero */
799 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
803 case FLOOR_MOD_EXPR: /* round toward negative infinity */
804 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
807 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
815 case CEIL_MOD_EXPR: /* round toward positive infinity */
816 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
818 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
826 case ROUND_MOD_EXPR: /* round to closest integer */
828 unsigned HOST_WIDE_INT labs_rem = *lrem;
829 HOST_WIDE_INT habs_rem = *hrem;
830 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
831 HOST_WIDE_INT habs_den = hden, htwice;
833 /* Get absolute values. */
835 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
837 neg_double (lden, hden, &labs_den, &habs_den);
839 /* If (2 * abs (lrem) >= abs (lden)), adjust the quotient. */
840 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
841 labs_rem, habs_rem, <wice, &htwice);
843 if (((unsigned HOST_WIDE_INT) habs_den
844 < (unsigned HOST_WIDE_INT) htwice)
845 || (((unsigned HOST_WIDE_INT) habs_den
846 == (unsigned HOST_WIDE_INT) htwice)
847 && (labs_den <= ltwice)))
851 add_double (*lquo, *hquo,
852 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
855 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
867 /* Compute true remainder: rem = num - (quo * den) */
868 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
869 neg_double (*lrem, *hrem, lrem, hrem);
870 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
874 /* If ARG2 divides ARG1 with zero remainder, carries out the division
875 of type CODE and returns the quotient.
876 Otherwise returns NULL_TREE. */
879 div_if_zero_remainder (enum tree_code code, const_tree arg1, const_tree arg2)
881 unsigned HOST_WIDE_INT int1l, int2l;
882 HOST_WIDE_INT int1h, int2h;
883 unsigned HOST_WIDE_INT quol, reml;
884 HOST_WIDE_INT quoh, remh;
885 tree type = TREE_TYPE (arg1);
886 int uns = TYPE_UNSIGNED (type);
888 int1l = TREE_INT_CST_LOW (arg1);
889 int1h = TREE_INT_CST_HIGH (arg1);
890 /* &obj[0] + -128 really should be compiled as &obj[-8] rather than
891 &obj[some_exotic_number]. */
892 if (POINTER_TYPE_P (type))
895 type = signed_type_for (type);
896 fit_double_type (int1l, int1h, &int1l, &int1h,
900 fit_double_type (int1l, int1h, &int1l, &int1h, type);
901 int2l = TREE_INT_CST_LOW (arg2);
902 int2h = TREE_INT_CST_HIGH (arg2);
904 div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
905 &quol, &quoh, &reml, &remh);
906 if (remh != 0 || reml != 0)
909 return build_int_cst_wide (type, quol, quoh);
912 /* This is nonzero if we should defer warnings about undefined
913 overflow. This facility exists because these warnings are a
914 special case. The code to estimate loop iterations does not want
915 to issue any warnings, since it works with expressions which do not
916 occur in user code. Various bits of cleanup code call fold(), but
917 only use the result if it has certain characteristics (e.g., is a
918 constant); that code only wants to issue a warning if the result is
921 static int fold_deferring_overflow_warnings;
923 /* If a warning about undefined overflow is deferred, this is the
924 warning. Note that this may cause us to turn two warnings into
925 one, but that is fine since it is sufficient to only give one
926 warning per expression. */
928 static const char* fold_deferred_overflow_warning;
930 /* If a warning about undefined overflow is deferred, this is the
931 level at which the warning should be emitted. */
933 static enum warn_strict_overflow_code fold_deferred_overflow_code;
935 /* Start deferring overflow warnings. We could use a stack here to
936 permit nested calls, but at present it is not necessary. */
939 fold_defer_overflow_warnings (void)
941 ++fold_deferring_overflow_warnings;
944 /* Stop deferring overflow warnings. If there is a pending warning,
945 and ISSUE is true, then issue the warning if appropriate. STMT is
946 the statement with which the warning should be associated (used for
947 location information); STMT may be NULL. CODE is the level of the
948 warning--a warn_strict_overflow_code value. This function will use
949 the smaller of CODE and the deferred code when deciding whether to
950 issue the warning. CODE may be zero to mean to always use the
954 fold_undefer_overflow_warnings (bool issue, const_gimple stmt, int code)
959 gcc_assert (fold_deferring_overflow_warnings > 0);
960 --fold_deferring_overflow_warnings;
961 if (fold_deferring_overflow_warnings > 0)
963 if (fold_deferred_overflow_warning != NULL
965 && code < (int) fold_deferred_overflow_code)
966 fold_deferred_overflow_code = (enum warn_strict_overflow_code) code;
970 warnmsg = fold_deferred_overflow_warning;
971 fold_deferred_overflow_warning = NULL;
973 if (!issue || warnmsg == NULL)
976 if (gimple_no_warning_p (stmt))
979 /* Use the smallest code level when deciding to issue the
981 if (code == 0 || code > (int) fold_deferred_overflow_code)
982 code = fold_deferred_overflow_code;
984 if (!issue_strict_overflow_warning (code))
988 locus = input_location;
990 locus = gimple_location (stmt);
991 warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
994 /* Stop deferring overflow warnings, ignoring any deferred
998 fold_undefer_and_ignore_overflow_warnings (void)
1000 fold_undefer_overflow_warnings (false, NULL, 0);
1003 /* Whether we are deferring overflow warnings. */
1006 fold_deferring_overflow_warnings_p (void)
1008 return fold_deferring_overflow_warnings > 0;
1011 /* This is called when we fold something based on the fact that signed
1012 overflow is undefined. */
1015 fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
1017 if (fold_deferring_overflow_warnings > 0)
1019 if (fold_deferred_overflow_warning == NULL
1020 || wc < fold_deferred_overflow_code)
1022 fold_deferred_overflow_warning = gmsgid;
1023 fold_deferred_overflow_code = wc;
1026 else if (issue_strict_overflow_warning (wc))
1027 warning (OPT_Wstrict_overflow, gmsgid);
1030 /* Return true if the built-in mathematical function specified by CODE
1031 is odd, i.e. -f(x) == f(-x). */
1034 negate_mathfn_p (enum built_in_function code)
1038 CASE_FLT_FN (BUILT_IN_ASIN):
1039 CASE_FLT_FN (BUILT_IN_ASINH):
1040 CASE_FLT_FN (BUILT_IN_ATAN):
1041 CASE_FLT_FN (BUILT_IN_ATANH):
1042 CASE_FLT_FN (BUILT_IN_CASIN):
1043 CASE_FLT_FN (BUILT_IN_CASINH):
1044 CASE_FLT_FN (BUILT_IN_CATAN):
1045 CASE_FLT_FN (BUILT_IN_CATANH):
1046 CASE_FLT_FN (BUILT_IN_CBRT):
1047 CASE_FLT_FN (BUILT_IN_CPROJ):
1048 CASE_FLT_FN (BUILT_IN_CSIN):
1049 CASE_FLT_FN (BUILT_IN_CSINH):
1050 CASE_FLT_FN (BUILT_IN_CTAN):
1051 CASE_FLT_FN (BUILT_IN_CTANH):
1052 CASE_FLT_FN (BUILT_IN_ERF):
1053 CASE_FLT_FN (BUILT_IN_LLROUND):
1054 CASE_FLT_FN (BUILT_IN_LROUND):
1055 CASE_FLT_FN (BUILT_IN_ROUND):
1056 CASE_FLT_FN (BUILT_IN_SIN):
1057 CASE_FLT_FN (BUILT_IN_SINH):
1058 CASE_FLT_FN (BUILT_IN_TAN):
1059 CASE_FLT_FN (BUILT_IN_TANH):
1060 CASE_FLT_FN (BUILT_IN_TRUNC):
1063 CASE_FLT_FN (BUILT_IN_LLRINT):
1064 CASE_FLT_FN (BUILT_IN_LRINT):
1065 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1066 CASE_FLT_FN (BUILT_IN_RINT):
1067 return !flag_rounding_math;
1075 /* Check whether we may negate an integer constant T without causing
1079 may_negate_without_overflow_p (const_tree t)
1081 unsigned HOST_WIDE_INT val;
1085 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1087 type = TREE_TYPE (t);
1088 if (TYPE_UNSIGNED (type))
1091 prec = TYPE_PRECISION (type);
1092 if (prec > HOST_BITS_PER_WIDE_INT)
1094 if (TREE_INT_CST_LOW (t) != 0)
1096 prec -= HOST_BITS_PER_WIDE_INT;
1097 val = TREE_INT_CST_HIGH (t);
1100 val = TREE_INT_CST_LOW (t);
1101 if (prec < HOST_BITS_PER_WIDE_INT)
1102 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1103 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1106 /* Determine whether an expression T can be cheaply negated using
1107 the function negate_expr without introducing undefined overflow. */
1110 negate_expr_p (tree t)
1117 type = TREE_TYPE (t);
1119 STRIP_SIGN_NOPS (t);
1120 switch (TREE_CODE (t))
1123 if (TYPE_OVERFLOW_WRAPS (type))
1126 /* Check that -CST will not overflow type. */
1127 return may_negate_without_overflow_p (t);
1129 return (INTEGRAL_TYPE_P (type)
1130 && TYPE_OVERFLOW_WRAPS (type));
1138 return negate_expr_p (TREE_REALPART (t))
1139 && negate_expr_p (TREE_IMAGPART (t));
1142 return negate_expr_p (TREE_OPERAND (t, 0))
1143 && negate_expr_p (TREE_OPERAND (t, 1));
1146 return negate_expr_p (TREE_OPERAND (t, 0));
1149 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1150 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1152 /* -(A + B) -> (-B) - A. */
1153 if (negate_expr_p (TREE_OPERAND (t, 1))
1154 && reorder_operands_p (TREE_OPERAND (t, 0),
1155 TREE_OPERAND (t, 1)))
1157 /* -(A + B) -> (-A) - B. */
1158 return negate_expr_p (TREE_OPERAND (t, 0));
1161 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1162 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1163 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1164 && reorder_operands_p (TREE_OPERAND (t, 0),
1165 TREE_OPERAND (t, 1));
1168 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1174 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1175 return negate_expr_p (TREE_OPERAND (t, 1))
1176 || negate_expr_p (TREE_OPERAND (t, 0));
1179 case TRUNC_DIV_EXPR:
1180 case ROUND_DIV_EXPR:
1181 case FLOOR_DIV_EXPR:
1183 case EXACT_DIV_EXPR:
1184 /* In general we can't negate A / B, because if A is INT_MIN and
1185 B is 1, we may turn this into INT_MIN / -1 which is undefined
1186 and actually traps on some architectures. But if overflow is
1187 undefined, we can negate, because - (INT_MIN / 1) is an
1189 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1190 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1192 return negate_expr_p (TREE_OPERAND (t, 1))
1193 || negate_expr_p (TREE_OPERAND (t, 0));
1196 /* Negate -((double)float) as (double)(-float). */
1197 if (TREE_CODE (type) == REAL_TYPE)
1199 tree tem = strip_float_extensions (t);
1201 return negate_expr_p (tem);
1206 /* Negate -f(x) as f(-x). */
1207 if (negate_mathfn_p (builtin_mathfn_code (t)))
1208 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1212 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1213 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1215 tree op1 = TREE_OPERAND (t, 1);
1216 if (TREE_INT_CST_HIGH (op1) == 0
1217 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1218 == TREE_INT_CST_LOW (op1))
1229 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1230 simplification is possible.
1231 If negate_expr_p would return true for T, NULL_TREE will never be
1235 fold_negate_expr (tree t)
1237 tree type = TREE_TYPE (t);
1240 switch (TREE_CODE (t))
1242 /* Convert - (~A) to A + 1. */
1244 if (INTEGRAL_TYPE_P (type))
1245 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1246 build_int_cst (type, 1));
1250 tem = fold_negate_const (t, type);
1251 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1252 || !TYPE_OVERFLOW_TRAPS (type))
1257 tem = fold_negate_const (t, type);
1258 /* Two's complement FP formats, such as c4x, may overflow. */
1259 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1264 tem = fold_negate_const (t, type);
1269 tree rpart = negate_expr (TREE_REALPART (t));
1270 tree ipart = negate_expr (TREE_IMAGPART (t));
1272 if ((TREE_CODE (rpart) == REAL_CST
1273 && TREE_CODE (ipart) == REAL_CST)
1274 || (TREE_CODE (rpart) == INTEGER_CST
1275 && TREE_CODE (ipart) == INTEGER_CST))
1276 return build_complex (type, rpart, ipart);
1281 if (negate_expr_p (t))
1282 return fold_build2 (COMPLEX_EXPR, type,
1283 fold_negate_expr (TREE_OPERAND (t, 0)),
1284 fold_negate_expr (TREE_OPERAND (t, 1)));
1288 if (negate_expr_p (t))
1289 return fold_build1 (CONJ_EXPR, type,
1290 fold_negate_expr (TREE_OPERAND (t, 0)));
1294 return TREE_OPERAND (t, 0);
1297 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1298 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1300 /* -(A + B) -> (-B) - A. */
1301 if (negate_expr_p (TREE_OPERAND (t, 1))
1302 && reorder_operands_p (TREE_OPERAND (t, 0),
1303 TREE_OPERAND (t, 1)))
1305 tem = negate_expr (TREE_OPERAND (t, 1));
1306 return fold_build2 (MINUS_EXPR, type,
1307 tem, TREE_OPERAND (t, 0));
1310 /* -(A + B) -> (-A) - B. */
1311 if (negate_expr_p (TREE_OPERAND (t, 0)))
1313 tem = negate_expr (TREE_OPERAND (t, 0));
1314 return fold_build2 (MINUS_EXPR, type,
1315 tem, TREE_OPERAND (t, 1));
1321 /* - (A - B) -> B - A */
1322 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1323 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1324 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1325 return fold_build2 (MINUS_EXPR, type,
1326 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1330 if (TYPE_UNSIGNED (type))
1336 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1338 tem = TREE_OPERAND (t, 1);
1339 if (negate_expr_p (tem))
1340 return fold_build2 (TREE_CODE (t), type,
1341 TREE_OPERAND (t, 0), negate_expr (tem));
1342 tem = TREE_OPERAND (t, 0);
1343 if (negate_expr_p (tem))
1344 return fold_build2 (TREE_CODE (t), type,
1345 negate_expr (tem), TREE_OPERAND (t, 1));
1349 case TRUNC_DIV_EXPR:
1350 case ROUND_DIV_EXPR:
1351 case FLOOR_DIV_EXPR:
1353 case EXACT_DIV_EXPR:
1354 /* In general we can't negate A / B, because if A is INT_MIN and
1355 B is 1, we may turn this into INT_MIN / -1 which is undefined
1356 and actually traps on some architectures. But if overflow is
1357 undefined, we can negate, because - (INT_MIN / 1) is an
1359 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1361 const char * const warnmsg = G_("assuming signed overflow does not "
1362 "occur when negating a division");
1363 tem = TREE_OPERAND (t, 1);
1364 if (negate_expr_p (tem))
1366 if (INTEGRAL_TYPE_P (type)
1367 && (TREE_CODE (tem) != INTEGER_CST
1368 || integer_onep (tem)))
1369 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1370 return fold_build2 (TREE_CODE (t), type,
1371 TREE_OPERAND (t, 0), negate_expr (tem));
1373 tem = TREE_OPERAND (t, 0);
1374 if (negate_expr_p (tem))
1376 if (INTEGRAL_TYPE_P (type)
1377 && (TREE_CODE (tem) != INTEGER_CST
1378 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1379 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1380 return fold_build2 (TREE_CODE (t), type,
1381 negate_expr (tem), TREE_OPERAND (t, 1));
1387 /* Convert -((double)float) into (double)(-float). */
1388 if (TREE_CODE (type) == REAL_TYPE)
1390 tem = strip_float_extensions (t);
1391 if (tem != t && negate_expr_p (tem))
1392 return fold_convert (type, negate_expr (tem));
1397 /* Negate -f(x) as f(-x). */
1398 if (negate_mathfn_p (builtin_mathfn_code (t))
1399 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1403 fndecl = get_callee_fndecl (t);
1404 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1405 return build_call_expr (fndecl, 1, arg);
1410 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1411 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1413 tree op1 = TREE_OPERAND (t, 1);
1414 if (TREE_INT_CST_HIGH (op1) == 0
1415 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1416 == TREE_INT_CST_LOW (op1))
1418 tree ntype = TYPE_UNSIGNED (type)
1419 ? signed_type_for (type)
1420 : unsigned_type_for (type);
1421 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1422 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1423 return fold_convert (type, temp);
1435 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1436 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1437 return NULL_TREE. */
1440 negate_expr (tree t)
1447 type = TREE_TYPE (t);
1448 STRIP_SIGN_NOPS (t);
1450 tem = fold_negate_expr (t);
1452 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1453 return fold_convert (type, tem);
1456 /* Split a tree IN into a constant, literal and variable parts that could be
1457 combined with CODE to make IN. "constant" means an expression with
1458 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1459 commutative arithmetic operation. Store the constant part into *CONP,
1460 the literal in *LITP and return the variable part. If a part isn't
1461 present, set it to null. If the tree does not decompose in this way,
1462 return the entire tree as the variable part and the other parts as null.
1464 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1465 case, we negate an operand that was subtracted. Except if it is a
1466 literal for which we use *MINUS_LITP instead.
1468 If NEGATE_P is true, we are negating all of IN, again except a literal
1469 for which we use *MINUS_LITP instead.
1471 If IN is itself a literal or constant, return it as appropriate.
1473 Note that we do not guarantee that any of the three values will be the
1474 same type as IN, but they will have the same signedness and mode. */
1477 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1478 tree *minus_litp, int negate_p)
1486 /* Strip any conversions that don't change the machine mode or signedness. */
1487 STRIP_SIGN_NOPS (in);
1489 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
1490 || TREE_CODE (in) == FIXED_CST)
1492 else if (TREE_CODE (in) == code
1493 || ((! FLOAT_TYPE_P (TREE_TYPE (in)) || flag_associative_math)
1494 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
1495 /* We can associate addition and subtraction together (even
1496 though the C standard doesn't say so) for integers because
1497 the value is not affected. For reals, the value might be
1498 affected, so we can't. */
1499 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1500 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1502 tree op0 = TREE_OPERAND (in, 0);
1503 tree op1 = TREE_OPERAND (in, 1);
1504 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1505 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1507 /* First see if either of the operands is a literal, then a constant. */
1508 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
1509 || TREE_CODE (op0) == FIXED_CST)
1510 *litp = op0, op0 = 0;
1511 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
1512 || TREE_CODE (op1) == FIXED_CST)
1513 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1515 if (op0 != 0 && TREE_CONSTANT (op0))
1516 *conp = op0, op0 = 0;
1517 else if (op1 != 0 && TREE_CONSTANT (op1))
1518 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1520 /* If we haven't dealt with either operand, this is not a case we can
1521 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1522 if (op0 != 0 && op1 != 0)
1527 var = op1, neg_var_p = neg1_p;
1529 /* Now do any needed negations. */
1531 *minus_litp = *litp, *litp = 0;
1533 *conp = negate_expr (*conp);
1535 var = negate_expr (var);
1537 else if (TREE_CONSTANT (in))
1545 *minus_litp = *litp, *litp = 0;
1546 else if (*minus_litp)
1547 *litp = *minus_litp, *minus_litp = 0;
1548 *conp = negate_expr (*conp);
1549 var = negate_expr (var);
1555 /* Re-associate trees split by the above function. T1 and T2 are either
1556 expressions to associate or null. Return the new expression, if any. If
1557 we build an operation, do it in TYPE and with CODE. */
1560 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1567 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1568 try to fold this since we will have infinite recursion. But do
1569 deal with any NEGATE_EXPRs. */
1570 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1571 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1573 if (code == PLUS_EXPR)
1575 if (TREE_CODE (t1) == NEGATE_EXPR)
1576 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1577 fold_convert (type, TREE_OPERAND (t1, 0)));
1578 else if (TREE_CODE (t2) == NEGATE_EXPR)
1579 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1580 fold_convert (type, TREE_OPERAND (t2, 0)));
1581 else if (integer_zerop (t2))
1582 return fold_convert (type, t1);
1584 else if (code == MINUS_EXPR)
1586 if (integer_zerop (t2))
1587 return fold_convert (type, t1);
1590 return build2 (code, type, fold_convert (type, t1),
1591 fold_convert (type, t2));
1594 return fold_build2 (code, type, fold_convert (type, t1),
1595 fold_convert (type, t2));
1598 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1599 for use in int_const_binop, size_binop and size_diffop. */
1602 int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
1604 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1606 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1621 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1622 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1623 && TYPE_MODE (type1) == TYPE_MODE (type2);
1627 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1628 to produce a new constant. Return NULL_TREE if we don't know how
1629 to evaluate CODE at compile-time.
1631 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1634 int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2, int notrunc)
1636 unsigned HOST_WIDE_INT int1l, int2l;
1637 HOST_WIDE_INT int1h, int2h;
1638 unsigned HOST_WIDE_INT low;
1640 unsigned HOST_WIDE_INT garbagel;
1641 HOST_WIDE_INT garbageh;
1643 tree type = TREE_TYPE (arg1);
1644 int uns = TYPE_UNSIGNED (type);
1646 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1649 int1l = TREE_INT_CST_LOW (arg1);
1650 int1h = TREE_INT_CST_HIGH (arg1);
1651 int2l = TREE_INT_CST_LOW (arg2);
1652 int2h = TREE_INT_CST_HIGH (arg2);
1657 low = int1l | int2l, hi = int1h | int2h;
1661 low = int1l ^ int2l, hi = int1h ^ int2h;
1665 low = int1l & int2l, hi = int1h & int2h;
1671 /* It's unclear from the C standard whether shifts can overflow.
1672 The following code ignores overflow; perhaps a C standard
1673 interpretation ruling is needed. */
1674 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1681 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1686 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1690 neg_double (int2l, int2h, &low, &hi);
1691 add_double (int1l, int1h, low, hi, &low, &hi);
1692 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1696 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1699 case TRUNC_DIV_EXPR:
1700 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1701 case EXACT_DIV_EXPR:
1702 /* This is a shortcut for a common special case. */
1703 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1704 && !TREE_OVERFLOW (arg1)
1705 && !TREE_OVERFLOW (arg2)
1706 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1708 if (code == CEIL_DIV_EXPR)
1711 low = int1l / int2l, hi = 0;
1715 /* ... fall through ... */
1717 case ROUND_DIV_EXPR:
1718 if (int2h == 0 && int2l == 0)
1720 if (int2h == 0 && int2l == 1)
1722 low = int1l, hi = int1h;
1725 if (int1l == int2l && int1h == int2h
1726 && ! (int1l == 0 && int1h == 0))
1731 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1732 &low, &hi, &garbagel, &garbageh);
1735 case TRUNC_MOD_EXPR:
1736 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1737 /* This is a shortcut for a common special case. */
1738 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1739 && !TREE_OVERFLOW (arg1)
1740 && !TREE_OVERFLOW (arg2)
1741 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1743 if (code == CEIL_MOD_EXPR)
1745 low = int1l % int2l, hi = 0;
1749 /* ... fall through ... */
1751 case ROUND_MOD_EXPR:
1752 if (int2h == 0 && int2l == 0)
1754 overflow = div_and_round_double (code, uns,
1755 int1l, int1h, int2l, int2h,
1756 &garbagel, &garbageh, &low, &hi);
1762 low = (((unsigned HOST_WIDE_INT) int1h
1763 < (unsigned HOST_WIDE_INT) int2h)
1764 || (((unsigned HOST_WIDE_INT) int1h
1765 == (unsigned HOST_WIDE_INT) int2h)
1768 low = (int1h < int2h
1769 || (int1h == int2h && int1l < int2l));
1771 if (low == (code == MIN_EXPR))
1772 low = int1l, hi = int1h;
1774 low = int2l, hi = int2h;
1783 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1785 /* Propagate overflow flags ourselves. */
1786 if (((!uns || is_sizetype) && overflow)
1787 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1790 TREE_OVERFLOW (t) = 1;
1794 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1795 ((!uns || is_sizetype) && overflow)
1796 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1801 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1802 constant. We assume ARG1 and ARG2 have the same data type, or at least
1803 are the same kind of constant and the same machine mode. Return zero if
1804 combining the constants is not allowed in the current operating mode.
1806 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1809 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1811 /* Sanity check for the recursive cases. */
1818 if (TREE_CODE (arg1) == INTEGER_CST)
1819 return int_const_binop (code, arg1, arg2, notrunc);
1821 if (TREE_CODE (arg1) == REAL_CST)
1823 enum machine_mode mode;
1826 REAL_VALUE_TYPE value;
1827 REAL_VALUE_TYPE result;
1831 /* The following codes are handled by real_arithmetic. */
1846 d1 = TREE_REAL_CST (arg1);
1847 d2 = TREE_REAL_CST (arg2);
1849 type = TREE_TYPE (arg1);
1850 mode = TYPE_MODE (type);
1852 /* Don't perform operation if we honor signaling NaNs and
1853 either operand is a NaN. */
1854 if (HONOR_SNANS (mode)
1855 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1858 /* Don't perform operation if it would raise a division
1859 by zero exception. */
1860 if (code == RDIV_EXPR
1861 && REAL_VALUES_EQUAL (d2, dconst0)
1862 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1865 /* If either operand is a NaN, just return it. Otherwise, set up
1866 for floating-point trap; we return an overflow. */
1867 if (REAL_VALUE_ISNAN (d1))
1869 else if (REAL_VALUE_ISNAN (d2))
1872 inexact = real_arithmetic (&value, code, &d1, &d2);
1873 real_convert (&result, mode, &value);
1875 /* Don't constant fold this floating point operation if
1876 the result has overflowed and flag_trapping_math. */
1877 if (flag_trapping_math
1878 && MODE_HAS_INFINITIES (mode)
1879 && REAL_VALUE_ISINF (result)
1880 && !REAL_VALUE_ISINF (d1)
1881 && !REAL_VALUE_ISINF (d2))
1884 /* Don't constant fold this floating point operation if the
1885 result may dependent upon the run-time rounding mode and
1886 flag_rounding_math is set, or if GCC's software emulation
1887 is unable to accurately represent the result. */
1888 if ((flag_rounding_math
1889 || (MODE_COMPOSITE_P (mode) && !flag_unsafe_math_optimizations))
1890 && (inexact || !real_identical (&result, &value)))
1893 t = build_real (type, result);
1895 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1899 if (TREE_CODE (arg1) == FIXED_CST)
1901 FIXED_VALUE_TYPE f1;
1902 FIXED_VALUE_TYPE f2;
1903 FIXED_VALUE_TYPE result;
1908 /* The following codes are handled by fixed_arithmetic. */
1914 case TRUNC_DIV_EXPR:
1915 f2 = TREE_FIXED_CST (arg2);
1920 f2.data.high = TREE_INT_CST_HIGH (arg2);
1921 f2.data.low = TREE_INT_CST_LOW (arg2);
1929 f1 = TREE_FIXED_CST (arg1);
1930 type = TREE_TYPE (arg1);
1931 sat_p = TYPE_SATURATING (type);
1932 overflow_p = fixed_arithmetic (&result, code, &f1, &f2, sat_p);
1933 t = build_fixed (type, result);
1934 /* Propagate overflow flags. */
1935 if (overflow_p | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1936 TREE_OVERFLOW (t) = 1;
1940 if (TREE_CODE (arg1) == COMPLEX_CST)
1942 tree type = TREE_TYPE (arg1);
1943 tree r1 = TREE_REALPART (arg1);
1944 tree i1 = TREE_IMAGPART (arg1);
1945 tree r2 = TREE_REALPART (arg2);
1946 tree i2 = TREE_IMAGPART (arg2);
1953 real = const_binop (code, r1, r2, notrunc);
1954 imag = const_binop (code, i1, i2, notrunc);
1958 real = const_binop (MINUS_EXPR,
1959 const_binop (MULT_EXPR, r1, r2, notrunc),
1960 const_binop (MULT_EXPR, i1, i2, notrunc),
1962 imag = const_binop (PLUS_EXPR,
1963 const_binop (MULT_EXPR, r1, i2, notrunc),
1964 const_binop (MULT_EXPR, i1, r2, notrunc),
1971 = const_binop (PLUS_EXPR,
1972 const_binop (MULT_EXPR, r2, r2, notrunc),
1973 const_binop (MULT_EXPR, i2, i2, notrunc),
1976 = const_binop (PLUS_EXPR,
1977 const_binop (MULT_EXPR, r1, r2, notrunc),
1978 const_binop (MULT_EXPR, i1, i2, notrunc),
1981 = const_binop (MINUS_EXPR,
1982 const_binop (MULT_EXPR, i1, r2, notrunc),
1983 const_binop (MULT_EXPR, r1, i2, notrunc),
1986 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1987 code = TRUNC_DIV_EXPR;
1989 real = const_binop (code, t1, magsquared, notrunc);
1990 imag = const_binop (code, t2, magsquared, notrunc);
1999 return build_complex (type, real, imag);
2002 if (TREE_CODE (arg1) == VECTOR_CST)
2004 tree type = TREE_TYPE(arg1);
2005 int count = TYPE_VECTOR_SUBPARTS (type), i;
2006 tree elements1, elements2, list = NULL_TREE;
2008 if(TREE_CODE(arg2) != VECTOR_CST)
2011 elements1 = TREE_VECTOR_CST_ELTS (arg1);
2012 elements2 = TREE_VECTOR_CST_ELTS (arg2);
2014 for (i = 0; i < count; i++)
2016 tree elem1, elem2, elem;
2018 /* The trailing elements can be empty and should be treated as 0 */
2020 elem1 = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2023 elem1 = TREE_VALUE(elements1);
2024 elements1 = TREE_CHAIN (elements1);
2028 elem2 = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2031 elem2 = TREE_VALUE(elements2);
2032 elements2 = TREE_CHAIN (elements2);
2035 elem = const_binop (code, elem1, elem2, notrunc);
2037 /* It is possible that const_binop cannot handle the given
2038 code and return NULL_TREE */
2039 if(elem == NULL_TREE)
2042 list = tree_cons (NULL_TREE, elem, list);
2044 return build_vector(type, nreverse(list));
2049 /* Create a size type INT_CST node with NUMBER sign extended. KIND
2050 indicates which particular sizetype to create. */
2053 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
2055 return build_int_cst (sizetype_tab[(int) kind], number);
2058 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2059 is a tree code. The type of the result is taken from the operands.
2060 Both must be equivalent integer types, ala int_binop_types_match_p.
2061 If the operands are constant, so is the result. */
2064 size_binop (enum tree_code code, tree arg0, tree arg1)
2066 tree type = TREE_TYPE (arg0);
2068 if (arg0 == error_mark_node || arg1 == error_mark_node)
2069 return error_mark_node;
2071 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
2074 /* Handle the special case of two integer constants faster. */
2075 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
2077 /* And some specific cases even faster than that. */
2078 if (code == PLUS_EXPR)
2080 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
2082 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2085 else if (code == MINUS_EXPR)
2087 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2090 else if (code == MULT_EXPR)
2092 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
2096 /* Handle general case of two integer constants. */
2097 return int_const_binop (code, arg0, arg1, 0);
2100 return fold_build2 (code, type, arg0, arg1);
2103 /* Given two values, either both of sizetype or both of bitsizetype,
2104 compute the difference between the two values. Return the value
2105 in signed type corresponding to the type of the operands. */
2108 size_diffop (tree arg0, tree arg1)
2110 tree type = TREE_TYPE (arg0);
2113 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
2116 /* If the type is already signed, just do the simple thing. */
2117 if (!TYPE_UNSIGNED (type))
2118 return size_binop (MINUS_EXPR, arg0, arg1);
2120 if (type == sizetype)
2122 else if (type == bitsizetype)
2123 ctype = sbitsizetype;
2125 ctype = signed_type_for (type);
2127 /* If either operand is not a constant, do the conversions to the signed
2128 type and subtract. The hardware will do the right thing with any
2129 overflow in the subtraction. */
2130 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2131 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
2132 fold_convert (ctype, arg1));
2134 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2135 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2136 overflow) and negate (which can't either). Special-case a result
2137 of zero while we're here. */
2138 if (tree_int_cst_equal (arg0, arg1))
2139 return build_int_cst (ctype, 0);
2140 else if (tree_int_cst_lt (arg1, arg0))
2141 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2143 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
2144 fold_convert (ctype, size_binop (MINUS_EXPR,
2148 /* A subroutine of fold_convert_const handling conversions of an
2149 INTEGER_CST to another integer type. */
2152 fold_convert_const_int_from_int (tree type, const_tree arg1)
2156 /* Given an integer constant, make new constant with new type,
2157 appropriately sign-extended or truncated. */
2158 t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
2159 TREE_INT_CST_HIGH (arg1),
2160 /* Don't set the overflow when
2161 converting from a pointer, */
2162 !POINTER_TYPE_P (TREE_TYPE (arg1))
2163 /* or to a sizetype with same signedness
2164 and the precision is unchanged.
2165 ??? sizetype is always sign-extended,
2166 but its signedness depends on the
2167 frontend. Thus we see spurious overflows
2168 here if we do not check this. */
2169 && !((TYPE_PRECISION (TREE_TYPE (arg1))
2170 == TYPE_PRECISION (type))
2171 && (TYPE_UNSIGNED (TREE_TYPE (arg1))
2172 == TYPE_UNSIGNED (type))
2173 && ((TREE_CODE (TREE_TYPE (arg1)) == INTEGER_TYPE
2174 && TYPE_IS_SIZETYPE (TREE_TYPE (arg1)))
2175 || (TREE_CODE (type) == INTEGER_TYPE
2176 && TYPE_IS_SIZETYPE (type)))),
2177 (TREE_INT_CST_HIGH (arg1) < 0
2178 && (TYPE_UNSIGNED (type)
2179 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2180 | TREE_OVERFLOW (arg1));
2185 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2186 to an integer type. */
2189 fold_convert_const_int_from_real (enum tree_code code, tree type, const_tree arg1)
2194 /* The following code implements the floating point to integer
2195 conversion rules required by the Java Language Specification,
2196 that IEEE NaNs are mapped to zero and values that overflow
2197 the target precision saturate, i.e. values greater than
2198 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2199 are mapped to INT_MIN. These semantics are allowed by the
2200 C and C++ standards that simply state that the behavior of
2201 FP-to-integer conversion is unspecified upon overflow. */
2203 HOST_WIDE_INT high, low;
2205 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2209 case FIX_TRUNC_EXPR:
2210 real_trunc (&r, VOIDmode, &x);
2217 /* If R is NaN, return zero and show we have an overflow. */
2218 if (REAL_VALUE_ISNAN (r))
2225 /* See if R is less than the lower bound or greater than the
2230 tree lt = TYPE_MIN_VALUE (type);
2231 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2232 if (REAL_VALUES_LESS (r, l))
2235 high = TREE_INT_CST_HIGH (lt);
2236 low = TREE_INT_CST_LOW (lt);
2242 tree ut = TYPE_MAX_VALUE (type);
2245 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2246 if (REAL_VALUES_LESS (u, r))
2249 high = TREE_INT_CST_HIGH (ut);
2250 low = TREE_INT_CST_LOW (ut);
2256 REAL_VALUE_TO_INT (&low, &high, r);
2258 t = force_fit_type_double (type, low, high, -1,
2259 overflow | TREE_OVERFLOW (arg1));
2263 /* A subroutine of fold_convert_const handling conversions of a
2264 FIXED_CST to an integer type. */
2267 fold_convert_const_int_from_fixed (tree type, const_tree arg1)
2270 double_int temp, temp_trunc;
2273 /* Right shift FIXED_CST to temp by fbit. */
2274 temp = TREE_FIXED_CST (arg1).data;
2275 mode = TREE_FIXED_CST (arg1).mode;
2276 if (GET_MODE_FBIT (mode) < 2 * HOST_BITS_PER_WIDE_INT)
2278 lshift_double (temp.low, temp.high,
2279 - GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2280 &temp.low, &temp.high, SIGNED_FIXED_POINT_MODE_P (mode));
2282 /* Left shift temp to temp_trunc by fbit. */
2283 lshift_double (temp.low, temp.high,
2284 GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2285 &temp_trunc.low, &temp_trunc.high,
2286 SIGNED_FIXED_POINT_MODE_P (mode));
2293 temp_trunc.high = 0;
2296 /* If FIXED_CST is negative, we need to round the value toward 0.
2297 By checking if the fractional bits are not zero to add 1 to temp. */
2298 if (SIGNED_FIXED_POINT_MODE_P (mode) && temp_trunc.high < 0
2299 && !double_int_equal_p (TREE_FIXED_CST (arg1).data, temp_trunc))
2304 temp = double_int_add (temp, one);
2307 /* Given a fixed-point constant, make new constant with new type,
2308 appropriately sign-extended or truncated. */
2309 t = force_fit_type_double (type, temp.low, temp.high, -1,
2311 && (TYPE_UNSIGNED (type)
2312 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2313 | TREE_OVERFLOW (arg1));
2318 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2319 to another floating point type. */
2322 fold_convert_const_real_from_real (tree type, const_tree arg1)
2324 REAL_VALUE_TYPE value;
2327 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2328 t = build_real (type, value);
2330 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2334 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2335 to a floating point type. */
2338 fold_convert_const_real_from_fixed (tree type, const_tree arg1)
2340 REAL_VALUE_TYPE value;
2343 real_convert_from_fixed (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1));
2344 t = build_real (type, value);
2346 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2350 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2351 to another fixed-point type. */
2354 fold_convert_const_fixed_from_fixed (tree type, const_tree arg1)
2356 FIXED_VALUE_TYPE value;
2360 overflow_p = fixed_convert (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1),
2361 TYPE_SATURATING (type));
2362 t = build_fixed (type, value);
2364 /* Propagate overflow flags. */
2365 if (overflow_p | TREE_OVERFLOW (arg1))
2366 TREE_OVERFLOW (t) = 1;
2370 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2371 to a fixed-point type. */
2374 fold_convert_const_fixed_from_int (tree type, const_tree arg1)
2376 FIXED_VALUE_TYPE value;
2380 overflow_p = fixed_convert_from_int (&value, TYPE_MODE (type),
2381 TREE_INT_CST (arg1),
2382 TYPE_UNSIGNED (TREE_TYPE (arg1)),
2383 TYPE_SATURATING (type));
2384 t = build_fixed (type, value);
2386 /* Propagate overflow flags. */
2387 if (overflow_p | TREE_OVERFLOW (arg1))
2388 TREE_OVERFLOW (t) = 1;
2392 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2393 to a fixed-point type. */
2396 fold_convert_const_fixed_from_real (tree type, const_tree arg1)
2398 FIXED_VALUE_TYPE value;
2402 overflow_p = fixed_convert_from_real (&value, TYPE_MODE (type),
2403 &TREE_REAL_CST (arg1),
2404 TYPE_SATURATING (type));
2405 t = build_fixed (type, value);
2407 /* Propagate overflow flags. */
2408 if (overflow_p | TREE_OVERFLOW (arg1))
2409 TREE_OVERFLOW (t) = 1;
2413 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2414 type TYPE. If no simplification can be done return NULL_TREE. */
2417 fold_convert_const (enum tree_code code, tree type, tree arg1)
2419 if (TREE_TYPE (arg1) == type)
2422 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type)
2423 || TREE_CODE (type) == OFFSET_TYPE)
2425 if (TREE_CODE (arg1) == INTEGER_CST)
2426 return fold_convert_const_int_from_int (type, arg1);
2427 else if (TREE_CODE (arg1) == REAL_CST)
2428 return fold_convert_const_int_from_real (code, type, arg1);
2429 else if (TREE_CODE (arg1) == FIXED_CST)
2430 return fold_convert_const_int_from_fixed (type, arg1);
2432 else if (TREE_CODE (type) == REAL_TYPE)
2434 if (TREE_CODE (arg1) == INTEGER_CST)
2435 return build_real_from_int_cst (type, arg1);
2436 else if (TREE_CODE (arg1) == REAL_CST)
2437 return fold_convert_const_real_from_real (type, arg1);
2438 else if (TREE_CODE (arg1) == FIXED_CST)
2439 return fold_convert_const_real_from_fixed (type, arg1);
2441 else if (TREE_CODE (type) == FIXED_POINT_TYPE)
2443 if (TREE_CODE (arg1) == FIXED_CST)
2444 return fold_convert_const_fixed_from_fixed (type, arg1);
2445 else if (TREE_CODE (arg1) == INTEGER_CST)
2446 return fold_convert_const_fixed_from_int (type, arg1);
2447 else if (TREE_CODE (arg1) == REAL_CST)
2448 return fold_convert_const_fixed_from_real (type, arg1);
2453 /* Construct a vector of zero elements of vector type TYPE. */
2456 build_zero_vector (tree type)
2461 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2462 units = TYPE_VECTOR_SUBPARTS (type);
2465 for (i = 0; i < units; i++)
2466 list = tree_cons (NULL_TREE, elem, list);
2467 return build_vector (type, list);
2470 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2473 fold_convertible_p (const_tree type, const_tree arg)
2475 tree orig = TREE_TYPE (arg);
2480 if (TREE_CODE (arg) == ERROR_MARK
2481 || TREE_CODE (type) == ERROR_MARK
2482 || TREE_CODE (orig) == ERROR_MARK)
2485 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2488 switch (TREE_CODE (type))
2490 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2491 case POINTER_TYPE: case REFERENCE_TYPE:
2493 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2494 || TREE_CODE (orig) == OFFSET_TYPE)
2496 return (TREE_CODE (orig) == VECTOR_TYPE
2497 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2500 case FIXED_POINT_TYPE:
2504 return TREE_CODE (type) == TREE_CODE (orig);
2511 /* Convert expression ARG to type TYPE. Used by the middle-end for
2512 simple conversions in preference to calling the front-end's convert. */
2515 fold_convert (tree type, tree arg)
2517 tree orig = TREE_TYPE (arg);
2523 if (TREE_CODE (arg) == ERROR_MARK
2524 || TREE_CODE (type) == ERROR_MARK
2525 || TREE_CODE (orig) == ERROR_MARK)
2526 return error_mark_node;
2528 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2529 return fold_build1 (NOP_EXPR, type, arg);
2531 switch (TREE_CODE (type))
2533 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2534 case POINTER_TYPE: case REFERENCE_TYPE:
2536 if (TREE_CODE (arg) == INTEGER_CST)
2538 tem = fold_convert_const (NOP_EXPR, type, arg);
2539 if (tem != NULL_TREE)
2542 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2543 || TREE_CODE (orig) == OFFSET_TYPE)
2544 return fold_build1 (NOP_EXPR, type, arg);
2545 if (TREE_CODE (orig) == COMPLEX_TYPE)
2547 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2548 return fold_convert (type, tem);
2550 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2551 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2552 return fold_build1 (NOP_EXPR, type, arg);
2555 if (TREE_CODE (arg) == INTEGER_CST)
2557 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2558 if (tem != NULL_TREE)
2561 else if (TREE_CODE (arg) == REAL_CST)
2563 tem = fold_convert_const (NOP_EXPR, type, arg);
2564 if (tem != NULL_TREE)
2567 else if (TREE_CODE (arg) == FIXED_CST)
2569 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2570 if (tem != NULL_TREE)
2574 switch (TREE_CODE (orig))
2577 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2578 case POINTER_TYPE: case REFERENCE_TYPE:
2579 return fold_build1 (FLOAT_EXPR, type, arg);
2582 return fold_build1 (NOP_EXPR, type, arg);
2584 case FIXED_POINT_TYPE:
2585 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2588 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2589 return fold_convert (type, tem);
2595 case FIXED_POINT_TYPE:
2596 if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
2597 || TREE_CODE (arg) == REAL_CST)
2599 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2600 if (tem != NULL_TREE)
2604 switch (TREE_CODE (orig))
2606 case FIXED_POINT_TYPE:
2611 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2614 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2615 return fold_convert (type, tem);
2622 switch (TREE_CODE (orig))
2625 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2626 case POINTER_TYPE: case REFERENCE_TYPE:
2628 case FIXED_POINT_TYPE:
2629 return build2 (COMPLEX_EXPR, type,
2630 fold_convert (TREE_TYPE (type), arg),
2631 fold_convert (TREE_TYPE (type), integer_zero_node));
2636 if (TREE_CODE (arg) == COMPLEX_EXPR)
2638 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2639 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2640 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2643 arg = save_expr (arg);
2644 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2645 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2646 rpart = fold_convert (TREE_TYPE (type), rpart);
2647 ipart = fold_convert (TREE_TYPE (type), ipart);
2648 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2656 if (integer_zerop (arg))
2657 return build_zero_vector (type);
2658 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2659 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2660 || TREE_CODE (orig) == VECTOR_TYPE);
2661 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2664 tem = fold_ignored_result (arg);
2665 if (TREE_CODE (tem) == MODIFY_EXPR)
2667 return fold_build1 (NOP_EXPR, type, tem);
2674 /* Return false if expr can be assumed not to be an lvalue, true
2678 maybe_lvalue_p (const_tree x)
2680 /* We only need to wrap lvalue tree codes. */
2681 switch (TREE_CODE (x))
2692 case ALIGN_INDIRECT_REF:
2693 case MISALIGNED_INDIRECT_REF:
2695 case ARRAY_RANGE_REF:
2701 case PREINCREMENT_EXPR:
2702 case PREDECREMENT_EXPR:
2704 case TRY_CATCH_EXPR:
2705 case WITH_CLEANUP_EXPR:
2716 /* Assume the worst for front-end tree codes. */
2717 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2725 /* Return an expr equal to X but certainly not valid as an lvalue. */
2730 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2735 if (! maybe_lvalue_p (x))
2737 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2740 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2741 Zero means allow extended lvalues. */
2743 int pedantic_lvalues;
2745 /* When pedantic, return an expr equal to X but certainly not valid as a
2746 pedantic lvalue. Otherwise, return X. */
2749 pedantic_non_lvalue (tree x)
2751 if (pedantic_lvalues)
2752 return non_lvalue (x);
2757 /* Given a tree comparison code, return the code that is the logical inverse
2758 of the given code. It is not safe to do this for floating-point
2759 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2760 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2763 invert_tree_comparison (enum tree_code code, bool honor_nans)
2765 if (honor_nans && flag_trapping_math)
2775 return honor_nans ? UNLE_EXPR : LE_EXPR;
2777 return honor_nans ? UNLT_EXPR : LT_EXPR;
2779 return honor_nans ? UNGE_EXPR : GE_EXPR;
2781 return honor_nans ? UNGT_EXPR : GT_EXPR;
2795 return UNORDERED_EXPR;
2796 case UNORDERED_EXPR:
2797 return ORDERED_EXPR;
2803 /* Similar, but return the comparison that results if the operands are
2804 swapped. This is safe for floating-point. */
2807 swap_tree_comparison (enum tree_code code)
2814 case UNORDERED_EXPR:
2840 /* Convert a comparison tree code from an enum tree_code representation
2841 into a compcode bit-based encoding. This function is the inverse of
2842 compcode_to_comparison. */
2844 static enum comparison_code
2845 comparison_to_compcode (enum tree_code code)
2862 return COMPCODE_ORD;
2863 case UNORDERED_EXPR:
2864 return COMPCODE_UNORD;
2866 return COMPCODE_UNLT;
2868 return COMPCODE_UNEQ;
2870 return COMPCODE_UNLE;
2872 return COMPCODE_UNGT;
2874 return COMPCODE_LTGT;
2876 return COMPCODE_UNGE;
2882 /* Convert a compcode bit-based encoding of a comparison operator back
2883 to GCC's enum tree_code representation. This function is the
2884 inverse of comparison_to_compcode. */
2886 static enum tree_code
2887 compcode_to_comparison (enum comparison_code code)
2904 return ORDERED_EXPR;
2905 case COMPCODE_UNORD:
2906 return UNORDERED_EXPR;
2924 /* Return a tree for the comparison which is the combination of
2925 doing the AND or OR (depending on CODE) of the two operations LCODE
2926 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2927 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2928 if this makes the transformation invalid. */
2931 combine_comparisons (enum tree_code code, enum tree_code lcode,
2932 enum tree_code rcode, tree truth_type,
2933 tree ll_arg, tree lr_arg)
2935 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2936 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2937 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2942 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2943 compcode = lcompcode & rcompcode;
2946 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2947 compcode = lcompcode | rcompcode;
2956 /* Eliminate unordered comparisons, as well as LTGT and ORD
2957 which are not used unless the mode has NaNs. */
2958 compcode &= ~COMPCODE_UNORD;
2959 if (compcode == COMPCODE_LTGT)
2960 compcode = COMPCODE_NE;
2961 else if (compcode == COMPCODE_ORD)
2962 compcode = COMPCODE_TRUE;
2964 else if (flag_trapping_math)
2966 /* Check that the original operation and the optimized ones will trap
2967 under the same condition. */
2968 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2969 && (lcompcode != COMPCODE_EQ)
2970 && (lcompcode != COMPCODE_ORD);
2971 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2972 && (rcompcode != COMPCODE_EQ)
2973 && (rcompcode != COMPCODE_ORD);
2974 bool trap = (compcode & COMPCODE_UNORD) == 0
2975 && (compcode != COMPCODE_EQ)
2976 && (compcode != COMPCODE_ORD);
2978 /* In a short-circuited boolean expression the LHS might be
2979 such that the RHS, if evaluated, will never trap. For
2980 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2981 if neither x nor y is NaN. (This is a mixed blessing: for
2982 example, the expression above will never trap, hence
2983 optimizing it to x < y would be invalid). */
2984 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2985 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2988 /* If the comparison was short-circuited, and only the RHS
2989 trapped, we may now generate a spurious trap. */
2991 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2994 /* If we changed the conditions that cause a trap, we lose. */
2995 if ((ltrap || rtrap) != trap)
2999 if (compcode == COMPCODE_TRUE)
3000 return constant_boolean_node (true, truth_type);
3001 else if (compcode == COMPCODE_FALSE)
3002 return constant_boolean_node (false, truth_type);
3005 enum tree_code tcode;
3007 tcode = compcode_to_comparison ((enum comparison_code) compcode);
3008 return fold_build2 (tcode, truth_type, ll_arg, lr_arg);
3012 /* Return nonzero if two operands (typically of the same tree node)
3013 are necessarily equal. If either argument has side-effects this
3014 function returns zero. FLAGS modifies behavior as follows:
3016 If OEP_ONLY_CONST is set, only return nonzero for constants.
3017 This function tests whether the operands are indistinguishable;
3018 it does not test whether they are equal using C's == operation.
3019 The distinction is important for IEEE floating point, because
3020 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
3021 (2) two NaNs may be indistinguishable, but NaN!=NaN.
3023 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
3024 even though it may hold multiple values during a function.
3025 This is because a GCC tree node guarantees that nothing else is
3026 executed between the evaluation of its "operands" (which may often
3027 be evaluated in arbitrary order). Hence if the operands themselves
3028 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
3029 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
3030 unset means assuming isochronic (or instantaneous) tree equivalence.
3031 Unless comparing arbitrary expression trees, such as from different
3032 statements, this flag can usually be left unset.
3034 If OEP_PURE_SAME is set, then pure functions with identical arguments
3035 are considered the same. It is used when the caller has other ways
3036 to ensure that global memory is unchanged in between. */
3039 operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
3041 /* If either is ERROR_MARK, they aren't equal. */
3042 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
3045 /* Check equality of integer constants before bailing out due to
3046 precision differences. */
3047 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
3048 return tree_int_cst_equal (arg0, arg1);
3050 /* If both types don't have the same signedness, then we can't consider
3051 them equal. We must check this before the STRIP_NOPS calls
3052 because they may change the signedness of the arguments. As pointers
3053 strictly don't have a signedness, require either two pointers or
3054 two non-pointers as well. */
3055 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1))
3056 || POINTER_TYPE_P (TREE_TYPE (arg0)) != POINTER_TYPE_P (TREE_TYPE (arg1)))
3059 /* If both types don't have the same precision, then it is not safe
3061 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
3067 /* In case both args are comparisons but with different comparison
3068 code, try to swap the comparison operands of one arg to produce
3069 a match and compare that variant. */
3070 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3071 && COMPARISON_CLASS_P (arg0)
3072 && COMPARISON_CLASS_P (arg1))
3074 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
3076 if (TREE_CODE (arg0) == swap_code)
3077 return operand_equal_p (TREE_OPERAND (arg0, 0),
3078 TREE_OPERAND (arg1, 1), flags)
3079 && operand_equal_p (TREE_OPERAND (arg0, 1),
3080 TREE_OPERAND (arg1, 0), flags);
3083 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3084 /* This is needed for conversions and for COMPONENT_REF.
3085 Might as well play it safe and always test this. */
3086 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
3087 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
3088 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
3091 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3092 We don't care about side effects in that case because the SAVE_EXPR
3093 takes care of that for us. In all other cases, two expressions are
3094 equal if they have no side effects. If we have two identical
3095 expressions with side effects that should be treated the same due
3096 to the only side effects being identical SAVE_EXPR's, that will
3097 be detected in the recursive calls below. */
3098 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
3099 && (TREE_CODE (arg0) == SAVE_EXPR
3100 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
3103 /* Next handle constant cases, those for which we can return 1 even
3104 if ONLY_CONST is set. */
3105 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
3106 switch (TREE_CODE (arg0))
3109 return tree_int_cst_equal (arg0, arg1);
3112 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
3113 TREE_FIXED_CST (arg1));
3116 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
3117 TREE_REAL_CST (arg1)))
3121 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
3123 /* If we do not distinguish between signed and unsigned zero,
3124 consider them equal. */
3125 if (real_zerop (arg0) && real_zerop (arg1))
3134 v1 = TREE_VECTOR_CST_ELTS (arg0);
3135 v2 = TREE_VECTOR_CST_ELTS (arg1);
3138 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
3141 v1 = TREE_CHAIN (v1);
3142 v2 = TREE_CHAIN (v2);
3149 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
3151 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
3155 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
3156 && ! memcmp (TREE_STRING_POINTER (arg0),
3157 TREE_STRING_POINTER (arg1),
3158 TREE_STRING_LENGTH (arg0)));
3161 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
3167 if (flags & OEP_ONLY_CONST)
3170 /* Define macros to test an operand from arg0 and arg1 for equality and a
3171 variant that allows null and views null as being different from any
3172 non-null value. In the latter case, if either is null, the both
3173 must be; otherwise, do the normal comparison. */
3174 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3175 TREE_OPERAND (arg1, N), flags)
3177 #define OP_SAME_WITH_NULL(N) \
3178 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3179 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3181 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
3184 /* Two conversions are equal only if signedness and modes match. */
3185 switch (TREE_CODE (arg0))
3188 case FIX_TRUNC_EXPR:
3189 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
3190 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3200 case tcc_comparison:
3202 if (OP_SAME (0) && OP_SAME (1))
3205 /* For commutative ops, allow the other order. */
3206 return (commutative_tree_code (TREE_CODE (arg0))
3207 && operand_equal_p (TREE_OPERAND (arg0, 0),
3208 TREE_OPERAND (arg1, 1), flags)
3209 && operand_equal_p (TREE_OPERAND (arg0, 1),
3210 TREE_OPERAND (arg1, 0), flags));
3213 /* If either of the pointer (or reference) expressions we are
3214 dereferencing contain a side effect, these cannot be equal. */
3215 if (TREE_SIDE_EFFECTS (arg0)
3216 || TREE_SIDE_EFFECTS (arg1))
3219 switch (TREE_CODE (arg0))
3222 case ALIGN_INDIRECT_REF:
3223 case MISALIGNED_INDIRECT_REF:
3229 case ARRAY_RANGE_REF:
3230 /* Operands 2 and 3 may be null.
3231 Compare the array index by value if it is constant first as we
3232 may have different types but same value here. */
3234 && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
3235 TREE_OPERAND (arg1, 1))
3237 && OP_SAME_WITH_NULL (2)
3238 && OP_SAME_WITH_NULL (3));
3241 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3242 may be NULL when we're called to compare MEM_EXPRs. */
3243 return OP_SAME_WITH_NULL (0)
3245 && OP_SAME_WITH_NULL (2);
3248 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3254 case tcc_expression:
3255 switch (TREE_CODE (arg0))
3258 case TRUTH_NOT_EXPR:
3261 case TRUTH_ANDIF_EXPR:
3262 case TRUTH_ORIF_EXPR:
3263 return OP_SAME (0) && OP_SAME (1);
3265 case TRUTH_AND_EXPR:
3267 case TRUTH_XOR_EXPR:
3268 if (OP_SAME (0) && OP_SAME (1))
3271 /* Otherwise take into account this is a commutative operation. */
3272 return (operand_equal_p (TREE_OPERAND (arg0, 0),
3273 TREE_OPERAND (arg1, 1), flags)
3274 && operand_equal_p (TREE_OPERAND (arg0, 1),
3275 TREE_OPERAND (arg1, 0), flags));
3278 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3285 switch (TREE_CODE (arg0))
3288 /* If the CALL_EXPRs call different functions, then they
3289 clearly can not be equal. */
3290 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
3295 unsigned int cef = call_expr_flags (arg0);
3296 if (flags & OEP_PURE_SAME)
3297 cef &= ECF_CONST | ECF_PURE;
3304 /* Now see if all the arguments are the same. */
3306 const_call_expr_arg_iterator iter0, iter1;
3308 for (a0 = first_const_call_expr_arg (arg0, &iter0),
3309 a1 = first_const_call_expr_arg (arg1, &iter1);
3311 a0 = next_const_call_expr_arg (&iter0),
3312 a1 = next_const_call_expr_arg (&iter1))
3313 if (! operand_equal_p (a0, a1, flags))
3316 /* If we get here and both argument lists are exhausted
3317 then the CALL_EXPRs are equal. */
3318 return ! (a0 || a1);
3324 case tcc_declaration:
3325 /* Consider __builtin_sqrt equal to sqrt. */
3326 return (TREE_CODE (arg0) == FUNCTION_DECL
3327 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
3328 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
3329 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
3336 #undef OP_SAME_WITH_NULL
3339 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3340 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3342 When in doubt, return 0. */
3345 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
3347 int unsignedp1, unsignedpo;
3348 tree primarg0, primarg1, primother;
3349 unsigned int correct_width;
3351 if (operand_equal_p (arg0, arg1, 0))
3354 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3355 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3358 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3359 and see if the inner values are the same. This removes any
3360 signedness comparison, which doesn't matter here. */
3361 primarg0 = arg0, primarg1 = arg1;
3362 STRIP_NOPS (primarg0);
3363 STRIP_NOPS (primarg1);
3364 if (operand_equal_p (primarg0, primarg1, 0))
3367 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3368 actual comparison operand, ARG0.
3370 First throw away any conversions to wider types
3371 already present in the operands. */
3373 primarg1 = get_narrower (arg1, &unsignedp1);
3374 primother = get_narrower (other, &unsignedpo);
3376 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3377 if (unsignedp1 == unsignedpo
3378 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3379 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3381 tree type = TREE_TYPE (arg0);
3383 /* Make sure shorter operand is extended the right way
3384 to match the longer operand. */
3385 primarg1 = fold_convert (signed_or_unsigned_type_for
3386 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3388 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3395 /* See if ARG is an expression that is either a comparison or is performing
3396 arithmetic on comparisons. The comparisons must only be comparing
3397 two different values, which will be stored in *CVAL1 and *CVAL2; if
3398 they are nonzero it means that some operands have already been found.
3399 No variables may be used anywhere else in the expression except in the
3400 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3401 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3403 If this is true, return 1. Otherwise, return zero. */
3406 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3408 enum tree_code code = TREE_CODE (arg);
3409 enum tree_code_class tclass = TREE_CODE_CLASS (code);
3411 /* We can handle some of the tcc_expression cases here. */
3412 if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
3414 else if (tclass == tcc_expression
3415 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3416 || code == COMPOUND_EXPR))
3417 tclass = tcc_binary;
3419 else if (tclass == tcc_expression && code == SAVE_EXPR
3420 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3422 /* If we've already found a CVAL1 or CVAL2, this expression is
3423 two complex to handle. */
3424 if (*cval1 || *cval2)
3434 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3437 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3438 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3439 cval1, cval2, save_p));
3444 case tcc_expression:
3445 if (code == COND_EXPR)
3446 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3447 cval1, cval2, save_p)
3448 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3449 cval1, cval2, save_p)
3450 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3451 cval1, cval2, save_p));
3454 case tcc_comparison:
3455 /* First see if we can handle the first operand, then the second. For
3456 the second operand, we know *CVAL1 can't be zero. It must be that
3457 one side of the comparison is each of the values; test for the
3458 case where this isn't true by failing if the two operands
3461 if (operand_equal_p (TREE_OPERAND (arg, 0),
3462 TREE_OPERAND (arg, 1), 0))
3466 *cval1 = TREE_OPERAND (arg, 0);
3467 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3469 else if (*cval2 == 0)
3470 *cval2 = TREE_OPERAND (arg, 0);
3471 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3476 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3478 else if (*cval2 == 0)
3479 *cval2 = TREE_OPERAND (arg, 1);
3480 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3492 /* ARG is a tree that is known to contain just arithmetic operations and
3493 comparisons. Evaluate the operations in the tree substituting NEW0 for
3494 any occurrence of OLD0 as an operand of a comparison and likewise for
3498 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3500 tree type = TREE_TYPE (arg);
3501 enum tree_code code = TREE_CODE (arg);
3502 enum tree_code_class tclass = TREE_CODE_CLASS (code);
3504 /* We can handle some of the tcc_expression cases here. */
3505 if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
3507 else if (tclass == tcc_expression
3508 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3509 tclass = tcc_binary;
3514 return fold_build1 (code, type,
3515 eval_subst (TREE_OPERAND (arg, 0),
3516 old0, new0, old1, new1));
3519 return fold_build2 (code, type,
3520 eval_subst (TREE_OPERAND (arg, 0),
3521 old0, new0, old1, new1),
3522 eval_subst (TREE_OPERAND (arg, 1),
3523 old0, new0, old1, new1));
3525 case tcc_expression:
3529 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3532 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3535 return fold_build3 (code, type,
3536 eval_subst (TREE_OPERAND (arg, 0),
3537 old0, new0, old1, new1),
3538 eval_subst (TREE_OPERAND (arg, 1),
3539 old0, new0, old1, new1),
3540 eval_subst (TREE_OPERAND (arg, 2),
3541 old0, new0, old1, new1));
3545 /* Fall through - ??? */
3547 case tcc_comparison:
3549 tree arg0 = TREE_OPERAND (arg, 0);
3550 tree arg1 = TREE_OPERAND (arg, 1);
3552 /* We need to check both for exact equality and tree equality. The
3553 former will be true if the operand has a side-effect. In that
3554 case, we know the operand occurred exactly once. */
3556 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3558 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3561 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3563 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3566 return fold_build2 (code, type, arg0, arg1);
3574 /* Return a tree for the case when the result of an expression is RESULT
3575 converted to TYPE and OMITTED was previously an operand of the expression
3576 but is now not needed (e.g., we folded OMITTED * 0).
3578 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3579 the conversion of RESULT to TYPE. */
3582 omit_one_operand (tree type, tree result, tree omitted)
3584 tree t = fold_convert (type, result);
3586 /* If the resulting operand is an empty statement, just return the omitted
3587 statement casted to void. */
3588 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3589 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3591 if (TREE_SIDE_EFFECTS (omitted))
3592 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3594 return non_lvalue (t);
3597 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3600 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3602 tree t = fold_convert (type, result);
3604 /* If the resulting operand is an empty statement, just return the omitted
3605 statement casted to void. */
3606 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3607 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3609 if (TREE_SIDE_EFFECTS (omitted))
3610 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3612 return pedantic_non_lvalue (t);
3615 /* Return a tree for the case when the result of an expression is RESULT
3616 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3617 of the expression but are now not needed.
3619 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3620 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3621 evaluated before OMITTED2. Otherwise, if neither has side effects,
3622 just do the conversion of RESULT to TYPE. */
3625 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3627 tree t = fold_convert (type, result);
3629 if (TREE_SIDE_EFFECTS (omitted2))
3630 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3631 if (TREE_SIDE_EFFECTS (omitted1))
3632 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3634 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3638 /* Return a simplified tree node for the truth-negation of ARG. This
3639 never alters ARG itself. We assume that ARG is an operation that
3640 returns a truth value (0 or 1).
3642 FIXME: one would think we would fold the result, but it causes
3643 problems with the dominator optimizer. */
3646 fold_truth_not_expr (tree arg)
3648 tree t, type = TREE_TYPE (arg);
3649 enum tree_code code = TREE_CODE (arg);
3651 /* If this is a comparison, we can simply invert it, except for
3652 floating-point non-equality comparisons, in which case we just
3653 enclose a TRUTH_NOT_EXPR around what we have. */
3655 if (TREE_CODE_CLASS (code) == tcc_comparison)
3657 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3658 if (FLOAT_TYPE_P (op_type)
3659 && flag_trapping_math
3660 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3661 && code != NE_EXPR && code != EQ_EXPR)
3664 code = invert_tree_comparison (code, HONOR_NANS (TYPE_MODE (op_type)));
3665 if (code == ERROR_MARK)
3668 t = build2 (code, type, TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3669 if (EXPR_HAS_LOCATION (arg))
3670 SET_EXPR_LOCATION (t, EXPR_LOCATION (arg));
3677 return constant_boolean_node (integer_zerop (arg), type);
3679 case TRUTH_AND_EXPR:
3680 t = build2 (TRUTH_OR_EXPR, type,
3681 invert_truthvalue (TREE_OPERAND (arg, 0)),
3682 invert_truthvalue (TREE_OPERAND (arg, 1)));
3686 t = build2 (TRUTH_AND_EXPR, type,
3687 invert_truthvalue (TREE_OPERAND (arg, 0)),
3688 invert_truthvalue (TREE_OPERAND (arg, 1)));
3691 case TRUTH_XOR_EXPR:
3692 /* Here we can invert either operand. We invert the first operand
3693 unless the second operand is a TRUTH_NOT_EXPR in which case our
3694 result is the XOR of the first operand with the inside of the
3695 negation of the second operand. */
3697 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3698 t = build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3699 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3701 t = build2 (TRUTH_XOR_EXPR, type,
3702 invert_truthvalue (TREE_OPERAND (arg, 0)),
3703 TREE_OPERAND (arg, 1));
3706 case TRUTH_ANDIF_EXPR:
3707 t = build2 (TRUTH_ORIF_EXPR, type,
3708 invert_truthvalue (TREE_OPERAND (arg, 0)),
3709 invert_truthvalue (TREE_OPERAND (arg, 1)));
3712 case TRUTH_ORIF_EXPR:
3713 t = build2 (TRUTH_ANDIF_EXPR, type,
3714 invert_truthvalue (TREE_OPERAND (arg, 0)),
3715 invert_truthvalue (TREE_OPERAND (arg, 1)));
3718 case TRUTH_NOT_EXPR:
3719 return TREE_OPERAND (arg, 0);
3723 tree arg1 = TREE_OPERAND (arg, 1);
3724 tree arg2 = TREE_OPERAND (arg, 2);
3725 /* A COND_EXPR may have a throw as one operand, which
3726 then has void type. Just leave void operands
3728 t = build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3729 VOID_TYPE_P (TREE_TYPE (arg1))
3730 ? arg1 : invert_truthvalue (arg1),
3731 VOID_TYPE_P (TREE_TYPE (arg2))
3732 ? arg2 : invert_truthvalue (arg2));
3737 t = build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3738 invert_truthvalue (TREE_OPERAND (arg, 1)));
3741 case NON_LVALUE_EXPR:
3742 return invert_truthvalue (TREE_OPERAND (arg, 0));
3745 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3747 t = build1 (TRUTH_NOT_EXPR, type, arg);
3751 /* ... fall through ... */
3754 t = build1 (TREE_CODE (arg), type,
3755 invert_truthvalue (TREE_OPERAND (arg, 0)));
3759 if (!integer_onep (TREE_OPERAND (arg, 1)))
3761 t = build2 (EQ_EXPR, type, arg, build_int_cst (type, 0));
3765 t = build1 (TRUTH_NOT_EXPR, type, arg);
3768 case CLEANUP_POINT_EXPR:
3769 t = build1 (CLEANUP_POINT_EXPR, type,
3770 invert_truthvalue (TREE_OPERAND (arg, 0)));
3778 if (t && EXPR_HAS_LOCATION (arg))
3779 SET_EXPR_LOCATION (t, EXPR_LOCATION (arg));
3784 /* Return a simplified tree node for the truth-negation of ARG. This
3785 never alters ARG itself. We assume that ARG is an operation that
3786 returns a truth value (0 or 1).
3788 FIXME: one would think we would fold the result, but it causes
3789 problems with the dominator optimizer. */
3792 invert_truthvalue (tree arg)
3796 if (TREE_CODE (arg) == ERROR_MARK)
3799 tem = fold_truth_not_expr (arg);
3801 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3806 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3807 operands are another bit-wise operation with a common input. If so,
3808 distribute the bit operations to save an operation and possibly two if
3809 constants are involved. For example, convert
3810 (A | B) & (A | C) into A | (B & C)
3811 Further simplification will occur if B and C are constants.
3813 If this optimization cannot be done, 0 will be returned. */
3816 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3821 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3822 || TREE_CODE (arg0) == code
3823 || (TREE_CODE (arg0) != BIT_AND_EXPR
3824 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3827 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3829 common = TREE_OPERAND (arg0, 0);
3830 left = TREE_OPERAND (arg0, 1);
3831 right = TREE_OPERAND (arg1, 1);
3833 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3835 common = TREE_OPERAND (arg0, 0);
3836 left = TREE_OPERAND (arg0, 1);
3837 right = TREE_OPERAND (arg1, 0);
3839 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3841 common = TREE_OPERAND (arg0, 1);
3842 left = TREE_OPERAND (arg0, 0);
3843 right = TREE_OPERAND (arg1, 1);
3845 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3847 common = TREE_OPERAND (arg0, 1);
3848 left = TREE_OPERAND (arg0, 0);
3849 right = TREE_OPERAND (arg1, 0);
3854 common = fold_convert (type, common);
3855 left = fold_convert (type, left);
3856 right = fold_convert (type, right);
3857 return fold_build2 (TREE_CODE (arg0), type, common,
3858 fold_build2 (code, type, left, right));
3861 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3862 with code CODE. This optimization is unsafe. */
3864 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3866 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3867 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3869 /* (A / C) +- (B / C) -> (A +- B) / C. */
3871 && operand_equal_p (TREE_OPERAND (arg0, 1),
3872 TREE_OPERAND (arg1, 1), 0))
3873 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3874 fold_build2 (code, type,
3875 TREE_OPERAND (arg0, 0),
3876 TREE_OPERAND (arg1, 0)),
3877 TREE_OPERAND (arg0, 1));
3879 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3880 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3881 TREE_OPERAND (arg1, 0), 0)
3882 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3883 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3885 REAL_VALUE_TYPE r0, r1;
3886 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3887 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3889 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3891 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3892 real_arithmetic (&r0, code, &r0, &r1);
3893 return fold_build2 (MULT_EXPR, type,
3894 TREE_OPERAND (arg0, 0),
3895 build_real (type, r0));
3901 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3902 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3905 make_bit_field_ref (tree inner, tree type, HOST_WIDE_INT bitsize,
3906 HOST_WIDE_INT bitpos, int unsignedp)
3908 tree result, bftype;
3912 tree size = TYPE_SIZE (TREE_TYPE (inner));
3913 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3914 || POINTER_TYPE_P (TREE_TYPE (inner)))
3915 && host_integerp (size, 0)
3916 && tree_low_cst (size, 0) == bitsize)
3917 return fold_convert (type, inner);
3921 if (TYPE_PRECISION (bftype) != bitsize
3922 || TYPE_UNSIGNED (bftype) == !unsignedp)
3923 bftype = build_nonstandard_integer_type (bitsize, 0);
3925 result = build3 (BIT_FIELD_REF, bftype, inner,
3926 size_int (bitsize), bitsize_int (bitpos));
3929 result = fold_convert (type, result);
3934 /* Optimize a bit-field compare.
3936 There are two cases: First is a compare against a constant and the
3937 second is a comparison of two items where the fields are at the same
3938 bit position relative to the start of a chunk (byte, halfword, word)
3939 large enough to contain it. In these cases we can avoid the shift
3940 implicit in bitfield extractions.
3942 For constants, we emit a compare of the shifted constant with the
3943 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3944 compared. For two fields at the same position, we do the ANDs with the
3945 similar mask and compare the result of the ANDs.
3947 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3948 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3949 are the left and right operands of the comparison, respectively.
3951 If the optimization described above can be done, we return the resulting
3952 tree. Otherwise we return zero. */
3955 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3958 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3959 tree type = TREE_TYPE (lhs);
3960 tree signed_type, unsigned_type;
3961 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3962 enum machine_mode lmode, rmode, nmode;
3963 int lunsignedp, runsignedp;
3964 int lvolatilep = 0, rvolatilep = 0;
3965 tree linner, rinner = NULL_TREE;
3969 /* Get all the information about the extractions being done. If the bit size
3970 if the same as the size of the underlying object, we aren't doing an
3971 extraction at all and so can do nothing. We also don't want to
3972 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3973 then will no longer be able to replace it. */
3974 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3975 &lunsignedp, &lvolatilep, false);
3976 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3977 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3982 /* If this is not a constant, we can only do something if bit positions,
3983 sizes, and signedness are the same. */
3984 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3985 &runsignedp, &rvolatilep, false);
3987 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3988 || lunsignedp != runsignedp || offset != 0
3989 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3993 /* See if we can find a mode to refer to this field. We should be able to,
3994 but fail if we can't. */
3995 nmode = get_best_mode (lbitsize, lbitpos,
3996 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3997 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3998 TYPE_ALIGN (TREE_TYPE (rinner))),
3999 word_mode, lvolatilep || rvolatilep);
4000 if (nmode == VOIDmode)
4003 /* Set signed and unsigned types of the precision of this mode for the
4005 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
4006 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
4008 /* Compute the bit position and size for the new reference and our offset
4009 within it. If the new reference is the same size as the original, we
4010 won't optimize anything, so return zero. */
4011 nbitsize = GET_MODE_BITSIZE (nmode);
4012 nbitpos = lbitpos & ~ (nbitsize - 1);
4014 if (nbitsize == lbitsize)
4017 if (BYTES_BIG_ENDIAN)
4018 lbitpos = nbitsize - lbitsize - lbitpos;
4020 /* Make the mask to be used against the extracted field. */
4021 mask = build_int_cst_type (unsigned_type, -1);
4022 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
4023 mask = const_binop (RSHIFT_EXPR, mask,
4024 size_int (nbitsize - lbitsize - lbitpos), 0);
4027 /* If not comparing with constant, just rework the comparison
4029 return fold_build2 (code, compare_type,
4030 fold_build2 (BIT_AND_EXPR, unsigned_type,
4031 make_bit_field_ref (linner,
4036 fold_build2 (BIT_AND_EXPR, unsigned_type,
4037 make_bit_field_ref (rinner,
4043 /* Otherwise, we are handling the constant case. See if the constant is too
4044 big for the field. Warn and return a tree of for 0 (false) if so. We do
4045 this not only for its own sake, but to avoid having to test for this
4046 error case below. If we didn't, we might generate wrong code.
4048 For unsigned fields, the constant shifted right by the field length should
4049 be all zero. For signed fields, the high-order bits should agree with
4054 if (! integer_zerop (const_binop (RSHIFT_EXPR,
4055 fold_convert (unsigned_type, rhs),
4056 size_int (lbitsize), 0)))
4058 warning (0, "comparison is always %d due to width of bit-field",
4060 return constant_boolean_node (code == NE_EXPR, compare_type);
4065 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
4066 size_int (lbitsize - 1), 0);
4067 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
4069 warning (0, "comparison is always %d due to width of bit-field",
4071 return constant_boolean_node (code == NE_EXPR, compare_type);
4075 /* Single-bit compares should always be against zero. */
4076 if (lbitsize == 1 && ! integer_zerop (rhs))
4078 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
4079 rhs = build_int_cst (type, 0);
4082 /* Make a new bitfield reference, shift the constant over the
4083 appropriate number of bits and mask it with the computed mask
4084 (in case this was a signed field). If we changed it, make a new one. */
4085 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
4088 TREE_SIDE_EFFECTS (lhs) = 1;
4089 TREE_THIS_VOLATILE (lhs) = 1;
4092 rhs = const_binop (BIT_AND_EXPR,
4093 const_binop (LSHIFT_EXPR,
4094 fold_convert (unsigned_type, rhs),
4095 size_int (lbitpos), 0),
4098 return build2 (code, compare_type,
4099 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
4103 /* Subroutine for fold_truthop: decode a field reference.
4105 If EXP is a comparison reference, we return the innermost reference.
4107 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
4108 set to the starting bit number.
4110 If the innermost field can be completely contained in a mode-sized
4111 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
4113 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
4114 otherwise it is not changed.
4116 *PUNSIGNEDP is set to the signedness of the field.
4118 *PMASK is set to the mask used. This is either contained in a
4119 BIT_AND_EXPR or derived from the width of the field.
4121 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
4123 Return 0 if this is not a component reference or is one that we can't
4124 do anything with. */
4127 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
4128 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
4129 int *punsignedp, int *pvolatilep,
4130 tree *pmask, tree *pand_mask)
4132 tree outer_type = 0;
4134 tree mask, inner, offset;
4136 unsigned int precision;
4138 /* All the optimizations using this function assume integer fields.
4139 There are problems with FP fields since the type_for_size call
4140 below can fail for, e.g., XFmode. */
4141 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
4144 /* We are interested in the bare arrangement of bits, so strip everything
4145 that doesn't affect the machine mode. However, record the type of the
4146 outermost expression if it may matter below. */
4147 if (CONVERT_EXPR_P (exp)
4148 || TREE_CODE (exp) == NON_LVALUE_EXPR)
4149 outer_type = TREE_TYPE (exp);
4152 if (TREE_CODE (exp) == BIT_AND_EXPR)
4154 and_mask = TREE_OPERAND (exp, 1);
4155 exp = TREE_OPERAND (exp, 0);
4156 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
4157 if (TREE_CODE (and_mask) != INTEGER_CST)
4161 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
4162 punsignedp, pvolatilep, false);
4163 if ((inner == exp && and_mask == 0)
4164 || *pbitsize < 0 || offset != 0
4165 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
4168 /* If the number of bits in the reference is the same as the bitsize of
4169 the outer type, then the outer type gives the signedness. Otherwise
4170 (in case of a small bitfield) the signedness is unchanged. */
4171 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
4172 *punsignedp = TYPE_UNSIGNED (outer_type);
4174 /* Compute the mask to access the bitfield. */
4175 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
4176 precision = TYPE_PRECISION (unsigned_type);
4178 mask = build_int_cst_type (unsigned_type, -1);
4180 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4181 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4183 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
4185 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
4186 fold_convert (unsigned_type, and_mask), mask);
4189 *pand_mask = and_mask;
4193 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
4197 all_ones_mask_p (const_tree mask, int size)
4199 tree type = TREE_TYPE (mask);
4200 unsigned int precision = TYPE_PRECISION (type);
4203 tmask = build_int_cst_type (signed_type_for (type), -1);
4206 tree_int_cst_equal (mask,
4207 const_binop (RSHIFT_EXPR,
4208 const_binop (LSHIFT_EXPR, tmask,
4209 size_int (precision - size),
4211 size_int (precision - size), 0));
4214 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
4215 represents the sign bit of EXP's type. If EXP represents a sign
4216 or zero extension, also test VAL against the unextended type.
4217 The return value is the (sub)expression whose sign bit is VAL,
4218 or NULL_TREE otherwise. */
4221 sign_bit_p (tree exp, const_tree val)
4223 unsigned HOST_WIDE_INT mask_lo, lo;
4224 HOST_WIDE_INT mask_hi, hi;
4228 /* Tree EXP must have an integral type. */
4229 t = TREE_TYPE (exp);
4230 if (! INTEGRAL_TYPE_P (t))
4233 /* Tree VAL must be an integer constant. */
4234 if (TREE_CODE (val) != INTEGER_CST
4235 || TREE_OVERFLOW (val))
4238 width = TYPE_PRECISION (t);
4239 if (width > HOST_BITS_PER_WIDE_INT)
4241 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
4244 mask_hi = ((unsigned HOST_WIDE_INT) -1
4245 >> (2 * HOST_BITS_PER_WIDE_INT - width));
4251 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
4254 mask_lo = ((unsigned HOST_WIDE_INT) -1
4255 >> (HOST_BITS_PER_WIDE_INT - width));
4258 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
4259 treat VAL as if it were unsigned. */
4260 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
4261 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
4264 /* Handle extension from a narrower type. */
4265 if (TREE_CODE (exp) == NOP_EXPR
4266 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
4267 return sign_bit_p (TREE_OPERAND (exp, 0), val);
4272 /* Subroutine for fold_truthop: determine if an operand is simple enough
4273 to be evaluated unconditionally. */
4276 simple_operand_p (const_tree exp)
4278 /* Strip any conversions that don't change the machine mode. */
4281 return (CONSTANT_CLASS_P (exp)
4282 || TREE_CODE (exp) == SSA_NAME
4284 && ! TREE_ADDRESSABLE (exp)
4285 && ! TREE_THIS_VOLATILE (exp)
4286 && ! DECL_NONLOCAL (exp)
4287 /* Don't regard global variables as simple. They may be
4288 allocated in ways unknown to the compiler (shared memory,
4289 #pragma weak, etc). */
4290 && ! TREE_PUBLIC (exp)
4291 && ! DECL_EXTERNAL (exp)
4292 /* Loading a static variable is unduly expensive, but global
4293 registers aren't expensive. */
4294 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
4297 /* The following functions are subroutines to fold_range_test and allow it to
4298 try to change a logical combination of comparisons into a range test.
4301 X == 2 || X == 3 || X == 4 || X == 5
4305 (unsigned) (X - 2) <= 3
4307 We describe each set of comparisons as being either inside or outside
4308 a range, using a variable named like IN_P, and then describe the
4309 range with a lower and upper bound. If one of the bounds is omitted,
4310 it represents either the highest or lowest value of the type.
4312 In the comments below, we represent a range by two numbers in brackets
4313 preceded by a "+" to designate being inside that range, or a "-" to
4314 designate being outside that range, so the condition can be inverted by
4315 flipping the prefix. An omitted bound is represented by a "-". For
4316 example, "- [-, 10]" means being outside the range starting at the lowest
4317 possible value and ending at 10, in other words, being greater than 10.
4318 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4321 We set up things so that the missing bounds are handled in a consistent
4322 manner so neither a missing bound nor "true" and "false" need to be
4323 handled using a special case. */
4325 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4326 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4327 and UPPER1_P are nonzero if the respective argument is an upper bound
4328 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4329 must be specified for a comparison. ARG1 will be converted to ARG0's
4330 type if both are specified. */
4333 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
4334 tree arg1, int upper1_p)
4340 /* If neither arg represents infinity, do the normal operation.
4341 Else, if not a comparison, return infinity. Else handle the special
4342 comparison rules. Note that most of the cases below won't occur, but
4343 are handled for consistency. */
4345 if (arg0 != 0 && arg1 != 0)
4347 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
4348 arg0, fold_convert (TREE_TYPE (arg0), arg1));
4350 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
4353 if (TREE_CODE_CLASS (code) != tcc_comparison)
4356 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4357 for neither. In real maths, we cannot assume open ended ranges are
4358 the same. But, this is computer arithmetic, where numbers are finite.
4359 We can therefore make the transformation of any unbounded range with
4360 the value Z, Z being greater than any representable number. This permits
4361 us to treat unbounded ranges as equal. */
4362 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
4363 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
4367 result = sgn0 == sgn1;
4370 result = sgn0 != sgn1;
4373 result = sgn0 < sgn1;
4376 result = sgn0 <= sgn1;
4379 result = sgn0 > sgn1;
4382 result = sgn0 >= sgn1;
4388 return constant_boolean_node (result, type);
4391 /* Given EXP, a logical expression, set the range it is testing into
4392 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4393 actually being tested. *PLOW and *PHIGH will be made of the same
4394 type as the returned expression. If EXP is not a comparison, we
4395 will most likely not be returning a useful value and range. Set
4396 *STRICT_OVERFLOW_P to true if the return value is only valid
4397 because signed overflow is undefined; otherwise, do not change
4398 *STRICT_OVERFLOW_P. */
4401 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4402 bool *strict_overflow_p)
4404 enum tree_code code;
4405 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4406 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4408 tree low, high, n_low, n_high;
4410 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4411 and see if we can refine the range. Some of the cases below may not
4412 happen, but it doesn't seem worth worrying about this. We "continue"
4413 the outer loop when we've changed something; otherwise we "break"
4414 the switch, which will "break" the while. */
4417 low = high = build_int_cst (TREE_TYPE (exp), 0);
4421 code = TREE_CODE (exp);
4422 exp_type = TREE_TYPE (exp);
4424 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4426 if (TREE_OPERAND_LENGTH (exp) > 0)
4427 arg0 = TREE_OPERAND (exp, 0);
4428 if (TREE_CODE_CLASS (code) == tcc_comparison
4429 || TREE_CODE_CLASS (code) == tcc_unary
4430 || TREE_CODE_CLASS (code) == tcc_binary)
4431 arg0_type = TREE_TYPE (arg0);
4432 if (TREE_CODE_CLASS (code) == tcc_binary
4433 || TREE_CODE_CLASS (code) == tcc_comparison
4434 || (TREE_CODE_CLASS (code) == tcc_expression
4435 && TREE_OPERAND_LENGTH (exp) > 1))
4436 arg1 = TREE_OPERAND (exp, 1);
4441 case TRUTH_NOT_EXPR:
4442 in_p = ! in_p, exp = arg0;
4445 case EQ_EXPR: case NE_EXPR:
4446 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4447 /* We can only do something if the range is testing for zero
4448 and if the second operand is an integer constant. Note that
4449 saying something is "in" the range we make is done by
4450 complementing IN_P since it will set in the initial case of
4451 being not equal to zero; "out" is leaving it alone. */
4452 if (low == 0 || high == 0
4453 || ! integer_zerop (low) || ! integer_zerop (high)
4454 || TREE_CODE (arg1) != INTEGER_CST)
4459 case NE_EXPR: /* - [c, c] */
4462 case EQ_EXPR: /* + [c, c] */
4463 in_p = ! in_p, low = high = arg1;
4465 case GT_EXPR: /* - [-, c] */
4466 low = 0, high = arg1;
4468 case GE_EXPR: /* + [c, -] */
4469 in_p = ! in_p, low = arg1, high = 0;
4471 case LT_EXPR: /* - [c, -] */
4472 low = arg1, high = 0;
4474 case LE_EXPR: /* + [-, c] */
4475 in_p = ! in_p, low = 0, high = arg1;
4481 /* If this is an unsigned comparison, we also know that EXP is
4482 greater than or equal to zero. We base the range tests we make
4483 on that fact, so we record it here so we can parse existing
4484 range tests. We test arg0_type since often the return type
4485 of, e.g. EQ_EXPR, is boolean. */
4486 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4488 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4490 build_int_cst (arg0_type, 0),
4494 in_p = n_in_p, low = n_low, high = n_high;
4496 /* If the high bound is missing, but we have a nonzero low
4497 bound, reverse the range so it goes from zero to the low bound
4499 if (high == 0 && low && ! integer_zerop (low))
4502 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4503 integer_one_node, 0);
4504 low = build_int_cst (arg0_type, 0);
4512 /* (-x) IN [a,b] -> x in [-b, -a] */
4513 n_low = range_binop (MINUS_EXPR, exp_type,
4514 build_int_cst (exp_type, 0),
4516 n_high = range_binop (MINUS_EXPR, exp_type,
4517 build_int_cst (exp_type, 0),
4519 low = n_low, high = n_high;
4525 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4526 build_int_cst (exp_type, 1));
4529 case PLUS_EXPR: case MINUS_EXPR:
4530 if (TREE_CODE (arg1) != INTEGER_CST)
4533 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4534 move a constant to the other side. */
4535 if (!TYPE_UNSIGNED (arg0_type)
4536 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4539 /* If EXP is signed, any overflow in the computation is undefined,
4540 so we don't worry about it so long as our computations on
4541 the bounds don't overflow. For unsigned, overflow is defined
4542 and this is exactly the right thing. */
4543 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4544 arg0_type, low, 0, arg1, 0);
4545 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4546 arg0_type, high, 1, arg1, 0);
4547 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4548 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4551 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4552 *strict_overflow_p = true;
4554 /* Check for an unsigned range which has wrapped around the maximum
4555 value thus making n_high < n_low, and normalize it. */
4556 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4558 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4559 integer_one_node, 0);
4560 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4561 integer_one_node, 0);
4563 /* If the range is of the form +/- [ x+1, x ], we won't
4564 be able to normalize it. But then, it represents the
4565 whole range or the empty set, so make it
4567 if (tree_int_cst_equal (n_low, low)
4568 && tree_int_cst_equal (n_high, high))
4574 low = n_low, high = n_high;
4579 CASE_CONVERT: case NON_LVALUE_EXPR:
4580 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4583 if (! INTEGRAL_TYPE_P (arg0_type)
4584 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4585 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4588 n_low = low, n_high = high;
4591 n_low = fold_convert (arg0_type, n_low);
4594 n_high = fold_convert (arg0_type, n_high);
4597 /* If we're converting arg0 from an unsigned type, to exp,
4598 a signed type, we will be doing the comparison as unsigned.
4599 The tests above have already verified that LOW and HIGH
4602 So we have to ensure that we will handle large unsigned
4603 values the same way that the current signed bounds treat
4606 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4610 /* For fixed-point modes, we need to pass the saturating flag
4611 as the 2nd parameter. */
4612 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
4613 equiv_type = lang_hooks.types.type_for_mode
4614 (TYPE_MODE (arg0_type),
4615 TYPE_SATURATING (arg0_type));
4617 equiv_type = lang_hooks.types.type_for_mode
4618 (TYPE_MODE (arg0_type), 1);
4620 /* A range without an upper bound is, naturally, unbounded.
4621 Since convert would have cropped a very large value, use
4622 the max value for the destination type. */
4624 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4625 : TYPE_MAX_VALUE (arg0_type);
4627 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4628 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4629 fold_convert (arg0_type,
4631 build_int_cst (arg0_type, 1));
4633 /* If the low bound is specified, "and" the range with the
4634 range for which the original unsigned value will be
4638 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4639 1, n_low, n_high, 1,
4640 fold_convert (arg0_type,
4645 in_p = (n_in_p == in_p);
4649 /* Otherwise, "or" the range with the range of the input
4650 that will be interpreted as negative. */
4651 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4652 0, n_low, n_high, 1,
4653 fold_convert (arg0_type,
4658 in_p = (in_p != n_in_p);
4663 low = n_low, high = n_high;
4673 /* If EXP is a constant, we can evaluate whether this is true or false. */
4674 if (TREE_CODE (exp) == INTEGER_CST)
4676 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4678 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4684 *pin_p = in_p, *plow = low, *phigh = high;
4688 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4689 type, TYPE, return an expression to test if EXP is in (or out of, depending
4690 on IN_P) the range. Return 0 if the test couldn't be created. */
4693 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4695 tree etype = TREE_TYPE (exp), value;
4697 #ifdef HAVE_canonicalize_funcptr_for_compare
4698 /* Disable this optimization for function pointer expressions
4699 on targets that require function pointer canonicalization. */
4700 if (HAVE_canonicalize_funcptr_for_compare
4701 && TREE_CODE (etype) == POINTER_TYPE
4702 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4708 value = build_range_check (type, exp, 1, low, high);
4710 return invert_truthvalue (value);
4715 if (low == 0 && high == 0)
4716 return build_int_cst (type, 1);
4719 return fold_build2 (LE_EXPR, type, exp,
4720 fold_convert (etype, high));
4723 return fold_build2 (GE_EXPR, type, exp,
4724 fold_convert (etype, low));
4726 if (operand_equal_p (low, high, 0))
4727 return fold_build2 (EQ_EXPR, type, exp,
4728 fold_convert (etype, low));
4730 if (integer_zerop (low))
4732 if (! TYPE_UNSIGNED (etype))
4734 etype = unsigned_type_for (etype);
4735 high = fold_convert (etype, high);
4736 exp = fold_convert (etype, exp);
4738 return build_range_check (type, exp, 1, 0, high);
4741 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4742 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4744 unsigned HOST_WIDE_INT lo;
4748 prec = TYPE_PRECISION (etype);
4749 if (prec <= HOST_BITS_PER_WIDE_INT)
4752 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4756 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4757 lo = (unsigned HOST_WIDE_INT) -1;
4760 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4762 if (TYPE_UNSIGNED (etype))
4764 tree signed_etype = signed_type_for (etype);
4765 if (TYPE_PRECISION (signed_etype) != TYPE_PRECISION (etype))
4767 = build_nonstandard_integer_type (TYPE_PRECISION (etype), 0);
4769 etype = signed_etype;
4770 exp = fold_convert (etype, exp);
4772 return fold_build2 (GT_EXPR, type, exp,
4773 build_int_cst (etype, 0));
4777 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4778 This requires wrap-around arithmetics for the type of the expression.
4779 First make sure that arithmetics in this type is valid, then make sure
4780 that it wraps around. */
4781 if (TREE_CODE (etype) == ENUMERAL_TYPE || TREE_CODE (etype) == BOOLEAN_TYPE)
4782 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4783 TYPE_UNSIGNED (etype));
4785 if (TREE_CODE (etype) == INTEGER_TYPE && !TYPE_OVERFLOW_WRAPS (etype))
4787 tree utype, minv, maxv;
4789 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4790 for the type in question, as we rely on this here. */
4791 utype = unsigned_type_for (etype);
4792 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4793 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4794 integer_one_node, 1);
4795 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4797 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4804 high = fold_convert (etype, high);
4805 low = fold_convert (etype, low);
4806 exp = fold_convert (etype, exp);
4808 value = const_binop (MINUS_EXPR, high, low, 0);
4811 if (POINTER_TYPE_P (etype))
4813 if (value != 0 && !TREE_OVERFLOW (value))
4815 low = fold_convert (sizetype, low);
4816 low = fold_build1 (NEGATE_EXPR, sizetype, low);
4817 return build_range_check (type,
4818 fold_build2 (POINTER_PLUS_EXPR, etype, exp, low),
4819 1, build_int_cst (etype, 0), value);
4824 if (value != 0 && !TREE_OVERFLOW (value))
4825 return build_range_check (type,
4826 fold_build2 (MINUS_EXPR, etype, exp, low),
4827 1, build_int_cst (etype, 0), value);
4832 /* Return the predecessor of VAL in its type, handling the infinite case. */
4835 range_predecessor (tree val)
4837 tree type = TREE_TYPE (val);
4839 if (INTEGRAL_TYPE_P (type)
4840 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4843 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4846 /* Return the successor of VAL in its type, handling the infinite case. */
4849 range_successor (tree val)
4851 tree type = TREE_TYPE (val);
4853 if (INTEGRAL_TYPE_P (type)
4854 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4857 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4860 /* Given two ranges, see if we can merge them into one. Return 1 if we
4861 can, 0 if we can't. Set the output range into the specified parameters. */
4864 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4865 tree high0, int in1_p, tree low1, tree high1)
4873 int lowequal = ((low0 == 0 && low1 == 0)
4874 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4875 low0, 0, low1, 0)));
4876 int highequal = ((high0 == 0 && high1 == 0)
4877 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4878 high0, 1, high1, 1)));
4880 /* Make range 0 be the range that starts first, or ends last if they
4881 start at the same value. Swap them if it isn't. */
4882 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4885 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4886 high1, 1, high0, 1))))
4888 temp = in0_p, in0_p = in1_p, in1_p = temp;
4889 tem = low0, low0 = low1, low1 = tem;
4890 tem = high0, high0 = high1, high1 = tem;
4893 /* Now flag two cases, whether the ranges are disjoint or whether the
4894 second range is totally subsumed in the first. Note that the tests
4895 below are simplified by the ones above. */
4896 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4897 high0, 1, low1, 0));
4898 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4899 high1, 1, high0, 1));
4901 /* We now have four cases, depending on whether we are including or
4902 excluding the two ranges. */
4905 /* If they don't overlap, the result is false. If the second range
4906 is a subset it is the result. Otherwise, the range is from the start
4907 of the second to the end of the first. */
4909 in_p = 0, low = high = 0;
4911 in_p = 1, low = low1, high = high1;
4913 in_p = 1, low = low1, high = high0;
4916 else if (in0_p && ! in1_p)
4918 /* If they don't overlap, the result is the first range. If they are
4919 equal, the result is false. If the second range is a subset of the
4920 first, and the ranges begin at the same place, we go from just after
4921 the end of the second range to the end of the first. If the second
4922 range is not a subset of the first, or if it is a subset and both
4923 ranges end at the same place, the range starts at the start of the
4924 first range and ends just before the second range.
4925 Otherwise, we can't describe this as a single range. */
4927 in_p = 1, low = low0, high = high0;
4928 else if (lowequal && highequal)
4929 in_p = 0, low = high = 0;
4930 else if (subset && lowequal)
4932 low = range_successor (high1);
4937 /* We are in the weird situation where high0 > high1 but
4938 high1 has no successor. Punt. */
4942 else if (! subset || highequal)
4945 high = range_predecessor (low1);
4949 /* low0 < low1 but low1 has no predecessor. Punt. */
4957 else if (! in0_p && in1_p)
4959 /* If they don't overlap, the result is the second range. If the second
4960 is a subset of the first, the result is false. Otherwise,
4961 the range starts just after the first range and ends at the
4962 end of the second. */
4964 in_p = 1, low = low1, high = high1;
4965 else if (subset || highequal)
4966 in_p = 0, low = high = 0;
4969 low = range_successor (high0);
4974 /* high1 > high0 but high0 has no successor. Punt. */
4982 /* The case where we are excluding both ranges. Here the complex case
4983 is if they don't overlap. In that case, the only time we have a
4984 range is if they are adjacent. If the second is a subset of the
4985 first, the result is the first. Otherwise, the range to exclude
4986 starts at the beginning of the first range and ends at the end of the
4990 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4991 range_successor (high0),
4993 in_p = 0, low = low0, high = high1;
4996 /* Canonicalize - [min, x] into - [-, x]. */
4997 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4998 switch (TREE_CODE (TREE_TYPE (low0)))
5001 if (TYPE_PRECISION (TREE_TYPE (low0))
5002 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
5006 if (tree_int_cst_equal (low0,
5007 TYPE_MIN_VALUE (TREE_TYPE (low0))))
5011 if (TYPE_UNSIGNED (TREE_TYPE (low0))
5012 && integer_zerop (low0))
5019 /* Canonicalize - [x, max] into - [x, -]. */
5020 if (high1 && TREE_CODE (high1) == INTEGER_CST)
5021 switch (TREE_CODE (TREE_TYPE (high1)))
5024 if (TYPE_PRECISION (TREE_TYPE (high1))
5025 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
5029 if (tree_int_cst_equal (high1,
5030 TYPE_MAX_VALUE (TREE_TYPE (high1))))
5034 if (TYPE_UNSIGNED (TREE_TYPE (high1))
5035 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
5037 integer_one_node, 1)))
5044 /* The ranges might be also adjacent between the maximum and
5045 minimum values of the given type. For
5046 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
5047 return + [x + 1, y - 1]. */
5048 if (low0 == 0 && high1 == 0)
5050 low = range_successor (high0);
5051 high = range_predecessor (low1);
5052 if (low == 0 || high == 0)
5062 in_p = 0, low = low0, high = high0;
5064 in_p = 0, low = low0, high = high1;
5067 *pin_p = in_p, *plow = low, *phigh = high;
5072 /* Subroutine of fold, looking inside expressions of the form
5073 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
5074 of the COND_EXPR. This function is being used also to optimize
5075 A op B ? C : A, by reversing the comparison first.
5077 Return a folded expression whose code is not a COND_EXPR
5078 anymore, or NULL_TREE if no folding opportunity is found. */
5081 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
5083 enum tree_code comp_code = TREE_CODE (arg0);
5084 tree arg00 = TREE_OPERAND (arg0, 0);
5085 tree arg01 = TREE_OPERAND (arg0, 1);
5086 tree arg1_type = TREE_TYPE (arg1);
5092 /* If we have A op 0 ? A : -A, consider applying the following
5095 A == 0? A : -A same as -A
5096 A != 0? A : -A same as A
5097 A >= 0? A : -A same as abs (A)
5098 A > 0? A : -A same as abs (A)
5099 A <= 0? A : -A same as -abs (A)
5100 A < 0? A : -A same as -abs (A)
5102 None of these transformations work for modes with signed
5103 zeros. If A is +/-0, the first two transformations will
5104 change the sign of the result (from +0 to -0, or vice
5105 versa). The last four will fix the sign of the result,
5106 even though the original expressions could be positive or
5107 negative, depending on the sign of A.
5109 Note that all these transformations are correct if A is
5110 NaN, since the two alternatives (A and -A) are also NaNs. */
5111 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
5112 && (FLOAT_TYPE_P (TREE_TYPE (arg01))
5113 ? real_zerop (arg01)
5114 : integer_zerop (arg01))
5115 && ((TREE_CODE (arg2) == NEGATE_EXPR
5116 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
5117 /* In the case that A is of the form X-Y, '-A' (arg2) may
5118 have already been folded to Y-X, check for that. */
5119 || (TREE_CODE (arg1) == MINUS_EXPR
5120 && TREE_CODE (arg2) == MINUS_EXPR
5121 && operand_equal_p (TREE_OPERAND (arg1, 0),
5122 TREE_OPERAND (arg2, 1), 0)
5123 && operand_equal_p (TREE_OPERAND (arg1, 1),
5124 TREE_OPERAND (arg2, 0), 0))))
5129 tem = fold_convert (arg1_type, arg1);
5130 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
5133 return pedantic_non_lvalue (fold_convert (type, arg1));
5136 if (flag_trapping_math)
5141 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5142 arg1 = fold_convert (signed_type_for
5143 (TREE_TYPE (arg1)), arg1);
5144 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5145 return pedantic_non_lvalue (fold_convert (type, tem));
5148 if (flag_trapping_math)
5152 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5153 arg1 = fold_convert (signed_type_for
5154 (TREE_TYPE (arg1)), arg1);
5155 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5156 return negate_expr (fold_convert (type, tem));
5158 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5162 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
5163 A == 0 ? A : 0 is always 0 unless A is -0. Note that
5164 both transformations are correct when A is NaN: A != 0
5165 is then true, and A == 0 is false. */
5167 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
5168 && integer_zerop (arg01) && integer_zerop (arg2))
5170 if (comp_code == NE_EXPR)
5171 return pedantic_non_lvalue (fold_convert (type, arg1));
5172 else if (comp_code == EQ_EXPR)
5173 return build_int_cst (type, 0);
5176 /* Try some transformations of A op B ? A : B.
5178 A == B? A : B same as B
5179 A != B? A : B same as A
5180 A >= B? A : B same as max (A, B)
5181 A > B? A : B same as max (B, A)
5182 A <= B? A : B same as min (A, B)
5183 A < B? A : B same as min (B, A)
5185 As above, these transformations don't work in the presence
5186 of signed zeros. For example, if A and B are zeros of
5187 opposite sign, the first two transformations will change
5188 the sign of the result. In the last four, the original
5189 expressions give different results for (A=+0, B=-0) and
5190 (A=-0, B=+0), but the transformed expressions do not.
5192 The first two transformations are correct if either A or B
5193 is a NaN. In the first transformation, the condition will
5194 be false, and B will indeed be chosen. In the case of the
5195 second transformation, the condition A != B will be true,
5196 and A will be chosen.
5198 The conversions to max() and min() are not correct if B is
5199 a number and A is not. The conditions in the original
5200 expressions will be false, so all four give B. The min()
5201 and max() versions would give a NaN instead. */
5202 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
5203 && operand_equal_for_comparison_p (arg01, arg2, arg00)
5204 /* Avoid these transformations if the COND_EXPR may be used
5205 as an lvalue in the C++ front-end. PR c++/19199. */
5207 || (strcmp (lang_hooks.name, "GNU C++") != 0
5208 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
5209 || ! maybe_lvalue_p (arg1)
5210 || ! maybe_lvalue_p (arg2)))
5212 tree comp_op0 = arg00;
5213 tree comp_op1 = arg01;
5214 tree comp_type = TREE_TYPE (comp_op0);
5216 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
5217 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
5227 return pedantic_non_lvalue (fold_convert (type, arg2));
5229 return pedantic_non_lvalue (fold_convert (type, arg1));
5234 /* In C++ a ?: expression can be an lvalue, so put the
5235 operand which will be used if they are equal first
5236 so that we can convert this back to the
5237 corresponding COND_EXPR. */
5238 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5240 comp_op0 = fold_convert (comp_type, comp_op0);
5241 comp_op1 = fold_convert (comp_type, comp_op1);
5242 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
5243 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
5244 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
5245 return pedantic_non_lvalue (fold_convert (type, tem));
5252 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5254 comp_op0 = fold_convert (comp_type, comp_op0);
5255 comp_op1 = fold_convert (comp_type, comp_op1);
5256 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
5257 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
5258 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
5259 return pedantic_non_lvalue (fold_convert (type, tem));
5263 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5264 return pedantic_non_lvalue (fold_convert (type, arg2));
5267 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5268 return pedantic_non_lvalue (fold_convert (type, arg1));
5271 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5276 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
5277 we might still be able to simplify this. For example,
5278 if C1 is one less or one more than C2, this might have started
5279 out as a MIN or MAX and been transformed by this function.
5280 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
5282 if (INTEGRAL_TYPE_P (type)
5283 && TREE_CODE (arg01) == INTEGER_CST
5284 && TREE_CODE (arg2) == INTEGER_CST)
5288 /* We can replace A with C1 in this case. */
5289 arg1 = fold_convert (type, arg01);
5290 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
5293 /* If C1 is C2 + 1, this is min(A, C2). */
5294 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5296 && operand_equal_p (arg01,
5297 const_binop (PLUS_EXPR, arg2,
5298 build_int_cst (type, 1), 0),
5300 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5302 fold_convert (type, arg1),
5307 /* If C1 is C2 - 1, this is min(A, C2). */
5308 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5310 && operand_equal_p (arg01,
5311 const_binop (MINUS_EXPR, arg2,
5312 build_int_cst (type, 1), 0),
5314 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5316 fold_convert (type, arg1),
5321 /* If C1 is C2 - 1, this is max(A, C2), but use ARG00's type for
5322 MAX_EXPR, to preserve the signedness of the comparison. */
5323 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5325 && operand_equal_p (arg01,
5326 const_binop (MINUS_EXPR, arg2,
5327 build_int_cst (type, 1), 0),
5329 return pedantic_non_lvalue (fold_convert (type,
5330 fold_build2 (MAX_EXPR, TREE_TYPE (arg00),
5332 fold_convert (TREE_TYPE (arg00),
5337 /* If C1 is C2 + 1, this is max(A, C2), with the same care as above. */
5338 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5340 && operand_equal_p (arg01,
5341 const_binop (PLUS_EXPR, arg2,
5342 build_int_cst (type, 1), 0),
5344 return pedantic_non_lvalue (fold_convert (type,
5345 fold_build2 (MAX_EXPR, TREE_TYPE (arg00),
5347 fold_convert (TREE_TYPE (arg00),
5361 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5362 #define LOGICAL_OP_NON_SHORT_CIRCUIT \
5363 (BRANCH_COST (optimize_function_for_speed_p (cfun), \
5367 /* EXP is some logical combination of boolean tests. See if we can
5368 merge it into some range test. Return the new tree if so. */
5371 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
5373 int or_op = (code == TRUTH_ORIF_EXPR
5374 || code == TRUTH_OR_EXPR);
5375 int in0_p, in1_p, in_p;
5376 tree low0, low1, low, high0, high1, high;
5377 bool strict_overflow_p = false;
5378 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
5379 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
5381 const char * const warnmsg = G_("assuming signed overflow does not occur "
5382 "when simplifying range test");
5384 /* If this is an OR operation, invert both sides; we will invert
5385 again at the end. */
5387 in0_p = ! in0_p, in1_p = ! in1_p;
5389 /* If both expressions are the same, if we can merge the ranges, and we
5390 can build the range test, return it or it inverted. If one of the
5391 ranges is always true or always false, consider it to be the same
5392 expression as the other. */
5393 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
5394 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
5396 && 0 != (tem = (build_range_check (type,
5398 : rhs != 0 ? rhs : integer_zero_node,
5401 if (strict_overflow_p)
5402 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
5403 return or_op ? invert_truthvalue (tem) : tem;
5406 /* On machines where the branch cost is expensive, if this is a
5407 short-circuited branch and the underlying object on both sides
5408 is the same, make a non-short-circuit operation. */
5409 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5410 && lhs != 0 && rhs != 0
5411 && (code == TRUTH_ANDIF_EXPR
5412 || code == TRUTH_ORIF_EXPR)
5413 && operand_equal_p (lhs, rhs, 0))
5415 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5416 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5417 which cases we can't do this. */
5418 if (simple_operand_p (lhs))
5419 return build2 (code == TRUTH_ANDIF_EXPR
5420 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5423 else if (lang_hooks.decls.global_bindings_p () == 0
5424 && ! CONTAINS_PLACEHOLDER_P (lhs))
5426 tree common = save_expr (lhs);
5428 if (0 != (lhs = build_range_check (type, common,
5429 or_op ? ! in0_p : in0_p,
5431 && (0 != (rhs = build_range_check (type, common,
5432 or_op ? ! in1_p : in1_p,
5435 if (strict_overflow_p)
5436 fold_overflow_warning (warnmsg,
5437 WARN_STRICT_OVERFLOW_COMPARISON);
5438 return build2 (code == TRUTH_ANDIF_EXPR
5439 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5448 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5449 bit value. Arrange things so the extra bits will be set to zero if and
5450 only if C is signed-extended to its full width. If MASK is nonzero,
5451 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5454 unextend (tree c, int p, int unsignedp, tree mask)
5456 tree type = TREE_TYPE (c);
5457 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5460 if (p == modesize || unsignedp)
5463 /* We work by getting just the sign bit into the low-order bit, then
5464 into the high-order bit, then sign-extend. We then XOR that value
5466 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5467 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5469 /* We must use a signed type in order to get an arithmetic right shift.
5470 However, we must also avoid introducing accidental overflows, so that
5471 a subsequent call to integer_zerop will work. Hence we must
5472 do the type conversion here. At this point, the constant is either
5473 zero or one, and the conversion to a signed type can never overflow.
5474 We could get an overflow if this conversion is done anywhere else. */
5475 if (TYPE_UNSIGNED (type))
5476 temp = fold_convert (signed_type_for (type), temp);
5478 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5479 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5481 temp = const_binop (BIT_AND_EXPR, temp,
5482 fold_convert (TREE_TYPE (c), mask), 0);
5483 /* If necessary, convert the type back to match the type of C. */
5484 if (TYPE_UNSIGNED (type))
5485 temp = fold_convert (type, temp);
5487 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5490 /* Find ways of folding logical expressions of LHS and RHS:
5491 Try to merge two comparisons to the same innermost item.
5492 Look for range tests like "ch >= '0' && ch <= '9'".
5493 Look for combinations of simple terms on machines with expensive branches
5494 and evaluate the RHS unconditionally.
5496 For example, if we have p->a == 2 && p->b == 4 and we can make an
5497 object large enough to span both A and B, we can do this with a comparison
5498 against the object ANDed with the a mask.
5500 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5501 operations to do this with one comparison.
5503 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5504 function and the one above.
5506 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5507 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5509 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5512 We return the simplified tree or 0 if no optimization is possible. */
5515 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5517 /* If this is the "or" of two comparisons, we can do something if
5518 the comparisons are NE_EXPR. If this is the "and", we can do something
5519 if the comparisons are EQ_EXPR. I.e.,
5520 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5522 WANTED_CODE is this operation code. For single bit fields, we can
5523 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5524 comparison for one-bit fields. */
5526 enum tree_code wanted_code;
5527 enum tree_code lcode, rcode;
5528 tree ll_arg, lr_arg, rl_arg, rr_arg;
5529 tree ll_inner, lr_inner, rl_inner, rr_inner;
5530 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5531 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5532 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
5533 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
5534 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5535 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5536 enum machine_mode lnmode, rnmode;
5537 tree ll_mask, lr_mask, rl_mask, rr_mask;
5538 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5539 tree l_const, r_const;
5540 tree lntype, rntype, result;
5541 HOST_WIDE_INT first_bit, end_bit;
5543 tree orig_lhs = lhs, orig_rhs = rhs;
5544 enum tree_code orig_code = code;
5546 /* Start by getting the comparison codes. Fail if anything is volatile.
5547 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5548 it were surrounded with a NE_EXPR. */
5550 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5553 lcode = TREE_CODE (lhs);
5554 rcode = TREE_CODE (rhs);
5556 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5558 lhs = build2 (NE_EXPR, truth_type, lhs,
5559 build_int_cst (TREE_TYPE (lhs), 0));
5563 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5565 rhs = build2 (NE_EXPR, truth_type, rhs,
5566 build_int_cst (TREE_TYPE (rhs), 0));
5570 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5571 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5574 ll_arg = TREE_OPERAND (lhs, 0);
5575 lr_arg = TREE_OPERAND (lhs, 1);
5576 rl_arg = TREE_OPERAND (rhs, 0);
5577 rr_arg = TREE_OPERAND (rhs, 1);
5579 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5580 if (simple_operand_p (ll_arg)
5581 && simple_operand_p (lr_arg))
5584 if (operand_equal_p (ll_arg, rl_arg, 0)
5585 && operand_equal_p (lr_arg, rr_arg, 0))
5587 result = combine_comparisons (code, lcode, rcode,
5588 truth_type, ll_arg, lr_arg);
5592 else if (operand_equal_p (ll_arg, rr_arg, 0)
5593 && operand_equal_p (lr_arg, rl_arg, 0))
5595 result = combine_comparisons (code, lcode,
5596 swap_tree_comparison (rcode),
5597 truth_type, ll_arg, lr_arg);
5603 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5604 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5606 /* If the RHS can be evaluated unconditionally and its operands are
5607 simple, it wins to evaluate the RHS unconditionally on machines
5608 with expensive branches. In this case, this isn't a comparison
5609 that can be merged. Avoid doing this if the RHS is a floating-point
5610 comparison since those can trap. */
5612 if (BRANCH_COST (optimize_function_for_speed_p (cfun),
5614 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5615 && simple_operand_p (rl_arg)
5616 && simple_operand_p (rr_arg))
5618 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5619 if (code == TRUTH_OR_EXPR
5620 && lcode == NE_EXPR && integer_zerop (lr_arg)
5621 && rcode == NE_EXPR && integer_zerop (rr_arg)
5622 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5623 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5624 return build2 (NE_EXPR, truth_type,
5625 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5627 build_int_cst (TREE_TYPE (ll_arg), 0));
5629 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5630 if (code == TRUTH_AND_EXPR
5631 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5632 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5633 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5634 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5635 return build2 (EQ_EXPR, truth_type,
5636 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5638 build_int_cst (TREE_TYPE (ll_arg), 0));
5640 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5642 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5643 return build2 (code, truth_type, lhs, rhs);
5648 /* See if the comparisons can be merged. Then get all the parameters for
5651 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5652 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5656 ll_inner = decode_field_reference (ll_arg,
5657 &ll_bitsize, &ll_bitpos, &ll_mode,
5658 &ll_unsignedp, &volatilep, &ll_mask,
5660 lr_inner = decode_field_reference (lr_arg,
5661 &lr_bitsize, &lr_bitpos, &lr_mode,
5662 &lr_unsignedp, &volatilep, &lr_mask,
5664 rl_inner = decode_field_reference (rl_arg,
5665 &rl_bitsize, &rl_bitpos, &rl_mode,
5666 &rl_unsignedp, &volatilep, &rl_mask,
5668 rr_inner = decode_field_reference (rr_arg,
5669 &rr_bitsize, &rr_bitpos, &rr_mode,
5670 &rr_unsignedp, &volatilep, &rr_mask,
5673 /* It must be true that the inner operation on the lhs of each
5674 comparison must be the same if we are to be able to do anything.
5675 Then see if we have constants. If not, the same must be true for
5677 if (volatilep || ll_inner == 0 || rl_inner == 0
5678 || ! operand_equal_p (ll_inner, rl_inner, 0))
5681 if (TREE_CODE (lr_arg) == INTEGER_CST
5682 && TREE_CODE (rr_arg) == INTEGER_CST)
5683 l_const = lr_arg, r_const = rr_arg;
5684 else if (lr_inner == 0 || rr_inner == 0
5685 || ! operand_equal_p (lr_inner, rr_inner, 0))
5688 l_const = r_const = 0;
5690 /* If either comparison code is not correct for our logical operation,
5691 fail. However, we can convert a one-bit comparison against zero into
5692 the opposite comparison against that bit being set in the field. */
5694 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5695 if (lcode != wanted_code)
5697 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5699 /* Make the left operand unsigned, since we are only interested
5700 in the value of one bit. Otherwise we are doing the wrong
5709 /* This is analogous to the code for l_const above. */
5710 if (rcode != wanted_code)
5712 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5721 /* See if we can find a mode that contains both fields being compared on
5722 the left. If we can't, fail. Otherwise, update all constants and masks
5723 to be relative to a field of that size. */
5724 first_bit = MIN (ll_bitpos, rl_bitpos);
5725 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5726 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5727 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5729 if (lnmode == VOIDmode)
5732 lnbitsize = GET_MODE_BITSIZE (lnmode);
5733 lnbitpos = first_bit & ~ (lnbitsize - 1);
5734 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5735 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5737 if (BYTES_BIG_ENDIAN)
5739 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5740 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5743 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5744 size_int (xll_bitpos), 0);
5745 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5746 size_int (xrl_bitpos), 0);
5750 l_const = fold_convert (lntype, l_const);
5751 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5752 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5753 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5754 fold_build1 (BIT_NOT_EXPR,
5758 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5760 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5765 r_const = fold_convert (lntype, r_const);
5766 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5767 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5768 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5769 fold_build1 (BIT_NOT_EXPR,
5773 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5775 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5779 /* If the right sides are not constant, do the same for it. Also,
5780 disallow this optimization if a size or signedness mismatch occurs
5781 between the left and right sides. */
5784 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
5785 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
5786 /* Make sure the two fields on the right
5787 correspond to the left without being swapped. */
5788 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
5791 first_bit = MIN (lr_bitpos, rr_bitpos);
5792 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
5793 rnmode = get_best_mode (end_bit - first_bit, first_bit,
5794 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
5796 if (rnmode == VOIDmode)
5799 rnbitsize = GET_MODE_BITSIZE (rnmode);
5800 rnbitpos = first_bit & ~ (rnbitsize - 1);
5801 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
5802 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
5804 if (BYTES_BIG_ENDIAN)
5806 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
5807 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
5810 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
5811 size_int (xlr_bitpos), 0);
5812 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
5813 size_int (xrr_bitpos), 0);
5815 /* Make a mask that corresponds to both fields being compared.
5816 Do this for both items being compared. If the operands are the
5817 same size and the bits being compared are in the same position
5818 then we can do this by masking both and comparing the masked
5820 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5821 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
5822 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
5824 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5825 ll_unsignedp || rl_unsignedp);
5826 if (! all_ones_mask_p (ll_mask, lnbitsize))
5827 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
5829 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
5830 lr_unsignedp || rr_unsignedp);
5831 if (! all_ones_mask_p (lr_mask, rnbitsize))
5832 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
5834 return build2 (wanted_code, truth_type, lhs, rhs);
5837 /* There is still another way we can do something: If both pairs of
5838 fields being compared are adjacent, we may be able to make a wider
5839 field containing them both.
5841 Note that we still must mask the lhs/rhs expressions. Furthermore,
5842 the mask must be shifted to account for the shift done by
5843 make_bit_field_ref. */
5844 if ((ll_bitsize + ll_bitpos == rl_bitpos
5845 && lr_bitsize + lr_bitpos == rr_bitpos)
5846 || (ll_bitpos == rl_bitpos + rl_bitsize
5847 && lr_bitpos == rr_bitpos + rr_bitsize))
5851 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
5852 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
5853 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
5854 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
5856 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
5857 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
5858 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
5859 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
5861 /* Convert to the smaller type before masking out unwanted bits. */
5863 if (lntype != rntype)
5865 if (lnbitsize > rnbitsize)
5867 lhs = fold_convert (rntype, lhs);
5868 ll_mask = fold_convert (rntype, ll_mask);
5871 else if (lnbitsize < rnbitsize)
5873 rhs = fold_convert (lntype, rhs);
5874 lr_mask = fold_convert (lntype, lr_mask);
5879 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
5880 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
5882 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
5883 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
5885 return build2 (wanted_code, truth_type, lhs, rhs);
5891 /* Handle the case of comparisons with constants. If there is something in
5892 common between the masks, those bits of the constants must be the same.
5893 If not, the condition is always false. Test for this to avoid generating
5894 incorrect code below. */
5895 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5896 if (! integer_zerop (result)
5897 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5898 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5900 if (wanted_code == NE_EXPR)
5902 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5903 return constant_boolean_node (true, truth_type);
5907 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5908 return constant_boolean_node (false, truth_type);
5912 /* Construct the expression we will return. First get the component
5913 reference we will make. Unless the mask is all ones the width of
5914 that field, perform the mask operation. Then compare with the
5916 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5917 ll_unsignedp || rl_unsignedp);
5919 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5920 if (! all_ones_mask_p (ll_mask, lnbitsize))
5921 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
5923 return build2 (wanted_code, truth_type, result,
5924 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
5927 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5931 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5934 enum tree_code op_code;
5937 int consts_equal, consts_lt;
5940 STRIP_SIGN_NOPS (arg0);
5942 op_code = TREE_CODE (arg0);
5943 minmax_const = TREE_OPERAND (arg0, 1);
5944 comp_const = fold_convert (TREE_TYPE (arg0), op1);
5945 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5946 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5947 inner = TREE_OPERAND (arg0, 0);
5949 /* If something does not permit us to optimize, return the original tree. */
5950 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5951 || TREE_CODE (comp_const) != INTEGER_CST
5952 || TREE_OVERFLOW (comp_const)
5953 || TREE_CODE (minmax_const) != INTEGER_CST
5954 || TREE_OVERFLOW (minmax_const))
5957 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5958 and GT_EXPR, doing the rest with recursive calls using logical
5962 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5964 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5967 return invert_truthvalue (tem);
5973 fold_build2 (TRUTH_ORIF_EXPR, type,
5974 optimize_minmax_comparison
5975 (EQ_EXPR, type, arg0, comp_const),
5976 optimize_minmax_comparison
5977 (GT_EXPR, type, arg0, comp_const));
5980 if (op_code == MAX_EXPR && consts_equal)
5981 /* MAX (X, 0) == 0 -> X <= 0 */
5982 return fold_build2 (LE_EXPR, type, inner, comp_const);
5984 else if (op_code == MAX_EXPR && consts_lt)
5985 /* MAX (X, 0) == 5 -> X == 5 */
5986 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5988 else if (op_code == MAX_EXPR)
5989 /* MAX (X, 0) == -1 -> false */
5990 return omit_one_operand (type, integer_zero_node, inner);
5992 else if (consts_equal)
5993 /* MIN (X, 0) == 0 -> X >= 0 */
5994 return fold_build2 (GE_EXPR, type, inner, comp_const);
5997 /* MIN (X, 0) == 5 -> false */
5998 return omit_one_operand (type, integer_zero_node, inner);
6001 /* MIN (X, 0) == -1 -> X == -1 */
6002 return fold_build2 (EQ_EXPR, type, inner, comp_const);
6005 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
6006 /* MAX (X, 0) > 0 -> X > 0
6007 MAX (X, 0) > 5 -> X > 5 */
6008 return fold_build2 (GT_EXPR, type, inner, comp_const);
6010 else if (op_code == MAX_EXPR)
6011 /* MAX (X, 0) > -1 -> true */
6012 return omit_one_operand (type, integer_one_node, inner);
6014 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
6015 /* MIN (X, 0) > 0 -> false
6016 MIN (X, 0) > 5 -> false */
6017 return omit_one_operand (type, integer_zero_node, inner);
6020 /* MIN (X, 0) > -1 -> X > -1 */
6021 return fold_build2 (GT_EXPR, type, inner, comp_const);
6028 /* T is an integer expression that is being multiplied, divided, or taken a
6029 modulus (CODE says which and what kind of divide or modulus) by a
6030 constant C. See if we can eliminate that operation by folding it with
6031 other operations already in T. WIDE_TYPE, if non-null, is a type that
6032 should be used for the computation if wider than our type.
6034 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
6035 (X * 2) + (Y * 4). We must, however, be assured that either the original
6036 expression would not overflow or that overflow is undefined for the type
6037 in the language in question.
6039 If we return a non-null expression, it is an equivalent form of the
6040 original computation, but need not be in the original type.
6042 We set *STRICT_OVERFLOW_P to true if the return values depends on
6043 signed overflow being undefined. Otherwise we do not change
6044 *STRICT_OVERFLOW_P. */
6047 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
6048 bool *strict_overflow_p)
6050 /* To avoid exponential search depth, refuse to allow recursion past
6051 three levels. Beyond that (1) it's highly unlikely that we'll find
6052 something interesting and (2) we've probably processed it before
6053 when we built the inner expression. */
6062 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
6069 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
6070 bool *strict_overflow_p)
6072 tree type = TREE_TYPE (t);
6073 enum tree_code tcode = TREE_CODE (t);
6074 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
6075 > GET_MODE_SIZE (TYPE_MODE (type)))
6076 ? wide_type : type);
6078 int same_p = tcode == code;
6079 tree op0 = NULL_TREE, op1 = NULL_TREE;
6080 bool sub_strict_overflow_p;
6082 /* Don't deal with constants of zero here; they confuse the code below. */
6083 if (integer_zerop (c))
6086 if (TREE_CODE_CLASS (tcode) == tcc_unary)
6087 op0 = TREE_OPERAND (t, 0);
6089 if (TREE_CODE_CLASS (tcode) == tcc_binary)
6090 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
6092 /* Note that we need not handle conditional operations here since fold
6093 already handles those cases. So just do arithmetic here. */
6097 /* For a constant, we can always simplify if we are a multiply
6098 or (for divide and modulus) if it is a multiple of our constant. */
6099 if (code == MULT_EXPR
6100 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
6101 return const_binop (code, fold_convert (ctype, t),
6102 fold_convert (ctype, c), 0);
6105 CASE_CONVERT: case NON_LVALUE_EXPR:
6106 /* If op0 is an expression ... */
6107 if ((COMPARISON_CLASS_P (op0)
6108 || UNARY_CLASS_P (op0)
6109 || BINARY_CLASS_P (op0)
6110 || VL_EXP_CLASS_P (op0)
6111 || EXPRESSION_CLASS_P (op0))
6112 /* ... and has wrapping overflow, and its type is smaller
6113 than ctype, then we cannot pass through as widening. */
6114 && ((TYPE_OVERFLOW_WRAPS (TREE_TYPE (op0))
6115 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
6116 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
6117 && (TYPE_PRECISION (ctype)
6118 > TYPE_PRECISION (TREE_TYPE (op0))))
6119 /* ... or this is a truncation (t is narrower than op0),
6120 then we cannot pass through this narrowing. */
6121 || (TYPE_PRECISION (type)
6122 < TYPE_PRECISION (TREE_TYPE (op0)))
6123 /* ... or signedness changes for division or modulus,
6124 then we cannot pass through this conversion. */
6125 || (code != MULT_EXPR
6126 && (TYPE_UNSIGNED (ctype)
6127 != TYPE_UNSIGNED (TREE_TYPE (op0))))
6128 /* ... or has undefined overflow while the converted to
6129 type has not, we cannot do the operation in the inner type
6130 as that would introduce undefined overflow. */
6131 || (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))
6132 && !TYPE_OVERFLOW_UNDEFINED (type))))
6135 /* Pass the constant down and see if we can make a simplification. If
6136 we can, replace this expression with the inner simplification for
6137 possible later conversion to our or some other type. */
6138 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
6139 && TREE_CODE (t2) == INTEGER_CST
6140 && !TREE_OVERFLOW (t2)
6141 && (0 != (t1 = extract_muldiv (op0, t2, code,
6143 ? ctype : NULL_TREE,
6144 strict_overflow_p))))
6149 /* If widening the type changes it from signed to unsigned, then we
6150 must avoid building ABS_EXPR itself as unsigned. */
6151 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
6153 tree cstype = (*signed_type_for) (ctype);
6154 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
6157 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
6158 return fold_convert (ctype, t1);
6162 /* If the constant is negative, we cannot simplify this. */
6163 if (tree_int_cst_sgn (c) == -1)
6167 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
6169 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
6172 case MIN_EXPR: case MAX_EXPR:
6173 /* If widening the type changes the signedness, then we can't perform
6174 this optimization as that changes the result. */
6175 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
6178 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
6179 sub_strict_overflow_p = false;
6180 if ((t1 = extract_muldiv (op0, c, code, wide_type,
6181 &sub_strict_overflow_p)) != 0
6182 && (t2 = extract_muldiv (op1, c, code, wide_type,
6183 &sub_strict_overflow_p)) != 0)
6185 if (tree_int_cst_sgn (c) < 0)
6186 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
6187 if (sub_strict_overflow_p)
6188 *strict_overflow_p = true;
6189 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6190 fold_convert (ctype, t2));
6194 case LSHIFT_EXPR: case RSHIFT_EXPR:
6195 /* If the second operand is constant, this is a multiplication
6196 or floor division, by a power of two, so we can treat it that
6197 way unless the multiplier or divisor overflows. Signed
6198 left-shift overflow is implementation-defined rather than
6199 undefined in C90, so do not convert signed left shift into
6201 if (TREE_CODE (op1) == INTEGER_CST
6202 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
6203 /* const_binop may not detect overflow correctly,
6204 so check for it explicitly here. */
6205 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
6206 && TREE_INT_CST_HIGH (op1) == 0
6207 && 0 != (t1 = fold_convert (ctype,
6208 const_binop (LSHIFT_EXPR,
6211 && !TREE_OVERFLOW (t1))
6212 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
6213 ? MULT_EXPR : FLOOR_DIV_EXPR,
6214 ctype, fold_convert (ctype, op0), t1),
6215 c, code, wide_type, strict_overflow_p);
6218 case PLUS_EXPR: case MINUS_EXPR:
6219 /* See if we can eliminate the operation on both sides. If we can, we
6220 can return a new PLUS or MINUS. If we can't, the only remaining
6221 cases where we can do anything are if the second operand is a
6223 sub_strict_overflow_p = false;
6224 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
6225 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
6226 if (t1 != 0 && t2 != 0
6227 && (code == MULT_EXPR
6228 /* If not multiplication, we can only do this if both operands
6229 are divisible by c. */
6230 || (multiple_of_p (ctype, op0, c)
6231 && multiple_of_p (ctype, op1, c))))
6233 if (sub_strict_overflow_p)
6234 *strict_overflow_p = true;
6235 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6236 fold_convert (ctype, t2));
6239 /* If this was a subtraction, negate OP1 and set it to be an addition.
6240 This simplifies the logic below. */
6241 if (tcode == MINUS_EXPR)
6242 tcode = PLUS_EXPR, op1 = negate_expr (op1);
6244 if (TREE_CODE (op1) != INTEGER_CST)
6247 /* If either OP1 or C are negative, this optimization is not safe for
6248 some of the division and remainder types while for others we need
6249 to change the code. */
6250 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
6252 if (code == CEIL_DIV_EXPR)
6253 code = FLOOR_DIV_EXPR;
6254 else if (code == FLOOR_DIV_EXPR)
6255 code = CEIL_DIV_EXPR;
6256 else if (code != MULT_EXPR
6257 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
6261 /* If it's a multiply or a division/modulus operation of a multiple
6262 of our constant, do the operation and verify it doesn't overflow. */
6263 if (code == MULT_EXPR
6264 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6266 op1 = const_binop (code, fold_convert (ctype, op1),
6267 fold_convert (ctype, c), 0);
6268 /* We allow the constant to overflow with wrapping semantics. */
6270 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
6276 /* If we have an unsigned type is not a sizetype, we cannot widen
6277 the operation since it will change the result if the original
6278 computation overflowed. */
6279 if (TYPE_UNSIGNED (ctype)
6280 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
6284 /* If we were able to eliminate our operation from the first side,
6285 apply our operation to the second side and reform the PLUS. */
6286 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
6287 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
6289 /* The last case is if we are a multiply. In that case, we can
6290 apply the distributive law to commute the multiply and addition
6291 if the multiplication of the constants doesn't overflow. */
6292 if (code == MULT_EXPR)
6293 return fold_build2 (tcode, ctype,
6294 fold_build2 (code, ctype,
6295 fold_convert (ctype, op0),
6296 fold_convert (ctype, c)),
6302 /* We have a special case here if we are doing something like
6303 (C * 8) % 4 since we know that's zero. */
6304 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
6305 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
6306 /* If the multiplication can overflow we cannot optimize this.
6307 ??? Until we can properly mark individual operations as
6308 not overflowing we need to treat sizetype special here as
6309 stor-layout relies on this opimization to make
6310 DECL_FIELD_BIT_OFFSET always a constant. */
6311 && (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t))
6312 || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
6313 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
6314 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
6315 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6317 *strict_overflow_p = true;
6318 return omit_one_operand (type, integer_zero_node, op0);
6321 /* ... fall through ... */
6323 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
6324 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
6325 /* If we can extract our operation from the LHS, do so and return a
6326 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
6327 do something only if the second operand is a constant. */
6329 && (t1 = extract_muldiv (op0, c, code, wide_type,
6330 strict_overflow_p)) != 0)
6331 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6332 fold_convert (ctype, op1));
6333 else if (tcode == MULT_EXPR && code == MULT_EXPR
6334 && (t1 = extract_muldiv (op1, c, code, wide_type,
6335 strict_overflow_p)) != 0)
6336 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6337 fold_convert (ctype, t1));
6338 else if (TREE_CODE (op1) != INTEGER_CST)
6341 /* If these are the same operation types, we can associate them
6342 assuming no overflow. */
6344 && 0 != (t1 = int_const_binop (MULT_EXPR, fold_convert (ctype, op1),
6345 fold_convert (ctype, c), 1))
6346 && 0 != (t1 = force_fit_type_double (ctype, TREE_INT_CST_LOW (t1),
6347 TREE_INT_CST_HIGH (t1),
6348 (TYPE_UNSIGNED (ctype)
6349 && tcode != MULT_EXPR) ? -1 : 1,
6350 TREE_OVERFLOW (t1)))
6351 && !TREE_OVERFLOW (t1))
6352 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
6354 /* If these operations "cancel" each other, we have the main
6355 optimizations of this pass, which occur when either constant is a
6356 multiple of the other, in which case we replace this with either an
6357 operation or CODE or TCODE.
6359 If we have an unsigned type that is not a sizetype, we cannot do
6360 this since it will change the result if the original computation
6362 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
6363 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
6364 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
6365 || (tcode == MULT_EXPR
6366 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
6367 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
6368 && code != MULT_EXPR)))
6370 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6372 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6373 *strict_overflow_p = true;
6374 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6375 fold_convert (ctype,
6376 const_binop (TRUNC_DIV_EXPR,
6379 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
6381 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6382 *strict_overflow_p = true;
6383 return fold_build2 (code, ctype, fold_convert (ctype, op0),
6384 fold_convert (ctype,
6385 const_binop (TRUNC_DIV_EXPR,
6398 /* Return a node which has the indicated constant VALUE (either 0 or
6399 1), and is of the indicated TYPE. */
6402 constant_boolean_node (int value, tree type)
6404 if (type == integer_type_node)
6405 return value ? integer_one_node : integer_zero_node;
6406 else if (type == boolean_type_node)
6407 return value ? boolean_true_node : boolean_false_node;
6409 return build_int_cst (type, value);
6413 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6414 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6415 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6416 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6417 COND is the first argument to CODE; otherwise (as in the example
6418 given here), it is the second argument. TYPE is the type of the
6419 original expression. Return NULL_TREE if no simplification is
6423 fold_binary_op_with_conditional_arg (enum tree_code code,
6424 tree type, tree op0, tree op1,
6425 tree cond, tree arg, int cond_first_p)
6427 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6428 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6429 tree test, true_value, false_value;
6430 tree lhs = NULL_TREE;
6431 tree rhs = NULL_TREE;
6433 /* This transformation is only worthwhile if we don't have to wrap
6434 arg in a SAVE_EXPR, and the operation can be simplified on at least
6435 one of the branches once its pushed inside the COND_EXPR. */
6436 if (!TREE_CONSTANT (arg))
6439 if (TREE_CODE (cond) == COND_EXPR)
6441 test = TREE_OPERAND (cond, 0);
6442 true_value = TREE_OPERAND (cond, 1);
6443 false_value = TREE_OPERAND (cond, 2);
6444 /* If this operand throws an expression, then it does not make
6445 sense to try to perform a logical or arithmetic operation
6447 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6449 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6454 tree testtype = TREE_TYPE (cond);
6456 true_value = constant_boolean_node (true, testtype);
6457 false_value = constant_boolean_node (false, testtype);
6460 arg = fold_convert (arg_type, arg);
6463 true_value = fold_convert (cond_type, true_value);
6465 lhs = fold_build2 (code, type, true_value, arg);
6467 lhs = fold_build2 (code, type, arg, true_value);
6471 false_value = fold_convert (cond_type, false_value);
6473 rhs = fold_build2 (code, type, false_value, arg);
6475 rhs = fold_build2 (code, type, arg, false_value);
6478 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6479 return fold_convert (type, test);
6483 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6485 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6486 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6487 ADDEND is the same as X.
6489 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6490 and finite. The problematic cases are when X is zero, and its mode
6491 has signed zeros. In the case of rounding towards -infinity,
6492 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6493 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6496 fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
6498 if (!real_zerop (addend))
6501 /* Don't allow the fold with -fsignaling-nans. */
6502 if (HONOR_SNANS (TYPE_MODE (type)))
6505 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6506 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6509 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6510 if (TREE_CODE (addend) == REAL_CST
6511 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6514 /* The mode has signed zeros, and we have to honor their sign.
6515 In this situation, there is only one case we can return true for.
6516 X - 0 is the same as X unless rounding towards -infinity is
6518 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6521 /* Subroutine of fold() that checks comparisons of built-in math
6522 functions against real constants.
6524 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6525 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6526 is the type of the result and ARG0 and ARG1 are the operands of the
6527 comparison. ARG1 must be a TREE_REAL_CST.
6529 The function returns the constant folded tree if a simplification
6530 can be made, and NULL_TREE otherwise. */
6533 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6534 tree type, tree arg0, tree arg1)
6538 if (BUILTIN_SQRT_P (fcode))
6540 tree arg = CALL_EXPR_ARG (arg0, 0);
6541 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6543 c = TREE_REAL_CST (arg1);
6544 if (REAL_VALUE_NEGATIVE (c))
6546 /* sqrt(x) < y is always false, if y is negative. */
6547 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6548 return omit_one_operand (type, integer_zero_node, arg);
6550 /* sqrt(x) > y is always true, if y is negative and we
6551 don't care about NaNs, i.e. negative values of x. */
6552 if (code == NE_EXPR || !HONOR_NANS (mode))
6553 return omit_one_operand (type, integer_one_node, arg);
6555 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6556 return fold_build2 (GE_EXPR, type, arg,
6557 build_real (TREE_TYPE (arg), dconst0));
6559 else if (code == GT_EXPR || code == GE_EXPR)
6563 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6564 real_convert (&c2, mode, &c2);
6566 if (REAL_VALUE_ISINF (c2))
6568 /* sqrt(x) > y is x == +Inf, when y is very large. */
6569 if (HONOR_INFINITIES (mode))
6570 return fold_build2 (EQ_EXPR, type, arg,
6571 build_real (TREE_TYPE (arg), c2));
6573 /* sqrt(x) > y is always false, when y is very large
6574 and we don't care about infinities. */
6575 return omit_one_operand (type, integer_zero_node, arg);
6578 /* sqrt(x) > c is the same as x > c*c. */
6579 return fold_build2 (code, type, arg,
6580 build_real (TREE_TYPE (arg), c2));
6582 else if (code == LT_EXPR || code == LE_EXPR)
6586 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6587 real_convert (&c2, mode, &c2);
6589 if (REAL_VALUE_ISINF (c2))
6591 /* sqrt(x) < y is always true, when y is a very large
6592 value and we don't care about NaNs or Infinities. */
6593 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6594 return omit_one_operand (type, integer_one_node, arg);
6596 /* sqrt(x) < y is x != +Inf when y is very large and we
6597 don't care about NaNs. */
6598 if (! HONOR_NANS (mode))
6599 return fold_build2 (NE_EXPR, type, arg,
6600 build_real (TREE_TYPE (arg), c2));
6602 /* sqrt(x) < y is x >= 0 when y is very large and we
6603 don't care about Infinities. */
6604 if (! HONOR_INFINITIES (mode))
6605 return fold_build2 (GE_EXPR, type, arg,
6606 build_real (TREE_TYPE (arg), dconst0));
6608 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6609 if (lang_hooks.decls.global_bindings_p () != 0
6610 || CONTAINS_PLACEHOLDER_P (arg))
6613 arg = save_expr (arg);
6614 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6615 fold_build2 (GE_EXPR, type, arg,
6616 build_real (TREE_TYPE (arg),
6618 fold_build2 (NE_EXPR, type, arg,
6619 build_real (TREE_TYPE (arg),
6623 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6624 if (! HONOR_NANS (mode))
6625 return fold_build2 (code, type, arg,
6626 build_real (TREE_TYPE (arg), c2));
6628 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6629 if (lang_hooks.decls.global_bindings_p () == 0
6630 && ! CONTAINS_PLACEHOLDER_P (arg))
6632 arg = save_expr (arg);
6633 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6634 fold_build2 (GE_EXPR, type, arg,
6635 build_real (TREE_TYPE (arg),
6637 fold_build2 (code, type, arg,
6638 build_real (TREE_TYPE (arg),
6647 /* Subroutine of fold() that optimizes comparisons against Infinities,
6648 either +Inf or -Inf.
6650 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6651 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6652 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6654 The function returns the constant folded tree if a simplification
6655 can be made, and NULL_TREE otherwise. */
6658 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6660 enum machine_mode mode;
6661 REAL_VALUE_TYPE max;
6665 mode = TYPE_MODE (TREE_TYPE (arg0));
6667 /* For negative infinity swap the sense of the comparison. */
6668 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6670 code = swap_tree_comparison (code);
6675 /* x > +Inf is always false, if with ignore sNANs. */
6676 if (HONOR_SNANS (mode))
6678 return omit_one_operand (type, integer_zero_node, arg0);
6681 /* x <= +Inf is always true, if we don't case about NaNs. */
6682 if (! HONOR_NANS (mode))
6683 return omit_one_operand (type, integer_one_node, arg0);
6685 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6686 if (lang_hooks.decls.global_bindings_p () == 0
6687 && ! CONTAINS_PLACEHOLDER_P (arg0))
6689 arg0 = save_expr (arg0);
6690 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6696 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6697 real_maxval (&max, neg, mode);
6698 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6699 arg0, build_real (TREE_TYPE (arg0), max));
6702 /* x < +Inf is always equal to x <= DBL_MAX. */
6703 real_maxval (&max, neg, mode);
6704 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6705 arg0, build_real (TREE_TYPE (arg0), max));
6708 /* x != +Inf is always equal to !(x > DBL_MAX). */
6709 real_maxval (&max, neg, mode);
6710 if (! HONOR_NANS (mode))
6711 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6712 arg0, build_real (TREE_TYPE (arg0), max));
6714 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6715 arg0, build_real (TREE_TYPE (arg0), max));
6716 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6725 /* Subroutine of fold() that optimizes comparisons of a division by
6726 a nonzero integer constant against an integer constant, i.e.
6729 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6730 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6731 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6733 The function returns the constant folded tree if a simplification
6734 can be made, and NULL_TREE otherwise. */
6737 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6739 tree prod, tmp, hi, lo;
6740 tree arg00 = TREE_OPERAND (arg0, 0);
6741 tree arg01 = TREE_OPERAND (arg0, 1);
6742 unsigned HOST_WIDE_INT lpart;
6743 HOST_WIDE_INT hpart;
6744 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6748 /* We have to do this the hard way to detect unsigned overflow.
6749 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6750 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6751 TREE_INT_CST_HIGH (arg01),
6752 TREE_INT_CST_LOW (arg1),
6753 TREE_INT_CST_HIGH (arg1),
6754 &lpart, &hpart, unsigned_p);
6755 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6757 neg_overflow = false;
6761 tmp = int_const_binop (MINUS_EXPR, arg01,
6762 build_int_cst (TREE_TYPE (arg01), 1), 0);
6765 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6766 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6767 TREE_INT_CST_HIGH (prod),
6768 TREE_INT_CST_LOW (tmp),
6769 TREE_INT_CST_HIGH (tmp),
6770 &lpart, &hpart, unsigned_p);
6771 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6772 -1, overflow | TREE_OVERFLOW (prod));
6774 else if (tree_int_cst_sgn (arg01) >= 0)
6776 tmp = int_const_binop (MINUS_EXPR, arg01,
6777 build_int_cst (TREE_TYPE (arg01), 1), 0);
6778 switch (tree_int_cst_sgn (arg1))
6781 neg_overflow = true;
6782 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6787 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6792 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6802 /* A negative divisor reverses the relational operators. */
6803 code = swap_tree_comparison (code);
6805 tmp = int_const_binop (PLUS_EXPR, arg01,
6806 build_int_cst (TREE_TYPE (arg01), 1), 0);
6807 switch (tree_int_cst_sgn (arg1))
6810 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6815 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6820 neg_overflow = true;
6821 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6833 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6834 return omit_one_operand (type, integer_zero_node, arg00);
6835 if (TREE_OVERFLOW (hi))
6836 return fold_build2 (GE_EXPR, type, arg00, lo);
6837 if (TREE_OVERFLOW (lo))
6838 return fold_build2 (LE_EXPR, type, arg00, hi);
6839 return build_range_check (type, arg00, 1, lo, hi);
6842 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6843 return omit_one_operand (type, integer_one_node, arg00);
6844 if (TREE_OVERFLOW (hi))
6845 return fold_build2 (LT_EXPR, type, arg00, lo);
6846 if (TREE_OVERFLOW (lo))
6847 return fold_build2 (GT_EXPR, type, arg00, hi);
6848 return build_range_check (type, arg00, 0, lo, hi);
6851 if (TREE_OVERFLOW (lo))
6853 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6854 return omit_one_operand (type, tmp, arg00);
6856 return fold_build2 (LT_EXPR, type, arg00, lo);
6859 if (TREE_OVERFLOW (hi))
6861 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6862 return omit_one_operand (type, tmp, arg00);
6864 return fold_build2 (LE_EXPR, type, arg00, hi);
6867 if (TREE_OVERFLOW (hi))
6869 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6870 return omit_one_operand (type, tmp, arg00);
6872 return fold_build2 (GT_EXPR, type, arg00, hi);
6875 if (TREE_OVERFLOW (lo))
6877 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6878 return omit_one_operand (type, tmp, arg00);
6880 return fold_build2 (GE_EXPR, type, arg00, lo);
6890 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6891 equality/inequality test, then return a simplified form of the test
6892 using a sign testing. Otherwise return NULL. TYPE is the desired
6896 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6899 /* If this is testing a single bit, we can optimize the test. */
6900 if ((code == NE_EXPR || code == EQ_EXPR)
6901 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6902 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6904 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6905 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6906 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6908 if (arg00 != NULL_TREE
6909 /* This is only a win if casting to a signed type is cheap,
6910 i.e. when arg00's type is not a partial mode. */
6911 && TYPE_PRECISION (TREE_TYPE (arg00))
6912 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6914 tree stype = signed_type_for (TREE_TYPE (arg00));
6915 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6916 result_type, fold_convert (stype, arg00),
6917 build_int_cst (stype, 0));
6924 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6925 equality/inequality test, then return a simplified form of
6926 the test using shifts and logical operations. Otherwise return
6927 NULL. TYPE is the desired result type. */
6930 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6933 /* If this is testing a single bit, we can optimize the test. */
6934 if ((code == NE_EXPR || code == EQ_EXPR)
6935 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6936 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6938 tree inner = TREE_OPERAND (arg0, 0);
6939 tree type = TREE_TYPE (arg0);
6940 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6941 enum machine_mode operand_mode = TYPE_MODE (type);
6943 tree signed_type, unsigned_type, intermediate_type;
6946 /* First, see if we can fold the single bit test into a sign-bit
6948 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6953 /* Otherwise we have (A & C) != 0 where C is a single bit,
6954 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6955 Similarly for (A & C) == 0. */
6957 /* If INNER is a right shift of a constant and it plus BITNUM does
6958 not overflow, adjust BITNUM and INNER. */
6959 if (TREE_CODE (inner) == RSHIFT_EXPR
6960 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6961 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6962 && bitnum < TYPE_PRECISION (type)
6963 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6964 bitnum - TYPE_PRECISION (type)))
6966 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6967 inner = TREE_OPERAND (inner, 0);
6970 /* If we are going to be able to omit the AND below, we must do our
6971 operations as unsigned. If we must use the AND, we have a choice.
6972 Normally unsigned is faster, but for some machines signed is. */
6973 #ifdef LOAD_EXTEND_OP
6974 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6975 && !flag_syntax_only) ? 0 : 1;
6980 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6981 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6982 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6983 inner = fold_convert (intermediate_type, inner);
6986 inner = build2 (RSHIFT_EXPR, intermediate_type,
6987 inner, size_int (bitnum));
6989 one = build_int_cst (intermediate_type, 1);
6991 if (code == EQ_EXPR)
6992 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6994 /* Put the AND last so it can combine with more things. */
6995 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6997 /* Make sure to return the proper type. */
6998 inner = fold_convert (result_type, inner);
7005 /* Check whether we are allowed to reorder operands arg0 and arg1,
7006 such that the evaluation of arg1 occurs before arg0. */
7009 reorder_operands_p (const_tree arg0, const_tree arg1)
7011 if (! flag_evaluation_order)
7013 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
7015 return ! TREE_SIDE_EFFECTS (arg0)
7016 && ! TREE_SIDE_EFFECTS (arg1);
7019 /* Test whether it is preferable two swap two operands, ARG0 and
7020 ARG1, for example because ARG0 is an integer constant and ARG1
7021 isn't. If REORDER is true, only recommend swapping if we can
7022 evaluate the operands in reverse order. */
7025 tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
7027 STRIP_SIGN_NOPS (arg0);
7028 STRIP_SIGN_NOPS (arg1);
7030 if (TREE_CODE (arg1) == INTEGER_CST)
7032 if (TREE_CODE (arg0) == INTEGER_CST)
7035 if (TREE_CODE (arg1) == REAL_CST)
7037 if (TREE_CODE (arg0) == REAL_CST)
7040 if (TREE_CODE (arg1) == FIXED_CST)
7042 if (TREE_CODE (arg0) == FIXED_CST)
7045 if (TREE_CODE (arg1) == COMPLEX_CST)
7047 if (TREE_CODE (arg0) == COMPLEX_CST)
7050 if (TREE_CONSTANT (arg1))
7052 if (TREE_CONSTANT (arg0))
7055 if (optimize_function_for_size_p (cfun))
7058 if (reorder && flag_evaluation_order
7059 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
7062 /* It is preferable to swap two SSA_NAME to ensure a canonical form
7063 for commutative and comparison operators. Ensuring a canonical
7064 form allows the optimizers to find additional redundancies without
7065 having to explicitly check for both orderings. */
7066 if (TREE_CODE (arg0) == SSA_NAME
7067 && TREE_CODE (arg1) == SSA_NAME
7068 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
7071 /* Put SSA_NAMEs last. */
7072 if (TREE_CODE (arg1) == SSA_NAME)
7074 if (TREE_CODE (arg0) == SSA_NAME)
7077 /* Put variables last. */
7086 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
7087 ARG0 is extended to a wider type. */
7090 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
7092 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
7094 tree shorter_type, outer_type;
7098 if (arg0_unw == arg0)
7100 shorter_type = TREE_TYPE (arg0_unw);
7102 #ifdef HAVE_canonicalize_funcptr_for_compare
7103 /* Disable this optimization if we're casting a function pointer
7104 type on targets that require function pointer canonicalization. */
7105 if (HAVE_canonicalize_funcptr_for_compare
7106 && TREE_CODE (shorter_type) == POINTER_TYPE
7107 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
7111 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
7114 arg1_unw = get_unwidened (arg1, NULL_TREE);
7116 /* If possible, express the comparison in the shorter mode. */
7117 if ((code == EQ_EXPR || code == NE_EXPR
7118 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
7119 && (TREE_TYPE (arg1_unw) == shorter_type
7120 || ((TYPE_PRECISION (shorter_type)
7121 >= TYPE_PRECISION (TREE_TYPE (arg1_unw)))
7122 && (TYPE_UNSIGNED (shorter_type)
7123 == TYPE_UNSIGNED (TREE_TYPE (arg1_unw))))
7124 || (TREE_CODE (arg1_unw) == INTEGER_CST
7125 && (TREE_CODE (shorter_type) == INTEGER_TYPE
7126 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
7127 && int_fits_type_p (arg1_unw, shorter_type))))
7128 return fold_build2 (code, type, arg0_unw,
7129 fold_convert (shorter_type, arg1_unw));
7131 if (TREE_CODE (arg1_unw) != INTEGER_CST
7132 || TREE_CODE (shorter_type) != INTEGER_TYPE
7133 || !int_fits_type_p (arg1_unw, shorter_type))
7136 /* If we are comparing with the integer that does not fit into the range
7137 of the shorter type, the result is known. */
7138 outer_type = TREE_TYPE (arg1_unw);
7139 min = lower_bound_in_type (outer_type, shorter_type);
7140 max = upper_bound_in_type (outer_type, shorter_type);
7142 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7144 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7151 return omit_one_operand (type, integer_zero_node, arg0);
7156 return omit_one_operand (type, integer_one_node, arg0);
7162 return omit_one_operand (type, integer_one_node, arg0);
7164 return omit_one_operand (type, integer_zero_node, arg0);
7169 return omit_one_operand (type, integer_zero_node, arg0);
7171 return omit_one_operand (type, integer_one_node, arg0);
7180 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
7181 ARG0 just the signedness is changed. */
7184 fold_sign_changed_comparison (enum tree_code code, tree type,
7185 tree arg0, tree arg1)
7188 tree inner_type, outer_type;
7190 if (!CONVERT_EXPR_P (arg0))
7193 outer_type = TREE_TYPE (arg0);
7194 arg0_inner = TREE_OPERAND (arg0, 0);
7195 inner_type = TREE_TYPE (arg0_inner);
7197 #ifdef HAVE_canonicalize_funcptr_for_compare
7198 /* Disable this optimization if we're casting a function pointer
7199 type on targets that require function pointer canonicalization. */
7200 if (HAVE_canonicalize_funcptr_for_compare
7201 && TREE_CODE (inner_type) == POINTER_TYPE
7202 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
7206 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
7209 if (TREE_CODE (arg1) != INTEGER_CST
7210 && !(CONVERT_EXPR_P (arg1)
7211 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
7214 if ((TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
7215 || POINTER_TYPE_P (inner_type) != POINTER_TYPE_P (outer_type))
7220 if (TREE_CODE (arg1) == INTEGER_CST)
7221 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
7222 TREE_INT_CST_HIGH (arg1), 0,
7223 TREE_OVERFLOW (arg1));
7225 arg1 = fold_convert (inner_type, arg1);
7227 return fold_build2 (code, type, arg0_inner, arg1);
7230 /* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
7231 step of the array. Reconstructs s and delta in the case of s * delta
7232 being an integer constant (and thus already folded).
7233 ADDR is the address. MULT is the multiplicative expression.
7234 If the function succeeds, the new address expression is returned. Otherwise
7235 NULL_TREE is returned. */
7238 try_move_mult_to_index (tree addr, tree op1)
7240 tree s, delta, step;
7241 tree ref = TREE_OPERAND (addr, 0), pref;
7246 /* Strip the nops that might be added when converting op1 to sizetype. */
7249 /* Canonicalize op1 into a possibly non-constant delta
7250 and an INTEGER_CST s. */
7251 if (TREE_CODE (op1) == MULT_EXPR)
7253 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
7258 if (TREE_CODE (arg0) == INTEGER_CST)
7263 else if (TREE_CODE (arg1) == INTEGER_CST)
7271 else if (TREE_CODE (op1) == INTEGER_CST)
7278 /* Simulate we are delta * 1. */
7280 s = integer_one_node;
7283 for (;; ref = TREE_OPERAND (ref, 0))
7285 if (TREE_CODE (ref) == ARRAY_REF)
7287 /* Remember if this was a multi-dimensional array. */
7288 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
7291 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
7295 step = array_ref_element_size (ref);
7296 if (TREE_CODE (step) != INTEGER_CST)
7301 if (! tree_int_cst_equal (step, s))
7306 /* Try if delta is a multiple of step. */
7307 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, op1, step);
7313 /* Only fold here if we can verify we do not overflow one
7314 dimension of a multi-dimensional array. */
7319 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
7320 || !INTEGRAL_TYPE_P (itype)
7321 || !TYPE_MAX_VALUE (itype)
7322 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
7325 tmp = fold_binary (PLUS_EXPR, itype,
7326 fold_convert (itype,
7327 TREE_OPERAND (ref, 1)),
7328 fold_convert (itype, delta));
7330 || TREE_CODE (tmp) != INTEGER_CST
7331 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
7340 if (!handled_component_p (ref))
7344 /* We found the suitable array reference. So copy everything up to it,
7345 and replace the index. */
7347 pref = TREE_OPERAND (addr, 0);
7348 ret = copy_node (pref);
7353 pref = TREE_OPERAND (pref, 0);
7354 TREE_OPERAND (pos, 0) = copy_node (pref);
7355 pos = TREE_OPERAND (pos, 0);
7358 TREE_OPERAND (pos, 1) = fold_build2 (PLUS_EXPR, itype,
7359 fold_convert (itype,
7360 TREE_OPERAND (pos, 1)),
7361 fold_convert (itype, delta));
7363 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
7367 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
7368 means A >= Y && A != MAX, but in this case we know that
7369 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
7372 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
7374 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
7376 if (TREE_CODE (bound) == LT_EXPR)
7377 a = TREE_OPERAND (bound, 0);
7378 else if (TREE_CODE (bound) == GT_EXPR)
7379 a = TREE_OPERAND (bound, 1);
7383 typea = TREE_TYPE (a);
7384 if (!INTEGRAL_TYPE_P (typea)
7385 && !POINTER_TYPE_P (typea))
7388 if (TREE_CODE (ineq) == LT_EXPR)
7390 a1 = TREE_OPERAND (ineq, 1);
7391 y = TREE_OPERAND (ineq, 0);
7393 else if (TREE_CODE (ineq) == GT_EXPR)
7395 a1 = TREE_OPERAND (ineq, 0);
7396 y = TREE_OPERAND (ineq, 1);
7401 if (TREE_TYPE (a1) != typea)
7404 if (POINTER_TYPE_P (typea))
7406 /* Convert the pointer types into integer before taking the difference. */
7407 tree ta = fold_convert (ssizetype, a);
7408 tree ta1 = fold_convert (ssizetype, a1);
7409 diff = fold_binary (MINUS_EXPR, ssizetype, ta1, ta);
7412 diff = fold_binary (MINUS_EXPR, typea, a1, a);
7414 if (!diff || !integer_onep (diff))
7417 return fold_build2 (GE_EXPR, type, a, y);
7420 /* Fold a sum or difference of at least one multiplication.
7421 Returns the folded tree or NULL if no simplification could be made. */
7424 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7426 tree arg00, arg01, arg10, arg11;
7427 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7429 /* (A * C) +- (B * C) -> (A+-B) * C.
7430 (A * C) +- A -> A * (C+-1).
7431 We are most concerned about the case where C is a constant,
7432 but other combinations show up during loop reduction. Since
7433 it is not difficult, try all four possibilities. */
7435 if (TREE_CODE (arg0) == MULT_EXPR)
7437 arg00 = TREE_OPERAND (arg0, 0);
7438 arg01 = TREE_OPERAND (arg0, 1);
7440 else if (TREE_CODE (arg0) == INTEGER_CST)
7442 arg00 = build_one_cst (type);
7447 /* We cannot generate constant 1 for fract. */
7448 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7451 arg01 = build_one_cst (type);
7453 if (TREE_CODE (arg1) == MULT_EXPR)
7455 arg10 = TREE_OPERAND (arg1, 0);
7456 arg11 = TREE_OPERAND (arg1, 1);
7458 else if (TREE_CODE (arg1) == INTEGER_CST)
7460 arg10 = build_one_cst (type);
7461 /* As we canonicalize A - 2 to A + -2 get rid of that sign for
7462 the purpose of this canonicalization. */
7463 if (TREE_INT_CST_HIGH (arg1) == -1
7464 && negate_expr_p (arg1)
7465 && code == PLUS_EXPR)
7467 arg11 = negate_expr (arg1);
7475 /* We cannot generate constant 1 for fract. */
7476 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7479 arg11 = build_one_cst (type);
7483 if (operand_equal_p (arg01, arg11, 0))
7484 same = arg01, alt0 = arg00, alt1 = arg10;
7485 else if (operand_equal_p (arg00, arg10, 0))
7486 same = arg00, alt0 = arg01, alt1 = arg11;
7487 else if (operand_equal_p (arg00, arg11, 0))
7488 same = arg00, alt0 = arg01, alt1 = arg10;
7489 else if (operand_equal_p (arg01, arg10, 0))
7490 same = arg01, alt0 = arg00, alt1 = arg11;
7492 /* No identical multiplicands; see if we can find a common
7493 power-of-two factor in non-power-of-two multiplies. This
7494 can help in multi-dimensional array access. */
7495 else if (host_integerp (arg01, 0)
7496 && host_integerp (arg11, 0))
7498 HOST_WIDE_INT int01, int11, tmp;
7501 int01 = TREE_INT_CST_LOW (arg01);
7502 int11 = TREE_INT_CST_LOW (arg11);
7504 /* Move min of absolute values to int11. */
7505 if ((int01 >= 0 ? int01 : -int01)
7506 < (int11 >= 0 ? int11 : -int11))
7508 tmp = int01, int01 = int11, int11 = tmp;
7509 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7516 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0
7517 /* The remainder should not be a constant, otherwise we
7518 end up folding i * 4 + 2 to (i * 2 + 1) * 2 which has
7519 increased the number of multiplications necessary. */
7520 && TREE_CODE (arg10) != INTEGER_CST)
7522 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7523 build_int_cst (TREE_TYPE (arg00),
7528 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7533 return fold_build2 (MULT_EXPR, type,
7534 fold_build2 (code, type,
7535 fold_convert (type, alt0),
7536 fold_convert (type, alt1)),
7537 fold_convert (type, same));
7542 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7543 specified by EXPR into the buffer PTR of length LEN bytes.
7544 Return the number of bytes placed in the buffer, or zero
7548 native_encode_int (const_tree expr, unsigned char *ptr, int len)
7550 tree type = TREE_TYPE (expr);
7551 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7552 int byte, offset, word, words;
7553 unsigned char value;
7555 if (total_bytes > len)
7557 words = total_bytes / UNITS_PER_WORD;
7559 for (byte = 0; byte < total_bytes; byte++)
7561 int bitpos = byte * BITS_PER_UNIT;
7562 if (bitpos < HOST_BITS_PER_WIDE_INT)
7563 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7565 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7566 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7568 if (total_bytes > UNITS_PER_WORD)
7570 word = byte / UNITS_PER_WORD;
7571 if (WORDS_BIG_ENDIAN)
7572 word = (words - 1) - word;
7573 offset = word * UNITS_PER_WORD;
7574 if (BYTES_BIG_ENDIAN)
7575 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7577 offset += byte % UNITS_PER_WORD;
7580 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7581 ptr[offset] = value;
7587 /* Subroutine of native_encode_expr. Encode the REAL_CST
7588 specified by EXPR into the buffer PTR of length LEN bytes.
7589 Return the number of bytes placed in the buffer, or zero
7593 native_encode_real (const_tree expr, unsigned char *ptr, int len)
7595 tree type = TREE_TYPE (expr);
7596 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7597 int byte, offset, word, words, bitpos;
7598 unsigned char value;
7600 /* There are always 32 bits in each long, no matter the size of
7601 the hosts long. We handle floating point representations with
7605 if (total_bytes > len)
7607 words = (32 / BITS_PER_UNIT) / UNITS_PER_WORD;
7609 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7611 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7612 bitpos += BITS_PER_UNIT)
7614 byte = (bitpos / BITS_PER_UNIT) & 3;
7615 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7617 if (UNITS_PER_WORD < 4)
7619 word = byte / UNITS_PER_WORD;
7620 if (WORDS_BIG_ENDIAN)
7621 word = (words - 1) - word;
7622 offset = word * UNITS_PER_WORD;
7623 if (BYTES_BIG_ENDIAN)
7624 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7626 offset += byte % UNITS_PER_WORD;
7629 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7630 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7635 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7636 specified by EXPR into the buffer PTR of length LEN bytes.
7637 Return the number of bytes placed in the buffer, or zero
7641 native_encode_complex (const_tree expr, unsigned char *ptr, int len)
7646 part = TREE_REALPART (expr);
7647 rsize = native_encode_expr (part, ptr, len);
7650 part = TREE_IMAGPART (expr);
7651 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7654 return rsize + isize;
7658 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7659 specified by EXPR into the buffer PTR of length LEN bytes.
7660 Return the number of bytes placed in the buffer, or zero
7664 native_encode_vector (const_tree expr, unsigned char *ptr, int len)
7666 int i, size, offset, count;
7667 tree itype, elem, elements;
7670 elements = TREE_VECTOR_CST_ELTS (expr);
7671 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7672 itype = TREE_TYPE (TREE_TYPE (expr));
7673 size = GET_MODE_SIZE (TYPE_MODE (itype));
7674 for (i = 0; i < count; i++)
7678 elem = TREE_VALUE (elements);
7679 elements = TREE_CHAIN (elements);
7686 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7691 if (offset + size > len)
7693 memset (ptr+offset, 0, size);
7701 /* Subroutine of native_encode_expr. Encode the STRING_CST
7702 specified by EXPR into the buffer PTR of length LEN bytes.
7703 Return the number of bytes placed in the buffer, or zero
7707 native_encode_string (const_tree expr, unsigned char *ptr, int len)
7709 tree type = TREE_TYPE (expr);
7710 HOST_WIDE_INT total_bytes;
7712 if (TREE_CODE (type) != ARRAY_TYPE
7713 || TREE_CODE (TREE_TYPE (type)) != INTEGER_TYPE
7714 || GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) != BITS_PER_UNIT
7715 || !host_integerp (TYPE_SIZE_UNIT (type), 0))
7717 total_bytes = tree_low_cst (TYPE_SIZE_UNIT (type), 0);
7718 if (total_bytes > len)
7720 if (TREE_STRING_LENGTH (expr) < total_bytes)
7722 memcpy (ptr, TREE_STRING_POINTER (expr), TREE_STRING_LENGTH (expr));
7723 memset (ptr + TREE_STRING_LENGTH (expr), 0,
7724 total_bytes - TREE_STRING_LENGTH (expr));
7727 memcpy (ptr, TREE_STRING_POINTER (expr), total_bytes);
7732 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7733 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7734 buffer PTR of length LEN bytes. Return the number of bytes
7735 placed in the buffer, or zero upon failure. */
7738 native_encode_expr (const_tree expr, unsigned char *ptr, int len)
7740 switch (TREE_CODE (expr))
7743 return native_encode_int (expr, ptr, len);
7746 return native_encode_real (expr, ptr, len);
7749 return native_encode_complex (expr, ptr, len);
7752 return native_encode_vector (expr, ptr, len);
7755 return native_encode_string (expr, ptr, len);
7763 /* Subroutine of native_interpret_expr. Interpret the contents of
7764 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7765 If the buffer cannot be interpreted, return NULL_TREE. */
7768 native_interpret_int (tree type, const unsigned char *ptr, int len)
7770 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7771 int byte, offset, word, words;
7772 unsigned char value;
7773 unsigned int HOST_WIDE_INT lo = 0;
7774 HOST_WIDE_INT hi = 0;
7776 if (total_bytes > len)
7778 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7780 words = total_bytes / UNITS_PER_WORD;
7782 for (byte = 0; byte < total_bytes; byte++)
7784 int bitpos = byte * BITS_PER_UNIT;
7785 if (total_bytes > UNITS_PER_WORD)
7787 word = byte / UNITS_PER_WORD;
7788 if (WORDS_BIG_ENDIAN)
7789 word = (words - 1) - word;
7790 offset = word * UNITS_PER_WORD;
7791 if (BYTES_BIG_ENDIAN)
7792 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7794 offset += byte % UNITS_PER_WORD;
7797 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7798 value = ptr[offset];
7800 if (bitpos < HOST_BITS_PER_WIDE_INT)
7801 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7803 hi |= (unsigned HOST_WIDE_INT) value
7804 << (bitpos - HOST_BITS_PER_WIDE_INT);
7807 return build_int_cst_wide_type (type, lo, hi);
7811 /* Subroutine of native_interpret_expr. Interpret the contents of
7812 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7813 If the buffer cannot be interpreted, return NULL_TREE. */
7816 native_interpret_real (tree type, const unsigned char *ptr, int len)
7818 enum machine_mode mode = TYPE_MODE (type);
7819 int total_bytes = GET_MODE_SIZE (mode);
7820 int byte, offset, word, words, bitpos;
7821 unsigned char value;
7822 /* There are always 32 bits in each long, no matter the size of
7823 the hosts long. We handle floating point representations with
7828 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7829 if (total_bytes > len || total_bytes > 24)
7831 words = (32 / BITS_PER_UNIT) / UNITS_PER_WORD;
7833 memset (tmp, 0, sizeof (tmp));
7834 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7835 bitpos += BITS_PER_UNIT)
7837 byte = (bitpos / BITS_PER_UNIT) & 3;
7838 if (UNITS_PER_WORD < 4)
7840 word = byte / UNITS_PER_WORD;
7841 if (WORDS_BIG_ENDIAN)
7842 word = (words - 1) - word;
7843 offset = word * UNITS_PER_WORD;
7844 if (BYTES_BIG_ENDIAN)
7845 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7847 offset += byte % UNITS_PER_WORD;
7850 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7851 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7853 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7856 real_from_target (&r, tmp, mode);
7857 return build_real (type, r);
7861 /* Subroutine of native_interpret_expr. Interpret the contents of
7862 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7863 If the buffer cannot be interpreted, return NULL_TREE. */
7866 native_interpret_complex (tree type, const unsigned char *ptr, int len)
7868 tree etype, rpart, ipart;
7871 etype = TREE_TYPE (type);
7872 size = GET_MODE_SIZE (TYPE_MODE (etype));
7875 rpart = native_interpret_expr (etype, ptr, size);
7878 ipart = native_interpret_expr (etype, ptr+size, size);
7881 return build_complex (type, rpart, ipart);
7885 /* Subroutine of native_interpret_expr. Interpret the contents of
7886 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7887 If the buffer cannot be interpreted, return NULL_TREE. */
7890 native_interpret_vector (tree type, const unsigned char *ptr, int len)
7892 tree etype, elem, elements;
7895 etype = TREE_TYPE (type);
7896 size = GET_MODE_SIZE (TYPE_MODE (etype));
7897 count = TYPE_VECTOR_SUBPARTS (type);
7898 if (size * count > len)
7901 elements = NULL_TREE;
7902 for (i = count - 1; i >= 0; i--)
7904 elem = native_interpret_expr (etype, ptr+(i*size), size);
7907 elements = tree_cons (NULL_TREE, elem, elements);
7909 return build_vector (type, elements);
7913 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7914 the buffer PTR of length LEN as a constant of type TYPE. For
7915 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7916 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7917 return NULL_TREE. */
7920 native_interpret_expr (tree type, const unsigned char *ptr, int len)
7922 switch (TREE_CODE (type))
7927 return native_interpret_int (type, ptr, len);
7930 return native_interpret_real (type, ptr, len);
7933 return native_interpret_complex (type, ptr, len);
7936 return native_interpret_vector (type, ptr, len);
7944 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7945 TYPE at compile-time. If we're unable to perform the conversion
7946 return NULL_TREE. */
7949 fold_view_convert_expr (tree type, tree expr)
7951 /* We support up to 512-bit values (for V8DFmode). */
7952 unsigned char buffer[64];
7955 /* Check that the host and target are sane. */
7956 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7959 len = native_encode_expr (expr, buffer, sizeof (buffer));
7963 return native_interpret_expr (type, buffer, len);
7966 /* Build an expression for the address of T. Folds away INDIRECT_REF
7967 to avoid confusing the gimplify process. */
7970 build_fold_addr_expr_with_type (tree t, tree ptrtype)
7972 /* The size of the object is not relevant when talking about its address. */
7973 if (TREE_CODE (t) == WITH_SIZE_EXPR)
7974 t = TREE_OPERAND (t, 0);
7976 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
7977 if (TREE_CODE (t) == INDIRECT_REF
7978 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
7980 t = TREE_OPERAND (t, 0);
7982 if (TREE_TYPE (t) != ptrtype)
7983 t = build1 (NOP_EXPR, ptrtype, t);
7986 t = build1 (ADDR_EXPR, ptrtype, t);
7991 /* Build an expression for the address of T. */
7994 build_fold_addr_expr (tree t)
7996 tree ptrtype = build_pointer_type (TREE_TYPE (t));
7998 return build_fold_addr_expr_with_type (t, ptrtype);
8001 /* Fold a unary expression of code CODE and type TYPE with operand
8002 OP0. Return the folded expression if folding is successful.
8003 Otherwise, return NULL_TREE. */
8006 fold_unary (enum tree_code code, tree type, tree op0)
8010 enum tree_code_class kind = TREE_CODE_CLASS (code);
8012 gcc_assert (IS_EXPR_CODE_CLASS (kind)
8013 && TREE_CODE_LENGTH (code) == 1);
8018 if (CONVERT_EXPR_CODE_P (code)
8019 || code == FLOAT_EXPR || code == ABS_EXPR)
8021 /* Don't use STRIP_NOPS, because signedness of argument type
8023 STRIP_SIGN_NOPS (arg0);
8027 /* Strip any conversions that don't change the mode. This
8028 is safe for every expression, except for a comparison
8029 expression because its signedness is derived from its
8032 Note that this is done as an internal manipulation within
8033 the constant folder, in order to find the simplest
8034 representation of the arguments so that their form can be
8035 studied. In any cases, the appropriate type conversions
8036 should be put back in the tree that will get out of the
8042 if (TREE_CODE_CLASS (code) == tcc_unary)
8044 if (TREE_CODE (arg0) == COMPOUND_EXPR)
8045 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
8046 fold_build1 (code, type,
8047 fold_convert (TREE_TYPE (op0),
8048 TREE_OPERAND (arg0, 1))));
8049 else if (TREE_CODE (arg0) == COND_EXPR)
8051 tree arg01 = TREE_OPERAND (arg0, 1);
8052 tree arg02 = TREE_OPERAND (arg0, 2);
8053 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
8054 arg01 = fold_build1 (code, type,
8055 fold_convert (TREE_TYPE (op0), arg01));
8056 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
8057 arg02 = fold_build1 (code, type,
8058 fold_convert (TREE_TYPE (op0), arg02));
8059 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
8062 /* If this was a conversion, and all we did was to move into
8063 inside the COND_EXPR, bring it back out. But leave it if
8064 it is a conversion from integer to integer and the
8065 result precision is no wider than a word since such a
8066 conversion is cheap and may be optimized away by combine,
8067 while it couldn't if it were outside the COND_EXPR. Then return
8068 so we don't get into an infinite recursion loop taking the
8069 conversion out and then back in. */
8071 if ((CONVERT_EXPR_CODE_P (code)
8072 || code == NON_LVALUE_EXPR)
8073 && TREE_CODE (tem) == COND_EXPR
8074 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
8075 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
8076 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
8077 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
8078 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
8079 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
8080 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
8082 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
8083 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
8084 || flag_syntax_only))
8085 tem = build1 (code, type,
8087 TREE_TYPE (TREE_OPERAND
8088 (TREE_OPERAND (tem, 1), 0)),
8089 TREE_OPERAND (tem, 0),
8090 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
8091 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
8094 else if (COMPARISON_CLASS_P (arg0))
8096 if (TREE_CODE (type) == BOOLEAN_TYPE)
8098 arg0 = copy_node (arg0);
8099 TREE_TYPE (arg0) = type;
8102 else if (TREE_CODE (type) != INTEGER_TYPE)
8103 return fold_build3 (COND_EXPR, type, arg0,
8104 fold_build1 (code, type,
8106 fold_build1 (code, type,
8107 integer_zero_node));
8114 /* Re-association barriers around constants and other re-association
8115 barriers can be removed. */
8116 if (CONSTANT_CLASS_P (op0)
8117 || TREE_CODE (op0) == PAREN_EXPR)
8118 return fold_convert (type, op0);
8123 case FIX_TRUNC_EXPR:
8124 if (TREE_TYPE (op0) == type)
8127 /* If we have (type) (a CMP b) and type is an integral type, return
8128 new expression involving the new type. */
8129 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
8130 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
8131 TREE_OPERAND (op0, 1));
8133 /* Handle cases of two conversions in a row. */
8134 if (CONVERT_EXPR_P (op0))
8136 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
8137 tree inter_type = TREE_TYPE (op0);
8138 int inside_int = INTEGRAL_TYPE_P (inside_type);
8139 int inside_ptr = POINTER_TYPE_P (inside_type);
8140 int inside_float = FLOAT_TYPE_P (inside_type);
8141 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
8142 unsigned int inside_prec = TYPE_PRECISION (inside_type);
8143 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
8144 int inter_int = INTEGRAL_TYPE_P (inter_type);
8145 int inter_ptr = POINTER_TYPE_P (inter_type);
8146 int inter_float = FLOAT_TYPE_P (inter_type);
8147 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
8148 unsigned int inter_prec = TYPE_PRECISION (inter_type);
8149 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
8150 int final_int = INTEGRAL_TYPE_P (type);
8151 int final_ptr = POINTER_TYPE_P (type);
8152 int final_float = FLOAT_TYPE_P (type);
8153 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
8154 unsigned int final_prec = TYPE_PRECISION (type);
8155 int final_unsignedp = TYPE_UNSIGNED (type);
8157 /* In addition to the cases of two conversions in a row
8158 handled below, if we are converting something to its own
8159 type via an object of identical or wider precision, neither
8160 conversion is needed. */
8161 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
8162 && (((inter_int || inter_ptr) && final_int)
8163 || (inter_float && final_float))
8164 && inter_prec >= final_prec)
8165 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8167 /* Likewise, if the intermediate and initial types are either both
8168 float or both integer, we don't need the middle conversion if the
8169 former is wider than the latter and doesn't change the signedness
8170 (for integers). Avoid this if the final type is a pointer since
8171 then we sometimes need the middle conversion. Likewise if the
8172 final type has a precision not equal to the size of its mode. */
8173 if (((inter_int && inside_int)
8174 || (inter_float && inside_float)
8175 || (inter_vec && inside_vec))
8176 && inter_prec >= inside_prec
8177 && (inter_float || inter_vec
8178 || inter_unsignedp == inside_unsignedp)
8179 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
8180 && TYPE_MODE (type) == TYPE_MODE (inter_type))
8182 && (! final_vec || inter_prec == inside_prec))
8183 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8185 /* If we have a sign-extension of a zero-extended value, we can
8186 replace that by a single zero-extension. */
8187 if (inside_int && inter_int && final_int
8188 && inside_prec < inter_prec && inter_prec < final_prec
8189 && inside_unsignedp && !inter_unsignedp)
8190 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8192 /* Two conversions in a row are not needed unless:
8193 - some conversion is floating-point (overstrict for now), or
8194 - some conversion is a vector (overstrict for now), or
8195 - the intermediate type is narrower than both initial and
8197 - the intermediate type and innermost type differ in signedness,
8198 and the outermost type is wider than the intermediate, or
8199 - the initial type is a pointer type and the precisions of the
8200 intermediate and final types differ, or
8201 - the final type is a pointer type and the precisions of the
8202 initial and intermediate types differ. */
8203 if (! inside_float && ! inter_float && ! final_float
8204 && ! inside_vec && ! inter_vec && ! final_vec
8205 && (inter_prec >= inside_prec || inter_prec >= final_prec)
8206 && ! (inside_int && inter_int
8207 && inter_unsignedp != inside_unsignedp
8208 && inter_prec < final_prec)
8209 && ((inter_unsignedp && inter_prec > inside_prec)
8210 == (final_unsignedp && final_prec > inter_prec))
8211 && ! (inside_ptr && inter_prec != final_prec)
8212 && ! (final_ptr && inside_prec != inter_prec)
8213 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
8214 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
8215 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8218 /* Handle (T *)&A.B.C for A being of type T and B and C
8219 living at offset zero. This occurs frequently in
8220 C++ upcasting and then accessing the base. */
8221 if (TREE_CODE (op0) == ADDR_EXPR
8222 && POINTER_TYPE_P (type)
8223 && handled_component_p (TREE_OPERAND (op0, 0)))
8225 HOST_WIDE_INT bitsize, bitpos;
8227 enum machine_mode mode;
8228 int unsignedp, volatilep;
8229 tree base = TREE_OPERAND (op0, 0);
8230 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
8231 &mode, &unsignedp, &volatilep, false);
8232 /* If the reference was to a (constant) zero offset, we can use
8233 the address of the base if it has the same base type
8234 as the result type. */
8235 if (! offset && bitpos == 0
8236 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
8237 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
8238 return fold_convert (type, build_fold_addr_expr (base));
8241 if (TREE_CODE (op0) == MODIFY_EXPR
8242 && TREE_CONSTANT (TREE_OPERAND (op0, 1))
8243 /* Detect assigning a bitfield. */
8244 && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
8246 (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
8248 /* Don't leave an assignment inside a conversion
8249 unless assigning a bitfield. */
8250 tem = fold_build1 (code, type, TREE_OPERAND (op0, 1));
8251 /* First do the assignment, then return converted constant. */
8252 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
8253 TREE_NO_WARNING (tem) = 1;
8254 TREE_USED (tem) = 1;
8258 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
8259 constants (if x has signed type, the sign bit cannot be set
8260 in c). This folds extension into the BIT_AND_EXPR.
8261 ??? We don't do it for BOOLEAN_TYPE or ENUMERAL_TYPE because they
8262 very likely don't have maximal range for their precision and this
8263 transformation effectively doesn't preserve non-maximal ranges. */
8264 if (TREE_CODE (type) == INTEGER_TYPE
8265 && TREE_CODE (op0) == BIT_AND_EXPR
8266 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
8269 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
8272 if (TYPE_UNSIGNED (TREE_TYPE (and))
8273 || (TYPE_PRECISION (type)
8274 <= TYPE_PRECISION (TREE_TYPE (and))))
8276 else if (TYPE_PRECISION (TREE_TYPE (and1))
8277 <= HOST_BITS_PER_WIDE_INT
8278 && host_integerp (and1, 1))
8280 unsigned HOST_WIDE_INT cst;
8282 cst = tree_low_cst (and1, 1);
8283 cst &= (HOST_WIDE_INT) -1
8284 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
8285 change = (cst == 0);
8286 #ifdef LOAD_EXTEND_OP
8288 && !flag_syntax_only
8289 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
8292 tree uns = unsigned_type_for (TREE_TYPE (and0));
8293 and0 = fold_convert (uns, and0);
8294 and1 = fold_convert (uns, and1);
8300 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
8301 TREE_INT_CST_HIGH (and1), 0,
8302 TREE_OVERFLOW (and1));
8303 return fold_build2 (BIT_AND_EXPR, type,
8304 fold_convert (type, and0), tem);
8308 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
8309 when one of the new casts will fold away. Conservatively we assume
8310 that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
8311 if (POINTER_TYPE_P (type)
8312 && TREE_CODE (arg0) == POINTER_PLUS_EXPR
8313 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8314 || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
8315 || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
8317 tree arg00 = TREE_OPERAND (arg0, 0);
8318 tree arg01 = TREE_OPERAND (arg0, 1);
8320 return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
8321 fold_convert (sizetype, arg01));
8324 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
8325 of the same precision, and X is an integer type not narrower than
8326 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
8327 if (INTEGRAL_TYPE_P (type)
8328 && TREE_CODE (op0) == BIT_NOT_EXPR
8329 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
8330 && CONVERT_EXPR_P (TREE_OPERAND (op0, 0))
8331 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
8333 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
8334 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
8335 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
8336 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
8339 /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the
8340 type of X and Y (integer types only). */
8341 if (INTEGRAL_TYPE_P (type)
8342 && TREE_CODE (op0) == MULT_EXPR
8343 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
8344 && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (op0)))
8346 /* Be careful not to introduce new overflows. */
8348 if (TYPE_OVERFLOW_WRAPS (type))
8351 mult_type = unsigned_type_for (type);
8353 if (TYPE_PRECISION (mult_type) < TYPE_PRECISION (TREE_TYPE (op0)))
8355 tem = fold_build2 (MULT_EXPR, mult_type,
8356 fold_convert (mult_type,
8357 TREE_OPERAND (op0, 0)),
8358 fold_convert (mult_type,
8359 TREE_OPERAND (op0, 1)));
8360 return fold_convert (type, tem);
8364 tem = fold_convert_const (code, type, op0);
8365 return tem ? tem : NULL_TREE;
8367 case FIXED_CONVERT_EXPR:
8368 tem = fold_convert_const (code, type, arg0);
8369 return tem ? tem : NULL_TREE;
8371 case VIEW_CONVERT_EXPR:
8372 if (TREE_TYPE (op0) == type)
8374 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
8375 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
8377 /* For integral conversions with the same precision or pointer
8378 conversions use a NOP_EXPR instead. */
8379 if ((INTEGRAL_TYPE_P (type)
8380 || POINTER_TYPE_P (type))
8381 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
8382 || POINTER_TYPE_P (TREE_TYPE (op0)))
8383 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
8384 return fold_convert (type, op0);
8386 /* Strip inner integral conversions that do not change the precision. */
8387 if (CONVERT_EXPR_P (op0)
8388 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
8389 || POINTER_TYPE_P (TREE_TYPE (op0)))
8390 && (INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
8391 || POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0))))
8392 && (TYPE_PRECISION (TREE_TYPE (op0))
8393 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
8394 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
8396 return fold_view_convert_expr (type, op0);
8399 tem = fold_negate_expr (arg0);
8401 return fold_convert (type, tem);
8405 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
8406 return fold_abs_const (arg0, type);
8407 else if (TREE_CODE (arg0) == NEGATE_EXPR)
8408 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
8409 /* Convert fabs((double)float) into (double)fabsf(float). */
8410 else if (TREE_CODE (arg0) == NOP_EXPR
8411 && TREE_CODE (type) == REAL_TYPE)
8413 tree targ0 = strip_float_extensions (arg0);
8415 return fold_convert (type, fold_build1 (ABS_EXPR,
8419 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
8420 else if (TREE_CODE (arg0) == ABS_EXPR)
8422 else if (tree_expr_nonnegative_p (arg0))
8425 /* Strip sign ops from argument. */
8426 if (TREE_CODE (type) == REAL_TYPE)
8428 tem = fold_strip_sign_ops (arg0);
8430 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
8435 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8436 return fold_convert (type, arg0);
8437 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8439 tree itype = TREE_TYPE (type);
8440 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
8441 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
8442 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
8444 if (TREE_CODE (arg0) == COMPLEX_CST)
8446 tree itype = TREE_TYPE (type);
8447 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
8448 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
8449 return build_complex (type, rpart, negate_expr (ipart));
8451 if (TREE_CODE (arg0) == CONJ_EXPR)
8452 return fold_convert (type, TREE_OPERAND (arg0, 0));
8456 if (TREE_CODE (arg0) == INTEGER_CST)
8457 return fold_not_const (arg0, type);
8458 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
8459 return fold_convert (type, TREE_OPERAND (arg0, 0));
8460 /* Convert ~ (-A) to A - 1. */
8461 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
8462 return fold_build2 (MINUS_EXPR, type,
8463 fold_convert (type, TREE_OPERAND (arg0, 0)),
8464 build_int_cst (type, 1));
8465 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
8466 else if (INTEGRAL_TYPE_P (type)
8467 && ((TREE_CODE (arg0) == MINUS_EXPR
8468 && integer_onep (TREE_OPERAND (arg0, 1)))
8469 || (TREE_CODE (arg0) == PLUS_EXPR
8470 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
8471 return fold_build1 (NEGATE_EXPR, type,
8472 fold_convert (type, TREE_OPERAND (arg0, 0)));
8473 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8474 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8475 && (tem = fold_unary (BIT_NOT_EXPR, type,
8477 TREE_OPERAND (arg0, 0)))))
8478 return fold_build2 (BIT_XOR_EXPR, type, tem,
8479 fold_convert (type, TREE_OPERAND (arg0, 1)));
8480 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8481 && (tem = fold_unary (BIT_NOT_EXPR, type,
8483 TREE_OPERAND (arg0, 1)))))
8484 return fold_build2 (BIT_XOR_EXPR, type,
8485 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
8486 /* Perform BIT_NOT_EXPR on each element individually. */
8487 else if (TREE_CODE (arg0) == VECTOR_CST)
8489 tree elements = TREE_VECTOR_CST_ELTS (arg0), elem, list = NULL_TREE;
8490 int count = TYPE_VECTOR_SUBPARTS (type), i;
8492 for (i = 0; i < count; i++)
8496 elem = TREE_VALUE (elements);
8497 elem = fold_unary (BIT_NOT_EXPR, TREE_TYPE (type), elem);
8498 if (elem == NULL_TREE)
8500 elements = TREE_CHAIN (elements);
8503 elem = build_int_cst (TREE_TYPE (type), -1);
8504 list = tree_cons (NULL_TREE, elem, list);
8507 return build_vector (type, nreverse (list));
8512 case TRUTH_NOT_EXPR:
8513 /* The argument to invert_truthvalue must have Boolean type. */
8514 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8515 arg0 = fold_convert (boolean_type_node, arg0);
8517 /* Note that the operand of this must be an int
8518 and its values must be 0 or 1.
8519 ("true" is a fixed value perhaps depending on the language,
8520 but we don't handle values other than 1 correctly yet.) */
8521 tem = fold_truth_not_expr (arg0);
8524 return fold_convert (type, tem);
8527 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8528 return fold_convert (type, arg0);
8529 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8530 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8531 TREE_OPERAND (arg0, 1));
8532 if (TREE_CODE (arg0) == COMPLEX_CST)
8533 return fold_convert (type, TREE_REALPART (arg0));
8534 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8536 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8537 tem = fold_build2 (TREE_CODE (arg0), itype,
8538 fold_build1 (REALPART_EXPR, itype,
8539 TREE_OPERAND (arg0, 0)),
8540 fold_build1 (REALPART_EXPR, itype,
8541 TREE_OPERAND (arg0, 1)));
8542 return fold_convert (type, tem);
8544 if (TREE_CODE (arg0) == CONJ_EXPR)
8546 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8547 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8548 return fold_convert (type, tem);
8550 if (TREE_CODE (arg0) == CALL_EXPR)
8552 tree fn = get_callee_fndecl (arg0);
8553 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8554 switch (DECL_FUNCTION_CODE (fn))
8556 CASE_FLT_FN (BUILT_IN_CEXPI):
8557 fn = mathfn_built_in (type, BUILT_IN_COS);
8559 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8569 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8570 return fold_convert (type, integer_zero_node);
8571 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8572 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8573 TREE_OPERAND (arg0, 0));
8574 if (TREE_CODE (arg0) == COMPLEX_CST)
8575 return fold_convert (type, TREE_IMAGPART (arg0));
8576 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8578 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8579 tem = fold_build2 (TREE_CODE (arg0), itype,
8580 fold_build1 (IMAGPART_EXPR, itype,
8581 TREE_OPERAND (arg0, 0)),
8582 fold_build1 (IMAGPART_EXPR, itype,
8583 TREE_OPERAND (arg0, 1)));
8584 return fold_convert (type, tem);
8586 if (TREE_CODE (arg0) == CONJ_EXPR)
8588 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8589 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8590 return fold_convert (type, negate_expr (tem));
8592 if (TREE_CODE (arg0) == CALL_EXPR)
8594 tree fn = get_callee_fndecl (arg0);
8595 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8596 switch (DECL_FUNCTION_CODE (fn))
8598 CASE_FLT_FN (BUILT_IN_CEXPI):
8599 fn = mathfn_built_in (type, BUILT_IN_SIN);
8601 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8612 } /* switch (code) */
8616 /* If the operation was a conversion do _not_ mark a resulting constant
8617 with TREE_OVERFLOW if the original constant was not. These conversions
8618 have implementation defined behavior and retaining the TREE_OVERFLOW
8619 flag here would confuse later passes such as VRP. */
8621 fold_unary_ignore_overflow (enum tree_code code, tree type, tree op0)
8623 tree res = fold_unary (code, type, op0);
8625 && TREE_CODE (res) == INTEGER_CST
8626 && TREE_CODE (op0) == INTEGER_CST
8627 && CONVERT_EXPR_CODE_P (code))
8628 TREE_OVERFLOW (res) = TREE_OVERFLOW (op0);
8633 /* Fold a binary expression of code CODE and type TYPE with operands
8634 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8635 Return the folded expression if folding is successful. Otherwise,
8636 return NULL_TREE. */
8639 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8641 enum tree_code compl_code;
8643 if (code == MIN_EXPR)
8644 compl_code = MAX_EXPR;
8645 else if (code == MAX_EXPR)
8646 compl_code = MIN_EXPR;
8650 /* MIN (MAX (a, b), b) == b. */
8651 if (TREE_CODE (op0) == compl_code
8652 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8653 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8655 /* MIN (MAX (b, a), b) == b. */
8656 if (TREE_CODE (op0) == compl_code
8657 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8658 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8659 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8661 /* MIN (a, MAX (a, b)) == a. */
8662 if (TREE_CODE (op1) == compl_code
8663 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8664 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8665 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8667 /* MIN (a, MAX (b, a)) == a. */
8668 if (TREE_CODE (op1) == compl_code
8669 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8670 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8671 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8676 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8677 by changing CODE to reduce the magnitude of constants involved in
8678 ARG0 of the comparison.
8679 Returns a canonicalized comparison tree if a simplification was
8680 possible, otherwise returns NULL_TREE.
8681 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8682 valid if signed overflow is undefined. */
8685 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8686 tree arg0, tree arg1,
8687 bool *strict_overflow_p)
8689 enum tree_code code0 = TREE_CODE (arg0);
8690 tree t, cst0 = NULL_TREE;
8694 /* Match A +- CST code arg1 and CST code arg1. We can change the
8695 first form only if overflow is undefined. */
8696 if (!((TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8697 /* In principle pointers also have undefined overflow behavior,
8698 but that causes problems elsewhere. */
8699 && !POINTER_TYPE_P (TREE_TYPE (arg0))
8700 && (code0 == MINUS_EXPR
8701 || code0 == PLUS_EXPR)
8702 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8703 || code0 == INTEGER_CST))
8706 /* Identify the constant in arg0 and its sign. */
8707 if (code0 == INTEGER_CST)
8710 cst0 = TREE_OPERAND (arg0, 1);
8711 sgn0 = tree_int_cst_sgn (cst0);
8713 /* Overflowed constants and zero will cause problems. */
8714 if (integer_zerop (cst0)
8715 || TREE_OVERFLOW (cst0))
8718 /* See if we can reduce the magnitude of the constant in
8719 arg0 by changing the comparison code. */
8720 if (code0 == INTEGER_CST)
8722 /* CST <= arg1 -> CST-1 < arg1. */
8723 if (code == LE_EXPR && sgn0 == 1)
8725 /* -CST < arg1 -> -CST-1 <= arg1. */
8726 else if (code == LT_EXPR && sgn0 == -1)
8728 /* CST > arg1 -> CST-1 >= arg1. */
8729 else if (code == GT_EXPR && sgn0 == 1)
8731 /* -CST >= arg1 -> -CST-1 > arg1. */
8732 else if (code == GE_EXPR && sgn0 == -1)
8736 /* arg1 code' CST' might be more canonical. */
8741 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8743 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8745 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8746 else if (code == GT_EXPR
8747 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8749 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8750 else if (code == LE_EXPR
8751 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8753 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8754 else if (code == GE_EXPR
8755 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8759 *strict_overflow_p = true;
8762 /* Now build the constant reduced in magnitude. But not if that
8763 would produce one outside of its types range. */
8764 if (INTEGRAL_TYPE_P (TREE_TYPE (cst0))
8766 && TYPE_MIN_VALUE (TREE_TYPE (cst0))
8767 && tree_int_cst_equal (cst0, TYPE_MIN_VALUE (TREE_TYPE (cst0))))
8769 && TYPE_MAX_VALUE (TREE_TYPE (cst0))
8770 && tree_int_cst_equal (cst0, TYPE_MAX_VALUE (TREE_TYPE (cst0))))))
8771 /* We cannot swap the comparison here as that would cause us to
8772 endlessly recurse. */
8775 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8776 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8777 if (code0 != INTEGER_CST)
8778 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8780 /* If swapping might yield to a more canonical form, do so. */
8782 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8784 return fold_build2 (code, type, t, arg1);
8787 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8788 overflow further. Try to decrease the magnitude of constants involved
8789 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8790 and put sole constants at the second argument position.
8791 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8794 maybe_canonicalize_comparison (enum tree_code code, tree type,
8795 tree arg0, tree arg1)
8798 bool strict_overflow_p;
8799 const char * const warnmsg = G_("assuming signed overflow does not occur "
8800 "when reducing constant in comparison");
8802 /* Try canonicalization by simplifying arg0. */
8803 strict_overflow_p = false;
8804 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8805 &strict_overflow_p);
8808 if (strict_overflow_p)
8809 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8813 /* Try canonicalization by simplifying arg1 using the swapped
8815 code = swap_tree_comparison (code);
8816 strict_overflow_p = false;
8817 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8818 &strict_overflow_p);
8819 if (t && strict_overflow_p)
8820 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8824 /* Return whether BASE + OFFSET + BITPOS may wrap around the address
8825 space. This is used to avoid issuing overflow warnings for
8826 expressions like &p->x which can not wrap. */
8829 pointer_may_wrap_p (tree base, tree offset, HOST_WIDE_INT bitpos)
8831 unsigned HOST_WIDE_INT offset_low, total_low;
8832 HOST_WIDE_INT size, offset_high, total_high;
8834 if (!POINTER_TYPE_P (TREE_TYPE (base)))
8840 if (offset == NULL_TREE)
8845 else if (TREE_CODE (offset) != INTEGER_CST || TREE_OVERFLOW (offset))
8849 offset_low = TREE_INT_CST_LOW (offset);
8850 offset_high = TREE_INT_CST_HIGH (offset);
8853 if (add_double_with_sign (offset_low, offset_high,
8854 bitpos / BITS_PER_UNIT, 0,
8855 &total_low, &total_high,
8859 if (total_high != 0)
8862 size = int_size_in_bytes (TREE_TYPE (TREE_TYPE (base)));
8866 /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
8868 if (TREE_CODE (base) == ADDR_EXPR)
8870 HOST_WIDE_INT base_size;
8872 base_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (base, 0)));
8873 if (base_size > 0 && size < base_size)
8877 return total_low > (unsigned HOST_WIDE_INT) size;
8880 /* Subroutine of fold_binary. This routine performs all of the
8881 transformations that are common to the equality/inequality
8882 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8883 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8884 fold_binary should call fold_binary. Fold a comparison with
8885 tree code CODE and type TYPE with operands OP0 and OP1. Return
8886 the folded comparison or NULL_TREE. */
8889 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8891 tree arg0, arg1, tem;
8896 STRIP_SIGN_NOPS (arg0);
8897 STRIP_SIGN_NOPS (arg1);
8899 tem = fold_relational_const (code, type, arg0, arg1);
8900 if (tem != NULL_TREE)
8903 /* If one arg is a real or integer constant, put it last. */
8904 if (tree_swap_operands_p (arg0, arg1, true))
8905 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8907 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8908 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8909 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8910 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8911 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8912 && (TREE_CODE (arg1) == INTEGER_CST
8913 && !TREE_OVERFLOW (arg1)))
8915 tree const1 = TREE_OPERAND (arg0, 1);
8917 tree variable = TREE_OPERAND (arg0, 0);
8920 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8922 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8923 TREE_TYPE (arg1), const2, const1);
8925 /* If the constant operation overflowed this can be
8926 simplified as a comparison against INT_MAX/INT_MIN. */
8927 if (TREE_CODE (lhs) == INTEGER_CST
8928 && TREE_OVERFLOW (lhs))
8930 int const1_sgn = tree_int_cst_sgn (const1);
8931 enum tree_code code2 = code;
8933 /* Get the sign of the constant on the lhs if the
8934 operation were VARIABLE + CONST1. */
8935 if (TREE_CODE (arg0) == MINUS_EXPR)
8936 const1_sgn = -const1_sgn;
8938 /* The sign of the constant determines if we overflowed
8939 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8940 Canonicalize to the INT_MIN overflow by swapping the comparison
8942 if (const1_sgn == -1)
8943 code2 = swap_tree_comparison (code);
8945 /* We now can look at the canonicalized case
8946 VARIABLE + 1 CODE2 INT_MIN
8947 and decide on the result. */
8948 if (code2 == LT_EXPR
8950 || code2 == EQ_EXPR)
8951 return omit_one_operand (type, boolean_false_node, variable);
8952 else if (code2 == NE_EXPR
8954 || code2 == GT_EXPR)
8955 return omit_one_operand (type, boolean_true_node, variable);
8958 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8959 && (TREE_CODE (lhs) != INTEGER_CST
8960 || !TREE_OVERFLOW (lhs)))
8962 fold_overflow_warning (("assuming signed overflow does not occur "
8963 "when changing X +- C1 cmp C2 to "
8965 WARN_STRICT_OVERFLOW_COMPARISON);
8966 return fold_build2 (code, type, variable, lhs);
8970 /* For comparisons of pointers we can decompose it to a compile time
8971 comparison of the base objects and the offsets into the object.
8972 This requires at least one operand being an ADDR_EXPR or a
8973 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8974 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8975 && (TREE_CODE (arg0) == ADDR_EXPR
8976 || TREE_CODE (arg1) == ADDR_EXPR
8977 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
8978 || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
8980 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8981 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8982 enum machine_mode mode;
8983 int volatilep, unsignedp;
8984 bool indirect_base0 = false, indirect_base1 = false;
8986 /* Get base and offset for the access. Strip ADDR_EXPR for
8987 get_inner_reference, but put it back by stripping INDIRECT_REF
8988 off the base object if possible. indirect_baseN will be true
8989 if baseN is not an address but refers to the object itself. */
8991 if (TREE_CODE (arg0) == ADDR_EXPR)
8993 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8994 &bitsize, &bitpos0, &offset0, &mode,
8995 &unsignedp, &volatilep, false);
8996 if (TREE_CODE (base0) == INDIRECT_REF)
8997 base0 = TREE_OPERAND (base0, 0);
8999 indirect_base0 = true;
9001 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9003 base0 = TREE_OPERAND (arg0, 0);
9004 offset0 = TREE_OPERAND (arg0, 1);
9008 if (TREE_CODE (arg1) == ADDR_EXPR)
9010 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
9011 &bitsize, &bitpos1, &offset1, &mode,
9012 &unsignedp, &volatilep, false);
9013 if (TREE_CODE (base1) == INDIRECT_REF)
9014 base1 = TREE_OPERAND (base1, 0);
9016 indirect_base1 = true;
9018 else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
9020 base1 = TREE_OPERAND (arg1, 0);
9021 offset1 = TREE_OPERAND (arg1, 1);
9024 /* If we have equivalent bases we might be able to simplify. */
9025 if (indirect_base0 == indirect_base1
9026 && operand_equal_p (base0, base1, 0))
9028 /* We can fold this expression to a constant if the non-constant
9029 offset parts are equal. */
9030 if ((offset0 == offset1
9031 || (offset0 && offset1
9032 && operand_equal_p (offset0, offset1, 0)))
9035 || POINTER_TYPE_OVERFLOW_UNDEFINED))
9040 && bitpos0 != bitpos1
9041 && (pointer_may_wrap_p (base0, offset0, bitpos0)
9042 || pointer_may_wrap_p (base1, offset1, bitpos1)))
9043 fold_overflow_warning (("assuming pointer wraparound does not "
9044 "occur when comparing P +- C1 with "
9046 WARN_STRICT_OVERFLOW_CONDITIONAL);
9051 return constant_boolean_node (bitpos0 == bitpos1, type);
9053 return constant_boolean_node (bitpos0 != bitpos1, type);
9055 return constant_boolean_node (bitpos0 < bitpos1, type);
9057 return constant_boolean_node (bitpos0 <= bitpos1, type);
9059 return constant_boolean_node (bitpos0 >= bitpos1, type);
9061 return constant_boolean_node (bitpos0 > bitpos1, type);
9065 /* We can simplify the comparison to a comparison of the variable
9066 offset parts if the constant offset parts are equal.
9067 Be careful to use signed size type here because otherwise we
9068 mess with array offsets in the wrong way. This is possible
9069 because pointer arithmetic is restricted to retain within an
9070 object and overflow on pointer differences is undefined as of
9071 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
9072 else if (bitpos0 == bitpos1
9073 && ((code == EQ_EXPR || code == NE_EXPR)
9074 || POINTER_TYPE_OVERFLOW_UNDEFINED))
9076 tree signed_size_type_node;
9077 signed_size_type_node = signed_type_for (size_type_node);
9079 /* By converting to signed size type we cover middle-end pointer
9080 arithmetic which operates on unsigned pointer types of size
9081 type size and ARRAY_REF offsets which are properly sign or
9082 zero extended from their type in case it is narrower than
9084 if (offset0 == NULL_TREE)
9085 offset0 = build_int_cst (signed_size_type_node, 0);
9087 offset0 = fold_convert (signed_size_type_node, offset0);
9088 if (offset1 == NULL_TREE)
9089 offset1 = build_int_cst (signed_size_type_node, 0);
9091 offset1 = fold_convert (signed_size_type_node, offset1);
9095 && (pointer_may_wrap_p (base0, offset0, bitpos0)
9096 || pointer_may_wrap_p (base1, offset1, bitpos1)))
9097 fold_overflow_warning (("assuming pointer wraparound does not "
9098 "occur when comparing P +- C1 with "
9100 WARN_STRICT_OVERFLOW_COMPARISON);
9102 return fold_build2 (code, type, offset0, offset1);
9105 /* For non-equal bases we can simplify if they are addresses
9106 of local binding decls or constants. */
9107 else if (indirect_base0 && indirect_base1
9108 /* We know that !operand_equal_p (base0, base1, 0)
9109 because the if condition was false. But make
9110 sure two decls are not the same. */
9112 && TREE_CODE (arg0) == ADDR_EXPR
9113 && TREE_CODE (arg1) == ADDR_EXPR
9114 && (((TREE_CODE (base0) == VAR_DECL
9115 || TREE_CODE (base0) == PARM_DECL)
9116 && (targetm.binds_local_p (base0)
9117 || CONSTANT_CLASS_P (base1)))
9118 || CONSTANT_CLASS_P (base0))
9119 && (((TREE_CODE (base1) == VAR_DECL
9120 || TREE_CODE (base1) == PARM_DECL)
9121 && (targetm.binds_local_p (base1)
9122 || CONSTANT_CLASS_P (base0)))
9123 || CONSTANT_CLASS_P (base1)))
9125 if (code == EQ_EXPR)
9126 return omit_two_operands (type, boolean_false_node, arg0, arg1);
9127 else if (code == NE_EXPR)
9128 return omit_two_operands (type, boolean_true_node, arg0, arg1);
9130 /* For equal offsets we can simplify to a comparison of the
9132 else if (bitpos0 == bitpos1
9134 ? base0 != TREE_OPERAND (arg0, 0) : base0 != arg0)
9136 ? base1 != TREE_OPERAND (arg1, 0) : base1 != arg1)
9137 && ((offset0 == offset1)
9138 || (offset0 && offset1
9139 && operand_equal_p (offset0, offset1, 0))))
9142 base0 = build_fold_addr_expr (base0);
9144 base1 = build_fold_addr_expr (base1);
9145 return fold_build2 (code, type, base0, base1);
9149 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
9150 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
9151 the resulting offset is smaller in absolute value than the
9153 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
9154 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
9155 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9156 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
9157 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
9158 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9159 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
9161 tree const1 = TREE_OPERAND (arg0, 1);
9162 tree const2 = TREE_OPERAND (arg1, 1);
9163 tree variable1 = TREE_OPERAND (arg0, 0);
9164 tree variable2 = TREE_OPERAND (arg1, 0);
9166 const char * const warnmsg = G_("assuming signed overflow does not "
9167 "occur when combining constants around "
9170 /* Put the constant on the side where it doesn't overflow and is
9171 of lower absolute value than before. */
9172 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
9173 ? MINUS_EXPR : PLUS_EXPR,
9175 if (!TREE_OVERFLOW (cst)
9176 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
9178 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
9179 return fold_build2 (code, type,
9181 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
9185 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
9186 ? MINUS_EXPR : PLUS_EXPR,
9188 if (!TREE_OVERFLOW (cst)
9189 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
9191 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
9192 return fold_build2 (code, type,
9193 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
9199 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
9200 signed arithmetic case. That form is created by the compiler
9201 often enough for folding it to be of value. One example is in
9202 computing loop trip counts after Operator Strength Reduction. */
9203 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
9204 && TREE_CODE (arg0) == MULT_EXPR
9205 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9206 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
9207 && integer_zerop (arg1))
9209 tree const1 = TREE_OPERAND (arg0, 1);
9210 tree const2 = arg1; /* zero */
9211 tree variable1 = TREE_OPERAND (arg0, 0);
9212 enum tree_code cmp_code = code;
9214 gcc_assert (!integer_zerop (const1));
9216 fold_overflow_warning (("assuming signed overflow does not occur when "
9217 "eliminating multiplication in comparison "
9219 WARN_STRICT_OVERFLOW_COMPARISON);
9221 /* If const1 is negative we swap the sense of the comparison. */
9222 if (tree_int_cst_sgn (const1) < 0)
9223 cmp_code = swap_tree_comparison (cmp_code);
9225 return fold_build2 (cmp_code, type, variable1, const2);
9228 tem = maybe_canonicalize_comparison (code, type, op0, op1);
9232 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
9234 tree targ0 = strip_float_extensions (arg0);
9235 tree targ1 = strip_float_extensions (arg1);
9236 tree newtype = TREE_TYPE (targ0);
9238 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
9239 newtype = TREE_TYPE (targ1);
9241 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9242 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
9243 return fold_build2 (code, type, fold_convert (newtype, targ0),
9244 fold_convert (newtype, targ1));
9246 /* (-a) CMP (-b) -> b CMP a */
9247 if (TREE_CODE (arg0) == NEGATE_EXPR
9248 && TREE_CODE (arg1) == NEGATE_EXPR)
9249 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
9250 TREE_OPERAND (arg0, 0));
9252 if (TREE_CODE (arg1) == REAL_CST)
9254 REAL_VALUE_TYPE cst;
9255 cst = TREE_REAL_CST (arg1);
9257 /* (-a) CMP CST -> a swap(CMP) (-CST) */
9258 if (TREE_CODE (arg0) == NEGATE_EXPR)
9259 return fold_build2 (swap_tree_comparison (code), type,
9260 TREE_OPERAND (arg0, 0),
9261 build_real (TREE_TYPE (arg1),
9262 REAL_VALUE_NEGATE (cst)));
9264 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
9265 /* a CMP (-0) -> a CMP 0 */
9266 if (REAL_VALUE_MINUS_ZERO (cst))
9267 return fold_build2 (code, type, arg0,
9268 build_real (TREE_TYPE (arg1), dconst0));
9270 /* x != NaN is always true, other ops are always false. */
9271 if (REAL_VALUE_ISNAN (cst)
9272 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
9274 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
9275 return omit_one_operand (type, tem, arg0);
9278 /* Fold comparisons against infinity. */
9279 if (REAL_VALUE_ISINF (cst)
9280 && MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1))))
9282 tem = fold_inf_compare (code, type, arg0, arg1);
9283 if (tem != NULL_TREE)
9288 /* If this is a comparison of a real constant with a PLUS_EXPR
9289 or a MINUS_EXPR of a real constant, we can convert it into a
9290 comparison with a revised real constant as long as no overflow
9291 occurs when unsafe_math_optimizations are enabled. */
9292 if (flag_unsafe_math_optimizations
9293 && TREE_CODE (arg1) == REAL_CST
9294 && (TREE_CODE (arg0) == PLUS_EXPR
9295 || TREE_CODE (arg0) == MINUS_EXPR)
9296 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
9297 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9298 ? MINUS_EXPR : PLUS_EXPR,
9299 arg1, TREE_OPERAND (arg0, 1), 0))
9300 && !TREE_OVERFLOW (tem))
9301 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9303 /* Likewise, we can simplify a comparison of a real constant with
9304 a MINUS_EXPR whose first operand is also a real constant, i.e.
9305 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
9306 floating-point types only if -fassociative-math is set. */
9307 if (flag_associative_math
9308 && TREE_CODE (arg1) == REAL_CST
9309 && TREE_CODE (arg0) == MINUS_EXPR
9310 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
9311 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
9313 && !TREE_OVERFLOW (tem))
9314 return fold_build2 (swap_tree_comparison (code), type,
9315 TREE_OPERAND (arg0, 1), tem);
9317 /* Fold comparisons against built-in math functions. */
9318 if (TREE_CODE (arg1) == REAL_CST
9319 && flag_unsafe_math_optimizations
9320 && ! flag_errno_math)
9322 enum built_in_function fcode = builtin_mathfn_code (arg0);
9324 if (fcode != END_BUILTINS)
9326 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
9327 if (tem != NULL_TREE)
9333 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
9334 && CONVERT_EXPR_P (arg0))
9336 /* If we are widening one operand of an integer comparison,
9337 see if the other operand is similarly being widened. Perhaps we
9338 can do the comparison in the narrower type. */
9339 tem = fold_widened_comparison (code, type, arg0, arg1);
9343 /* Or if we are changing signedness. */
9344 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
9349 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9350 constant, we can simplify it. */
9351 if (TREE_CODE (arg1) == INTEGER_CST
9352 && (TREE_CODE (arg0) == MIN_EXPR
9353 || TREE_CODE (arg0) == MAX_EXPR)
9354 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9356 tem = optimize_minmax_comparison (code, type, op0, op1);
9361 /* Simplify comparison of something with itself. (For IEEE
9362 floating-point, we can only do some of these simplifications.) */
9363 if (operand_equal_p (arg0, arg1, 0))
9368 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9369 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9370 return constant_boolean_node (1, type);
9375 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9376 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9377 return constant_boolean_node (1, type);
9378 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9381 /* For NE, we can only do this simplification if integer
9382 or we don't honor IEEE floating point NaNs. */
9383 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
9384 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9386 /* ... fall through ... */
9389 return constant_boolean_node (0, type);
9395 /* If we are comparing an expression that just has comparisons
9396 of two integer values, arithmetic expressions of those comparisons,
9397 and constants, we can simplify it. There are only three cases
9398 to check: the two values can either be equal, the first can be
9399 greater, or the second can be greater. Fold the expression for
9400 those three values. Since each value must be 0 or 1, we have
9401 eight possibilities, each of which corresponds to the constant 0
9402 or 1 or one of the six possible comparisons.
9404 This handles common cases like (a > b) == 0 but also handles
9405 expressions like ((x > y) - (y > x)) > 0, which supposedly
9406 occur in macroized code. */
9408 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
9410 tree cval1 = 0, cval2 = 0;
9413 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
9414 /* Don't handle degenerate cases here; they should already
9415 have been handled anyway. */
9416 && cval1 != 0 && cval2 != 0
9417 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
9418 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
9419 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
9420 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
9421 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
9422 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
9423 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9425 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9426 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9428 /* We can't just pass T to eval_subst in case cval1 or cval2
9429 was the same as ARG1. */
9432 = fold_build2 (code, type,
9433 eval_subst (arg0, cval1, maxval,
9437 = fold_build2 (code, type,
9438 eval_subst (arg0, cval1, maxval,
9442 = fold_build2 (code, type,
9443 eval_subst (arg0, cval1, minval,
9447 /* All three of these results should be 0 or 1. Confirm they are.
9448 Then use those values to select the proper code to use. */
9450 if (TREE_CODE (high_result) == INTEGER_CST
9451 && TREE_CODE (equal_result) == INTEGER_CST
9452 && TREE_CODE (low_result) == INTEGER_CST)
9454 /* Make a 3-bit mask with the high-order bit being the
9455 value for `>', the next for '=', and the low for '<'. */
9456 switch ((integer_onep (high_result) * 4)
9457 + (integer_onep (equal_result) * 2)
9458 + integer_onep (low_result))
9462 return omit_one_operand (type, integer_zero_node, arg0);
9483 return omit_one_operand (type, integer_one_node, arg0);
9487 return save_expr (build2 (code, type, cval1, cval2));
9488 return fold_build2 (code, type, cval1, cval2);
9493 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9494 into a single range test. */
9495 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9496 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9497 && TREE_CODE (arg1) == INTEGER_CST
9498 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9499 && !integer_zerop (TREE_OPERAND (arg0, 1))
9500 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9501 && !TREE_OVERFLOW (arg1))
9503 tem = fold_div_compare (code, type, arg0, arg1);
9504 if (tem != NULL_TREE)
9508 /* Fold ~X op ~Y as Y op X. */
9509 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9510 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9512 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9513 return fold_build2 (code, type,
9514 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
9515 TREE_OPERAND (arg0, 0));
9518 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
9519 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9520 && TREE_CODE (arg1) == INTEGER_CST)
9522 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9523 return fold_build2 (swap_tree_comparison (code), type,
9524 TREE_OPERAND (arg0, 0),
9525 fold_build1 (BIT_NOT_EXPR, cmp_type,
9526 fold_convert (cmp_type, arg1)));
9533 /* Subroutine of fold_binary. Optimize complex multiplications of the
9534 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9535 argument EXPR represents the expression "z" of type TYPE. */
9538 fold_mult_zconjz (tree type, tree expr)
9540 tree itype = TREE_TYPE (type);
9541 tree rpart, ipart, tem;
9543 if (TREE_CODE (expr) == COMPLEX_EXPR)
9545 rpart = TREE_OPERAND (expr, 0);
9546 ipart = TREE_OPERAND (expr, 1);
9548 else if (TREE_CODE (expr) == COMPLEX_CST)
9550 rpart = TREE_REALPART (expr);
9551 ipart = TREE_IMAGPART (expr);
9555 expr = save_expr (expr);
9556 rpart = fold_build1 (REALPART_EXPR, itype, expr);
9557 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
9560 rpart = save_expr (rpart);
9561 ipart = save_expr (ipart);
9562 tem = fold_build2 (PLUS_EXPR, itype,
9563 fold_build2 (MULT_EXPR, itype, rpart, rpart),
9564 fold_build2 (MULT_EXPR, itype, ipart, ipart));
9565 return fold_build2 (COMPLEX_EXPR, type, tem,
9566 fold_convert (itype, integer_zero_node));
9570 /* Subroutine of fold_binary. If P is the value of EXPR, computes
9571 power-of-two M and (arbitrary) N such that M divides (P-N). This condition
9572 guarantees that P and N have the same least significant log2(M) bits.
9573 N is not otherwise constrained. In particular, N is not normalized to
9574 0 <= N < M as is common. In general, the precise value of P is unknown.
9575 M is chosen as large as possible such that constant N can be determined.
9577 Returns M and sets *RESIDUE to N.
9579 If ALLOW_FUNC_ALIGN is true, do take functions' DECL_ALIGN_UNIT into
9580 account. This is not always possible due to PR 35705.
9583 static unsigned HOST_WIDE_INT
9584 get_pointer_modulus_and_residue (tree expr, unsigned HOST_WIDE_INT *residue,
9585 bool allow_func_align)
9587 enum tree_code code;
9591 code = TREE_CODE (expr);
9592 if (code == ADDR_EXPR)
9594 expr = TREE_OPERAND (expr, 0);
9595 if (handled_component_p (expr))
9597 HOST_WIDE_INT bitsize, bitpos;
9599 enum machine_mode mode;
9600 int unsignedp, volatilep;
9602 expr = get_inner_reference (expr, &bitsize, &bitpos, &offset,
9603 &mode, &unsignedp, &volatilep, false);
9604 *residue = bitpos / BITS_PER_UNIT;
9607 if (TREE_CODE (offset) == INTEGER_CST)
9608 *residue += TREE_INT_CST_LOW (offset);
9610 /* We don't handle more complicated offset expressions. */
9616 && (allow_func_align || TREE_CODE (expr) != FUNCTION_DECL))
9617 return DECL_ALIGN_UNIT (expr);
9619 else if (code == POINTER_PLUS_EXPR)
9622 unsigned HOST_WIDE_INT modulus;
9623 enum tree_code inner_code;
9625 op0 = TREE_OPERAND (expr, 0);
9627 modulus = get_pointer_modulus_and_residue (op0, residue,
9630 op1 = TREE_OPERAND (expr, 1);
9632 inner_code = TREE_CODE (op1);
9633 if (inner_code == INTEGER_CST)
9635 *residue += TREE_INT_CST_LOW (op1);
9638 else if (inner_code == MULT_EXPR)
9640 op1 = TREE_OPERAND (op1, 1);
9641 if (TREE_CODE (op1) == INTEGER_CST)
9643 unsigned HOST_WIDE_INT align;
9645 /* Compute the greatest power-of-2 divisor of op1. */
9646 align = TREE_INT_CST_LOW (op1);
9649 /* If align is non-zero and less than *modulus, replace
9650 *modulus with align., If align is 0, then either op1 is 0
9651 or the greatest power-of-2 divisor of op1 doesn't fit in an
9652 unsigned HOST_WIDE_INT. In either case, no additional
9653 constraint is imposed. */
9655 modulus = MIN (modulus, align);
9662 /* If we get here, we were unable to determine anything useful about the
9668 /* Fold a binary expression of code CODE and type TYPE with operands
9669 OP0 and OP1. Return the folded expression if folding is
9670 successful. Otherwise, return NULL_TREE. */
9673 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
9675 enum tree_code_class kind = TREE_CODE_CLASS (code);
9676 tree arg0, arg1, tem;
9677 tree t1 = NULL_TREE;
9678 bool strict_overflow_p;
9680 gcc_assert (IS_EXPR_CODE_CLASS (kind)
9681 && TREE_CODE_LENGTH (code) == 2
9683 && op1 != NULL_TREE);
9688 /* Strip any conversions that don't change the mode. This is
9689 safe for every expression, except for a comparison expression
9690 because its signedness is derived from its operands. So, in
9691 the latter case, only strip conversions that don't change the
9692 signedness. MIN_EXPR/MAX_EXPR also need signedness of arguments
9695 Note that this is done as an internal manipulation within the
9696 constant folder, in order to find the simplest representation
9697 of the arguments so that their form can be studied. In any
9698 cases, the appropriate type conversions should be put back in
9699 the tree that will get out of the constant folder. */
9701 if (kind == tcc_comparison || code == MIN_EXPR || code == MAX_EXPR)
9703 STRIP_SIGN_NOPS (arg0);
9704 STRIP_SIGN_NOPS (arg1);
9712 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9713 constant but we can't do arithmetic on them. */
9714 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9715 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9716 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == FIXED_CST)
9717 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == INTEGER_CST)
9718 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9719 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9721 if (kind == tcc_binary)
9723 /* Make sure type and arg0 have the same saturating flag. */
9724 gcc_assert (TYPE_SATURATING (type)
9725 == TYPE_SATURATING (TREE_TYPE (arg0)));
9726 tem = const_binop (code, arg0, arg1, 0);
9728 else if (kind == tcc_comparison)
9729 tem = fold_relational_const (code, type, arg0, arg1);
9733 if (tem != NULL_TREE)
9735 if (TREE_TYPE (tem) != type)
9736 tem = fold_convert (type, tem);
9741 /* If this is a commutative operation, and ARG0 is a constant, move it
9742 to ARG1 to reduce the number of tests below. */
9743 if (commutative_tree_code (code)
9744 && tree_swap_operands_p (arg0, arg1, true))
9745 return fold_build2 (code, type, op1, op0);
9747 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9749 First check for cases where an arithmetic operation is applied to a
9750 compound, conditional, or comparison operation. Push the arithmetic
9751 operation inside the compound or conditional to see if any folding
9752 can then be done. Convert comparison to conditional for this purpose.
9753 The also optimizes non-constant cases that used to be done in
9756 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9757 one of the operands is a comparison and the other is a comparison, a
9758 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9759 code below would make the expression more complex. Change it to a
9760 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9761 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9763 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9764 || code == EQ_EXPR || code == NE_EXPR)
9765 && ((truth_value_p (TREE_CODE (arg0))
9766 && (truth_value_p (TREE_CODE (arg1))
9767 || (TREE_CODE (arg1) == BIT_AND_EXPR
9768 && integer_onep (TREE_OPERAND (arg1, 1)))))
9769 || (truth_value_p (TREE_CODE (arg1))
9770 && (truth_value_p (TREE_CODE (arg0))
9771 || (TREE_CODE (arg0) == BIT_AND_EXPR
9772 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9774 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9775 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9778 fold_convert (boolean_type_node, arg0),
9779 fold_convert (boolean_type_node, arg1));
9781 if (code == EQ_EXPR)
9782 tem = invert_truthvalue (tem);
9784 return fold_convert (type, tem);
9787 if (TREE_CODE_CLASS (code) == tcc_binary
9788 || TREE_CODE_CLASS (code) == tcc_comparison)
9790 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9791 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9792 fold_build2 (code, type,
9793 fold_convert (TREE_TYPE (op0),
9794 TREE_OPERAND (arg0, 1)),
9796 if (TREE_CODE (arg1) == COMPOUND_EXPR
9797 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9798 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9799 fold_build2 (code, type, op0,
9800 fold_convert (TREE_TYPE (op1),
9801 TREE_OPERAND (arg1, 1))));
9803 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9805 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9807 /*cond_first_p=*/1);
9808 if (tem != NULL_TREE)
9812 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9814 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9816 /*cond_first_p=*/0);
9817 if (tem != NULL_TREE)
9824 case POINTER_PLUS_EXPR:
9825 /* 0 +p index -> (type)index */
9826 if (integer_zerop (arg0))
9827 return non_lvalue (fold_convert (type, arg1));
9829 /* PTR +p 0 -> PTR */
9830 if (integer_zerop (arg1))
9831 return non_lvalue (fold_convert (type, arg0));
9833 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9834 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9835 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9836 return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
9837 fold_convert (sizetype, arg1),
9838 fold_convert (sizetype, arg0)));
9840 /* index +p PTR -> PTR +p index */
9841 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9842 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9843 return fold_build2 (POINTER_PLUS_EXPR, type,
9844 fold_convert (type, arg1),
9845 fold_convert (sizetype, arg0));
9847 /* (PTR +p B) +p A -> PTR +p (B + A) */
9848 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9851 tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
9852 tree arg00 = TREE_OPERAND (arg0, 0);
9853 inner = fold_build2 (PLUS_EXPR, sizetype,
9854 arg01, fold_convert (sizetype, arg1));
9855 return fold_convert (type,
9856 fold_build2 (POINTER_PLUS_EXPR,
9857 TREE_TYPE (arg00), arg00, inner));
9860 /* PTR_CST +p CST -> CST1 */
9861 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9862 return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
9864 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9865 of the array. Loop optimizer sometimes produce this type of
9867 if (TREE_CODE (arg0) == ADDR_EXPR)
9869 tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
9871 return fold_convert (type, tem);
9877 /* A + (-B) -> A - B */
9878 if (TREE_CODE (arg1) == NEGATE_EXPR)
9879 return fold_build2 (MINUS_EXPR, type,
9880 fold_convert (type, arg0),
9881 fold_convert (type, TREE_OPERAND (arg1, 0)));
9882 /* (-A) + B -> B - A */
9883 if (TREE_CODE (arg0) == NEGATE_EXPR
9884 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9885 return fold_build2 (MINUS_EXPR, type,
9886 fold_convert (type, arg1),
9887 fold_convert (type, TREE_OPERAND (arg0, 0)));
9889 if (INTEGRAL_TYPE_P (type))
9891 /* Convert ~A + 1 to -A. */
9892 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9893 && integer_onep (arg1))
9894 return fold_build1 (NEGATE_EXPR, type,
9895 fold_convert (type, TREE_OPERAND (arg0, 0)));
9898 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9899 && !TYPE_OVERFLOW_TRAPS (type))
9901 tree tem = TREE_OPERAND (arg0, 0);
9904 if (operand_equal_p (tem, arg1, 0))
9906 t1 = build_int_cst_type (type, -1);
9907 return omit_one_operand (type, t1, arg1);
9912 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9913 && !TYPE_OVERFLOW_TRAPS (type))
9915 tree tem = TREE_OPERAND (arg1, 0);
9918 if (operand_equal_p (arg0, tem, 0))
9920 t1 = build_int_cst_type (type, -1);
9921 return omit_one_operand (type, t1, arg0);
9925 /* X + (X / CST) * -CST is X % CST. */
9926 if (TREE_CODE (arg1) == MULT_EXPR
9927 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9928 && operand_equal_p (arg0,
9929 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
9931 tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
9932 tree cst1 = TREE_OPERAND (arg1, 1);
9933 tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
9934 if (sum && integer_zerop (sum))
9935 return fold_convert (type,
9936 fold_build2 (TRUNC_MOD_EXPR,
9937 TREE_TYPE (arg0), arg0, cst0));
9941 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9942 same or one. Make sure type is not saturating.
9943 fold_plusminus_mult_expr will re-associate. */
9944 if ((TREE_CODE (arg0) == MULT_EXPR
9945 || TREE_CODE (arg1) == MULT_EXPR)
9946 && !TYPE_SATURATING (type)
9947 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9949 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9954 if (! FLOAT_TYPE_P (type))
9956 if (integer_zerop (arg1))
9957 return non_lvalue (fold_convert (type, arg0));
9959 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9960 with a constant, and the two constants have no bits in common,
9961 we should treat this as a BIT_IOR_EXPR since this may produce more
9963 if (TREE_CODE (arg0) == BIT_AND_EXPR
9964 && TREE_CODE (arg1) == BIT_AND_EXPR
9965 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9966 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9967 && integer_zerop (const_binop (BIT_AND_EXPR,
9968 TREE_OPERAND (arg0, 1),
9969 TREE_OPERAND (arg1, 1), 0)))
9971 code = BIT_IOR_EXPR;
9975 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9976 (plus (plus (mult) (mult)) (foo)) so that we can
9977 take advantage of the factoring cases below. */
9978 if (((TREE_CODE (arg0) == PLUS_EXPR
9979 || TREE_CODE (arg0) == MINUS_EXPR)
9980 && TREE_CODE (arg1) == MULT_EXPR)
9981 || ((TREE_CODE (arg1) == PLUS_EXPR
9982 || TREE_CODE (arg1) == MINUS_EXPR)
9983 && TREE_CODE (arg0) == MULT_EXPR))
9985 tree parg0, parg1, parg, marg;
9986 enum tree_code pcode;
9988 if (TREE_CODE (arg1) == MULT_EXPR)
9989 parg = arg0, marg = arg1;
9991 parg = arg1, marg = arg0;
9992 pcode = TREE_CODE (parg);
9993 parg0 = TREE_OPERAND (parg, 0);
9994 parg1 = TREE_OPERAND (parg, 1);
9998 if (TREE_CODE (parg0) == MULT_EXPR
9999 && TREE_CODE (parg1) != MULT_EXPR)
10000 return fold_build2 (pcode, type,
10001 fold_build2 (PLUS_EXPR, type,
10002 fold_convert (type, parg0),
10003 fold_convert (type, marg)),
10004 fold_convert (type, parg1));
10005 if (TREE_CODE (parg0) != MULT_EXPR
10006 && TREE_CODE (parg1) == MULT_EXPR)
10007 return fold_build2 (PLUS_EXPR, type,
10008 fold_convert (type, parg0),
10009 fold_build2 (pcode, type,
10010 fold_convert (type, marg),
10011 fold_convert (type,
10017 /* See if ARG1 is zero and X + ARG1 reduces to X. */
10018 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
10019 return non_lvalue (fold_convert (type, arg0));
10021 /* Likewise if the operands are reversed. */
10022 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
10023 return non_lvalue (fold_convert (type, arg1));
10025 /* Convert X + -C into X - C. */
10026 if (TREE_CODE (arg1) == REAL_CST
10027 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
10029 tem = fold_negate_const (arg1, type);
10030 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
10031 return fold_build2 (MINUS_EXPR, type,
10032 fold_convert (type, arg0),
10033 fold_convert (type, tem));
10036 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
10037 to __complex__ ( x, y ). This is not the same for SNaNs or
10038 if signed zeros are involved. */
10039 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10040 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10041 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10043 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10044 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10045 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10046 bool arg0rz = false, arg0iz = false;
10047 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10048 || (arg0i && (arg0iz = real_zerop (arg0i))))
10050 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10051 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10052 if (arg0rz && arg1i && real_zerop (arg1i))
10054 tree rp = arg1r ? arg1r
10055 : build1 (REALPART_EXPR, rtype, arg1);
10056 tree ip = arg0i ? arg0i
10057 : build1 (IMAGPART_EXPR, rtype, arg0);
10058 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10060 else if (arg0iz && arg1r && real_zerop (arg1r))
10062 tree rp = arg0r ? arg0r
10063 : build1 (REALPART_EXPR, rtype, arg0);
10064 tree ip = arg1i ? arg1i
10065 : build1 (IMAGPART_EXPR, rtype, arg1);
10066 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10071 if (flag_unsafe_math_optimizations
10072 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10073 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10074 && (tem = distribute_real_division (code, type, arg0, arg1)))
10077 /* Convert x+x into x*2.0. */
10078 if (operand_equal_p (arg0, arg1, 0)
10079 && SCALAR_FLOAT_TYPE_P (type))
10080 return fold_build2 (MULT_EXPR, type, arg0,
10081 build_real (type, dconst2));
10083 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
10084 We associate floats only if the user has specified
10085 -fassociative-math. */
10086 if (flag_associative_math
10087 && TREE_CODE (arg1) == PLUS_EXPR
10088 && TREE_CODE (arg0) != MULT_EXPR)
10090 tree tree10 = TREE_OPERAND (arg1, 0);
10091 tree tree11 = TREE_OPERAND (arg1, 1);
10092 if (TREE_CODE (tree11) == MULT_EXPR
10093 && TREE_CODE (tree10) == MULT_EXPR)
10096 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
10097 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
10100 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
10101 We associate floats only if the user has specified
10102 -fassociative-math. */
10103 if (flag_associative_math
10104 && TREE_CODE (arg0) == PLUS_EXPR
10105 && TREE_CODE (arg1) != MULT_EXPR)
10107 tree tree00 = TREE_OPERAND (arg0, 0);
10108 tree tree01 = TREE_OPERAND (arg0, 1);
10109 if (TREE_CODE (tree01) == MULT_EXPR
10110 && TREE_CODE (tree00) == MULT_EXPR)
10113 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
10114 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
10120 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
10121 is a rotate of A by C1 bits. */
10122 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
10123 is a rotate of A by B bits. */
10125 enum tree_code code0, code1;
10127 code0 = TREE_CODE (arg0);
10128 code1 = TREE_CODE (arg1);
10129 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
10130 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
10131 && operand_equal_p (TREE_OPERAND (arg0, 0),
10132 TREE_OPERAND (arg1, 0), 0)
10133 && (rtype = TREE_TYPE (TREE_OPERAND (arg0, 0)),
10134 TYPE_UNSIGNED (rtype))
10135 /* Only create rotates in complete modes. Other cases are not
10136 expanded properly. */
10137 && TYPE_PRECISION (rtype) == GET_MODE_PRECISION (TYPE_MODE (rtype)))
10139 tree tree01, tree11;
10140 enum tree_code code01, code11;
10142 tree01 = TREE_OPERAND (arg0, 1);
10143 tree11 = TREE_OPERAND (arg1, 1);
10144 STRIP_NOPS (tree01);
10145 STRIP_NOPS (tree11);
10146 code01 = TREE_CODE (tree01);
10147 code11 = TREE_CODE (tree11);
10148 if (code01 == INTEGER_CST
10149 && code11 == INTEGER_CST
10150 && TREE_INT_CST_HIGH (tree01) == 0
10151 && TREE_INT_CST_HIGH (tree11) == 0
10152 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
10153 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
10154 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
10155 code0 == LSHIFT_EXPR ? tree01 : tree11);
10156 else if (code11 == MINUS_EXPR)
10158 tree tree110, tree111;
10159 tree110 = TREE_OPERAND (tree11, 0);
10160 tree111 = TREE_OPERAND (tree11, 1);
10161 STRIP_NOPS (tree110);
10162 STRIP_NOPS (tree111);
10163 if (TREE_CODE (tree110) == INTEGER_CST
10164 && 0 == compare_tree_int (tree110,
10166 (TREE_TYPE (TREE_OPERAND
10168 && operand_equal_p (tree01, tree111, 0))
10169 return build2 ((code0 == LSHIFT_EXPR
10172 type, TREE_OPERAND (arg0, 0), tree01);
10174 else if (code01 == MINUS_EXPR)
10176 tree tree010, tree011;
10177 tree010 = TREE_OPERAND (tree01, 0);
10178 tree011 = TREE_OPERAND (tree01, 1);
10179 STRIP_NOPS (tree010);
10180 STRIP_NOPS (tree011);
10181 if (TREE_CODE (tree010) == INTEGER_CST
10182 && 0 == compare_tree_int (tree010,
10184 (TREE_TYPE (TREE_OPERAND
10186 && operand_equal_p (tree11, tree011, 0))
10187 return build2 ((code0 != LSHIFT_EXPR
10190 type, TREE_OPERAND (arg0, 0), tree11);
10196 /* In most languages, can't associate operations on floats through
10197 parentheses. Rather than remember where the parentheses were, we
10198 don't associate floats at all, unless the user has specified
10199 -fassociative-math.
10200 And, we need to make sure type is not saturating. */
10202 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
10203 && !TYPE_SATURATING (type))
10205 tree var0, con0, lit0, minus_lit0;
10206 tree var1, con1, lit1, minus_lit1;
10209 /* Split both trees into variables, constants, and literals. Then
10210 associate each group together, the constants with literals,
10211 then the result with variables. This increases the chances of
10212 literals being recombined later and of generating relocatable
10213 expressions for the sum of a constant and literal. */
10214 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
10215 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
10216 code == MINUS_EXPR);
10218 /* With undefined overflow we can only associate constants
10219 with one variable. */
10220 if (((POINTER_TYPE_P (type) && POINTER_TYPE_OVERFLOW_UNDEFINED)
10221 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
10227 if (TREE_CODE (tmp0) == NEGATE_EXPR)
10228 tmp0 = TREE_OPERAND (tmp0, 0);
10229 if (TREE_CODE (tmp1) == NEGATE_EXPR)
10230 tmp1 = TREE_OPERAND (tmp1, 0);
10231 /* The only case we can still associate with two variables
10232 is if they are the same, modulo negation. */
10233 if (!operand_equal_p (tmp0, tmp1, 0))
10237 /* Only do something if we found more than two objects. Otherwise,
10238 nothing has changed and we risk infinite recursion. */
10240 && (2 < ((var0 != 0) + (var1 != 0)
10241 + (con0 != 0) + (con1 != 0)
10242 + (lit0 != 0) + (lit1 != 0)
10243 + (minus_lit0 != 0) + (minus_lit1 != 0))))
10245 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
10246 if (code == MINUS_EXPR)
10249 var0 = associate_trees (var0, var1, code, type);
10250 con0 = associate_trees (con0, con1, code, type);
10251 lit0 = associate_trees (lit0, lit1, code, type);
10252 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
10254 /* Preserve the MINUS_EXPR if the negative part of the literal is
10255 greater than the positive part. Otherwise, the multiplicative
10256 folding code (i.e extract_muldiv) may be fooled in case
10257 unsigned constants are subtracted, like in the following
10258 example: ((X*2 + 4) - 8U)/2. */
10259 if (minus_lit0 && lit0)
10261 if (TREE_CODE (lit0) == INTEGER_CST
10262 && TREE_CODE (minus_lit0) == INTEGER_CST
10263 && tree_int_cst_lt (lit0, minus_lit0))
10265 minus_lit0 = associate_trees (minus_lit0, lit0,
10271 lit0 = associate_trees (lit0, minus_lit0,
10279 return fold_convert (type,
10280 associate_trees (var0, minus_lit0,
10281 MINUS_EXPR, type));
10284 con0 = associate_trees (con0, minus_lit0,
10286 return fold_convert (type,
10287 associate_trees (var0, con0,
10292 con0 = associate_trees (con0, lit0, code, type);
10293 return fold_convert (type, associate_trees (var0, con0,
10301 /* Pointer simplifications for subtraction, simple reassociations. */
10302 if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
10304 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
10305 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
10306 && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
10308 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10309 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10310 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10311 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10312 return fold_build2 (PLUS_EXPR, type,
10313 fold_build2 (MINUS_EXPR, type, arg00, arg10),
10314 fold_build2 (MINUS_EXPR, type, arg01, arg11));
10316 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
10317 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
10319 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10320 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10321 tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
10323 return fold_build2 (PLUS_EXPR, type, tmp, arg01);
10326 /* A - (-B) -> A + B */
10327 if (TREE_CODE (arg1) == NEGATE_EXPR)
10328 return fold_build2 (PLUS_EXPR, type, op0,
10329 fold_convert (type, TREE_OPERAND (arg1, 0)));
10330 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
10331 if (TREE_CODE (arg0) == NEGATE_EXPR
10332 && (FLOAT_TYPE_P (type)
10333 || INTEGRAL_TYPE_P (type))
10334 && negate_expr_p (arg1)
10335 && reorder_operands_p (arg0, arg1))
10336 return fold_build2 (MINUS_EXPR, type,
10337 fold_convert (type, negate_expr (arg1)),
10338 fold_convert (type, TREE_OPERAND (arg0, 0)));
10339 /* Convert -A - 1 to ~A. */
10340 if (INTEGRAL_TYPE_P (type)
10341 && TREE_CODE (arg0) == NEGATE_EXPR
10342 && integer_onep (arg1)
10343 && !TYPE_OVERFLOW_TRAPS (type))
10344 return fold_build1 (BIT_NOT_EXPR, type,
10345 fold_convert (type, TREE_OPERAND (arg0, 0)));
10347 /* Convert -1 - A to ~A. */
10348 if (INTEGRAL_TYPE_P (type)
10349 && integer_all_onesp (arg0))
10350 return fold_build1 (BIT_NOT_EXPR, type, op1);
10353 /* X - (X / CST) * CST is X % CST. */
10354 if (INTEGRAL_TYPE_P (type)
10355 && TREE_CODE (arg1) == MULT_EXPR
10356 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
10357 && operand_equal_p (arg0,
10358 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
10359 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
10360 TREE_OPERAND (arg1, 1), 0))
10361 return fold_convert (type,
10362 fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
10363 arg0, TREE_OPERAND (arg1, 1)));
10365 if (! FLOAT_TYPE_P (type))
10367 if (integer_zerop (arg0))
10368 return negate_expr (fold_convert (type, arg1));
10369 if (integer_zerop (arg1))
10370 return non_lvalue (fold_convert (type, arg0));
10372 /* Fold A - (A & B) into ~B & A. */
10373 if (!TREE_SIDE_EFFECTS (arg0)
10374 && TREE_CODE (arg1) == BIT_AND_EXPR)
10376 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
10378 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10379 return fold_build2 (BIT_AND_EXPR, type,
10380 fold_build1 (BIT_NOT_EXPR, type, arg10),
10381 fold_convert (type, arg0));
10383 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10385 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10386 return fold_build2 (BIT_AND_EXPR, type,
10387 fold_build1 (BIT_NOT_EXPR, type, arg11),
10388 fold_convert (type, arg0));
10392 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
10393 any power of 2 minus 1. */
10394 if (TREE_CODE (arg0) == BIT_AND_EXPR
10395 && TREE_CODE (arg1) == BIT_AND_EXPR
10396 && operand_equal_p (TREE_OPERAND (arg0, 0),
10397 TREE_OPERAND (arg1, 0), 0))
10399 tree mask0 = TREE_OPERAND (arg0, 1);
10400 tree mask1 = TREE_OPERAND (arg1, 1);
10401 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
10403 if (operand_equal_p (tem, mask1, 0))
10405 tem = fold_build2 (BIT_XOR_EXPR, type,
10406 TREE_OPERAND (arg0, 0), mask1);
10407 return fold_build2 (MINUS_EXPR, type, tem, mask1);
10412 /* See if ARG1 is zero and X - ARG1 reduces to X. */
10413 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
10414 return non_lvalue (fold_convert (type, arg0));
10416 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
10417 ARG0 is zero and X + ARG0 reduces to X, since that would mean
10418 (-ARG1 + ARG0) reduces to -ARG1. */
10419 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
10420 return negate_expr (fold_convert (type, arg1));
10422 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
10423 __complex__ ( x, -y ). This is not the same for SNaNs or if
10424 signed zeros are involved. */
10425 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10426 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10427 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10429 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10430 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10431 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10432 bool arg0rz = false, arg0iz = false;
10433 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10434 || (arg0i && (arg0iz = real_zerop (arg0i))))
10436 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10437 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10438 if (arg0rz && arg1i && real_zerop (arg1i))
10440 tree rp = fold_build1 (NEGATE_EXPR, rtype,
10442 : build1 (REALPART_EXPR, rtype, arg1));
10443 tree ip = arg0i ? arg0i
10444 : build1 (IMAGPART_EXPR, rtype, arg0);
10445 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10447 else if (arg0iz && arg1r && real_zerop (arg1r))
10449 tree rp = arg0r ? arg0r
10450 : build1 (REALPART_EXPR, rtype, arg0);
10451 tree ip = fold_build1 (NEGATE_EXPR, rtype,
10453 : build1 (IMAGPART_EXPR, rtype, arg1));
10454 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10459 /* Fold &x - &x. This can happen from &x.foo - &x.
10460 This is unsafe for certain floats even in non-IEEE formats.
10461 In IEEE, it is unsafe because it does wrong for NaNs.
10462 Also note that operand_equal_p is always false if an operand
10465 if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
10466 && operand_equal_p (arg0, arg1, 0))
10467 return fold_convert (type, integer_zero_node);
10469 /* A - B -> A + (-B) if B is easily negatable. */
10470 if (negate_expr_p (arg1)
10471 && ((FLOAT_TYPE_P (type)
10472 /* Avoid this transformation if B is a positive REAL_CST. */
10473 && (TREE_CODE (arg1) != REAL_CST
10474 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
10475 || INTEGRAL_TYPE_P (type)))
10476 return fold_build2 (PLUS_EXPR, type,
10477 fold_convert (type, arg0),
10478 fold_convert (type, negate_expr (arg1)));
10480 /* Try folding difference of addresses. */
10482 HOST_WIDE_INT diff;
10484 if ((TREE_CODE (arg0) == ADDR_EXPR
10485 || TREE_CODE (arg1) == ADDR_EXPR)
10486 && ptr_difference_const (arg0, arg1, &diff))
10487 return build_int_cst_type (type, diff);
10490 /* Fold &a[i] - &a[j] to i-j. */
10491 if (TREE_CODE (arg0) == ADDR_EXPR
10492 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
10493 && TREE_CODE (arg1) == ADDR_EXPR
10494 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
10496 tree aref0 = TREE_OPERAND (arg0, 0);
10497 tree aref1 = TREE_OPERAND (arg1, 0);
10498 if (operand_equal_p (TREE_OPERAND (aref0, 0),
10499 TREE_OPERAND (aref1, 0), 0))
10501 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
10502 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
10503 tree esz = array_ref_element_size (aref0);
10504 tree diff = build2 (MINUS_EXPR, type, op0, op1);
10505 return fold_build2 (MULT_EXPR, type, diff,
10506 fold_convert (type, esz));
10511 if (FLOAT_TYPE_P (type)
10512 && flag_unsafe_math_optimizations
10513 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10514 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10515 && (tem = distribute_real_division (code, type, arg0, arg1)))
10518 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
10519 same or one. Make sure type is not saturating.
10520 fold_plusminus_mult_expr will re-associate. */
10521 if ((TREE_CODE (arg0) == MULT_EXPR
10522 || TREE_CODE (arg1) == MULT_EXPR)
10523 && !TYPE_SATURATING (type)
10524 && (!FLOAT_TYPE_P (type) || flag_associative_math))
10526 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
10534 /* (-A) * (-B) -> A * B */
10535 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10536 return fold_build2 (MULT_EXPR, type,
10537 fold_convert (type, TREE_OPERAND (arg0, 0)),
10538 fold_convert (type, negate_expr (arg1)));
10539 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10540 return fold_build2 (MULT_EXPR, type,
10541 fold_convert (type, negate_expr (arg0)),
10542 fold_convert (type, TREE_OPERAND (arg1, 0)));
10544 if (! FLOAT_TYPE_P (type))
10546 if (integer_zerop (arg1))
10547 return omit_one_operand (type, arg1, arg0);
10548 if (integer_onep (arg1))
10549 return non_lvalue (fold_convert (type, arg0));
10550 /* Transform x * -1 into -x. Make sure to do the negation
10551 on the original operand with conversions not stripped
10552 because we can only strip non-sign-changing conversions. */
10553 if (integer_all_onesp (arg1))
10554 return fold_convert (type, negate_expr (op0));
10555 /* Transform x * -C into -x * C if x is easily negatable. */
10556 if (TREE_CODE (arg1) == INTEGER_CST
10557 && tree_int_cst_sgn (arg1) == -1
10558 && negate_expr_p (arg0)
10559 && (tem = negate_expr (arg1)) != arg1
10560 && !TREE_OVERFLOW (tem))
10561 return fold_build2 (MULT_EXPR, type,
10562 fold_convert (type, negate_expr (arg0)), tem);
10564 /* (a * (1 << b)) is (a << b) */
10565 if (TREE_CODE (arg1) == LSHIFT_EXPR
10566 && integer_onep (TREE_OPERAND (arg1, 0)))
10567 return fold_build2 (LSHIFT_EXPR, type, op0,
10568 TREE_OPERAND (arg1, 1));
10569 if (TREE_CODE (arg0) == LSHIFT_EXPR
10570 && integer_onep (TREE_OPERAND (arg0, 0)))
10571 return fold_build2 (LSHIFT_EXPR, type, op1,
10572 TREE_OPERAND (arg0, 1));
10574 /* (A + A) * C -> A * 2 * C */
10575 if (TREE_CODE (arg0) == PLUS_EXPR
10576 && TREE_CODE (arg1) == INTEGER_CST
10577 && operand_equal_p (TREE_OPERAND (arg0, 0),
10578 TREE_OPERAND (arg0, 1), 0))
10579 return fold_build2 (MULT_EXPR, type,
10580 omit_one_operand (type, TREE_OPERAND (arg0, 0),
10581 TREE_OPERAND (arg0, 1)),
10582 fold_build2 (MULT_EXPR, type,
10583 build_int_cst (type, 2) , arg1));
10585 strict_overflow_p = false;
10586 if (TREE_CODE (arg1) == INTEGER_CST
10587 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10588 &strict_overflow_p)))
10590 if (strict_overflow_p)
10591 fold_overflow_warning (("assuming signed overflow does not "
10592 "occur when simplifying "
10594 WARN_STRICT_OVERFLOW_MISC);
10595 return fold_convert (type, tem);
10598 /* Optimize z * conj(z) for integer complex numbers. */
10599 if (TREE_CODE (arg0) == CONJ_EXPR
10600 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10601 return fold_mult_zconjz (type, arg1);
10602 if (TREE_CODE (arg1) == CONJ_EXPR
10603 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10604 return fold_mult_zconjz (type, arg0);
10608 /* Maybe fold x * 0 to 0. The expressions aren't the same
10609 when x is NaN, since x * 0 is also NaN. Nor are they the
10610 same in modes with signed zeros, since multiplying a
10611 negative value by 0 gives -0, not +0. */
10612 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10613 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10614 && real_zerop (arg1))
10615 return omit_one_operand (type, arg1, arg0);
10616 /* In IEEE floating point, x*1 is not equivalent to x for snans.
10617 Likewise for complex arithmetic with signed zeros. */
10618 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10619 && (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10620 || !COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10621 && real_onep (arg1))
10622 return non_lvalue (fold_convert (type, arg0));
10624 /* Transform x * -1.0 into -x. */
10625 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10626 && (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10627 || !COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10628 && real_minus_onep (arg1))
10629 return fold_convert (type, negate_expr (arg0));
10631 /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
10632 the result for floating point types due to rounding so it is applied
10633 only if -fassociative-math was specify. */
10634 if (flag_associative_math
10635 && TREE_CODE (arg0) == RDIV_EXPR
10636 && TREE_CODE (arg1) == REAL_CST
10637 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
10639 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
10642 return fold_build2 (RDIV_EXPR, type, tem,
10643 TREE_OPERAND (arg0, 1));
10646 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10647 if (operand_equal_p (arg0, arg1, 0))
10649 tree tem = fold_strip_sign_ops (arg0);
10650 if (tem != NULL_TREE)
10652 tem = fold_convert (type, tem);
10653 return fold_build2 (MULT_EXPR, type, tem, tem);
10657 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10658 This is not the same for NaNs or if signed zeros are
10660 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10661 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10662 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10663 && TREE_CODE (arg1) == COMPLEX_CST
10664 && real_zerop (TREE_REALPART (arg1)))
10666 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10667 if (real_onep (TREE_IMAGPART (arg1)))
10668 return fold_build2 (COMPLEX_EXPR, type,
10669 negate_expr (fold_build1 (IMAGPART_EXPR,
10671 fold_build1 (REALPART_EXPR, rtype, arg0));
10672 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10673 return fold_build2 (COMPLEX_EXPR, type,
10674 fold_build1 (IMAGPART_EXPR, rtype, arg0),
10675 negate_expr (fold_build1 (REALPART_EXPR,
10679 /* Optimize z * conj(z) for floating point complex numbers.
10680 Guarded by flag_unsafe_math_optimizations as non-finite
10681 imaginary components don't produce scalar results. */
10682 if (flag_unsafe_math_optimizations
10683 && TREE_CODE (arg0) == CONJ_EXPR
10684 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10685 return fold_mult_zconjz (type, arg1);
10686 if (flag_unsafe_math_optimizations
10687 && TREE_CODE (arg1) == CONJ_EXPR
10688 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10689 return fold_mult_zconjz (type, arg0);
10691 if (flag_unsafe_math_optimizations)
10693 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10694 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10696 /* Optimizations of root(...)*root(...). */
10697 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
10700 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10701 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10703 /* Optimize sqrt(x)*sqrt(x) as x. */
10704 if (BUILTIN_SQRT_P (fcode0)
10705 && operand_equal_p (arg00, arg10, 0)
10706 && ! HONOR_SNANS (TYPE_MODE (type)))
10709 /* Optimize root(x)*root(y) as root(x*y). */
10710 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10711 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10712 return build_call_expr (rootfn, 1, arg);
10715 /* Optimize expN(x)*expN(y) as expN(x+y). */
10716 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
10718 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10719 tree arg = fold_build2 (PLUS_EXPR, type,
10720 CALL_EXPR_ARG (arg0, 0),
10721 CALL_EXPR_ARG (arg1, 0));
10722 return build_call_expr (expfn, 1, arg);
10725 /* Optimizations of pow(...)*pow(...). */
10726 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
10727 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
10728 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
10730 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10731 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10732 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10733 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10735 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10736 if (operand_equal_p (arg01, arg11, 0))
10738 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10739 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10740 return build_call_expr (powfn, 2, arg, arg01);
10743 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10744 if (operand_equal_p (arg00, arg10, 0))
10746 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10747 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
10748 return build_call_expr (powfn, 2, arg00, arg);
10752 /* Optimize tan(x)*cos(x) as sin(x). */
10753 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
10754 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
10755 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
10756 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
10757 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
10758 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
10759 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10760 CALL_EXPR_ARG (arg1, 0), 0))
10762 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
10764 if (sinfn != NULL_TREE)
10765 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
10768 /* Optimize x*pow(x,c) as pow(x,c+1). */
10769 if (fcode1 == BUILT_IN_POW
10770 || fcode1 == BUILT_IN_POWF
10771 || fcode1 == BUILT_IN_POWL)
10773 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10774 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10775 if (TREE_CODE (arg11) == REAL_CST
10776 && !TREE_OVERFLOW (arg11)
10777 && operand_equal_p (arg0, arg10, 0))
10779 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10783 c = TREE_REAL_CST (arg11);
10784 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10785 arg = build_real (type, c);
10786 return build_call_expr (powfn, 2, arg0, arg);
10790 /* Optimize pow(x,c)*x as pow(x,c+1). */
10791 if (fcode0 == BUILT_IN_POW
10792 || fcode0 == BUILT_IN_POWF
10793 || fcode0 == BUILT_IN_POWL)
10795 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10796 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10797 if (TREE_CODE (arg01) == REAL_CST
10798 && !TREE_OVERFLOW (arg01)
10799 && operand_equal_p (arg1, arg00, 0))
10801 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10805 c = TREE_REAL_CST (arg01);
10806 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10807 arg = build_real (type, c);
10808 return build_call_expr (powfn, 2, arg1, arg);
10812 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10813 if (optimize_function_for_speed_p (cfun)
10814 && operand_equal_p (arg0, arg1, 0))
10816 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
10820 tree arg = build_real (type, dconst2);
10821 return build_call_expr (powfn, 2, arg0, arg);
10830 if (integer_all_onesp (arg1))
10831 return omit_one_operand (type, arg1, arg0);
10832 if (integer_zerop (arg1))
10833 return non_lvalue (fold_convert (type, arg0));
10834 if (operand_equal_p (arg0, arg1, 0))
10835 return non_lvalue (fold_convert (type, arg0));
10837 /* ~X | X is -1. */
10838 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10839 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10841 t1 = fold_convert (type, integer_zero_node);
10842 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10843 return omit_one_operand (type, t1, arg1);
10846 /* X | ~X is -1. */
10847 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10848 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10850 t1 = fold_convert (type, integer_zero_node);
10851 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10852 return omit_one_operand (type, t1, arg0);
10855 /* Canonicalize (X & C1) | C2. */
10856 if (TREE_CODE (arg0) == BIT_AND_EXPR
10857 && TREE_CODE (arg1) == INTEGER_CST
10858 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10860 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, hi3, lo3, mlo, mhi;
10861 int width = TYPE_PRECISION (type), w;
10862 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10863 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10864 hi2 = TREE_INT_CST_HIGH (arg1);
10865 lo2 = TREE_INT_CST_LOW (arg1);
10867 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10868 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10869 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10871 if (width > HOST_BITS_PER_WIDE_INT)
10873 mhi = (unsigned HOST_WIDE_INT) -1
10874 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10880 mlo = (unsigned HOST_WIDE_INT) -1
10881 >> (HOST_BITS_PER_WIDE_INT - width);
10884 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10885 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10886 return fold_build2 (BIT_IOR_EXPR, type,
10887 TREE_OPERAND (arg0, 0), arg1);
10889 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
10890 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
10891 mode which allows further optimizations. */
10898 for (w = BITS_PER_UNIT;
10899 w <= width && w <= HOST_BITS_PER_WIDE_INT;
10902 unsigned HOST_WIDE_INT mask
10903 = (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
10904 if (((lo1 | lo2) & mask) == mask
10905 && (lo1 & ~mask) == 0 && hi1 == 0)
10912 if (hi3 != hi1 || lo3 != lo1)
10913 return fold_build2 (BIT_IOR_EXPR, type,
10914 fold_build2 (BIT_AND_EXPR, type,
10915 TREE_OPERAND (arg0, 0),
10916 build_int_cst_wide (type,
10921 /* (X & Y) | Y is (X, Y). */
10922 if (TREE_CODE (arg0) == BIT_AND_EXPR
10923 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10924 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10925 /* (X & Y) | X is (Y, X). */
10926 if (TREE_CODE (arg0) == BIT_AND_EXPR
10927 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10928 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10929 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10930 /* X | (X & Y) is (Y, X). */
10931 if (TREE_CODE (arg1) == BIT_AND_EXPR
10932 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10933 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10934 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10935 /* X | (Y & X) is (Y, X). */
10936 if (TREE_CODE (arg1) == BIT_AND_EXPR
10937 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10938 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10939 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10941 t1 = distribute_bit_expr (code, type, arg0, arg1);
10942 if (t1 != NULL_TREE)
10945 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10947 This results in more efficient code for machines without a NAND
10948 instruction. Combine will canonicalize to the first form
10949 which will allow use of NAND instructions provided by the
10950 backend if they exist. */
10951 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10952 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10954 return fold_build1 (BIT_NOT_EXPR, type,
10955 build2 (BIT_AND_EXPR, type,
10956 fold_convert (type,
10957 TREE_OPERAND (arg0, 0)),
10958 fold_convert (type,
10959 TREE_OPERAND (arg1, 0))));
10962 /* See if this can be simplified into a rotate first. If that
10963 is unsuccessful continue in the association code. */
10967 if (integer_zerop (arg1))
10968 return non_lvalue (fold_convert (type, arg0));
10969 if (integer_all_onesp (arg1))
10970 return fold_build1 (BIT_NOT_EXPR, type, op0);
10971 if (operand_equal_p (arg0, arg1, 0))
10972 return omit_one_operand (type, integer_zero_node, arg0);
10974 /* ~X ^ X is -1. */
10975 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10976 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10978 t1 = fold_convert (type, integer_zero_node);
10979 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10980 return omit_one_operand (type, t1, arg1);
10983 /* X ^ ~X is -1. */
10984 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10985 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10987 t1 = fold_convert (type, integer_zero_node);
10988 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10989 return omit_one_operand (type, t1, arg0);
10992 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10993 with a constant, and the two constants have no bits in common,
10994 we should treat this as a BIT_IOR_EXPR since this may produce more
10995 simplifications. */
10996 if (TREE_CODE (arg0) == BIT_AND_EXPR
10997 && TREE_CODE (arg1) == BIT_AND_EXPR
10998 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10999 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
11000 && integer_zerop (const_binop (BIT_AND_EXPR,
11001 TREE_OPERAND (arg0, 1),
11002 TREE_OPERAND (arg1, 1), 0)))
11004 code = BIT_IOR_EXPR;
11008 /* (X | Y) ^ X -> Y & ~ X*/
11009 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11010 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11012 tree t2 = TREE_OPERAND (arg0, 1);
11013 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
11015 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
11016 fold_convert (type, t1));
11020 /* (Y | X) ^ X -> Y & ~ X*/
11021 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11022 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11024 tree t2 = TREE_OPERAND (arg0, 0);
11025 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
11027 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
11028 fold_convert (type, t1));
11032 /* X ^ (X | Y) -> Y & ~ X*/
11033 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11034 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
11036 tree t2 = TREE_OPERAND (arg1, 1);
11037 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
11039 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
11040 fold_convert (type, t1));
11044 /* X ^ (Y | X) -> Y & ~ X*/
11045 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11046 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
11048 tree t2 = TREE_OPERAND (arg1, 0);
11049 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
11051 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
11052 fold_convert (type, t1));
11056 /* Convert ~X ^ ~Y to X ^ Y. */
11057 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11058 && TREE_CODE (arg1) == BIT_NOT_EXPR)
11059 return fold_build2 (code, type,
11060 fold_convert (type, TREE_OPERAND (arg0, 0)),
11061 fold_convert (type, TREE_OPERAND (arg1, 0)));
11063 /* Convert ~X ^ C to X ^ ~C. */
11064 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11065 && TREE_CODE (arg1) == INTEGER_CST)
11066 return fold_build2 (code, type,
11067 fold_convert (type, TREE_OPERAND (arg0, 0)),
11068 fold_build1 (BIT_NOT_EXPR, type, arg1));
11070 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
11071 if (TREE_CODE (arg0) == BIT_AND_EXPR
11072 && integer_onep (TREE_OPERAND (arg0, 1))
11073 && integer_onep (arg1))
11074 return fold_build2 (EQ_EXPR, type, arg0,
11075 build_int_cst (TREE_TYPE (arg0), 0));
11077 /* Fold (X & Y) ^ Y as ~X & Y. */
11078 if (TREE_CODE (arg0) == BIT_AND_EXPR
11079 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11081 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
11082 return fold_build2 (BIT_AND_EXPR, type,
11083 fold_build1 (BIT_NOT_EXPR, type, tem),
11084 fold_convert (type, arg1));
11086 /* Fold (X & Y) ^ X as ~Y & X. */
11087 if (TREE_CODE (arg0) == BIT_AND_EXPR
11088 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11089 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11091 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
11092 return fold_build2 (BIT_AND_EXPR, type,
11093 fold_build1 (BIT_NOT_EXPR, type, tem),
11094 fold_convert (type, arg1));
11096 /* Fold X ^ (X & Y) as X & ~Y. */
11097 if (TREE_CODE (arg1) == BIT_AND_EXPR
11098 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11100 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
11101 return fold_build2 (BIT_AND_EXPR, type,
11102 fold_convert (type, arg0),
11103 fold_build1 (BIT_NOT_EXPR, type, tem));
11105 /* Fold X ^ (Y & X) as ~Y & X. */
11106 if (TREE_CODE (arg1) == BIT_AND_EXPR
11107 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
11108 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
11110 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
11111 return fold_build2 (BIT_AND_EXPR, type,
11112 fold_build1 (BIT_NOT_EXPR, type, tem),
11113 fold_convert (type, arg0));
11116 /* See if this can be simplified into a rotate first. If that
11117 is unsuccessful continue in the association code. */
11121 if (integer_all_onesp (arg1))
11122 return non_lvalue (fold_convert (type, arg0));
11123 if (integer_zerop (arg1))
11124 return omit_one_operand (type, arg1, arg0);
11125 if (operand_equal_p (arg0, arg1, 0))
11126 return non_lvalue (fold_convert (type, arg0));
11128 /* ~X & X is always zero. */
11129 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11130 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11131 return omit_one_operand (type, integer_zero_node, arg1);
11133 /* X & ~X is always zero. */
11134 if (TREE_CODE (arg1) == BIT_NOT_EXPR
11135 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11136 return omit_one_operand (type, integer_zero_node, arg0);
11138 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
11139 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11140 && TREE_CODE (arg1) == INTEGER_CST
11141 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11143 tree tmp1 = fold_convert (type, arg1);
11144 tree tmp2 = fold_convert (type, TREE_OPERAND (arg0, 0));
11145 tree tmp3 = fold_convert (type, TREE_OPERAND (arg0, 1));
11146 tmp2 = fold_build2 (BIT_AND_EXPR, type, tmp2, tmp1);
11147 tmp3 = fold_build2 (BIT_AND_EXPR, type, tmp3, tmp1);
11148 return fold_convert (type,
11149 fold_build2 (BIT_IOR_EXPR, type, tmp2, tmp3));
11152 /* (X | Y) & Y is (X, Y). */
11153 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11154 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11155 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
11156 /* (X | Y) & X is (Y, X). */
11157 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11158 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11159 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11160 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
11161 /* X & (X | Y) is (Y, X). */
11162 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11163 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
11164 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
11165 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
11166 /* X & (Y | X) is (Y, X). */
11167 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11168 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
11169 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
11170 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
11172 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
11173 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11174 && integer_onep (TREE_OPERAND (arg0, 1))
11175 && integer_onep (arg1))
11177 tem = TREE_OPERAND (arg0, 0);
11178 return fold_build2 (EQ_EXPR, type,
11179 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
11180 build_int_cst (TREE_TYPE (tem), 1)),
11181 build_int_cst (TREE_TYPE (tem), 0));
11183 /* Fold ~X & 1 as (X & 1) == 0. */
11184 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11185 && integer_onep (arg1))
11187 tem = TREE_OPERAND (arg0, 0);
11188 return fold_build2 (EQ_EXPR, type,
11189 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
11190 build_int_cst (TREE_TYPE (tem), 1)),
11191 build_int_cst (TREE_TYPE (tem), 0));
11194 /* Fold (X ^ Y) & Y as ~X & Y. */
11195 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11196 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11198 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
11199 return fold_build2 (BIT_AND_EXPR, type,
11200 fold_build1 (BIT_NOT_EXPR, type, tem),
11201 fold_convert (type, arg1));
11203 /* Fold (X ^ Y) & X as ~Y & X. */
11204 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11205 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11206 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11208 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
11209 return fold_build2 (BIT_AND_EXPR, type,
11210 fold_build1 (BIT_NOT_EXPR, type, tem),
11211 fold_convert (type, arg1));
11213 /* Fold X & (X ^ Y) as X & ~Y. */
11214 if (TREE_CODE (arg1) == BIT_XOR_EXPR
11215 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11217 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
11218 return fold_build2 (BIT_AND_EXPR, type,
11219 fold_convert (type, arg0),
11220 fold_build1 (BIT_NOT_EXPR, type, tem));
11222 /* Fold X & (Y ^ X) as ~Y & X. */
11223 if (TREE_CODE (arg1) == BIT_XOR_EXPR
11224 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
11225 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
11227 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
11228 return fold_build2 (BIT_AND_EXPR, type,
11229 fold_build1 (BIT_NOT_EXPR, type, tem),
11230 fold_convert (type, arg0));
11233 t1 = distribute_bit_expr (code, type, arg0, arg1);
11234 if (t1 != NULL_TREE)
11236 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
11237 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
11238 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
11241 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
11243 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
11244 && (~TREE_INT_CST_LOW (arg1)
11245 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
11246 return fold_convert (type, TREE_OPERAND (arg0, 0));
11249 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
11251 This results in more efficient code for machines without a NOR
11252 instruction. Combine will canonicalize to the first form
11253 which will allow use of NOR instructions provided by the
11254 backend if they exist. */
11255 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11256 && TREE_CODE (arg1) == BIT_NOT_EXPR)
11258 return fold_build1 (BIT_NOT_EXPR, type,
11259 build2 (BIT_IOR_EXPR, type,
11260 fold_convert (type,
11261 TREE_OPERAND (arg0, 0)),
11262 fold_convert (type,
11263 TREE_OPERAND (arg1, 0))));
11266 /* If arg0 is derived from the address of an object or function, we may
11267 be able to fold this expression using the object or function's
11269 if (POINTER_TYPE_P (TREE_TYPE (arg0)) && host_integerp (arg1, 1))
11271 unsigned HOST_WIDE_INT modulus, residue;
11272 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (arg1);
11274 modulus = get_pointer_modulus_and_residue (arg0, &residue,
11275 integer_onep (arg1));
11277 /* This works because modulus is a power of 2. If this weren't the
11278 case, we'd have to replace it by its greatest power-of-2
11279 divisor: modulus & -modulus. */
11281 return build_int_cst (type, residue & low);
11284 /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
11285 (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
11286 if the new mask might be further optimized. */
11287 if ((TREE_CODE (arg0) == LSHIFT_EXPR
11288 || TREE_CODE (arg0) == RSHIFT_EXPR)
11289 && host_integerp (TREE_OPERAND (arg0, 1), 1)
11290 && host_integerp (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)))
11291 && tree_low_cst (TREE_OPERAND (arg0, 1), 1)
11292 < TYPE_PRECISION (TREE_TYPE (arg0))
11293 && TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
11294 && tree_low_cst (TREE_OPERAND (arg0, 1), 1) > 0)
11296 unsigned int shiftc = tree_low_cst (TREE_OPERAND (arg0, 1), 1);
11297 unsigned HOST_WIDE_INT mask
11298 = tree_low_cst (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)));
11299 unsigned HOST_WIDE_INT newmask, zerobits = 0;
11300 tree shift_type = TREE_TYPE (arg0);
11302 if (TREE_CODE (arg0) == LSHIFT_EXPR)
11303 zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
11304 else if (TREE_CODE (arg0) == RSHIFT_EXPR
11305 && TYPE_PRECISION (TREE_TYPE (arg0))
11306 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg0))))
11308 unsigned int prec = TYPE_PRECISION (TREE_TYPE (arg0));
11309 tree arg00 = TREE_OPERAND (arg0, 0);
11310 /* See if more bits can be proven as zero because of
11312 if (TREE_CODE (arg00) == NOP_EXPR
11313 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
11315 tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
11316 if (TYPE_PRECISION (inner_type)
11317 == GET_MODE_BITSIZE (TYPE_MODE (inner_type))
11318 && TYPE_PRECISION (inner_type) < prec)
11320 prec = TYPE_PRECISION (inner_type);
11321 /* See if we can shorten the right shift. */
11323 shift_type = inner_type;
11326 zerobits = ~(unsigned HOST_WIDE_INT) 0;
11327 zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
11328 zerobits <<= prec - shiftc;
11329 /* For arithmetic shift if sign bit could be set, zerobits
11330 can contain actually sign bits, so no transformation is
11331 possible, unless MASK masks them all away. In that
11332 case the shift needs to be converted into logical shift. */
11333 if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
11334 && prec == TYPE_PRECISION (TREE_TYPE (arg0)))
11336 if ((mask & zerobits) == 0)
11337 shift_type = unsigned_type_for (TREE_TYPE (arg0));
11343 /* ((X << 16) & 0xff00) is (X, 0). */
11344 if ((mask & zerobits) == mask)
11345 return omit_one_operand (type, build_int_cst (type, 0), arg0);
11347 newmask = mask | zerobits;
11348 if (newmask != mask && (newmask & (newmask + 1)) == 0)
11352 /* Only do the transformation if NEWMASK is some integer
11354 for (prec = BITS_PER_UNIT;
11355 prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
11356 if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
11358 if (prec < HOST_BITS_PER_WIDE_INT
11359 || newmask == ~(unsigned HOST_WIDE_INT) 0)
11361 if (shift_type != TREE_TYPE (arg0))
11363 tem = fold_build2 (TREE_CODE (arg0), shift_type,
11364 fold_convert (shift_type,
11365 TREE_OPERAND (arg0, 0)),
11366 TREE_OPERAND (arg0, 1));
11367 tem = fold_convert (type, tem);
11371 return fold_build2 (BIT_AND_EXPR, type, tem,
11372 build_int_cst_type (TREE_TYPE (op1),
11381 /* Don't touch a floating-point divide by zero unless the mode
11382 of the constant can represent infinity. */
11383 if (TREE_CODE (arg1) == REAL_CST
11384 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
11385 && real_zerop (arg1))
11388 /* Optimize A / A to 1.0 if we don't care about
11389 NaNs or Infinities. Skip the transformation
11390 for non-real operands. */
11391 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
11392 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
11393 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
11394 && operand_equal_p (arg0, arg1, 0))
11396 tree r = build_real (TREE_TYPE (arg0), dconst1);
11398 return omit_two_operands (type, r, arg0, arg1);
11401 /* The complex version of the above A / A optimization. */
11402 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
11403 && operand_equal_p (arg0, arg1, 0))
11405 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
11406 if (! HONOR_NANS (TYPE_MODE (elem_type))
11407 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
11409 tree r = build_real (elem_type, dconst1);
11410 /* omit_two_operands will call fold_convert for us. */
11411 return omit_two_operands (type, r, arg0, arg1);
11415 /* (-A) / (-B) -> A / B */
11416 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
11417 return fold_build2 (RDIV_EXPR, type,
11418 TREE_OPERAND (arg0, 0),
11419 negate_expr (arg1));
11420 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
11421 return fold_build2 (RDIV_EXPR, type,
11422 negate_expr (arg0),
11423 TREE_OPERAND (arg1, 0));
11425 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
11426 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11427 && real_onep (arg1))
11428 return non_lvalue (fold_convert (type, arg0));
11430 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
11431 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11432 && real_minus_onep (arg1))
11433 return non_lvalue (fold_convert (type, negate_expr (arg0)));
11435 /* If ARG1 is a constant, we can convert this to a multiply by the
11436 reciprocal. This does not have the same rounding properties,
11437 so only do this if -freciprocal-math. We can actually
11438 always safely do it if ARG1 is a power of two, but it's hard to
11439 tell if it is or not in a portable manner. */
11440 if (TREE_CODE (arg1) == REAL_CST)
11442 if (flag_reciprocal_math
11443 && 0 != (tem = const_binop (code, build_real (type, dconst1),
11445 return fold_build2 (MULT_EXPR, type, arg0, tem);
11446 /* Find the reciprocal if optimizing and the result is exact. */
11450 r = TREE_REAL_CST (arg1);
11451 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
11453 tem = build_real (type, r);
11454 return fold_build2 (MULT_EXPR, type,
11455 fold_convert (type, arg0), tem);
11459 /* Convert A/B/C to A/(B*C). */
11460 if (flag_reciprocal_math
11461 && TREE_CODE (arg0) == RDIV_EXPR)
11462 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
11463 fold_build2 (MULT_EXPR, type,
11464 TREE_OPERAND (arg0, 1), arg1));
11466 /* Convert A/(B/C) to (A/B)*C. */
11467 if (flag_reciprocal_math
11468 && TREE_CODE (arg1) == RDIV_EXPR)
11469 return fold_build2 (MULT_EXPR, type,
11470 fold_build2 (RDIV_EXPR, type, arg0,
11471 TREE_OPERAND (arg1, 0)),
11472 TREE_OPERAND (arg1, 1));
11474 /* Convert C1/(X*C2) into (C1/C2)/X. */
11475 if (flag_reciprocal_math
11476 && TREE_CODE (arg1) == MULT_EXPR
11477 && TREE_CODE (arg0) == REAL_CST
11478 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
11480 tree tem = const_binop (RDIV_EXPR, arg0,
11481 TREE_OPERAND (arg1, 1), 0);
11483 return fold_build2 (RDIV_EXPR, type, tem,
11484 TREE_OPERAND (arg1, 0));
11487 if (flag_unsafe_math_optimizations)
11489 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
11490 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
11492 /* Optimize sin(x)/cos(x) as tan(x). */
11493 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
11494 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
11495 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
11496 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11497 CALL_EXPR_ARG (arg1, 0), 0))
11499 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11501 if (tanfn != NULL_TREE)
11502 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11505 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
11506 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
11507 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
11508 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
11509 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11510 CALL_EXPR_ARG (arg1, 0), 0))
11512 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11514 if (tanfn != NULL_TREE)
11516 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11517 return fold_build2 (RDIV_EXPR, type,
11518 build_real (type, dconst1), tmp);
11522 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
11523 NaNs or Infinities. */
11524 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
11525 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
11526 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
11528 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11529 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11531 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11532 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11533 && operand_equal_p (arg00, arg01, 0))
11535 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11537 if (cosfn != NULL_TREE)
11538 return build_call_expr (cosfn, 1, arg00);
11542 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11543 NaNs or Infinities. */
11544 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
11545 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
11546 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
11548 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11549 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11551 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11552 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11553 && operand_equal_p (arg00, arg01, 0))
11555 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11557 if (cosfn != NULL_TREE)
11559 tree tmp = build_call_expr (cosfn, 1, arg00);
11560 return fold_build2 (RDIV_EXPR, type,
11561 build_real (type, dconst1),
11567 /* Optimize pow(x,c)/x as pow(x,c-1). */
11568 if (fcode0 == BUILT_IN_POW
11569 || fcode0 == BUILT_IN_POWF
11570 || fcode0 == BUILT_IN_POWL)
11572 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11573 tree arg01 = CALL_EXPR_ARG (arg0, 1);
11574 if (TREE_CODE (arg01) == REAL_CST
11575 && !TREE_OVERFLOW (arg01)
11576 && operand_equal_p (arg1, arg00, 0))
11578 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
11582 c = TREE_REAL_CST (arg01);
11583 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
11584 arg = build_real (type, c);
11585 return build_call_expr (powfn, 2, arg1, arg);
11589 /* Optimize a/root(b/c) into a*root(c/b). */
11590 if (BUILTIN_ROOT_P (fcode1))
11592 tree rootarg = CALL_EXPR_ARG (arg1, 0);
11594 if (TREE_CODE (rootarg) == RDIV_EXPR)
11596 tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11597 tree b = TREE_OPERAND (rootarg, 0);
11598 tree c = TREE_OPERAND (rootarg, 1);
11600 tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
11602 tmp = build_call_expr (rootfn, 1, tmp);
11603 return fold_build2 (MULT_EXPR, type, arg0, tmp);
11607 /* Optimize x/expN(y) into x*expN(-y). */
11608 if (BUILTIN_EXPONENT_P (fcode1))
11610 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11611 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
11612 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
11613 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11616 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11617 if (fcode1 == BUILT_IN_POW
11618 || fcode1 == BUILT_IN_POWF
11619 || fcode1 == BUILT_IN_POWL)
11621 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11622 tree arg10 = CALL_EXPR_ARG (arg1, 0);
11623 tree arg11 = CALL_EXPR_ARG (arg1, 1);
11624 tree neg11 = fold_convert (type, negate_expr (arg11));
11625 arg1 = build_call_expr (powfn, 2, arg10, neg11);
11626 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11631 case TRUNC_DIV_EXPR:
11632 case FLOOR_DIV_EXPR:
11633 /* Simplify A / (B << N) where A and B are positive and B is
11634 a power of 2, to A >> (N + log2(B)). */
11635 strict_overflow_p = false;
11636 if (TREE_CODE (arg1) == LSHIFT_EXPR
11637 && (TYPE_UNSIGNED (type)
11638 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11640 tree sval = TREE_OPERAND (arg1, 0);
11641 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
11643 tree sh_cnt = TREE_OPERAND (arg1, 1);
11644 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
11646 if (strict_overflow_p)
11647 fold_overflow_warning (("assuming signed overflow does not "
11648 "occur when simplifying A / (B << N)"),
11649 WARN_STRICT_OVERFLOW_MISC);
11651 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
11652 sh_cnt, build_int_cst (NULL_TREE, pow2));
11653 return fold_build2 (RSHIFT_EXPR, type,
11654 fold_convert (type, arg0), sh_cnt);
11658 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
11659 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
11660 if (INTEGRAL_TYPE_P (type)
11661 && TYPE_UNSIGNED (type)
11662 && code == FLOOR_DIV_EXPR)
11663 return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
11667 case ROUND_DIV_EXPR:
11668 case CEIL_DIV_EXPR:
11669 case EXACT_DIV_EXPR:
11670 if (integer_onep (arg1))
11671 return non_lvalue (fold_convert (type, arg0));
11672 if (integer_zerop (arg1))
11674 /* X / -1 is -X. */
11675 if (!TYPE_UNSIGNED (type)
11676 && TREE_CODE (arg1) == INTEGER_CST
11677 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11678 && TREE_INT_CST_HIGH (arg1) == -1)
11679 return fold_convert (type, negate_expr (arg0));
11681 /* Convert -A / -B to A / B when the type is signed and overflow is
11683 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11684 && TREE_CODE (arg0) == NEGATE_EXPR
11685 && negate_expr_p (arg1))
11687 if (INTEGRAL_TYPE_P (type))
11688 fold_overflow_warning (("assuming signed overflow does not occur "
11689 "when distributing negation across "
11691 WARN_STRICT_OVERFLOW_MISC);
11692 return fold_build2 (code, type,
11693 fold_convert (type, TREE_OPERAND (arg0, 0)),
11694 fold_convert (type, negate_expr (arg1)));
11696 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11697 && TREE_CODE (arg1) == NEGATE_EXPR
11698 && negate_expr_p (arg0))
11700 if (INTEGRAL_TYPE_P (type))
11701 fold_overflow_warning (("assuming signed overflow does not occur "
11702 "when distributing negation across "
11704 WARN_STRICT_OVERFLOW_MISC);
11705 return fold_build2 (code, type,
11706 fold_convert (type, negate_expr (arg0)),
11707 fold_convert (type, TREE_OPERAND (arg1, 0)));
11710 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11711 operation, EXACT_DIV_EXPR.
11713 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11714 At one time others generated faster code, it's not clear if they do
11715 after the last round to changes to the DIV code in expmed.c. */
11716 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
11717 && multiple_of_p (type, arg0, arg1))
11718 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
11720 strict_overflow_p = false;
11721 if (TREE_CODE (arg1) == INTEGER_CST
11722 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11723 &strict_overflow_p)))
11725 if (strict_overflow_p)
11726 fold_overflow_warning (("assuming signed overflow does not occur "
11727 "when simplifying division"),
11728 WARN_STRICT_OVERFLOW_MISC);
11729 return fold_convert (type, tem);
11734 case CEIL_MOD_EXPR:
11735 case FLOOR_MOD_EXPR:
11736 case ROUND_MOD_EXPR:
11737 case TRUNC_MOD_EXPR:
11738 /* X % 1 is always zero, but be sure to preserve any side
11740 if (integer_onep (arg1))
11741 return omit_one_operand (type, integer_zero_node, arg0);
11743 /* X % 0, return X % 0 unchanged so that we can get the
11744 proper warnings and errors. */
11745 if (integer_zerop (arg1))
11748 /* 0 % X is always zero, but be sure to preserve any side
11749 effects in X. Place this after checking for X == 0. */
11750 if (integer_zerop (arg0))
11751 return omit_one_operand (type, integer_zero_node, arg1);
11753 /* X % -1 is zero. */
11754 if (!TYPE_UNSIGNED (type)
11755 && TREE_CODE (arg1) == INTEGER_CST
11756 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11757 && TREE_INT_CST_HIGH (arg1) == -1)
11758 return omit_one_operand (type, integer_zero_node, arg0);
11760 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11761 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11762 strict_overflow_p = false;
11763 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
11764 && (TYPE_UNSIGNED (type)
11765 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11768 /* Also optimize A % (C << N) where C is a power of 2,
11769 to A & ((C << N) - 1). */
11770 if (TREE_CODE (arg1) == LSHIFT_EXPR)
11771 c = TREE_OPERAND (arg1, 0);
11773 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
11775 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
11776 build_int_cst (TREE_TYPE (arg1), 1));
11777 if (strict_overflow_p)
11778 fold_overflow_warning (("assuming signed overflow does not "
11779 "occur when simplifying "
11780 "X % (power of two)"),
11781 WARN_STRICT_OVERFLOW_MISC);
11782 return fold_build2 (BIT_AND_EXPR, type,
11783 fold_convert (type, arg0),
11784 fold_convert (type, mask));
11788 /* X % -C is the same as X % C. */
11789 if (code == TRUNC_MOD_EXPR
11790 && !TYPE_UNSIGNED (type)
11791 && TREE_CODE (arg1) == INTEGER_CST
11792 && !TREE_OVERFLOW (arg1)
11793 && TREE_INT_CST_HIGH (arg1) < 0
11794 && !TYPE_OVERFLOW_TRAPS (type)
11795 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11796 && !sign_bit_p (arg1, arg1))
11797 return fold_build2 (code, type, fold_convert (type, arg0),
11798 fold_convert (type, negate_expr (arg1)));
11800 /* X % -Y is the same as X % Y. */
11801 if (code == TRUNC_MOD_EXPR
11802 && !TYPE_UNSIGNED (type)
11803 && TREE_CODE (arg1) == NEGATE_EXPR
11804 && !TYPE_OVERFLOW_TRAPS (type))
11805 return fold_build2 (code, type, fold_convert (type, arg0),
11806 fold_convert (type, TREE_OPERAND (arg1, 0)));
11808 if (TREE_CODE (arg1) == INTEGER_CST
11809 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11810 &strict_overflow_p)))
11812 if (strict_overflow_p)
11813 fold_overflow_warning (("assuming signed overflow does not occur "
11814 "when simplifying modulus"),
11815 WARN_STRICT_OVERFLOW_MISC);
11816 return fold_convert (type, tem);
11823 if (integer_all_onesp (arg0))
11824 return omit_one_operand (type, arg0, arg1);
11828 /* Optimize -1 >> x for arithmetic right shifts. */
11829 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type)
11830 && tree_expr_nonnegative_p (arg1))
11831 return omit_one_operand (type, arg0, arg1);
11832 /* ... fall through ... */
11836 if (integer_zerop (arg1))
11837 return non_lvalue (fold_convert (type, arg0));
11838 if (integer_zerop (arg0))
11839 return omit_one_operand (type, arg0, arg1);
11841 /* Since negative shift count is not well-defined,
11842 don't try to compute it in the compiler. */
11843 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
11846 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11847 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
11848 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11849 && host_integerp (TREE_OPERAND (arg0, 1), false)
11850 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11852 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
11853 + TREE_INT_CST_LOW (arg1));
11855 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11856 being well defined. */
11857 if (low >= TYPE_PRECISION (type))
11859 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
11860 low = low % TYPE_PRECISION (type);
11861 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
11862 return omit_one_operand (type, build_int_cst (type, 0),
11863 TREE_OPERAND (arg0, 0));
11865 low = TYPE_PRECISION (type) - 1;
11868 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11869 build_int_cst (type, low));
11872 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11873 into x & ((unsigned)-1 >> c) for unsigned types. */
11874 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
11875 || (TYPE_UNSIGNED (type)
11876 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
11877 && host_integerp (arg1, false)
11878 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11879 && host_integerp (TREE_OPERAND (arg0, 1), false)
11880 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11882 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
11883 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
11889 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
11891 lshift = build_int_cst (type, -1);
11892 lshift = int_const_binop (code, lshift, arg1, 0);
11894 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
11898 /* Rewrite an LROTATE_EXPR by a constant into an
11899 RROTATE_EXPR by a new constant. */
11900 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
11902 tree tem = build_int_cst (TREE_TYPE (arg1),
11903 TYPE_PRECISION (type));
11904 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
11905 return fold_build2 (RROTATE_EXPR, type, op0, tem);
11908 /* If we have a rotate of a bit operation with the rotate count and
11909 the second operand of the bit operation both constant,
11910 permute the two operations. */
11911 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11912 && (TREE_CODE (arg0) == BIT_AND_EXPR
11913 || TREE_CODE (arg0) == BIT_IOR_EXPR
11914 || TREE_CODE (arg0) == BIT_XOR_EXPR)
11915 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11916 return fold_build2 (TREE_CODE (arg0), type,
11917 fold_build2 (code, type,
11918 TREE_OPERAND (arg0, 0), arg1),
11919 fold_build2 (code, type,
11920 TREE_OPERAND (arg0, 1), arg1));
11922 /* Two consecutive rotates adding up to the precision of the
11923 type can be ignored. */
11924 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11925 && TREE_CODE (arg0) == RROTATE_EXPR
11926 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11927 && TREE_INT_CST_HIGH (arg1) == 0
11928 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
11929 && ((TREE_INT_CST_LOW (arg1)
11930 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
11931 == (unsigned int) TYPE_PRECISION (type)))
11932 return TREE_OPERAND (arg0, 0);
11934 /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
11935 (X & C2) >> C1 into (X >> C1) & (C2 >> C1)
11936 if the latter can be further optimized. */
11937 if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
11938 && TREE_CODE (arg0) == BIT_AND_EXPR
11939 && TREE_CODE (arg1) == INTEGER_CST
11940 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11942 tree mask = fold_build2 (code, type,
11943 fold_convert (type, TREE_OPERAND (arg0, 1)),
11945 tree shift = fold_build2 (code, type,
11946 fold_convert (type, TREE_OPERAND (arg0, 0)),
11948 tem = fold_binary (BIT_AND_EXPR, type, shift, mask);
11956 if (operand_equal_p (arg0, arg1, 0))
11957 return omit_one_operand (type, arg0, arg1);
11958 if (INTEGRAL_TYPE_P (type)
11959 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
11960 return omit_one_operand (type, arg1, arg0);
11961 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
11967 if (operand_equal_p (arg0, arg1, 0))
11968 return omit_one_operand (type, arg0, arg1);
11969 if (INTEGRAL_TYPE_P (type)
11970 && TYPE_MAX_VALUE (type)
11971 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
11972 return omit_one_operand (type, arg1, arg0);
11973 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
11978 case TRUTH_ANDIF_EXPR:
11979 /* Note that the operands of this must be ints
11980 and their values must be 0 or 1.
11981 ("true" is a fixed value perhaps depending on the language.) */
11982 /* If first arg is constant zero, return it. */
11983 if (integer_zerop (arg0))
11984 return fold_convert (type, arg0);
11985 case TRUTH_AND_EXPR:
11986 /* If either arg is constant true, drop it. */
11987 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11988 return non_lvalue (fold_convert (type, arg1));
11989 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
11990 /* Preserve sequence points. */
11991 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11992 return non_lvalue (fold_convert (type, arg0));
11993 /* If second arg is constant zero, result is zero, but first arg
11994 must be evaluated. */
11995 if (integer_zerop (arg1))
11996 return omit_one_operand (type, arg1, arg0);
11997 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11998 case will be handled here. */
11999 if (integer_zerop (arg0))
12000 return omit_one_operand (type, arg0, arg1);
12002 /* !X && X is always false. */
12003 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
12004 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
12005 return omit_one_operand (type, integer_zero_node, arg1);
12006 /* X && !X is always false. */
12007 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
12008 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
12009 return omit_one_operand (type, integer_zero_node, arg0);
12011 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
12012 means A >= Y && A != MAX, but in this case we know that
12015 if (!TREE_SIDE_EFFECTS (arg0)
12016 && !TREE_SIDE_EFFECTS (arg1))
12018 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
12019 if (tem && !operand_equal_p (tem, arg0, 0))
12020 return fold_build2 (code, type, tem, arg1);
12022 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
12023 if (tem && !operand_equal_p (tem, arg1, 0))
12024 return fold_build2 (code, type, arg0, tem);
12028 /* We only do these simplifications if we are optimizing. */
12032 /* Check for things like (A || B) && (A || C). We can convert this
12033 to A || (B && C). Note that either operator can be any of the four
12034 truth and/or operations and the transformation will still be
12035 valid. Also note that we only care about order for the
12036 ANDIF and ORIF operators. If B contains side effects, this
12037 might change the truth-value of A. */
12038 if (TREE_CODE (arg0) == TREE_CODE (arg1)
12039 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
12040 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
12041 || TREE_CODE (arg0) == TRUTH_AND_EXPR
12042 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
12043 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
12045 tree a00 = TREE_OPERAND (arg0, 0);
12046 tree a01 = TREE_OPERAND (arg0, 1);
12047 tree a10 = TREE_OPERAND (arg1, 0);
12048 tree a11 = TREE_OPERAND (arg1, 1);
12049 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
12050 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
12051 && (code == TRUTH_AND_EXPR
12052 || code == TRUTH_OR_EXPR));
12054 if (operand_equal_p (a00, a10, 0))
12055 return fold_build2 (TREE_CODE (arg0), type, a00,
12056 fold_build2 (code, type, a01, a11));
12057 else if (commutative && operand_equal_p (a00, a11, 0))
12058 return fold_build2 (TREE_CODE (arg0), type, a00,
12059 fold_build2 (code, type, a01, a10));
12060 else if (commutative && operand_equal_p (a01, a10, 0))
12061 return fold_build2 (TREE_CODE (arg0), type, a01,
12062 fold_build2 (code, type, a00, a11));
12064 /* This case if tricky because we must either have commutative
12065 operators or else A10 must not have side-effects. */
12067 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
12068 && operand_equal_p (a01, a11, 0))
12069 return fold_build2 (TREE_CODE (arg0), type,
12070 fold_build2 (code, type, a00, a10),
12074 /* See if we can build a range comparison. */
12075 if (0 != (tem = fold_range_test (code, type, op0, op1)))
12078 /* Check for the possibility of merging component references. If our
12079 lhs is another similar operation, try to merge its rhs with our
12080 rhs. Then try to merge our lhs and rhs. */
12081 if (TREE_CODE (arg0) == code
12082 && 0 != (tem = fold_truthop (code, type,
12083 TREE_OPERAND (arg0, 1), arg1)))
12084 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
12086 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
12091 case TRUTH_ORIF_EXPR:
12092 /* Note that the operands of this must be ints
12093 and their values must be 0 or true.
12094 ("true" is a fixed value perhaps depending on the language.) */
12095 /* If first arg is constant true, return it. */
12096 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
12097 return fold_convert (type, arg0);
12098 case TRUTH_OR_EXPR:
12099 /* If either arg is constant zero, drop it. */
12100 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
12101 return non_lvalue (fold_convert (type, arg1));
12102 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
12103 /* Preserve sequence points. */
12104 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
12105 return non_lvalue (fold_convert (type, arg0));
12106 /* If second arg is constant true, result is true, but we must
12107 evaluate first arg. */
12108 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
12109 return omit_one_operand (type, arg1, arg0);
12110 /* Likewise for first arg, but note this only occurs here for
12112 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
12113 return omit_one_operand (type, arg0, arg1);
12115 /* !X || X is always true. */
12116 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
12117 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
12118 return omit_one_operand (type, integer_one_node, arg1);
12119 /* X || !X is always true. */
12120 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
12121 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
12122 return omit_one_operand (type, integer_one_node, arg0);
12126 case TRUTH_XOR_EXPR:
12127 /* If the second arg is constant zero, drop it. */
12128 if (integer_zerop (arg1))
12129 return non_lvalue (fold_convert (type, arg0));
12130 /* If the second arg is constant true, this is a logical inversion. */
12131 if (integer_onep (arg1))
12133 /* Only call invert_truthvalue if operand is a truth value. */
12134 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
12135 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
12137 tem = invert_truthvalue (arg0);
12138 return non_lvalue (fold_convert (type, tem));
12140 /* Identical arguments cancel to zero. */
12141 if (operand_equal_p (arg0, arg1, 0))
12142 return omit_one_operand (type, integer_zero_node, arg0);
12144 /* !X ^ X is always true. */
12145 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
12146 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
12147 return omit_one_operand (type, integer_one_node, arg1);
12149 /* X ^ !X is always true. */
12150 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
12151 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
12152 return omit_one_operand (type, integer_one_node, arg0);
12158 tem = fold_comparison (code, type, op0, op1);
12159 if (tem != NULL_TREE)
12162 /* bool_var != 0 becomes bool_var. */
12163 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
12164 && code == NE_EXPR)
12165 return non_lvalue (fold_convert (type, arg0));
12167 /* bool_var == 1 becomes bool_var. */
12168 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
12169 && code == EQ_EXPR)
12170 return non_lvalue (fold_convert (type, arg0));
12172 /* bool_var != 1 becomes !bool_var. */
12173 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
12174 && code == NE_EXPR)
12175 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
12177 /* bool_var == 0 becomes !bool_var. */
12178 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
12179 && code == EQ_EXPR)
12180 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
12182 /* If this is an equality comparison of the address of two non-weak,
12183 unaliased symbols neither of which are extern (since we do not
12184 have access to attributes for externs), then we know the result. */
12185 if (TREE_CODE (arg0) == ADDR_EXPR
12186 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
12187 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
12188 && ! lookup_attribute ("alias",
12189 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
12190 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
12191 && TREE_CODE (arg1) == ADDR_EXPR
12192 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
12193 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
12194 && ! lookup_attribute ("alias",
12195 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
12196 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
12198 /* We know that we're looking at the address of two
12199 non-weak, unaliased, static _DECL nodes.
12201 It is both wasteful and incorrect to call operand_equal_p
12202 to compare the two ADDR_EXPR nodes. It is wasteful in that
12203 all we need to do is test pointer equality for the arguments
12204 to the two ADDR_EXPR nodes. It is incorrect to use
12205 operand_equal_p as that function is NOT equivalent to a
12206 C equality test. It can in fact return false for two
12207 objects which would test as equal using the C equality
12209 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
12210 return constant_boolean_node (equal
12211 ? code == EQ_EXPR : code != EQ_EXPR,
12215 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
12216 a MINUS_EXPR of a constant, we can convert it into a comparison with
12217 a revised constant as long as no overflow occurs. */
12218 if (TREE_CODE (arg1) == INTEGER_CST
12219 && (TREE_CODE (arg0) == PLUS_EXPR
12220 || TREE_CODE (arg0) == MINUS_EXPR)
12221 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12222 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
12223 ? MINUS_EXPR : PLUS_EXPR,
12224 fold_convert (TREE_TYPE (arg0), arg1),
12225 TREE_OPERAND (arg0, 1), 0))
12226 && !TREE_OVERFLOW (tem))
12227 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
12229 /* Similarly for a NEGATE_EXPR. */
12230 if (TREE_CODE (arg0) == NEGATE_EXPR
12231 && TREE_CODE (arg1) == INTEGER_CST
12232 && 0 != (tem = negate_expr (arg1))
12233 && TREE_CODE (tem) == INTEGER_CST
12234 && !TREE_OVERFLOW (tem))
12235 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
12237 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
12238 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12239 && TREE_CODE (arg1) == INTEGER_CST
12240 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12241 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12242 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
12243 fold_convert (TREE_TYPE (arg0), arg1),
12244 TREE_OPERAND (arg0, 1)));
12246 /* Transform comparisons of the form X +- Y CMP X to Y CMP 0. */
12247 if ((TREE_CODE (arg0) == PLUS_EXPR
12248 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
12249 || TREE_CODE (arg0) == MINUS_EXPR)
12250 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12251 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
12252 || POINTER_TYPE_P (TREE_TYPE (arg0))))
12254 tree val = TREE_OPERAND (arg0, 1);
12255 return omit_two_operands (type,
12256 fold_build2 (code, type,
12258 build_int_cst (TREE_TYPE (val),
12260 TREE_OPERAND (arg0, 0), arg1);
12263 /* Transform comparisons of the form C - X CMP X if C % 2 == 1. */
12264 if (TREE_CODE (arg0) == MINUS_EXPR
12265 && TREE_CODE (TREE_OPERAND (arg0, 0)) == INTEGER_CST
12266 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0)
12267 && (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 0)) & 1) == 1)
12269 return omit_two_operands (type,
12271 ? boolean_true_node : boolean_false_node,
12272 TREE_OPERAND (arg0, 1), arg1);
12275 /* If we have X - Y == 0, we can convert that to X == Y and similarly
12276 for !=. Don't do this for ordered comparisons due to overflow. */
12277 if (TREE_CODE (arg0) == MINUS_EXPR
12278 && integer_zerop (arg1))
12279 return fold_build2 (code, type,
12280 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
12282 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
12283 if (TREE_CODE (arg0) == ABS_EXPR
12284 && (integer_zerop (arg1) || real_zerop (arg1)))
12285 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
12287 /* If this is an EQ or NE comparison with zero and ARG0 is
12288 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
12289 two operations, but the latter can be done in one less insn
12290 on machines that have only two-operand insns or on which a
12291 constant cannot be the first operand. */
12292 if (TREE_CODE (arg0) == BIT_AND_EXPR
12293 && integer_zerop (arg1))
12295 tree arg00 = TREE_OPERAND (arg0, 0);
12296 tree arg01 = TREE_OPERAND (arg0, 1);
12297 if (TREE_CODE (arg00) == LSHIFT_EXPR
12298 && integer_onep (TREE_OPERAND (arg00, 0)))
12300 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
12301 arg01, TREE_OPERAND (arg00, 1));
12302 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
12303 build_int_cst (TREE_TYPE (arg0), 1));
12304 return fold_build2 (code, type,
12305 fold_convert (TREE_TYPE (arg1), tem), arg1);
12307 else if (TREE_CODE (arg01) == LSHIFT_EXPR
12308 && integer_onep (TREE_OPERAND (arg01, 0)))
12310 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
12311 arg00, TREE_OPERAND (arg01, 1));
12312 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
12313 build_int_cst (TREE_TYPE (arg0), 1));
12314 return fold_build2 (code, type,
12315 fold_convert (TREE_TYPE (arg1), tem), arg1);
12319 /* If this is an NE or EQ comparison of zero against the result of a
12320 signed MOD operation whose second operand is a power of 2, make
12321 the MOD operation unsigned since it is simpler and equivalent. */
12322 if (integer_zerop (arg1)
12323 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
12324 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
12325 || TREE_CODE (arg0) == CEIL_MOD_EXPR
12326 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
12327 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
12328 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12330 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
12331 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
12332 fold_convert (newtype,
12333 TREE_OPERAND (arg0, 0)),
12334 fold_convert (newtype,
12335 TREE_OPERAND (arg0, 1)));
12337 return fold_build2 (code, type, newmod,
12338 fold_convert (newtype, arg1));
12341 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
12342 C1 is a valid shift constant, and C2 is a power of two, i.e.
12344 if (TREE_CODE (arg0) == BIT_AND_EXPR
12345 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
12346 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
12348 && integer_pow2p (TREE_OPERAND (arg0, 1))
12349 && integer_zerop (arg1))
12351 tree itype = TREE_TYPE (arg0);
12352 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
12353 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
12355 /* Check for a valid shift count. */
12356 if (TREE_INT_CST_HIGH (arg001) == 0
12357 && TREE_INT_CST_LOW (arg001) < prec)
12359 tree arg01 = TREE_OPERAND (arg0, 1);
12360 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12361 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
12362 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
12363 can be rewritten as (X & (C2 << C1)) != 0. */
12364 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
12366 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
12367 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
12368 return fold_build2 (code, type, tem, arg1);
12370 /* Otherwise, for signed (arithmetic) shifts,
12371 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
12372 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
12373 else if (!TYPE_UNSIGNED (itype))
12374 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
12375 arg000, build_int_cst (itype, 0));
12376 /* Otherwise, of unsigned (logical) shifts,
12377 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
12378 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
12380 return omit_one_operand (type,
12381 code == EQ_EXPR ? integer_one_node
12382 : integer_zero_node,
12387 /* If this is an NE comparison of zero with an AND of one, remove the
12388 comparison since the AND will give the correct value. */
12389 if (code == NE_EXPR
12390 && integer_zerop (arg1)
12391 && TREE_CODE (arg0) == BIT_AND_EXPR
12392 && integer_onep (TREE_OPERAND (arg0, 1)))
12393 return fold_convert (type, arg0);
12395 /* If we have (A & C) == C where C is a power of 2, convert this into
12396 (A & C) != 0. Similarly for NE_EXPR. */
12397 if (TREE_CODE (arg0) == BIT_AND_EXPR
12398 && integer_pow2p (TREE_OPERAND (arg0, 1))
12399 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12400 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12401 arg0, fold_convert (TREE_TYPE (arg0),
12402 integer_zero_node));
12404 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
12405 bit, then fold the expression into A < 0 or A >= 0. */
12406 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
12410 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
12411 Similarly for NE_EXPR. */
12412 if (TREE_CODE (arg0) == BIT_AND_EXPR
12413 && TREE_CODE (arg1) == INTEGER_CST
12414 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12416 tree notc = fold_build1 (BIT_NOT_EXPR,
12417 TREE_TYPE (TREE_OPERAND (arg0, 1)),
12418 TREE_OPERAND (arg0, 1));
12419 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12421 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
12422 if (integer_nonzerop (dandnotc))
12423 return omit_one_operand (type, rslt, arg0);
12426 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
12427 Similarly for NE_EXPR. */
12428 if (TREE_CODE (arg0) == BIT_IOR_EXPR
12429 && TREE_CODE (arg1) == INTEGER_CST
12430 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12432 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
12433 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12434 TREE_OPERAND (arg0, 1), notd);
12435 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
12436 if (integer_nonzerop (candnotd))
12437 return omit_one_operand (type, rslt, arg0);
12440 /* If this is a comparison of a field, we may be able to simplify it. */
12441 if ((TREE_CODE (arg0) == COMPONENT_REF
12442 || TREE_CODE (arg0) == BIT_FIELD_REF)
12443 /* Handle the constant case even without -O
12444 to make sure the warnings are given. */
12445 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
12447 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
12452 /* Optimize comparisons of strlen vs zero to a compare of the
12453 first character of the string vs zero. To wit,
12454 strlen(ptr) == 0 => *ptr == 0
12455 strlen(ptr) != 0 => *ptr != 0
12456 Other cases should reduce to one of these two (or a constant)
12457 due to the return value of strlen being unsigned. */
12458 if (TREE_CODE (arg0) == CALL_EXPR
12459 && integer_zerop (arg1))
12461 tree fndecl = get_callee_fndecl (arg0);
12464 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
12465 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
12466 && call_expr_nargs (arg0) == 1
12467 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
12469 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
12470 return fold_build2 (code, type, iref,
12471 build_int_cst (TREE_TYPE (iref), 0));
12475 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
12476 of X. Similarly fold (X >> C) == 0 into X >= 0. */
12477 if (TREE_CODE (arg0) == RSHIFT_EXPR
12478 && integer_zerop (arg1)
12479 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12481 tree arg00 = TREE_OPERAND (arg0, 0);
12482 tree arg01 = TREE_OPERAND (arg0, 1);
12483 tree itype = TREE_TYPE (arg00);
12484 if (TREE_INT_CST_HIGH (arg01) == 0
12485 && TREE_INT_CST_LOW (arg01)
12486 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
12488 if (TYPE_UNSIGNED (itype))
12490 itype = signed_type_for (itype);
12491 arg00 = fold_convert (itype, arg00);
12493 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
12494 type, arg00, build_int_cst (itype, 0));
12498 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
12499 if (integer_zerop (arg1)
12500 && TREE_CODE (arg0) == BIT_XOR_EXPR)
12501 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12502 TREE_OPERAND (arg0, 1));
12504 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
12505 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12506 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12507 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12508 build_int_cst (TREE_TYPE (arg1), 0));
12509 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
12510 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12511 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12512 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
12513 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
12514 build_int_cst (TREE_TYPE (arg1), 0));
12516 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
12517 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12518 && TREE_CODE (arg1) == INTEGER_CST
12519 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12520 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12521 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
12522 TREE_OPERAND (arg0, 1), arg1));
12524 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
12525 (X & C) == 0 when C is a single bit. */
12526 if (TREE_CODE (arg0) == BIT_AND_EXPR
12527 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
12528 && integer_zerop (arg1)
12529 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12531 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12532 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
12533 TREE_OPERAND (arg0, 1));
12534 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
12538 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12539 constant C is a power of two, i.e. a single bit. */
12540 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12541 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12542 && integer_zerop (arg1)
12543 && integer_pow2p (TREE_OPERAND (arg0, 1))
12544 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12545 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12547 tree arg00 = TREE_OPERAND (arg0, 0);
12548 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12549 arg00, build_int_cst (TREE_TYPE (arg00), 0));
12552 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12553 when is C is a power of two, i.e. a single bit. */
12554 if (TREE_CODE (arg0) == BIT_AND_EXPR
12555 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
12556 && integer_zerop (arg1)
12557 && integer_pow2p (TREE_OPERAND (arg0, 1))
12558 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12559 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12561 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12562 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
12563 arg000, TREE_OPERAND (arg0, 1));
12564 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12565 tem, build_int_cst (TREE_TYPE (tem), 0));
12568 if (integer_zerop (arg1)
12569 && tree_expr_nonzero_p (arg0))
12571 tree res = constant_boolean_node (code==NE_EXPR, type);
12572 return omit_one_operand (type, res, arg0);
12575 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12576 if (TREE_CODE (arg0) == NEGATE_EXPR
12577 && TREE_CODE (arg1) == NEGATE_EXPR)
12578 return fold_build2 (code, type,
12579 TREE_OPERAND (arg0, 0),
12580 TREE_OPERAND (arg1, 0));
12582 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12583 if (TREE_CODE (arg0) == BIT_AND_EXPR
12584 && TREE_CODE (arg1) == BIT_AND_EXPR)
12586 tree arg00 = TREE_OPERAND (arg0, 0);
12587 tree arg01 = TREE_OPERAND (arg0, 1);
12588 tree arg10 = TREE_OPERAND (arg1, 0);
12589 tree arg11 = TREE_OPERAND (arg1, 1);
12590 tree itype = TREE_TYPE (arg0);
12592 if (operand_equal_p (arg01, arg11, 0))
12593 return fold_build2 (code, type,
12594 fold_build2 (BIT_AND_EXPR, itype,
12595 fold_build2 (BIT_XOR_EXPR, itype,
12598 build_int_cst (itype, 0));
12600 if (operand_equal_p (arg01, arg10, 0))
12601 return fold_build2 (code, type,
12602 fold_build2 (BIT_AND_EXPR, itype,
12603 fold_build2 (BIT_XOR_EXPR, itype,
12606 build_int_cst (itype, 0));
12608 if (operand_equal_p (arg00, arg11, 0))
12609 return fold_build2 (code, type,
12610 fold_build2 (BIT_AND_EXPR, itype,
12611 fold_build2 (BIT_XOR_EXPR, itype,
12614 build_int_cst (itype, 0));
12616 if (operand_equal_p (arg00, arg10, 0))
12617 return fold_build2 (code, type,
12618 fold_build2 (BIT_AND_EXPR, itype,
12619 fold_build2 (BIT_XOR_EXPR, itype,
12622 build_int_cst (itype, 0));
12625 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12626 && TREE_CODE (arg1) == BIT_XOR_EXPR)
12628 tree arg00 = TREE_OPERAND (arg0, 0);
12629 tree arg01 = TREE_OPERAND (arg0, 1);
12630 tree arg10 = TREE_OPERAND (arg1, 0);
12631 tree arg11 = TREE_OPERAND (arg1, 1);
12632 tree itype = TREE_TYPE (arg0);
12634 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12635 operand_equal_p guarantees no side-effects so we don't need
12636 to use omit_one_operand on Z. */
12637 if (operand_equal_p (arg01, arg11, 0))
12638 return fold_build2 (code, type, arg00, arg10);
12639 if (operand_equal_p (arg01, arg10, 0))
12640 return fold_build2 (code, type, arg00, arg11);
12641 if (operand_equal_p (arg00, arg11, 0))
12642 return fold_build2 (code, type, arg01, arg10);
12643 if (operand_equal_p (arg00, arg10, 0))
12644 return fold_build2 (code, type, arg01, arg11);
12646 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12647 if (TREE_CODE (arg01) == INTEGER_CST
12648 && TREE_CODE (arg11) == INTEGER_CST)
12649 return fold_build2 (code, type,
12650 fold_build2 (BIT_XOR_EXPR, itype, arg00,
12651 fold_build2 (BIT_XOR_EXPR, itype,
12656 /* Attempt to simplify equality/inequality comparisons of complex
12657 values. Only lower the comparison if the result is known or
12658 can be simplified to a single scalar comparison. */
12659 if ((TREE_CODE (arg0) == COMPLEX_EXPR
12660 || TREE_CODE (arg0) == COMPLEX_CST)
12661 && (TREE_CODE (arg1) == COMPLEX_EXPR
12662 || TREE_CODE (arg1) == COMPLEX_CST))
12664 tree real0, imag0, real1, imag1;
12667 if (TREE_CODE (arg0) == COMPLEX_EXPR)
12669 real0 = TREE_OPERAND (arg0, 0);
12670 imag0 = TREE_OPERAND (arg0, 1);
12674 real0 = TREE_REALPART (arg0);
12675 imag0 = TREE_IMAGPART (arg0);
12678 if (TREE_CODE (arg1) == COMPLEX_EXPR)
12680 real1 = TREE_OPERAND (arg1, 0);
12681 imag1 = TREE_OPERAND (arg1, 1);
12685 real1 = TREE_REALPART (arg1);
12686 imag1 = TREE_IMAGPART (arg1);
12689 rcond = fold_binary (code, type, real0, real1);
12690 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
12692 if (integer_zerop (rcond))
12694 if (code == EQ_EXPR)
12695 return omit_two_operands (type, boolean_false_node,
12697 return fold_build2 (NE_EXPR, type, imag0, imag1);
12701 if (code == NE_EXPR)
12702 return omit_two_operands (type, boolean_true_node,
12704 return fold_build2 (EQ_EXPR, type, imag0, imag1);
12708 icond = fold_binary (code, type, imag0, imag1);
12709 if (icond && TREE_CODE (icond) == INTEGER_CST)
12711 if (integer_zerop (icond))
12713 if (code == EQ_EXPR)
12714 return omit_two_operands (type, boolean_false_node,
12716 return fold_build2 (NE_EXPR, type, real0, real1);
12720 if (code == NE_EXPR)
12721 return omit_two_operands (type, boolean_true_node,
12723 return fold_build2 (EQ_EXPR, type, real0, real1);
12734 tem = fold_comparison (code, type, op0, op1);
12735 if (tem != NULL_TREE)
12738 /* Transform comparisons of the form X +- C CMP X. */
12739 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12740 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12741 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
12742 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
12743 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12744 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
12746 tree arg01 = TREE_OPERAND (arg0, 1);
12747 enum tree_code code0 = TREE_CODE (arg0);
12750 if (TREE_CODE (arg01) == REAL_CST)
12751 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
12753 is_positive = tree_int_cst_sgn (arg01);
12755 /* (X - c) > X becomes false. */
12756 if (code == GT_EXPR
12757 && ((code0 == MINUS_EXPR && is_positive >= 0)
12758 || (code0 == PLUS_EXPR && is_positive <= 0)))
12760 if (TREE_CODE (arg01) == INTEGER_CST
12761 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12762 fold_overflow_warning (("assuming signed overflow does not "
12763 "occur when assuming that (X - c) > X "
12764 "is always false"),
12765 WARN_STRICT_OVERFLOW_ALL);
12766 return constant_boolean_node (0, type);
12769 /* Likewise (X + c) < X becomes false. */
12770 if (code == LT_EXPR
12771 && ((code0 == PLUS_EXPR && is_positive >= 0)
12772 || (code0 == MINUS_EXPR && is_positive <= 0)))
12774 if (TREE_CODE (arg01) == INTEGER_CST
12775 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12776 fold_overflow_warning (("assuming signed overflow does not "
12777 "occur when assuming that "
12778 "(X + c) < X is always false"),
12779 WARN_STRICT_OVERFLOW_ALL);
12780 return constant_boolean_node (0, type);
12783 /* Convert (X - c) <= X to true. */
12784 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12786 && ((code0 == MINUS_EXPR && is_positive >= 0)
12787 || (code0 == PLUS_EXPR && is_positive <= 0)))
12789 if (TREE_CODE (arg01) == INTEGER_CST
12790 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12791 fold_overflow_warning (("assuming signed overflow does not "
12792 "occur when assuming that "
12793 "(X - c) <= X is always true"),
12794 WARN_STRICT_OVERFLOW_ALL);
12795 return constant_boolean_node (1, type);
12798 /* Convert (X + c) >= X to true. */
12799 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12801 && ((code0 == PLUS_EXPR && is_positive >= 0)
12802 || (code0 == MINUS_EXPR && is_positive <= 0)))
12804 if (TREE_CODE (arg01) == INTEGER_CST
12805 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12806 fold_overflow_warning (("assuming signed overflow does not "
12807 "occur when assuming that "
12808 "(X + c) >= X is always true"),
12809 WARN_STRICT_OVERFLOW_ALL);
12810 return constant_boolean_node (1, type);
12813 if (TREE_CODE (arg01) == INTEGER_CST)
12815 /* Convert X + c > X and X - c < X to true for integers. */
12816 if (code == GT_EXPR
12817 && ((code0 == PLUS_EXPR && is_positive > 0)
12818 || (code0 == MINUS_EXPR && is_positive < 0)))
12820 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12821 fold_overflow_warning (("assuming signed overflow does "
12822 "not occur when assuming that "
12823 "(X + c) > X is always true"),
12824 WARN_STRICT_OVERFLOW_ALL);
12825 return constant_boolean_node (1, type);
12828 if (code == LT_EXPR
12829 && ((code0 == MINUS_EXPR && is_positive > 0)
12830 || (code0 == PLUS_EXPR && is_positive < 0)))
12832 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12833 fold_overflow_warning (("assuming signed overflow does "
12834 "not occur when assuming that "
12835 "(X - c) < X is always true"),
12836 WARN_STRICT_OVERFLOW_ALL);
12837 return constant_boolean_node (1, type);
12840 /* Convert X + c <= X and X - c >= X to false for integers. */
12841 if (code == LE_EXPR
12842 && ((code0 == PLUS_EXPR && is_positive > 0)
12843 || (code0 == MINUS_EXPR && is_positive < 0)))
12845 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12846 fold_overflow_warning (("assuming signed overflow does "
12847 "not occur when assuming that "
12848 "(X + c) <= X is always false"),
12849 WARN_STRICT_OVERFLOW_ALL);
12850 return constant_boolean_node (0, type);
12853 if (code == GE_EXPR
12854 && ((code0 == MINUS_EXPR && is_positive > 0)
12855 || (code0 == PLUS_EXPR && is_positive < 0)))
12857 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12858 fold_overflow_warning (("assuming signed overflow does "
12859 "not occur when assuming that "
12860 "(X - c) >= X is always false"),
12861 WARN_STRICT_OVERFLOW_ALL);
12862 return constant_boolean_node (0, type);
12867 /* Comparisons with the highest or lowest possible integer of
12868 the specified precision will have known values. */
12870 tree arg1_type = TREE_TYPE (arg1);
12871 unsigned int width = TYPE_PRECISION (arg1_type);
12873 if (TREE_CODE (arg1) == INTEGER_CST
12874 && width <= 2 * HOST_BITS_PER_WIDE_INT
12875 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
12877 HOST_WIDE_INT signed_max_hi;
12878 unsigned HOST_WIDE_INT signed_max_lo;
12879 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
12881 if (width <= HOST_BITS_PER_WIDE_INT)
12883 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12888 if (TYPE_UNSIGNED (arg1_type))
12890 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12896 max_lo = signed_max_lo;
12897 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12903 width -= HOST_BITS_PER_WIDE_INT;
12904 signed_max_lo = -1;
12905 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12910 if (TYPE_UNSIGNED (arg1_type))
12912 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12917 max_hi = signed_max_hi;
12918 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12922 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
12923 && TREE_INT_CST_LOW (arg1) == max_lo)
12927 return omit_one_operand (type, integer_zero_node, arg0);
12930 return fold_build2 (EQ_EXPR, type, op0, op1);
12933 return omit_one_operand (type, integer_one_node, arg0);
12936 return fold_build2 (NE_EXPR, type, op0, op1);
12938 /* The GE_EXPR and LT_EXPR cases above are not normally
12939 reached because of previous transformations. */
12944 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12946 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
12950 arg1 = const_binop (PLUS_EXPR, arg1,
12951 build_int_cst (TREE_TYPE (arg1), 1), 0);
12952 return fold_build2 (EQ_EXPR, type,
12953 fold_convert (TREE_TYPE (arg1), arg0),
12956 arg1 = const_binop (PLUS_EXPR, arg1,
12957 build_int_cst (TREE_TYPE (arg1), 1), 0);
12958 return fold_build2 (NE_EXPR, type,
12959 fold_convert (TREE_TYPE (arg1), arg0),
12964 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12966 && TREE_INT_CST_LOW (arg1) == min_lo)
12970 return omit_one_operand (type, integer_zero_node, arg0);
12973 return fold_build2 (EQ_EXPR, type, op0, op1);
12976 return omit_one_operand (type, integer_one_node, arg0);
12979 return fold_build2 (NE_EXPR, type, op0, op1);
12984 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12986 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
12990 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12991 return fold_build2 (NE_EXPR, type,
12992 fold_convert (TREE_TYPE (arg1), arg0),
12995 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12996 return fold_build2 (EQ_EXPR, type,
12997 fold_convert (TREE_TYPE (arg1), arg0),
13003 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
13004 && TREE_INT_CST_LOW (arg1) == signed_max_lo
13005 && TYPE_UNSIGNED (arg1_type)
13006 /* We will flip the signedness of the comparison operator
13007 associated with the mode of arg1, so the sign bit is
13008 specified by this mode. Check that arg1 is the signed
13009 max associated with this sign bit. */
13010 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
13011 /* signed_type does not work on pointer types. */
13012 && INTEGRAL_TYPE_P (arg1_type))
13014 /* The following case also applies to X < signed_max+1
13015 and X >= signed_max+1 because previous transformations. */
13016 if (code == LE_EXPR || code == GT_EXPR)
13019 st = signed_type_for (TREE_TYPE (arg1));
13020 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
13021 type, fold_convert (st, arg0),
13022 build_int_cst (st, 0));
13028 /* If we are comparing an ABS_EXPR with a constant, we can
13029 convert all the cases into explicit comparisons, but they may
13030 well not be faster than doing the ABS and one comparison.
13031 But ABS (X) <= C is a range comparison, which becomes a subtraction
13032 and a comparison, and is probably faster. */
13033 if (code == LE_EXPR
13034 && TREE_CODE (arg1) == INTEGER_CST
13035 && TREE_CODE (arg0) == ABS_EXPR
13036 && ! TREE_SIDE_EFFECTS (arg0)
13037 && (0 != (tem = negate_expr (arg1)))
13038 && TREE_CODE (tem) == INTEGER_CST
13039 && !TREE_OVERFLOW (tem))
13040 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13041 build2 (GE_EXPR, type,
13042 TREE_OPERAND (arg0, 0), tem),
13043 build2 (LE_EXPR, type,
13044 TREE_OPERAND (arg0, 0), arg1));
13046 /* Convert ABS_EXPR<x> >= 0 to true. */
13047 strict_overflow_p = false;
13048 if (code == GE_EXPR
13049 && (integer_zerop (arg1)
13050 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
13051 && real_zerop (arg1)))
13052 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
13054 if (strict_overflow_p)
13055 fold_overflow_warning (("assuming signed overflow does not occur "
13056 "when simplifying comparison of "
13057 "absolute value and zero"),
13058 WARN_STRICT_OVERFLOW_CONDITIONAL);
13059 return omit_one_operand (type, integer_one_node, arg0);
13062 /* Convert ABS_EXPR<x> < 0 to false. */
13063 strict_overflow_p = false;
13064 if (code == LT_EXPR
13065 && (integer_zerop (arg1) || real_zerop (arg1))
13066 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
13068 if (strict_overflow_p)
13069 fold_overflow_warning (("assuming signed overflow does not occur "
13070 "when simplifying comparison of "
13071 "absolute value and zero"),
13072 WARN_STRICT_OVERFLOW_CONDITIONAL);
13073 return omit_one_operand (type, integer_zero_node, arg0);
13076 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
13077 and similarly for >= into !=. */
13078 if ((code == LT_EXPR || code == GE_EXPR)
13079 && TYPE_UNSIGNED (TREE_TYPE (arg0))
13080 && TREE_CODE (arg1) == LSHIFT_EXPR
13081 && integer_onep (TREE_OPERAND (arg1, 0)))
13082 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
13083 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
13084 TREE_OPERAND (arg1, 1)),
13085 build_int_cst (TREE_TYPE (arg0), 0));
13087 if ((code == LT_EXPR || code == GE_EXPR)
13088 && TYPE_UNSIGNED (TREE_TYPE (arg0))
13089 && CONVERT_EXPR_P (arg1)
13090 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
13091 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
13093 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
13094 fold_convert (TREE_TYPE (arg0),
13095 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
13096 TREE_OPERAND (TREE_OPERAND (arg1, 0),
13098 build_int_cst (TREE_TYPE (arg0), 0));
13102 case UNORDERED_EXPR:
13110 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
13112 t1 = fold_relational_const (code, type, arg0, arg1);
13113 if (t1 != NULL_TREE)
13117 /* If the first operand is NaN, the result is constant. */
13118 if (TREE_CODE (arg0) == REAL_CST
13119 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
13120 && (code != LTGT_EXPR || ! flag_trapping_math))
13122 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
13123 ? integer_zero_node
13124 : integer_one_node;
13125 return omit_one_operand (type, t1, arg1);
13128 /* If the second operand is NaN, the result is constant. */
13129 if (TREE_CODE (arg1) == REAL_CST
13130 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
13131 && (code != LTGT_EXPR || ! flag_trapping_math))
13133 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
13134 ? integer_zero_node
13135 : integer_one_node;
13136 return omit_one_operand (type, t1, arg0);
13139 /* Simplify unordered comparison of something with itself. */
13140 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
13141 && operand_equal_p (arg0, arg1, 0))
13142 return constant_boolean_node (1, type);
13144 if (code == LTGT_EXPR
13145 && !flag_trapping_math
13146 && operand_equal_p (arg0, arg1, 0))
13147 return constant_boolean_node (0, type);
13149 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
13151 tree targ0 = strip_float_extensions (arg0);
13152 tree targ1 = strip_float_extensions (arg1);
13153 tree newtype = TREE_TYPE (targ0);
13155 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
13156 newtype = TREE_TYPE (targ1);
13158 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
13159 return fold_build2 (code, type, fold_convert (newtype, targ0),
13160 fold_convert (newtype, targ1));
13165 case COMPOUND_EXPR:
13166 /* When pedantic, a compound expression can be neither an lvalue
13167 nor an integer constant expression. */
13168 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
13170 /* Don't let (0, 0) be null pointer constant. */
13171 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
13172 : fold_convert (type, arg1);
13173 return pedantic_non_lvalue (tem);
13176 if ((TREE_CODE (arg0) == REAL_CST
13177 && TREE_CODE (arg1) == REAL_CST)
13178 || (TREE_CODE (arg0) == INTEGER_CST
13179 && TREE_CODE (arg1) == INTEGER_CST))
13180 return build_complex (type, arg0, arg1);
13184 /* An ASSERT_EXPR should never be passed to fold_binary. */
13185 gcc_unreachable ();
13189 } /* switch (code) */
13192 /* Callback for walk_tree, looking for LABEL_EXPR.
13193 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
13194 Do not check the sub-tree of GOTO_EXPR. */
13197 contains_label_1 (tree *tp,
13198 int *walk_subtrees,
13199 void *data ATTRIBUTE_UNUSED)
13201 switch (TREE_CODE (*tp))
13206 *walk_subtrees = 0;
13213 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
13214 accessible from outside the sub-tree. Returns NULL_TREE if no
13215 addressable label is found. */
13218 contains_label_p (tree st)
13220 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
13223 /* Fold a ternary expression of code CODE and type TYPE with operands
13224 OP0, OP1, and OP2. Return the folded expression if folding is
13225 successful. Otherwise, return NULL_TREE. */
13228 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
13231 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
13232 enum tree_code_class kind = TREE_CODE_CLASS (code);
13234 gcc_assert (IS_EXPR_CODE_CLASS (kind)
13235 && TREE_CODE_LENGTH (code) == 3);
13237 /* Strip any conversions that don't change the mode. This is safe
13238 for every expression, except for a comparison expression because
13239 its signedness is derived from its operands. So, in the latter
13240 case, only strip conversions that don't change the signedness.
13242 Note that this is done as an internal manipulation within the
13243 constant folder, in order to find the simplest representation of
13244 the arguments so that their form can be studied. In any cases,
13245 the appropriate type conversions should be put back in the tree
13246 that will get out of the constant folder. */
13261 case COMPONENT_REF:
13262 if (TREE_CODE (arg0) == CONSTRUCTOR
13263 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
13265 unsigned HOST_WIDE_INT idx;
13267 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
13274 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
13275 so all simple results must be passed through pedantic_non_lvalue. */
13276 if (TREE_CODE (arg0) == INTEGER_CST)
13278 tree unused_op = integer_zerop (arg0) ? op1 : op2;
13279 tem = integer_zerop (arg0) ? op2 : op1;
13280 /* Only optimize constant conditions when the selected branch
13281 has the same type as the COND_EXPR. This avoids optimizing
13282 away "c ? x : throw", where the throw has a void type.
13283 Avoid throwing away that operand which contains label. */
13284 if ((!TREE_SIDE_EFFECTS (unused_op)
13285 || !contains_label_p (unused_op))
13286 && (! VOID_TYPE_P (TREE_TYPE (tem))
13287 || VOID_TYPE_P (type)))
13288 return pedantic_non_lvalue (tem);
13291 if (operand_equal_p (arg1, op2, 0))
13292 return pedantic_omit_one_operand (type, arg1, arg0);
13294 /* If we have A op B ? A : C, we may be able to convert this to a
13295 simpler expression, depending on the operation and the values
13296 of B and C. Signed zeros prevent all of these transformations,
13297 for reasons given above each one.
13299 Also try swapping the arguments and inverting the conditional. */
13300 if (COMPARISON_CLASS_P (arg0)
13301 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
13302 arg1, TREE_OPERAND (arg0, 1))
13303 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
13305 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
13310 if (COMPARISON_CLASS_P (arg0)
13311 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
13313 TREE_OPERAND (arg0, 1))
13314 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
13316 tem = fold_truth_not_expr (arg0);
13317 if (tem && COMPARISON_CLASS_P (tem))
13319 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
13325 /* If the second operand is simpler than the third, swap them
13326 since that produces better jump optimization results. */
13327 if (truth_value_p (TREE_CODE (arg0))
13328 && tree_swap_operands_p (op1, op2, false))
13330 /* See if this can be inverted. If it can't, possibly because
13331 it was a floating-point inequality comparison, don't do
13333 tem = fold_truth_not_expr (arg0);
13335 return fold_build3 (code, type, tem, op2, op1);
13338 /* Convert A ? 1 : 0 to simply A. */
13339 if (integer_onep (op1)
13340 && integer_zerop (op2)
13341 /* If we try to convert OP0 to our type, the
13342 call to fold will try to move the conversion inside
13343 a COND, which will recurse. In that case, the COND_EXPR
13344 is probably the best choice, so leave it alone. */
13345 && type == TREE_TYPE (arg0))
13346 return pedantic_non_lvalue (arg0);
13348 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
13349 over COND_EXPR in cases such as floating point comparisons. */
13350 if (integer_zerop (op1)
13351 && integer_onep (op2)
13352 && truth_value_p (TREE_CODE (arg0)))
13353 return pedantic_non_lvalue (fold_convert (type,
13354 invert_truthvalue (arg0)));
13356 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
13357 if (TREE_CODE (arg0) == LT_EXPR
13358 && integer_zerop (TREE_OPERAND (arg0, 1))
13359 && integer_zerop (op2)
13360 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
13362 /* sign_bit_p only checks ARG1 bits within A's precision.
13363 If <sign bit of A> has wider type than A, bits outside
13364 of A's precision in <sign bit of A> need to be checked.
13365 If they are all 0, this optimization needs to be done
13366 in unsigned A's type, if they are all 1 in signed A's type,
13367 otherwise this can't be done. */
13368 if (TYPE_PRECISION (TREE_TYPE (tem))
13369 < TYPE_PRECISION (TREE_TYPE (arg1))
13370 && TYPE_PRECISION (TREE_TYPE (tem))
13371 < TYPE_PRECISION (type))
13373 unsigned HOST_WIDE_INT mask_lo;
13374 HOST_WIDE_INT mask_hi;
13375 int inner_width, outer_width;
13378 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
13379 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
13380 if (outer_width > TYPE_PRECISION (type))
13381 outer_width = TYPE_PRECISION (type);
13383 if (outer_width > HOST_BITS_PER_WIDE_INT)
13385 mask_hi = ((unsigned HOST_WIDE_INT) -1
13386 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
13392 mask_lo = ((unsigned HOST_WIDE_INT) -1
13393 >> (HOST_BITS_PER_WIDE_INT - outer_width));
13395 if (inner_width > HOST_BITS_PER_WIDE_INT)
13397 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
13398 >> (HOST_BITS_PER_WIDE_INT - inner_width));
13402 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
13403 >> (HOST_BITS_PER_WIDE_INT - inner_width));
13405 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
13406 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
13408 tem_type = signed_type_for (TREE_TYPE (tem));
13409 tem = fold_convert (tem_type, tem);
13411 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
13412 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
13414 tem_type = unsigned_type_for (TREE_TYPE (tem));
13415 tem = fold_convert (tem_type, tem);
13422 return fold_convert (type,
13423 fold_build2 (BIT_AND_EXPR,
13424 TREE_TYPE (tem), tem,
13425 fold_convert (TREE_TYPE (tem),
13429 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
13430 already handled above. */
13431 if (TREE_CODE (arg0) == BIT_AND_EXPR
13432 && integer_onep (TREE_OPERAND (arg0, 1))
13433 && integer_zerop (op2)
13434 && integer_pow2p (arg1))
13436 tree tem = TREE_OPERAND (arg0, 0);
13438 if (TREE_CODE (tem) == RSHIFT_EXPR
13439 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
13440 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
13441 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
13442 return fold_build2 (BIT_AND_EXPR, type,
13443 TREE_OPERAND (tem, 0), arg1);
13446 /* A & N ? N : 0 is simply A & N if N is a power of two. This
13447 is probably obsolete because the first operand should be a
13448 truth value (that's why we have the two cases above), but let's
13449 leave it in until we can confirm this for all front-ends. */
13450 if (integer_zerop (op2)
13451 && TREE_CODE (arg0) == NE_EXPR
13452 && integer_zerop (TREE_OPERAND (arg0, 1))
13453 && integer_pow2p (arg1)
13454 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
13455 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
13456 arg1, OEP_ONLY_CONST))
13457 return pedantic_non_lvalue (fold_convert (type,
13458 TREE_OPERAND (arg0, 0)));
13460 /* Convert A ? B : 0 into A && B if A and B are truth values. */
13461 if (integer_zerop (op2)
13462 && truth_value_p (TREE_CODE (arg0))
13463 && truth_value_p (TREE_CODE (arg1)))
13464 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13465 fold_convert (type, arg0),
13468 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
13469 if (integer_onep (op2)
13470 && truth_value_p (TREE_CODE (arg0))
13471 && truth_value_p (TREE_CODE (arg1)))
13473 /* Only perform transformation if ARG0 is easily inverted. */
13474 tem = fold_truth_not_expr (arg0);
13476 return fold_build2 (TRUTH_ORIF_EXPR, type,
13477 fold_convert (type, tem),
13481 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
13482 if (integer_zerop (arg1)
13483 && truth_value_p (TREE_CODE (arg0))
13484 && truth_value_p (TREE_CODE (op2)))
13486 /* Only perform transformation if ARG0 is easily inverted. */
13487 tem = fold_truth_not_expr (arg0);
13489 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13490 fold_convert (type, tem),
13494 /* Convert A ? 1 : B into A || B if A and B are truth values. */
13495 if (integer_onep (arg1)
13496 && truth_value_p (TREE_CODE (arg0))
13497 && truth_value_p (TREE_CODE (op2)))
13498 return fold_build2 (TRUTH_ORIF_EXPR, type,
13499 fold_convert (type, arg0),
13505 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
13506 of fold_ternary on them. */
13507 gcc_unreachable ();
13509 case BIT_FIELD_REF:
13510 if ((TREE_CODE (arg0) == VECTOR_CST
13511 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
13512 && type == TREE_TYPE (TREE_TYPE (arg0)))
13514 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
13515 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
13518 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
13519 && (idx % width) == 0
13520 && (idx = idx / width)
13521 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
13523 tree elements = NULL_TREE;
13525 if (TREE_CODE (arg0) == VECTOR_CST)
13526 elements = TREE_VECTOR_CST_ELTS (arg0);
13529 unsigned HOST_WIDE_INT idx;
13532 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
13533 elements = tree_cons (NULL_TREE, value, elements);
13535 while (idx-- > 0 && elements)
13536 elements = TREE_CHAIN (elements);
13538 return TREE_VALUE (elements);
13540 return fold_convert (type, integer_zero_node);
13544 /* A bit-field-ref that referenced the full argument can be stripped. */
13545 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
13546 && TYPE_PRECISION (TREE_TYPE (arg0)) == tree_low_cst (arg1, 1)
13547 && integer_zerop (op2))
13548 return fold_convert (type, arg0);
13554 } /* switch (code) */
13557 /* Perform constant folding and related simplification of EXPR.
13558 The related simplifications include x*1 => x, x*0 => 0, etc.,
13559 and application of the associative law.
13560 NOP_EXPR conversions may be removed freely (as long as we
13561 are careful not to change the type of the overall expression).
13562 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13563 but we can constant-fold them if they have constant operands. */
13565 #ifdef ENABLE_FOLD_CHECKING
13566 # define fold(x) fold_1 (x)
13567 static tree fold_1 (tree);
13573 const tree t = expr;
13574 enum tree_code code = TREE_CODE (t);
13575 enum tree_code_class kind = TREE_CODE_CLASS (code);
13578 /* Return right away if a constant. */
13579 if (kind == tcc_constant)
13582 /* CALL_EXPR-like objects with variable numbers of operands are
13583 treated specially. */
13584 if (kind == tcc_vl_exp)
13586 if (code == CALL_EXPR)
13588 tem = fold_call_expr (expr, false);
13589 return tem ? tem : expr;
13594 if (IS_EXPR_CODE_CLASS (kind))
13596 tree type = TREE_TYPE (t);
13597 tree op0, op1, op2;
13599 switch (TREE_CODE_LENGTH (code))
13602 op0 = TREE_OPERAND (t, 0);
13603 tem = fold_unary (code, type, op0);
13604 return tem ? tem : expr;
13606 op0 = TREE_OPERAND (t, 0);
13607 op1 = TREE_OPERAND (t, 1);
13608 tem = fold_binary (code, type, op0, op1);
13609 return tem ? tem : expr;
13611 op0 = TREE_OPERAND (t, 0);
13612 op1 = TREE_OPERAND (t, 1);
13613 op2 = TREE_OPERAND (t, 2);
13614 tem = fold_ternary (code, type, op0, op1, op2);
13615 return tem ? tem : expr;
13625 tree op0 = TREE_OPERAND (t, 0);
13626 tree op1 = TREE_OPERAND (t, 1);
13628 if (TREE_CODE (op1) == INTEGER_CST
13629 && TREE_CODE (op0) == CONSTRUCTOR
13630 && ! type_contains_placeholder_p (TREE_TYPE (op0)))
13632 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (op0);
13633 unsigned HOST_WIDE_INT end = VEC_length (constructor_elt, elts);
13634 unsigned HOST_WIDE_INT begin = 0;
13636 /* Find a matching index by means of a binary search. */
13637 while (begin != end)
13639 unsigned HOST_WIDE_INT middle = (begin + end) / 2;
13640 tree index = VEC_index (constructor_elt, elts, middle)->index;
13642 if (TREE_CODE (index) == INTEGER_CST
13643 && tree_int_cst_lt (index, op1))
13644 begin = middle + 1;
13645 else if (TREE_CODE (index) == INTEGER_CST
13646 && tree_int_cst_lt (op1, index))
13648 else if (TREE_CODE (index) == RANGE_EXPR
13649 && tree_int_cst_lt (TREE_OPERAND (index, 1), op1))
13650 begin = middle + 1;
13651 else if (TREE_CODE (index) == RANGE_EXPR
13652 && tree_int_cst_lt (op1, TREE_OPERAND (index, 0)))
13655 return VEC_index (constructor_elt, elts, middle)->value;
13663 return fold (DECL_INITIAL (t));
13667 } /* switch (code) */
13670 #ifdef ENABLE_FOLD_CHECKING
13673 static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
13674 static void fold_check_failed (const_tree, const_tree);
13675 void print_fold_checksum (const_tree);
13677 /* When --enable-checking=fold, compute a digest of expr before
13678 and after actual fold call to see if fold did not accidentally
13679 change original expr. */
13685 struct md5_ctx ctx;
13686 unsigned char checksum_before[16], checksum_after[16];
13689 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13690 md5_init_ctx (&ctx);
13691 fold_checksum_tree (expr, &ctx, ht);
13692 md5_finish_ctx (&ctx, checksum_before);
13695 ret = fold_1 (expr);
13697 md5_init_ctx (&ctx);
13698 fold_checksum_tree (expr, &ctx, ht);
13699 md5_finish_ctx (&ctx, checksum_after);
13702 if (memcmp (checksum_before, checksum_after, 16))
13703 fold_check_failed (expr, ret);
13709 print_fold_checksum (const_tree expr)
13711 struct md5_ctx ctx;
13712 unsigned char checksum[16], cnt;
13715 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13716 md5_init_ctx (&ctx);
13717 fold_checksum_tree (expr, &ctx, ht);
13718 md5_finish_ctx (&ctx, checksum);
13720 for (cnt = 0; cnt < 16; ++cnt)
13721 fprintf (stderr, "%02x", checksum[cnt]);
13722 putc ('\n', stderr);
13726 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
13728 internal_error ("fold check: original tree changed by fold");
13732 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
13735 enum tree_code code;
13736 union tree_node buf;
13741 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
13742 <= sizeof (struct tree_function_decl))
13743 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
13746 slot = (const void **) htab_find_slot (ht, expr, INSERT);
13750 code = TREE_CODE (expr);
13751 if (TREE_CODE_CLASS (code) == tcc_declaration
13752 && DECL_ASSEMBLER_NAME_SET_P (expr))
13754 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13755 memcpy ((char *) &buf, expr, tree_size (expr));
13756 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
13757 expr = (tree) &buf;
13759 else if (TREE_CODE_CLASS (code) == tcc_type
13760 && (TYPE_POINTER_TO (expr)
13761 || TYPE_REFERENCE_TO (expr)
13762 || TYPE_CACHED_VALUES_P (expr)
13763 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)
13764 || TYPE_NEXT_VARIANT (expr)))
13766 /* Allow these fields to be modified. */
13768 memcpy ((char *) &buf, expr, tree_size (expr));
13769 expr = tmp = (tree) &buf;
13770 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
13771 TYPE_POINTER_TO (tmp) = NULL;
13772 TYPE_REFERENCE_TO (tmp) = NULL;
13773 TYPE_NEXT_VARIANT (tmp) = NULL;
13774 if (TYPE_CACHED_VALUES_P (tmp))
13776 TYPE_CACHED_VALUES_P (tmp) = 0;
13777 TYPE_CACHED_VALUES (tmp) = NULL;
13780 md5_process_bytes (expr, tree_size (expr), ctx);
13781 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
13782 if (TREE_CODE_CLASS (code) != tcc_type
13783 && TREE_CODE_CLASS (code) != tcc_declaration
13784 && code != TREE_LIST
13785 && code != SSA_NAME)
13786 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
13787 switch (TREE_CODE_CLASS (code))
13793 md5_process_bytes (TREE_STRING_POINTER (expr),
13794 TREE_STRING_LENGTH (expr), ctx);
13797 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
13798 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
13801 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
13807 case tcc_exceptional:
13811 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
13812 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
13813 expr = TREE_CHAIN (expr);
13814 goto recursive_label;
13817 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
13818 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
13824 case tcc_expression:
13825 case tcc_reference:
13826 case tcc_comparison:
13829 case tcc_statement:
13831 len = TREE_OPERAND_LENGTH (expr);
13832 for (i = 0; i < len; ++i)
13833 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
13835 case tcc_declaration:
13836 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
13837 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
13838 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
13840 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
13841 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
13842 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
13843 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
13844 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
13846 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
13847 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
13849 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
13851 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
13852 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
13853 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
13857 if (TREE_CODE (expr) == ENUMERAL_TYPE)
13858 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
13859 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
13860 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
13861 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
13862 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
13863 if (INTEGRAL_TYPE_P (expr)
13864 || SCALAR_FLOAT_TYPE_P (expr))
13866 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
13867 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
13869 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
13870 if (TREE_CODE (expr) == RECORD_TYPE
13871 || TREE_CODE (expr) == UNION_TYPE
13872 || TREE_CODE (expr) == QUAL_UNION_TYPE)
13873 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
13874 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
13881 /* Helper function for outputting the checksum of a tree T. When
13882 debugging with gdb, you can "define mynext" to be "next" followed
13883 by "call debug_fold_checksum (op0)", then just trace down till the
13887 debug_fold_checksum (const_tree t)
13890 unsigned char checksum[16];
13891 struct md5_ctx ctx;
13892 htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13894 md5_init_ctx (&ctx);
13895 fold_checksum_tree (t, &ctx, ht);
13896 md5_finish_ctx (&ctx, checksum);
13899 for (i = 0; i < 16; i++)
13900 fprintf (stderr, "%d ", checksum[i]);
13902 fprintf (stderr, "\n");
13907 /* Fold a unary tree expression with code CODE of type TYPE with an
13908 operand OP0. Return a folded expression if successful. Otherwise,
13909 return a tree expression with code CODE of type TYPE with an
13913 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
13916 #ifdef ENABLE_FOLD_CHECKING
13917 unsigned char checksum_before[16], checksum_after[16];
13918 struct md5_ctx ctx;
13921 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13922 md5_init_ctx (&ctx);
13923 fold_checksum_tree (op0, &ctx, ht);
13924 md5_finish_ctx (&ctx, checksum_before);
13928 tem = fold_unary (code, type, op0);
13930 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
13932 #ifdef ENABLE_FOLD_CHECKING
13933 md5_init_ctx (&ctx);
13934 fold_checksum_tree (op0, &ctx, ht);
13935 md5_finish_ctx (&ctx, checksum_after);
13938 if (memcmp (checksum_before, checksum_after, 16))
13939 fold_check_failed (op0, tem);
13944 /* Fold a binary tree expression with code CODE of type TYPE with
13945 operands OP0 and OP1. Return a folded expression if successful.
13946 Otherwise, return a tree expression with code CODE of type TYPE
13947 with operands OP0 and OP1. */
13950 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
13954 #ifdef ENABLE_FOLD_CHECKING
13955 unsigned char checksum_before_op0[16],
13956 checksum_before_op1[16],
13957 checksum_after_op0[16],
13958 checksum_after_op1[16];
13959 struct md5_ctx ctx;
13962 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13963 md5_init_ctx (&ctx);
13964 fold_checksum_tree (op0, &ctx, ht);
13965 md5_finish_ctx (&ctx, checksum_before_op0);
13968 md5_init_ctx (&ctx);
13969 fold_checksum_tree (op1, &ctx, ht);
13970 md5_finish_ctx (&ctx, checksum_before_op1);
13974 tem = fold_binary (code, type, op0, op1);
13976 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
13978 #ifdef ENABLE_FOLD_CHECKING
13979 md5_init_ctx (&ctx);
13980 fold_checksum_tree (op0, &ctx, ht);
13981 md5_finish_ctx (&ctx, checksum_after_op0);
13984 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13985 fold_check_failed (op0, tem);
13987 md5_init_ctx (&ctx);
13988 fold_checksum_tree (op1, &ctx, ht);
13989 md5_finish_ctx (&ctx, checksum_after_op1);
13992 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13993 fold_check_failed (op1, tem);
13998 /* Fold a ternary tree expression with code CODE of type TYPE with
13999 operands OP0, OP1, and OP2. Return a folded expression if
14000 successful. Otherwise, return a tree expression with code CODE of
14001 type TYPE with operands OP0, OP1, and OP2. */
14004 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
14008 #ifdef ENABLE_FOLD_CHECKING
14009 unsigned char checksum_before_op0[16],
14010 checksum_before_op1[16],
14011 checksum_before_op2[16],
14012 checksum_after_op0[16],
14013 checksum_after_op1[16],
14014 checksum_after_op2[16];
14015 struct md5_ctx ctx;
14018 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
14019 md5_init_ctx (&ctx);
14020 fold_checksum_tree (op0, &ctx, ht);
14021 md5_finish_ctx (&ctx, checksum_before_op0);
14024 md5_init_ctx (&ctx);
14025 fold_checksum_tree (op1, &ctx, ht);
14026 md5_finish_ctx (&ctx, checksum_before_op1);
14029 md5_init_ctx (&ctx);
14030 fold_checksum_tree (op2, &ctx, ht);
14031 md5_finish_ctx (&ctx, checksum_before_op2);
14035 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
14036 tem = fold_ternary (code, type, op0, op1, op2);
14038 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
14040 #ifdef ENABLE_FOLD_CHECKING
14041 md5_init_ctx (&ctx);
14042 fold_checksum_tree (op0, &ctx, ht);
14043 md5_finish_ctx (&ctx, checksum_after_op0);
14046 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
14047 fold_check_failed (op0, tem);
14049 md5_init_ctx (&ctx);
14050 fold_checksum_tree (op1, &ctx, ht);
14051 md5_finish_ctx (&ctx, checksum_after_op1);
14054 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
14055 fold_check_failed (op1, tem);
14057 md5_init_ctx (&ctx);
14058 fold_checksum_tree (op2, &ctx, ht);
14059 md5_finish_ctx (&ctx, checksum_after_op2);
14062 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
14063 fold_check_failed (op2, tem);
14068 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
14069 arguments in ARGARRAY, and a null static chain.
14070 Return a folded expression if successful. Otherwise, return a CALL_EXPR
14071 of type TYPE from the given operands as constructed by build_call_array. */
14074 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
14077 #ifdef ENABLE_FOLD_CHECKING
14078 unsigned char checksum_before_fn[16],
14079 checksum_before_arglist[16],
14080 checksum_after_fn[16],
14081 checksum_after_arglist[16];
14082 struct md5_ctx ctx;
14086 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
14087 md5_init_ctx (&ctx);
14088 fold_checksum_tree (fn, &ctx, ht);
14089 md5_finish_ctx (&ctx, checksum_before_fn);
14092 md5_init_ctx (&ctx);
14093 for (i = 0; i < nargs; i++)
14094 fold_checksum_tree (argarray[i], &ctx, ht);
14095 md5_finish_ctx (&ctx, checksum_before_arglist);
14099 tem = fold_builtin_call_array (type, fn, nargs, argarray);
14101 #ifdef ENABLE_FOLD_CHECKING
14102 md5_init_ctx (&ctx);
14103 fold_checksum_tree (fn, &ctx, ht);
14104 md5_finish_ctx (&ctx, checksum_after_fn);
14107 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
14108 fold_check_failed (fn, tem);
14110 md5_init_ctx (&ctx);
14111 for (i = 0; i < nargs; i++)
14112 fold_checksum_tree (argarray[i], &ctx, ht);
14113 md5_finish_ctx (&ctx, checksum_after_arglist);
14116 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
14117 fold_check_failed (NULL_TREE, tem);
14122 /* Perform constant folding and related simplification of initializer
14123 expression EXPR. These behave identically to "fold_buildN" but ignore
14124 potential run-time traps and exceptions that fold must preserve. */
14126 #define START_FOLD_INIT \
14127 int saved_signaling_nans = flag_signaling_nans;\
14128 int saved_trapping_math = flag_trapping_math;\
14129 int saved_rounding_math = flag_rounding_math;\
14130 int saved_trapv = flag_trapv;\
14131 int saved_folding_initializer = folding_initializer;\
14132 flag_signaling_nans = 0;\
14133 flag_trapping_math = 0;\
14134 flag_rounding_math = 0;\
14136 folding_initializer = 1;
14138 #define END_FOLD_INIT \
14139 flag_signaling_nans = saved_signaling_nans;\
14140 flag_trapping_math = saved_trapping_math;\
14141 flag_rounding_math = saved_rounding_math;\
14142 flag_trapv = saved_trapv;\
14143 folding_initializer = saved_folding_initializer;
14146 fold_build1_initializer (enum tree_code code, tree type, tree op)
14151 result = fold_build1 (code, type, op);
14158 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
14163 result = fold_build2 (code, type, op0, op1);
14170 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
14176 result = fold_build3 (code, type, op0, op1, op2);
14183 fold_build_call_array_initializer (tree type, tree fn,
14184 int nargs, tree *argarray)
14189 result = fold_build_call_array (type, fn, nargs, argarray);
14195 #undef START_FOLD_INIT
14196 #undef END_FOLD_INIT
14198 /* Determine if first argument is a multiple of second argument. Return 0 if
14199 it is not, or we cannot easily determined it to be.
14201 An example of the sort of thing we care about (at this point; this routine
14202 could surely be made more general, and expanded to do what the *_DIV_EXPR's
14203 fold cases do now) is discovering that
14205 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
14211 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
14213 This code also handles discovering that
14215 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
14217 is a multiple of 8 so we don't have to worry about dealing with a
14218 possible remainder.
14220 Note that we *look* inside a SAVE_EXPR only to determine how it was
14221 calculated; it is not safe for fold to do much of anything else with the
14222 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
14223 at run time. For example, the latter example above *cannot* be implemented
14224 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
14225 evaluation time of the original SAVE_EXPR is not necessarily the same at
14226 the time the new expression is evaluated. The only optimization of this
14227 sort that would be valid is changing
14229 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
14233 SAVE_EXPR (I) * SAVE_EXPR (J)
14235 (where the same SAVE_EXPR (J) is used in the original and the
14236 transformed version). */
14239 multiple_of_p (tree type, const_tree top, const_tree bottom)
14241 if (operand_equal_p (top, bottom, 0))
14244 if (TREE_CODE (type) != INTEGER_TYPE)
14247 switch (TREE_CODE (top))
14250 /* Bitwise and provides a power of two multiple. If the mask is
14251 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
14252 if (!integer_pow2p (bottom))
14257 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
14258 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
14262 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
14263 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
14266 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
14270 op1 = TREE_OPERAND (top, 1);
14271 /* const_binop may not detect overflow correctly,
14272 so check for it explicitly here. */
14273 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
14274 > TREE_INT_CST_LOW (op1)
14275 && TREE_INT_CST_HIGH (op1) == 0
14276 && 0 != (t1 = fold_convert (type,
14277 const_binop (LSHIFT_EXPR,
14280 && !TREE_OVERFLOW (t1))
14281 return multiple_of_p (type, t1, bottom);
14286 /* Can't handle conversions from non-integral or wider integral type. */
14287 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
14288 || (TYPE_PRECISION (type)
14289 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
14292 /* .. fall through ... */
14295 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
14298 if (TREE_CODE (bottom) != INTEGER_CST
14299 || integer_zerop (bottom)
14300 || (TYPE_UNSIGNED (type)
14301 && (tree_int_cst_sgn (top) < 0
14302 || tree_int_cst_sgn (bottom) < 0)))
14304 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
14312 /* Return true if CODE or TYPE is known to be non-negative. */
14315 tree_simple_nonnegative_warnv_p (enum tree_code code, tree type)
14317 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
14318 && truth_value_p (code))
14319 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
14320 have a signed:1 type (where the value is -1 and 0). */
14325 /* Return true if (CODE OP0) is known to be non-negative. If the return
14326 value is based on the assumption that signed overflow is undefined,
14327 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14328 *STRICT_OVERFLOW_P. */
14331 tree_unary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
14332 bool *strict_overflow_p)
14334 if (TYPE_UNSIGNED (type))
14340 /* We can't return 1 if flag_wrapv is set because
14341 ABS_EXPR<INT_MIN> = INT_MIN. */
14342 if (!INTEGRAL_TYPE_P (type))
14344 if (TYPE_OVERFLOW_UNDEFINED (type))
14346 *strict_overflow_p = true;
14351 case NON_LVALUE_EXPR:
14353 case FIX_TRUNC_EXPR:
14354 return tree_expr_nonnegative_warnv_p (op0,
14355 strict_overflow_p);
14359 tree inner_type = TREE_TYPE (op0);
14360 tree outer_type = type;
14362 if (TREE_CODE (outer_type) == REAL_TYPE)
14364 if (TREE_CODE (inner_type) == REAL_TYPE)
14365 return tree_expr_nonnegative_warnv_p (op0,
14366 strict_overflow_p);
14367 if (TREE_CODE (inner_type) == INTEGER_TYPE)
14369 if (TYPE_UNSIGNED (inner_type))
14371 return tree_expr_nonnegative_warnv_p (op0,
14372 strict_overflow_p);
14375 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
14377 if (TREE_CODE (inner_type) == REAL_TYPE)
14378 return tree_expr_nonnegative_warnv_p (op0,
14379 strict_overflow_p);
14380 if (TREE_CODE (inner_type) == INTEGER_TYPE)
14381 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
14382 && TYPE_UNSIGNED (inner_type);
14388 return tree_simple_nonnegative_warnv_p (code, type);
14391 /* We don't know sign of `t', so be conservative and return false. */
14395 /* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
14396 value is based on the assumption that signed overflow is undefined,
14397 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14398 *STRICT_OVERFLOW_P. */
14401 tree_binary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
14402 tree op1, bool *strict_overflow_p)
14404 if (TYPE_UNSIGNED (type))
14409 case POINTER_PLUS_EXPR:
14411 if (FLOAT_TYPE_P (type))
14412 return (tree_expr_nonnegative_warnv_p (op0,
14414 && tree_expr_nonnegative_warnv_p (op1,
14415 strict_overflow_p));
14417 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
14418 both unsigned and at least 2 bits shorter than the result. */
14419 if (TREE_CODE (type) == INTEGER_TYPE
14420 && TREE_CODE (op0) == NOP_EXPR
14421 && TREE_CODE (op1) == NOP_EXPR)
14423 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
14424 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
14425 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
14426 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
14428 unsigned int prec = MAX (TYPE_PRECISION (inner1),
14429 TYPE_PRECISION (inner2)) + 1;
14430 return prec < TYPE_PRECISION (type);
14436 if (FLOAT_TYPE_P (type))
14438 /* x * x for floating point x is always non-negative. */
14439 if (operand_equal_p (op0, op1, 0))
14441 return (tree_expr_nonnegative_warnv_p (op0,
14443 && tree_expr_nonnegative_warnv_p (op1,
14444 strict_overflow_p));
14447 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
14448 both unsigned and their total bits is shorter than the result. */
14449 if (TREE_CODE (type) == INTEGER_TYPE
14450 && (TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == INTEGER_CST)
14451 && (TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == INTEGER_CST))
14453 tree inner0 = (TREE_CODE (op0) == NOP_EXPR)
14454 ? TREE_TYPE (TREE_OPERAND (op0, 0))
14456 tree inner1 = (TREE_CODE (op1) == NOP_EXPR)
14457 ? TREE_TYPE (TREE_OPERAND (op1, 0))
14460 bool unsigned0 = TYPE_UNSIGNED (inner0);
14461 bool unsigned1 = TYPE_UNSIGNED (inner1);
14463 if (TREE_CODE (op0) == INTEGER_CST)
14464 unsigned0 = unsigned0 || tree_int_cst_sgn (op0) >= 0;
14466 if (TREE_CODE (op1) == INTEGER_CST)
14467 unsigned1 = unsigned1 || tree_int_cst_sgn (op1) >= 0;
14469 if (TREE_CODE (inner0) == INTEGER_TYPE && unsigned0
14470 && TREE_CODE (inner1) == INTEGER_TYPE && unsigned1)
14472 unsigned int precision0 = (TREE_CODE (op0) == INTEGER_CST)
14473 ? tree_int_cst_min_precision (op0, /*unsignedp=*/true)
14474 : TYPE_PRECISION (inner0);
14476 unsigned int precision1 = (TREE_CODE (op1) == INTEGER_CST)
14477 ? tree_int_cst_min_precision (op1, /*unsignedp=*/true)
14478 : TYPE_PRECISION (inner1);
14480 return precision0 + precision1 < TYPE_PRECISION (type);
14487 return (tree_expr_nonnegative_warnv_p (op0,
14489 || tree_expr_nonnegative_warnv_p (op1,
14490 strict_overflow_p));
14496 case TRUNC_DIV_EXPR:
14497 case CEIL_DIV_EXPR:
14498 case FLOOR_DIV_EXPR:
14499 case ROUND_DIV_EXPR:
14500 return (tree_expr_nonnegative_warnv_p (op0,
14502 && tree_expr_nonnegative_warnv_p (op1,
14503 strict_overflow_p));
14505 case TRUNC_MOD_EXPR:
14506 case CEIL_MOD_EXPR:
14507 case FLOOR_MOD_EXPR:
14508 case ROUND_MOD_EXPR:
14509 return tree_expr_nonnegative_warnv_p (op0,
14510 strict_overflow_p);
14512 return tree_simple_nonnegative_warnv_p (code, type);
14515 /* We don't know sign of `t', so be conservative and return false. */
14519 /* Return true if T is known to be non-negative. If the return
14520 value is based on the assumption that signed overflow is undefined,
14521 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14522 *STRICT_OVERFLOW_P. */
14525 tree_single_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14527 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14530 switch (TREE_CODE (t))
14533 return tree_int_cst_sgn (t) >= 0;
14536 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
14539 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
14542 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14544 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
14545 strict_overflow_p));
14547 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14550 /* We don't know sign of `t', so be conservative and return false. */
14554 /* Return true if T is known to be non-negative. If the return
14555 value is based on the assumption that signed overflow is undefined,
14556 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14557 *STRICT_OVERFLOW_P. */
14560 tree_call_nonnegative_warnv_p (tree type, tree fndecl,
14561 tree arg0, tree arg1, bool *strict_overflow_p)
14563 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
14564 switch (DECL_FUNCTION_CODE (fndecl))
14566 CASE_FLT_FN (BUILT_IN_ACOS):
14567 CASE_FLT_FN (BUILT_IN_ACOSH):
14568 CASE_FLT_FN (BUILT_IN_CABS):
14569 CASE_FLT_FN (BUILT_IN_COSH):
14570 CASE_FLT_FN (BUILT_IN_ERFC):
14571 CASE_FLT_FN (BUILT_IN_EXP):
14572 CASE_FLT_FN (BUILT_IN_EXP10):
14573 CASE_FLT_FN (BUILT_IN_EXP2):
14574 CASE_FLT_FN (BUILT_IN_FABS):
14575 CASE_FLT_FN (BUILT_IN_FDIM):
14576 CASE_FLT_FN (BUILT_IN_HYPOT):
14577 CASE_FLT_FN (BUILT_IN_POW10):
14578 CASE_INT_FN (BUILT_IN_FFS):
14579 CASE_INT_FN (BUILT_IN_PARITY):
14580 CASE_INT_FN (BUILT_IN_POPCOUNT):
14581 case BUILT_IN_BSWAP32:
14582 case BUILT_IN_BSWAP64:
14586 CASE_FLT_FN (BUILT_IN_SQRT):
14587 /* sqrt(-0.0) is -0.0. */
14588 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
14590 return tree_expr_nonnegative_warnv_p (arg0,
14591 strict_overflow_p);
14593 CASE_FLT_FN (BUILT_IN_ASINH):
14594 CASE_FLT_FN (BUILT_IN_ATAN):
14595 CASE_FLT_FN (BUILT_IN_ATANH):
14596 CASE_FLT_FN (BUILT_IN_CBRT):
14597 CASE_FLT_FN (BUILT_IN_CEIL):
14598 CASE_FLT_FN (BUILT_IN_ERF):
14599 CASE_FLT_FN (BUILT_IN_EXPM1):
14600 CASE_FLT_FN (BUILT_IN_FLOOR):
14601 CASE_FLT_FN (BUILT_IN_FMOD):
14602 CASE_FLT_FN (BUILT_IN_FREXP):
14603 CASE_FLT_FN (BUILT_IN_LCEIL):
14604 CASE_FLT_FN (BUILT_IN_LDEXP):
14605 CASE_FLT_FN (BUILT_IN_LFLOOR):
14606 CASE_FLT_FN (BUILT_IN_LLCEIL):
14607 CASE_FLT_FN (BUILT_IN_LLFLOOR):
14608 CASE_FLT_FN (BUILT_IN_LLRINT):
14609 CASE_FLT_FN (BUILT_IN_LLROUND):
14610 CASE_FLT_FN (BUILT_IN_LRINT):
14611 CASE_FLT_FN (BUILT_IN_LROUND):
14612 CASE_FLT_FN (BUILT_IN_MODF):
14613 CASE_FLT_FN (BUILT_IN_NEARBYINT):
14614 CASE_FLT_FN (BUILT_IN_RINT):
14615 CASE_FLT_FN (BUILT_IN_ROUND):
14616 CASE_FLT_FN (BUILT_IN_SCALB):
14617 CASE_FLT_FN (BUILT_IN_SCALBLN):
14618 CASE_FLT_FN (BUILT_IN_SCALBN):
14619 CASE_FLT_FN (BUILT_IN_SIGNBIT):
14620 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
14621 CASE_FLT_FN (BUILT_IN_SINH):
14622 CASE_FLT_FN (BUILT_IN_TANH):
14623 CASE_FLT_FN (BUILT_IN_TRUNC):
14624 /* True if the 1st argument is nonnegative. */
14625 return tree_expr_nonnegative_warnv_p (arg0,
14626 strict_overflow_p);
14628 CASE_FLT_FN (BUILT_IN_FMAX):
14629 /* True if the 1st OR 2nd arguments are nonnegative. */
14630 return (tree_expr_nonnegative_warnv_p (arg0,
14632 || (tree_expr_nonnegative_warnv_p (arg1,
14633 strict_overflow_p)));
14635 CASE_FLT_FN (BUILT_IN_FMIN):
14636 /* True if the 1st AND 2nd arguments are nonnegative. */
14637 return (tree_expr_nonnegative_warnv_p (arg0,
14639 && (tree_expr_nonnegative_warnv_p (arg1,
14640 strict_overflow_p)));
14642 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14643 /* True if the 2nd argument is nonnegative. */
14644 return tree_expr_nonnegative_warnv_p (arg1,
14645 strict_overflow_p);
14647 CASE_FLT_FN (BUILT_IN_POWI):
14648 /* True if the 1st argument is nonnegative or the second
14649 argument is an even integer. */
14650 if (TREE_CODE (arg1) == INTEGER_CST
14651 && (TREE_INT_CST_LOW (arg1) & 1) == 0)
14653 return tree_expr_nonnegative_warnv_p (arg0,
14654 strict_overflow_p);
14656 CASE_FLT_FN (BUILT_IN_POW):
14657 /* True if the 1st argument is nonnegative or the second
14658 argument is an even integer valued real. */
14659 if (TREE_CODE (arg1) == REAL_CST)
14664 c = TREE_REAL_CST (arg1);
14665 n = real_to_integer (&c);
14668 REAL_VALUE_TYPE cint;
14669 real_from_integer (&cint, VOIDmode, n,
14670 n < 0 ? -1 : 0, 0);
14671 if (real_identical (&c, &cint))
14675 return tree_expr_nonnegative_warnv_p (arg0,
14676 strict_overflow_p);
14681 return tree_simple_nonnegative_warnv_p (CALL_EXPR,
14685 /* Return true if T is known to be non-negative. If the return
14686 value is based on the assumption that signed overflow is undefined,
14687 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14688 *STRICT_OVERFLOW_P. */
14691 tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14693 enum tree_code code = TREE_CODE (t);
14694 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14701 tree temp = TARGET_EXPR_SLOT (t);
14702 t = TARGET_EXPR_INITIAL (t);
14704 /* If the initializer is non-void, then it's a normal expression
14705 that will be assigned to the slot. */
14706 if (!VOID_TYPE_P (t))
14707 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
14709 /* Otherwise, the initializer sets the slot in some way. One common
14710 way is an assignment statement at the end of the initializer. */
14713 if (TREE_CODE (t) == BIND_EXPR)
14714 t = expr_last (BIND_EXPR_BODY (t));
14715 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
14716 || TREE_CODE (t) == TRY_CATCH_EXPR)
14717 t = expr_last (TREE_OPERAND (t, 0));
14718 else if (TREE_CODE (t) == STATEMENT_LIST)
14723 if (TREE_CODE (t) == MODIFY_EXPR
14724 && TREE_OPERAND (t, 0) == temp)
14725 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14726 strict_overflow_p);
14733 tree arg0 = call_expr_nargs (t) > 0 ? CALL_EXPR_ARG (t, 0) : NULL_TREE;
14734 tree arg1 = call_expr_nargs (t) > 1 ? CALL_EXPR_ARG (t, 1) : NULL_TREE;
14736 return tree_call_nonnegative_warnv_p (TREE_TYPE (t),
14737 get_callee_fndecl (t),
14740 strict_overflow_p);
14742 case COMPOUND_EXPR:
14744 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14745 strict_overflow_p);
14747 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
14748 strict_overflow_p);
14750 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14751 strict_overflow_p);
14754 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14758 /* We don't know sign of `t', so be conservative and return false. */
14762 /* Return true if T is known to be non-negative. If the return
14763 value is based on the assumption that signed overflow is undefined,
14764 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14765 *STRICT_OVERFLOW_P. */
14768 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14770 enum tree_code code;
14771 if (t == error_mark_node)
14774 code = TREE_CODE (t);
14775 switch (TREE_CODE_CLASS (code))
14778 case tcc_comparison:
14779 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14781 TREE_OPERAND (t, 0),
14782 TREE_OPERAND (t, 1),
14783 strict_overflow_p);
14786 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14788 TREE_OPERAND (t, 0),
14789 strict_overflow_p);
14792 case tcc_declaration:
14793 case tcc_reference:
14794 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14802 case TRUTH_AND_EXPR:
14803 case TRUTH_OR_EXPR:
14804 case TRUTH_XOR_EXPR:
14805 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14807 TREE_OPERAND (t, 0),
14808 TREE_OPERAND (t, 1),
14809 strict_overflow_p);
14810 case TRUTH_NOT_EXPR:
14811 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14813 TREE_OPERAND (t, 0),
14814 strict_overflow_p);
14821 case WITH_SIZE_EXPR:
14825 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14828 return tree_invalid_nonnegative_warnv_p (t, strict_overflow_p);
14832 /* Return true if `t' is known to be non-negative. Handle warnings
14833 about undefined signed overflow. */
14836 tree_expr_nonnegative_p (tree t)
14838 bool ret, strict_overflow_p;
14840 strict_overflow_p = false;
14841 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
14842 if (strict_overflow_p)
14843 fold_overflow_warning (("assuming signed overflow does not occur when "
14844 "determining that expression is always "
14846 WARN_STRICT_OVERFLOW_MISC);
14851 /* Return true when (CODE OP0) is an address and is known to be nonzero.
14852 For floating point we further ensure that T is not denormal.
14853 Similar logic is present in nonzero_address in rtlanal.h.
14855 If the return value is based on the assumption that signed overflow
14856 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14857 change *STRICT_OVERFLOW_P. */
14860 tree_unary_nonzero_warnv_p (enum tree_code code, tree type, tree op0,
14861 bool *strict_overflow_p)
14866 return tree_expr_nonzero_warnv_p (op0,
14867 strict_overflow_p);
14871 tree inner_type = TREE_TYPE (op0);
14872 tree outer_type = type;
14874 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
14875 && tree_expr_nonzero_warnv_p (op0,
14876 strict_overflow_p));
14880 case NON_LVALUE_EXPR:
14881 return tree_expr_nonzero_warnv_p (op0,
14882 strict_overflow_p);
14891 /* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
14892 For floating point we further ensure that T is not denormal.
14893 Similar logic is present in nonzero_address in rtlanal.h.
14895 If the return value is based on the assumption that signed overflow
14896 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14897 change *STRICT_OVERFLOW_P. */
14900 tree_binary_nonzero_warnv_p (enum tree_code code,
14903 tree op1, bool *strict_overflow_p)
14905 bool sub_strict_overflow_p;
14908 case POINTER_PLUS_EXPR:
14910 if (TYPE_OVERFLOW_UNDEFINED (type))
14912 /* With the presence of negative values it is hard
14913 to say something. */
14914 sub_strict_overflow_p = false;
14915 if (!tree_expr_nonnegative_warnv_p (op0,
14916 &sub_strict_overflow_p)
14917 || !tree_expr_nonnegative_warnv_p (op1,
14918 &sub_strict_overflow_p))
14920 /* One of operands must be positive and the other non-negative. */
14921 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14922 overflows, on a twos-complement machine the sum of two
14923 nonnegative numbers can never be zero. */
14924 return (tree_expr_nonzero_warnv_p (op0,
14926 || tree_expr_nonzero_warnv_p (op1,
14927 strict_overflow_p));
14932 if (TYPE_OVERFLOW_UNDEFINED (type))
14934 if (tree_expr_nonzero_warnv_p (op0,
14936 && tree_expr_nonzero_warnv_p (op1,
14937 strict_overflow_p))
14939 *strict_overflow_p = true;
14946 sub_strict_overflow_p = false;
14947 if (tree_expr_nonzero_warnv_p (op0,
14948 &sub_strict_overflow_p)
14949 && tree_expr_nonzero_warnv_p (op1,
14950 &sub_strict_overflow_p))
14952 if (sub_strict_overflow_p)
14953 *strict_overflow_p = true;
14958 sub_strict_overflow_p = false;
14959 if (tree_expr_nonzero_warnv_p (op0,
14960 &sub_strict_overflow_p))
14962 if (sub_strict_overflow_p)
14963 *strict_overflow_p = true;
14965 /* When both operands are nonzero, then MAX must be too. */
14966 if (tree_expr_nonzero_warnv_p (op1,
14967 strict_overflow_p))
14970 /* MAX where operand 0 is positive is positive. */
14971 return tree_expr_nonnegative_warnv_p (op0,
14972 strict_overflow_p);
14974 /* MAX where operand 1 is positive is positive. */
14975 else if (tree_expr_nonzero_warnv_p (op1,
14976 &sub_strict_overflow_p)
14977 && tree_expr_nonnegative_warnv_p (op1,
14978 &sub_strict_overflow_p))
14980 if (sub_strict_overflow_p)
14981 *strict_overflow_p = true;
14987 return (tree_expr_nonzero_warnv_p (op1,
14989 || tree_expr_nonzero_warnv_p (op0,
14990 strict_overflow_p));
14999 /* Return true when T is an address and is known to be nonzero.
15000 For floating point we further ensure that T is not denormal.
15001 Similar logic is present in nonzero_address in rtlanal.h.
15003 If the return value is based on the assumption that signed overflow
15004 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
15005 change *STRICT_OVERFLOW_P. */
15008 tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
15010 bool sub_strict_overflow_p;
15011 switch (TREE_CODE (t))
15014 return !integer_zerop (t);
15018 tree base = get_base_address (TREE_OPERAND (t, 0));
15023 /* Weak declarations may link to NULL. Other things may also be NULL
15024 so protect with -fdelete-null-pointer-checks; but not variables
15025 allocated on the stack. */
15027 && (flag_delete_null_pointer_checks
15028 || (TREE_CODE (base) == VAR_DECL && !TREE_STATIC (base))))
15029 return !VAR_OR_FUNCTION_DECL_P (base) || !DECL_WEAK (base);
15031 /* Constants are never weak. */
15032 if (CONSTANT_CLASS_P (base))
15039 sub_strict_overflow_p = false;
15040 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
15041 &sub_strict_overflow_p)
15042 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
15043 &sub_strict_overflow_p))
15045 if (sub_strict_overflow_p)
15046 *strict_overflow_p = true;
15057 /* Return true when T is an address and is known to be nonzero.
15058 For floating point we further ensure that T is not denormal.
15059 Similar logic is present in nonzero_address in rtlanal.h.
15061 If the return value is based on the assumption that signed overflow
15062 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
15063 change *STRICT_OVERFLOW_P. */
15066 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
15068 tree type = TREE_TYPE (t);
15069 enum tree_code code;
15071 /* Doing something useful for floating point would need more work. */
15072 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
15075 code = TREE_CODE (t);
15076 switch (TREE_CODE_CLASS (code))
15079 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
15080 strict_overflow_p);
15082 case tcc_comparison:
15083 return tree_binary_nonzero_warnv_p (code, type,
15084 TREE_OPERAND (t, 0),
15085 TREE_OPERAND (t, 1),
15086 strict_overflow_p);
15088 case tcc_declaration:
15089 case tcc_reference:
15090 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
15098 case TRUTH_NOT_EXPR:
15099 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
15100 strict_overflow_p);
15102 case TRUTH_AND_EXPR:
15103 case TRUTH_OR_EXPR:
15104 case TRUTH_XOR_EXPR:
15105 return tree_binary_nonzero_warnv_p (code, type,
15106 TREE_OPERAND (t, 0),
15107 TREE_OPERAND (t, 1),
15108 strict_overflow_p);
15115 case WITH_SIZE_EXPR:
15119 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
15121 case COMPOUND_EXPR:
15124 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
15125 strict_overflow_p);
15128 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
15129 strict_overflow_p);
15132 return alloca_call_p (t);
15140 /* Return true when T is an address and is known to be nonzero.
15141 Handle warnings about undefined signed overflow. */
15144 tree_expr_nonzero_p (tree t)
15146 bool ret, strict_overflow_p;
15148 strict_overflow_p = false;
15149 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
15150 if (strict_overflow_p)
15151 fold_overflow_warning (("assuming signed overflow does not occur when "
15152 "determining that expression is always "
15154 WARN_STRICT_OVERFLOW_MISC);
15158 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
15159 attempt to fold the expression to a constant without modifying TYPE,
15162 If the expression could be simplified to a constant, then return
15163 the constant. If the expression would not be simplified to a
15164 constant, then return NULL_TREE. */
15167 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
15169 tree tem = fold_binary (code, type, op0, op1);
15170 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
15173 /* Given the components of a unary expression CODE, TYPE and OP0,
15174 attempt to fold the expression to a constant without modifying
15177 If the expression could be simplified to a constant, then return
15178 the constant. If the expression would not be simplified to a
15179 constant, then return NULL_TREE. */
15182 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
15184 tree tem = fold_unary (code, type, op0);
15185 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
15188 /* If EXP represents referencing an element in a constant string
15189 (either via pointer arithmetic or array indexing), return the
15190 tree representing the value accessed, otherwise return NULL. */
15193 fold_read_from_constant_string (tree exp)
15195 if ((TREE_CODE (exp) == INDIRECT_REF
15196 || TREE_CODE (exp) == ARRAY_REF)
15197 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
15199 tree exp1 = TREE_OPERAND (exp, 0);
15203 if (TREE_CODE (exp) == INDIRECT_REF)
15204 string = string_constant (exp1, &index);
15207 tree low_bound = array_ref_low_bound (exp);
15208 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
15210 /* Optimize the special-case of a zero lower bound.
15212 We convert the low_bound to sizetype to avoid some problems
15213 with constant folding. (E.g. suppose the lower bound is 1,
15214 and its mode is QI. Without the conversion,l (ARRAY
15215 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
15216 +INDEX), which becomes (ARRAY+255+INDEX). Oops!) */
15217 if (! integer_zerop (low_bound))
15218 index = size_diffop (index, fold_convert (sizetype, low_bound));
15224 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
15225 && TREE_CODE (string) == STRING_CST
15226 && TREE_CODE (index) == INTEGER_CST
15227 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
15228 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
15230 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
15231 return build_int_cst_type (TREE_TYPE (exp),
15232 (TREE_STRING_POINTER (string)
15233 [TREE_INT_CST_LOW (index)]));
15238 /* Return the tree for neg (ARG0) when ARG0 is known to be either
15239 an integer constant, real, or fixed-point constant.
15241 TYPE is the type of the result. */
15244 fold_negate_const (tree arg0, tree type)
15246 tree t = NULL_TREE;
15248 switch (TREE_CODE (arg0))
15252 unsigned HOST_WIDE_INT low;
15253 HOST_WIDE_INT high;
15254 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
15255 TREE_INT_CST_HIGH (arg0),
15257 t = force_fit_type_double (type, low, high, 1,
15258 (overflow | TREE_OVERFLOW (arg0))
15259 && !TYPE_UNSIGNED (type));
15264 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
15269 FIXED_VALUE_TYPE f;
15270 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
15271 &(TREE_FIXED_CST (arg0)), NULL,
15272 TYPE_SATURATING (type));
15273 t = build_fixed (type, f);
15274 /* Propagate overflow flags. */
15275 if (overflow_p | TREE_OVERFLOW (arg0))
15276 TREE_OVERFLOW (t) = 1;
15281 gcc_unreachable ();
15287 /* Return the tree for abs (ARG0) when ARG0 is known to be either
15288 an integer constant or real constant.
15290 TYPE is the type of the result. */
15293 fold_abs_const (tree arg0, tree type)
15295 tree t = NULL_TREE;
15297 switch (TREE_CODE (arg0))
15300 /* If the value is unsigned, then the absolute value is
15301 the same as the ordinary value. */
15302 if (TYPE_UNSIGNED (type))
15304 /* Similarly, if the value is non-negative. */
15305 else if (INT_CST_LT (integer_minus_one_node, arg0))
15307 /* If the value is negative, then the absolute value is
15311 unsigned HOST_WIDE_INT low;
15312 HOST_WIDE_INT high;
15313 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
15314 TREE_INT_CST_HIGH (arg0),
15316 t = force_fit_type_double (type, low, high, -1,
15317 overflow | TREE_OVERFLOW (arg0));
15322 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
15323 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
15329 gcc_unreachable ();
15335 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
15336 constant. TYPE is the type of the result. */
15339 fold_not_const (tree arg0, tree type)
15341 tree t = NULL_TREE;
15343 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
15345 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
15346 ~TREE_INT_CST_HIGH (arg0), 0,
15347 TREE_OVERFLOW (arg0));
15352 /* Given CODE, a relational operator, the target type, TYPE and two
15353 constant operands OP0 and OP1, return the result of the
15354 relational operation. If the result is not a compile time
15355 constant, then return NULL_TREE. */
15358 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
15360 int result, invert;
15362 /* From here on, the only cases we handle are when the result is
15363 known to be a constant. */
15365 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
15367 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
15368 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
15370 /* Handle the cases where either operand is a NaN. */
15371 if (real_isnan (c0) || real_isnan (c1))
15381 case UNORDERED_EXPR:
15395 if (flag_trapping_math)
15401 gcc_unreachable ();
15404 return constant_boolean_node (result, type);
15407 return constant_boolean_node (real_compare (code, c0, c1), type);
15410 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
15412 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
15413 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
15414 return constant_boolean_node (fixed_compare (code, c0, c1), type);
15417 /* Handle equality/inequality of complex constants. */
15418 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
15420 tree rcond = fold_relational_const (code, type,
15421 TREE_REALPART (op0),
15422 TREE_REALPART (op1));
15423 tree icond = fold_relational_const (code, type,
15424 TREE_IMAGPART (op0),
15425 TREE_IMAGPART (op1));
15426 if (code == EQ_EXPR)
15427 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
15428 else if (code == NE_EXPR)
15429 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
15434 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
15436 To compute GT, swap the arguments and do LT.
15437 To compute GE, do LT and invert the result.
15438 To compute LE, swap the arguments, do LT and invert the result.
15439 To compute NE, do EQ and invert the result.
15441 Therefore, the code below must handle only EQ and LT. */
15443 if (code == LE_EXPR || code == GT_EXPR)
15448 code = swap_tree_comparison (code);
15451 /* Note that it is safe to invert for real values here because we
15452 have already handled the one case that it matters. */
15455 if (code == NE_EXPR || code == GE_EXPR)
15458 code = invert_tree_comparison (code, false);
15461 /* Compute a result for LT or EQ if args permit;
15462 Otherwise return T. */
15463 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
15465 if (code == EQ_EXPR)
15466 result = tree_int_cst_equal (op0, op1);
15467 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
15468 result = INT_CST_LT_UNSIGNED (op0, op1);
15470 result = INT_CST_LT (op0, op1);
15477 return constant_boolean_node (result, type);
15480 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
15481 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
15485 fold_build_cleanup_point_expr (tree type, tree expr)
15487 /* If the expression does not have side effects then we don't have to wrap
15488 it with a cleanup point expression. */
15489 if (!TREE_SIDE_EFFECTS (expr))
15492 /* If the expression is a return, check to see if the expression inside the
15493 return has no side effects or the right hand side of the modify expression
15494 inside the return. If either don't have side effects set we don't need to
15495 wrap the expression in a cleanup point expression. Note we don't check the
15496 left hand side of the modify because it should always be a return decl. */
15497 if (TREE_CODE (expr) == RETURN_EXPR)
15499 tree op = TREE_OPERAND (expr, 0);
15500 if (!op || !TREE_SIDE_EFFECTS (op))
15502 op = TREE_OPERAND (op, 1);
15503 if (!TREE_SIDE_EFFECTS (op))
15507 return build1 (CLEANUP_POINT_EXPR, type, expr);
15510 /* Given a pointer value OP0 and a type TYPE, return a simplified version
15511 of an indirection through OP0, or NULL_TREE if no simplification is
15515 fold_indirect_ref_1 (tree type, tree op0)
15521 subtype = TREE_TYPE (sub);
15522 if (!POINTER_TYPE_P (subtype))
15525 if (TREE_CODE (sub) == ADDR_EXPR)
15527 tree op = TREE_OPERAND (sub, 0);
15528 tree optype = TREE_TYPE (op);
15529 /* *&CONST_DECL -> to the value of the const decl. */
15530 if (TREE_CODE (op) == CONST_DECL)
15531 return DECL_INITIAL (op);
15532 /* *&p => p; make sure to handle *&"str"[cst] here. */
15533 if (type == optype)
15535 tree fop = fold_read_from_constant_string (op);
15541 /* *(foo *)&fooarray => fooarray[0] */
15542 else if (TREE_CODE (optype) == ARRAY_TYPE
15543 && type == TREE_TYPE (optype))
15545 tree type_domain = TYPE_DOMAIN (optype);
15546 tree min_val = size_zero_node;
15547 if (type_domain && TYPE_MIN_VALUE (type_domain))
15548 min_val = TYPE_MIN_VALUE (type_domain);
15549 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
15551 /* *(foo *)&complexfoo => __real__ complexfoo */
15552 else if (TREE_CODE (optype) == COMPLEX_TYPE
15553 && type == TREE_TYPE (optype))
15554 return fold_build1 (REALPART_EXPR, type, op);
15555 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
15556 else if (TREE_CODE (optype) == VECTOR_TYPE
15557 && type == TREE_TYPE (optype))
15559 tree part_width = TYPE_SIZE (type);
15560 tree index = bitsize_int (0);
15561 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
15565 /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
15566 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15567 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15569 tree op00 = TREE_OPERAND (sub, 0);
15570 tree op01 = TREE_OPERAND (sub, 1);
15574 op00type = TREE_TYPE (op00);
15575 if (TREE_CODE (op00) == ADDR_EXPR
15576 && TREE_CODE (TREE_TYPE (op00type)) == VECTOR_TYPE
15577 && type == TREE_TYPE (TREE_TYPE (op00type)))
15579 HOST_WIDE_INT offset = tree_low_cst (op01, 0);
15580 tree part_width = TYPE_SIZE (type);
15581 unsigned HOST_WIDE_INT part_widthi = tree_low_cst (part_width, 0)/BITS_PER_UNIT;
15582 unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
15583 tree index = bitsize_int (indexi);
15585 if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (op00type)))
15586 return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (op00, 0),
15587 part_width, index);
15593 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
15594 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15595 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15597 tree op00 = TREE_OPERAND (sub, 0);
15598 tree op01 = TREE_OPERAND (sub, 1);
15602 op00type = TREE_TYPE (op00);
15603 if (TREE_CODE (op00) == ADDR_EXPR
15604 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
15605 && type == TREE_TYPE (TREE_TYPE (op00type)))
15607 tree size = TYPE_SIZE_UNIT (type);
15608 if (tree_int_cst_equal (size, op01))
15609 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
15613 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
15614 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
15615 && type == TREE_TYPE (TREE_TYPE (subtype)))
15618 tree min_val = size_zero_node;
15619 sub = build_fold_indirect_ref (sub);
15620 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
15621 if (type_domain && TYPE_MIN_VALUE (type_domain))
15622 min_val = TYPE_MIN_VALUE (type_domain);
15623 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
15629 /* Builds an expression for an indirection through T, simplifying some
15633 build_fold_indirect_ref (tree t)
15635 tree type = TREE_TYPE (TREE_TYPE (t));
15636 tree sub = fold_indirect_ref_1 (type, t);
15641 return build1 (INDIRECT_REF, type, t);
15644 /* Given an INDIRECT_REF T, return either T or a simplified version. */
15647 fold_indirect_ref (tree t)
15649 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
15657 /* Strip non-trapping, non-side-effecting tree nodes from an expression
15658 whose result is ignored. The type of the returned tree need not be
15659 the same as the original expression. */
15662 fold_ignored_result (tree t)
15664 if (!TREE_SIDE_EFFECTS (t))
15665 return integer_zero_node;
15668 switch (TREE_CODE_CLASS (TREE_CODE (t)))
15671 t = TREE_OPERAND (t, 0);
15675 case tcc_comparison:
15676 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15677 t = TREE_OPERAND (t, 0);
15678 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
15679 t = TREE_OPERAND (t, 1);
15684 case tcc_expression:
15685 switch (TREE_CODE (t))
15687 case COMPOUND_EXPR:
15688 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15690 t = TREE_OPERAND (t, 0);
15694 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
15695 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
15697 t = TREE_OPERAND (t, 0);
15710 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
15711 This can only be applied to objects of a sizetype. */
15714 round_up (tree value, int divisor)
15716 tree div = NULL_TREE;
15718 gcc_assert (divisor > 0);
15722 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15723 have to do anything. Only do this when we are not given a const,
15724 because in that case, this check is more expensive than just
15726 if (TREE_CODE (value) != INTEGER_CST)
15728 div = build_int_cst (TREE_TYPE (value), divisor);
15730 if (multiple_of_p (TREE_TYPE (value), value, div))
15734 /* If divisor is a power of two, simplify this to bit manipulation. */
15735 if (divisor == (divisor & -divisor))
15737 if (TREE_CODE (value) == INTEGER_CST)
15739 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
15740 unsigned HOST_WIDE_INT high;
15743 if ((low & (divisor - 1)) == 0)
15746 overflow_p = TREE_OVERFLOW (value);
15747 high = TREE_INT_CST_HIGH (value);
15748 low &= ~(divisor - 1);
15757 return force_fit_type_double (TREE_TYPE (value), low, high,
15764 t = build_int_cst (TREE_TYPE (value), divisor - 1);
15765 value = size_binop (PLUS_EXPR, value, t);
15766 t = build_int_cst (TREE_TYPE (value), -divisor);
15767 value = size_binop (BIT_AND_EXPR, value, t);
15773 div = build_int_cst (TREE_TYPE (value), divisor);
15774 value = size_binop (CEIL_DIV_EXPR, value, div);
15775 value = size_binop (MULT_EXPR, value, div);
15781 /* Likewise, but round down. */
15784 round_down (tree value, int divisor)
15786 tree div = NULL_TREE;
15788 gcc_assert (divisor > 0);
15792 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15793 have to do anything. Only do this when we are not given a const,
15794 because in that case, this check is more expensive than just
15796 if (TREE_CODE (value) != INTEGER_CST)
15798 div = build_int_cst (TREE_TYPE (value), divisor);
15800 if (multiple_of_p (TREE_TYPE (value), value, div))
15804 /* If divisor is a power of two, simplify this to bit manipulation. */
15805 if (divisor == (divisor & -divisor))
15809 t = build_int_cst (TREE_TYPE (value), -divisor);
15810 value = size_binop (BIT_AND_EXPR, value, t);
15815 div = build_int_cst (TREE_TYPE (value), divisor);
15816 value = size_binop (FLOOR_DIV_EXPR, value, div);
15817 value = size_binop (MULT_EXPR, value, div);
15823 /* Returns the pointer to the base of the object addressed by EXP and
15824 extracts the information about the offset of the access, storing it
15825 to PBITPOS and POFFSET. */
15828 split_address_to_core_and_offset (tree exp,
15829 HOST_WIDE_INT *pbitpos, tree *poffset)
15832 enum machine_mode mode;
15833 int unsignedp, volatilep;
15834 HOST_WIDE_INT bitsize;
15836 if (TREE_CODE (exp) == ADDR_EXPR)
15838 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
15839 poffset, &mode, &unsignedp, &volatilep,
15841 core = build_fold_addr_expr (core);
15847 *poffset = NULL_TREE;
15853 /* Returns true if addresses of E1 and E2 differ by a constant, false
15854 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15857 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
15860 HOST_WIDE_INT bitpos1, bitpos2;
15861 tree toffset1, toffset2, tdiff, type;
15863 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
15864 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
15866 if (bitpos1 % BITS_PER_UNIT != 0
15867 || bitpos2 % BITS_PER_UNIT != 0
15868 || !operand_equal_p (core1, core2, 0))
15871 if (toffset1 && toffset2)
15873 type = TREE_TYPE (toffset1);
15874 if (type != TREE_TYPE (toffset2))
15875 toffset2 = fold_convert (type, toffset2);
15877 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
15878 if (!cst_and_fits_in_hwi (tdiff))
15881 *diff = int_cst_value (tdiff);
15883 else if (toffset1 || toffset2)
15885 /* If only one of the offsets is non-constant, the difference cannot
15892 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
15896 /* Simplify the floating point expression EXP when the sign of the
15897 result is not significant. Return NULL_TREE if no simplification
15901 fold_strip_sign_ops (tree exp)
15905 switch (TREE_CODE (exp))
15909 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15910 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
15914 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
15916 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15917 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15918 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
15919 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
15920 arg0 ? arg0 : TREE_OPERAND (exp, 0),
15921 arg1 ? arg1 : TREE_OPERAND (exp, 1));
15924 case COMPOUND_EXPR:
15925 arg0 = TREE_OPERAND (exp, 0);
15926 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15928 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
15932 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15933 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
15935 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
15936 arg0 ? arg0 : TREE_OPERAND (exp, 1),
15937 arg1 ? arg1 : TREE_OPERAND (exp, 2));
15942 const enum built_in_function fcode = builtin_mathfn_code (exp);
15945 CASE_FLT_FN (BUILT_IN_COPYSIGN):
15946 /* Strip copysign function call, return the 1st argument. */
15947 arg0 = CALL_EXPR_ARG (exp, 0);
15948 arg1 = CALL_EXPR_ARG (exp, 1);
15949 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
15952 /* Strip sign ops from the argument of "odd" math functions. */
15953 if (negate_mathfn_p (fcode))
15955 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
15957 return build_call_expr (get_callee_fndecl (exp), 1, arg0);