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
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 tree combine_comparisons (enum tree_code, enum tree_code,
107 enum tree_code, tree, tree, tree);
108 static int operand_equal_for_comparison_p (tree, tree, tree);
109 static int twoval_comparison_p (tree, tree *, tree *, int *);
110 static tree eval_subst (tree, tree, tree, tree, tree);
111 static tree pedantic_omit_one_operand (tree, tree, tree);
112 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
113 static tree make_bit_field_ref (tree, tree, HOST_WIDE_INT, HOST_WIDE_INT, int);
114 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
115 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
116 enum machine_mode *, int *, int *,
118 static int all_ones_mask_p (const_tree, int);
119 static tree sign_bit_p (tree, const_tree);
120 static int simple_operand_p (const_tree);
121 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
122 static tree range_predecessor (tree);
123 static tree range_successor (tree);
124 static tree make_range (tree, int *, tree *, tree *, bool *);
125 static tree build_range_check (tree, tree, int, tree, tree);
126 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
128 static tree fold_range_test (enum tree_code, tree, tree, tree);
129 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
130 static tree unextend (tree, int, int, tree);
131 static tree fold_truthop (enum tree_code, tree, tree, tree);
132 static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
133 static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
134 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
135 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
138 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
140 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
141 static tree fold_div_compare (enum tree_code, tree, tree, tree);
142 static bool reorder_operands_p (const_tree, const_tree);
143 static tree fold_negate_const (tree, tree);
144 static tree fold_not_const (tree, tree);
145 static tree fold_relational_const (enum tree_code, tree, tree, tree);
148 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
149 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
150 and SUM1. Then this yields nonzero if overflow occurred during the
153 Overflow occurs if A and B have the same sign, but A and SUM differ in
154 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
156 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
158 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
159 We do that by representing the two-word integer in 4 words, with only
160 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
161 number. The value of the word is LOWPART + HIGHPART * BASE. */
164 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
165 #define HIGHPART(x) \
166 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
167 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
169 /* Unpack a two-word integer into 4 words.
170 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
171 WORDS points to the array of HOST_WIDE_INTs. */
174 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
176 words[0] = LOWPART (low);
177 words[1] = HIGHPART (low);
178 words[2] = LOWPART (hi);
179 words[3] = HIGHPART (hi);
182 /* Pack an array of 4 words into a two-word integer.
183 WORDS points to the array of words.
184 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
187 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
190 *low = words[0] + words[1] * BASE;
191 *hi = words[2] + words[3] * BASE;
194 /* Force the double-word integer L1, H1 to be within the range of the
195 integer type TYPE. Stores the properly truncated and sign-extended
196 double-word integer in *LV, *HV. Returns true if the operation
197 overflows, that is, argument and result are different. */
200 fit_double_type (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
201 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, const_tree type)
203 unsigned HOST_WIDE_INT low0 = l1;
204 HOST_WIDE_INT high0 = h1;
206 int sign_extended_type;
208 if (POINTER_TYPE_P (type)
209 || TREE_CODE (type) == OFFSET_TYPE)
212 prec = TYPE_PRECISION (type);
214 /* Size types *are* sign extended. */
215 sign_extended_type = (!TYPE_UNSIGNED (type)
216 || (TREE_CODE (type) == INTEGER_TYPE
217 && TYPE_IS_SIZETYPE (type)));
219 /* First clear all bits that are beyond the type's precision. */
220 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
222 else if (prec > HOST_BITS_PER_WIDE_INT)
223 h1 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
227 if (prec < HOST_BITS_PER_WIDE_INT)
228 l1 &= ~((HOST_WIDE_INT) (-1) << prec);
231 /* Then do sign extension if necessary. */
232 if (!sign_extended_type)
233 /* No sign extension */;
234 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
235 /* Correct width already. */;
236 else if (prec > HOST_BITS_PER_WIDE_INT)
238 /* Sign extend top half? */
239 if (h1 & ((unsigned HOST_WIDE_INT)1
240 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
241 h1 |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
243 else if (prec == HOST_BITS_PER_WIDE_INT)
245 if ((HOST_WIDE_INT)l1 < 0)
250 /* Sign extend bottom half? */
251 if (l1 & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
254 l1 |= (HOST_WIDE_INT)(-1) << prec;
261 /* If the value didn't fit, signal overflow. */
262 return l1 != low0 || h1 != high0;
265 /* We force the double-int HIGH:LOW to the range of the type TYPE by
266 sign or zero extending it.
267 OVERFLOWABLE indicates if we are interested
268 in overflow of the value, when >0 we are only interested in signed
269 overflow, for <0 we are interested in any overflow. OVERFLOWED
270 indicates whether overflow has already occurred. CONST_OVERFLOWED
271 indicates whether constant overflow has already occurred. We force
272 T's value to be within range of T's type (by setting to 0 or 1 all
273 the bits outside the type's range). We set TREE_OVERFLOWED if,
274 OVERFLOWED is nonzero,
275 or OVERFLOWABLE is >0 and signed overflow occurs
276 or OVERFLOWABLE is <0 and any overflow occurs
277 We return a new tree node for the extended double-int. The node
278 is shared if no overflow flags are set. */
281 force_fit_type_double (tree type, unsigned HOST_WIDE_INT low,
282 HOST_WIDE_INT high, int overflowable,
285 int sign_extended_type;
288 /* Size types *are* sign extended. */
289 sign_extended_type = (!TYPE_UNSIGNED (type)
290 || (TREE_CODE (type) == INTEGER_TYPE
291 && TYPE_IS_SIZETYPE (type)));
293 overflow = fit_double_type (low, high, &low, &high, type);
295 /* If we need to set overflow flags, return a new unshared node. */
296 if (overflowed || overflow)
300 || (overflowable > 0 && sign_extended_type))
302 tree t = make_node (INTEGER_CST);
303 TREE_INT_CST_LOW (t) = low;
304 TREE_INT_CST_HIGH (t) = high;
305 TREE_TYPE (t) = type;
306 TREE_OVERFLOW (t) = 1;
311 /* Else build a shared node. */
312 return build_int_cst_wide (type, low, high);
315 /* Add two doubleword integers with doubleword result.
316 Return nonzero if the operation overflows according to UNSIGNED_P.
317 Each argument is given as two `HOST_WIDE_INT' pieces.
318 One argument is L1 and H1; the other, L2 and H2.
319 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
322 add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
323 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
324 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
327 unsigned HOST_WIDE_INT l;
331 h = h1 + h2 + (l < l1);
337 return (unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1;
339 return OVERFLOW_SUM_SIGN (h1, h2, h);
342 /* Negate a doubleword integer with doubleword result.
343 Return nonzero if the operation overflows, assuming it's signed.
344 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
345 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
348 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
349 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
355 return (*hv & h1) < 0;
365 /* Multiply two doubleword integers with doubleword result.
366 Return nonzero if the operation overflows according to UNSIGNED_P.
367 Each argument is given as two `HOST_WIDE_INT' pieces.
368 One argument is L1 and H1; the other, L2 and H2.
369 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
372 mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
373 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
374 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
377 HOST_WIDE_INT arg1[4];
378 HOST_WIDE_INT arg2[4];
379 HOST_WIDE_INT prod[4 * 2];
380 unsigned HOST_WIDE_INT carry;
382 unsigned HOST_WIDE_INT toplow, neglow;
383 HOST_WIDE_INT tophigh, neghigh;
385 encode (arg1, l1, h1);
386 encode (arg2, l2, h2);
388 memset (prod, 0, sizeof prod);
390 for (i = 0; i < 4; i++)
393 for (j = 0; j < 4; j++)
396 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
397 carry += arg1[i] * arg2[j];
398 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
400 prod[k] = LOWPART (carry);
401 carry = HIGHPART (carry);
406 decode (prod, lv, hv);
407 decode (prod + 4, &toplow, &tophigh);
409 /* Unsigned overflow is immediate. */
411 return (toplow | tophigh) != 0;
413 /* Check for signed overflow by calculating the signed representation of the
414 top half of the result; it should agree with the low half's sign bit. */
417 neg_double (l2, h2, &neglow, &neghigh);
418 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
422 neg_double (l1, h1, &neglow, &neghigh);
423 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
425 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
428 /* Shift the doubleword integer in L1, H1 left by COUNT places
429 keeping only PREC bits of result.
430 Shift right if COUNT is negative.
431 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
432 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
435 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
436 HOST_WIDE_INT count, unsigned int prec,
437 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
439 unsigned HOST_WIDE_INT signmask;
443 rshift_double (l1, h1, -count, prec, lv, hv, arith);
447 if (SHIFT_COUNT_TRUNCATED)
450 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
452 /* Shifting by the host word size is undefined according to the
453 ANSI standard, so we must handle this as a special case. */
457 else if (count >= HOST_BITS_PER_WIDE_INT)
459 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
464 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
465 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
469 /* Sign extend all bits that are beyond the precision. */
471 signmask = -((prec > HOST_BITS_PER_WIDE_INT
472 ? ((unsigned HOST_WIDE_INT) *hv
473 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
474 : (*lv >> (prec - 1))) & 1);
476 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
478 else if (prec >= HOST_BITS_PER_WIDE_INT)
480 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
481 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
486 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
487 *lv |= signmask << prec;
491 /* Shift the doubleword integer in L1, H1 right by COUNT places
492 keeping only PREC bits of result. COUNT must be positive.
493 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
494 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
497 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
498 HOST_WIDE_INT count, unsigned int prec,
499 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
502 unsigned HOST_WIDE_INT signmask;
505 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
508 if (SHIFT_COUNT_TRUNCATED)
511 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
513 /* Shifting by the host word size is undefined according to the
514 ANSI standard, so we must handle this as a special case. */
518 else if (count >= HOST_BITS_PER_WIDE_INT)
521 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
525 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
527 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
530 /* Zero / sign extend all bits that are beyond the precision. */
532 if (count >= (HOST_WIDE_INT)prec)
537 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
539 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
541 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
542 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
547 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
548 *lv |= signmask << (prec - count);
552 /* Rotate the doubleword integer in L1, H1 left by COUNT places
553 keeping only PREC bits of result.
554 Rotate right if COUNT is negative.
555 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
558 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
559 HOST_WIDE_INT count, unsigned int prec,
560 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
562 unsigned HOST_WIDE_INT s1l, s2l;
563 HOST_WIDE_INT s1h, s2h;
569 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
570 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
575 /* Rotate the doubleword integer in L1, H1 left by COUNT places
576 keeping only PREC bits of result. COUNT must be positive.
577 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
580 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
581 HOST_WIDE_INT count, unsigned int prec,
582 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
584 unsigned HOST_WIDE_INT s1l, s2l;
585 HOST_WIDE_INT s1h, s2h;
591 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
592 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
597 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
598 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
599 CODE is a tree code for a kind of division, one of
600 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
602 It controls how the quotient is rounded to an integer.
603 Return nonzero if the operation overflows.
604 UNS nonzero says do unsigned division. */
607 div_and_round_double (enum tree_code code, int uns,
608 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
609 HOST_WIDE_INT hnum_orig,
610 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
611 HOST_WIDE_INT hden_orig,
612 unsigned HOST_WIDE_INT *lquo,
613 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
617 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
618 HOST_WIDE_INT den[4], quo[4];
620 unsigned HOST_WIDE_INT work;
621 unsigned HOST_WIDE_INT carry = 0;
622 unsigned HOST_WIDE_INT lnum = lnum_orig;
623 HOST_WIDE_INT hnum = hnum_orig;
624 unsigned HOST_WIDE_INT lden = lden_orig;
625 HOST_WIDE_INT hden = hden_orig;
628 if (hden == 0 && lden == 0)
629 overflow = 1, lden = 1;
631 /* Calculate quotient sign and convert operands to unsigned. */
637 /* (minimum integer) / (-1) is the only overflow case. */
638 if (neg_double (lnum, hnum, &lnum, &hnum)
639 && ((HOST_WIDE_INT) lden & hden) == -1)
645 neg_double (lden, hden, &lden, &hden);
649 if (hnum == 0 && hden == 0)
650 { /* single precision */
652 /* This unsigned division rounds toward zero. */
658 { /* trivial case: dividend < divisor */
659 /* hden != 0 already checked. */
666 memset (quo, 0, sizeof quo);
668 memset (num, 0, sizeof num); /* to zero 9th element */
669 memset (den, 0, sizeof den);
671 encode (num, lnum, hnum);
672 encode (den, lden, hden);
674 /* Special code for when the divisor < BASE. */
675 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
677 /* hnum != 0 already checked. */
678 for (i = 4 - 1; i >= 0; i--)
680 work = num[i] + carry * BASE;
681 quo[i] = work / lden;
687 /* Full double precision division,
688 with thanks to Don Knuth's "Seminumerical Algorithms". */
689 int num_hi_sig, den_hi_sig;
690 unsigned HOST_WIDE_INT quo_est, scale;
692 /* Find the highest nonzero divisor digit. */
693 for (i = 4 - 1;; i--)
700 /* Insure that the first digit of the divisor is at least BASE/2.
701 This is required by the quotient digit estimation algorithm. */
703 scale = BASE / (den[den_hi_sig] + 1);
705 { /* scale divisor and dividend */
707 for (i = 0; i <= 4 - 1; i++)
709 work = (num[i] * scale) + carry;
710 num[i] = LOWPART (work);
711 carry = HIGHPART (work);
716 for (i = 0; i <= 4 - 1; i++)
718 work = (den[i] * scale) + carry;
719 den[i] = LOWPART (work);
720 carry = HIGHPART (work);
721 if (den[i] != 0) den_hi_sig = i;
728 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
730 /* Guess the next quotient digit, quo_est, by dividing the first
731 two remaining dividend digits by the high order quotient digit.
732 quo_est is never low and is at most 2 high. */
733 unsigned HOST_WIDE_INT tmp;
735 num_hi_sig = i + den_hi_sig + 1;
736 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
737 if (num[num_hi_sig] != den[den_hi_sig])
738 quo_est = work / den[den_hi_sig];
742 /* Refine quo_est so it's usually correct, and at most one high. */
743 tmp = work - quo_est * den[den_hi_sig];
745 && (den[den_hi_sig - 1] * quo_est
746 > (tmp * BASE + num[num_hi_sig - 2])))
749 /* Try QUO_EST as the quotient digit, by multiplying the
750 divisor by QUO_EST and subtracting from the remaining dividend.
751 Keep in mind that QUO_EST is the I - 1st digit. */
754 for (j = 0; j <= den_hi_sig; j++)
756 work = quo_est * den[j] + carry;
757 carry = HIGHPART (work);
758 work = num[i + j] - LOWPART (work);
759 num[i + j] = LOWPART (work);
760 carry += HIGHPART (work) != 0;
763 /* If quo_est was high by one, then num[i] went negative and
764 we need to correct things. */
765 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
768 carry = 0; /* add divisor back in */
769 for (j = 0; j <= den_hi_sig; j++)
771 work = num[i + j] + den[j] + carry;
772 carry = HIGHPART (work);
773 num[i + j] = LOWPART (work);
776 num [num_hi_sig] += carry;
779 /* Store the quotient digit. */
784 decode (quo, lquo, hquo);
787 /* If result is negative, make it so. */
789 neg_double (*lquo, *hquo, lquo, hquo);
791 /* Compute trial remainder: rem = num - (quo * den) */
792 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
793 neg_double (*lrem, *hrem, lrem, hrem);
794 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
799 case TRUNC_MOD_EXPR: /* round toward zero */
800 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
804 case FLOOR_MOD_EXPR: /* round toward negative infinity */
805 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
808 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
816 case CEIL_MOD_EXPR: /* round toward positive infinity */
817 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
819 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
827 case ROUND_MOD_EXPR: /* round to closest integer */
829 unsigned HOST_WIDE_INT labs_rem = *lrem;
830 HOST_WIDE_INT habs_rem = *hrem;
831 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
832 HOST_WIDE_INT habs_den = hden, htwice;
834 /* Get absolute values. */
836 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
838 neg_double (lden, hden, &labs_den, &habs_den);
840 /* If (2 * abs (lrem) >= abs (lden)), adjust the quotient. */
841 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
842 labs_rem, habs_rem, <wice, &htwice);
844 if (((unsigned HOST_WIDE_INT) habs_den
845 < (unsigned HOST_WIDE_INT) htwice)
846 || (((unsigned HOST_WIDE_INT) habs_den
847 == (unsigned HOST_WIDE_INT) htwice)
848 && (labs_den <= ltwice)))
852 add_double (*lquo, *hquo,
853 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
856 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
868 /* Compute true remainder: rem = num - (quo * den) */
869 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
870 neg_double (*lrem, *hrem, lrem, hrem);
871 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
875 /* If ARG2 divides ARG1 with zero remainder, carries out the division
876 of type CODE and returns the quotient.
877 Otherwise returns NULL_TREE. */
880 div_if_zero_remainder (enum tree_code code, const_tree arg1, const_tree arg2)
882 unsigned HOST_WIDE_INT int1l, int2l;
883 HOST_WIDE_INT int1h, int2h;
884 unsigned HOST_WIDE_INT quol, reml;
885 HOST_WIDE_INT quoh, remh;
886 tree type = TREE_TYPE (arg1);
887 int uns = TYPE_UNSIGNED (type);
889 int1l = TREE_INT_CST_LOW (arg1);
890 int1h = TREE_INT_CST_HIGH (arg1);
891 /* &obj[0] + -128 really should be compiled as &obj[-8] rather than
892 &obj[some_exotic_number]. */
893 if (POINTER_TYPE_P (type))
896 type = signed_type_for (type);
897 fit_double_type (int1l, int1h, &int1l, &int1h,
901 fit_double_type (int1l, int1h, &int1l, &int1h, type);
902 int2l = TREE_INT_CST_LOW (arg2);
903 int2h = TREE_INT_CST_HIGH (arg2);
905 div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
906 &quol, &quoh, &reml, &remh);
907 if (remh != 0 || reml != 0)
910 return build_int_cst_wide (type, quol, quoh);
913 /* This is nonzero if we should defer warnings about undefined
914 overflow. This facility exists because these warnings are a
915 special case. The code to estimate loop iterations does not want
916 to issue any warnings, since it works with expressions which do not
917 occur in user code. Various bits of cleanup code call fold(), but
918 only use the result if it has certain characteristics (e.g., is a
919 constant); that code only wants to issue a warning if the result is
922 static int fold_deferring_overflow_warnings;
924 /* If a warning about undefined overflow is deferred, this is the
925 warning. Note that this may cause us to turn two warnings into
926 one, but that is fine since it is sufficient to only give one
927 warning per expression. */
929 static const char* fold_deferred_overflow_warning;
931 /* If a warning about undefined overflow is deferred, this is the
932 level at which the warning should be emitted. */
934 static enum warn_strict_overflow_code fold_deferred_overflow_code;
936 /* Start deferring overflow warnings. We could use a stack here to
937 permit nested calls, but at present it is not necessary. */
940 fold_defer_overflow_warnings (void)
942 ++fold_deferring_overflow_warnings;
945 /* Stop deferring overflow warnings. If there is a pending warning,
946 and ISSUE is true, then issue the warning if appropriate. STMT is
947 the statement with which the warning should be associated (used for
948 location information); STMT may be NULL. CODE is the level of the
949 warning--a warn_strict_overflow_code value. This function will use
950 the smaller of CODE and the deferred code when deciding whether to
951 issue the warning. CODE may be zero to mean to always use the
955 fold_undefer_overflow_warnings (bool issue, const_gimple stmt, int code)
960 gcc_assert (fold_deferring_overflow_warnings > 0);
961 --fold_deferring_overflow_warnings;
962 if (fold_deferring_overflow_warnings > 0)
964 if (fold_deferred_overflow_warning != NULL
966 && code < (int) fold_deferred_overflow_code)
967 fold_deferred_overflow_code = code;
971 warnmsg = fold_deferred_overflow_warning;
972 fold_deferred_overflow_warning = NULL;
974 if (!issue || warnmsg == NULL)
977 if (gimple_no_warning_p (stmt))
980 /* Use the smallest code level when deciding to issue the
982 if (code == 0 || code > (int) fold_deferred_overflow_code)
983 code = fold_deferred_overflow_code;
985 if (!issue_strict_overflow_warning (code))
989 locus = input_location;
991 locus = gimple_location (stmt);
992 warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
995 /* Stop deferring overflow warnings, ignoring any deferred
999 fold_undefer_and_ignore_overflow_warnings (void)
1001 fold_undefer_overflow_warnings (false, NULL, 0);
1004 /* Whether we are deferring overflow warnings. */
1007 fold_deferring_overflow_warnings_p (void)
1009 return fold_deferring_overflow_warnings > 0;
1012 /* This is called when we fold something based on the fact that signed
1013 overflow is undefined. */
1016 fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
1018 if (fold_deferring_overflow_warnings > 0)
1020 if (fold_deferred_overflow_warning == NULL
1021 || wc < fold_deferred_overflow_code)
1023 fold_deferred_overflow_warning = gmsgid;
1024 fold_deferred_overflow_code = wc;
1027 else if (issue_strict_overflow_warning (wc))
1028 warning (OPT_Wstrict_overflow, gmsgid);
1031 /* Return true if the built-in mathematical function specified by CODE
1032 is odd, i.e. -f(x) == f(-x). */
1035 negate_mathfn_p (enum built_in_function code)
1039 CASE_FLT_FN (BUILT_IN_ASIN):
1040 CASE_FLT_FN (BUILT_IN_ASINH):
1041 CASE_FLT_FN (BUILT_IN_ATAN):
1042 CASE_FLT_FN (BUILT_IN_ATANH):
1043 CASE_FLT_FN (BUILT_IN_CASIN):
1044 CASE_FLT_FN (BUILT_IN_CASINH):
1045 CASE_FLT_FN (BUILT_IN_CATAN):
1046 CASE_FLT_FN (BUILT_IN_CATANH):
1047 CASE_FLT_FN (BUILT_IN_CBRT):
1048 CASE_FLT_FN (BUILT_IN_CPROJ):
1049 CASE_FLT_FN (BUILT_IN_CSIN):
1050 CASE_FLT_FN (BUILT_IN_CSINH):
1051 CASE_FLT_FN (BUILT_IN_CTAN):
1052 CASE_FLT_FN (BUILT_IN_CTANH):
1053 CASE_FLT_FN (BUILT_IN_ERF):
1054 CASE_FLT_FN (BUILT_IN_LLROUND):
1055 CASE_FLT_FN (BUILT_IN_LROUND):
1056 CASE_FLT_FN (BUILT_IN_ROUND):
1057 CASE_FLT_FN (BUILT_IN_SIN):
1058 CASE_FLT_FN (BUILT_IN_SINH):
1059 CASE_FLT_FN (BUILT_IN_TAN):
1060 CASE_FLT_FN (BUILT_IN_TANH):
1061 CASE_FLT_FN (BUILT_IN_TRUNC):
1064 CASE_FLT_FN (BUILT_IN_LLRINT):
1065 CASE_FLT_FN (BUILT_IN_LRINT):
1066 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1067 CASE_FLT_FN (BUILT_IN_RINT):
1068 return !flag_rounding_math;
1076 /* Check whether we may negate an integer constant T without causing
1080 may_negate_without_overflow_p (const_tree t)
1082 unsigned HOST_WIDE_INT val;
1086 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1088 type = TREE_TYPE (t);
1089 if (TYPE_UNSIGNED (type))
1092 prec = TYPE_PRECISION (type);
1093 if (prec > HOST_BITS_PER_WIDE_INT)
1095 if (TREE_INT_CST_LOW (t) != 0)
1097 prec -= HOST_BITS_PER_WIDE_INT;
1098 val = TREE_INT_CST_HIGH (t);
1101 val = TREE_INT_CST_LOW (t);
1102 if (prec < HOST_BITS_PER_WIDE_INT)
1103 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1104 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1107 /* Determine whether an expression T can be cheaply negated using
1108 the function negate_expr without introducing undefined overflow. */
1111 negate_expr_p (tree t)
1118 type = TREE_TYPE (t);
1120 STRIP_SIGN_NOPS (t);
1121 switch (TREE_CODE (t))
1124 if (TYPE_OVERFLOW_WRAPS (type))
1127 /* Check that -CST will not overflow type. */
1128 return may_negate_without_overflow_p (t);
1130 return (INTEGRAL_TYPE_P (type)
1131 && TYPE_OVERFLOW_WRAPS (type));
1139 return negate_expr_p (TREE_REALPART (t))
1140 && negate_expr_p (TREE_IMAGPART (t));
1143 return negate_expr_p (TREE_OPERAND (t, 0))
1144 && negate_expr_p (TREE_OPERAND (t, 1));
1147 return negate_expr_p (TREE_OPERAND (t, 0));
1150 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1151 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1153 /* -(A + B) -> (-B) - A. */
1154 if (negate_expr_p (TREE_OPERAND (t, 1))
1155 && reorder_operands_p (TREE_OPERAND (t, 0),
1156 TREE_OPERAND (t, 1)))
1158 /* -(A + B) -> (-A) - B. */
1159 return negate_expr_p (TREE_OPERAND (t, 0));
1162 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1163 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1164 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1165 && reorder_operands_p (TREE_OPERAND (t, 0),
1166 TREE_OPERAND (t, 1));
1169 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1175 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1176 return negate_expr_p (TREE_OPERAND (t, 1))
1177 || negate_expr_p (TREE_OPERAND (t, 0));
1180 case TRUNC_DIV_EXPR:
1181 case ROUND_DIV_EXPR:
1182 case FLOOR_DIV_EXPR:
1184 case EXACT_DIV_EXPR:
1185 /* In general we can't negate A / B, because if A is INT_MIN and
1186 B is 1, we may turn this into INT_MIN / -1 which is undefined
1187 and actually traps on some architectures. But if overflow is
1188 undefined, we can negate, because - (INT_MIN / 1) is an
1190 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1191 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1193 return negate_expr_p (TREE_OPERAND (t, 1))
1194 || negate_expr_p (TREE_OPERAND (t, 0));
1197 /* Negate -((double)float) as (double)(-float). */
1198 if (TREE_CODE (type) == REAL_TYPE)
1200 tree tem = strip_float_extensions (t);
1202 return negate_expr_p (tem);
1207 /* Negate -f(x) as f(-x). */
1208 if (negate_mathfn_p (builtin_mathfn_code (t)))
1209 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1213 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1214 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1216 tree op1 = TREE_OPERAND (t, 1);
1217 if (TREE_INT_CST_HIGH (op1) == 0
1218 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1219 == TREE_INT_CST_LOW (op1))
1230 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1231 simplification is possible.
1232 If negate_expr_p would return true for T, NULL_TREE will never be
1236 fold_negate_expr (tree t)
1238 tree type = TREE_TYPE (t);
1241 switch (TREE_CODE (t))
1243 /* Convert - (~A) to A + 1. */
1245 if (INTEGRAL_TYPE_P (type))
1246 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1247 build_int_cst (type, 1));
1251 tem = fold_negate_const (t, type);
1252 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1253 || !TYPE_OVERFLOW_TRAPS (type))
1258 tem = fold_negate_const (t, type);
1259 /* Two's complement FP formats, such as c4x, may overflow. */
1260 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1265 tem = fold_negate_const (t, type);
1270 tree rpart = negate_expr (TREE_REALPART (t));
1271 tree ipart = negate_expr (TREE_IMAGPART (t));
1273 if ((TREE_CODE (rpart) == REAL_CST
1274 && TREE_CODE (ipart) == REAL_CST)
1275 || (TREE_CODE (rpart) == INTEGER_CST
1276 && TREE_CODE (ipart) == INTEGER_CST))
1277 return build_complex (type, rpart, ipart);
1282 if (negate_expr_p (t))
1283 return fold_build2 (COMPLEX_EXPR, type,
1284 fold_negate_expr (TREE_OPERAND (t, 0)),
1285 fold_negate_expr (TREE_OPERAND (t, 1)));
1289 if (negate_expr_p (t))
1290 return fold_build1 (CONJ_EXPR, type,
1291 fold_negate_expr (TREE_OPERAND (t, 0)));
1295 return TREE_OPERAND (t, 0);
1298 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1299 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1301 /* -(A + B) -> (-B) - A. */
1302 if (negate_expr_p (TREE_OPERAND (t, 1))
1303 && reorder_operands_p (TREE_OPERAND (t, 0),
1304 TREE_OPERAND (t, 1)))
1306 tem = negate_expr (TREE_OPERAND (t, 1));
1307 return fold_build2 (MINUS_EXPR, type,
1308 tem, TREE_OPERAND (t, 0));
1311 /* -(A + B) -> (-A) - B. */
1312 if (negate_expr_p (TREE_OPERAND (t, 0)))
1314 tem = negate_expr (TREE_OPERAND (t, 0));
1315 return fold_build2 (MINUS_EXPR, type,
1316 tem, TREE_OPERAND (t, 1));
1322 /* - (A - B) -> B - A */
1323 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1324 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1325 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1326 return fold_build2 (MINUS_EXPR, type,
1327 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1331 if (TYPE_UNSIGNED (type))
1337 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1339 tem = TREE_OPERAND (t, 1);
1340 if (negate_expr_p (tem))
1341 return fold_build2 (TREE_CODE (t), type,
1342 TREE_OPERAND (t, 0), negate_expr (tem));
1343 tem = TREE_OPERAND (t, 0);
1344 if (negate_expr_p (tem))
1345 return fold_build2 (TREE_CODE (t), type,
1346 negate_expr (tem), TREE_OPERAND (t, 1));
1350 case TRUNC_DIV_EXPR:
1351 case ROUND_DIV_EXPR:
1352 case FLOOR_DIV_EXPR:
1354 case EXACT_DIV_EXPR:
1355 /* In general we can't negate A / B, because if A is INT_MIN and
1356 B is 1, we may turn this into INT_MIN / -1 which is undefined
1357 and actually traps on some architectures. But if overflow is
1358 undefined, we can negate, because - (INT_MIN / 1) is an
1360 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1362 const char * const warnmsg = G_("assuming signed overflow does not "
1363 "occur when negating a division");
1364 tem = TREE_OPERAND (t, 1);
1365 if (negate_expr_p (tem))
1367 if (INTEGRAL_TYPE_P (type)
1368 && (TREE_CODE (tem) != INTEGER_CST
1369 || integer_onep (tem)))
1370 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1371 return fold_build2 (TREE_CODE (t), type,
1372 TREE_OPERAND (t, 0), negate_expr (tem));
1374 tem = TREE_OPERAND (t, 0);
1375 if (negate_expr_p (tem))
1377 if (INTEGRAL_TYPE_P (type)
1378 && (TREE_CODE (tem) != INTEGER_CST
1379 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1380 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1381 return fold_build2 (TREE_CODE (t), type,
1382 negate_expr (tem), TREE_OPERAND (t, 1));
1388 /* Convert -((double)float) into (double)(-float). */
1389 if (TREE_CODE (type) == REAL_TYPE)
1391 tem = strip_float_extensions (t);
1392 if (tem != t && negate_expr_p (tem))
1393 return fold_convert (type, negate_expr (tem));
1398 /* Negate -f(x) as f(-x). */
1399 if (negate_mathfn_p (builtin_mathfn_code (t))
1400 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1404 fndecl = get_callee_fndecl (t);
1405 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1406 return build_call_expr (fndecl, 1, arg);
1411 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1412 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1414 tree op1 = TREE_OPERAND (t, 1);
1415 if (TREE_INT_CST_HIGH (op1) == 0
1416 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1417 == TREE_INT_CST_LOW (op1))
1419 tree ntype = TYPE_UNSIGNED (type)
1420 ? signed_type_for (type)
1421 : unsigned_type_for (type);
1422 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1423 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1424 return fold_convert (type, temp);
1436 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1437 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1438 return NULL_TREE. */
1441 negate_expr (tree t)
1448 type = TREE_TYPE (t);
1449 STRIP_SIGN_NOPS (t);
1451 tem = fold_negate_expr (t);
1453 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1454 return fold_convert (type, tem);
1457 /* Split a tree IN into a constant, literal and variable parts that could be
1458 combined with CODE to make IN. "constant" means an expression with
1459 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1460 commutative arithmetic operation. Store the constant part into *CONP,
1461 the literal in *LITP and return the variable part. If a part isn't
1462 present, set it to null. If the tree does not decompose in this way,
1463 return the entire tree as the variable part and the other parts as null.
1465 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1466 case, we negate an operand that was subtracted. Except if it is a
1467 literal for which we use *MINUS_LITP instead.
1469 If NEGATE_P is true, we are negating all of IN, again except a literal
1470 for which we use *MINUS_LITP instead.
1472 If IN is itself a literal or constant, return it as appropriate.
1474 Note that we do not guarantee that any of the three values will be the
1475 same type as IN, but they will have the same signedness and mode. */
1478 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1479 tree *minus_litp, int negate_p)
1487 /* Strip any conversions that don't change the machine mode or signedness. */
1488 STRIP_SIGN_NOPS (in);
1490 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
1491 || TREE_CODE (in) == FIXED_CST)
1493 else if (TREE_CODE (in) == code
1494 || ((! FLOAT_TYPE_P (TREE_TYPE (in)) || flag_associative_math)
1495 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
1496 /* We can associate addition and subtraction together (even
1497 though the C standard doesn't say so) for integers because
1498 the value is not affected. For reals, the value might be
1499 affected, so we can't. */
1500 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1501 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1503 tree op0 = TREE_OPERAND (in, 0);
1504 tree op1 = TREE_OPERAND (in, 1);
1505 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1506 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1508 /* First see if either of the operands is a literal, then a constant. */
1509 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
1510 || TREE_CODE (op0) == FIXED_CST)
1511 *litp = op0, op0 = 0;
1512 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
1513 || TREE_CODE (op1) == FIXED_CST)
1514 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1516 if (op0 != 0 && TREE_CONSTANT (op0))
1517 *conp = op0, op0 = 0;
1518 else if (op1 != 0 && TREE_CONSTANT (op1))
1519 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1521 /* If we haven't dealt with either operand, this is not a case we can
1522 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1523 if (op0 != 0 && op1 != 0)
1528 var = op1, neg_var_p = neg1_p;
1530 /* Now do any needed negations. */
1532 *minus_litp = *litp, *litp = 0;
1534 *conp = negate_expr (*conp);
1536 var = negate_expr (var);
1538 else if (TREE_CONSTANT (in))
1546 *minus_litp = *litp, *litp = 0;
1547 else if (*minus_litp)
1548 *litp = *minus_litp, *minus_litp = 0;
1549 *conp = negate_expr (*conp);
1550 var = negate_expr (var);
1556 /* Re-associate trees split by the above function. T1 and T2 are either
1557 expressions to associate or null. Return the new expression, if any. If
1558 we build an operation, do it in TYPE and with CODE. */
1561 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1568 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1569 try to fold this since we will have infinite recursion. But do
1570 deal with any NEGATE_EXPRs. */
1571 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1572 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1574 if (code == PLUS_EXPR)
1576 if (TREE_CODE (t1) == NEGATE_EXPR)
1577 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1578 fold_convert (type, TREE_OPERAND (t1, 0)));
1579 else if (TREE_CODE (t2) == NEGATE_EXPR)
1580 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1581 fold_convert (type, TREE_OPERAND (t2, 0)));
1582 else if (integer_zerop (t2))
1583 return fold_convert (type, t1);
1585 else if (code == MINUS_EXPR)
1587 if (integer_zerop (t2))
1588 return fold_convert (type, t1);
1591 return build2 (code, type, fold_convert (type, t1),
1592 fold_convert (type, t2));
1595 return fold_build2 (code, type, fold_convert (type, t1),
1596 fold_convert (type, t2));
1599 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1600 for use in int_const_binop, size_binop and size_diffop. */
1603 int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
1605 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1607 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1622 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1623 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1624 && TYPE_MODE (type1) == TYPE_MODE (type2);
1628 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1629 to produce a new constant. Return NULL_TREE if we don't know how
1630 to evaluate CODE at compile-time.
1632 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1635 int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2, int notrunc)
1637 unsigned HOST_WIDE_INT int1l, int2l;
1638 HOST_WIDE_INT int1h, int2h;
1639 unsigned HOST_WIDE_INT low;
1641 unsigned HOST_WIDE_INT garbagel;
1642 HOST_WIDE_INT garbageh;
1644 tree type = TREE_TYPE (arg1);
1645 int uns = TYPE_UNSIGNED (type);
1647 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1650 int1l = TREE_INT_CST_LOW (arg1);
1651 int1h = TREE_INT_CST_HIGH (arg1);
1652 int2l = TREE_INT_CST_LOW (arg2);
1653 int2h = TREE_INT_CST_HIGH (arg2);
1658 low = int1l | int2l, hi = int1h | int2h;
1662 low = int1l ^ int2l, hi = int1h ^ int2h;
1666 low = int1l & int2l, hi = int1h & int2h;
1672 /* It's unclear from the C standard whether shifts can overflow.
1673 The following code ignores overflow; perhaps a C standard
1674 interpretation ruling is needed. */
1675 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1682 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1687 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1691 neg_double (int2l, int2h, &low, &hi);
1692 add_double (int1l, int1h, low, hi, &low, &hi);
1693 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1697 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1700 case TRUNC_DIV_EXPR:
1701 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1702 case EXACT_DIV_EXPR:
1703 /* This is a shortcut for a common special case. */
1704 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1705 && !TREE_OVERFLOW (arg1)
1706 && !TREE_OVERFLOW (arg2)
1707 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1709 if (code == CEIL_DIV_EXPR)
1712 low = int1l / int2l, hi = 0;
1716 /* ... fall through ... */
1718 case ROUND_DIV_EXPR:
1719 if (int2h == 0 && int2l == 0)
1721 if (int2h == 0 && int2l == 1)
1723 low = int1l, hi = int1h;
1726 if (int1l == int2l && int1h == int2h
1727 && ! (int1l == 0 && int1h == 0))
1732 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1733 &low, &hi, &garbagel, &garbageh);
1736 case TRUNC_MOD_EXPR:
1737 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1738 /* This is a shortcut for a common special case. */
1739 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1740 && !TREE_OVERFLOW (arg1)
1741 && !TREE_OVERFLOW (arg2)
1742 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1744 if (code == CEIL_MOD_EXPR)
1746 low = int1l % int2l, hi = 0;
1750 /* ... fall through ... */
1752 case ROUND_MOD_EXPR:
1753 if (int2h == 0 && int2l == 0)
1755 overflow = div_and_round_double (code, uns,
1756 int1l, int1h, int2l, int2h,
1757 &garbagel, &garbageh, &low, &hi);
1763 low = (((unsigned HOST_WIDE_INT) int1h
1764 < (unsigned HOST_WIDE_INT) int2h)
1765 || (((unsigned HOST_WIDE_INT) int1h
1766 == (unsigned HOST_WIDE_INT) int2h)
1769 low = (int1h < int2h
1770 || (int1h == int2h && int1l < int2l));
1772 if (low == (code == MIN_EXPR))
1773 low = int1l, hi = int1h;
1775 low = int2l, hi = int2h;
1784 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1786 /* Propagate overflow flags ourselves. */
1787 if (((!uns || is_sizetype) && overflow)
1788 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1791 TREE_OVERFLOW (t) = 1;
1795 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1796 ((!uns || is_sizetype) && overflow)
1797 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1802 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1803 constant. We assume ARG1 and ARG2 have the same data type, or at least
1804 are the same kind of constant and the same machine mode. Return zero if
1805 combining the constants is not allowed in the current operating mode.
1807 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1810 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1812 /* Sanity check for the recursive cases. */
1819 if (TREE_CODE (arg1) == INTEGER_CST)
1820 return int_const_binop (code, arg1, arg2, notrunc);
1822 if (TREE_CODE (arg1) == REAL_CST)
1824 enum machine_mode mode;
1827 REAL_VALUE_TYPE value;
1828 REAL_VALUE_TYPE result;
1832 /* The following codes are handled by real_arithmetic. */
1847 d1 = TREE_REAL_CST (arg1);
1848 d2 = TREE_REAL_CST (arg2);
1850 type = TREE_TYPE (arg1);
1851 mode = TYPE_MODE (type);
1853 /* Don't perform operation if we honor signaling NaNs and
1854 either operand is a NaN. */
1855 if (HONOR_SNANS (mode)
1856 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1859 /* Don't perform operation if it would raise a division
1860 by zero exception. */
1861 if (code == RDIV_EXPR
1862 && REAL_VALUES_EQUAL (d2, dconst0)
1863 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1866 /* If either operand is a NaN, just return it. Otherwise, set up
1867 for floating-point trap; we return an overflow. */
1868 if (REAL_VALUE_ISNAN (d1))
1870 else if (REAL_VALUE_ISNAN (d2))
1873 inexact = real_arithmetic (&value, code, &d1, &d2);
1874 real_convert (&result, mode, &value);
1876 /* Don't constant fold this floating point operation if
1877 the result has overflowed and flag_trapping_math. */
1878 if (flag_trapping_math
1879 && MODE_HAS_INFINITIES (mode)
1880 && REAL_VALUE_ISINF (result)
1881 && !REAL_VALUE_ISINF (d1)
1882 && !REAL_VALUE_ISINF (d2))
1885 /* Don't constant fold this floating point operation if the
1886 result may dependent upon the run-time rounding mode and
1887 flag_rounding_math is set, or if GCC's software emulation
1888 is unable to accurately represent the result. */
1889 if ((flag_rounding_math
1890 || (MODE_COMPOSITE_P (mode) && !flag_unsafe_math_optimizations))
1891 && (inexact || !real_identical (&result, &value)))
1894 t = build_real (type, result);
1896 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1900 if (TREE_CODE (arg1) == FIXED_CST)
1902 FIXED_VALUE_TYPE f1;
1903 FIXED_VALUE_TYPE f2;
1904 FIXED_VALUE_TYPE result;
1909 /* The following codes are handled by fixed_arithmetic. */
1915 case TRUNC_DIV_EXPR:
1916 f2 = TREE_FIXED_CST (arg2);
1921 f2.data.high = TREE_INT_CST_HIGH (arg2);
1922 f2.data.low = TREE_INT_CST_LOW (arg2);
1930 f1 = TREE_FIXED_CST (arg1);
1931 type = TREE_TYPE (arg1);
1932 sat_p = TYPE_SATURATING (type);
1933 overflow_p = fixed_arithmetic (&result, code, &f1, &f2, sat_p);
1934 t = build_fixed (type, result);
1935 /* Propagate overflow flags. */
1936 if (overflow_p | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1938 TREE_OVERFLOW (t) = 1;
1939 TREE_CONSTANT_OVERFLOW (t) = 1;
1941 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1942 TREE_CONSTANT_OVERFLOW (t) = 1;
1946 if (TREE_CODE (arg1) == COMPLEX_CST)
1948 tree type = TREE_TYPE (arg1);
1949 tree r1 = TREE_REALPART (arg1);
1950 tree i1 = TREE_IMAGPART (arg1);
1951 tree r2 = TREE_REALPART (arg2);
1952 tree i2 = TREE_IMAGPART (arg2);
1959 real = const_binop (code, r1, r2, notrunc);
1960 imag = const_binop (code, i1, i2, notrunc);
1964 real = const_binop (MINUS_EXPR,
1965 const_binop (MULT_EXPR, r1, r2, notrunc),
1966 const_binop (MULT_EXPR, i1, i2, notrunc),
1968 imag = const_binop (PLUS_EXPR,
1969 const_binop (MULT_EXPR, r1, i2, notrunc),
1970 const_binop (MULT_EXPR, i1, r2, notrunc),
1977 = const_binop (PLUS_EXPR,
1978 const_binop (MULT_EXPR, r2, r2, notrunc),
1979 const_binop (MULT_EXPR, i2, i2, notrunc),
1982 = const_binop (PLUS_EXPR,
1983 const_binop (MULT_EXPR, r1, r2, notrunc),
1984 const_binop (MULT_EXPR, i1, i2, notrunc),
1987 = const_binop (MINUS_EXPR,
1988 const_binop (MULT_EXPR, i1, r2, notrunc),
1989 const_binop (MULT_EXPR, r1, i2, notrunc),
1992 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1993 code = TRUNC_DIV_EXPR;
1995 real = const_binop (code, t1, magsquared, notrunc);
1996 imag = const_binop (code, t2, magsquared, notrunc);
2005 return build_complex (type, real, imag);
2011 /* Create a size type INT_CST node with NUMBER sign extended. KIND
2012 indicates which particular sizetype to create. */
2015 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
2017 return build_int_cst (sizetype_tab[(int) kind], number);
2020 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2021 is a tree code. The type of the result is taken from the operands.
2022 Both must be equivalent integer types, ala int_binop_types_match_p.
2023 If the operands are constant, so is the result. */
2026 size_binop (enum tree_code code, tree arg0, tree arg1)
2028 tree type = TREE_TYPE (arg0);
2030 if (arg0 == error_mark_node || arg1 == error_mark_node)
2031 return error_mark_node;
2033 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
2036 /* Handle the special case of two integer constants faster. */
2037 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
2039 /* And some specific cases even faster than that. */
2040 if (code == PLUS_EXPR)
2042 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
2044 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2047 else if (code == MINUS_EXPR)
2049 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2052 else if (code == MULT_EXPR)
2054 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
2058 /* Handle general case of two integer constants. */
2059 return int_const_binop (code, arg0, arg1, 0);
2062 return fold_build2 (code, type, arg0, arg1);
2065 /* Given two values, either both of sizetype or both of bitsizetype,
2066 compute the difference between the two values. Return the value
2067 in signed type corresponding to the type of the operands. */
2070 size_diffop (tree arg0, tree arg1)
2072 tree type = TREE_TYPE (arg0);
2075 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
2078 /* If the type is already signed, just do the simple thing. */
2079 if (!TYPE_UNSIGNED (type))
2080 return size_binop (MINUS_EXPR, arg0, arg1);
2082 if (type == sizetype)
2084 else if (type == bitsizetype)
2085 ctype = sbitsizetype;
2087 ctype = signed_type_for (type);
2089 /* If either operand is not a constant, do the conversions to the signed
2090 type and subtract. The hardware will do the right thing with any
2091 overflow in the subtraction. */
2092 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2093 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
2094 fold_convert (ctype, arg1));
2096 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2097 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2098 overflow) and negate (which can't either). Special-case a result
2099 of zero while we're here. */
2100 if (tree_int_cst_equal (arg0, arg1))
2101 return build_int_cst (ctype, 0);
2102 else if (tree_int_cst_lt (arg1, arg0))
2103 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2105 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
2106 fold_convert (ctype, size_binop (MINUS_EXPR,
2110 /* A subroutine of fold_convert_const handling conversions of an
2111 INTEGER_CST to another integer type. */
2114 fold_convert_const_int_from_int (tree type, const_tree arg1)
2118 /* Given an integer constant, make new constant with new type,
2119 appropriately sign-extended or truncated. */
2120 t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
2121 TREE_INT_CST_HIGH (arg1),
2122 /* Don't set the overflow when
2123 converting from a pointer, */
2124 !POINTER_TYPE_P (TREE_TYPE (arg1))
2125 /* or to a sizetype with same signedness
2126 and the precision is unchanged.
2127 ??? sizetype is always sign-extended,
2128 but its signedness depends on the
2129 frontend. Thus we see spurious overflows
2130 here if we do not check this. */
2131 && !((TYPE_PRECISION (TREE_TYPE (arg1))
2132 == TYPE_PRECISION (type))
2133 && (TYPE_UNSIGNED (TREE_TYPE (arg1))
2134 == TYPE_UNSIGNED (type))
2135 && ((TREE_CODE (TREE_TYPE (arg1)) == INTEGER_TYPE
2136 && TYPE_IS_SIZETYPE (TREE_TYPE (arg1)))
2137 || (TREE_CODE (type) == INTEGER_TYPE
2138 && TYPE_IS_SIZETYPE (type)))),
2139 (TREE_INT_CST_HIGH (arg1) < 0
2140 && (TYPE_UNSIGNED (type)
2141 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2142 | TREE_OVERFLOW (arg1));
2147 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2148 to an integer type. */
2151 fold_convert_const_int_from_real (enum tree_code code, tree type, const_tree arg1)
2156 /* The following code implements the floating point to integer
2157 conversion rules required by the Java Language Specification,
2158 that IEEE NaNs are mapped to zero and values that overflow
2159 the target precision saturate, i.e. values greater than
2160 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2161 are mapped to INT_MIN. These semantics are allowed by the
2162 C and C++ standards that simply state that the behavior of
2163 FP-to-integer conversion is unspecified upon overflow. */
2165 HOST_WIDE_INT high, low;
2167 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2171 case FIX_TRUNC_EXPR:
2172 real_trunc (&r, VOIDmode, &x);
2179 /* If R is NaN, return zero and show we have an overflow. */
2180 if (REAL_VALUE_ISNAN (r))
2187 /* See if R is less than the lower bound or greater than the
2192 tree lt = TYPE_MIN_VALUE (type);
2193 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2194 if (REAL_VALUES_LESS (r, l))
2197 high = TREE_INT_CST_HIGH (lt);
2198 low = TREE_INT_CST_LOW (lt);
2204 tree ut = TYPE_MAX_VALUE (type);
2207 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2208 if (REAL_VALUES_LESS (u, r))
2211 high = TREE_INT_CST_HIGH (ut);
2212 low = TREE_INT_CST_LOW (ut);
2218 REAL_VALUE_TO_INT (&low, &high, r);
2220 t = force_fit_type_double (type, low, high, -1,
2221 overflow | TREE_OVERFLOW (arg1));
2225 /* A subroutine of fold_convert_const handling conversions of a
2226 FIXED_CST to an integer type. */
2229 fold_convert_const_int_from_fixed (tree type, const_tree arg1)
2232 double_int temp, temp_trunc;
2235 /* Right shift FIXED_CST to temp by fbit. */
2236 temp = TREE_FIXED_CST (arg1).data;
2237 mode = TREE_FIXED_CST (arg1).mode;
2238 if (GET_MODE_FBIT (mode) < 2 * HOST_BITS_PER_WIDE_INT)
2240 lshift_double (temp.low, temp.high,
2241 - GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2242 &temp.low, &temp.high, SIGNED_FIXED_POINT_MODE_P (mode));
2244 /* Left shift temp to temp_trunc by fbit. */
2245 lshift_double (temp.low, temp.high,
2246 GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2247 &temp_trunc.low, &temp_trunc.high,
2248 SIGNED_FIXED_POINT_MODE_P (mode));
2255 temp_trunc.high = 0;
2258 /* If FIXED_CST is negative, we need to round the value toward 0.
2259 By checking if the fractional bits are not zero to add 1 to temp. */
2260 if (SIGNED_FIXED_POINT_MODE_P (mode) && temp_trunc.high < 0
2261 && !double_int_equal_p (TREE_FIXED_CST (arg1).data, temp_trunc))
2266 temp = double_int_add (temp, one);
2269 /* Given a fixed-point constant, make new constant with new type,
2270 appropriately sign-extended or truncated. */
2271 t = force_fit_type_double (type, temp.low, temp.high, -1,
2273 && (TYPE_UNSIGNED (type)
2274 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2275 | TREE_OVERFLOW (arg1));
2280 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2281 to another floating point type. */
2284 fold_convert_const_real_from_real (tree type, const_tree arg1)
2286 REAL_VALUE_TYPE value;
2289 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2290 t = build_real (type, value);
2292 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2296 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2297 to a floating point type. */
2300 fold_convert_const_real_from_fixed (tree type, const_tree arg1)
2302 REAL_VALUE_TYPE value;
2305 real_convert_from_fixed (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1));
2306 t = build_real (type, value);
2308 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2309 TREE_CONSTANT_OVERFLOW (t)
2310 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2314 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2315 to another fixed-point type. */
2318 fold_convert_const_fixed_from_fixed (tree type, const_tree arg1)
2320 FIXED_VALUE_TYPE value;
2324 overflow_p = fixed_convert (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1),
2325 TYPE_SATURATING (type));
2326 t = build_fixed (type, value);
2328 /* Propagate overflow flags. */
2329 if (overflow_p | TREE_OVERFLOW (arg1))
2331 TREE_OVERFLOW (t) = 1;
2332 TREE_CONSTANT_OVERFLOW (t) = 1;
2334 else if (TREE_CONSTANT_OVERFLOW (arg1))
2335 TREE_CONSTANT_OVERFLOW (t) = 1;
2339 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2340 to a fixed-point type. */
2343 fold_convert_const_fixed_from_int (tree type, const_tree arg1)
2345 FIXED_VALUE_TYPE value;
2349 overflow_p = fixed_convert_from_int (&value, TYPE_MODE (type),
2350 TREE_INT_CST (arg1),
2351 TYPE_UNSIGNED (TREE_TYPE (arg1)),
2352 TYPE_SATURATING (type));
2353 t = build_fixed (type, value);
2355 /* Propagate overflow flags. */
2356 if (overflow_p | TREE_OVERFLOW (arg1))
2358 TREE_OVERFLOW (t) = 1;
2359 TREE_CONSTANT_OVERFLOW (t) = 1;
2361 else if (TREE_CONSTANT_OVERFLOW (arg1))
2362 TREE_CONSTANT_OVERFLOW (t) = 1;
2366 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2367 to a fixed-point type. */
2370 fold_convert_const_fixed_from_real (tree type, const_tree arg1)
2372 FIXED_VALUE_TYPE value;
2376 overflow_p = fixed_convert_from_real (&value, TYPE_MODE (type),
2377 &TREE_REAL_CST (arg1),
2378 TYPE_SATURATING (type));
2379 t = build_fixed (type, value);
2381 /* Propagate overflow flags. */
2382 if (overflow_p | TREE_OVERFLOW (arg1))
2384 TREE_OVERFLOW (t) = 1;
2385 TREE_CONSTANT_OVERFLOW (t) = 1;
2387 else if (TREE_CONSTANT_OVERFLOW (arg1))
2388 TREE_CONSTANT_OVERFLOW (t) = 1;
2392 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2393 type TYPE. If no simplification can be done return NULL_TREE. */
2396 fold_convert_const (enum tree_code code, tree type, tree arg1)
2398 if (TREE_TYPE (arg1) == type)
2401 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type)
2402 || TREE_CODE (type) == OFFSET_TYPE)
2404 if (TREE_CODE (arg1) == INTEGER_CST)
2405 return fold_convert_const_int_from_int (type, arg1);
2406 else if (TREE_CODE (arg1) == REAL_CST)
2407 return fold_convert_const_int_from_real (code, type, arg1);
2408 else if (TREE_CODE (arg1) == FIXED_CST)
2409 return fold_convert_const_int_from_fixed (type, arg1);
2411 else if (TREE_CODE (type) == REAL_TYPE)
2413 if (TREE_CODE (arg1) == INTEGER_CST)
2414 return build_real_from_int_cst (type, arg1);
2415 else if (TREE_CODE (arg1) == REAL_CST)
2416 return fold_convert_const_real_from_real (type, arg1);
2417 else if (TREE_CODE (arg1) == FIXED_CST)
2418 return fold_convert_const_real_from_fixed (type, arg1);
2420 else if (TREE_CODE (type) == FIXED_POINT_TYPE)
2422 if (TREE_CODE (arg1) == FIXED_CST)
2423 return fold_convert_const_fixed_from_fixed (type, arg1);
2424 else if (TREE_CODE (arg1) == INTEGER_CST)
2425 return fold_convert_const_fixed_from_int (type, arg1);
2426 else if (TREE_CODE (arg1) == REAL_CST)
2427 return fold_convert_const_fixed_from_real (type, arg1);
2432 /* Construct a vector of zero elements of vector type TYPE. */
2435 build_zero_vector (tree type)
2440 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2441 units = TYPE_VECTOR_SUBPARTS (type);
2444 for (i = 0; i < units; i++)
2445 list = tree_cons (NULL_TREE, elem, list);
2446 return build_vector (type, list);
2449 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2452 fold_convertible_p (const_tree type, const_tree arg)
2454 tree orig = TREE_TYPE (arg);
2459 if (TREE_CODE (arg) == ERROR_MARK
2460 || TREE_CODE (type) == ERROR_MARK
2461 || TREE_CODE (orig) == ERROR_MARK)
2464 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2467 switch (TREE_CODE (type))
2469 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2470 case POINTER_TYPE: case REFERENCE_TYPE:
2472 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2473 || TREE_CODE (orig) == OFFSET_TYPE)
2475 return (TREE_CODE (orig) == VECTOR_TYPE
2476 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2479 case FIXED_POINT_TYPE:
2483 return TREE_CODE (type) == TREE_CODE (orig);
2490 /* Convert expression ARG to type TYPE. Used by the middle-end for
2491 simple conversions in preference to calling the front-end's convert. */
2494 fold_convert (tree type, tree arg)
2496 tree orig = TREE_TYPE (arg);
2502 if (TREE_CODE (arg) == ERROR_MARK
2503 || TREE_CODE (type) == ERROR_MARK
2504 || TREE_CODE (orig) == ERROR_MARK)
2505 return error_mark_node;
2507 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2508 return fold_build1 (NOP_EXPR, type, arg);
2510 switch (TREE_CODE (type))
2512 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2513 case POINTER_TYPE: case REFERENCE_TYPE:
2515 if (TREE_CODE (arg) == INTEGER_CST)
2517 tem = fold_convert_const (NOP_EXPR, type, arg);
2518 if (tem != NULL_TREE)
2521 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2522 || TREE_CODE (orig) == OFFSET_TYPE)
2523 return fold_build1 (NOP_EXPR, type, arg);
2524 if (TREE_CODE (orig) == COMPLEX_TYPE)
2526 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2527 return fold_convert (type, tem);
2529 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2530 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2531 return fold_build1 (NOP_EXPR, type, arg);
2534 if (TREE_CODE (arg) == INTEGER_CST)
2536 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2537 if (tem != NULL_TREE)
2540 else if (TREE_CODE (arg) == REAL_CST)
2542 tem = fold_convert_const (NOP_EXPR, type, arg);
2543 if (tem != NULL_TREE)
2546 else if (TREE_CODE (arg) == FIXED_CST)
2548 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2549 if (tem != NULL_TREE)
2553 switch (TREE_CODE (orig))
2556 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2557 case POINTER_TYPE: case REFERENCE_TYPE:
2558 return fold_build1 (FLOAT_EXPR, type, arg);
2561 return fold_build1 (NOP_EXPR, type, arg);
2563 case FIXED_POINT_TYPE:
2564 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2567 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2568 return fold_convert (type, tem);
2574 case FIXED_POINT_TYPE:
2575 if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
2576 || TREE_CODE (arg) == REAL_CST)
2578 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2579 if (tem != NULL_TREE)
2583 switch (TREE_CODE (orig))
2585 case FIXED_POINT_TYPE:
2590 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2593 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2594 return fold_convert (type, tem);
2601 switch (TREE_CODE (orig))
2604 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2605 case POINTER_TYPE: case REFERENCE_TYPE:
2607 case FIXED_POINT_TYPE:
2608 return build2 (COMPLEX_EXPR, type,
2609 fold_convert (TREE_TYPE (type), arg),
2610 fold_convert (TREE_TYPE (type), integer_zero_node));
2615 if (TREE_CODE (arg) == COMPLEX_EXPR)
2617 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2618 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2619 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2622 arg = save_expr (arg);
2623 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2624 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2625 rpart = fold_convert (TREE_TYPE (type), rpart);
2626 ipart = fold_convert (TREE_TYPE (type), ipart);
2627 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2635 if (integer_zerop (arg))
2636 return build_zero_vector (type);
2637 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2638 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2639 || TREE_CODE (orig) == VECTOR_TYPE);
2640 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2643 tem = fold_ignored_result (arg);
2644 if (TREE_CODE (tem) == MODIFY_EXPR)
2646 return fold_build1 (NOP_EXPR, type, tem);
2653 /* Return false if expr can be assumed not to be an lvalue, true
2657 maybe_lvalue_p (const_tree x)
2659 /* We only need to wrap lvalue tree codes. */
2660 switch (TREE_CODE (x))
2671 case ALIGN_INDIRECT_REF:
2672 case MISALIGNED_INDIRECT_REF:
2674 case ARRAY_RANGE_REF:
2680 case PREINCREMENT_EXPR:
2681 case PREDECREMENT_EXPR:
2683 case TRY_CATCH_EXPR:
2684 case WITH_CLEANUP_EXPR:
2695 /* Assume the worst for front-end tree codes. */
2696 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2704 /* Return an expr equal to X but certainly not valid as an lvalue. */
2709 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2714 if (! maybe_lvalue_p (x))
2716 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2719 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2720 Zero means allow extended lvalues. */
2722 int pedantic_lvalues;
2724 /* When pedantic, return an expr equal to X but certainly not valid as a
2725 pedantic lvalue. Otherwise, return X. */
2728 pedantic_non_lvalue (tree x)
2730 if (pedantic_lvalues)
2731 return non_lvalue (x);
2736 /* Given a tree comparison code, return the code that is the logical inverse
2737 of the given code. It is not safe to do this for floating-point
2738 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2739 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2742 invert_tree_comparison (enum tree_code code, bool honor_nans)
2744 if (honor_nans && flag_trapping_math)
2754 return honor_nans ? UNLE_EXPR : LE_EXPR;
2756 return honor_nans ? UNLT_EXPR : LT_EXPR;
2758 return honor_nans ? UNGE_EXPR : GE_EXPR;
2760 return honor_nans ? UNGT_EXPR : GT_EXPR;
2774 return UNORDERED_EXPR;
2775 case UNORDERED_EXPR:
2776 return ORDERED_EXPR;
2782 /* Similar, but return the comparison that results if the operands are
2783 swapped. This is safe for floating-point. */
2786 swap_tree_comparison (enum tree_code code)
2793 case UNORDERED_EXPR:
2819 /* Convert a comparison tree code from an enum tree_code representation
2820 into a compcode bit-based encoding. This function is the inverse of
2821 compcode_to_comparison. */
2823 static enum comparison_code
2824 comparison_to_compcode (enum tree_code code)
2841 return COMPCODE_ORD;
2842 case UNORDERED_EXPR:
2843 return COMPCODE_UNORD;
2845 return COMPCODE_UNLT;
2847 return COMPCODE_UNEQ;
2849 return COMPCODE_UNLE;
2851 return COMPCODE_UNGT;
2853 return COMPCODE_LTGT;
2855 return COMPCODE_UNGE;
2861 /* Convert a compcode bit-based encoding of a comparison operator back
2862 to GCC's enum tree_code representation. This function is the
2863 inverse of comparison_to_compcode. */
2865 static enum tree_code
2866 compcode_to_comparison (enum comparison_code code)
2883 return ORDERED_EXPR;
2884 case COMPCODE_UNORD:
2885 return UNORDERED_EXPR;
2903 /* Return a tree for the comparison which is the combination of
2904 doing the AND or OR (depending on CODE) of the two operations LCODE
2905 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2906 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2907 if this makes the transformation invalid. */
2910 combine_comparisons (enum tree_code code, enum tree_code lcode,
2911 enum tree_code rcode, tree truth_type,
2912 tree ll_arg, tree lr_arg)
2914 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2915 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2916 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2917 enum comparison_code compcode;
2921 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2922 compcode = lcompcode & rcompcode;
2925 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2926 compcode = lcompcode | rcompcode;
2935 /* Eliminate unordered comparisons, as well as LTGT and ORD
2936 which are not used unless the mode has NaNs. */
2937 compcode &= ~COMPCODE_UNORD;
2938 if (compcode == COMPCODE_LTGT)
2939 compcode = COMPCODE_NE;
2940 else if (compcode == COMPCODE_ORD)
2941 compcode = COMPCODE_TRUE;
2943 else if (flag_trapping_math)
2945 /* Check that the original operation and the optimized ones will trap
2946 under the same condition. */
2947 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2948 && (lcompcode != COMPCODE_EQ)
2949 && (lcompcode != COMPCODE_ORD);
2950 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2951 && (rcompcode != COMPCODE_EQ)
2952 && (rcompcode != COMPCODE_ORD);
2953 bool trap = (compcode & COMPCODE_UNORD) == 0
2954 && (compcode != COMPCODE_EQ)
2955 && (compcode != COMPCODE_ORD);
2957 /* In a short-circuited boolean expression the LHS might be
2958 such that the RHS, if evaluated, will never trap. For
2959 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2960 if neither x nor y is NaN. (This is a mixed blessing: for
2961 example, the expression above will never trap, hence
2962 optimizing it to x < y would be invalid). */
2963 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2964 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2967 /* If the comparison was short-circuited, and only the RHS
2968 trapped, we may now generate a spurious trap. */
2970 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2973 /* If we changed the conditions that cause a trap, we lose. */
2974 if ((ltrap || rtrap) != trap)
2978 if (compcode == COMPCODE_TRUE)
2979 return constant_boolean_node (true, truth_type);
2980 else if (compcode == COMPCODE_FALSE)
2981 return constant_boolean_node (false, truth_type);
2983 return fold_build2 (compcode_to_comparison (compcode),
2984 truth_type, ll_arg, lr_arg);
2987 /* Return nonzero if two operands (typically of the same tree node)
2988 are necessarily equal. If either argument has side-effects this
2989 function returns zero. FLAGS modifies behavior as follows:
2991 If OEP_ONLY_CONST is set, only return nonzero for constants.
2992 This function tests whether the operands are indistinguishable;
2993 it does not test whether they are equal using C's == operation.
2994 The distinction is important for IEEE floating point, because
2995 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2996 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2998 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2999 even though it may hold multiple values during a function.
3000 This is because a GCC tree node guarantees that nothing else is
3001 executed between the evaluation of its "operands" (which may often
3002 be evaluated in arbitrary order). Hence if the operands themselves
3003 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
3004 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
3005 unset means assuming isochronic (or instantaneous) tree equivalence.
3006 Unless comparing arbitrary expression trees, such as from different
3007 statements, this flag can usually be left unset.
3009 If OEP_PURE_SAME is set, then pure functions with identical arguments
3010 are considered the same. It is used when the caller has other ways
3011 to ensure that global memory is unchanged in between. */
3014 operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
3016 /* If either is ERROR_MARK, they aren't equal. */
3017 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
3020 /* Check equality of integer constants before bailing out due to
3021 precision differences. */
3022 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
3023 return tree_int_cst_equal (arg0, arg1);
3025 /* If both types don't have the same signedness, then we can't consider
3026 them equal. We must check this before the STRIP_NOPS calls
3027 because they may change the signedness of the arguments. As pointers
3028 strictly don't have a signedness, require either two pointers or
3029 two non-pointers as well. */
3030 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1))
3031 || POINTER_TYPE_P (TREE_TYPE (arg0)) != POINTER_TYPE_P (TREE_TYPE (arg1)))
3034 /* If both types don't have the same precision, then it is not safe
3036 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
3042 /* In case both args are comparisons but with different comparison
3043 code, try to swap the comparison operands of one arg to produce
3044 a match and compare that variant. */
3045 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3046 && COMPARISON_CLASS_P (arg0)
3047 && COMPARISON_CLASS_P (arg1))
3049 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
3051 if (TREE_CODE (arg0) == swap_code)
3052 return operand_equal_p (TREE_OPERAND (arg0, 0),
3053 TREE_OPERAND (arg1, 1), flags)
3054 && operand_equal_p (TREE_OPERAND (arg0, 1),
3055 TREE_OPERAND (arg1, 0), flags);
3058 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3059 /* This is needed for conversions and for COMPONENT_REF.
3060 Might as well play it safe and always test this. */
3061 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
3062 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
3063 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
3066 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3067 We don't care about side effects in that case because the SAVE_EXPR
3068 takes care of that for us. In all other cases, two expressions are
3069 equal if they have no side effects. If we have two identical
3070 expressions with side effects that should be treated the same due
3071 to the only side effects being identical SAVE_EXPR's, that will
3072 be detected in the recursive calls below. */
3073 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
3074 && (TREE_CODE (arg0) == SAVE_EXPR
3075 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
3078 /* Next handle constant cases, those for which we can return 1 even
3079 if ONLY_CONST is set. */
3080 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
3081 switch (TREE_CODE (arg0))
3084 return tree_int_cst_equal (arg0, arg1);
3087 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
3088 TREE_FIXED_CST (arg1));
3091 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
3092 TREE_REAL_CST (arg1)))
3096 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
3098 /* If we do not distinguish between signed and unsigned zero,
3099 consider them equal. */
3100 if (real_zerop (arg0) && real_zerop (arg1))
3109 v1 = TREE_VECTOR_CST_ELTS (arg0);
3110 v2 = TREE_VECTOR_CST_ELTS (arg1);
3113 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
3116 v1 = TREE_CHAIN (v1);
3117 v2 = TREE_CHAIN (v2);
3124 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
3126 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
3130 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
3131 && ! memcmp (TREE_STRING_POINTER (arg0),
3132 TREE_STRING_POINTER (arg1),
3133 TREE_STRING_LENGTH (arg0)));
3136 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
3142 if (flags & OEP_ONLY_CONST)
3145 /* Define macros to test an operand from arg0 and arg1 for equality and a
3146 variant that allows null and views null as being different from any
3147 non-null value. In the latter case, if either is null, the both
3148 must be; otherwise, do the normal comparison. */
3149 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3150 TREE_OPERAND (arg1, N), flags)
3152 #define OP_SAME_WITH_NULL(N) \
3153 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3154 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3156 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
3159 /* Two conversions are equal only if signedness and modes match. */
3160 switch (TREE_CODE (arg0))
3163 case FIX_TRUNC_EXPR:
3164 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
3165 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3175 case tcc_comparison:
3177 if (OP_SAME (0) && OP_SAME (1))
3180 /* For commutative ops, allow the other order. */
3181 return (commutative_tree_code (TREE_CODE (arg0))
3182 && operand_equal_p (TREE_OPERAND (arg0, 0),
3183 TREE_OPERAND (arg1, 1), flags)
3184 && operand_equal_p (TREE_OPERAND (arg0, 1),
3185 TREE_OPERAND (arg1, 0), flags));
3188 /* If either of the pointer (or reference) expressions we are
3189 dereferencing contain a side effect, these cannot be equal. */
3190 if (TREE_SIDE_EFFECTS (arg0)
3191 || TREE_SIDE_EFFECTS (arg1))
3194 switch (TREE_CODE (arg0))
3197 case ALIGN_INDIRECT_REF:
3198 case MISALIGNED_INDIRECT_REF:
3204 case ARRAY_RANGE_REF:
3205 /* Operands 2 and 3 may be null.
3206 Compare the array index by value if it is constant first as we
3207 may have different types but same value here. */
3209 && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
3210 TREE_OPERAND (arg1, 1))
3212 && OP_SAME_WITH_NULL (2)
3213 && OP_SAME_WITH_NULL (3));
3216 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3217 may be NULL when we're called to compare MEM_EXPRs. */
3218 return OP_SAME_WITH_NULL (0)
3220 && OP_SAME_WITH_NULL (2);
3223 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3229 case tcc_expression:
3230 switch (TREE_CODE (arg0))
3233 case TRUTH_NOT_EXPR:
3236 case TRUTH_ANDIF_EXPR:
3237 case TRUTH_ORIF_EXPR:
3238 return OP_SAME (0) && OP_SAME (1);
3240 case TRUTH_AND_EXPR:
3242 case TRUTH_XOR_EXPR:
3243 if (OP_SAME (0) && OP_SAME (1))
3246 /* Otherwise take into account this is a commutative operation. */
3247 return (operand_equal_p (TREE_OPERAND (arg0, 0),
3248 TREE_OPERAND (arg1, 1), flags)
3249 && operand_equal_p (TREE_OPERAND (arg0, 1),
3250 TREE_OPERAND (arg1, 0), flags));
3253 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3260 switch (TREE_CODE (arg0))
3263 /* If the CALL_EXPRs call different functions, then they
3264 clearly can not be equal. */
3265 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
3270 unsigned int cef = call_expr_flags (arg0);
3271 if (flags & OEP_PURE_SAME)
3272 cef &= ECF_CONST | ECF_PURE;
3279 /* Now see if all the arguments are the same. */
3281 const_call_expr_arg_iterator iter0, iter1;
3283 for (a0 = first_const_call_expr_arg (arg0, &iter0),
3284 a1 = first_const_call_expr_arg (arg1, &iter1);
3286 a0 = next_const_call_expr_arg (&iter0),
3287 a1 = next_const_call_expr_arg (&iter1))
3288 if (! operand_equal_p (a0, a1, flags))
3291 /* If we get here and both argument lists are exhausted
3292 then the CALL_EXPRs are equal. */
3293 return ! (a0 || a1);
3299 case tcc_declaration:
3300 /* Consider __builtin_sqrt equal to sqrt. */
3301 return (TREE_CODE (arg0) == FUNCTION_DECL
3302 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
3303 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
3304 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
3311 #undef OP_SAME_WITH_NULL
3314 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3315 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3317 When in doubt, return 0. */
3320 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
3322 int unsignedp1, unsignedpo;
3323 tree primarg0, primarg1, primother;
3324 unsigned int correct_width;
3326 if (operand_equal_p (arg0, arg1, 0))
3329 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3330 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3333 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3334 and see if the inner values are the same. This removes any
3335 signedness comparison, which doesn't matter here. */
3336 primarg0 = arg0, primarg1 = arg1;
3337 STRIP_NOPS (primarg0);
3338 STRIP_NOPS (primarg1);
3339 if (operand_equal_p (primarg0, primarg1, 0))
3342 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3343 actual comparison operand, ARG0.
3345 First throw away any conversions to wider types
3346 already present in the operands. */
3348 primarg1 = get_narrower (arg1, &unsignedp1);
3349 primother = get_narrower (other, &unsignedpo);
3351 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3352 if (unsignedp1 == unsignedpo
3353 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3354 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3356 tree type = TREE_TYPE (arg0);
3358 /* Make sure shorter operand is extended the right way
3359 to match the longer operand. */
3360 primarg1 = fold_convert (signed_or_unsigned_type_for
3361 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3363 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3370 /* See if ARG is an expression that is either a comparison or is performing
3371 arithmetic on comparisons. The comparisons must only be comparing
3372 two different values, which will be stored in *CVAL1 and *CVAL2; if
3373 they are nonzero it means that some operands have already been found.
3374 No variables may be used anywhere else in the expression except in the
3375 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3376 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3378 If this is true, return 1. Otherwise, return zero. */
3381 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3383 enum tree_code code = TREE_CODE (arg);
3384 enum tree_code_class tclass = TREE_CODE_CLASS (code);
3386 /* We can handle some of the tcc_expression cases here. */
3387 if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
3389 else if (tclass == tcc_expression
3390 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3391 || code == COMPOUND_EXPR))
3392 tclass = tcc_binary;
3394 else if (tclass == tcc_expression && code == SAVE_EXPR
3395 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3397 /* If we've already found a CVAL1 or CVAL2, this expression is
3398 two complex to handle. */
3399 if (*cval1 || *cval2)
3409 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3412 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3413 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3414 cval1, cval2, save_p));
3419 case tcc_expression:
3420 if (code == COND_EXPR)
3421 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3422 cval1, cval2, save_p)
3423 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3424 cval1, cval2, save_p)
3425 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3426 cval1, cval2, save_p));
3429 case tcc_comparison:
3430 /* First see if we can handle the first operand, then the second. For
3431 the second operand, we know *CVAL1 can't be zero. It must be that
3432 one side of the comparison is each of the values; test for the
3433 case where this isn't true by failing if the two operands
3436 if (operand_equal_p (TREE_OPERAND (arg, 0),
3437 TREE_OPERAND (arg, 1), 0))
3441 *cval1 = TREE_OPERAND (arg, 0);
3442 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3444 else if (*cval2 == 0)
3445 *cval2 = TREE_OPERAND (arg, 0);
3446 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3451 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3453 else if (*cval2 == 0)
3454 *cval2 = TREE_OPERAND (arg, 1);
3455 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3467 /* ARG is a tree that is known to contain just arithmetic operations and
3468 comparisons. Evaluate the operations in the tree substituting NEW0 for
3469 any occurrence of OLD0 as an operand of a comparison and likewise for
3473 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3475 tree type = TREE_TYPE (arg);
3476 enum tree_code code = TREE_CODE (arg);
3477 enum tree_code_class tclass = TREE_CODE_CLASS (code);
3479 /* We can handle some of the tcc_expression cases here. */
3480 if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
3482 else if (tclass == tcc_expression
3483 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3484 tclass = tcc_binary;
3489 return fold_build1 (code, type,
3490 eval_subst (TREE_OPERAND (arg, 0),
3491 old0, new0, old1, new1));
3494 return fold_build2 (code, type,
3495 eval_subst (TREE_OPERAND (arg, 0),
3496 old0, new0, old1, new1),
3497 eval_subst (TREE_OPERAND (arg, 1),
3498 old0, new0, old1, new1));
3500 case tcc_expression:
3504 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3507 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3510 return fold_build3 (code, type,
3511 eval_subst (TREE_OPERAND (arg, 0),
3512 old0, new0, old1, new1),
3513 eval_subst (TREE_OPERAND (arg, 1),
3514 old0, new0, old1, new1),
3515 eval_subst (TREE_OPERAND (arg, 2),
3516 old0, new0, old1, new1));
3520 /* Fall through - ??? */
3522 case tcc_comparison:
3524 tree arg0 = TREE_OPERAND (arg, 0);
3525 tree arg1 = TREE_OPERAND (arg, 1);
3527 /* We need to check both for exact equality and tree equality. The
3528 former will be true if the operand has a side-effect. In that
3529 case, we know the operand occurred exactly once. */
3531 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3533 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3536 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3538 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3541 return fold_build2 (code, type, arg0, arg1);
3549 /* Return a tree for the case when the result of an expression is RESULT
3550 converted to TYPE and OMITTED was previously an operand of the expression
3551 but is now not needed (e.g., we folded OMITTED * 0).
3553 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3554 the conversion of RESULT to TYPE. */
3557 omit_one_operand (tree type, tree result, tree omitted)
3559 tree t = fold_convert (type, result);
3561 /* If the resulting operand is an empty statement, just return the omitted
3562 statement casted to void. */
3563 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3564 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3566 if (TREE_SIDE_EFFECTS (omitted))
3567 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3569 return non_lvalue (t);
3572 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3575 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3577 tree t = fold_convert (type, result);
3579 /* If the resulting operand is an empty statement, just return the omitted
3580 statement casted to void. */
3581 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3582 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3584 if (TREE_SIDE_EFFECTS (omitted))
3585 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3587 return pedantic_non_lvalue (t);
3590 /* Return a tree for the case when the result of an expression is RESULT
3591 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3592 of the expression but are now not needed.
3594 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3595 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3596 evaluated before OMITTED2. Otherwise, if neither has side effects,
3597 just do the conversion of RESULT to TYPE. */
3600 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3602 tree t = fold_convert (type, result);
3604 if (TREE_SIDE_EFFECTS (omitted2))
3605 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3606 if (TREE_SIDE_EFFECTS (omitted1))
3607 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3609 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3613 /* Return a simplified tree node for the truth-negation of ARG. This
3614 never alters ARG itself. We assume that ARG is an operation that
3615 returns a truth value (0 or 1).
3617 FIXME: one would think we would fold the result, but it causes
3618 problems with the dominator optimizer. */
3621 fold_truth_not_expr (tree arg)
3623 tree type = TREE_TYPE (arg);
3624 enum tree_code code = TREE_CODE (arg);
3626 /* If this is a comparison, we can simply invert it, except for
3627 floating-point non-equality comparisons, in which case we just
3628 enclose a TRUTH_NOT_EXPR around what we have. */
3630 if (TREE_CODE_CLASS (code) == tcc_comparison)
3632 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3633 if (FLOAT_TYPE_P (op_type)
3634 && flag_trapping_math
3635 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3636 && code != NE_EXPR && code != EQ_EXPR)
3640 code = invert_tree_comparison (code,
3641 HONOR_NANS (TYPE_MODE (op_type)));
3642 if (code == ERROR_MARK)
3645 return build2 (code, type,
3646 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3653 return constant_boolean_node (integer_zerop (arg), type);
3655 case TRUTH_AND_EXPR:
3656 return build2 (TRUTH_OR_EXPR, type,
3657 invert_truthvalue (TREE_OPERAND (arg, 0)),
3658 invert_truthvalue (TREE_OPERAND (arg, 1)));
3661 return build2 (TRUTH_AND_EXPR, type,
3662 invert_truthvalue (TREE_OPERAND (arg, 0)),
3663 invert_truthvalue (TREE_OPERAND (arg, 1)));
3665 case TRUTH_XOR_EXPR:
3666 /* Here we can invert either operand. We invert the first operand
3667 unless the second operand is a TRUTH_NOT_EXPR in which case our
3668 result is the XOR of the first operand with the inside of the
3669 negation of the second operand. */
3671 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3672 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3673 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3675 return build2 (TRUTH_XOR_EXPR, type,
3676 invert_truthvalue (TREE_OPERAND (arg, 0)),
3677 TREE_OPERAND (arg, 1));
3679 case TRUTH_ANDIF_EXPR:
3680 return build2 (TRUTH_ORIF_EXPR, type,
3681 invert_truthvalue (TREE_OPERAND (arg, 0)),
3682 invert_truthvalue (TREE_OPERAND (arg, 1)));
3684 case TRUTH_ORIF_EXPR:
3685 return build2 (TRUTH_ANDIF_EXPR, type,
3686 invert_truthvalue (TREE_OPERAND (arg, 0)),
3687 invert_truthvalue (TREE_OPERAND (arg, 1)));
3689 case TRUTH_NOT_EXPR:
3690 return TREE_OPERAND (arg, 0);
3694 tree arg1 = TREE_OPERAND (arg, 1);
3695 tree arg2 = TREE_OPERAND (arg, 2);
3696 /* A COND_EXPR may have a throw as one operand, which
3697 then has void type. Just leave void operands
3699 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3700 VOID_TYPE_P (TREE_TYPE (arg1))
3701 ? arg1 : invert_truthvalue (arg1),
3702 VOID_TYPE_P (TREE_TYPE (arg2))
3703 ? arg2 : invert_truthvalue (arg2));
3707 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3708 invert_truthvalue (TREE_OPERAND (arg, 1)));
3710 case NON_LVALUE_EXPR:
3711 return invert_truthvalue (TREE_OPERAND (arg, 0));
3714 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3715 return build1 (TRUTH_NOT_EXPR, type, arg);
3719 return build1 (TREE_CODE (arg), type,
3720 invert_truthvalue (TREE_OPERAND (arg, 0)));
3723 if (!integer_onep (TREE_OPERAND (arg, 1)))
3725 return build2 (EQ_EXPR, type, arg,
3726 build_int_cst (type, 0));
3729 return build1 (TRUTH_NOT_EXPR, type, arg);
3731 case CLEANUP_POINT_EXPR:
3732 return build1 (CLEANUP_POINT_EXPR, type,
3733 invert_truthvalue (TREE_OPERAND (arg, 0)));
3742 /* Return a simplified tree node for the truth-negation of ARG. This
3743 never alters ARG itself. We assume that ARG is an operation that
3744 returns a truth value (0 or 1).
3746 FIXME: one would think we would fold the result, but it causes
3747 problems with the dominator optimizer. */
3750 invert_truthvalue (tree arg)
3754 if (TREE_CODE (arg) == ERROR_MARK)
3757 tem = fold_truth_not_expr (arg);
3759 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3764 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3765 operands are another bit-wise operation with a common input. If so,
3766 distribute the bit operations to save an operation and possibly two if
3767 constants are involved. For example, convert
3768 (A | B) & (A | C) into A | (B & C)
3769 Further simplification will occur if B and C are constants.
3771 If this optimization cannot be done, 0 will be returned. */
3774 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3779 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3780 || TREE_CODE (arg0) == code
3781 || (TREE_CODE (arg0) != BIT_AND_EXPR
3782 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3785 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3787 common = TREE_OPERAND (arg0, 0);
3788 left = TREE_OPERAND (arg0, 1);
3789 right = TREE_OPERAND (arg1, 1);
3791 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3793 common = TREE_OPERAND (arg0, 0);
3794 left = TREE_OPERAND (arg0, 1);
3795 right = TREE_OPERAND (arg1, 0);
3797 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3799 common = TREE_OPERAND (arg0, 1);
3800 left = TREE_OPERAND (arg0, 0);
3801 right = TREE_OPERAND (arg1, 1);
3803 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3805 common = TREE_OPERAND (arg0, 1);
3806 left = TREE_OPERAND (arg0, 0);
3807 right = TREE_OPERAND (arg1, 0);
3812 common = fold_convert (type, common);
3813 left = fold_convert (type, left);
3814 right = fold_convert (type, right);
3815 return fold_build2 (TREE_CODE (arg0), type, common,
3816 fold_build2 (code, type, left, right));
3819 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3820 with code CODE. This optimization is unsafe. */
3822 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3824 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3825 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3827 /* (A / C) +- (B / C) -> (A +- B) / C. */
3829 && operand_equal_p (TREE_OPERAND (arg0, 1),
3830 TREE_OPERAND (arg1, 1), 0))
3831 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3832 fold_build2 (code, type,
3833 TREE_OPERAND (arg0, 0),
3834 TREE_OPERAND (arg1, 0)),
3835 TREE_OPERAND (arg0, 1));
3837 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3838 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3839 TREE_OPERAND (arg1, 0), 0)
3840 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3841 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3843 REAL_VALUE_TYPE r0, r1;
3844 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3845 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3847 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3849 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3850 real_arithmetic (&r0, code, &r0, &r1);
3851 return fold_build2 (MULT_EXPR, type,
3852 TREE_OPERAND (arg0, 0),
3853 build_real (type, r0));
3859 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3860 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3863 make_bit_field_ref (tree inner, tree type, HOST_WIDE_INT bitsize,
3864 HOST_WIDE_INT bitpos, int unsignedp)
3866 tree result, bftype;
3870 tree size = TYPE_SIZE (TREE_TYPE (inner));
3871 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3872 || POINTER_TYPE_P (TREE_TYPE (inner)))
3873 && host_integerp (size, 0)
3874 && tree_low_cst (size, 0) == bitsize)
3875 return fold_convert (type, inner);
3879 if (TYPE_PRECISION (bftype) != bitsize
3880 || TYPE_UNSIGNED (bftype) == !unsignedp)
3881 bftype = build_nonstandard_integer_type (bitsize, 0);
3883 result = build3 (BIT_FIELD_REF, bftype, inner,
3884 size_int (bitsize), bitsize_int (bitpos));
3887 result = fold_convert (type, result);
3892 /* Optimize a bit-field compare.
3894 There are two cases: First is a compare against a constant and the
3895 second is a comparison of two items where the fields are at the same
3896 bit position relative to the start of a chunk (byte, halfword, word)
3897 large enough to contain it. In these cases we can avoid the shift
3898 implicit in bitfield extractions.
3900 For constants, we emit a compare of the shifted constant with the
3901 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3902 compared. For two fields at the same position, we do the ANDs with the
3903 similar mask and compare the result of the ANDs.
3905 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3906 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3907 are the left and right operands of the comparison, respectively.
3909 If the optimization described above can be done, we return the resulting
3910 tree. Otherwise we return zero. */
3913 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3916 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3917 tree type = TREE_TYPE (lhs);
3918 tree signed_type, unsigned_type;
3919 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3920 enum machine_mode lmode, rmode, nmode;
3921 int lunsignedp, runsignedp;
3922 int lvolatilep = 0, rvolatilep = 0;
3923 tree linner, rinner = NULL_TREE;
3927 /* Get all the information about the extractions being done. If the bit size
3928 if the same as the size of the underlying object, we aren't doing an
3929 extraction at all and so can do nothing. We also don't want to
3930 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3931 then will no longer be able to replace it. */
3932 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3933 &lunsignedp, &lvolatilep, false);
3934 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3935 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3940 /* If this is not a constant, we can only do something if bit positions,
3941 sizes, and signedness are the same. */
3942 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3943 &runsignedp, &rvolatilep, false);
3945 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3946 || lunsignedp != runsignedp || offset != 0
3947 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3951 /* See if we can find a mode to refer to this field. We should be able to,
3952 but fail if we can't. */
3953 nmode = get_best_mode (lbitsize, lbitpos,
3954 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3955 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3956 TYPE_ALIGN (TREE_TYPE (rinner))),
3957 word_mode, lvolatilep || rvolatilep);
3958 if (nmode == VOIDmode)
3961 /* Set signed and unsigned types of the precision of this mode for the
3963 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3964 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3966 /* Compute the bit position and size for the new reference and our offset
3967 within it. If the new reference is the same size as the original, we
3968 won't optimize anything, so return zero. */
3969 nbitsize = GET_MODE_BITSIZE (nmode);
3970 nbitpos = lbitpos & ~ (nbitsize - 1);
3972 if (nbitsize == lbitsize)
3975 if (BYTES_BIG_ENDIAN)
3976 lbitpos = nbitsize - lbitsize - lbitpos;
3978 /* Make the mask to be used against the extracted field. */
3979 mask = build_int_cst_type (unsigned_type, -1);
3980 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3981 mask = const_binop (RSHIFT_EXPR, mask,
3982 size_int (nbitsize - lbitsize - lbitpos), 0);
3985 /* If not comparing with constant, just rework the comparison
3987 return fold_build2 (code, compare_type,
3988 fold_build2 (BIT_AND_EXPR, unsigned_type,
3989 make_bit_field_ref (linner,
3994 fold_build2 (BIT_AND_EXPR, unsigned_type,
3995 make_bit_field_ref (rinner,
4001 /* Otherwise, we are handling the constant case. See if the constant is too
4002 big for the field. Warn and return a tree of for 0 (false) if so. We do
4003 this not only for its own sake, but to avoid having to test for this
4004 error case below. If we didn't, we might generate wrong code.
4006 For unsigned fields, the constant shifted right by the field length should
4007 be all zero. For signed fields, the high-order bits should agree with
4012 if (! integer_zerop (const_binop (RSHIFT_EXPR,
4013 fold_convert (unsigned_type, rhs),
4014 size_int (lbitsize), 0)))
4016 warning (0, "comparison is always %d due to width of bit-field",
4018 return constant_boolean_node (code == NE_EXPR, compare_type);
4023 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
4024 size_int (lbitsize - 1), 0);
4025 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
4027 warning (0, "comparison is always %d due to width of bit-field",
4029 return constant_boolean_node (code == NE_EXPR, compare_type);
4033 /* Single-bit compares should always be against zero. */
4034 if (lbitsize == 1 && ! integer_zerop (rhs))
4036 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
4037 rhs = build_int_cst (type, 0);
4040 /* Make a new bitfield reference, shift the constant over the
4041 appropriate number of bits and mask it with the computed mask
4042 (in case this was a signed field). If we changed it, make a new one. */
4043 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
4046 TREE_SIDE_EFFECTS (lhs) = 1;
4047 TREE_THIS_VOLATILE (lhs) = 1;
4050 rhs = const_binop (BIT_AND_EXPR,
4051 const_binop (LSHIFT_EXPR,
4052 fold_convert (unsigned_type, rhs),
4053 size_int (lbitpos), 0),
4056 return build2 (code, compare_type,
4057 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
4061 /* Subroutine for fold_truthop: decode a field reference.
4063 If EXP is a comparison reference, we return the innermost reference.
4065 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
4066 set to the starting bit number.
4068 If the innermost field can be completely contained in a mode-sized
4069 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
4071 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
4072 otherwise it is not changed.
4074 *PUNSIGNEDP is set to the signedness of the field.
4076 *PMASK is set to the mask used. This is either contained in a
4077 BIT_AND_EXPR or derived from the width of the field.
4079 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
4081 Return 0 if this is not a component reference or is one that we can't
4082 do anything with. */
4085 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
4086 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
4087 int *punsignedp, int *pvolatilep,
4088 tree *pmask, tree *pand_mask)
4090 tree outer_type = 0;
4092 tree mask, inner, offset;
4094 unsigned int precision;
4096 /* All the optimizations using this function assume integer fields.
4097 There are problems with FP fields since the type_for_size call
4098 below can fail for, e.g., XFmode. */
4099 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
4102 /* We are interested in the bare arrangement of bits, so strip everything
4103 that doesn't affect the machine mode. However, record the type of the
4104 outermost expression if it may matter below. */
4105 if (CONVERT_EXPR_P (exp)
4106 || TREE_CODE (exp) == NON_LVALUE_EXPR)
4107 outer_type = TREE_TYPE (exp);
4110 if (TREE_CODE (exp) == BIT_AND_EXPR)
4112 and_mask = TREE_OPERAND (exp, 1);
4113 exp = TREE_OPERAND (exp, 0);
4114 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
4115 if (TREE_CODE (and_mask) != INTEGER_CST)
4119 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
4120 punsignedp, pvolatilep, false);
4121 if ((inner == exp && and_mask == 0)
4122 || *pbitsize < 0 || offset != 0
4123 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
4126 /* If the number of bits in the reference is the same as the bitsize of
4127 the outer type, then the outer type gives the signedness. Otherwise
4128 (in case of a small bitfield) the signedness is unchanged. */
4129 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
4130 *punsignedp = TYPE_UNSIGNED (outer_type);
4132 /* Compute the mask to access the bitfield. */
4133 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
4134 precision = TYPE_PRECISION (unsigned_type);
4136 mask = build_int_cst_type (unsigned_type, -1);
4138 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4139 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4141 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
4143 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
4144 fold_convert (unsigned_type, and_mask), mask);
4147 *pand_mask = and_mask;
4151 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
4155 all_ones_mask_p (const_tree mask, int size)
4157 tree type = TREE_TYPE (mask);
4158 unsigned int precision = TYPE_PRECISION (type);
4161 tmask = build_int_cst_type (signed_type_for (type), -1);
4164 tree_int_cst_equal (mask,
4165 const_binop (RSHIFT_EXPR,
4166 const_binop (LSHIFT_EXPR, tmask,
4167 size_int (precision - size),
4169 size_int (precision - size), 0));
4172 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
4173 represents the sign bit of EXP's type. If EXP represents a sign
4174 or zero extension, also test VAL against the unextended type.
4175 The return value is the (sub)expression whose sign bit is VAL,
4176 or NULL_TREE otherwise. */
4179 sign_bit_p (tree exp, const_tree val)
4181 unsigned HOST_WIDE_INT mask_lo, lo;
4182 HOST_WIDE_INT mask_hi, hi;
4186 /* Tree EXP must have an integral type. */
4187 t = TREE_TYPE (exp);
4188 if (! INTEGRAL_TYPE_P (t))
4191 /* Tree VAL must be an integer constant. */
4192 if (TREE_CODE (val) != INTEGER_CST
4193 || TREE_OVERFLOW (val))
4196 width = TYPE_PRECISION (t);
4197 if (width > HOST_BITS_PER_WIDE_INT)
4199 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
4202 mask_hi = ((unsigned HOST_WIDE_INT) -1
4203 >> (2 * HOST_BITS_PER_WIDE_INT - width));
4209 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
4212 mask_lo = ((unsigned HOST_WIDE_INT) -1
4213 >> (HOST_BITS_PER_WIDE_INT - width));
4216 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
4217 treat VAL as if it were unsigned. */
4218 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
4219 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
4222 /* Handle extension from a narrower type. */
4223 if (TREE_CODE (exp) == NOP_EXPR
4224 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
4225 return sign_bit_p (TREE_OPERAND (exp, 0), val);
4230 /* Subroutine for fold_truthop: determine if an operand is simple enough
4231 to be evaluated unconditionally. */
4234 simple_operand_p (const_tree exp)
4236 /* Strip any conversions that don't change the machine mode. */
4239 return (CONSTANT_CLASS_P (exp)
4240 || TREE_CODE (exp) == SSA_NAME
4242 && ! TREE_ADDRESSABLE (exp)
4243 && ! TREE_THIS_VOLATILE (exp)
4244 && ! DECL_NONLOCAL (exp)
4245 /* Don't regard global variables as simple. They may be
4246 allocated in ways unknown to the compiler (shared memory,
4247 #pragma weak, etc). */
4248 && ! TREE_PUBLIC (exp)
4249 && ! DECL_EXTERNAL (exp)
4250 /* Loading a static variable is unduly expensive, but global
4251 registers aren't expensive. */
4252 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
4255 /* The following functions are subroutines to fold_range_test and allow it to
4256 try to change a logical combination of comparisons into a range test.
4259 X == 2 || X == 3 || X == 4 || X == 5
4263 (unsigned) (X - 2) <= 3
4265 We describe each set of comparisons as being either inside or outside
4266 a range, using a variable named like IN_P, and then describe the
4267 range with a lower and upper bound. If one of the bounds is omitted,
4268 it represents either the highest or lowest value of the type.
4270 In the comments below, we represent a range by two numbers in brackets
4271 preceded by a "+" to designate being inside that range, or a "-" to
4272 designate being outside that range, so the condition can be inverted by
4273 flipping the prefix. An omitted bound is represented by a "-". For
4274 example, "- [-, 10]" means being outside the range starting at the lowest
4275 possible value and ending at 10, in other words, being greater than 10.
4276 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4279 We set up things so that the missing bounds are handled in a consistent
4280 manner so neither a missing bound nor "true" and "false" need to be
4281 handled using a special case. */
4283 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4284 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4285 and UPPER1_P are nonzero if the respective argument is an upper bound
4286 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4287 must be specified for a comparison. ARG1 will be converted to ARG0's
4288 type if both are specified. */
4291 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
4292 tree arg1, int upper1_p)
4298 /* If neither arg represents infinity, do the normal operation.
4299 Else, if not a comparison, return infinity. Else handle the special
4300 comparison rules. Note that most of the cases below won't occur, but
4301 are handled for consistency. */
4303 if (arg0 != 0 && arg1 != 0)
4305 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
4306 arg0, fold_convert (TREE_TYPE (arg0), arg1));
4308 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
4311 if (TREE_CODE_CLASS (code) != tcc_comparison)
4314 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4315 for neither. In real maths, we cannot assume open ended ranges are
4316 the same. But, this is computer arithmetic, where numbers are finite.
4317 We can therefore make the transformation of any unbounded range with
4318 the value Z, Z being greater than any representable number. This permits
4319 us to treat unbounded ranges as equal. */
4320 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
4321 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
4325 result = sgn0 == sgn1;
4328 result = sgn0 != sgn1;
4331 result = sgn0 < sgn1;
4334 result = sgn0 <= sgn1;
4337 result = sgn0 > sgn1;
4340 result = sgn0 >= sgn1;
4346 return constant_boolean_node (result, type);
4349 /* Given EXP, a logical expression, set the range it is testing into
4350 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4351 actually being tested. *PLOW and *PHIGH will be made of the same
4352 type as the returned expression. If EXP is not a comparison, we
4353 will most likely not be returning a useful value and range. Set
4354 *STRICT_OVERFLOW_P to true if the return value is only valid
4355 because signed overflow is undefined; otherwise, do not change
4356 *STRICT_OVERFLOW_P. */
4359 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4360 bool *strict_overflow_p)
4362 enum tree_code code;
4363 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4364 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4366 tree low, high, n_low, n_high;
4368 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4369 and see if we can refine the range. Some of the cases below may not
4370 happen, but it doesn't seem worth worrying about this. We "continue"
4371 the outer loop when we've changed something; otherwise we "break"
4372 the switch, which will "break" the while. */
4375 low = high = build_int_cst (TREE_TYPE (exp), 0);
4379 code = TREE_CODE (exp);
4380 exp_type = TREE_TYPE (exp);
4382 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4384 if (TREE_OPERAND_LENGTH (exp) > 0)
4385 arg0 = TREE_OPERAND (exp, 0);
4386 if (TREE_CODE_CLASS (code) == tcc_comparison
4387 || TREE_CODE_CLASS (code) == tcc_unary
4388 || TREE_CODE_CLASS (code) == tcc_binary)
4389 arg0_type = TREE_TYPE (arg0);
4390 if (TREE_CODE_CLASS (code) == tcc_binary
4391 || TREE_CODE_CLASS (code) == tcc_comparison
4392 || (TREE_CODE_CLASS (code) == tcc_expression
4393 && TREE_OPERAND_LENGTH (exp) > 1))
4394 arg1 = TREE_OPERAND (exp, 1);
4399 case TRUTH_NOT_EXPR:
4400 in_p = ! in_p, exp = arg0;
4403 case EQ_EXPR: case NE_EXPR:
4404 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4405 /* We can only do something if the range is testing for zero
4406 and if the second operand is an integer constant. Note that
4407 saying something is "in" the range we make is done by
4408 complementing IN_P since it will set in the initial case of
4409 being not equal to zero; "out" is leaving it alone. */
4410 if (low == 0 || high == 0
4411 || ! integer_zerop (low) || ! integer_zerop (high)
4412 || TREE_CODE (arg1) != INTEGER_CST)
4417 case NE_EXPR: /* - [c, c] */
4420 case EQ_EXPR: /* + [c, c] */
4421 in_p = ! in_p, low = high = arg1;
4423 case GT_EXPR: /* - [-, c] */
4424 low = 0, high = arg1;
4426 case GE_EXPR: /* + [c, -] */
4427 in_p = ! in_p, low = arg1, high = 0;
4429 case LT_EXPR: /* - [c, -] */
4430 low = arg1, high = 0;
4432 case LE_EXPR: /* + [-, c] */
4433 in_p = ! in_p, low = 0, high = arg1;
4439 /* If this is an unsigned comparison, we also know that EXP is
4440 greater than or equal to zero. We base the range tests we make
4441 on that fact, so we record it here so we can parse existing
4442 range tests. We test arg0_type since often the return type
4443 of, e.g. EQ_EXPR, is boolean. */
4444 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4446 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4448 build_int_cst (arg0_type, 0),
4452 in_p = n_in_p, low = n_low, high = n_high;
4454 /* If the high bound is missing, but we have a nonzero low
4455 bound, reverse the range so it goes from zero to the low bound
4457 if (high == 0 && low && ! integer_zerop (low))
4460 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4461 integer_one_node, 0);
4462 low = build_int_cst (arg0_type, 0);
4470 /* (-x) IN [a,b] -> x in [-b, -a] */
4471 n_low = range_binop (MINUS_EXPR, exp_type,
4472 build_int_cst (exp_type, 0),
4474 n_high = range_binop (MINUS_EXPR, exp_type,
4475 build_int_cst (exp_type, 0),
4477 low = n_low, high = n_high;
4483 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4484 build_int_cst (exp_type, 1));
4487 case PLUS_EXPR: case MINUS_EXPR:
4488 if (TREE_CODE (arg1) != INTEGER_CST)
4491 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4492 move a constant to the other side. */
4493 if (!TYPE_UNSIGNED (arg0_type)
4494 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4497 /* If EXP is signed, any overflow in the computation is undefined,
4498 so we don't worry about it so long as our computations on
4499 the bounds don't overflow. For unsigned, overflow is defined
4500 and this is exactly the right thing. */
4501 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4502 arg0_type, low, 0, arg1, 0);
4503 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4504 arg0_type, high, 1, arg1, 0);
4505 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4506 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4509 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4510 *strict_overflow_p = true;
4512 /* Check for an unsigned range which has wrapped around the maximum
4513 value thus making n_high < n_low, and normalize it. */
4514 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4516 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4517 integer_one_node, 0);
4518 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4519 integer_one_node, 0);
4521 /* If the range is of the form +/- [ x+1, x ], we won't
4522 be able to normalize it. But then, it represents the
4523 whole range or the empty set, so make it
4525 if (tree_int_cst_equal (n_low, low)
4526 && tree_int_cst_equal (n_high, high))
4532 low = n_low, high = n_high;
4537 CASE_CONVERT: case NON_LVALUE_EXPR:
4538 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4541 if (! INTEGRAL_TYPE_P (arg0_type)
4542 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4543 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4546 n_low = low, n_high = high;
4549 n_low = fold_convert (arg0_type, n_low);
4552 n_high = fold_convert (arg0_type, n_high);
4555 /* If we're converting arg0 from an unsigned type, to exp,
4556 a signed type, we will be doing the comparison as unsigned.
4557 The tests above have already verified that LOW and HIGH
4560 So we have to ensure that we will handle large unsigned
4561 values the same way that the current signed bounds treat
4564 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4568 /* For fixed-point modes, we need to pass the saturating flag
4569 as the 2nd parameter. */
4570 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
4571 equiv_type = lang_hooks.types.type_for_mode
4572 (TYPE_MODE (arg0_type),
4573 TYPE_SATURATING (arg0_type));
4575 equiv_type = lang_hooks.types.type_for_mode
4576 (TYPE_MODE (arg0_type), 1);
4578 /* A range without an upper bound is, naturally, unbounded.
4579 Since convert would have cropped a very large value, use
4580 the max value for the destination type. */
4582 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4583 : TYPE_MAX_VALUE (arg0_type);
4585 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4586 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4587 fold_convert (arg0_type,
4589 build_int_cst (arg0_type, 1));
4591 /* If the low bound is specified, "and" the range with the
4592 range for which the original unsigned value will be
4596 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4597 1, n_low, n_high, 1,
4598 fold_convert (arg0_type,
4603 in_p = (n_in_p == in_p);
4607 /* Otherwise, "or" the range with the range of the input
4608 that will be interpreted as negative. */
4609 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4610 0, n_low, n_high, 1,
4611 fold_convert (arg0_type,
4616 in_p = (in_p != n_in_p);
4621 low = n_low, high = n_high;
4631 /* If EXP is a constant, we can evaluate whether this is true or false. */
4632 if (TREE_CODE (exp) == INTEGER_CST)
4634 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4636 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4642 *pin_p = in_p, *plow = low, *phigh = high;
4646 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4647 type, TYPE, return an expression to test if EXP is in (or out of, depending
4648 on IN_P) the range. Return 0 if the test couldn't be created. */
4651 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4653 tree etype = TREE_TYPE (exp);
4656 #ifdef HAVE_canonicalize_funcptr_for_compare
4657 /* Disable this optimization for function pointer expressions
4658 on targets that require function pointer canonicalization. */
4659 if (HAVE_canonicalize_funcptr_for_compare
4660 && TREE_CODE (etype) == POINTER_TYPE
4661 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4667 value = build_range_check (type, exp, 1, low, high);
4669 return invert_truthvalue (value);
4674 if (low == 0 && high == 0)
4675 return build_int_cst (type, 1);
4678 return fold_build2 (LE_EXPR, type, exp,
4679 fold_convert (etype, high));
4682 return fold_build2 (GE_EXPR, type, exp,
4683 fold_convert (etype, low));
4685 if (operand_equal_p (low, high, 0))
4686 return fold_build2 (EQ_EXPR, type, exp,
4687 fold_convert (etype, low));
4689 if (integer_zerop (low))
4691 if (! TYPE_UNSIGNED (etype))
4693 etype = unsigned_type_for (etype);
4694 high = fold_convert (etype, high);
4695 exp = fold_convert (etype, exp);
4697 return build_range_check (type, exp, 1, 0, high);
4700 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4701 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4703 unsigned HOST_WIDE_INT lo;
4707 prec = TYPE_PRECISION (etype);
4708 if (prec <= HOST_BITS_PER_WIDE_INT)
4711 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4715 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4716 lo = (unsigned HOST_WIDE_INT) -1;
4719 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4721 if (TYPE_UNSIGNED (etype))
4723 tree signed_etype = signed_type_for (etype);
4724 if (TYPE_PRECISION (signed_etype) != TYPE_PRECISION (etype))
4726 = build_nonstandard_integer_type (TYPE_PRECISION (etype), 0);
4728 etype = signed_etype;
4729 exp = fold_convert (etype, exp);
4731 return fold_build2 (GT_EXPR, type, exp,
4732 build_int_cst (etype, 0));
4736 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4737 This requires wrap-around arithmetics for the type of the expression. */
4738 switch (TREE_CODE (etype))
4741 /* There is no requirement that LOW be within the range of ETYPE
4742 if the latter is a subtype. It must, however, be within the base
4743 type of ETYPE. So be sure we do the subtraction in that type. */
4744 if (TREE_TYPE (etype))
4745 etype = TREE_TYPE (etype);
4750 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4751 TYPE_UNSIGNED (etype));
4758 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4759 if (TREE_CODE (etype) == INTEGER_TYPE
4760 && !TYPE_OVERFLOW_WRAPS (etype))
4762 tree utype, minv, maxv;
4764 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4765 for the type in question, as we rely on this here. */
4766 utype = unsigned_type_for (etype);
4767 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4768 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4769 integer_one_node, 1);
4770 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4772 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4779 high = fold_convert (etype, high);
4780 low = fold_convert (etype, low);
4781 exp = fold_convert (etype, exp);
4783 value = const_binop (MINUS_EXPR, high, low, 0);
4786 if (POINTER_TYPE_P (etype))
4788 if (value != 0 && !TREE_OVERFLOW (value))
4790 low = fold_convert (sizetype, low);
4791 low = fold_build1 (NEGATE_EXPR, sizetype, low);
4792 return build_range_check (type,
4793 fold_build2 (POINTER_PLUS_EXPR, etype, exp, low),
4794 1, build_int_cst (etype, 0), value);
4799 if (value != 0 && !TREE_OVERFLOW (value))
4800 return build_range_check (type,
4801 fold_build2 (MINUS_EXPR, etype, exp, low),
4802 1, build_int_cst (etype, 0), value);
4807 /* Return the predecessor of VAL in its type, handling the infinite case. */
4810 range_predecessor (tree val)
4812 tree type = TREE_TYPE (val);
4814 if (INTEGRAL_TYPE_P (type)
4815 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4818 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4821 /* Return the successor of VAL in its type, handling the infinite case. */
4824 range_successor (tree val)
4826 tree type = TREE_TYPE (val);
4828 if (INTEGRAL_TYPE_P (type)
4829 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4832 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4835 /* Given two ranges, see if we can merge them into one. Return 1 if we
4836 can, 0 if we can't. Set the output range into the specified parameters. */
4839 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4840 tree high0, int in1_p, tree low1, tree high1)
4848 int lowequal = ((low0 == 0 && low1 == 0)
4849 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4850 low0, 0, low1, 0)));
4851 int highequal = ((high0 == 0 && high1 == 0)
4852 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4853 high0, 1, high1, 1)));
4855 /* Make range 0 be the range that starts first, or ends last if they
4856 start at the same value. Swap them if it isn't. */
4857 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4860 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4861 high1, 1, high0, 1))))
4863 temp = in0_p, in0_p = in1_p, in1_p = temp;
4864 tem = low0, low0 = low1, low1 = tem;
4865 tem = high0, high0 = high1, high1 = tem;
4868 /* Now flag two cases, whether the ranges are disjoint or whether the
4869 second range is totally subsumed in the first. Note that the tests
4870 below are simplified by the ones above. */
4871 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4872 high0, 1, low1, 0));
4873 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4874 high1, 1, high0, 1));
4876 /* We now have four cases, depending on whether we are including or
4877 excluding the two ranges. */
4880 /* If they don't overlap, the result is false. If the second range
4881 is a subset it is the result. Otherwise, the range is from the start
4882 of the second to the end of the first. */
4884 in_p = 0, low = high = 0;
4886 in_p = 1, low = low1, high = high1;
4888 in_p = 1, low = low1, high = high0;
4891 else if (in0_p && ! in1_p)
4893 /* If they don't overlap, the result is the first range. If they are
4894 equal, the result is false. If the second range is a subset of the
4895 first, and the ranges begin at the same place, we go from just after
4896 the end of the second range to the end of the first. If the second
4897 range is not a subset of the first, or if it is a subset and both
4898 ranges end at the same place, the range starts at the start of the
4899 first range and ends just before the second range.
4900 Otherwise, we can't describe this as a single range. */
4902 in_p = 1, low = low0, high = high0;
4903 else if (lowequal && highequal)
4904 in_p = 0, low = high = 0;
4905 else if (subset && lowequal)
4907 low = range_successor (high1);
4912 /* We are in the weird situation where high0 > high1 but
4913 high1 has no successor. Punt. */
4917 else if (! subset || highequal)
4920 high = range_predecessor (low1);
4924 /* low0 < low1 but low1 has no predecessor. Punt. */
4932 else if (! in0_p && in1_p)
4934 /* If they don't overlap, the result is the second range. If the second
4935 is a subset of the first, the result is false. Otherwise,
4936 the range starts just after the first range and ends at the
4937 end of the second. */
4939 in_p = 1, low = low1, high = high1;
4940 else if (subset || highequal)
4941 in_p = 0, low = high = 0;
4944 low = range_successor (high0);
4949 /* high1 > high0 but high0 has no successor. Punt. */
4957 /* The case where we are excluding both ranges. Here the complex case
4958 is if they don't overlap. In that case, the only time we have a
4959 range is if they are adjacent. If the second is a subset of the
4960 first, the result is the first. Otherwise, the range to exclude
4961 starts at the beginning of the first range and ends at the end of the
4965 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4966 range_successor (high0),
4968 in_p = 0, low = low0, high = high1;
4971 /* Canonicalize - [min, x] into - [-, x]. */
4972 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4973 switch (TREE_CODE (TREE_TYPE (low0)))
4976 if (TYPE_PRECISION (TREE_TYPE (low0))
4977 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4981 if (tree_int_cst_equal (low0,
4982 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4986 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4987 && integer_zerop (low0))
4994 /* Canonicalize - [x, max] into - [x, -]. */
4995 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4996 switch (TREE_CODE (TREE_TYPE (high1)))
4999 if (TYPE_PRECISION (TREE_TYPE (high1))
5000 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
5004 if (tree_int_cst_equal (high1,
5005 TYPE_MAX_VALUE (TREE_TYPE (high1))))
5009 if (TYPE_UNSIGNED (TREE_TYPE (high1))
5010 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
5012 integer_one_node, 1)))
5019 /* The ranges might be also adjacent between the maximum and
5020 minimum values of the given type. For
5021 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
5022 return + [x + 1, y - 1]. */
5023 if (low0 == 0 && high1 == 0)
5025 low = range_successor (high0);
5026 high = range_predecessor (low1);
5027 if (low == 0 || high == 0)
5037 in_p = 0, low = low0, high = high0;
5039 in_p = 0, low = low0, high = high1;
5042 *pin_p = in_p, *plow = low, *phigh = high;
5047 /* Subroutine of fold, looking inside expressions of the form
5048 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
5049 of the COND_EXPR. This function is being used also to optimize
5050 A op B ? C : A, by reversing the comparison first.
5052 Return a folded expression whose code is not a COND_EXPR
5053 anymore, or NULL_TREE if no folding opportunity is found. */
5056 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
5058 enum tree_code comp_code = TREE_CODE (arg0);
5059 tree arg00 = TREE_OPERAND (arg0, 0);
5060 tree arg01 = TREE_OPERAND (arg0, 1);
5061 tree arg1_type = TREE_TYPE (arg1);
5067 /* If we have A op 0 ? A : -A, consider applying the following
5070 A == 0? A : -A same as -A
5071 A != 0? A : -A same as A
5072 A >= 0? A : -A same as abs (A)
5073 A > 0? A : -A same as abs (A)
5074 A <= 0? A : -A same as -abs (A)
5075 A < 0? A : -A same as -abs (A)
5077 None of these transformations work for modes with signed
5078 zeros. If A is +/-0, the first two transformations will
5079 change the sign of the result (from +0 to -0, or vice
5080 versa). The last four will fix the sign of the result,
5081 even though the original expressions could be positive or
5082 negative, depending on the sign of A.
5084 Note that all these transformations are correct if A is
5085 NaN, since the two alternatives (A and -A) are also NaNs. */
5086 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
5087 && (FLOAT_TYPE_P (TREE_TYPE (arg01))
5088 ? real_zerop (arg01)
5089 : integer_zerop (arg01))
5090 && ((TREE_CODE (arg2) == NEGATE_EXPR
5091 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
5092 /* In the case that A is of the form X-Y, '-A' (arg2) may
5093 have already been folded to Y-X, check for that. */
5094 || (TREE_CODE (arg1) == MINUS_EXPR
5095 && TREE_CODE (arg2) == MINUS_EXPR
5096 && operand_equal_p (TREE_OPERAND (arg1, 0),
5097 TREE_OPERAND (arg2, 1), 0)
5098 && operand_equal_p (TREE_OPERAND (arg1, 1),
5099 TREE_OPERAND (arg2, 0), 0))))
5104 tem = fold_convert (arg1_type, arg1);
5105 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
5108 return pedantic_non_lvalue (fold_convert (type, arg1));
5111 if (flag_trapping_math)
5116 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5117 arg1 = fold_convert (signed_type_for
5118 (TREE_TYPE (arg1)), arg1);
5119 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5120 return pedantic_non_lvalue (fold_convert (type, tem));
5123 if (flag_trapping_math)
5127 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5128 arg1 = fold_convert (signed_type_for
5129 (TREE_TYPE (arg1)), arg1);
5130 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5131 return negate_expr (fold_convert (type, tem));
5133 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5137 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
5138 A == 0 ? A : 0 is always 0 unless A is -0. Note that
5139 both transformations are correct when A is NaN: A != 0
5140 is then true, and A == 0 is false. */
5142 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
5143 && integer_zerop (arg01) && integer_zerop (arg2))
5145 if (comp_code == NE_EXPR)
5146 return pedantic_non_lvalue (fold_convert (type, arg1));
5147 else if (comp_code == EQ_EXPR)
5148 return build_int_cst (type, 0);
5151 /* Try some transformations of A op B ? A : B.
5153 A == B? A : B same as B
5154 A != B? A : B same as A
5155 A >= B? A : B same as max (A, B)
5156 A > B? A : B same as max (B, A)
5157 A <= B? A : B same as min (A, B)
5158 A < B? A : B same as min (B, A)
5160 As above, these transformations don't work in the presence
5161 of signed zeros. For example, if A and B are zeros of
5162 opposite sign, the first two transformations will change
5163 the sign of the result. In the last four, the original
5164 expressions give different results for (A=+0, B=-0) and
5165 (A=-0, B=+0), but the transformed expressions do not.
5167 The first two transformations are correct if either A or B
5168 is a NaN. In the first transformation, the condition will
5169 be false, and B will indeed be chosen. In the case of the
5170 second transformation, the condition A != B will be true,
5171 and A will be chosen.
5173 The conversions to max() and min() are not correct if B is
5174 a number and A is not. The conditions in the original
5175 expressions will be false, so all four give B. The min()
5176 and max() versions would give a NaN instead. */
5177 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
5178 && operand_equal_for_comparison_p (arg01, arg2, arg00)
5179 /* Avoid these transformations if the COND_EXPR may be used
5180 as an lvalue in the C++ front-end. PR c++/19199. */
5182 || (strcmp (lang_hooks.name, "GNU C++") != 0
5183 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
5184 || ! maybe_lvalue_p (arg1)
5185 || ! maybe_lvalue_p (arg2)))
5187 tree comp_op0 = arg00;
5188 tree comp_op1 = arg01;
5189 tree comp_type = TREE_TYPE (comp_op0);
5191 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
5192 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
5202 return pedantic_non_lvalue (fold_convert (type, arg2));
5204 return pedantic_non_lvalue (fold_convert (type, arg1));
5209 /* In C++ a ?: expression can be an lvalue, so put the
5210 operand which will be used if they are equal first
5211 so that we can convert this back to the
5212 corresponding COND_EXPR. */
5213 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5215 comp_op0 = fold_convert (comp_type, comp_op0);
5216 comp_op1 = fold_convert (comp_type, comp_op1);
5217 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
5218 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
5219 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
5220 return pedantic_non_lvalue (fold_convert (type, tem));
5227 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5229 comp_op0 = fold_convert (comp_type, comp_op0);
5230 comp_op1 = fold_convert (comp_type, comp_op1);
5231 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
5232 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
5233 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
5234 return pedantic_non_lvalue (fold_convert (type, tem));
5238 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5239 return pedantic_non_lvalue (fold_convert (type, arg2));
5242 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5243 return pedantic_non_lvalue (fold_convert (type, arg1));
5246 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5251 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
5252 we might still be able to simplify this. For example,
5253 if C1 is one less or one more than C2, this might have started
5254 out as a MIN or MAX and been transformed by this function.
5255 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
5257 if (INTEGRAL_TYPE_P (type)
5258 && TREE_CODE (arg01) == INTEGER_CST
5259 && TREE_CODE (arg2) == INTEGER_CST)
5263 /* We can replace A with C1 in this case. */
5264 arg1 = fold_convert (type, arg01);
5265 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
5268 /* If C1 is C2 + 1, this is min(A, C2). */
5269 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5271 && operand_equal_p (arg01,
5272 const_binop (PLUS_EXPR, arg2,
5273 build_int_cst (type, 1), 0),
5275 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5277 fold_convert (type, arg1),
5282 /* If C1 is C2 - 1, this is min(A, C2). */
5283 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5285 && operand_equal_p (arg01,
5286 const_binop (MINUS_EXPR, arg2,
5287 build_int_cst (type, 1), 0),
5289 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5291 fold_convert (type, arg1),
5296 /* If C1 is C2 - 1, this is max(A, C2). */
5297 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5299 && operand_equal_p (arg01,
5300 const_binop (MINUS_EXPR, arg2,
5301 build_int_cst (type, 1), 0),
5303 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5305 fold_convert (type, arg1),
5310 /* If C1 is C2 + 1, this is max(A, C2). */
5311 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5313 && operand_equal_p (arg01,
5314 const_binop (PLUS_EXPR, arg2,
5315 build_int_cst (type, 1), 0),
5317 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5319 fold_convert (type, arg1),
5333 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5334 #define LOGICAL_OP_NON_SHORT_CIRCUIT \
5335 (BRANCH_COST (optimize_function_for_speed_p (cfun), \
5339 /* EXP is some logical combination of boolean tests. See if we can
5340 merge it into some range test. Return the new tree if so. */
5343 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
5345 int or_op = (code == TRUTH_ORIF_EXPR
5346 || code == TRUTH_OR_EXPR);
5347 int in0_p, in1_p, in_p;
5348 tree low0, low1, low, high0, high1, high;
5349 bool strict_overflow_p = false;
5350 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
5351 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
5353 const char * const warnmsg = G_("assuming signed overflow does not occur "
5354 "when simplifying range test");
5356 /* If this is an OR operation, invert both sides; we will invert
5357 again at the end. */
5359 in0_p = ! in0_p, in1_p = ! in1_p;
5361 /* If both expressions are the same, if we can merge the ranges, and we
5362 can build the range test, return it or it inverted. If one of the
5363 ranges is always true or always false, consider it to be the same
5364 expression as the other. */
5365 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
5366 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
5368 && 0 != (tem = (build_range_check (type,
5370 : rhs != 0 ? rhs : integer_zero_node,
5373 if (strict_overflow_p)
5374 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
5375 return or_op ? invert_truthvalue (tem) : tem;
5378 /* On machines where the branch cost is expensive, if this is a
5379 short-circuited branch and the underlying object on both sides
5380 is the same, make a non-short-circuit operation. */
5381 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5382 && lhs != 0 && rhs != 0
5383 && (code == TRUTH_ANDIF_EXPR
5384 || code == TRUTH_ORIF_EXPR)
5385 && operand_equal_p (lhs, rhs, 0))
5387 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5388 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5389 which cases we can't do this. */
5390 if (simple_operand_p (lhs))
5391 return build2 (code == TRUTH_ANDIF_EXPR
5392 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5395 else if (lang_hooks.decls.global_bindings_p () == 0
5396 && ! CONTAINS_PLACEHOLDER_P (lhs))
5398 tree common = save_expr (lhs);
5400 if (0 != (lhs = build_range_check (type, common,
5401 or_op ? ! in0_p : in0_p,
5403 && (0 != (rhs = build_range_check (type, common,
5404 or_op ? ! in1_p : in1_p,
5407 if (strict_overflow_p)
5408 fold_overflow_warning (warnmsg,
5409 WARN_STRICT_OVERFLOW_COMPARISON);
5410 return build2 (code == TRUTH_ANDIF_EXPR
5411 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5420 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5421 bit value. Arrange things so the extra bits will be set to zero if and
5422 only if C is signed-extended to its full width. If MASK is nonzero,
5423 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5426 unextend (tree c, int p, int unsignedp, tree mask)
5428 tree type = TREE_TYPE (c);
5429 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5432 if (p == modesize || unsignedp)
5435 /* We work by getting just the sign bit into the low-order bit, then
5436 into the high-order bit, then sign-extend. We then XOR that value
5438 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5439 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5441 /* We must use a signed type in order to get an arithmetic right shift.
5442 However, we must also avoid introducing accidental overflows, so that
5443 a subsequent call to integer_zerop will work. Hence we must
5444 do the type conversion here. At this point, the constant is either
5445 zero or one, and the conversion to a signed type can never overflow.
5446 We could get an overflow if this conversion is done anywhere else. */
5447 if (TYPE_UNSIGNED (type))
5448 temp = fold_convert (signed_type_for (type), temp);
5450 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5451 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5453 temp = const_binop (BIT_AND_EXPR, temp,
5454 fold_convert (TREE_TYPE (c), mask), 0);
5455 /* If necessary, convert the type back to match the type of C. */
5456 if (TYPE_UNSIGNED (type))
5457 temp = fold_convert (type, temp);
5459 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5462 /* Find ways of folding logical expressions of LHS and RHS:
5463 Try to merge two comparisons to the same innermost item.
5464 Look for range tests like "ch >= '0' && ch <= '9'".
5465 Look for combinations of simple terms on machines with expensive branches
5466 and evaluate the RHS unconditionally.
5468 For example, if we have p->a == 2 && p->b == 4 and we can make an
5469 object large enough to span both A and B, we can do this with a comparison
5470 against the object ANDed with the a mask.
5472 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5473 operations to do this with one comparison.
5475 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5476 function and the one above.
5478 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5479 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5481 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5484 We return the simplified tree or 0 if no optimization is possible. */
5487 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5489 /* If this is the "or" of two comparisons, we can do something if
5490 the comparisons are NE_EXPR. If this is the "and", we can do something
5491 if the comparisons are EQ_EXPR. I.e.,
5492 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5494 WANTED_CODE is this operation code. For single bit fields, we can
5495 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5496 comparison for one-bit fields. */
5498 enum tree_code wanted_code;
5499 enum tree_code lcode, rcode;
5500 tree ll_arg, lr_arg, rl_arg, rr_arg;
5501 tree ll_inner, lr_inner, rl_inner, rr_inner;
5502 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5503 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5504 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
5505 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
5506 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5507 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5508 enum machine_mode lnmode, rnmode;
5509 tree ll_mask, lr_mask, rl_mask, rr_mask;
5510 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5511 tree l_const, r_const;
5512 tree lntype, rntype, result;
5513 HOST_WIDE_INT first_bit, end_bit;
5515 tree orig_lhs = lhs, orig_rhs = rhs;
5516 enum tree_code orig_code = code;
5518 /* Start by getting the comparison codes. Fail if anything is volatile.
5519 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5520 it were surrounded with a NE_EXPR. */
5522 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5525 lcode = TREE_CODE (lhs);
5526 rcode = TREE_CODE (rhs);
5528 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5530 lhs = build2 (NE_EXPR, truth_type, lhs,
5531 build_int_cst (TREE_TYPE (lhs), 0));
5535 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5537 rhs = build2 (NE_EXPR, truth_type, rhs,
5538 build_int_cst (TREE_TYPE (rhs), 0));
5542 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5543 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5546 ll_arg = TREE_OPERAND (lhs, 0);
5547 lr_arg = TREE_OPERAND (lhs, 1);
5548 rl_arg = TREE_OPERAND (rhs, 0);
5549 rr_arg = TREE_OPERAND (rhs, 1);
5551 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5552 if (simple_operand_p (ll_arg)
5553 && simple_operand_p (lr_arg))
5556 if (operand_equal_p (ll_arg, rl_arg, 0)
5557 && operand_equal_p (lr_arg, rr_arg, 0))
5559 result = combine_comparisons (code, lcode, rcode,
5560 truth_type, ll_arg, lr_arg);
5564 else if (operand_equal_p (ll_arg, rr_arg, 0)
5565 && operand_equal_p (lr_arg, rl_arg, 0))
5567 result = combine_comparisons (code, lcode,
5568 swap_tree_comparison (rcode),
5569 truth_type, ll_arg, lr_arg);
5575 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5576 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5578 /* If the RHS can be evaluated unconditionally and its operands are
5579 simple, it wins to evaluate the RHS unconditionally on machines
5580 with expensive branches. In this case, this isn't a comparison
5581 that can be merged. Avoid doing this if the RHS is a floating-point
5582 comparison since those can trap. */
5584 if (BRANCH_COST (optimize_function_for_speed_p (cfun),
5586 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5587 && simple_operand_p (rl_arg)
5588 && simple_operand_p (rr_arg))
5590 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5591 if (code == TRUTH_OR_EXPR
5592 && lcode == NE_EXPR && integer_zerop (lr_arg)
5593 && rcode == NE_EXPR && integer_zerop (rr_arg)
5594 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5595 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5596 return build2 (NE_EXPR, truth_type,
5597 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5599 build_int_cst (TREE_TYPE (ll_arg), 0));
5601 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5602 if (code == TRUTH_AND_EXPR
5603 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5604 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5605 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5606 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5607 return build2 (EQ_EXPR, truth_type,
5608 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5610 build_int_cst (TREE_TYPE (ll_arg), 0));
5612 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5614 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5615 return build2 (code, truth_type, lhs, rhs);
5620 /* See if the comparisons can be merged. Then get all the parameters for
5623 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5624 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5628 ll_inner = decode_field_reference (ll_arg,
5629 &ll_bitsize, &ll_bitpos, &ll_mode,
5630 &ll_unsignedp, &volatilep, &ll_mask,
5632 lr_inner = decode_field_reference (lr_arg,
5633 &lr_bitsize, &lr_bitpos, &lr_mode,
5634 &lr_unsignedp, &volatilep, &lr_mask,
5636 rl_inner = decode_field_reference (rl_arg,
5637 &rl_bitsize, &rl_bitpos, &rl_mode,
5638 &rl_unsignedp, &volatilep, &rl_mask,
5640 rr_inner = decode_field_reference (rr_arg,
5641 &rr_bitsize, &rr_bitpos, &rr_mode,
5642 &rr_unsignedp, &volatilep, &rr_mask,
5645 /* It must be true that the inner operation on the lhs of each
5646 comparison must be the same if we are to be able to do anything.
5647 Then see if we have constants. If not, the same must be true for
5649 if (volatilep || ll_inner == 0 || rl_inner == 0
5650 || ! operand_equal_p (ll_inner, rl_inner, 0))
5653 if (TREE_CODE (lr_arg) == INTEGER_CST
5654 && TREE_CODE (rr_arg) == INTEGER_CST)
5655 l_const = lr_arg, r_const = rr_arg;
5656 else if (lr_inner == 0 || rr_inner == 0
5657 || ! operand_equal_p (lr_inner, rr_inner, 0))
5660 l_const = r_const = 0;
5662 /* If either comparison code is not correct for our logical operation,
5663 fail. However, we can convert a one-bit comparison against zero into
5664 the opposite comparison against that bit being set in the field. */
5666 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5667 if (lcode != wanted_code)
5669 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5671 /* Make the left operand unsigned, since we are only interested
5672 in the value of one bit. Otherwise we are doing the wrong
5681 /* This is analogous to the code for l_const above. */
5682 if (rcode != wanted_code)
5684 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5693 /* See if we can find a mode that contains both fields being compared on
5694 the left. If we can't, fail. Otherwise, update all constants and masks
5695 to be relative to a field of that size. */
5696 first_bit = MIN (ll_bitpos, rl_bitpos);
5697 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5698 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5699 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5701 if (lnmode == VOIDmode)
5704 lnbitsize = GET_MODE_BITSIZE (lnmode);
5705 lnbitpos = first_bit & ~ (lnbitsize - 1);
5706 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5707 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5709 if (BYTES_BIG_ENDIAN)
5711 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5712 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5715 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5716 size_int (xll_bitpos), 0);
5717 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5718 size_int (xrl_bitpos), 0);
5722 l_const = fold_convert (lntype, l_const);
5723 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5724 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5725 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5726 fold_build1 (BIT_NOT_EXPR,
5730 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5732 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5737 r_const = fold_convert (lntype, r_const);
5738 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5739 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5740 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5741 fold_build1 (BIT_NOT_EXPR,
5745 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5747 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5751 /* If the right sides are not constant, do the same for it. Also,
5752 disallow this optimization if a size or signedness mismatch occurs
5753 between the left and right sides. */
5756 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
5757 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
5758 /* Make sure the two fields on the right
5759 correspond to the left without being swapped. */
5760 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
5763 first_bit = MIN (lr_bitpos, rr_bitpos);
5764 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
5765 rnmode = get_best_mode (end_bit - first_bit, first_bit,
5766 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
5768 if (rnmode == VOIDmode)
5771 rnbitsize = GET_MODE_BITSIZE (rnmode);
5772 rnbitpos = first_bit & ~ (rnbitsize - 1);
5773 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
5774 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
5776 if (BYTES_BIG_ENDIAN)
5778 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
5779 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
5782 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
5783 size_int (xlr_bitpos), 0);
5784 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
5785 size_int (xrr_bitpos), 0);
5787 /* Make a mask that corresponds to both fields being compared.
5788 Do this for both items being compared. If the operands are the
5789 same size and the bits being compared are in the same position
5790 then we can do this by masking both and comparing the masked
5792 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5793 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
5794 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
5796 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5797 ll_unsignedp || rl_unsignedp);
5798 if (! all_ones_mask_p (ll_mask, lnbitsize))
5799 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
5801 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
5802 lr_unsignedp || rr_unsignedp);
5803 if (! all_ones_mask_p (lr_mask, rnbitsize))
5804 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
5806 return build2 (wanted_code, truth_type, lhs, rhs);
5809 /* There is still another way we can do something: If both pairs of
5810 fields being compared are adjacent, we may be able to make a wider
5811 field containing them both.
5813 Note that we still must mask the lhs/rhs expressions. Furthermore,
5814 the mask must be shifted to account for the shift done by
5815 make_bit_field_ref. */
5816 if ((ll_bitsize + ll_bitpos == rl_bitpos
5817 && lr_bitsize + lr_bitpos == rr_bitpos)
5818 || (ll_bitpos == rl_bitpos + rl_bitsize
5819 && lr_bitpos == rr_bitpos + rr_bitsize))
5823 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
5824 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
5825 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
5826 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
5828 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
5829 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
5830 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
5831 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
5833 /* Convert to the smaller type before masking out unwanted bits. */
5835 if (lntype != rntype)
5837 if (lnbitsize > rnbitsize)
5839 lhs = fold_convert (rntype, lhs);
5840 ll_mask = fold_convert (rntype, ll_mask);
5843 else if (lnbitsize < rnbitsize)
5845 rhs = fold_convert (lntype, rhs);
5846 lr_mask = fold_convert (lntype, lr_mask);
5851 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
5852 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
5854 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
5855 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
5857 return build2 (wanted_code, truth_type, lhs, rhs);
5863 /* Handle the case of comparisons with constants. If there is something in
5864 common between the masks, those bits of the constants must be the same.
5865 If not, the condition is always false. Test for this to avoid generating
5866 incorrect code below. */
5867 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5868 if (! integer_zerop (result)
5869 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5870 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5872 if (wanted_code == NE_EXPR)
5874 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5875 return constant_boolean_node (true, truth_type);
5879 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5880 return constant_boolean_node (false, truth_type);
5884 /* Construct the expression we will return. First get the component
5885 reference we will make. Unless the mask is all ones the width of
5886 that field, perform the mask operation. Then compare with the
5888 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5889 ll_unsignedp || rl_unsignedp);
5891 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5892 if (! all_ones_mask_p (ll_mask, lnbitsize))
5893 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
5895 return build2 (wanted_code, truth_type, result,
5896 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
5899 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5903 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5906 enum tree_code op_code;
5909 int consts_equal, consts_lt;
5912 STRIP_SIGN_NOPS (arg0);
5914 op_code = TREE_CODE (arg0);
5915 minmax_const = TREE_OPERAND (arg0, 1);
5916 comp_const = fold_convert (TREE_TYPE (arg0), op1);
5917 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5918 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5919 inner = TREE_OPERAND (arg0, 0);
5921 /* If something does not permit us to optimize, return the original tree. */
5922 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5923 || TREE_CODE (comp_const) != INTEGER_CST
5924 || TREE_OVERFLOW (comp_const)
5925 || TREE_CODE (minmax_const) != INTEGER_CST
5926 || TREE_OVERFLOW (minmax_const))
5929 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5930 and GT_EXPR, doing the rest with recursive calls using logical
5934 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5936 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5939 return invert_truthvalue (tem);
5945 fold_build2 (TRUTH_ORIF_EXPR, type,
5946 optimize_minmax_comparison
5947 (EQ_EXPR, type, arg0, comp_const),
5948 optimize_minmax_comparison
5949 (GT_EXPR, type, arg0, comp_const));
5952 if (op_code == MAX_EXPR && consts_equal)
5953 /* MAX (X, 0) == 0 -> X <= 0 */
5954 return fold_build2 (LE_EXPR, type, inner, comp_const);
5956 else if (op_code == MAX_EXPR && consts_lt)
5957 /* MAX (X, 0) == 5 -> X == 5 */
5958 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5960 else if (op_code == MAX_EXPR)
5961 /* MAX (X, 0) == -1 -> false */
5962 return omit_one_operand (type, integer_zero_node, inner);
5964 else if (consts_equal)
5965 /* MIN (X, 0) == 0 -> X >= 0 */
5966 return fold_build2 (GE_EXPR, type, inner, comp_const);
5969 /* MIN (X, 0) == 5 -> false */
5970 return omit_one_operand (type, integer_zero_node, inner);
5973 /* MIN (X, 0) == -1 -> X == -1 */
5974 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5977 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5978 /* MAX (X, 0) > 0 -> X > 0
5979 MAX (X, 0) > 5 -> X > 5 */
5980 return fold_build2 (GT_EXPR, type, inner, comp_const);
5982 else if (op_code == MAX_EXPR)
5983 /* MAX (X, 0) > -1 -> true */
5984 return omit_one_operand (type, integer_one_node, inner);
5986 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5987 /* MIN (X, 0) > 0 -> false
5988 MIN (X, 0) > 5 -> false */
5989 return omit_one_operand (type, integer_zero_node, inner);
5992 /* MIN (X, 0) > -1 -> X > -1 */
5993 return fold_build2 (GT_EXPR, type, inner, comp_const);
6000 /* T is an integer expression that is being multiplied, divided, or taken a
6001 modulus (CODE says which and what kind of divide or modulus) by a
6002 constant C. See if we can eliminate that operation by folding it with
6003 other operations already in T. WIDE_TYPE, if non-null, is a type that
6004 should be used for the computation if wider than our type.
6006 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
6007 (X * 2) + (Y * 4). We must, however, be assured that either the original
6008 expression would not overflow or that overflow is undefined for the type
6009 in the language in question.
6011 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
6012 the machine has a multiply-accumulate insn or that this is part of an
6013 addressing calculation.
6015 If we return a non-null expression, it is an equivalent form of the
6016 original computation, but need not be in the original type.
6018 We set *STRICT_OVERFLOW_P to true if the return values depends on
6019 signed overflow being undefined. Otherwise we do not change
6020 *STRICT_OVERFLOW_P. */
6023 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
6024 bool *strict_overflow_p)
6026 /* To avoid exponential search depth, refuse to allow recursion past
6027 three levels. Beyond that (1) it's highly unlikely that we'll find
6028 something interesting and (2) we've probably processed it before
6029 when we built the inner expression. */
6038 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
6045 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
6046 bool *strict_overflow_p)
6048 tree type = TREE_TYPE (t);
6049 enum tree_code tcode = TREE_CODE (t);
6050 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
6051 > GET_MODE_SIZE (TYPE_MODE (type)))
6052 ? wide_type : type);
6054 int same_p = tcode == code;
6055 tree op0 = NULL_TREE, op1 = NULL_TREE;
6056 bool sub_strict_overflow_p;
6058 /* Don't deal with constants of zero here; they confuse the code below. */
6059 if (integer_zerop (c))
6062 if (TREE_CODE_CLASS (tcode) == tcc_unary)
6063 op0 = TREE_OPERAND (t, 0);
6065 if (TREE_CODE_CLASS (tcode) == tcc_binary)
6066 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
6068 /* Note that we need not handle conditional operations here since fold
6069 already handles those cases. So just do arithmetic here. */
6073 /* For a constant, we can always simplify if we are a multiply
6074 or (for divide and modulus) if it is a multiple of our constant. */
6075 if (code == MULT_EXPR
6076 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
6077 return const_binop (code, fold_convert (ctype, t),
6078 fold_convert (ctype, c), 0);
6081 CASE_CONVERT: case NON_LVALUE_EXPR:
6082 /* If op0 is an expression ... */
6083 if ((COMPARISON_CLASS_P (op0)
6084 || UNARY_CLASS_P (op0)
6085 || BINARY_CLASS_P (op0)
6086 || VL_EXP_CLASS_P (op0)
6087 || EXPRESSION_CLASS_P (op0))
6088 /* ... and has wrapping overflow, and its type is smaller
6089 than ctype, then we cannot pass through as widening. */
6090 && ((TYPE_OVERFLOW_WRAPS (TREE_TYPE (op0))
6091 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
6092 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
6093 && (TYPE_PRECISION (ctype)
6094 > TYPE_PRECISION (TREE_TYPE (op0))))
6095 /* ... or this is a truncation (t is narrower than op0),
6096 then we cannot pass through this narrowing. */
6097 || (TYPE_PRECISION (type)
6098 < TYPE_PRECISION (TREE_TYPE (op0)))
6099 /* ... or signedness changes for division or modulus,
6100 then we cannot pass through this conversion. */
6101 || (code != MULT_EXPR
6102 && (TYPE_UNSIGNED (ctype)
6103 != TYPE_UNSIGNED (TREE_TYPE (op0))))
6104 /* ... or has undefined overflow while the converted to
6105 type has not, we cannot do the operation in the inner type
6106 as that would introduce undefined overflow. */
6107 || (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))
6108 && !TYPE_OVERFLOW_UNDEFINED (type))))
6111 /* Pass the constant down and see if we can make a simplification. If
6112 we can, replace this expression with the inner simplification for
6113 possible later conversion to our or some other type. */
6114 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
6115 && TREE_CODE (t2) == INTEGER_CST
6116 && !TREE_OVERFLOW (t2)
6117 && (0 != (t1 = extract_muldiv (op0, t2, code,
6119 ? ctype : NULL_TREE,
6120 strict_overflow_p))))
6125 /* If widening the type changes it from signed to unsigned, then we
6126 must avoid building ABS_EXPR itself as unsigned. */
6127 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
6129 tree cstype = (*signed_type_for) (ctype);
6130 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
6133 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
6134 return fold_convert (ctype, t1);
6138 /* If the constant is negative, we cannot simplify this. */
6139 if (tree_int_cst_sgn (c) == -1)
6143 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
6145 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
6148 case MIN_EXPR: case MAX_EXPR:
6149 /* If widening the type changes the signedness, then we can't perform
6150 this optimization as that changes the result. */
6151 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
6154 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
6155 sub_strict_overflow_p = false;
6156 if ((t1 = extract_muldiv (op0, c, code, wide_type,
6157 &sub_strict_overflow_p)) != 0
6158 && (t2 = extract_muldiv (op1, c, code, wide_type,
6159 &sub_strict_overflow_p)) != 0)
6161 if (tree_int_cst_sgn (c) < 0)
6162 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
6163 if (sub_strict_overflow_p)
6164 *strict_overflow_p = true;
6165 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6166 fold_convert (ctype, t2));
6170 case LSHIFT_EXPR: case RSHIFT_EXPR:
6171 /* If the second operand is constant, this is a multiplication
6172 or floor division, by a power of two, so we can treat it that
6173 way unless the multiplier or divisor overflows. Signed
6174 left-shift overflow is implementation-defined rather than
6175 undefined in C90, so do not convert signed left shift into
6177 if (TREE_CODE (op1) == INTEGER_CST
6178 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
6179 /* const_binop may not detect overflow correctly,
6180 so check for it explicitly here. */
6181 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
6182 && TREE_INT_CST_HIGH (op1) == 0
6183 && 0 != (t1 = fold_convert (ctype,
6184 const_binop (LSHIFT_EXPR,
6187 && !TREE_OVERFLOW (t1))
6188 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
6189 ? MULT_EXPR : FLOOR_DIV_EXPR,
6190 ctype, fold_convert (ctype, op0), t1),
6191 c, code, wide_type, strict_overflow_p);
6194 case PLUS_EXPR: case MINUS_EXPR:
6195 /* See if we can eliminate the operation on both sides. If we can, we
6196 can return a new PLUS or MINUS. If we can't, the only remaining
6197 cases where we can do anything are if the second operand is a
6199 sub_strict_overflow_p = false;
6200 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
6201 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
6202 if (t1 != 0 && t2 != 0
6203 && (code == MULT_EXPR
6204 /* If not multiplication, we can only do this if both operands
6205 are divisible by c. */
6206 || (multiple_of_p (ctype, op0, c)
6207 && multiple_of_p (ctype, op1, c))))
6209 if (sub_strict_overflow_p)
6210 *strict_overflow_p = true;
6211 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6212 fold_convert (ctype, t2));
6215 /* If this was a subtraction, negate OP1 and set it to be an addition.
6216 This simplifies the logic below. */
6217 if (tcode == MINUS_EXPR)
6218 tcode = PLUS_EXPR, op1 = negate_expr (op1);
6220 if (TREE_CODE (op1) != INTEGER_CST)
6223 /* If either OP1 or C are negative, this optimization is not safe for
6224 some of the division and remainder types while for others we need
6225 to change the code. */
6226 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
6228 if (code == CEIL_DIV_EXPR)
6229 code = FLOOR_DIV_EXPR;
6230 else if (code == FLOOR_DIV_EXPR)
6231 code = CEIL_DIV_EXPR;
6232 else if (code != MULT_EXPR
6233 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
6237 /* If it's a multiply or a division/modulus operation of a multiple
6238 of our constant, do the operation and verify it doesn't overflow. */
6239 if (code == MULT_EXPR
6240 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6242 op1 = const_binop (code, fold_convert (ctype, op1),
6243 fold_convert (ctype, c), 0);
6244 /* We allow the constant to overflow with wrapping semantics. */
6246 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
6252 /* If we have an unsigned type is not a sizetype, we cannot widen
6253 the operation since it will change the result if the original
6254 computation overflowed. */
6255 if (TYPE_UNSIGNED (ctype)
6256 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
6260 /* If we were able to eliminate our operation from the first side,
6261 apply our operation to the second side and reform the PLUS. */
6262 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
6263 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
6265 /* The last case is if we are a multiply. In that case, we can
6266 apply the distributive law to commute the multiply and addition
6267 if the multiplication of the constants doesn't overflow. */
6268 if (code == MULT_EXPR)
6269 return fold_build2 (tcode, ctype,
6270 fold_build2 (code, ctype,
6271 fold_convert (ctype, op0),
6272 fold_convert (ctype, c)),
6278 /* We have a special case here if we are doing something like
6279 (C * 8) % 4 since we know that's zero. */
6280 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
6281 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
6282 /* If the multiplication can overflow we cannot optimize this.
6283 ??? Until we can properly mark individual operations as
6284 not overflowing we need to treat sizetype special here as
6285 stor-layout relies on this opimization to make
6286 DECL_FIELD_BIT_OFFSET always a constant. */
6287 && (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t))
6288 || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
6289 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
6290 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
6291 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6293 *strict_overflow_p = true;
6294 return omit_one_operand (type, integer_zero_node, op0);
6297 /* ... fall through ... */
6299 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
6300 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
6301 /* If we can extract our operation from the LHS, do so and return a
6302 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
6303 do something only if the second operand is a constant. */
6305 && (t1 = extract_muldiv (op0, c, code, wide_type,
6306 strict_overflow_p)) != 0)
6307 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6308 fold_convert (ctype, op1));
6309 else if (tcode == MULT_EXPR && code == MULT_EXPR
6310 && (t1 = extract_muldiv (op1, c, code, wide_type,
6311 strict_overflow_p)) != 0)
6312 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6313 fold_convert (ctype, t1));
6314 else if (TREE_CODE (op1) != INTEGER_CST)
6317 /* If these are the same operation types, we can associate them
6318 assuming no overflow. */
6320 && 0 != (t1 = int_const_binop (MULT_EXPR, fold_convert (ctype, op1),
6321 fold_convert (ctype, c), 1))
6322 && 0 != (t1 = force_fit_type_double (ctype, TREE_INT_CST_LOW (t1),
6323 TREE_INT_CST_HIGH (t1),
6324 (TYPE_UNSIGNED (ctype)
6325 && tcode != MULT_EXPR) ? -1 : 1,
6326 TREE_OVERFLOW (t1)))
6327 && !TREE_OVERFLOW (t1))
6328 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
6330 /* If these operations "cancel" each other, we have the main
6331 optimizations of this pass, which occur when either constant is a
6332 multiple of the other, in which case we replace this with either an
6333 operation or CODE or TCODE.
6335 If we have an unsigned type that is not a sizetype, we cannot do
6336 this since it will change the result if the original computation
6338 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
6339 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
6340 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
6341 || (tcode == MULT_EXPR
6342 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
6343 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
6344 && code != MULT_EXPR)))
6346 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6348 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6349 *strict_overflow_p = true;
6350 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6351 fold_convert (ctype,
6352 const_binop (TRUNC_DIV_EXPR,
6355 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
6357 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6358 *strict_overflow_p = true;
6359 return fold_build2 (code, ctype, fold_convert (ctype, op0),
6360 fold_convert (ctype,
6361 const_binop (TRUNC_DIV_EXPR,
6374 /* Return a node which has the indicated constant VALUE (either 0 or
6375 1), and is of the indicated TYPE. */
6378 constant_boolean_node (int value, tree type)
6380 if (type == integer_type_node)
6381 return value ? integer_one_node : integer_zero_node;
6382 else if (type == boolean_type_node)
6383 return value ? boolean_true_node : boolean_false_node;
6385 return build_int_cst (type, value);
6389 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6390 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6391 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6392 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6393 COND is the first argument to CODE; otherwise (as in the example
6394 given here), it is the second argument. TYPE is the type of the
6395 original expression. Return NULL_TREE if no simplification is
6399 fold_binary_op_with_conditional_arg (enum tree_code code,
6400 tree type, tree op0, tree op1,
6401 tree cond, tree arg, int cond_first_p)
6403 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6404 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6405 tree test, true_value, false_value;
6406 tree lhs = NULL_TREE;
6407 tree rhs = NULL_TREE;
6409 /* This transformation is only worthwhile if we don't have to wrap
6410 arg in a SAVE_EXPR, and the operation can be simplified on at least
6411 one of the branches once its pushed inside the COND_EXPR. */
6412 if (!TREE_CONSTANT (arg))
6415 if (TREE_CODE (cond) == COND_EXPR)
6417 test = TREE_OPERAND (cond, 0);
6418 true_value = TREE_OPERAND (cond, 1);
6419 false_value = TREE_OPERAND (cond, 2);
6420 /* If this operand throws an expression, then it does not make
6421 sense to try to perform a logical or arithmetic operation
6423 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6425 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6430 tree testtype = TREE_TYPE (cond);
6432 true_value = constant_boolean_node (true, testtype);
6433 false_value = constant_boolean_node (false, testtype);
6436 arg = fold_convert (arg_type, arg);
6439 true_value = fold_convert (cond_type, true_value);
6441 lhs = fold_build2 (code, type, true_value, arg);
6443 lhs = fold_build2 (code, type, arg, true_value);
6447 false_value = fold_convert (cond_type, false_value);
6449 rhs = fold_build2 (code, type, false_value, arg);
6451 rhs = fold_build2 (code, type, arg, false_value);
6454 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6455 return fold_convert (type, test);
6459 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6461 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6462 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6463 ADDEND is the same as X.
6465 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6466 and finite. The problematic cases are when X is zero, and its mode
6467 has signed zeros. In the case of rounding towards -infinity,
6468 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6469 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6472 fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
6474 if (!real_zerop (addend))
6477 /* Don't allow the fold with -fsignaling-nans. */
6478 if (HONOR_SNANS (TYPE_MODE (type)))
6481 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6482 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6485 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6486 if (TREE_CODE (addend) == REAL_CST
6487 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6490 /* The mode has signed zeros, and we have to honor their sign.
6491 In this situation, there is only one case we can return true for.
6492 X - 0 is the same as X unless rounding towards -infinity is
6494 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6497 /* Subroutine of fold() that checks comparisons of built-in math
6498 functions against real constants.
6500 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6501 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6502 is the type of the result and ARG0 and ARG1 are the operands of the
6503 comparison. ARG1 must be a TREE_REAL_CST.
6505 The function returns the constant folded tree if a simplification
6506 can be made, and NULL_TREE otherwise. */
6509 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6510 tree type, tree arg0, tree arg1)
6514 if (BUILTIN_SQRT_P (fcode))
6516 tree arg = CALL_EXPR_ARG (arg0, 0);
6517 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6519 c = TREE_REAL_CST (arg1);
6520 if (REAL_VALUE_NEGATIVE (c))
6522 /* sqrt(x) < y is always false, if y is negative. */
6523 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6524 return omit_one_operand (type, integer_zero_node, arg);
6526 /* sqrt(x) > y is always true, if y is negative and we
6527 don't care about NaNs, i.e. negative values of x. */
6528 if (code == NE_EXPR || !HONOR_NANS (mode))
6529 return omit_one_operand (type, integer_one_node, arg);
6531 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6532 return fold_build2 (GE_EXPR, type, arg,
6533 build_real (TREE_TYPE (arg), dconst0));
6535 else if (code == GT_EXPR || code == GE_EXPR)
6539 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6540 real_convert (&c2, mode, &c2);
6542 if (REAL_VALUE_ISINF (c2))
6544 /* sqrt(x) > y is x == +Inf, when y is very large. */
6545 if (HONOR_INFINITIES (mode))
6546 return fold_build2 (EQ_EXPR, type, arg,
6547 build_real (TREE_TYPE (arg), c2));
6549 /* sqrt(x) > y is always false, when y is very large
6550 and we don't care about infinities. */
6551 return omit_one_operand (type, integer_zero_node, arg);
6554 /* sqrt(x) > c is the same as x > c*c. */
6555 return fold_build2 (code, type, arg,
6556 build_real (TREE_TYPE (arg), c2));
6558 else if (code == LT_EXPR || code == LE_EXPR)
6562 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6563 real_convert (&c2, mode, &c2);
6565 if (REAL_VALUE_ISINF (c2))
6567 /* sqrt(x) < y is always true, when y is a very large
6568 value and we don't care about NaNs or Infinities. */
6569 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6570 return omit_one_operand (type, integer_one_node, arg);
6572 /* sqrt(x) < y is x != +Inf when y is very large and we
6573 don't care about NaNs. */
6574 if (! HONOR_NANS (mode))
6575 return fold_build2 (NE_EXPR, type, arg,
6576 build_real (TREE_TYPE (arg), c2));
6578 /* sqrt(x) < y is x >= 0 when y is very large and we
6579 don't care about Infinities. */
6580 if (! HONOR_INFINITIES (mode))
6581 return fold_build2 (GE_EXPR, type, arg,
6582 build_real (TREE_TYPE (arg), dconst0));
6584 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6585 if (lang_hooks.decls.global_bindings_p () != 0
6586 || CONTAINS_PLACEHOLDER_P (arg))
6589 arg = save_expr (arg);
6590 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6591 fold_build2 (GE_EXPR, type, arg,
6592 build_real (TREE_TYPE (arg),
6594 fold_build2 (NE_EXPR, type, arg,
6595 build_real (TREE_TYPE (arg),
6599 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6600 if (! HONOR_NANS (mode))
6601 return fold_build2 (code, type, arg,
6602 build_real (TREE_TYPE (arg), c2));
6604 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6605 if (lang_hooks.decls.global_bindings_p () == 0
6606 && ! CONTAINS_PLACEHOLDER_P (arg))
6608 arg = save_expr (arg);
6609 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6610 fold_build2 (GE_EXPR, type, arg,
6611 build_real (TREE_TYPE (arg),
6613 fold_build2 (code, type, arg,
6614 build_real (TREE_TYPE (arg),
6623 /* Subroutine of fold() that optimizes comparisons against Infinities,
6624 either +Inf or -Inf.
6626 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6627 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6628 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6630 The function returns the constant folded tree if a simplification
6631 can be made, and NULL_TREE otherwise. */
6634 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6636 enum machine_mode mode;
6637 REAL_VALUE_TYPE max;
6641 mode = TYPE_MODE (TREE_TYPE (arg0));
6643 /* For negative infinity swap the sense of the comparison. */
6644 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6646 code = swap_tree_comparison (code);
6651 /* x > +Inf is always false, if with ignore sNANs. */
6652 if (HONOR_SNANS (mode))
6654 return omit_one_operand (type, integer_zero_node, arg0);
6657 /* x <= +Inf is always true, if we don't case about NaNs. */
6658 if (! HONOR_NANS (mode))
6659 return omit_one_operand (type, integer_one_node, arg0);
6661 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6662 if (lang_hooks.decls.global_bindings_p () == 0
6663 && ! CONTAINS_PLACEHOLDER_P (arg0))
6665 arg0 = save_expr (arg0);
6666 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6672 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6673 real_maxval (&max, neg, mode);
6674 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6675 arg0, build_real (TREE_TYPE (arg0), max));
6678 /* x < +Inf is always equal to x <= DBL_MAX. */
6679 real_maxval (&max, neg, mode);
6680 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6681 arg0, build_real (TREE_TYPE (arg0), max));
6684 /* x != +Inf is always equal to !(x > DBL_MAX). */
6685 real_maxval (&max, neg, mode);
6686 if (! HONOR_NANS (mode))
6687 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6688 arg0, build_real (TREE_TYPE (arg0), max));
6690 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6691 arg0, build_real (TREE_TYPE (arg0), max));
6692 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6701 /* Subroutine of fold() that optimizes comparisons of a division by
6702 a nonzero integer constant against an integer constant, i.e.
6705 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6706 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6707 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6709 The function returns the constant folded tree if a simplification
6710 can be made, and NULL_TREE otherwise. */
6713 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6715 tree prod, tmp, hi, lo;
6716 tree arg00 = TREE_OPERAND (arg0, 0);
6717 tree arg01 = TREE_OPERAND (arg0, 1);
6718 unsigned HOST_WIDE_INT lpart;
6719 HOST_WIDE_INT hpart;
6720 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6724 /* We have to do this the hard way to detect unsigned overflow.
6725 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6726 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6727 TREE_INT_CST_HIGH (arg01),
6728 TREE_INT_CST_LOW (arg1),
6729 TREE_INT_CST_HIGH (arg1),
6730 &lpart, &hpart, unsigned_p);
6731 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6733 neg_overflow = false;
6737 tmp = int_const_binop (MINUS_EXPR, arg01,
6738 build_int_cst (TREE_TYPE (arg01), 1), 0);
6741 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6742 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6743 TREE_INT_CST_HIGH (prod),
6744 TREE_INT_CST_LOW (tmp),
6745 TREE_INT_CST_HIGH (tmp),
6746 &lpart, &hpart, unsigned_p);
6747 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6748 -1, overflow | TREE_OVERFLOW (prod));
6750 else if (tree_int_cst_sgn (arg01) >= 0)
6752 tmp = int_const_binop (MINUS_EXPR, arg01,
6753 build_int_cst (TREE_TYPE (arg01), 1), 0);
6754 switch (tree_int_cst_sgn (arg1))
6757 neg_overflow = true;
6758 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6763 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6768 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6778 /* A negative divisor reverses the relational operators. */
6779 code = swap_tree_comparison (code);
6781 tmp = int_const_binop (PLUS_EXPR, arg01,
6782 build_int_cst (TREE_TYPE (arg01), 1), 0);
6783 switch (tree_int_cst_sgn (arg1))
6786 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6791 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6796 neg_overflow = true;
6797 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6809 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6810 return omit_one_operand (type, integer_zero_node, arg00);
6811 if (TREE_OVERFLOW (hi))
6812 return fold_build2 (GE_EXPR, type, arg00, lo);
6813 if (TREE_OVERFLOW (lo))
6814 return fold_build2 (LE_EXPR, type, arg00, hi);
6815 return build_range_check (type, arg00, 1, lo, hi);
6818 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6819 return omit_one_operand (type, integer_one_node, arg00);
6820 if (TREE_OVERFLOW (hi))
6821 return fold_build2 (LT_EXPR, type, arg00, lo);
6822 if (TREE_OVERFLOW (lo))
6823 return fold_build2 (GT_EXPR, type, arg00, hi);
6824 return build_range_check (type, arg00, 0, lo, hi);
6827 if (TREE_OVERFLOW (lo))
6829 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6830 return omit_one_operand (type, tmp, arg00);
6832 return fold_build2 (LT_EXPR, type, arg00, lo);
6835 if (TREE_OVERFLOW (hi))
6837 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6838 return omit_one_operand (type, tmp, arg00);
6840 return fold_build2 (LE_EXPR, type, arg00, hi);
6843 if (TREE_OVERFLOW (hi))
6845 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6846 return omit_one_operand (type, tmp, arg00);
6848 return fold_build2 (GT_EXPR, type, arg00, hi);
6851 if (TREE_OVERFLOW (lo))
6853 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6854 return omit_one_operand (type, tmp, arg00);
6856 return fold_build2 (GE_EXPR, type, arg00, lo);
6866 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6867 equality/inequality test, then return a simplified form of the test
6868 using a sign testing. Otherwise return NULL. TYPE is the desired
6872 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6875 /* If this is testing a single bit, we can optimize the test. */
6876 if ((code == NE_EXPR || code == EQ_EXPR)
6877 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6878 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6880 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6881 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6882 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6884 if (arg00 != NULL_TREE
6885 /* This is only a win if casting to a signed type is cheap,
6886 i.e. when arg00's type is not a partial mode. */
6887 && TYPE_PRECISION (TREE_TYPE (arg00))
6888 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6890 tree stype = signed_type_for (TREE_TYPE (arg00));
6891 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6892 result_type, fold_convert (stype, arg00),
6893 build_int_cst (stype, 0));
6900 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6901 equality/inequality test, then return a simplified form of
6902 the test using shifts and logical operations. Otherwise return
6903 NULL. TYPE is the desired result type. */
6906 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6909 /* If this is testing a single bit, we can optimize the test. */
6910 if ((code == NE_EXPR || code == EQ_EXPR)
6911 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6912 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6914 tree inner = TREE_OPERAND (arg0, 0);
6915 tree type = TREE_TYPE (arg0);
6916 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6917 enum machine_mode operand_mode = TYPE_MODE (type);
6919 tree signed_type, unsigned_type, intermediate_type;
6922 /* First, see if we can fold the single bit test into a sign-bit
6924 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6929 /* Otherwise we have (A & C) != 0 where C is a single bit,
6930 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6931 Similarly for (A & C) == 0. */
6933 /* If INNER is a right shift of a constant and it plus BITNUM does
6934 not overflow, adjust BITNUM and INNER. */
6935 if (TREE_CODE (inner) == RSHIFT_EXPR
6936 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6937 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6938 && bitnum < TYPE_PRECISION (type)
6939 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6940 bitnum - TYPE_PRECISION (type)))
6942 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6943 inner = TREE_OPERAND (inner, 0);
6946 /* If we are going to be able to omit the AND below, we must do our
6947 operations as unsigned. If we must use the AND, we have a choice.
6948 Normally unsigned is faster, but for some machines signed is. */
6949 #ifdef LOAD_EXTEND_OP
6950 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6951 && !flag_syntax_only) ? 0 : 1;
6956 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6957 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6958 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6959 inner = fold_convert (intermediate_type, inner);
6962 inner = build2 (RSHIFT_EXPR, intermediate_type,
6963 inner, size_int (bitnum));
6965 one = build_int_cst (intermediate_type, 1);
6967 if (code == EQ_EXPR)
6968 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6970 /* Put the AND last so it can combine with more things. */
6971 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6973 /* Make sure to return the proper type. */
6974 inner = fold_convert (result_type, inner);
6981 /* Check whether we are allowed to reorder operands arg0 and arg1,
6982 such that the evaluation of arg1 occurs before arg0. */
6985 reorder_operands_p (const_tree arg0, const_tree arg1)
6987 if (! flag_evaluation_order)
6989 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6991 return ! TREE_SIDE_EFFECTS (arg0)
6992 && ! TREE_SIDE_EFFECTS (arg1);
6995 /* Test whether it is preferable two swap two operands, ARG0 and
6996 ARG1, for example because ARG0 is an integer constant and ARG1
6997 isn't. If REORDER is true, only recommend swapping if we can
6998 evaluate the operands in reverse order. */
7001 tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
7003 STRIP_SIGN_NOPS (arg0);
7004 STRIP_SIGN_NOPS (arg1);
7006 if (TREE_CODE (arg1) == INTEGER_CST)
7008 if (TREE_CODE (arg0) == INTEGER_CST)
7011 if (TREE_CODE (arg1) == REAL_CST)
7013 if (TREE_CODE (arg0) == REAL_CST)
7016 if (TREE_CODE (arg1) == FIXED_CST)
7018 if (TREE_CODE (arg0) == FIXED_CST)
7021 if (TREE_CODE (arg1) == COMPLEX_CST)
7023 if (TREE_CODE (arg0) == COMPLEX_CST)
7026 if (TREE_CONSTANT (arg1))
7028 if (TREE_CONSTANT (arg0))
7031 if (optimize_function_for_size_p (cfun))
7034 if (reorder && flag_evaluation_order
7035 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
7038 /* It is preferable to swap two SSA_NAME to ensure a canonical form
7039 for commutative and comparison operators. Ensuring a canonical
7040 form allows the optimizers to find additional redundancies without
7041 having to explicitly check for both orderings. */
7042 if (TREE_CODE (arg0) == SSA_NAME
7043 && TREE_CODE (arg1) == SSA_NAME
7044 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
7047 /* Put SSA_NAMEs last. */
7048 if (TREE_CODE (arg1) == SSA_NAME)
7050 if (TREE_CODE (arg0) == SSA_NAME)
7053 /* Put variables last. */
7062 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
7063 ARG0 is extended to a wider type. */
7066 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
7068 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
7070 tree shorter_type, outer_type;
7074 if (arg0_unw == arg0)
7076 shorter_type = TREE_TYPE (arg0_unw);
7078 #ifdef HAVE_canonicalize_funcptr_for_compare
7079 /* Disable this optimization if we're casting a function pointer
7080 type on targets that require function pointer canonicalization. */
7081 if (HAVE_canonicalize_funcptr_for_compare
7082 && TREE_CODE (shorter_type) == POINTER_TYPE
7083 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
7087 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
7090 arg1_unw = get_unwidened (arg1, NULL_TREE);
7092 /* If possible, express the comparison in the shorter mode. */
7093 if ((code == EQ_EXPR || code == NE_EXPR
7094 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
7095 && (TREE_TYPE (arg1_unw) == shorter_type
7096 || ((TYPE_PRECISION (shorter_type)
7097 >= TYPE_PRECISION (TREE_TYPE (arg1_unw)))
7098 && (TYPE_UNSIGNED (shorter_type)
7099 == TYPE_UNSIGNED (TREE_TYPE (arg1_unw))))
7100 || (TREE_CODE (arg1_unw) == INTEGER_CST
7101 && (TREE_CODE (shorter_type) == INTEGER_TYPE
7102 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
7103 && int_fits_type_p (arg1_unw, shorter_type))))
7104 return fold_build2 (code, type, arg0_unw,
7105 fold_convert (shorter_type, arg1_unw));
7107 if (TREE_CODE (arg1_unw) != INTEGER_CST
7108 || TREE_CODE (shorter_type) != INTEGER_TYPE
7109 || !int_fits_type_p (arg1_unw, shorter_type))
7112 /* If we are comparing with the integer that does not fit into the range
7113 of the shorter type, the result is known. */
7114 outer_type = TREE_TYPE (arg1_unw);
7115 min = lower_bound_in_type (outer_type, shorter_type);
7116 max = upper_bound_in_type (outer_type, shorter_type);
7118 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7120 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7127 return omit_one_operand (type, integer_zero_node, arg0);
7132 return omit_one_operand (type, integer_one_node, arg0);
7138 return omit_one_operand (type, integer_one_node, arg0);
7140 return omit_one_operand (type, integer_zero_node, arg0);
7145 return omit_one_operand (type, integer_zero_node, arg0);
7147 return omit_one_operand (type, integer_one_node, arg0);
7156 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
7157 ARG0 just the signedness is changed. */
7160 fold_sign_changed_comparison (enum tree_code code, tree type,
7161 tree arg0, tree arg1)
7164 tree inner_type, outer_type;
7166 if (!CONVERT_EXPR_P (arg0))
7169 outer_type = TREE_TYPE (arg0);
7170 arg0_inner = TREE_OPERAND (arg0, 0);
7171 inner_type = TREE_TYPE (arg0_inner);
7173 #ifdef HAVE_canonicalize_funcptr_for_compare
7174 /* Disable this optimization if we're casting a function pointer
7175 type on targets that require function pointer canonicalization. */
7176 if (HAVE_canonicalize_funcptr_for_compare
7177 && TREE_CODE (inner_type) == POINTER_TYPE
7178 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
7182 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
7185 /* If the conversion is from an integral subtype to its basetype
7187 if (TREE_TYPE (inner_type) == outer_type)
7190 if (TREE_CODE (arg1) != INTEGER_CST
7191 && !(CONVERT_EXPR_P (arg1)
7192 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
7195 if ((TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
7196 || POINTER_TYPE_P (inner_type) != POINTER_TYPE_P (outer_type))
7201 if (TREE_CODE (arg1) == INTEGER_CST)
7202 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
7203 TREE_INT_CST_HIGH (arg1), 0,
7204 TREE_OVERFLOW (arg1));
7206 arg1 = fold_convert (inner_type, arg1);
7208 return fold_build2 (code, type, arg0_inner, arg1);
7211 /* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
7212 step of the array. Reconstructs s and delta in the case of s * delta
7213 being an integer constant (and thus already folded).
7214 ADDR is the address. MULT is the multiplicative expression.
7215 If the function succeeds, the new address expression is returned. Otherwise
7216 NULL_TREE is returned. */
7219 try_move_mult_to_index (tree addr, tree op1)
7221 tree s, delta, step;
7222 tree ref = TREE_OPERAND (addr, 0), pref;
7227 /* Strip the nops that might be added when converting op1 to sizetype. */
7230 /* Canonicalize op1 into a possibly non-constant delta
7231 and an INTEGER_CST s. */
7232 if (TREE_CODE (op1) == MULT_EXPR)
7234 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
7239 if (TREE_CODE (arg0) == INTEGER_CST)
7244 else if (TREE_CODE (arg1) == INTEGER_CST)
7252 else if (TREE_CODE (op1) == INTEGER_CST)
7259 /* Simulate we are delta * 1. */
7261 s = integer_one_node;
7264 for (;; ref = TREE_OPERAND (ref, 0))
7266 if (TREE_CODE (ref) == ARRAY_REF)
7268 /* Remember if this was a multi-dimensional array. */
7269 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
7272 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
7276 step = array_ref_element_size (ref);
7277 if (TREE_CODE (step) != INTEGER_CST)
7282 if (! tree_int_cst_equal (step, s))
7287 /* Try if delta is a multiple of step. */
7288 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, op1, step);
7294 /* Only fold here if we can verify we do not overflow one
7295 dimension of a multi-dimensional array. */
7300 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
7301 || !INTEGRAL_TYPE_P (itype)
7302 || !TYPE_MAX_VALUE (itype)
7303 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
7306 tmp = fold_binary (PLUS_EXPR, itype,
7307 fold_convert (itype,
7308 TREE_OPERAND (ref, 1)),
7309 fold_convert (itype, delta));
7311 || TREE_CODE (tmp) != INTEGER_CST
7312 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
7321 if (!handled_component_p (ref))
7325 /* We found the suitable array reference. So copy everything up to it,
7326 and replace the index. */
7328 pref = TREE_OPERAND (addr, 0);
7329 ret = copy_node (pref);
7334 pref = TREE_OPERAND (pref, 0);
7335 TREE_OPERAND (pos, 0) = copy_node (pref);
7336 pos = TREE_OPERAND (pos, 0);
7339 TREE_OPERAND (pos, 1) = fold_build2 (PLUS_EXPR, itype,
7340 fold_convert (itype,
7341 TREE_OPERAND (pos, 1)),
7342 fold_convert (itype, delta));
7344 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
7348 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
7349 means A >= Y && A != MAX, but in this case we know that
7350 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
7353 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
7355 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
7357 if (TREE_CODE (bound) == LT_EXPR)
7358 a = TREE_OPERAND (bound, 0);
7359 else if (TREE_CODE (bound) == GT_EXPR)
7360 a = TREE_OPERAND (bound, 1);
7364 typea = TREE_TYPE (a);
7365 if (!INTEGRAL_TYPE_P (typea)
7366 && !POINTER_TYPE_P (typea))
7369 if (TREE_CODE (ineq) == LT_EXPR)
7371 a1 = TREE_OPERAND (ineq, 1);
7372 y = TREE_OPERAND (ineq, 0);
7374 else if (TREE_CODE (ineq) == GT_EXPR)
7376 a1 = TREE_OPERAND (ineq, 0);
7377 y = TREE_OPERAND (ineq, 1);
7382 if (TREE_TYPE (a1) != typea)
7385 if (POINTER_TYPE_P (typea))
7387 /* Convert the pointer types into integer before taking the difference. */
7388 tree ta = fold_convert (ssizetype, a);
7389 tree ta1 = fold_convert (ssizetype, a1);
7390 diff = fold_binary (MINUS_EXPR, ssizetype, ta1, ta);
7393 diff = fold_binary (MINUS_EXPR, typea, a1, a);
7395 if (!diff || !integer_onep (diff))
7398 return fold_build2 (GE_EXPR, type, a, y);
7401 /* Fold a sum or difference of at least one multiplication.
7402 Returns the folded tree or NULL if no simplification could be made. */
7405 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7407 tree arg00, arg01, arg10, arg11;
7408 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7410 /* (A * C) +- (B * C) -> (A+-B) * C.
7411 (A * C) +- A -> A * (C+-1).
7412 We are most concerned about the case where C is a constant,
7413 but other combinations show up during loop reduction. Since
7414 it is not difficult, try all four possibilities. */
7416 if (TREE_CODE (arg0) == MULT_EXPR)
7418 arg00 = TREE_OPERAND (arg0, 0);
7419 arg01 = TREE_OPERAND (arg0, 1);
7421 else if (TREE_CODE (arg0) == INTEGER_CST)
7423 arg00 = build_one_cst (type);
7428 /* We cannot generate constant 1 for fract. */
7429 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7432 arg01 = build_one_cst (type);
7434 if (TREE_CODE (arg1) == MULT_EXPR)
7436 arg10 = TREE_OPERAND (arg1, 0);
7437 arg11 = TREE_OPERAND (arg1, 1);
7439 else if (TREE_CODE (arg1) == INTEGER_CST)
7441 arg10 = build_one_cst (type);
7446 /* We cannot generate constant 1 for fract. */
7447 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7450 arg11 = build_one_cst (type);
7454 if (operand_equal_p (arg01, arg11, 0))
7455 same = arg01, alt0 = arg00, alt1 = arg10;
7456 else if (operand_equal_p (arg00, arg10, 0))
7457 same = arg00, alt0 = arg01, alt1 = arg11;
7458 else if (operand_equal_p (arg00, arg11, 0))
7459 same = arg00, alt0 = arg01, alt1 = arg10;
7460 else if (operand_equal_p (arg01, arg10, 0))
7461 same = arg01, alt0 = arg00, alt1 = arg11;
7463 /* No identical multiplicands; see if we can find a common
7464 power-of-two factor in non-power-of-two multiplies. This
7465 can help in multi-dimensional array access. */
7466 else if (host_integerp (arg01, 0)
7467 && host_integerp (arg11, 0))
7469 HOST_WIDE_INT int01, int11, tmp;
7472 int01 = TREE_INT_CST_LOW (arg01);
7473 int11 = TREE_INT_CST_LOW (arg11);
7475 /* Move min of absolute values to int11. */
7476 if ((int01 >= 0 ? int01 : -int01)
7477 < (int11 >= 0 ? int11 : -int11))
7479 tmp = int01, int01 = int11, int11 = tmp;
7480 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7487 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
7489 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7490 build_int_cst (TREE_TYPE (arg00),
7495 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7500 return fold_build2 (MULT_EXPR, type,
7501 fold_build2 (code, type,
7502 fold_convert (type, alt0),
7503 fold_convert (type, alt1)),
7504 fold_convert (type, same));
7509 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7510 specified by EXPR into the buffer PTR of length LEN bytes.
7511 Return the number of bytes placed in the buffer, or zero
7515 native_encode_int (const_tree expr, unsigned char *ptr, int len)
7517 tree type = TREE_TYPE (expr);
7518 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7519 int byte, offset, word, words;
7520 unsigned char value;
7522 if (total_bytes > len)
7524 words = total_bytes / UNITS_PER_WORD;
7526 for (byte = 0; byte < total_bytes; byte++)
7528 int bitpos = byte * BITS_PER_UNIT;
7529 if (bitpos < HOST_BITS_PER_WIDE_INT)
7530 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7532 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7533 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7535 if (total_bytes > UNITS_PER_WORD)
7537 word = byte / UNITS_PER_WORD;
7538 if (WORDS_BIG_ENDIAN)
7539 word = (words - 1) - word;
7540 offset = word * UNITS_PER_WORD;
7541 if (BYTES_BIG_ENDIAN)
7542 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7544 offset += byte % UNITS_PER_WORD;
7547 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7548 ptr[offset] = value;
7554 /* Subroutine of native_encode_expr. Encode the REAL_CST
7555 specified by EXPR into the buffer PTR of length LEN bytes.
7556 Return the number of bytes placed in the buffer, or zero
7560 native_encode_real (const_tree expr, unsigned char *ptr, int len)
7562 tree type = TREE_TYPE (expr);
7563 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7564 int byte, offset, word, words, bitpos;
7565 unsigned char value;
7567 /* There are always 32 bits in each long, no matter the size of
7568 the hosts long. We handle floating point representations with
7572 if (total_bytes > len)
7574 words = (32 / BITS_PER_UNIT) / UNITS_PER_WORD;
7576 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7578 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7579 bitpos += BITS_PER_UNIT)
7581 byte = (bitpos / BITS_PER_UNIT) & 3;
7582 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7584 if (UNITS_PER_WORD < 4)
7586 word = byte / UNITS_PER_WORD;
7587 if (WORDS_BIG_ENDIAN)
7588 word = (words - 1) - word;
7589 offset = word * UNITS_PER_WORD;
7590 if (BYTES_BIG_ENDIAN)
7591 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7593 offset += byte % UNITS_PER_WORD;
7596 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7597 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7602 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7603 specified by EXPR into the buffer PTR of length LEN bytes.
7604 Return the number of bytes placed in the buffer, or zero
7608 native_encode_complex (const_tree expr, unsigned char *ptr, int len)
7613 part = TREE_REALPART (expr);
7614 rsize = native_encode_expr (part, ptr, len);
7617 part = TREE_IMAGPART (expr);
7618 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7621 return rsize + isize;
7625 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7626 specified by EXPR into the buffer PTR of length LEN bytes.
7627 Return the number of bytes placed in the buffer, or zero
7631 native_encode_vector (const_tree expr, unsigned char *ptr, int len)
7633 int i, size, offset, count;
7634 tree itype, elem, elements;
7637 elements = TREE_VECTOR_CST_ELTS (expr);
7638 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7639 itype = TREE_TYPE (TREE_TYPE (expr));
7640 size = GET_MODE_SIZE (TYPE_MODE (itype));
7641 for (i = 0; i < count; i++)
7645 elem = TREE_VALUE (elements);
7646 elements = TREE_CHAIN (elements);
7653 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7658 if (offset + size > len)
7660 memset (ptr+offset, 0, size);
7668 /* Subroutine of native_encode_expr. Encode the STRING_CST
7669 specified by EXPR into the buffer PTR of length LEN bytes.
7670 Return the number of bytes placed in the buffer, or zero
7674 native_encode_string (const_tree expr, unsigned char *ptr, int len)
7676 tree type = TREE_TYPE (expr);
7677 HOST_WIDE_INT total_bytes;
7679 if (TREE_CODE (type) != ARRAY_TYPE
7680 || TREE_CODE (TREE_TYPE (type)) != INTEGER_TYPE
7681 || GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) != BITS_PER_UNIT
7682 || !host_integerp (TYPE_SIZE_UNIT (type), 0))
7684 total_bytes = tree_low_cst (TYPE_SIZE_UNIT (type), 0);
7685 if (total_bytes > len)
7687 if (TREE_STRING_LENGTH (expr) < total_bytes)
7689 memcpy (ptr, TREE_STRING_POINTER (expr), TREE_STRING_LENGTH (expr));
7690 memset (ptr + TREE_STRING_LENGTH (expr), 0,
7691 total_bytes - TREE_STRING_LENGTH (expr));
7694 memcpy (ptr, TREE_STRING_POINTER (expr), total_bytes);
7699 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7700 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7701 buffer PTR of length LEN bytes. Return the number of bytes
7702 placed in the buffer, or zero upon failure. */
7705 native_encode_expr (const_tree expr, unsigned char *ptr, int len)
7707 switch (TREE_CODE (expr))
7710 return native_encode_int (expr, ptr, len);
7713 return native_encode_real (expr, ptr, len);
7716 return native_encode_complex (expr, ptr, len);
7719 return native_encode_vector (expr, ptr, len);
7722 return native_encode_string (expr, ptr, len);
7730 /* Subroutine of native_interpret_expr. Interpret the contents of
7731 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7732 If the buffer cannot be interpreted, return NULL_TREE. */
7735 native_interpret_int (tree type, const unsigned char *ptr, int len)
7737 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7738 int byte, offset, word, words;
7739 unsigned char value;
7740 unsigned int HOST_WIDE_INT lo = 0;
7741 HOST_WIDE_INT hi = 0;
7743 if (total_bytes > len)
7745 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7747 words = total_bytes / UNITS_PER_WORD;
7749 for (byte = 0; byte < total_bytes; byte++)
7751 int bitpos = byte * BITS_PER_UNIT;
7752 if (total_bytes > UNITS_PER_WORD)
7754 word = byte / UNITS_PER_WORD;
7755 if (WORDS_BIG_ENDIAN)
7756 word = (words - 1) - word;
7757 offset = word * UNITS_PER_WORD;
7758 if (BYTES_BIG_ENDIAN)
7759 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7761 offset += byte % UNITS_PER_WORD;
7764 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7765 value = ptr[offset];
7767 if (bitpos < HOST_BITS_PER_WIDE_INT)
7768 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7770 hi |= (unsigned HOST_WIDE_INT) value
7771 << (bitpos - HOST_BITS_PER_WIDE_INT);
7774 return build_int_cst_wide_type (type, lo, hi);
7778 /* Subroutine of native_interpret_expr. Interpret the contents of
7779 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7780 If the buffer cannot be interpreted, return NULL_TREE. */
7783 native_interpret_real (tree type, const unsigned char *ptr, int len)
7785 enum machine_mode mode = TYPE_MODE (type);
7786 int total_bytes = GET_MODE_SIZE (mode);
7787 int byte, offset, word, words, bitpos;
7788 unsigned char value;
7789 /* There are always 32 bits in each long, no matter the size of
7790 the hosts long. We handle floating point representations with
7795 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7796 if (total_bytes > len || total_bytes > 24)
7798 words = (32 / BITS_PER_UNIT) / UNITS_PER_WORD;
7800 memset (tmp, 0, sizeof (tmp));
7801 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7802 bitpos += BITS_PER_UNIT)
7804 byte = (bitpos / BITS_PER_UNIT) & 3;
7805 if (UNITS_PER_WORD < 4)
7807 word = byte / UNITS_PER_WORD;
7808 if (WORDS_BIG_ENDIAN)
7809 word = (words - 1) - word;
7810 offset = word * UNITS_PER_WORD;
7811 if (BYTES_BIG_ENDIAN)
7812 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7814 offset += byte % UNITS_PER_WORD;
7817 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7818 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7820 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7823 real_from_target (&r, tmp, mode);
7824 return build_real (type, r);
7828 /* Subroutine of native_interpret_expr. Interpret the contents of
7829 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7830 If the buffer cannot be interpreted, return NULL_TREE. */
7833 native_interpret_complex (tree type, const unsigned char *ptr, int len)
7835 tree etype, rpart, ipart;
7838 etype = TREE_TYPE (type);
7839 size = GET_MODE_SIZE (TYPE_MODE (etype));
7842 rpart = native_interpret_expr (etype, ptr, size);
7845 ipart = native_interpret_expr (etype, ptr+size, size);
7848 return build_complex (type, rpart, ipart);
7852 /* Subroutine of native_interpret_expr. Interpret the contents of
7853 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7854 If the buffer cannot be interpreted, return NULL_TREE. */
7857 native_interpret_vector (tree type, const unsigned char *ptr, int len)
7859 tree etype, elem, elements;
7862 etype = TREE_TYPE (type);
7863 size = GET_MODE_SIZE (TYPE_MODE (etype));
7864 count = TYPE_VECTOR_SUBPARTS (type);
7865 if (size * count > len)
7868 elements = NULL_TREE;
7869 for (i = count - 1; i >= 0; i--)
7871 elem = native_interpret_expr (etype, ptr+(i*size), size);
7874 elements = tree_cons (NULL_TREE, elem, elements);
7876 return build_vector (type, elements);
7880 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7881 the buffer PTR of length LEN as a constant of type TYPE. For
7882 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7883 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7884 return NULL_TREE. */
7887 native_interpret_expr (tree type, const unsigned char *ptr, int len)
7889 switch (TREE_CODE (type))
7894 return native_interpret_int (type, ptr, len);
7897 return native_interpret_real (type, ptr, len);
7900 return native_interpret_complex (type, ptr, len);
7903 return native_interpret_vector (type, ptr, len);
7911 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7912 TYPE at compile-time. If we're unable to perform the conversion
7913 return NULL_TREE. */
7916 fold_view_convert_expr (tree type, tree expr)
7918 /* We support up to 512-bit values (for V8DFmode). */
7919 unsigned char buffer[64];
7922 /* Check that the host and target are sane. */
7923 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7926 len = native_encode_expr (expr, buffer, sizeof (buffer));
7930 return native_interpret_expr (type, buffer, len);
7933 /* Build an expression for the address of T. Folds away INDIRECT_REF
7934 to avoid confusing the gimplify process. When IN_FOLD is true
7935 avoid modifications of T. */
7938 build_fold_addr_expr_with_type_1 (tree t, tree ptrtype, bool in_fold)
7940 /* The size of the object is not relevant when talking about its address. */
7941 if (TREE_CODE (t) == WITH_SIZE_EXPR)
7942 t = TREE_OPERAND (t, 0);
7944 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
7945 if (TREE_CODE (t) == INDIRECT_REF
7946 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
7948 t = TREE_OPERAND (t, 0);
7950 if (TREE_TYPE (t) != ptrtype)
7951 t = build1 (NOP_EXPR, ptrtype, t);
7957 while (handled_component_p (base))
7958 base = TREE_OPERAND (base, 0);
7961 TREE_ADDRESSABLE (base) = 1;
7963 t = build1 (ADDR_EXPR, ptrtype, t);
7966 t = build1 (ADDR_EXPR, ptrtype, t);
7971 /* Build an expression for the address of T with type PTRTYPE. This
7972 function modifies the input parameter 'T' by sometimes setting the
7973 TREE_ADDRESSABLE flag. */
7976 build_fold_addr_expr_with_type (tree t, tree ptrtype)
7978 return build_fold_addr_expr_with_type_1 (t, ptrtype, false);
7981 /* Build an expression for the address of T. This function modifies
7982 the input parameter 'T' by sometimes setting the TREE_ADDRESSABLE
7983 flag. When called from fold functions, use fold_addr_expr instead. */
7986 build_fold_addr_expr (tree t)
7988 return build_fold_addr_expr_with_type_1 (t,
7989 build_pointer_type (TREE_TYPE (t)),
7993 /* Same as build_fold_addr_expr, builds an expression for the address
7994 of T, but avoids touching the input node 't'. Fold functions
7995 should use this version. */
7998 fold_addr_expr (tree t)
8000 tree ptrtype = build_pointer_type (TREE_TYPE (t));
8002 return build_fold_addr_expr_with_type_1 (t, ptrtype, true);
8005 /* Fold a unary expression of code CODE and type TYPE with operand
8006 OP0. Return the folded expression if folding is successful.
8007 Otherwise, return NULL_TREE. */
8010 fold_unary (enum tree_code code, tree type, tree op0)
8014 enum tree_code_class kind = TREE_CODE_CLASS (code);
8016 gcc_assert (IS_EXPR_CODE_CLASS (kind)
8017 && TREE_CODE_LENGTH (code) == 1);
8022 if (CONVERT_EXPR_CODE_P (code)
8023 || code == FLOAT_EXPR || code == ABS_EXPR)
8025 /* Don't use STRIP_NOPS, because signedness of argument type
8027 STRIP_SIGN_NOPS (arg0);
8031 /* Strip any conversions that don't change the mode. This
8032 is safe for every expression, except for a comparison
8033 expression because its signedness is derived from its
8036 Note that this is done as an internal manipulation within
8037 the constant folder, in order to find the simplest
8038 representation of the arguments so that their form can be
8039 studied. In any cases, the appropriate type conversions
8040 should be put back in the tree that will get out of the
8046 if (TREE_CODE_CLASS (code) == tcc_unary)
8048 if (TREE_CODE (arg0) == COMPOUND_EXPR)
8049 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
8050 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
8051 else if (TREE_CODE (arg0) == COND_EXPR)
8053 tree arg01 = TREE_OPERAND (arg0, 1);
8054 tree arg02 = TREE_OPERAND (arg0, 2);
8055 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
8056 arg01 = fold_build1 (code, type, arg01);
8057 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
8058 arg02 = fold_build1 (code, type, 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 final types are either both
8168 float or both integer, we don't need the middle conversion if
8169 it is wider than the final type and doesn't change the signedness
8170 (for integers). Avoid this if the final type is a pointer
8171 since then we sometimes need the inner conversion. Likewise if
8172 the outer 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, 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
8267 /* Not if the conversion is to the sub-type. */
8268 && TREE_TYPE (type) != TREE_TYPE (op0))
8271 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
8274 if (TYPE_UNSIGNED (TREE_TYPE (and))
8275 || (TYPE_PRECISION (type)
8276 <= TYPE_PRECISION (TREE_TYPE (and))))
8278 else if (TYPE_PRECISION (TREE_TYPE (and1))
8279 <= HOST_BITS_PER_WIDE_INT
8280 && host_integerp (and1, 1))
8282 unsigned HOST_WIDE_INT cst;
8284 cst = tree_low_cst (and1, 1);
8285 cst &= (HOST_WIDE_INT) -1
8286 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
8287 change = (cst == 0);
8288 #ifdef LOAD_EXTEND_OP
8290 && !flag_syntax_only
8291 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
8294 tree uns = unsigned_type_for (TREE_TYPE (and0));
8295 and0 = fold_convert (uns, and0);
8296 and1 = fold_convert (uns, and1);
8302 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
8303 TREE_INT_CST_HIGH (and1), 0,
8304 TREE_OVERFLOW (and1));
8305 return fold_build2 (BIT_AND_EXPR, type,
8306 fold_convert (type, and0), tem);
8310 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
8311 when one of the new casts will fold away. Conservatively we assume
8312 that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
8313 if (POINTER_TYPE_P (type)
8314 && TREE_CODE (arg0) == POINTER_PLUS_EXPR
8315 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8316 || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
8317 || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
8319 tree arg00 = TREE_OPERAND (arg0, 0);
8320 tree arg01 = TREE_OPERAND (arg0, 1);
8322 return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
8323 fold_convert (sizetype, arg01));
8326 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
8327 of the same precision, and X is an integer type not narrower than
8328 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
8329 if (INTEGRAL_TYPE_P (type)
8330 && TREE_CODE (op0) == BIT_NOT_EXPR
8331 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
8332 && CONVERT_EXPR_P (TREE_OPERAND (op0, 0))
8333 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
8335 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
8336 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
8337 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
8338 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
8341 /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the
8342 type of X and Y (integer types only). */
8343 if (INTEGRAL_TYPE_P (type)
8344 && TREE_CODE (op0) == MULT_EXPR
8345 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
8346 && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (op0)))
8348 /* Be careful not to introduce new overflows. */
8350 if (TYPE_OVERFLOW_WRAPS (type))
8353 mult_type = unsigned_type_for (type);
8355 if (TYPE_PRECISION (mult_type) < TYPE_PRECISION (TREE_TYPE (op0)))
8357 tem = fold_build2 (MULT_EXPR, mult_type,
8358 fold_convert (mult_type,
8359 TREE_OPERAND (op0, 0)),
8360 fold_convert (mult_type,
8361 TREE_OPERAND (op0, 1)));
8362 return fold_convert (type, tem);
8366 tem = fold_convert_const (code, type, op0);
8367 return tem ? tem : NULL_TREE;
8369 case FIXED_CONVERT_EXPR:
8370 tem = fold_convert_const (code, type, arg0);
8371 return tem ? tem : NULL_TREE;
8373 case VIEW_CONVERT_EXPR:
8374 if (TREE_TYPE (op0) == type)
8376 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
8377 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
8379 /* For integral conversions with the same precision or pointer
8380 conversions use a NOP_EXPR instead. */
8381 if ((INTEGRAL_TYPE_P (type)
8382 || POINTER_TYPE_P (type))
8383 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
8384 || POINTER_TYPE_P (TREE_TYPE (op0)))
8385 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0))
8386 /* Do not muck with VIEW_CONVERT_EXPRs that convert from
8387 a sub-type to its base type as generated by the Ada FE. */
8388 && !(INTEGRAL_TYPE_P (TREE_TYPE (op0))
8389 && TREE_TYPE (TREE_TYPE (op0))))
8390 return fold_convert (type, op0);
8392 /* Strip inner integral conversions that do not change the precision. */
8393 if (CONVERT_EXPR_P (op0)
8394 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
8395 || POINTER_TYPE_P (TREE_TYPE (op0)))
8396 && (INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
8397 || POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0))))
8398 && (TYPE_PRECISION (TREE_TYPE (op0))
8399 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
8400 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
8402 return fold_view_convert_expr (type, op0);
8405 tem = fold_negate_expr (arg0);
8407 return fold_convert (type, tem);
8411 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
8412 return fold_abs_const (arg0, type);
8413 else if (TREE_CODE (arg0) == NEGATE_EXPR)
8414 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
8415 /* Convert fabs((double)float) into (double)fabsf(float). */
8416 else if (TREE_CODE (arg0) == NOP_EXPR
8417 && TREE_CODE (type) == REAL_TYPE)
8419 tree targ0 = strip_float_extensions (arg0);
8421 return fold_convert (type, fold_build1 (ABS_EXPR,
8425 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
8426 else if (TREE_CODE (arg0) == ABS_EXPR)
8428 else if (tree_expr_nonnegative_p (arg0))
8431 /* Strip sign ops from argument. */
8432 if (TREE_CODE (type) == REAL_TYPE)
8434 tem = fold_strip_sign_ops (arg0);
8436 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
8441 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8442 return fold_convert (type, arg0);
8443 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8445 tree itype = TREE_TYPE (type);
8446 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
8447 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
8448 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
8450 if (TREE_CODE (arg0) == COMPLEX_CST)
8452 tree itype = TREE_TYPE (type);
8453 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
8454 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
8455 return build_complex (type, rpart, negate_expr (ipart));
8457 if (TREE_CODE (arg0) == CONJ_EXPR)
8458 return fold_convert (type, TREE_OPERAND (arg0, 0));
8462 if (TREE_CODE (arg0) == INTEGER_CST)
8463 return fold_not_const (arg0, type);
8464 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
8465 return fold_convert (type, TREE_OPERAND (arg0, 0));
8466 /* Convert ~ (-A) to A - 1. */
8467 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
8468 return fold_build2 (MINUS_EXPR, type,
8469 fold_convert (type, TREE_OPERAND (arg0, 0)),
8470 build_int_cst (type, 1));
8471 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
8472 else if (INTEGRAL_TYPE_P (type)
8473 && ((TREE_CODE (arg0) == MINUS_EXPR
8474 && integer_onep (TREE_OPERAND (arg0, 1)))
8475 || (TREE_CODE (arg0) == PLUS_EXPR
8476 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
8477 return fold_build1 (NEGATE_EXPR, type,
8478 fold_convert (type, TREE_OPERAND (arg0, 0)));
8479 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8480 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8481 && (tem = fold_unary (BIT_NOT_EXPR, type,
8483 TREE_OPERAND (arg0, 0)))))
8484 return fold_build2 (BIT_XOR_EXPR, type, tem,
8485 fold_convert (type, TREE_OPERAND (arg0, 1)));
8486 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8487 && (tem = fold_unary (BIT_NOT_EXPR, type,
8489 TREE_OPERAND (arg0, 1)))))
8490 return fold_build2 (BIT_XOR_EXPR, type,
8491 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
8492 /* Perform BIT_NOT_EXPR on each element individually. */
8493 else if (TREE_CODE (arg0) == VECTOR_CST)
8495 tree elements = TREE_VECTOR_CST_ELTS (arg0), elem, list = NULL_TREE;
8496 int count = TYPE_VECTOR_SUBPARTS (type), i;
8498 for (i = 0; i < count; i++)
8502 elem = TREE_VALUE (elements);
8503 elem = fold_unary (BIT_NOT_EXPR, TREE_TYPE (type), elem);
8504 if (elem == NULL_TREE)
8506 elements = TREE_CHAIN (elements);
8509 elem = build_int_cst (TREE_TYPE (type), -1);
8510 list = tree_cons (NULL_TREE, elem, list);
8513 return build_vector (type, nreverse (list));
8518 case TRUTH_NOT_EXPR:
8519 /* The argument to invert_truthvalue must have Boolean type. */
8520 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8521 arg0 = fold_convert (boolean_type_node, arg0);
8523 /* Note that the operand of this must be an int
8524 and its values must be 0 or 1.
8525 ("true" is a fixed value perhaps depending on the language,
8526 but we don't handle values other than 1 correctly yet.) */
8527 tem = fold_truth_not_expr (arg0);
8530 return fold_convert (type, tem);
8533 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8534 return fold_convert (type, arg0);
8535 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8536 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8537 TREE_OPERAND (arg0, 1));
8538 if (TREE_CODE (arg0) == COMPLEX_CST)
8539 return fold_convert (type, TREE_REALPART (arg0));
8540 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8542 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8543 tem = fold_build2 (TREE_CODE (arg0), itype,
8544 fold_build1 (REALPART_EXPR, itype,
8545 TREE_OPERAND (arg0, 0)),
8546 fold_build1 (REALPART_EXPR, itype,
8547 TREE_OPERAND (arg0, 1)));
8548 return fold_convert (type, tem);
8550 if (TREE_CODE (arg0) == CONJ_EXPR)
8552 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8553 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8554 return fold_convert (type, tem);
8556 if (TREE_CODE (arg0) == CALL_EXPR)
8558 tree fn = get_callee_fndecl (arg0);
8559 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8560 switch (DECL_FUNCTION_CODE (fn))
8562 CASE_FLT_FN (BUILT_IN_CEXPI):
8563 fn = mathfn_built_in (type, BUILT_IN_COS);
8565 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8575 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8576 return fold_convert (type, integer_zero_node);
8577 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8578 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8579 TREE_OPERAND (arg0, 0));
8580 if (TREE_CODE (arg0) == COMPLEX_CST)
8581 return fold_convert (type, TREE_IMAGPART (arg0));
8582 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8584 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8585 tem = fold_build2 (TREE_CODE (arg0), itype,
8586 fold_build1 (IMAGPART_EXPR, itype,
8587 TREE_OPERAND (arg0, 0)),
8588 fold_build1 (IMAGPART_EXPR, itype,
8589 TREE_OPERAND (arg0, 1)));
8590 return fold_convert (type, tem);
8592 if (TREE_CODE (arg0) == CONJ_EXPR)
8594 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8595 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8596 return fold_convert (type, negate_expr (tem));
8598 if (TREE_CODE (arg0) == CALL_EXPR)
8600 tree fn = get_callee_fndecl (arg0);
8601 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8602 switch (DECL_FUNCTION_CODE (fn))
8604 CASE_FLT_FN (BUILT_IN_CEXPI):
8605 fn = mathfn_built_in (type, BUILT_IN_SIN);
8607 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8618 } /* switch (code) */
8621 /* Fold a binary expression of code CODE and type TYPE with operands
8622 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8623 Return the folded expression if folding is successful. Otherwise,
8624 return NULL_TREE. */
8627 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8629 enum tree_code compl_code;
8631 if (code == MIN_EXPR)
8632 compl_code = MAX_EXPR;
8633 else if (code == MAX_EXPR)
8634 compl_code = MIN_EXPR;
8638 /* MIN (MAX (a, b), b) == b. */
8639 if (TREE_CODE (op0) == compl_code
8640 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8641 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8643 /* MIN (MAX (b, a), b) == b. */
8644 if (TREE_CODE (op0) == compl_code
8645 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8646 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8647 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8649 /* MIN (a, MAX (a, b)) == a. */
8650 if (TREE_CODE (op1) == compl_code
8651 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8652 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8653 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8655 /* MIN (a, MAX (b, a)) == a. */
8656 if (TREE_CODE (op1) == compl_code
8657 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8658 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8659 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8664 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8665 by changing CODE to reduce the magnitude of constants involved in
8666 ARG0 of the comparison.
8667 Returns a canonicalized comparison tree if a simplification was
8668 possible, otherwise returns NULL_TREE.
8669 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8670 valid if signed overflow is undefined. */
8673 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8674 tree arg0, tree arg1,
8675 bool *strict_overflow_p)
8677 enum tree_code code0 = TREE_CODE (arg0);
8678 tree t, cst0 = NULL_TREE;
8682 /* Match A +- CST code arg1 and CST code arg1. We can change the
8683 first form only if overflow is undefined. */
8684 if (!((TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8685 /* In principle pointers also have undefined overflow behavior,
8686 but that causes problems elsewhere. */
8687 && !POINTER_TYPE_P (TREE_TYPE (arg0))
8688 && (code0 == MINUS_EXPR
8689 || code0 == PLUS_EXPR)
8690 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8691 || code0 == INTEGER_CST))
8694 /* Identify the constant in arg0 and its sign. */
8695 if (code0 == INTEGER_CST)
8698 cst0 = TREE_OPERAND (arg0, 1);
8699 sgn0 = tree_int_cst_sgn (cst0);
8701 /* Overflowed constants and zero will cause problems. */
8702 if (integer_zerop (cst0)
8703 || TREE_OVERFLOW (cst0))
8706 /* See if we can reduce the magnitude of the constant in
8707 arg0 by changing the comparison code. */
8708 if (code0 == INTEGER_CST)
8710 /* CST <= arg1 -> CST-1 < arg1. */
8711 if (code == LE_EXPR && sgn0 == 1)
8713 /* -CST < arg1 -> -CST-1 <= arg1. */
8714 else if (code == LT_EXPR && sgn0 == -1)
8716 /* CST > arg1 -> CST-1 >= arg1. */
8717 else if (code == GT_EXPR && sgn0 == 1)
8719 /* -CST >= arg1 -> -CST-1 > arg1. */
8720 else if (code == GE_EXPR && sgn0 == -1)
8724 /* arg1 code' CST' might be more canonical. */
8729 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8731 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8733 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8734 else if (code == GT_EXPR
8735 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8737 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8738 else if (code == LE_EXPR
8739 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8741 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8742 else if (code == GE_EXPR
8743 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8747 *strict_overflow_p = true;
8750 /* Now build the constant reduced in magnitude. But not if that
8751 would produce one outside of its types range. */
8752 if (INTEGRAL_TYPE_P (TREE_TYPE (cst0))
8754 && TYPE_MIN_VALUE (TREE_TYPE (cst0))
8755 && tree_int_cst_equal (cst0, TYPE_MIN_VALUE (TREE_TYPE (cst0))))
8757 && TYPE_MAX_VALUE (TREE_TYPE (cst0))
8758 && tree_int_cst_equal (cst0, TYPE_MAX_VALUE (TREE_TYPE (cst0))))))
8759 /* We cannot swap the comparison here as that would cause us to
8760 endlessly recurse. */
8763 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8764 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8765 if (code0 != INTEGER_CST)
8766 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8768 /* If swapping might yield to a more canonical form, do so. */
8770 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8772 return fold_build2 (code, type, t, arg1);
8775 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8776 overflow further. Try to decrease the magnitude of constants involved
8777 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8778 and put sole constants at the second argument position.
8779 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8782 maybe_canonicalize_comparison (enum tree_code code, tree type,
8783 tree arg0, tree arg1)
8786 bool strict_overflow_p;
8787 const char * const warnmsg = G_("assuming signed overflow does not occur "
8788 "when reducing constant in comparison");
8790 /* Try canonicalization by simplifying arg0. */
8791 strict_overflow_p = false;
8792 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8793 &strict_overflow_p);
8796 if (strict_overflow_p)
8797 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8801 /* Try canonicalization by simplifying arg1 using the swapped
8803 code = swap_tree_comparison (code);
8804 strict_overflow_p = false;
8805 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8806 &strict_overflow_p);
8807 if (t && strict_overflow_p)
8808 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8812 /* Return whether BASE + OFFSET + BITPOS may wrap around the address
8813 space. This is used to avoid issuing overflow warnings for
8814 expressions like &p->x which can not wrap. */
8817 pointer_may_wrap_p (tree base, tree offset, HOST_WIDE_INT bitpos)
8819 unsigned HOST_WIDE_INT offset_low, total_low;
8820 HOST_WIDE_INT size, offset_high, total_high;
8822 if (!POINTER_TYPE_P (TREE_TYPE (base)))
8828 if (offset == NULL_TREE)
8833 else if (TREE_CODE (offset) != INTEGER_CST || TREE_OVERFLOW (offset))
8837 offset_low = TREE_INT_CST_LOW (offset);
8838 offset_high = TREE_INT_CST_HIGH (offset);
8841 if (add_double_with_sign (offset_low, offset_high,
8842 bitpos / BITS_PER_UNIT, 0,
8843 &total_low, &total_high,
8847 if (total_high != 0)
8850 size = int_size_in_bytes (TREE_TYPE (TREE_TYPE (base)));
8854 /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
8856 if (TREE_CODE (base) == ADDR_EXPR)
8858 HOST_WIDE_INT base_size;
8860 base_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (base, 0)));
8861 if (base_size > 0 && size < base_size)
8865 return total_low > (unsigned HOST_WIDE_INT) size;
8868 /* Subroutine of fold_binary. This routine performs all of the
8869 transformations that are common to the equality/inequality
8870 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8871 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8872 fold_binary should call fold_binary. Fold a comparison with
8873 tree code CODE and type TYPE with operands OP0 and OP1. Return
8874 the folded comparison or NULL_TREE. */
8877 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8879 tree arg0, arg1, tem;
8884 STRIP_SIGN_NOPS (arg0);
8885 STRIP_SIGN_NOPS (arg1);
8887 tem = fold_relational_const (code, type, arg0, arg1);
8888 if (tem != NULL_TREE)
8891 /* If one arg is a real or integer constant, put it last. */
8892 if (tree_swap_operands_p (arg0, arg1, true))
8893 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8895 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8896 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8897 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8898 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8899 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8900 && (TREE_CODE (arg1) == INTEGER_CST
8901 && !TREE_OVERFLOW (arg1)))
8903 tree const1 = TREE_OPERAND (arg0, 1);
8905 tree variable = TREE_OPERAND (arg0, 0);
8908 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8910 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8911 TREE_TYPE (arg1), const2, const1);
8913 /* If the constant operation overflowed this can be
8914 simplified as a comparison against INT_MAX/INT_MIN. */
8915 if (TREE_CODE (lhs) == INTEGER_CST
8916 && TREE_OVERFLOW (lhs))
8918 int const1_sgn = tree_int_cst_sgn (const1);
8919 enum tree_code code2 = code;
8921 /* Get the sign of the constant on the lhs if the
8922 operation were VARIABLE + CONST1. */
8923 if (TREE_CODE (arg0) == MINUS_EXPR)
8924 const1_sgn = -const1_sgn;
8926 /* The sign of the constant determines if we overflowed
8927 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8928 Canonicalize to the INT_MIN overflow by swapping the comparison
8930 if (const1_sgn == -1)
8931 code2 = swap_tree_comparison (code);
8933 /* We now can look at the canonicalized case
8934 VARIABLE + 1 CODE2 INT_MIN
8935 and decide on the result. */
8936 if (code2 == LT_EXPR
8938 || code2 == EQ_EXPR)
8939 return omit_one_operand (type, boolean_false_node, variable);
8940 else if (code2 == NE_EXPR
8942 || code2 == GT_EXPR)
8943 return omit_one_operand (type, boolean_true_node, variable);
8946 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8947 && (TREE_CODE (lhs) != INTEGER_CST
8948 || !TREE_OVERFLOW (lhs)))
8950 fold_overflow_warning (("assuming signed overflow does not occur "
8951 "when changing X +- C1 cmp C2 to "
8953 WARN_STRICT_OVERFLOW_COMPARISON);
8954 return fold_build2 (code, type, variable, lhs);
8958 /* For comparisons of pointers we can decompose it to a compile time
8959 comparison of the base objects and the offsets into the object.
8960 This requires at least one operand being an ADDR_EXPR or a
8961 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8962 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8963 && (TREE_CODE (arg0) == ADDR_EXPR
8964 || TREE_CODE (arg1) == ADDR_EXPR
8965 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
8966 || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
8968 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8969 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8970 enum machine_mode mode;
8971 int volatilep, unsignedp;
8972 bool indirect_base0 = false, indirect_base1 = false;
8974 /* Get base and offset for the access. Strip ADDR_EXPR for
8975 get_inner_reference, but put it back by stripping INDIRECT_REF
8976 off the base object if possible. indirect_baseN will be true
8977 if baseN is not an address but refers to the object itself. */
8979 if (TREE_CODE (arg0) == ADDR_EXPR)
8981 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8982 &bitsize, &bitpos0, &offset0, &mode,
8983 &unsignedp, &volatilep, false);
8984 if (TREE_CODE (base0) == INDIRECT_REF)
8985 base0 = TREE_OPERAND (base0, 0);
8987 indirect_base0 = true;
8989 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
8991 base0 = TREE_OPERAND (arg0, 0);
8992 offset0 = TREE_OPERAND (arg0, 1);
8996 if (TREE_CODE (arg1) == ADDR_EXPR)
8998 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8999 &bitsize, &bitpos1, &offset1, &mode,
9000 &unsignedp, &volatilep, false);
9001 if (TREE_CODE (base1) == INDIRECT_REF)
9002 base1 = TREE_OPERAND (base1, 0);
9004 indirect_base1 = true;
9006 else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
9008 base1 = TREE_OPERAND (arg1, 0);
9009 offset1 = TREE_OPERAND (arg1, 1);
9012 /* If we have equivalent bases we might be able to simplify. */
9013 if (indirect_base0 == indirect_base1
9014 && operand_equal_p (base0, base1, 0))
9016 /* We can fold this expression to a constant if the non-constant
9017 offset parts are equal. */
9018 if ((offset0 == offset1
9019 || (offset0 && offset1
9020 && operand_equal_p (offset0, offset1, 0)))
9023 || POINTER_TYPE_OVERFLOW_UNDEFINED))
9028 && bitpos0 != bitpos1
9029 && (pointer_may_wrap_p (base0, offset0, bitpos0)
9030 || pointer_may_wrap_p (base1, offset1, bitpos1)))
9031 fold_overflow_warning (("assuming pointer wraparound does not "
9032 "occur when comparing P +- C1 with "
9034 WARN_STRICT_OVERFLOW_CONDITIONAL);
9039 return build_int_cst (boolean_type_node, bitpos0 == bitpos1);
9041 return build_int_cst (boolean_type_node, bitpos0 != bitpos1);
9043 return build_int_cst (boolean_type_node, bitpos0 < bitpos1);
9045 return build_int_cst (boolean_type_node, bitpos0 <= bitpos1);
9047 return build_int_cst (boolean_type_node, bitpos0 >= bitpos1);
9049 return build_int_cst (boolean_type_node, bitpos0 > bitpos1);
9053 /* We can simplify the comparison to a comparison of the variable
9054 offset parts if the constant offset parts are equal.
9055 Be careful to use signed size type here because otherwise we
9056 mess with array offsets in the wrong way. This is possible
9057 because pointer arithmetic is restricted to retain within an
9058 object and overflow on pointer differences is undefined as of
9059 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
9060 else if (bitpos0 == bitpos1
9061 && ((code == EQ_EXPR || code == NE_EXPR)
9062 || POINTER_TYPE_OVERFLOW_UNDEFINED))
9064 tree signed_size_type_node;
9065 signed_size_type_node = signed_type_for (size_type_node);
9067 /* By converting to signed size type we cover middle-end pointer
9068 arithmetic which operates on unsigned pointer types of size
9069 type size and ARRAY_REF offsets which are properly sign or
9070 zero extended from their type in case it is narrower than
9072 if (offset0 == NULL_TREE)
9073 offset0 = build_int_cst (signed_size_type_node, 0);
9075 offset0 = fold_convert (signed_size_type_node, offset0);
9076 if (offset1 == NULL_TREE)
9077 offset1 = build_int_cst (signed_size_type_node, 0);
9079 offset1 = fold_convert (signed_size_type_node, offset1);
9083 && (pointer_may_wrap_p (base0, offset0, bitpos0)
9084 || pointer_may_wrap_p (base1, offset1, bitpos1)))
9085 fold_overflow_warning (("assuming pointer wraparound does not "
9086 "occur when comparing P +- C1 with "
9088 WARN_STRICT_OVERFLOW_COMPARISON);
9090 return fold_build2 (code, type, offset0, offset1);
9093 /* For non-equal bases we can simplify if they are addresses
9094 of local binding decls or constants. */
9095 else if (indirect_base0 && indirect_base1
9096 /* We know that !operand_equal_p (base0, base1, 0)
9097 because the if condition was false. But make
9098 sure two decls are not the same. */
9100 && TREE_CODE (arg0) == ADDR_EXPR
9101 && TREE_CODE (arg1) == ADDR_EXPR
9102 && (((TREE_CODE (base0) == VAR_DECL
9103 || TREE_CODE (base0) == PARM_DECL)
9104 && (targetm.binds_local_p (base0)
9105 || CONSTANT_CLASS_P (base1)))
9106 || CONSTANT_CLASS_P (base0))
9107 && (((TREE_CODE (base1) == VAR_DECL
9108 || TREE_CODE (base1) == PARM_DECL)
9109 && (targetm.binds_local_p (base1)
9110 || CONSTANT_CLASS_P (base0)))
9111 || CONSTANT_CLASS_P (base1)))
9113 if (code == EQ_EXPR)
9114 return omit_two_operands (type, boolean_false_node, arg0, arg1);
9115 else if (code == NE_EXPR)
9116 return omit_two_operands (type, boolean_true_node, arg0, arg1);
9118 /* For equal offsets we can simplify to a comparison of the
9120 else if (bitpos0 == bitpos1
9122 ? base0 != TREE_OPERAND (arg0, 0) : base0 != arg0)
9124 ? base1 != TREE_OPERAND (arg1, 0) : base1 != arg1)
9125 && ((offset0 == offset1)
9126 || (offset0 && offset1
9127 && operand_equal_p (offset0, offset1, 0))))
9130 base0 = fold_addr_expr (base0);
9132 base1 = fold_addr_expr (base1);
9133 return fold_build2 (code, type, base0, base1);
9137 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
9138 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
9139 the resulting offset is smaller in absolute value than the
9141 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
9142 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
9143 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9144 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
9145 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
9146 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9147 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
9149 tree const1 = TREE_OPERAND (arg0, 1);
9150 tree const2 = TREE_OPERAND (arg1, 1);
9151 tree variable1 = TREE_OPERAND (arg0, 0);
9152 tree variable2 = TREE_OPERAND (arg1, 0);
9154 const char * const warnmsg = G_("assuming signed overflow does not "
9155 "occur when combining constants around "
9158 /* Put the constant on the side where it doesn't overflow and is
9159 of lower absolute value than before. */
9160 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
9161 ? MINUS_EXPR : PLUS_EXPR,
9163 if (!TREE_OVERFLOW (cst)
9164 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
9166 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
9167 return fold_build2 (code, type,
9169 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
9173 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
9174 ? MINUS_EXPR : PLUS_EXPR,
9176 if (!TREE_OVERFLOW (cst)
9177 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
9179 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
9180 return fold_build2 (code, type,
9181 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
9187 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
9188 signed arithmetic case. That form is created by the compiler
9189 often enough for folding it to be of value. One example is in
9190 computing loop trip counts after Operator Strength Reduction. */
9191 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
9192 && TREE_CODE (arg0) == MULT_EXPR
9193 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9194 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
9195 && integer_zerop (arg1))
9197 tree const1 = TREE_OPERAND (arg0, 1);
9198 tree const2 = arg1; /* zero */
9199 tree variable1 = TREE_OPERAND (arg0, 0);
9200 enum tree_code cmp_code = code;
9202 gcc_assert (!integer_zerop (const1));
9204 fold_overflow_warning (("assuming signed overflow does not occur when "
9205 "eliminating multiplication in comparison "
9207 WARN_STRICT_OVERFLOW_COMPARISON);
9209 /* If const1 is negative we swap the sense of the comparison. */
9210 if (tree_int_cst_sgn (const1) < 0)
9211 cmp_code = swap_tree_comparison (cmp_code);
9213 return fold_build2 (cmp_code, type, variable1, const2);
9216 tem = maybe_canonicalize_comparison (code, type, op0, op1);
9220 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
9222 tree targ0 = strip_float_extensions (arg0);
9223 tree targ1 = strip_float_extensions (arg1);
9224 tree newtype = TREE_TYPE (targ0);
9226 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
9227 newtype = TREE_TYPE (targ1);
9229 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9230 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
9231 return fold_build2 (code, type, fold_convert (newtype, targ0),
9232 fold_convert (newtype, targ1));
9234 /* (-a) CMP (-b) -> b CMP a */
9235 if (TREE_CODE (arg0) == NEGATE_EXPR
9236 && TREE_CODE (arg1) == NEGATE_EXPR)
9237 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
9238 TREE_OPERAND (arg0, 0));
9240 if (TREE_CODE (arg1) == REAL_CST)
9242 REAL_VALUE_TYPE cst;
9243 cst = TREE_REAL_CST (arg1);
9245 /* (-a) CMP CST -> a swap(CMP) (-CST) */
9246 if (TREE_CODE (arg0) == NEGATE_EXPR)
9247 return fold_build2 (swap_tree_comparison (code), type,
9248 TREE_OPERAND (arg0, 0),
9249 build_real (TREE_TYPE (arg1),
9250 REAL_VALUE_NEGATE (cst)));
9252 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
9253 /* a CMP (-0) -> a CMP 0 */
9254 if (REAL_VALUE_MINUS_ZERO (cst))
9255 return fold_build2 (code, type, arg0,
9256 build_real (TREE_TYPE (arg1), dconst0));
9258 /* x != NaN is always true, other ops are always false. */
9259 if (REAL_VALUE_ISNAN (cst)
9260 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
9262 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
9263 return omit_one_operand (type, tem, arg0);
9266 /* Fold comparisons against infinity. */
9267 if (REAL_VALUE_ISINF (cst))
9269 tem = fold_inf_compare (code, type, arg0, arg1);
9270 if (tem != NULL_TREE)
9275 /* If this is a comparison of a real constant with a PLUS_EXPR
9276 or a MINUS_EXPR of a real constant, we can convert it into a
9277 comparison with a revised real constant as long as no overflow
9278 occurs when unsafe_math_optimizations are enabled. */
9279 if (flag_unsafe_math_optimizations
9280 && TREE_CODE (arg1) == REAL_CST
9281 && (TREE_CODE (arg0) == PLUS_EXPR
9282 || TREE_CODE (arg0) == MINUS_EXPR)
9283 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
9284 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9285 ? MINUS_EXPR : PLUS_EXPR,
9286 arg1, TREE_OPERAND (arg0, 1), 0))
9287 && !TREE_OVERFLOW (tem))
9288 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9290 /* Likewise, we can simplify a comparison of a real constant with
9291 a MINUS_EXPR whose first operand is also a real constant, i.e.
9292 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
9293 floating-point types only if -fassociative-math is set. */
9294 if (flag_associative_math
9295 && TREE_CODE (arg1) == REAL_CST
9296 && TREE_CODE (arg0) == MINUS_EXPR
9297 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
9298 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
9300 && !TREE_OVERFLOW (tem))
9301 return fold_build2 (swap_tree_comparison (code), type,
9302 TREE_OPERAND (arg0, 1), tem);
9304 /* Fold comparisons against built-in math functions. */
9305 if (TREE_CODE (arg1) == REAL_CST
9306 && flag_unsafe_math_optimizations
9307 && ! flag_errno_math)
9309 enum built_in_function fcode = builtin_mathfn_code (arg0);
9311 if (fcode != END_BUILTINS)
9313 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
9314 if (tem != NULL_TREE)
9320 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
9321 && CONVERT_EXPR_P (arg0))
9323 /* If we are widening one operand of an integer comparison,
9324 see if the other operand is similarly being widened. Perhaps we
9325 can do the comparison in the narrower type. */
9326 tem = fold_widened_comparison (code, type, arg0, arg1);
9330 /* Or if we are changing signedness. */
9331 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
9336 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9337 constant, we can simplify it. */
9338 if (TREE_CODE (arg1) == INTEGER_CST
9339 && (TREE_CODE (arg0) == MIN_EXPR
9340 || TREE_CODE (arg0) == MAX_EXPR)
9341 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9343 tem = optimize_minmax_comparison (code, type, op0, op1);
9348 /* Simplify comparison of something with itself. (For IEEE
9349 floating-point, we can only do some of these simplifications.) */
9350 if (operand_equal_p (arg0, arg1, 0))
9355 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9356 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9357 return constant_boolean_node (1, type);
9362 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9363 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9364 return constant_boolean_node (1, type);
9365 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9368 /* For NE, we can only do this simplification if integer
9369 or we don't honor IEEE floating point NaNs. */
9370 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
9371 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9373 /* ... fall through ... */
9376 return constant_boolean_node (0, type);
9382 /* If we are comparing an expression that just has comparisons
9383 of two integer values, arithmetic expressions of those comparisons,
9384 and constants, we can simplify it. There are only three cases
9385 to check: the two values can either be equal, the first can be
9386 greater, or the second can be greater. Fold the expression for
9387 those three values. Since each value must be 0 or 1, we have
9388 eight possibilities, each of which corresponds to the constant 0
9389 or 1 or one of the six possible comparisons.
9391 This handles common cases like (a > b) == 0 but also handles
9392 expressions like ((x > y) - (y > x)) > 0, which supposedly
9393 occur in macroized code. */
9395 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
9397 tree cval1 = 0, cval2 = 0;
9400 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
9401 /* Don't handle degenerate cases here; they should already
9402 have been handled anyway. */
9403 && cval1 != 0 && cval2 != 0
9404 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
9405 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
9406 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
9407 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
9408 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
9409 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
9410 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9412 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9413 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9415 /* We can't just pass T to eval_subst in case cval1 or cval2
9416 was the same as ARG1. */
9419 = fold_build2 (code, type,
9420 eval_subst (arg0, cval1, maxval,
9424 = fold_build2 (code, type,
9425 eval_subst (arg0, cval1, maxval,
9429 = fold_build2 (code, type,
9430 eval_subst (arg0, cval1, minval,
9434 /* All three of these results should be 0 or 1. Confirm they are.
9435 Then use those values to select the proper code to use. */
9437 if (TREE_CODE (high_result) == INTEGER_CST
9438 && TREE_CODE (equal_result) == INTEGER_CST
9439 && TREE_CODE (low_result) == INTEGER_CST)
9441 /* Make a 3-bit mask with the high-order bit being the
9442 value for `>', the next for '=', and the low for '<'. */
9443 switch ((integer_onep (high_result) * 4)
9444 + (integer_onep (equal_result) * 2)
9445 + integer_onep (low_result))
9449 return omit_one_operand (type, integer_zero_node, arg0);
9470 return omit_one_operand (type, integer_one_node, arg0);
9474 return save_expr (build2 (code, type, cval1, cval2));
9475 return fold_build2 (code, type, cval1, cval2);
9480 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9481 into a single range test. */
9482 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9483 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9484 && TREE_CODE (arg1) == INTEGER_CST
9485 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9486 && !integer_zerop (TREE_OPERAND (arg0, 1))
9487 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9488 && !TREE_OVERFLOW (arg1))
9490 tem = fold_div_compare (code, type, arg0, arg1);
9491 if (tem != NULL_TREE)
9495 /* Fold ~X op ~Y as Y op X. */
9496 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9497 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9499 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9500 return fold_build2 (code, type,
9501 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
9502 TREE_OPERAND (arg0, 0));
9505 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
9506 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9507 && TREE_CODE (arg1) == INTEGER_CST)
9509 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9510 return fold_build2 (swap_tree_comparison (code), type,
9511 TREE_OPERAND (arg0, 0),
9512 fold_build1 (BIT_NOT_EXPR, cmp_type,
9513 fold_convert (cmp_type, arg1)));
9520 /* Subroutine of fold_binary. Optimize complex multiplications of the
9521 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9522 argument EXPR represents the expression "z" of type TYPE. */
9525 fold_mult_zconjz (tree type, tree expr)
9527 tree itype = TREE_TYPE (type);
9528 tree rpart, ipart, tem;
9530 if (TREE_CODE (expr) == COMPLEX_EXPR)
9532 rpart = TREE_OPERAND (expr, 0);
9533 ipart = TREE_OPERAND (expr, 1);
9535 else if (TREE_CODE (expr) == COMPLEX_CST)
9537 rpart = TREE_REALPART (expr);
9538 ipart = TREE_IMAGPART (expr);
9542 expr = save_expr (expr);
9543 rpart = fold_build1 (REALPART_EXPR, itype, expr);
9544 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
9547 rpart = save_expr (rpart);
9548 ipart = save_expr (ipart);
9549 tem = fold_build2 (PLUS_EXPR, itype,
9550 fold_build2 (MULT_EXPR, itype, rpart, rpart),
9551 fold_build2 (MULT_EXPR, itype, ipart, ipart));
9552 return fold_build2 (COMPLEX_EXPR, type, tem,
9553 fold_convert (itype, integer_zero_node));
9557 /* Subroutine of fold_binary. If P is the value of EXPR, computes
9558 power-of-two M and (arbitrary) N such that M divides (P-N). This condition
9559 guarantees that P and N have the same least significant log2(M) bits.
9560 N is not otherwise constrained. In particular, N is not normalized to
9561 0 <= N < M as is common. In general, the precise value of P is unknown.
9562 M is chosen as large as possible such that constant N can be determined.
9564 Returns M and sets *RESIDUE to N. */
9566 static unsigned HOST_WIDE_INT
9567 get_pointer_modulus_and_residue (tree expr, unsigned HOST_WIDE_INT *residue)
9569 enum tree_code code;
9573 code = TREE_CODE (expr);
9574 if (code == ADDR_EXPR)
9576 expr = TREE_OPERAND (expr, 0);
9577 if (handled_component_p (expr))
9579 HOST_WIDE_INT bitsize, bitpos;
9581 enum machine_mode mode;
9582 int unsignedp, volatilep;
9584 expr = get_inner_reference (expr, &bitsize, &bitpos, &offset,
9585 &mode, &unsignedp, &volatilep, false);
9586 *residue = bitpos / BITS_PER_UNIT;
9589 if (TREE_CODE (offset) == INTEGER_CST)
9590 *residue += TREE_INT_CST_LOW (offset);
9592 /* We don't handle more complicated offset expressions. */
9597 if (DECL_P (expr) && TREE_CODE (expr) != FUNCTION_DECL)
9598 return DECL_ALIGN_UNIT (expr);
9600 else if (code == POINTER_PLUS_EXPR)
9603 unsigned HOST_WIDE_INT modulus;
9604 enum tree_code inner_code;
9606 op0 = TREE_OPERAND (expr, 0);
9608 modulus = get_pointer_modulus_and_residue (op0, residue);
9610 op1 = TREE_OPERAND (expr, 1);
9612 inner_code = TREE_CODE (op1);
9613 if (inner_code == INTEGER_CST)
9615 *residue += TREE_INT_CST_LOW (op1);
9618 else if (inner_code == MULT_EXPR)
9620 op1 = TREE_OPERAND (op1, 1);
9621 if (TREE_CODE (op1) == INTEGER_CST)
9623 unsigned HOST_WIDE_INT align;
9625 /* Compute the greatest power-of-2 divisor of op1. */
9626 align = TREE_INT_CST_LOW (op1);
9629 /* If align is non-zero and less than *modulus, replace
9630 *modulus with align., If align is 0, then either op1 is 0
9631 or the greatest power-of-2 divisor of op1 doesn't fit in an
9632 unsigned HOST_WIDE_INT. In either case, no additional
9633 constraint is imposed. */
9635 modulus = MIN (modulus, align);
9642 /* If we get here, we were unable to determine anything useful about the
9648 /* Fold a binary expression of code CODE and type TYPE with operands
9649 OP0 and OP1. Return the folded expression if folding is
9650 successful. Otherwise, return NULL_TREE. */
9653 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
9655 enum tree_code_class kind = TREE_CODE_CLASS (code);
9656 tree arg0, arg1, tem;
9657 tree t1 = NULL_TREE;
9658 bool strict_overflow_p;
9660 gcc_assert (IS_EXPR_CODE_CLASS (kind)
9661 && TREE_CODE_LENGTH (code) == 2
9663 && op1 != NULL_TREE);
9668 /* Strip any conversions that don't change the mode. This is
9669 safe for every expression, except for a comparison expression
9670 because its signedness is derived from its operands. So, in
9671 the latter case, only strip conversions that don't change the
9672 signedness. MIN_EXPR/MAX_EXPR also need signedness of arguments
9675 Note that this is done as an internal manipulation within the
9676 constant folder, in order to find the simplest representation
9677 of the arguments so that their form can be studied. In any
9678 cases, the appropriate type conversions should be put back in
9679 the tree that will get out of the constant folder. */
9681 if (kind == tcc_comparison || code == MIN_EXPR || code == MAX_EXPR)
9683 STRIP_SIGN_NOPS (arg0);
9684 STRIP_SIGN_NOPS (arg1);
9692 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9693 constant but we can't do arithmetic on them. */
9694 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9695 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9696 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == FIXED_CST)
9697 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == INTEGER_CST)
9698 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9699 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9701 if (kind == tcc_binary)
9703 /* Make sure type and arg0 have the same saturating flag. */
9704 gcc_assert (TYPE_SATURATING (type)
9705 == TYPE_SATURATING (TREE_TYPE (arg0)));
9706 tem = const_binop (code, arg0, arg1, 0);
9708 else if (kind == tcc_comparison)
9709 tem = fold_relational_const (code, type, arg0, arg1);
9713 if (tem != NULL_TREE)
9715 if (TREE_TYPE (tem) != type)
9716 tem = fold_convert (type, tem);
9721 /* If this is a commutative operation, and ARG0 is a constant, move it
9722 to ARG1 to reduce the number of tests below. */
9723 if (commutative_tree_code (code)
9724 && tree_swap_operands_p (arg0, arg1, true))
9725 return fold_build2 (code, type, op1, op0);
9727 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9729 First check for cases where an arithmetic operation is applied to a
9730 compound, conditional, or comparison operation. Push the arithmetic
9731 operation inside the compound or conditional to see if any folding
9732 can then be done. Convert comparison to conditional for this purpose.
9733 The also optimizes non-constant cases that used to be done in
9736 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9737 one of the operands is a comparison and the other is a comparison, a
9738 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9739 code below would make the expression more complex. Change it to a
9740 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9741 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9743 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9744 || code == EQ_EXPR || code == NE_EXPR)
9745 && ((truth_value_p (TREE_CODE (arg0))
9746 && (truth_value_p (TREE_CODE (arg1))
9747 || (TREE_CODE (arg1) == BIT_AND_EXPR
9748 && integer_onep (TREE_OPERAND (arg1, 1)))))
9749 || (truth_value_p (TREE_CODE (arg1))
9750 && (truth_value_p (TREE_CODE (arg0))
9751 || (TREE_CODE (arg0) == BIT_AND_EXPR
9752 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9754 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9755 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9758 fold_convert (boolean_type_node, arg0),
9759 fold_convert (boolean_type_node, arg1));
9761 if (code == EQ_EXPR)
9762 tem = invert_truthvalue (tem);
9764 return fold_convert (type, tem);
9767 if (TREE_CODE_CLASS (code) == tcc_binary
9768 || TREE_CODE_CLASS (code) == tcc_comparison)
9770 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9771 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9772 fold_build2 (code, type,
9773 fold_convert (TREE_TYPE (op0),
9774 TREE_OPERAND (arg0, 1)),
9776 if (TREE_CODE (arg1) == COMPOUND_EXPR
9777 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9778 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9779 fold_build2 (code, type, op0,
9780 fold_convert (TREE_TYPE (op1),
9781 TREE_OPERAND (arg1, 1))));
9783 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9785 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9787 /*cond_first_p=*/1);
9788 if (tem != NULL_TREE)
9792 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9794 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9796 /*cond_first_p=*/0);
9797 if (tem != NULL_TREE)
9804 case POINTER_PLUS_EXPR:
9805 /* 0 +p index -> (type)index */
9806 if (integer_zerop (arg0))
9807 return non_lvalue (fold_convert (type, arg1));
9809 /* PTR +p 0 -> PTR */
9810 if (integer_zerop (arg1))
9811 return non_lvalue (fold_convert (type, arg0));
9813 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9814 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9815 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9816 return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
9817 fold_convert (sizetype, arg1),
9818 fold_convert (sizetype, arg0)));
9820 /* index +p PTR -> PTR +p index */
9821 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9822 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9823 return fold_build2 (POINTER_PLUS_EXPR, type,
9824 fold_convert (type, arg1),
9825 fold_convert (sizetype, arg0));
9827 /* (PTR +p B) +p A -> PTR +p (B + A) */
9828 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9831 tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
9832 tree arg00 = TREE_OPERAND (arg0, 0);
9833 inner = fold_build2 (PLUS_EXPR, sizetype,
9834 arg01, fold_convert (sizetype, arg1));
9835 return fold_convert (type,
9836 fold_build2 (POINTER_PLUS_EXPR,
9837 TREE_TYPE (arg00), arg00, inner));
9840 /* PTR_CST +p CST -> CST1 */
9841 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9842 return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
9844 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9845 of the array. Loop optimizer sometimes produce this type of
9847 if (TREE_CODE (arg0) == ADDR_EXPR)
9849 tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
9851 return fold_convert (type, tem);
9857 /* PTR + INT -> (INT)(PTR p+ INT) */
9858 if (POINTER_TYPE_P (TREE_TYPE (arg0))
9859 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9860 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9863 fold_convert (sizetype, arg1)));
9864 /* INT + PTR -> (INT)(PTR p+ INT) */
9865 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9866 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9867 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9870 fold_convert (sizetype, arg0)));
9871 /* A + (-B) -> A - B */
9872 if (TREE_CODE (arg1) == NEGATE_EXPR)
9873 return fold_build2 (MINUS_EXPR, type,
9874 fold_convert (type, arg0),
9875 fold_convert (type, TREE_OPERAND (arg1, 0)));
9876 /* (-A) + B -> B - A */
9877 if (TREE_CODE (arg0) == NEGATE_EXPR
9878 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9879 return fold_build2 (MINUS_EXPR, type,
9880 fold_convert (type, arg1),
9881 fold_convert (type, TREE_OPERAND (arg0, 0)));
9883 if (INTEGRAL_TYPE_P (type))
9885 /* Convert ~A + 1 to -A. */
9886 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9887 && integer_onep (arg1))
9888 return fold_build1 (NEGATE_EXPR, type,
9889 fold_convert (type, TREE_OPERAND (arg0, 0)));
9892 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9893 && !TYPE_OVERFLOW_TRAPS (type))
9895 tree tem = TREE_OPERAND (arg0, 0);
9898 if (operand_equal_p (tem, arg1, 0))
9900 t1 = build_int_cst_type (type, -1);
9901 return omit_one_operand (type, t1, arg1);
9906 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9907 && !TYPE_OVERFLOW_TRAPS (type))
9909 tree tem = TREE_OPERAND (arg1, 0);
9912 if (operand_equal_p (arg0, tem, 0))
9914 t1 = build_int_cst_type (type, -1);
9915 return omit_one_operand (type, t1, arg0);
9919 /* X + (X / CST) * -CST is X % CST. */
9920 if (TREE_CODE (arg1) == MULT_EXPR
9921 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9922 && operand_equal_p (arg0,
9923 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
9925 tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
9926 tree cst1 = TREE_OPERAND (arg1, 1);
9927 tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
9928 if (sum && integer_zerop (sum))
9929 return fold_convert (type,
9930 fold_build2 (TRUNC_MOD_EXPR,
9931 TREE_TYPE (arg0), arg0, cst0));
9935 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9936 same or one. Make sure type is not saturating.
9937 fold_plusminus_mult_expr will re-associate. */
9938 if ((TREE_CODE (arg0) == MULT_EXPR
9939 || TREE_CODE (arg1) == MULT_EXPR)
9940 && !TYPE_SATURATING (type)
9941 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9943 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9948 if (! FLOAT_TYPE_P (type))
9950 if (integer_zerop (arg1))
9951 return non_lvalue (fold_convert (type, arg0));
9953 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9954 with a constant, and the two constants have no bits in common,
9955 we should treat this as a BIT_IOR_EXPR since this may produce more
9957 if (TREE_CODE (arg0) == BIT_AND_EXPR
9958 && TREE_CODE (arg1) == BIT_AND_EXPR
9959 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9960 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9961 && integer_zerop (const_binop (BIT_AND_EXPR,
9962 TREE_OPERAND (arg0, 1),
9963 TREE_OPERAND (arg1, 1), 0)))
9965 code = BIT_IOR_EXPR;
9969 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9970 (plus (plus (mult) (mult)) (foo)) so that we can
9971 take advantage of the factoring cases below. */
9972 if (((TREE_CODE (arg0) == PLUS_EXPR
9973 || TREE_CODE (arg0) == MINUS_EXPR)
9974 && TREE_CODE (arg1) == MULT_EXPR)
9975 || ((TREE_CODE (arg1) == PLUS_EXPR
9976 || TREE_CODE (arg1) == MINUS_EXPR)
9977 && TREE_CODE (arg0) == MULT_EXPR))
9979 tree parg0, parg1, parg, marg;
9980 enum tree_code pcode;
9982 if (TREE_CODE (arg1) == MULT_EXPR)
9983 parg = arg0, marg = arg1;
9985 parg = arg1, marg = arg0;
9986 pcode = TREE_CODE (parg);
9987 parg0 = TREE_OPERAND (parg, 0);
9988 parg1 = TREE_OPERAND (parg, 1);
9992 if (TREE_CODE (parg0) == MULT_EXPR
9993 && TREE_CODE (parg1) != MULT_EXPR)
9994 return fold_build2 (pcode, type,
9995 fold_build2 (PLUS_EXPR, type,
9996 fold_convert (type, parg0),
9997 fold_convert (type, marg)),
9998 fold_convert (type, parg1));
9999 if (TREE_CODE (parg0) != MULT_EXPR
10000 && TREE_CODE (parg1) == MULT_EXPR)
10001 return fold_build2 (PLUS_EXPR, type,
10002 fold_convert (type, parg0),
10003 fold_build2 (pcode, type,
10004 fold_convert (type, marg),
10005 fold_convert (type,
10011 /* See if ARG1 is zero and X + ARG1 reduces to X. */
10012 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
10013 return non_lvalue (fold_convert (type, arg0));
10015 /* Likewise if the operands are reversed. */
10016 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
10017 return non_lvalue (fold_convert (type, arg1));
10019 /* Convert X + -C into X - C. */
10020 if (TREE_CODE (arg1) == REAL_CST
10021 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
10023 tem = fold_negate_const (arg1, type);
10024 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
10025 return fold_build2 (MINUS_EXPR, type,
10026 fold_convert (type, arg0),
10027 fold_convert (type, tem));
10030 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
10031 to __complex__ ( x, y ). This is not the same for SNaNs or
10032 if signed zeros are involved. */
10033 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10034 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10035 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10037 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10038 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10039 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10040 bool arg0rz = false, arg0iz = false;
10041 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10042 || (arg0i && (arg0iz = real_zerop (arg0i))))
10044 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10045 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10046 if (arg0rz && arg1i && real_zerop (arg1i))
10048 tree rp = arg1r ? arg1r
10049 : build1 (REALPART_EXPR, rtype, arg1);
10050 tree ip = arg0i ? arg0i
10051 : build1 (IMAGPART_EXPR, rtype, arg0);
10052 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10054 else if (arg0iz && arg1r && real_zerop (arg1r))
10056 tree rp = arg0r ? arg0r
10057 : build1 (REALPART_EXPR, rtype, arg0);
10058 tree ip = arg1i ? arg1i
10059 : build1 (IMAGPART_EXPR, rtype, arg1);
10060 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10065 if (flag_unsafe_math_optimizations
10066 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10067 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10068 && (tem = distribute_real_division (code, type, arg0, arg1)))
10071 /* Convert x+x into x*2.0. */
10072 if (operand_equal_p (arg0, arg1, 0)
10073 && SCALAR_FLOAT_TYPE_P (type))
10074 return fold_build2 (MULT_EXPR, type, arg0,
10075 build_real (type, dconst2));
10077 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
10078 We associate floats only if the user has specified
10079 -fassociative-math. */
10080 if (flag_associative_math
10081 && TREE_CODE (arg1) == PLUS_EXPR
10082 && TREE_CODE (arg0) != MULT_EXPR)
10084 tree tree10 = TREE_OPERAND (arg1, 0);
10085 tree tree11 = TREE_OPERAND (arg1, 1);
10086 if (TREE_CODE (tree11) == MULT_EXPR
10087 && TREE_CODE (tree10) == MULT_EXPR)
10090 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
10091 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
10094 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
10095 We associate floats only if the user has specified
10096 -fassociative-math. */
10097 if (flag_associative_math
10098 && TREE_CODE (arg0) == PLUS_EXPR
10099 && TREE_CODE (arg1) != MULT_EXPR)
10101 tree tree00 = TREE_OPERAND (arg0, 0);
10102 tree tree01 = TREE_OPERAND (arg0, 1);
10103 if (TREE_CODE (tree01) == MULT_EXPR
10104 && TREE_CODE (tree00) == MULT_EXPR)
10107 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
10108 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
10114 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
10115 is a rotate of A by C1 bits. */
10116 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
10117 is a rotate of A by B bits. */
10119 enum tree_code code0, code1;
10121 code0 = TREE_CODE (arg0);
10122 code1 = TREE_CODE (arg1);
10123 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
10124 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
10125 && operand_equal_p (TREE_OPERAND (arg0, 0),
10126 TREE_OPERAND (arg1, 0), 0)
10127 && (rtype = TREE_TYPE (TREE_OPERAND (arg0, 0)),
10128 TYPE_UNSIGNED (rtype))
10129 /* Only create rotates in complete modes. Other cases are not
10130 expanded properly. */
10131 && TYPE_PRECISION (rtype) == GET_MODE_PRECISION (TYPE_MODE (rtype)))
10133 tree tree01, tree11;
10134 enum tree_code code01, code11;
10136 tree01 = TREE_OPERAND (arg0, 1);
10137 tree11 = TREE_OPERAND (arg1, 1);
10138 STRIP_NOPS (tree01);
10139 STRIP_NOPS (tree11);
10140 code01 = TREE_CODE (tree01);
10141 code11 = TREE_CODE (tree11);
10142 if (code01 == INTEGER_CST
10143 && code11 == INTEGER_CST
10144 && TREE_INT_CST_HIGH (tree01) == 0
10145 && TREE_INT_CST_HIGH (tree11) == 0
10146 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
10147 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
10148 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
10149 code0 == LSHIFT_EXPR ? tree01 : tree11);
10150 else if (code11 == MINUS_EXPR)
10152 tree tree110, tree111;
10153 tree110 = TREE_OPERAND (tree11, 0);
10154 tree111 = TREE_OPERAND (tree11, 1);
10155 STRIP_NOPS (tree110);
10156 STRIP_NOPS (tree111);
10157 if (TREE_CODE (tree110) == INTEGER_CST
10158 && 0 == compare_tree_int (tree110,
10160 (TREE_TYPE (TREE_OPERAND
10162 && operand_equal_p (tree01, tree111, 0))
10163 return build2 ((code0 == LSHIFT_EXPR
10166 type, TREE_OPERAND (arg0, 0), tree01);
10168 else if (code01 == MINUS_EXPR)
10170 tree tree010, tree011;
10171 tree010 = TREE_OPERAND (tree01, 0);
10172 tree011 = TREE_OPERAND (tree01, 1);
10173 STRIP_NOPS (tree010);
10174 STRIP_NOPS (tree011);
10175 if (TREE_CODE (tree010) == INTEGER_CST
10176 && 0 == compare_tree_int (tree010,
10178 (TREE_TYPE (TREE_OPERAND
10180 && operand_equal_p (tree11, tree011, 0))
10181 return build2 ((code0 != LSHIFT_EXPR
10184 type, TREE_OPERAND (arg0, 0), tree11);
10190 /* In most languages, can't associate operations on floats through
10191 parentheses. Rather than remember where the parentheses were, we
10192 don't associate floats at all, unless the user has specified
10193 -fassociative-math.
10194 And, we need to make sure type is not saturating. */
10196 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
10197 && !TYPE_SATURATING (type))
10199 tree var0, con0, lit0, minus_lit0;
10200 tree var1, con1, lit1, minus_lit1;
10203 /* Split both trees into variables, constants, and literals. Then
10204 associate each group together, the constants with literals,
10205 then the result with variables. This increases the chances of
10206 literals being recombined later and of generating relocatable
10207 expressions for the sum of a constant and literal. */
10208 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
10209 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
10210 code == MINUS_EXPR);
10212 /* With undefined overflow we can only associate constants
10213 with one variable. */
10214 if (((POINTER_TYPE_P (type) && POINTER_TYPE_OVERFLOW_UNDEFINED)
10215 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
10221 if (TREE_CODE (tmp0) == NEGATE_EXPR)
10222 tmp0 = TREE_OPERAND (tmp0, 0);
10223 if (TREE_CODE (tmp1) == NEGATE_EXPR)
10224 tmp1 = TREE_OPERAND (tmp1, 0);
10225 /* The only case we can still associate with two variables
10226 is if they are the same, modulo negation. */
10227 if (!operand_equal_p (tmp0, tmp1, 0))
10231 /* Only do something if we found more than two objects. Otherwise,
10232 nothing has changed and we risk infinite recursion. */
10234 && (2 < ((var0 != 0) + (var1 != 0)
10235 + (con0 != 0) + (con1 != 0)
10236 + (lit0 != 0) + (lit1 != 0)
10237 + (minus_lit0 != 0) + (minus_lit1 != 0))))
10239 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
10240 if (code == MINUS_EXPR)
10243 var0 = associate_trees (var0, var1, code, type);
10244 con0 = associate_trees (con0, con1, code, type);
10245 lit0 = associate_trees (lit0, lit1, code, type);
10246 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
10248 /* Preserve the MINUS_EXPR if the negative part of the literal is
10249 greater than the positive part. Otherwise, the multiplicative
10250 folding code (i.e extract_muldiv) may be fooled in case
10251 unsigned constants are subtracted, like in the following
10252 example: ((X*2 + 4) - 8U)/2. */
10253 if (minus_lit0 && lit0)
10255 if (TREE_CODE (lit0) == INTEGER_CST
10256 && TREE_CODE (minus_lit0) == INTEGER_CST
10257 && tree_int_cst_lt (lit0, minus_lit0))
10259 minus_lit0 = associate_trees (minus_lit0, lit0,
10265 lit0 = associate_trees (lit0, minus_lit0,
10273 return fold_convert (type,
10274 associate_trees (var0, minus_lit0,
10275 MINUS_EXPR, type));
10278 con0 = associate_trees (con0, minus_lit0,
10280 return fold_convert (type,
10281 associate_trees (var0, con0,
10286 con0 = associate_trees (con0, lit0, code, type);
10287 return fold_convert (type, associate_trees (var0, con0,
10295 /* Pointer simplifications for subtraction, simple reassociations. */
10296 if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
10298 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
10299 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
10300 && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
10302 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10303 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10304 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10305 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10306 return fold_build2 (PLUS_EXPR, type,
10307 fold_build2 (MINUS_EXPR, type, arg00, arg10),
10308 fold_build2 (MINUS_EXPR, type, arg01, arg11));
10310 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
10311 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
10313 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10314 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10315 tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
10317 return fold_build2 (PLUS_EXPR, type, tmp, arg01);
10320 /* A - (-B) -> A + B */
10321 if (TREE_CODE (arg1) == NEGATE_EXPR)
10322 return fold_build2 (PLUS_EXPR, type, op0,
10323 fold_convert (type, TREE_OPERAND (arg1, 0)));
10324 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
10325 if (TREE_CODE (arg0) == NEGATE_EXPR
10326 && (FLOAT_TYPE_P (type)
10327 || INTEGRAL_TYPE_P (type))
10328 && negate_expr_p (arg1)
10329 && reorder_operands_p (arg0, arg1))
10330 return fold_build2 (MINUS_EXPR, type,
10331 fold_convert (type, negate_expr (arg1)),
10332 fold_convert (type, TREE_OPERAND (arg0, 0)));
10333 /* Convert -A - 1 to ~A. */
10334 if (INTEGRAL_TYPE_P (type)
10335 && TREE_CODE (arg0) == NEGATE_EXPR
10336 && integer_onep (arg1)
10337 && !TYPE_OVERFLOW_TRAPS (type))
10338 return fold_build1 (BIT_NOT_EXPR, type,
10339 fold_convert (type, TREE_OPERAND (arg0, 0)));
10341 /* Convert -1 - A to ~A. */
10342 if (INTEGRAL_TYPE_P (type)
10343 && integer_all_onesp (arg0))
10344 return fold_build1 (BIT_NOT_EXPR, type, op1);
10347 /* X - (X / CST) * CST is X % CST. */
10348 if (INTEGRAL_TYPE_P (type)
10349 && TREE_CODE (arg1) == MULT_EXPR
10350 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
10351 && operand_equal_p (arg0,
10352 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
10353 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
10354 TREE_OPERAND (arg1, 1), 0))
10355 return fold_convert (type,
10356 fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
10357 arg0, TREE_OPERAND (arg1, 1)));
10359 if (! FLOAT_TYPE_P (type))
10361 if (integer_zerop (arg0))
10362 return negate_expr (fold_convert (type, arg1));
10363 if (integer_zerop (arg1))
10364 return non_lvalue (fold_convert (type, arg0));
10366 /* Fold A - (A & B) into ~B & A. */
10367 if (!TREE_SIDE_EFFECTS (arg0)
10368 && TREE_CODE (arg1) == BIT_AND_EXPR)
10370 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
10372 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10373 return fold_build2 (BIT_AND_EXPR, type,
10374 fold_build1 (BIT_NOT_EXPR, type, arg10),
10375 fold_convert (type, arg0));
10377 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10379 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10380 return fold_build2 (BIT_AND_EXPR, type,
10381 fold_build1 (BIT_NOT_EXPR, type, arg11),
10382 fold_convert (type, arg0));
10386 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
10387 any power of 2 minus 1. */
10388 if (TREE_CODE (arg0) == BIT_AND_EXPR
10389 && TREE_CODE (arg1) == BIT_AND_EXPR
10390 && operand_equal_p (TREE_OPERAND (arg0, 0),
10391 TREE_OPERAND (arg1, 0), 0))
10393 tree mask0 = TREE_OPERAND (arg0, 1);
10394 tree mask1 = TREE_OPERAND (arg1, 1);
10395 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
10397 if (operand_equal_p (tem, mask1, 0))
10399 tem = fold_build2 (BIT_XOR_EXPR, type,
10400 TREE_OPERAND (arg0, 0), mask1);
10401 return fold_build2 (MINUS_EXPR, type, tem, mask1);
10406 /* See if ARG1 is zero and X - ARG1 reduces to X. */
10407 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
10408 return non_lvalue (fold_convert (type, arg0));
10410 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
10411 ARG0 is zero and X + ARG0 reduces to X, since that would mean
10412 (-ARG1 + ARG0) reduces to -ARG1. */
10413 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
10414 return negate_expr (fold_convert (type, arg1));
10416 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
10417 __complex__ ( x, -y ). This is not the same for SNaNs or if
10418 signed zeros are involved. */
10419 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10420 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10421 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10423 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10424 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10425 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10426 bool arg0rz = false, arg0iz = false;
10427 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10428 || (arg0i && (arg0iz = real_zerop (arg0i))))
10430 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10431 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10432 if (arg0rz && arg1i && real_zerop (arg1i))
10434 tree rp = fold_build1 (NEGATE_EXPR, rtype,
10436 : build1 (REALPART_EXPR, rtype, arg1));
10437 tree ip = arg0i ? arg0i
10438 : build1 (IMAGPART_EXPR, rtype, arg0);
10439 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10441 else if (arg0iz && arg1r && real_zerop (arg1r))
10443 tree rp = arg0r ? arg0r
10444 : build1 (REALPART_EXPR, rtype, arg0);
10445 tree ip = fold_build1 (NEGATE_EXPR, rtype,
10447 : build1 (IMAGPART_EXPR, rtype, arg1));
10448 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10453 /* Fold &x - &x. This can happen from &x.foo - &x.
10454 This is unsafe for certain floats even in non-IEEE formats.
10455 In IEEE, it is unsafe because it does wrong for NaNs.
10456 Also note that operand_equal_p is always false if an operand
10459 if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
10460 && operand_equal_p (arg0, arg1, 0))
10461 return fold_convert (type, integer_zero_node);
10463 /* A - B -> A + (-B) if B is easily negatable. */
10464 if (negate_expr_p (arg1)
10465 && ((FLOAT_TYPE_P (type)
10466 /* Avoid this transformation if B is a positive REAL_CST. */
10467 && (TREE_CODE (arg1) != REAL_CST
10468 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
10469 || INTEGRAL_TYPE_P (type)))
10470 return fold_build2 (PLUS_EXPR, type,
10471 fold_convert (type, arg0),
10472 fold_convert (type, negate_expr (arg1)));
10474 /* Try folding difference of addresses. */
10476 HOST_WIDE_INT diff;
10478 if ((TREE_CODE (arg0) == ADDR_EXPR
10479 || TREE_CODE (arg1) == ADDR_EXPR)
10480 && ptr_difference_const (arg0, arg1, &diff))
10481 return build_int_cst_type (type, diff);
10484 /* Fold &a[i] - &a[j] to i-j. */
10485 if (TREE_CODE (arg0) == ADDR_EXPR
10486 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
10487 && TREE_CODE (arg1) == ADDR_EXPR
10488 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
10490 tree aref0 = TREE_OPERAND (arg0, 0);
10491 tree aref1 = TREE_OPERAND (arg1, 0);
10492 if (operand_equal_p (TREE_OPERAND (aref0, 0),
10493 TREE_OPERAND (aref1, 0), 0))
10495 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
10496 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
10497 tree esz = array_ref_element_size (aref0);
10498 tree diff = build2 (MINUS_EXPR, type, op0, op1);
10499 return fold_build2 (MULT_EXPR, type, diff,
10500 fold_convert (type, esz));
10505 if (flag_unsafe_math_optimizations
10506 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10507 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10508 && (tem = distribute_real_division (code, type, arg0, arg1)))
10511 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
10512 same or one. Make sure type is not saturating.
10513 fold_plusminus_mult_expr will re-associate. */
10514 if ((TREE_CODE (arg0) == MULT_EXPR
10515 || TREE_CODE (arg1) == MULT_EXPR)
10516 && !TYPE_SATURATING (type)
10517 && (!FLOAT_TYPE_P (type) || flag_associative_math))
10519 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
10527 /* (-A) * (-B) -> A * B */
10528 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10529 return fold_build2 (MULT_EXPR, type,
10530 fold_convert (type, TREE_OPERAND (arg0, 0)),
10531 fold_convert (type, negate_expr (arg1)));
10532 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10533 return fold_build2 (MULT_EXPR, type,
10534 fold_convert (type, negate_expr (arg0)),
10535 fold_convert (type, TREE_OPERAND (arg1, 0)));
10537 if (! FLOAT_TYPE_P (type))
10539 if (integer_zerop (arg1))
10540 return omit_one_operand (type, arg1, arg0);
10541 if (integer_onep (arg1))
10542 return non_lvalue (fold_convert (type, arg0));
10543 /* Transform x * -1 into -x. Make sure to do the negation
10544 on the original operand with conversions not stripped
10545 because we can only strip non-sign-changing conversions. */
10546 if (integer_all_onesp (arg1))
10547 return fold_convert (type, negate_expr (op0));
10548 /* Transform x * -C into -x * C if x is easily negatable. */
10549 if (TREE_CODE (arg1) == INTEGER_CST
10550 && tree_int_cst_sgn (arg1) == -1
10551 && negate_expr_p (arg0)
10552 && (tem = negate_expr (arg1)) != arg1
10553 && !TREE_OVERFLOW (tem))
10554 return fold_build2 (MULT_EXPR, type,
10555 fold_convert (type, negate_expr (arg0)), tem);
10557 /* (a * (1 << b)) is (a << b) */
10558 if (TREE_CODE (arg1) == LSHIFT_EXPR
10559 && integer_onep (TREE_OPERAND (arg1, 0)))
10560 return fold_build2 (LSHIFT_EXPR, type, op0,
10561 TREE_OPERAND (arg1, 1));
10562 if (TREE_CODE (arg0) == LSHIFT_EXPR
10563 && integer_onep (TREE_OPERAND (arg0, 0)))
10564 return fold_build2 (LSHIFT_EXPR, type, op1,
10565 TREE_OPERAND (arg0, 1));
10567 /* (A + A) * C -> A * 2 * C */
10568 if (TREE_CODE (arg0) == PLUS_EXPR
10569 && TREE_CODE (arg1) == INTEGER_CST
10570 && operand_equal_p (TREE_OPERAND (arg0, 0),
10571 TREE_OPERAND (arg0, 1), 0))
10572 return fold_build2 (MULT_EXPR, type,
10573 omit_one_operand (type, TREE_OPERAND (arg0, 0),
10574 TREE_OPERAND (arg0, 1)),
10575 fold_build2 (MULT_EXPR, type,
10576 build_int_cst (type, 2) , arg1));
10578 strict_overflow_p = false;
10579 if (TREE_CODE (arg1) == INTEGER_CST
10580 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10581 &strict_overflow_p)))
10583 if (strict_overflow_p)
10584 fold_overflow_warning (("assuming signed overflow does not "
10585 "occur when simplifying "
10587 WARN_STRICT_OVERFLOW_MISC);
10588 return fold_convert (type, tem);
10591 /* Optimize z * conj(z) for integer complex numbers. */
10592 if (TREE_CODE (arg0) == CONJ_EXPR
10593 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10594 return fold_mult_zconjz (type, arg1);
10595 if (TREE_CODE (arg1) == CONJ_EXPR
10596 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10597 return fold_mult_zconjz (type, arg0);
10601 /* Maybe fold x * 0 to 0. The expressions aren't the same
10602 when x is NaN, since x * 0 is also NaN. Nor are they the
10603 same in modes with signed zeros, since multiplying a
10604 negative value by 0 gives -0, not +0. */
10605 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10606 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10607 && real_zerop (arg1))
10608 return omit_one_operand (type, arg1, arg0);
10609 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
10610 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10611 && real_onep (arg1))
10612 return non_lvalue (fold_convert (type, arg0));
10614 /* Transform x * -1.0 into -x. */
10615 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10616 && real_minus_onep (arg1))
10617 return fold_convert (type, negate_expr (arg0));
10619 /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
10620 the result for floating point types due to rounding so it is applied
10621 only if -fassociative-math was specify. */
10622 if (flag_associative_math
10623 && TREE_CODE (arg0) == RDIV_EXPR
10624 && TREE_CODE (arg1) == REAL_CST
10625 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
10627 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
10630 return fold_build2 (RDIV_EXPR, type, tem,
10631 TREE_OPERAND (arg0, 1));
10634 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10635 if (operand_equal_p (arg0, arg1, 0))
10637 tree tem = fold_strip_sign_ops (arg0);
10638 if (tem != NULL_TREE)
10640 tem = fold_convert (type, tem);
10641 return fold_build2 (MULT_EXPR, type, tem, tem);
10645 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10646 This is not the same for NaNs or if signed zeros are
10648 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10649 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10650 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10651 && TREE_CODE (arg1) == COMPLEX_CST
10652 && real_zerop (TREE_REALPART (arg1)))
10654 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10655 if (real_onep (TREE_IMAGPART (arg1)))
10656 return fold_build2 (COMPLEX_EXPR, type,
10657 negate_expr (fold_build1 (IMAGPART_EXPR,
10659 fold_build1 (REALPART_EXPR, rtype, arg0));
10660 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10661 return fold_build2 (COMPLEX_EXPR, type,
10662 fold_build1 (IMAGPART_EXPR, rtype, arg0),
10663 negate_expr (fold_build1 (REALPART_EXPR,
10667 /* Optimize z * conj(z) for floating point complex numbers.
10668 Guarded by flag_unsafe_math_optimizations as non-finite
10669 imaginary components don't produce scalar results. */
10670 if (flag_unsafe_math_optimizations
10671 && TREE_CODE (arg0) == CONJ_EXPR
10672 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10673 return fold_mult_zconjz (type, arg1);
10674 if (flag_unsafe_math_optimizations
10675 && TREE_CODE (arg1) == CONJ_EXPR
10676 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10677 return fold_mult_zconjz (type, arg0);
10679 if (flag_unsafe_math_optimizations)
10681 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10682 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10684 /* Optimizations of root(...)*root(...). */
10685 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
10688 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10689 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10691 /* Optimize sqrt(x)*sqrt(x) as x. */
10692 if (BUILTIN_SQRT_P (fcode0)
10693 && operand_equal_p (arg00, arg10, 0)
10694 && ! HONOR_SNANS (TYPE_MODE (type)))
10697 /* Optimize root(x)*root(y) as root(x*y). */
10698 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10699 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10700 return build_call_expr (rootfn, 1, arg);
10703 /* Optimize expN(x)*expN(y) as expN(x+y). */
10704 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
10706 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10707 tree arg = fold_build2 (PLUS_EXPR, type,
10708 CALL_EXPR_ARG (arg0, 0),
10709 CALL_EXPR_ARG (arg1, 0));
10710 return build_call_expr (expfn, 1, arg);
10713 /* Optimizations of pow(...)*pow(...). */
10714 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
10715 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
10716 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
10718 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10719 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10720 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10721 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10723 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10724 if (operand_equal_p (arg01, arg11, 0))
10726 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10727 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10728 return build_call_expr (powfn, 2, arg, arg01);
10731 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10732 if (operand_equal_p (arg00, arg10, 0))
10734 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10735 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
10736 return build_call_expr (powfn, 2, arg00, arg);
10740 /* Optimize tan(x)*cos(x) as sin(x). */
10741 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
10742 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
10743 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
10744 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
10745 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
10746 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
10747 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10748 CALL_EXPR_ARG (arg1, 0), 0))
10750 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
10752 if (sinfn != NULL_TREE)
10753 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
10756 /* Optimize x*pow(x,c) as pow(x,c+1). */
10757 if (fcode1 == BUILT_IN_POW
10758 || fcode1 == BUILT_IN_POWF
10759 || fcode1 == BUILT_IN_POWL)
10761 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10762 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10763 if (TREE_CODE (arg11) == REAL_CST
10764 && !TREE_OVERFLOW (arg11)
10765 && operand_equal_p (arg0, arg10, 0))
10767 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10771 c = TREE_REAL_CST (arg11);
10772 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10773 arg = build_real (type, c);
10774 return build_call_expr (powfn, 2, arg0, arg);
10778 /* Optimize pow(x,c)*x as pow(x,c+1). */
10779 if (fcode0 == BUILT_IN_POW
10780 || fcode0 == BUILT_IN_POWF
10781 || fcode0 == BUILT_IN_POWL)
10783 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10784 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10785 if (TREE_CODE (arg01) == REAL_CST
10786 && !TREE_OVERFLOW (arg01)
10787 && operand_equal_p (arg1, arg00, 0))
10789 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10793 c = TREE_REAL_CST (arg01);
10794 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10795 arg = build_real (type, c);
10796 return build_call_expr (powfn, 2, arg1, arg);
10800 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10801 if (optimize_function_for_speed_p (cfun)
10802 && operand_equal_p (arg0, arg1, 0))
10804 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
10808 tree arg = build_real (type, dconst2);
10809 return build_call_expr (powfn, 2, arg0, arg);
10818 if (integer_all_onesp (arg1))
10819 return omit_one_operand (type, arg1, arg0);
10820 if (integer_zerop (arg1))
10821 return non_lvalue (fold_convert (type, arg0));
10822 if (operand_equal_p (arg0, arg1, 0))
10823 return non_lvalue (fold_convert (type, arg0));
10825 /* ~X | X is -1. */
10826 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10827 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10829 t1 = fold_convert (type, integer_zero_node);
10830 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10831 return omit_one_operand (type, t1, arg1);
10834 /* X | ~X is -1. */
10835 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10836 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10838 t1 = fold_convert (type, integer_zero_node);
10839 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10840 return omit_one_operand (type, t1, arg0);
10843 /* Canonicalize (X & C1) | C2. */
10844 if (TREE_CODE (arg0) == BIT_AND_EXPR
10845 && TREE_CODE (arg1) == INTEGER_CST
10846 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10848 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, hi3, lo3, mlo, mhi;
10849 int width = TYPE_PRECISION (type), w;
10850 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10851 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10852 hi2 = TREE_INT_CST_HIGH (arg1);
10853 lo2 = TREE_INT_CST_LOW (arg1);
10855 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10856 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10857 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10859 if (width > HOST_BITS_PER_WIDE_INT)
10861 mhi = (unsigned HOST_WIDE_INT) -1
10862 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10868 mlo = (unsigned HOST_WIDE_INT) -1
10869 >> (HOST_BITS_PER_WIDE_INT - width);
10872 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10873 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10874 return fold_build2 (BIT_IOR_EXPR, type,
10875 TREE_OPERAND (arg0, 0), arg1);
10877 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
10878 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
10879 mode which allows further optimizations. */
10886 for (w = BITS_PER_UNIT;
10887 w <= width && w <= HOST_BITS_PER_WIDE_INT;
10890 unsigned HOST_WIDE_INT mask
10891 = (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
10892 if (((lo1 | lo2) & mask) == mask
10893 && (lo1 & ~mask) == 0 && hi1 == 0)
10900 if (hi3 != hi1 || lo3 != lo1)
10901 return fold_build2 (BIT_IOR_EXPR, type,
10902 fold_build2 (BIT_AND_EXPR, type,
10903 TREE_OPERAND (arg0, 0),
10904 build_int_cst_wide (type,
10909 /* (X & Y) | Y is (X, Y). */
10910 if (TREE_CODE (arg0) == BIT_AND_EXPR
10911 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10912 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10913 /* (X & Y) | X is (Y, X). */
10914 if (TREE_CODE (arg0) == BIT_AND_EXPR
10915 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10916 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10917 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10918 /* X | (X & Y) is (Y, X). */
10919 if (TREE_CODE (arg1) == BIT_AND_EXPR
10920 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10921 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10922 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10923 /* X | (Y & X) is (Y, X). */
10924 if (TREE_CODE (arg1) == BIT_AND_EXPR
10925 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10926 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10927 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10929 t1 = distribute_bit_expr (code, type, arg0, arg1);
10930 if (t1 != NULL_TREE)
10933 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10935 This results in more efficient code for machines without a NAND
10936 instruction. Combine will canonicalize to the first form
10937 which will allow use of NAND instructions provided by the
10938 backend if they exist. */
10939 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10940 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10942 return fold_build1 (BIT_NOT_EXPR, type,
10943 build2 (BIT_AND_EXPR, type,
10944 fold_convert (type,
10945 TREE_OPERAND (arg0, 0)),
10946 fold_convert (type,
10947 TREE_OPERAND (arg1, 0))));
10950 /* See if this can be simplified into a rotate first. If that
10951 is unsuccessful continue in the association code. */
10955 if (integer_zerop (arg1))
10956 return non_lvalue (fold_convert (type, arg0));
10957 if (integer_all_onesp (arg1))
10958 return fold_build1 (BIT_NOT_EXPR, type, op0);
10959 if (operand_equal_p (arg0, arg1, 0))
10960 return omit_one_operand (type, integer_zero_node, arg0);
10962 /* ~X ^ X is -1. */
10963 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10964 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10966 t1 = fold_convert (type, integer_zero_node);
10967 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10968 return omit_one_operand (type, t1, arg1);
10971 /* X ^ ~X is -1. */
10972 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10973 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10975 t1 = fold_convert (type, integer_zero_node);
10976 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10977 return omit_one_operand (type, t1, arg0);
10980 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10981 with a constant, and the two constants have no bits in common,
10982 we should treat this as a BIT_IOR_EXPR since this may produce more
10983 simplifications. */
10984 if (TREE_CODE (arg0) == BIT_AND_EXPR
10985 && TREE_CODE (arg1) == BIT_AND_EXPR
10986 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10987 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10988 && integer_zerop (const_binop (BIT_AND_EXPR,
10989 TREE_OPERAND (arg0, 1),
10990 TREE_OPERAND (arg1, 1), 0)))
10992 code = BIT_IOR_EXPR;
10996 /* (X | Y) ^ X -> Y & ~ X*/
10997 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10998 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11000 tree t2 = TREE_OPERAND (arg0, 1);
11001 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
11003 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
11004 fold_convert (type, t1));
11008 /* (Y | X) ^ X -> Y & ~ X*/
11009 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11010 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11012 tree t2 = TREE_OPERAND (arg0, 0);
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 /* X ^ (X | Y) -> Y & ~ X*/
11021 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11022 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
11024 tree t2 = TREE_OPERAND (arg1, 1);
11025 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
11027 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
11028 fold_convert (type, t1));
11032 /* X ^ (Y | X) -> Y & ~ X*/
11033 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11034 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
11036 tree t2 = TREE_OPERAND (arg1, 0);
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 /* Convert ~X ^ ~Y to X ^ Y. */
11045 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11046 && TREE_CODE (arg1) == BIT_NOT_EXPR)
11047 return fold_build2 (code, type,
11048 fold_convert (type, TREE_OPERAND (arg0, 0)),
11049 fold_convert (type, TREE_OPERAND (arg1, 0)));
11051 /* Convert ~X ^ C to X ^ ~C. */
11052 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11053 && TREE_CODE (arg1) == INTEGER_CST)
11054 return fold_build2 (code, type,
11055 fold_convert (type, TREE_OPERAND (arg0, 0)),
11056 fold_build1 (BIT_NOT_EXPR, type, arg1));
11058 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
11059 if (TREE_CODE (arg0) == BIT_AND_EXPR
11060 && integer_onep (TREE_OPERAND (arg0, 1))
11061 && integer_onep (arg1))
11062 return fold_build2 (EQ_EXPR, type, arg0,
11063 build_int_cst (TREE_TYPE (arg0), 0));
11065 /* Fold (X & Y) ^ Y as ~X & Y. */
11066 if (TREE_CODE (arg0) == BIT_AND_EXPR
11067 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11069 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
11070 return fold_build2 (BIT_AND_EXPR, type,
11071 fold_build1 (BIT_NOT_EXPR, type, tem),
11072 fold_convert (type, arg1));
11074 /* Fold (X & Y) ^ X as ~Y & X. */
11075 if (TREE_CODE (arg0) == BIT_AND_EXPR
11076 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11077 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11079 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
11080 return fold_build2 (BIT_AND_EXPR, type,
11081 fold_build1 (BIT_NOT_EXPR, type, tem),
11082 fold_convert (type, arg1));
11084 /* Fold X ^ (X & Y) as X & ~Y. */
11085 if (TREE_CODE (arg1) == BIT_AND_EXPR
11086 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11088 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
11089 return fold_build2 (BIT_AND_EXPR, type,
11090 fold_convert (type, arg0),
11091 fold_build1 (BIT_NOT_EXPR, type, tem));
11093 /* Fold X ^ (Y & X) as ~Y & X. */
11094 if (TREE_CODE (arg1) == BIT_AND_EXPR
11095 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
11096 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
11098 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
11099 return fold_build2 (BIT_AND_EXPR, type,
11100 fold_build1 (BIT_NOT_EXPR, type, tem),
11101 fold_convert (type, arg0));
11104 /* See if this can be simplified into a rotate first. If that
11105 is unsuccessful continue in the association code. */
11109 if (integer_all_onesp (arg1))
11110 return non_lvalue (fold_convert (type, arg0));
11111 if (integer_zerop (arg1))
11112 return omit_one_operand (type, arg1, arg0);
11113 if (operand_equal_p (arg0, arg1, 0))
11114 return non_lvalue (fold_convert (type, arg0));
11116 /* ~X & X is always zero. */
11117 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11118 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11119 return omit_one_operand (type, integer_zero_node, arg1);
11121 /* X & ~X is always zero. */
11122 if (TREE_CODE (arg1) == BIT_NOT_EXPR
11123 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11124 return omit_one_operand (type, integer_zero_node, arg0);
11126 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
11127 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11128 && TREE_CODE (arg1) == INTEGER_CST
11129 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11131 tree tmp1 = fold_convert (type, arg1);
11132 tree tmp2 = fold_convert (type, TREE_OPERAND (arg0, 0));
11133 tree tmp3 = fold_convert (type, TREE_OPERAND (arg0, 1));
11134 tmp2 = fold_build2 (BIT_AND_EXPR, type, tmp2, tmp1);
11135 tmp3 = fold_build2 (BIT_AND_EXPR, type, tmp3, tmp1);
11136 return fold_convert (type,
11137 fold_build2 (BIT_IOR_EXPR, type, tmp2, tmp3));
11140 /* (X | Y) & Y is (X, Y). */
11141 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11142 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11143 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
11144 /* (X | Y) & X is (Y, X). */
11145 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11146 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11147 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11148 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
11149 /* X & (X | Y) is (Y, X). */
11150 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11151 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
11152 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
11153 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
11154 /* X & (Y | X) is (Y, X). */
11155 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11156 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
11157 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
11158 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
11160 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
11161 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11162 && integer_onep (TREE_OPERAND (arg0, 1))
11163 && integer_onep (arg1))
11165 tem = TREE_OPERAND (arg0, 0);
11166 return fold_build2 (EQ_EXPR, type,
11167 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
11168 build_int_cst (TREE_TYPE (tem), 1)),
11169 build_int_cst (TREE_TYPE (tem), 0));
11171 /* Fold ~X & 1 as (X & 1) == 0. */
11172 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11173 && integer_onep (arg1))
11175 tem = TREE_OPERAND (arg0, 0);
11176 return fold_build2 (EQ_EXPR, type,
11177 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
11178 build_int_cst (TREE_TYPE (tem), 1)),
11179 build_int_cst (TREE_TYPE (tem), 0));
11182 /* Fold (X ^ Y) & Y as ~X & Y. */
11183 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11184 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11186 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
11187 return fold_build2 (BIT_AND_EXPR, type,
11188 fold_build1 (BIT_NOT_EXPR, type, tem),
11189 fold_convert (type, arg1));
11191 /* Fold (X ^ Y) & X as ~Y & X. */
11192 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11193 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11194 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11196 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
11197 return fold_build2 (BIT_AND_EXPR, type,
11198 fold_build1 (BIT_NOT_EXPR, type, tem),
11199 fold_convert (type, arg1));
11201 /* Fold X & (X ^ Y) as X & ~Y. */
11202 if (TREE_CODE (arg1) == BIT_XOR_EXPR
11203 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11205 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
11206 return fold_build2 (BIT_AND_EXPR, type,
11207 fold_convert (type, arg0),
11208 fold_build1 (BIT_NOT_EXPR, type, tem));
11210 /* Fold X & (Y ^ X) as ~Y & X. */
11211 if (TREE_CODE (arg1) == BIT_XOR_EXPR
11212 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
11213 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
11215 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
11216 return fold_build2 (BIT_AND_EXPR, type,
11217 fold_build1 (BIT_NOT_EXPR, type, tem),
11218 fold_convert (type, arg0));
11221 t1 = distribute_bit_expr (code, type, arg0, arg1);
11222 if (t1 != NULL_TREE)
11224 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
11225 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
11226 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
11229 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
11231 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
11232 && (~TREE_INT_CST_LOW (arg1)
11233 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
11234 return fold_convert (type, TREE_OPERAND (arg0, 0));
11237 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
11239 This results in more efficient code for machines without a NOR
11240 instruction. Combine will canonicalize to the first form
11241 which will allow use of NOR instructions provided by the
11242 backend if they exist. */
11243 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11244 && TREE_CODE (arg1) == BIT_NOT_EXPR)
11246 return fold_build1 (BIT_NOT_EXPR, type,
11247 build2 (BIT_IOR_EXPR, type,
11248 fold_convert (type,
11249 TREE_OPERAND (arg0, 0)),
11250 fold_convert (type,
11251 TREE_OPERAND (arg1, 0))));
11254 /* If arg0 is derived from the address of an object or function, we may
11255 be able to fold this expression using the object or function's
11257 if (POINTER_TYPE_P (TREE_TYPE (arg0)) && host_integerp (arg1, 1))
11259 unsigned HOST_WIDE_INT modulus, residue;
11260 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (arg1);
11262 modulus = get_pointer_modulus_and_residue (arg0, &residue);
11264 /* This works because modulus is a power of 2. If this weren't the
11265 case, we'd have to replace it by its greatest power-of-2
11266 divisor: modulus & -modulus. */
11268 return build_int_cst (type, residue & low);
11271 /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
11272 (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
11273 if the new mask might be further optimized. */
11274 if ((TREE_CODE (arg0) == LSHIFT_EXPR
11275 || TREE_CODE (arg0) == RSHIFT_EXPR)
11276 && host_integerp (TREE_OPERAND (arg0, 1), 1)
11277 && host_integerp (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)))
11278 && tree_low_cst (TREE_OPERAND (arg0, 1), 1)
11279 < TYPE_PRECISION (TREE_TYPE (arg0))
11280 && TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
11281 && tree_low_cst (TREE_OPERAND (arg0, 1), 1) > 0)
11283 unsigned int shiftc = tree_low_cst (TREE_OPERAND (arg0, 1), 1);
11284 unsigned HOST_WIDE_INT mask
11285 = tree_low_cst (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)));
11286 unsigned HOST_WIDE_INT newmask, zerobits = 0;
11287 tree shift_type = TREE_TYPE (arg0);
11289 if (TREE_CODE (arg0) == LSHIFT_EXPR)
11290 zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
11291 else if (TREE_CODE (arg0) == RSHIFT_EXPR
11292 && TYPE_PRECISION (TREE_TYPE (arg0))
11293 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg0))))
11295 unsigned int prec = TYPE_PRECISION (TREE_TYPE (arg0));
11296 tree arg00 = TREE_OPERAND (arg0, 0);
11297 /* See if more bits can be proven as zero because of
11299 if (TREE_CODE (arg00) == NOP_EXPR
11300 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
11302 tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
11303 if (TYPE_PRECISION (inner_type)
11304 == GET_MODE_BITSIZE (TYPE_MODE (inner_type))
11305 && TYPE_PRECISION (inner_type) < prec)
11307 prec = TYPE_PRECISION (inner_type);
11308 /* See if we can shorten the right shift. */
11310 shift_type = inner_type;
11313 zerobits = ~(unsigned HOST_WIDE_INT) 0;
11314 zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
11315 zerobits <<= prec - shiftc;
11316 /* For arithmetic shift if sign bit could be set, zerobits
11317 can contain actually sign bits, so no transformation is
11318 possible, unless MASK masks them all away. In that
11319 case the shift needs to be converted into logical shift. */
11320 if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
11321 && prec == TYPE_PRECISION (TREE_TYPE (arg0)))
11323 if ((mask & zerobits) == 0)
11324 shift_type = unsigned_type_for (TREE_TYPE (arg0));
11330 /* ((X << 16) & 0xff00) is (X, 0). */
11331 if ((mask & zerobits) == mask)
11332 return omit_one_operand (type, build_int_cst (type, 0), arg0);
11334 newmask = mask | zerobits;
11335 if (newmask != mask && (newmask & (newmask + 1)) == 0)
11339 /* Only do the transformation if NEWMASK is some integer
11341 for (prec = BITS_PER_UNIT;
11342 prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
11343 if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
11345 if (prec < HOST_BITS_PER_WIDE_INT
11346 || newmask == ~(unsigned HOST_WIDE_INT) 0)
11348 if (shift_type != TREE_TYPE (arg0))
11350 tem = fold_build2 (TREE_CODE (arg0), shift_type,
11351 fold_convert (shift_type,
11352 TREE_OPERAND (arg0, 0)),
11353 TREE_OPERAND (arg0, 1));
11354 tem = fold_convert (type, tem);
11358 return fold_build2 (BIT_AND_EXPR, type, tem,
11359 build_int_cst_type (TREE_TYPE (op1),
11368 /* Don't touch a floating-point divide by zero unless the mode
11369 of the constant can represent infinity. */
11370 if (TREE_CODE (arg1) == REAL_CST
11371 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
11372 && real_zerop (arg1))
11375 /* Optimize A / A to 1.0 if we don't care about
11376 NaNs or Infinities. Skip the transformation
11377 for non-real operands. */
11378 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
11379 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
11380 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
11381 && operand_equal_p (arg0, arg1, 0))
11383 tree r = build_real (TREE_TYPE (arg0), dconst1);
11385 return omit_two_operands (type, r, arg0, arg1);
11388 /* The complex version of the above A / A optimization. */
11389 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
11390 && operand_equal_p (arg0, arg1, 0))
11392 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
11393 if (! HONOR_NANS (TYPE_MODE (elem_type))
11394 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
11396 tree r = build_real (elem_type, dconst1);
11397 /* omit_two_operands will call fold_convert for us. */
11398 return omit_two_operands (type, r, arg0, arg1);
11402 /* (-A) / (-B) -> A / B */
11403 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
11404 return fold_build2 (RDIV_EXPR, type,
11405 TREE_OPERAND (arg0, 0),
11406 negate_expr (arg1));
11407 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
11408 return fold_build2 (RDIV_EXPR, type,
11409 negate_expr (arg0),
11410 TREE_OPERAND (arg1, 0));
11412 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
11413 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11414 && real_onep (arg1))
11415 return non_lvalue (fold_convert (type, arg0));
11417 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
11418 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11419 && real_minus_onep (arg1))
11420 return non_lvalue (fold_convert (type, negate_expr (arg0)));
11422 /* If ARG1 is a constant, we can convert this to a multiply by the
11423 reciprocal. This does not have the same rounding properties,
11424 so only do this if -freciprocal-math. We can actually
11425 always safely do it if ARG1 is a power of two, but it's hard to
11426 tell if it is or not in a portable manner. */
11427 if (TREE_CODE (arg1) == REAL_CST)
11429 if (flag_reciprocal_math
11430 && 0 != (tem = const_binop (code, build_real (type, dconst1),
11432 return fold_build2 (MULT_EXPR, type, arg0, tem);
11433 /* Find the reciprocal if optimizing and the result is exact. */
11437 r = TREE_REAL_CST (arg1);
11438 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
11440 tem = build_real (type, r);
11441 return fold_build2 (MULT_EXPR, type,
11442 fold_convert (type, arg0), tem);
11446 /* Convert A/B/C to A/(B*C). */
11447 if (flag_reciprocal_math
11448 && TREE_CODE (arg0) == RDIV_EXPR)
11449 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
11450 fold_build2 (MULT_EXPR, type,
11451 TREE_OPERAND (arg0, 1), arg1));
11453 /* Convert A/(B/C) to (A/B)*C. */
11454 if (flag_reciprocal_math
11455 && TREE_CODE (arg1) == RDIV_EXPR)
11456 return fold_build2 (MULT_EXPR, type,
11457 fold_build2 (RDIV_EXPR, type, arg0,
11458 TREE_OPERAND (arg1, 0)),
11459 TREE_OPERAND (arg1, 1));
11461 /* Convert C1/(X*C2) into (C1/C2)/X. */
11462 if (flag_reciprocal_math
11463 && TREE_CODE (arg1) == MULT_EXPR
11464 && TREE_CODE (arg0) == REAL_CST
11465 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
11467 tree tem = const_binop (RDIV_EXPR, arg0,
11468 TREE_OPERAND (arg1, 1), 0);
11470 return fold_build2 (RDIV_EXPR, type, tem,
11471 TREE_OPERAND (arg1, 0));
11474 if (flag_unsafe_math_optimizations)
11476 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
11477 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
11479 /* Optimize sin(x)/cos(x) as tan(x). */
11480 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
11481 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
11482 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
11483 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11484 CALL_EXPR_ARG (arg1, 0), 0))
11486 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11488 if (tanfn != NULL_TREE)
11489 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11492 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
11493 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
11494 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
11495 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
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)
11503 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11504 return fold_build2 (RDIV_EXPR, type,
11505 build_real (type, dconst1), tmp);
11509 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
11510 NaNs or Infinities. */
11511 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
11512 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
11513 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
11515 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11516 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11518 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11519 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11520 && operand_equal_p (arg00, arg01, 0))
11522 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11524 if (cosfn != NULL_TREE)
11525 return build_call_expr (cosfn, 1, arg00);
11529 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11530 NaNs or Infinities. */
11531 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
11532 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
11533 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
11535 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11536 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11538 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11539 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11540 && operand_equal_p (arg00, arg01, 0))
11542 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11544 if (cosfn != NULL_TREE)
11546 tree tmp = build_call_expr (cosfn, 1, arg00);
11547 return fold_build2 (RDIV_EXPR, type,
11548 build_real (type, dconst1),
11554 /* Optimize pow(x,c)/x as pow(x,c-1). */
11555 if (fcode0 == BUILT_IN_POW
11556 || fcode0 == BUILT_IN_POWF
11557 || fcode0 == BUILT_IN_POWL)
11559 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11560 tree arg01 = CALL_EXPR_ARG (arg0, 1);
11561 if (TREE_CODE (arg01) == REAL_CST
11562 && !TREE_OVERFLOW (arg01)
11563 && operand_equal_p (arg1, arg00, 0))
11565 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
11569 c = TREE_REAL_CST (arg01);
11570 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
11571 arg = build_real (type, c);
11572 return build_call_expr (powfn, 2, arg1, arg);
11576 /* Optimize a/root(b/c) into a*root(c/b). */
11577 if (BUILTIN_ROOT_P (fcode1))
11579 tree rootarg = CALL_EXPR_ARG (arg1, 0);
11581 if (TREE_CODE (rootarg) == RDIV_EXPR)
11583 tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11584 tree b = TREE_OPERAND (rootarg, 0);
11585 tree c = TREE_OPERAND (rootarg, 1);
11587 tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
11589 tmp = build_call_expr (rootfn, 1, tmp);
11590 return fold_build2 (MULT_EXPR, type, arg0, tmp);
11594 /* Optimize x/expN(y) into x*expN(-y). */
11595 if (BUILTIN_EXPONENT_P (fcode1))
11597 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11598 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
11599 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
11600 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11603 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11604 if (fcode1 == BUILT_IN_POW
11605 || fcode1 == BUILT_IN_POWF
11606 || fcode1 == BUILT_IN_POWL)
11608 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11609 tree arg10 = CALL_EXPR_ARG (arg1, 0);
11610 tree arg11 = CALL_EXPR_ARG (arg1, 1);
11611 tree neg11 = fold_convert (type, negate_expr (arg11));
11612 arg1 = build_call_expr (powfn, 2, arg10, neg11);
11613 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11618 case TRUNC_DIV_EXPR:
11619 case FLOOR_DIV_EXPR:
11620 /* Simplify A / (B << N) where A and B are positive and B is
11621 a power of 2, to A >> (N + log2(B)). */
11622 strict_overflow_p = false;
11623 if (TREE_CODE (arg1) == LSHIFT_EXPR
11624 && (TYPE_UNSIGNED (type)
11625 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11627 tree sval = TREE_OPERAND (arg1, 0);
11628 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
11630 tree sh_cnt = TREE_OPERAND (arg1, 1);
11631 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
11633 if (strict_overflow_p)
11634 fold_overflow_warning (("assuming signed overflow does not "
11635 "occur when simplifying A / (B << N)"),
11636 WARN_STRICT_OVERFLOW_MISC);
11638 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
11639 sh_cnt, build_int_cst (NULL_TREE, pow2));
11640 return fold_build2 (RSHIFT_EXPR, type,
11641 fold_convert (type, arg0), sh_cnt);
11645 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
11646 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
11647 if (INTEGRAL_TYPE_P (type)
11648 && TYPE_UNSIGNED (type)
11649 && code == FLOOR_DIV_EXPR)
11650 return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
11654 case ROUND_DIV_EXPR:
11655 case CEIL_DIV_EXPR:
11656 case EXACT_DIV_EXPR:
11657 if (integer_onep (arg1))
11658 return non_lvalue (fold_convert (type, arg0));
11659 if (integer_zerop (arg1))
11661 /* X / -1 is -X. */
11662 if (!TYPE_UNSIGNED (type)
11663 && TREE_CODE (arg1) == INTEGER_CST
11664 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11665 && TREE_INT_CST_HIGH (arg1) == -1)
11666 return fold_convert (type, negate_expr (arg0));
11668 /* Convert -A / -B to A / B when the type is signed and overflow is
11670 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11671 && TREE_CODE (arg0) == NEGATE_EXPR
11672 && negate_expr_p (arg1))
11674 if (INTEGRAL_TYPE_P (type))
11675 fold_overflow_warning (("assuming signed overflow does not occur "
11676 "when distributing negation across "
11678 WARN_STRICT_OVERFLOW_MISC);
11679 return fold_build2 (code, type,
11680 fold_convert (type, TREE_OPERAND (arg0, 0)),
11681 negate_expr (arg1));
11683 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11684 && TREE_CODE (arg1) == NEGATE_EXPR
11685 && negate_expr_p (arg0))
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, negate_expr (arg0),
11693 TREE_OPERAND (arg1, 0));
11696 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11697 operation, EXACT_DIV_EXPR.
11699 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11700 At one time others generated faster code, it's not clear if they do
11701 after the last round to changes to the DIV code in expmed.c. */
11702 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
11703 && multiple_of_p (type, arg0, arg1))
11704 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
11706 strict_overflow_p = false;
11707 if (TREE_CODE (arg1) == INTEGER_CST
11708 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11709 &strict_overflow_p)))
11711 if (strict_overflow_p)
11712 fold_overflow_warning (("assuming signed overflow does not occur "
11713 "when simplifying division"),
11714 WARN_STRICT_OVERFLOW_MISC);
11715 return fold_convert (type, tem);
11720 case CEIL_MOD_EXPR:
11721 case FLOOR_MOD_EXPR:
11722 case ROUND_MOD_EXPR:
11723 case TRUNC_MOD_EXPR:
11724 /* X % 1 is always zero, but be sure to preserve any side
11726 if (integer_onep (arg1))
11727 return omit_one_operand (type, integer_zero_node, arg0);
11729 /* X % 0, return X % 0 unchanged so that we can get the
11730 proper warnings and errors. */
11731 if (integer_zerop (arg1))
11734 /* 0 % X is always zero, but be sure to preserve any side
11735 effects in X. Place this after checking for X == 0. */
11736 if (integer_zerop (arg0))
11737 return omit_one_operand (type, integer_zero_node, arg1);
11739 /* X % -1 is zero. */
11740 if (!TYPE_UNSIGNED (type)
11741 && TREE_CODE (arg1) == INTEGER_CST
11742 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11743 && TREE_INT_CST_HIGH (arg1) == -1)
11744 return omit_one_operand (type, integer_zero_node, arg0);
11746 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11747 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11748 strict_overflow_p = false;
11749 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
11750 && (TYPE_UNSIGNED (type)
11751 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11754 /* Also optimize A % (C << N) where C is a power of 2,
11755 to A & ((C << N) - 1). */
11756 if (TREE_CODE (arg1) == LSHIFT_EXPR)
11757 c = TREE_OPERAND (arg1, 0);
11759 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
11761 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
11762 build_int_cst (TREE_TYPE (arg1), 1));
11763 if (strict_overflow_p)
11764 fold_overflow_warning (("assuming signed overflow does not "
11765 "occur when simplifying "
11766 "X % (power of two)"),
11767 WARN_STRICT_OVERFLOW_MISC);
11768 return fold_build2 (BIT_AND_EXPR, type,
11769 fold_convert (type, arg0),
11770 fold_convert (type, mask));
11774 /* X % -C is the same as X % C. */
11775 if (code == TRUNC_MOD_EXPR
11776 && !TYPE_UNSIGNED (type)
11777 && TREE_CODE (arg1) == INTEGER_CST
11778 && !TREE_OVERFLOW (arg1)
11779 && TREE_INT_CST_HIGH (arg1) < 0
11780 && !TYPE_OVERFLOW_TRAPS (type)
11781 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11782 && !sign_bit_p (arg1, arg1))
11783 return fold_build2 (code, type, fold_convert (type, arg0),
11784 fold_convert (type, negate_expr (arg1)));
11786 /* X % -Y is the same as X % Y. */
11787 if (code == TRUNC_MOD_EXPR
11788 && !TYPE_UNSIGNED (type)
11789 && TREE_CODE (arg1) == NEGATE_EXPR
11790 && !TYPE_OVERFLOW_TRAPS (type))
11791 return fold_build2 (code, type, fold_convert (type, arg0),
11792 fold_convert (type, TREE_OPERAND (arg1, 0)));
11794 if (TREE_CODE (arg1) == INTEGER_CST
11795 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11796 &strict_overflow_p)))
11798 if (strict_overflow_p)
11799 fold_overflow_warning (("assuming signed overflow does not occur "
11800 "when simplifying modulus"),
11801 WARN_STRICT_OVERFLOW_MISC);
11802 return fold_convert (type, tem);
11809 if (integer_all_onesp (arg0))
11810 return omit_one_operand (type, arg0, arg1);
11814 /* Optimize -1 >> x for arithmetic right shifts. */
11815 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type)
11816 && tree_expr_nonnegative_p (arg1))
11817 return omit_one_operand (type, arg0, arg1);
11818 /* ... fall through ... */
11822 if (integer_zerop (arg1))
11823 return non_lvalue (fold_convert (type, arg0));
11824 if (integer_zerop (arg0))
11825 return omit_one_operand (type, arg0, arg1);
11827 /* Since negative shift count is not well-defined,
11828 don't try to compute it in the compiler. */
11829 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
11832 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11833 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
11834 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11835 && host_integerp (TREE_OPERAND (arg0, 1), false)
11836 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11838 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
11839 + TREE_INT_CST_LOW (arg1));
11841 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11842 being well defined. */
11843 if (low >= TYPE_PRECISION (type))
11845 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
11846 low = low % TYPE_PRECISION (type);
11847 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
11848 return build_int_cst (type, 0);
11850 low = TYPE_PRECISION (type) - 1;
11853 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11854 build_int_cst (type, low));
11857 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11858 into x & ((unsigned)-1 >> c) for unsigned types. */
11859 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
11860 || (TYPE_UNSIGNED (type)
11861 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
11862 && host_integerp (arg1, false)
11863 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11864 && host_integerp (TREE_OPERAND (arg0, 1), false)
11865 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11867 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
11868 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
11874 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
11876 lshift = build_int_cst (type, -1);
11877 lshift = int_const_binop (code, lshift, arg1, 0);
11879 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
11883 /* Rewrite an LROTATE_EXPR by a constant into an
11884 RROTATE_EXPR by a new constant. */
11885 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
11887 tree tem = build_int_cst (TREE_TYPE (arg1),
11888 TYPE_PRECISION (type));
11889 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
11890 return fold_build2 (RROTATE_EXPR, type, op0, tem);
11893 /* If we have a rotate of a bit operation with the rotate count and
11894 the second operand of the bit operation both constant,
11895 permute the two operations. */
11896 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11897 && (TREE_CODE (arg0) == BIT_AND_EXPR
11898 || TREE_CODE (arg0) == BIT_IOR_EXPR
11899 || TREE_CODE (arg0) == BIT_XOR_EXPR)
11900 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11901 return fold_build2 (TREE_CODE (arg0), type,
11902 fold_build2 (code, type,
11903 TREE_OPERAND (arg0, 0), arg1),
11904 fold_build2 (code, type,
11905 TREE_OPERAND (arg0, 1), arg1));
11907 /* Two consecutive rotates adding up to the precision of the
11908 type can be ignored. */
11909 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11910 && TREE_CODE (arg0) == RROTATE_EXPR
11911 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11912 && TREE_INT_CST_HIGH (arg1) == 0
11913 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
11914 && ((TREE_INT_CST_LOW (arg1)
11915 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
11916 == (unsigned int) TYPE_PRECISION (type)))
11917 return TREE_OPERAND (arg0, 0);
11919 /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
11920 (X & C2) >> C1 into (X >> C1) & (C2 >> C1)
11921 if the latter can be further optimized. */
11922 if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
11923 && TREE_CODE (arg0) == BIT_AND_EXPR
11924 && TREE_CODE (arg1) == INTEGER_CST
11925 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11927 tree mask = fold_build2 (code, type,
11928 fold_convert (type, TREE_OPERAND (arg0, 1)),
11930 tree shift = fold_build2 (code, type,
11931 fold_convert (type, TREE_OPERAND (arg0, 0)),
11933 tem = fold_binary (BIT_AND_EXPR, type, shift, mask);
11941 if (operand_equal_p (arg0, arg1, 0))
11942 return omit_one_operand (type, arg0, arg1);
11943 if (INTEGRAL_TYPE_P (type)
11944 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
11945 return omit_one_operand (type, arg1, arg0);
11946 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
11952 if (operand_equal_p (arg0, arg1, 0))
11953 return omit_one_operand (type, arg0, arg1);
11954 if (INTEGRAL_TYPE_P (type)
11955 && TYPE_MAX_VALUE (type)
11956 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
11957 return omit_one_operand (type, arg1, arg0);
11958 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
11963 case TRUTH_ANDIF_EXPR:
11964 /* Note that the operands of this must be ints
11965 and their values must be 0 or 1.
11966 ("true" is a fixed value perhaps depending on the language.) */
11967 /* If first arg is constant zero, return it. */
11968 if (integer_zerop (arg0))
11969 return fold_convert (type, arg0);
11970 case TRUTH_AND_EXPR:
11971 /* If either arg is constant true, drop it. */
11972 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11973 return non_lvalue (fold_convert (type, arg1));
11974 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
11975 /* Preserve sequence points. */
11976 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11977 return non_lvalue (fold_convert (type, arg0));
11978 /* If second arg is constant zero, result is zero, but first arg
11979 must be evaluated. */
11980 if (integer_zerop (arg1))
11981 return omit_one_operand (type, arg1, arg0);
11982 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11983 case will be handled here. */
11984 if (integer_zerop (arg0))
11985 return omit_one_operand (type, arg0, arg1);
11987 /* !X && X is always false. */
11988 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11989 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11990 return omit_one_operand (type, integer_zero_node, arg1);
11991 /* X && !X is always false. */
11992 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11993 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11994 return omit_one_operand (type, integer_zero_node, arg0);
11996 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
11997 means A >= Y && A != MAX, but in this case we know that
12000 if (!TREE_SIDE_EFFECTS (arg0)
12001 && !TREE_SIDE_EFFECTS (arg1))
12003 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
12004 if (tem && !operand_equal_p (tem, arg0, 0))
12005 return fold_build2 (code, type, tem, arg1);
12007 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
12008 if (tem && !operand_equal_p (tem, arg1, 0))
12009 return fold_build2 (code, type, arg0, tem);
12013 /* We only do these simplifications if we are optimizing. */
12017 /* Check for things like (A || B) && (A || C). We can convert this
12018 to A || (B && C). Note that either operator can be any of the four
12019 truth and/or operations and the transformation will still be
12020 valid. Also note that we only care about order for the
12021 ANDIF and ORIF operators. If B contains side effects, this
12022 might change the truth-value of A. */
12023 if (TREE_CODE (arg0) == TREE_CODE (arg1)
12024 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
12025 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
12026 || TREE_CODE (arg0) == TRUTH_AND_EXPR
12027 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
12028 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
12030 tree a00 = TREE_OPERAND (arg0, 0);
12031 tree a01 = TREE_OPERAND (arg0, 1);
12032 tree a10 = TREE_OPERAND (arg1, 0);
12033 tree a11 = TREE_OPERAND (arg1, 1);
12034 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
12035 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
12036 && (code == TRUTH_AND_EXPR
12037 || code == TRUTH_OR_EXPR));
12039 if (operand_equal_p (a00, a10, 0))
12040 return fold_build2 (TREE_CODE (arg0), type, a00,
12041 fold_build2 (code, type, a01, a11));
12042 else if (commutative && operand_equal_p (a00, a11, 0))
12043 return fold_build2 (TREE_CODE (arg0), type, a00,
12044 fold_build2 (code, type, a01, a10));
12045 else if (commutative && operand_equal_p (a01, a10, 0))
12046 return fold_build2 (TREE_CODE (arg0), type, a01,
12047 fold_build2 (code, type, a00, a11));
12049 /* This case if tricky because we must either have commutative
12050 operators or else A10 must not have side-effects. */
12052 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
12053 && operand_equal_p (a01, a11, 0))
12054 return fold_build2 (TREE_CODE (arg0), type,
12055 fold_build2 (code, type, a00, a10),
12059 /* See if we can build a range comparison. */
12060 if (0 != (tem = fold_range_test (code, type, op0, op1)))
12063 /* Check for the possibility of merging component references. If our
12064 lhs is another similar operation, try to merge its rhs with our
12065 rhs. Then try to merge our lhs and rhs. */
12066 if (TREE_CODE (arg0) == code
12067 && 0 != (tem = fold_truthop (code, type,
12068 TREE_OPERAND (arg0, 1), arg1)))
12069 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
12071 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
12076 case TRUTH_ORIF_EXPR:
12077 /* Note that the operands of this must be ints
12078 and their values must be 0 or true.
12079 ("true" is a fixed value perhaps depending on the language.) */
12080 /* If first arg is constant true, return it. */
12081 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
12082 return fold_convert (type, arg0);
12083 case TRUTH_OR_EXPR:
12084 /* If either arg is constant zero, drop it. */
12085 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
12086 return non_lvalue (fold_convert (type, arg1));
12087 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
12088 /* Preserve sequence points. */
12089 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
12090 return non_lvalue (fold_convert (type, arg0));
12091 /* If second arg is constant true, result is true, but we must
12092 evaluate first arg. */
12093 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
12094 return omit_one_operand (type, arg1, arg0);
12095 /* Likewise for first arg, but note this only occurs here for
12097 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
12098 return omit_one_operand (type, arg0, arg1);
12100 /* !X || X is always true. */
12101 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
12102 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
12103 return omit_one_operand (type, integer_one_node, arg1);
12104 /* X || !X is always true. */
12105 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
12106 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
12107 return omit_one_operand (type, integer_one_node, arg0);
12111 case TRUTH_XOR_EXPR:
12112 /* If the second arg is constant zero, drop it. */
12113 if (integer_zerop (arg1))
12114 return non_lvalue (fold_convert (type, arg0));
12115 /* If the second arg is constant true, this is a logical inversion. */
12116 if (integer_onep (arg1))
12118 /* Only call invert_truthvalue if operand is a truth value. */
12119 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
12120 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
12122 tem = invert_truthvalue (arg0);
12123 return non_lvalue (fold_convert (type, tem));
12125 /* Identical arguments cancel to zero. */
12126 if (operand_equal_p (arg0, arg1, 0))
12127 return omit_one_operand (type, integer_zero_node, arg0);
12129 /* !X ^ X is always true. */
12130 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
12131 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
12132 return omit_one_operand (type, integer_one_node, arg1);
12134 /* X ^ !X is always true. */
12135 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
12136 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
12137 return omit_one_operand (type, integer_one_node, arg0);
12143 tem = fold_comparison (code, type, op0, op1);
12144 if (tem != NULL_TREE)
12147 /* bool_var != 0 becomes bool_var. */
12148 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
12149 && code == NE_EXPR)
12150 return non_lvalue (fold_convert (type, arg0));
12152 /* bool_var == 1 becomes bool_var. */
12153 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
12154 && code == EQ_EXPR)
12155 return non_lvalue (fold_convert (type, arg0));
12157 /* bool_var != 1 becomes !bool_var. */
12158 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
12159 && code == NE_EXPR)
12160 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
12162 /* bool_var == 0 becomes !bool_var. */
12163 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
12164 && code == EQ_EXPR)
12165 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
12167 /* If this is an equality comparison of the address of two non-weak,
12168 unaliased symbols neither of which are extern (since we do not
12169 have access to attributes for externs), then we know the result. */
12170 if (TREE_CODE (arg0) == ADDR_EXPR
12171 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
12172 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
12173 && ! lookup_attribute ("alias",
12174 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
12175 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
12176 && TREE_CODE (arg1) == ADDR_EXPR
12177 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
12178 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
12179 && ! lookup_attribute ("alias",
12180 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
12181 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
12183 /* We know that we're looking at the address of two
12184 non-weak, unaliased, static _DECL nodes.
12186 It is both wasteful and incorrect to call operand_equal_p
12187 to compare the two ADDR_EXPR nodes. It is wasteful in that
12188 all we need to do is test pointer equality for the arguments
12189 to the two ADDR_EXPR nodes. It is incorrect to use
12190 operand_equal_p as that function is NOT equivalent to a
12191 C equality test. It can in fact return false for two
12192 objects which would test as equal using the C equality
12194 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
12195 return constant_boolean_node (equal
12196 ? code == EQ_EXPR : code != EQ_EXPR,
12200 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
12201 a MINUS_EXPR of a constant, we can convert it into a comparison with
12202 a revised constant as long as no overflow occurs. */
12203 if (TREE_CODE (arg1) == INTEGER_CST
12204 && (TREE_CODE (arg0) == PLUS_EXPR
12205 || TREE_CODE (arg0) == MINUS_EXPR)
12206 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12207 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
12208 ? MINUS_EXPR : PLUS_EXPR,
12209 fold_convert (TREE_TYPE (arg0), arg1),
12210 TREE_OPERAND (arg0, 1), 0))
12211 && !TREE_OVERFLOW (tem))
12212 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
12214 /* Similarly for a NEGATE_EXPR. */
12215 if (TREE_CODE (arg0) == NEGATE_EXPR
12216 && TREE_CODE (arg1) == INTEGER_CST
12217 && 0 != (tem = negate_expr (arg1))
12218 && TREE_CODE (tem) == INTEGER_CST
12219 && !TREE_OVERFLOW (tem))
12220 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
12222 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
12223 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12224 && TREE_CODE (arg1) == INTEGER_CST
12225 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12226 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12227 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
12228 fold_convert (TREE_TYPE (arg0), arg1),
12229 TREE_OPERAND (arg0, 1)));
12231 /* Transform comparisons of the form X +- C CMP X. */
12232 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12233 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12234 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12235 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
12236 || POINTER_TYPE_P (TREE_TYPE (arg0))))
12238 tree cst = TREE_OPERAND (arg0, 1);
12240 if (code == EQ_EXPR
12241 && !integer_zerop (cst))
12242 return omit_two_operands (type, boolean_false_node,
12243 TREE_OPERAND (arg0, 0), arg1);
12245 return omit_two_operands (type, boolean_true_node,
12246 TREE_OPERAND (arg0, 0), arg1);
12249 /* If we have X - Y == 0, we can convert that to X == Y and similarly
12250 for !=. Don't do this for ordered comparisons due to overflow. */
12251 if (TREE_CODE (arg0) == MINUS_EXPR
12252 && integer_zerop (arg1))
12253 return fold_build2 (code, type,
12254 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
12256 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
12257 if (TREE_CODE (arg0) == ABS_EXPR
12258 && (integer_zerop (arg1) || real_zerop (arg1)))
12259 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
12261 /* If this is an EQ or NE comparison with zero and ARG0 is
12262 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
12263 two operations, but the latter can be done in one less insn
12264 on machines that have only two-operand insns or on which a
12265 constant cannot be the first operand. */
12266 if (TREE_CODE (arg0) == BIT_AND_EXPR
12267 && integer_zerop (arg1))
12269 tree arg00 = TREE_OPERAND (arg0, 0);
12270 tree arg01 = TREE_OPERAND (arg0, 1);
12271 if (TREE_CODE (arg00) == LSHIFT_EXPR
12272 && integer_onep (TREE_OPERAND (arg00, 0)))
12274 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
12275 arg01, TREE_OPERAND (arg00, 1));
12276 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
12277 build_int_cst (TREE_TYPE (arg0), 1));
12278 return fold_build2 (code, type,
12279 fold_convert (TREE_TYPE (arg1), tem), arg1);
12281 else if (TREE_CODE (arg01) == LSHIFT_EXPR
12282 && integer_onep (TREE_OPERAND (arg01, 0)))
12284 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
12285 arg00, TREE_OPERAND (arg01, 1));
12286 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
12287 build_int_cst (TREE_TYPE (arg0), 1));
12288 return fold_build2 (code, type,
12289 fold_convert (TREE_TYPE (arg1), tem), arg1);
12293 /* If this is an NE or EQ comparison of zero against the result of a
12294 signed MOD operation whose second operand is a power of 2, make
12295 the MOD operation unsigned since it is simpler and equivalent. */
12296 if (integer_zerop (arg1)
12297 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
12298 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
12299 || TREE_CODE (arg0) == CEIL_MOD_EXPR
12300 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
12301 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
12302 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12304 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
12305 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
12306 fold_convert (newtype,
12307 TREE_OPERAND (arg0, 0)),
12308 fold_convert (newtype,
12309 TREE_OPERAND (arg0, 1)));
12311 return fold_build2 (code, type, newmod,
12312 fold_convert (newtype, arg1));
12315 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
12316 C1 is a valid shift constant, and C2 is a power of two, i.e.
12318 if (TREE_CODE (arg0) == BIT_AND_EXPR
12319 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
12320 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
12322 && integer_pow2p (TREE_OPERAND (arg0, 1))
12323 && integer_zerop (arg1))
12325 tree itype = TREE_TYPE (arg0);
12326 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
12327 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
12329 /* Check for a valid shift count. */
12330 if (TREE_INT_CST_HIGH (arg001) == 0
12331 && TREE_INT_CST_LOW (arg001) < prec)
12333 tree arg01 = TREE_OPERAND (arg0, 1);
12334 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12335 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
12336 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
12337 can be rewritten as (X & (C2 << C1)) != 0. */
12338 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
12340 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
12341 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
12342 return fold_build2 (code, type, tem, arg1);
12344 /* Otherwise, for signed (arithmetic) shifts,
12345 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
12346 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
12347 else if (!TYPE_UNSIGNED (itype))
12348 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
12349 arg000, build_int_cst (itype, 0));
12350 /* Otherwise, of unsigned (logical) shifts,
12351 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
12352 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
12354 return omit_one_operand (type,
12355 code == EQ_EXPR ? integer_one_node
12356 : integer_zero_node,
12361 /* If this is an NE comparison of zero with an AND of one, remove the
12362 comparison since the AND will give the correct value. */
12363 if (code == NE_EXPR
12364 && integer_zerop (arg1)
12365 && TREE_CODE (arg0) == BIT_AND_EXPR
12366 && integer_onep (TREE_OPERAND (arg0, 1)))
12367 return fold_convert (type, arg0);
12369 /* If we have (A & C) == C where C is a power of 2, convert this into
12370 (A & C) != 0. Similarly for NE_EXPR. */
12371 if (TREE_CODE (arg0) == BIT_AND_EXPR
12372 && integer_pow2p (TREE_OPERAND (arg0, 1))
12373 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12374 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12375 arg0, fold_convert (TREE_TYPE (arg0),
12376 integer_zero_node));
12378 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
12379 bit, then fold the expression into A < 0 or A >= 0. */
12380 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
12384 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
12385 Similarly for NE_EXPR. */
12386 if (TREE_CODE (arg0) == BIT_AND_EXPR
12387 && TREE_CODE (arg1) == INTEGER_CST
12388 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12390 tree notc = fold_build1 (BIT_NOT_EXPR,
12391 TREE_TYPE (TREE_OPERAND (arg0, 1)),
12392 TREE_OPERAND (arg0, 1));
12393 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12395 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
12396 if (integer_nonzerop (dandnotc))
12397 return omit_one_operand (type, rslt, arg0);
12400 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
12401 Similarly for NE_EXPR. */
12402 if (TREE_CODE (arg0) == BIT_IOR_EXPR
12403 && TREE_CODE (arg1) == INTEGER_CST
12404 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12406 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
12407 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12408 TREE_OPERAND (arg0, 1), notd);
12409 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
12410 if (integer_nonzerop (candnotd))
12411 return omit_one_operand (type, rslt, arg0);
12414 /* If this is a comparison of a field, we may be able to simplify it. */
12415 if ((TREE_CODE (arg0) == COMPONENT_REF
12416 || TREE_CODE (arg0) == BIT_FIELD_REF)
12417 /* Handle the constant case even without -O
12418 to make sure the warnings are given. */
12419 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
12421 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
12426 /* Optimize comparisons of strlen vs zero to a compare of the
12427 first character of the string vs zero. To wit,
12428 strlen(ptr) == 0 => *ptr == 0
12429 strlen(ptr) != 0 => *ptr != 0
12430 Other cases should reduce to one of these two (or a constant)
12431 due to the return value of strlen being unsigned. */
12432 if (TREE_CODE (arg0) == CALL_EXPR
12433 && integer_zerop (arg1))
12435 tree fndecl = get_callee_fndecl (arg0);
12438 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
12439 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
12440 && call_expr_nargs (arg0) == 1
12441 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
12443 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
12444 return fold_build2 (code, type, iref,
12445 build_int_cst (TREE_TYPE (iref), 0));
12449 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
12450 of X. Similarly fold (X >> C) == 0 into X >= 0. */
12451 if (TREE_CODE (arg0) == RSHIFT_EXPR
12452 && integer_zerop (arg1)
12453 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12455 tree arg00 = TREE_OPERAND (arg0, 0);
12456 tree arg01 = TREE_OPERAND (arg0, 1);
12457 tree itype = TREE_TYPE (arg00);
12458 if (TREE_INT_CST_HIGH (arg01) == 0
12459 && TREE_INT_CST_LOW (arg01)
12460 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
12462 if (TYPE_UNSIGNED (itype))
12464 itype = signed_type_for (itype);
12465 arg00 = fold_convert (itype, arg00);
12467 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
12468 type, arg00, build_int_cst (itype, 0));
12472 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
12473 if (integer_zerop (arg1)
12474 && TREE_CODE (arg0) == BIT_XOR_EXPR)
12475 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12476 TREE_OPERAND (arg0, 1));
12478 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
12479 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12480 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12481 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12482 build_int_cst (TREE_TYPE (arg1), 0));
12483 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
12484 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12485 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12486 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
12487 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
12488 build_int_cst (TREE_TYPE (arg1), 0));
12490 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
12491 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12492 && TREE_CODE (arg1) == INTEGER_CST
12493 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12494 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12495 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
12496 TREE_OPERAND (arg0, 1), arg1));
12498 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
12499 (X & C) == 0 when C is a single bit. */
12500 if (TREE_CODE (arg0) == BIT_AND_EXPR
12501 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
12502 && integer_zerop (arg1)
12503 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12505 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12506 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
12507 TREE_OPERAND (arg0, 1));
12508 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
12512 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12513 constant C is a power of two, i.e. a single bit. */
12514 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12515 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12516 && integer_zerop (arg1)
12517 && integer_pow2p (TREE_OPERAND (arg0, 1))
12518 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12519 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12521 tree arg00 = TREE_OPERAND (arg0, 0);
12522 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12523 arg00, build_int_cst (TREE_TYPE (arg00), 0));
12526 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12527 when is C is a power of two, i.e. a single bit. */
12528 if (TREE_CODE (arg0) == BIT_AND_EXPR
12529 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
12530 && integer_zerop (arg1)
12531 && integer_pow2p (TREE_OPERAND (arg0, 1))
12532 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12533 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12535 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12536 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
12537 arg000, TREE_OPERAND (arg0, 1));
12538 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12539 tem, build_int_cst (TREE_TYPE (tem), 0));
12542 if (integer_zerop (arg1)
12543 && tree_expr_nonzero_p (arg0))
12545 tree res = constant_boolean_node (code==NE_EXPR, type);
12546 return omit_one_operand (type, res, arg0);
12549 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12550 if (TREE_CODE (arg0) == NEGATE_EXPR
12551 && TREE_CODE (arg1) == NEGATE_EXPR)
12552 return fold_build2 (code, type,
12553 TREE_OPERAND (arg0, 0),
12554 TREE_OPERAND (arg1, 0));
12556 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12557 if (TREE_CODE (arg0) == BIT_AND_EXPR
12558 && TREE_CODE (arg1) == BIT_AND_EXPR)
12560 tree arg00 = TREE_OPERAND (arg0, 0);
12561 tree arg01 = TREE_OPERAND (arg0, 1);
12562 tree arg10 = TREE_OPERAND (arg1, 0);
12563 tree arg11 = TREE_OPERAND (arg1, 1);
12564 tree itype = TREE_TYPE (arg0);
12566 if (operand_equal_p (arg01, arg11, 0))
12567 return fold_build2 (code, type,
12568 fold_build2 (BIT_AND_EXPR, itype,
12569 fold_build2 (BIT_XOR_EXPR, itype,
12572 build_int_cst (itype, 0));
12574 if (operand_equal_p (arg01, arg10, 0))
12575 return fold_build2 (code, type,
12576 fold_build2 (BIT_AND_EXPR, itype,
12577 fold_build2 (BIT_XOR_EXPR, itype,
12580 build_int_cst (itype, 0));
12582 if (operand_equal_p (arg00, arg11, 0))
12583 return fold_build2 (code, type,
12584 fold_build2 (BIT_AND_EXPR, itype,
12585 fold_build2 (BIT_XOR_EXPR, itype,
12588 build_int_cst (itype, 0));
12590 if (operand_equal_p (arg00, arg10, 0))
12591 return fold_build2 (code, type,
12592 fold_build2 (BIT_AND_EXPR, itype,
12593 fold_build2 (BIT_XOR_EXPR, itype,
12596 build_int_cst (itype, 0));
12599 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12600 && TREE_CODE (arg1) == BIT_XOR_EXPR)
12602 tree arg00 = TREE_OPERAND (arg0, 0);
12603 tree arg01 = TREE_OPERAND (arg0, 1);
12604 tree arg10 = TREE_OPERAND (arg1, 0);
12605 tree arg11 = TREE_OPERAND (arg1, 1);
12606 tree itype = TREE_TYPE (arg0);
12608 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12609 operand_equal_p guarantees no side-effects so we don't need
12610 to use omit_one_operand on Z. */
12611 if (operand_equal_p (arg01, arg11, 0))
12612 return fold_build2 (code, type, arg00, arg10);
12613 if (operand_equal_p (arg01, arg10, 0))
12614 return fold_build2 (code, type, arg00, arg11);
12615 if (operand_equal_p (arg00, arg11, 0))
12616 return fold_build2 (code, type, arg01, arg10);
12617 if (operand_equal_p (arg00, arg10, 0))
12618 return fold_build2 (code, type, arg01, arg11);
12620 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12621 if (TREE_CODE (arg01) == INTEGER_CST
12622 && TREE_CODE (arg11) == INTEGER_CST)
12623 return fold_build2 (code, type,
12624 fold_build2 (BIT_XOR_EXPR, itype, arg00,
12625 fold_build2 (BIT_XOR_EXPR, itype,
12630 /* Attempt to simplify equality/inequality comparisons of complex
12631 values. Only lower the comparison if the result is known or
12632 can be simplified to a single scalar comparison. */
12633 if ((TREE_CODE (arg0) == COMPLEX_EXPR
12634 || TREE_CODE (arg0) == COMPLEX_CST)
12635 && (TREE_CODE (arg1) == COMPLEX_EXPR
12636 || TREE_CODE (arg1) == COMPLEX_CST))
12638 tree real0, imag0, real1, imag1;
12641 if (TREE_CODE (arg0) == COMPLEX_EXPR)
12643 real0 = TREE_OPERAND (arg0, 0);
12644 imag0 = TREE_OPERAND (arg0, 1);
12648 real0 = TREE_REALPART (arg0);
12649 imag0 = TREE_IMAGPART (arg0);
12652 if (TREE_CODE (arg1) == COMPLEX_EXPR)
12654 real1 = TREE_OPERAND (arg1, 0);
12655 imag1 = TREE_OPERAND (arg1, 1);
12659 real1 = TREE_REALPART (arg1);
12660 imag1 = TREE_IMAGPART (arg1);
12663 rcond = fold_binary (code, type, real0, real1);
12664 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
12666 if (integer_zerop (rcond))
12668 if (code == EQ_EXPR)
12669 return omit_two_operands (type, boolean_false_node,
12671 return fold_build2 (NE_EXPR, type, imag0, imag1);
12675 if (code == NE_EXPR)
12676 return omit_two_operands (type, boolean_true_node,
12678 return fold_build2 (EQ_EXPR, type, imag0, imag1);
12682 icond = fold_binary (code, type, imag0, imag1);
12683 if (icond && TREE_CODE (icond) == INTEGER_CST)
12685 if (integer_zerop (icond))
12687 if (code == EQ_EXPR)
12688 return omit_two_operands (type, boolean_false_node,
12690 return fold_build2 (NE_EXPR, type, real0, real1);
12694 if (code == NE_EXPR)
12695 return omit_two_operands (type, boolean_true_node,
12697 return fold_build2 (EQ_EXPR, type, real0, real1);
12708 tem = fold_comparison (code, type, op0, op1);
12709 if (tem != NULL_TREE)
12712 /* Transform comparisons of the form X +- C CMP X. */
12713 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12714 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12715 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
12716 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
12717 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12718 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
12720 tree arg01 = TREE_OPERAND (arg0, 1);
12721 enum tree_code code0 = TREE_CODE (arg0);
12724 if (TREE_CODE (arg01) == REAL_CST)
12725 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
12727 is_positive = tree_int_cst_sgn (arg01);
12729 /* (X - c) > X becomes false. */
12730 if (code == GT_EXPR
12731 && ((code0 == MINUS_EXPR && is_positive >= 0)
12732 || (code0 == PLUS_EXPR && is_positive <= 0)))
12734 if (TREE_CODE (arg01) == INTEGER_CST
12735 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12736 fold_overflow_warning (("assuming signed overflow does not "
12737 "occur when assuming that (X - c) > X "
12738 "is always false"),
12739 WARN_STRICT_OVERFLOW_ALL);
12740 return constant_boolean_node (0, type);
12743 /* Likewise (X + c) < X becomes false. */
12744 if (code == LT_EXPR
12745 && ((code0 == PLUS_EXPR && is_positive >= 0)
12746 || (code0 == MINUS_EXPR && is_positive <= 0)))
12748 if (TREE_CODE (arg01) == INTEGER_CST
12749 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12750 fold_overflow_warning (("assuming signed overflow does not "
12751 "occur when assuming that "
12752 "(X + c) < X is always false"),
12753 WARN_STRICT_OVERFLOW_ALL);
12754 return constant_boolean_node (0, type);
12757 /* Convert (X - c) <= X to true. */
12758 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12760 && ((code0 == MINUS_EXPR && is_positive >= 0)
12761 || (code0 == PLUS_EXPR && is_positive <= 0)))
12763 if (TREE_CODE (arg01) == INTEGER_CST
12764 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12765 fold_overflow_warning (("assuming signed overflow does not "
12766 "occur when assuming that "
12767 "(X - c) <= X is always true"),
12768 WARN_STRICT_OVERFLOW_ALL);
12769 return constant_boolean_node (1, type);
12772 /* Convert (X + c) >= X to true. */
12773 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12775 && ((code0 == PLUS_EXPR && is_positive >= 0)
12776 || (code0 == MINUS_EXPR && is_positive <= 0)))
12778 if (TREE_CODE (arg01) == INTEGER_CST
12779 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12780 fold_overflow_warning (("assuming signed overflow does not "
12781 "occur when assuming that "
12782 "(X + c) >= X is always true"),
12783 WARN_STRICT_OVERFLOW_ALL);
12784 return constant_boolean_node (1, type);
12787 if (TREE_CODE (arg01) == INTEGER_CST)
12789 /* Convert X + c > X and X - c < X to true for integers. */
12790 if (code == GT_EXPR
12791 && ((code0 == PLUS_EXPR && is_positive > 0)
12792 || (code0 == MINUS_EXPR && is_positive < 0)))
12794 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12795 fold_overflow_warning (("assuming signed overflow does "
12796 "not occur when assuming that "
12797 "(X + c) > X is always true"),
12798 WARN_STRICT_OVERFLOW_ALL);
12799 return constant_boolean_node (1, type);
12802 if (code == LT_EXPR
12803 && ((code0 == MINUS_EXPR && is_positive > 0)
12804 || (code0 == PLUS_EXPR && is_positive < 0)))
12806 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12807 fold_overflow_warning (("assuming signed overflow does "
12808 "not occur when assuming that "
12809 "(X - c) < X is always true"),
12810 WARN_STRICT_OVERFLOW_ALL);
12811 return constant_boolean_node (1, type);
12814 /* Convert X + c <= X and X - c >= X to false for integers. */
12815 if (code == LE_EXPR
12816 && ((code0 == PLUS_EXPR && is_positive > 0)
12817 || (code0 == MINUS_EXPR && is_positive < 0)))
12819 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12820 fold_overflow_warning (("assuming signed overflow does "
12821 "not occur when assuming that "
12822 "(X + c) <= X is always false"),
12823 WARN_STRICT_OVERFLOW_ALL);
12824 return constant_boolean_node (0, type);
12827 if (code == GE_EXPR
12828 && ((code0 == MINUS_EXPR && is_positive > 0)
12829 || (code0 == PLUS_EXPR && is_positive < 0)))
12831 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12832 fold_overflow_warning (("assuming signed overflow does "
12833 "not occur when assuming that "
12834 "(X - c) >= X is always false"),
12835 WARN_STRICT_OVERFLOW_ALL);
12836 return constant_boolean_node (0, type);
12841 /* Comparisons with the highest or lowest possible integer of
12842 the specified precision will have known values. */
12844 tree arg1_type = TREE_TYPE (arg1);
12845 unsigned int width = TYPE_PRECISION (arg1_type);
12847 if (TREE_CODE (arg1) == INTEGER_CST
12848 && width <= 2 * HOST_BITS_PER_WIDE_INT
12849 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
12851 HOST_WIDE_INT signed_max_hi;
12852 unsigned HOST_WIDE_INT signed_max_lo;
12853 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
12855 if (width <= HOST_BITS_PER_WIDE_INT)
12857 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12862 if (TYPE_UNSIGNED (arg1_type))
12864 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12870 max_lo = signed_max_lo;
12871 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12877 width -= HOST_BITS_PER_WIDE_INT;
12878 signed_max_lo = -1;
12879 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12884 if (TYPE_UNSIGNED (arg1_type))
12886 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12891 max_hi = signed_max_hi;
12892 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12896 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
12897 && TREE_INT_CST_LOW (arg1) == max_lo)
12901 return omit_one_operand (type, integer_zero_node, arg0);
12904 return fold_build2 (EQ_EXPR, type, op0, op1);
12907 return omit_one_operand (type, integer_one_node, arg0);
12910 return fold_build2 (NE_EXPR, type, op0, op1);
12912 /* The GE_EXPR and LT_EXPR cases above are not normally
12913 reached because of previous transformations. */
12918 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12920 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
12924 arg1 = const_binop (PLUS_EXPR, arg1,
12925 build_int_cst (TREE_TYPE (arg1), 1), 0);
12926 return fold_build2 (EQ_EXPR, type,
12927 fold_convert (TREE_TYPE (arg1), arg0),
12930 arg1 = const_binop (PLUS_EXPR, arg1,
12931 build_int_cst (TREE_TYPE (arg1), 1), 0);
12932 return fold_build2 (NE_EXPR, type,
12933 fold_convert (TREE_TYPE (arg1), arg0),
12938 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12940 && TREE_INT_CST_LOW (arg1) == min_lo)
12944 return omit_one_operand (type, integer_zero_node, arg0);
12947 return fold_build2 (EQ_EXPR, type, op0, op1);
12950 return omit_one_operand (type, integer_one_node, arg0);
12953 return fold_build2 (NE_EXPR, type, op0, op1);
12958 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12960 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
12964 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12965 return fold_build2 (NE_EXPR, type,
12966 fold_convert (TREE_TYPE (arg1), arg0),
12969 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12970 return fold_build2 (EQ_EXPR, type,
12971 fold_convert (TREE_TYPE (arg1), arg0),
12977 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
12978 && TREE_INT_CST_LOW (arg1) == signed_max_lo
12979 && TYPE_UNSIGNED (arg1_type)
12980 /* We will flip the signedness of the comparison operator
12981 associated with the mode of arg1, so the sign bit is
12982 specified by this mode. Check that arg1 is the signed
12983 max associated with this sign bit. */
12984 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
12985 /* signed_type does not work on pointer types. */
12986 && INTEGRAL_TYPE_P (arg1_type))
12988 /* The following case also applies to X < signed_max+1
12989 and X >= signed_max+1 because previous transformations. */
12990 if (code == LE_EXPR || code == GT_EXPR)
12993 st = signed_type_for (TREE_TYPE (arg1));
12994 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
12995 type, fold_convert (st, arg0),
12996 build_int_cst (st, 0));
13002 /* If we are comparing an ABS_EXPR with a constant, we can
13003 convert all the cases into explicit comparisons, but they may
13004 well not be faster than doing the ABS and one comparison.
13005 But ABS (X) <= C is a range comparison, which becomes a subtraction
13006 and a comparison, and is probably faster. */
13007 if (code == LE_EXPR
13008 && TREE_CODE (arg1) == INTEGER_CST
13009 && TREE_CODE (arg0) == ABS_EXPR
13010 && ! TREE_SIDE_EFFECTS (arg0)
13011 && (0 != (tem = negate_expr (arg1)))
13012 && TREE_CODE (tem) == INTEGER_CST
13013 && !TREE_OVERFLOW (tem))
13014 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13015 build2 (GE_EXPR, type,
13016 TREE_OPERAND (arg0, 0), tem),
13017 build2 (LE_EXPR, type,
13018 TREE_OPERAND (arg0, 0), arg1));
13020 /* Convert ABS_EXPR<x> >= 0 to true. */
13021 strict_overflow_p = false;
13022 if (code == GE_EXPR
13023 && (integer_zerop (arg1)
13024 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
13025 && real_zerop (arg1)))
13026 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
13028 if (strict_overflow_p)
13029 fold_overflow_warning (("assuming signed overflow does not occur "
13030 "when simplifying comparison of "
13031 "absolute value and zero"),
13032 WARN_STRICT_OVERFLOW_CONDITIONAL);
13033 return omit_one_operand (type, integer_one_node, arg0);
13036 /* Convert ABS_EXPR<x> < 0 to false. */
13037 strict_overflow_p = false;
13038 if (code == LT_EXPR
13039 && (integer_zerop (arg1) || real_zerop (arg1))
13040 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
13042 if (strict_overflow_p)
13043 fold_overflow_warning (("assuming signed overflow does not occur "
13044 "when simplifying comparison of "
13045 "absolute value and zero"),
13046 WARN_STRICT_OVERFLOW_CONDITIONAL);
13047 return omit_one_operand (type, integer_zero_node, arg0);
13050 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
13051 and similarly for >= into !=. */
13052 if ((code == LT_EXPR || code == GE_EXPR)
13053 && TYPE_UNSIGNED (TREE_TYPE (arg0))
13054 && TREE_CODE (arg1) == LSHIFT_EXPR
13055 && integer_onep (TREE_OPERAND (arg1, 0)))
13056 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
13057 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
13058 TREE_OPERAND (arg1, 1)),
13059 build_int_cst (TREE_TYPE (arg0), 0));
13061 if ((code == LT_EXPR || code == GE_EXPR)
13062 && TYPE_UNSIGNED (TREE_TYPE (arg0))
13063 && CONVERT_EXPR_P (arg1)
13064 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
13065 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
13067 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
13068 fold_convert (TREE_TYPE (arg0),
13069 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
13070 TREE_OPERAND (TREE_OPERAND (arg1, 0),
13072 build_int_cst (TREE_TYPE (arg0), 0));
13076 case UNORDERED_EXPR:
13084 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
13086 t1 = fold_relational_const (code, type, arg0, arg1);
13087 if (t1 != NULL_TREE)
13091 /* If the first operand is NaN, the result is constant. */
13092 if (TREE_CODE (arg0) == REAL_CST
13093 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
13094 && (code != LTGT_EXPR || ! flag_trapping_math))
13096 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
13097 ? integer_zero_node
13098 : integer_one_node;
13099 return omit_one_operand (type, t1, arg1);
13102 /* If the second operand is NaN, the result is constant. */
13103 if (TREE_CODE (arg1) == REAL_CST
13104 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
13105 && (code != LTGT_EXPR || ! flag_trapping_math))
13107 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
13108 ? integer_zero_node
13109 : integer_one_node;
13110 return omit_one_operand (type, t1, arg0);
13113 /* Simplify unordered comparison of something with itself. */
13114 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
13115 && operand_equal_p (arg0, arg1, 0))
13116 return constant_boolean_node (1, type);
13118 if (code == LTGT_EXPR
13119 && !flag_trapping_math
13120 && operand_equal_p (arg0, arg1, 0))
13121 return constant_boolean_node (0, type);
13123 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
13125 tree targ0 = strip_float_extensions (arg0);
13126 tree targ1 = strip_float_extensions (arg1);
13127 tree newtype = TREE_TYPE (targ0);
13129 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
13130 newtype = TREE_TYPE (targ1);
13132 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
13133 return fold_build2 (code, type, fold_convert (newtype, targ0),
13134 fold_convert (newtype, targ1));
13139 case COMPOUND_EXPR:
13140 /* When pedantic, a compound expression can be neither an lvalue
13141 nor an integer constant expression. */
13142 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
13144 /* Don't let (0, 0) be null pointer constant. */
13145 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
13146 : fold_convert (type, arg1);
13147 return pedantic_non_lvalue (tem);
13150 if ((TREE_CODE (arg0) == REAL_CST
13151 && TREE_CODE (arg1) == REAL_CST)
13152 || (TREE_CODE (arg0) == INTEGER_CST
13153 && TREE_CODE (arg1) == INTEGER_CST))
13154 return build_complex (type, arg0, arg1);
13158 /* An ASSERT_EXPR should never be passed to fold_binary. */
13159 gcc_unreachable ();
13163 } /* switch (code) */
13166 /* Callback for walk_tree, looking for LABEL_EXPR.
13167 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
13168 Do not check the sub-tree of GOTO_EXPR. */
13171 contains_label_1 (tree *tp,
13172 int *walk_subtrees,
13173 void *data ATTRIBUTE_UNUSED)
13175 switch (TREE_CODE (*tp))
13180 *walk_subtrees = 0;
13187 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
13188 accessible from outside the sub-tree. Returns NULL_TREE if no
13189 addressable label is found. */
13192 contains_label_p (tree st)
13194 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
13197 /* Fold a ternary expression of code CODE and type TYPE with operands
13198 OP0, OP1, and OP2. Return the folded expression if folding is
13199 successful. Otherwise, return NULL_TREE. */
13202 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
13205 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
13206 enum tree_code_class kind = TREE_CODE_CLASS (code);
13208 gcc_assert (IS_EXPR_CODE_CLASS (kind)
13209 && TREE_CODE_LENGTH (code) == 3);
13211 /* Strip any conversions that don't change the mode. This is safe
13212 for every expression, except for a comparison expression because
13213 its signedness is derived from its operands. So, in the latter
13214 case, only strip conversions that don't change the signedness.
13216 Note that this is done as an internal manipulation within the
13217 constant folder, in order to find the simplest representation of
13218 the arguments so that their form can be studied. In any cases,
13219 the appropriate type conversions should be put back in the tree
13220 that will get out of the constant folder. */
13235 case COMPONENT_REF:
13236 if (TREE_CODE (arg0) == CONSTRUCTOR
13237 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
13239 unsigned HOST_WIDE_INT idx;
13241 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
13248 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
13249 so all simple results must be passed through pedantic_non_lvalue. */
13250 if (TREE_CODE (arg0) == INTEGER_CST)
13252 tree unused_op = integer_zerop (arg0) ? op1 : op2;
13253 tem = integer_zerop (arg0) ? op2 : op1;
13254 /* Only optimize constant conditions when the selected branch
13255 has the same type as the COND_EXPR. This avoids optimizing
13256 away "c ? x : throw", where the throw has a void type.
13257 Avoid throwing away that operand which contains label. */
13258 if ((!TREE_SIDE_EFFECTS (unused_op)
13259 || !contains_label_p (unused_op))
13260 && (! VOID_TYPE_P (TREE_TYPE (tem))
13261 || VOID_TYPE_P (type)))
13262 return pedantic_non_lvalue (tem);
13265 if (operand_equal_p (arg1, op2, 0))
13266 return pedantic_omit_one_operand (type, arg1, arg0);
13268 /* If we have A op B ? A : C, we may be able to convert this to a
13269 simpler expression, depending on the operation and the values
13270 of B and C. Signed zeros prevent all of these transformations,
13271 for reasons given above each one.
13273 Also try swapping the arguments and inverting the conditional. */
13274 if (COMPARISON_CLASS_P (arg0)
13275 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
13276 arg1, TREE_OPERAND (arg0, 1))
13277 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
13279 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
13284 if (COMPARISON_CLASS_P (arg0)
13285 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
13287 TREE_OPERAND (arg0, 1))
13288 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
13290 tem = fold_truth_not_expr (arg0);
13291 if (tem && COMPARISON_CLASS_P (tem))
13293 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
13299 /* If the second operand is simpler than the third, swap them
13300 since that produces better jump optimization results. */
13301 if (truth_value_p (TREE_CODE (arg0))
13302 && tree_swap_operands_p (op1, op2, false))
13304 /* See if this can be inverted. If it can't, possibly because
13305 it was a floating-point inequality comparison, don't do
13307 tem = fold_truth_not_expr (arg0);
13309 return fold_build3 (code, type, tem, op2, op1);
13312 /* Convert A ? 1 : 0 to simply A. */
13313 if (integer_onep (op1)
13314 && integer_zerop (op2)
13315 /* If we try to convert OP0 to our type, the
13316 call to fold will try to move the conversion inside
13317 a COND, which will recurse. In that case, the COND_EXPR
13318 is probably the best choice, so leave it alone. */
13319 && type == TREE_TYPE (arg0))
13320 return pedantic_non_lvalue (arg0);
13322 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
13323 over COND_EXPR in cases such as floating point comparisons. */
13324 if (integer_zerop (op1)
13325 && integer_onep (op2)
13326 && truth_value_p (TREE_CODE (arg0)))
13327 return pedantic_non_lvalue (fold_convert (type,
13328 invert_truthvalue (arg0)));
13330 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
13331 if (TREE_CODE (arg0) == LT_EXPR
13332 && integer_zerop (TREE_OPERAND (arg0, 1))
13333 && integer_zerop (op2)
13334 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
13336 /* sign_bit_p only checks ARG1 bits within A's precision.
13337 If <sign bit of A> has wider type than A, bits outside
13338 of A's precision in <sign bit of A> need to be checked.
13339 If they are all 0, this optimization needs to be done
13340 in unsigned A's type, if they are all 1 in signed A's type,
13341 otherwise this can't be done. */
13342 if (TYPE_PRECISION (TREE_TYPE (tem))
13343 < TYPE_PRECISION (TREE_TYPE (arg1))
13344 && TYPE_PRECISION (TREE_TYPE (tem))
13345 < TYPE_PRECISION (type))
13347 unsigned HOST_WIDE_INT mask_lo;
13348 HOST_WIDE_INT mask_hi;
13349 int inner_width, outer_width;
13352 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
13353 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
13354 if (outer_width > TYPE_PRECISION (type))
13355 outer_width = TYPE_PRECISION (type);
13357 if (outer_width > HOST_BITS_PER_WIDE_INT)
13359 mask_hi = ((unsigned HOST_WIDE_INT) -1
13360 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
13366 mask_lo = ((unsigned HOST_WIDE_INT) -1
13367 >> (HOST_BITS_PER_WIDE_INT - outer_width));
13369 if (inner_width > HOST_BITS_PER_WIDE_INT)
13371 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
13372 >> (HOST_BITS_PER_WIDE_INT - inner_width));
13376 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
13377 >> (HOST_BITS_PER_WIDE_INT - inner_width));
13379 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
13380 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
13382 tem_type = signed_type_for (TREE_TYPE (tem));
13383 tem = fold_convert (tem_type, tem);
13385 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
13386 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
13388 tem_type = unsigned_type_for (TREE_TYPE (tem));
13389 tem = fold_convert (tem_type, tem);
13396 return fold_convert (type,
13397 fold_build2 (BIT_AND_EXPR,
13398 TREE_TYPE (tem), tem,
13399 fold_convert (TREE_TYPE (tem),
13403 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
13404 already handled above. */
13405 if (TREE_CODE (arg0) == BIT_AND_EXPR
13406 && integer_onep (TREE_OPERAND (arg0, 1))
13407 && integer_zerop (op2)
13408 && integer_pow2p (arg1))
13410 tree tem = TREE_OPERAND (arg0, 0);
13412 if (TREE_CODE (tem) == RSHIFT_EXPR
13413 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
13414 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
13415 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
13416 return fold_build2 (BIT_AND_EXPR, type,
13417 TREE_OPERAND (tem, 0), arg1);
13420 /* A & N ? N : 0 is simply A & N if N is a power of two. This
13421 is probably obsolete because the first operand should be a
13422 truth value (that's why we have the two cases above), but let's
13423 leave it in until we can confirm this for all front-ends. */
13424 if (integer_zerop (op2)
13425 && TREE_CODE (arg0) == NE_EXPR
13426 && integer_zerop (TREE_OPERAND (arg0, 1))
13427 && integer_pow2p (arg1)
13428 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
13429 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
13430 arg1, OEP_ONLY_CONST))
13431 return pedantic_non_lvalue (fold_convert (type,
13432 TREE_OPERAND (arg0, 0)));
13434 /* Convert A ? B : 0 into A && B if A and B are truth values. */
13435 if (integer_zerop (op2)
13436 && truth_value_p (TREE_CODE (arg0))
13437 && truth_value_p (TREE_CODE (arg1)))
13438 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13439 fold_convert (type, arg0),
13442 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
13443 if (integer_onep (op2)
13444 && truth_value_p (TREE_CODE (arg0))
13445 && truth_value_p (TREE_CODE (arg1)))
13447 /* Only perform transformation if ARG0 is easily inverted. */
13448 tem = fold_truth_not_expr (arg0);
13450 return fold_build2 (TRUTH_ORIF_EXPR, type,
13451 fold_convert (type, tem),
13455 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
13456 if (integer_zerop (arg1)
13457 && truth_value_p (TREE_CODE (arg0))
13458 && truth_value_p (TREE_CODE (op2)))
13460 /* Only perform transformation if ARG0 is easily inverted. */
13461 tem = fold_truth_not_expr (arg0);
13463 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13464 fold_convert (type, tem),
13468 /* Convert A ? 1 : B into A || B if A and B are truth values. */
13469 if (integer_onep (arg1)
13470 && truth_value_p (TREE_CODE (arg0))
13471 && truth_value_p (TREE_CODE (op2)))
13472 return fold_build2 (TRUTH_ORIF_EXPR, type,
13473 fold_convert (type, arg0),
13479 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
13480 of fold_ternary on them. */
13481 gcc_unreachable ();
13483 case BIT_FIELD_REF:
13484 if ((TREE_CODE (arg0) == VECTOR_CST
13485 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
13486 && type == TREE_TYPE (TREE_TYPE (arg0)))
13488 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
13489 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
13492 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
13493 && (idx % width) == 0
13494 && (idx = idx / width)
13495 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
13497 tree elements = NULL_TREE;
13499 if (TREE_CODE (arg0) == VECTOR_CST)
13500 elements = TREE_VECTOR_CST_ELTS (arg0);
13503 unsigned HOST_WIDE_INT idx;
13506 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
13507 elements = tree_cons (NULL_TREE, value, elements);
13509 while (idx-- > 0 && elements)
13510 elements = TREE_CHAIN (elements);
13512 return TREE_VALUE (elements);
13514 return fold_convert (type, integer_zero_node);
13518 /* A bit-field-ref that referenced the full argument can be stripped. */
13519 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
13520 && TYPE_PRECISION (TREE_TYPE (arg0)) == tree_low_cst (arg1, 1)
13521 && integer_zerop (op2))
13522 return fold_convert (type, arg0);
13528 } /* switch (code) */
13531 /* Perform constant folding and related simplification of EXPR.
13532 The related simplifications include x*1 => x, x*0 => 0, etc.,
13533 and application of the associative law.
13534 NOP_EXPR conversions may be removed freely (as long as we
13535 are careful not to change the type of the overall expression).
13536 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13537 but we can constant-fold them if they have constant operands. */
13539 #ifdef ENABLE_FOLD_CHECKING
13540 # define fold(x) fold_1 (x)
13541 static tree fold_1 (tree);
13547 const tree t = expr;
13548 enum tree_code code = TREE_CODE (t);
13549 enum tree_code_class kind = TREE_CODE_CLASS (code);
13552 /* Return right away if a constant. */
13553 if (kind == tcc_constant)
13556 /* CALL_EXPR-like objects with variable numbers of operands are
13557 treated specially. */
13558 if (kind == tcc_vl_exp)
13560 if (code == CALL_EXPR)
13562 tem = fold_call_expr (expr, false);
13563 return tem ? tem : expr;
13568 if (IS_EXPR_CODE_CLASS (kind))
13570 tree type = TREE_TYPE (t);
13571 tree op0, op1, op2;
13573 switch (TREE_CODE_LENGTH (code))
13576 op0 = TREE_OPERAND (t, 0);
13577 tem = fold_unary (code, type, op0);
13578 return tem ? tem : expr;
13580 op0 = TREE_OPERAND (t, 0);
13581 op1 = TREE_OPERAND (t, 1);
13582 tem = fold_binary (code, type, op0, op1);
13583 return tem ? tem : expr;
13585 op0 = TREE_OPERAND (t, 0);
13586 op1 = TREE_OPERAND (t, 1);
13587 op2 = TREE_OPERAND (t, 2);
13588 tem = fold_ternary (code, type, op0, op1, op2);
13589 return tem ? tem : expr;
13599 tree op0 = TREE_OPERAND (t, 0);
13600 tree op1 = TREE_OPERAND (t, 1);
13602 if (TREE_CODE (op1) == INTEGER_CST
13603 && TREE_CODE (op0) == CONSTRUCTOR
13604 && ! type_contains_placeholder_p (TREE_TYPE (op0)))
13606 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (op0);
13607 unsigned HOST_WIDE_INT end = VEC_length (constructor_elt, elts);
13608 unsigned HOST_WIDE_INT begin = 0;
13610 /* Find a matching index by means of a binary search. */
13611 while (begin != end)
13613 unsigned HOST_WIDE_INT middle = (begin + end) / 2;
13614 tree index = VEC_index (constructor_elt, elts, middle)->index;
13616 if (TREE_CODE (index) == INTEGER_CST
13617 && tree_int_cst_lt (index, op1))
13618 begin = middle + 1;
13619 else if (TREE_CODE (index) == INTEGER_CST
13620 && tree_int_cst_lt (op1, index))
13622 else if (TREE_CODE (index) == RANGE_EXPR
13623 && tree_int_cst_lt (TREE_OPERAND (index, 1), op1))
13624 begin = middle + 1;
13625 else if (TREE_CODE (index) == RANGE_EXPR
13626 && tree_int_cst_lt (op1, TREE_OPERAND (index, 0)))
13629 return VEC_index (constructor_elt, elts, middle)->value;
13637 return fold (DECL_INITIAL (t));
13641 } /* switch (code) */
13644 #ifdef ENABLE_FOLD_CHECKING
13647 static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
13648 static void fold_check_failed (const_tree, const_tree);
13649 void print_fold_checksum (const_tree);
13651 /* When --enable-checking=fold, compute a digest of expr before
13652 and after actual fold call to see if fold did not accidentally
13653 change original expr. */
13659 struct md5_ctx ctx;
13660 unsigned char checksum_before[16], checksum_after[16];
13663 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13664 md5_init_ctx (&ctx);
13665 fold_checksum_tree (expr, &ctx, ht);
13666 md5_finish_ctx (&ctx, checksum_before);
13669 ret = fold_1 (expr);
13671 md5_init_ctx (&ctx);
13672 fold_checksum_tree (expr, &ctx, ht);
13673 md5_finish_ctx (&ctx, checksum_after);
13676 if (memcmp (checksum_before, checksum_after, 16))
13677 fold_check_failed (expr, ret);
13683 print_fold_checksum (const_tree expr)
13685 struct md5_ctx ctx;
13686 unsigned char checksum[16], cnt;
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);
13694 for (cnt = 0; cnt < 16; ++cnt)
13695 fprintf (stderr, "%02x", checksum[cnt]);
13696 putc ('\n', stderr);
13700 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
13702 internal_error ("fold check: original tree changed by fold");
13706 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
13709 enum tree_code code;
13710 union tree_node buf;
13715 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
13716 <= sizeof (struct tree_function_decl))
13717 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
13720 slot = (const void **) htab_find_slot (ht, expr, INSERT);
13724 code = TREE_CODE (expr);
13725 if (TREE_CODE_CLASS (code) == tcc_declaration
13726 && DECL_ASSEMBLER_NAME_SET_P (expr))
13728 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13729 memcpy ((char *) &buf, expr, tree_size (expr));
13730 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
13731 expr = (tree) &buf;
13733 else if (TREE_CODE_CLASS (code) == tcc_type
13734 && (TYPE_POINTER_TO (expr)
13735 || TYPE_REFERENCE_TO (expr)
13736 || TYPE_CACHED_VALUES_P (expr)
13737 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)
13738 || TYPE_NEXT_VARIANT (expr)))
13740 /* Allow these fields to be modified. */
13742 memcpy ((char *) &buf, expr, tree_size (expr));
13743 expr = tmp = (tree) &buf;
13744 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
13745 TYPE_POINTER_TO (tmp) = NULL;
13746 TYPE_REFERENCE_TO (tmp) = NULL;
13747 TYPE_NEXT_VARIANT (tmp) = NULL;
13748 if (TYPE_CACHED_VALUES_P (tmp))
13750 TYPE_CACHED_VALUES_P (tmp) = 0;
13751 TYPE_CACHED_VALUES (tmp) = NULL;
13754 md5_process_bytes (expr, tree_size (expr), ctx);
13755 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
13756 if (TREE_CODE_CLASS (code) != tcc_type
13757 && TREE_CODE_CLASS (code) != tcc_declaration
13758 && code != TREE_LIST
13759 && code != SSA_NAME)
13760 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
13761 switch (TREE_CODE_CLASS (code))
13767 md5_process_bytes (TREE_STRING_POINTER (expr),
13768 TREE_STRING_LENGTH (expr), ctx);
13771 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
13772 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
13775 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
13781 case tcc_exceptional:
13785 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
13786 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
13787 expr = TREE_CHAIN (expr);
13788 goto recursive_label;
13791 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
13792 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
13798 case tcc_expression:
13799 case tcc_reference:
13800 case tcc_comparison:
13803 case tcc_statement:
13805 len = TREE_OPERAND_LENGTH (expr);
13806 for (i = 0; i < len; ++i)
13807 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
13809 case tcc_declaration:
13810 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
13811 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
13812 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
13814 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
13815 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
13816 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
13817 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
13818 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
13820 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
13821 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
13823 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
13825 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
13826 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
13827 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
13831 if (TREE_CODE (expr) == ENUMERAL_TYPE)
13832 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
13833 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
13834 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
13835 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
13836 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
13837 if (INTEGRAL_TYPE_P (expr)
13838 || SCALAR_FLOAT_TYPE_P (expr))
13840 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
13841 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
13843 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
13844 if (TREE_CODE (expr) == RECORD_TYPE
13845 || TREE_CODE (expr) == UNION_TYPE
13846 || TREE_CODE (expr) == QUAL_UNION_TYPE)
13847 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
13848 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
13855 /* Helper function for outputting the checksum of a tree T. When
13856 debugging with gdb, you can "define mynext" to be "next" followed
13857 by "call debug_fold_checksum (op0)", then just trace down till the
13861 debug_fold_checksum (const_tree t)
13864 unsigned char checksum[16];
13865 struct md5_ctx ctx;
13866 htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13868 md5_init_ctx (&ctx);
13869 fold_checksum_tree (t, &ctx, ht);
13870 md5_finish_ctx (&ctx, checksum);
13873 for (i = 0; i < 16; i++)
13874 fprintf (stderr, "%d ", checksum[i]);
13876 fprintf (stderr, "\n");
13881 /* Fold a unary tree expression with code CODE of type TYPE with an
13882 operand OP0. Return a folded expression if successful. Otherwise,
13883 return a tree expression with code CODE of type TYPE with an
13887 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
13890 #ifdef ENABLE_FOLD_CHECKING
13891 unsigned char checksum_before[16], checksum_after[16];
13892 struct md5_ctx ctx;
13895 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13896 md5_init_ctx (&ctx);
13897 fold_checksum_tree (op0, &ctx, ht);
13898 md5_finish_ctx (&ctx, checksum_before);
13902 tem = fold_unary (code, type, op0);
13904 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
13906 #ifdef ENABLE_FOLD_CHECKING
13907 md5_init_ctx (&ctx);
13908 fold_checksum_tree (op0, &ctx, ht);
13909 md5_finish_ctx (&ctx, checksum_after);
13912 if (memcmp (checksum_before, checksum_after, 16))
13913 fold_check_failed (op0, tem);
13918 /* Fold a binary tree expression with code CODE of type TYPE with
13919 operands OP0 and OP1. Return a folded expression if successful.
13920 Otherwise, return a tree expression with code CODE of type TYPE
13921 with operands OP0 and OP1. */
13924 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
13928 #ifdef ENABLE_FOLD_CHECKING
13929 unsigned char checksum_before_op0[16],
13930 checksum_before_op1[16],
13931 checksum_after_op0[16],
13932 checksum_after_op1[16];
13933 struct md5_ctx ctx;
13936 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13937 md5_init_ctx (&ctx);
13938 fold_checksum_tree (op0, &ctx, ht);
13939 md5_finish_ctx (&ctx, checksum_before_op0);
13942 md5_init_ctx (&ctx);
13943 fold_checksum_tree (op1, &ctx, ht);
13944 md5_finish_ctx (&ctx, checksum_before_op1);
13948 tem = fold_binary (code, type, op0, op1);
13950 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
13952 #ifdef ENABLE_FOLD_CHECKING
13953 md5_init_ctx (&ctx);
13954 fold_checksum_tree (op0, &ctx, ht);
13955 md5_finish_ctx (&ctx, checksum_after_op0);
13958 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13959 fold_check_failed (op0, tem);
13961 md5_init_ctx (&ctx);
13962 fold_checksum_tree (op1, &ctx, ht);
13963 md5_finish_ctx (&ctx, checksum_after_op1);
13966 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13967 fold_check_failed (op1, tem);
13972 /* Fold a ternary tree expression with code CODE of type TYPE with
13973 operands OP0, OP1, and OP2. Return a folded expression if
13974 successful. Otherwise, return a tree expression with code CODE of
13975 type TYPE with operands OP0, OP1, and OP2. */
13978 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
13982 #ifdef ENABLE_FOLD_CHECKING
13983 unsigned char checksum_before_op0[16],
13984 checksum_before_op1[16],
13985 checksum_before_op2[16],
13986 checksum_after_op0[16],
13987 checksum_after_op1[16],
13988 checksum_after_op2[16];
13989 struct md5_ctx ctx;
13992 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13993 md5_init_ctx (&ctx);
13994 fold_checksum_tree (op0, &ctx, ht);
13995 md5_finish_ctx (&ctx, checksum_before_op0);
13998 md5_init_ctx (&ctx);
13999 fold_checksum_tree (op1, &ctx, ht);
14000 md5_finish_ctx (&ctx, checksum_before_op1);
14003 md5_init_ctx (&ctx);
14004 fold_checksum_tree (op2, &ctx, ht);
14005 md5_finish_ctx (&ctx, checksum_before_op2);
14009 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
14010 tem = fold_ternary (code, type, op0, op1, op2);
14012 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
14014 #ifdef ENABLE_FOLD_CHECKING
14015 md5_init_ctx (&ctx);
14016 fold_checksum_tree (op0, &ctx, ht);
14017 md5_finish_ctx (&ctx, checksum_after_op0);
14020 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
14021 fold_check_failed (op0, tem);
14023 md5_init_ctx (&ctx);
14024 fold_checksum_tree (op1, &ctx, ht);
14025 md5_finish_ctx (&ctx, checksum_after_op1);
14028 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
14029 fold_check_failed (op1, tem);
14031 md5_init_ctx (&ctx);
14032 fold_checksum_tree (op2, &ctx, ht);
14033 md5_finish_ctx (&ctx, checksum_after_op2);
14036 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
14037 fold_check_failed (op2, tem);
14042 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
14043 arguments in ARGARRAY, and a null static chain.
14044 Return a folded expression if successful. Otherwise, return a CALL_EXPR
14045 of type TYPE from the given operands as constructed by build_call_array. */
14048 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
14051 #ifdef ENABLE_FOLD_CHECKING
14052 unsigned char checksum_before_fn[16],
14053 checksum_before_arglist[16],
14054 checksum_after_fn[16],
14055 checksum_after_arglist[16];
14056 struct md5_ctx ctx;
14060 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
14061 md5_init_ctx (&ctx);
14062 fold_checksum_tree (fn, &ctx, ht);
14063 md5_finish_ctx (&ctx, checksum_before_fn);
14066 md5_init_ctx (&ctx);
14067 for (i = 0; i < nargs; i++)
14068 fold_checksum_tree (argarray[i], &ctx, ht);
14069 md5_finish_ctx (&ctx, checksum_before_arglist);
14073 tem = fold_builtin_call_array (type, fn, nargs, argarray);
14075 #ifdef ENABLE_FOLD_CHECKING
14076 md5_init_ctx (&ctx);
14077 fold_checksum_tree (fn, &ctx, ht);
14078 md5_finish_ctx (&ctx, checksum_after_fn);
14081 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
14082 fold_check_failed (fn, tem);
14084 md5_init_ctx (&ctx);
14085 for (i = 0; i < nargs; i++)
14086 fold_checksum_tree (argarray[i], &ctx, ht);
14087 md5_finish_ctx (&ctx, checksum_after_arglist);
14090 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
14091 fold_check_failed (NULL_TREE, tem);
14096 /* Perform constant folding and related simplification of initializer
14097 expression EXPR. These behave identically to "fold_buildN" but ignore
14098 potential run-time traps and exceptions that fold must preserve. */
14100 #define START_FOLD_INIT \
14101 int saved_signaling_nans = flag_signaling_nans;\
14102 int saved_trapping_math = flag_trapping_math;\
14103 int saved_rounding_math = flag_rounding_math;\
14104 int saved_trapv = flag_trapv;\
14105 int saved_folding_initializer = folding_initializer;\
14106 flag_signaling_nans = 0;\
14107 flag_trapping_math = 0;\
14108 flag_rounding_math = 0;\
14110 folding_initializer = 1;
14112 #define END_FOLD_INIT \
14113 flag_signaling_nans = saved_signaling_nans;\
14114 flag_trapping_math = saved_trapping_math;\
14115 flag_rounding_math = saved_rounding_math;\
14116 flag_trapv = saved_trapv;\
14117 folding_initializer = saved_folding_initializer;
14120 fold_build1_initializer (enum tree_code code, tree type, tree op)
14125 result = fold_build1 (code, type, op);
14132 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
14137 result = fold_build2 (code, type, op0, op1);
14144 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
14150 result = fold_build3 (code, type, op0, op1, op2);
14157 fold_build_call_array_initializer (tree type, tree fn,
14158 int nargs, tree *argarray)
14163 result = fold_build_call_array (type, fn, nargs, argarray);
14169 #undef START_FOLD_INIT
14170 #undef END_FOLD_INIT
14172 /* Determine if first argument is a multiple of second argument. Return 0 if
14173 it is not, or we cannot easily determined it to be.
14175 An example of the sort of thing we care about (at this point; this routine
14176 could surely be made more general, and expanded to do what the *_DIV_EXPR's
14177 fold cases do now) is discovering that
14179 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
14185 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
14187 This code also handles discovering that
14189 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
14191 is a multiple of 8 so we don't have to worry about dealing with a
14192 possible remainder.
14194 Note that we *look* inside a SAVE_EXPR only to determine how it was
14195 calculated; it is not safe for fold to do much of anything else with the
14196 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
14197 at run time. For example, the latter example above *cannot* be implemented
14198 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
14199 evaluation time of the original SAVE_EXPR is not necessarily the same at
14200 the time the new expression is evaluated. The only optimization of this
14201 sort that would be valid is changing
14203 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
14207 SAVE_EXPR (I) * SAVE_EXPR (J)
14209 (where the same SAVE_EXPR (J) is used in the original and the
14210 transformed version). */
14213 multiple_of_p (tree type, const_tree top, const_tree bottom)
14215 if (operand_equal_p (top, bottom, 0))
14218 if (TREE_CODE (type) != INTEGER_TYPE)
14221 switch (TREE_CODE (top))
14224 /* Bitwise and provides a power of two multiple. If the mask is
14225 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
14226 if (!integer_pow2p (bottom))
14231 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
14232 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
14236 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
14237 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
14240 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
14244 op1 = TREE_OPERAND (top, 1);
14245 /* const_binop may not detect overflow correctly,
14246 so check for it explicitly here. */
14247 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
14248 > TREE_INT_CST_LOW (op1)
14249 && TREE_INT_CST_HIGH (op1) == 0
14250 && 0 != (t1 = fold_convert (type,
14251 const_binop (LSHIFT_EXPR,
14254 && !TREE_OVERFLOW (t1))
14255 return multiple_of_p (type, t1, bottom);
14260 /* Can't handle conversions from non-integral or wider integral type. */
14261 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
14262 || (TYPE_PRECISION (type)
14263 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
14266 /* .. fall through ... */
14269 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
14272 if (TREE_CODE (bottom) != INTEGER_CST
14273 || integer_zerop (bottom)
14274 || (TYPE_UNSIGNED (type)
14275 && (tree_int_cst_sgn (top) < 0
14276 || tree_int_cst_sgn (bottom) < 0)))
14278 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
14286 /* Return true if CODE or TYPE is known to be non-negative. */
14289 tree_simple_nonnegative_warnv_p (enum tree_code code, tree type)
14291 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
14292 && truth_value_p (code))
14293 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
14294 have a signed:1 type (where the value is -1 and 0). */
14299 /* Return true if (CODE OP0) is known to be non-negative. If the return
14300 value is based on the assumption that signed overflow is undefined,
14301 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14302 *STRICT_OVERFLOW_P. */
14305 tree_unary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
14306 bool *strict_overflow_p)
14308 if (TYPE_UNSIGNED (type))
14314 /* We can't return 1 if flag_wrapv is set because
14315 ABS_EXPR<INT_MIN> = INT_MIN. */
14316 if (!INTEGRAL_TYPE_P (type))
14318 if (TYPE_OVERFLOW_UNDEFINED (type))
14320 *strict_overflow_p = true;
14325 case NON_LVALUE_EXPR:
14327 case FIX_TRUNC_EXPR:
14328 return tree_expr_nonnegative_warnv_p (op0,
14329 strict_overflow_p);
14333 tree inner_type = TREE_TYPE (op0);
14334 tree outer_type = type;
14336 if (TREE_CODE (outer_type) == REAL_TYPE)
14338 if (TREE_CODE (inner_type) == REAL_TYPE)
14339 return tree_expr_nonnegative_warnv_p (op0,
14340 strict_overflow_p);
14341 if (TREE_CODE (inner_type) == INTEGER_TYPE)
14343 if (TYPE_UNSIGNED (inner_type))
14345 return tree_expr_nonnegative_warnv_p (op0,
14346 strict_overflow_p);
14349 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
14351 if (TREE_CODE (inner_type) == REAL_TYPE)
14352 return tree_expr_nonnegative_warnv_p (op0,
14353 strict_overflow_p);
14354 if (TREE_CODE (inner_type) == INTEGER_TYPE)
14355 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
14356 && TYPE_UNSIGNED (inner_type);
14362 return tree_simple_nonnegative_warnv_p (code, type);
14365 /* We don't know sign of `t', so be conservative and return false. */
14369 /* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
14370 value is based on the assumption that signed overflow is undefined,
14371 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14372 *STRICT_OVERFLOW_P. */
14375 tree_binary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
14376 tree op1, bool *strict_overflow_p)
14378 if (TYPE_UNSIGNED (type))
14383 case POINTER_PLUS_EXPR:
14385 if (FLOAT_TYPE_P (type))
14386 return (tree_expr_nonnegative_warnv_p (op0,
14388 && tree_expr_nonnegative_warnv_p (op1,
14389 strict_overflow_p));
14391 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
14392 both unsigned and at least 2 bits shorter than the result. */
14393 if (TREE_CODE (type) == INTEGER_TYPE
14394 && TREE_CODE (op0) == NOP_EXPR
14395 && TREE_CODE (op1) == NOP_EXPR)
14397 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
14398 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
14399 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
14400 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
14402 unsigned int prec = MAX (TYPE_PRECISION (inner1),
14403 TYPE_PRECISION (inner2)) + 1;
14404 return prec < TYPE_PRECISION (type);
14410 if (FLOAT_TYPE_P (type))
14412 /* x * x for floating point x is always non-negative. */
14413 if (operand_equal_p (op0, op1, 0))
14415 return (tree_expr_nonnegative_warnv_p (op0,
14417 && tree_expr_nonnegative_warnv_p (op1,
14418 strict_overflow_p));
14421 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
14422 both unsigned and their total bits is shorter than the result. */
14423 if (TREE_CODE (type) == INTEGER_TYPE
14424 && (TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == INTEGER_CST)
14425 && (TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == INTEGER_CST))
14427 tree inner0 = (TREE_CODE (op0) == NOP_EXPR)
14428 ? TREE_TYPE (TREE_OPERAND (op0, 0))
14430 tree inner1 = (TREE_CODE (op1) == NOP_EXPR)
14431 ? TREE_TYPE (TREE_OPERAND (op1, 0))
14434 bool unsigned0 = TYPE_UNSIGNED (inner0);
14435 bool unsigned1 = TYPE_UNSIGNED (inner1);
14437 if (TREE_CODE (op0) == INTEGER_CST)
14438 unsigned0 = unsigned0 || tree_int_cst_sgn (op0) >= 0;
14440 if (TREE_CODE (op1) == INTEGER_CST)
14441 unsigned1 = unsigned1 || tree_int_cst_sgn (op1) >= 0;
14443 if (TREE_CODE (inner0) == INTEGER_TYPE && unsigned0
14444 && TREE_CODE (inner1) == INTEGER_TYPE && unsigned1)
14446 unsigned int precision0 = (TREE_CODE (op0) == INTEGER_CST)
14447 ? tree_int_cst_min_precision (op0, /*unsignedp=*/true)
14448 : TYPE_PRECISION (inner0);
14450 unsigned int precision1 = (TREE_CODE (op1) == INTEGER_CST)
14451 ? tree_int_cst_min_precision (op1, /*unsignedp=*/true)
14452 : TYPE_PRECISION (inner1);
14454 return precision0 + precision1 < TYPE_PRECISION (type);
14461 return (tree_expr_nonnegative_warnv_p (op0,
14463 || tree_expr_nonnegative_warnv_p (op1,
14464 strict_overflow_p));
14470 case TRUNC_DIV_EXPR:
14471 case CEIL_DIV_EXPR:
14472 case FLOOR_DIV_EXPR:
14473 case ROUND_DIV_EXPR:
14474 return (tree_expr_nonnegative_warnv_p (op0,
14476 && tree_expr_nonnegative_warnv_p (op1,
14477 strict_overflow_p));
14479 case TRUNC_MOD_EXPR:
14480 case CEIL_MOD_EXPR:
14481 case FLOOR_MOD_EXPR:
14482 case ROUND_MOD_EXPR:
14483 return tree_expr_nonnegative_warnv_p (op0,
14484 strict_overflow_p);
14486 return tree_simple_nonnegative_warnv_p (code, type);
14489 /* We don't know sign of `t', so be conservative and return false. */
14493 /* Return true if T is known to be non-negative. If the return
14494 value is based on the assumption that signed overflow is undefined,
14495 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14496 *STRICT_OVERFLOW_P. */
14499 tree_single_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14501 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14504 switch (TREE_CODE (t))
14507 return tree_int_cst_sgn (t) >= 0;
14510 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
14513 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
14516 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14518 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
14519 strict_overflow_p));
14521 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14524 /* We don't know sign of `t', so be conservative and return false. */
14528 /* Return true if T is known to be non-negative. If the return
14529 value is based on the assumption that signed overflow is undefined,
14530 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14531 *STRICT_OVERFLOW_P. */
14534 tree_call_nonnegative_warnv_p (tree type, tree fndecl,
14535 tree arg0, tree arg1, bool *strict_overflow_p)
14537 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
14538 switch (DECL_FUNCTION_CODE (fndecl))
14540 CASE_FLT_FN (BUILT_IN_ACOS):
14541 CASE_FLT_FN (BUILT_IN_ACOSH):
14542 CASE_FLT_FN (BUILT_IN_CABS):
14543 CASE_FLT_FN (BUILT_IN_COSH):
14544 CASE_FLT_FN (BUILT_IN_ERFC):
14545 CASE_FLT_FN (BUILT_IN_EXP):
14546 CASE_FLT_FN (BUILT_IN_EXP10):
14547 CASE_FLT_FN (BUILT_IN_EXP2):
14548 CASE_FLT_FN (BUILT_IN_FABS):
14549 CASE_FLT_FN (BUILT_IN_FDIM):
14550 CASE_FLT_FN (BUILT_IN_HYPOT):
14551 CASE_FLT_FN (BUILT_IN_POW10):
14552 CASE_INT_FN (BUILT_IN_FFS):
14553 CASE_INT_FN (BUILT_IN_PARITY):
14554 CASE_INT_FN (BUILT_IN_POPCOUNT):
14555 case BUILT_IN_BSWAP32:
14556 case BUILT_IN_BSWAP64:
14560 CASE_FLT_FN (BUILT_IN_SQRT):
14561 /* sqrt(-0.0) is -0.0. */
14562 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
14564 return tree_expr_nonnegative_warnv_p (arg0,
14565 strict_overflow_p);
14567 CASE_FLT_FN (BUILT_IN_ASINH):
14568 CASE_FLT_FN (BUILT_IN_ATAN):
14569 CASE_FLT_FN (BUILT_IN_ATANH):
14570 CASE_FLT_FN (BUILT_IN_CBRT):
14571 CASE_FLT_FN (BUILT_IN_CEIL):
14572 CASE_FLT_FN (BUILT_IN_ERF):
14573 CASE_FLT_FN (BUILT_IN_EXPM1):
14574 CASE_FLT_FN (BUILT_IN_FLOOR):
14575 CASE_FLT_FN (BUILT_IN_FMOD):
14576 CASE_FLT_FN (BUILT_IN_FREXP):
14577 CASE_FLT_FN (BUILT_IN_LCEIL):
14578 CASE_FLT_FN (BUILT_IN_LDEXP):
14579 CASE_FLT_FN (BUILT_IN_LFLOOR):
14580 CASE_FLT_FN (BUILT_IN_LLCEIL):
14581 CASE_FLT_FN (BUILT_IN_LLFLOOR):
14582 CASE_FLT_FN (BUILT_IN_LLRINT):
14583 CASE_FLT_FN (BUILT_IN_LLROUND):
14584 CASE_FLT_FN (BUILT_IN_LRINT):
14585 CASE_FLT_FN (BUILT_IN_LROUND):
14586 CASE_FLT_FN (BUILT_IN_MODF):
14587 CASE_FLT_FN (BUILT_IN_NEARBYINT):
14588 CASE_FLT_FN (BUILT_IN_RINT):
14589 CASE_FLT_FN (BUILT_IN_ROUND):
14590 CASE_FLT_FN (BUILT_IN_SCALB):
14591 CASE_FLT_FN (BUILT_IN_SCALBLN):
14592 CASE_FLT_FN (BUILT_IN_SCALBN):
14593 CASE_FLT_FN (BUILT_IN_SIGNBIT):
14594 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
14595 CASE_FLT_FN (BUILT_IN_SINH):
14596 CASE_FLT_FN (BUILT_IN_TANH):
14597 CASE_FLT_FN (BUILT_IN_TRUNC):
14598 /* True if the 1st argument is nonnegative. */
14599 return tree_expr_nonnegative_warnv_p (arg0,
14600 strict_overflow_p);
14602 CASE_FLT_FN (BUILT_IN_FMAX):
14603 /* True if the 1st OR 2nd arguments are nonnegative. */
14604 return (tree_expr_nonnegative_warnv_p (arg0,
14606 || (tree_expr_nonnegative_warnv_p (arg1,
14607 strict_overflow_p)));
14609 CASE_FLT_FN (BUILT_IN_FMIN):
14610 /* True if the 1st AND 2nd arguments are nonnegative. */
14611 return (tree_expr_nonnegative_warnv_p (arg0,
14613 && (tree_expr_nonnegative_warnv_p (arg1,
14614 strict_overflow_p)));
14616 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14617 /* True if the 2nd argument is nonnegative. */
14618 return tree_expr_nonnegative_warnv_p (arg1,
14619 strict_overflow_p);
14621 CASE_FLT_FN (BUILT_IN_POWI):
14622 /* True if the 1st argument is nonnegative or the second
14623 argument is an even integer. */
14624 if (TREE_CODE (arg1) == INTEGER_CST
14625 && (TREE_INT_CST_LOW (arg1) & 1) == 0)
14627 return tree_expr_nonnegative_warnv_p (arg0,
14628 strict_overflow_p);
14630 CASE_FLT_FN (BUILT_IN_POW):
14631 /* True if the 1st argument is nonnegative or the second
14632 argument is an even integer valued real. */
14633 if (TREE_CODE (arg1) == REAL_CST)
14638 c = TREE_REAL_CST (arg1);
14639 n = real_to_integer (&c);
14642 REAL_VALUE_TYPE cint;
14643 real_from_integer (&cint, VOIDmode, n,
14644 n < 0 ? -1 : 0, 0);
14645 if (real_identical (&c, &cint))
14649 return tree_expr_nonnegative_warnv_p (arg0,
14650 strict_overflow_p);
14655 return tree_simple_nonnegative_warnv_p (CALL_EXPR,
14659 /* Return true if T is known to be non-negative. If the return
14660 value is based on the assumption that signed overflow is undefined,
14661 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14662 *STRICT_OVERFLOW_P. */
14665 tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14667 enum tree_code code = TREE_CODE (t);
14668 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14675 tree temp = TARGET_EXPR_SLOT (t);
14676 t = TARGET_EXPR_INITIAL (t);
14678 /* If the initializer is non-void, then it's a normal expression
14679 that will be assigned to the slot. */
14680 if (!VOID_TYPE_P (t))
14681 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
14683 /* Otherwise, the initializer sets the slot in some way. One common
14684 way is an assignment statement at the end of the initializer. */
14687 if (TREE_CODE (t) == BIND_EXPR)
14688 t = expr_last (BIND_EXPR_BODY (t));
14689 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
14690 || TREE_CODE (t) == TRY_CATCH_EXPR)
14691 t = expr_last (TREE_OPERAND (t, 0));
14692 else if (TREE_CODE (t) == STATEMENT_LIST)
14697 if (TREE_CODE (t) == MODIFY_EXPR
14698 && TREE_OPERAND (t, 0) == temp)
14699 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14700 strict_overflow_p);
14707 tree arg0 = call_expr_nargs (t) > 0 ? CALL_EXPR_ARG (t, 0) : NULL_TREE;
14708 tree arg1 = call_expr_nargs (t) > 1 ? CALL_EXPR_ARG (t, 1) : NULL_TREE;
14710 return tree_call_nonnegative_warnv_p (TREE_TYPE (t),
14711 get_callee_fndecl (t),
14714 strict_overflow_p);
14716 case COMPOUND_EXPR:
14718 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14719 strict_overflow_p);
14721 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
14722 strict_overflow_p);
14724 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14725 strict_overflow_p);
14728 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14732 /* We don't know sign of `t', so be conservative and return false. */
14736 /* Return true if T is known to be non-negative. If the return
14737 value is based on the assumption that signed overflow is undefined,
14738 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14739 *STRICT_OVERFLOW_P. */
14742 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14744 enum tree_code code;
14745 if (t == error_mark_node)
14748 code = TREE_CODE (t);
14749 switch (TREE_CODE_CLASS (code))
14752 case tcc_comparison:
14753 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14755 TREE_OPERAND (t, 0),
14756 TREE_OPERAND (t, 1),
14757 strict_overflow_p);
14760 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14762 TREE_OPERAND (t, 0),
14763 strict_overflow_p);
14766 case tcc_declaration:
14767 case tcc_reference:
14768 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14776 case TRUTH_AND_EXPR:
14777 case TRUTH_OR_EXPR:
14778 case TRUTH_XOR_EXPR:
14779 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14781 TREE_OPERAND (t, 0),
14782 TREE_OPERAND (t, 1),
14783 strict_overflow_p);
14784 case TRUTH_NOT_EXPR:
14785 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14787 TREE_OPERAND (t, 0),
14788 strict_overflow_p);
14795 case WITH_SIZE_EXPR:
14799 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14802 return tree_invalid_nonnegative_warnv_p (t, strict_overflow_p);
14806 /* Return true if `t' is known to be non-negative. Handle warnings
14807 about undefined signed overflow. */
14810 tree_expr_nonnegative_p (tree t)
14812 bool ret, strict_overflow_p;
14814 strict_overflow_p = false;
14815 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
14816 if (strict_overflow_p)
14817 fold_overflow_warning (("assuming signed overflow does not occur when "
14818 "determining that expression is always "
14820 WARN_STRICT_OVERFLOW_MISC);
14825 /* Return true when (CODE OP0) is an address and is known to be nonzero.
14826 For floating point we further ensure that T is not denormal.
14827 Similar logic is present in nonzero_address in rtlanal.h.
14829 If the return value is based on the assumption that signed overflow
14830 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14831 change *STRICT_OVERFLOW_P. */
14834 tree_unary_nonzero_warnv_p (enum tree_code code, tree type, tree op0,
14835 bool *strict_overflow_p)
14840 return tree_expr_nonzero_warnv_p (op0,
14841 strict_overflow_p);
14845 tree inner_type = TREE_TYPE (op0);
14846 tree outer_type = type;
14848 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
14849 && tree_expr_nonzero_warnv_p (op0,
14850 strict_overflow_p));
14854 case NON_LVALUE_EXPR:
14855 return tree_expr_nonzero_warnv_p (op0,
14856 strict_overflow_p);
14865 /* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
14866 For floating point we further ensure that T is not denormal.
14867 Similar logic is present in nonzero_address in rtlanal.h.
14869 If the return value is based on the assumption that signed overflow
14870 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14871 change *STRICT_OVERFLOW_P. */
14874 tree_binary_nonzero_warnv_p (enum tree_code code,
14877 tree op1, bool *strict_overflow_p)
14879 bool sub_strict_overflow_p;
14882 case POINTER_PLUS_EXPR:
14884 if (TYPE_OVERFLOW_UNDEFINED (type))
14886 /* With the presence of negative values it is hard
14887 to say something. */
14888 sub_strict_overflow_p = false;
14889 if (!tree_expr_nonnegative_warnv_p (op0,
14890 &sub_strict_overflow_p)
14891 || !tree_expr_nonnegative_warnv_p (op1,
14892 &sub_strict_overflow_p))
14894 /* One of operands must be positive and the other non-negative. */
14895 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14896 overflows, on a twos-complement machine the sum of two
14897 nonnegative numbers can never be zero. */
14898 return (tree_expr_nonzero_warnv_p (op0,
14900 || tree_expr_nonzero_warnv_p (op1,
14901 strict_overflow_p));
14906 if (TYPE_OVERFLOW_UNDEFINED (type))
14908 if (tree_expr_nonzero_warnv_p (op0,
14910 && tree_expr_nonzero_warnv_p (op1,
14911 strict_overflow_p))
14913 *strict_overflow_p = true;
14920 sub_strict_overflow_p = false;
14921 if (tree_expr_nonzero_warnv_p (op0,
14922 &sub_strict_overflow_p)
14923 && tree_expr_nonzero_warnv_p (op1,
14924 &sub_strict_overflow_p))
14926 if (sub_strict_overflow_p)
14927 *strict_overflow_p = true;
14932 sub_strict_overflow_p = false;
14933 if (tree_expr_nonzero_warnv_p (op0,
14934 &sub_strict_overflow_p))
14936 if (sub_strict_overflow_p)
14937 *strict_overflow_p = true;
14939 /* When both operands are nonzero, then MAX must be too. */
14940 if (tree_expr_nonzero_warnv_p (op1,
14941 strict_overflow_p))
14944 /* MAX where operand 0 is positive is positive. */
14945 return tree_expr_nonnegative_warnv_p (op0,
14946 strict_overflow_p);
14948 /* MAX where operand 1 is positive is positive. */
14949 else if (tree_expr_nonzero_warnv_p (op1,
14950 &sub_strict_overflow_p)
14951 && tree_expr_nonnegative_warnv_p (op1,
14952 &sub_strict_overflow_p))
14954 if (sub_strict_overflow_p)
14955 *strict_overflow_p = true;
14961 return (tree_expr_nonzero_warnv_p (op1,
14963 || tree_expr_nonzero_warnv_p (op0,
14964 strict_overflow_p));
14973 /* Return true when T is an address and is known to be nonzero.
14974 For floating point we further ensure that T is not denormal.
14975 Similar logic is present in nonzero_address in rtlanal.h.
14977 If the return value is based on the assumption that signed overflow
14978 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14979 change *STRICT_OVERFLOW_P. */
14982 tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14984 bool sub_strict_overflow_p;
14985 switch (TREE_CODE (t))
14988 return !integer_zerop (t);
14992 tree base = get_base_address (TREE_OPERAND (t, 0));
14997 /* Weak declarations may link to NULL. */
14998 if (VAR_OR_FUNCTION_DECL_P (base))
14999 return !DECL_WEAK (base);
15001 /* Constants are never weak. */
15002 if (CONSTANT_CLASS_P (base))
15009 sub_strict_overflow_p = false;
15010 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
15011 &sub_strict_overflow_p)
15012 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
15013 &sub_strict_overflow_p))
15015 if (sub_strict_overflow_p)
15016 *strict_overflow_p = true;
15027 /* Return true when T is an address and is known to be nonzero.
15028 For floating point we further ensure that T is not denormal.
15029 Similar logic is present in nonzero_address in rtlanal.h.
15031 If the return value is based on the assumption that signed overflow
15032 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
15033 change *STRICT_OVERFLOW_P. */
15036 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
15038 tree type = TREE_TYPE (t);
15039 enum tree_code code;
15041 /* Doing something useful for floating point would need more work. */
15042 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
15045 code = TREE_CODE (t);
15046 switch (TREE_CODE_CLASS (code))
15049 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
15050 strict_overflow_p);
15052 case tcc_comparison:
15053 return tree_binary_nonzero_warnv_p (code, type,
15054 TREE_OPERAND (t, 0),
15055 TREE_OPERAND (t, 1),
15056 strict_overflow_p);
15058 case tcc_declaration:
15059 case tcc_reference:
15060 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
15068 case TRUTH_NOT_EXPR:
15069 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
15070 strict_overflow_p);
15072 case TRUTH_AND_EXPR:
15073 case TRUTH_OR_EXPR:
15074 case TRUTH_XOR_EXPR:
15075 return tree_binary_nonzero_warnv_p (code, type,
15076 TREE_OPERAND (t, 0),
15077 TREE_OPERAND (t, 1),
15078 strict_overflow_p);
15085 case WITH_SIZE_EXPR:
15089 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
15091 case COMPOUND_EXPR:
15094 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
15095 strict_overflow_p);
15098 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
15099 strict_overflow_p);
15102 return alloca_call_p (t);
15110 /* Return true when T is an address and is known to be nonzero.
15111 Handle warnings about undefined signed overflow. */
15114 tree_expr_nonzero_p (tree t)
15116 bool ret, strict_overflow_p;
15118 strict_overflow_p = false;
15119 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
15120 if (strict_overflow_p)
15121 fold_overflow_warning (("assuming signed overflow does not occur when "
15122 "determining that expression is always "
15124 WARN_STRICT_OVERFLOW_MISC);
15128 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
15129 attempt to fold the expression to a constant without modifying TYPE,
15132 If the expression could be simplified to a constant, then return
15133 the constant. If the expression would not be simplified to a
15134 constant, then return NULL_TREE. */
15137 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
15139 tree tem = fold_binary (code, type, op0, op1);
15140 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
15143 /* Given the components of a unary expression CODE, TYPE and OP0,
15144 attempt to fold the expression to a constant without modifying
15147 If the expression could be simplified to a constant, then return
15148 the constant. If the expression would not be simplified to a
15149 constant, then return NULL_TREE. */
15152 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
15154 tree tem = fold_unary (code, type, op0);
15155 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
15158 /* If EXP represents referencing an element in a constant string
15159 (either via pointer arithmetic or array indexing), return the
15160 tree representing the value accessed, otherwise return NULL. */
15163 fold_read_from_constant_string (tree exp)
15165 if ((TREE_CODE (exp) == INDIRECT_REF
15166 || TREE_CODE (exp) == ARRAY_REF)
15167 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
15169 tree exp1 = TREE_OPERAND (exp, 0);
15173 if (TREE_CODE (exp) == INDIRECT_REF)
15174 string = string_constant (exp1, &index);
15177 tree low_bound = array_ref_low_bound (exp);
15178 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
15180 /* Optimize the special-case of a zero lower bound.
15182 We convert the low_bound to sizetype to avoid some problems
15183 with constant folding. (E.g. suppose the lower bound is 1,
15184 and its mode is QI. Without the conversion,l (ARRAY
15185 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
15186 +INDEX), which becomes (ARRAY+255+INDEX). Oops!) */
15187 if (! integer_zerop (low_bound))
15188 index = size_diffop (index, fold_convert (sizetype, low_bound));
15194 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
15195 && TREE_CODE (string) == STRING_CST
15196 && TREE_CODE (index) == INTEGER_CST
15197 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
15198 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
15200 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
15201 return build_int_cst_type (TREE_TYPE (exp),
15202 (TREE_STRING_POINTER (string)
15203 [TREE_INT_CST_LOW (index)]));
15208 /* Return the tree for neg (ARG0) when ARG0 is known to be either
15209 an integer constant, real, or fixed-point constant.
15211 TYPE is the type of the result. */
15214 fold_negate_const (tree arg0, tree type)
15216 tree t = NULL_TREE;
15218 switch (TREE_CODE (arg0))
15222 unsigned HOST_WIDE_INT low;
15223 HOST_WIDE_INT high;
15224 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
15225 TREE_INT_CST_HIGH (arg0),
15227 t = force_fit_type_double (type, low, high, 1,
15228 (overflow | TREE_OVERFLOW (arg0))
15229 && !TYPE_UNSIGNED (type));
15234 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
15239 FIXED_VALUE_TYPE f;
15240 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
15241 &(TREE_FIXED_CST (arg0)), NULL,
15242 TYPE_SATURATING (type));
15243 t = build_fixed (type, f);
15244 /* Propagate overflow flags. */
15245 if (overflow_p | TREE_OVERFLOW (arg0))
15247 TREE_OVERFLOW (t) = 1;
15248 TREE_CONSTANT_OVERFLOW (t) = 1;
15250 else if (TREE_CONSTANT_OVERFLOW (arg0))
15251 TREE_CONSTANT_OVERFLOW (t) = 1;
15256 gcc_unreachable ();
15262 /* Return the tree for abs (ARG0) when ARG0 is known to be either
15263 an integer constant or real constant.
15265 TYPE is the type of the result. */
15268 fold_abs_const (tree arg0, tree type)
15270 tree t = NULL_TREE;
15272 switch (TREE_CODE (arg0))
15275 /* If the value is unsigned, then the absolute value is
15276 the same as the ordinary value. */
15277 if (TYPE_UNSIGNED (type))
15279 /* Similarly, if the value is non-negative. */
15280 else if (INT_CST_LT (integer_minus_one_node, arg0))
15282 /* If the value is negative, then the absolute value is
15286 unsigned HOST_WIDE_INT low;
15287 HOST_WIDE_INT high;
15288 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
15289 TREE_INT_CST_HIGH (arg0),
15291 t = force_fit_type_double (type, low, high, -1,
15292 overflow | TREE_OVERFLOW (arg0));
15297 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
15298 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
15304 gcc_unreachable ();
15310 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
15311 constant. TYPE is the type of the result. */
15314 fold_not_const (tree arg0, tree type)
15316 tree t = NULL_TREE;
15318 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
15320 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
15321 ~TREE_INT_CST_HIGH (arg0), 0,
15322 TREE_OVERFLOW (arg0));
15327 /* Given CODE, a relational operator, the target type, TYPE and two
15328 constant operands OP0 and OP1, return the result of the
15329 relational operation. If the result is not a compile time
15330 constant, then return NULL_TREE. */
15333 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
15335 int result, invert;
15337 /* From here on, the only cases we handle are when the result is
15338 known to be a constant. */
15340 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
15342 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
15343 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
15345 /* Handle the cases where either operand is a NaN. */
15346 if (real_isnan (c0) || real_isnan (c1))
15356 case UNORDERED_EXPR:
15370 if (flag_trapping_math)
15376 gcc_unreachable ();
15379 return constant_boolean_node (result, type);
15382 return constant_boolean_node (real_compare (code, c0, c1), type);
15385 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
15387 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
15388 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
15389 return constant_boolean_node (fixed_compare (code, c0, c1), type);
15392 /* Handle equality/inequality of complex constants. */
15393 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
15395 tree rcond = fold_relational_const (code, type,
15396 TREE_REALPART (op0),
15397 TREE_REALPART (op1));
15398 tree icond = fold_relational_const (code, type,
15399 TREE_IMAGPART (op0),
15400 TREE_IMAGPART (op1));
15401 if (code == EQ_EXPR)
15402 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
15403 else if (code == NE_EXPR)
15404 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
15409 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
15411 To compute GT, swap the arguments and do LT.
15412 To compute GE, do LT and invert the result.
15413 To compute LE, swap the arguments, do LT and invert the result.
15414 To compute NE, do EQ and invert the result.
15416 Therefore, the code below must handle only EQ and LT. */
15418 if (code == LE_EXPR || code == GT_EXPR)
15423 code = swap_tree_comparison (code);
15426 /* Note that it is safe to invert for real values here because we
15427 have already handled the one case that it matters. */
15430 if (code == NE_EXPR || code == GE_EXPR)
15433 code = invert_tree_comparison (code, false);
15436 /* Compute a result for LT or EQ if args permit;
15437 Otherwise return T. */
15438 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
15440 if (code == EQ_EXPR)
15441 result = tree_int_cst_equal (op0, op1);
15442 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
15443 result = INT_CST_LT_UNSIGNED (op0, op1);
15445 result = INT_CST_LT (op0, op1);
15452 return constant_boolean_node (result, type);
15455 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
15456 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
15460 fold_build_cleanup_point_expr (tree type, tree expr)
15462 /* If the expression does not have side effects then we don't have to wrap
15463 it with a cleanup point expression. */
15464 if (!TREE_SIDE_EFFECTS (expr))
15467 /* If the expression is a return, check to see if the expression inside the
15468 return has no side effects or the right hand side of the modify expression
15469 inside the return. If either don't have side effects set we don't need to
15470 wrap the expression in a cleanup point expression. Note we don't check the
15471 left hand side of the modify because it should always be a return decl. */
15472 if (TREE_CODE (expr) == RETURN_EXPR)
15474 tree op = TREE_OPERAND (expr, 0);
15475 if (!op || !TREE_SIDE_EFFECTS (op))
15477 op = TREE_OPERAND (op, 1);
15478 if (!TREE_SIDE_EFFECTS (op))
15482 return build1 (CLEANUP_POINT_EXPR, type, expr);
15485 /* Given a pointer value OP0 and a type TYPE, return a simplified version
15486 of an indirection through OP0, or NULL_TREE if no simplification is
15490 fold_indirect_ref_1 (tree type, tree op0)
15496 subtype = TREE_TYPE (sub);
15497 if (!POINTER_TYPE_P (subtype))
15500 if (TREE_CODE (sub) == ADDR_EXPR)
15502 tree op = TREE_OPERAND (sub, 0);
15503 tree optype = TREE_TYPE (op);
15504 /* *&CONST_DECL -> to the value of the const decl. */
15505 if (TREE_CODE (op) == CONST_DECL)
15506 return DECL_INITIAL (op);
15507 /* *&p => p; make sure to handle *&"str"[cst] here. */
15508 if (type == optype)
15510 tree fop = fold_read_from_constant_string (op);
15516 /* *(foo *)&fooarray => fooarray[0] */
15517 else if (TREE_CODE (optype) == ARRAY_TYPE
15518 && type == TREE_TYPE (optype))
15520 tree type_domain = TYPE_DOMAIN (optype);
15521 tree min_val = size_zero_node;
15522 if (type_domain && TYPE_MIN_VALUE (type_domain))
15523 min_val = TYPE_MIN_VALUE (type_domain);
15524 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
15526 /* *(foo *)&complexfoo => __real__ complexfoo */
15527 else if (TREE_CODE (optype) == COMPLEX_TYPE
15528 && type == TREE_TYPE (optype))
15529 return fold_build1 (REALPART_EXPR, type, op);
15530 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
15531 else if (TREE_CODE (optype) == VECTOR_TYPE
15532 && type == TREE_TYPE (optype))
15534 tree part_width = TYPE_SIZE (type);
15535 tree index = bitsize_int (0);
15536 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
15540 /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
15541 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15542 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15544 tree op00 = TREE_OPERAND (sub, 0);
15545 tree op01 = TREE_OPERAND (sub, 1);
15549 op00type = TREE_TYPE (op00);
15550 if (TREE_CODE (op00) == ADDR_EXPR
15551 && TREE_CODE (TREE_TYPE (op00type)) == VECTOR_TYPE
15552 && type == TREE_TYPE (TREE_TYPE (op00type)))
15554 HOST_WIDE_INT offset = tree_low_cst (op01, 0);
15555 tree part_width = TYPE_SIZE (type);
15556 unsigned HOST_WIDE_INT part_widthi = tree_low_cst (part_width, 0)/BITS_PER_UNIT;
15557 unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
15558 tree index = bitsize_int (indexi);
15560 if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (op00type)))
15561 return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (op00, 0),
15562 part_width, index);
15568 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
15569 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15570 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15572 tree op00 = TREE_OPERAND (sub, 0);
15573 tree op01 = TREE_OPERAND (sub, 1);
15577 op00type = TREE_TYPE (op00);
15578 if (TREE_CODE (op00) == ADDR_EXPR
15579 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
15580 && type == TREE_TYPE (TREE_TYPE (op00type)))
15582 tree size = TYPE_SIZE_UNIT (type);
15583 if (tree_int_cst_equal (size, op01))
15584 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
15588 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
15589 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
15590 && type == TREE_TYPE (TREE_TYPE (subtype)))
15593 tree min_val = size_zero_node;
15594 sub = build_fold_indirect_ref (sub);
15595 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
15596 if (type_domain && TYPE_MIN_VALUE (type_domain))
15597 min_val = TYPE_MIN_VALUE (type_domain);
15598 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
15604 /* Builds an expression for an indirection through T, simplifying some
15608 build_fold_indirect_ref (tree t)
15610 tree type = TREE_TYPE (TREE_TYPE (t));
15611 tree sub = fold_indirect_ref_1 (type, t);
15616 return build1 (INDIRECT_REF, type, t);
15619 /* Given an INDIRECT_REF T, return either T or a simplified version. */
15622 fold_indirect_ref (tree t)
15624 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
15632 /* Strip non-trapping, non-side-effecting tree nodes from an expression
15633 whose result is ignored. The type of the returned tree need not be
15634 the same as the original expression. */
15637 fold_ignored_result (tree t)
15639 if (!TREE_SIDE_EFFECTS (t))
15640 return integer_zero_node;
15643 switch (TREE_CODE_CLASS (TREE_CODE (t)))
15646 t = TREE_OPERAND (t, 0);
15650 case tcc_comparison:
15651 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15652 t = TREE_OPERAND (t, 0);
15653 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
15654 t = TREE_OPERAND (t, 1);
15659 case tcc_expression:
15660 switch (TREE_CODE (t))
15662 case COMPOUND_EXPR:
15663 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15665 t = TREE_OPERAND (t, 0);
15669 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
15670 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
15672 t = TREE_OPERAND (t, 0);
15685 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
15686 This can only be applied to objects of a sizetype. */
15689 round_up (tree value, int divisor)
15691 tree div = NULL_TREE;
15693 gcc_assert (divisor > 0);
15697 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15698 have to do anything. Only do this when we are not given a const,
15699 because in that case, this check is more expensive than just
15701 if (TREE_CODE (value) != INTEGER_CST)
15703 div = build_int_cst (TREE_TYPE (value), divisor);
15705 if (multiple_of_p (TREE_TYPE (value), value, div))
15709 /* If divisor is a power of two, simplify this to bit manipulation. */
15710 if (divisor == (divisor & -divisor))
15712 if (TREE_CODE (value) == INTEGER_CST)
15714 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
15715 unsigned HOST_WIDE_INT high;
15718 if ((low & (divisor - 1)) == 0)
15721 overflow_p = TREE_OVERFLOW (value);
15722 high = TREE_INT_CST_HIGH (value);
15723 low &= ~(divisor - 1);
15732 return force_fit_type_double (TREE_TYPE (value), low, high,
15739 t = build_int_cst (TREE_TYPE (value), divisor - 1);
15740 value = size_binop (PLUS_EXPR, value, t);
15741 t = build_int_cst (TREE_TYPE (value), -divisor);
15742 value = size_binop (BIT_AND_EXPR, value, t);
15748 div = build_int_cst (TREE_TYPE (value), divisor);
15749 value = size_binop (CEIL_DIV_EXPR, value, div);
15750 value = size_binop (MULT_EXPR, value, div);
15756 /* Likewise, but round down. */
15759 round_down (tree value, int divisor)
15761 tree div = NULL_TREE;
15763 gcc_assert (divisor > 0);
15767 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15768 have to do anything. Only do this when we are not given a const,
15769 because in that case, this check is more expensive than just
15771 if (TREE_CODE (value) != INTEGER_CST)
15773 div = build_int_cst (TREE_TYPE (value), divisor);
15775 if (multiple_of_p (TREE_TYPE (value), value, div))
15779 /* If divisor is a power of two, simplify this to bit manipulation. */
15780 if (divisor == (divisor & -divisor))
15784 t = build_int_cst (TREE_TYPE (value), -divisor);
15785 value = size_binop (BIT_AND_EXPR, value, t);
15790 div = build_int_cst (TREE_TYPE (value), divisor);
15791 value = size_binop (FLOOR_DIV_EXPR, value, div);
15792 value = size_binop (MULT_EXPR, value, div);
15798 /* Returns the pointer to the base of the object addressed by EXP and
15799 extracts the information about the offset of the access, storing it
15800 to PBITPOS and POFFSET. */
15803 split_address_to_core_and_offset (tree exp,
15804 HOST_WIDE_INT *pbitpos, tree *poffset)
15807 enum machine_mode mode;
15808 int unsignedp, volatilep;
15809 HOST_WIDE_INT bitsize;
15811 if (TREE_CODE (exp) == ADDR_EXPR)
15813 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
15814 poffset, &mode, &unsignedp, &volatilep,
15816 core = fold_addr_expr (core);
15822 *poffset = NULL_TREE;
15828 /* Returns true if addresses of E1 and E2 differ by a constant, false
15829 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15832 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
15835 HOST_WIDE_INT bitpos1, bitpos2;
15836 tree toffset1, toffset2, tdiff, type;
15838 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
15839 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
15841 if (bitpos1 % BITS_PER_UNIT != 0
15842 || bitpos2 % BITS_PER_UNIT != 0
15843 || !operand_equal_p (core1, core2, 0))
15846 if (toffset1 && toffset2)
15848 type = TREE_TYPE (toffset1);
15849 if (type != TREE_TYPE (toffset2))
15850 toffset2 = fold_convert (type, toffset2);
15852 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
15853 if (!cst_and_fits_in_hwi (tdiff))
15856 *diff = int_cst_value (tdiff);
15858 else if (toffset1 || toffset2)
15860 /* If only one of the offsets is non-constant, the difference cannot
15867 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
15871 /* Simplify the floating point expression EXP when the sign of the
15872 result is not significant. Return NULL_TREE if no simplification
15876 fold_strip_sign_ops (tree exp)
15880 switch (TREE_CODE (exp))
15884 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15885 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
15889 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
15891 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15892 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15893 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
15894 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
15895 arg0 ? arg0 : TREE_OPERAND (exp, 0),
15896 arg1 ? arg1 : TREE_OPERAND (exp, 1));
15899 case COMPOUND_EXPR:
15900 arg0 = TREE_OPERAND (exp, 0);
15901 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15903 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
15907 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15908 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
15910 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
15911 arg0 ? arg0 : TREE_OPERAND (exp, 1),
15912 arg1 ? arg1 : TREE_OPERAND (exp, 2));
15917 const enum built_in_function fcode = builtin_mathfn_code (exp);
15920 CASE_FLT_FN (BUILT_IN_COPYSIGN):
15921 /* Strip copysign function call, return the 1st argument. */
15922 arg0 = CALL_EXPR_ARG (exp, 0);
15923 arg1 = CALL_EXPR_ARG (exp, 1);
15924 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
15927 /* Strip sign ops from the argument of "odd" math functions. */
15928 if (negate_mathfn_p (fcode))
15930 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
15932 return build_call_expr (get_callee_fndecl (exp), 1, arg0);