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
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"
65 #include "langhooks.h"
68 /* Nonzero if we are folding constants inside an initializer; zero
70 int folding_initializer = 0;
72 /* The following constants represent a bit based encoding of GCC's
73 comparison operators. This encoding simplifies transformations
74 on relational comparison operators, such as AND and OR. */
75 enum comparison_code {
94 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
95 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
96 static bool negate_mathfn_p (enum built_in_function);
97 static bool negate_expr_p (tree);
98 static tree negate_expr (tree);
99 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
100 static tree associate_trees (tree, tree, enum tree_code, tree);
101 static tree const_binop (enum tree_code, tree, tree, int);
102 static enum comparison_code comparison_to_compcode (enum tree_code);
103 static enum tree_code compcode_to_comparison (enum comparison_code);
104 static tree combine_comparisons (enum tree_code, enum tree_code,
105 enum tree_code, tree, tree, tree);
106 static int truth_value_p (enum tree_code);
107 static int operand_equal_for_comparison_p (tree, tree, tree);
108 static int twoval_comparison_p (tree, tree *, tree *, int *);
109 static tree eval_subst (tree, tree, tree, tree, tree);
110 static tree pedantic_omit_one_operand (tree, tree, tree);
111 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
112 static tree make_bit_field_ref (tree, tree, int, int, int);
113 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
114 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
115 enum machine_mode *, int *, int *,
117 static int all_ones_mask_p (const_tree, int);
118 static tree sign_bit_p (tree, const_tree);
119 static int simple_operand_p (const_tree);
120 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
121 static tree range_predecessor (tree);
122 static tree range_successor (tree);
123 static tree make_range (tree, int *, tree *, tree *, bool *);
124 static tree build_range_check (tree, tree, int, tree, tree);
125 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
127 static tree fold_range_test (enum tree_code, tree, tree, tree);
128 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
129 static tree unextend (tree, int, int, tree);
130 static tree fold_truthop (enum tree_code, tree, tree, tree);
131 static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
132 static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
133 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
134 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
137 static bool fold_real_zero_addition_p (const_tree, const_tree, int);
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)) */
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_tree 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 (stmt != NULL_TREE && TREE_NO_WARNING (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))
988 if (stmt == NULL_TREE || !expr_has_location (stmt))
989 locus = input_location;
991 locus = expr_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_TREE, 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 gcc_assert (!flag_wrapv && !flag_trapv);
1019 if (fold_deferring_overflow_warnings > 0)
1021 if (fold_deferred_overflow_warning == NULL
1022 || wc < fold_deferred_overflow_code)
1024 fold_deferred_overflow_warning = gmsgid;
1025 fold_deferred_overflow_code = wc;
1028 else if (issue_strict_overflow_warning (wc))
1029 warning (OPT_Wstrict_overflow, gmsgid);
1032 /* Return true if the built-in mathematical function specified by CODE
1033 is odd, i.e. -f(x) == f(-x). */
1036 negate_mathfn_p (enum built_in_function code)
1040 CASE_FLT_FN (BUILT_IN_ASIN):
1041 CASE_FLT_FN (BUILT_IN_ASINH):
1042 CASE_FLT_FN (BUILT_IN_ATAN):
1043 CASE_FLT_FN (BUILT_IN_ATANH):
1044 CASE_FLT_FN (BUILT_IN_CASIN):
1045 CASE_FLT_FN (BUILT_IN_CASINH):
1046 CASE_FLT_FN (BUILT_IN_CATAN):
1047 CASE_FLT_FN (BUILT_IN_CATANH):
1048 CASE_FLT_FN (BUILT_IN_CBRT):
1049 CASE_FLT_FN (BUILT_IN_CPROJ):
1050 CASE_FLT_FN (BUILT_IN_CSIN):
1051 CASE_FLT_FN (BUILT_IN_CSINH):
1052 CASE_FLT_FN (BUILT_IN_CTAN):
1053 CASE_FLT_FN (BUILT_IN_CTANH):
1054 CASE_FLT_FN (BUILT_IN_ERF):
1055 CASE_FLT_FN (BUILT_IN_LLROUND):
1056 CASE_FLT_FN (BUILT_IN_LROUND):
1057 CASE_FLT_FN (BUILT_IN_ROUND):
1058 CASE_FLT_FN (BUILT_IN_SIN):
1059 CASE_FLT_FN (BUILT_IN_SINH):
1060 CASE_FLT_FN (BUILT_IN_TAN):
1061 CASE_FLT_FN (BUILT_IN_TANH):
1062 CASE_FLT_FN (BUILT_IN_TRUNC):
1065 CASE_FLT_FN (BUILT_IN_LLRINT):
1066 CASE_FLT_FN (BUILT_IN_LRINT):
1067 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1068 CASE_FLT_FN (BUILT_IN_RINT):
1069 return !flag_rounding_math;
1077 /* Check whether we may negate an integer constant T without causing
1081 may_negate_without_overflow_p (const_tree t)
1083 unsigned HOST_WIDE_INT val;
1087 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1089 type = TREE_TYPE (t);
1090 if (TYPE_UNSIGNED (type))
1093 prec = TYPE_PRECISION (type);
1094 if (prec > HOST_BITS_PER_WIDE_INT)
1096 if (TREE_INT_CST_LOW (t) != 0)
1098 prec -= HOST_BITS_PER_WIDE_INT;
1099 val = TREE_INT_CST_HIGH (t);
1102 val = TREE_INT_CST_LOW (t);
1103 if (prec < HOST_BITS_PER_WIDE_INT)
1104 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1105 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1108 /* Determine whether an expression T can be cheaply negated using
1109 the function negate_expr without introducing undefined overflow. */
1112 negate_expr_p (tree t)
1119 type = TREE_TYPE (t);
1121 STRIP_SIGN_NOPS (t);
1122 switch (TREE_CODE (t))
1125 if (TYPE_OVERFLOW_WRAPS (type))
1128 /* Check that -CST will not overflow type. */
1129 return may_negate_without_overflow_p (t);
1131 return (INTEGRAL_TYPE_P (type)
1132 && TYPE_OVERFLOW_WRAPS (type));
1140 return negate_expr_p (TREE_REALPART (t))
1141 && negate_expr_p (TREE_IMAGPART (t));
1144 return negate_expr_p (TREE_OPERAND (t, 0))
1145 && negate_expr_p (TREE_OPERAND (t, 1));
1148 return negate_expr_p (TREE_OPERAND (t, 0));
1151 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1152 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1154 /* -(A + B) -> (-B) - A. */
1155 if (negate_expr_p (TREE_OPERAND (t, 1))
1156 && reorder_operands_p (TREE_OPERAND (t, 0),
1157 TREE_OPERAND (t, 1)))
1159 /* -(A + B) -> (-A) - B. */
1160 return negate_expr_p (TREE_OPERAND (t, 0));
1163 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1164 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1165 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1166 && reorder_operands_p (TREE_OPERAND (t, 0),
1167 TREE_OPERAND (t, 1));
1170 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1176 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1177 return negate_expr_p (TREE_OPERAND (t, 1))
1178 || negate_expr_p (TREE_OPERAND (t, 0));
1181 case TRUNC_DIV_EXPR:
1182 case ROUND_DIV_EXPR:
1183 case FLOOR_DIV_EXPR:
1185 case EXACT_DIV_EXPR:
1186 /* In general we can't negate A / B, because if A is INT_MIN and
1187 B is 1, we may turn this into INT_MIN / -1 which is undefined
1188 and actually traps on some architectures. But if overflow is
1189 undefined, we can negate, because - (INT_MIN / 1) is an
1191 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1192 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1194 return negate_expr_p (TREE_OPERAND (t, 1))
1195 || negate_expr_p (TREE_OPERAND (t, 0));
1198 /* Negate -((double)float) as (double)(-float). */
1199 if (TREE_CODE (type) == REAL_TYPE)
1201 tree tem = strip_float_extensions (t);
1203 return negate_expr_p (tem);
1208 /* Negate -f(x) as f(-x). */
1209 if (negate_mathfn_p (builtin_mathfn_code (t)))
1210 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1214 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1215 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1217 tree op1 = TREE_OPERAND (t, 1);
1218 if (TREE_INT_CST_HIGH (op1) == 0
1219 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1220 == TREE_INT_CST_LOW (op1))
1231 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1232 simplification is possible.
1233 If negate_expr_p would return true for T, NULL_TREE will never be
1237 fold_negate_expr (tree t)
1239 tree type = TREE_TYPE (t);
1242 switch (TREE_CODE (t))
1244 /* Convert - (~A) to A + 1. */
1246 if (INTEGRAL_TYPE_P (type))
1247 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1248 build_int_cst (type, 1));
1252 tem = fold_negate_const (t, type);
1253 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1254 || !TYPE_OVERFLOW_TRAPS (type))
1259 tem = fold_negate_const (t, type);
1260 /* Two's complement FP formats, such as c4x, may overflow. */
1261 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1266 tem = fold_negate_const (t, type);
1271 tree rpart = negate_expr (TREE_REALPART (t));
1272 tree ipart = negate_expr (TREE_IMAGPART (t));
1274 if ((TREE_CODE (rpart) == REAL_CST
1275 && TREE_CODE (ipart) == REAL_CST)
1276 || (TREE_CODE (rpart) == INTEGER_CST
1277 && TREE_CODE (ipart) == INTEGER_CST))
1278 return build_complex (type, rpart, ipart);
1283 if (negate_expr_p (t))
1284 return fold_build2 (COMPLEX_EXPR, type,
1285 fold_negate_expr (TREE_OPERAND (t, 0)),
1286 fold_negate_expr (TREE_OPERAND (t, 1)));
1290 if (negate_expr_p (t))
1291 return fold_build1 (CONJ_EXPR, type,
1292 fold_negate_expr (TREE_OPERAND (t, 0)));
1296 return TREE_OPERAND (t, 0);
1299 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1300 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1302 /* -(A + B) -> (-B) - A. */
1303 if (negate_expr_p (TREE_OPERAND (t, 1))
1304 && reorder_operands_p (TREE_OPERAND (t, 0),
1305 TREE_OPERAND (t, 1)))
1307 tem = negate_expr (TREE_OPERAND (t, 1));
1308 return fold_build2 (MINUS_EXPR, type,
1309 tem, TREE_OPERAND (t, 0));
1312 /* -(A + B) -> (-A) - B. */
1313 if (negate_expr_p (TREE_OPERAND (t, 0)))
1315 tem = negate_expr (TREE_OPERAND (t, 0));
1316 return fold_build2 (MINUS_EXPR, type,
1317 tem, TREE_OPERAND (t, 1));
1323 /* - (A - B) -> B - A */
1324 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1325 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1326 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1327 return fold_build2 (MINUS_EXPR, type,
1328 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1332 if (TYPE_UNSIGNED (type))
1338 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1340 tem = TREE_OPERAND (t, 1);
1341 if (negate_expr_p (tem))
1342 return fold_build2 (TREE_CODE (t), type,
1343 TREE_OPERAND (t, 0), negate_expr (tem));
1344 tem = TREE_OPERAND (t, 0);
1345 if (negate_expr_p (tem))
1346 return fold_build2 (TREE_CODE (t), type,
1347 negate_expr (tem), TREE_OPERAND (t, 1));
1351 case TRUNC_DIV_EXPR:
1352 case ROUND_DIV_EXPR:
1353 case FLOOR_DIV_EXPR:
1355 case EXACT_DIV_EXPR:
1356 /* In general we can't negate A / B, because if A is INT_MIN and
1357 B is 1, we may turn this into INT_MIN / -1 which is undefined
1358 and actually traps on some architectures. But if overflow is
1359 undefined, we can negate, because - (INT_MIN / 1) is an
1361 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1363 const char * const warnmsg = G_("assuming signed overflow does not "
1364 "occur when negating a division");
1365 tem = TREE_OPERAND (t, 1);
1366 if (negate_expr_p (tem))
1368 if (INTEGRAL_TYPE_P (type)
1369 && (TREE_CODE (tem) != INTEGER_CST
1370 || integer_onep (tem)))
1371 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1372 return fold_build2 (TREE_CODE (t), type,
1373 TREE_OPERAND (t, 0), negate_expr (tem));
1375 tem = TREE_OPERAND (t, 0);
1376 if (negate_expr_p (tem))
1378 if (INTEGRAL_TYPE_P (type)
1379 && (TREE_CODE (tem) != INTEGER_CST
1380 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1381 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1382 return fold_build2 (TREE_CODE (t), type,
1383 negate_expr (tem), TREE_OPERAND (t, 1));
1389 /* Convert -((double)float) into (double)(-float). */
1390 if (TREE_CODE (type) == REAL_TYPE)
1392 tem = strip_float_extensions (t);
1393 if (tem != t && negate_expr_p (tem))
1394 return fold_convert (type, negate_expr (tem));
1399 /* Negate -f(x) as f(-x). */
1400 if (negate_mathfn_p (builtin_mathfn_code (t))
1401 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1405 fndecl = get_callee_fndecl (t);
1406 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1407 return build_call_expr (fndecl, 1, arg);
1412 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1413 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1415 tree op1 = TREE_OPERAND (t, 1);
1416 if (TREE_INT_CST_HIGH (op1) == 0
1417 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1418 == TREE_INT_CST_LOW (op1))
1420 tree ntype = TYPE_UNSIGNED (type)
1421 ? signed_type_for (type)
1422 : unsigned_type_for (type);
1423 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1424 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1425 return fold_convert (type, temp);
1437 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1438 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1439 return NULL_TREE. */
1442 negate_expr (tree t)
1449 type = TREE_TYPE (t);
1450 STRIP_SIGN_NOPS (t);
1452 tem = fold_negate_expr (t);
1454 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1455 return fold_convert (type, tem);
1458 /* Split a tree IN into a constant, literal and variable parts that could be
1459 combined with CODE to make IN. "constant" means an expression with
1460 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1461 commutative arithmetic operation. Store the constant part into *CONP,
1462 the literal in *LITP and return the variable part. If a part isn't
1463 present, set it to null. If the tree does not decompose in this way,
1464 return the entire tree as the variable part and the other parts as null.
1466 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1467 case, we negate an operand that was subtracted. Except if it is a
1468 literal for which we use *MINUS_LITP instead.
1470 If NEGATE_P is true, we are negating all of IN, again except a literal
1471 for which we use *MINUS_LITP instead.
1473 If IN is itself a literal or constant, return it as appropriate.
1475 Note that we do not guarantee that any of the three values will be the
1476 same type as IN, but they will have the same signedness and mode. */
1479 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1480 tree *minus_litp, int negate_p)
1488 /* Strip any conversions that don't change the machine mode or signedness. */
1489 STRIP_SIGN_NOPS (in);
1491 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
1492 || TREE_CODE (in) == FIXED_CST)
1494 else if (TREE_CODE (in) == code
1495 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1496 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
1497 /* We can associate addition and subtraction together (even
1498 though the C standard doesn't say so) for integers because
1499 the value is not affected. For reals, the value might be
1500 affected, so we can't. */
1501 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1502 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1504 tree op0 = TREE_OPERAND (in, 0);
1505 tree op1 = TREE_OPERAND (in, 1);
1506 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1507 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1509 /* First see if either of the operands is a literal, then a constant. */
1510 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
1511 || TREE_CODE (op0) == FIXED_CST)
1512 *litp = op0, op0 = 0;
1513 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
1514 || TREE_CODE (op1) == FIXED_CST)
1515 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1517 if (op0 != 0 && TREE_CONSTANT (op0))
1518 *conp = op0, op0 = 0;
1519 else if (op1 != 0 && TREE_CONSTANT (op1))
1520 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1522 /* If we haven't dealt with either operand, this is not a case we can
1523 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1524 if (op0 != 0 && op1 != 0)
1529 var = op1, neg_var_p = neg1_p;
1531 /* Now do any needed negations. */
1533 *minus_litp = *litp, *litp = 0;
1535 *conp = negate_expr (*conp);
1537 var = negate_expr (var);
1539 else if (TREE_CONSTANT (in))
1547 *minus_litp = *litp, *litp = 0;
1548 else if (*minus_litp)
1549 *litp = *minus_litp, *minus_litp = 0;
1550 *conp = negate_expr (*conp);
1551 var = negate_expr (var);
1557 /* Re-associate trees split by the above function. T1 and T2 are either
1558 expressions to associate or null. Return the new expression, if any. If
1559 we build an operation, do it in TYPE and with CODE. */
1562 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1569 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1570 try to fold this since we will have infinite recursion. But do
1571 deal with any NEGATE_EXPRs. */
1572 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1573 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1575 if (code == PLUS_EXPR)
1577 if (TREE_CODE (t1) == NEGATE_EXPR)
1578 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1579 fold_convert (type, TREE_OPERAND (t1, 0)));
1580 else if (TREE_CODE (t2) == NEGATE_EXPR)
1581 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1582 fold_convert (type, TREE_OPERAND (t2, 0)));
1583 else if (integer_zerop (t2))
1584 return fold_convert (type, t1);
1586 else if (code == MINUS_EXPR)
1588 if (integer_zerop (t2))
1589 return fold_convert (type, t1);
1592 return build2 (code, type, fold_convert (type, t1),
1593 fold_convert (type, t2));
1596 return fold_build2 (code, type, fold_convert (type, t1),
1597 fold_convert (type, t2));
1600 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1601 for use in int_const_binop, size_binop and size_diffop. */
1604 int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
1606 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1608 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1623 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1624 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1625 && TYPE_MODE (type1) == TYPE_MODE (type2);
1629 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1630 to produce a new constant. Return NULL_TREE if we don't know how
1631 to evaluate CODE at compile-time.
1633 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1636 int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2, int notrunc)
1638 unsigned HOST_WIDE_INT int1l, int2l;
1639 HOST_WIDE_INT int1h, int2h;
1640 unsigned HOST_WIDE_INT low;
1642 unsigned HOST_WIDE_INT garbagel;
1643 HOST_WIDE_INT garbageh;
1645 tree type = TREE_TYPE (arg1);
1646 int uns = TYPE_UNSIGNED (type);
1648 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1651 int1l = TREE_INT_CST_LOW (arg1);
1652 int1h = TREE_INT_CST_HIGH (arg1);
1653 int2l = TREE_INT_CST_LOW (arg2);
1654 int2h = TREE_INT_CST_HIGH (arg2);
1659 low = int1l | int2l, hi = int1h | int2h;
1663 low = int1l ^ int2l, hi = int1h ^ int2h;
1667 low = int1l & int2l, hi = int1h & int2h;
1673 /* It's unclear from the C standard whether shifts can overflow.
1674 The following code ignores overflow; perhaps a C standard
1675 interpretation ruling is needed. */
1676 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1683 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1688 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1692 neg_double (int2l, int2h, &low, &hi);
1693 add_double (int1l, int1h, low, hi, &low, &hi);
1694 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1698 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1701 case TRUNC_DIV_EXPR:
1702 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1703 case EXACT_DIV_EXPR:
1704 /* This is a shortcut for a common special case. */
1705 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1706 && !TREE_OVERFLOW (arg1)
1707 && !TREE_OVERFLOW (arg2)
1708 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1710 if (code == CEIL_DIV_EXPR)
1713 low = int1l / int2l, hi = 0;
1717 /* ... fall through ... */
1719 case ROUND_DIV_EXPR:
1720 if (int2h == 0 && int2l == 0)
1722 if (int2h == 0 && int2l == 1)
1724 low = int1l, hi = int1h;
1727 if (int1l == int2l && int1h == int2h
1728 && ! (int1l == 0 && int1h == 0))
1733 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1734 &low, &hi, &garbagel, &garbageh);
1737 case TRUNC_MOD_EXPR:
1738 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1739 /* This is a shortcut for a common special case. */
1740 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1741 && !TREE_OVERFLOW (arg1)
1742 && !TREE_OVERFLOW (arg2)
1743 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1745 if (code == CEIL_MOD_EXPR)
1747 low = int1l % int2l, hi = 0;
1751 /* ... fall through ... */
1753 case ROUND_MOD_EXPR:
1754 if (int2h == 0 && int2l == 0)
1756 overflow = div_and_round_double (code, uns,
1757 int1l, int1h, int2l, int2h,
1758 &garbagel, &garbageh, &low, &hi);
1764 low = (((unsigned HOST_WIDE_INT) int1h
1765 < (unsigned HOST_WIDE_INT) int2h)
1766 || (((unsigned HOST_WIDE_INT) int1h
1767 == (unsigned HOST_WIDE_INT) int2h)
1770 low = (int1h < int2h
1771 || (int1h == int2h && int1l < int2l));
1773 if (low == (code == MIN_EXPR))
1774 low = int1l, hi = int1h;
1776 low = int2l, hi = int2h;
1785 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1787 /* Propagate overflow flags ourselves. */
1788 if (((!uns || is_sizetype) && overflow)
1789 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1792 TREE_OVERFLOW (t) = 1;
1796 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1797 ((!uns || is_sizetype) && overflow)
1798 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1803 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1804 constant. We assume ARG1 and ARG2 have the same data type, or at least
1805 are the same kind of constant and the same machine mode. Return zero if
1806 combining the constants is not allowed in the current operating mode.
1808 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1811 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1813 /* Sanity check for the recursive cases. */
1820 if (TREE_CODE (arg1) == INTEGER_CST)
1821 return int_const_binop (code, arg1, arg2, notrunc);
1823 if (TREE_CODE (arg1) == REAL_CST)
1825 enum machine_mode mode;
1828 REAL_VALUE_TYPE value;
1829 REAL_VALUE_TYPE result;
1833 /* The following codes are handled by real_arithmetic. */
1848 d1 = TREE_REAL_CST (arg1);
1849 d2 = TREE_REAL_CST (arg2);
1851 type = TREE_TYPE (arg1);
1852 mode = TYPE_MODE (type);
1854 /* Don't perform operation if we honor signaling NaNs and
1855 either operand is a NaN. */
1856 if (HONOR_SNANS (mode)
1857 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1860 /* Don't perform operation if it would raise a division
1861 by zero exception. */
1862 if (code == RDIV_EXPR
1863 && REAL_VALUES_EQUAL (d2, dconst0)
1864 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1867 /* If either operand is a NaN, just return it. Otherwise, set up
1868 for floating-point trap; we return an overflow. */
1869 if (REAL_VALUE_ISNAN (d1))
1871 else if (REAL_VALUE_ISNAN (d2))
1874 inexact = real_arithmetic (&value, code, &d1, &d2);
1875 real_convert (&result, mode, &value);
1877 /* Don't constant fold this floating point operation if
1878 the result has overflowed and flag_trapping_math. */
1879 if (flag_trapping_math
1880 && MODE_HAS_INFINITIES (mode)
1881 && REAL_VALUE_ISINF (result)
1882 && !REAL_VALUE_ISINF (d1)
1883 && !REAL_VALUE_ISINF (d2))
1886 /* Don't constant fold this floating point operation if the
1887 result may dependent upon the run-time rounding mode and
1888 flag_rounding_math is set, or if GCC's software emulation
1889 is unable to accurately represent the result. */
1890 if ((flag_rounding_math
1891 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1892 && !flag_unsafe_math_optimizations))
1893 && (inexact || !real_identical (&result, &value)))
1896 t = build_real (type, result);
1898 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1902 if (TREE_CODE (arg1) == FIXED_CST)
1904 FIXED_VALUE_TYPE f1;
1905 FIXED_VALUE_TYPE f2;
1906 FIXED_VALUE_TYPE result;
1911 /* The following codes are handled by fixed_arithmetic. */
1917 case TRUNC_DIV_EXPR:
1918 f2 = TREE_FIXED_CST (arg2);
1923 f2.data.high = TREE_INT_CST_HIGH (arg2);
1924 f2.data.low = TREE_INT_CST_LOW (arg2);
1932 f1 = TREE_FIXED_CST (arg1);
1933 type = TREE_TYPE (arg1);
1934 sat_p = TYPE_SATURATING (type);
1935 overflow_p = fixed_arithmetic (&result, code, &f1, &f2, sat_p);
1936 t = build_fixed (type, result);
1937 /* Propagate overflow flags. */
1938 if (overflow_p | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1940 TREE_OVERFLOW (t) = 1;
1941 TREE_CONSTANT_OVERFLOW (t) = 1;
1943 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1944 TREE_CONSTANT_OVERFLOW (t) = 1;
1948 if (TREE_CODE (arg1) == COMPLEX_CST)
1950 tree type = TREE_TYPE (arg1);
1951 tree r1 = TREE_REALPART (arg1);
1952 tree i1 = TREE_IMAGPART (arg1);
1953 tree r2 = TREE_REALPART (arg2);
1954 tree i2 = TREE_IMAGPART (arg2);
1961 real = const_binop (code, r1, r2, notrunc);
1962 imag = const_binop (code, i1, i2, notrunc);
1966 real = const_binop (MINUS_EXPR,
1967 const_binop (MULT_EXPR, r1, r2, notrunc),
1968 const_binop (MULT_EXPR, i1, i2, notrunc),
1970 imag = const_binop (PLUS_EXPR,
1971 const_binop (MULT_EXPR, r1, i2, notrunc),
1972 const_binop (MULT_EXPR, i1, r2, notrunc),
1979 = const_binop (PLUS_EXPR,
1980 const_binop (MULT_EXPR, r2, r2, notrunc),
1981 const_binop (MULT_EXPR, i2, i2, notrunc),
1984 = const_binop (PLUS_EXPR,
1985 const_binop (MULT_EXPR, r1, r2, notrunc),
1986 const_binop (MULT_EXPR, i1, i2, notrunc),
1989 = const_binop (MINUS_EXPR,
1990 const_binop (MULT_EXPR, i1, r2, notrunc),
1991 const_binop (MULT_EXPR, r1, i2, notrunc),
1994 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1995 code = TRUNC_DIV_EXPR;
1997 real = const_binop (code, t1, magsquared, notrunc);
1998 imag = const_binop (code, t2, magsquared, notrunc);
2007 return build_complex (type, real, imag);
2013 /* Create a size type INT_CST node with NUMBER sign extended. KIND
2014 indicates which particular sizetype to create. */
2017 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
2019 return build_int_cst (sizetype_tab[(int) kind], number);
2022 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2023 is a tree code. The type of the result is taken from the operands.
2024 Both must be equivalent integer types, ala int_binop_types_match_p.
2025 If the operands are constant, so is the result. */
2028 size_binop (enum tree_code code, tree arg0, tree arg1)
2030 tree type = TREE_TYPE (arg0);
2032 if (arg0 == error_mark_node || arg1 == error_mark_node)
2033 return error_mark_node;
2035 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
2038 /* Handle the special case of two integer constants faster. */
2039 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
2041 /* And some specific cases even faster than that. */
2042 if (code == PLUS_EXPR)
2044 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
2046 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2049 else if (code == MINUS_EXPR)
2051 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2054 else if (code == MULT_EXPR)
2056 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
2060 /* Handle general case of two integer constants. */
2061 return int_const_binop (code, arg0, arg1, 0);
2064 return fold_build2 (code, type, arg0, arg1);
2067 /* Given two values, either both of sizetype or both of bitsizetype,
2068 compute the difference between the two values. Return the value
2069 in signed type corresponding to the type of the operands. */
2072 size_diffop (tree arg0, tree arg1)
2074 tree type = TREE_TYPE (arg0);
2077 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
2080 /* If the type is already signed, just do the simple thing. */
2081 if (!TYPE_UNSIGNED (type))
2082 return size_binop (MINUS_EXPR, arg0, arg1);
2084 if (type == sizetype)
2086 else if (type == bitsizetype)
2087 ctype = sbitsizetype;
2089 ctype = signed_type_for (type);
2091 /* If either operand is not a constant, do the conversions to the signed
2092 type and subtract. The hardware will do the right thing with any
2093 overflow in the subtraction. */
2094 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2095 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
2096 fold_convert (ctype, arg1));
2098 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2099 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2100 overflow) and negate (which can't either). Special-case a result
2101 of zero while we're here. */
2102 if (tree_int_cst_equal (arg0, arg1))
2103 return build_int_cst (ctype, 0);
2104 else if (tree_int_cst_lt (arg1, arg0))
2105 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2107 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
2108 fold_convert (ctype, size_binop (MINUS_EXPR,
2112 /* A subroutine of fold_convert_const handling conversions of an
2113 INTEGER_CST to another integer type. */
2116 fold_convert_const_int_from_int (tree type, const_tree arg1)
2120 /* Given an integer constant, make new constant with new type,
2121 appropriately sign-extended or truncated. */
2122 t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
2123 TREE_INT_CST_HIGH (arg1),
2124 /* Don't set the overflow when
2125 converting a pointer */
2126 !POINTER_TYPE_P (TREE_TYPE (arg1)),
2127 (TREE_INT_CST_HIGH (arg1) < 0
2128 && (TYPE_UNSIGNED (type)
2129 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2130 | TREE_OVERFLOW (arg1));
2135 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2136 to an integer type. */
2139 fold_convert_const_int_from_real (enum tree_code code, tree type, const_tree arg1)
2144 /* The following code implements the floating point to integer
2145 conversion rules required by the Java Language Specification,
2146 that IEEE NaNs are mapped to zero and values that overflow
2147 the target precision saturate, i.e. values greater than
2148 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2149 are mapped to INT_MIN. These semantics are allowed by the
2150 C and C++ standards that simply state that the behavior of
2151 FP-to-integer conversion is unspecified upon overflow. */
2153 HOST_WIDE_INT high, low;
2155 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2159 case FIX_TRUNC_EXPR:
2160 real_trunc (&r, VOIDmode, &x);
2167 /* If R is NaN, return zero and show we have an overflow. */
2168 if (REAL_VALUE_ISNAN (r))
2175 /* See if R is less than the lower bound or greater than the
2180 tree lt = TYPE_MIN_VALUE (type);
2181 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2182 if (REAL_VALUES_LESS (r, l))
2185 high = TREE_INT_CST_HIGH (lt);
2186 low = TREE_INT_CST_LOW (lt);
2192 tree ut = TYPE_MAX_VALUE (type);
2195 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2196 if (REAL_VALUES_LESS (u, r))
2199 high = TREE_INT_CST_HIGH (ut);
2200 low = TREE_INT_CST_LOW (ut);
2206 REAL_VALUE_TO_INT (&low, &high, r);
2208 t = force_fit_type_double (type, low, high, -1,
2209 overflow | TREE_OVERFLOW (arg1));
2213 /* A subroutine of fold_convert_const handling conversions of a
2214 FIXED_CST to an integer type. */
2217 fold_convert_const_int_from_fixed (tree type, const_tree arg1)
2220 double_int temp, temp_trunc;
2223 /* Right shift FIXED_CST to temp by fbit. */
2224 temp = TREE_FIXED_CST (arg1).data;
2225 mode = TREE_FIXED_CST (arg1).mode;
2226 if (GET_MODE_FBIT (mode) < 2 * HOST_BITS_PER_WIDE_INT)
2228 lshift_double (temp.low, temp.high,
2229 - GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2230 &temp.low, &temp.high, SIGNED_FIXED_POINT_MODE_P (mode));
2232 /* Left shift temp to temp_trunc by fbit. */
2233 lshift_double (temp.low, temp.high,
2234 GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2235 &temp_trunc.low, &temp_trunc.high,
2236 SIGNED_FIXED_POINT_MODE_P (mode));
2243 temp_trunc.high = 0;
2246 /* If FIXED_CST is negative, we need to round the value toward 0.
2247 By checking if the fractional bits are not zero to add 1 to temp. */
2248 if (SIGNED_FIXED_POINT_MODE_P (mode) && temp_trunc.high < 0
2249 && !double_int_equal_p (TREE_FIXED_CST (arg1).data, temp_trunc))
2254 temp = double_int_add (temp, one);
2257 /* Given a fixed-point constant, make new constant with new type,
2258 appropriately sign-extended or truncated. */
2259 t = force_fit_type_double (type, temp.low, temp.high, -1,
2261 && (TYPE_UNSIGNED (type)
2262 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2263 | TREE_OVERFLOW (arg1));
2268 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2269 to another floating point type. */
2272 fold_convert_const_real_from_real (tree type, const_tree arg1)
2274 REAL_VALUE_TYPE value;
2277 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2278 t = build_real (type, value);
2280 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2284 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2285 to a floating point type. */
2288 fold_convert_const_real_from_fixed (tree type, const_tree arg1)
2290 REAL_VALUE_TYPE value;
2293 real_convert_from_fixed (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1));
2294 t = build_real (type, value);
2296 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2297 TREE_CONSTANT_OVERFLOW (t)
2298 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2302 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2303 to another fixed-point type. */
2306 fold_convert_const_fixed_from_fixed (tree type, const_tree arg1)
2308 FIXED_VALUE_TYPE value;
2312 overflow_p = fixed_convert (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1),
2313 TYPE_SATURATING (type));
2314 t = build_fixed (type, value);
2316 /* Propagate overflow flags. */
2317 if (overflow_p | TREE_OVERFLOW (arg1))
2319 TREE_OVERFLOW (t) = 1;
2320 TREE_CONSTANT_OVERFLOW (t) = 1;
2322 else if (TREE_CONSTANT_OVERFLOW (arg1))
2323 TREE_CONSTANT_OVERFLOW (t) = 1;
2327 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2328 to a fixed-point type. */
2331 fold_convert_const_fixed_from_int (tree type, const_tree arg1)
2333 FIXED_VALUE_TYPE value;
2337 overflow_p = fixed_convert_from_int (&value, TYPE_MODE (type),
2338 TREE_INT_CST (arg1),
2339 TYPE_UNSIGNED (TREE_TYPE (arg1)),
2340 TYPE_SATURATING (type));
2341 t = build_fixed (type, value);
2343 /* Propagate overflow flags. */
2344 if (overflow_p | TREE_OVERFLOW (arg1))
2346 TREE_OVERFLOW (t) = 1;
2347 TREE_CONSTANT_OVERFLOW (t) = 1;
2349 else if (TREE_CONSTANT_OVERFLOW (arg1))
2350 TREE_CONSTANT_OVERFLOW (t) = 1;
2354 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2355 to a fixed-point type. */
2358 fold_convert_const_fixed_from_real (tree type, const_tree arg1)
2360 FIXED_VALUE_TYPE value;
2364 overflow_p = fixed_convert_from_real (&value, TYPE_MODE (type),
2365 &TREE_REAL_CST (arg1),
2366 TYPE_SATURATING (type));
2367 t = build_fixed (type, value);
2369 /* Propagate overflow flags. */
2370 if (overflow_p | TREE_OVERFLOW (arg1))
2372 TREE_OVERFLOW (t) = 1;
2373 TREE_CONSTANT_OVERFLOW (t) = 1;
2375 else if (TREE_CONSTANT_OVERFLOW (arg1))
2376 TREE_CONSTANT_OVERFLOW (t) = 1;
2380 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2381 type TYPE. If no simplification can be done return NULL_TREE. */
2384 fold_convert_const (enum tree_code code, tree type, tree arg1)
2386 if (TREE_TYPE (arg1) == type)
2389 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2391 if (TREE_CODE (arg1) == INTEGER_CST)
2392 return fold_convert_const_int_from_int (type, arg1);
2393 else if (TREE_CODE (arg1) == REAL_CST)
2394 return fold_convert_const_int_from_real (code, type, arg1);
2395 else if (TREE_CODE (arg1) == FIXED_CST)
2396 return fold_convert_const_int_from_fixed (type, arg1);
2398 else if (TREE_CODE (type) == REAL_TYPE)
2400 if (TREE_CODE (arg1) == INTEGER_CST)
2401 return build_real_from_int_cst (type, arg1);
2402 else if (TREE_CODE (arg1) == REAL_CST)
2403 return fold_convert_const_real_from_real (type, arg1);
2404 else if (TREE_CODE (arg1) == FIXED_CST)
2405 return fold_convert_const_real_from_fixed (type, arg1);
2407 else if (TREE_CODE (type) == FIXED_POINT_TYPE)
2409 if (TREE_CODE (arg1) == FIXED_CST)
2410 return fold_convert_const_fixed_from_fixed (type, arg1);
2411 else if (TREE_CODE (arg1) == INTEGER_CST)
2412 return fold_convert_const_fixed_from_int (type, arg1);
2413 else if (TREE_CODE (arg1) == REAL_CST)
2414 return fold_convert_const_fixed_from_real (type, arg1);
2419 /* Construct a vector of zero elements of vector type TYPE. */
2422 build_zero_vector (tree type)
2427 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2428 units = TYPE_VECTOR_SUBPARTS (type);
2431 for (i = 0; i < units; i++)
2432 list = tree_cons (NULL_TREE, elem, list);
2433 return build_vector (type, list);
2436 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2439 fold_convertible_p (const_tree type, const_tree arg)
2441 tree orig = TREE_TYPE (arg);
2446 if (TREE_CODE (arg) == ERROR_MARK
2447 || TREE_CODE (type) == ERROR_MARK
2448 || TREE_CODE (orig) == ERROR_MARK)
2451 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2454 switch (TREE_CODE (type))
2456 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2457 case POINTER_TYPE: case REFERENCE_TYPE:
2459 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2460 || TREE_CODE (orig) == OFFSET_TYPE)
2462 return (TREE_CODE (orig) == VECTOR_TYPE
2463 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2466 return TREE_CODE (type) == TREE_CODE (orig);
2470 /* Convert expression ARG to type TYPE. Used by the middle-end for
2471 simple conversions in preference to calling the front-end's convert. */
2474 fold_convert (tree type, tree arg)
2476 tree orig = TREE_TYPE (arg);
2482 if (TREE_CODE (arg) == ERROR_MARK
2483 || TREE_CODE (type) == ERROR_MARK
2484 || TREE_CODE (orig) == ERROR_MARK)
2485 return error_mark_node;
2487 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2488 return fold_build1 (NOP_EXPR, type, arg);
2490 switch (TREE_CODE (type))
2492 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2493 case POINTER_TYPE: case REFERENCE_TYPE:
2495 if (TREE_CODE (arg) == INTEGER_CST)
2497 tem = fold_convert_const (NOP_EXPR, type, arg);
2498 if (tem != NULL_TREE)
2501 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2502 || TREE_CODE (orig) == OFFSET_TYPE)
2503 return fold_build1 (NOP_EXPR, type, arg);
2504 if (TREE_CODE (orig) == COMPLEX_TYPE)
2506 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2507 return fold_convert (type, tem);
2509 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2510 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2511 return fold_build1 (NOP_EXPR, type, arg);
2514 if (TREE_CODE (arg) == INTEGER_CST)
2516 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2517 if (tem != NULL_TREE)
2520 else if (TREE_CODE (arg) == REAL_CST)
2522 tem = fold_convert_const (NOP_EXPR, type, arg);
2523 if (tem != NULL_TREE)
2526 else if (TREE_CODE (arg) == FIXED_CST)
2528 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2529 if (tem != NULL_TREE)
2533 switch (TREE_CODE (orig))
2536 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2537 case POINTER_TYPE: case REFERENCE_TYPE:
2538 return fold_build1 (FLOAT_EXPR, type, arg);
2541 return fold_build1 (NOP_EXPR, type, arg);
2543 case FIXED_POINT_TYPE:
2544 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2547 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2548 return fold_convert (type, tem);
2554 case FIXED_POINT_TYPE:
2555 if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
2556 || TREE_CODE (arg) == REAL_CST)
2558 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2559 if (tem != NULL_TREE)
2563 switch (TREE_CODE (orig))
2565 case FIXED_POINT_TYPE:
2570 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2573 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2574 return fold_convert (type, tem);
2581 switch (TREE_CODE (orig))
2584 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2585 case POINTER_TYPE: case REFERENCE_TYPE:
2587 case FIXED_POINT_TYPE:
2588 return build2 (COMPLEX_EXPR, type,
2589 fold_convert (TREE_TYPE (type), arg),
2590 fold_convert (TREE_TYPE (type), integer_zero_node));
2595 if (TREE_CODE (arg) == COMPLEX_EXPR)
2597 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2598 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2599 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2602 arg = save_expr (arg);
2603 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2604 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2605 rpart = fold_convert (TREE_TYPE (type), rpart);
2606 ipart = fold_convert (TREE_TYPE (type), ipart);
2607 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2615 if (integer_zerop (arg))
2616 return build_zero_vector (type);
2617 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2618 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2619 || TREE_CODE (orig) == VECTOR_TYPE);
2620 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2623 tem = fold_ignored_result (arg);
2624 if (TREE_CODE (tem) == GIMPLE_MODIFY_STMT)
2626 return fold_build1 (NOP_EXPR, type, tem);
2633 /* Return false if expr can be assumed not to be an lvalue, true
2637 maybe_lvalue_p (const_tree x)
2639 /* We only need to wrap lvalue tree codes. */
2640 switch (TREE_CODE (x))
2651 case ALIGN_INDIRECT_REF:
2652 case MISALIGNED_INDIRECT_REF:
2654 case ARRAY_RANGE_REF:
2660 case PREINCREMENT_EXPR:
2661 case PREDECREMENT_EXPR:
2663 case TRY_CATCH_EXPR:
2664 case WITH_CLEANUP_EXPR:
2667 case GIMPLE_MODIFY_STMT:
2676 /* Assume the worst for front-end tree codes. */
2677 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2685 /* Return an expr equal to X but certainly not valid as an lvalue. */
2690 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2695 if (! maybe_lvalue_p (x))
2697 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2700 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2701 Zero means allow extended lvalues. */
2703 int pedantic_lvalues;
2705 /* When pedantic, return an expr equal to X but certainly not valid as a
2706 pedantic lvalue. Otherwise, return X. */
2709 pedantic_non_lvalue (tree x)
2711 if (pedantic_lvalues)
2712 return non_lvalue (x);
2717 /* Given a tree comparison code, return the code that is the logical inverse
2718 of the given code. It is not safe to do this for floating-point
2719 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2720 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2723 invert_tree_comparison (enum tree_code code, bool honor_nans)
2725 if (honor_nans && flag_trapping_math)
2735 return honor_nans ? UNLE_EXPR : LE_EXPR;
2737 return honor_nans ? UNLT_EXPR : LT_EXPR;
2739 return honor_nans ? UNGE_EXPR : GE_EXPR;
2741 return honor_nans ? UNGT_EXPR : GT_EXPR;
2755 return UNORDERED_EXPR;
2756 case UNORDERED_EXPR:
2757 return ORDERED_EXPR;
2763 /* Similar, but return the comparison that results if the operands are
2764 swapped. This is safe for floating-point. */
2767 swap_tree_comparison (enum tree_code code)
2774 case UNORDERED_EXPR:
2800 /* Convert a comparison tree code from an enum tree_code representation
2801 into a compcode bit-based encoding. This function is the inverse of
2802 compcode_to_comparison. */
2804 static enum comparison_code
2805 comparison_to_compcode (enum tree_code code)
2822 return COMPCODE_ORD;
2823 case UNORDERED_EXPR:
2824 return COMPCODE_UNORD;
2826 return COMPCODE_UNLT;
2828 return COMPCODE_UNEQ;
2830 return COMPCODE_UNLE;
2832 return COMPCODE_UNGT;
2834 return COMPCODE_LTGT;
2836 return COMPCODE_UNGE;
2842 /* Convert a compcode bit-based encoding of a comparison operator back
2843 to GCC's enum tree_code representation. This function is the
2844 inverse of comparison_to_compcode. */
2846 static enum tree_code
2847 compcode_to_comparison (enum comparison_code code)
2864 return ORDERED_EXPR;
2865 case COMPCODE_UNORD:
2866 return UNORDERED_EXPR;
2884 /* Return a tree for the comparison which is the combination of
2885 doing the AND or OR (depending on CODE) of the two operations LCODE
2886 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2887 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2888 if this makes the transformation invalid. */
2891 combine_comparisons (enum tree_code code, enum tree_code lcode,
2892 enum tree_code rcode, tree truth_type,
2893 tree ll_arg, tree lr_arg)
2895 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2896 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2897 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2898 enum comparison_code compcode;
2902 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2903 compcode = lcompcode & rcompcode;
2906 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2907 compcode = lcompcode | rcompcode;
2916 /* Eliminate unordered comparisons, as well as LTGT and ORD
2917 which are not used unless the mode has NaNs. */
2918 compcode &= ~COMPCODE_UNORD;
2919 if (compcode == COMPCODE_LTGT)
2920 compcode = COMPCODE_NE;
2921 else if (compcode == COMPCODE_ORD)
2922 compcode = COMPCODE_TRUE;
2924 else if (flag_trapping_math)
2926 /* Check that the original operation and the optimized ones will trap
2927 under the same condition. */
2928 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2929 && (lcompcode != COMPCODE_EQ)
2930 && (lcompcode != COMPCODE_ORD);
2931 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2932 && (rcompcode != COMPCODE_EQ)
2933 && (rcompcode != COMPCODE_ORD);
2934 bool trap = (compcode & COMPCODE_UNORD) == 0
2935 && (compcode != COMPCODE_EQ)
2936 && (compcode != COMPCODE_ORD);
2938 /* In a short-circuited boolean expression the LHS might be
2939 such that the RHS, if evaluated, will never trap. For
2940 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2941 if neither x nor y is NaN. (This is a mixed blessing: for
2942 example, the expression above will never trap, hence
2943 optimizing it to x < y would be invalid). */
2944 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2945 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2948 /* If the comparison was short-circuited, and only the RHS
2949 trapped, we may now generate a spurious trap. */
2951 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2954 /* If we changed the conditions that cause a trap, we lose. */
2955 if ((ltrap || rtrap) != trap)
2959 if (compcode == COMPCODE_TRUE)
2960 return constant_boolean_node (true, truth_type);
2961 else if (compcode == COMPCODE_FALSE)
2962 return constant_boolean_node (false, truth_type);
2964 return fold_build2 (compcode_to_comparison (compcode),
2965 truth_type, ll_arg, lr_arg);
2968 /* Return nonzero if CODE is a tree code that represents a truth value. */
2971 truth_value_p (enum tree_code code)
2973 return (TREE_CODE_CLASS (code) == tcc_comparison
2974 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2975 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2976 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2979 /* Return nonzero if two operands (typically of the same tree node)
2980 are necessarily equal. If either argument has side-effects this
2981 function returns zero. FLAGS modifies behavior as follows:
2983 If OEP_ONLY_CONST is set, only return nonzero for constants.
2984 This function tests whether the operands are indistinguishable;
2985 it does not test whether they are equal using C's == operation.
2986 The distinction is important for IEEE floating point, because
2987 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2988 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2990 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2991 even though it may hold multiple values during a function.
2992 This is because a GCC tree node guarantees that nothing else is
2993 executed between the evaluation of its "operands" (which may often
2994 be evaluated in arbitrary order). Hence if the operands themselves
2995 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2996 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2997 unset means assuming isochronic (or instantaneous) tree equivalence.
2998 Unless comparing arbitrary expression trees, such as from different
2999 statements, this flag can usually be left unset.
3001 If OEP_PURE_SAME is set, then pure functions with identical arguments
3002 are considered the same. It is used when the caller has other ways
3003 to ensure that global memory is unchanged in between. */
3006 operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
3008 /* If either is ERROR_MARK, they aren't equal. */
3009 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
3012 /* If both types don't have the same signedness, then we can't consider
3013 them equal. We must check this before the STRIP_NOPS calls
3014 because they may change the signedness of the arguments. */
3015 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3018 /* If both types don't have the same precision, then it is not safe
3020 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
3026 /* In case both args are comparisons but with different comparison
3027 code, try to swap the comparison operands of one arg to produce
3028 a match and compare that variant. */
3029 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3030 && COMPARISON_CLASS_P (arg0)
3031 && COMPARISON_CLASS_P (arg1))
3033 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
3035 if (TREE_CODE (arg0) == swap_code)
3036 return operand_equal_p (TREE_OPERAND (arg0, 0),
3037 TREE_OPERAND (arg1, 1), flags)
3038 && operand_equal_p (TREE_OPERAND (arg0, 1),
3039 TREE_OPERAND (arg1, 0), flags);
3042 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3043 /* This is needed for conversions and for COMPONENT_REF.
3044 Might as well play it safe and always test this. */
3045 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
3046 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
3047 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
3050 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3051 We don't care about side effects in that case because the SAVE_EXPR
3052 takes care of that for us. In all other cases, two expressions are
3053 equal if they have no side effects. If we have two identical
3054 expressions with side effects that should be treated the same due
3055 to the only side effects being identical SAVE_EXPR's, that will
3056 be detected in the recursive calls below. */
3057 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
3058 && (TREE_CODE (arg0) == SAVE_EXPR
3059 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
3062 /* Next handle constant cases, those for which we can return 1 even
3063 if ONLY_CONST is set. */
3064 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
3065 switch (TREE_CODE (arg0))
3068 return tree_int_cst_equal (arg0, arg1);
3071 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
3072 TREE_FIXED_CST (arg1));
3075 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
3076 TREE_REAL_CST (arg1)))
3080 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
3082 /* If we do not distinguish between signed and unsigned zero,
3083 consider them equal. */
3084 if (real_zerop (arg0) && real_zerop (arg1))
3093 v1 = TREE_VECTOR_CST_ELTS (arg0);
3094 v2 = TREE_VECTOR_CST_ELTS (arg1);
3097 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
3100 v1 = TREE_CHAIN (v1);
3101 v2 = TREE_CHAIN (v2);
3108 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
3110 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
3114 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
3115 && ! memcmp (TREE_STRING_POINTER (arg0),
3116 TREE_STRING_POINTER (arg1),
3117 TREE_STRING_LENGTH (arg0)));
3120 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
3126 if (flags & OEP_ONLY_CONST)
3129 /* Define macros to test an operand from arg0 and arg1 for equality and a
3130 variant that allows null and views null as being different from any
3131 non-null value. In the latter case, if either is null, the both
3132 must be; otherwise, do the normal comparison. */
3133 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3134 TREE_OPERAND (arg1, N), flags)
3136 #define OP_SAME_WITH_NULL(N) \
3137 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3138 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3140 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
3143 /* Two conversions are equal only if signedness and modes match. */
3144 switch (TREE_CODE (arg0))
3148 case FIX_TRUNC_EXPR:
3149 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
3150 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3160 case tcc_comparison:
3162 if (OP_SAME (0) && OP_SAME (1))
3165 /* For commutative ops, allow the other order. */
3166 return (commutative_tree_code (TREE_CODE (arg0))
3167 && operand_equal_p (TREE_OPERAND (arg0, 0),
3168 TREE_OPERAND (arg1, 1), flags)
3169 && operand_equal_p (TREE_OPERAND (arg0, 1),
3170 TREE_OPERAND (arg1, 0), flags));
3173 /* If either of the pointer (or reference) expressions we are
3174 dereferencing contain a side effect, these cannot be equal. */
3175 if (TREE_SIDE_EFFECTS (arg0)
3176 || TREE_SIDE_EFFECTS (arg1))
3179 switch (TREE_CODE (arg0))
3182 case ALIGN_INDIRECT_REF:
3183 case MISALIGNED_INDIRECT_REF:
3189 case ARRAY_RANGE_REF:
3190 /* Operands 2 and 3 may be null.
3191 Compare the array index by value if it is constant first as we
3192 may have different types but same value here. */
3194 && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
3195 TREE_OPERAND (arg1, 1))
3197 && OP_SAME_WITH_NULL (2)
3198 && OP_SAME_WITH_NULL (3));
3201 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3202 may be NULL when we're called to compare MEM_EXPRs. */
3203 return OP_SAME_WITH_NULL (0)
3205 && OP_SAME_WITH_NULL (2);
3208 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3214 case tcc_expression:
3215 switch (TREE_CODE (arg0))
3218 case TRUTH_NOT_EXPR:
3221 case TRUTH_ANDIF_EXPR:
3222 case TRUTH_ORIF_EXPR:
3223 return OP_SAME (0) && OP_SAME (1);
3225 case TRUTH_AND_EXPR:
3227 case TRUTH_XOR_EXPR:
3228 if (OP_SAME (0) && OP_SAME (1))
3231 /* Otherwise take into account this is a commutative operation. */
3232 return (operand_equal_p (TREE_OPERAND (arg0, 0),
3233 TREE_OPERAND (arg1, 1), flags)
3234 && operand_equal_p (TREE_OPERAND (arg0, 1),
3235 TREE_OPERAND (arg1, 0), flags));
3242 switch (TREE_CODE (arg0))
3245 /* If the CALL_EXPRs call different functions, then they
3246 clearly can not be equal. */
3247 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
3252 unsigned int cef = call_expr_flags (arg0);
3253 if (flags & OEP_PURE_SAME)
3254 cef &= ECF_CONST | ECF_PURE;
3261 /* Now see if all the arguments are the same. */
3263 const_call_expr_arg_iterator iter0, iter1;
3265 for (a0 = first_const_call_expr_arg (arg0, &iter0),
3266 a1 = first_const_call_expr_arg (arg1, &iter1);
3268 a0 = next_const_call_expr_arg (&iter0),
3269 a1 = next_const_call_expr_arg (&iter1))
3270 if (! operand_equal_p (a0, a1, flags))
3273 /* If we get here and both argument lists are exhausted
3274 then the CALL_EXPRs are equal. */
3275 return ! (a0 || a1);
3281 case tcc_declaration:
3282 /* Consider __builtin_sqrt equal to sqrt. */
3283 return (TREE_CODE (arg0) == FUNCTION_DECL
3284 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
3285 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
3286 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
3293 #undef OP_SAME_WITH_NULL
3296 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3297 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3299 When in doubt, return 0. */
3302 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
3304 int unsignedp1, unsignedpo;
3305 tree primarg0, primarg1, primother;
3306 unsigned int correct_width;
3308 if (operand_equal_p (arg0, arg1, 0))
3311 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3312 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3315 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3316 and see if the inner values are the same. This removes any
3317 signedness comparison, which doesn't matter here. */
3318 primarg0 = arg0, primarg1 = arg1;
3319 STRIP_NOPS (primarg0);
3320 STRIP_NOPS (primarg1);
3321 if (operand_equal_p (primarg0, primarg1, 0))
3324 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3325 actual comparison operand, ARG0.
3327 First throw away any conversions to wider types
3328 already present in the operands. */
3330 primarg1 = get_narrower (arg1, &unsignedp1);
3331 primother = get_narrower (other, &unsignedpo);
3333 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3334 if (unsignedp1 == unsignedpo
3335 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3336 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3338 tree type = TREE_TYPE (arg0);
3340 /* Make sure shorter operand is extended the right way
3341 to match the longer operand. */
3342 primarg1 = fold_convert (signed_or_unsigned_type_for
3343 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3345 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3352 /* See if ARG is an expression that is either a comparison or is performing
3353 arithmetic on comparisons. The comparisons must only be comparing
3354 two different values, which will be stored in *CVAL1 and *CVAL2; if
3355 they are nonzero it means that some operands have already been found.
3356 No variables may be used anywhere else in the expression except in the
3357 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3358 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3360 If this is true, return 1. Otherwise, return zero. */
3363 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3365 enum tree_code code = TREE_CODE (arg);
3366 enum tree_code_class class = TREE_CODE_CLASS (code);
3368 /* We can handle some of the tcc_expression cases here. */
3369 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3371 else if (class == tcc_expression
3372 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3373 || code == COMPOUND_EXPR))
3376 else if (class == tcc_expression && code == SAVE_EXPR
3377 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3379 /* If we've already found a CVAL1 or CVAL2, this expression is
3380 two complex to handle. */
3381 if (*cval1 || *cval2)
3391 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3394 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3395 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3396 cval1, cval2, save_p));
3401 case tcc_expression:
3402 if (code == COND_EXPR)
3403 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3404 cval1, cval2, save_p)
3405 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3406 cval1, cval2, save_p)
3407 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3408 cval1, cval2, save_p));
3411 case tcc_comparison:
3412 /* First see if we can handle the first operand, then the second. For
3413 the second operand, we know *CVAL1 can't be zero. It must be that
3414 one side of the comparison is each of the values; test for the
3415 case where this isn't true by failing if the two operands
3418 if (operand_equal_p (TREE_OPERAND (arg, 0),
3419 TREE_OPERAND (arg, 1), 0))
3423 *cval1 = TREE_OPERAND (arg, 0);
3424 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3426 else if (*cval2 == 0)
3427 *cval2 = TREE_OPERAND (arg, 0);
3428 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3433 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3435 else if (*cval2 == 0)
3436 *cval2 = TREE_OPERAND (arg, 1);
3437 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3449 /* ARG is a tree that is known to contain just arithmetic operations and
3450 comparisons. Evaluate the operations in the tree substituting NEW0 for
3451 any occurrence of OLD0 as an operand of a comparison and likewise for
3455 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3457 tree type = TREE_TYPE (arg);
3458 enum tree_code code = TREE_CODE (arg);
3459 enum tree_code_class class = TREE_CODE_CLASS (code);
3461 /* We can handle some of the tcc_expression cases here. */
3462 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3464 else if (class == tcc_expression
3465 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3471 return fold_build1 (code, type,
3472 eval_subst (TREE_OPERAND (arg, 0),
3473 old0, new0, old1, new1));
3476 return fold_build2 (code, type,
3477 eval_subst (TREE_OPERAND (arg, 0),
3478 old0, new0, old1, new1),
3479 eval_subst (TREE_OPERAND (arg, 1),
3480 old0, new0, old1, new1));
3482 case tcc_expression:
3486 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3489 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3492 return fold_build3 (code, type,
3493 eval_subst (TREE_OPERAND (arg, 0),
3494 old0, new0, old1, new1),
3495 eval_subst (TREE_OPERAND (arg, 1),
3496 old0, new0, old1, new1),
3497 eval_subst (TREE_OPERAND (arg, 2),
3498 old0, new0, old1, new1));
3502 /* Fall through - ??? */
3504 case tcc_comparison:
3506 tree arg0 = TREE_OPERAND (arg, 0);
3507 tree arg1 = TREE_OPERAND (arg, 1);
3509 /* We need to check both for exact equality and tree equality. The
3510 former will be true if the operand has a side-effect. In that
3511 case, we know the operand occurred exactly once. */
3513 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3515 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3518 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3520 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3523 return fold_build2 (code, type, arg0, arg1);
3531 /* Return a tree for the case when the result of an expression is RESULT
3532 converted to TYPE and OMITTED was previously an operand of the expression
3533 but is now not needed (e.g., we folded OMITTED * 0).
3535 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3536 the conversion of RESULT to TYPE. */
3539 omit_one_operand (tree type, tree result, tree omitted)
3541 tree t = fold_convert (type, result);
3543 /* If the resulting operand is an empty statement, just return the omitted
3544 statement casted to void. */
3545 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3546 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3548 if (TREE_SIDE_EFFECTS (omitted))
3549 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3551 return non_lvalue (t);
3554 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3557 pedantic_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 pedantic_non_lvalue (t);
3572 /* Return a tree for the case when the result of an expression is RESULT
3573 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3574 of the expression but are now not needed.
3576 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3577 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3578 evaluated before OMITTED2. Otherwise, if neither has side effects,
3579 just do the conversion of RESULT to TYPE. */
3582 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3584 tree t = fold_convert (type, result);
3586 if (TREE_SIDE_EFFECTS (omitted2))
3587 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3588 if (TREE_SIDE_EFFECTS (omitted1))
3589 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3591 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3595 /* Return a simplified tree node for the truth-negation of ARG. This
3596 never alters ARG itself. We assume that ARG is an operation that
3597 returns a truth value (0 or 1).
3599 FIXME: one would think we would fold the result, but it causes
3600 problems with the dominator optimizer. */
3603 fold_truth_not_expr (tree arg)
3605 tree type = TREE_TYPE (arg);
3606 enum tree_code code = TREE_CODE (arg);
3608 /* If this is a comparison, we can simply invert it, except for
3609 floating-point non-equality comparisons, in which case we just
3610 enclose a TRUTH_NOT_EXPR around what we have. */
3612 if (TREE_CODE_CLASS (code) == tcc_comparison)
3614 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3615 if (FLOAT_TYPE_P (op_type)
3616 && flag_trapping_math
3617 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3618 && code != NE_EXPR && code != EQ_EXPR)
3622 code = invert_tree_comparison (code,
3623 HONOR_NANS (TYPE_MODE (op_type)));
3624 if (code == ERROR_MARK)
3627 return build2 (code, type,
3628 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3635 return constant_boolean_node (integer_zerop (arg), type);
3637 case TRUTH_AND_EXPR:
3638 return build2 (TRUTH_OR_EXPR, type,
3639 invert_truthvalue (TREE_OPERAND (arg, 0)),
3640 invert_truthvalue (TREE_OPERAND (arg, 1)));
3643 return build2 (TRUTH_AND_EXPR, type,
3644 invert_truthvalue (TREE_OPERAND (arg, 0)),
3645 invert_truthvalue (TREE_OPERAND (arg, 1)));
3647 case TRUTH_XOR_EXPR:
3648 /* Here we can invert either operand. We invert the first operand
3649 unless the second operand is a TRUTH_NOT_EXPR in which case our
3650 result is the XOR of the first operand with the inside of the
3651 negation of the second operand. */
3653 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3654 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3655 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3657 return build2 (TRUTH_XOR_EXPR, type,
3658 invert_truthvalue (TREE_OPERAND (arg, 0)),
3659 TREE_OPERAND (arg, 1));
3661 case TRUTH_ANDIF_EXPR:
3662 return build2 (TRUTH_ORIF_EXPR, type,
3663 invert_truthvalue (TREE_OPERAND (arg, 0)),
3664 invert_truthvalue (TREE_OPERAND (arg, 1)));
3666 case TRUTH_ORIF_EXPR:
3667 return build2 (TRUTH_ANDIF_EXPR, type,
3668 invert_truthvalue (TREE_OPERAND (arg, 0)),
3669 invert_truthvalue (TREE_OPERAND (arg, 1)));
3671 case TRUTH_NOT_EXPR:
3672 return TREE_OPERAND (arg, 0);
3676 tree arg1 = TREE_OPERAND (arg, 1);
3677 tree arg2 = TREE_OPERAND (arg, 2);
3678 /* A COND_EXPR may have a throw as one operand, which
3679 then has void type. Just leave void operands
3681 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3682 VOID_TYPE_P (TREE_TYPE (arg1))
3683 ? arg1 : invert_truthvalue (arg1),
3684 VOID_TYPE_P (TREE_TYPE (arg2))
3685 ? arg2 : invert_truthvalue (arg2));
3689 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3690 invert_truthvalue (TREE_OPERAND (arg, 1)));
3692 case NON_LVALUE_EXPR:
3693 return invert_truthvalue (TREE_OPERAND (arg, 0));
3696 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3697 return build1 (TRUTH_NOT_EXPR, type, arg);
3701 return build1 (TREE_CODE (arg), type,
3702 invert_truthvalue (TREE_OPERAND (arg, 0)));
3705 if (!integer_onep (TREE_OPERAND (arg, 1)))
3707 return build2 (EQ_EXPR, type, arg,
3708 build_int_cst (type, 0));
3711 return build1 (TRUTH_NOT_EXPR, type, arg);
3713 case CLEANUP_POINT_EXPR:
3714 return build1 (CLEANUP_POINT_EXPR, type,
3715 invert_truthvalue (TREE_OPERAND (arg, 0)));
3724 /* Return a simplified tree node for the truth-negation of ARG. This
3725 never alters ARG itself. We assume that ARG is an operation that
3726 returns a truth value (0 or 1).
3728 FIXME: one would think we would fold the result, but it causes
3729 problems with the dominator optimizer. */
3732 invert_truthvalue (tree arg)
3736 if (TREE_CODE (arg) == ERROR_MARK)
3739 tem = fold_truth_not_expr (arg);
3741 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3746 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3747 operands are another bit-wise operation with a common input. If so,
3748 distribute the bit operations to save an operation and possibly two if
3749 constants are involved. For example, convert
3750 (A | B) & (A | C) into A | (B & C)
3751 Further simplification will occur if B and C are constants.
3753 If this optimization cannot be done, 0 will be returned. */
3756 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3761 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3762 || TREE_CODE (arg0) == code
3763 || (TREE_CODE (arg0) != BIT_AND_EXPR
3764 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3767 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3769 common = TREE_OPERAND (arg0, 0);
3770 left = TREE_OPERAND (arg0, 1);
3771 right = TREE_OPERAND (arg1, 1);
3773 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3775 common = TREE_OPERAND (arg0, 0);
3776 left = TREE_OPERAND (arg0, 1);
3777 right = TREE_OPERAND (arg1, 0);
3779 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3781 common = TREE_OPERAND (arg0, 1);
3782 left = TREE_OPERAND (arg0, 0);
3783 right = TREE_OPERAND (arg1, 1);
3785 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3787 common = TREE_OPERAND (arg0, 1);
3788 left = TREE_OPERAND (arg0, 0);
3789 right = TREE_OPERAND (arg1, 0);
3794 return fold_build2 (TREE_CODE (arg0), type, common,
3795 fold_build2 (code, type, left, right));
3798 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3799 with code CODE. This optimization is unsafe. */
3801 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3803 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3804 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3806 /* (A / C) +- (B / C) -> (A +- B) / C. */
3808 && operand_equal_p (TREE_OPERAND (arg0, 1),
3809 TREE_OPERAND (arg1, 1), 0))
3810 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3811 fold_build2 (code, type,
3812 TREE_OPERAND (arg0, 0),
3813 TREE_OPERAND (arg1, 0)),
3814 TREE_OPERAND (arg0, 1));
3816 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3817 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3818 TREE_OPERAND (arg1, 0), 0)
3819 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3820 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3822 REAL_VALUE_TYPE r0, r1;
3823 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3824 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3826 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3828 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3829 real_arithmetic (&r0, code, &r0, &r1);
3830 return fold_build2 (MULT_EXPR, type,
3831 TREE_OPERAND (arg0, 0),
3832 build_real (type, r0));
3838 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3839 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3842 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3849 tree size = TYPE_SIZE (TREE_TYPE (inner));
3850 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3851 || POINTER_TYPE_P (TREE_TYPE (inner)))
3852 && host_integerp (size, 0)
3853 && tree_low_cst (size, 0) == bitsize)
3854 return fold_convert (type, inner);
3857 result = build3 (BIT_FIELD_REF, type, inner,
3858 size_int (bitsize), bitsize_int (bitpos));
3860 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3865 /* Optimize a bit-field compare.
3867 There are two cases: First is a compare against a constant and the
3868 second is a comparison of two items where the fields are at the same
3869 bit position relative to the start of a chunk (byte, halfword, word)
3870 large enough to contain it. In these cases we can avoid the shift
3871 implicit in bitfield extractions.
3873 For constants, we emit a compare of the shifted constant with the
3874 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3875 compared. For two fields at the same position, we do the ANDs with the
3876 similar mask and compare the result of the ANDs.
3878 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3879 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3880 are the left and right operands of the comparison, respectively.
3882 If the optimization described above can be done, we return the resulting
3883 tree. Otherwise we return zero. */
3886 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3889 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3890 tree type = TREE_TYPE (lhs);
3891 tree signed_type, unsigned_type;
3892 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3893 enum machine_mode lmode, rmode, nmode;
3894 int lunsignedp, runsignedp;
3895 int lvolatilep = 0, rvolatilep = 0;
3896 tree linner, rinner = NULL_TREE;
3900 /* Get all the information about the extractions being done. If the bit size
3901 if the same as the size of the underlying object, we aren't doing an
3902 extraction at all and so can do nothing. We also don't want to
3903 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3904 then will no longer be able to replace it. */
3905 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3906 &lunsignedp, &lvolatilep, false);
3907 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3908 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3913 /* If this is not a constant, we can only do something if bit positions,
3914 sizes, and signedness are the same. */
3915 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3916 &runsignedp, &rvolatilep, false);
3918 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3919 || lunsignedp != runsignedp || offset != 0
3920 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3924 /* See if we can find a mode to refer to this field. We should be able to,
3925 but fail if we can't. */
3926 nmode = get_best_mode (lbitsize, lbitpos,
3927 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3928 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3929 TYPE_ALIGN (TREE_TYPE (rinner))),
3930 word_mode, lvolatilep || rvolatilep);
3931 if (nmode == VOIDmode)
3934 /* Set signed and unsigned types of the precision of this mode for the
3936 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3937 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3939 /* Compute the bit position and size for the new reference and our offset
3940 within it. If the new reference is the same size as the original, we
3941 won't optimize anything, so return zero. */
3942 nbitsize = GET_MODE_BITSIZE (nmode);
3943 nbitpos = lbitpos & ~ (nbitsize - 1);
3945 if (nbitsize == lbitsize)
3948 if (BYTES_BIG_ENDIAN)
3949 lbitpos = nbitsize - lbitsize - lbitpos;
3951 /* Make the mask to be used against the extracted field. */
3952 mask = build_int_cst_type (unsigned_type, -1);
3953 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3954 mask = const_binop (RSHIFT_EXPR, mask,
3955 size_int (nbitsize - lbitsize - lbitpos), 0);
3958 /* If not comparing with constant, just rework the comparison
3960 return fold_build2 (code, compare_type,
3961 fold_build2 (BIT_AND_EXPR, unsigned_type,
3962 make_bit_field_ref (linner,
3967 fold_build2 (BIT_AND_EXPR, unsigned_type,
3968 make_bit_field_ref (rinner,
3974 /* Otherwise, we are handling the constant case. See if the constant is too
3975 big for the field. Warn and return a tree of for 0 (false) if so. We do
3976 this not only for its own sake, but to avoid having to test for this
3977 error case below. If we didn't, we might generate wrong code.
3979 For unsigned fields, the constant shifted right by the field length should
3980 be all zero. For signed fields, the high-order bits should agree with
3985 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3986 fold_convert (unsigned_type, rhs),
3987 size_int (lbitsize), 0)))
3989 warning (0, "comparison is always %d due to width of bit-field",
3991 return constant_boolean_node (code == NE_EXPR, compare_type);
3996 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3997 size_int (lbitsize - 1), 0);
3998 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
4000 warning (0, "comparison is always %d due to width of bit-field",
4002 return constant_boolean_node (code == NE_EXPR, compare_type);
4006 /* Single-bit compares should always be against zero. */
4007 if (lbitsize == 1 && ! integer_zerop (rhs))
4009 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
4010 rhs = build_int_cst (type, 0);
4013 /* Make a new bitfield reference, shift the constant over the
4014 appropriate number of bits and mask it with the computed mask
4015 (in case this was a signed field). If we changed it, make a new one. */
4016 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
4019 TREE_SIDE_EFFECTS (lhs) = 1;
4020 TREE_THIS_VOLATILE (lhs) = 1;
4023 rhs = const_binop (BIT_AND_EXPR,
4024 const_binop (LSHIFT_EXPR,
4025 fold_convert (unsigned_type, rhs),
4026 size_int (lbitpos), 0),
4029 return build2 (code, compare_type,
4030 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
4034 /* Subroutine for fold_truthop: decode a field reference.
4036 If EXP is a comparison reference, we return the innermost reference.
4038 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
4039 set to the starting bit number.
4041 If the innermost field can be completely contained in a mode-sized
4042 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
4044 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
4045 otherwise it is not changed.
4047 *PUNSIGNEDP is set to the signedness of the field.
4049 *PMASK is set to the mask used. This is either contained in a
4050 BIT_AND_EXPR or derived from the width of the field.
4052 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
4054 Return 0 if this is not a component reference or is one that we can't
4055 do anything with. */
4058 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
4059 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
4060 int *punsignedp, int *pvolatilep,
4061 tree *pmask, tree *pand_mask)
4063 tree outer_type = 0;
4065 tree mask, inner, offset;
4067 unsigned int precision;
4069 /* All the optimizations using this function assume integer fields.
4070 There are problems with FP fields since the type_for_size call
4071 below can fail for, e.g., XFmode. */
4072 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
4075 /* We are interested in the bare arrangement of bits, so strip everything
4076 that doesn't affect the machine mode. However, record the type of the
4077 outermost expression if it may matter below. */
4078 if (TREE_CODE (exp) == NOP_EXPR
4079 || TREE_CODE (exp) == CONVERT_EXPR
4080 || TREE_CODE (exp) == NON_LVALUE_EXPR)
4081 outer_type = TREE_TYPE (exp);
4084 if (TREE_CODE (exp) == BIT_AND_EXPR)
4086 and_mask = TREE_OPERAND (exp, 1);
4087 exp = TREE_OPERAND (exp, 0);
4088 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
4089 if (TREE_CODE (and_mask) != INTEGER_CST)
4093 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
4094 punsignedp, pvolatilep, false);
4095 if ((inner == exp && and_mask == 0)
4096 || *pbitsize < 0 || offset != 0
4097 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
4100 /* If the number of bits in the reference is the same as the bitsize of
4101 the outer type, then the outer type gives the signedness. Otherwise
4102 (in case of a small bitfield) the signedness is unchanged. */
4103 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
4104 *punsignedp = TYPE_UNSIGNED (outer_type);
4106 /* Compute the mask to access the bitfield. */
4107 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
4108 precision = TYPE_PRECISION (unsigned_type);
4110 mask = build_int_cst_type (unsigned_type, -1);
4112 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4113 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4115 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
4117 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
4118 fold_convert (unsigned_type, and_mask), mask);
4121 *pand_mask = and_mask;
4125 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
4129 all_ones_mask_p (const_tree mask, int size)
4131 tree type = TREE_TYPE (mask);
4132 unsigned int precision = TYPE_PRECISION (type);
4135 tmask = build_int_cst_type (signed_type_for (type), -1);
4138 tree_int_cst_equal (mask,
4139 const_binop (RSHIFT_EXPR,
4140 const_binop (LSHIFT_EXPR, tmask,
4141 size_int (precision - size),
4143 size_int (precision - size), 0));
4146 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
4147 represents the sign bit of EXP's type. If EXP represents a sign
4148 or zero extension, also test VAL against the unextended type.
4149 The return value is the (sub)expression whose sign bit is VAL,
4150 or NULL_TREE otherwise. */
4153 sign_bit_p (tree exp, const_tree val)
4155 unsigned HOST_WIDE_INT mask_lo, lo;
4156 HOST_WIDE_INT mask_hi, hi;
4160 /* Tree EXP must have an integral type. */
4161 t = TREE_TYPE (exp);
4162 if (! INTEGRAL_TYPE_P (t))
4165 /* Tree VAL must be an integer constant. */
4166 if (TREE_CODE (val) != INTEGER_CST
4167 || TREE_OVERFLOW (val))
4170 width = TYPE_PRECISION (t);
4171 if (width > HOST_BITS_PER_WIDE_INT)
4173 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
4176 mask_hi = ((unsigned HOST_WIDE_INT) -1
4177 >> (2 * HOST_BITS_PER_WIDE_INT - width));
4183 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
4186 mask_lo = ((unsigned HOST_WIDE_INT) -1
4187 >> (HOST_BITS_PER_WIDE_INT - width));
4190 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
4191 treat VAL as if it were unsigned. */
4192 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
4193 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
4196 /* Handle extension from a narrower type. */
4197 if (TREE_CODE (exp) == NOP_EXPR
4198 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
4199 return sign_bit_p (TREE_OPERAND (exp, 0), val);
4204 /* Subroutine for fold_truthop: determine if an operand is simple enough
4205 to be evaluated unconditionally. */
4208 simple_operand_p (const_tree exp)
4210 /* Strip any conversions that don't change the machine mode. */
4213 return (CONSTANT_CLASS_P (exp)
4214 || TREE_CODE (exp) == SSA_NAME
4216 && ! TREE_ADDRESSABLE (exp)
4217 && ! TREE_THIS_VOLATILE (exp)
4218 && ! DECL_NONLOCAL (exp)
4219 /* Don't regard global variables as simple. They may be
4220 allocated in ways unknown to the compiler (shared memory,
4221 #pragma weak, etc). */
4222 && ! TREE_PUBLIC (exp)
4223 && ! DECL_EXTERNAL (exp)
4224 /* Loading a static variable is unduly expensive, but global
4225 registers aren't expensive. */
4226 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
4229 /* The following functions are subroutines to fold_range_test and allow it to
4230 try to change a logical combination of comparisons into a range test.
4233 X == 2 || X == 3 || X == 4 || X == 5
4237 (unsigned) (X - 2) <= 3
4239 We describe each set of comparisons as being either inside or outside
4240 a range, using a variable named like IN_P, and then describe the
4241 range with a lower and upper bound. If one of the bounds is omitted,
4242 it represents either the highest or lowest value of the type.
4244 In the comments below, we represent a range by two numbers in brackets
4245 preceded by a "+" to designate being inside that range, or a "-" to
4246 designate being outside that range, so the condition can be inverted by
4247 flipping the prefix. An omitted bound is represented by a "-". For
4248 example, "- [-, 10]" means being outside the range starting at the lowest
4249 possible value and ending at 10, in other words, being greater than 10.
4250 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4253 We set up things so that the missing bounds are handled in a consistent
4254 manner so neither a missing bound nor "true" and "false" need to be
4255 handled using a special case. */
4257 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4258 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4259 and UPPER1_P are nonzero if the respective argument is an upper bound
4260 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4261 must be specified for a comparison. ARG1 will be converted to ARG0's
4262 type if both are specified. */
4265 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
4266 tree arg1, int upper1_p)
4272 /* If neither arg represents infinity, do the normal operation.
4273 Else, if not a comparison, return infinity. Else handle the special
4274 comparison rules. Note that most of the cases below won't occur, but
4275 are handled for consistency. */
4277 if (arg0 != 0 && arg1 != 0)
4279 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
4280 arg0, fold_convert (TREE_TYPE (arg0), arg1));
4282 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
4285 if (TREE_CODE_CLASS (code) != tcc_comparison)
4288 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4289 for neither. In real maths, we cannot assume open ended ranges are
4290 the same. But, this is computer arithmetic, where numbers are finite.
4291 We can therefore make the transformation of any unbounded range with
4292 the value Z, Z being greater than any representable number. This permits
4293 us to treat unbounded ranges as equal. */
4294 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
4295 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
4299 result = sgn0 == sgn1;
4302 result = sgn0 != sgn1;
4305 result = sgn0 < sgn1;
4308 result = sgn0 <= sgn1;
4311 result = sgn0 > sgn1;
4314 result = sgn0 >= sgn1;
4320 return constant_boolean_node (result, type);
4323 /* Given EXP, a logical expression, set the range it is testing into
4324 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4325 actually being tested. *PLOW and *PHIGH will be made of the same
4326 type as the returned expression. If EXP is not a comparison, we
4327 will most likely not be returning a useful value and range. Set
4328 *STRICT_OVERFLOW_P to true if the return value is only valid
4329 because signed overflow is undefined; otherwise, do not change
4330 *STRICT_OVERFLOW_P. */
4333 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4334 bool *strict_overflow_p)
4336 enum tree_code code;
4337 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4338 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4340 tree low, high, n_low, n_high;
4342 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4343 and see if we can refine the range. Some of the cases below may not
4344 happen, but it doesn't seem worth worrying about this. We "continue"
4345 the outer loop when we've changed something; otherwise we "break"
4346 the switch, which will "break" the while. */
4349 low = high = build_int_cst (TREE_TYPE (exp), 0);
4353 code = TREE_CODE (exp);
4354 exp_type = TREE_TYPE (exp);
4356 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4358 if (TREE_OPERAND_LENGTH (exp) > 0)
4359 arg0 = TREE_OPERAND (exp, 0);
4360 if (TREE_CODE_CLASS (code) == tcc_comparison
4361 || TREE_CODE_CLASS (code) == tcc_unary
4362 || TREE_CODE_CLASS (code) == tcc_binary)
4363 arg0_type = TREE_TYPE (arg0);
4364 if (TREE_CODE_CLASS (code) == tcc_binary
4365 || TREE_CODE_CLASS (code) == tcc_comparison
4366 || (TREE_CODE_CLASS (code) == tcc_expression
4367 && TREE_OPERAND_LENGTH (exp) > 1))
4368 arg1 = TREE_OPERAND (exp, 1);
4373 case TRUTH_NOT_EXPR:
4374 in_p = ! in_p, exp = arg0;
4377 case EQ_EXPR: case NE_EXPR:
4378 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4379 /* We can only do something if the range is testing for zero
4380 and if the second operand is an integer constant. Note that
4381 saying something is "in" the range we make is done by
4382 complementing IN_P since it will set in the initial case of
4383 being not equal to zero; "out" is leaving it alone. */
4384 if (low == 0 || high == 0
4385 || ! integer_zerop (low) || ! integer_zerop (high)
4386 || TREE_CODE (arg1) != INTEGER_CST)
4391 case NE_EXPR: /* - [c, c] */
4394 case EQ_EXPR: /* + [c, c] */
4395 in_p = ! in_p, low = high = arg1;
4397 case GT_EXPR: /* - [-, c] */
4398 low = 0, high = arg1;
4400 case GE_EXPR: /* + [c, -] */
4401 in_p = ! in_p, low = arg1, high = 0;
4403 case LT_EXPR: /* - [c, -] */
4404 low = arg1, high = 0;
4406 case LE_EXPR: /* + [-, c] */
4407 in_p = ! in_p, low = 0, high = arg1;
4413 /* If this is an unsigned comparison, we also know that EXP is
4414 greater than or equal to zero. We base the range tests we make
4415 on that fact, so we record it here so we can parse existing
4416 range tests. We test arg0_type since often the return type
4417 of, e.g. EQ_EXPR, is boolean. */
4418 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4420 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4422 build_int_cst (arg0_type, 0),
4426 in_p = n_in_p, low = n_low, high = n_high;
4428 /* If the high bound is missing, but we have a nonzero low
4429 bound, reverse the range so it goes from zero to the low bound
4431 if (high == 0 && low && ! integer_zerop (low))
4434 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4435 integer_one_node, 0);
4436 low = build_int_cst (arg0_type, 0);
4444 /* (-x) IN [a,b] -> x in [-b, -a] */
4445 n_low = range_binop (MINUS_EXPR, exp_type,
4446 build_int_cst (exp_type, 0),
4448 n_high = range_binop (MINUS_EXPR, exp_type,
4449 build_int_cst (exp_type, 0),
4451 low = n_low, high = n_high;
4457 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4458 build_int_cst (exp_type, 1));
4461 case PLUS_EXPR: case MINUS_EXPR:
4462 if (TREE_CODE (arg1) != INTEGER_CST)
4465 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4466 move a constant to the other side. */
4467 if (!TYPE_UNSIGNED (arg0_type)
4468 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4471 /* If EXP is signed, any overflow in the computation is undefined,
4472 so we don't worry about it so long as our computations on
4473 the bounds don't overflow. For unsigned, overflow is defined
4474 and this is exactly the right thing. */
4475 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4476 arg0_type, low, 0, arg1, 0);
4477 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4478 arg0_type, high, 1, arg1, 0);
4479 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4480 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4483 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4484 *strict_overflow_p = true;
4486 /* Check for an unsigned range which has wrapped around the maximum
4487 value thus making n_high < n_low, and normalize it. */
4488 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4490 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4491 integer_one_node, 0);
4492 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4493 integer_one_node, 0);
4495 /* If the range is of the form +/- [ x+1, x ], we won't
4496 be able to normalize it. But then, it represents the
4497 whole range or the empty set, so make it
4499 if (tree_int_cst_equal (n_low, low)
4500 && tree_int_cst_equal (n_high, high))
4506 low = n_low, high = n_high;
4511 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
4512 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4515 if (! INTEGRAL_TYPE_P (arg0_type)
4516 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4517 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4520 n_low = low, n_high = high;
4523 n_low = fold_convert (arg0_type, n_low);
4526 n_high = fold_convert (arg0_type, n_high);
4529 /* If we're converting arg0 from an unsigned type, to exp,
4530 a signed type, we will be doing the comparison as unsigned.
4531 The tests above have already verified that LOW and HIGH
4534 So we have to ensure that we will handle large unsigned
4535 values the same way that the current signed bounds treat
4538 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4542 /* For fixed-point modes, we need to pass the saturating flag
4543 as the 2nd parameter. */
4544 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
4545 equiv_type = lang_hooks.types.type_for_mode
4546 (TYPE_MODE (arg0_type),
4547 TYPE_SATURATING (arg0_type));
4549 equiv_type = lang_hooks.types.type_for_mode
4550 (TYPE_MODE (arg0_type), 1);
4552 /* A range without an upper bound is, naturally, unbounded.
4553 Since convert would have cropped a very large value, use
4554 the max value for the destination type. */
4556 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4557 : TYPE_MAX_VALUE (arg0_type);
4559 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4560 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4561 fold_convert (arg0_type,
4563 build_int_cst (arg0_type, 1));
4565 /* If the low bound is specified, "and" the range with the
4566 range for which the original unsigned value will be
4570 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4571 1, n_low, n_high, 1,
4572 fold_convert (arg0_type,
4577 in_p = (n_in_p == in_p);
4581 /* Otherwise, "or" the range with the range of the input
4582 that will be interpreted as negative. */
4583 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4584 0, n_low, n_high, 1,
4585 fold_convert (arg0_type,
4590 in_p = (in_p != n_in_p);
4595 low = n_low, high = n_high;
4605 /* If EXP is a constant, we can evaluate whether this is true or false. */
4606 if (TREE_CODE (exp) == INTEGER_CST)
4608 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4610 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4616 *pin_p = in_p, *plow = low, *phigh = high;
4620 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4621 type, TYPE, return an expression to test if EXP is in (or out of, depending
4622 on IN_P) the range. Return 0 if the test couldn't be created. */
4625 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4627 tree etype = TREE_TYPE (exp);
4630 #ifdef HAVE_canonicalize_funcptr_for_compare
4631 /* Disable this optimization for function pointer expressions
4632 on targets that require function pointer canonicalization. */
4633 if (HAVE_canonicalize_funcptr_for_compare
4634 && TREE_CODE (etype) == POINTER_TYPE
4635 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4641 value = build_range_check (type, exp, 1, low, high);
4643 return invert_truthvalue (value);
4648 if (low == 0 && high == 0)
4649 return build_int_cst (type, 1);
4652 return fold_build2 (LE_EXPR, type, exp,
4653 fold_convert (etype, high));
4656 return fold_build2 (GE_EXPR, type, exp,
4657 fold_convert (etype, low));
4659 if (operand_equal_p (low, high, 0))
4660 return fold_build2 (EQ_EXPR, type, exp,
4661 fold_convert (etype, low));
4663 if (integer_zerop (low))
4665 if (! TYPE_UNSIGNED (etype))
4667 etype = unsigned_type_for (etype);
4668 high = fold_convert (etype, high);
4669 exp = fold_convert (etype, exp);
4671 return build_range_check (type, exp, 1, 0, high);
4674 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4675 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4677 unsigned HOST_WIDE_INT lo;
4681 prec = TYPE_PRECISION (etype);
4682 if (prec <= HOST_BITS_PER_WIDE_INT)
4685 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4689 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4690 lo = (unsigned HOST_WIDE_INT) -1;
4693 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4695 if (TYPE_UNSIGNED (etype))
4697 etype = signed_type_for (etype);
4698 exp = fold_convert (etype, exp);
4700 return fold_build2 (GT_EXPR, type, exp,
4701 build_int_cst (etype, 0));
4705 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4706 This requires wrap-around arithmetics for the type of the expression. */
4707 switch (TREE_CODE (etype))
4710 /* There is no requirement that LOW be within the range of ETYPE
4711 if the latter is a subtype. It must, however, be within the base
4712 type of ETYPE. So be sure we do the subtraction in that type. */
4713 if (TREE_TYPE (etype))
4714 etype = TREE_TYPE (etype);
4719 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4720 TYPE_UNSIGNED (etype));
4727 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4728 if (TREE_CODE (etype) == INTEGER_TYPE
4729 && !TYPE_OVERFLOW_WRAPS (etype))
4731 tree utype, minv, maxv;
4733 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4734 for the type in question, as we rely on this here. */
4735 utype = unsigned_type_for (etype);
4736 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4737 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4738 integer_one_node, 1);
4739 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4741 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4748 high = fold_convert (etype, high);
4749 low = fold_convert (etype, low);
4750 exp = fold_convert (etype, exp);
4752 value = const_binop (MINUS_EXPR, high, low, 0);
4755 if (POINTER_TYPE_P (etype))
4757 if (value != 0 && !TREE_OVERFLOW (value))
4759 low = fold_convert (sizetype, low);
4760 low = fold_build1 (NEGATE_EXPR, sizetype, low);
4761 return build_range_check (type,
4762 fold_build2 (POINTER_PLUS_EXPR, etype, exp, low),
4763 1, build_int_cst (etype, 0), value);
4768 if (value != 0 && !TREE_OVERFLOW (value))
4769 return build_range_check (type,
4770 fold_build2 (MINUS_EXPR, etype, exp, low),
4771 1, build_int_cst (etype, 0), value);
4776 /* Return the predecessor of VAL in its type, handling the infinite case. */
4779 range_predecessor (tree val)
4781 tree type = TREE_TYPE (val);
4783 if (INTEGRAL_TYPE_P (type)
4784 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4787 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4790 /* Return the successor of VAL in its type, handling the infinite case. */
4793 range_successor (tree val)
4795 tree type = TREE_TYPE (val);
4797 if (INTEGRAL_TYPE_P (type)
4798 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4801 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4804 /* Given two ranges, see if we can merge them into one. Return 1 if we
4805 can, 0 if we can't. Set the output range into the specified parameters. */
4808 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4809 tree high0, int in1_p, tree low1, tree high1)
4817 int lowequal = ((low0 == 0 && low1 == 0)
4818 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4819 low0, 0, low1, 0)));
4820 int highequal = ((high0 == 0 && high1 == 0)
4821 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4822 high0, 1, high1, 1)));
4824 /* Make range 0 be the range that starts first, or ends last if they
4825 start at the same value. Swap them if it isn't. */
4826 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4829 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4830 high1, 1, high0, 1))))
4832 temp = in0_p, in0_p = in1_p, in1_p = temp;
4833 tem = low0, low0 = low1, low1 = tem;
4834 tem = high0, high0 = high1, high1 = tem;
4837 /* Now flag two cases, whether the ranges are disjoint or whether the
4838 second range is totally subsumed in the first. Note that the tests
4839 below are simplified by the ones above. */
4840 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4841 high0, 1, low1, 0));
4842 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4843 high1, 1, high0, 1));
4845 /* We now have four cases, depending on whether we are including or
4846 excluding the two ranges. */
4849 /* If they don't overlap, the result is false. If the second range
4850 is a subset it is the result. Otherwise, the range is from the start
4851 of the second to the end of the first. */
4853 in_p = 0, low = high = 0;
4855 in_p = 1, low = low1, high = high1;
4857 in_p = 1, low = low1, high = high0;
4860 else if (in0_p && ! in1_p)
4862 /* If they don't overlap, the result is the first range. If they are
4863 equal, the result is false. If the second range is a subset of the
4864 first, and the ranges begin at the same place, we go from just after
4865 the end of the second range to the end of the first. If the second
4866 range is not a subset of the first, or if it is a subset and both
4867 ranges end at the same place, the range starts at the start of the
4868 first range and ends just before the second range.
4869 Otherwise, we can't describe this as a single range. */
4871 in_p = 1, low = low0, high = high0;
4872 else if (lowequal && highequal)
4873 in_p = 0, low = high = 0;
4874 else if (subset && lowequal)
4876 low = range_successor (high1);
4881 /* We are in the weird situation where high0 > high1 but
4882 high1 has no successor. Punt. */
4886 else if (! subset || highequal)
4889 high = range_predecessor (low1);
4893 /* low0 < low1 but low1 has no predecessor. Punt. */
4901 else if (! in0_p && in1_p)
4903 /* If they don't overlap, the result is the second range. If the second
4904 is a subset of the first, the result is false. Otherwise,
4905 the range starts just after the first range and ends at the
4906 end of the second. */
4908 in_p = 1, low = low1, high = high1;
4909 else if (subset || highequal)
4910 in_p = 0, low = high = 0;
4913 low = range_successor (high0);
4918 /* high1 > high0 but high0 has no successor. Punt. */
4926 /* The case where we are excluding both ranges. Here the complex case
4927 is if they don't overlap. In that case, the only time we have a
4928 range is if they are adjacent. If the second is a subset of the
4929 first, the result is the first. Otherwise, the range to exclude
4930 starts at the beginning of the first range and ends at the end of the
4934 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4935 range_successor (high0),
4937 in_p = 0, low = low0, high = high1;
4940 /* Canonicalize - [min, x] into - [-, x]. */
4941 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4942 switch (TREE_CODE (TREE_TYPE (low0)))
4945 if (TYPE_PRECISION (TREE_TYPE (low0))
4946 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4950 if (tree_int_cst_equal (low0,
4951 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4955 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4956 && integer_zerop (low0))
4963 /* Canonicalize - [x, max] into - [x, -]. */
4964 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4965 switch (TREE_CODE (TREE_TYPE (high1)))
4968 if (TYPE_PRECISION (TREE_TYPE (high1))
4969 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4973 if (tree_int_cst_equal (high1,
4974 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4978 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4979 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4981 integer_one_node, 1)))
4988 /* The ranges might be also adjacent between the maximum and
4989 minimum values of the given type. For
4990 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4991 return + [x + 1, y - 1]. */
4992 if (low0 == 0 && high1 == 0)
4994 low = range_successor (high0);
4995 high = range_predecessor (low1);
4996 if (low == 0 || high == 0)
5006 in_p = 0, low = low0, high = high0;
5008 in_p = 0, low = low0, high = high1;
5011 *pin_p = in_p, *plow = low, *phigh = high;
5016 /* Subroutine of fold, looking inside expressions of the form
5017 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
5018 of the COND_EXPR. This function is being used also to optimize
5019 A op B ? C : A, by reversing the comparison first.
5021 Return a folded expression whose code is not a COND_EXPR
5022 anymore, or NULL_TREE if no folding opportunity is found. */
5025 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
5027 enum tree_code comp_code = TREE_CODE (arg0);
5028 tree arg00 = TREE_OPERAND (arg0, 0);
5029 tree arg01 = TREE_OPERAND (arg0, 1);
5030 tree arg1_type = TREE_TYPE (arg1);
5036 /* If we have A op 0 ? A : -A, consider applying the following
5039 A == 0? A : -A same as -A
5040 A != 0? A : -A same as A
5041 A >= 0? A : -A same as abs (A)
5042 A > 0? A : -A same as abs (A)
5043 A <= 0? A : -A same as -abs (A)
5044 A < 0? A : -A same as -abs (A)
5046 None of these transformations work for modes with signed
5047 zeros. If A is +/-0, the first two transformations will
5048 change the sign of the result (from +0 to -0, or vice
5049 versa). The last four will fix the sign of the result,
5050 even though the original expressions could be positive or
5051 negative, depending on the sign of A.
5053 Note that all these transformations are correct if A is
5054 NaN, since the two alternatives (A and -A) are also NaNs. */
5055 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
5056 ? real_zerop (arg01)
5057 : integer_zerop (arg01))
5058 && ((TREE_CODE (arg2) == NEGATE_EXPR
5059 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
5060 /* In the case that A is of the form X-Y, '-A' (arg2) may
5061 have already been folded to Y-X, check for that. */
5062 || (TREE_CODE (arg1) == MINUS_EXPR
5063 && TREE_CODE (arg2) == MINUS_EXPR
5064 && operand_equal_p (TREE_OPERAND (arg1, 0),
5065 TREE_OPERAND (arg2, 1), 0)
5066 && operand_equal_p (TREE_OPERAND (arg1, 1),
5067 TREE_OPERAND (arg2, 0), 0))))
5072 tem = fold_convert (arg1_type, arg1);
5073 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
5076 return pedantic_non_lvalue (fold_convert (type, arg1));
5079 if (flag_trapping_math)
5084 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5085 arg1 = fold_convert (signed_type_for
5086 (TREE_TYPE (arg1)), arg1);
5087 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5088 return pedantic_non_lvalue (fold_convert (type, tem));
5091 if (flag_trapping_math)
5095 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5096 arg1 = fold_convert (signed_type_for
5097 (TREE_TYPE (arg1)), arg1);
5098 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5099 return negate_expr (fold_convert (type, tem));
5101 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5105 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
5106 A == 0 ? A : 0 is always 0 unless A is -0. Note that
5107 both transformations are correct when A is NaN: A != 0
5108 is then true, and A == 0 is false. */
5110 if (integer_zerop (arg01) && integer_zerop (arg2))
5112 if (comp_code == NE_EXPR)
5113 return pedantic_non_lvalue (fold_convert (type, arg1));
5114 else if (comp_code == EQ_EXPR)
5115 return build_int_cst (type, 0);
5118 /* Try some transformations of A op B ? A : B.
5120 A == B? A : B same as B
5121 A != B? A : B same as A
5122 A >= B? A : B same as max (A, B)
5123 A > B? A : B same as max (B, A)
5124 A <= B? A : B same as min (A, B)
5125 A < B? A : B same as min (B, A)
5127 As above, these transformations don't work in the presence
5128 of signed zeros. For example, if A and B are zeros of
5129 opposite sign, the first two transformations will change
5130 the sign of the result. In the last four, the original
5131 expressions give different results for (A=+0, B=-0) and
5132 (A=-0, B=+0), but the transformed expressions do not.
5134 The first two transformations are correct if either A or B
5135 is a NaN. In the first transformation, the condition will
5136 be false, and B will indeed be chosen. In the case of the
5137 second transformation, the condition A != B will be true,
5138 and A will be chosen.
5140 The conversions to max() and min() are not correct if B is
5141 a number and A is not. The conditions in the original
5142 expressions will be false, so all four give B. The min()
5143 and max() versions would give a NaN instead. */
5144 if (operand_equal_for_comparison_p (arg01, arg2, arg00)
5145 /* Avoid these transformations if the COND_EXPR may be used
5146 as an lvalue in the C++ front-end. PR c++/19199. */
5148 || (strcmp (lang_hooks.name, "GNU C++") != 0
5149 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
5150 || ! maybe_lvalue_p (arg1)
5151 || ! maybe_lvalue_p (arg2)))
5153 tree comp_op0 = arg00;
5154 tree comp_op1 = arg01;
5155 tree comp_type = TREE_TYPE (comp_op0);
5157 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
5158 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
5168 return pedantic_non_lvalue (fold_convert (type, arg2));
5170 return pedantic_non_lvalue (fold_convert (type, arg1));
5175 /* In C++ a ?: expression can be an lvalue, so put the
5176 operand which will be used if they are equal first
5177 so that we can convert this back to the
5178 corresponding COND_EXPR. */
5179 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5181 comp_op0 = fold_convert (comp_type, comp_op0);
5182 comp_op1 = fold_convert (comp_type, comp_op1);
5183 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
5184 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
5185 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
5186 return pedantic_non_lvalue (fold_convert (type, tem));
5193 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5195 comp_op0 = fold_convert (comp_type, comp_op0);
5196 comp_op1 = fold_convert (comp_type, comp_op1);
5197 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
5198 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
5199 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
5200 return pedantic_non_lvalue (fold_convert (type, tem));
5204 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5205 return pedantic_non_lvalue (fold_convert (type, arg2));
5208 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5209 return pedantic_non_lvalue (fold_convert (type, arg1));
5212 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5217 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
5218 we might still be able to simplify this. For example,
5219 if C1 is one less or one more than C2, this might have started
5220 out as a MIN or MAX and been transformed by this function.
5221 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
5223 if (INTEGRAL_TYPE_P (type)
5224 && TREE_CODE (arg01) == INTEGER_CST
5225 && TREE_CODE (arg2) == INTEGER_CST)
5229 /* We can replace A with C1 in this case. */
5230 arg1 = fold_convert (type, arg01);
5231 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
5234 /* If C1 is C2 + 1, this is min(A, C2). */
5235 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5237 && operand_equal_p (arg01,
5238 const_binop (PLUS_EXPR, arg2,
5239 build_int_cst (type, 1), 0),
5241 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5243 fold_convert (type, arg1),
5248 /* If C1 is C2 - 1, this is min(A, C2). */
5249 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5251 && operand_equal_p (arg01,
5252 const_binop (MINUS_EXPR, arg2,
5253 build_int_cst (type, 1), 0),
5255 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5257 fold_convert (type, arg1),
5262 /* If C1 is C2 - 1, this is max(A, C2). */
5263 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5265 && operand_equal_p (arg01,
5266 const_binop (MINUS_EXPR, arg2,
5267 build_int_cst (type, 1), 0),
5269 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5271 fold_convert (type, arg1),
5276 /* If C1 is C2 + 1, this is max(A, C2). */
5277 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5279 && operand_equal_p (arg01,
5280 const_binop (PLUS_EXPR, arg2,
5281 build_int_cst (type, 1), 0),
5283 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5285 fold_convert (type, arg1),
5299 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5300 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
5303 /* EXP is some logical combination of boolean tests. See if we can
5304 merge it into some range test. Return the new tree if so. */
5307 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
5309 int or_op = (code == TRUTH_ORIF_EXPR
5310 || code == TRUTH_OR_EXPR);
5311 int in0_p, in1_p, in_p;
5312 tree low0, low1, low, high0, high1, high;
5313 bool strict_overflow_p = false;
5314 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
5315 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
5317 const char * const warnmsg = G_("assuming signed overflow does not occur "
5318 "when simplifying range test");
5320 /* If this is an OR operation, invert both sides; we will invert
5321 again at the end. */
5323 in0_p = ! in0_p, in1_p = ! in1_p;
5325 /* If both expressions are the same, if we can merge the ranges, and we
5326 can build the range test, return it or it inverted. If one of the
5327 ranges is always true or always false, consider it to be the same
5328 expression as the other. */
5329 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
5330 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
5332 && 0 != (tem = (build_range_check (type,
5334 : rhs != 0 ? rhs : integer_zero_node,
5337 if (strict_overflow_p)
5338 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
5339 return or_op ? invert_truthvalue (tem) : tem;
5342 /* On machines where the branch cost is expensive, if this is a
5343 short-circuited branch and the underlying object on both sides
5344 is the same, make a non-short-circuit operation. */
5345 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5346 && lhs != 0 && rhs != 0
5347 && (code == TRUTH_ANDIF_EXPR
5348 || code == TRUTH_ORIF_EXPR)
5349 && operand_equal_p (lhs, rhs, 0))
5351 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5352 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5353 which cases we can't do this. */
5354 if (simple_operand_p (lhs))
5355 return build2 (code == TRUTH_ANDIF_EXPR
5356 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5359 else if (lang_hooks.decls.global_bindings_p () == 0
5360 && ! CONTAINS_PLACEHOLDER_P (lhs))
5362 tree common = save_expr (lhs);
5364 if (0 != (lhs = build_range_check (type, common,
5365 or_op ? ! in0_p : in0_p,
5367 && (0 != (rhs = build_range_check (type, common,
5368 or_op ? ! in1_p : in1_p,
5371 if (strict_overflow_p)
5372 fold_overflow_warning (warnmsg,
5373 WARN_STRICT_OVERFLOW_COMPARISON);
5374 return build2 (code == TRUTH_ANDIF_EXPR
5375 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5384 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5385 bit value. Arrange things so the extra bits will be set to zero if and
5386 only if C is signed-extended to its full width. If MASK is nonzero,
5387 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5390 unextend (tree c, int p, int unsignedp, tree mask)
5392 tree type = TREE_TYPE (c);
5393 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5396 if (p == modesize || unsignedp)
5399 /* We work by getting just the sign bit into the low-order bit, then
5400 into the high-order bit, then sign-extend. We then XOR that value
5402 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5403 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5405 /* We must use a signed type in order to get an arithmetic right shift.
5406 However, we must also avoid introducing accidental overflows, so that
5407 a subsequent call to integer_zerop will work. Hence we must
5408 do the type conversion here. At this point, the constant is either
5409 zero or one, and the conversion to a signed type can never overflow.
5410 We could get an overflow if this conversion is done anywhere else. */
5411 if (TYPE_UNSIGNED (type))
5412 temp = fold_convert (signed_type_for (type), temp);
5414 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5415 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5417 temp = const_binop (BIT_AND_EXPR, temp,
5418 fold_convert (TREE_TYPE (c), mask), 0);
5419 /* If necessary, convert the type back to match the type of C. */
5420 if (TYPE_UNSIGNED (type))
5421 temp = fold_convert (type, temp);
5423 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5426 /* Find ways of folding logical expressions of LHS and RHS:
5427 Try to merge two comparisons to the same innermost item.
5428 Look for range tests like "ch >= '0' && ch <= '9'".
5429 Look for combinations of simple terms on machines with expensive branches
5430 and evaluate the RHS unconditionally.
5432 For example, if we have p->a == 2 && p->b == 4 and we can make an
5433 object large enough to span both A and B, we can do this with a comparison
5434 against the object ANDed with the a mask.
5436 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5437 operations to do this with one comparison.
5439 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5440 function and the one above.
5442 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5443 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5445 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5448 We return the simplified tree or 0 if no optimization is possible. */
5451 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5453 /* If this is the "or" of two comparisons, we can do something if
5454 the comparisons are NE_EXPR. If this is the "and", we can do something
5455 if the comparisons are EQ_EXPR. I.e.,
5456 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5458 WANTED_CODE is this operation code. For single bit fields, we can
5459 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5460 comparison for one-bit fields. */
5462 enum tree_code wanted_code;
5463 enum tree_code lcode, rcode;
5464 tree ll_arg, lr_arg, rl_arg, rr_arg;
5465 tree ll_inner, lr_inner, rl_inner, rr_inner;
5466 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5467 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5468 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
5469 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
5470 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5471 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5472 enum machine_mode lnmode, rnmode;
5473 tree ll_mask, lr_mask, rl_mask, rr_mask;
5474 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5475 tree l_const, r_const;
5476 tree lntype, rntype, result;
5477 int first_bit, end_bit;
5479 tree orig_lhs = lhs, orig_rhs = rhs;
5480 enum tree_code orig_code = code;
5482 /* Start by getting the comparison codes. Fail if anything is volatile.
5483 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5484 it were surrounded with a NE_EXPR. */
5486 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5489 lcode = TREE_CODE (lhs);
5490 rcode = TREE_CODE (rhs);
5492 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5494 lhs = build2 (NE_EXPR, truth_type, lhs,
5495 build_int_cst (TREE_TYPE (lhs), 0));
5499 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5501 rhs = build2 (NE_EXPR, truth_type, rhs,
5502 build_int_cst (TREE_TYPE (rhs), 0));
5506 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5507 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5510 ll_arg = TREE_OPERAND (lhs, 0);
5511 lr_arg = TREE_OPERAND (lhs, 1);
5512 rl_arg = TREE_OPERAND (rhs, 0);
5513 rr_arg = TREE_OPERAND (rhs, 1);
5515 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5516 if (simple_operand_p (ll_arg)
5517 && simple_operand_p (lr_arg))
5520 if (operand_equal_p (ll_arg, rl_arg, 0)
5521 && operand_equal_p (lr_arg, rr_arg, 0))
5523 result = combine_comparisons (code, lcode, rcode,
5524 truth_type, ll_arg, lr_arg);
5528 else if (operand_equal_p (ll_arg, rr_arg, 0)
5529 && operand_equal_p (lr_arg, rl_arg, 0))
5531 result = combine_comparisons (code, lcode,
5532 swap_tree_comparison (rcode),
5533 truth_type, ll_arg, lr_arg);
5539 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5540 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5542 /* If the RHS can be evaluated unconditionally and its operands are
5543 simple, it wins to evaluate the RHS unconditionally on machines
5544 with expensive branches. In this case, this isn't a comparison
5545 that can be merged. Avoid doing this if the RHS is a floating-point
5546 comparison since those can trap. */
5548 if (BRANCH_COST >= 2
5549 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5550 && simple_operand_p (rl_arg)
5551 && simple_operand_p (rr_arg))
5553 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5554 if (code == TRUTH_OR_EXPR
5555 && lcode == NE_EXPR && integer_zerop (lr_arg)
5556 && rcode == NE_EXPR && integer_zerop (rr_arg)
5557 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5558 return build2 (NE_EXPR, truth_type,
5559 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5561 build_int_cst (TREE_TYPE (ll_arg), 0));
5563 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5564 if (code == TRUTH_AND_EXPR
5565 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5566 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5567 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5568 return build2 (EQ_EXPR, truth_type,
5569 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5571 build_int_cst (TREE_TYPE (ll_arg), 0));
5573 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5575 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5576 return build2 (code, truth_type, lhs, rhs);
5581 /* See if the comparisons can be merged. Then get all the parameters for
5584 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5585 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5589 ll_inner = decode_field_reference (ll_arg,
5590 &ll_bitsize, &ll_bitpos, &ll_mode,
5591 &ll_unsignedp, &volatilep, &ll_mask,
5593 lr_inner = decode_field_reference (lr_arg,
5594 &lr_bitsize, &lr_bitpos, &lr_mode,
5595 &lr_unsignedp, &volatilep, &lr_mask,
5597 rl_inner = decode_field_reference (rl_arg,
5598 &rl_bitsize, &rl_bitpos, &rl_mode,
5599 &rl_unsignedp, &volatilep, &rl_mask,
5601 rr_inner = decode_field_reference (rr_arg,
5602 &rr_bitsize, &rr_bitpos, &rr_mode,
5603 &rr_unsignedp, &volatilep, &rr_mask,
5606 /* It must be true that the inner operation on the lhs of each
5607 comparison must be the same if we are to be able to do anything.
5608 Then see if we have constants. If not, the same must be true for
5610 if (volatilep || ll_inner == 0 || rl_inner == 0
5611 || ! operand_equal_p (ll_inner, rl_inner, 0))
5614 if (TREE_CODE (lr_arg) == INTEGER_CST
5615 && TREE_CODE (rr_arg) == INTEGER_CST)
5616 l_const = lr_arg, r_const = rr_arg;
5617 else if (lr_inner == 0 || rr_inner == 0
5618 || ! operand_equal_p (lr_inner, rr_inner, 0))
5621 l_const = r_const = 0;
5623 /* If either comparison code is not correct for our logical operation,
5624 fail. However, we can convert a one-bit comparison against zero into
5625 the opposite comparison against that bit being set in the field. */
5627 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5628 if (lcode != wanted_code)
5630 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5632 /* Make the left operand unsigned, since we are only interested
5633 in the value of one bit. Otherwise we are doing the wrong
5642 /* This is analogous to the code for l_const above. */
5643 if (rcode != wanted_code)
5645 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5654 /* See if we can find a mode that contains both fields being compared on
5655 the left. If we can't, fail. Otherwise, update all constants and masks
5656 to be relative to a field of that size. */
5657 first_bit = MIN (ll_bitpos, rl_bitpos);
5658 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5659 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5660 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5662 if (lnmode == VOIDmode)
5665 lnbitsize = GET_MODE_BITSIZE (lnmode);
5666 lnbitpos = first_bit & ~ (lnbitsize - 1);
5667 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5668 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5670 if (BYTES_BIG_ENDIAN)
5672 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5673 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5676 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5677 size_int (xll_bitpos), 0);
5678 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5679 size_int (xrl_bitpos), 0);
5683 l_const = fold_convert (lntype, l_const);
5684 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5685 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5686 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5687 fold_build1 (BIT_NOT_EXPR,
5691 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5693 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5698 r_const = fold_convert (lntype, r_const);
5699 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5700 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5701 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5702 fold_build1 (BIT_NOT_EXPR,
5706 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5708 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5712 /* If the right sides are not constant, do the same for it. Also,
5713 disallow this optimization if a size or signedness mismatch occurs
5714 between the left and right sides. */
5717 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
5718 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
5719 /* Make sure the two fields on the right
5720 correspond to the left without being swapped. */
5721 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
5724 first_bit = MIN (lr_bitpos, rr_bitpos);
5725 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
5726 rnmode = get_best_mode (end_bit - first_bit, first_bit,
5727 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
5729 if (rnmode == VOIDmode)
5732 rnbitsize = GET_MODE_BITSIZE (rnmode);
5733 rnbitpos = first_bit & ~ (rnbitsize - 1);
5734 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
5735 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
5737 if (BYTES_BIG_ENDIAN)
5739 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
5740 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
5743 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
5744 size_int (xlr_bitpos), 0);
5745 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
5746 size_int (xrr_bitpos), 0);
5748 /* Make a mask that corresponds to both fields being compared.
5749 Do this for both items being compared. If the operands are the
5750 same size and the bits being compared are in the same position
5751 then we can do this by masking both and comparing the masked
5753 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5754 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
5755 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
5757 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5758 ll_unsignedp || rl_unsignedp);
5759 if (! all_ones_mask_p (ll_mask, lnbitsize))
5760 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
5762 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
5763 lr_unsignedp || rr_unsignedp);
5764 if (! all_ones_mask_p (lr_mask, rnbitsize))
5765 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
5767 return build2 (wanted_code, truth_type, lhs, rhs);
5770 /* There is still another way we can do something: If both pairs of
5771 fields being compared are adjacent, we may be able to make a wider
5772 field containing them both.
5774 Note that we still must mask the lhs/rhs expressions. Furthermore,
5775 the mask must be shifted to account for the shift done by
5776 make_bit_field_ref. */
5777 if ((ll_bitsize + ll_bitpos == rl_bitpos
5778 && lr_bitsize + lr_bitpos == rr_bitpos)
5779 || (ll_bitpos == rl_bitpos + rl_bitsize
5780 && lr_bitpos == rr_bitpos + rr_bitsize))
5784 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
5785 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
5786 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
5787 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
5789 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
5790 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
5791 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
5792 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
5794 /* Convert to the smaller type before masking out unwanted bits. */
5796 if (lntype != rntype)
5798 if (lnbitsize > rnbitsize)
5800 lhs = fold_convert (rntype, lhs);
5801 ll_mask = fold_convert (rntype, ll_mask);
5804 else if (lnbitsize < rnbitsize)
5806 rhs = fold_convert (lntype, rhs);
5807 lr_mask = fold_convert (lntype, lr_mask);
5812 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
5813 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
5815 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
5816 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
5818 return build2 (wanted_code, truth_type, lhs, rhs);
5824 /* Handle the case of comparisons with constants. If there is something in
5825 common between the masks, those bits of the constants must be the same.
5826 If not, the condition is always false. Test for this to avoid generating
5827 incorrect code below. */
5828 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5829 if (! integer_zerop (result)
5830 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5831 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5833 if (wanted_code == NE_EXPR)
5835 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5836 return constant_boolean_node (true, truth_type);
5840 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5841 return constant_boolean_node (false, truth_type);
5845 /* Construct the expression we will return. First get the component
5846 reference we will make. Unless the mask is all ones the width of
5847 that field, perform the mask operation. Then compare with the
5849 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5850 ll_unsignedp || rl_unsignedp);
5852 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5853 if (! all_ones_mask_p (ll_mask, lnbitsize))
5854 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
5856 return build2 (wanted_code, truth_type, result,
5857 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
5860 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5864 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5867 enum tree_code op_code;
5868 tree comp_const = op1;
5870 int consts_equal, consts_lt;
5873 STRIP_SIGN_NOPS (arg0);
5875 op_code = TREE_CODE (arg0);
5876 minmax_const = TREE_OPERAND (arg0, 1);
5877 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5878 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5879 inner = TREE_OPERAND (arg0, 0);
5881 /* If something does not permit us to optimize, return the original tree. */
5882 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5883 || TREE_CODE (comp_const) != INTEGER_CST
5884 || TREE_OVERFLOW (comp_const)
5885 || TREE_CODE (minmax_const) != INTEGER_CST
5886 || TREE_OVERFLOW (minmax_const))
5889 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5890 and GT_EXPR, doing the rest with recursive calls using logical
5894 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5896 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5899 return invert_truthvalue (tem);
5905 fold_build2 (TRUTH_ORIF_EXPR, type,
5906 optimize_minmax_comparison
5907 (EQ_EXPR, type, arg0, comp_const),
5908 optimize_minmax_comparison
5909 (GT_EXPR, type, arg0, comp_const));
5912 if (op_code == MAX_EXPR && consts_equal)
5913 /* MAX (X, 0) == 0 -> X <= 0 */
5914 return fold_build2 (LE_EXPR, type, inner, comp_const);
5916 else if (op_code == MAX_EXPR && consts_lt)
5917 /* MAX (X, 0) == 5 -> X == 5 */
5918 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5920 else if (op_code == MAX_EXPR)
5921 /* MAX (X, 0) == -1 -> false */
5922 return omit_one_operand (type, integer_zero_node, inner);
5924 else if (consts_equal)
5925 /* MIN (X, 0) == 0 -> X >= 0 */
5926 return fold_build2 (GE_EXPR, type, inner, comp_const);
5929 /* MIN (X, 0) == 5 -> false */
5930 return omit_one_operand (type, integer_zero_node, inner);
5933 /* MIN (X, 0) == -1 -> X == -1 */
5934 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5937 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5938 /* MAX (X, 0) > 0 -> X > 0
5939 MAX (X, 0) > 5 -> X > 5 */
5940 return fold_build2 (GT_EXPR, type, inner, comp_const);
5942 else if (op_code == MAX_EXPR)
5943 /* MAX (X, 0) > -1 -> true */
5944 return omit_one_operand (type, integer_one_node, inner);
5946 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5947 /* MIN (X, 0) > 0 -> false
5948 MIN (X, 0) > 5 -> false */
5949 return omit_one_operand (type, integer_zero_node, inner);
5952 /* MIN (X, 0) > -1 -> X > -1 */
5953 return fold_build2 (GT_EXPR, type, inner, comp_const);
5960 /* T is an integer expression that is being multiplied, divided, or taken a
5961 modulus (CODE says which and what kind of divide or modulus) by a
5962 constant C. See if we can eliminate that operation by folding it with
5963 other operations already in T. WIDE_TYPE, if non-null, is a type that
5964 should be used for the computation if wider than our type.
5966 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5967 (X * 2) + (Y * 4). We must, however, be assured that either the original
5968 expression would not overflow or that overflow is undefined for the type
5969 in the language in question.
5971 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5972 the machine has a multiply-accumulate insn or that this is part of an
5973 addressing calculation.
5975 If we return a non-null expression, it is an equivalent form of the
5976 original computation, but need not be in the original type.
5978 We set *STRICT_OVERFLOW_P to true if the return values depends on
5979 signed overflow being undefined. Otherwise we do not change
5980 *STRICT_OVERFLOW_P. */
5983 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
5984 bool *strict_overflow_p)
5986 /* To avoid exponential search depth, refuse to allow recursion past
5987 three levels. Beyond that (1) it's highly unlikely that we'll find
5988 something interesting and (2) we've probably processed it before
5989 when we built the inner expression. */
5998 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
6005 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
6006 bool *strict_overflow_p)
6008 tree type = TREE_TYPE (t);
6009 enum tree_code tcode = TREE_CODE (t);
6010 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
6011 > GET_MODE_SIZE (TYPE_MODE (type)))
6012 ? wide_type : type);
6014 int same_p = tcode == code;
6015 tree op0 = NULL_TREE, op1 = NULL_TREE;
6016 bool sub_strict_overflow_p;
6018 /* Don't deal with constants of zero here; they confuse the code below. */
6019 if (integer_zerop (c))
6022 if (TREE_CODE_CLASS (tcode) == tcc_unary)
6023 op0 = TREE_OPERAND (t, 0);
6025 if (TREE_CODE_CLASS (tcode) == tcc_binary)
6026 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
6028 /* Note that we need not handle conditional operations here since fold
6029 already handles those cases. So just do arithmetic here. */
6033 /* For a constant, we can always simplify if we are a multiply
6034 or (for divide and modulus) if it is a multiple of our constant. */
6035 if (code == MULT_EXPR
6036 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
6037 return const_binop (code, fold_convert (ctype, t),
6038 fold_convert (ctype, c), 0);
6041 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
6042 /* If op0 is an expression ... */
6043 if ((COMPARISON_CLASS_P (op0)
6044 || UNARY_CLASS_P (op0)
6045 || BINARY_CLASS_P (op0)
6046 || VL_EXP_CLASS_P (op0)
6047 || EXPRESSION_CLASS_P (op0))
6048 /* ... and is unsigned, and its type is smaller than ctype,
6049 then we cannot pass through as widening. */
6050 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
6051 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
6052 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
6053 && (GET_MODE_SIZE (TYPE_MODE (ctype))
6054 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
6055 /* ... or this is a truncation (t is narrower than op0),
6056 then we cannot pass through this narrowing. */
6057 || (GET_MODE_SIZE (TYPE_MODE (type))
6058 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
6059 /* ... or signedness changes for division or modulus,
6060 then we cannot pass through this conversion. */
6061 || (code != MULT_EXPR
6062 && (TYPE_UNSIGNED (ctype)
6063 != TYPE_UNSIGNED (TREE_TYPE (op0))))
6064 /* ... or has undefined overflow while the converted to
6065 type has not, we cannot do the operation in the inner type
6066 as that would introduce undefined overflow. */
6067 || (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))
6068 && !TYPE_OVERFLOW_UNDEFINED (type))))
6071 /* Pass the constant down and see if we can make a simplification. If
6072 we can, replace this expression with the inner simplification for
6073 possible later conversion to our or some other type. */
6074 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
6075 && TREE_CODE (t2) == INTEGER_CST
6076 && !TREE_OVERFLOW (t2)
6077 && (0 != (t1 = extract_muldiv (op0, t2, code,
6079 ? ctype : NULL_TREE,
6080 strict_overflow_p))))
6085 /* If widening the type changes it from signed to unsigned, then we
6086 must avoid building ABS_EXPR itself as unsigned. */
6087 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
6089 tree cstype = (*signed_type_for) (ctype);
6090 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
6093 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
6094 return fold_convert (ctype, t1);
6100 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
6102 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
6105 case MIN_EXPR: case MAX_EXPR:
6106 /* If widening the type changes the signedness, then we can't perform
6107 this optimization as that changes the result. */
6108 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
6111 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
6112 sub_strict_overflow_p = false;
6113 if ((t1 = extract_muldiv (op0, c, code, wide_type,
6114 &sub_strict_overflow_p)) != 0
6115 && (t2 = extract_muldiv (op1, c, code, wide_type,
6116 &sub_strict_overflow_p)) != 0)
6118 if (tree_int_cst_sgn (c) < 0)
6119 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
6120 if (sub_strict_overflow_p)
6121 *strict_overflow_p = true;
6122 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6123 fold_convert (ctype, t2));
6127 case LSHIFT_EXPR: case RSHIFT_EXPR:
6128 /* If the second operand is constant, this is a multiplication
6129 or floor division, by a power of two, so we can treat it that
6130 way unless the multiplier or divisor overflows. Signed
6131 left-shift overflow is implementation-defined rather than
6132 undefined in C90, so do not convert signed left shift into
6134 if (TREE_CODE (op1) == INTEGER_CST
6135 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
6136 /* const_binop may not detect overflow correctly,
6137 so check for it explicitly here. */
6138 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
6139 && TREE_INT_CST_HIGH (op1) == 0
6140 && 0 != (t1 = fold_convert (ctype,
6141 const_binop (LSHIFT_EXPR,
6144 && !TREE_OVERFLOW (t1))
6145 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
6146 ? MULT_EXPR : FLOOR_DIV_EXPR,
6147 ctype, fold_convert (ctype, op0), t1),
6148 c, code, wide_type, strict_overflow_p);
6151 case PLUS_EXPR: case MINUS_EXPR:
6152 /* See if we can eliminate the operation on both sides. If we can, we
6153 can return a new PLUS or MINUS. If we can't, the only remaining
6154 cases where we can do anything are if the second operand is a
6156 sub_strict_overflow_p = false;
6157 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
6158 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
6159 if (t1 != 0 && t2 != 0
6160 && (code == MULT_EXPR
6161 /* If not multiplication, we can only do this if both operands
6162 are divisible by c. */
6163 || (multiple_of_p (ctype, op0, c)
6164 && multiple_of_p (ctype, op1, c))))
6166 if (sub_strict_overflow_p)
6167 *strict_overflow_p = true;
6168 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6169 fold_convert (ctype, t2));
6172 /* If this was a subtraction, negate OP1 and set it to be an addition.
6173 This simplifies the logic below. */
6174 if (tcode == MINUS_EXPR)
6175 tcode = PLUS_EXPR, op1 = negate_expr (op1);
6177 if (TREE_CODE (op1) != INTEGER_CST)
6180 /* If either OP1 or C are negative, this optimization is not safe for
6181 some of the division and remainder types while for others we need
6182 to change the code. */
6183 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
6185 if (code == CEIL_DIV_EXPR)
6186 code = FLOOR_DIV_EXPR;
6187 else if (code == FLOOR_DIV_EXPR)
6188 code = CEIL_DIV_EXPR;
6189 else if (code != MULT_EXPR
6190 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
6194 /* If it's a multiply or a division/modulus operation of a multiple
6195 of our constant, do the operation and verify it doesn't overflow. */
6196 if (code == MULT_EXPR
6197 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6199 op1 = const_binop (code, fold_convert (ctype, op1),
6200 fold_convert (ctype, c), 0);
6201 /* We allow the constant to overflow with wrapping semantics. */
6203 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
6209 /* If we have an unsigned type is not a sizetype, we cannot widen
6210 the operation since it will change the result if the original
6211 computation overflowed. */
6212 if (TYPE_UNSIGNED (ctype)
6213 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
6217 /* If we were able to eliminate our operation from the first side,
6218 apply our operation to the second side and reform the PLUS. */
6219 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
6220 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
6222 /* The last case is if we are a multiply. In that case, we can
6223 apply the distributive law to commute the multiply and addition
6224 if the multiplication of the constants doesn't overflow. */
6225 if (code == MULT_EXPR)
6226 return fold_build2 (tcode, ctype,
6227 fold_build2 (code, ctype,
6228 fold_convert (ctype, op0),
6229 fold_convert (ctype, c)),
6235 /* We have a special case here if we are doing something like
6236 (C * 8) % 4 since we know that's zero. */
6237 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
6238 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
6239 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
6240 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6241 return omit_one_operand (type, integer_zero_node, op0);
6243 /* ... fall through ... */
6245 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
6246 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
6247 /* If we can extract our operation from the LHS, do so and return a
6248 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
6249 do something only if the second operand is a constant. */
6251 && (t1 = extract_muldiv (op0, c, code, wide_type,
6252 strict_overflow_p)) != 0)
6253 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6254 fold_convert (ctype, op1));
6255 else if (tcode == MULT_EXPR && code == MULT_EXPR
6256 && (t1 = extract_muldiv (op1, c, code, wide_type,
6257 strict_overflow_p)) != 0)
6258 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6259 fold_convert (ctype, t1));
6260 else if (TREE_CODE (op1) != INTEGER_CST)
6263 /* If these are the same operation types, we can associate them
6264 assuming no overflow. */
6266 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
6267 fold_convert (ctype, c), 0))
6268 && !TREE_OVERFLOW (t1))
6269 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
6271 /* If these operations "cancel" each other, we have the main
6272 optimizations of this pass, which occur when either constant is a
6273 multiple of the other, in which case we replace this with either an
6274 operation or CODE or TCODE.
6276 If we have an unsigned type that is not a sizetype, we cannot do
6277 this since it will change the result if the original computation
6279 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
6280 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
6281 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
6282 || (tcode == MULT_EXPR
6283 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
6284 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
6285 && code != MULT_EXPR)))
6287 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6289 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6290 *strict_overflow_p = true;
6291 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6292 fold_convert (ctype,
6293 const_binop (TRUNC_DIV_EXPR,
6296 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
6298 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6299 *strict_overflow_p = true;
6300 return fold_build2 (code, ctype, fold_convert (ctype, op0),
6301 fold_convert (ctype,
6302 const_binop (TRUNC_DIV_EXPR,
6315 /* Return a node which has the indicated constant VALUE (either 0 or
6316 1), and is of the indicated TYPE. */
6319 constant_boolean_node (int value, tree type)
6321 if (type == integer_type_node)
6322 return value ? integer_one_node : integer_zero_node;
6323 else if (type == boolean_type_node)
6324 return value ? boolean_true_node : boolean_false_node;
6326 return build_int_cst (type, value);
6330 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6331 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6332 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6333 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6334 COND is the first argument to CODE; otherwise (as in the example
6335 given here), it is the second argument. TYPE is the type of the
6336 original expression. Return NULL_TREE if no simplification is
6340 fold_binary_op_with_conditional_arg (enum tree_code code,
6341 tree type, tree op0, tree op1,
6342 tree cond, tree arg, int cond_first_p)
6344 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6345 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6346 tree test, true_value, false_value;
6347 tree lhs = NULL_TREE;
6348 tree rhs = NULL_TREE;
6350 /* This transformation is only worthwhile if we don't have to wrap
6351 arg in a SAVE_EXPR, and the operation can be simplified on at least
6352 one of the branches once its pushed inside the COND_EXPR. */
6353 if (!TREE_CONSTANT (arg))
6356 if (TREE_CODE (cond) == COND_EXPR)
6358 test = TREE_OPERAND (cond, 0);
6359 true_value = TREE_OPERAND (cond, 1);
6360 false_value = TREE_OPERAND (cond, 2);
6361 /* If this operand throws an expression, then it does not make
6362 sense to try to perform a logical or arithmetic operation
6364 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6366 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6371 tree testtype = TREE_TYPE (cond);
6373 true_value = constant_boolean_node (true, testtype);
6374 false_value = constant_boolean_node (false, testtype);
6377 arg = fold_convert (arg_type, arg);
6380 true_value = fold_convert (cond_type, true_value);
6382 lhs = fold_build2 (code, type, true_value, arg);
6384 lhs = fold_build2 (code, type, arg, true_value);
6388 false_value = fold_convert (cond_type, false_value);
6390 rhs = fold_build2 (code, type, false_value, arg);
6392 rhs = fold_build2 (code, type, arg, false_value);
6395 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6396 return fold_convert (type, test);
6400 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6402 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6403 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6404 ADDEND is the same as X.
6406 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6407 and finite. The problematic cases are when X is zero, and its mode
6408 has signed zeros. In the case of rounding towards -infinity,
6409 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6410 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6413 fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
6415 if (!real_zerop (addend))
6418 /* Don't allow the fold with -fsignaling-nans. */
6419 if (HONOR_SNANS (TYPE_MODE (type)))
6422 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6423 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6426 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6427 if (TREE_CODE (addend) == REAL_CST
6428 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6431 /* The mode has signed zeros, and we have to honor their sign.
6432 In this situation, there is only one case we can return true for.
6433 X - 0 is the same as X unless rounding towards -infinity is
6435 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6438 /* Subroutine of fold() that checks comparisons of built-in math
6439 functions against real constants.
6441 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6442 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6443 is the type of the result and ARG0 and ARG1 are the operands of the
6444 comparison. ARG1 must be a TREE_REAL_CST.
6446 The function returns the constant folded tree if a simplification
6447 can be made, and NULL_TREE otherwise. */
6450 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6451 tree type, tree arg0, tree arg1)
6455 if (BUILTIN_SQRT_P (fcode))
6457 tree arg = CALL_EXPR_ARG (arg0, 0);
6458 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6460 c = TREE_REAL_CST (arg1);
6461 if (REAL_VALUE_NEGATIVE (c))
6463 /* sqrt(x) < y is always false, if y is negative. */
6464 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6465 return omit_one_operand (type, integer_zero_node, arg);
6467 /* sqrt(x) > y is always true, if y is negative and we
6468 don't care about NaNs, i.e. negative values of x. */
6469 if (code == NE_EXPR || !HONOR_NANS (mode))
6470 return omit_one_operand (type, integer_one_node, arg);
6472 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6473 return fold_build2 (GE_EXPR, type, arg,
6474 build_real (TREE_TYPE (arg), dconst0));
6476 else if (code == GT_EXPR || code == GE_EXPR)
6480 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6481 real_convert (&c2, mode, &c2);
6483 if (REAL_VALUE_ISINF (c2))
6485 /* sqrt(x) > y is x == +Inf, when y is very large. */
6486 if (HONOR_INFINITIES (mode))
6487 return fold_build2 (EQ_EXPR, type, arg,
6488 build_real (TREE_TYPE (arg), c2));
6490 /* sqrt(x) > y is always false, when y is very large
6491 and we don't care about infinities. */
6492 return omit_one_operand (type, integer_zero_node, arg);
6495 /* sqrt(x) > c is the same as x > c*c. */
6496 return fold_build2 (code, type, arg,
6497 build_real (TREE_TYPE (arg), c2));
6499 else if (code == LT_EXPR || code == LE_EXPR)
6503 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6504 real_convert (&c2, mode, &c2);
6506 if (REAL_VALUE_ISINF (c2))
6508 /* sqrt(x) < y is always true, when y is a very large
6509 value and we don't care about NaNs or Infinities. */
6510 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6511 return omit_one_operand (type, integer_one_node, arg);
6513 /* sqrt(x) < y is x != +Inf when y is very large and we
6514 don't care about NaNs. */
6515 if (! HONOR_NANS (mode))
6516 return fold_build2 (NE_EXPR, type, arg,
6517 build_real (TREE_TYPE (arg), c2));
6519 /* sqrt(x) < y is x >= 0 when y is very large and we
6520 don't care about Infinities. */
6521 if (! HONOR_INFINITIES (mode))
6522 return fold_build2 (GE_EXPR, type, arg,
6523 build_real (TREE_TYPE (arg), dconst0));
6525 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6526 if (lang_hooks.decls.global_bindings_p () != 0
6527 || CONTAINS_PLACEHOLDER_P (arg))
6530 arg = save_expr (arg);
6531 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6532 fold_build2 (GE_EXPR, type, arg,
6533 build_real (TREE_TYPE (arg),
6535 fold_build2 (NE_EXPR, type, arg,
6536 build_real (TREE_TYPE (arg),
6540 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6541 if (! HONOR_NANS (mode))
6542 return fold_build2 (code, type, arg,
6543 build_real (TREE_TYPE (arg), c2));
6545 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6546 if (lang_hooks.decls.global_bindings_p () == 0
6547 && ! CONTAINS_PLACEHOLDER_P (arg))
6549 arg = save_expr (arg);
6550 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6551 fold_build2 (GE_EXPR, type, arg,
6552 build_real (TREE_TYPE (arg),
6554 fold_build2 (code, type, arg,
6555 build_real (TREE_TYPE (arg),
6564 /* Subroutine of fold() that optimizes comparisons against Infinities,
6565 either +Inf or -Inf.
6567 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6568 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6569 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6571 The function returns the constant folded tree if a simplification
6572 can be made, and NULL_TREE otherwise. */
6575 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6577 enum machine_mode mode;
6578 REAL_VALUE_TYPE max;
6582 mode = TYPE_MODE (TREE_TYPE (arg0));
6584 /* For negative infinity swap the sense of the comparison. */
6585 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6587 code = swap_tree_comparison (code);
6592 /* x > +Inf is always false, if with ignore sNANs. */
6593 if (HONOR_SNANS (mode))
6595 return omit_one_operand (type, integer_zero_node, arg0);
6598 /* x <= +Inf is always true, if we don't case about NaNs. */
6599 if (! HONOR_NANS (mode))
6600 return omit_one_operand (type, integer_one_node, arg0);
6602 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6603 if (lang_hooks.decls.global_bindings_p () == 0
6604 && ! CONTAINS_PLACEHOLDER_P (arg0))
6606 arg0 = save_expr (arg0);
6607 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6613 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6614 real_maxval (&max, neg, mode);
6615 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6616 arg0, build_real (TREE_TYPE (arg0), max));
6619 /* x < +Inf is always equal to x <= DBL_MAX. */
6620 real_maxval (&max, neg, mode);
6621 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6622 arg0, build_real (TREE_TYPE (arg0), max));
6625 /* x != +Inf is always equal to !(x > DBL_MAX). */
6626 real_maxval (&max, neg, mode);
6627 if (! HONOR_NANS (mode))
6628 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6629 arg0, build_real (TREE_TYPE (arg0), max));
6631 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6632 arg0, build_real (TREE_TYPE (arg0), max));
6633 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6642 /* Subroutine of fold() that optimizes comparisons of a division by
6643 a nonzero integer constant against an integer constant, i.e.
6646 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6647 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6648 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6650 The function returns the constant folded tree if a simplification
6651 can be made, and NULL_TREE otherwise. */
6654 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6656 tree prod, tmp, hi, lo;
6657 tree arg00 = TREE_OPERAND (arg0, 0);
6658 tree arg01 = TREE_OPERAND (arg0, 1);
6659 unsigned HOST_WIDE_INT lpart;
6660 HOST_WIDE_INT hpart;
6661 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6665 /* We have to do this the hard way to detect unsigned overflow.
6666 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6667 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6668 TREE_INT_CST_HIGH (arg01),
6669 TREE_INT_CST_LOW (arg1),
6670 TREE_INT_CST_HIGH (arg1),
6671 &lpart, &hpart, unsigned_p);
6672 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6674 neg_overflow = false;
6678 tmp = int_const_binop (MINUS_EXPR, arg01,
6679 build_int_cst (TREE_TYPE (arg01), 1), 0);
6682 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6683 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6684 TREE_INT_CST_HIGH (prod),
6685 TREE_INT_CST_LOW (tmp),
6686 TREE_INT_CST_HIGH (tmp),
6687 &lpart, &hpart, unsigned_p);
6688 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6689 -1, overflow | TREE_OVERFLOW (prod));
6691 else if (tree_int_cst_sgn (arg01) >= 0)
6693 tmp = int_const_binop (MINUS_EXPR, arg01,
6694 build_int_cst (TREE_TYPE (arg01), 1), 0);
6695 switch (tree_int_cst_sgn (arg1))
6698 neg_overflow = true;
6699 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6704 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6709 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6719 /* A negative divisor reverses the relational operators. */
6720 code = swap_tree_comparison (code);
6722 tmp = int_const_binop (PLUS_EXPR, arg01,
6723 build_int_cst (TREE_TYPE (arg01), 1), 0);
6724 switch (tree_int_cst_sgn (arg1))
6727 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6732 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6737 neg_overflow = true;
6738 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6750 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6751 return omit_one_operand (type, integer_zero_node, arg00);
6752 if (TREE_OVERFLOW (hi))
6753 return fold_build2 (GE_EXPR, type, arg00, lo);
6754 if (TREE_OVERFLOW (lo))
6755 return fold_build2 (LE_EXPR, type, arg00, hi);
6756 return build_range_check (type, arg00, 1, lo, hi);
6759 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6760 return omit_one_operand (type, integer_one_node, arg00);
6761 if (TREE_OVERFLOW (hi))
6762 return fold_build2 (LT_EXPR, type, arg00, lo);
6763 if (TREE_OVERFLOW (lo))
6764 return fold_build2 (GT_EXPR, type, arg00, hi);
6765 return build_range_check (type, arg00, 0, lo, hi);
6768 if (TREE_OVERFLOW (lo))
6770 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6771 return omit_one_operand (type, tmp, arg00);
6773 return fold_build2 (LT_EXPR, type, arg00, lo);
6776 if (TREE_OVERFLOW (hi))
6778 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6779 return omit_one_operand (type, tmp, arg00);
6781 return fold_build2 (LE_EXPR, type, arg00, hi);
6784 if (TREE_OVERFLOW (hi))
6786 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6787 return omit_one_operand (type, tmp, arg00);
6789 return fold_build2 (GT_EXPR, type, arg00, hi);
6792 if (TREE_OVERFLOW (lo))
6794 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6795 return omit_one_operand (type, tmp, arg00);
6797 return fold_build2 (GE_EXPR, type, arg00, lo);
6807 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6808 equality/inequality test, then return a simplified form of the test
6809 using a sign testing. Otherwise return NULL. TYPE is the desired
6813 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6816 /* If this is testing a single bit, we can optimize the test. */
6817 if ((code == NE_EXPR || code == EQ_EXPR)
6818 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6819 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6821 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6822 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6823 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6825 if (arg00 != NULL_TREE
6826 /* This is only a win if casting to a signed type is cheap,
6827 i.e. when arg00's type is not a partial mode. */
6828 && TYPE_PRECISION (TREE_TYPE (arg00))
6829 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6831 tree stype = signed_type_for (TREE_TYPE (arg00));
6832 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6833 result_type, fold_convert (stype, arg00),
6834 build_int_cst (stype, 0));
6841 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6842 equality/inequality test, then return a simplified form of
6843 the test using shifts and logical operations. Otherwise return
6844 NULL. TYPE is the desired result type. */
6847 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6850 /* If this is testing a single bit, we can optimize the test. */
6851 if ((code == NE_EXPR || code == EQ_EXPR)
6852 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6853 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6855 tree inner = TREE_OPERAND (arg0, 0);
6856 tree type = TREE_TYPE (arg0);
6857 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6858 enum machine_mode operand_mode = TYPE_MODE (type);
6860 tree signed_type, unsigned_type, intermediate_type;
6863 /* First, see if we can fold the single bit test into a sign-bit
6865 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6870 /* Otherwise we have (A & C) != 0 where C is a single bit,
6871 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6872 Similarly for (A & C) == 0. */
6874 /* If INNER is a right shift of a constant and it plus BITNUM does
6875 not overflow, adjust BITNUM and INNER. */
6876 if (TREE_CODE (inner) == RSHIFT_EXPR
6877 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6878 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6879 && bitnum < TYPE_PRECISION (type)
6880 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6881 bitnum - TYPE_PRECISION (type)))
6883 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6884 inner = TREE_OPERAND (inner, 0);
6887 /* If we are going to be able to omit the AND below, we must do our
6888 operations as unsigned. If we must use the AND, we have a choice.
6889 Normally unsigned is faster, but for some machines signed is. */
6890 #ifdef LOAD_EXTEND_OP
6891 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6892 && !flag_syntax_only) ? 0 : 1;
6897 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6898 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6899 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6900 inner = fold_convert (intermediate_type, inner);
6903 inner = build2 (RSHIFT_EXPR, intermediate_type,
6904 inner, size_int (bitnum));
6906 one = build_int_cst (intermediate_type, 1);
6908 if (code == EQ_EXPR)
6909 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6911 /* Put the AND last so it can combine with more things. */
6912 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6914 /* Make sure to return the proper type. */
6915 inner = fold_convert (result_type, inner);
6922 /* Check whether we are allowed to reorder operands arg0 and arg1,
6923 such that the evaluation of arg1 occurs before arg0. */
6926 reorder_operands_p (const_tree arg0, const_tree arg1)
6928 if (! flag_evaluation_order)
6930 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6932 return ! TREE_SIDE_EFFECTS (arg0)
6933 && ! TREE_SIDE_EFFECTS (arg1);
6936 /* Test whether it is preferable two swap two operands, ARG0 and
6937 ARG1, for example because ARG0 is an integer constant and ARG1
6938 isn't. If REORDER is true, only recommend swapping if we can
6939 evaluate the operands in reverse order. */
6942 tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
6944 STRIP_SIGN_NOPS (arg0);
6945 STRIP_SIGN_NOPS (arg1);
6947 if (TREE_CODE (arg1) == INTEGER_CST)
6949 if (TREE_CODE (arg0) == INTEGER_CST)
6952 if (TREE_CODE (arg1) == REAL_CST)
6954 if (TREE_CODE (arg0) == REAL_CST)
6957 if (TREE_CODE (arg1) == FIXED_CST)
6959 if (TREE_CODE (arg0) == FIXED_CST)
6962 if (TREE_CODE (arg1) == COMPLEX_CST)
6964 if (TREE_CODE (arg0) == COMPLEX_CST)
6967 if (TREE_CONSTANT (arg1))
6969 if (TREE_CONSTANT (arg0))
6975 if (reorder && flag_evaluation_order
6976 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6979 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6980 for commutative and comparison operators. Ensuring a canonical
6981 form allows the optimizers to find additional redundancies without
6982 having to explicitly check for both orderings. */
6983 if (TREE_CODE (arg0) == SSA_NAME
6984 && TREE_CODE (arg1) == SSA_NAME
6985 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6988 /* Put SSA_NAMEs last. */
6989 if (TREE_CODE (arg1) == SSA_NAME)
6991 if (TREE_CODE (arg0) == SSA_NAME)
6994 /* Put variables last. */
7003 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
7004 ARG0 is extended to a wider type. */
7007 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
7009 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
7011 tree shorter_type, outer_type;
7015 if (arg0_unw == arg0)
7017 shorter_type = TREE_TYPE (arg0_unw);
7019 #ifdef HAVE_canonicalize_funcptr_for_compare
7020 /* Disable this optimization if we're casting a function pointer
7021 type on targets that require function pointer canonicalization. */
7022 if (HAVE_canonicalize_funcptr_for_compare
7023 && TREE_CODE (shorter_type) == POINTER_TYPE
7024 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
7028 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
7031 arg1_unw = get_unwidened (arg1, shorter_type);
7033 /* If possible, express the comparison in the shorter mode. */
7034 if ((code == EQ_EXPR || code == NE_EXPR
7035 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
7036 && (TREE_TYPE (arg1_unw) == shorter_type
7037 || (TREE_CODE (arg1_unw) == INTEGER_CST
7038 && (TREE_CODE (shorter_type) == INTEGER_TYPE
7039 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
7040 && int_fits_type_p (arg1_unw, shorter_type))))
7041 return fold_build2 (code, type, arg0_unw,
7042 fold_convert (shorter_type, arg1_unw));
7044 if (TREE_CODE (arg1_unw) != INTEGER_CST
7045 || TREE_CODE (shorter_type) != INTEGER_TYPE
7046 || !int_fits_type_p (arg1_unw, shorter_type))
7049 /* If we are comparing with the integer that does not fit into the range
7050 of the shorter type, the result is known. */
7051 outer_type = TREE_TYPE (arg1_unw);
7052 min = lower_bound_in_type (outer_type, shorter_type);
7053 max = upper_bound_in_type (outer_type, shorter_type);
7055 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7057 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7064 return omit_one_operand (type, integer_zero_node, arg0);
7069 return omit_one_operand (type, integer_one_node, arg0);
7075 return omit_one_operand (type, integer_one_node, arg0);
7077 return omit_one_operand (type, integer_zero_node, arg0);
7082 return omit_one_operand (type, integer_zero_node, arg0);
7084 return omit_one_operand (type, integer_one_node, arg0);
7093 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
7094 ARG0 just the signedness is changed. */
7097 fold_sign_changed_comparison (enum tree_code code, tree type,
7098 tree arg0, tree arg1)
7101 tree inner_type, outer_type;
7103 if (TREE_CODE (arg0) != NOP_EXPR
7104 && TREE_CODE (arg0) != CONVERT_EXPR)
7107 outer_type = TREE_TYPE (arg0);
7108 arg0_inner = TREE_OPERAND (arg0, 0);
7109 inner_type = TREE_TYPE (arg0_inner);
7111 #ifdef HAVE_canonicalize_funcptr_for_compare
7112 /* Disable this optimization if we're casting a function pointer
7113 type on targets that require function pointer canonicalization. */
7114 if (HAVE_canonicalize_funcptr_for_compare
7115 && TREE_CODE (inner_type) == POINTER_TYPE
7116 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
7120 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
7123 if (TREE_CODE (arg1) != INTEGER_CST
7124 && !((TREE_CODE (arg1) == NOP_EXPR
7125 || TREE_CODE (arg1) == CONVERT_EXPR)
7126 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
7129 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
7134 if (TREE_CODE (arg1) == INTEGER_CST)
7135 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
7136 TREE_INT_CST_HIGH (arg1), 0,
7137 TREE_OVERFLOW (arg1));
7139 arg1 = fold_convert (inner_type, arg1);
7141 return fold_build2 (code, type, arg0_inner, arg1);
7144 /* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
7145 step of the array. Reconstructs s and delta in the case of s * delta
7146 being an integer constant (and thus already folded).
7147 ADDR is the address. MULT is the multiplicative expression.
7148 If the function succeeds, the new address expression is returned. Otherwise
7149 NULL_TREE is returned. */
7152 try_move_mult_to_index (tree addr, tree op1)
7154 tree s, delta, step;
7155 tree ref = TREE_OPERAND (addr, 0), pref;
7160 /* Strip the nops that might be added when converting op1 to sizetype. */
7163 /* Canonicalize op1 into a possibly non-constant delta
7164 and an INTEGER_CST s. */
7165 if (TREE_CODE (op1) == MULT_EXPR)
7167 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
7172 if (TREE_CODE (arg0) == INTEGER_CST)
7177 else if (TREE_CODE (arg1) == INTEGER_CST)
7185 else if (TREE_CODE (op1) == INTEGER_CST)
7192 /* Simulate we are delta * 1. */
7194 s = integer_one_node;
7197 for (;; ref = TREE_OPERAND (ref, 0))
7199 if (TREE_CODE (ref) == ARRAY_REF)
7201 /* Remember if this was a multi-dimensional array. */
7202 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
7205 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
7209 step = array_ref_element_size (ref);
7210 if (TREE_CODE (step) != INTEGER_CST)
7215 if (! tree_int_cst_equal (step, s))
7220 /* Try if delta is a multiple of step. */
7221 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
7227 /* Only fold here if we can verify we do not overflow one
7228 dimension of a multi-dimensional array. */
7233 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
7234 || !INTEGRAL_TYPE_P (itype)
7235 || !TYPE_MAX_VALUE (itype)
7236 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
7239 tmp = fold_binary (PLUS_EXPR, itype,
7240 fold_convert (itype,
7241 TREE_OPERAND (ref, 1)),
7242 fold_convert (itype, delta));
7244 || TREE_CODE (tmp) != INTEGER_CST
7245 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
7254 if (!handled_component_p (ref))
7258 /* We found the suitable array reference. So copy everything up to it,
7259 and replace the index. */
7261 pref = TREE_OPERAND (addr, 0);
7262 ret = copy_node (pref);
7267 pref = TREE_OPERAND (pref, 0);
7268 TREE_OPERAND (pos, 0) = copy_node (pref);
7269 pos = TREE_OPERAND (pos, 0);
7272 TREE_OPERAND (pos, 1) = fold_build2 (PLUS_EXPR, itype,
7273 fold_convert (itype,
7274 TREE_OPERAND (pos, 1)),
7275 fold_convert (itype, delta));
7277 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
7281 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
7282 means A >= Y && A != MAX, but in this case we know that
7283 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
7286 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
7288 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
7290 if (TREE_CODE (bound) == LT_EXPR)
7291 a = TREE_OPERAND (bound, 0);
7292 else if (TREE_CODE (bound) == GT_EXPR)
7293 a = TREE_OPERAND (bound, 1);
7297 typea = TREE_TYPE (a);
7298 if (!INTEGRAL_TYPE_P (typea)
7299 && !POINTER_TYPE_P (typea))
7302 if (TREE_CODE (ineq) == LT_EXPR)
7304 a1 = TREE_OPERAND (ineq, 1);
7305 y = TREE_OPERAND (ineq, 0);
7307 else if (TREE_CODE (ineq) == GT_EXPR)
7309 a1 = TREE_OPERAND (ineq, 0);
7310 y = TREE_OPERAND (ineq, 1);
7315 if (TREE_TYPE (a1) != typea)
7318 if (POINTER_TYPE_P (typea))
7320 /* Convert the pointer types into integer before taking the difference. */
7321 tree ta = fold_convert (ssizetype, a);
7322 tree ta1 = fold_convert (ssizetype, a1);
7323 diff = fold_binary (MINUS_EXPR, ssizetype, ta1, ta);
7326 diff = fold_binary (MINUS_EXPR, typea, a1, a);
7328 if (!diff || !integer_onep (diff))
7331 return fold_build2 (GE_EXPR, type, a, y);
7334 /* Fold a sum or difference of at least one multiplication.
7335 Returns the folded tree or NULL if no simplification could be made. */
7338 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7340 tree arg00, arg01, arg10, arg11;
7341 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7343 /* (A * C) +- (B * C) -> (A+-B) * C.
7344 (A * C) +- A -> A * (C+-1).
7345 We are most concerned about the case where C is a constant,
7346 but other combinations show up during loop reduction. Since
7347 it is not difficult, try all four possibilities. */
7349 if (TREE_CODE (arg0) == MULT_EXPR)
7351 arg00 = TREE_OPERAND (arg0, 0);
7352 arg01 = TREE_OPERAND (arg0, 1);
7354 else if (TREE_CODE (arg0) == INTEGER_CST)
7356 arg00 = build_one_cst (type);
7361 /* We cannot generate constant 1 for fract. */
7362 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7365 arg01 = build_one_cst (type);
7367 if (TREE_CODE (arg1) == MULT_EXPR)
7369 arg10 = TREE_OPERAND (arg1, 0);
7370 arg11 = TREE_OPERAND (arg1, 1);
7372 else if (TREE_CODE (arg1) == INTEGER_CST)
7374 arg10 = build_one_cst (type);
7379 /* We cannot generate constant 1 for fract. */
7380 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7383 arg11 = build_one_cst (type);
7387 if (operand_equal_p (arg01, arg11, 0))
7388 same = arg01, alt0 = arg00, alt1 = arg10;
7389 else if (operand_equal_p (arg00, arg10, 0))
7390 same = arg00, alt0 = arg01, alt1 = arg11;
7391 else if (operand_equal_p (arg00, arg11, 0))
7392 same = arg00, alt0 = arg01, alt1 = arg10;
7393 else if (operand_equal_p (arg01, arg10, 0))
7394 same = arg01, alt0 = arg00, alt1 = arg11;
7396 /* No identical multiplicands; see if we can find a common
7397 power-of-two factor in non-power-of-two multiplies. This
7398 can help in multi-dimensional array access. */
7399 else if (host_integerp (arg01, 0)
7400 && host_integerp (arg11, 0))
7402 HOST_WIDE_INT int01, int11, tmp;
7405 int01 = TREE_INT_CST_LOW (arg01);
7406 int11 = TREE_INT_CST_LOW (arg11);
7408 /* Move min of absolute values to int11. */
7409 if ((int01 >= 0 ? int01 : -int01)
7410 < (int11 >= 0 ? int11 : -int11))
7412 tmp = int01, int01 = int11, int11 = tmp;
7413 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7420 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
7422 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7423 build_int_cst (TREE_TYPE (arg00),
7428 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7433 return fold_build2 (MULT_EXPR, type,
7434 fold_build2 (code, type,
7435 fold_convert (type, alt0),
7436 fold_convert (type, alt1)),
7437 fold_convert (type, same));
7442 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7443 specified by EXPR into the buffer PTR of length LEN bytes.
7444 Return the number of bytes placed in the buffer, or zero
7448 native_encode_int (const_tree expr, unsigned char *ptr, int len)
7450 tree type = TREE_TYPE (expr);
7451 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7452 int byte, offset, word, words;
7453 unsigned char value;
7455 if (total_bytes > len)
7457 words = total_bytes / UNITS_PER_WORD;
7459 for (byte = 0; byte < total_bytes; byte++)
7461 int bitpos = byte * BITS_PER_UNIT;
7462 if (bitpos < HOST_BITS_PER_WIDE_INT)
7463 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7465 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7466 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7468 if (total_bytes > UNITS_PER_WORD)
7470 word = byte / UNITS_PER_WORD;
7471 if (WORDS_BIG_ENDIAN)
7472 word = (words - 1) - word;
7473 offset = word * UNITS_PER_WORD;
7474 if (BYTES_BIG_ENDIAN)
7475 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7477 offset += byte % UNITS_PER_WORD;
7480 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7481 ptr[offset] = value;
7487 /* Subroutine of native_encode_expr. Encode the REAL_CST
7488 specified by EXPR into the buffer PTR of length LEN bytes.
7489 Return the number of bytes placed in the buffer, or zero
7493 native_encode_real (const_tree expr, unsigned char *ptr, int len)
7495 tree type = TREE_TYPE (expr);
7496 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7497 int byte, offset, word, words, bitpos;
7498 unsigned char value;
7500 /* There are always 32 bits in each long, no matter the size of
7501 the hosts long. We handle floating point representations with
7505 if (total_bytes > len)
7507 words = 32 / UNITS_PER_WORD;
7509 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7511 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7512 bitpos += BITS_PER_UNIT)
7514 byte = (bitpos / BITS_PER_UNIT) & 3;
7515 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7517 if (UNITS_PER_WORD < 4)
7519 word = byte / UNITS_PER_WORD;
7520 if (WORDS_BIG_ENDIAN)
7521 word = (words - 1) - word;
7522 offset = word * UNITS_PER_WORD;
7523 if (BYTES_BIG_ENDIAN)
7524 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7526 offset += byte % UNITS_PER_WORD;
7529 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7530 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7535 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7536 specified by EXPR into the buffer PTR of length LEN bytes.
7537 Return the number of bytes placed in the buffer, or zero
7541 native_encode_complex (const_tree expr, unsigned char *ptr, int len)
7546 part = TREE_REALPART (expr);
7547 rsize = native_encode_expr (part, ptr, len);
7550 part = TREE_IMAGPART (expr);
7551 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7554 return rsize + isize;
7558 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7559 specified by EXPR into the buffer PTR of length LEN bytes.
7560 Return the number of bytes placed in the buffer, or zero
7564 native_encode_vector (const_tree expr, unsigned char *ptr, int len)
7566 int i, size, offset, count;
7567 tree itype, elem, elements;
7570 elements = TREE_VECTOR_CST_ELTS (expr);
7571 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7572 itype = TREE_TYPE (TREE_TYPE (expr));
7573 size = GET_MODE_SIZE (TYPE_MODE (itype));
7574 for (i = 0; i < count; i++)
7578 elem = TREE_VALUE (elements);
7579 elements = TREE_CHAIN (elements);
7586 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7591 if (offset + size > len)
7593 memset (ptr+offset, 0, size);
7601 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7602 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7603 buffer PTR of length LEN bytes. Return the number of bytes
7604 placed in the buffer, or zero upon failure. */
7607 native_encode_expr (const_tree expr, unsigned char *ptr, int len)
7609 switch (TREE_CODE (expr))
7612 return native_encode_int (expr, ptr, len);
7615 return native_encode_real (expr, ptr, len);
7618 return native_encode_complex (expr, ptr, len);
7621 return native_encode_vector (expr, ptr, len);
7629 /* Subroutine of native_interpret_expr. Interpret the contents of
7630 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7631 If the buffer cannot be interpreted, return NULL_TREE. */
7634 native_interpret_int (tree type, const unsigned char *ptr, int len)
7636 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7637 int byte, offset, word, words;
7638 unsigned char value;
7639 unsigned int HOST_WIDE_INT lo = 0;
7640 HOST_WIDE_INT hi = 0;
7642 if (total_bytes > len)
7644 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7646 words = total_bytes / UNITS_PER_WORD;
7648 for (byte = 0; byte < total_bytes; byte++)
7650 int bitpos = byte * BITS_PER_UNIT;
7651 if (total_bytes > UNITS_PER_WORD)
7653 word = byte / UNITS_PER_WORD;
7654 if (WORDS_BIG_ENDIAN)
7655 word = (words - 1) - word;
7656 offset = word * UNITS_PER_WORD;
7657 if (BYTES_BIG_ENDIAN)
7658 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7660 offset += byte % UNITS_PER_WORD;
7663 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7664 value = ptr[offset];
7666 if (bitpos < HOST_BITS_PER_WIDE_INT)
7667 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7669 hi |= (unsigned HOST_WIDE_INT) value
7670 << (bitpos - HOST_BITS_PER_WIDE_INT);
7673 return build_int_cst_wide_type (type, lo, hi);
7677 /* Subroutine of native_interpret_expr. Interpret the contents of
7678 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7679 If the buffer cannot be interpreted, return NULL_TREE. */
7682 native_interpret_real (tree type, const unsigned char *ptr, int len)
7684 enum machine_mode mode = TYPE_MODE (type);
7685 int total_bytes = GET_MODE_SIZE (mode);
7686 int byte, offset, word, words, bitpos;
7687 unsigned char value;
7688 /* There are always 32 bits in each long, no matter the size of
7689 the hosts long. We handle floating point representations with
7694 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7695 if (total_bytes > len || total_bytes > 24)
7697 words = 32 / UNITS_PER_WORD;
7699 memset (tmp, 0, sizeof (tmp));
7700 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7701 bitpos += BITS_PER_UNIT)
7703 byte = (bitpos / BITS_PER_UNIT) & 3;
7704 if (UNITS_PER_WORD < 4)
7706 word = byte / UNITS_PER_WORD;
7707 if (WORDS_BIG_ENDIAN)
7708 word = (words - 1) - word;
7709 offset = word * UNITS_PER_WORD;
7710 if (BYTES_BIG_ENDIAN)
7711 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7713 offset += byte % UNITS_PER_WORD;
7716 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7717 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7719 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7722 real_from_target (&r, tmp, mode);
7723 return build_real (type, r);
7727 /* Subroutine of native_interpret_expr. Interpret the contents of
7728 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7729 If the buffer cannot be interpreted, return NULL_TREE. */
7732 native_interpret_complex (tree type, const unsigned char *ptr, int len)
7734 tree etype, rpart, ipart;
7737 etype = TREE_TYPE (type);
7738 size = GET_MODE_SIZE (TYPE_MODE (etype));
7741 rpart = native_interpret_expr (etype, ptr, size);
7744 ipart = native_interpret_expr (etype, ptr+size, size);
7747 return build_complex (type, rpart, ipart);
7751 /* Subroutine of native_interpret_expr. Interpret the contents of
7752 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7753 If the buffer cannot be interpreted, return NULL_TREE. */
7756 native_interpret_vector (tree type, const unsigned char *ptr, int len)
7758 tree etype, elem, elements;
7761 etype = TREE_TYPE (type);
7762 size = GET_MODE_SIZE (TYPE_MODE (etype));
7763 count = TYPE_VECTOR_SUBPARTS (type);
7764 if (size * count > len)
7767 elements = NULL_TREE;
7768 for (i = count - 1; i >= 0; i--)
7770 elem = native_interpret_expr (etype, ptr+(i*size), size);
7773 elements = tree_cons (NULL_TREE, elem, elements);
7775 return build_vector (type, elements);
7779 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7780 the buffer PTR of length LEN as a constant of type TYPE. For
7781 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7782 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7783 return NULL_TREE. */
7786 native_interpret_expr (tree type, const unsigned char *ptr, int len)
7788 switch (TREE_CODE (type))
7793 return native_interpret_int (type, ptr, len);
7796 return native_interpret_real (type, ptr, len);
7799 return native_interpret_complex (type, ptr, len);
7802 return native_interpret_vector (type, ptr, len);
7810 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7811 TYPE at compile-time. If we're unable to perform the conversion
7812 return NULL_TREE. */
7815 fold_view_convert_expr (tree type, tree expr)
7817 /* We support up to 512-bit values (for V8DFmode). */
7818 unsigned char buffer[64];
7821 /* Check that the host and target are sane. */
7822 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7825 len = native_encode_expr (expr, buffer, sizeof (buffer));
7829 return native_interpret_expr (type, buffer, len);
7832 /* Build an expression for the address of T. Folds away INDIRECT_REF
7833 to avoid confusing the gimplify process. When IN_FOLD is true
7834 avoid modifications of T. */
7837 build_fold_addr_expr_with_type_1 (tree t, tree ptrtype, bool in_fold)
7839 /* The size of the object is not relevant when talking about its address. */
7840 if (TREE_CODE (t) == WITH_SIZE_EXPR)
7841 t = TREE_OPERAND (t, 0);
7843 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
7844 if (TREE_CODE (t) == INDIRECT_REF
7845 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
7847 t = TREE_OPERAND (t, 0);
7849 if (TREE_TYPE (t) != ptrtype)
7850 t = build1 (NOP_EXPR, ptrtype, t);
7856 while (handled_component_p (base))
7857 base = TREE_OPERAND (base, 0);
7860 TREE_ADDRESSABLE (base) = 1;
7862 t = build1 (ADDR_EXPR, ptrtype, t);
7865 t = build1 (ADDR_EXPR, ptrtype, t);
7870 /* Build an expression for the address of T with type PTRTYPE. This
7871 function modifies the input parameter 'T' by sometimes setting the
7872 TREE_ADDRESSABLE flag. */
7875 build_fold_addr_expr_with_type (tree t, tree ptrtype)
7877 return build_fold_addr_expr_with_type_1 (t, ptrtype, false);
7880 /* Build an expression for the address of T. This function modifies
7881 the input parameter 'T' by sometimes setting the TREE_ADDRESSABLE
7882 flag. When called from fold functions, use fold_addr_expr instead. */
7885 build_fold_addr_expr (tree t)
7887 return build_fold_addr_expr_with_type_1 (t,
7888 build_pointer_type (TREE_TYPE (t)),
7892 /* Same as build_fold_addr_expr, builds an expression for the address
7893 of T, but avoids touching the input node 't'. Fold functions
7894 should use this version. */
7897 fold_addr_expr (tree t)
7899 tree ptrtype = build_pointer_type (TREE_TYPE (t));
7901 return build_fold_addr_expr_with_type_1 (t, ptrtype, true);
7904 /* Fold a unary expression of code CODE and type TYPE with operand
7905 OP0. Return the folded expression if folding is successful.
7906 Otherwise, return NULL_TREE. */
7909 fold_unary (enum tree_code code, tree type, tree op0)
7913 enum tree_code_class kind = TREE_CODE_CLASS (code);
7915 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7916 && TREE_CODE_LENGTH (code) == 1);
7921 if (code == NOP_EXPR || code == CONVERT_EXPR
7922 || code == FLOAT_EXPR || code == ABS_EXPR)
7924 /* Don't use STRIP_NOPS, because signedness of argument type
7926 STRIP_SIGN_NOPS (arg0);
7930 /* Strip any conversions that don't change the mode. This
7931 is safe for every expression, except for a comparison
7932 expression because its signedness is derived from its
7935 Note that this is done as an internal manipulation within
7936 the constant folder, in order to find the simplest
7937 representation of the arguments so that their form can be
7938 studied. In any cases, the appropriate type conversions
7939 should be put back in the tree that will get out of the
7945 if (TREE_CODE_CLASS (code) == tcc_unary)
7947 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7948 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7949 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
7950 else if (TREE_CODE (arg0) == COND_EXPR)
7952 tree arg01 = TREE_OPERAND (arg0, 1);
7953 tree arg02 = TREE_OPERAND (arg0, 2);
7954 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7955 arg01 = fold_build1 (code, type, arg01);
7956 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7957 arg02 = fold_build1 (code, type, arg02);
7958 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
7961 /* If this was a conversion, and all we did was to move into
7962 inside the COND_EXPR, bring it back out. But leave it if
7963 it is a conversion from integer to integer and the
7964 result precision is no wider than a word since such a
7965 conversion is cheap and may be optimized away by combine,
7966 while it couldn't if it were outside the COND_EXPR. Then return
7967 so we don't get into an infinite recursion loop taking the
7968 conversion out and then back in. */
7970 if ((code == NOP_EXPR || code == CONVERT_EXPR
7971 || code == NON_LVALUE_EXPR)
7972 && TREE_CODE (tem) == COND_EXPR
7973 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7974 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7975 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7976 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7977 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7978 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7979 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7981 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7982 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7983 || flag_syntax_only))
7984 tem = build1 (code, type,
7986 TREE_TYPE (TREE_OPERAND
7987 (TREE_OPERAND (tem, 1), 0)),
7988 TREE_OPERAND (tem, 0),
7989 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7990 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
7993 else if (COMPARISON_CLASS_P (arg0))
7995 if (TREE_CODE (type) == BOOLEAN_TYPE)
7997 arg0 = copy_node (arg0);
7998 TREE_TYPE (arg0) = type;
8001 else if (TREE_CODE (type) != INTEGER_TYPE)
8002 return fold_build3 (COND_EXPR, type, arg0,
8003 fold_build1 (code, type,
8005 fold_build1 (code, type,
8006 integer_zero_node));
8015 case FIX_TRUNC_EXPR:
8016 if (TREE_TYPE (op0) == type)
8019 /* If we have (type) (a CMP b) and type is an integral type, return
8020 new expression involving the new type. */
8021 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
8022 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
8023 TREE_OPERAND (op0, 1));
8025 /* Handle cases of two conversions in a row. */
8026 if (TREE_CODE (op0) == NOP_EXPR
8027 || TREE_CODE (op0) == CONVERT_EXPR)
8029 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
8030 tree inter_type = TREE_TYPE (op0);
8031 int inside_int = INTEGRAL_TYPE_P (inside_type);
8032 int inside_ptr = POINTER_TYPE_P (inside_type);
8033 int inside_float = FLOAT_TYPE_P (inside_type);
8034 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
8035 unsigned int inside_prec = TYPE_PRECISION (inside_type);
8036 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
8037 int inter_int = INTEGRAL_TYPE_P (inter_type);
8038 int inter_ptr = POINTER_TYPE_P (inter_type);
8039 int inter_float = FLOAT_TYPE_P (inter_type);
8040 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
8041 unsigned int inter_prec = TYPE_PRECISION (inter_type);
8042 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
8043 int final_int = INTEGRAL_TYPE_P (type);
8044 int final_ptr = POINTER_TYPE_P (type);
8045 int final_float = FLOAT_TYPE_P (type);
8046 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
8047 unsigned int final_prec = TYPE_PRECISION (type);
8048 int final_unsignedp = TYPE_UNSIGNED (type);
8050 /* In addition to the cases of two conversions in a row
8051 handled below, if we are converting something to its own
8052 type via an object of identical or wider precision, neither
8053 conversion is needed. */
8054 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
8055 && (((inter_int || inter_ptr) && final_int)
8056 || (inter_float && final_float))
8057 && inter_prec >= final_prec)
8058 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8060 /* Likewise, if the intermediate and final types are either both
8061 float or both integer, we don't need the middle conversion if
8062 it is wider than the final type and doesn't change the signedness
8063 (for integers). Avoid this if the final type is a pointer
8064 since then we sometimes need the inner conversion. Likewise if
8065 the outer has a precision not equal to the size of its mode. */
8066 if (((inter_int && inside_int)
8067 || (inter_float && inside_float)
8068 || (inter_vec && inside_vec))
8069 && inter_prec >= inside_prec
8070 && (inter_float || inter_vec
8071 || inter_unsignedp == inside_unsignedp)
8072 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
8073 && TYPE_MODE (type) == TYPE_MODE (inter_type))
8075 && (! final_vec || inter_prec == inside_prec))
8076 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8078 /* If we have a sign-extension of a zero-extended value, we can
8079 replace that by a single zero-extension. */
8080 if (inside_int && inter_int && final_int
8081 && inside_prec < inter_prec && inter_prec < final_prec
8082 && inside_unsignedp && !inter_unsignedp)
8083 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8085 /* Two conversions in a row are not needed unless:
8086 - some conversion is floating-point (overstrict for now), or
8087 - some conversion is a vector (overstrict for now), or
8088 - the intermediate type is narrower than both initial and
8090 - the intermediate type and innermost type differ in signedness,
8091 and the outermost type is wider than the intermediate, or
8092 - the initial type is a pointer type and the precisions of the
8093 intermediate and final types differ, or
8094 - the final type is a pointer type and the precisions of the
8095 initial and intermediate types differ.
8096 - the initial type is a pointer to an array and the final type
8098 if (! inside_float && ! inter_float && ! final_float
8099 && ! inside_vec && ! inter_vec && ! final_vec
8100 && (inter_prec >= inside_prec || inter_prec >= final_prec)
8101 && ! (inside_int && inter_int
8102 && inter_unsignedp != inside_unsignedp
8103 && inter_prec < final_prec)
8104 && ((inter_unsignedp && inter_prec > inside_prec)
8105 == (final_unsignedp && final_prec > inter_prec))
8106 && ! (inside_ptr && inter_prec != final_prec)
8107 && ! (final_ptr && inside_prec != inter_prec)
8108 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
8109 && TYPE_MODE (type) == TYPE_MODE (inter_type))
8110 && ! (inside_ptr && final_ptr
8111 && TREE_CODE (TREE_TYPE (inside_type)) == ARRAY_TYPE
8112 && TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
8113 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8116 /* Handle (T *)&A.B.C for A being of type T and B and C
8117 living at offset zero. This occurs frequently in
8118 C++ upcasting and then accessing the base. */
8119 if (TREE_CODE (op0) == ADDR_EXPR
8120 && POINTER_TYPE_P (type)
8121 && handled_component_p (TREE_OPERAND (op0, 0)))
8123 HOST_WIDE_INT bitsize, bitpos;
8125 enum machine_mode mode;
8126 int unsignedp, volatilep;
8127 tree base = TREE_OPERAND (op0, 0);
8128 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
8129 &mode, &unsignedp, &volatilep, false);
8130 /* If the reference was to a (constant) zero offset, we can use
8131 the address of the base if it has the same base type
8132 as the result type. */
8133 if (! offset && bitpos == 0
8134 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
8135 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
8136 return fold_convert (type, fold_addr_expr (base));
8139 if ((TREE_CODE (op0) == MODIFY_EXPR
8140 || TREE_CODE (op0) == GIMPLE_MODIFY_STMT)
8141 && TREE_CONSTANT (GENERIC_TREE_OPERAND (op0, 1))
8142 /* Detect assigning a bitfield. */
8143 && !(TREE_CODE (GENERIC_TREE_OPERAND (op0, 0)) == COMPONENT_REF
8145 (TREE_OPERAND (GENERIC_TREE_OPERAND (op0, 0), 1))))
8147 /* Don't leave an assignment inside a conversion
8148 unless assigning a bitfield. */
8149 tem = fold_build1 (code, type, GENERIC_TREE_OPERAND (op0, 1));
8150 /* First do the assignment, then return converted constant. */
8151 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
8152 TREE_NO_WARNING (tem) = 1;
8153 TREE_USED (tem) = 1;
8157 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
8158 constants (if x has signed type, the sign bit cannot be set
8159 in c). This folds extension into the BIT_AND_EXPR. */
8160 if (INTEGRAL_TYPE_P (type)
8161 && TREE_CODE (type) != BOOLEAN_TYPE
8162 && TREE_CODE (op0) == BIT_AND_EXPR
8163 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
8166 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
8169 if (TYPE_UNSIGNED (TREE_TYPE (and))
8170 || (TYPE_PRECISION (type)
8171 <= TYPE_PRECISION (TREE_TYPE (and))))
8173 else if (TYPE_PRECISION (TREE_TYPE (and1))
8174 <= HOST_BITS_PER_WIDE_INT
8175 && host_integerp (and1, 1))
8177 unsigned HOST_WIDE_INT cst;
8179 cst = tree_low_cst (and1, 1);
8180 cst &= (HOST_WIDE_INT) -1
8181 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
8182 change = (cst == 0);
8183 #ifdef LOAD_EXTEND_OP
8185 && !flag_syntax_only
8186 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
8189 tree uns = unsigned_type_for (TREE_TYPE (and0));
8190 and0 = fold_convert (uns, and0);
8191 and1 = fold_convert (uns, and1);
8197 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
8198 TREE_INT_CST_HIGH (and1), 0,
8199 TREE_OVERFLOW (and1));
8200 return fold_build2 (BIT_AND_EXPR, type,
8201 fold_convert (type, and0), tem);
8205 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
8206 when one of the new casts will fold away. Conservatively we assume
8207 that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
8208 if (POINTER_TYPE_P (type)
8209 && TREE_CODE (arg0) == POINTER_PLUS_EXPR
8210 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8211 || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
8212 || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
8214 tree arg00 = TREE_OPERAND (arg0, 0);
8215 tree arg01 = TREE_OPERAND (arg0, 1);
8217 return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
8218 fold_convert (sizetype, arg01));
8221 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
8222 of the same precision, and X is an integer type not narrower than
8223 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
8224 if (INTEGRAL_TYPE_P (type)
8225 && TREE_CODE (op0) == BIT_NOT_EXPR
8226 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
8227 && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
8228 || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
8229 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
8231 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
8232 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
8233 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
8234 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
8237 tem = fold_convert_const (code, type, op0);
8238 return tem ? tem : NULL_TREE;
8240 case FIXED_CONVERT_EXPR:
8241 tem = fold_convert_const (code, type, arg0);
8242 return tem ? tem : NULL_TREE;
8244 case VIEW_CONVERT_EXPR:
8245 if (TREE_TYPE (op0) == type)
8247 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
8248 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
8249 return fold_view_convert_expr (type, op0);
8252 tem = fold_negate_expr (arg0);
8254 return fold_convert (type, tem);
8258 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
8259 return fold_abs_const (arg0, type);
8260 else if (TREE_CODE (arg0) == NEGATE_EXPR)
8261 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
8262 /* Convert fabs((double)float) into (double)fabsf(float). */
8263 else if (TREE_CODE (arg0) == NOP_EXPR
8264 && TREE_CODE (type) == REAL_TYPE)
8266 tree targ0 = strip_float_extensions (arg0);
8268 return fold_convert (type, fold_build1 (ABS_EXPR,
8272 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
8273 else if (TREE_CODE (arg0) == ABS_EXPR)
8275 else if (tree_expr_nonnegative_p (arg0))
8278 /* Strip sign ops from argument. */
8279 if (TREE_CODE (type) == REAL_TYPE)
8281 tem = fold_strip_sign_ops (arg0);
8283 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
8288 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8289 return fold_convert (type, arg0);
8290 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8292 tree itype = TREE_TYPE (type);
8293 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
8294 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
8295 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
8297 if (TREE_CODE (arg0) == COMPLEX_CST)
8299 tree itype = TREE_TYPE (type);
8300 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
8301 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
8302 return build_complex (type, rpart, negate_expr (ipart));
8304 if (TREE_CODE (arg0) == CONJ_EXPR)
8305 return fold_convert (type, TREE_OPERAND (arg0, 0));
8309 if (TREE_CODE (arg0) == INTEGER_CST)
8310 return fold_not_const (arg0, type);
8311 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
8312 return TREE_OPERAND (op0, 0);
8313 /* Convert ~ (-A) to A - 1. */
8314 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
8315 return fold_build2 (MINUS_EXPR, type,
8316 fold_convert (type, TREE_OPERAND (arg0, 0)),
8317 build_int_cst (type, 1));
8318 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
8319 else if (INTEGRAL_TYPE_P (type)
8320 && ((TREE_CODE (arg0) == MINUS_EXPR
8321 && integer_onep (TREE_OPERAND (arg0, 1)))
8322 || (TREE_CODE (arg0) == PLUS_EXPR
8323 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
8324 return fold_build1 (NEGATE_EXPR, type,
8325 fold_convert (type, TREE_OPERAND (arg0, 0)));
8326 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8327 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8328 && (tem = fold_unary (BIT_NOT_EXPR, type,
8330 TREE_OPERAND (arg0, 0)))))
8331 return fold_build2 (BIT_XOR_EXPR, type, tem,
8332 fold_convert (type, TREE_OPERAND (arg0, 1)));
8333 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8334 && (tem = fold_unary (BIT_NOT_EXPR, type,
8336 TREE_OPERAND (arg0, 1)))))
8337 return fold_build2 (BIT_XOR_EXPR, type,
8338 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
8339 /* Perform BIT_NOT_EXPR on each element individually. */
8340 else if (TREE_CODE (arg0) == VECTOR_CST)
8342 tree elements = TREE_VECTOR_CST_ELTS (arg0), elem, list = NULL_TREE;
8343 int count = TYPE_VECTOR_SUBPARTS (type), i;
8345 for (i = 0; i < count; i++)
8349 elem = TREE_VALUE (elements);
8350 elem = fold_unary (BIT_NOT_EXPR, TREE_TYPE (type), elem);
8351 if (elem == NULL_TREE)
8353 elements = TREE_CHAIN (elements);
8356 elem = build_int_cst (TREE_TYPE (type), -1);
8357 list = tree_cons (NULL_TREE, elem, list);
8360 return build_vector (type, nreverse (list));
8365 case TRUTH_NOT_EXPR:
8366 /* The argument to invert_truthvalue must have Boolean type. */
8367 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8368 arg0 = fold_convert (boolean_type_node, arg0);
8370 /* Note that the operand of this must be an int
8371 and its values must be 0 or 1.
8372 ("true" is a fixed value perhaps depending on the language,
8373 but we don't handle values other than 1 correctly yet.) */
8374 tem = fold_truth_not_expr (arg0);
8377 return fold_convert (type, tem);
8380 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8381 return fold_convert (type, arg0);
8382 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8383 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8384 TREE_OPERAND (arg0, 1));
8385 if (TREE_CODE (arg0) == COMPLEX_CST)
8386 return fold_convert (type, TREE_REALPART (arg0));
8387 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8389 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8390 tem = fold_build2 (TREE_CODE (arg0), itype,
8391 fold_build1 (REALPART_EXPR, itype,
8392 TREE_OPERAND (arg0, 0)),
8393 fold_build1 (REALPART_EXPR, itype,
8394 TREE_OPERAND (arg0, 1)));
8395 return fold_convert (type, tem);
8397 if (TREE_CODE (arg0) == CONJ_EXPR)
8399 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8400 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8401 return fold_convert (type, tem);
8403 if (TREE_CODE (arg0) == CALL_EXPR)
8405 tree fn = get_callee_fndecl (arg0);
8406 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8407 switch (DECL_FUNCTION_CODE (fn))
8409 CASE_FLT_FN (BUILT_IN_CEXPI):
8410 fn = mathfn_built_in (type, BUILT_IN_COS);
8412 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8422 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8423 return fold_convert (type, integer_zero_node);
8424 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8425 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8426 TREE_OPERAND (arg0, 0));
8427 if (TREE_CODE (arg0) == COMPLEX_CST)
8428 return fold_convert (type, TREE_IMAGPART (arg0));
8429 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8431 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8432 tem = fold_build2 (TREE_CODE (arg0), itype,
8433 fold_build1 (IMAGPART_EXPR, itype,
8434 TREE_OPERAND (arg0, 0)),
8435 fold_build1 (IMAGPART_EXPR, itype,
8436 TREE_OPERAND (arg0, 1)));
8437 return fold_convert (type, tem);
8439 if (TREE_CODE (arg0) == CONJ_EXPR)
8441 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8442 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8443 return fold_convert (type, negate_expr (tem));
8445 if (TREE_CODE (arg0) == CALL_EXPR)
8447 tree fn = get_callee_fndecl (arg0);
8448 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8449 switch (DECL_FUNCTION_CODE (fn))
8451 CASE_FLT_FN (BUILT_IN_CEXPI):
8452 fn = mathfn_built_in (type, BUILT_IN_SIN);
8454 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8465 } /* switch (code) */
8468 /* Fold a binary expression of code CODE and type TYPE with operands
8469 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8470 Return the folded expression if folding is successful. Otherwise,
8471 return NULL_TREE. */
8474 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8476 enum tree_code compl_code;
8478 if (code == MIN_EXPR)
8479 compl_code = MAX_EXPR;
8480 else if (code == MAX_EXPR)
8481 compl_code = MIN_EXPR;
8485 /* MIN (MAX (a, b), b) == b. */
8486 if (TREE_CODE (op0) == compl_code
8487 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8488 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8490 /* MIN (MAX (b, a), b) == b. */
8491 if (TREE_CODE (op0) == compl_code
8492 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8493 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8494 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8496 /* MIN (a, MAX (a, b)) == a. */
8497 if (TREE_CODE (op1) == compl_code
8498 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8499 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8500 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8502 /* MIN (a, MAX (b, a)) == a. */
8503 if (TREE_CODE (op1) == compl_code
8504 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8505 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8506 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8511 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8512 by changing CODE to reduce the magnitude of constants involved in
8513 ARG0 of the comparison.
8514 Returns a canonicalized comparison tree if a simplification was
8515 possible, otherwise returns NULL_TREE.
8516 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8517 valid if signed overflow is undefined. */
8520 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8521 tree arg0, tree arg1,
8522 bool *strict_overflow_p)
8524 enum tree_code code0 = TREE_CODE (arg0);
8525 tree t, cst0 = NULL_TREE;
8529 /* Match A +- CST code arg1 and CST code arg1. */
8530 if (!(((code0 == MINUS_EXPR
8531 || code0 == PLUS_EXPR)
8532 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8533 || code0 == INTEGER_CST))
8536 /* Identify the constant in arg0 and its sign. */
8537 if (code0 == INTEGER_CST)
8540 cst0 = TREE_OPERAND (arg0, 1);
8541 sgn0 = tree_int_cst_sgn (cst0);
8543 /* Overflowed constants and zero will cause problems. */
8544 if (integer_zerop (cst0)
8545 || TREE_OVERFLOW (cst0))
8548 /* See if we can reduce the magnitude of the constant in
8549 arg0 by changing the comparison code. */
8550 if (code0 == INTEGER_CST)
8552 /* CST <= arg1 -> CST-1 < arg1. */
8553 if (code == LE_EXPR && sgn0 == 1)
8555 /* -CST < arg1 -> -CST-1 <= arg1. */
8556 else if (code == LT_EXPR && sgn0 == -1)
8558 /* CST > arg1 -> CST-1 >= arg1. */
8559 else if (code == GT_EXPR && sgn0 == 1)
8561 /* -CST >= arg1 -> -CST-1 > arg1. */
8562 else if (code == GE_EXPR && sgn0 == -1)
8566 /* arg1 code' CST' might be more canonical. */
8571 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8573 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8575 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8576 else if (code == GT_EXPR
8577 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8579 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8580 else if (code == LE_EXPR
8581 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8583 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8584 else if (code == GE_EXPR
8585 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8589 *strict_overflow_p = true;
8592 /* Now build the constant reduced in magnitude. */
8593 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8594 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8595 if (code0 != INTEGER_CST)
8596 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8598 /* If swapping might yield to a more canonical form, do so. */
8600 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8602 return fold_build2 (code, type, t, arg1);
8605 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8606 overflow further. Try to decrease the magnitude of constants involved
8607 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8608 and put sole constants at the second argument position.
8609 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8612 maybe_canonicalize_comparison (enum tree_code code, tree type,
8613 tree arg0, tree arg1)
8616 bool strict_overflow_p;
8617 const char * const warnmsg = G_("assuming signed overflow does not occur "
8618 "when reducing constant in comparison");
8620 /* In principle pointers also have undefined overflow behavior,
8621 but that causes problems elsewhere. */
8622 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8623 || POINTER_TYPE_P (TREE_TYPE (arg0)))
8626 /* Try canonicalization by simplifying arg0. */
8627 strict_overflow_p = false;
8628 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8629 &strict_overflow_p);
8632 if (strict_overflow_p)
8633 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8637 /* Try canonicalization by simplifying arg1 using the swapped
8639 code = swap_tree_comparison (code);
8640 strict_overflow_p = false;
8641 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8642 &strict_overflow_p);
8643 if (t && strict_overflow_p)
8644 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8648 /* Subroutine of fold_binary. This routine performs all of the
8649 transformations that are common to the equality/inequality
8650 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8651 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8652 fold_binary should call fold_binary. Fold a comparison with
8653 tree code CODE and type TYPE with operands OP0 and OP1. Return
8654 the folded comparison or NULL_TREE. */
8657 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8659 tree arg0, arg1, tem;
8664 STRIP_SIGN_NOPS (arg0);
8665 STRIP_SIGN_NOPS (arg1);
8667 tem = fold_relational_const (code, type, arg0, arg1);
8668 if (tem != NULL_TREE)
8671 /* If one arg is a real or integer constant, put it last. */
8672 if (tree_swap_operands_p (arg0, arg1, true))
8673 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8675 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8676 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8677 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8678 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8679 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8680 && (TREE_CODE (arg1) == INTEGER_CST
8681 && !TREE_OVERFLOW (arg1)))
8683 tree const1 = TREE_OPERAND (arg0, 1);
8685 tree variable = TREE_OPERAND (arg0, 0);
8688 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8690 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8691 TREE_TYPE (arg1), const2, const1);
8693 /* If the constant operation overflowed this can be
8694 simplified as a comparison against INT_MAX/INT_MIN. */
8695 if (TREE_CODE (lhs) == INTEGER_CST
8696 && TREE_OVERFLOW (lhs))
8698 int const1_sgn = tree_int_cst_sgn (const1);
8699 enum tree_code code2 = code;
8701 /* Get the sign of the constant on the lhs if the
8702 operation were VARIABLE + CONST1. */
8703 if (TREE_CODE (arg0) == MINUS_EXPR)
8704 const1_sgn = -const1_sgn;
8706 /* The sign of the constant determines if we overflowed
8707 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8708 Canonicalize to the INT_MIN overflow by swapping the comparison
8710 if (const1_sgn == -1)
8711 code2 = swap_tree_comparison (code);
8713 /* We now can look at the canonicalized case
8714 VARIABLE + 1 CODE2 INT_MIN
8715 and decide on the result. */
8716 if (code2 == LT_EXPR
8718 || code2 == EQ_EXPR)
8719 return omit_one_operand (type, boolean_false_node, variable);
8720 else if (code2 == NE_EXPR
8722 || code2 == GT_EXPR)
8723 return omit_one_operand (type, boolean_true_node, variable);
8726 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8727 && (TREE_CODE (lhs) != INTEGER_CST
8728 || !TREE_OVERFLOW (lhs)))
8730 fold_overflow_warning (("assuming signed overflow does not occur "
8731 "when changing X +- C1 cmp C2 to "
8733 WARN_STRICT_OVERFLOW_COMPARISON);
8734 return fold_build2 (code, type, variable, lhs);
8738 /* For comparisons of pointers we can decompose it to a compile time
8739 comparison of the base objects and the offsets into the object.
8740 This requires at least one operand being an ADDR_EXPR or a
8741 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8742 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8743 && (TREE_CODE (arg0) == ADDR_EXPR
8744 || TREE_CODE (arg1) == ADDR_EXPR
8745 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
8746 || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
8748 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8749 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8750 enum machine_mode mode;
8751 int volatilep, unsignedp;
8752 bool indirect_base0 = false;
8754 /* Get base and offset for the access. Strip ADDR_EXPR for
8755 get_inner_reference, but put it back by stripping INDIRECT_REF
8756 off the base object if possible. */
8758 if (TREE_CODE (arg0) == ADDR_EXPR)
8760 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8761 &bitsize, &bitpos0, &offset0, &mode,
8762 &unsignedp, &volatilep, false);
8763 if (TREE_CODE (base0) == INDIRECT_REF)
8764 base0 = TREE_OPERAND (base0, 0);
8766 indirect_base0 = true;
8768 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
8770 base0 = TREE_OPERAND (arg0, 0);
8771 offset0 = TREE_OPERAND (arg0, 1);
8775 if (TREE_CODE (arg1) == ADDR_EXPR)
8777 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8778 &bitsize, &bitpos1, &offset1, &mode,
8779 &unsignedp, &volatilep, false);
8780 /* We have to make sure to have an indirect/non-indirect base1
8781 just the same as we did for base0. */
8782 if (TREE_CODE (base1) == INDIRECT_REF
8784 base1 = TREE_OPERAND (base1, 0);
8785 else if (!indirect_base0)
8788 else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
8790 base1 = TREE_OPERAND (arg1, 0);
8791 offset1 = TREE_OPERAND (arg1, 1);
8793 else if (indirect_base0)
8796 /* If we have equivalent bases we might be able to simplify. */
8798 && operand_equal_p (base0, base1, 0))
8800 /* We can fold this expression to a constant if the non-constant
8801 offset parts are equal. */
8802 if (offset0 == offset1
8803 || (offset0 && offset1
8804 && operand_equal_p (offset0, offset1, 0)))
8809 return build_int_cst (boolean_type_node, bitpos0 == bitpos1);
8811 return build_int_cst (boolean_type_node, bitpos0 != bitpos1);
8813 return build_int_cst (boolean_type_node, bitpos0 < bitpos1);
8815 return build_int_cst (boolean_type_node, bitpos0 <= bitpos1);
8817 return build_int_cst (boolean_type_node, bitpos0 >= bitpos1);
8819 return build_int_cst (boolean_type_node, bitpos0 > bitpos1);
8823 /* We can simplify the comparison to a comparison of the variable
8824 offset parts if the constant offset parts are equal.
8825 Be careful to use signed size type here because otherwise we
8826 mess with array offsets in the wrong way. This is possible
8827 because pointer arithmetic is restricted to retain within an
8828 object and overflow on pointer differences is undefined as of
8829 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8830 else if (bitpos0 == bitpos1)
8832 tree signed_size_type_node;
8833 signed_size_type_node = signed_type_for (size_type_node);
8835 /* By converting to signed size type we cover middle-end pointer
8836 arithmetic which operates on unsigned pointer types of size
8837 type size and ARRAY_REF offsets which are properly sign or
8838 zero extended from their type in case it is narrower than
8840 if (offset0 == NULL_TREE)
8841 offset0 = build_int_cst (signed_size_type_node, 0);
8843 offset0 = fold_convert (signed_size_type_node, offset0);
8844 if (offset1 == NULL_TREE)
8845 offset1 = build_int_cst (signed_size_type_node, 0);
8847 offset1 = fold_convert (signed_size_type_node, offset1);
8849 return fold_build2 (code, type, offset0, offset1);
8854 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8855 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8856 the resulting offset is smaller in absolute value than the
8858 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8859 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8860 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8861 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8862 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
8863 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8864 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
8866 tree const1 = TREE_OPERAND (arg0, 1);
8867 tree const2 = TREE_OPERAND (arg1, 1);
8868 tree variable1 = TREE_OPERAND (arg0, 0);
8869 tree variable2 = TREE_OPERAND (arg1, 0);
8871 const char * const warnmsg = G_("assuming signed overflow does not "
8872 "occur when combining constants around "
8875 /* Put the constant on the side where it doesn't overflow and is
8876 of lower absolute value than before. */
8877 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8878 ? MINUS_EXPR : PLUS_EXPR,
8880 if (!TREE_OVERFLOW (cst)
8881 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
8883 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8884 return fold_build2 (code, type,
8886 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
8890 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8891 ? MINUS_EXPR : PLUS_EXPR,
8893 if (!TREE_OVERFLOW (cst)
8894 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
8896 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8897 return fold_build2 (code, type,
8898 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
8904 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
8905 signed arithmetic case. That form is created by the compiler
8906 often enough for folding it to be of value. One example is in
8907 computing loop trip counts after Operator Strength Reduction. */
8908 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8909 && TREE_CODE (arg0) == MULT_EXPR
8910 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8911 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8912 && integer_zerop (arg1))
8914 tree const1 = TREE_OPERAND (arg0, 1);
8915 tree const2 = arg1; /* zero */
8916 tree variable1 = TREE_OPERAND (arg0, 0);
8917 enum tree_code cmp_code = code;
8919 gcc_assert (!integer_zerop (const1));
8921 fold_overflow_warning (("assuming signed overflow does not occur when "
8922 "eliminating multiplication in comparison "
8924 WARN_STRICT_OVERFLOW_COMPARISON);
8926 /* If const1 is negative we swap the sense of the comparison. */
8927 if (tree_int_cst_sgn (const1) < 0)
8928 cmp_code = swap_tree_comparison (cmp_code);
8930 return fold_build2 (cmp_code, type, variable1, const2);
8933 tem = maybe_canonicalize_comparison (code, type, op0, op1);
8937 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8939 tree targ0 = strip_float_extensions (arg0);
8940 tree targ1 = strip_float_extensions (arg1);
8941 tree newtype = TREE_TYPE (targ0);
8943 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8944 newtype = TREE_TYPE (targ1);
8946 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8947 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8948 return fold_build2 (code, type, fold_convert (newtype, targ0),
8949 fold_convert (newtype, targ1));
8951 /* (-a) CMP (-b) -> b CMP a */
8952 if (TREE_CODE (arg0) == NEGATE_EXPR
8953 && TREE_CODE (arg1) == NEGATE_EXPR)
8954 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8955 TREE_OPERAND (arg0, 0));
8957 if (TREE_CODE (arg1) == REAL_CST)
8959 REAL_VALUE_TYPE cst;
8960 cst = TREE_REAL_CST (arg1);
8962 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8963 if (TREE_CODE (arg0) == NEGATE_EXPR)
8964 return fold_build2 (swap_tree_comparison (code), type,
8965 TREE_OPERAND (arg0, 0),
8966 build_real (TREE_TYPE (arg1),
8967 REAL_VALUE_NEGATE (cst)));
8969 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8970 /* a CMP (-0) -> a CMP 0 */
8971 if (REAL_VALUE_MINUS_ZERO (cst))
8972 return fold_build2 (code, type, arg0,
8973 build_real (TREE_TYPE (arg1), dconst0));
8975 /* x != NaN is always true, other ops are always false. */
8976 if (REAL_VALUE_ISNAN (cst)
8977 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8979 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8980 return omit_one_operand (type, tem, arg0);
8983 /* Fold comparisons against infinity. */
8984 if (REAL_VALUE_ISINF (cst))
8986 tem = fold_inf_compare (code, type, arg0, arg1);
8987 if (tem != NULL_TREE)
8992 /* If this is a comparison of a real constant with a PLUS_EXPR
8993 or a MINUS_EXPR of a real constant, we can convert it into a
8994 comparison with a revised real constant as long as no overflow
8995 occurs when unsafe_math_optimizations are enabled. */
8996 if (flag_unsafe_math_optimizations
8997 && TREE_CODE (arg1) == REAL_CST
8998 && (TREE_CODE (arg0) == PLUS_EXPR
8999 || TREE_CODE (arg0) == MINUS_EXPR)
9000 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
9001 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9002 ? MINUS_EXPR : PLUS_EXPR,
9003 arg1, TREE_OPERAND (arg0, 1), 0))
9004 && !TREE_OVERFLOW (tem))
9005 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9007 /* Likewise, we can simplify a comparison of a real constant with
9008 a MINUS_EXPR whose first operand is also a real constant, i.e.
9009 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
9010 floating-point types only if -fassociative-math is set. */
9011 if (flag_associative_math
9012 && TREE_CODE (arg1) == REAL_CST
9013 && TREE_CODE (arg0) == MINUS_EXPR
9014 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
9015 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
9017 && !TREE_OVERFLOW (tem))
9018 return fold_build2 (swap_tree_comparison (code), type,
9019 TREE_OPERAND (arg0, 1), tem);
9021 /* Fold comparisons against built-in math functions. */
9022 if (TREE_CODE (arg1) == REAL_CST
9023 && flag_unsafe_math_optimizations
9024 && ! flag_errno_math)
9026 enum built_in_function fcode = builtin_mathfn_code (arg0);
9028 if (fcode != END_BUILTINS)
9030 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
9031 if (tem != NULL_TREE)
9037 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
9038 && (TREE_CODE (arg0) == NOP_EXPR
9039 || TREE_CODE (arg0) == CONVERT_EXPR))
9041 /* If we are widening one operand of an integer comparison,
9042 see if the other operand is similarly being widened. Perhaps we
9043 can do the comparison in the narrower type. */
9044 tem = fold_widened_comparison (code, type, arg0, arg1);
9048 /* Or if we are changing signedness. */
9049 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
9054 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9055 constant, we can simplify it. */
9056 if (TREE_CODE (arg1) == INTEGER_CST
9057 && (TREE_CODE (arg0) == MIN_EXPR
9058 || TREE_CODE (arg0) == MAX_EXPR)
9059 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9061 tem = optimize_minmax_comparison (code, type, op0, op1);
9066 /* Simplify comparison of something with itself. (For IEEE
9067 floating-point, we can only do some of these simplifications.) */
9068 if (operand_equal_p (arg0, arg1, 0))
9073 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9074 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9075 return constant_boolean_node (1, type);
9080 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9081 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9082 return constant_boolean_node (1, type);
9083 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9086 /* For NE, we can only do this simplification if integer
9087 or we don't honor IEEE floating point NaNs. */
9088 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
9089 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9091 /* ... fall through ... */
9094 return constant_boolean_node (0, type);
9100 /* If we are comparing an expression that just has comparisons
9101 of two integer values, arithmetic expressions of those comparisons,
9102 and constants, we can simplify it. There are only three cases
9103 to check: the two values can either be equal, the first can be
9104 greater, or the second can be greater. Fold the expression for
9105 those three values. Since each value must be 0 or 1, we have
9106 eight possibilities, each of which corresponds to the constant 0
9107 or 1 or one of the six possible comparisons.
9109 This handles common cases like (a > b) == 0 but also handles
9110 expressions like ((x > y) - (y > x)) > 0, which supposedly
9111 occur in macroized code. */
9113 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
9115 tree cval1 = 0, cval2 = 0;
9118 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
9119 /* Don't handle degenerate cases here; they should already
9120 have been handled anyway. */
9121 && cval1 != 0 && cval2 != 0
9122 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
9123 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
9124 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
9125 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
9126 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
9127 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
9128 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9130 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9131 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9133 /* We can't just pass T to eval_subst in case cval1 or cval2
9134 was the same as ARG1. */
9137 = fold_build2 (code, type,
9138 eval_subst (arg0, cval1, maxval,
9142 = fold_build2 (code, type,
9143 eval_subst (arg0, cval1, maxval,
9147 = fold_build2 (code, type,
9148 eval_subst (arg0, cval1, minval,
9152 /* All three of these results should be 0 or 1. Confirm they are.
9153 Then use those values to select the proper code to use. */
9155 if (TREE_CODE (high_result) == INTEGER_CST
9156 && TREE_CODE (equal_result) == INTEGER_CST
9157 && TREE_CODE (low_result) == INTEGER_CST)
9159 /* Make a 3-bit mask with the high-order bit being the
9160 value for `>', the next for '=', and the low for '<'. */
9161 switch ((integer_onep (high_result) * 4)
9162 + (integer_onep (equal_result) * 2)
9163 + integer_onep (low_result))
9167 return omit_one_operand (type, integer_zero_node, arg0);
9188 return omit_one_operand (type, integer_one_node, arg0);
9192 return save_expr (build2 (code, type, cval1, cval2));
9193 return fold_build2 (code, type, cval1, cval2);
9198 /* Fold a comparison of the address of COMPONENT_REFs with the same
9199 type and component to a comparison of the address of the base
9200 object. In short, &x->a OP &y->a to x OP y and
9201 &x->a OP &y.a to x OP &y */
9202 if (TREE_CODE (arg0) == ADDR_EXPR
9203 && TREE_CODE (TREE_OPERAND (arg0, 0)) == COMPONENT_REF
9204 && TREE_CODE (arg1) == ADDR_EXPR
9205 && TREE_CODE (TREE_OPERAND (arg1, 0)) == COMPONENT_REF)
9207 tree cref0 = TREE_OPERAND (arg0, 0);
9208 tree cref1 = TREE_OPERAND (arg1, 0);
9209 if (TREE_OPERAND (cref0, 1) == TREE_OPERAND (cref1, 1))
9211 tree op0 = TREE_OPERAND (cref0, 0);
9212 tree op1 = TREE_OPERAND (cref1, 0);
9213 return fold_build2 (code, type,
9214 fold_addr_expr (op0),
9215 fold_addr_expr (op1));
9219 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9220 into a single range test. */
9221 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9222 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9223 && TREE_CODE (arg1) == INTEGER_CST
9224 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9225 && !integer_zerop (TREE_OPERAND (arg0, 1))
9226 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9227 && !TREE_OVERFLOW (arg1))
9229 tem = fold_div_compare (code, type, arg0, arg1);
9230 if (tem != NULL_TREE)
9234 /* Fold ~X op ~Y as Y op X. */
9235 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9236 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9238 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9239 return fold_build2 (code, type,
9240 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
9241 TREE_OPERAND (arg0, 0));
9244 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
9245 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9246 && TREE_CODE (arg1) == INTEGER_CST)
9248 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9249 return fold_build2 (swap_tree_comparison (code), type,
9250 TREE_OPERAND (arg0, 0),
9251 fold_build1 (BIT_NOT_EXPR, cmp_type,
9252 fold_convert (cmp_type, arg1)));
9259 /* Subroutine of fold_binary. Optimize complex multiplications of the
9260 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9261 argument EXPR represents the expression "z" of type TYPE. */
9264 fold_mult_zconjz (tree type, tree expr)
9266 tree itype = TREE_TYPE (type);
9267 tree rpart, ipart, tem;
9269 if (TREE_CODE (expr) == COMPLEX_EXPR)
9271 rpart = TREE_OPERAND (expr, 0);
9272 ipart = TREE_OPERAND (expr, 1);
9274 else if (TREE_CODE (expr) == COMPLEX_CST)
9276 rpart = TREE_REALPART (expr);
9277 ipart = TREE_IMAGPART (expr);
9281 expr = save_expr (expr);
9282 rpart = fold_build1 (REALPART_EXPR, itype, expr);
9283 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
9286 rpart = save_expr (rpart);
9287 ipart = save_expr (ipart);
9288 tem = fold_build2 (PLUS_EXPR, itype,
9289 fold_build2 (MULT_EXPR, itype, rpart, rpart),
9290 fold_build2 (MULT_EXPR, itype, ipart, ipart));
9291 return fold_build2 (COMPLEX_EXPR, type, tem,
9292 fold_convert (itype, integer_zero_node));
9296 /* Subroutine of fold_binary. If P is the value of EXPR, computes
9297 power-of-two M and (arbitrary) N such that M divides (P-N). This condition
9298 guarantees that P and N have the same least significant log2(M) bits.
9299 N is not otherwise constrained. In particular, N is not normalized to
9300 0 <= N < M as is common. In general, the precise value of P is unknown.
9301 M is chosen as large as possible such that constant N can be determined.
9303 Returns M and sets *RESIDUE to N. */
9305 static unsigned HOST_WIDE_INT
9306 get_pointer_modulus_and_residue (tree expr, unsigned HOST_WIDE_INT *residue)
9308 enum tree_code code;
9312 code = TREE_CODE (expr);
9313 if (code == ADDR_EXPR)
9315 expr = TREE_OPERAND (expr, 0);
9316 if (handled_component_p (expr))
9318 HOST_WIDE_INT bitsize, bitpos;
9320 enum machine_mode mode;
9321 int unsignedp, volatilep;
9323 expr = get_inner_reference (expr, &bitsize, &bitpos, &offset,
9324 &mode, &unsignedp, &volatilep, false);
9325 *residue = bitpos / BITS_PER_UNIT;
9328 if (TREE_CODE (offset) == INTEGER_CST)
9329 *residue += TREE_INT_CST_LOW (offset);
9331 /* We don't handle more complicated offset expressions. */
9337 return DECL_ALIGN_UNIT (expr);
9339 else if (code == POINTER_PLUS_EXPR)
9342 unsigned HOST_WIDE_INT modulus;
9343 enum tree_code inner_code;
9345 op0 = TREE_OPERAND (expr, 0);
9347 modulus = get_pointer_modulus_and_residue (op0, residue);
9349 op1 = TREE_OPERAND (expr, 1);
9351 inner_code = TREE_CODE (op1);
9352 if (inner_code == INTEGER_CST)
9354 *residue += TREE_INT_CST_LOW (op1);
9357 else if (inner_code == MULT_EXPR)
9359 op1 = TREE_OPERAND (op1, 1);
9360 if (TREE_CODE (op1) == INTEGER_CST)
9362 unsigned HOST_WIDE_INT align;
9364 /* Compute the greatest power-of-2 divisor of op1. */
9365 align = TREE_INT_CST_LOW (op1);
9368 /* If align is non-zero and less than *modulus, replace
9369 *modulus with align., If align is 0, then either op1 is 0
9370 or the greatest power-of-2 divisor of op1 doesn't fit in an
9371 unsigned HOST_WIDE_INT. In either case, no additional
9372 constraint is imposed. */
9374 modulus = MIN (modulus, align);
9381 /* If we get here, we were unable to determine anything useful about the
9387 /* Fold a binary expression of code CODE and type TYPE with operands
9388 OP0 and OP1. Return the folded expression if folding is
9389 successful. Otherwise, return NULL_TREE. */
9392 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
9394 enum tree_code_class kind = TREE_CODE_CLASS (code);
9395 tree arg0, arg1, tem;
9396 tree t1 = NULL_TREE;
9397 bool strict_overflow_p;
9399 gcc_assert ((IS_EXPR_CODE_CLASS (kind)
9400 || IS_GIMPLE_STMT_CODE_CLASS (kind))
9401 && TREE_CODE_LENGTH (code) == 2
9403 && op1 != NULL_TREE);
9408 /* Strip any conversions that don't change the mode. This is
9409 safe for every expression, except for a comparison expression
9410 because its signedness is derived from its operands. So, in
9411 the latter case, only strip conversions that don't change the
9414 Note that this is done as an internal manipulation within the
9415 constant folder, in order to find the simplest representation
9416 of the arguments so that their form can be studied. In any
9417 cases, the appropriate type conversions should be put back in
9418 the tree that will get out of the constant folder. */
9420 if (kind == tcc_comparison)
9422 STRIP_SIGN_NOPS (arg0);
9423 STRIP_SIGN_NOPS (arg1);
9431 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9432 constant but we can't do arithmetic on them. */
9433 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9434 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9435 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == FIXED_CST)
9436 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == INTEGER_CST)
9437 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9438 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9440 if (kind == tcc_binary)
9442 /* Make sure type and arg0 have the same saturating flag. */
9443 gcc_assert (TYPE_SATURATING (type)
9444 == TYPE_SATURATING (TREE_TYPE (arg0)));
9445 tem = const_binop (code, arg0, arg1, 0);
9447 else if (kind == tcc_comparison)
9448 tem = fold_relational_const (code, type, arg0, arg1);
9452 if (tem != NULL_TREE)
9454 if (TREE_TYPE (tem) != type)
9455 tem = fold_convert (type, tem);
9460 /* If this is a commutative operation, and ARG0 is a constant, move it
9461 to ARG1 to reduce the number of tests below. */
9462 if (commutative_tree_code (code)
9463 && tree_swap_operands_p (arg0, arg1, true))
9464 return fold_build2 (code, type, op1, op0);
9466 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9468 First check for cases where an arithmetic operation is applied to a
9469 compound, conditional, or comparison operation. Push the arithmetic
9470 operation inside the compound or conditional to see if any folding
9471 can then be done. Convert comparison to conditional for this purpose.
9472 The also optimizes non-constant cases that used to be done in
9475 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9476 one of the operands is a comparison and the other is a comparison, a
9477 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9478 code below would make the expression more complex. Change it to a
9479 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9480 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9482 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9483 || code == EQ_EXPR || code == NE_EXPR)
9484 && ((truth_value_p (TREE_CODE (arg0))
9485 && (truth_value_p (TREE_CODE (arg1))
9486 || (TREE_CODE (arg1) == BIT_AND_EXPR
9487 && integer_onep (TREE_OPERAND (arg1, 1)))))
9488 || (truth_value_p (TREE_CODE (arg1))
9489 && (truth_value_p (TREE_CODE (arg0))
9490 || (TREE_CODE (arg0) == BIT_AND_EXPR
9491 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9493 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9494 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9497 fold_convert (boolean_type_node, arg0),
9498 fold_convert (boolean_type_node, arg1));
9500 if (code == EQ_EXPR)
9501 tem = invert_truthvalue (tem);
9503 return fold_convert (type, tem);
9506 if (TREE_CODE_CLASS (code) == tcc_binary
9507 || TREE_CODE_CLASS (code) == tcc_comparison)
9509 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9510 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9511 fold_build2 (code, type,
9512 fold_convert (TREE_TYPE (op0),
9513 TREE_OPERAND (arg0, 1)),
9515 if (TREE_CODE (arg1) == COMPOUND_EXPR
9516 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9517 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9518 fold_build2 (code, type, op0,
9519 fold_convert (TREE_TYPE (op1),
9520 TREE_OPERAND (arg1, 1))));
9522 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9524 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9526 /*cond_first_p=*/1);
9527 if (tem != NULL_TREE)
9531 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9533 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9535 /*cond_first_p=*/0);
9536 if (tem != NULL_TREE)
9543 case POINTER_PLUS_EXPR:
9544 /* 0 +p index -> (type)index */
9545 if (integer_zerop (arg0))
9546 return non_lvalue (fold_convert (type, arg1));
9548 /* PTR +p 0 -> PTR */
9549 if (integer_zerop (arg1))
9550 return non_lvalue (fold_convert (type, arg0));
9552 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9553 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9554 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9555 return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
9556 fold_convert (sizetype, arg1),
9557 fold_convert (sizetype, arg0)));
9559 /* index +p PTR -> PTR +p index */
9560 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9561 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9562 return fold_build2 (POINTER_PLUS_EXPR, type,
9563 fold_convert (type, arg1),
9564 fold_convert (sizetype, arg0));
9566 /* (PTR +p B) +p A -> PTR +p (B + A) */
9567 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9570 tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
9571 tree arg00 = TREE_OPERAND (arg0, 0);
9572 inner = fold_build2 (PLUS_EXPR, sizetype,
9573 arg01, fold_convert (sizetype, arg1));
9574 return fold_convert (type,
9575 fold_build2 (POINTER_PLUS_EXPR,
9576 TREE_TYPE (arg00), arg00, inner));
9579 /* PTR_CST +p CST -> CST1 */
9580 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9581 return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
9583 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9584 of the array. Loop optimizer sometimes produce this type of
9586 if (TREE_CODE (arg0) == ADDR_EXPR)
9588 tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
9590 return fold_convert (type, tem);
9596 /* PTR + INT -> (INT)(PTR p+ INT) */
9597 if (POINTER_TYPE_P (TREE_TYPE (arg0))
9598 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9599 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9602 fold_convert (sizetype, arg1)));
9603 /* INT + PTR -> (INT)(PTR p+ INT) */
9604 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9605 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9606 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9609 fold_convert (sizetype, arg0)));
9610 /* A + (-B) -> A - B */
9611 if (TREE_CODE (arg1) == NEGATE_EXPR)
9612 return fold_build2 (MINUS_EXPR, type,
9613 fold_convert (type, arg0),
9614 fold_convert (type, TREE_OPERAND (arg1, 0)));
9615 /* (-A) + B -> B - A */
9616 if (TREE_CODE (arg0) == NEGATE_EXPR
9617 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9618 return fold_build2 (MINUS_EXPR, type,
9619 fold_convert (type, arg1),
9620 fold_convert (type, TREE_OPERAND (arg0, 0)));
9622 if (INTEGRAL_TYPE_P (type))
9624 /* Convert ~A + 1 to -A. */
9625 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9626 && integer_onep (arg1))
9627 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
9630 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9631 && !TYPE_OVERFLOW_TRAPS (type))
9633 tree tem = TREE_OPERAND (arg0, 0);
9636 if (operand_equal_p (tem, arg1, 0))
9638 t1 = build_int_cst_type (type, -1);
9639 return omit_one_operand (type, t1, arg1);
9644 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9645 && !TYPE_OVERFLOW_TRAPS (type))
9647 tree tem = TREE_OPERAND (arg1, 0);
9650 if (operand_equal_p (arg0, tem, 0))
9652 t1 = build_int_cst_type (type, -1);
9653 return omit_one_operand (type, t1, arg0);
9657 /* X + (X / CST) * -CST is X % CST. */
9658 if (TREE_CODE (arg1) == MULT_EXPR
9659 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9660 && operand_equal_p (arg0,
9661 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
9663 tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
9664 tree cst1 = TREE_OPERAND (arg1, 1);
9665 tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
9666 if (sum && integer_zerop (sum))
9667 return fold_convert (type,
9668 fold_build2 (TRUNC_MOD_EXPR,
9669 TREE_TYPE (arg0), arg0, cst0));
9673 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9674 same or one. Make sure type is not saturating.
9675 fold_plusminus_mult_expr will re-associate. */
9676 if ((TREE_CODE (arg0) == MULT_EXPR
9677 || TREE_CODE (arg1) == MULT_EXPR)
9678 && !TYPE_SATURATING (type)
9679 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9681 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9686 if (! FLOAT_TYPE_P (type))
9688 if (integer_zerop (arg1))
9689 return non_lvalue (fold_convert (type, arg0));
9691 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9692 with a constant, and the two constants have no bits in common,
9693 we should treat this as a BIT_IOR_EXPR since this may produce more
9695 if (TREE_CODE (arg0) == BIT_AND_EXPR
9696 && TREE_CODE (arg1) == BIT_AND_EXPR
9697 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9698 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9699 && integer_zerop (const_binop (BIT_AND_EXPR,
9700 TREE_OPERAND (arg0, 1),
9701 TREE_OPERAND (arg1, 1), 0)))
9703 code = BIT_IOR_EXPR;
9707 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9708 (plus (plus (mult) (mult)) (foo)) so that we can
9709 take advantage of the factoring cases below. */
9710 if (((TREE_CODE (arg0) == PLUS_EXPR
9711 || TREE_CODE (arg0) == MINUS_EXPR)
9712 && TREE_CODE (arg1) == MULT_EXPR)
9713 || ((TREE_CODE (arg1) == PLUS_EXPR
9714 || TREE_CODE (arg1) == MINUS_EXPR)
9715 && TREE_CODE (arg0) == MULT_EXPR))
9717 tree parg0, parg1, parg, marg;
9718 enum tree_code pcode;
9720 if (TREE_CODE (arg1) == MULT_EXPR)
9721 parg = arg0, marg = arg1;
9723 parg = arg1, marg = arg0;
9724 pcode = TREE_CODE (parg);
9725 parg0 = TREE_OPERAND (parg, 0);
9726 parg1 = TREE_OPERAND (parg, 1);
9730 if (TREE_CODE (parg0) == MULT_EXPR
9731 && TREE_CODE (parg1) != MULT_EXPR)
9732 return fold_build2 (pcode, type,
9733 fold_build2 (PLUS_EXPR, type,
9734 fold_convert (type, parg0),
9735 fold_convert (type, marg)),
9736 fold_convert (type, parg1));
9737 if (TREE_CODE (parg0) != MULT_EXPR
9738 && TREE_CODE (parg1) == MULT_EXPR)
9739 return fold_build2 (PLUS_EXPR, type,
9740 fold_convert (type, parg0),
9741 fold_build2 (pcode, type,
9742 fold_convert (type, marg),
9749 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9750 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
9751 return non_lvalue (fold_convert (type, arg0));
9753 /* Likewise if the operands are reversed. */
9754 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9755 return non_lvalue (fold_convert (type, arg1));
9757 /* Convert X + -C into X - C. */
9758 if (TREE_CODE (arg1) == REAL_CST
9759 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
9761 tem = fold_negate_const (arg1, type);
9762 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
9763 return fold_build2 (MINUS_EXPR, type,
9764 fold_convert (type, arg0),
9765 fold_convert (type, tem));
9768 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9769 to __complex__ ( x, y ). This is not the same for SNaNs or
9770 if signed zeros are involved. */
9771 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9772 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9773 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9775 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9776 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9777 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9778 bool arg0rz = false, arg0iz = false;
9779 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9780 || (arg0i && (arg0iz = real_zerop (arg0i))))
9782 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9783 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9784 if (arg0rz && arg1i && real_zerop (arg1i))
9786 tree rp = arg1r ? arg1r
9787 : build1 (REALPART_EXPR, rtype, arg1);
9788 tree ip = arg0i ? arg0i
9789 : build1 (IMAGPART_EXPR, rtype, arg0);
9790 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9792 else if (arg0iz && arg1r && real_zerop (arg1r))
9794 tree rp = arg0r ? arg0r
9795 : build1 (REALPART_EXPR, rtype, arg0);
9796 tree ip = arg1i ? arg1i
9797 : build1 (IMAGPART_EXPR, rtype, arg1);
9798 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9803 if (flag_unsafe_math_optimizations
9804 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9805 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9806 && (tem = distribute_real_division (code, type, arg0, arg1)))
9809 /* Convert x+x into x*2.0. */
9810 if (operand_equal_p (arg0, arg1, 0)
9811 && SCALAR_FLOAT_TYPE_P (type))
9812 return fold_build2 (MULT_EXPR, type, arg0,
9813 build_real (type, dconst2));
9815 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
9816 We associate floats only if the user has specified
9817 -fassociative-math. */
9818 if (flag_associative_math
9819 && TREE_CODE (arg1) == PLUS_EXPR
9820 && TREE_CODE (arg0) != MULT_EXPR)
9822 tree tree10 = TREE_OPERAND (arg1, 0);
9823 tree tree11 = TREE_OPERAND (arg1, 1);
9824 if (TREE_CODE (tree11) == MULT_EXPR
9825 && TREE_CODE (tree10) == MULT_EXPR)
9828 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
9829 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
9832 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
9833 We associate floats only if the user has specified
9834 -fassociative-math. */
9835 if (flag_associative_math
9836 && TREE_CODE (arg0) == PLUS_EXPR
9837 && TREE_CODE (arg1) != MULT_EXPR)
9839 tree tree00 = TREE_OPERAND (arg0, 0);
9840 tree tree01 = TREE_OPERAND (arg0, 1);
9841 if (TREE_CODE (tree01) == MULT_EXPR
9842 && TREE_CODE (tree00) == MULT_EXPR)
9845 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
9846 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
9852 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9853 is a rotate of A by C1 bits. */
9854 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9855 is a rotate of A by B bits. */
9857 enum tree_code code0, code1;
9858 code0 = TREE_CODE (arg0);
9859 code1 = TREE_CODE (arg1);
9860 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
9861 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
9862 && operand_equal_p (TREE_OPERAND (arg0, 0),
9863 TREE_OPERAND (arg1, 0), 0)
9864 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
9866 tree tree01, tree11;
9867 enum tree_code code01, code11;
9869 tree01 = TREE_OPERAND (arg0, 1);
9870 tree11 = TREE_OPERAND (arg1, 1);
9871 STRIP_NOPS (tree01);
9872 STRIP_NOPS (tree11);
9873 code01 = TREE_CODE (tree01);
9874 code11 = TREE_CODE (tree11);
9875 if (code01 == INTEGER_CST
9876 && code11 == INTEGER_CST
9877 && TREE_INT_CST_HIGH (tree01) == 0
9878 && TREE_INT_CST_HIGH (tree11) == 0
9879 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
9880 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
9881 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
9882 code0 == LSHIFT_EXPR ? tree01 : tree11);
9883 else if (code11 == MINUS_EXPR)
9885 tree tree110, tree111;
9886 tree110 = TREE_OPERAND (tree11, 0);
9887 tree111 = TREE_OPERAND (tree11, 1);
9888 STRIP_NOPS (tree110);
9889 STRIP_NOPS (tree111);
9890 if (TREE_CODE (tree110) == INTEGER_CST
9891 && 0 == compare_tree_int (tree110,
9893 (TREE_TYPE (TREE_OPERAND
9895 && operand_equal_p (tree01, tree111, 0))
9896 return build2 ((code0 == LSHIFT_EXPR
9899 type, TREE_OPERAND (arg0, 0), tree01);
9901 else if (code01 == MINUS_EXPR)
9903 tree tree010, tree011;
9904 tree010 = TREE_OPERAND (tree01, 0);
9905 tree011 = TREE_OPERAND (tree01, 1);
9906 STRIP_NOPS (tree010);
9907 STRIP_NOPS (tree011);
9908 if (TREE_CODE (tree010) == INTEGER_CST
9909 && 0 == compare_tree_int (tree010,
9911 (TREE_TYPE (TREE_OPERAND
9913 && operand_equal_p (tree11, tree011, 0))
9914 return build2 ((code0 != LSHIFT_EXPR
9917 type, TREE_OPERAND (arg0, 0), tree11);
9923 /* In most languages, can't associate operations on floats through
9924 parentheses. Rather than remember where the parentheses were, we
9925 don't associate floats at all, unless the user has specified
9927 And, we need to make sure type is not saturating. */
9929 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
9930 && !TYPE_SATURATING (type))
9932 tree var0, con0, lit0, minus_lit0;
9933 tree var1, con1, lit1, minus_lit1;
9936 /* Split both trees into variables, constants, and literals. Then
9937 associate each group together, the constants with literals,
9938 then the result with variables. This increases the chances of
9939 literals being recombined later and of generating relocatable
9940 expressions for the sum of a constant and literal. */
9941 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
9942 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
9943 code == MINUS_EXPR);
9945 /* With undefined overflow we can only associate constants
9946 with one variable. */
9947 if ((POINTER_TYPE_P (type)
9948 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
9954 if (TREE_CODE (tmp0) == NEGATE_EXPR)
9955 tmp0 = TREE_OPERAND (tmp0, 0);
9956 if (TREE_CODE (tmp1) == NEGATE_EXPR)
9957 tmp1 = TREE_OPERAND (tmp1, 0);
9958 /* The only case we can still associate with two variables
9959 is if they are the same, modulo negation. */
9960 if (!operand_equal_p (tmp0, tmp1, 0))
9964 /* Only do something if we found more than two objects. Otherwise,
9965 nothing has changed and we risk infinite recursion. */
9967 && (2 < ((var0 != 0) + (var1 != 0)
9968 + (con0 != 0) + (con1 != 0)
9969 + (lit0 != 0) + (lit1 != 0)
9970 + (minus_lit0 != 0) + (minus_lit1 != 0))))
9972 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9973 if (code == MINUS_EXPR)
9976 var0 = associate_trees (var0, var1, code, type);
9977 con0 = associate_trees (con0, con1, code, type);
9978 lit0 = associate_trees (lit0, lit1, code, type);
9979 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
9981 /* Preserve the MINUS_EXPR if the negative part of the literal is
9982 greater than the positive part. Otherwise, the multiplicative
9983 folding code (i.e extract_muldiv) may be fooled in case
9984 unsigned constants are subtracted, like in the following
9985 example: ((X*2 + 4) - 8U)/2. */
9986 if (minus_lit0 && lit0)
9988 if (TREE_CODE (lit0) == INTEGER_CST
9989 && TREE_CODE (minus_lit0) == INTEGER_CST
9990 && tree_int_cst_lt (lit0, minus_lit0))
9992 minus_lit0 = associate_trees (minus_lit0, lit0,
9998 lit0 = associate_trees (lit0, minus_lit0,
10006 return fold_convert (type,
10007 associate_trees (var0, minus_lit0,
10008 MINUS_EXPR, type));
10011 con0 = associate_trees (con0, minus_lit0,
10013 return fold_convert (type,
10014 associate_trees (var0, con0,
10019 con0 = associate_trees (con0, lit0, code, type);
10020 return fold_convert (type, associate_trees (var0, con0,
10028 /* Pointer simplifications for subtraction, simple reassociations. */
10029 if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
10031 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
10032 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
10033 && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
10035 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10036 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10037 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10038 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10039 return fold_build2 (PLUS_EXPR, type,
10040 fold_build2 (MINUS_EXPR, type, arg00, arg10),
10041 fold_build2 (MINUS_EXPR, type, arg01, arg11));
10043 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
10044 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
10046 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10047 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10048 tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
10050 return fold_build2 (PLUS_EXPR, type, tmp, arg01);
10053 /* A - (-B) -> A + B */
10054 if (TREE_CODE (arg1) == NEGATE_EXPR)
10055 return fold_build2 (PLUS_EXPR, type, op0,
10056 fold_convert (type, TREE_OPERAND (arg1, 0)));
10057 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
10058 if (TREE_CODE (arg0) == NEGATE_EXPR
10059 && (FLOAT_TYPE_P (type)
10060 || INTEGRAL_TYPE_P (type))
10061 && negate_expr_p (arg1)
10062 && reorder_operands_p (arg0, arg1))
10063 return fold_build2 (MINUS_EXPR, type,
10064 fold_convert (type, negate_expr (arg1)),
10065 fold_convert (type, TREE_OPERAND (arg0, 0)));
10066 /* Convert -A - 1 to ~A. */
10067 if (INTEGRAL_TYPE_P (type)
10068 && TREE_CODE (arg0) == NEGATE_EXPR
10069 && integer_onep (arg1)
10070 && !TYPE_OVERFLOW_TRAPS (type))
10071 return fold_build1 (BIT_NOT_EXPR, type,
10072 fold_convert (type, TREE_OPERAND (arg0, 0)));
10074 /* Convert -1 - A to ~A. */
10075 if (INTEGRAL_TYPE_P (type)
10076 && integer_all_onesp (arg0))
10077 return fold_build1 (BIT_NOT_EXPR, type, op1);
10080 /* X - (X / CST) * CST is X % CST. */
10081 if (INTEGRAL_TYPE_P (type)
10082 && TREE_CODE (arg1) == MULT_EXPR
10083 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
10084 && operand_equal_p (arg0,
10085 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
10086 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
10087 TREE_OPERAND (arg1, 1), 0))
10088 return fold_convert (type,
10089 fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
10090 arg0, TREE_OPERAND (arg1, 1)));
10092 if (! FLOAT_TYPE_P (type))
10094 if (integer_zerop (arg0))
10095 return negate_expr (fold_convert (type, arg1));
10096 if (integer_zerop (arg1))
10097 return non_lvalue (fold_convert (type, arg0));
10099 /* Fold A - (A & B) into ~B & A. */
10100 if (!TREE_SIDE_EFFECTS (arg0)
10101 && TREE_CODE (arg1) == BIT_AND_EXPR)
10103 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
10105 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10106 return fold_build2 (BIT_AND_EXPR, type,
10107 fold_build1 (BIT_NOT_EXPR, type, arg10),
10108 fold_convert (type, arg0));
10110 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10112 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10113 return fold_build2 (BIT_AND_EXPR, type,
10114 fold_build1 (BIT_NOT_EXPR, type, arg11),
10115 fold_convert (type, arg0));
10119 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
10120 any power of 2 minus 1. */
10121 if (TREE_CODE (arg0) == BIT_AND_EXPR
10122 && TREE_CODE (arg1) == BIT_AND_EXPR
10123 && operand_equal_p (TREE_OPERAND (arg0, 0),
10124 TREE_OPERAND (arg1, 0), 0))
10126 tree mask0 = TREE_OPERAND (arg0, 1);
10127 tree mask1 = TREE_OPERAND (arg1, 1);
10128 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
10130 if (operand_equal_p (tem, mask1, 0))
10132 tem = fold_build2 (BIT_XOR_EXPR, type,
10133 TREE_OPERAND (arg0, 0), mask1);
10134 return fold_build2 (MINUS_EXPR, type, tem, mask1);
10139 /* See if ARG1 is zero and X - ARG1 reduces to X. */
10140 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
10141 return non_lvalue (fold_convert (type, arg0));
10143 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
10144 ARG0 is zero and X + ARG0 reduces to X, since that would mean
10145 (-ARG1 + ARG0) reduces to -ARG1. */
10146 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
10147 return negate_expr (fold_convert (type, arg1));
10149 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
10150 __complex__ ( x, -y ). This is not the same for SNaNs or if
10151 signed zeros are involved. */
10152 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10153 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10154 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10156 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10157 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10158 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10159 bool arg0rz = false, arg0iz = false;
10160 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10161 || (arg0i && (arg0iz = real_zerop (arg0i))))
10163 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10164 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10165 if (arg0rz && arg1i && real_zerop (arg1i))
10167 tree rp = fold_build1 (NEGATE_EXPR, rtype,
10169 : build1 (REALPART_EXPR, rtype, arg1));
10170 tree ip = arg0i ? arg0i
10171 : build1 (IMAGPART_EXPR, rtype, arg0);
10172 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10174 else if (arg0iz && arg1r && real_zerop (arg1r))
10176 tree rp = arg0r ? arg0r
10177 : build1 (REALPART_EXPR, rtype, arg0);
10178 tree ip = fold_build1 (NEGATE_EXPR, rtype,
10180 : build1 (IMAGPART_EXPR, rtype, arg1));
10181 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10186 /* Fold &x - &x. This can happen from &x.foo - &x.
10187 This is unsafe for certain floats even in non-IEEE formats.
10188 In IEEE, it is unsafe because it does wrong for NaNs.
10189 Also note that operand_equal_p is always false if an operand
10192 if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
10193 && operand_equal_p (arg0, arg1, 0))
10194 return fold_convert (type, integer_zero_node);
10196 /* A - B -> A + (-B) if B is easily negatable. */
10197 if (negate_expr_p (arg1)
10198 && ((FLOAT_TYPE_P (type)
10199 /* Avoid this transformation if B is a positive REAL_CST. */
10200 && (TREE_CODE (arg1) != REAL_CST
10201 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
10202 || INTEGRAL_TYPE_P (type)))
10203 return fold_build2 (PLUS_EXPR, type,
10204 fold_convert (type, arg0),
10205 fold_convert (type, negate_expr (arg1)));
10207 /* Try folding difference of addresses. */
10209 HOST_WIDE_INT diff;
10211 if ((TREE_CODE (arg0) == ADDR_EXPR
10212 || TREE_CODE (arg1) == ADDR_EXPR)
10213 && ptr_difference_const (arg0, arg1, &diff))
10214 return build_int_cst_type (type, diff);
10217 /* Fold &a[i] - &a[j] to i-j. */
10218 if (TREE_CODE (arg0) == ADDR_EXPR
10219 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
10220 && TREE_CODE (arg1) == ADDR_EXPR
10221 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
10223 tree aref0 = TREE_OPERAND (arg0, 0);
10224 tree aref1 = TREE_OPERAND (arg1, 0);
10225 if (operand_equal_p (TREE_OPERAND (aref0, 0),
10226 TREE_OPERAND (aref1, 0), 0))
10228 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
10229 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
10230 tree esz = array_ref_element_size (aref0);
10231 tree diff = build2 (MINUS_EXPR, type, op0, op1);
10232 return fold_build2 (MULT_EXPR, type, diff,
10233 fold_convert (type, esz));
10238 if (flag_unsafe_math_optimizations
10239 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10240 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10241 && (tem = distribute_real_division (code, type, arg0, arg1)))
10244 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
10245 same or one. Make sure type is not saturating.
10246 fold_plusminus_mult_expr will re-associate. */
10247 if ((TREE_CODE (arg0) == MULT_EXPR
10248 || TREE_CODE (arg1) == MULT_EXPR)
10249 && !TYPE_SATURATING (type)
10250 && (!FLOAT_TYPE_P (type) || flag_associative_math))
10252 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
10260 /* (-A) * (-B) -> A * B */
10261 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10262 return fold_build2 (MULT_EXPR, type,
10263 fold_convert (type, TREE_OPERAND (arg0, 0)),
10264 fold_convert (type, negate_expr (arg1)));
10265 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10266 return fold_build2 (MULT_EXPR, type,
10267 fold_convert (type, negate_expr (arg0)),
10268 fold_convert (type, TREE_OPERAND (arg1, 0)));
10270 if (! FLOAT_TYPE_P (type))
10272 if (integer_zerop (arg1))
10273 return omit_one_operand (type, arg1, arg0);
10274 if (integer_onep (arg1))
10275 return non_lvalue (fold_convert (type, arg0));
10276 /* Transform x * -1 into -x. Make sure to do the negation
10277 on the original operand with conversions not stripped
10278 because we can only strip non-sign-changing conversions. */
10279 if (integer_all_onesp (arg1))
10280 return fold_convert (type, negate_expr (op0));
10281 /* Transform x * -C into -x * C if x is easily negatable. */
10282 if (TREE_CODE (arg1) == INTEGER_CST
10283 && tree_int_cst_sgn (arg1) == -1
10284 && negate_expr_p (arg0)
10285 && (tem = negate_expr (arg1)) != arg1
10286 && !TREE_OVERFLOW (tem))
10287 return fold_build2 (MULT_EXPR, type,
10288 fold_convert (type, negate_expr (arg0)), tem);
10290 /* (a * (1 << b)) is (a << b) */
10291 if (TREE_CODE (arg1) == LSHIFT_EXPR
10292 && integer_onep (TREE_OPERAND (arg1, 0)))
10293 return fold_build2 (LSHIFT_EXPR, type, op0,
10294 TREE_OPERAND (arg1, 1));
10295 if (TREE_CODE (arg0) == LSHIFT_EXPR
10296 && integer_onep (TREE_OPERAND (arg0, 0)))
10297 return fold_build2 (LSHIFT_EXPR, type, op1,
10298 TREE_OPERAND (arg0, 1));
10300 strict_overflow_p = false;
10301 if (TREE_CODE (arg1) == INTEGER_CST
10302 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10303 &strict_overflow_p)))
10305 if (strict_overflow_p)
10306 fold_overflow_warning (("assuming signed overflow does not "
10307 "occur when simplifying "
10309 WARN_STRICT_OVERFLOW_MISC);
10310 return fold_convert (type, tem);
10313 /* Optimize z * conj(z) for integer complex numbers. */
10314 if (TREE_CODE (arg0) == CONJ_EXPR
10315 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10316 return fold_mult_zconjz (type, arg1);
10317 if (TREE_CODE (arg1) == CONJ_EXPR
10318 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10319 return fold_mult_zconjz (type, arg0);
10323 /* Maybe fold x * 0 to 0. The expressions aren't the same
10324 when x is NaN, since x * 0 is also NaN. Nor are they the
10325 same in modes with signed zeros, since multiplying a
10326 negative value by 0 gives -0, not +0. */
10327 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10328 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10329 && real_zerop (arg1))
10330 return omit_one_operand (type, arg1, arg0);
10331 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
10332 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10333 && real_onep (arg1))
10334 return non_lvalue (fold_convert (type, arg0));
10336 /* Transform x * -1.0 into -x. */
10337 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10338 && real_minus_onep (arg1))
10339 return fold_convert (type, negate_expr (arg0));
10341 /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
10342 the result for floating point types due to rounding so it is applied
10343 only if -fassociative-math was specify. */
10344 if (flag_associative_math
10345 && TREE_CODE (arg0) == RDIV_EXPR
10346 && TREE_CODE (arg1) == REAL_CST
10347 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
10349 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
10352 return fold_build2 (RDIV_EXPR, type, tem,
10353 TREE_OPERAND (arg0, 1));
10356 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10357 if (operand_equal_p (arg0, arg1, 0))
10359 tree tem = fold_strip_sign_ops (arg0);
10360 if (tem != NULL_TREE)
10362 tem = fold_convert (type, tem);
10363 return fold_build2 (MULT_EXPR, type, tem, tem);
10367 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10368 This is not the same for NaNs or if signed zeros are
10370 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10371 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10372 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10373 && TREE_CODE (arg1) == COMPLEX_CST
10374 && real_zerop (TREE_REALPART (arg1)))
10376 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10377 if (real_onep (TREE_IMAGPART (arg1)))
10378 return fold_build2 (COMPLEX_EXPR, type,
10379 negate_expr (fold_build1 (IMAGPART_EXPR,
10381 fold_build1 (REALPART_EXPR, rtype, arg0));
10382 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10383 return fold_build2 (COMPLEX_EXPR, type,
10384 fold_build1 (IMAGPART_EXPR, rtype, arg0),
10385 negate_expr (fold_build1 (REALPART_EXPR,
10389 /* Optimize z * conj(z) for floating point complex numbers.
10390 Guarded by flag_unsafe_math_optimizations as non-finite
10391 imaginary components don't produce scalar results. */
10392 if (flag_unsafe_math_optimizations
10393 && TREE_CODE (arg0) == CONJ_EXPR
10394 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10395 return fold_mult_zconjz (type, arg1);
10396 if (flag_unsafe_math_optimizations
10397 && TREE_CODE (arg1) == CONJ_EXPR
10398 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10399 return fold_mult_zconjz (type, arg0);
10401 if (flag_unsafe_math_optimizations)
10403 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10404 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10406 /* Optimizations of root(...)*root(...). */
10407 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
10410 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10411 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10413 /* Optimize sqrt(x)*sqrt(x) as x. */
10414 if (BUILTIN_SQRT_P (fcode0)
10415 && operand_equal_p (arg00, arg10, 0)
10416 && ! HONOR_SNANS (TYPE_MODE (type)))
10419 /* Optimize root(x)*root(y) as root(x*y). */
10420 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10421 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10422 return build_call_expr (rootfn, 1, arg);
10425 /* Optimize expN(x)*expN(y) as expN(x+y). */
10426 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
10428 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10429 tree arg = fold_build2 (PLUS_EXPR, type,
10430 CALL_EXPR_ARG (arg0, 0),
10431 CALL_EXPR_ARG (arg1, 0));
10432 return build_call_expr (expfn, 1, arg);
10435 /* Optimizations of pow(...)*pow(...). */
10436 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
10437 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
10438 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
10440 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10441 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10442 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10443 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10445 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10446 if (operand_equal_p (arg01, arg11, 0))
10448 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10449 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10450 return build_call_expr (powfn, 2, arg, arg01);
10453 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10454 if (operand_equal_p (arg00, arg10, 0))
10456 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10457 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
10458 return build_call_expr (powfn, 2, arg00, arg);
10462 /* Optimize tan(x)*cos(x) as sin(x). */
10463 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
10464 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
10465 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
10466 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
10467 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
10468 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
10469 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10470 CALL_EXPR_ARG (arg1, 0), 0))
10472 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
10474 if (sinfn != NULL_TREE)
10475 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
10478 /* Optimize x*pow(x,c) as pow(x,c+1). */
10479 if (fcode1 == BUILT_IN_POW
10480 || fcode1 == BUILT_IN_POWF
10481 || fcode1 == BUILT_IN_POWL)
10483 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10484 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10485 if (TREE_CODE (arg11) == REAL_CST
10486 && !TREE_OVERFLOW (arg11)
10487 && operand_equal_p (arg0, arg10, 0))
10489 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10493 c = TREE_REAL_CST (arg11);
10494 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10495 arg = build_real (type, c);
10496 return build_call_expr (powfn, 2, arg0, arg);
10500 /* Optimize pow(x,c)*x as pow(x,c+1). */
10501 if (fcode0 == BUILT_IN_POW
10502 || fcode0 == BUILT_IN_POWF
10503 || fcode0 == BUILT_IN_POWL)
10505 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10506 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10507 if (TREE_CODE (arg01) == REAL_CST
10508 && !TREE_OVERFLOW (arg01)
10509 && operand_equal_p (arg1, arg00, 0))
10511 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10515 c = TREE_REAL_CST (arg01);
10516 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10517 arg = build_real (type, c);
10518 return build_call_expr (powfn, 2, arg1, arg);
10522 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10523 if (! optimize_size
10524 && operand_equal_p (arg0, arg1, 0))
10526 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
10530 tree arg = build_real (type, dconst2);
10531 return build_call_expr (powfn, 2, arg0, arg);
10540 if (integer_all_onesp (arg1))
10541 return omit_one_operand (type, arg1, arg0);
10542 if (integer_zerop (arg1))
10543 return non_lvalue (fold_convert (type, arg0));
10544 if (operand_equal_p (arg0, arg1, 0))
10545 return non_lvalue (fold_convert (type, arg0));
10547 /* ~X | X is -1. */
10548 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10549 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10551 t1 = fold_convert (type, integer_zero_node);
10552 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10553 return omit_one_operand (type, t1, arg1);
10556 /* X | ~X is -1. */
10557 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10558 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10560 t1 = fold_convert (type, integer_zero_node);
10561 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10562 return omit_one_operand (type, t1, arg0);
10565 /* Canonicalize (X & C1) | C2. */
10566 if (TREE_CODE (arg0) == BIT_AND_EXPR
10567 && TREE_CODE (arg1) == INTEGER_CST
10568 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10570 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, mlo, mhi;
10571 int width = TYPE_PRECISION (type);
10572 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10573 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10574 hi2 = TREE_INT_CST_HIGH (arg1);
10575 lo2 = TREE_INT_CST_LOW (arg1);
10577 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10578 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10579 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10581 if (width > HOST_BITS_PER_WIDE_INT)
10583 mhi = (unsigned HOST_WIDE_INT) -1
10584 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10590 mlo = (unsigned HOST_WIDE_INT) -1
10591 >> (HOST_BITS_PER_WIDE_INT - width);
10594 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10595 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10596 return fold_build2 (BIT_IOR_EXPR, type,
10597 TREE_OPERAND (arg0, 0), arg1);
10599 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2. */
10602 if ((hi1 & ~hi2) != hi1 || (lo1 & ~lo2) != lo1)
10603 return fold_build2 (BIT_IOR_EXPR, type,
10604 fold_build2 (BIT_AND_EXPR, type,
10605 TREE_OPERAND (arg0, 0),
10606 build_int_cst_wide (type,
10612 /* (X & Y) | Y is (X, Y). */
10613 if (TREE_CODE (arg0) == BIT_AND_EXPR
10614 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10615 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10616 /* (X & Y) | X is (Y, X). */
10617 if (TREE_CODE (arg0) == BIT_AND_EXPR
10618 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10619 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10620 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10621 /* X | (X & Y) is (Y, X). */
10622 if (TREE_CODE (arg1) == BIT_AND_EXPR
10623 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10624 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10625 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10626 /* X | (Y & X) is (Y, X). */
10627 if (TREE_CODE (arg1) == BIT_AND_EXPR
10628 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10629 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10630 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10632 t1 = distribute_bit_expr (code, type, arg0, arg1);
10633 if (t1 != NULL_TREE)
10636 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10638 This results in more efficient code for machines without a NAND
10639 instruction. Combine will canonicalize to the first form
10640 which will allow use of NAND instructions provided by the
10641 backend if they exist. */
10642 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10643 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10645 return fold_build1 (BIT_NOT_EXPR, type,
10646 build2 (BIT_AND_EXPR, type,
10647 TREE_OPERAND (arg0, 0),
10648 TREE_OPERAND (arg1, 0)));
10651 /* See if this can be simplified into a rotate first. If that
10652 is unsuccessful continue in the association code. */
10656 if (integer_zerop (arg1))
10657 return non_lvalue (fold_convert (type, arg0));
10658 if (integer_all_onesp (arg1))
10659 return fold_build1 (BIT_NOT_EXPR, type, op0);
10660 if (operand_equal_p (arg0, arg1, 0))
10661 return omit_one_operand (type, integer_zero_node, arg0);
10663 /* ~X ^ X is -1. */
10664 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10665 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10667 t1 = fold_convert (type, integer_zero_node);
10668 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10669 return omit_one_operand (type, t1, arg1);
10672 /* X ^ ~X is -1. */
10673 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10674 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10676 t1 = fold_convert (type, integer_zero_node);
10677 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10678 return omit_one_operand (type, t1, arg0);
10681 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10682 with a constant, and the two constants have no bits in common,
10683 we should treat this as a BIT_IOR_EXPR since this may produce more
10684 simplifications. */
10685 if (TREE_CODE (arg0) == BIT_AND_EXPR
10686 && TREE_CODE (arg1) == BIT_AND_EXPR
10687 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10688 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10689 && integer_zerop (const_binop (BIT_AND_EXPR,
10690 TREE_OPERAND (arg0, 1),
10691 TREE_OPERAND (arg1, 1), 0)))
10693 code = BIT_IOR_EXPR;
10697 /* (X | Y) ^ X -> Y & ~ X*/
10698 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10699 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10701 tree t2 = TREE_OPERAND (arg0, 1);
10702 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10704 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10705 fold_convert (type, t1));
10709 /* (Y | X) ^ X -> Y & ~ X*/
10710 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10711 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10713 tree t2 = TREE_OPERAND (arg0, 0);
10714 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10716 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10717 fold_convert (type, t1));
10721 /* X ^ (X | Y) -> Y & ~ X*/
10722 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10723 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
10725 tree t2 = TREE_OPERAND (arg1, 1);
10726 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10728 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10729 fold_convert (type, t1));
10733 /* X ^ (Y | X) -> Y & ~ X*/
10734 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10735 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
10737 tree t2 = TREE_OPERAND (arg1, 0);
10738 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10740 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10741 fold_convert (type, t1));
10745 /* Convert ~X ^ ~Y to X ^ Y. */
10746 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10747 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10748 return fold_build2 (code, type,
10749 fold_convert (type, TREE_OPERAND (arg0, 0)),
10750 fold_convert (type, TREE_OPERAND (arg1, 0)));
10752 /* Convert ~X ^ C to X ^ ~C. */
10753 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10754 && TREE_CODE (arg1) == INTEGER_CST)
10755 return fold_build2 (code, type,
10756 fold_convert (type, TREE_OPERAND (arg0, 0)),
10757 fold_build1 (BIT_NOT_EXPR, type, arg1));
10759 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10760 if (TREE_CODE (arg0) == BIT_AND_EXPR
10761 && integer_onep (TREE_OPERAND (arg0, 1))
10762 && integer_onep (arg1))
10763 return fold_build2 (EQ_EXPR, type, arg0,
10764 build_int_cst (TREE_TYPE (arg0), 0));
10766 /* Fold (X & Y) ^ Y as ~X & Y. */
10767 if (TREE_CODE (arg0) == BIT_AND_EXPR
10768 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10770 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10771 return fold_build2 (BIT_AND_EXPR, type,
10772 fold_build1 (BIT_NOT_EXPR, type, tem),
10773 fold_convert (type, arg1));
10775 /* Fold (X & Y) ^ X as ~Y & X. */
10776 if (TREE_CODE (arg0) == BIT_AND_EXPR
10777 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10778 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10780 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10781 return fold_build2 (BIT_AND_EXPR, type,
10782 fold_build1 (BIT_NOT_EXPR, type, tem),
10783 fold_convert (type, arg1));
10785 /* Fold X ^ (X & Y) as X & ~Y. */
10786 if (TREE_CODE (arg1) == BIT_AND_EXPR
10787 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10789 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10790 return fold_build2 (BIT_AND_EXPR, type,
10791 fold_convert (type, arg0),
10792 fold_build1 (BIT_NOT_EXPR, type, tem));
10794 /* Fold X ^ (Y & X) as ~Y & X. */
10795 if (TREE_CODE (arg1) == BIT_AND_EXPR
10796 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10797 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10799 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10800 return fold_build2 (BIT_AND_EXPR, type,
10801 fold_build1 (BIT_NOT_EXPR, type, tem),
10802 fold_convert (type, arg0));
10805 /* See if this can be simplified into a rotate first. If that
10806 is unsuccessful continue in the association code. */
10810 if (integer_all_onesp (arg1))
10811 return non_lvalue (fold_convert (type, arg0));
10812 if (integer_zerop (arg1))
10813 return omit_one_operand (type, arg1, arg0);
10814 if (operand_equal_p (arg0, arg1, 0))
10815 return non_lvalue (fold_convert (type, arg0));
10817 /* ~X & X is always zero. */
10818 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10819 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10820 return omit_one_operand (type, integer_zero_node, arg1);
10822 /* X & ~X is always zero. */
10823 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10824 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10825 return omit_one_operand (type, integer_zero_node, arg0);
10827 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
10828 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10829 && TREE_CODE (arg1) == INTEGER_CST
10830 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10832 tree tmp1 = fold_convert (TREE_TYPE (arg0), arg1);
10833 tree tmp2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10834 TREE_OPERAND (arg0, 0), tmp1);
10835 tree tmp3 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10836 TREE_OPERAND (arg0, 1), tmp1);
10837 return fold_convert (type,
10838 fold_build2 (BIT_IOR_EXPR, TREE_TYPE (arg0),
10842 /* (X | Y) & Y is (X, Y). */
10843 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10844 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10845 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10846 /* (X | Y) & X is (Y, X). */
10847 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10848 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10849 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10850 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10851 /* X & (X | Y) is (Y, X). */
10852 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10853 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10854 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10855 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10856 /* X & (Y | X) is (Y, X). */
10857 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10858 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10859 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10860 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10862 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10863 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10864 && integer_onep (TREE_OPERAND (arg0, 1))
10865 && integer_onep (arg1))
10867 tem = TREE_OPERAND (arg0, 0);
10868 return fold_build2 (EQ_EXPR, type,
10869 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10870 build_int_cst (TREE_TYPE (tem), 1)),
10871 build_int_cst (TREE_TYPE (tem), 0));
10873 /* Fold ~X & 1 as (X & 1) == 0. */
10874 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10875 && integer_onep (arg1))
10877 tem = TREE_OPERAND (arg0, 0);
10878 return fold_build2 (EQ_EXPR, type,
10879 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10880 build_int_cst (TREE_TYPE (tem), 1)),
10881 build_int_cst (TREE_TYPE (tem), 0));
10884 /* Fold (X ^ Y) & Y as ~X & Y. */
10885 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10886 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10888 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10889 return fold_build2 (BIT_AND_EXPR, type,
10890 fold_build1 (BIT_NOT_EXPR, type, tem),
10891 fold_convert (type, arg1));
10893 /* Fold (X ^ Y) & X as ~Y & X. */
10894 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10895 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10896 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10898 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10899 return fold_build2 (BIT_AND_EXPR, type,
10900 fold_build1 (BIT_NOT_EXPR, type, tem),
10901 fold_convert (type, arg1));
10903 /* Fold X & (X ^ Y) as X & ~Y. */
10904 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10905 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10907 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10908 return fold_build2 (BIT_AND_EXPR, type,
10909 fold_convert (type, arg0),
10910 fold_build1 (BIT_NOT_EXPR, type, tem));
10912 /* Fold X & (Y ^ X) as ~Y & X. */
10913 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10914 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10915 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10917 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10918 return fold_build2 (BIT_AND_EXPR, type,
10919 fold_build1 (BIT_NOT_EXPR, type, tem),
10920 fold_convert (type, arg0));
10923 t1 = distribute_bit_expr (code, type, arg0, arg1);
10924 if (t1 != NULL_TREE)
10926 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10927 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
10928 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
10931 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
10933 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
10934 && (~TREE_INT_CST_LOW (arg1)
10935 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
10936 return fold_convert (type, TREE_OPERAND (arg0, 0));
10939 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
10941 This results in more efficient code for machines without a NOR
10942 instruction. Combine will canonicalize to the first form
10943 which will allow use of NOR instructions provided by the
10944 backend if they exist. */
10945 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10946 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10948 return fold_build1 (BIT_NOT_EXPR, type,
10949 build2 (BIT_IOR_EXPR, type,
10950 fold_convert (type,
10951 TREE_OPERAND (arg0, 0)),
10952 fold_convert (type,
10953 TREE_OPERAND (arg1, 0))));
10956 /* If arg0 is derived from the address of an object or function, we may
10957 be able to fold this expression using the object or function's
10959 if (POINTER_TYPE_P (TREE_TYPE (arg0)) && host_integerp (arg1, 1))
10961 unsigned HOST_WIDE_INT modulus, residue;
10962 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (arg1);
10964 modulus = get_pointer_modulus_and_residue (arg0, &residue);
10966 /* This works because modulus is a power of 2. If this weren't the
10967 case, we'd have to replace it by its greatest power-of-2
10968 divisor: modulus & -modulus. */
10970 return build_int_cst (type, residue & low);
10976 /* Don't touch a floating-point divide by zero unless the mode
10977 of the constant can represent infinity. */
10978 if (TREE_CODE (arg1) == REAL_CST
10979 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
10980 && real_zerop (arg1))
10983 /* Optimize A / A to 1.0 if we don't care about
10984 NaNs or Infinities. Skip the transformation
10985 for non-real operands. */
10986 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
10987 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10988 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
10989 && operand_equal_p (arg0, arg1, 0))
10991 tree r = build_real (TREE_TYPE (arg0), dconst1);
10993 return omit_two_operands (type, r, arg0, arg1);
10996 /* The complex version of the above A / A optimization. */
10997 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10998 && operand_equal_p (arg0, arg1, 0))
11000 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
11001 if (! HONOR_NANS (TYPE_MODE (elem_type))
11002 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
11004 tree r = build_real (elem_type, dconst1);
11005 /* omit_two_operands will call fold_convert for us. */
11006 return omit_two_operands (type, r, arg0, arg1);
11010 /* (-A) / (-B) -> A / B */
11011 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
11012 return fold_build2 (RDIV_EXPR, type,
11013 TREE_OPERAND (arg0, 0),
11014 negate_expr (arg1));
11015 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
11016 return fold_build2 (RDIV_EXPR, type,
11017 negate_expr (arg0),
11018 TREE_OPERAND (arg1, 0));
11020 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
11021 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11022 && real_onep (arg1))
11023 return non_lvalue (fold_convert (type, arg0));
11025 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
11026 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11027 && real_minus_onep (arg1))
11028 return non_lvalue (fold_convert (type, negate_expr (arg0)));
11030 /* If ARG1 is a constant, we can convert this to a multiply by the
11031 reciprocal. This does not have the same rounding properties,
11032 so only do this if -freciprocal-math. We can actually
11033 always safely do it if ARG1 is a power of two, but it's hard to
11034 tell if it is or not in a portable manner. */
11035 if (TREE_CODE (arg1) == REAL_CST)
11037 if (flag_reciprocal_math
11038 && 0 != (tem = const_binop (code, build_real (type, dconst1),
11040 return fold_build2 (MULT_EXPR, type, arg0, tem);
11041 /* Find the reciprocal if optimizing and the result is exact. */
11045 r = TREE_REAL_CST (arg1);
11046 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
11048 tem = build_real (type, r);
11049 return fold_build2 (MULT_EXPR, type,
11050 fold_convert (type, arg0), tem);
11054 /* Convert A/B/C to A/(B*C). */
11055 if (flag_reciprocal_math
11056 && TREE_CODE (arg0) == RDIV_EXPR)
11057 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
11058 fold_build2 (MULT_EXPR, type,
11059 TREE_OPERAND (arg0, 1), arg1));
11061 /* Convert A/(B/C) to (A/B)*C. */
11062 if (flag_reciprocal_math
11063 && TREE_CODE (arg1) == RDIV_EXPR)
11064 return fold_build2 (MULT_EXPR, type,
11065 fold_build2 (RDIV_EXPR, type, arg0,
11066 TREE_OPERAND (arg1, 0)),
11067 TREE_OPERAND (arg1, 1));
11069 /* Convert C1/(X*C2) into (C1/C2)/X. */
11070 if (flag_reciprocal_math
11071 && TREE_CODE (arg1) == MULT_EXPR
11072 && TREE_CODE (arg0) == REAL_CST
11073 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
11075 tree tem = const_binop (RDIV_EXPR, arg0,
11076 TREE_OPERAND (arg1, 1), 0);
11078 return fold_build2 (RDIV_EXPR, type, tem,
11079 TREE_OPERAND (arg1, 0));
11082 if (flag_unsafe_math_optimizations)
11084 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
11085 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
11087 /* Optimize sin(x)/cos(x) as tan(x). */
11088 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
11089 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
11090 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
11091 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11092 CALL_EXPR_ARG (arg1, 0), 0))
11094 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11096 if (tanfn != NULL_TREE)
11097 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11100 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
11101 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
11102 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
11103 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
11104 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11105 CALL_EXPR_ARG (arg1, 0), 0))
11107 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11109 if (tanfn != NULL_TREE)
11111 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11112 return fold_build2 (RDIV_EXPR, type,
11113 build_real (type, dconst1), tmp);
11117 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
11118 NaNs or Infinities. */
11119 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
11120 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
11121 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
11123 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11124 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11126 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11127 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11128 && operand_equal_p (arg00, arg01, 0))
11130 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11132 if (cosfn != NULL_TREE)
11133 return build_call_expr (cosfn, 1, arg00);
11137 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11138 NaNs or Infinities. */
11139 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
11140 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
11141 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
11143 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11144 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11146 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11147 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11148 && operand_equal_p (arg00, arg01, 0))
11150 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11152 if (cosfn != NULL_TREE)
11154 tree tmp = build_call_expr (cosfn, 1, arg00);
11155 return fold_build2 (RDIV_EXPR, type,
11156 build_real (type, dconst1),
11162 /* Optimize pow(x,c)/x as pow(x,c-1). */
11163 if (fcode0 == BUILT_IN_POW
11164 || fcode0 == BUILT_IN_POWF
11165 || fcode0 == BUILT_IN_POWL)
11167 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11168 tree arg01 = CALL_EXPR_ARG (arg0, 1);
11169 if (TREE_CODE (arg01) == REAL_CST
11170 && !TREE_OVERFLOW (arg01)
11171 && operand_equal_p (arg1, arg00, 0))
11173 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
11177 c = TREE_REAL_CST (arg01);
11178 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
11179 arg = build_real (type, c);
11180 return build_call_expr (powfn, 2, arg1, arg);
11184 /* Optimize a/root(b/c) into a*root(c/b). */
11185 if (BUILTIN_ROOT_P (fcode1))
11187 tree rootarg = CALL_EXPR_ARG (arg1, 0);
11189 if (TREE_CODE (rootarg) == RDIV_EXPR)
11191 tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11192 tree b = TREE_OPERAND (rootarg, 0);
11193 tree c = TREE_OPERAND (rootarg, 1);
11195 tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
11197 tmp = build_call_expr (rootfn, 1, tmp);
11198 return fold_build2 (MULT_EXPR, type, arg0, tmp);
11202 /* Optimize x/expN(y) into x*expN(-y). */
11203 if (BUILTIN_EXPONENT_P (fcode1))
11205 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11206 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
11207 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
11208 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11211 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11212 if (fcode1 == BUILT_IN_POW
11213 || fcode1 == BUILT_IN_POWF
11214 || fcode1 == BUILT_IN_POWL)
11216 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11217 tree arg10 = CALL_EXPR_ARG (arg1, 0);
11218 tree arg11 = CALL_EXPR_ARG (arg1, 1);
11219 tree neg11 = fold_convert (type, negate_expr (arg11));
11220 arg1 = build_call_expr (powfn, 2, arg10, neg11);
11221 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11226 case TRUNC_DIV_EXPR:
11227 case FLOOR_DIV_EXPR:
11228 /* Simplify A / (B << N) where A and B are positive and B is
11229 a power of 2, to A >> (N + log2(B)). */
11230 strict_overflow_p = false;
11231 if (TREE_CODE (arg1) == LSHIFT_EXPR
11232 && (TYPE_UNSIGNED (type)
11233 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11235 tree sval = TREE_OPERAND (arg1, 0);
11236 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
11238 tree sh_cnt = TREE_OPERAND (arg1, 1);
11239 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
11241 if (strict_overflow_p)
11242 fold_overflow_warning (("assuming signed overflow does not "
11243 "occur when simplifying A / (B << N)"),
11244 WARN_STRICT_OVERFLOW_MISC);
11246 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
11247 sh_cnt, build_int_cst (NULL_TREE, pow2));
11248 return fold_build2 (RSHIFT_EXPR, type,
11249 fold_convert (type, arg0), sh_cnt);
11253 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
11254 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
11255 if (INTEGRAL_TYPE_P (type)
11256 && TYPE_UNSIGNED (type)
11257 && code == FLOOR_DIV_EXPR)
11258 return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
11262 case ROUND_DIV_EXPR:
11263 case CEIL_DIV_EXPR:
11264 case EXACT_DIV_EXPR:
11265 if (integer_onep (arg1))
11266 return non_lvalue (fold_convert (type, arg0));
11267 if (integer_zerop (arg1))
11269 /* X / -1 is -X. */
11270 if (!TYPE_UNSIGNED (type)
11271 && TREE_CODE (arg1) == INTEGER_CST
11272 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11273 && TREE_INT_CST_HIGH (arg1) == -1)
11274 return fold_convert (type, negate_expr (arg0));
11276 /* Convert -A / -B to A / B when the type is signed and overflow is
11278 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11279 && TREE_CODE (arg0) == NEGATE_EXPR
11280 && negate_expr_p (arg1))
11282 if (INTEGRAL_TYPE_P (type))
11283 fold_overflow_warning (("assuming signed overflow does not occur "
11284 "when distributing negation across "
11286 WARN_STRICT_OVERFLOW_MISC);
11287 return fold_build2 (code, type,
11288 fold_convert (type, TREE_OPERAND (arg0, 0)),
11289 negate_expr (arg1));
11291 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11292 && TREE_CODE (arg1) == NEGATE_EXPR
11293 && negate_expr_p (arg0))
11295 if (INTEGRAL_TYPE_P (type))
11296 fold_overflow_warning (("assuming signed overflow does not occur "
11297 "when distributing negation across "
11299 WARN_STRICT_OVERFLOW_MISC);
11300 return fold_build2 (code, type, negate_expr (arg0),
11301 TREE_OPERAND (arg1, 0));
11304 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11305 operation, EXACT_DIV_EXPR.
11307 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11308 At one time others generated faster code, it's not clear if they do
11309 after the last round to changes to the DIV code in expmed.c. */
11310 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
11311 && multiple_of_p (type, arg0, arg1))
11312 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
11314 strict_overflow_p = false;
11315 if (TREE_CODE (arg1) == INTEGER_CST
11316 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11317 &strict_overflow_p)))
11319 if (strict_overflow_p)
11320 fold_overflow_warning (("assuming signed overflow does not occur "
11321 "when simplifying division"),
11322 WARN_STRICT_OVERFLOW_MISC);
11323 return fold_convert (type, tem);
11328 case CEIL_MOD_EXPR:
11329 case FLOOR_MOD_EXPR:
11330 case ROUND_MOD_EXPR:
11331 case TRUNC_MOD_EXPR:
11332 /* X % 1 is always zero, but be sure to preserve any side
11334 if (integer_onep (arg1))
11335 return omit_one_operand (type, integer_zero_node, arg0);
11337 /* X % 0, return X % 0 unchanged so that we can get the
11338 proper warnings and errors. */
11339 if (integer_zerop (arg1))
11342 /* 0 % X is always zero, but be sure to preserve any side
11343 effects in X. Place this after checking for X == 0. */
11344 if (integer_zerop (arg0))
11345 return omit_one_operand (type, integer_zero_node, arg1);
11347 /* X % -1 is zero. */
11348 if (!TYPE_UNSIGNED (type)
11349 && TREE_CODE (arg1) == INTEGER_CST
11350 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11351 && TREE_INT_CST_HIGH (arg1) == -1)
11352 return omit_one_operand (type, integer_zero_node, arg0);
11354 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11355 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11356 strict_overflow_p = false;
11357 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
11358 && (TYPE_UNSIGNED (type)
11359 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11362 /* Also optimize A % (C << N) where C is a power of 2,
11363 to A & ((C << N) - 1). */
11364 if (TREE_CODE (arg1) == LSHIFT_EXPR)
11365 c = TREE_OPERAND (arg1, 0);
11367 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
11369 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
11370 build_int_cst (TREE_TYPE (arg1), 1));
11371 if (strict_overflow_p)
11372 fold_overflow_warning (("assuming signed overflow does not "
11373 "occur when simplifying "
11374 "X % (power of two)"),
11375 WARN_STRICT_OVERFLOW_MISC);
11376 return fold_build2 (BIT_AND_EXPR, type,
11377 fold_convert (type, arg0),
11378 fold_convert (type, mask));
11382 /* X % -C is the same as X % C. */
11383 if (code == TRUNC_MOD_EXPR
11384 && !TYPE_UNSIGNED (type)
11385 && TREE_CODE (arg1) == INTEGER_CST
11386 && !TREE_OVERFLOW (arg1)
11387 && TREE_INT_CST_HIGH (arg1) < 0
11388 && !TYPE_OVERFLOW_TRAPS (type)
11389 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11390 && !sign_bit_p (arg1, arg1))
11391 return fold_build2 (code, type, fold_convert (type, arg0),
11392 fold_convert (type, negate_expr (arg1)));
11394 /* X % -Y is the same as X % Y. */
11395 if (code == TRUNC_MOD_EXPR
11396 && !TYPE_UNSIGNED (type)
11397 && TREE_CODE (arg1) == NEGATE_EXPR
11398 && !TYPE_OVERFLOW_TRAPS (type))
11399 return fold_build2 (code, type, fold_convert (type, arg0),
11400 fold_convert (type, TREE_OPERAND (arg1, 0)));
11402 if (TREE_CODE (arg1) == INTEGER_CST
11403 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11404 &strict_overflow_p)))
11406 if (strict_overflow_p)
11407 fold_overflow_warning (("assuming signed overflow does not occur "
11408 "when simplifying modulos"),
11409 WARN_STRICT_OVERFLOW_MISC);
11410 return fold_convert (type, tem);
11417 if (integer_all_onesp (arg0))
11418 return omit_one_operand (type, arg0, arg1);
11422 /* Optimize -1 >> x for arithmetic right shifts. */
11423 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
11424 return omit_one_operand (type, arg0, arg1);
11425 /* ... fall through ... */
11429 if (integer_zerop (arg1))
11430 return non_lvalue (fold_convert (type, arg0));
11431 if (integer_zerop (arg0))
11432 return omit_one_operand (type, arg0, arg1);
11434 /* Since negative shift count is not well-defined,
11435 don't try to compute it in the compiler. */
11436 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
11439 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11440 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
11441 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11442 && host_integerp (TREE_OPERAND (arg0, 1), false)
11443 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11445 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
11446 + TREE_INT_CST_LOW (arg1));
11448 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11449 being well defined. */
11450 if (low >= TYPE_PRECISION (type))
11452 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
11453 low = low % TYPE_PRECISION (type);
11454 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
11455 return build_int_cst (type, 0);
11457 low = TYPE_PRECISION (type) - 1;
11460 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11461 build_int_cst (type, low));
11464 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11465 into x & ((unsigned)-1 >> c) for unsigned types. */
11466 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
11467 || (TYPE_UNSIGNED (type)
11468 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
11469 && host_integerp (arg1, false)
11470 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11471 && host_integerp (TREE_OPERAND (arg0, 1), false)
11472 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11474 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
11475 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
11481 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
11483 lshift = build_int_cst (type, -1);
11484 lshift = int_const_binop (code, lshift, arg1, 0);
11486 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
11490 /* Rewrite an LROTATE_EXPR by a constant into an
11491 RROTATE_EXPR by a new constant. */
11492 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
11494 tree tem = build_int_cst (TREE_TYPE (arg1),
11495 GET_MODE_BITSIZE (TYPE_MODE (type)));
11496 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
11497 return fold_build2 (RROTATE_EXPR, type, op0, tem);
11500 /* If we have a rotate of a bit operation with the rotate count and
11501 the second operand of the bit operation both constant,
11502 permute the two operations. */
11503 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11504 && (TREE_CODE (arg0) == BIT_AND_EXPR
11505 || TREE_CODE (arg0) == BIT_IOR_EXPR
11506 || TREE_CODE (arg0) == BIT_XOR_EXPR)
11507 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11508 return fold_build2 (TREE_CODE (arg0), type,
11509 fold_build2 (code, type,
11510 TREE_OPERAND (arg0, 0), arg1),
11511 fold_build2 (code, type,
11512 TREE_OPERAND (arg0, 1), arg1));
11514 /* Two consecutive rotates adding up to the width of the mode can
11516 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11517 && TREE_CODE (arg0) == RROTATE_EXPR
11518 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11519 && TREE_INT_CST_HIGH (arg1) == 0
11520 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
11521 && ((TREE_INT_CST_LOW (arg1)
11522 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
11523 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
11524 return TREE_OPERAND (arg0, 0);
11529 if (operand_equal_p (arg0, arg1, 0))
11530 return omit_one_operand (type, arg0, arg1);
11531 if (INTEGRAL_TYPE_P (type)
11532 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
11533 return omit_one_operand (type, arg1, arg0);
11534 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
11540 if (operand_equal_p (arg0, arg1, 0))
11541 return omit_one_operand (type, arg0, arg1);
11542 if (INTEGRAL_TYPE_P (type)
11543 && TYPE_MAX_VALUE (type)
11544 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
11545 return omit_one_operand (type, arg1, arg0);
11546 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
11551 case TRUTH_ANDIF_EXPR:
11552 /* Note that the operands of this must be ints
11553 and their values must be 0 or 1.
11554 ("true" is a fixed value perhaps depending on the language.) */
11555 /* If first arg is constant zero, return it. */
11556 if (integer_zerop (arg0))
11557 return fold_convert (type, arg0);
11558 case TRUTH_AND_EXPR:
11559 /* If either arg is constant true, drop it. */
11560 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11561 return non_lvalue (fold_convert (type, arg1));
11562 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
11563 /* Preserve sequence points. */
11564 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11565 return non_lvalue (fold_convert (type, arg0));
11566 /* If second arg is constant zero, result is zero, but first arg
11567 must be evaluated. */
11568 if (integer_zerop (arg1))
11569 return omit_one_operand (type, arg1, arg0);
11570 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11571 case will be handled here. */
11572 if (integer_zerop (arg0))
11573 return omit_one_operand (type, arg0, arg1);
11575 /* !X && X is always false. */
11576 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11577 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11578 return omit_one_operand (type, integer_zero_node, arg1);
11579 /* X && !X is always false. */
11580 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11581 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11582 return omit_one_operand (type, integer_zero_node, arg0);
11584 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
11585 means A >= Y && A != MAX, but in this case we know that
11588 if (!TREE_SIDE_EFFECTS (arg0)
11589 && !TREE_SIDE_EFFECTS (arg1))
11591 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
11592 if (tem && !operand_equal_p (tem, arg0, 0))
11593 return fold_build2 (code, type, tem, arg1);
11595 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
11596 if (tem && !operand_equal_p (tem, arg1, 0))
11597 return fold_build2 (code, type, arg0, tem);
11601 /* We only do these simplifications if we are optimizing. */
11605 /* Check for things like (A || B) && (A || C). We can convert this
11606 to A || (B && C). Note that either operator can be any of the four
11607 truth and/or operations and the transformation will still be
11608 valid. Also note that we only care about order for the
11609 ANDIF and ORIF operators. If B contains side effects, this
11610 might change the truth-value of A. */
11611 if (TREE_CODE (arg0) == TREE_CODE (arg1)
11612 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
11613 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
11614 || TREE_CODE (arg0) == TRUTH_AND_EXPR
11615 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
11616 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
11618 tree a00 = TREE_OPERAND (arg0, 0);
11619 tree a01 = TREE_OPERAND (arg0, 1);
11620 tree a10 = TREE_OPERAND (arg1, 0);
11621 tree a11 = TREE_OPERAND (arg1, 1);
11622 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
11623 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
11624 && (code == TRUTH_AND_EXPR
11625 || code == TRUTH_OR_EXPR));
11627 if (operand_equal_p (a00, a10, 0))
11628 return fold_build2 (TREE_CODE (arg0), type, a00,
11629 fold_build2 (code, type, a01, a11));
11630 else if (commutative && operand_equal_p (a00, a11, 0))
11631 return fold_build2 (TREE_CODE (arg0), type, a00,
11632 fold_build2 (code, type, a01, a10));
11633 else if (commutative && operand_equal_p (a01, a10, 0))
11634 return fold_build2 (TREE_CODE (arg0), type, a01,
11635 fold_build2 (code, type, a00, a11));
11637 /* This case if tricky because we must either have commutative
11638 operators or else A10 must not have side-effects. */
11640 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
11641 && operand_equal_p (a01, a11, 0))
11642 return fold_build2 (TREE_CODE (arg0), type,
11643 fold_build2 (code, type, a00, a10),
11647 /* See if we can build a range comparison. */
11648 if (0 != (tem = fold_range_test (code, type, op0, op1)))
11651 /* Check for the possibility of merging component references. If our
11652 lhs is another similar operation, try to merge its rhs with our
11653 rhs. Then try to merge our lhs and rhs. */
11654 if (TREE_CODE (arg0) == code
11655 && 0 != (tem = fold_truthop (code, type,
11656 TREE_OPERAND (arg0, 1), arg1)))
11657 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11659 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
11664 case TRUTH_ORIF_EXPR:
11665 /* Note that the operands of this must be ints
11666 and their values must be 0 or true.
11667 ("true" is a fixed value perhaps depending on the language.) */
11668 /* If first arg is constant true, return it. */
11669 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11670 return fold_convert (type, arg0);
11671 case TRUTH_OR_EXPR:
11672 /* If either arg is constant zero, drop it. */
11673 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
11674 return non_lvalue (fold_convert (type, arg1));
11675 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
11676 /* Preserve sequence points. */
11677 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11678 return non_lvalue (fold_convert (type, arg0));
11679 /* If second arg is constant true, result is true, but we must
11680 evaluate first arg. */
11681 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
11682 return omit_one_operand (type, arg1, arg0);
11683 /* Likewise for first arg, but note this only occurs here for
11685 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11686 return omit_one_operand (type, arg0, arg1);
11688 /* !X || X is always true. */
11689 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11690 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11691 return omit_one_operand (type, integer_one_node, arg1);
11692 /* X || !X is always true. */
11693 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11694 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11695 return omit_one_operand (type, integer_one_node, arg0);
11699 case TRUTH_XOR_EXPR:
11700 /* If the second arg is constant zero, drop it. */
11701 if (integer_zerop (arg1))
11702 return non_lvalue (fold_convert (type, arg0));
11703 /* If the second arg is constant true, this is a logical inversion. */
11704 if (integer_onep (arg1))
11706 /* Only call invert_truthvalue if operand is a truth value. */
11707 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
11708 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
11710 tem = invert_truthvalue (arg0);
11711 return non_lvalue (fold_convert (type, tem));
11713 /* Identical arguments cancel to zero. */
11714 if (operand_equal_p (arg0, arg1, 0))
11715 return omit_one_operand (type, integer_zero_node, arg0);
11717 /* !X ^ X is always true. */
11718 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11719 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11720 return omit_one_operand (type, integer_one_node, arg1);
11722 /* X ^ !X is always true. */
11723 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11724 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11725 return omit_one_operand (type, integer_one_node, arg0);
11731 tem = fold_comparison (code, type, op0, op1);
11732 if (tem != NULL_TREE)
11735 /* bool_var != 0 becomes bool_var. */
11736 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11737 && code == NE_EXPR)
11738 return non_lvalue (fold_convert (type, arg0));
11740 /* bool_var == 1 becomes bool_var. */
11741 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11742 && code == EQ_EXPR)
11743 return non_lvalue (fold_convert (type, arg0));
11745 /* bool_var != 1 becomes !bool_var. */
11746 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11747 && code == NE_EXPR)
11748 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11750 /* bool_var == 0 becomes !bool_var. */
11751 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11752 && code == EQ_EXPR)
11753 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11755 /* If this is an equality comparison of the address of two non-weak,
11756 unaliased symbols neither of which are extern (since we do not
11757 have access to attributes for externs), then we know the result. */
11758 if (TREE_CODE (arg0) == ADDR_EXPR
11759 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
11760 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
11761 && ! lookup_attribute ("alias",
11762 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
11763 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
11764 && TREE_CODE (arg1) == ADDR_EXPR
11765 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
11766 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
11767 && ! lookup_attribute ("alias",
11768 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
11769 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
11771 /* We know that we're looking at the address of two
11772 non-weak, unaliased, static _DECL nodes.
11774 It is both wasteful and incorrect to call operand_equal_p
11775 to compare the two ADDR_EXPR nodes. It is wasteful in that
11776 all we need to do is test pointer equality for the arguments
11777 to the two ADDR_EXPR nodes. It is incorrect to use
11778 operand_equal_p as that function is NOT equivalent to a
11779 C equality test. It can in fact return false for two
11780 objects which would test as equal using the C equality
11782 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
11783 return constant_boolean_node (equal
11784 ? code == EQ_EXPR : code != EQ_EXPR,
11788 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
11789 a MINUS_EXPR of a constant, we can convert it into a comparison with
11790 a revised constant as long as no overflow occurs. */
11791 if (TREE_CODE (arg1) == INTEGER_CST
11792 && (TREE_CODE (arg0) == PLUS_EXPR
11793 || TREE_CODE (arg0) == MINUS_EXPR)
11794 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11795 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
11796 ? MINUS_EXPR : PLUS_EXPR,
11797 fold_convert (TREE_TYPE (arg0), arg1),
11798 TREE_OPERAND (arg0, 1), 0))
11799 && !TREE_OVERFLOW (tem))
11800 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11802 /* Similarly for a NEGATE_EXPR. */
11803 if (TREE_CODE (arg0) == NEGATE_EXPR
11804 && TREE_CODE (arg1) == INTEGER_CST
11805 && 0 != (tem = negate_expr (arg1))
11806 && TREE_CODE (tem) == INTEGER_CST
11807 && !TREE_OVERFLOW (tem))
11808 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11810 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
11811 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11812 && TREE_CODE (arg1) == INTEGER_CST
11813 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11814 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11815 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
11816 fold_convert (TREE_TYPE (arg0), arg1),
11817 TREE_OPERAND (arg0, 1)));
11819 /* Transform comparisons of the form X +- C CMP X. */
11820 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11821 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11822 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11823 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
11824 || POINTER_TYPE_P (TREE_TYPE (arg0))))
11826 tree cst = TREE_OPERAND (arg0, 1);
11828 if (code == EQ_EXPR
11829 && !integer_zerop (cst))
11830 return omit_two_operands (type, boolean_false_node,
11831 TREE_OPERAND (arg0, 0), arg1);
11833 return omit_two_operands (type, boolean_true_node,
11834 TREE_OPERAND (arg0, 0), arg1);
11837 /* If we have X - Y == 0, we can convert that to X == Y and similarly
11838 for !=. Don't do this for ordered comparisons due to overflow. */
11839 if (TREE_CODE (arg0) == MINUS_EXPR
11840 && integer_zerop (arg1))
11841 return fold_build2 (code, type,
11842 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
11844 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
11845 if (TREE_CODE (arg0) == ABS_EXPR
11846 && (integer_zerop (arg1) || real_zerop (arg1)))
11847 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
11849 /* If this is an EQ or NE comparison with zero and ARG0 is
11850 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
11851 two operations, but the latter can be done in one less insn
11852 on machines that have only two-operand insns or on which a
11853 constant cannot be the first operand. */
11854 if (TREE_CODE (arg0) == BIT_AND_EXPR
11855 && integer_zerop (arg1))
11857 tree arg00 = TREE_OPERAND (arg0, 0);
11858 tree arg01 = TREE_OPERAND (arg0, 1);
11859 if (TREE_CODE (arg00) == LSHIFT_EXPR
11860 && integer_onep (TREE_OPERAND (arg00, 0)))
11862 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
11863 arg01, TREE_OPERAND (arg00, 1));
11864 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11865 build_int_cst (TREE_TYPE (arg0), 1));
11866 return fold_build2 (code, type,
11867 fold_convert (TREE_TYPE (arg1), tem), arg1);
11869 else if (TREE_CODE (arg01) == LSHIFT_EXPR
11870 && integer_onep (TREE_OPERAND (arg01, 0)))
11872 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
11873 arg00, TREE_OPERAND (arg01, 1));
11874 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11875 build_int_cst (TREE_TYPE (arg0), 1));
11876 return fold_build2 (code, type,
11877 fold_convert (TREE_TYPE (arg1), tem), arg1);
11881 /* If this is an NE or EQ comparison of zero against the result of a
11882 signed MOD operation whose second operand is a power of 2, make
11883 the MOD operation unsigned since it is simpler and equivalent. */
11884 if (integer_zerop (arg1)
11885 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
11886 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
11887 || TREE_CODE (arg0) == CEIL_MOD_EXPR
11888 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
11889 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
11890 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11892 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
11893 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
11894 fold_convert (newtype,
11895 TREE_OPERAND (arg0, 0)),
11896 fold_convert (newtype,
11897 TREE_OPERAND (arg0, 1)));
11899 return fold_build2 (code, type, newmod,
11900 fold_convert (newtype, arg1));
11903 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
11904 C1 is a valid shift constant, and C2 is a power of two, i.e.
11906 if (TREE_CODE (arg0) == BIT_AND_EXPR
11907 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
11908 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
11910 && integer_pow2p (TREE_OPERAND (arg0, 1))
11911 && integer_zerop (arg1))
11913 tree itype = TREE_TYPE (arg0);
11914 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
11915 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
11917 /* Check for a valid shift count. */
11918 if (TREE_INT_CST_HIGH (arg001) == 0
11919 && TREE_INT_CST_LOW (arg001) < prec)
11921 tree arg01 = TREE_OPERAND (arg0, 1);
11922 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11923 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
11924 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
11925 can be rewritten as (X & (C2 << C1)) != 0. */
11926 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
11928 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
11929 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
11930 return fold_build2 (code, type, tem, arg1);
11932 /* Otherwise, for signed (arithmetic) shifts,
11933 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
11934 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
11935 else if (!TYPE_UNSIGNED (itype))
11936 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
11937 arg000, build_int_cst (itype, 0));
11938 /* Otherwise, of unsigned (logical) shifts,
11939 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
11940 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
11942 return omit_one_operand (type,
11943 code == EQ_EXPR ? integer_one_node
11944 : integer_zero_node,
11949 /* If this is an NE comparison of zero with an AND of one, remove the
11950 comparison since the AND will give the correct value. */
11951 if (code == NE_EXPR
11952 && integer_zerop (arg1)
11953 && TREE_CODE (arg0) == BIT_AND_EXPR
11954 && integer_onep (TREE_OPERAND (arg0, 1)))
11955 return fold_convert (type, arg0);
11957 /* If we have (A & C) == C where C is a power of 2, convert this into
11958 (A & C) != 0. Similarly for NE_EXPR. */
11959 if (TREE_CODE (arg0) == BIT_AND_EXPR
11960 && integer_pow2p (TREE_OPERAND (arg0, 1))
11961 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11962 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11963 arg0, fold_convert (TREE_TYPE (arg0),
11964 integer_zero_node));
11966 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
11967 bit, then fold the expression into A < 0 or A >= 0. */
11968 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
11972 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
11973 Similarly for NE_EXPR. */
11974 if (TREE_CODE (arg0) == BIT_AND_EXPR
11975 && TREE_CODE (arg1) == INTEGER_CST
11976 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11978 tree notc = fold_build1 (BIT_NOT_EXPR,
11979 TREE_TYPE (TREE_OPERAND (arg0, 1)),
11980 TREE_OPERAND (arg0, 1));
11981 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11983 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11984 if (integer_nonzerop (dandnotc))
11985 return omit_one_operand (type, rslt, arg0);
11988 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
11989 Similarly for NE_EXPR. */
11990 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11991 && TREE_CODE (arg1) == INTEGER_CST
11992 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11994 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
11995 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11996 TREE_OPERAND (arg0, 1), notd);
11997 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11998 if (integer_nonzerop (candnotd))
11999 return omit_one_operand (type, rslt, arg0);
12002 /* If this is a comparison of a field, we may be able to simplify it. */
12003 if ((TREE_CODE (arg0) == COMPONENT_REF
12004 || TREE_CODE (arg0) == BIT_FIELD_REF)
12005 /* Handle the constant case even without -O
12006 to make sure the warnings are given. */
12007 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
12009 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
12014 /* Optimize comparisons of strlen vs zero to a compare of the
12015 first character of the string vs zero. To wit,
12016 strlen(ptr) == 0 => *ptr == 0
12017 strlen(ptr) != 0 => *ptr != 0
12018 Other cases should reduce to one of these two (or a constant)
12019 due to the return value of strlen being unsigned. */
12020 if (TREE_CODE (arg0) == CALL_EXPR
12021 && integer_zerop (arg1))
12023 tree fndecl = get_callee_fndecl (arg0);
12026 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
12027 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
12028 && call_expr_nargs (arg0) == 1
12029 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
12031 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
12032 return fold_build2 (code, type, iref,
12033 build_int_cst (TREE_TYPE (iref), 0));
12037 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
12038 of X. Similarly fold (X >> C) == 0 into X >= 0. */
12039 if (TREE_CODE (arg0) == RSHIFT_EXPR
12040 && integer_zerop (arg1)
12041 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12043 tree arg00 = TREE_OPERAND (arg0, 0);
12044 tree arg01 = TREE_OPERAND (arg0, 1);
12045 tree itype = TREE_TYPE (arg00);
12046 if (TREE_INT_CST_HIGH (arg01) == 0
12047 && TREE_INT_CST_LOW (arg01)
12048 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
12050 if (TYPE_UNSIGNED (itype))
12052 itype = signed_type_for (itype);
12053 arg00 = fold_convert (itype, arg00);
12055 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
12056 type, arg00, build_int_cst (itype, 0));
12060 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
12061 if (integer_zerop (arg1)
12062 && TREE_CODE (arg0) == BIT_XOR_EXPR)
12063 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12064 TREE_OPERAND (arg0, 1));
12066 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
12067 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12068 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12069 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12070 build_int_cst (TREE_TYPE (arg1), 0));
12071 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
12072 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12073 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12074 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
12075 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
12076 build_int_cst (TREE_TYPE (arg1), 0));
12078 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
12079 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12080 && TREE_CODE (arg1) == INTEGER_CST
12081 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12082 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12083 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
12084 TREE_OPERAND (arg0, 1), arg1));
12086 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
12087 (X & C) == 0 when C is a single bit. */
12088 if (TREE_CODE (arg0) == BIT_AND_EXPR
12089 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
12090 && integer_zerop (arg1)
12091 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12093 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12094 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
12095 TREE_OPERAND (arg0, 1));
12096 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
12100 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12101 constant C is a power of two, i.e. a single bit. */
12102 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12103 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12104 && integer_zerop (arg1)
12105 && integer_pow2p (TREE_OPERAND (arg0, 1))
12106 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12107 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12109 tree arg00 = TREE_OPERAND (arg0, 0);
12110 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12111 arg00, build_int_cst (TREE_TYPE (arg00), 0));
12114 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12115 when is C is a power of two, i.e. a single bit. */
12116 if (TREE_CODE (arg0) == BIT_AND_EXPR
12117 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
12118 && integer_zerop (arg1)
12119 && integer_pow2p (TREE_OPERAND (arg0, 1))
12120 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12121 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12123 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12124 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
12125 arg000, TREE_OPERAND (arg0, 1));
12126 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12127 tem, build_int_cst (TREE_TYPE (tem), 0));
12130 if (integer_zerop (arg1)
12131 && tree_expr_nonzero_p (arg0))
12133 tree res = constant_boolean_node (code==NE_EXPR, type);
12134 return omit_one_operand (type, res, arg0);
12137 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12138 if (TREE_CODE (arg0) == NEGATE_EXPR
12139 && TREE_CODE (arg1) == NEGATE_EXPR)
12140 return fold_build2 (code, type,
12141 TREE_OPERAND (arg0, 0),
12142 TREE_OPERAND (arg1, 0));
12144 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12145 if (TREE_CODE (arg0) == BIT_AND_EXPR
12146 && TREE_CODE (arg1) == BIT_AND_EXPR)
12148 tree arg00 = TREE_OPERAND (arg0, 0);
12149 tree arg01 = TREE_OPERAND (arg0, 1);
12150 tree arg10 = TREE_OPERAND (arg1, 0);
12151 tree arg11 = TREE_OPERAND (arg1, 1);
12152 tree itype = TREE_TYPE (arg0);
12154 if (operand_equal_p (arg01, arg11, 0))
12155 return fold_build2 (code, type,
12156 fold_build2 (BIT_AND_EXPR, itype,
12157 fold_build2 (BIT_XOR_EXPR, itype,
12160 build_int_cst (itype, 0));
12162 if (operand_equal_p (arg01, arg10, 0))
12163 return fold_build2 (code, type,
12164 fold_build2 (BIT_AND_EXPR, itype,
12165 fold_build2 (BIT_XOR_EXPR, itype,
12168 build_int_cst (itype, 0));
12170 if (operand_equal_p (arg00, arg11, 0))
12171 return fold_build2 (code, type,
12172 fold_build2 (BIT_AND_EXPR, itype,
12173 fold_build2 (BIT_XOR_EXPR, itype,
12176 build_int_cst (itype, 0));
12178 if (operand_equal_p (arg00, arg10, 0))
12179 return fold_build2 (code, type,
12180 fold_build2 (BIT_AND_EXPR, itype,
12181 fold_build2 (BIT_XOR_EXPR, itype,
12184 build_int_cst (itype, 0));
12187 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12188 && TREE_CODE (arg1) == BIT_XOR_EXPR)
12190 tree arg00 = TREE_OPERAND (arg0, 0);
12191 tree arg01 = TREE_OPERAND (arg0, 1);
12192 tree arg10 = TREE_OPERAND (arg1, 0);
12193 tree arg11 = TREE_OPERAND (arg1, 1);
12194 tree itype = TREE_TYPE (arg0);
12196 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12197 operand_equal_p guarantees no side-effects so we don't need
12198 to use omit_one_operand on Z. */
12199 if (operand_equal_p (arg01, arg11, 0))
12200 return fold_build2 (code, type, arg00, arg10);
12201 if (operand_equal_p (arg01, arg10, 0))
12202 return fold_build2 (code, type, arg00, arg11);
12203 if (operand_equal_p (arg00, arg11, 0))
12204 return fold_build2 (code, type, arg01, arg10);
12205 if (operand_equal_p (arg00, arg10, 0))
12206 return fold_build2 (code, type, arg01, arg11);
12208 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12209 if (TREE_CODE (arg01) == INTEGER_CST
12210 && TREE_CODE (arg11) == INTEGER_CST)
12211 return fold_build2 (code, type,
12212 fold_build2 (BIT_XOR_EXPR, itype, arg00,
12213 fold_build2 (BIT_XOR_EXPR, itype,
12218 /* Attempt to simplify equality/inequality comparisons of complex
12219 values. Only lower the comparison if the result is known or
12220 can be simplified to a single scalar comparison. */
12221 if ((TREE_CODE (arg0) == COMPLEX_EXPR
12222 || TREE_CODE (arg0) == COMPLEX_CST)
12223 && (TREE_CODE (arg1) == COMPLEX_EXPR
12224 || TREE_CODE (arg1) == COMPLEX_CST))
12226 tree real0, imag0, real1, imag1;
12229 if (TREE_CODE (arg0) == COMPLEX_EXPR)
12231 real0 = TREE_OPERAND (arg0, 0);
12232 imag0 = TREE_OPERAND (arg0, 1);
12236 real0 = TREE_REALPART (arg0);
12237 imag0 = TREE_IMAGPART (arg0);
12240 if (TREE_CODE (arg1) == COMPLEX_EXPR)
12242 real1 = TREE_OPERAND (arg1, 0);
12243 imag1 = TREE_OPERAND (arg1, 1);
12247 real1 = TREE_REALPART (arg1);
12248 imag1 = TREE_IMAGPART (arg1);
12251 rcond = fold_binary (code, type, real0, real1);
12252 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
12254 if (integer_zerop (rcond))
12256 if (code == EQ_EXPR)
12257 return omit_two_operands (type, boolean_false_node,
12259 return fold_build2 (NE_EXPR, type, imag0, imag1);
12263 if (code == NE_EXPR)
12264 return omit_two_operands (type, boolean_true_node,
12266 return fold_build2 (EQ_EXPR, type, imag0, imag1);
12270 icond = fold_binary (code, type, imag0, imag1);
12271 if (icond && TREE_CODE (icond) == INTEGER_CST)
12273 if (integer_zerop (icond))
12275 if (code == EQ_EXPR)
12276 return omit_two_operands (type, boolean_false_node,
12278 return fold_build2 (NE_EXPR, type, real0, real1);
12282 if (code == NE_EXPR)
12283 return omit_two_operands (type, boolean_true_node,
12285 return fold_build2 (EQ_EXPR, type, real0, real1);
12296 tem = fold_comparison (code, type, op0, op1);
12297 if (tem != NULL_TREE)
12300 /* Transform comparisons of the form X +- C CMP X. */
12301 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12302 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12303 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
12304 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
12305 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12306 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
12308 tree arg01 = TREE_OPERAND (arg0, 1);
12309 enum tree_code code0 = TREE_CODE (arg0);
12312 if (TREE_CODE (arg01) == REAL_CST)
12313 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
12315 is_positive = tree_int_cst_sgn (arg01);
12317 /* (X - c) > X becomes false. */
12318 if (code == GT_EXPR
12319 && ((code0 == MINUS_EXPR && is_positive >= 0)
12320 || (code0 == PLUS_EXPR && is_positive <= 0)))
12322 if (TREE_CODE (arg01) == INTEGER_CST
12323 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12324 fold_overflow_warning (("assuming signed overflow does not "
12325 "occur when assuming that (X - c) > X "
12326 "is always false"),
12327 WARN_STRICT_OVERFLOW_ALL);
12328 return constant_boolean_node (0, type);
12331 /* Likewise (X + c) < X becomes false. */
12332 if (code == LT_EXPR
12333 && ((code0 == PLUS_EXPR && is_positive >= 0)
12334 || (code0 == MINUS_EXPR && is_positive <= 0)))
12336 if (TREE_CODE (arg01) == INTEGER_CST
12337 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12338 fold_overflow_warning (("assuming signed overflow does not "
12339 "occur when assuming that "
12340 "(X + c) < X is always false"),
12341 WARN_STRICT_OVERFLOW_ALL);
12342 return constant_boolean_node (0, type);
12345 /* Convert (X - c) <= X to true. */
12346 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12348 && ((code0 == MINUS_EXPR && is_positive >= 0)
12349 || (code0 == PLUS_EXPR && is_positive <= 0)))
12351 if (TREE_CODE (arg01) == INTEGER_CST
12352 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12353 fold_overflow_warning (("assuming signed overflow does not "
12354 "occur when assuming that "
12355 "(X - c) <= X is always true"),
12356 WARN_STRICT_OVERFLOW_ALL);
12357 return constant_boolean_node (1, type);
12360 /* Convert (X + c) >= X to true. */
12361 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12363 && ((code0 == PLUS_EXPR && is_positive >= 0)
12364 || (code0 == MINUS_EXPR && is_positive <= 0)))
12366 if (TREE_CODE (arg01) == INTEGER_CST
12367 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12368 fold_overflow_warning (("assuming signed overflow does not "
12369 "occur when assuming that "
12370 "(X + c) >= X is always true"),
12371 WARN_STRICT_OVERFLOW_ALL);
12372 return constant_boolean_node (1, type);
12375 if (TREE_CODE (arg01) == INTEGER_CST)
12377 /* Convert X + c > X and X - c < X to true for integers. */
12378 if (code == GT_EXPR
12379 && ((code0 == PLUS_EXPR && is_positive > 0)
12380 || (code0 == MINUS_EXPR && is_positive < 0)))
12382 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12383 fold_overflow_warning (("assuming signed overflow does "
12384 "not occur when assuming that "
12385 "(X + c) > X is always true"),
12386 WARN_STRICT_OVERFLOW_ALL);
12387 return constant_boolean_node (1, type);
12390 if (code == LT_EXPR
12391 && ((code0 == MINUS_EXPR && is_positive > 0)
12392 || (code0 == PLUS_EXPR && is_positive < 0)))
12394 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12395 fold_overflow_warning (("assuming signed overflow does "
12396 "not occur when assuming that "
12397 "(X - c) < X is always true"),
12398 WARN_STRICT_OVERFLOW_ALL);
12399 return constant_boolean_node (1, type);
12402 /* Convert X + c <= X and X - c >= X to false for integers. */
12403 if (code == LE_EXPR
12404 && ((code0 == PLUS_EXPR && is_positive > 0)
12405 || (code0 == MINUS_EXPR && is_positive < 0)))
12407 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12408 fold_overflow_warning (("assuming signed overflow does "
12409 "not occur when assuming that "
12410 "(X + c) <= X is always false"),
12411 WARN_STRICT_OVERFLOW_ALL);
12412 return constant_boolean_node (0, type);
12415 if (code == GE_EXPR
12416 && ((code0 == MINUS_EXPR && is_positive > 0)
12417 || (code0 == PLUS_EXPR && is_positive < 0)))
12419 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12420 fold_overflow_warning (("assuming signed overflow does "
12421 "not occur when assuming that "
12422 "(X - c) >= X is always false"),
12423 WARN_STRICT_OVERFLOW_ALL);
12424 return constant_boolean_node (0, type);
12429 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
12430 This transformation affects the cases which are handled in later
12431 optimizations involving comparisons with non-negative constants. */
12432 if (TREE_CODE (arg1) == INTEGER_CST
12433 && TREE_CODE (arg0) != INTEGER_CST
12434 && tree_int_cst_sgn (arg1) > 0)
12436 if (code == GE_EXPR)
12438 arg1 = const_binop (MINUS_EXPR, arg1,
12439 build_int_cst (TREE_TYPE (arg1), 1), 0);
12440 return fold_build2 (GT_EXPR, type, arg0,
12441 fold_convert (TREE_TYPE (arg0), arg1));
12443 if (code == LT_EXPR)
12445 arg1 = const_binop (MINUS_EXPR, arg1,
12446 build_int_cst (TREE_TYPE (arg1), 1), 0);
12447 return fold_build2 (LE_EXPR, type, arg0,
12448 fold_convert (TREE_TYPE (arg0), arg1));
12452 /* Comparisons with the highest or lowest possible integer of
12453 the specified precision will have known values. */
12455 tree arg1_type = TREE_TYPE (arg1);
12456 unsigned int width = TYPE_PRECISION (arg1_type);
12458 if (TREE_CODE (arg1) == INTEGER_CST
12459 && !TREE_OVERFLOW (arg1)
12460 && width <= 2 * HOST_BITS_PER_WIDE_INT
12461 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
12463 HOST_WIDE_INT signed_max_hi;
12464 unsigned HOST_WIDE_INT signed_max_lo;
12465 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
12467 if (width <= HOST_BITS_PER_WIDE_INT)
12469 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12474 if (TYPE_UNSIGNED (arg1_type))
12476 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12482 max_lo = signed_max_lo;
12483 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12489 width -= HOST_BITS_PER_WIDE_INT;
12490 signed_max_lo = -1;
12491 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12496 if (TYPE_UNSIGNED (arg1_type))
12498 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12503 max_hi = signed_max_hi;
12504 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12508 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
12509 && TREE_INT_CST_LOW (arg1) == max_lo)
12513 return omit_one_operand (type, integer_zero_node, arg0);
12516 return fold_build2 (EQ_EXPR, type, op0, op1);
12519 return omit_one_operand (type, integer_one_node, arg0);
12522 return fold_build2 (NE_EXPR, type, op0, op1);
12524 /* The GE_EXPR and LT_EXPR cases above are not normally
12525 reached because of previous transformations. */
12530 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12532 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
12536 arg1 = const_binop (PLUS_EXPR, arg1,
12537 build_int_cst (TREE_TYPE (arg1), 1), 0);
12538 return fold_build2 (EQ_EXPR, type,
12539 fold_convert (TREE_TYPE (arg1), arg0),
12542 arg1 = const_binop (PLUS_EXPR, arg1,
12543 build_int_cst (TREE_TYPE (arg1), 1), 0);
12544 return fold_build2 (NE_EXPR, type,
12545 fold_convert (TREE_TYPE (arg1), arg0),
12550 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12552 && TREE_INT_CST_LOW (arg1) == min_lo)
12556 return omit_one_operand (type, integer_zero_node, arg0);
12559 return fold_build2 (EQ_EXPR, type, op0, op1);
12562 return omit_one_operand (type, integer_one_node, arg0);
12565 return fold_build2 (NE_EXPR, type, op0, op1);
12570 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12572 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
12576 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12577 return fold_build2 (NE_EXPR, type,
12578 fold_convert (TREE_TYPE (arg1), arg0),
12581 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12582 return fold_build2 (EQ_EXPR, type,
12583 fold_convert (TREE_TYPE (arg1), arg0),
12589 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
12590 && TREE_INT_CST_LOW (arg1) == signed_max_lo
12591 && TYPE_UNSIGNED (arg1_type)
12592 /* We will flip the signedness of the comparison operator
12593 associated with the mode of arg1, so the sign bit is
12594 specified by this mode. Check that arg1 is the signed
12595 max associated with this sign bit. */
12596 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
12597 /* signed_type does not work on pointer types. */
12598 && INTEGRAL_TYPE_P (arg1_type))
12600 /* The following case also applies to X < signed_max+1
12601 and X >= signed_max+1 because previous transformations. */
12602 if (code == LE_EXPR || code == GT_EXPR)
12605 st = signed_type_for (TREE_TYPE (arg1));
12606 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
12607 type, fold_convert (st, arg0),
12608 build_int_cst (st, 0));
12614 /* If we are comparing an ABS_EXPR with a constant, we can
12615 convert all the cases into explicit comparisons, but they may
12616 well not be faster than doing the ABS and one comparison.
12617 But ABS (X) <= C is a range comparison, which becomes a subtraction
12618 and a comparison, and is probably faster. */
12619 if (code == LE_EXPR
12620 && TREE_CODE (arg1) == INTEGER_CST
12621 && TREE_CODE (arg0) == ABS_EXPR
12622 && ! TREE_SIDE_EFFECTS (arg0)
12623 && (0 != (tem = negate_expr (arg1)))
12624 && TREE_CODE (tem) == INTEGER_CST
12625 && !TREE_OVERFLOW (tem))
12626 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12627 build2 (GE_EXPR, type,
12628 TREE_OPERAND (arg0, 0), tem),
12629 build2 (LE_EXPR, type,
12630 TREE_OPERAND (arg0, 0), arg1));
12632 /* Convert ABS_EXPR<x> >= 0 to true. */
12633 strict_overflow_p = false;
12634 if (code == GE_EXPR
12635 && (integer_zerop (arg1)
12636 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
12637 && real_zerop (arg1)))
12638 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12640 if (strict_overflow_p)
12641 fold_overflow_warning (("assuming signed overflow does not occur "
12642 "when simplifying comparison of "
12643 "absolute value and zero"),
12644 WARN_STRICT_OVERFLOW_CONDITIONAL);
12645 return omit_one_operand (type, integer_one_node, arg0);
12648 /* Convert ABS_EXPR<x> < 0 to false. */
12649 strict_overflow_p = false;
12650 if (code == LT_EXPR
12651 && (integer_zerop (arg1) || real_zerop (arg1))
12652 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12654 if (strict_overflow_p)
12655 fold_overflow_warning (("assuming signed overflow does not occur "
12656 "when simplifying comparison of "
12657 "absolute value and zero"),
12658 WARN_STRICT_OVERFLOW_CONDITIONAL);
12659 return omit_one_operand (type, integer_zero_node, arg0);
12662 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
12663 and similarly for >= into !=. */
12664 if ((code == LT_EXPR || code == GE_EXPR)
12665 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12666 && TREE_CODE (arg1) == LSHIFT_EXPR
12667 && integer_onep (TREE_OPERAND (arg1, 0)))
12668 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12669 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12670 TREE_OPERAND (arg1, 1)),
12671 build_int_cst (TREE_TYPE (arg0), 0));
12673 if ((code == LT_EXPR || code == GE_EXPR)
12674 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12675 && (TREE_CODE (arg1) == NOP_EXPR
12676 || TREE_CODE (arg1) == CONVERT_EXPR)
12677 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
12678 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
12680 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12681 fold_convert (TREE_TYPE (arg0),
12682 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12683 TREE_OPERAND (TREE_OPERAND (arg1, 0),
12685 build_int_cst (TREE_TYPE (arg0), 0));
12689 case UNORDERED_EXPR:
12697 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
12699 t1 = fold_relational_const (code, type, arg0, arg1);
12700 if (t1 != NULL_TREE)
12704 /* If the first operand is NaN, the result is constant. */
12705 if (TREE_CODE (arg0) == REAL_CST
12706 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
12707 && (code != LTGT_EXPR || ! flag_trapping_math))
12709 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12710 ? integer_zero_node
12711 : integer_one_node;
12712 return omit_one_operand (type, t1, arg1);
12715 /* If the second operand is NaN, the result is constant. */
12716 if (TREE_CODE (arg1) == REAL_CST
12717 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
12718 && (code != LTGT_EXPR || ! flag_trapping_math))
12720 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12721 ? integer_zero_node
12722 : integer_one_node;
12723 return omit_one_operand (type, t1, arg0);
12726 /* Simplify unordered comparison of something with itself. */
12727 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
12728 && operand_equal_p (arg0, arg1, 0))
12729 return constant_boolean_node (1, type);
12731 if (code == LTGT_EXPR
12732 && !flag_trapping_math
12733 && operand_equal_p (arg0, arg1, 0))
12734 return constant_boolean_node (0, type);
12736 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12738 tree targ0 = strip_float_extensions (arg0);
12739 tree targ1 = strip_float_extensions (arg1);
12740 tree newtype = TREE_TYPE (targ0);
12742 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
12743 newtype = TREE_TYPE (targ1);
12745 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
12746 return fold_build2 (code, type, fold_convert (newtype, targ0),
12747 fold_convert (newtype, targ1));
12752 case COMPOUND_EXPR:
12753 /* When pedantic, a compound expression can be neither an lvalue
12754 nor an integer constant expression. */
12755 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
12757 /* Don't let (0, 0) be null pointer constant. */
12758 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
12759 : fold_convert (type, arg1);
12760 return pedantic_non_lvalue (tem);
12763 if ((TREE_CODE (arg0) == REAL_CST
12764 && TREE_CODE (arg1) == REAL_CST)
12765 || (TREE_CODE (arg0) == INTEGER_CST
12766 && TREE_CODE (arg1) == INTEGER_CST))
12767 return build_complex (type, arg0, arg1);
12771 /* An ASSERT_EXPR should never be passed to fold_binary. */
12772 gcc_unreachable ();
12776 } /* switch (code) */
12779 /* Callback for walk_tree, looking for LABEL_EXPR.
12780 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
12781 Do not check the sub-tree of GOTO_EXPR. */
12784 contains_label_1 (tree *tp,
12785 int *walk_subtrees,
12786 void *data ATTRIBUTE_UNUSED)
12788 switch (TREE_CODE (*tp))
12793 *walk_subtrees = 0;
12800 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
12801 accessible from outside the sub-tree. Returns NULL_TREE if no
12802 addressable label is found. */
12805 contains_label_p (tree st)
12807 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
12810 /* Fold a ternary expression of code CODE and type TYPE with operands
12811 OP0, OP1, and OP2. Return the folded expression if folding is
12812 successful. Otherwise, return NULL_TREE. */
12815 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
12818 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
12819 enum tree_code_class kind = TREE_CODE_CLASS (code);
12821 gcc_assert (IS_EXPR_CODE_CLASS (kind)
12822 && TREE_CODE_LENGTH (code) == 3);
12824 /* Strip any conversions that don't change the mode. This is safe
12825 for every expression, except for a comparison expression because
12826 its signedness is derived from its operands. So, in the latter
12827 case, only strip conversions that don't change the signedness.
12829 Note that this is done as an internal manipulation within the
12830 constant folder, in order to find the simplest representation of
12831 the arguments so that their form can be studied. In any cases,
12832 the appropriate type conversions should be put back in the tree
12833 that will get out of the constant folder. */
12848 case COMPONENT_REF:
12849 if (TREE_CODE (arg0) == CONSTRUCTOR
12850 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
12852 unsigned HOST_WIDE_INT idx;
12854 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
12861 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
12862 so all simple results must be passed through pedantic_non_lvalue. */
12863 if (TREE_CODE (arg0) == INTEGER_CST)
12865 tree unused_op = integer_zerop (arg0) ? op1 : op2;
12866 tem = integer_zerop (arg0) ? op2 : op1;
12867 /* Only optimize constant conditions when the selected branch
12868 has the same type as the COND_EXPR. This avoids optimizing
12869 away "c ? x : throw", where the throw has a void type.
12870 Avoid throwing away that operand which contains label. */
12871 if ((!TREE_SIDE_EFFECTS (unused_op)
12872 || !contains_label_p (unused_op))
12873 && (! VOID_TYPE_P (TREE_TYPE (tem))
12874 || VOID_TYPE_P (type)))
12875 return pedantic_non_lvalue (tem);
12878 if (operand_equal_p (arg1, op2, 0))
12879 return pedantic_omit_one_operand (type, arg1, arg0);
12881 /* If we have A op B ? A : C, we may be able to convert this to a
12882 simpler expression, depending on the operation and the values
12883 of B and C. Signed zeros prevent all of these transformations,
12884 for reasons given above each one.
12886 Also try swapping the arguments and inverting the conditional. */
12887 if (COMPARISON_CLASS_P (arg0)
12888 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12889 arg1, TREE_OPERAND (arg0, 1))
12890 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
12892 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
12897 if (COMPARISON_CLASS_P (arg0)
12898 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12900 TREE_OPERAND (arg0, 1))
12901 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
12903 tem = fold_truth_not_expr (arg0);
12904 if (tem && COMPARISON_CLASS_P (tem))
12906 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
12912 /* If the second operand is simpler than the third, swap them
12913 since that produces better jump optimization results. */
12914 if (truth_value_p (TREE_CODE (arg0))
12915 && tree_swap_operands_p (op1, op2, false))
12917 /* See if this can be inverted. If it can't, possibly because
12918 it was a floating-point inequality comparison, don't do
12920 tem = fold_truth_not_expr (arg0);
12922 return fold_build3 (code, type, tem, op2, op1);
12925 /* Convert A ? 1 : 0 to simply A. */
12926 if (integer_onep (op1)
12927 && integer_zerop (op2)
12928 /* If we try to convert OP0 to our type, the
12929 call to fold will try to move the conversion inside
12930 a COND, which will recurse. In that case, the COND_EXPR
12931 is probably the best choice, so leave it alone. */
12932 && type == TREE_TYPE (arg0))
12933 return pedantic_non_lvalue (arg0);
12935 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
12936 over COND_EXPR in cases such as floating point comparisons. */
12937 if (integer_zerop (op1)
12938 && integer_onep (op2)
12939 && truth_value_p (TREE_CODE (arg0)))
12940 return pedantic_non_lvalue (fold_convert (type,
12941 invert_truthvalue (arg0)));
12943 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
12944 if (TREE_CODE (arg0) == LT_EXPR
12945 && integer_zerop (TREE_OPERAND (arg0, 1))
12946 && integer_zerop (op2)
12947 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
12949 /* sign_bit_p only checks ARG1 bits within A's precision.
12950 If <sign bit of A> has wider type than A, bits outside
12951 of A's precision in <sign bit of A> need to be checked.
12952 If they are all 0, this optimization needs to be done
12953 in unsigned A's type, if they are all 1 in signed A's type,
12954 otherwise this can't be done. */
12955 if (TYPE_PRECISION (TREE_TYPE (tem))
12956 < TYPE_PRECISION (TREE_TYPE (arg1))
12957 && TYPE_PRECISION (TREE_TYPE (tem))
12958 < TYPE_PRECISION (type))
12960 unsigned HOST_WIDE_INT mask_lo;
12961 HOST_WIDE_INT mask_hi;
12962 int inner_width, outer_width;
12965 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
12966 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
12967 if (outer_width > TYPE_PRECISION (type))
12968 outer_width = TYPE_PRECISION (type);
12970 if (outer_width > HOST_BITS_PER_WIDE_INT)
12972 mask_hi = ((unsigned HOST_WIDE_INT) -1
12973 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
12979 mask_lo = ((unsigned HOST_WIDE_INT) -1
12980 >> (HOST_BITS_PER_WIDE_INT - outer_width));
12982 if (inner_width > HOST_BITS_PER_WIDE_INT)
12984 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
12985 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12989 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
12990 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12992 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
12993 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
12995 tem_type = signed_type_for (TREE_TYPE (tem));
12996 tem = fold_convert (tem_type, tem);
12998 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
12999 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
13001 tem_type = unsigned_type_for (TREE_TYPE (tem));
13002 tem = fold_convert (tem_type, tem);
13009 return fold_convert (type,
13010 fold_build2 (BIT_AND_EXPR,
13011 TREE_TYPE (tem), tem,
13012 fold_convert (TREE_TYPE (tem),
13016 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
13017 already handled above. */
13018 if (TREE_CODE (arg0) == BIT_AND_EXPR
13019 && integer_onep (TREE_OPERAND (arg0, 1))
13020 && integer_zerop (op2)
13021 && integer_pow2p (arg1))
13023 tree tem = TREE_OPERAND (arg0, 0);
13025 if (TREE_CODE (tem) == RSHIFT_EXPR
13026 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
13027 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
13028 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
13029 return fold_build2 (BIT_AND_EXPR, type,
13030 TREE_OPERAND (tem, 0), arg1);
13033 /* A & N ? N : 0 is simply A & N if N is a power of two. This
13034 is probably obsolete because the first operand should be a
13035 truth value (that's why we have the two cases above), but let's
13036 leave it in until we can confirm this for all front-ends. */
13037 if (integer_zerop (op2)
13038 && TREE_CODE (arg0) == NE_EXPR
13039 && integer_zerop (TREE_OPERAND (arg0, 1))
13040 && integer_pow2p (arg1)
13041 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
13042 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
13043 arg1, OEP_ONLY_CONST))
13044 return pedantic_non_lvalue (fold_convert (type,
13045 TREE_OPERAND (arg0, 0)));
13047 /* Convert A ? B : 0 into A && B if A and B are truth values. */
13048 if (integer_zerop (op2)
13049 && truth_value_p (TREE_CODE (arg0))
13050 && truth_value_p (TREE_CODE (arg1)))
13051 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13052 fold_convert (type, arg0),
13055 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
13056 if (integer_onep (op2)
13057 && truth_value_p (TREE_CODE (arg0))
13058 && truth_value_p (TREE_CODE (arg1)))
13060 /* Only perform transformation if ARG0 is easily inverted. */
13061 tem = fold_truth_not_expr (arg0);
13063 return fold_build2 (TRUTH_ORIF_EXPR, type,
13064 fold_convert (type, tem),
13068 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
13069 if (integer_zerop (arg1)
13070 && truth_value_p (TREE_CODE (arg0))
13071 && truth_value_p (TREE_CODE (op2)))
13073 /* Only perform transformation if ARG0 is easily inverted. */
13074 tem = fold_truth_not_expr (arg0);
13076 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13077 fold_convert (type, tem),
13081 /* Convert A ? 1 : B into A || B if A and B are truth values. */
13082 if (integer_onep (arg1)
13083 && truth_value_p (TREE_CODE (arg0))
13084 && truth_value_p (TREE_CODE (op2)))
13085 return fold_build2 (TRUTH_ORIF_EXPR, type,
13086 fold_convert (type, arg0),
13092 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
13093 of fold_ternary on them. */
13094 gcc_unreachable ();
13096 case BIT_FIELD_REF:
13097 if ((TREE_CODE (arg0) == VECTOR_CST
13098 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
13099 && type == TREE_TYPE (TREE_TYPE (arg0))
13100 && host_integerp (arg1, 1)
13101 && host_integerp (op2, 1))
13103 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
13104 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
13107 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
13108 && (idx % width) == 0
13109 && (idx = idx / width)
13110 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
13112 tree elements = NULL_TREE;
13114 if (TREE_CODE (arg0) == VECTOR_CST)
13115 elements = TREE_VECTOR_CST_ELTS (arg0);
13118 unsigned HOST_WIDE_INT idx;
13121 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
13122 elements = tree_cons (NULL_TREE, value, elements);
13124 while (idx-- > 0 && elements)
13125 elements = TREE_CHAIN (elements);
13127 return TREE_VALUE (elements);
13129 return fold_convert (type, integer_zero_node);
13136 } /* switch (code) */
13139 /* Perform constant folding and related simplification of EXPR.
13140 The related simplifications include x*1 => x, x*0 => 0, etc.,
13141 and application of the associative law.
13142 NOP_EXPR conversions may be removed freely (as long as we
13143 are careful not to change the type of the overall expression).
13144 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13145 but we can constant-fold them if they have constant operands. */
13147 #ifdef ENABLE_FOLD_CHECKING
13148 # define fold(x) fold_1 (x)
13149 static tree fold_1 (tree);
13155 const tree t = expr;
13156 enum tree_code code = TREE_CODE (t);
13157 enum tree_code_class kind = TREE_CODE_CLASS (code);
13160 /* Return right away if a constant. */
13161 if (kind == tcc_constant)
13164 /* CALL_EXPR-like objects with variable numbers of operands are
13165 treated specially. */
13166 if (kind == tcc_vl_exp)
13168 if (code == CALL_EXPR)
13170 tem = fold_call_expr (expr, false);
13171 return tem ? tem : expr;
13176 if (IS_EXPR_CODE_CLASS (kind)
13177 || IS_GIMPLE_STMT_CODE_CLASS (kind))
13179 tree type = TREE_TYPE (t);
13180 tree op0, op1, op2;
13182 switch (TREE_CODE_LENGTH (code))
13185 op0 = TREE_OPERAND (t, 0);
13186 tem = fold_unary (code, type, op0);
13187 return tem ? tem : expr;
13189 op0 = TREE_OPERAND (t, 0);
13190 op1 = TREE_OPERAND (t, 1);
13191 tem = fold_binary (code, type, op0, op1);
13192 return tem ? tem : expr;
13194 op0 = TREE_OPERAND (t, 0);
13195 op1 = TREE_OPERAND (t, 1);
13196 op2 = TREE_OPERAND (t, 2);
13197 tem = fold_ternary (code, type, op0, op1, op2);
13198 return tem ? tem : expr;
13207 return fold (DECL_INITIAL (t));
13211 } /* switch (code) */
13214 #ifdef ENABLE_FOLD_CHECKING
13217 static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
13218 static void fold_check_failed (const_tree, const_tree);
13219 void print_fold_checksum (const_tree);
13221 /* When --enable-checking=fold, compute a digest of expr before
13222 and after actual fold call to see if fold did not accidentally
13223 change original expr. */
13229 struct md5_ctx ctx;
13230 unsigned char checksum_before[16], checksum_after[16];
13233 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13234 md5_init_ctx (&ctx);
13235 fold_checksum_tree (expr, &ctx, ht);
13236 md5_finish_ctx (&ctx, checksum_before);
13239 ret = fold_1 (expr);
13241 md5_init_ctx (&ctx);
13242 fold_checksum_tree (expr, &ctx, ht);
13243 md5_finish_ctx (&ctx, checksum_after);
13246 if (memcmp (checksum_before, checksum_after, 16))
13247 fold_check_failed (expr, ret);
13253 print_fold_checksum (const_tree expr)
13255 struct md5_ctx ctx;
13256 unsigned char checksum[16], cnt;
13259 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13260 md5_init_ctx (&ctx);
13261 fold_checksum_tree (expr, &ctx, ht);
13262 md5_finish_ctx (&ctx, checksum);
13264 for (cnt = 0; cnt < 16; ++cnt)
13265 fprintf (stderr, "%02x", checksum[cnt]);
13266 putc ('\n', stderr);
13270 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
13272 internal_error ("fold check: original tree changed by fold");
13276 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
13279 enum tree_code code;
13280 struct tree_function_decl buf;
13285 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
13286 <= sizeof (struct tree_function_decl))
13287 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
13290 slot = (const void **) htab_find_slot (ht, expr, INSERT);
13294 code = TREE_CODE (expr);
13295 if (TREE_CODE_CLASS (code) == tcc_declaration
13296 && DECL_ASSEMBLER_NAME_SET_P (expr))
13298 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13299 memcpy ((char *) &buf, expr, tree_size (expr));
13300 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
13301 expr = (tree) &buf;
13303 else if (TREE_CODE_CLASS (code) == tcc_type
13304 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
13305 || TYPE_CACHED_VALUES_P (expr)
13306 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
13308 /* Allow these fields to be modified. */
13310 memcpy ((char *) &buf, expr, tree_size (expr));
13311 expr = tmp = (tree) &buf;
13312 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
13313 TYPE_POINTER_TO (tmp) = NULL;
13314 TYPE_REFERENCE_TO (tmp) = NULL;
13315 if (TYPE_CACHED_VALUES_P (tmp))
13317 TYPE_CACHED_VALUES_P (tmp) = 0;
13318 TYPE_CACHED_VALUES (tmp) = NULL;
13321 md5_process_bytes (expr, tree_size (expr), ctx);
13322 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
13323 if (TREE_CODE_CLASS (code) != tcc_type
13324 && TREE_CODE_CLASS (code) != tcc_declaration
13325 && code != TREE_LIST
13326 && code != SSA_NAME)
13327 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
13328 switch (TREE_CODE_CLASS (code))
13334 md5_process_bytes (TREE_STRING_POINTER (expr),
13335 TREE_STRING_LENGTH (expr), ctx);
13338 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
13339 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
13342 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
13348 case tcc_exceptional:
13352 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
13353 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
13354 expr = TREE_CHAIN (expr);
13355 goto recursive_label;
13358 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
13359 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
13365 case tcc_expression:
13366 case tcc_reference:
13367 case tcc_comparison:
13370 case tcc_statement:
13372 len = TREE_OPERAND_LENGTH (expr);
13373 for (i = 0; i < len; ++i)
13374 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
13376 case tcc_declaration:
13377 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
13378 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
13379 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
13381 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
13382 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
13383 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
13384 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
13385 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
13387 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
13388 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
13390 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
13392 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
13393 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
13394 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
13398 if (TREE_CODE (expr) == ENUMERAL_TYPE)
13399 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
13400 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
13401 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
13402 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
13403 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
13404 if (INTEGRAL_TYPE_P (expr)
13405 || SCALAR_FLOAT_TYPE_P (expr))
13407 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
13408 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
13410 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
13411 if (TREE_CODE (expr) == RECORD_TYPE
13412 || TREE_CODE (expr) == UNION_TYPE
13413 || TREE_CODE (expr) == QUAL_UNION_TYPE)
13414 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
13415 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
13422 /* Helper function for outputting the checksum of a tree T. When
13423 debugging with gdb, you can "define mynext" to be "next" followed
13424 by "call debug_fold_checksum (op0)", then just trace down till the
13428 debug_fold_checksum (const_tree t)
13431 unsigned char checksum[16];
13432 struct md5_ctx ctx;
13433 htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13435 md5_init_ctx (&ctx);
13436 fold_checksum_tree (t, &ctx, ht);
13437 md5_finish_ctx (&ctx, checksum);
13440 for (i = 0; i < 16; i++)
13441 fprintf (stderr, "%d ", checksum[i]);
13443 fprintf (stderr, "\n");
13448 /* Fold a unary tree expression with code CODE of type TYPE with an
13449 operand OP0. Return a folded expression if successful. Otherwise,
13450 return a tree expression with code CODE of type TYPE with an
13454 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
13457 #ifdef ENABLE_FOLD_CHECKING
13458 unsigned char checksum_before[16], checksum_after[16];
13459 struct md5_ctx ctx;
13462 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13463 md5_init_ctx (&ctx);
13464 fold_checksum_tree (op0, &ctx, ht);
13465 md5_finish_ctx (&ctx, checksum_before);
13469 tem = fold_unary (code, type, op0);
13471 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
13473 #ifdef ENABLE_FOLD_CHECKING
13474 md5_init_ctx (&ctx);
13475 fold_checksum_tree (op0, &ctx, ht);
13476 md5_finish_ctx (&ctx, checksum_after);
13479 if (memcmp (checksum_before, checksum_after, 16))
13480 fold_check_failed (op0, tem);
13485 /* Fold a binary tree expression with code CODE of type TYPE with
13486 operands OP0 and OP1. Return a folded expression if successful.
13487 Otherwise, return a tree expression with code CODE of type TYPE
13488 with operands OP0 and OP1. */
13491 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
13495 #ifdef ENABLE_FOLD_CHECKING
13496 unsigned char checksum_before_op0[16],
13497 checksum_before_op1[16],
13498 checksum_after_op0[16],
13499 checksum_after_op1[16];
13500 struct md5_ctx ctx;
13503 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13504 md5_init_ctx (&ctx);
13505 fold_checksum_tree (op0, &ctx, ht);
13506 md5_finish_ctx (&ctx, checksum_before_op0);
13509 md5_init_ctx (&ctx);
13510 fold_checksum_tree (op1, &ctx, ht);
13511 md5_finish_ctx (&ctx, checksum_before_op1);
13515 tem = fold_binary (code, type, op0, op1);
13517 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
13519 #ifdef ENABLE_FOLD_CHECKING
13520 md5_init_ctx (&ctx);
13521 fold_checksum_tree (op0, &ctx, ht);
13522 md5_finish_ctx (&ctx, checksum_after_op0);
13525 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13526 fold_check_failed (op0, tem);
13528 md5_init_ctx (&ctx);
13529 fold_checksum_tree (op1, &ctx, ht);
13530 md5_finish_ctx (&ctx, checksum_after_op1);
13533 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13534 fold_check_failed (op1, tem);
13539 /* Fold a ternary tree expression with code CODE of type TYPE with
13540 operands OP0, OP1, and OP2. Return a folded expression if
13541 successful. Otherwise, return a tree expression with code CODE of
13542 type TYPE with operands OP0, OP1, and OP2. */
13545 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
13549 #ifdef ENABLE_FOLD_CHECKING
13550 unsigned char checksum_before_op0[16],
13551 checksum_before_op1[16],
13552 checksum_before_op2[16],
13553 checksum_after_op0[16],
13554 checksum_after_op1[16],
13555 checksum_after_op2[16];
13556 struct md5_ctx ctx;
13559 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13560 md5_init_ctx (&ctx);
13561 fold_checksum_tree (op0, &ctx, ht);
13562 md5_finish_ctx (&ctx, checksum_before_op0);
13565 md5_init_ctx (&ctx);
13566 fold_checksum_tree (op1, &ctx, ht);
13567 md5_finish_ctx (&ctx, checksum_before_op1);
13570 md5_init_ctx (&ctx);
13571 fold_checksum_tree (op2, &ctx, ht);
13572 md5_finish_ctx (&ctx, checksum_before_op2);
13576 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
13577 tem = fold_ternary (code, type, op0, op1, op2);
13579 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
13581 #ifdef ENABLE_FOLD_CHECKING
13582 md5_init_ctx (&ctx);
13583 fold_checksum_tree (op0, &ctx, ht);
13584 md5_finish_ctx (&ctx, checksum_after_op0);
13587 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13588 fold_check_failed (op0, tem);
13590 md5_init_ctx (&ctx);
13591 fold_checksum_tree (op1, &ctx, ht);
13592 md5_finish_ctx (&ctx, checksum_after_op1);
13595 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13596 fold_check_failed (op1, tem);
13598 md5_init_ctx (&ctx);
13599 fold_checksum_tree (op2, &ctx, ht);
13600 md5_finish_ctx (&ctx, checksum_after_op2);
13603 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
13604 fold_check_failed (op2, tem);
13609 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
13610 arguments in ARGARRAY, and a null static chain.
13611 Return a folded expression if successful. Otherwise, return a CALL_EXPR
13612 of type TYPE from the given operands as constructed by build_call_array. */
13615 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
13618 #ifdef ENABLE_FOLD_CHECKING
13619 unsigned char checksum_before_fn[16],
13620 checksum_before_arglist[16],
13621 checksum_after_fn[16],
13622 checksum_after_arglist[16];
13623 struct md5_ctx ctx;
13627 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13628 md5_init_ctx (&ctx);
13629 fold_checksum_tree (fn, &ctx, ht);
13630 md5_finish_ctx (&ctx, checksum_before_fn);
13633 md5_init_ctx (&ctx);
13634 for (i = 0; i < nargs; i++)
13635 fold_checksum_tree (argarray[i], &ctx, ht);
13636 md5_finish_ctx (&ctx, checksum_before_arglist);
13640 tem = fold_builtin_call_array (type, fn, nargs, argarray);
13642 #ifdef ENABLE_FOLD_CHECKING
13643 md5_init_ctx (&ctx);
13644 fold_checksum_tree (fn, &ctx, ht);
13645 md5_finish_ctx (&ctx, checksum_after_fn);
13648 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
13649 fold_check_failed (fn, tem);
13651 md5_init_ctx (&ctx);
13652 for (i = 0; i < nargs; i++)
13653 fold_checksum_tree (argarray[i], &ctx, ht);
13654 md5_finish_ctx (&ctx, checksum_after_arglist);
13657 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
13658 fold_check_failed (NULL_TREE, tem);
13663 /* Perform constant folding and related simplification of initializer
13664 expression EXPR. These behave identically to "fold_buildN" but ignore
13665 potential run-time traps and exceptions that fold must preserve. */
13667 #define START_FOLD_INIT \
13668 int saved_signaling_nans = flag_signaling_nans;\
13669 int saved_trapping_math = flag_trapping_math;\
13670 int saved_rounding_math = flag_rounding_math;\
13671 int saved_trapv = flag_trapv;\
13672 int saved_folding_initializer = folding_initializer;\
13673 flag_signaling_nans = 0;\
13674 flag_trapping_math = 0;\
13675 flag_rounding_math = 0;\
13677 folding_initializer = 1;
13679 #define END_FOLD_INIT \
13680 flag_signaling_nans = saved_signaling_nans;\
13681 flag_trapping_math = saved_trapping_math;\
13682 flag_rounding_math = saved_rounding_math;\
13683 flag_trapv = saved_trapv;\
13684 folding_initializer = saved_folding_initializer;
13687 fold_build1_initializer (enum tree_code code, tree type, tree op)
13692 result = fold_build1 (code, type, op);
13699 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
13704 result = fold_build2 (code, type, op0, op1);
13711 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
13717 result = fold_build3 (code, type, op0, op1, op2);
13724 fold_build_call_array_initializer (tree type, tree fn,
13725 int nargs, tree *argarray)
13730 result = fold_build_call_array (type, fn, nargs, argarray);
13736 #undef START_FOLD_INIT
13737 #undef END_FOLD_INIT
13739 /* Determine if first argument is a multiple of second argument. Return 0 if
13740 it is not, or we cannot easily determined it to be.
13742 An example of the sort of thing we care about (at this point; this routine
13743 could surely be made more general, and expanded to do what the *_DIV_EXPR's
13744 fold cases do now) is discovering that
13746 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13752 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
13754 This code also handles discovering that
13756 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13758 is a multiple of 8 so we don't have to worry about dealing with a
13759 possible remainder.
13761 Note that we *look* inside a SAVE_EXPR only to determine how it was
13762 calculated; it is not safe for fold to do much of anything else with the
13763 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
13764 at run time. For example, the latter example above *cannot* be implemented
13765 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
13766 evaluation time of the original SAVE_EXPR is not necessarily the same at
13767 the time the new expression is evaluated. The only optimization of this
13768 sort that would be valid is changing
13770 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
13774 SAVE_EXPR (I) * SAVE_EXPR (J)
13776 (where the same SAVE_EXPR (J) is used in the original and the
13777 transformed version). */
13780 multiple_of_p (tree type, const_tree top, const_tree bottom)
13782 if (operand_equal_p (top, bottom, 0))
13785 if (TREE_CODE (type) != INTEGER_TYPE)
13788 switch (TREE_CODE (top))
13791 /* Bitwise and provides a power of two multiple. If the mask is
13792 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
13793 if (!integer_pow2p (bottom))
13798 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13799 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13803 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13804 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13807 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
13811 op1 = TREE_OPERAND (top, 1);
13812 /* const_binop may not detect overflow correctly,
13813 so check for it explicitly here. */
13814 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
13815 > TREE_INT_CST_LOW (op1)
13816 && TREE_INT_CST_HIGH (op1) == 0
13817 && 0 != (t1 = fold_convert (type,
13818 const_binop (LSHIFT_EXPR,
13821 && !TREE_OVERFLOW (t1))
13822 return multiple_of_p (type, t1, bottom);
13827 /* Can't handle conversions from non-integral or wider integral type. */
13828 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
13829 || (TYPE_PRECISION (type)
13830 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
13833 /* .. fall through ... */
13836 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
13839 if (TREE_CODE (bottom) != INTEGER_CST
13840 || integer_zerop (bottom)
13841 || (TYPE_UNSIGNED (type)
13842 && (tree_int_cst_sgn (top) < 0
13843 || tree_int_cst_sgn (bottom) < 0)))
13845 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
13853 /* Return true if `t' is known to be non-negative. If the return
13854 value is based on the assumption that signed overflow is undefined,
13855 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13856 *STRICT_OVERFLOW_P. */
13859 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
13861 if (t == error_mark_node)
13864 if (TYPE_UNSIGNED (TREE_TYPE (t)))
13867 switch (TREE_CODE (t))
13870 /* Query VRP to see if it has recorded any information about
13871 the range of this object. */
13872 return ssa_name_nonnegative_p (t);
13875 /* We can't return 1 if flag_wrapv is set because
13876 ABS_EXPR<INT_MIN> = INT_MIN. */
13877 if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
13879 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
13881 *strict_overflow_p = true;
13887 return tree_int_cst_sgn (t) >= 0;
13890 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
13893 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
13895 case POINTER_PLUS_EXPR:
13897 if (FLOAT_TYPE_P (TREE_TYPE (t)))
13898 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13900 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13901 strict_overflow_p));
13903 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
13904 both unsigned and at least 2 bits shorter than the result. */
13905 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
13906 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
13907 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
13909 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
13910 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
13911 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13912 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13914 unsigned int prec = MAX (TYPE_PRECISION (inner1),
13915 TYPE_PRECISION (inner2)) + 1;
13916 return prec < TYPE_PRECISION (TREE_TYPE (t));
13922 if (FLOAT_TYPE_P (TREE_TYPE (t)))
13924 /* x * x for floating point x is always non-negative. */
13925 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
13927 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13929 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13930 strict_overflow_p));
13933 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
13934 both unsigned and their total bits is shorter than the result. */
13935 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
13936 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
13937 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
13939 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
13940 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
13941 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13942 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13943 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
13944 < TYPE_PRECISION (TREE_TYPE (t));
13950 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13952 || tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13953 strict_overflow_p));
13959 case TRUNC_DIV_EXPR:
13960 case CEIL_DIV_EXPR:
13961 case FLOOR_DIV_EXPR:
13962 case ROUND_DIV_EXPR:
13963 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13965 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13966 strict_overflow_p));
13968 case TRUNC_MOD_EXPR:
13969 case CEIL_MOD_EXPR:
13970 case FLOOR_MOD_EXPR:
13971 case ROUND_MOD_EXPR:
13973 case NON_LVALUE_EXPR:
13975 case FIX_TRUNC_EXPR:
13976 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13977 strict_overflow_p);
13979 case COMPOUND_EXPR:
13981 case GIMPLE_MODIFY_STMT:
13982 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
13983 strict_overflow_p);
13986 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
13987 strict_overflow_p);
13990 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13992 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
13993 strict_overflow_p));
13997 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
13998 tree outer_type = TREE_TYPE (t);
14000 if (TREE_CODE (outer_type) == REAL_TYPE)
14002 if (TREE_CODE (inner_type) == REAL_TYPE)
14003 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14004 strict_overflow_p);
14005 if (TREE_CODE (inner_type) == INTEGER_TYPE)
14007 if (TYPE_UNSIGNED (inner_type))
14009 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14010 strict_overflow_p);
14013 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
14015 if (TREE_CODE (inner_type) == REAL_TYPE)
14016 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t,0),
14017 strict_overflow_p);
14018 if (TREE_CODE (inner_type) == INTEGER_TYPE)
14019 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
14020 && TYPE_UNSIGNED (inner_type);
14027 tree temp = TARGET_EXPR_SLOT (t);
14028 t = TARGET_EXPR_INITIAL (t);
14030 /* If the initializer is non-void, then it's a normal expression
14031 that will be assigned to the slot. */
14032 if (!VOID_TYPE_P (t))
14033 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
14035 /* Otherwise, the initializer sets the slot in some way. One common
14036 way is an assignment statement at the end of the initializer. */
14039 if (TREE_CODE (t) == BIND_EXPR)
14040 t = expr_last (BIND_EXPR_BODY (t));
14041 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
14042 || TREE_CODE (t) == TRY_CATCH_EXPR)
14043 t = expr_last (TREE_OPERAND (t, 0));
14044 else if (TREE_CODE (t) == STATEMENT_LIST)
14049 if ((TREE_CODE (t) == MODIFY_EXPR
14050 || TREE_CODE (t) == GIMPLE_MODIFY_STMT)
14051 && GENERIC_TREE_OPERAND (t, 0) == temp)
14052 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14053 strict_overflow_p);
14060 tree fndecl = get_callee_fndecl (t);
14061 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
14062 switch (DECL_FUNCTION_CODE (fndecl))
14064 CASE_FLT_FN (BUILT_IN_ACOS):
14065 CASE_FLT_FN (BUILT_IN_ACOSH):
14066 CASE_FLT_FN (BUILT_IN_CABS):
14067 CASE_FLT_FN (BUILT_IN_COSH):
14068 CASE_FLT_FN (BUILT_IN_ERFC):
14069 CASE_FLT_FN (BUILT_IN_EXP):
14070 CASE_FLT_FN (BUILT_IN_EXP10):
14071 CASE_FLT_FN (BUILT_IN_EXP2):
14072 CASE_FLT_FN (BUILT_IN_FABS):
14073 CASE_FLT_FN (BUILT_IN_FDIM):
14074 CASE_FLT_FN (BUILT_IN_HYPOT):
14075 CASE_FLT_FN (BUILT_IN_POW10):
14076 CASE_INT_FN (BUILT_IN_FFS):
14077 CASE_INT_FN (BUILT_IN_PARITY):
14078 CASE_INT_FN (BUILT_IN_POPCOUNT):
14079 case BUILT_IN_BSWAP32:
14080 case BUILT_IN_BSWAP64:
14084 CASE_FLT_FN (BUILT_IN_SQRT):
14085 /* sqrt(-0.0) is -0.0. */
14086 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
14088 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14089 strict_overflow_p);
14091 CASE_FLT_FN (BUILT_IN_ASINH):
14092 CASE_FLT_FN (BUILT_IN_ATAN):
14093 CASE_FLT_FN (BUILT_IN_ATANH):
14094 CASE_FLT_FN (BUILT_IN_CBRT):
14095 CASE_FLT_FN (BUILT_IN_CEIL):
14096 CASE_FLT_FN (BUILT_IN_ERF):
14097 CASE_FLT_FN (BUILT_IN_EXPM1):
14098 CASE_FLT_FN (BUILT_IN_FLOOR):
14099 CASE_FLT_FN (BUILT_IN_FMOD):
14100 CASE_FLT_FN (BUILT_IN_FREXP):
14101 CASE_FLT_FN (BUILT_IN_LCEIL):
14102 CASE_FLT_FN (BUILT_IN_LDEXP):
14103 CASE_FLT_FN (BUILT_IN_LFLOOR):
14104 CASE_FLT_FN (BUILT_IN_LLCEIL):
14105 CASE_FLT_FN (BUILT_IN_LLFLOOR):
14106 CASE_FLT_FN (BUILT_IN_LLRINT):
14107 CASE_FLT_FN (BUILT_IN_LLROUND):
14108 CASE_FLT_FN (BUILT_IN_LRINT):
14109 CASE_FLT_FN (BUILT_IN_LROUND):
14110 CASE_FLT_FN (BUILT_IN_MODF):
14111 CASE_FLT_FN (BUILT_IN_NEARBYINT):
14112 CASE_FLT_FN (BUILT_IN_RINT):
14113 CASE_FLT_FN (BUILT_IN_ROUND):
14114 CASE_FLT_FN (BUILT_IN_SCALB):
14115 CASE_FLT_FN (BUILT_IN_SCALBLN):
14116 CASE_FLT_FN (BUILT_IN_SCALBN):
14117 CASE_FLT_FN (BUILT_IN_SIGNBIT):
14118 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
14119 CASE_FLT_FN (BUILT_IN_SINH):
14120 CASE_FLT_FN (BUILT_IN_TANH):
14121 CASE_FLT_FN (BUILT_IN_TRUNC):
14122 /* True if the 1st argument is nonnegative. */
14123 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14124 strict_overflow_p);
14126 CASE_FLT_FN (BUILT_IN_FMAX):
14127 /* True if the 1st OR 2nd arguments are nonnegative. */
14128 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14130 || (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14131 strict_overflow_p)));
14133 CASE_FLT_FN (BUILT_IN_FMIN):
14134 /* True if the 1st AND 2nd arguments are nonnegative. */
14135 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14137 && (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14138 strict_overflow_p)));
14140 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14141 /* True if the 2nd argument is nonnegative. */
14142 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14143 strict_overflow_p);
14145 CASE_FLT_FN (BUILT_IN_POWI):
14146 /* True if the 1st argument is nonnegative or the second
14147 argument is an even integer. */
14148 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == INTEGER_CST)
14150 tree arg1 = CALL_EXPR_ARG (t, 1);
14151 if ((TREE_INT_CST_LOW (arg1) & 1) == 0)
14154 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14155 strict_overflow_p);
14157 CASE_FLT_FN (BUILT_IN_POW):
14158 /* True if the 1st argument is nonnegative or the second
14159 argument is an even integer valued real. */
14160 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == REAL_CST)
14165 c = TREE_REAL_CST (CALL_EXPR_ARG (t, 1));
14166 n = real_to_integer (&c);
14169 REAL_VALUE_TYPE cint;
14170 real_from_integer (&cint, VOIDmode, n,
14171 n < 0 ? -1 : 0, 0);
14172 if (real_identical (&c, &cint))
14176 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14177 strict_overflow_p);
14184 /* ... fall through ... */
14188 tree type = TREE_TYPE (t);
14189 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
14190 && truth_value_p (TREE_CODE (t)))
14191 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
14192 have a signed:1 type (where the value is -1 and 0). */
14197 /* We don't know sign of `t', so be conservative and return false. */
14201 /* Return true if `t' is known to be non-negative. Handle warnings
14202 about undefined signed overflow. */
14205 tree_expr_nonnegative_p (tree t)
14207 bool ret, strict_overflow_p;
14209 strict_overflow_p = false;
14210 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
14211 if (strict_overflow_p)
14212 fold_overflow_warning (("assuming signed overflow does not occur when "
14213 "determining that expression is always "
14215 WARN_STRICT_OVERFLOW_MISC);
14219 /* Return true when T is an address and is known to be nonzero.
14220 For floating point we further ensure that T is not denormal.
14221 Similar logic is present in nonzero_address in rtlanal.h.
14223 If the return value is based on the assumption that signed overflow
14224 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14225 change *STRICT_OVERFLOW_P. */
14228 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14230 tree type = TREE_TYPE (t);
14231 bool sub_strict_overflow_p;
14233 /* Doing something useful for floating point would need more work. */
14234 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
14237 switch (TREE_CODE (t))
14240 /* Query VRP to see if it has recorded any information about
14241 the range of this object. */
14242 return ssa_name_nonzero_p (t);
14245 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14246 strict_overflow_p);
14249 return !integer_zerop (t);
14251 case POINTER_PLUS_EXPR:
14253 if (TYPE_OVERFLOW_UNDEFINED (type))
14255 /* With the presence of negative values it is hard
14256 to say something. */
14257 sub_strict_overflow_p = false;
14258 if (!tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14259 &sub_strict_overflow_p)
14260 || !tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14261 &sub_strict_overflow_p))
14263 /* One of operands must be positive and the other non-negative. */
14264 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14265 overflows, on a twos-complement machine the sum of two
14266 nonnegative numbers can never be zero. */
14267 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14269 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14270 strict_overflow_p));
14275 if (TYPE_OVERFLOW_UNDEFINED (type))
14277 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14279 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14280 strict_overflow_p))
14282 *strict_overflow_p = true;
14290 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
14291 tree outer_type = TREE_TYPE (t);
14293 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
14294 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14295 strict_overflow_p));
14301 tree base = get_base_address (TREE_OPERAND (t, 0));
14306 /* Weak declarations may link to NULL. */
14307 if (VAR_OR_FUNCTION_DECL_P (base))
14308 return !DECL_WEAK (base);
14310 /* Constants are never weak. */
14311 if (CONSTANT_CLASS_P (base))
14318 sub_strict_overflow_p = false;
14319 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14320 &sub_strict_overflow_p)
14321 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
14322 &sub_strict_overflow_p))
14324 if (sub_strict_overflow_p)
14325 *strict_overflow_p = true;
14331 sub_strict_overflow_p = false;
14332 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14333 &sub_strict_overflow_p)
14334 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14335 &sub_strict_overflow_p))
14337 if (sub_strict_overflow_p)
14338 *strict_overflow_p = true;
14343 sub_strict_overflow_p = false;
14344 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14345 &sub_strict_overflow_p))
14347 if (sub_strict_overflow_p)
14348 *strict_overflow_p = true;
14350 /* When both operands are nonzero, then MAX must be too. */
14351 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14352 strict_overflow_p))
14355 /* MAX where operand 0 is positive is positive. */
14356 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14357 strict_overflow_p);
14359 /* MAX where operand 1 is positive is positive. */
14360 else if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14361 &sub_strict_overflow_p)
14362 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14363 &sub_strict_overflow_p))
14365 if (sub_strict_overflow_p)
14366 *strict_overflow_p = true;
14371 case COMPOUND_EXPR:
14373 case GIMPLE_MODIFY_STMT:
14375 return tree_expr_nonzero_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14376 strict_overflow_p);
14379 case NON_LVALUE_EXPR:
14380 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14381 strict_overflow_p);
14384 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14386 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14387 strict_overflow_p));
14390 return alloca_call_p (t);
14398 /* Return true when T is an address and is known to be nonzero.
14399 Handle warnings about undefined signed overflow. */
14402 tree_expr_nonzero_p (tree t)
14404 bool ret, strict_overflow_p;
14406 strict_overflow_p = false;
14407 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
14408 if (strict_overflow_p)
14409 fold_overflow_warning (("assuming signed overflow does not occur when "
14410 "determining that expression is always "
14412 WARN_STRICT_OVERFLOW_MISC);
14416 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
14417 attempt to fold the expression to a constant without modifying TYPE,
14420 If the expression could be simplified to a constant, then return
14421 the constant. If the expression would not be simplified to a
14422 constant, then return NULL_TREE. */
14425 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
14427 tree tem = fold_binary (code, type, op0, op1);
14428 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14431 /* Given the components of a unary expression CODE, TYPE and OP0,
14432 attempt to fold the expression to a constant without modifying
14435 If the expression could be simplified to a constant, then return
14436 the constant. If the expression would not be simplified to a
14437 constant, then return NULL_TREE. */
14440 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
14442 tree tem = fold_unary (code, type, op0);
14443 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14446 /* If EXP represents referencing an element in a constant string
14447 (either via pointer arithmetic or array indexing), return the
14448 tree representing the value accessed, otherwise return NULL. */
14451 fold_read_from_constant_string (tree exp)
14453 if ((TREE_CODE (exp) == INDIRECT_REF
14454 || TREE_CODE (exp) == ARRAY_REF)
14455 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
14457 tree exp1 = TREE_OPERAND (exp, 0);
14461 if (TREE_CODE (exp) == INDIRECT_REF)
14462 string = string_constant (exp1, &index);
14465 tree low_bound = array_ref_low_bound (exp);
14466 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
14468 /* Optimize the special-case of a zero lower bound.
14470 We convert the low_bound to sizetype to avoid some problems
14471 with constant folding. (E.g. suppose the lower bound is 1,
14472 and its mode is QI. Without the conversion,l (ARRAY
14473 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
14474 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
14475 if (! integer_zerop (low_bound))
14476 index = size_diffop (index, fold_convert (sizetype, low_bound));
14482 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
14483 && TREE_CODE (string) == STRING_CST
14484 && TREE_CODE (index) == INTEGER_CST
14485 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
14486 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
14488 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
14489 return build_int_cst_type (TREE_TYPE (exp),
14490 (TREE_STRING_POINTER (string)
14491 [TREE_INT_CST_LOW (index)]));
14496 /* Return the tree for neg (ARG0) when ARG0 is known to be either
14497 an integer constant, real, or fixed-point constant.
14499 TYPE is the type of the result. */
14502 fold_negate_const (tree arg0, tree type)
14504 tree t = NULL_TREE;
14506 switch (TREE_CODE (arg0))
14510 unsigned HOST_WIDE_INT low;
14511 HOST_WIDE_INT high;
14512 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14513 TREE_INT_CST_HIGH (arg0),
14515 t = force_fit_type_double (type, low, high, 1,
14516 (overflow | TREE_OVERFLOW (arg0))
14517 && !TYPE_UNSIGNED (type));
14522 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14527 FIXED_VALUE_TYPE f;
14528 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
14529 &(TREE_FIXED_CST (arg0)), NULL,
14530 TYPE_SATURATING (type));
14531 t = build_fixed (type, f);
14532 /* Propagate overflow flags. */
14533 if (overflow_p | TREE_OVERFLOW (arg0))
14535 TREE_OVERFLOW (t) = 1;
14536 TREE_CONSTANT_OVERFLOW (t) = 1;
14538 else if (TREE_CONSTANT_OVERFLOW (arg0))
14539 TREE_CONSTANT_OVERFLOW (t) = 1;
14544 gcc_unreachable ();
14550 /* Return the tree for abs (ARG0) when ARG0 is known to be either
14551 an integer constant or real constant.
14553 TYPE is the type of the result. */
14556 fold_abs_const (tree arg0, tree type)
14558 tree t = NULL_TREE;
14560 switch (TREE_CODE (arg0))
14563 /* If the value is unsigned, then the absolute value is
14564 the same as the ordinary value. */
14565 if (TYPE_UNSIGNED (type))
14567 /* Similarly, if the value is non-negative. */
14568 else if (INT_CST_LT (integer_minus_one_node, arg0))
14570 /* If the value is negative, then the absolute value is
14574 unsigned HOST_WIDE_INT low;
14575 HOST_WIDE_INT high;
14576 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14577 TREE_INT_CST_HIGH (arg0),
14579 t = force_fit_type_double (type, low, high, -1,
14580 overflow | TREE_OVERFLOW (arg0));
14585 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
14586 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14592 gcc_unreachable ();
14598 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
14599 constant. TYPE is the type of the result. */
14602 fold_not_const (tree arg0, tree type)
14604 tree t = NULL_TREE;
14606 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
14608 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
14609 ~TREE_INT_CST_HIGH (arg0), 0,
14610 TREE_OVERFLOW (arg0));
14615 /* Given CODE, a relational operator, the target type, TYPE and two
14616 constant operands OP0 and OP1, return the result of the
14617 relational operation. If the result is not a compile time
14618 constant, then return NULL_TREE. */
14621 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
14623 int result, invert;
14625 /* From here on, the only cases we handle are when the result is
14626 known to be a constant. */
14628 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
14630 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
14631 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
14633 /* Handle the cases where either operand is a NaN. */
14634 if (real_isnan (c0) || real_isnan (c1))
14644 case UNORDERED_EXPR:
14658 if (flag_trapping_math)
14664 gcc_unreachable ();
14667 return constant_boolean_node (result, type);
14670 return constant_boolean_node (real_compare (code, c0, c1), type);
14673 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
14675 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
14676 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
14677 return constant_boolean_node (fixed_compare (code, c0, c1), type);
14680 /* Handle equality/inequality of complex constants. */
14681 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
14683 tree rcond = fold_relational_const (code, type,
14684 TREE_REALPART (op0),
14685 TREE_REALPART (op1));
14686 tree icond = fold_relational_const (code, type,
14687 TREE_IMAGPART (op0),
14688 TREE_IMAGPART (op1));
14689 if (code == EQ_EXPR)
14690 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
14691 else if (code == NE_EXPR)
14692 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
14697 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14699 To compute GT, swap the arguments and do LT.
14700 To compute GE, do LT and invert the result.
14701 To compute LE, swap the arguments, do LT and invert the result.
14702 To compute NE, do EQ and invert the result.
14704 Therefore, the code below must handle only EQ and LT. */
14706 if (code == LE_EXPR || code == GT_EXPR)
14711 code = swap_tree_comparison (code);
14714 /* Note that it is safe to invert for real values here because we
14715 have already handled the one case that it matters. */
14718 if (code == NE_EXPR || code == GE_EXPR)
14721 code = invert_tree_comparison (code, false);
14724 /* Compute a result for LT or EQ if args permit;
14725 Otherwise return T. */
14726 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
14728 if (code == EQ_EXPR)
14729 result = tree_int_cst_equal (op0, op1);
14730 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
14731 result = INT_CST_LT_UNSIGNED (op0, op1);
14733 result = INT_CST_LT (op0, op1);
14740 return constant_boolean_node (result, type);
14743 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
14744 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
14748 fold_build_cleanup_point_expr (tree type, tree expr)
14750 /* If the expression does not have side effects then we don't have to wrap
14751 it with a cleanup point expression. */
14752 if (!TREE_SIDE_EFFECTS (expr))
14755 /* If the expression is a return, check to see if the expression inside the
14756 return has no side effects or the right hand side of the modify expression
14757 inside the return. If either don't have side effects set we don't need to
14758 wrap the expression in a cleanup point expression. Note we don't check the
14759 left hand side of the modify because it should always be a return decl. */
14760 if (TREE_CODE (expr) == RETURN_EXPR)
14762 tree op = TREE_OPERAND (expr, 0);
14763 if (!op || !TREE_SIDE_EFFECTS (op))
14765 op = TREE_OPERAND (op, 1);
14766 if (!TREE_SIDE_EFFECTS (op))
14770 return build1 (CLEANUP_POINT_EXPR, type, expr);
14773 /* Given a pointer value OP0 and a type TYPE, return a simplified version
14774 of an indirection through OP0, or NULL_TREE if no simplification is
14778 fold_indirect_ref_1 (tree type, tree op0)
14784 subtype = TREE_TYPE (sub);
14785 if (!POINTER_TYPE_P (subtype))
14788 if (TREE_CODE (sub) == ADDR_EXPR)
14790 tree op = TREE_OPERAND (sub, 0);
14791 tree optype = TREE_TYPE (op);
14792 /* *&CONST_DECL -> to the value of the const decl. */
14793 if (TREE_CODE (op) == CONST_DECL)
14794 return DECL_INITIAL (op);
14795 /* *&p => p; make sure to handle *&"str"[cst] here. */
14796 if (type == optype)
14798 tree fop = fold_read_from_constant_string (op);
14804 /* *(foo *)&fooarray => fooarray[0] */
14805 else if (TREE_CODE (optype) == ARRAY_TYPE
14806 && type == TREE_TYPE (optype))
14808 tree type_domain = TYPE_DOMAIN (optype);
14809 tree min_val = size_zero_node;
14810 if (type_domain && TYPE_MIN_VALUE (type_domain))
14811 min_val = TYPE_MIN_VALUE (type_domain);
14812 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
14814 /* *(foo *)&complexfoo => __real__ complexfoo */
14815 else if (TREE_CODE (optype) == COMPLEX_TYPE
14816 && type == TREE_TYPE (optype))
14817 return fold_build1 (REALPART_EXPR, type, op);
14818 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
14819 else if (TREE_CODE (optype) == VECTOR_TYPE
14820 && type == TREE_TYPE (optype))
14822 tree part_width = TYPE_SIZE (type);
14823 tree index = bitsize_int (0);
14824 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
14828 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
14829 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
14830 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
14832 tree op00 = TREE_OPERAND (sub, 0);
14833 tree op01 = TREE_OPERAND (sub, 1);
14837 op00type = TREE_TYPE (op00);
14838 if (TREE_CODE (op00) == ADDR_EXPR
14839 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
14840 && type == TREE_TYPE (TREE_TYPE (op00type)))
14842 tree size = TYPE_SIZE_UNIT (type);
14843 if (tree_int_cst_equal (size, op01))
14844 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
14848 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
14849 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
14850 && type == TREE_TYPE (TREE_TYPE (subtype)))
14853 tree min_val = size_zero_node;
14854 sub = build_fold_indirect_ref (sub);
14855 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
14856 if (type_domain && TYPE_MIN_VALUE (type_domain))
14857 min_val = TYPE_MIN_VALUE (type_domain);
14858 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
14864 /* Builds an expression for an indirection through T, simplifying some
14868 build_fold_indirect_ref (tree t)
14870 tree type = TREE_TYPE (TREE_TYPE (t));
14871 tree sub = fold_indirect_ref_1 (type, t);
14876 return build1 (INDIRECT_REF, type, t);
14879 /* Given an INDIRECT_REF T, return either T or a simplified version. */
14882 fold_indirect_ref (tree t)
14884 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
14892 /* Strip non-trapping, non-side-effecting tree nodes from an expression
14893 whose result is ignored. The type of the returned tree need not be
14894 the same as the original expression. */
14897 fold_ignored_result (tree t)
14899 if (!TREE_SIDE_EFFECTS (t))
14900 return integer_zero_node;
14903 switch (TREE_CODE_CLASS (TREE_CODE (t)))
14906 t = TREE_OPERAND (t, 0);
14910 case tcc_comparison:
14911 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
14912 t = TREE_OPERAND (t, 0);
14913 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
14914 t = TREE_OPERAND (t, 1);
14919 case tcc_expression:
14920 switch (TREE_CODE (t))
14922 case COMPOUND_EXPR:
14923 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
14925 t = TREE_OPERAND (t, 0);
14929 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
14930 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
14932 t = TREE_OPERAND (t, 0);
14945 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
14946 This can only be applied to objects of a sizetype. */
14949 round_up (tree value, int divisor)
14951 tree div = NULL_TREE;
14953 gcc_assert (divisor > 0);
14957 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14958 have to do anything. Only do this when we are not given a const,
14959 because in that case, this check is more expensive than just
14961 if (TREE_CODE (value) != INTEGER_CST)
14963 div = build_int_cst (TREE_TYPE (value), divisor);
14965 if (multiple_of_p (TREE_TYPE (value), value, div))
14969 /* If divisor is a power of two, simplify this to bit manipulation. */
14970 if (divisor == (divisor & -divisor))
14972 if (TREE_CODE (value) == INTEGER_CST)
14974 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
14975 unsigned HOST_WIDE_INT high;
14978 if ((low & (divisor - 1)) == 0)
14981 overflow_p = TREE_OVERFLOW (value);
14982 high = TREE_INT_CST_HIGH (value);
14983 low &= ~(divisor - 1);
14992 return force_fit_type_double (TREE_TYPE (value), low, high,
14999 t = build_int_cst (TREE_TYPE (value), divisor - 1);
15000 value = size_binop (PLUS_EXPR, value, t);
15001 t = build_int_cst (TREE_TYPE (value), -divisor);
15002 value = size_binop (BIT_AND_EXPR, value, t);
15008 div = build_int_cst (TREE_TYPE (value), divisor);
15009 value = size_binop (CEIL_DIV_EXPR, value, div);
15010 value = size_binop (MULT_EXPR, value, div);
15016 /* Likewise, but round down. */
15019 round_down (tree value, int divisor)
15021 tree div = NULL_TREE;
15023 gcc_assert (divisor > 0);
15027 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15028 have to do anything. Only do this when we are not given a const,
15029 because in that case, this check is more expensive than just
15031 if (TREE_CODE (value) != INTEGER_CST)
15033 div = build_int_cst (TREE_TYPE (value), divisor);
15035 if (multiple_of_p (TREE_TYPE (value), value, div))
15039 /* If divisor is a power of two, simplify this to bit manipulation. */
15040 if (divisor == (divisor & -divisor))
15044 t = build_int_cst (TREE_TYPE (value), -divisor);
15045 value = size_binop (BIT_AND_EXPR, value, t);
15050 div = build_int_cst (TREE_TYPE (value), divisor);
15051 value = size_binop (FLOOR_DIV_EXPR, value, div);
15052 value = size_binop (MULT_EXPR, value, div);
15058 /* Returns the pointer to the base of the object addressed by EXP and
15059 extracts the information about the offset of the access, storing it
15060 to PBITPOS and POFFSET. */
15063 split_address_to_core_and_offset (tree exp,
15064 HOST_WIDE_INT *pbitpos, tree *poffset)
15067 enum machine_mode mode;
15068 int unsignedp, volatilep;
15069 HOST_WIDE_INT bitsize;
15071 if (TREE_CODE (exp) == ADDR_EXPR)
15073 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
15074 poffset, &mode, &unsignedp, &volatilep,
15076 core = fold_addr_expr (core);
15082 *poffset = NULL_TREE;
15088 /* Returns true if addresses of E1 and E2 differ by a constant, false
15089 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15092 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
15095 HOST_WIDE_INT bitpos1, bitpos2;
15096 tree toffset1, toffset2, tdiff, type;
15098 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
15099 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
15101 if (bitpos1 % BITS_PER_UNIT != 0
15102 || bitpos2 % BITS_PER_UNIT != 0
15103 || !operand_equal_p (core1, core2, 0))
15106 if (toffset1 && toffset2)
15108 type = TREE_TYPE (toffset1);
15109 if (type != TREE_TYPE (toffset2))
15110 toffset2 = fold_convert (type, toffset2);
15112 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
15113 if (!cst_and_fits_in_hwi (tdiff))
15116 *diff = int_cst_value (tdiff);
15118 else if (toffset1 || toffset2)
15120 /* If only one of the offsets is non-constant, the difference cannot
15127 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
15131 /* Simplify the floating point expression EXP when the sign of the
15132 result is not significant. Return NULL_TREE if no simplification
15136 fold_strip_sign_ops (tree exp)
15140 switch (TREE_CODE (exp))
15144 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15145 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
15149 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
15151 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15152 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15153 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
15154 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
15155 arg0 ? arg0 : TREE_OPERAND (exp, 0),
15156 arg1 ? arg1 : TREE_OPERAND (exp, 1));
15159 case COMPOUND_EXPR:
15160 arg0 = TREE_OPERAND (exp, 0);
15161 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15163 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
15167 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15168 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
15170 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
15171 arg0 ? arg0 : TREE_OPERAND (exp, 1),
15172 arg1 ? arg1 : TREE_OPERAND (exp, 2));
15177 const enum built_in_function fcode = builtin_mathfn_code (exp);
15180 CASE_FLT_FN (BUILT_IN_COPYSIGN):
15181 /* Strip copysign function call, return the 1st argument. */
15182 arg0 = CALL_EXPR_ARG (exp, 0);
15183 arg1 = CALL_EXPR_ARG (exp, 1);
15184 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
15187 /* Strip sign ops from the argument of "odd" math functions. */
15188 if (negate_mathfn_p (fcode))
15190 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
15192 return build_call_expr (get_callee_fndecl (exp), 1, arg0);