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 /* Use the smallest code level when deciding to issue the
979 if (code == 0 || code > (int) fold_deferred_overflow_code)
980 code = fold_deferred_overflow_code;
982 if (!issue_strict_overflow_warning (code))
985 if (stmt == NULL_TREE || !expr_has_location (stmt))
986 locus = input_location;
988 locus = expr_location (stmt);
989 warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
992 /* Stop deferring overflow warnings, ignoring any deferred
996 fold_undefer_and_ignore_overflow_warnings (void)
998 fold_undefer_overflow_warnings (false, NULL_TREE, 0);
1001 /* Whether we are deferring overflow warnings. */
1004 fold_deferring_overflow_warnings_p (void)
1006 return fold_deferring_overflow_warnings > 0;
1009 /* This is called when we fold something based on the fact that signed
1010 overflow is undefined. */
1013 fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
1015 gcc_assert (!flag_wrapv && !flag_trapv);
1016 if (fold_deferring_overflow_warnings > 0)
1018 if (fold_deferred_overflow_warning == NULL
1019 || wc < fold_deferred_overflow_code)
1021 fold_deferred_overflow_warning = gmsgid;
1022 fold_deferred_overflow_code = wc;
1025 else if (issue_strict_overflow_warning (wc))
1026 warning (OPT_Wstrict_overflow, gmsgid);
1029 /* Return true if the built-in mathematical function specified by CODE
1030 is odd, i.e. -f(x) == f(-x). */
1033 negate_mathfn_p (enum built_in_function code)
1037 CASE_FLT_FN (BUILT_IN_ASIN):
1038 CASE_FLT_FN (BUILT_IN_ASINH):
1039 CASE_FLT_FN (BUILT_IN_ATAN):
1040 CASE_FLT_FN (BUILT_IN_ATANH):
1041 CASE_FLT_FN (BUILT_IN_CASIN):
1042 CASE_FLT_FN (BUILT_IN_CASINH):
1043 CASE_FLT_FN (BUILT_IN_CATAN):
1044 CASE_FLT_FN (BUILT_IN_CATANH):
1045 CASE_FLT_FN (BUILT_IN_CBRT):
1046 CASE_FLT_FN (BUILT_IN_CPROJ):
1047 CASE_FLT_FN (BUILT_IN_CSIN):
1048 CASE_FLT_FN (BUILT_IN_CSINH):
1049 CASE_FLT_FN (BUILT_IN_CTAN):
1050 CASE_FLT_FN (BUILT_IN_CTANH):
1051 CASE_FLT_FN (BUILT_IN_ERF):
1052 CASE_FLT_FN (BUILT_IN_LLROUND):
1053 CASE_FLT_FN (BUILT_IN_LROUND):
1054 CASE_FLT_FN (BUILT_IN_ROUND):
1055 CASE_FLT_FN (BUILT_IN_SIN):
1056 CASE_FLT_FN (BUILT_IN_SINH):
1057 CASE_FLT_FN (BUILT_IN_TAN):
1058 CASE_FLT_FN (BUILT_IN_TANH):
1059 CASE_FLT_FN (BUILT_IN_TRUNC):
1062 CASE_FLT_FN (BUILT_IN_LLRINT):
1063 CASE_FLT_FN (BUILT_IN_LRINT):
1064 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1065 CASE_FLT_FN (BUILT_IN_RINT):
1066 return !flag_rounding_math;
1074 /* Check whether we may negate an integer constant T without causing
1078 may_negate_without_overflow_p (const_tree t)
1080 unsigned HOST_WIDE_INT val;
1084 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1086 type = TREE_TYPE (t);
1087 if (TYPE_UNSIGNED (type))
1090 prec = TYPE_PRECISION (type);
1091 if (prec > HOST_BITS_PER_WIDE_INT)
1093 if (TREE_INT_CST_LOW (t) != 0)
1095 prec -= HOST_BITS_PER_WIDE_INT;
1096 val = TREE_INT_CST_HIGH (t);
1099 val = TREE_INT_CST_LOW (t);
1100 if (prec < HOST_BITS_PER_WIDE_INT)
1101 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1102 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1105 /* Determine whether an expression T can be cheaply negated using
1106 the function negate_expr without introducing undefined overflow. */
1109 negate_expr_p (tree t)
1116 type = TREE_TYPE (t);
1118 STRIP_SIGN_NOPS (t);
1119 switch (TREE_CODE (t))
1122 if (TYPE_OVERFLOW_WRAPS (type))
1125 /* Check that -CST will not overflow type. */
1126 return may_negate_without_overflow_p (t);
1128 return (INTEGRAL_TYPE_P (type)
1129 && TYPE_OVERFLOW_WRAPS (type));
1137 return negate_expr_p (TREE_REALPART (t))
1138 && negate_expr_p (TREE_IMAGPART (t));
1141 return negate_expr_p (TREE_OPERAND (t, 0))
1142 && negate_expr_p (TREE_OPERAND (t, 1));
1145 return negate_expr_p (TREE_OPERAND (t, 0));
1148 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1149 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1151 /* -(A + B) -> (-B) - A. */
1152 if (negate_expr_p (TREE_OPERAND (t, 1))
1153 && reorder_operands_p (TREE_OPERAND (t, 0),
1154 TREE_OPERAND (t, 1)))
1156 /* -(A + B) -> (-A) - B. */
1157 return negate_expr_p (TREE_OPERAND (t, 0));
1160 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1161 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1162 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1163 && reorder_operands_p (TREE_OPERAND (t, 0),
1164 TREE_OPERAND (t, 1));
1167 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1173 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1174 return negate_expr_p (TREE_OPERAND (t, 1))
1175 || negate_expr_p (TREE_OPERAND (t, 0));
1178 case TRUNC_DIV_EXPR:
1179 case ROUND_DIV_EXPR:
1180 case FLOOR_DIV_EXPR:
1182 case EXACT_DIV_EXPR:
1183 /* In general we can't negate A / B, because if A is INT_MIN and
1184 B is 1, we may turn this into INT_MIN / -1 which is undefined
1185 and actually traps on some architectures. But if overflow is
1186 undefined, we can negate, because - (INT_MIN / 1) is an
1188 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1189 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1191 return negate_expr_p (TREE_OPERAND (t, 1))
1192 || negate_expr_p (TREE_OPERAND (t, 0));
1195 /* Negate -((double)float) as (double)(-float). */
1196 if (TREE_CODE (type) == REAL_TYPE)
1198 tree tem = strip_float_extensions (t);
1200 return negate_expr_p (tem);
1205 /* Negate -f(x) as f(-x). */
1206 if (negate_mathfn_p (builtin_mathfn_code (t)))
1207 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1211 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1212 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1214 tree op1 = TREE_OPERAND (t, 1);
1215 if (TREE_INT_CST_HIGH (op1) == 0
1216 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1217 == TREE_INT_CST_LOW (op1))
1228 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1229 simplification is possible.
1230 If negate_expr_p would return true for T, NULL_TREE will never be
1234 fold_negate_expr (tree t)
1236 tree type = TREE_TYPE (t);
1239 switch (TREE_CODE (t))
1241 /* Convert - (~A) to A + 1. */
1243 if (INTEGRAL_TYPE_P (type))
1244 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1245 build_int_cst (type, 1));
1249 tem = fold_negate_const (t, type);
1250 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1251 || !TYPE_OVERFLOW_TRAPS (type))
1256 tem = fold_negate_const (t, type);
1257 /* Two's complement FP formats, such as c4x, may overflow. */
1258 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1263 tem = fold_negate_const (t, type);
1268 tree rpart = negate_expr (TREE_REALPART (t));
1269 tree ipart = negate_expr (TREE_IMAGPART (t));
1271 if ((TREE_CODE (rpart) == REAL_CST
1272 && TREE_CODE (ipart) == REAL_CST)
1273 || (TREE_CODE (rpart) == INTEGER_CST
1274 && TREE_CODE (ipart) == INTEGER_CST))
1275 return build_complex (type, rpart, ipart);
1280 if (negate_expr_p (t))
1281 return fold_build2 (COMPLEX_EXPR, type,
1282 fold_negate_expr (TREE_OPERAND (t, 0)),
1283 fold_negate_expr (TREE_OPERAND (t, 1)));
1287 if (negate_expr_p (t))
1288 return fold_build1 (CONJ_EXPR, type,
1289 fold_negate_expr (TREE_OPERAND (t, 0)));
1293 return TREE_OPERAND (t, 0);
1296 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1297 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1299 /* -(A + B) -> (-B) - A. */
1300 if (negate_expr_p (TREE_OPERAND (t, 1))
1301 && reorder_operands_p (TREE_OPERAND (t, 0),
1302 TREE_OPERAND (t, 1)))
1304 tem = negate_expr (TREE_OPERAND (t, 1));
1305 return fold_build2 (MINUS_EXPR, type,
1306 tem, TREE_OPERAND (t, 0));
1309 /* -(A + B) -> (-A) - B. */
1310 if (negate_expr_p (TREE_OPERAND (t, 0)))
1312 tem = negate_expr (TREE_OPERAND (t, 0));
1313 return fold_build2 (MINUS_EXPR, type,
1314 tem, TREE_OPERAND (t, 1));
1320 /* - (A - B) -> B - A */
1321 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1322 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1323 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1324 return fold_build2 (MINUS_EXPR, type,
1325 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1329 if (TYPE_UNSIGNED (type))
1335 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1337 tem = TREE_OPERAND (t, 1);
1338 if (negate_expr_p (tem))
1339 return fold_build2 (TREE_CODE (t), type,
1340 TREE_OPERAND (t, 0), negate_expr (tem));
1341 tem = TREE_OPERAND (t, 0);
1342 if (negate_expr_p (tem))
1343 return fold_build2 (TREE_CODE (t), type,
1344 negate_expr (tem), TREE_OPERAND (t, 1));
1348 case TRUNC_DIV_EXPR:
1349 case ROUND_DIV_EXPR:
1350 case FLOOR_DIV_EXPR:
1352 case EXACT_DIV_EXPR:
1353 /* In general we can't negate A / B, because if A is INT_MIN and
1354 B is 1, we may turn this into INT_MIN / -1 which is undefined
1355 and actually traps on some architectures. But if overflow is
1356 undefined, we can negate, because - (INT_MIN / 1) is an
1358 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1360 const char * const warnmsg = G_("assuming signed overflow does not "
1361 "occur when negating a division");
1362 tem = TREE_OPERAND (t, 1);
1363 if (negate_expr_p (tem))
1365 if (INTEGRAL_TYPE_P (type)
1366 && (TREE_CODE (tem) != INTEGER_CST
1367 || integer_onep (tem)))
1368 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1369 return fold_build2 (TREE_CODE (t), type,
1370 TREE_OPERAND (t, 0), negate_expr (tem));
1372 tem = TREE_OPERAND (t, 0);
1373 if (negate_expr_p (tem))
1375 if (INTEGRAL_TYPE_P (type)
1376 && (TREE_CODE (tem) != INTEGER_CST
1377 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1378 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1379 return fold_build2 (TREE_CODE (t), type,
1380 negate_expr (tem), TREE_OPERAND (t, 1));
1386 /* Convert -((double)float) into (double)(-float). */
1387 if (TREE_CODE (type) == REAL_TYPE)
1389 tem = strip_float_extensions (t);
1390 if (tem != t && negate_expr_p (tem))
1391 return fold_convert (type, negate_expr (tem));
1396 /* Negate -f(x) as f(-x). */
1397 if (negate_mathfn_p (builtin_mathfn_code (t))
1398 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1402 fndecl = get_callee_fndecl (t);
1403 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1404 return build_call_expr (fndecl, 1, arg);
1409 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1410 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1412 tree op1 = TREE_OPERAND (t, 1);
1413 if (TREE_INT_CST_HIGH (op1) == 0
1414 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1415 == TREE_INT_CST_LOW (op1))
1417 tree ntype = TYPE_UNSIGNED (type)
1418 ? signed_type_for (type)
1419 : unsigned_type_for (type);
1420 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1421 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1422 return fold_convert (type, temp);
1434 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1435 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1436 return NULL_TREE. */
1439 negate_expr (tree t)
1446 type = TREE_TYPE (t);
1447 STRIP_SIGN_NOPS (t);
1449 tem = fold_negate_expr (t);
1451 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1452 return fold_convert (type, tem);
1455 /* Split a tree IN into a constant, literal and variable parts that could be
1456 combined with CODE to make IN. "constant" means an expression with
1457 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1458 commutative arithmetic operation. Store the constant part into *CONP,
1459 the literal in *LITP and return the variable part. If a part isn't
1460 present, set it to null. If the tree does not decompose in this way,
1461 return the entire tree as the variable part and the other parts as null.
1463 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1464 case, we negate an operand that was subtracted. Except if it is a
1465 literal for which we use *MINUS_LITP instead.
1467 If NEGATE_P is true, we are negating all of IN, again except a literal
1468 for which we use *MINUS_LITP instead.
1470 If IN is itself a literal or constant, return it as appropriate.
1472 Note that we do not guarantee that any of the three values will be the
1473 same type as IN, but they will have the same signedness and mode. */
1476 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1477 tree *minus_litp, int negate_p)
1485 /* Strip any conversions that don't change the machine mode or signedness. */
1486 STRIP_SIGN_NOPS (in);
1488 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
1489 || TREE_CODE (in) == FIXED_CST)
1491 else if (TREE_CODE (in) == code
1492 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1493 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
1494 /* We can associate addition and subtraction together (even
1495 though the C standard doesn't say so) for integers because
1496 the value is not affected. For reals, the value might be
1497 affected, so we can't. */
1498 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1499 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1501 tree op0 = TREE_OPERAND (in, 0);
1502 tree op1 = TREE_OPERAND (in, 1);
1503 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1504 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1506 /* First see if either of the operands is a literal, then a constant. */
1507 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
1508 || TREE_CODE (op0) == FIXED_CST)
1509 *litp = op0, op0 = 0;
1510 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
1511 || TREE_CODE (op1) == FIXED_CST)
1512 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1514 if (op0 != 0 && TREE_CONSTANT (op0))
1515 *conp = op0, op0 = 0;
1516 else if (op1 != 0 && TREE_CONSTANT (op1))
1517 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1519 /* If we haven't dealt with either operand, this is not a case we can
1520 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1521 if (op0 != 0 && op1 != 0)
1526 var = op1, neg_var_p = neg1_p;
1528 /* Now do any needed negations. */
1530 *minus_litp = *litp, *litp = 0;
1532 *conp = negate_expr (*conp);
1534 var = negate_expr (var);
1536 else if (TREE_CONSTANT (in))
1544 *minus_litp = *litp, *litp = 0;
1545 else if (*minus_litp)
1546 *litp = *minus_litp, *minus_litp = 0;
1547 *conp = negate_expr (*conp);
1548 var = negate_expr (var);
1554 /* Re-associate trees split by the above function. T1 and T2 are either
1555 expressions to associate or null. Return the new expression, if any. If
1556 we build an operation, do it in TYPE and with CODE. */
1559 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1566 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1567 try to fold this since we will have infinite recursion. But do
1568 deal with any NEGATE_EXPRs. */
1569 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1570 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1572 if (code == PLUS_EXPR)
1574 if (TREE_CODE (t1) == NEGATE_EXPR)
1575 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1576 fold_convert (type, TREE_OPERAND (t1, 0)));
1577 else if (TREE_CODE (t2) == NEGATE_EXPR)
1578 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1579 fold_convert (type, TREE_OPERAND (t2, 0)));
1580 else if (integer_zerop (t2))
1581 return fold_convert (type, t1);
1583 else if (code == MINUS_EXPR)
1585 if (integer_zerop (t2))
1586 return fold_convert (type, t1);
1589 return build2 (code, type, fold_convert (type, t1),
1590 fold_convert (type, t2));
1593 return fold_build2 (code, type, fold_convert (type, t1),
1594 fold_convert (type, t2));
1597 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1598 for use in int_const_binop, size_binop and size_diffop. */
1601 int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
1603 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1605 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1620 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1621 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1622 && TYPE_MODE (type1) == TYPE_MODE (type2);
1626 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1627 to produce a new constant. Return NULL_TREE if we don't know how
1628 to evaluate CODE at compile-time.
1630 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1633 int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2, int notrunc)
1635 unsigned HOST_WIDE_INT int1l, int2l;
1636 HOST_WIDE_INT int1h, int2h;
1637 unsigned HOST_WIDE_INT low;
1639 unsigned HOST_WIDE_INT garbagel;
1640 HOST_WIDE_INT garbageh;
1642 tree type = TREE_TYPE (arg1);
1643 int uns = TYPE_UNSIGNED (type);
1645 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1648 int1l = TREE_INT_CST_LOW (arg1);
1649 int1h = TREE_INT_CST_HIGH (arg1);
1650 int2l = TREE_INT_CST_LOW (arg2);
1651 int2h = TREE_INT_CST_HIGH (arg2);
1656 low = int1l | int2l, hi = int1h | int2h;
1660 low = int1l ^ int2l, hi = int1h ^ int2h;
1664 low = int1l & int2l, hi = int1h & int2h;
1670 /* It's unclear from the C standard whether shifts can overflow.
1671 The following code ignores overflow; perhaps a C standard
1672 interpretation ruling is needed. */
1673 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1680 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1685 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1689 neg_double (int2l, int2h, &low, &hi);
1690 add_double (int1l, int1h, low, hi, &low, &hi);
1691 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1695 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1698 case TRUNC_DIV_EXPR:
1699 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1700 case EXACT_DIV_EXPR:
1701 /* This is a shortcut for a common special case. */
1702 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1703 && !TREE_OVERFLOW (arg1)
1704 && !TREE_OVERFLOW (arg2)
1705 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1707 if (code == CEIL_DIV_EXPR)
1710 low = int1l / int2l, hi = 0;
1714 /* ... fall through ... */
1716 case ROUND_DIV_EXPR:
1717 if (int2h == 0 && int2l == 0)
1719 if (int2h == 0 && int2l == 1)
1721 low = int1l, hi = int1h;
1724 if (int1l == int2l && int1h == int2h
1725 && ! (int1l == 0 && int1h == 0))
1730 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1731 &low, &hi, &garbagel, &garbageh);
1734 case TRUNC_MOD_EXPR:
1735 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1736 /* This is a shortcut for a common special case. */
1737 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1738 && !TREE_OVERFLOW (arg1)
1739 && !TREE_OVERFLOW (arg2)
1740 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1742 if (code == CEIL_MOD_EXPR)
1744 low = int1l % int2l, hi = 0;
1748 /* ... fall through ... */
1750 case ROUND_MOD_EXPR:
1751 if (int2h == 0 && int2l == 0)
1753 overflow = div_and_round_double (code, uns,
1754 int1l, int1h, int2l, int2h,
1755 &garbagel, &garbageh, &low, &hi);
1761 low = (((unsigned HOST_WIDE_INT) int1h
1762 < (unsigned HOST_WIDE_INT) int2h)
1763 || (((unsigned HOST_WIDE_INT) int1h
1764 == (unsigned HOST_WIDE_INT) int2h)
1767 low = (int1h < int2h
1768 || (int1h == int2h && int1l < int2l));
1770 if (low == (code == MIN_EXPR))
1771 low = int1l, hi = int1h;
1773 low = int2l, hi = int2h;
1782 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1784 /* Propagate overflow flags ourselves. */
1785 if (((!uns || is_sizetype) && overflow)
1786 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1789 TREE_OVERFLOW (t) = 1;
1793 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1794 ((!uns || is_sizetype) && overflow)
1795 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1800 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1801 constant. We assume ARG1 and ARG2 have the same data type, or at least
1802 are the same kind of constant and the same machine mode. Return zero if
1803 combining the constants is not allowed in the current operating mode.
1805 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1808 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1810 /* Sanity check for the recursive cases. */
1817 if (TREE_CODE (arg1) == INTEGER_CST)
1818 return int_const_binop (code, arg1, arg2, notrunc);
1820 if (TREE_CODE (arg1) == REAL_CST)
1822 enum machine_mode mode;
1825 REAL_VALUE_TYPE value;
1826 REAL_VALUE_TYPE result;
1830 /* The following codes are handled by real_arithmetic. */
1845 d1 = TREE_REAL_CST (arg1);
1846 d2 = TREE_REAL_CST (arg2);
1848 type = TREE_TYPE (arg1);
1849 mode = TYPE_MODE (type);
1851 /* Don't perform operation if we honor signaling NaNs and
1852 either operand is a NaN. */
1853 if (HONOR_SNANS (mode)
1854 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1857 /* Don't perform operation if it would raise a division
1858 by zero exception. */
1859 if (code == RDIV_EXPR
1860 && REAL_VALUES_EQUAL (d2, dconst0)
1861 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1864 /* If either operand is a NaN, just return it. Otherwise, set up
1865 for floating-point trap; we return an overflow. */
1866 if (REAL_VALUE_ISNAN (d1))
1868 else if (REAL_VALUE_ISNAN (d2))
1871 inexact = real_arithmetic (&value, code, &d1, &d2);
1872 real_convert (&result, mode, &value);
1874 /* Don't constant fold this floating point operation if
1875 the result has overflowed and flag_trapping_math. */
1876 if (flag_trapping_math
1877 && MODE_HAS_INFINITIES (mode)
1878 && REAL_VALUE_ISINF (result)
1879 && !REAL_VALUE_ISINF (d1)
1880 && !REAL_VALUE_ISINF (d2))
1883 /* Don't constant fold this floating point operation if the
1884 result may dependent upon the run-time rounding mode and
1885 flag_rounding_math is set, or if GCC's software emulation
1886 is unable to accurately represent the result. */
1887 if ((flag_rounding_math
1888 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1889 && !flag_unsafe_math_optimizations))
1890 && (inexact || !real_identical (&result, &value)))
1893 t = build_real (type, result);
1895 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1899 if (TREE_CODE (arg1) == FIXED_CST)
1901 FIXED_VALUE_TYPE f1;
1902 FIXED_VALUE_TYPE f2;
1903 FIXED_VALUE_TYPE result;
1908 /* The following codes are handled by fixed_arithmetic. */
1914 case TRUNC_DIV_EXPR:
1915 f2 = TREE_FIXED_CST (arg2);
1920 f2.data.high = TREE_INT_CST_HIGH (arg2);
1921 f2.data.low = TREE_INT_CST_LOW (arg2);
1929 f1 = TREE_FIXED_CST (arg1);
1930 type = TREE_TYPE (arg1);
1931 sat_p = TYPE_SATURATING (type);
1932 overflow_p = fixed_arithmetic (&result, code, &f1, &f2, sat_p);
1933 t = build_fixed (type, result);
1934 /* Propagate overflow flags. */
1935 if (overflow_p | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1937 TREE_OVERFLOW (t) = 1;
1938 TREE_CONSTANT_OVERFLOW (t) = 1;
1940 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1941 TREE_CONSTANT_OVERFLOW (t) = 1;
1945 if (TREE_CODE (arg1) == COMPLEX_CST)
1947 tree type = TREE_TYPE (arg1);
1948 tree r1 = TREE_REALPART (arg1);
1949 tree i1 = TREE_IMAGPART (arg1);
1950 tree r2 = TREE_REALPART (arg2);
1951 tree i2 = TREE_IMAGPART (arg2);
1958 real = const_binop (code, r1, r2, notrunc);
1959 imag = const_binop (code, i1, i2, notrunc);
1963 real = const_binop (MINUS_EXPR,
1964 const_binop (MULT_EXPR, r1, r2, notrunc),
1965 const_binop (MULT_EXPR, i1, i2, notrunc),
1967 imag = const_binop (PLUS_EXPR,
1968 const_binop (MULT_EXPR, r1, i2, notrunc),
1969 const_binop (MULT_EXPR, i1, r2, notrunc),
1976 = const_binop (PLUS_EXPR,
1977 const_binop (MULT_EXPR, r2, r2, notrunc),
1978 const_binop (MULT_EXPR, i2, i2, notrunc),
1981 = const_binop (PLUS_EXPR,
1982 const_binop (MULT_EXPR, r1, r2, notrunc),
1983 const_binop (MULT_EXPR, i1, i2, notrunc),
1986 = const_binop (MINUS_EXPR,
1987 const_binop (MULT_EXPR, i1, r2, notrunc),
1988 const_binop (MULT_EXPR, r1, i2, notrunc),
1991 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1992 code = TRUNC_DIV_EXPR;
1994 real = const_binop (code, t1, magsquared, notrunc);
1995 imag = const_binop (code, t2, magsquared, notrunc);
2004 return build_complex (type, real, imag);
2010 /* Create a size type INT_CST node with NUMBER sign extended. KIND
2011 indicates which particular sizetype to create. */
2014 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
2016 return build_int_cst (sizetype_tab[(int) kind], number);
2019 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2020 is a tree code. The type of the result is taken from the operands.
2021 Both must be equivalent integer types, ala int_binop_types_match_p.
2022 If the operands are constant, so is the result. */
2025 size_binop (enum tree_code code, tree arg0, tree arg1)
2027 tree type = TREE_TYPE (arg0);
2029 if (arg0 == error_mark_node || arg1 == error_mark_node)
2030 return error_mark_node;
2032 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
2035 /* Handle the special case of two integer constants faster. */
2036 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
2038 /* And some specific cases even faster than that. */
2039 if (code == PLUS_EXPR)
2041 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
2043 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2046 else if (code == MINUS_EXPR)
2048 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2051 else if (code == MULT_EXPR)
2053 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
2057 /* Handle general case of two integer constants. */
2058 return int_const_binop (code, arg0, arg1, 0);
2061 return fold_build2 (code, type, arg0, arg1);
2064 /* Given two values, either both of sizetype or both of bitsizetype,
2065 compute the difference between the two values. Return the value
2066 in signed type corresponding to the type of the operands. */
2069 size_diffop (tree arg0, tree arg1)
2071 tree type = TREE_TYPE (arg0);
2074 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
2077 /* If the type is already signed, just do the simple thing. */
2078 if (!TYPE_UNSIGNED (type))
2079 return size_binop (MINUS_EXPR, arg0, arg1);
2081 if (type == sizetype)
2083 else if (type == bitsizetype)
2084 ctype = sbitsizetype;
2086 ctype = signed_type_for (type);
2088 /* If either operand is not a constant, do the conversions to the signed
2089 type and subtract. The hardware will do the right thing with any
2090 overflow in the subtraction. */
2091 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2092 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
2093 fold_convert (ctype, arg1));
2095 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2096 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2097 overflow) and negate (which can't either). Special-case a result
2098 of zero while we're here. */
2099 if (tree_int_cst_equal (arg0, arg1))
2100 return build_int_cst (ctype, 0);
2101 else if (tree_int_cst_lt (arg1, arg0))
2102 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2104 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
2105 fold_convert (ctype, size_binop (MINUS_EXPR,
2109 /* A subroutine of fold_convert_const handling conversions of an
2110 INTEGER_CST to another integer type. */
2113 fold_convert_const_int_from_int (tree type, const_tree arg1)
2117 /* Given an integer constant, make new constant with new type,
2118 appropriately sign-extended or truncated. */
2119 t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
2120 TREE_INT_CST_HIGH (arg1),
2121 /* Don't set the overflow when
2122 converting a pointer */
2123 !POINTER_TYPE_P (TREE_TYPE (arg1)),
2124 (TREE_INT_CST_HIGH (arg1) < 0
2125 && (TYPE_UNSIGNED (type)
2126 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2127 | TREE_OVERFLOW (arg1));
2132 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2133 to an integer type. */
2136 fold_convert_const_int_from_real (enum tree_code code, tree type, const_tree arg1)
2141 /* The following code implements the floating point to integer
2142 conversion rules required by the Java Language Specification,
2143 that IEEE NaNs are mapped to zero and values that overflow
2144 the target precision saturate, i.e. values greater than
2145 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2146 are mapped to INT_MIN. These semantics are allowed by the
2147 C and C++ standards that simply state that the behavior of
2148 FP-to-integer conversion is unspecified upon overflow. */
2150 HOST_WIDE_INT high, low;
2152 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2156 case FIX_TRUNC_EXPR:
2157 real_trunc (&r, VOIDmode, &x);
2164 /* If R is NaN, return zero and show we have an overflow. */
2165 if (REAL_VALUE_ISNAN (r))
2172 /* See if R is less than the lower bound or greater than the
2177 tree lt = TYPE_MIN_VALUE (type);
2178 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2179 if (REAL_VALUES_LESS (r, l))
2182 high = TREE_INT_CST_HIGH (lt);
2183 low = TREE_INT_CST_LOW (lt);
2189 tree ut = TYPE_MAX_VALUE (type);
2192 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2193 if (REAL_VALUES_LESS (u, r))
2196 high = TREE_INT_CST_HIGH (ut);
2197 low = TREE_INT_CST_LOW (ut);
2203 REAL_VALUE_TO_INT (&low, &high, r);
2205 t = force_fit_type_double (type, low, high, -1,
2206 overflow | TREE_OVERFLOW (arg1));
2210 /* A subroutine of fold_convert_const handling conversions of a
2211 FIXED_CST to an integer type. */
2214 fold_convert_const_int_from_fixed (tree type, const_tree arg1)
2217 double_int temp, temp_trunc;
2220 /* Right shift FIXED_CST to temp by fbit. */
2221 temp = TREE_FIXED_CST (arg1).data;
2222 mode = TREE_FIXED_CST (arg1).mode;
2223 if (GET_MODE_FBIT (mode) < 2 * HOST_BITS_PER_WIDE_INT)
2225 lshift_double (temp.low, temp.high,
2226 - GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2227 &temp.low, &temp.high, SIGNED_FIXED_POINT_MODE_P (mode));
2229 /* Left shift temp to temp_trunc by fbit. */
2230 lshift_double (temp.low, temp.high,
2231 GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2232 &temp_trunc.low, &temp_trunc.high,
2233 SIGNED_FIXED_POINT_MODE_P (mode));
2240 temp_trunc.high = 0;
2243 /* If FIXED_CST is negative, we need to round the value toward 0.
2244 By checking if the fractional bits are not zero to add 1 to temp. */
2245 if (SIGNED_FIXED_POINT_MODE_P (mode) && temp_trunc.high < 0
2246 && !double_int_equal_p (TREE_FIXED_CST (arg1).data, temp_trunc))
2251 temp = double_int_add (temp, one);
2254 /* Given a fixed-point constant, make new constant with new type,
2255 appropriately sign-extended or truncated. */
2256 t = force_fit_type_double (type, temp.low, temp.high, -1,
2258 && (TYPE_UNSIGNED (type)
2259 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2260 | TREE_OVERFLOW (arg1));
2265 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2266 to another floating point type. */
2269 fold_convert_const_real_from_real (tree type, const_tree arg1)
2271 REAL_VALUE_TYPE value;
2274 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2275 t = build_real (type, value);
2277 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2281 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2282 to a floating point type. */
2285 fold_convert_const_real_from_fixed (tree type, const_tree arg1)
2287 REAL_VALUE_TYPE value;
2290 real_convert_from_fixed (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1));
2291 t = build_real (type, value);
2293 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2294 TREE_CONSTANT_OVERFLOW (t)
2295 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2299 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2300 to another fixed-point type. */
2303 fold_convert_const_fixed_from_fixed (tree type, const_tree arg1)
2305 FIXED_VALUE_TYPE value;
2309 overflow_p = fixed_convert (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1),
2310 TYPE_SATURATING (type));
2311 t = build_fixed (type, value);
2313 /* Propagate overflow flags. */
2314 if (overflow_p | TREE_OVERFLOW (arg1))
2316 TREE_OVERFLOW (t) = 1;
2317 TREE_CONSTANT_OVERFLOW (t) = 1;
2319 else if (TREE_CONSTANT_OVERFLOW (arg1))
2320 TREE_CONSTANT_OVERFLOW (t) = 1;
2324 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2325 to a fixed-point type. */
2328 fold_convert_const_fixed_from_int (tree type, const_tree arg1)
2330 FIXED_VALUE_TYPE value;
2334 overflow_p = fixed_convert_from_int (&value, TYPE_MODE (type),
2335 TREE_INT_CST (arg1),
2336 TYPE_UNSIGNED (TREE_TYPE (arg1)),
2337 TYPE_SATURATING (type));
2338 t = build_fixed (type, value);
2340 /* Propagate overflow flags. */
2341 if (overflow_p | TREE_OVERFLOW (arg1))
2343 TREE_OVERFLOW (t) = 1;
2344 TREE_CONSTANT_OVERFLOW (t) = 1;
2346 else if (TREE_CONSTANT_OVERFLOW (arg1))
2347 TREE_CONSTANT_OVERFLOW (t) = 1;
2351 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2352 to a fixed-point type. */
2355 fold_convert_const_fixed_from_real (tree type, const_tree arg1)
2357 FIXED_VALUE_TYPE value;
2361 overflow_p = fixed_convert_from_real (&value, TYPE_MODE (type),
2362 &TREE_REAL_CST (arg1),
2363 TYPE_SATURATING (type));
2364 t = build_fixed (type, value);
2366 /* Propagate overflow flags. */
2367 if (overflow_p | TREE_OVERFLOW (arg1))
2369 TREE_OVERFLOW (t) = 1;
2370 TREE_CONSTANT_OVERFLOW (t) = 1;
2372 else if (TREE_CONSTANT_OVERFLOW (arg1))
2373 TREE_CONSTANT_OVERFLOW (t) = 1;
2377 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2378 type TYPE. If no simplification can be done return NULL_TREE. */
2381 fold_convert_const (enum tree_code code, tree type, tree arg1)
2383 if (TREE_TYPE (arg1) == type)
2386 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2388 if (TREE_CODE (arg1) == INTEGER_CST)
2389 return fold_convert_const_int_from_int (type, arg1);
2390 else if (TREE_CODE (arg1) == REAL_CST)
2391 return fold_convert_const_int_from_real (code, type, arg1);
2392 else if (TREE_CODE (arg1) == FIXED_CST)
2393 return fold_convert_const_int_from_fixed (type, arg1);
2395 else if (TREE_CODE (type) == REAL_TYPE)
2397 if (TREE_CODE (arg1) == INTEGER_CST)
2398 return build_real_from_int_cst (type, arg1);
2399 else if (TREE_CODE (arg1) == REAL_CST)
2400 return fold_convert_const_real_from_real (type, arg1);
2401 else if (TREE_CODE (arg1) == FIXED_CST)
2402 return fold_convert_const_real_from_fixed (type, arg1);
2404 else if (TREE_CODE (type) == FIXED_POINT_TYPE)
2406 if (TREE_CODE (arg1) == FIXED_CST)
2407 return fold_convert_const_fixed_from_fixed (type, arg1);
2408 else if (TREE_CODE (arg1) == INTEGER_CST)
2409 return fold_convert_const_fixed_from_int (type, arg1);
2410 else if (TREE_CODE (arg1) == REAL_CST)
2411 return fold_convert_const_fixed_from_real (type, arg1);
2416 /* Construct a vector of zero elements of vector type TYPE. */
2419 build_zero_vector (tree type)
2424 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2425 units = TYPE_VECTOR_SUBPARTS (type);
2428 for (i = 0; i < units; i++)
2429 list = tree_cons (NULL_TREE, elem, list);
2430 return build_vector (type, list);
2433 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2436 fold_convertible_p (const_tree type, const_tree arg)
2438 tree orig = TREE_TYPE (arg);
2443 if (TREE_CODE (arg) == ERROR_MARK
2444 || TREE_CODE (type) == ERROR_MARK
2445 || TREE_CODE (orig) == ERROR_MARK)
2448 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2451 switch (TREE_CODE (type))
2453 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2454 case POINTER_TYPE: case REFERENCE_TYPE:
2456 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2457 || TREE_CODE (orig) == OFFSET_TYPE)
2459 return (TREE_CODE (orig) == VECTOR_TYPE
2460 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2463 return TREE_CODE (type) == TREE_CODE (orig);
2467 /* Convert expression ARG to type TYPE. Used by the middle-end for
2468 simple conversions in preference to calling the front-end's convert. */
2471 fold_convert (tree type, tree arg)
2473 tree orig = TREE_TYPE (arg);
2479 if (TREE_CODE (arg) == ERROR_MARK
2480 || TREE_CODE (type) == ERROR_MARK
2481 || TREE_CODE (orig) == ERROR_MARK)
2482 return error_mark_node;
2484 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2485 return fold_build1 (NOP_EXPR, type, arg);
2487 switch (TREE_CODE (type))
2489 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2490 case POINTER_TYPE: case REFERENCE_TYPE:
2492 if (TREE_CODE (arg) == INTEGER_CST)
2494 tem = fold_convert_const (NOP_EXPR, type, arg);
2495 if (tem != NULL_TREE)
2498 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2499 || TREE_CODE (orig) == OFFSET_TYPE)
2500 return fold_build1 (NOP_EXPR, type, arg);
2501 if (TREE_CODE (orig) == COMPLEX_TYPE)
2503 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2504 return fold_convert (type, tem);
2506 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2507 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2508 return fold_build1 (NOP_EXPR, type, arg);
2511 if (TREE_CODE (arg) == INTEGER_CST)
2513 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2514 if (tem != NULL_TREE)
2517 else if (TREE_CODE (arg) == REAL_CST)
2519 tem = fold_convert_const (NOP_EXPR, type, arg);
2520 if (tem != NULL_TREE)
2523 else if (TREE_CODE (arg) == FIXED_CST)
2525 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2526 if (tem != NULL_TREE)
2530 switch (TREE_CODE (orig))
2533 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2534 case POINTER_TYPE: case REFERENCE_TYPE:
2535 return fold_build1 (FLOAT_EXPR, type, arg);
2538 return fold_build1 (NOP_EXPR, type, arg);
2540 case FIXED_POINT_TYPE:
2541 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2544 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2545 return fold_convert (type, tem);
2551 case FIXED_POINT_TYPE:
2552 if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
2553 || TREE_CODE (arg) == REAL_CST)
2555 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2556 if (tem != NULL_TREE)
2560 switch (TREE_CODE (orig))
2562 case FIXED_POINT_TYPE:
2567 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2570 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2571 return fold_convert (type, tem);
2578 switch (TREE_CODE (orig))
2581 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2582 case POINTER_TYPE: case REFERENCE_TYPE:
2584 case FIXED_POINT_TYPE:
2585 return build2 (COMPLEX_EXPR, type,
2586 fold_convert (TREE_TYPE (type), arg),
2587 fold_convert (TREE_TYPE (type), integer_zero_node));
2592 if (TREE_CODE (arg) == COMPLEX_EXPR)
2594 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2595 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2596 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2599 arg = save_expr (arg);
2600 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2601 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2602 rpart = fold_convert (TREE_TYPE (type), rpart);
2603 ipart = fold_convert (TREE_TYPE (type), ipart);
2604 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2612 if (integer_zerop (arg))
2613 return build_zero_vector (type);
2614 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2615 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2616 || TREE_CODE (orig) == VECTOR_TYPE);
2617 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2620 tem = fold_ignored_result (arg);
2621 if (TREE_CODE (tem) == GIMPLE_MODIFY_STMT)
2623 return fold_build1 (NOP_EXPR, type, tem);
2630 /* Return false if expr can be assumed not to be an lvalue, true
2634 maybe_lvalue_p (const_tree x)
2636 /* We only need to wrap lvalue tree codes. */
2637 switch (TREE_CODE (x))
2648 case ALIGN_INDIRECT_REF:
2649 case MISALIGNED_INDIRECT_REF:
2651 case ARRAY_RANGE_REF:
2657 case PREINCREMENT_EXPR:
2658 case PREDECREMENT_EXPR:
2660 case TRY_CATCH_EXPR:
2661 case WITH_CLEANUP_EXPR:
2664 case GIMPLE_MODIFY_STMT:
2673 /* Assume the worst for front-end tree codes. */
2674 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2682 /* Return an expr equal to X but certainly not valid as an lvalue. */
2687 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2692 if (! maybe_lvalue_p (x))
2694 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2697 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2698 Zero means allow extended lvalues. */
2700 int pedantic_lvalues;
2702 /* When pedantic, return an expr equal to X but certainly not valid as a
2703 pedantic lvalue. Otherwise, return X. */
2706 pedantic_non_lvalue (tree x)
2708 if (pedantic_lvalues)
2709 return non_lvalue (x);
2714 /* Given a tree comparison code, return the code that is the logical inverse
2715 of the given code. It is not safe to do this for floating-point
2716 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2717 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2720 invert_tree_comparison (enum tree_code code, bool honor_nans)
2722 if (honor_nans && flag_trapping_math)
2732 return honor_nans ? UNLE_EXPR : LE_EXPR;
2734 return honor_nans ? UNLT_EXPR : LT_EXPR;
2736 return honor_nans ? UNGE_EXPR : GE_EXPR;
2738 return honor_nans ? UNGT_EXPR : GT_EXPR;
2752 return UNORDERED_EXPR;
2753 case UNORDERED_EXPR:
2754 return ORDERED_EXPR;
2760 /* Similar, but return the comparison that results if the operands are
2761 swapped. This is safe for floating-point. */
2764 swap_tree_comparison (enum tree_code code)
2771 case UNORDERED_EXPR:
2797 /* Convert a comparison tree code from an enum tree_code representation
2798 into a compcode bit-based encoding. This function is the inverse of
2799 compcode_to_comparison. */
2801 static enum comparison_code
2802 comparison_to_compcode (enum tree_code code)
2819 return COMPCODE_ORD;
2820 case UNORDERED_EXPR:
2821 return COMPCODE_UNORD;
2823 return COMPCODE_UNLT;
2825 return COMPCODE_UNEQ;
2827 return COMPCODE_UNLE;
2829 return COMPCODE_UNGT;
2831 return COMPCODE_LTGT;
2833 return COMPCODE_UNGE;
2839 /* Convert a compcode bit-based encoding of a comparison operator back
2840 to GCC's enum tree_code representation. This function is the
2841 inverse of comparison_to_compcode. */
2843 static enum tree_code
2844 compcode_to_comparison (enum comparison_code code)
2861 return ORDERED_EXPR;
2862 case COMPCODE_UNORD:
2863 return UNORDERED_EXPR;
2881 /* Return a tree for the comparison which is the combination of
2882 doing the AND or OR (depending on CODE) of the two operations LCODE
2883 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2884 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2885 if this makes the transformation invalid. */
2888 combine_comparisons (enum tree_code code, enum tree_code lcode,
2889 enum tree_code rcode, tree truth_type,
2890 tree ll_arg, tree lr_arg)
2892 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2893 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2894 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2895 enum comparison_code compcode;
2899 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2900 compcode = lcompcode & rcompcode;
2903 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2904 compcode = lcompcode | rcompcode;
2913 /* Eliminate unordered comparisons, as well as LTGT and ORD
2914 which are not used unless the mode has NaNs. */
2915 compcode &= ~COMPCODE_UNORD;
2916 if (compcode == COMPCODE_LTGT)
2917 compcode = COMPCODE_NE;
2918 else if (compcode == COMPCODE_ORD)
2919 compcode = COMPCODE_TRUE;
2921 else if (flag_trapping_math)
2923 /* Check that the original operation and the optimized ones will trap
2924 under the same condition. */
2925 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2926 && (lcompcode != COMPCODE_EQ)
2927 && (lcompcode != COMPCODE_ORD);
2928 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2929 && (rcompcode != COMPCODE_EQ)
2930 && (rcompcode != COMPCODE_ORD);
2931 bool trap = (compcode & COMPCODE_UNORD) == 0
2932 && (compcode != COMPCODE_EQ)
2933 && (compcode != COMPCODE_ORD);
2935 /* In a short-circuited boolean expression the LHS might be
2936 such that the RHS, if evaluated, will never trap. For
2937 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2938 if neither x nor y is NaN. (This is a mixed blessing: for
2939 example, the expression above will never trap, hence
2940 optimizing it to x < y would be invalid). */
2941 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2942 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2945 /* If the comparison was short-circuited, and only the RHS
2946 trapped, we may now generate a spurious trap. */
2948 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2951 /* If we changed the conditions that cause a trap, we lose. */
2952 if ((ltrap || rtrap) != trap)
2956 if (compcode == COMPCODE_TRUE)
2957 return constant_boolean_node (true, truth_type);
2958 else if (compcode == COMPCODE_FALSE)
2959 return constant_boolean_node (false, truth_type);
2961 return fold_build2 (compcode_to_comparison (compcode),
2962 truth_type, ll_arg, lr_arg);
2965 /* Return nonzero if CODE is a tree code that represents a truth value. */
2968 truth_value_p (enum tree_code code)
2970 return (TREE_CODE_CLASS (code) == tcc_comparison
2971 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2972 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2973 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2976 /* Return nonzero if two operands (typically of the same tree node)
2977 are necessarily equal. If either argument has side-effects this
2978 function returns zero. FLAGS modifies behavior as follows:
2980 If OEP_ONLY_CONST is set, only return nonzero for constants.
2981 This function tests whether the operands are indistinguishable;
2982 it does not test whether they are equal using C's == operation.
2983 The distinction is important for IEEE floating point, because
2984 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2985 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2987 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2988 even though it may hold multiple values during a function.
2989 This is because a GCC tree node guarantees that nothing else is
2990 executed between the evaluation of its "operands" (which may often
2991 be evaluated in arbitrary order). Hence if the operands themselves
2992 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2993 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2994 unset means assuming isochronic (or instantaneous) tree equivalence.
2995 Unless comparing arbitrary expression trees, such as from different
2996 statements, this flag can usually be left unset.
2998 If OEP_PURE_SAME is set, then pure functions with identical arguments
2999 are considered the same. It is used when the caller has other ways
3000 to ensure that global memory is unchanged in between. */
3003 operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
3005 /* If either is ERROR_MARK, they aren't equal. */
3006 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
3009 /* If both types don't have the same signedness, then we can't consider
3010 them equal. We must check this before the STRIP_NOPS calls
3011 because they may change the signedness of the arguments. */
3012 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3015 /* If both types don't have the same precision, then it is not safe
3017 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
3023 /* In case both args are comparisons but with different comparison
3024 code, try to swap the comparison operands of one arg to produce
3025 a match and compare that variant. */
3026 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3027 && COMPARISON_CLASS_P (arg0)
3028 && COMPARISON_CLASS_P (arg1))
3030 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
3032 if (TREE_CODE (arg0) == swap_code)
3033 return operand_equal_p (TREE_OPERAND (arg0, 0),
3034 TREE_OPERAND (arg1, 1), flags)
3035 && operand_equal_p (TREE_OPERAND (arg0, 1),
3036 TREE_OPERAND (arg1, 0), flags);
3039 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3040 /* This is needed for conversions and for COMPONENT_REF.
3041 Might as well play it safe and always test this. */
3042 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
3043 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
3044 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
3047 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3048 We don't care about side effects in that case because the SAVE_EXPR
3049 takes care of that for us. In all other cases, two expressions are
3050 equal if they have no side effects. If we have two identical
3051 expressions with side effects that should be treated the same due
3052 to the only side effects being identical SAVE_EXPR's, that will
3053 be detected in the recursive calls below. */
3054 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
3055 && (TREE_CODE (arg0) == SAVE_EXPR
3056 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
3059 /* Next handle constant cases, those for which we can return 1 even
3060 if ONLY_CONST is set. */
3061 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
3062 switch (TREE_CODE (arg0))
3065 return tree_int_cst_equal (arg0, arg1);
3068 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
3069 TREE_FIXED_CST (arg1));
3072 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
3073 TREE_REAL_CST (arg1)))
3077 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
3079 /* If we do not distinguish between signed and unsigned zero,
3080 consider them equal. */
3081 if (real_zerop (arg0) && real_zerop (arg1))
3090 v1 = TREE_VECTOR_CST_ELTS (arg0);
3091 v2 = TREE_VECTOR_CST_ELTS (arg1);
3094 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
3097 v1 = TREE_CHAIN (v1);
3098 v2 = TREE_CHAIN (v2);
3105 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
3107 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
3111 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
3112 && ! memcmp (TREE_STRING_POINTER (arg0),
3113 TREE_STRING_POINTER (arg1),
3114 TREE_STRING_LENGTH (arg0)));
3117 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
3123 if (flags & OEP_ONLY_CONST)
3126 /* Define macros to test an operand from arg0 and arg1 for equality and a
3127 variant that allows null and views null as being different from any
3128 non-null value. In the latter case, if either is null, the both
3129 must be; otherwise, do the normal comparison. */
3130 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3131 TREE_OPERAND (arg1, N), flags)
3133 #define OP_SAME_WITH_NULL(N) \
3134 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3135 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3137 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
3140 /* Two conversions are equal only if signedness and modes match. */
3141 switch (TREE_CODE (arg0))
3145 case FIX_TRUNC_EXPR:
3146 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
3147 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3157 case tcc_comparison:
3159 if (OP_SAME (0) && OP_SAME (1))
3162 /* For commutative ops, allow the other order. */
3163 return (commutative_tree_code (TREE_CODE (arg0))
3164 && operand_equal_p (TREE_OPERAND (arg0, 0),
3165 TREE_OPERAND (arg1, 1), flags)
3166 && operand_equal_p (TREE_OPERAND (arg0, 1),
3167 TREE_OPERAND (arg1, 0), flags));
3170 /* If either of the pointer (or reference) expressions we are
3171 dereferencing contain a side effect, these cannot be equal. */
3172 if (TREE_SIDE_EFFECTS (arg0)
3173 || TREE_SIDE_EFFECTS (arg1))
3176 switch (TREE_CODE (arg0))
3179 case ALIGN_INDIRECT_REF:
3180 case MISALIGNED_INDIRECT_REF:
3186 case ARRAY_RANGE_REF:
3187 /* Operands 2 and 3 may be null.
3188 Compare the array index by value if it is constant first as we
3189 may have different types but same value here. */
3191 && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
3192 TREE_OPERAND (arg1, 1))
3194 && OP_SAME_WITH_NULL (2)
3195 && OP_SAME_WITH_NULL (3));
3198 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3199 may be NULL when we're called to compare MEM_EXPRs. */
3200 return OP_SAME_WITH_NULL (0)
3202 && OP_SAME_WITH_NULL (2);
3205 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3211 case tcc_expression:
3212 switch (TREE_CODE (arg0))
3215 case TRUTH_NOT_EXPR:
3218 case TRUTH_ANDIF_EXPR:
3219 case TRUTH_ORIF_EXPR:
3220 return OP_SAME (0) && OP_SAME (1);
3222 case TRUTH_AND_EXPR:
3224 case TRUTH_XOR_EXPR:
3225 if (OP_SAME (0) && OP_SAME (1))
3228 /* Otherwise take into account this is a commutative operation. */
3229 return (operand_equal_p (TREE_OPERAND (arg0, 0),
3230 TREE_OPERAND (arg1, 1), flags)
3231 && operand_equal_p (TREE_OPERAND (arg0, 1),
3232 TREE_OPERAND (arg1, 0), flags));
3239 switch (TREE_CODE (arg0))
3242 /* If the CALL_EXPRs call different functions, then they
3243 clearly can not be equal. */
3244 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
3249 unsigned int cef = call_expr_flags (arg0);
3250 if (flags & OEP_PURE_SAME)
3251 cef &= ECF_CONST | ECF_PURE;
3258 /* Now see if all the arguments are the same. */
3260 const_call_expr_arg_iterator iter0, iter1;
3262 for (a0 = first_const_call_expr_arg (arg0, &iter0),
3263 a1 = first_const_call_expr_arg (arg1, &iter1);
3265 a0 = next_const_call_expr_arg (&iter0),
3266 a1 = next_const_call_expr_arg (&iter1))
3267 if (! operand_equal_p (a0, a1, flags))
3270 /* If we get here and both argument lists are exhausted
3271 then the CALL_EXPRs are equal. */
3272 return ! (a0 || a1);
3278 case tcc_declaration:
3279 /* Consider __builtin_sqrt equal to sqrt. */
3280 return (TREE_CODE (arg0) == FUNCTION_DECL
3281 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
3282 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
3283 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
3290 #undef OP_SAME_WITH_NULL
3293 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3294 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3296 When in doubt, return 0. */
3299 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
3301 int unsignedp1, unsignedpo;
3302 tree primarg0, primarg1, primother;
3303 unsigned int correct_width;
3305 if (operand_equal_p (arg0, arg1, 0))
3308 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3309 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3312 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3313 and see if the inner values are the same. This removes any
3314 signedness comparison, which doesn't matter here. */
3315 primarg0 = arg0, primarg1 = arg1;
3316 STRIP_NOPS (primarg0);
3317 STRIP_NOPS (primarg1);
3318 if (operand_equal_p (primarg0, primarg1, 0))
3321 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3322 actual comparison operand, ARG0.
3324 First throw away any conversions to wider types
3325 already present in the operands. */
3327 primarg1 = get_narrower (arg1, &unsignedp1);
3328 primother = get_narrower (other, &unsignedpo);
3330 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3331 if (unsignedp1 == unsignedpo
3332 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3333 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3335 tree type = TREE_TYPE (arg0);
3337 /* Make sure shorter operand is extended the right way
3338 to match the longer operand. */
3339 primarg1 = fold_convert (signed_or_unsigned_type_for
3340 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3342 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3349 /* See if ARG is an expression that is either a comparison or is performing
3350 arithmetic on comparisons. The comparisons must only be comparing
3351 two different values, which will be stored in *CVAL1 and *CVAL2; if
3352 they are nonzero it means that some operands have already been found.
3353 No variables may be used anywhere else in the expression except in the
3354 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3355 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3357 If this is true, return 1. Otherwise, return zero. */
3360 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3362 enum tree_code code = TREE_CODE (arg);
3363 enum tree_code_class class = TREE_CODE_CLASS (code);
3365 /* We can handle some of the tcc_expression cases here. */
3366 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3368 else if (class == tcc_expression
3369 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3370 || code == COMPOUND_EXPR))
3373 else if (class == tcc_expression && code == SAVE_EXPR
3374 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3376 /* If we've already found a CVAL1 or CVAL2, this expression is
3377 two complex to handle. */
3378 if (*cval1 || *cval2)
3388 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3391 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3392 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3393 cval1, cval2, save_p));
3398 case tcc_expression:
3399 if (code == COND_EXPR)
3400 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3401 cval1, cval2, save_p)
3402 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3403 cval1, cval2, save_p)
3404 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3405 cval1, cval2, save_p));
3408 case tcc_comparison:
3409 /* First see if we can handle the first operand, then the second. For
3410 the second operand, we know *CVAL1 can't be zero. It must be that
3411 one side of the comparison is each of the values; test for the
3412 case where this isn't true by failing if the two operands
3415 if (operand_equal_p (TREE_OPERAND (arg, 0),
3416 TREE_OPERAND (arg, 1), 0))
3420 *cval1 = TREE_OPERAND (arg, 0);
3421 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3423 else if (*cval2 == 0)
3424 *cval2 = TREE_OPERAND (arg, 0);
3425 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3430 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3432 else if (*cval2 == 0)
3433 *cval2 = TREE_OPERAND (arg, 1);
3434 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3446 /* ARG is a tree that is known to contain just arithmetic operations and
3447 comparisons. Evaluate the operations in the tree substituting NEW0 for
3448 any occurrence of OLD0 as an operand of a comparison and likewise for
3452 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3454 tree type = TREE_TYPE (arg);
3455 enum tree_code code = TREE_CODE (arg);
3456 enum tree_code_class class = TREE_CODE_CLASS (code);
3458 /* We can handle some of the tcc_expression cases here. */
3459 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3461 else if (class == tcc_expression
3462 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3468 return fold_build1 (code, type,
3469 eval_subst (TREE_OPERAND (arg, 0),
3470 old0, new0, old1, new1));
3473 return fold_build2 (code, type,
3474 eval_subst (TREE_OPERAND (arg, 0),
3475 old0, new0, old1, new1),
3476 eval_subst (TREE_OPERAND (arg, 1),
3477 old0, new0, old1, new1));
3479 case tcc_expression:
3483 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3486 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3489 return fold_build3 (code, type,
3490 eval_subst (TREE_OPERAND (arg, 0),
3491 old0, new0, old1, new1),
3492 eval_subst (TREE_OPERAND (arg, 1),
3493 old0, new0, old1, new1),
3494 eval_subst (TREE_OPERAND (arg, 2),
3495 old0, new0, old1, new1));
3499 /* Fall through - ??? */
3501 case tcc_comparison:
3503 tree arg0 = TREE_OPERAND (arg, 0);
3504 tree arg1 = TREE_OPERAND (arg, 1);
3506 /* We need to check both for exact equality and tree equality. The
3507 former will be true if the operand has a side-effect. In that
3508 case, we know the operand occurred exactly once. */
3510 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3512 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3515 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3517 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3520 return fold_build2 (code, type, arg0, arg1);
3528 /* Return a tree for the case when the result of an expression is RESULT
3529 converted to TYPE and OMITTED was previously an operand of the expression
3530 but is now not needed (e.g., we folded OMITTED * 0).
3532 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3533 the conversion of RESULT to TYPE. */
3536 omit_one_operand (tree type, tree result, tree omitted)
3538 tree t = fold_convert (type, result);
3540 /* If the resulting operand is an empty statement, just return the omitted
3541 statement casted to void. */
3542 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3543 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3545 if (TREE_SIDE_EFFECTS (omitted))
3546 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3548 return non_lvalue (t);
3551 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3554 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3556 tree t = fold_convert (type, result);
3558 /* If the resulting operand is an empty statement, just return the omitted
3559 statement casted to void. */
3560 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3561 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3563 if (TREE_SIDE_EFFECTS (omitted))
3564 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3566 return pedantic_non_lvalue (t);
3569 /* Return a tree for the case when the result of an expression is RESULT
3570 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3571 of the expression but are now not needed.
3573 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3574 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3575 evaluated before OMITTED2. Otherwise, if neither has side effects,
3576 just do the conversion of RESULT to TYPE. */
3579 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3581 tree t = fold_convert (type, result);
3583 if (TREE_SIDE_EFFECTS (omitted2))
3584 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3585 if (TREE_SIDE_EFFECTS (omitted1))
3586 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3588 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3592 /* Return a simplified tree node for the truth-negation of ARG. This
3593 never alters ARG itself. We assume that ARG is an operation that
3594 returns a truth value (0 or 1).
3596 FIXME: one would think we would fold the result, but it causes
3597 problems with the dominator optimizer. */
3600 fold_truth_not_expr (tree arg)
3602 tree type = TREE_TYPE (arg);
3603 enum tree_code code = TREE_CODE (arg);
3605 /* If this is a comparison, we can simply invert it, except for
3606 floating-point non-equality comparisons, in which case we just
3607 enclose a TRUTH_NOT_EXPR around what we have. */
3609 if (TREE_CODE_CLASS (code) == tcc_comparison)
3611 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3612 if (FLOAT_TYPE_P (op_type)
3613 && flag_trapping_math
3614 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3615 && code != NE_EXPR && code != EQ_EXPR)
3619 code = invert_tree_comparison (code,
3620 HONOR_NANS (TYPE_MODE (op_type)));
3621 if (code == ERROR_MARK)
3624 return build2 (code, type,
3625 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3632 return constant_boolean_node (integer_zerop (arg), type);
3634 case TRUTH_AND_EXPR:
3635 return build2 (TRUTH_OR_EXPR, type,
3636 invert_truthvalue (TREE_OPERAND (arg, 0)),
3637 invert_truthvalue (TREE_OPERAND (arg, 1)));
3640 return build2 (TRUTH_AND_EXPR, type,
3641 invert_truthvalue (TREE_OPERAND (arg, 0)),
3642 invert_truthvalue (TREE_OPERAND (arg, 1)));
3644 case TRUTH_XOR_EXPR:
3645 /* Here we can invert either operand. We invert the first operand
3646 unless the second operand is a TRUTH_NOT_EXPR in which case our
3647 result is the XOR of the first operand with the inside of the
3648 negation of the second operand. */
3650 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3651 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3652 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3654 return build2 (TRUTH_XOR_EXPR, type,
3655 invert_truthvalue (TREE_OPERAND (arg, 0)),
3656 TREE_OPERAND (arg, 1));
3658 case TRUTH_ANDIF_EXPR:
3659 return build2 (TRUTH_ORIF_EXPR, type,
3660 invert_truthvalue (TREE_OPERAND (arg, 0)),
3661 invert_truthvalue (TREE_OPERAND (arg, 1)));
3663 case TRUTH_ORIF_EXPR:
3664 return build2 (TRUTH_ANDIF_EXPR, type,
3665 invert_truthvalue (TREE_OPERAND (arg, 0)),
3666 invert_truthvalue (TREE_OPERAND (arg, 1)));
3668 case TRUTH_NOT_EXPR:
3669 return TREE_OPERAND (arg, 0);
3673 tree arg1 = TREE_OPERAND (arg, 1);
3674 tree arg2 = TREE_OPERAND (arg, 2);
3675 /* A COND_EXPR may have a throw as one operand, which
3676 then has void type. Just leave void operands
3678 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3679 VOID_TYPE_P (TREE_TYPE (arg1))
3680 ? arg1 : invert_truthvalue (arg1),
3681 VOID_TYPE_P (TREE_TYPE (arg2))
3682 ? arg2 : invert_truthvalue (arg2));
3686 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3687 invert_truthvalue (TREE_OPERAND (arg, 1)));
3689 case NON_LVALUE_EXPR:
3690 return invert_truthvalue (TREE_OPERAND (arg, 0));
3693 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3694 return build1 (TRUTH_NOT_EXPR, type, arg);
3698 return build1 (TREE_CODE (arg), type,
3699 invert_truthvalue (TREE_OPERAND (arg, 0)));
3702 if (!integer_onep (TREE_OPERAND (arg, 1)))
3704 return build2 (EQ_EXPR, type, arg,
3705 build_int_cst (type, 0));
3708 return build1 (TRUTH_NOT_EXPR, type, arg);
3710 case CLEANUP_POINT_EXPR:
3711 return build1 (CLEANUP_POINT_EXPR, type,
3712 invert_truthvalue (TREE_OPERAND (arg, 0)));
3721 /* Return a simplified tree node for the truth-negation of ARG. This
3722 never alters ARG itself. We assume that ARG is an operation that
3723 returns a truth value (0 or 1).
3725 FIXME: one would think we would fold the result, but it causes
3726 problems with the dominator optimizer. */
3729 invert_truthvalue (tree arg)
3733 if (TREE_CODE (arg) == ERROR_MARK)
3736 tem = fold_truth_not_expr (arg);
3738 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3743 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3744 operands are another bit-wise operation with a common input. If so,
3745 distribute the bit operations to save an operation and possibly two if
3746 constants are involved. For example, convert
3747 (A | B) & (A | C) into A | (B & C)
3748 Further simplification will occur if B and C are constants.
3750 If this optimization cannot be done, 0 will be returned. */
3753 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3758 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3759 || TREE_CODE (arg0) == code
3760 || (TREE_CODE (arg0) != BIT_AND_EXPR
3761 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3764 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3766 common = TREE_OPERAND (arg0, 0);
3767 left = TREE_OPERAND (arg0, 1);
3768 right = TREE_OPERAND (arg1, 1);
3770 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3772 common = TREE_OPERAND (arg0, 0);
3773 left = TREE_OPERAND (arg0, 1);
3774 right = TREE_OPERAND (arg1, 0);
3776 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3778 common = TREE_OPERAND (arg0, 1);
3779 left = TREE_OPERAND (arg0, 0);
3780 right = TREE_OPERAND (arg1, 1);
3782 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3784 common = TREE_OPERAND (arg0, 1);
3785 left = TREE_OPERAND (arg0, 0);
3786 right = TREE_OPERAND (arg1, 0);
3791 return fold_build2 (TREE_CODE (arg0), type, common,
3792 fold_build2 (code, type, left, right));
3795 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3796 with code CODE. This optimization is unsafe. */
3798 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3800 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3801 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3803 /* (A / C) +- (B / C) -> (A +- B) / C. */
3805 && operand_equal_p (TREE_OPERAND (arg0, 1),
3806 TREE_OPERAND (arg1, 1), 0))
3807 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3808 fold_build2 (code, type,
3809 TREE_OPERAND (arg0, 0),
3810 TREE_OPERAND (arg1, 0)),
3811 TREE_OPERAND (arg0, 1));
3813 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3814 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3815 TREE_OPERAND (arg1, 0), 0)
3816 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3817 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3819 REAL_VALUE_TYPE r0, r1;
3820 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3821 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3823 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3825 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3826 real_arithmetic (&r0, code, &r0, &r1);
3827 return fold_build2 (MULT_EXPR, type,
3828 TREE_OPERAND (arg0, 0),
3829 build_real (type, r0));
3835 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3836 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3839 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3846 tree size = TYPE_SIZE (TREE_TYPE (inner));
3847 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3848 || POINTER_TYPE_P (TREE_TYPE (inner)))
3849 && host_integerp (size, 0)
3850 && tree_low_cst (size, 0) == bitsize)
3851 return fold_convert (type, inner);
3854 result = build3 (BIT_FIELD_REF, type, inner,
3855 size_int (bitsize), bitsize_int (bitpos));
3857 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3862 /* Optimize a bit-field compare.
3864 There are two cases: First is a compare against a constant and the
3865 second is a comparison of two items where the fields are at the same
3866 bit position relative to the start of a chunk (byte, halfword, word)
3867 large enough to contain it. In these cases we can avoid the shift
3868 implicit in bitfield extractions.
3870 For constants, we emit a compare of the shifted constant with the
3871 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3872 compared. For two fields at the same position, we do the ANDs with the
3873 similar mask and compare the result of the ANDs.
3875 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3876 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3877 are the left and right operands of the comparison, respectively.
3879 If the optimization described above can be done, we return the resulting
3880 tree. Otherwise we return zero. */
3883 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3886 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3887 tree type = TREE_TYPE (lhs);
3888 tree signed_type, unsigned_type;
3889 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3890 enum machine_mode lmode, rmode, nmode;
3891 int lunsignedp, runsignedp;
3892 int lvolatilep = 0, rvolatilep = 0;
3893 tree linner, rinner = NULL_TREE;
3897 /* Get all the information about the extractions being done. If the bit size
3898 if the same as the size of the underlying object, we aren't doing an
3899 extraction at all and so can do nothing. We also don't want to
3900 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3901 then will no longer be able to replace it. */
3902 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3903 &lunsignedp, &lvolatilep, false);
3904 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3905 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3910 /* If this is not a constant, we can only do something if bit positions,
3911 sizes, and signedness are the same. */
3912 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3913 &runsignedp, &rvolatilep, false);
3915 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3916 || lunsignedp != runsignedp || offset != 0
3917 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3921 /* See if we can find a mode to refer to this field. We should be able to,
3922 but fail if we can't. */
3923 nmode = get_best_mode (lbitsize, lbitpos,
3924 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3925 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3926 TYPE_ALIGN (TREE_TYPE (rinner))),
3927 word_mode, lvolatilep || rvolatilep);
3928 if (nmode == VOIDmode)
3931 /* Set signed and unsigned types of the precision of this mode for the
3933 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3934 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3936 /* Compute the bit position and size for the new reference and our offset
3937 within it. If the new reference is the same size as the original, we
3938 won't optimize anything, so return zero. */
3939 nbitsize = GET_MODE_BITSIZE (nmode);
3940 nbitpos = lbitpos & ~ (nbitsize - 1);
3942 if (nbitsize == lbitsize)
3945 if (BYTES_BIG_ENDIAN)
3946 lbitpos = nbitsize - lbitsize - lbitpos;
3948 /* Make the mask to be used against the extracted field. */
3949 mask = build_int_cst_type (unsigned_type, -1);
3950 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3951 mask = const_binop (RSHIFT_EXPR, mask,
3952 size_int (nbitsize - lbitsize - lbitpos), 0);
3955 /* If not comparing with constant, just rework the comparison
3957 return fold_build2 (code, compare_type,
3958 fold_build2 (BIT_AND_EXPR, unsigned_type,
3959 make_bit_field_ref (linner,
3964 fold_build2 (BIT_AND_EXPR, unsigned_type,
3965 make_bit_field_ref (rinner,
3971 /* Otherwise, we are handling the constant case. See if the constant is too
3972 big for the field. Warn and return a tree of for 0 (false) if so. We do
3973 this not only for its own sake, but to avoid having to test for this
3974 error case below. If we didn't, we might generate wrong code.
3976 For unsigned fields, the constant shifted right by the field length should
3977 be all zero. For signed fields, the high-order bits should agree with
3982 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3983 fold_convert (unsigned_type, rhs),
3984 size_int (lbitsize), 0)))
3986 warning (0, "comparison is always %d due to width of bit-field",
3988 return constant_boolean_node (code == NE_EXPR, compare_type);
3993 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3994 size_int (lbitsize - 1), 0);
3995 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3997 warning (0, "comparison is always %d due to width of bit-field",
3999 return constant_boolean_node (code == NE_EXPR, compare_type);
4003 /* Single-bit compares should always be against zero. */
4004 if (lbitsize == 1 && ! integer_zerop (rhs))
4006 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
4007 rhs = build_int_cst (type, 0);
4010 /* Make a new bitfield reference, shift the constant over the
4011 appropriate number of bits and mask it with the computed mask
4012 (in case this was a signed field). If we changed it, make a new one. */
4013 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
4016 TREE_SIDE_EFFECTS (lhs) = 1;
4017 TREE_THIS_VOLATILE (lhs) = 1;
4020 rhs = const_binop (BIT_AND_EXPR,
4021 const_binop (LSHIFT_EXPR,
4022 fold_convert (unsigned_type, rhs),
4023 size_int (lbitpos), 0),
4026 return build2 (code, compare_type,
4027 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
4031 /* Subroutine for fold_truthop: decode a field reference.
4033 If EXP is a comparison reference, we return the innermost reference.
4035 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
4036 set to the starting bit number.
4038 If the innermost field can be completely contained in a mode-sized
4039 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
4041 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
4042 otherwise it is not changed.
4044 *PUNSIGNEDP is set to the signedness of the field.
4046 *PMASK is set to the mask used. This is either contained in a
4047 BIT_AND_EXPR or derived from the width of the field.
4049 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
4051 Return 0 if this is not a component reference or is one that we can't
4052 do anything with. */
4055 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
4056 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
4057 int *punsignedp, int *pvolatilep,
4058 tree *pmask, tree *pand_mask)
4060 tree outer_type = 0;
4062 tree mask, inner, offset;
4064 unsigned int precision;
4066 /* All the optimizations using this function assume integer fields.
4067 There are problems with FP fields since the type_for_size call
4068 below can fail for, e.g., XFmode. */
4069 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
4072 /* We are interested in the bare arrangement of bits, so strip everything
4073 that doesn't affect the machine mode. However, record the type of the
4074 outermost expression if it may matter below. */
4075 if (TREE_CODE (exp) == NOP_EXPR
4076 || TREE_CODE (exp) == CONVERT_EXPR
4077 || TREE_CODE (exp) == NON_LVALUE_EXPR)
4078 outer_type = TREE_TYPE (exp);
4081 if (TREE_CODE (exp) == BIT_AND_EXPR)
4083 and_mask = TREE_OPERAND (exp, 1);
4084 exp = TREE_OPERAND (exp, 0);
4085 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
4086 if (TREE_CODE (and_mask) != INTEGER_CST)
4090 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
4091 punsignedp, pvolatilep, false);
4092 if ((inner == exp && and_mask == 0)
4093 || *pbitsize < 0 || offset != 0
4094 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
4097 /* If the number of bits in the reference is the same as the bitsize of
4098 the outer type, then the outer type gives the signedness. Otherwise
4099 (in case of a small bitfield) the signedness is unchanged. */
4100 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
4101 *punsignedp = TYPE_UNSIGNED (outer_type);
4103 /* Compute the mask to access the bitfield. */
4104 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
4105 precision = TYPE_PRECISION (unsigned_type);
4107 mask = build_int_cst_type (unsigned_type, -1);
4109 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4110 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4112 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
4114 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
4115 fold_convert (unsigned_type, and_mask), mask);
4118 *pand_mask = and_mask;
4122 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
4126 all_ones_mask_p (const_tree mask, int size)
4128 tree type = TREE_TYPE (mask);
4129 unsigned int precision = TYPE_PRECISION (type);
4132 tmask = build_int_cst_type (signed_type_for (type), -1);
4135 tree_int_cst_equal (mask,
4136 const_binop (RSHIFT_EXPR,
4137 const_binop (LSHIFT_EXPR, tmask,
4138 size_int (precision - size),
4140 size_int (precision - size), 0));
4143 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
4144 represents the sign bit of EXP's type. If EXP represents a sign
4145 or zero extension, also test VAL against the unextended type.
4146 The return value is the (sub)expression whose sign bit is VAL,
4147 or NULL_TREE otherwise. */
4150 sign_bit_p (tree exp, const_tree val)
4152 unsigned HOST_WIDE_INT mask_lo, lo;
4153 HOST_WIDE_INT mask_hi, hi;
4157 /* Tree EXP must have an integral type. */
4158 t = TREE_TYPE (exp);
4159 if (! INTEGRAL_TYPE_P (t))
4162 /* Tree VAL must be an integer constant. */
4163 if (TREE_CODE (val) != INTEGER_CST
4164 || TREE_OVERFLOW (val))
4167 width = TYPE_PRECISION (t);
4168 if (width > HOST_BITS_PER_WIDE_INT)
4170 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
4173 mask_hi = ((unsigned HOST_WIDE_INT) -1
4174 >> (2 * HOST_BITS_PER_WIDE_INT - width));
4180 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
4183 mask_lo = ((unsigned HOST_WIDE_INT) -1
4184 >> (HOST_BITS_PER_WIDE_INT - width));
4187 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
4188 treat VAL as if it were unsigned. */
4189 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
4190 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
4193 /* Handle extension from a narrower type. */
4194 if (TREE_CODE (exp) == NOP_EXPR
4195 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
4196 return sign_bit_p (TREE_OPERAND (exp, 0), val);
4201 /* Subroutine for fold_truthop: determine if an operand is simple enough
4202 to be evaluated unconditionally. */
4205 simple_operand_p (const_tree exp)
4207 /* Strip any conversions that don't change the machine mode. */
4210 return (CONSTANT_CLASS_P (exp)
4211 || TREE_CODE (exp) == SSA_NAME
4213 && ! TREE_ADDRESSABLE (exp)
4214 && ! TREE_THIS_VOLATILE (exp)
4215 && ! DECL_NONLOCAL (exp)
4216 /* Don't regard global variables as simple. They may be
4217 allocated in ways unknown to the compiler (shared memory,
4218 #pragma weak, etc). */
4219 && ! TREE_PUBLIC (exp)
4220 && ! DECL_EXTERNAL (exp)
4221 /* Loading a static variable is unduly expensive, but global
4222 registers aren't expensive. */
4223 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
4226 /* The following functions are subroutines to fold_range_test and allow it to
4227 try to change a logical combination of comparisons into a range test.
4230 X == 2 || X == 3 || X == 4 || X == 5
4234 (unsigned) (X - 2) <= 3
4236 We describe each set of comparisons as being either inside or outside
4237 a range, using a variable named like IN_P, and then describe the
4238 range with a lower and upper bound. If one of the bounds is omitted,
4239 it represents either the highest or lowest value of the type.
4241 In the comments below, we represent a range by two numbers in brackets
4242 preceded by a "+" to designate being inside that range, or a "-" to
4243 designate being outside that range, so the condition can be inverted by
4244 flipping the prefix. An omitted bound is represented by a "-". For
4245 example, "- [-, 10]" means being outside the range starting at the lowest
4246 possible value and ending at 10, in other words, being greater than 10.
4247 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4250 We set up things so that the missing bounds are handled in a consistent
4251 manner so neither a missing bound nor "true" and "false" need to be
4252 handled using a special case. */
4254 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4255 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4256 and UPPER1_P are nonzero if the respective argument is an upper bound
4257 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4258 must be specified for a comparison. ARG1 will be converted to ARG0's
4259 type if both are specified. */
4262 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
4263 tree arg1, int upper1_p)
4269 /* If neither arg represents infinity, do the normal operation.
4270 Else, if not a comparison, return infinity. Else handle the special
4271 comparison rules. Note that most of the cases below won't occur, but
4272 are handled for consistency. */
4274 if (arg0 != 0 && arg1 != 0)
4276 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
4277 arg0, fold_convert (TREE_TYPE (arg0), arg1));
4279 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
4282 if (TREE_CODE_CLASS (code) != tcc_comparison)
4285 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4286 for neither. In real maths, we cannot assume open ended ranges are
4287 the same. But, this is computer arithmetic, where numbers are finite.
4288 We can therefore make the transformation of any unbounded range with
4289 the value Z, Z being greater than any representable number. This permits
4290 us to treat unbounded ranges as equal. */
4291 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
4292 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
4296 result = sgn0 == sgn1;
4299 result = sgn0 != sgn1;
4302 result = sgn0 < sgn1;
4305 result = sgn0 <= sgn1;
4308 result = sgn0 > sgn1;
4311 result = sgn0 >= sgn1;
4317 return constant_boolean_node (result, type);
4320 /* Given EXP, a logical expression, set the range it is testing into
4321 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4322 actually being tested. *PLOW and *PHIGH will be made of the same
4323 type as the returned expression. If EXP is not a comparison, we
4324 will most likely not be returning a useful value and range. Set
4325 *STRICT_OVERFLOW_P to true if the return value is only valid
4326 because signed overflow is undefined; otherwise, do not change
4327 *STRICT_OVERFLOW_P. */
4330 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4331 bool *strict_overflow_p)
4333 enum tree_code code;
4334 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4335 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4337 tree low, high, n_low, n_high;
4339 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4340 and see if we can refine the range. Some of the cases below may not
4341 happen, but it doesn't seem worth worrying about this. We "continue"
4342 the outer loop when we've changed something; otherwise we "break"
4343 the switch, which will "break" the while. */
4346 low = high = build_int_cst (TREE_TYPE (exp), 0);
4350 code = TREE_CODE (exp);
4351 exp_type = TREE_TYPE (exp);
4353 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4355 if (TREE_OPERAND_LENGTH (exp) > 0)
4356 arg0 = TREE_OPERAND (exp, 0);
4357 if (TREE_CODE_CLASS (code) == tcc_comparison
4358 || TREE_CODE_CLASS (code) == tcc_unary
4359 || TREE_CODE_CLASS (code) == tcc_binary)
4360 arg0_type = TREE_TYPE (arg0);
4361 if (TREE_CODE_CLASS (code) == tcc_binary
4362 || TREE_CODE_CLASS (code) == tcc_comparison
4363 || (TREE_CODE_CLASS (code) == tcc_expression
4364 && TREE_OPERAND_LENGTH (exp) > 1))
4365 arg1 = TREE_OPERAND (exp, 1);
4370 case TRUTH_NOT_EXPR:
4371 in_p = ! in_p, exp = arg0;
4374 case EQ_EXPR: case NE_EXPR:
4375 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4376 /* We can only do something if the range is testing for zero
4377 and if the second operand is an integer constant. Note that
4378 saying something is "in" the range we make is done by
4379 complementing IN_P since it will set in the initial case of
4380 being not equal to zero; "out" is leaving it alone. */
4381 if (low == 0 || high == 0
4382 || ! integer_zerop (low) || ! integer_zerop (high)
4383 || TREE_CODE (arg1) != INTEGER_CST)
4388 case NE_EXPR: /* - [c, c] */
4391 case EQ_EXPR: /* + [c, c] */
4392 in_p = ! in_p, low = high = arg1;
4394 case GT_EXPR: /* - [-, c] */
4395 low = 0, high = arg1;
4397 case GE_EXPR: /* + [c, -] */
4398 in_p = ! in_p, low = arg1, high = 0;
4400 case LT_EXPR: /* - [c, -] */
4401 low = arg1, high = 0;
4403 case LE_EXPR: /* + [-, c] */
4404 in_p = ! in_p, low = 0, high = arg1;
4410 /* If this is an unsigned comparison, we also know that EXP is
4411 greater than or equal to zero. We base the range tests we make
4412 on that fact, so we record it here so we can parse existing
4413 range tests. We test arg0_type since often the return type
4414 of, e.g. EQ_EXPR, is boolean. */
4415 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4417 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4419 build_int_cst (arg0_type, 0),
4423 in_p = n_in_p, low = n_low, high = n_high;
4425 /* If the high bound is missing, but we have a nonzero low
4426 bound, reverse the range so it goes from zero to the low bound
4428 if (high == 0 && low && ! integer_zerop (low))
4431 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4432 integer_one_node, 0);
4433 low = build_int_cst (arg0_type, 0);
4441 /* (-x) IN [a,b] -> x in [-b, -a] */
4442 n_low = range_binop (MINUS_EXPR, exp_type,
4443 build_int_cst (exp_type, 0),
4445 n_high = range_binop (MINUS_EXPR, exp_type,
4446 build_int_cst (exp_type, 0),
4448 low = n_low, high = n_high;
4454 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4455 build_int_cst (exp_type, 1));
4458 case PLUS_EXPR: case MINUS_EXPR:
4459 if (TREE_CODE (arg1) != INTEGER_CST)
4462 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4463 move a constant to the other side. */
4464 if (!TYPE_UNSIGNED (arg0_type)
4465 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4468 /* If EXP is signed, any overflow in the computation is undefined,
4469 so we don't worry about it so long as our computations on
4470 the bounds don't overflow. For unsigned, overflow is defined
4471 and this is exactly the right thing. */
4472 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4473 arg0_type, low, 0, arg1, 0);
4474 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4475 arg0_type, high, 1, arg1, 0);
4476 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4477 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4480 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4481 *strict_overflow_p = true;
4483 /* Check for an unsigned range which has wrapped around the maximum
4484 value thus making n_high < n_low, and normalize it. */
4485 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4487 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4488 integer_one_node, 0);
4489 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4490 integer_one_node, 0);
4492 /* If the range is of the form +/- [ x+1, x ], we won't
4493 be able to normalize it. But then, it represents the
4494 whole range or the empty set, so make it
4496 if (tree_int_cst_equal (n_low, low)
4497 && tree_int_cst_equal (n_high, high))
4503 low = n_low, high = n_high;
4508 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
4509 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4512 if (! INTEGRAL_TYPE_P (arg0_type)
4513 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4514 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4517 n_low = low, n_high = high;
4520 n_low = fold_convert (arg0_type, n_low);
4523 n_high = fold_convert (arg0_type, n_high);
4526 /* If we're converting arg0 from an unsigned type, to exp,
4527 a signed type, we will be doing the comparison as unsigned.
4528 The tests above have already verified that LOW and HIGH
4531 So we have to ensure that we will handle large unsigned
4532 values the same way that the current signed bounds treat
4535 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4539 /* For fixed-point modes, we need to pass the saturating flag
4540 as the 2nd parameter. */
4541 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
4542 equiv_type = lang_hooks.types.type_for_mode
4543 (TYPE_MODE (arg0_type),
4544 TYPE_SATURATING (arg0_type));
4546 equiv_type = lang_hooks.types.type_for_mode
4547 (TYPE_MODE (arg0_type), 1);
4549 /* A range without an upper bound is, naturally, unbounded.
4550 Since convert would have cropped a very large value, use
4551 the max value for the destination type. */
4553 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4554 : TYPE_MAX_VALUE (arg0_type);
4556 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4557 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4558 fold_convert (arg0_type,
4560 build_int_cst (arg0_type, 1));
4562 /* If the low bound is specified, "and" the range with the
4563 range for which the original unsigned value will be
4567 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4568 1, n_low, n_high, 1,
4569 fold_convert (arg0_type,
4574 in_p = (n_in_p == in_p);
4578 /* Otherwise, "or" the range with the range of the input
4579 that will be interpreted as negative. */
4580 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4581 0, n_low, n_high, 1,
4582 fold_convert (arg0_type,
4587 in_p = (in_p != n_in_p);
4592 low = n_low, high = n_high;
4602 /* If EXP is a constant, we can evaluate whether this is true or false. */
4603 if (TREE_CODE (exp) == INTEGER_CST)
4605 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4607 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4613 *pin_p = in_p, *plow = low, *phigh = high;
4617 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4618 type, TYPE, return an expression to test if EXP is in (or out of, depending
4619 on IN_P) the range. Return 0 if the test couldn't be created. */
4622 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4624 tree etype = TREE_TYPE (exp);
4627 #ifdef HAVE_canonicalize_funcptr_for_compare
4628 /* Disable this optimization for function pointer expressions
4629 on targets that require function pointer canonicalization. */
4630 if (HAVE_canonicalize_funcptr_for_compare
4631 && TREE_CODE (etype) == POINTER_TYPE
4632 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4638 value = build_range_check (type, exp, 1, low, high);
4640 return invert_truthvalue (value);
4645 if (low == 0 && high == 0)
4646 return build_int_cst (type, 1);
4649 return fold_build2 (LE_EXPR, type, exp,
4650 fold_convert (etype, high));
4653 return fold_build2 (GE_EXPR, type, exp,
4654 fold_convert (etype, low));
4656 if (operand_equal_p (low, high, 0))
4657 return fold_build2 (EQ_EXPR, type, exp,
4658 fold_convert (etype, low));
4660 if (integer_zerop (low))
4662 if (! TYPE_UNSIGNED (etype))
4664 etype = unsigned_type_for (etype);
4665 high = fold_convert (etype, high);
4666 exp = fold_convert (etype, exp);
4668 return build_range_check (type, exp, 1, 0, high);
4671 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4672 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4674 unsigned HOST_WIDE_INT lo;
4678 prec = TYPE_PRECISION (etype);
4679 if (prec <= HOST_BITS_PER_WIDE_INT)
4682 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4686 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4687 lo = (unsigned HOST_WIDE_INT) -1;
4690 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4692 if (TYPE_UNSIGNED (etype))
4694 etype = signed_type_for (etype);
4695 exp = fold_convert (etype, exp);
4697 return fold_build2 (GT_EXPR, type, exp,
4698 build_int_cst (etype, 0));
4702 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4703 This requires wrap-around arithmetics for the type of the expression. */
4704 switch (TREE_CODE (etype))
4707 /* There is no requirement that LOW be within the range of ETYPE
4708 if the latter is a subtype. It must, however, be within the base
4709 type of ETYPE. So be sure we do the subtraction in that type. */
4710 if (TREE_TYPE (etype))
4711 etype = TREE_TYPE (etype);
4716 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4717 TYPE_UNSIGNED (etype));
4724 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4725 if (TREE_CODE (etype) == INTEGER_TYPE
4726 && !TYPE_OVERFLOW_WRAPS (etype))
4728 tree utype, minv, maxv;
4730 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4731 for the type in question, as we rely on this here. */
4732 utype = unsigned_type_for (etype);
4733 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4734 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4735 integer_one_node, 1);
4736 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4738 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4745 high = fold_convert (etype, high);
4746 low = fold_convert (etype, low);
4747 exp = fold_convert (etype, exp);
4749 value = const_binop (MINUS_EXPR, high, low, 0);
4752 if (POINTER_TYPE_P (etype))
4754 if (value != 0 && !TREE_OVERFLOW (value))
4756 low = fold_convert (sizetype, low);
4757 low = fold_build1 (NEGATE_EXPR, sizetype, low);
4758 return build_range_check (type,
4759 fold_build2 (POINTER_PLUS_EXPR, etype, exp, low),
4760 1, build_int_cst (etype, 0), value);
4765 if (value != 0 && !TREE_OVERFLOW (value))
4766 return build_range_check (type,
4767 fold_build2 (MINUS_EXPR, etype, exp, low),
4768 1, build_int_cst (etype, 0), value);
4773 /* Return the predecessor of VAL in its type, handling the infinite case. */
4776 range_predecessor (tree val)
4778 tree type = TREE_TYPE (val);
4780 if (INTEGRAL_TYPE_P (type)
4781 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4784 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4787 /* Return the successor of VAL in its type, handling the infinite case. */
4790 range_successor (tree val)
4792 tree type = TREE_TYPE (val);
4794 if (INTEGRAL_TYPE_P (type)
4795 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4798 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4801 /* Given two ranges, see if we can merge them into one. Return 1 if we
4802 can, 0 if we can't. Set the output range into the specified parameters. */
4805 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4806 tree high0, int in1_p, tree low1, tree high1)
4814 int lowequal = ((low0 == 0 && low1 == 0)
4815 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4816 low0, 0, low1, 0)));
4817 int highequal = ((high0 == 0 && high1 == 0)
4818 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4819 high0, 1, high1, 1)));
4821 /* Make range 0 be the range that starts first, or ends last if they
4822 start at the same value. Swap them if it isn't. */
4823 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4826 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4827 high1, 1, high0, 1))))
4829 temp = in0_p, in0_p = in1_p, in1_p = temp;
4830 tem = low0, low0 = low1, low1 = tem;
4831 tem = high0, high0 = high1, high1 = tem;
4834 /* Now flag two cases, whether the ranges are disjoint or whether the
4835 second range is totally subsumed in the first. Note that the tests
4836 below are simplified by the ones above. */
4837 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4838 high0, 1, low1, 0));
4839 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4840 high1, 1, high0, 1));
4842 /* We now have four cases, depending on whether we are including or
4843 excluding the two ranges. */
4846 /* If they don't overlap, the result is false. If the second range
4847 is a subset it is the result. Otherwise, the range is from the start
4848 of the second to the end of the first. */
4850 in_p = 0, low = high = 0;
4852 in_p = 1, low = low1, high = high1;
4854 in_p = 1, low = low1, high = high0;
4857 else if (in0_p && ! in1_p)
4859 /* If they don't overlap, the result is the first range. If they are
4860 equal, the result is false. If the second range is a subset of the
4861 first, and the ranges begin at the same place, we go from just after
4862 the end of the second range to the end of the first. If the second
4863 range is not a subset of the first, or if it is a subset and both
4864 ranges end at the same place, the range starts at the start of the
4865 first range and ends just before the second range.
4866 Otherwise, we can't describe this as a single range. */
4868 in_p = 1, low = low0, high = high0;
4869 else if (lowequal && highequal)
4870 in_p = 0, low = high = 0;
4871 else if (subset && lowequal)
4873 low = range_successor (high1);
4878 /* We are in the weird situation where high0 > high1 but
4879 high1 has no successor. Punt. */
4883 else if (! subset || highequal)
4886 high = range_predecessor (low1);
4890 /* low0 < low1 but low1 has no predecessor. Punt. */
4898 else if (! in0_p && in1_p)
4900 /* If they don't overlap, the result is the second range. If the second
4901 is a subset of the first, the result is false. Otherwise,
4902 the range starts just after the first range and ends at the
4903 end of the second. */
4905 in_p = 1, low = low1, high = high1;
4906 else if (subset || highequal)
4907 in_p = 0, low = high = 0;
4910 low = range_successor (high0);
4915 /* high1 > high0 but high0 has no successor. Punt. */
4923 /* The case where we are excluding both ranges. Here the complex case
4924 is if they don't overlap. In that case, the only time we have a
4925 range is if they are adjacent. If the second is a subset of the
4926 first, the result is the first. Otherwise, the range to exclude
4927 starts at the beginning of the first range and ends at the end of the
4931 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4932 range_successor (high0),
4934 in_p = 0, low = low0, high = high1;
4937 /* Canonicalize - [min, x] into - [-, x]. */
4938 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4939 switch (TREE_CODE (TREE_TYPE (low0)))
4942 if (TYPE_PRECISION (TREE_TYPE (low0))
4943 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4947 if (tree_int_cst_equal (low0,
4948 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4952 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4953 && integer_zerop (low0))
4960 /* Canonicalize - [x, max] into - [x, -]. */
4961 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4962 switch (TREE_CODE (TREE_TYPE (high1)))
4965 if (TYPE_PRECISION (TREE_TYPE (high1))
4966 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4970 if (tree_int_cst_equal (high1,
4971 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4975 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4976 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4978 integer_one_node, 1)))
4985 /* The ranges might be also adjacent between the maximum and
4986 minimum values of the given type. For
4987 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4988 return + [x + 1, y - 1]. */
4989 if (low0 == 0 && high1 == 0)
4991 low = range_successor (high0);
4992 high = range_predecessor (low1);
4993 if (low == 0 || high == 0)
5003 in_p = 0, low = low0, high = high0;
5005 in_p = 0, low = low0, high = high1;
5008 *pin_p = in_p, *plow = low, *phigh = high;
5013 /* Subroutine of fold, looking inside expressions of the form
5014 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
5015 of the COND_EXPR. This function is being used also to optimize
5016 A op B ? C : A, by reversing the comparison first.
5018 Return a folded expression whose code is not a COND_EXPR
5019 anymore, or NULL_TREE if no folding opportunity is found. */
5022 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
5024 enum tree_code comp_code = TREE_CODE (arg0);
5025 tree arg00 = TREE_OPERAND (arg0, 0);
5026 tree arg01 = TREE_OPERAND (arg0, 1);
5027 tree arg1_type = TREE_TYPE (arg1);
5033 /* If we have A op 0 ? A : -A, consider applying the following
5036 A == 0? A : -A same as -A
5037 A != 0? A : -A same as A
5038 A >= 0? A : -A same as abs (A)
5039 A > 0? A : -A same as abs (A)
5040 A <= 0? A : -A same as -abs (A)
5041 A < 0? A : -A same as -abs (A)
5043 None of these transformations work for modes with signed
5044 zeros. If A is +/-0, the first two transformations will
5045 change the sign of the result (from +0 to -0, or vice
5046 versa). The last four will fix the sign of the result,
5047 even though the original expressions could be positive or
5048 negative, depending on the sign of A.
5050 Note that all these transformations are correct if A is
5051 NaN, since the two alternatives (A and -A) are also NaNs. */
5052 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
5053 ? real_zerop (arg01)
5054 : integer_zerop (arg01))
5055 && ((TREE_CODE (arg2) == NEGATE_EXPR
5056 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
5057 /* In the case that A is of the form X-Y, '-A' (arg2) may
5058 have already been folded to Y-X, check for that. */
5059 || (TREE_CODE (arg1) == MINUS_EXPR
5060 && TREE_CODE (arg2) == MINUS_EXPR
5061 && operand_equal_p (TREE_OPERAND (arg1, 0),
5062 TREE_OPERAND (arg2, 1), 0)
5063 && operand_equal_p (TREE_OPERAND (arg1, 1),
5064 TREE_OPERAND (arg2, 0), 0))))
5069 tem = fold_convert (arg1_type, arg1);
5070 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
5073 return pedantic_non_lvalue (fold_convert (type, arg1));
5076 if (flag_trapping_math)
5081 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5082 arg1 = fold_convert (signed_type_for
5083 (TREE_TYPE (arg1)), arg1);
5084 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5085 return pedantic_non_lvalue (fold_convert (type, tem));
5088 if (flag_trapping_math)
5092 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5093 arg1 = fold_convert (signed_type_for
5094 (TREE_TYPE (arg1)), arg1);
5095 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5096 return negate_expr (fold_convert (type, tem));
5098 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5102 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
5103 A == 0 ? A : 0 is always 0 unless A is -0. Note that
5104 both transformations are correct when A is NaN: A != 0
5105 is then true, and A == 0 is false. */
5107 if (integer_zerop (arg01) && integer_zerop (arg2))
5109 if (comp_code == NE_EXPR)
5110 return pedantic_non_lvalue (fold_convert (type, arg1));
5111 else if (comp_code == EQ_EXPR)
5112 return build_int_cst (type, 0);
5115 /* Try some transformations of A op B ? A : B.
5117 A == B? A : B same as B
5118 A != B? A : B same as A
5119 A >= B? A : B same as max (A, B)
5120 A > B? A : B same as max (B, A)
5121 A <= B? A : B same as min (A, B)
5122 A < B? A : B same as min (B, A)
5124 As above, these transformations don't work in the presence
5125 of signed zeros. For example, if A and B are zeros of
5126 opposite sign, the first two transformations will change
5127 the sign of the result. In the last four, the original
5128 expressions give different results for (A=+0, B=-0) and
5129 (A=-0, B=+0), but the transformed expressions do not.
5131 The first two transformations are correct if either A or B
5132 is a NaN. In the first transformation, the condition will
5133 be false, and B will indeed be chosen. In the case of the
5134 second transformation, the condition A != B will be true,
5135 and A will be chosen.
5137 The conversions to max() and min() are not correct if B is
5138 a number and A is not. The conditions in the original
5139 expressions will be false, so all four give B. The min()
5140 and max() versions would give a NaN instead. */
5141 if (operand_equal_for_comparison_p (arg01, arg2, arg00)
5142 /* Avoid these transformations if the COND_EXPR may be used
5143 as an lvalue in the C++ front-end. PR c++/19199. */
5145 || (strcmp (lang_hooks.name, "GNU C++") != 0
5146 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
5147 || ! maybe_lvalue_p (arg1)
5148 || ! maybe_lvalue_p (arg2)))
5150 tree comp_op0 = arg00;
5151 tree comp_op1 = arg01;
5152 tree comp_type = TREE_TYPE (comp_op0);
5154 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
5155 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
5165 return pedantic_non_lvalue (fold_convert (type, arg2));
5167 return pedantic_non_lvalue (fold_convert (type, arg1));
5172 /* In C++ a ?: expression can be an lvalue, so put the
5173 operand which will be used if they are equal first
5174 so that we can convert this back to the
5175 corresponding COND_EXPR. */
5176 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5178 comp_op0 = fold_convert (comp_type, comp_op0);
5179 comp_op1 = fold_convert (comp_type, comp_op1);
5180 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
5181 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
5182 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
5183 return pedantic_non_lvalue (fold_convert (type, tem));
5190 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5192 comp_op0 = fold_convert (comp_type, comp_op0);
5193 comp_op1 = fold_convert (comp_type, comp_op1);
5194 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
5195 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
5196 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
5197 return pedantic_non_lvalue (fold_convert (type, tem));
5201 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5202 return pedantic_non_lvalue (fold_convert (type, arg2));
5205 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5206 return pedantic_non_lvalue (fold_convert (type, arg1));
5209 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5214 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
5215 we might still be able to simplify this. For example,
5216 if C1 is one less or one more than C2, this might have started
5217 out as a MIN or MAX and been transformed by this function.
5218 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
5220 if (INTEGRAL_TYPE_P (type)
5221 && TREE_CODE (arg01) == INTEGER_CST
5222 && TREE_CODE (arg2) == INTEGER_CST)
5226 /* We can replace A with C1 in this case. */
5227 arg1 = fold_convert (type, arg01);
5228 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
5231 /* If C1 is C2 + 1, this is min(A, C2). */
5232 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5234 && operand_equal_p (arg01,
5235 const_binop (PLUS_EXPR, arg2,
5236 build_int_cst (type, 1), 0),
5238 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5240 fold_convert (type, arg1),
5245 /* If C1 is C2 - 1, this is min(A, C2). */
5246 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5248 && operand_equal_p (arg01,
5249 const_binop (MINUS_EXPR, arg2,
5250 build_int_cst (type, 1), 0),
5252 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5254 fold_convert (type, arg1),
5259 /* If C1 is C2 - 1, this is max(A, C2). */
5260 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5262 && operand_equal_p (arg01,
5263 const_binop (MINUS_EXPR, arg2,
5264 build_int_cst (type, 1), 0),
5266 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5268 fold_convert (type, arg1),
5273 /* If C1 is C2 + 1, this is max(A, C2). */
5274 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5276 && operand_equal_p (arg01,
5277 const_binop (PLUS_EXPR, arg2,
5278 build_int_cst (type, 1), 0),
5280 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5282 fold_convert (type, arg1),
5296 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5297 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
5300 /* EXP is some logical combination of boolean tests. See if we can
5301 merge it into some range test. Return the new tree if so. */
5304 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
5306 int or_op = (code == TRUTH_ORIF_EXPR
5307 || code == TRUTH_OR_EXPR);
5308 int in0_p, in1_p, in_p;
5309 tree low0, low1, low, high0, high1, high;
5310 bool strict_overflow_p = false;
5311 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
5312 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
5314 const char * const warnmsg = G_("assuming signed overflow does not occur "
5315 "when simplifying range test");
5317 /* If this is an OR operation, invert both sides; we will invert
5318 again at the end. */
5320 in0_p = ! in0_p, in1_p = ! in1_p;
5322 /* If both expressions are the same, if we can merge the ranges, and we
5323 can build the range test, return it or it inverted. If one of the
5324 ranges is always true or always false, consider it to be the same
5325 expression as the other. */
5326 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
5327 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
5329 && 0 != (tem = (build_range_check (type,
5331 : rhs != 0 ? rhs : integer_zero_node,
5334 if (strict_overflow_p)
5335 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
5336 return or_op ? invert_truthvalue (tem) : tem;
5339 /* On machines where the branch cost is expensive, if this is a
5340 short-circuited branch and the underlying object on both sides
5341 is the same, make a non-short-circuit operation. */
5342 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5343 && lhs != 0 && rhs != 0
5344 && (code == TRUTH_ANDIF_EXPR
5345 || code == TRUTH_ORIF_EXPR)
5346 && operand_equal_p (lhs, rhs, 0))
5348 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5349 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5350 which cases we can't do this. */
5351 if (simple_operand_p (lhs))
5352 return build2 (code == TRUTH_ANDIF_EXPR
5353 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5356 else if (lang_hooks.decls.global_bindings_p () == 0
5357 && ! CONTAINS_PLACEHOLDER_P (lhs))
5359 tree common = save_expr (lhs);
5361 if (0 != (lhs = build_range_check (type, common,
5362 or_op ? ! in0_p : in0_p,
5364 && (0 != (rhs = build_range_check (type, common,
5365 or_op ? ! in1_p : in1_p,
5368 if (strict_overflow_p)
5369 fold_overflow_warning (warnmsg,
5370 WARN_STRICT_OVERFLOW_COMPARISON);
5371 return build2 (code == TRUTH_ANDIF_EXPR
5372 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5381 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5382 bit value. Arrange things so the extra bits will be set to zero if and
5383 only if C is signed-extended to its full width. If MASK is nonzero,
5384 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5387 unextend (tree c, int p, int unsignedp, tree mask)
5389 tree type = TREE_TYPE (c);
5390 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5393 if (p == modesize || unsignedp)
5396 /* We work by getting just the sign bit into the low-order bit, then
5397 into the high-order bit, then sign-extend. We then XOR that value
5399 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5400 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5402 /* We must use a signed type in order to get an arithmetic right shift.
5403 However, we must also avoid introducing accidental overflows, so that
5404 a subsequent call to integer_zerop will work. Hence we must
5405 do the type conversion here. At this point, the constant is either
5406 zero or one, and the conversion to a signed type can never overflow.
5407 We could get an overflow if this conversion is done anywhere else. */
5408 if (TYPE_UNSIGNED (type))
5409 temp = fold_convert (signed_type_for (type), temp);
5411 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5412 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5414 temp = const_binop (BIT_AND_EXPR, temp,
5415 fold_convert (TREE_TYPE (c), mask), 0);
5416 /* If necessary, convert the type back to match the type of C. */
5417 if (TYPE_UNSIGNED (type))
5418 temp = fold_convert (type, temp);
5420 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5423 /* Find ways of folding logical expressions of LHS and RHS:
5424 Try to merge two comparisons to the same innermost item.
5425 Look for range tests like "ch >= '0' && ch <= '9'".
5426 Look for combinations of simple terms on machines with expensive branches
5427 and evaluate the RHS unconditionally.
5429 For example, if we have p->a == 2 && p->b == 4 and we can make an
5430 object large enough to span both A and B, we can do this with a comparison
5431 against the object ANDed with the a mask.
5433 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5434 operations to do this with one comparison.
5436 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5437 function and the one above.
5439 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5440 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5442 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5445 We return the simplified tree or 0 if no optimization is possible. */
5448 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5450 /* If this is the "or" of two comparisons, we can do something if
5451 the comparisons are NE_EXPR. If this is the "and", we can do something
5452 if the comparisons are EQ_EXPR. I.e.,
5453 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5455 WANTED_CODE is this operation code. For single bit fields, we can
5456 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5457 comparison for one-bit fields. */
5459 enum tree_code wanted_code;
5460 enum tree_code lcode, rcode;
5461 tree ll_arg, lr_arg, rl_arg, rr_arg;
5462 tree ll_inner, lr_inner, rl_inner, rr_inner;
5463 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5464 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5465 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
5466 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
5467 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5468 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5469 enum machine_mode lnmode, rnmode;
5470 tree ll_mask, lr_mask, rl_mask, rr_mask;
5471 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5472 tree l_const, r_const;
5473 tree lntype, rntype, result;
5474 int first_bit, end_bit;
5476 tree orig_lhs = lhs, orig_rhs = rhs;
5477 enum tree_code orig_code = code;
5479 /* Start by getting the comparison codes. Fail if anything is volatile.
5480 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5481 it were surrounded with a NE_EXPR. */
5483 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5486 lcode = TREE_CODE (lhs);
5487 rcode = TREE_CODE (rhs);
5489 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5491 lhs = build2 (NE_EXPR, truth_type, lhs,
5492 build_int_cst (TREE_TYPE (lhs), 0));
5496 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5498 rhs = build2 (NE_EXPR, truth_type, rhs,
5499 build_int_cst (TREE_TYPE (rhs), 0));
5503 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5504 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5507 ll_arg = TREE_OPERAND (lhs, 0);
5508 lr_arg = TREE_OPERAND (lhs, 1);
5509 rl_arg = TREE_OPERAND (rhs, 0);
5510 rr_arg = TREE_OPERAND (rhs, 1);
5512 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5513 if (simple_operand_p (ll_arg)
5514 && simple_operand_p (lr_arg))
5517 if (operand_equal_p (ll_arg, rl_arg, 0)
5518 && operand_equal_p (lr_arg, rr_arg, 0))
5520 result = combine_comparisons (code, lcode, rcode,
5521 truth_type, ll_arg, lr_arg);
5525 else if (operand_equal_p (ll_arg, rr_arg, 0)
5526 && operand_equal_p (lr_arg, rl_arg, 0))
5528 result = combine_comparisons (code, lcode,
5529 swap_tree_comparison (rcode),
5530 truth_type, ll_arg, lr_arg);
5536 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5537 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5539 /* If the RHS can be evaluated unconditionally and its operands are
5540 simple, it wins to evaluate the RHS unconditionally on machines
5541 with expensive branches. In this case, this isn't a comparison
5542 that can be merged. Avoid doing this if the RHS is a floating-point
5543 comparison since those can trap. */
5545 if (BRANCH_COST >= 2
5546 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5547 && simple_operand_p (rl_arg)
5548 && simple_operand_p (rr_arg))
5550 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5551 if (code == TRUTH_OR_EXPR
5552 && lcode == NE_EXPR && integer_zerop (lr_arg)
5553 && rcode == NE_EXPR && integer_zerop (rr_arg)
5554 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5555 return build2 (NE_EXPR, truth_type,
5556 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5558 build_int_cst (TREE_TYPE (ll_arg), 0));
5560 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5561 if (code == TRUTH_AND_EXPR
5562 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5563 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5564 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5565 return build2 (EQ_EXPR, truth_type,
5566 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5568 build_int_cst (TREE_TYPE (ll_arg), 0));
5570 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5572 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5573 return build2 (code, truth_type, lhs, rhs);
5578 /* See if the comparisons can be merged. Then get all the parameters for
5581 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5582 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5586 ll_inner = decode_field_reference (ll_arg,
5587 &ll_bitsize, &ll_bitpos, &ll_mode,
5588 &ll_unsignedp, &volatilep, &ll_mask,
5590 lr_inner = decode_field_reference (lr_arg,
5591 &lr_bitsize, &lr_bitpos, &lr_mode,
5592 &lr_unsignedp, &volatilep, &lr_mask,
5594 rl_inner = decode_field_reference (rl_arg,
5595 &rl_bitsize, &rl_bitpos, &rl_mode,
5596 &rl_unsignedp, &volatilep, &rl_mask,
5598 rr_inner = decode_field_reference (rr_arg,
5599 &rr_bitsize, &rr_bitpos, &rr_mode,
5600 &rr_unsignedp, &volatilep, &rr_mask,
5603 /* It must be true that the inner operation on the lhs of each
5604 comparison must be the same if we are to be able to do anything.
5605 Then see if we have constants. If not, the same must be true for
5607 if (volatilep || ll_inner == 0 || rl_inner == 0
5608 || ! operand_equal_p (ll_inner, rl_inner, 0))
5611 if (TREE_CODE (lr_arg) == INTEGER_CST
5612 && TREE_CODE (rr_arg) == INTEGER_CST)
5613 l_const = lr_arg, r_const = rr_arg;
5614 else if (lr_inner == 0 || rr_inner == 0
5615 || ! operand_equal_p (lr_inner, rr_inner, 0))
5618 l_const = r_const = 0;
5620 /* If either comparison code is not correct for our logical operation,
5621 fail. However, we can convert a one-bit comparison against zero into
5622 the opposite comparison against that bit being set in the field. */
5624 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5625 if (lcode != wanted_code)
5627 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5629 /* Make the left operand unsigned, since we are only interested
5630 in the value of one bit. Otherwise we are doing the wrong
5639 /* This is analogous to the code for l_const above. */
5640 if (rcode != wanted_code)
5642 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5651 /* See if we can find a mode that contains both fields being compared on
5652 the left. If we can't, fail. Otherwise, update all constants and masks
5653 to be relative to a field of that size. */
5654 first_bit = MIN (ll_bitpos, rl_bitpos);
5655 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5656 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5657 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5659 if (lnmode == VOIDmode)
5662 lnbitsize = GET_MODE_BITSIZE (lnmode);
5663 lnbitpos = first_bit & ~ (lnbitsize - 1);
5664 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5665 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5667 if (BYTES_BIG_ENDIAN)
5669 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5670 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5673 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5674 size_int (xll_bitpos), 0);
5675 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5676 size_int (xrl_bitpos), 0);
5680 l_const = fold_convert (lntype, l_const);
5681 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5682 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5683 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5684 fold_build1 (BIT_NOT_EXPR,
5688 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5690 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5695 r_const = fold_convert (lntype, r_const);
5696 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5697 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5698 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5699 fold_build1 (BIT_NOT_EXPR,
5703 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5705 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5709 /* If the right sides are not constant, do the same for it. Also,
5710 disallow this optimization if a size or signedness mismatch occurs
5711 between the left and right sides. */
5714 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
5715 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
5716 /* Make sure the two fields on the right
5717 correspond to the left without being swapped. */
5718 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
5721 first_bit = MIN (lr_bitpos, rr_bitpos);
5722 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
5723 rnmode = get_best_mode (end_bit - first_bit, first_bit,
5724 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
5726 if (rnmode == VOIDmode)
5729 rnbitsize = GET_MODE_BITSIZE (rnmode);
5730 rnbitpos = first_bit & ~ (rnbitsize - 1);
5731 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
5732 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
5734 if (BYTES_BIG_ENDIAN)
5736 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
5737 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
5740 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
5741 size_int (xlr_bitpos), 0);
5742 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
5743 size_int (xrr_bitpos), 0);
5745 /* Make a mask that corresponds to both fields being compared.
5746 Do this for both items being compared. If the operands are the
5747 same size and the bits being compared are in the same position
5748 then we can do this by masking both and comparing the masked
5750 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5751 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
5752 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
5754 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5755 ll_unsignedp || rl_unsignedp);
5756 if (! all_ones_mask_p (ll_mask, lnbitsize))
5757 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
5759 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
5760 lr_unsignedp || rr_unsignedp);
5761 if (! all_ones_mask_p (lr_mask, rnbitsize))
5762 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
5764 return build2 (wanted_code, truth_type, lhs, rhs);
5767 /* There is still another way we can do something: If both pairs of
5768 fields being compared are adjacent, we may be able to make a wider
5769 field containing them both.
5771 Note that we still must mask the lhs/rhs expressions. Furthermore,
5772 the mask must be shifted to account for the shift done by
5773 make_bit_field_ref. */
5774 if ((ll_bitsize + ll_bitpos == rl_bitpos
5775 && lr_bitsize + lr_bitpos == rr_bitpos)
5776 || (ll_bitpos == rl_bitpos + rl_bitsize
5777 && lr_bitpos == rr_bitpos + rr_bitsize))
5781 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
5782 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
5783 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
5784 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
5786 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
5787 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
5788 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
5789 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
5791 /* Convert to the smaller type before masking out unwanted bits. */
5793 if (lntype != rntype)
5795 if (lnbitsize > rnbitsize)
5797 lhs = fold_convert (rntype, lhs);
5798 ll_mask = fold_convert (rntype, ll_mask);
5801 else if (lnbitsize < rnbitsize)
5803 rhs = fold_convert (lntype, rhs);
5804 lr_mask = fold_convert (lntype, lr_mask);
5809 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
5810 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
5812 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
5813 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
5815 return build2 (wanted_code, truth_type, lhs, rhs);
5821 /* Handle the case of comparisons with constants. If there is something in
5822 common between the masks, those bits of the constants must be the same.
5823 If not, the condition is always false. Test for this to avoid generating
5824 incorrect code below. */
5825 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5826 if (! integer_zerop (result)
5827 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5828 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5830 if (wanted_code == NE_EXPR)
5832 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5833 return constant_boolean_node (true, truth_type);
5837 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5838 return constant_boolean_node (false, truth_type);
5842 /* Construct the expression we will return. First get the component
5843 reference we will make. Unless the mask is all ones the width of
5844 that field, perform the mask operation. Then compare with the
5846 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5847 ll_unsignedp || rl_unsignedp);
5849 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5850 if (! all_ones_mask_p (ll_mask, lnbitsize))
5851 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
5853 return build2 (wanted_code, truth_type, result,
5854 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
5857 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5861 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5864 enum tree_code op_code;
5865 tree comp_const = op1;
5867 int consts_equal, consts_lt;
5870 STRIP_SIGN_NOPS (arg0);
5872 op_code = TREE_CODE (arg0);
5873 minmax_const = TREE_OPERAND (arg0, 1);
5874 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5875 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5876 inner = TREE_OPERAND (arg0, 0);
5878 /* If something does not permit us to optimize, return the original tree. */
5879 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5880 || TREE_CODE (comp_const) != INTEGER_CST
5881 || TREE_OVERFLOW (comp_const)
5882 || TREE_CODE (minmax_const) != INTEGER_CST
5883 || TREE_OVERFLOW (minmax_const))
5886 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5887 and GT_EXPR, doing the rest with recursive calls using logical
5891 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5893 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5896 return invert_truthvalue (tem);
5902 fold_build2 (TRUTH_ORIF_EXPR, type,
5903 optimize_minmax_comparison
5904 (EQ_EXPR, type, arg0, comp_const),
5905 optimize_minmax_comparison
5906 (GT_EXPR, type, arg0, comp_const));
5909 if (op_code == MAX_EXPR && consts_equal)
5910 /* MAX (X, 0) == 0 -> X <= 0 */
5911 return fold_build2 (LE_EXPR, type, inner, comp_const);
5913 else if (op_code == MAX_EXPR && consts_lt)
5914 /* MAX (X, 0) == 5 -> X == 5 */
5915 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5917 else if (op_code == MAX_EXPR)
5918 /* MAX (X, 0) == -1 -> false */
5919 return omit_one_operand (type, integer_zero_node, inner);
5921 else if (consts_equal)
5922 /* MIN (X, 0) == 0 -> X >= 0 */
5923 return fold_build2 (GE_EXPR, type, inner, comp_const);
5926 /* MIN (X, 0) == 5 -> false */
5927 return omit_one_operand (type, integer_zero_node, inner);
5930 /* MIN (X, 0) == -1 -> X == -1 */
5931 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5934 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5935 /* MAX (X, 0) > 0 -> X > 0
5936 MAX (X, 0) > 5 -> X > 5 */
5937 return fold_build2 (GT_EXPR, type, inner, comp_const);
5939 else if (op_code == MAX_EXPR)
5940 /* MAX (X, 0) > -1 -> true */
5941 return omit_one_operand (type, integer_one_node, inner);
5943 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5944 /* MIN (X, 0) > 0 -> false
5945 MIN (X, 0) > 5 -> false */
5946 return omit_one_operand (type, integer_zero_node, inner);
5949 /* MIN (X, 0) > -1 -> X > -1 */
5950 return fold_build2 (GT_EXPR, type, inner, comp_const);
5957 /* T is an integer expression that is being multiplied, divided, or taken a
5958 modulus (CODE says which and what kind of divide or modulus) by a
5959 constant C. See if we can eliminate that operation by folding it with
5960 other operations already in T. WIDE_TYPE, if non-null, is a type that
5961 should be used for the computation if wider than our type.
5963 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5964 (X * 2) + (Y * 4). We must, however, be assured that either the original
5965 expression would not overflow or that overflow is undefined for the type
5966 in the language in question.
5968 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5969 the machine has a multiply-accumulate insn or that this is part of an
5970 addressing calculation.
5972 If we return a non-null expression, it is an equivalent form of the
5973 original computation, but need not be in the original type.
5975 We set *STRICT_OVERFLOW_P to true if the return values depends on
5976 signed overflow being undefined. Otherwise we do not change
5977 *STRICT_OVERFLOW_P. */
5980 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
5981 bool *strict_overflow_p)
5983 /* To avoid exponential search depth, refuse to allow recursion past
5984 three levels. Beyond that (1) it's highly unlikely that we'll find
5985 something interesting and (2) we've probably processed it before
5986 when we built the inner expression. */
5995 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
6002 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
6003 bool *strict_overflow_p)
6005 tree type = TREE_TYPE (t);
6006 enum tree_code tcode = TREE_CODE (t);
6007 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
6008 > GET_MODE_SIZE (TYPE_MODE (type)))
6009 ? wide_type : type);
6011 int same_p = tcode == code;
6012 tree op0 = NULL_TREE, op1 = NULL_TREE;
6013 bool sub_strict_overflow_p;
6015 /* Don't deal with constants of zero here; they confuse the code below. */
6016 if (integer_zerop (c))
6019 if (TREE_CODE_CLASS (tcode) == tcc_unary)
6020 op0 = TREE_OPERAND (t, 0);
6022 if (TREE_CODE_CLASS (tcode) == tcc_binary)
6023 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
6025 /* Note that we need not handle conditional operations here since fold
6026 already handles those cases. So just do arithmetic here. */
6030 /* For a constant, we can always simplify if we are a multiply
6031 or (for divide and modulus) if it is a multiple of our constant. */
6032 if (code == MULT_EXPR
6033 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
6034 return const_binop (code, fold_convert (ctype, t),
6035 fold_convert (ctype, c), 0);
6038 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
6039 /* If op0 is an expression ... */
6040 if ((COMPARISON_CLASS_P (op0)
6041 || UNARY_CLASS_P (op0)
6042 || BINARY_CLASS_P (op0)
6043 || VL_EXP_CLASS_P (op0)
6044 || EXPRESSION_CLASS_P (op0))
6045 /* ... and is unsigned, and its type is smaller than ctype,
6046 then we cannot pass through as widening. */
6047 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
6048 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
6049 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
6050 && (GET_MODE_SIZE (TYPE_MODE (ctype))
6051 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
6052 /* ... or this is a truncation (t is narrower than op0),
6053 then we cannot pass through this narrowing. */
6054 || (GET_MODE_SIZE (TYPE_MODE (type))
6055 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
6056 /* ... or signedness changes for division or modulus,
6057 then we cannot pass through this conversion. */
6058 || (code != MULT_EXPR
6059 && (TYPE_UNSIGNED (ctype)
6060 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
6063 /* Pass the constant down and see if we can make a simplification. If
6064 we can, replace this expression with the inner simplification for
6065 possible later conversion to our or some other type. */
6066 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
6067 && TREE_CODE (t2) == INTEGER_CST
6068 && !TREE_OVERFLOW (t2)
6069 && (0 != (t1 = extract_muldiv (op0, t2, code,
6071 ? ctype : NULL_TREE,
6072 strict_overflow_p))))
6077 /* If widening the type changes it from signed to unsigned, then we
6078 must avoid building ABS_EXPR itself as unsigned. */
6079 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
6081 tree cstype = (*signed_type_for) (ctype);
6082 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
6085 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
6086 return fold_convert (ctype, t1);
6092 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
6094 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
6097 case MIN_EXPR: case MAX_EXPR:
6098 /* If widening the type changes the signedness, then we can't perform
6099 this optimization as that changes the result. */
6100 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
6103 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
6104 sub_strict_overflow_p = false;
6105 if ((t1 = extract_muldiv (op0, c, code, wide_type,
6106 &sub_strict_overflow_p)) != 0
6107 && (t2 = extract_muldiv (op1, c, code, wide_type,
6108 &sub_strict_overflow_p)) != 0)
6110 if (tree_int_cst_sgn (c) < 0)
6111 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
6112 if (sub_strict_overflow_p)
6113 *strict_overflow_p = true;
6114 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6115 fold_convert (ctype, t2));
6119 case LSHIFT_EXPR: case RSHIFT_EXPR:
6120 /* If the second operand is constant, this is a multiplication
6121 or floor division, by a power of two, so we can treat it that
6122 way unless the multiplier or divisor overflows. Signed
6123 left-shift overflow is implementation-defined rather than
6124 undefined in C90, so do not convert signed left shift into
6126 if (TREE_CODE (op1) == INTEGER_CST
6127 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
6128 /* const_binop may not detect overflow correctly,
6129 so check for it explicitly here. */
6130 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
6131 && TREE_INT_CST_HIGH (op1) == 0
6132 && 0 != (t1 = fold_convert (ctype,
6133 const_binop (LSHIFT_EXPR,
6136 && !TREE_OVERFLOW (t1))
6137 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
6138 ? MULT_EXPR : FLOOR_DIV_EXPR,
6139 ctype, fold_convert (ctype, op0), t1),
6140 c, code, wide_type, strict_overflow_p);
6143 case PLUS_EXPR: case MINUS_EXPR:
6144 /* See if we can eliminate the operation on both sides. If we can, we
6145 can return a new PLUS or MINUS. If we can't, the only remaining
6146 cases where we can do anything are if the second operand is a
6148 sub_strict_overflow_p = false;
6149 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
6150 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
6151 if (t1 != 0 && t2 != 0
6152 && (code == MULT_EXPR
6153 /* If not multiplication, we can only do this if both operands
6154 are divisible by c. */
6155 || (multiple_of_p (ctype, op0, c)
6156 && multiple_of_p (ctype, op1, c))))
6158 if (sub_strict_overflow_p)
6159 *strict_overflow_p = true;
6160 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6161 fold_convert (ctype, t2));
6164 /* If this was a subtraction, negate OP1 and set it to be an addition.
6165 This simplifies the logic below. */
6166 if (tcode == MINUS_EXPR)
6167 tcode = PLUS_EXPR, op1 = negate_expr (op1);
6169 if (TREE_CODE (op1) != INTEGER_CST)
6172 /* If either OP1 or C are negative, this optimization is not safe for
6173 some of the division and remainder types while for others we need
6174 to change the code. */
6175 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
6177 if (code == CEIL_DIV_EXPR)
6178 code = FLOOR_DIV_EXPR;
6179 else if (code == FLOOR_DIV_EXPR)
6180 code = CEIL_DIV_EXPR;
6181 else if (code != MULT_EXPR
6182 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
6186 /* If it's a multiply or a division/modulus operation of a multiple
6187 of our constant, do the operation and verify it doesn't overflow. */
6188 if (code == MULT_EXPR
6189 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6191 op1 = const_binop (code, fold_convert (ctype, op1),
6192 fold_convert (ctype, c), 0);
6193 /* We allow the constant to overflow with wrapping semantics. */
6195 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
6201 /* If we have an unsigned type is not a sizetype, we cannot widen
6202 the operation since it will change the result if the original
6203 computation overflowed. */
6204 if (TYPE_UNSIGNED (ctype)
6205 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
6209 /* If we were able to eliminate our operation from the first side,
6210 apply our operation to the second side and reform the PLUS. */
6211 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
6212 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
6214 /* The last case is if we are a multiply. In that case, we can
6215 apply the distributive law to commute the multiply and addition
6216 if the multiplication of the constants doesn't overflow. */
6217 if (code == MULT_EXPR)
6218 return fold_build2 (tcode, ctype,
6219 fold_build2 (code, ctype,
6220 fold_convert (ctype, op0),
6221 fold_convert (ctype, c)),
6227 /* We have a special case here if we are doing something like
6228 (C * 8) % 4 since we know that's zero. */
6229 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
6230 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
6231 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
6232 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6233 return omit_one_operand (type, integer_zero_node, op0);
6235 /* ... fall through ... */
6237 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
6238 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
6239 /* If we can extract our operation from the LHS, do so and return a
6240 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
6241 do something only if the second operand is a constant. */
6243 && (t1 = extract_muldiv (op0, c, code, wide_type,
6244 strict_overflow_p)) != 0)
6245 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6246 fold_convert (ctype, op1));
6247 else if (tcode == MULT_EXPR && code == MULT_EXPR
6248 && (t1 = extract_muldiv (op1, c, code, wide_type,
6249 strict_overflow_p)) != 0)
6250 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6251 fold_convert (ctype, t1));
6252 else if (TREE_CODE (op1) != INTEGER_CST)
6255 /* If these are the same operation types, we can associate them
6256 assuming no overflow. */
6258 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
6259 fold_convert (ctype, c), 0))
6260 && !TREE_OVERFLOW (t1))
6261 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
6263 /* If these operations "cancel" each other, we have the main
6264 optimizations of this pass, which occur when either constant is a
6265 multiple of the other, in which case we replace this with either an
6266 operation or CODE or TCODE.
6268 If we have an unsigned type that is not a sizetype, we cannot do
6269 this since it will change the result if the original computation
6271 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
6272 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
6273 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
6274 || (tcode == MULT_EXPR
6275 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
6276 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
6277 && code != MULT_EXPR)))
6279 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6281 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6282 *strict_overflow_p = true;
6283 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6284 fold_convert (ctype,
6285 const_binop (TRUNC_DIV_EXPR,
6288 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
6290 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6291 *strict_overflow_p = true;
6292 return fold_build2 (code, ctype, fold_convert (ctype, op0),
6293 fold_convert (ctype,
6294 const_binop (TRUNC_DIV_EXPR,
6307 /* Return a node which has the indicated constant VALUE (either 0 or
6308 1), and is of the indicated TYPE. */
6311 constant_boolean_node (int value, tree type)
6313 if (type == integer_type_node)
6314 return value ? integer_one_node : integer_zero_node;
6315 else if (type == boolean_type_node)
6316 return value ? boolean_true_node : boolean_false_node;
6318 return build_int_cst (type, value);
6322 /* Return true if expr looks like an ARRAY_REF and set base and
6323 offset to the appropriate trees. If there is no offset,
6324 offset is set to NULL_TREE. Base will be canonicalized to
6325 something you can get the element type from using
6326 TREE_TYPE (TREE_TYPE (base)). Offset will be the offset
6327 in bytes to the base in sizetype. */
6330 extract_array_ref (tree expr, tree *base, tree *offset)
6332 /* One canonical form is a PLUS_EXPR with the first
6333 argument being an ADDR_EXPR with a possible NOP_EXPR
6335 if (TREE_CODE (expr) == POINTER_PLUS_EXPR)
6337 tree op0 = TREE_OPERAND (expr, 0);
6338 tree inner_base, dummy1;
6339 /* Strip NOP_EXPRs here because the C frontends and/or
6340 folders present us (int *)&x.a p+ 4 possibly. */
6342 if (extract_array_ref (op0, &inner_base, &dummy1))
6345 *offset = fold_convert (sizetype, TREE_OPERAND (expr, 1));
6346 if (dummy1 != NULL_TREE)
6347 *offset = fold_build2 (PLUS_EXPR, sizetype,
6352 /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
6353 which we transform into an ADDR_EXPR with appropriate
6354 offset. For other arguments to the ADDR_EXPR we assume
6355 zero offset and as such do not care about the ADDR_EXPR
6356 type and strip possible nops from it. */
6357 else if (TREE_CODE (expr) == ADDR_EXPR)
6359 tree op0 = TREE_OPERAND (expr, 0);
6360 if (TREE_CODE (op0) == ARRAY_REF)
6362 tree idx = TREE_OPERAND (op0, 1);
6363 *base = TREE_OPERAND (op0, 0);
6364 *offset = fold_build2 (MULT_EXPR, TREE_TYPE (idx), idx,
6365 array_ref_element_size (op0));
6366 *offset = fold_convert (sizetype, *offset);
6370 /* Handle array-to-pointer decay as &a. */
6371 if (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE)
6372 *base = TREE_OPERAND (expr, 0);
6375 *offset = NULL_TREE;
6379 /* The next canonical form is a VAR_DECL with POINTER_TYPE. */
6380 else if (SSA_VAR_P (expr)
6381 && TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
6384 *offset = NULL_TREE;
6392 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6393 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6394 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6395 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6396 COND is the first argument to CODE; otherwise (as in the example
6397 given here), it is the second argument. TYPE is the type of the
6398 original expression. Return NULL_TREE if no simplification is
6402 fold_binary_op_with_conditional_arg (enum tree_code code,
6403 tree type, tree op0, tree op1,
6404 tree cond, tree arg, int cond_first_p)
6406 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6407 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6408 tree test, true_value, false_value;
6409 tree lhs = NULL_TREE;
6410 tree rhs = NULL_TREE;
6412 /* This transformation is only worthwhile if we don't have to wrap
6413 arg in a SAVE_EXPR, and the operation can be simplified on at least
6414 one of the branches once its pushed inside the COND_EXPR. */
6415 if (!TREE_CONSTANT (arg))
6418 if (TREE_CODE (cond) == COND_EXPR)
6420 test = TREE_OPERAND (cond, 0);
6421 true_value = TREE_OPERAND (cond, 1);
6422 false_value = TREE_OPERAND (cond, 2);
6423 /* If this operand throws an expression, then it does not make
6424 sense to try to perform a logical or arithmetic operation
6426 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6428 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6433 tree testtype = TREE_TYPE (cond);
6435 true_value = constant_boolean_node (true, testtype);
6436 false_value = constant_boolean_node (false, testtype);
6439 arg = fold_convert (arg_type, arg);
6442 true_value = fold_convert (cond_type, true_value);
6444 lhs = fold_build2 (code, type, true_value, arg);
6446 lhs = fold_build2 (code, type, arg, true_value);
6450 false_value = fold_convert (cond_type, false_value);
6452 rhs = fold_build2 (code, type, false_value, arg);
6454 rhs = fold_build2 (code, type, arg, false_value);
6457 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6458 return fold_convert (type, test);
6462 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6464 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6465 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6466 ADDEND is the same as X.
6468 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6469 and finite. The problematic cases are when X is zero, and its mode
6470 has signed zeros. In the case of rounding towards -infinity,
6471 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6472 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6475 fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
6477 if (!real_zerop (addend))
6480 /* Don't allow the fold with -fsignaling-nans. */
6481 if (HONOR_SNANS (TYPE_MODE (type)))
6484 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6485 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6488 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6489 if (TREE_CODE (addend) == REAL_CST
6490 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6493 /* The mode has signed zeros, and we have to honor their sign.
6494 In this situation, there is only one case we can return true for.
6495 X - 0 is the same as X unless rounding towards -infinity is
6497 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6500 /* Subroutine of fold() that checks comparisons of built-in math
6501 functions against real constants.
6503 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6504 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6505 is the type of the result and ARG0 and ARG1 are the operands of the
6506 comparison. ARG1 must be a TREE_REAL_CST.
6508 The function returns the constant folded tree if a simplification
6509 can be made, and NULL_TREE otherwise. */
6512 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6513 tree type, tree arg0, tree arg1)
6517 if (BUILTIN_SQRT_P (fcode))
6519 tree arg = CALL_EXPR_ARG (arg0, 0);
6520 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6522 c = TREE_REAL_CST (arg1);
6523 if (REAL_VALUE_NEGATIVE (c))
6525 /* sqrt(x) < y is always false, if y is negative. */
6526 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6527 return omit_one_operand (type, integer_zero_node, arg);
6529 /* sqrt(x) > y is always true, if y is negative and we
6530 don't care about NaNs, i.e. negative values of x. */
6531 if (code == NE_EXPR || !HONOR_NANS (mode))
6532 return omit_one_operand (type, integer_one_node, arg);
6534 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6535 return fold_build2 (GE_EXPR, type, arg,
6536 build_real (TREE_TYPE (arg), dconst0));
6538 else if (code == GT_EXPR || code == GE_EXPR)
6542 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6543 real_convert (&c2, mode, &c2);
6545 if (REAL_VALUE_ISINF (c2))
6547 /* sqrt(x) > y is x == +Inf, when y is very large. */
6548 if (HONOR_INFINITIES (mode))
6549 return fold_build2 (EQ_EXPR, type, arg,
6550 build_real (TREE_TYPE (arg), c2));
6552 /* sqrt(x) > y is always false, when y is very large
6553 and we don't care about infinities. */
6554 return omit_one_operand (type, integer_zero_node, arg);
6557 /* sqrt(x) > c is the same as x > c*c. */
6558 return fold_build2 (code, type, arg,
6559 build_real (TREE_TYPE (arg), c2));
6561 else if (code == LT_EXPR || code == LE_EXPR)
6565 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6566 real_convert (&c2, mode, &c2);
6568 if (REAL_VALUE_ISINF (c2))
6570 /* sqrt(x) < y is always true, when y is a very large
6571 value and we don't care about NaNs or Infinities. */
6572 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6573 return omit_one_operand (type, integer_one_node, arg);
6575 /* sqrt(x) < y is x != +Inf when y is very large and we
6576 don't care about NaNs. */
6577 if (! HONOR_NANS (mode))
6578 return fold_build2 (NE_EXPR, type, arg,
6579 build_real (TREE_TYPE (arg), c2));
6581 /* sqrt(x) < y is x >= 0 when y is very large and we
6582 don't care about Infinities. */
6583 if (! HONOR_INFINITIES (mode))
6584 return fold_build2 (GE_EXPR, type, arg,
6585 build_real (TREE_TYPE (arg), dconst0));
6587 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6588 if (lang_hooks.decls.global_bindings_p () != 0
6589 || CONTAINS_PLACEHOLDER_P (arg))
6592 arg = save_expr (arg);
6593 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6594 fold_build2 (GE_EXPR, type, arg,
6595 build_real (TREE_TYPE (arg),
6597 fold_build2 (NE_EXPR, type, arg,
6598 build_real (TREE_TYPE (arg),
6602 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6603 if (! HONOR_NANS (mode))
6604 return fold_build2 (code, type, arg,
6605 build_real (TREE_TYPE (arg), c2));
6607 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6608 if (lang_hooks.decls.global_bindings_p () == 0
6609 && ! CONTAINS_PLACEHOLDER_P (arg))
6611 arg = save_expr (arg);
6612 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6613 fold_build2 (GE_EXPR, type, arg,
6614 build_real (TREE_TYPE (arg),
6616 fold_build2 (code, type, arg,
6617 build_real (TREE_TYPE (arg),
6626 /* Subroutine of fold() that optimizes comparisons against Infinities,
6627 either +Inf or -Inf.
6629 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6630 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6631 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6633 The function returns the constant folded tree if a simplification
6634 can be made, and NULL_TREE otherwise. */
6637 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6639 enum machine_mode mode;
6640 REAL_VALUE_TYPE max;
6644 mode = TYPE_MODE (TREE_TYPE (arg0));
6646 /* For negative infinity swap the sense of the comparison. */
6647 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6649 code = swap_tree_comparison (code);
6654 /* x > +Inf is always false, if with ignore sNANs. */
6655 if (HONOR_SNANS (mode))
6657 return omit_one_operand (type, integer_zero_node, arg0);
6660 /* x <= +Inf is always true, if we don't case about NaNs. */
6661 if (! HONOR_NANS (mode))
6662 return omit_one_operand (type, integer_one_node, arg0);
6664 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6665 if (lang_hooks.decls.global_bindings_p () == 0
6666 && ! CONTAINS_PLACEHOLDER_P (arg0))
6668 arg0 = save_expr (arg0);
6669 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6675 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6676 real_maxval (&max, neg, mode);
6677 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6678 arg0, build_real (TREE_TYPE (arg0), max));
6681 /* x < +Inf is always equal to x <= DBL_MAX. */
6682 real_maxval (&max, neg, mode);
6683 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6684 arg0, build_real (TREE_TYPE (arg0), max));
6687 /* x != +Inf is always equal to !(x > DBL_MAX). */
6688 real_maxval (&max, neg, mode);
6689 if (! HONOR_NANS (mode))
6690 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6691 arg0, build_real (TREE_TYPE (arg0), max));
6693 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6694 arg0, build_real (TREE_TYPE (arg0), max));
6695 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6704 /* Subroutine of fold() that optimizes comparisons of a division by
6705 a nonzero integer constant against an integer constant, i.e.
6708 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6709 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6710 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6712 The function returns the constant folded tree if a simplification
6713 can be made, and NULL_TREE otherwise. */
6716 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6718 tree prod, tmp, hi, lo;
6719 tree arg00 = TREE_OPERAND (arg0, 0);
6720 tree arg01 = TREE_OPERAND (arg0, 1);
6721 unsigned HOST_WIDE_INT lpart;
6722 HOST_WIDE_INT hpart;
6723 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6727 /* We have to do this the hard way to detect unsigned overflow.
6728 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6729 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6730 TREE_INT_CST_HIGH (arg01),
6731 TREE_INT_CST_LOW (arg1),
6732 TREE_INT_CST_HIGH (arg1),
6733 &lpart, &hpart, unsigned_p);
6734 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6736 neg_overflow = false;
6740 tmp = int_const_binop (MINUS_EXPR, arg01,
6741 build_int_cst (TREE_TYPE (arg01), 1), 0);
6744 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6745 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6746 TREE_INT_CST_HIGH (prod),
6747 TREE_INT_CST_LOW (tmp),
6748 TREE_INT_CST_HIGH (tmp),
6749 &lpart, &hpart, unsigned_p);
6750 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6751 -1, overflow | TREE_OVERFLOW (prod));
6753 else if (tree_int_cst_sgn (arg01) >= 0)
6755 tmp = int_const_binop (MINUS_EXPR, arg01,
6756 build_int_cst (TREE_TYPE (arg01), 1), 0);
6757 switch (tree_int_cst_sgn (arg1))
6760 neg_overflow = true;
6761 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6766 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6771 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6781 /* A negative divisor reverses the relational operators. */
6782 code = swap_tree_comparison (code);
6784 tmp = int_const_binop (PLUS_EXPR, arg01,
6785 build_int_cst (TREE_TYPE (arg01), 1), 0);
6786 switch (tree_int_cst_sgn (arg1))
6789 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6794 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6799 neg_overflow = true;
6800 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6812 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6813 return omit_one_operand (type, integer_zero_node, arg00);
6814 if (TREE_OVERFLOW (hi))
6815 return fold_build2 (GE_EXPR, type, arg00, lo);
6816 if (TREE_OVERFLOW (lo))
6817 return fold_build2 (LE_EXPR, type, arg00, hi);
6818 return build_range_check (type, arg00, 1, lo, hi);
6821 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6822 return omit_one_operand (type, integer_one_node, arg00);
6823 if (TREE_OVERFLOW (hi))
6824 return fold_build2 (LT_EXPR, type, arg00, lo);
6825 if (TREE_OVERFLOW (lo))
6826 return fold_build2 (GT_EXPR, type, arg00, hi);
6827 return build_range_check (type, arg00, 0, lo, hi);
6830 if (TREE_OVERFLOW (lo))
6832 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6833 return omit_one_operand (type, tmp, arg00);
6835 return fold_build2 (LT_EXPR, type, arg00, lo);
6838 if (TREE_OVERFLOW (hi))
6840 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6841 return omit_one_operand (type, tmp, arg00);
6843 return fold_build2 (LE_EXPR, type, arg00, hi);
6846 if (TREE_OVERFLOW (hi))
6848 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6849 return omit_one_operand (type, tmp, arg00);
6851 return fold_build2 (GT_EXPR, type, arg00, hi);
6854 if (TREE_OVERFLOW (lo))
6856 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6857 return omit_one_operand (type, tmp, arg00);
6859 return fold_build2 (GE_EXPR, type, arg00, lo);
6869 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6870 equality/inequality test, then return a simplified form of the test
6871 using a sign testing. Otherwise return NULL. TYPE is the desired
6875 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6878 /* If this is testing a single bit, we can optimize the test. */
6879 if ((code == NE_EXPR || code == EQ_EXPR)
6880 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6881 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6883 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6884 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6885 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6887 if (arg00 != NULL_TREE
6888 /* This is only a win if casting to a signed type is cheap,
6889 i.e. when arg00's type is not a partial mode. */
6890 && TYPE_PRECISION (TREE_TYPE (arg00))
6891 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6893 tree stype = signed_type_for (TREE_TYPE (arg00));
6894 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6895 result_type, fold_convert (stype, arg00),
6896 build_int_cst (stype, 0));
6903 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6904 equality/inequality test, then return a simplified form of
6905 the test using shifts and logical operations. Otherwise return
6906 NULL. TYPE is the desired result type. */
6909 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6912 /* If this is testing a single bit, we can optimize the test. */
6913 if ((code == NE_EXPR || code == EQ_EXPR)
6914 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6915 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6917 tree inner = TREE_OPERAND (arg0, 0);
6918 tree type = TREE_TYPE (arg0);
6919 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6920 enum machine_mode operand_mode = TYPE_MODE (type);
6922 tree signed_type, unsigned_type, intermediate_type;
6925 /* First, see if we can fold the single bit test into a sign-bit
6927 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6932 /* Otherwise we have (A & C) != 0 where C is a single bit,
6933 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6934 Similarly for (A & C) == 0. */
6936 /* If INNER is a right shift of a constant and it plus BITNUM does
6937 not overflow, adjust BITNUM and INNER. */
6938 if (TREE_CODE (inner) == RSHIFT_EXPR
6939 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6940 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6941 && bitnum < TYPE_PRECISION (type)
6942 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6943 bitnum - TYPE_PRECISION (type)))
6945 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6946 inner = TREE_OPERAND (inner, 0);
6949 /* If we are going to be able to omit the AND below, we must do our
6950 operations as unsigned. If we must use the AND, we have a choice.
6951 Normally unsigned is faster, but for some machines signed is. */
6952 #ifdef LOAD_EXTEND_OP
6953 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6954 && !flag_syntax_only) ? 0 : 1;
6959 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6960 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6961 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6962 inner = fold_convert (intermediate_type, inner);
6965 inner = build2 (RSHIFT_EXPR, intermediate_type,
6966 inner, size_int (bitnum));
6968 one = build_int_cst (intermediate_type, 1);
6970 if (code == EQ_EXPR)
6971 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6973 /* Put the AND last so it can combine with more things. */
6974 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6976 /* Make sure to return the proper type. */
6977 inner = fold_convert (result_type, inner);
6984 /* Check whether we are allowed to reorder operands arg0 and arg1,
6985 such that the evaluation of arg1 occurs before arg0. */
6988 reorder_operands_p (const_tree arg0, const_tree arg1)
6990 if (! flag_evaluation_order)
6992 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6994 return ! TREE_SIDE_EFFECTS (arg0)
6995 && ! TREE_SIDE_EFFECTS (arg1);
6998 /* Test whether it is preferable two swap two operands, ARG0 and
6999 ARG1, for example because ARG0 is an integer constant and ARG1
7000 isn't. If REORDER is true, only recommend swapping if we can
7001 evaluate the operands in reverse order. */
7004 tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
7006 STRIP_SIGN_NOPS (arg0);
7007 STRIP_SIGN_NOPS (arg1);
7009 if (TREE_CODE (arg1) == INTEGER_CST)
7011 if (TREE_CODE (arg0) == INTEGER_CST)
7014 if (TREE_CODE (arg1) == REAL_CST)
7016 if (TREE_CODE (arg0) == REAL_CST)
7019 if (TREE_CODE (arg1) == FIXED_CST)
7021 if (TREE_CODE (arg0) == FIXED_CST)
7024 if (TREE_CODE (arg1) == COMPLEX_CST)
7026 if (TREE_CODE (arg0) == COMPLEX_CST)
7029 if (TREE_CONSTANT (arg1))
7031 if (TREE_CONSTANT (arg0))
7037 if (reorder && flag_evaluation_order
7038 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
7041 /* It is preferable to swap two SSA_NAME to ensure a canonical form
7042 for commutative and comparison operators. Ensuring a canonical
7043 form allows the optimizers to find additional redundancies without
7044 having to explicitly check for both orderings. */
7045 if (TREE_CODE (arg0) == SSA_NAME
7046 && TREE_CODE (arg1) == SSA_NAME
7047 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
7050 /* Put SSA_NAMEs last. */
7051 if (TREE_CODE (arg1) == SSA_NAME)
7053 if (TREE_CODE (arg0) == SSA_NAME)
7056 /* Put variables last. */
7065 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
7066 ARG0 is extended to a wider type. */
7069 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
7071 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
7073 tree shorter_type, outer_type;
7077 if (arg0_unw == arg0)
7079 shorter_type = TREE_TYPE (arg0_unw);
7081 #ifdef HAVE_canonicalize_funcptr_for_compare
7082 /* Disable this optimization if we're casting a function pointer
7083 type on targets that require function pointer canonicalization. */
7084 if (HAVE_canonicalize_funcptr_for_compare
7085 && TREE_CODE (shorter_type) == POINTER_TYPE
7086 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
7090 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
7093 arg1_unw = get_unwidened (arg1, shorter_type);
7095 /* If possible, express the comparison in the shorter mode. */
7096 if ((code == EQ_EXPR || code == NE_EXPR
7097 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
7098 && (TREE_TYPE (arg1_unw) == shorter_type
7099 || (TREE_CODE (arg1_unw) == INTEGER_CST
7100 && (TREE_CODE (shorter_type) == INTEGER_TYPE
7101 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
7102 && int_fits_type_p (arg1_unw, shorter_type))))
7103 return fold_build2 (code, type, arg0_unw,
7104 fold_convert (shorter_type, arg1_unw));
7106 if (TREE_CODE (arg1_unw) != INTEGER_CST
7107 || TREE_CODE (shorter_type) != INTEGER_TYPE
7108 || !int_fits_type_p (arg1_unw, shorter_type))
7111 /* If we are comparing with the integer that does not fit into the range
7112 of the shorter type, the result is known. */
7113 outer_type = TREE_TYPE (arg1_unw);
7114 min = lower_bound_in_type (outer_type, shorter_type);
7115 max = upper_bound_in_type (outer_type, shorter_type);
7117 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7119 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7126 return omit_one_operand (type, integer_zero_node, arg0);
7131 return omit_one_operand (type, integer_one_node, arg0);
7137 return omit_one_operand (type, integer_one_node, arg0);
7139 return omit_one_operand (type, integer_zero_node, arg0);
7144 return omit_one_operand (type, integer_zero_node, arg0);
7146 return omit_one_operand (type, integer_one_node, arg0);
7155 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
7156 ARG0 just the signedness is changed. */
7159 fold_sign_changed_comparison (enum tree_code code, tree type,
7160 tree arg0, tree arg1)
7163 tree inner_type, outer_type;
7165 if (TREE_CODE (arg0) != NOP_EXPR
7166 && TREE_CODE (arg0) != CONVERT_EXPR)
7169 outer_type = TREE_TYPE (arg0);
7170 arg0_inner = TREE_OPERAND (arg0, 0);
7171 inner_type = TREE_TYPE (arg0_inner);
7173 #ifdef HAVE_canonicalize_funcptr_for_compare
7174 /* Disable this optimization if we're casting a function pointer
7175 type on targets that require function pointer canonicalization. */
7176 if (HAVE_canonicalize_funcptr_for_compare
7177 && TREE_CODE (inner_type) == POINTER_TYPE
7178 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
7182 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
7185 if (TREE_CODE (arg1) != INTEGER_CST
7186 && !((TREE_CODE (arg1) == NOP_EXPR
7187 || TREE_CODE (arg1) == CONVERT_EXPR)
7188 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
7191 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
7196 if (TREE_CODE (arg1) == INTEGER_CST)
7197 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
7198 TREE_INT_CST_HIGH (arg1), 0,
7199 TREE_OVERFLOW (arg1));
7201 arg1 = fold_convert (inner_type, arg1);
7203 return fold_build2 (code, type, arg0_inner, arg1);
7206 /* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
7207 step of the array. Reconstructs s and delta in the case of s * delta
7208 being an integer constant (and thus already folded).
7209 ADDR is the address. MULT is the multiplicative expression.
7210 If the function succeeds, the new address expression is returned. Otherwise
7211 NULL_TREE is returned. */
7214 try_move_mult_to_index (tree addr, tree op1)
7216 tree s, delta, step;
7217 tree ref = TREE_OPERAND (addr, 0), pref;
7222 /* Strip the nops that might be added when converting op1 to sizetype. */
7225 /* Canonicalize op1 into a possibly non-constant delta
7226 and an INTEGER_CST s. */
7227 if (TREE_CODE (op1) == MULT_EXPR)
7229 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
7234 if (TREE_CODE (arg0) == INTEGER_CST)
7239 else if (TREE_CODE (arg1) == INTEGER_CST)
7247 else if (TREE_CODE (op1) == INTEGER_CST)
7254 /* Simulate we are delta * 1. */
7256 s = integer_one_node;
7259 for (;; ref = TREE_OPERAND (ref, 0))
7261 if (TREE_CODE (ref) == ARRAY_REF)
7263 /* Remember if this was a multi-dimensional array. */
7264 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
7267 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
7271 step = array_ref_element_size (ref);
7272 if (TREE_CODE (step) != INTEGER_CST)
7277 if (! tree_int_cst_equal (step, s))
7282 /* Try if delta is a multiple of step. */
7283 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
7289 /* Only fold here if we can verify we do not overflow one
7290 dimension of a multi-dimensional array. */
7295 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
7296 || !INTEGRAL_TYPE_P (itype)
7297 || !TYPE_MAX_VALUE (itype)
7298 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
7301 tmp = fold_binary (PLUS_EXPR, itype,
7302 fold_convert (itype,
7303 TREE_OPERAND (ref, 1)),
7304 fold_convert (itype, delta));
7306 || TREE_CODE (tmp) != INTEGER_CST
7307 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
7316 if (!handled_component_p (ref))
7320 /* We found the suitable array reference. So copy everything up to it,
7321 and replace the index. */
7323 pref = TREE_OPERAND (addr, 0);
7324 ret = copy_node (pref);
7329 pref = TREE_OPERAND (pref, 0);
7330 TREE_OPERAND (pos, 0) = copy_node (pref);
7331 pos = TREE_OPERAND (pos, 0);
7334 TREE_OPERAND (pos, 1) = fold_build2 (PLUS_EXPR, itype,
7335 fold_convert (itype,
7336 TREE_OPERAND (pos, 1)),
7337 fold_convert (itype, delta));
7339 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
7343 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
7344 means A >= Y && A != MAX, but in this case we know that
7345 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
7348 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
7350 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
7352 if (TREE_CODE (bound) == LT_EXPR)
7353 a = TREE_OPERAND (bound, 0);
7354 else if (TREE_CODE (bound) == GT_EXPR)
7355 a = TREE_OPERAND (bound, 1);
7359 typea = TREE_TYPE (a);
7360 if (!INTEGRAL_TYPE_P (typea)
7361 && !POINTER_TYPE_P (typea))
7364 if (TREE_CODE (ineq) == LT_EXPR)
7366 a1 = TREE_OPERAND (ineq, 1);
7367 y = TREE_OPERAND (ineq, 0);
7369 else if (TREE_CODE (ineq) == GT_EXPR)
7371 a1 = TREE_OPERAND (ineq, 0);
7372 y = TREE_OPERAND (ineq, 1);
7377 if (TREE_TYPE (a1) != typea)
7380 if (POINTER_TYPE_P (typea))
7382 /* Convert the pointer types into integer before taking the difference. */
7383 tree ta = fold_convert (ssizetype, a);
7384 tree ta1 = fold_convert (ssizetype, a1);
7385 diff = fold_binary (MINUS_EXPR, ssizetype, ta1, ta);
7388 diff = fold_binary (MINUS_EXPR, typea, a1, a);
7390 if (!diff || !integer_onep (diff))
7393 return fold_build2 (GE_EXPR, type, a, y);
7396 /* Fold a sum or difference of at least one multiplication.
7397 Returns the folded tree or NULL if no simplification could be made. */
7400 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7402 tree arg00, arg01, arg10, arg11;
7403 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7405 /* (A * C) +- (B * C) -> (A+-B) * C.
7406 (A * C) +- A -> A * (C+-1).
7407 We are most concerned about the case where C is a constant,
7408 but other combinations show up during loop reduction. Since
7409 it is not difficult, try all four possibilities. */
7411 if (TREE_CODE (arg0) == MULT_EXPR)
7413 arg00 = TREE_OPERAND (arg0, 0);
7414 arg01 = TREE_OPERAND (arg0, 1);
7416 else if (TREE_CODE (arg0) == INTEGER_CST)
7418 arg00 = build_one_cst (type);
7423 /* We cannot generate constant 1 for fract. */
7424 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7427 arg01 = build_one_cst (type);
7429 if (TREE_CODE (arg1) == MULT_EXPR)
7431 arg10 = TREE_OPERAND (arg1, 0);
7432 arg11 = TREE_OPERAND (arg1, 1);
7434 else if (TREE_CODE (arg1) == INTEGER_CST)
7436 arg10 = build_one_cst (type);
7441 /* We cannot generate constant 1 for fract. */
7442 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7445 arg11 = build_one_cst (type);
7449 if (operand_equal_p (arg01, arg11, 0))
7450 same = arg01, alt0 = arg00, alt1 = arg10;
7451 else if (operand_equal_p (arg00, arg10, 0))
7452 same = arg00, alt0 = arg01, alt1 = arg11;
7453 else if (operand_equal_p (arg00, arg11, 0))
7454 same = arg00, alt0 = arg01, alt1 = arg10;
7455 else if (operand_equal_p (arg01, arg10, 0))
7456 same = arg01, alt0 = arg00, alt1 = arg11;
7458 /* No identical multiplicands; see if we can find a common
7459 power-of-two factor in non-power-of-two multiplies. This
7460 can help in multi-dimensional array access. */
7461 else if (host_integerp (arg01, 0)
7462 && host_integerp (arg11, 0))
7464 HOST_WIDE_INT int01, int11, tmp;
7467 int01 = TREE_INT_CST_LOW (arg01);
7468 int11 = TREE_INT_CST_LOW (arg11);
7470 /* Move min of absolute values to int11. */
7471 if ((int01 >= 0 ? int01 : -int01)
7472 < (int11 >= 0 ? int11 : -int11))
7474 tmp = int01, int01 = int11, int11 = tmp;
7475 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7482 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
7484 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7485 build_int_cst (TREE_TYPE (arg00),
7490 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7495 return fold_build2 (MULT_EXPR, type,
7496 fold_build2 (code, type,
7497 fold_convert (type, alt0),
7498 fold_convert (type, alt1)),
7499 fold_convert (type, same));
7504 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7505 specified by EXPR into the buffer PTR of length LEN bytes.
7506 Return the number of bytes placed in the buffer, or zero
7510 native_encode_int (const_tree expr, unsigned char *ptr, int len)
7512 tree type = TREE_TYPE (expr);
7513 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7514 int byte, offset, word, words;
7515 unsigned char value;
7517 if (total_bytes > len)
7519 words = total_bytes / UNITS_PER_WORD;
7521 for (byte = 0; byte < total_bytes; byte++)
7523 int bitpos = byte * BITS_PER_UNIT;
7524 if (bitpos < HOST_BITS_PER_WIDE_INT)
7525 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7527 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7528 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7530 if (total_bytes > UNITS_PER_WORD)
7532 word = byte / UNITS_PER_WORD;
7533 if (WORDS_BIG_ENDIAN)
7534 word = (words - 1) - word;
7535 offset = word * UNITS_PER_WORD;
7536 if (BYTES_BIG_ENDIAN)
7537 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7539 offset += byte % UNITS_PER_WORD;
7542 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7543 ptr[offset] = value;
7549 /* Subroutine of native_encode_expr. Encode the REAL_CST
7550 specified by EXPR into the buffer PTR of length LEN bytes.
7551 Return the number of bytes placed in the buffer, or zero
7555 native_encode_real (const_tree expr, unsigned char *ptr, int len)
7557 tree type = TREE_TYPE (expr);
7558 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7559 int byte, offset, word, words, bitpos;
7560 unsigned char value;
7562 /* There are always 32 bits in each long, no matter the size of
7563 the hosts long. We handle floating point representations with
7567 if (total_bytes > len)
7569 words = 32 / UNITS_PER_WORD;
7571 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7573 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7574 bitpos += BITS_PER_UNIT)
7576 byte = (bitpos / BITS_PER_UNIT) & 3;
7577 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7579 if (UNITS_PER_WORD < 4)
7581 word = byte / UNITS_PER_WORD;
7582 if (WORDS_BIG_ENDIAN)
7583 word = (words - 1) - word;
7584 offset = word * UNITS_PER_WORD;
7585 if (BYTES_BIG_ENDIAN)
7586 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7588 offset += byte % UNITS_PER_WORD;
7591 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7592 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7597 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7598 specified by EXPR into the buffer PTR of length LEN bytes.
7599 Return the number of bytes placed in the buffer, or zero
7603 native_encode_complex (const_tree expr, unsigned char *ptr, int len)
7608 part = TREE_REALPART (expr);
7609 rsize = native_encode_expr (part, ptr, len);
7612 part = TREE_IMAGPART (expr);
7613 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7616 return rsize + isize;
7620 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7621 specified by EXPR into the buffer PTR of length LEN bytes.
7622 Return the number of bytes placed in the buffer, or zero
7626 native_encode_vector (const_tree expr, unsigned char *ptr, int len)
7628 int i, size, offset, count;
7629 tree itype, elem, elements;
7632 elements = TREE_VECTOR_CST_ELTS (expr);
7633 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7634 itype = TREE_TYPE (TREE_TYPE (expr));
7635 size = GET_MODE_SIZE (TYPE_MODE (itype));
7636 for (i = 0; i < count; i++)
7640 elem = TREE_VALUE (elements);
7641 elements = TREE_CHAIN (elements);
7648 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7653 if (offset + size > len)
7655 memset (ptr+offset, 0, size);
7663 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7664 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7665 buffer PTR of length LEN bytes. Return the number of bytes
7666 placed in the buffer, or zero upon failure. */
7669 native_encode_expr (const_tree expr, unsigned char *ptr, int len)
7671 switch (TREE_CODE (expr))
7674 return native_encode_int (expr, ptr, len);
7677 return native_encode_real (expr, ptr, len);
7680 return native_encode_complex (expr, ptr, len);
7683 return native_encode_vector (expr, ptr, len);
7691 /* Subroutine of native_interpret_expr. Interpret the contents of
7692 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7693 If the buffer cannot be interpreted, return NULL_TREE. */
7696 native_interpret_int (tree type, const unsigned char *ptr, int len)
7698 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7699 int byte, offset, word, words;
7700 unsigned char value;
7701 unsigned int HOST_WIDE_INT lo = 0;
7702 HOST_WIDE_INT hi = 0;
7704 if (total_bytes > len)
7706 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7708 words = total_bytes / UNITS_PER_WORD;
7710 for (byte = 0; byte < total_bytes; byte++)
7712 int bitpos = byte * BITS_PER_UNIT;
7713 if (total_bytes > UNITS_PER_WORD)
7715 word = byte / UNITS_PER_WORD;
7716 if (WORDS_BIG_ENDIAN)
7717 word = (words - 1) - word;
7718 offset = word * UNITS_PER_WORD;
7719 if (BYTES_BIG_ENDIAN)
7720 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7722 offset += byte % UNITS_PER_WORD;
7725 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7726 value = ptr[offset];
7728 if (bitpos < HOST_BITS_PER_WIDE_INT)
7729 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7731 hi |= (unsigned HOST_WIDE_INT) value
7732 << (bitpos - HOST_BITS_PER_WIDE_INT);
7735 return build_int_cst_wide_type (type, lo, hi);
7739 /* Subroutine of native_interpret_expr. Interpret the contents of
7740 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7741 If the buffer cannot be interpreted, return NULL_TREE. */
7744 native_interpret_real (tree type, const unsigned char *ptr, int len)
7746 enum machine_mode mode = TYPE_MODE (type);
7747 int total_bytes = GET_MODE_SIZE (mode);
7748 int byte, offset, word, words, bitpos;
7749 unsigned char value;
7750 /* There are always 32 bits in each long, no matter the size of
7751 the hosts long. We handle floating point representations with
7756 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7757 if (total_bytes > len || total_bytes > 24)
7759 words = 32 / UNITS_PER_WORD;
7761 memset (tmp, 0, sizeof (tmp));
7762 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7763 bitpos += BITS_PER_UNIT)
7765 byte = (bitpos / BITS_PER_UNIT) & 3;
7766 if (UNITS_PER_WORD < 4)
7768 word = byte / UNITS_PER_WORD;
7769 if (WORDS_BIG_ENDIAN)
7770 word = (words - 1) - word;
7771 offset = word * UNITS_PER_WORD;
7772 if (BYTES_BIG_ENDIAN)
7773 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7775 offset += byte % UNITS_PER_WORD;
7778 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7779 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7781 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7784 real_from_target (&r, tmp, mode);
7785 return build_real (type, r);
7789 /* Subroutine of native_interpret_expr. Interpret the contents of
7790 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7791 If the buffer cannot be interpreted, return NULL_TREE. */
7794 native_interpret_complex (tree type, const unsigned char *ptr, int len)
7796 tree etype, rpart, ipart;
7799 etype = TREE_TYPE (type);
7800 size = GET_MODE_SIZE (TYPE_MODE (etype));
7803 rpart = native_interpret_expr (etype, ptr, size);
7806 ipart = native_interpret_expr (etype, ptr+size, size);
7809 return build_complex (type, rpart, ipart);
7813 /* Subroutine of native_interpret_expr. Interpret the contents of
7814 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7815 If the buffer cannot be interpreted, return NULL_TREE. */
7818 native_interpret_vector (tree type, const unsigned char *ptr, int len)
7820 tree etype, elem, elements;
7823 etype = TREE_TYPE (type);
7824 size = GET_MODE_SIZE (TYPE_MODE (etype));
7825 count = TYPE_VECTOR_SUBPARTS (type);
7826 if (size * count > len)
7829 elements = NULL_TREE;
7830 for (i = count - 1; i >= 0; i--)
7832 elem = native_interpret_expr (etype, ptr+(i*size), size);
7835 elements = tree_cons (NULL_TREE, elem, elements);
7837 return build_vector (type, elements);
7841 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7842 the buffer PTR of length LEN as a constant of type TYPE. For
7843 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7844 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7845 return NULL_TREE. */
7848 native_interpret_expr (tree type, const unsigned char *ptr, int len)
7850 switch (TREE_CODE (type))
7855 return native_interpret_int (type, ptr, len);
7858 return native_interpret_real (type, ptr, len);
7861 return native_interpret_complex (type, ptr, len);
7864 return native_interpret_vector (type, ptr, len);
7872 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7873 TYPE at compile-time. If we're unable to perform the conversion
7874 return NULL_TREE. */
7877 fold_view_convert_expr (tree type, tree expr)
7879 /* We support up to 512-bit values (for V8DFmode). */
7880 unsigned char buffer[64];
7883 /* Check that the host and target are sane. */
7884 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7887 len = native_encode_expr (expr, buffer, sizeof (buffer));
7891 return native_interpret_expr (type, buffer, len);
7894 /* Build an expression for the address of T. Folds away INDIRECT_REF
7895 to avoid confusing the gimplify process. When IN_FOLD is true
7896 avoid modifications of T. */
7899 build_fold_addr_expr_with_type_1 (tree t, tree ptrtype, bool in_fold)
7901 /* The size of the object is not relevant when talking about its address. */
7902 if (TREE_CODE (t) == WITH_SIZE_EXPR)
7903 t = TREE_OPERAND (t, 0);
7905 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
7906 if (TREE_CODE (t) == INDIRECT_REF
7907 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
7909 t = TREE_OPERAND (t, 0);
7911 if (TREE_TYPE (t) != ptrtype)
7912 t = build1 (NOP_EXPR, ptrtype, t);
7918 while (handled_component_p (base))
7919 base = TREE_OPERAND (base, 0);
7922 TREE_ADDRESSABLE (base) = 1;
7924 t = build1 (ADDR_EXPR, ptrtype, t);
7927 t = build1 (ADDR_EXPR, ptrtype, t);
7932 /* Build an expression for the address of T with type PTRTYPE. This
7933 function modifies the input parameter 'T' by sometimes setting the
7934 TREE_ADDRESSABLE flag. */
7937 build_fold_addr_expr_with_type (tree t, tree ptrtype)
7939 return build_fold_addr_expr_with_type_1 (t, ptrtype, false);
7942 /* Build an expression for the address of T. This function modifies
7943 the input parameter 'T' by sometimes setting the TREE_ADDRESSABLE
7944 flag. When called from fold functions, use fold_addr_expr instead. */
7947 build_fold_addr_expr (tree t)
7949 return build_fold_addr_expr_with_type_1 (t,
7950 build_pointer_type (TREE_TYPE (t)),
7954 /* Same as build_fold_addr_expr, builds an expression for the address
7955 of T, but avoids touching the input node 't'. Fold functions
7956 should use this version. */
7959 fold_addr_expr (tree t)
7961 tree ptrtype = build_pointer_type (TREE_TYPE (t));
7963 return build_fold_addr_expr_with_type_1 (t, ptrtype, true);
7966 /* Fold a unary expression of code CODE and type TYPE with operand
7967 OP0. Return the folded expression if folding is successful.
7968 Otherwise, return NULL_TREE. */
7971 fold_unary (enum tree_code code, tree type, tree op0)
7975 enum tree_code_class kind = TREE_CODE_CLASS (code);
7977 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7978 && TREE_CODE_LENGTH (code) == 1);
7983 if (code == NOP_EXPR || code == CONVERT_EXPR
7984 || code == FLOAT_EXPR || code == ABS_EXPR)
7986 /* Don't use STRIP_NOPS, because signedness of argument type
7988 STRIP_SIGN_NOPS (arg0);
7992 /* Strip any conversions that don't change the mode. This
7993 is safe for every expression, except for a comparison
7994 expression because its signedness is derived from its
7997 Note that this is done as an internal manipulation within
7998 the constant folder, in order to find the simplest
7999 representation of the arguments so that their form can be
8000 studied. In any cases, the appropriate type conversions
8001 should be put back in the tree that will get out of the
8007 if (TREE_CODE_CLASS (code) == tcc_unary)
8009 if (TREE_CODE (arg0) == COMPOUND_EXPR)
8010 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
8011 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
8012 else if (TREE_CODE (arg0) == COND_EXPR)
8014 tree arg01 = TREE_OPERAND (arg0, 1);
8015 tree arg02 = TREE_OPERAND (arg0, 2);
8016 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
8017 arg01 = fold_build1 (code, type, arg01);
8018 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
8019 arg02 = fold_build1 (code, type, arg02);
8020 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
8023 /* If this was a conversion, and all we did was to move into
8024 inside the COND_EXPR, bring it back out. But leave it if
8025 it is a conversion from integer to integer and the
8026 result precision is no wider than a word since such a
8027 conversion is cheap and may be optimized away by combine,
8028 while it couldn't if it were outside the COND_EXPR. Then return
8029 so we don't get into an infinite recursion loop taking the
8030 conversion out and then back in. */
8032 if ((code == NOP_EXPR || code == CONVERT_EXPR
8033 || code == NON_LVALUE_EXPR)
8034 && TREE_CODE (tem) == COND_EXPR
8035 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
8036 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
8037 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
8038 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
8039 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
8040 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
8041 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
8043 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
8044 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
8045 || flag_syntax_only))
8046 tem = build1 (code, type,
8048 TREE_TYPE (TREE_OPERAND
8049 (TREE_OPERAND (tem, 1), 0)),
8050 TREE_OPERAND (tem, 0),
8051 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
8052 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
8055 else if (COMPARISON_CLASS_P (arg0))
8057 if (TREE_CODE (type) == BOOLEAN_TYPE)
8059 arg0 = copy_node (arg0);
8060 TREE_TYPE (arg0) = type;
8063 else if (TREE_CODE (type) != INTEGER_TYPE)
8064 return fold_build3 (COND_EXPR, type, arg0,
8065 fold_build1 (code, type,
8067 fold_build1 (code, type,
8068 integer_zero_node));
8077 case FIX_TRUNC_EXPR:
8078 if (TREE_TYPE (op0) == type)
8081 /* If we have (type) (a CMP b) and type is an integral type, return
8082 new expression involving the new type. */
8083 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
8084 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
8085 TREE_OPERAND (op0, 1));
8087 /* Handle cases of two conversions in a row. */
8088 if (TREE_CODE (op0) == NOP_EXPR
8089 || TREE_CODE (op0) == CONVERT_EXPR)
8091 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
8092 tree inter_type = TREE_TYPE (op0);
8093 int inside_int = INTEGRAL_TYPE_P (inside_type);
8094 int inside_ptr = POINTER_TYPE_P (inside_type);
8095 int inside_float = FLOAT_TYPE_P (inside_type);
8096 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
8097 unsigned int inside_prec = TYPE_PRECISION (inside_type);
8098 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
8099 int inter_int = INTEGRAL_TYPE_P (inter_type);
8100 int inter_ptr = POINTER_TYPE_P (inter_type);
8101 int inter_float = FLOAT_TYPE_P (inter_type);
8102 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
8103 unsigned int inter_prec = TYPE_PRECISION (inter_type);
8104 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
8105 int final_int = INTEGRAL_TYPE_P (type);
8106 int final_ptr = POINTER_TYPE_P (type);
8107 int final_float = FLOAT_TYPE_P (type);
8108 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
8109 unsigned int final_prec = TYPE_PRECISION (type);
8110 int final_unsignedp = TYPE_UNSIGNED (type);
8112 /* In addition to the cases of two conversions in a row
8113 handled below, if we are converting something to its own
8114 type via an object of identical or wider precision, neither
8115 conversion is needed. */
8116 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
8117 && (((inter_int || inter_ptr) && final_int)
8118 || (inter_float && final_float))
8119 && inter_prec >= final_prec)
8120 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8122 /* Likewise, if the intermediate and final types are either both
8123 float or both integer, we don't need the middle conversion if
8124 it is wider than the final type and doesn't change the signedness
8125 (for integers). Avoid this if the final type is a pointer
8126 since then we sometimes need the inner conversion. Likewise if
8127 the outer has a precision not equal to the size of its mode. */
8128 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
8129 || (inter_float && inside_float)
8130 || (inter_vec && inside_vec))
8131 && inter_prec >= inside_prec
8132 && (inter_float || inter_vec
8133 || inter_unsignedp == inside_unsignedp)
8134 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
8135 && TYPE_MODE (type) == TYPE_MODE (inter_type))
8137 && (! final_vec || inter_prec == inside_prec))
8138 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8140 /* If we have a sign-extension of a zero-extended value, we can
8141 replace that by a single zero-extension. */
8142 if (inside_int && inter_int && final_int
8143 && inside_prec < inter_prec && inter_prec < final_prec
8144 && inside_unsignedp && !inter_unsignedp)
8145 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8147 /* Two conversions in a row are not needed unless:
8148 - some conversion is floating-point (overstrict for now), or
8149 - some conversion is a vector (overstrict for now), or
8150 - the intermediate type is narrower than both initial and
8152 - the intermediate type and innermost type differ in signedness,
8153 and the outermost type is wider than the intermediate, or
8154 - the initial type is a pointer type and the precisions of the
8155 intermediate and final types differ, or
8156 - the final type is a pointer type and the precisions of the
8157 initial and intermediate types differ.
8158 - the final type is a pointer type and the initial type not
8159 - the initial type is a pointer to an array and the final type
8161 if (! inside_float && ! inter_float && ! final_float
8162 && ! inside_vec && ! inter_vec && ! final_vec
8163 && (inter_prec >= inside_prec || inter_prec >= final_prec)
8164 && ! (inside_int && inter_int
8165 && inter_unsignedp != inside_unsignedp
8166 && inter_prec < final_prec)
8167 && ((inter_unsignedp && inter_prec > inside_prec)
8168 == (final_unsignedp && final_prec > inter_prec))
8169 && ! (inside_ptr && inter_prec != final_prec)
8170 && ! (final_ptr && inside_prec != inter_prec)
8171 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
8172 && TYPE_MODE (type) == TYPE_MODE (inter_type))
8173 && final_ptr == inside_ptr
8175 && TREE_CODE (TREE_TYPE (inside_type)) == ARRAY_TYPE
8176 && TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
8177 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8180 /* Handle (T *)&A.B.C for A being of type T and B and C
8181 living at offset zero. This occurs frequently in
8182 C++ upcasting and then accessing the base. */
8183 if (TREE_CODE (op0) == ADDR_EXPR
8184 && POINTER_TYPE_P (type)
8185 && handled_component_p (TREE_OPERAND (op0, 0)))
8187 HOST_WIDE_INT bitsize, bitpos;
8189 enum machine_mode mode;
8190 int unsignedp, volatilep;
8191 tree base = TREE_OPERAND (op0, 0);
8192 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
8193 &mode, &unsignedp, &volatilep, false);
8194 /* If the reference was to a (constant) zero offset, we can use
8195 the address of the base if it has the same base type
8196 as the result type. */
8197 if (! offset && bitpos == 0
8198 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
8199 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
8200 return fold_convert (type, fold_addr_expr (base));
8203 if ((TREE_CODE (op0) == MODIFY_EXPR
8204 || TREE_CODE (op0) == GIMPLE_MODIFY_STMT)
8205 && TREE_CONSTANT (GENERIC_TREE_OPERAND (op0, 1))
8206 /* Detect assigning a bitfield. */
8207 && !(TREE_CODE (GENERIC_TREE_OPERAND (op0, 0)) == COMPONENT_REF
8209 (TREE_OPERAND (GENERIC_TREE_OPERAND (op0, 0), 1))))
8211 /* Don't leave an assignment inside a conversion
8212 unless assigning a bitfield. */
8213 tem = fold_build1 (code, type, GENERIC_TREE_OPERAND (op0, 1));
8214 /* First do the assignment, then return converted constant. */
8215 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
8216 TREE_NO_WARNING (tem) = 1;
8217 TREE_USED (tem) = 1;
8221 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
8222 constants (if x has signed type, the sign bit cannot be set
8223 in c). This folds extension into the BIT_AND_EXPR. */
8224 if (INTEGRAL_TYPE_P (type)
8225 && TREE_CODE (type) != BOOLEAN_TYPE
8226 && TREE_CODE (op0) == BIT_AND_EXPR
8227 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
8230 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
8233 if (TYPE_UNSIGNED (TREE_TYPE (and))
8234 || (TYPE_PRECISION (type)
8235 <= TYPE_PRECISION (TREE_TYPE (and))))
8237 else if (TYPE_PRECISION (TREE_TYPE (and1))
8238 <= HOST_BITS_PER_WIDE_INT
8239 && host_integerp (and1, 1))
8241 unsigned HOST_WIDE_INT cst;
8243 cst = tree_low_cst (and1, 1);
8244 cst &= (HOST_WIDE_INT) -1
8245 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
8246 change = (cst == 0);
8247 #ifdef LOAD_EXTEND_OP
8249 && !flag_syntax_only
8250 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
8253 tree uns = unsigned_type_for (TREE_TYPE (and0));
8254 and0 = fold_convert (uns, and0);
8255 and1 = fold_convert (uns, and1);
8261 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
8262 TREE_INT_CST_HIGH (and1), 0,
8263 TREE_OVERFLOW (and1));
8264 return fold_build2 (BIT_AND_EXPR, type,
8265 fold_convert (type, and0), tem);
8269 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
8270 when one of the new casts will fold away. Conservatively we assume
8271 that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
8272 if (POINTER_TYPE_P (type)
8273 && TREE_CODE (arg0) == POINTER_PLUS_EXPR
8274 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8275 || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
8276 || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
8278 tree arg00 = TREE_OPERAND (arg0, 0);
8279 tree arg01 = TREE_OPERAND (arg0, 1);
8281 return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
8282 fold_convert (sizetype, arg01));
8285 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
8286 of the same precision, and X is an integer type not narrower than
8287 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
8288 if (INTEGRAL_TYPE_P (type)
8289 && TREE_CODE (op0) == BIT_NOT_EXPR
8290 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
8291 && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
8292 || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
8293 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
8295 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
8296 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
8297 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
8298 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
8301 tem = fold_convert_const (code, type, op0);
8302 return tem ? tem : NULL_TREE;
8304 case FIXED_CONVERT_EXPR:
8305 tem = fold_convert_const (code, type, arg0);
8306 return tem ? tem : NULL_TREE;
8308 case VIEW_CONVERT_EXPR:
8309 if (TREE_TYPE (op0) == type)
8311 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
8312 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
8313 return fold_view_convert_expr (type, op0);
8316 tem = fold_negate_expr (arg0);
8318 return fold_convert (type, tem);
8322 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
8323 return fold_abs_const (arg0, type);
8324 else if (TREE_CODE (arg0) == NEGATE_EXPR)
8325 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
8326 /* Convert fabs((double)float) into (double)fabsf(float). */
8327 else if (TREE_CODE (arg0) == NOP_EXPR
8328 && TREE_CODE (type) == REAL_TYPE)
8330 tree targ0 = strip_float_extensions (arg0);
8332 return fold_convert (type, fold_build1 (ABS_EXPR,
8336 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
8337 else if (TREE_CODE (arg0) == ABS_EXPR)
8339 else if (tree_expr_nonnegative_p (arg0))
8342 /* Strip sign ops from argument. */
8343 if (TREE_CODE (type) == REAL_TYPE)
8345 tem = fold_strip_sign_ops (arg0);
8347 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
8352 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8353 return fold_convert (type, arg0);
8354 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8356 tree itype = TREE_TYPE (type);
8357 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
8358 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
8359 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
8361 if (TREE_CODE (arg0) == COMPLEX_CST)
8363 tree itype = TREE_TYPE (type);
8364 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
8365 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
8366 return build_complex (type, rpart, negate_expr (ipart));
8368 if (TREE_CODE (arg0) == CONJ_EXPR)
8369 return fold_convert (type, TREE_OPERAND (arg0, 0));
8373 if (TREE_CODE (arg0) == INTEGER_CST)
8374 return fold_not_const (arg0, type);
8375 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
8376 return TREE_OPERAND (arg0, 0);
8377 /* Convert ~ (-A) to A - 1. */
8378 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
8379 return fold_build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
8380 build_int_cst (type, 1));
8381 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
8382 else if (INTEGRAL_TYPE_P (type)
8383 && ((TREE_CODE (arg0) == MINUS_EXPR
8384 && integer_onep (TREE_OPERAND (arg0, 1)))
8385 || (TREE_CODE (arg0) == PLUS_EXPR
8386 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
8387 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
8388 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8389 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8390 && (tem = fold_unary (BIT_NOT_EXPR, type,
8392 TREE_OPERAND (arg0, 0)))))
8393 return fold_build2 (BIT_XOR_EXPR, type, tem,
8394 fold_convert (type, TREE_OPERAND (arg0, 1)));
8395 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8396 && (tem = fold_unary (BIT_NOT_EXPR, type,
8398 TREE_OPERAND (arg0, 1)))))
8399 return fold_build2 (BIT_XOR_EXPR, type,
8400 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
8401 /* Perform BIT_NOT_EXPR on each element individually. */
8402 else if (TREE_CODE (arg0) == VECTOR_CST)
8404 tree elements = TREE_VECTOR_CST_ELTS (arg0), elem, list = NULL_TREE;
8405 int count = TYPE_VECTOR_SUBPARTS (type), i;
8407 for (i = 0; i < count; i++)
8411 elem = TREE_VALUE (elements);
8412 elem = fold_unary (BIT_NOT_EXPR, TREE_TYPE (type), elem);
8413 if (elem == NULL_TREE)
8415 elements = TREE_CHAIN (elements);
8418 elem = build_int_cst (TREE_TYPE (type), -1);
8419 list = tree_cons (NULL_TREE, elem, list);
8422 return build_vector (type, nreverse (list));
8427 case TRUTH_NOT_EXPR:
8428 /* The argument to invert_truthvalue must have Boolean type. */
8429 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8430 arg0 = fold_convert (boolean_type_node, arg0);
8432 /* Note that the operand of this must be an int
8433 and its values must be 0 or 1.
8434 ("true" is a fixed value perhaps depending on the language,
8435 but we don't handle values other than 1 correctly yet.) */
8436 tem = fold_truth_not_expr (arg0);
8439 return fold_convert (type, tem);
8442 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8443 return fold_convert (type, arg0);
8444 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8445 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8446 TREE_OPERAND (arg0, 1));
8447 if (TREE_CODE (arg0) == COMPLEX_CST)
8448 return fold_convert (type, TREE_REALPART (arg0));
8449 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8451 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8452 tem = fold_build2 (TREE_CODE (arg0), itype,
8453 fold_build1 (REALPART_EXPR, itype,
8454 TREE_OPERAND (arg0, 0)),
8455 fold_build1 (REALPART_EXPR, itype,
8456 TREE_OPERAND (arg0, 1)));
8457 return fold_convert (type, tem);
8459 if (TREE_CODE (arg0) == CONJ_EXPR)
8461 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8462 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8463 return fold_convert (type, tem);
8465 if (TREE_CODE (arg0) == CALL_EXPR)
8467 tree fn = get_callee_fndecl (arg0);
8468 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8469 switch (DECL_FUNCTION_CODE (fn))
8471 CASE_FLT_FN (BUILT_IN_CEXPI):
8472 fn = mathfn_built_in (type, BUILT_IN_COS);
8474 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8484 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8485 return fold_convert (type, integer_zero_node);
8486 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8487 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8488 TREE_OPERAND (arg0, 0));
8489 if (TREE_CODE (arg0) == COMPLEX_CST)
8490 return fold_convert (type, TREE_IMAGPART (arg0));
8491 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8493 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8494 tem = fold_build2 (TREE_CODE (arg0), itype,
8495 fold_build1 (IMAGPART_EXPR, itype,
8496 TREE_OPERAND (arg0, 0)),
8497 fold_build1 (IMAGPART_EXPR, itype,
8498 TREE_OPERAND (arg0, 1)));
8499 return fold_convert (type, tem);
8501 if (TREE_CODE (arg0) == CONJ_EXPR)
8503 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8504 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8505 return fold_convert (type, negate_expr (tem));
8507 if (TREE_CODE (arg0) == CALL_EXPR)
8509 tree fn = get_callee_fndecl (arg0);
8510 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8511 switch (DECL_FUNCTION_CODE (fn))
8513 CASE_FLT_FN (BUILT_IN_CEXPI):
8514 fn = mathfn_built_in (type, BUILT_IN_SIN);
8516 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8527 } /* switch (code) */
8530 /* Fold a binary expression of code CODE and type TYPE with operands
8531 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8532 Return the folded expression if folding is successful. Otherwise,
8533 return NULL_TREE. */
8536 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8538 enum tree_code compl_code;
8540 if (code == MIN_EXPR)
8541 compl_code = MAX_EXPR;
8542 else if (code == MAX_EXPR)
8543 compl_code = MIN_EXPR;
8547 /* MIN (MAX (a, b), b) == b. */
8548 if (TREE_CODE (op0) == compl_code
8549 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8550 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8552 /* MIN (MAX (b, a), b) == b. */
8553 if (TREE_CODE (op0) == compl_code
8554 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8555 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8556 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8558 /* MIN (a, MAX (a, b)) == a. */
8559 if (TREE_CODE (op1) == compl_code
8560 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8561 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8562 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8564 /* MIN (a, MAX (b, a)) == a. */
8565 if (TREE_CODE (op1) == compl_code
8566 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8567 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8568 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8573 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8574 by changing CODE to reduce the magnitude of constants involved in
8575 ARG0 of the comparison.
8576 Returns a canonicalized comparison tree if a simplification was
8577 possible, otherwise returns NULL_TREE.
8578 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8579 valid if signed overflow is undefined. */
8582 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8583 tree arg0, tree arg1,
8584 bool *strict_overflow_p)
8586 enum tree_code code0 = TREE_CODE (arg0);
8587 tree t, cst0 = NULL_TREE;
8591 /* Match A +- CST code arg1 and CST code arg1. */
8592 if (!(((code0 == MINUS_EXPR
8593 || code0 == PLUS_EXPR)
8594 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8595 || code0 == INTEGER_CST))
8598 /* Identify the constant in arg0 and its sign. */
8599 if (code0 == INTEGER_CST)
8602 cst0 = TREE_OPERAND (arg0, 1);
8603 sgn0 = tree_int_cst_sgn (cst0);
8605 /* Overflowed constants and zero will cause problems. */
8606 if (integer_zerop (cst0)
8607 || TREE_OVERFLOW (cst0))
8610 /* See if we can reduce the magnitude of the constant in
8611 arg0 by changing the comparison code. */
8612 if (code0 == INTEGER_CST)
8614 /* CST <= arg1 -> CST-1 < arg1. */
8615 if (code == LE_EXPR && sgn0 == 1)
8617 /* -CST < arg1 -> -CST-1 <= arg1. */
8618 else if (code == LT_EXPR && sgn0 == -1)
8620 /* CST > arg1 -> CST-1 >= arg1. */
8621 else if (code == GT_EXPR && sgn0 == 1)
8623 /* -CST >= arg1 -> -CST-1 > arg1. */
8624 else if (code == GE_EXPR && sgn0 == -1)
8628 /* arg1 code' CST' might be more canonical. */
8633 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8635 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8637 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8638 else if (code == GT_EXPR
8639 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8641 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8642 else if (code == LE_EXPR
8643 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8645 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8646 else if (code == GE_EXPR
8647 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8651 *strict_overflow_p = true;
8654 /* Now build the constant reduced in magnitude. */
8655 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8656 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8657 if (code0 != INTEGER_CST)
8658 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8660 /* If swapping might yield to a more canonical form, do so. */
8662 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8664 return fold_build2 (code, type, t, arg1);
8667 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8668 overflow further. Try to decrease the magnitude of constants involved
8669 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8670 and put sole constants at the second argument position.
8671 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8674 maybe_canonicalize_comparison (enum tree_code code, tree type,
8675 tree arg0, tree arg1)
8678 bool strict_overflow_p;
8679 const char * const warnmsg = G_("assuming signed overflow does not occur "
8680 "when reducing constant in comparison");
8682 /* In principle pointers also have undefined overflow behavior,
8683 but that causes problems elsewhere. */
8684 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8685 || POINTER_TYPE_P (TREE_TYPE (arg0)))
8688 /* Try canonicalization by simplifying arg0. */
8689 strict_overflow_p = false;
8690 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8691 &strict_overflow_p);
8694 if (strict_overflow_p)
8695 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8699 /* Try canonicalization by simplifying arg1 using the swapped
8701 code = swap_tree_comparison (code);
8702 strict_overflow_p = false;
8703 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8704 &strict_overflow_p);
8705 if (t && strict_overflow_p)
8706 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8710 /* Subroutine of fold_binary. This routine performs all of the
8711 transformations that are common to the equality/inequality
8712 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8713 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8714 fold_binary should call fold_binary. Fold a comparison with
8715 tree code CODE and type TYPE with operands OP0 and OP1. Return
8716 the folded comparison or NULL_TREE. */
8719 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8721 tree arg0, arg1, tem;
8726 STRIP_SIGN_NOPS (arg0);
8727 STRIP_SIGN_NOPS (arg1);
8729 tem = fold_relational_const (code, type, arg0, arg1);
8730 if (tem != NULL_TREE)
8733 /* If one arg is a real or integer constant, put it last. */
8734 if (tree_swap_operands_p (arg0, arg1, true))
8735 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8737 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8738 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8739 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8740 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8741 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8742 && (TREE_CODE (arg1) == INTEGER_CST
8743 && !TREE_OVERFLOW (arg1)))
8745 tree const1 = TREE_OPERAND (arg0, 1);
8747 tree variable = TREE_OPERAND (arg0, 0);
8750 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8752 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8753 TREE_TYPE (arg1), const2, const1);
8755 /* If the constant operation overflowed this can be
8756 simplified as a comparison against INT_MAX/INT_MIN. */
8757 if (TREE_CODE (lhs) == INTEGER_CST
8758 && TREE_OVERFLOW (lhs))
8760 int const1_sgn = tree_int_cst_sgn (const1);
8761 enum tree_code code2 = code;
8763 /* Get the sign of the constant on the lhs if the
8764 operation were VARIABLE + CONST1. */
8765 if (TREE_CODE (arg0) == MINUS_EXPR)
8766 const1_sgn = -const1_sgn;
8768 /* The sign of the constant determines if we overflowed
8769 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8770 Canonicalize to the INT_MIN overflow by swapping the comparison
8772 if (const1_sgn == -1)
8773 code2 = swap_tree_comparison (code);
8775 /* We now can look at the canonicalized case
8776 VARIABLE + 1 CODE2 INT_MIN
8777 and decide on the result. */
8778 if (code2 == LT_EXPR
8780 || code2 == EQ_EXPR)
8781 return omit_one_operand (type, boolean_false_node, variable);
8782 else if (code2 == NE_EXPR
8784 || code2 == GT_EXPR)
8785 return omit_one_operand (type, boolean_true_node, variable);
8788 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8789 && (TREE_CODE (lhs) != INTEGER_CST
8790 || !TREE_OVERFLOW (lhs)))
8792 fold_overflow_warning (("assuming signed overflow does not occur "
8793 "when changing X +- C1 cmp C2 to "
8795 WARN_STRICT_OVERFLOW_COMPARISON);
8796 return fold_build2 (code, type, variable, lhs);
8800 /* For comparisons of pointers we can decompose it to a compile time
8801 comparison of the base objects and the offsets into the object.
8802 This requires at least one operand being an ADDR_EXPR to do more
8803 than the operand_equal_p test below. */
8804 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8805 && (TREE_CODE (arg0) == ADDR_EXPR
8806 || TREE_CODE (arg1) == ADDR_EXPR))
8808 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8809 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8810 enum machine_mode mode;
8811 int volatilep, unsignedp;
8812 bool indirect_base0 = false;
8814 /* Get base and offset for the access. Strip ADDR_EXPR for
8815 get_inner_reference, but put it back by stripping INDIRECT_REF
8816 off the base object if possible. */
8818 if (TREE_CODE (arg0) == ADDR_EXPR)
8820 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8821 &bitsize, &bitpos0, &offset0, &mode,
8822 &unsignedp, &volatilep, false);
8823 if (TREE_CODE (base0) == INDIRECT_REF)
8824 base0 = TREE_OPERAND (base0, 0);
8826 indirect_base0 = true;
8830 if (TREE_CODE (arg1) == ADDR_EXPR)
8832 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8833 &bitsize, &bitpos1, &offset1, &mode,
8834 &unsignedp, &volatilep, false);
8835 /* We have to make sure to have an indirect/non-indirect base1
8836 just the same as we did for base0. */
8837 if (TREE_CODE (base1) == INDIRECT_REF
8839 base1 = TREE_OPERAND (base1, 0);
8840 else if (!indirect_base0)
8843 else if (indirect_base0)
8846 /* If we have equivalent bases we might be able to simplify. */
8848 && operand_equal_p (base0, base1, 0))
8850 /* We can fold this expression to a constant if the non-constant
8851 offset parts are equal. */
8852 if (offset0 == offset1
8853 || (offset0 && offset1
8854 && operand_equal_p (offset0, offset1, 0)))
8859 return build_int_cst (boolean_type_node, bitpos0 == bitpos1);
8861 return build_int_cst (boolean_type_node, bitpos0 != bitpos1);
8863 return build_int_cst (boolean_type_node, bitpos0 < bitpos1);
8865 return build_int_cst (boolean_type_node, bitpos0 <= bitpos1);
8867 return build_int_cst (boolean_type_node, bitpos0 >= bitpos1);
8869 return build_int_cst (boolean_type_node, bitpos0 > bitpos1);
8873 /* We can simplify the comparison to a comparison of the variable
8874 offset parts if the constant offset parts are equal.
8875 Be careful to use signed size type here because otherwise we
8876 mess with array offsets in the wrong way. This is possible
8877 because pointer arithmetic is restricted to retain within an
8878 object and overflow on pointer differences is undefined as of
8879 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8880 else if (bitpos0 == bitpos1)
8882 tree signed_size_type_node;
8883 signed_size_type_node = signed_type_for (size_type_node);
8885 /* By converting to signed size type we cover middle-end pointer
8886 arithmetic which operates on unsigned pointer types of size
8887 type size and ARRAY_REF offsets which are properly sign or
8888 zero extended from their type in case it is narrower than
8890 if (offset0 == NULL_TREE)
8891 offset0 = build_int_cst (signed_size_type_node, 0);
8893 offset0 = fold_convert (signed_size_type_node, offset0);
8894 if (offset1 == NULL_TREE)
8895 offset1 = build_int_cst (signed_size_type_node, 0);
8897 offset1 = fold_convert (signed_size_type_node, offset1);
8899 return fold_build2 (code, type, offset0, offset1);
8904 /* If this is a comparison of two exprs that look like an ARRAY_REF of the
8905 same object, then we can fold this to a comparison of the two offsets in
8906 signed size type. This is possible because pointer arithmetic is
8907 restricted to retain within an object and overflow on pointer differences
8908 is undefined as of 6.5.6/8 and /9 with respect to the signed ptrdiff_t.
8910 We check flag_wrapv directly because pointers types are unsigned,
8911 and therefore TYPE_OVERFLOW_WRAPS returns true for them. That is
8912 normally what we want to avoid certain odd overflow cases, but
8914 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8916 && !TYPE_OVERFLOW_TRAPS (TREE_TYPE (arg0)))
8918 tree base0, offset0, base1, offset1;
8920 if (extract_array_ref (arg0, &base0, &offset0)
8921 && extract_array_ref (arg1, &base1, &offset1)
8922 && operand_equal_p (base0, base1, 0))
8924 tree signed_size_type_node;
8925 signed_size_type_node = signed_type_for (size_type_node);
8927 /* By converting to signed size type we cover middle-end pointer
8928 arithmetic which operates on unsigned pointer types of size
8929 type size and ARRAY_REF offsets which are properly sign or
8930 zero extended from their type in case it is narrower than
8932 if (offset0 == NULL_TREE)
8933 offset0 = build_int_cst (signed_size_type_node, 0);
8935 offset0 = fold_convert (signed_size_type_node, offset0);
8936 if (offset1 == NULL_TREE)
8937 offset1 = build_int_cst (signed_size_type_node, 0);
8939 offset1 = fold_convert (signed_size_type_node, offset1);
8941 return fold_build2 (code, type, offset0, offset1);
8945 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8946 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8947 the resulting offset is smaller in absolute value than the
8949 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8950 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8951 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8952 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8953 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
8954 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8955 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
8957 tree const1 = TREE_OPERAND (arg0, 1);
8958 tree const2 = TREE_OPERAND (arg1, 1);
8959 tree variable1 = TREE_OPERAND (arg0, 0);
8960 tree variable2 = TREE_OPERAND (arg1, 0);
8962 const char * const warnmsg = G_("assuming signed overflow does not "
8963 "occur when combining constants around "
8966 /* Put the constant on the side where it doesn't overflow and is
8967 of lower absolute value than before. */
8968 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8969 ? MINUS_EXPR : PLUS_EXPR,
8971 if (!TREE_OVERFLOW (cst)
8972 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
8974 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8975 return fold_build2 (code, type,
8977 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
8981 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8982 ? MINUS_EXPR : PLUS_EXPR,
8984 if (!TREE_OVERFLOW (cst)
8985 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
8987 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8988 return fold_build2 (code, type,
8989 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
8995 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
8996 signed arithmetic case. That form is created by the compiler
8997 often enough for folding it to be of value. One example is in
8998 computing loop trip counts after Operator Strength Reduction. */
8999 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
9000 && TREE_CODE (arg0) == MULT_EXPR
9001 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9002 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
9003 && integer_zerop (arg1))
9005 tree const1 = TREE_OPERAND (arg0, 1);
9006 tree const2 = arg1; /* zero */
9007 tree variable1 = TREE_OPERAND (arg0, 0);
9008 enum tree_code cmp_code = code;
9010 gcc_assert (!integer_zerop (const1));
9012 fold_overflow_warning (("assuming signed overflow does not occur when "
9013 "eliminating multiplication in comparison "
9015 WARN_STRICT_OVERFLOW_COMPARISON);
9017 /* If const1 is negative we swap the sense of the comparison. */
9018 if (tree_int_cst_sgn (const1) < 0)
9019 cmp_code = swap_tree_comparison (cmp_code);
9021 return fold_build2 (cmp_code, type, variable1, const2);
9024 tem = maybe_canonicalize_comparison (code, type, op0, op1);
9028 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
9030 tree targ0 = strip_float_extensions (arg0);
9031 tree targ1 = strip_float_extensions (arg1);
9032 tree newtype = TREE_TYPE (targ0);
9034 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
9035 newtype = TREE_TYPE (targ1);
9037 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9038 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
9039 return fold_build2 (code, type, fold_convert (newtype, targ0),
9040 fold_convert (newtype, targ1));
9042 /* (-a) CMP (-b) -> b CMP a */
9043 if (TREE_CODE (arg0) == NEGATE_EXPR
9044 && TREE_CODE (arg1) == NEGATE_EXPR)
9045 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
9046 TREE_OPERAND (arg0, 0));
9048 if (TREE_CODE (arg1) == REAL_CST)
9050 REAL_VALUE_TYPE cst;
9051 cst = TREE_REAL_CST (arg1);
9053 /* (-a) CMP CST -> a swap(CMP) (-CST) */
9054 if (TREE_CODE (arg0) == NEGATE_EXPR)
9055 return fold_build2 (swap_tree_comparison (code), type,
9056 TREE_OPERAND (arg0, 0),
9057 build_real (TREE_TYPE (arg1),
9058 REAL_VALUE_NEGATE (cst)));
9060 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
9061 /* a CMP (-0) -> a CMP 0 */
9062 if (REAL_VALUE_MINUS_ZERO (cst))
9063 return fold_build2 (code, type, arg0,
9064 build_real (TREE_TYPE (arg1), dconst0));
9066 /* x != NaN is always true, other ops are always false. */
9067 if (REAL_VALUE_ISNAN (cst)
9068 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
9070 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
9071 return omit_one_operand (type, tem, arg0);
9074 /* Fold comparisons against infinity. */
9075 if (REAL_VALUE_ISINF (cst))
9077 tem = fold_inf_compare (code, type, arg0, arg1);
9078 if (tem != NULL_TREE)
9083 /* If this is a comparison of a real constant with a PLUS_EXPR
9084 or a MINUS_EXPR of a real constant, we can convert it into a
9085 comparison with a revised real constant as long as no overflow
9086 occurs when unsafe_math_optimizations are enabled. */
9087 if (flag_unsafe_math_optimizations
9088 && TREE_CODE (arg1) == REAL_CST
9089 && (TREE_CODE (arg0) == PLUS_EXPR
9090 || TREE_CODE (arg0) == MINUS_EXPR)
9091 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
9092 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9093 ? MINUS_EXPR : PLUS_EXPR,
9094 arg1, TREE_OPERAND (arg0, 1), 0))
9095 && !TREE_OVERFLOW (tem))
9096 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9098 /* Likewise, we can simplify a comparison of a real constant with
9099 a MINUS_EXPR whose first operand is also a real constant, i.e.
9100 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
9101 floating-point types only if -fassociative-math is set. */
9102 if (flag_associative_math
9103 && TREE_CODE (arg1) == REAL_CST
9104 && TREE_CODE (arg0) == MINUS_EXPR
9105 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
9106 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
9108 && !TREE_OVERFLOW (tem))
9109 return fold_build2 (swap_tree_comparison (code), type,
9110 TREE_OPERAND (arg0, 1), tem);
9112 /* Fold comparisons against built-in math functions. */
9113 if (TREE_CODE (arg1) == REAL_CST
9114 && flag_unsafe_math_optimizations
9115 && ! flag_errno_math)
9117 enum built_in_function fcode = builtin_mathfn_code (arg0);
9119 if (fcode != END_BUILTINS)
9121 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
9122 if (tem != NULL_TREE)
9128 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
9129 && (TREE_CODE (arg0) == NOP_EXPR
9130 || TREE_CODE (arg0) == CONVERT_EXPR))
9132 /* If we are widening one operand of an integer comparison,
9133 see if the other operand is similarly being widened. Perhaps we
9134 can do the comparison in the narrower type. */
9135 tem = fold_widened_comparison (code, type, arg0, arg1);
9139 /* Or if we are changing signedness. */
9140 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
9145 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9146 constant, we can simplify it. */
9147 if (TREE_CODE (arg1) == INTEGER_CST
9148 && (TREE_CODE (arg0) == MIN_EXPR
9149 || TREE_CODE (arg0) == MAX_EXPR)
9150 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9152 tem = optimize_minmax_comparison (code, type, op0, op1);
9157 /* Simplify comparison of something with itself. (For IEEE
9158 floating-point, we can only do some of these simplifications.) */
9159 if (operand_equal_p (arg0, arg1, 0))
9164 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9165 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9166 return constant_boolean_node (1, type);
9171 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9172 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9173 return constant_boolean_node (1, type);
9174 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9177 /* For NE, we can only do this simplification if integer
9178 or we don't honor IEEE floating point NaNs. */
9179 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
9180 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9182 /* ... fall through ... */
9185 return constant_boolean_node (0, type);
9191 /* If we are comparing an expression that just has comparisons
9192 of two integer values, arithmetic expressions of those comparisons,
9193 and constants, we can simplify it. There are only three cases
9194 to check: the two values can either be equal, the first can be
9195 greater, or the second can be greater. Fold the expression for
9196 those three values. Since each value must be 0 or 1, we have
9197 eight possibilities, each of which corresponds to the constant 0
9198 or 1 or one of the six possible comparisons.
9200 This handles common cases like (a > b) == 0 but also handles
9201 expressions like ((x > y) - (y > x)) > 0, which supposedly
9202 occur in macroized code. */
9204 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
9206 tree cval1 = 0, cval2 = 0;
9209 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
9210 /* Don't handle degenerate cases here; they should already
9211 have been handled anyway. */
9212 && cval1 != 0 && cval2 != 0
9213 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
9214 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
9215 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
9216 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
9217 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
9218 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
9219 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9221 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9222 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9224 /* We can't just pass T to eval_subst in case cval1 or cval2
9225 was the same as ARG1. */
9228 = fold_build2 (code, type,
9229 eval_subst (arg0, cval1, maxval,
9233 = fold_build2 (code, type,
9234 eval_subst (arg0, cval1, maxval,
9238 = fold_build2 (code, type,
9239 eval_subst (arg0, cval1, minval,
9243 /* All three of these results should be 0 or 1. Confirm they are.
9244 Then use those values to select the proper code to use. */
9246 if (TREE_CODE (high_result) == INTEGER_CST
9247 && TREE_CODE (equal_result) == INTEGER_CST
9248 && TREE_CODE (low_result) == INTEGER_CST)
9250 /* Make a 3-bit mask with the high-order bit being the
9251 value for `>', the next for '=', and the low for '<'. */
9252 switch ((integer_onep (high_result) * 4)
9253 + (integer_onep (equal_result) * 2)
9254 + integer_onep (low_result))
9258 return omit_one_operand (type, integer_zero_node, arg0);
9279 return omit_one_operand (type, integer_one_node, arg0);
9283 return save_expr (build2 (code, type, cval1, cval2));
9284 return fold_build2 (code, type, cval1, cval2);
9289 /* Fold a comparison of the address of COMPONENT_REFs with the same
9290 type and component to a comparison of the address of the base
9291 object. In short, &x->a OP &y->a to x OP y and
9292 &x->a OP &y.a to x OP &y */
9293 if (TREE_CODE (arg0) == ADDR_EXPR
9294 && TREE_CODE (TREE_OPERAND (arg0, 0)) == COMPONENT_REF
9295 && TREE_CODE (arg1) == ADDR_EXPR
9296 && TREE_CODE (TREE_OPERAND (arg1, 0)) == COMPONENT_REF)
9298 tree cref0 = TREE_OPERAND (arg0, 0);
9299 tree cref1 = TREE_OPERAND (arg1, 0);
9300 if (TREE_OPERAND (cref0, 1) == TREE_OPERAND (cref1, 1))
9302 tree op0 = TREE_OPERAND (cref0, 0);
9303 tree op1 = TREE_OPERAND (cref1, 0);
9304 return fold_build2 (code, type,
9305 fold_addr_expr (op0),
9306 fold_addr_expr (op1));
9310 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9311 into a single range test. */
9312 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9313 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9314 && TREE_CODE (arg1) == INTEGER_CST
9315 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9316 && !integer_zerop (TREE_OPERAND (arg0, 1))
9317 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9318 && !TREE_OVERFLOW (arg1))
9320 tem = fold_div_compare (code, type, arg0, arg1);
9321 if (tem != NULL_TREE)
9325 /* Fold ~X op ~Y as Y op X. */
9326 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9327 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9329 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9330 return fold_build2 (code, type,
9331 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
9332 TREE_OPERAND (arg0, 0));
9335 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
9336 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9337 && TREE_CODE (arg1) == INTEGER_CST)
9339 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9340 return fold_build2 (swap_tree_comparison (code), type,
9341 TREE_OPERAND (arg0, 0),
9342 fold_build1 (BIT_NOT_EXPR, cmp_type,
9343 fold_convert (cmp_type, arg1)));
9350 /* Subroutine of fold_binary. Optimize complex multiplications of the
9351 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9352 argument EXPR represents the expression "z" of type TYPE. */
9355 fold_mult_zconjz (tree type, tree expr)
9357 tree itype = TREE_TYPE (type);
9358 tree rpart, ipart, tem;
9360 if (TREE_CODE (expr) == COMPLEX_EXPR)
9362 rpart = TREE_OPERAND (expr, 0);
9363 ipart = TREE_OPERAND (expr, 1);
9365 else if (TREE_CODE (expr) == COMPLEX_CST)
9367 rpart = TREE_REALPART (expr);
9368 ipart = TREE_IMAGPART (expr);
9372 expr = save_expr (expr);
9373 rpart = fold_build1 (REALPART_EXPR, itype, expr);
9374 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
9377 rpart = save_expr (rpart);
9378 ipart = save_expr (ipart);
9379 tem = fold_build2 (PLUS_EXPR, itype,
9380 fold_build2 (MULT_EXPR, itype, rpart, rpart),
9381 fold_build2 (MULT_EXPR, itype, ipart, ipart));
9382 return fold_build2 (COMPLEX_EXPR, type, tem,
9383 fold_convert (itype, integer_zero_node));
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 TREE_OPERAND (arg0, 1), op1));
9513 if (TREE_CODE (arg1) == COMPOUND_EXPR
9514 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9515 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9516 fold_build2 (code, type,
9517 op0, TREE_OPERAND (arg1, 1)));
9519 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9521 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9523 /*cond_first_p=*/1);
9524 if (tem != NULL_TREE)
9528 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9530 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9532 /*cond_first_p=*/0);
9533 if (tem != NULL_TREE)
9540 case POINTER_PLUS_EXPR:
9541 /* 0 +p index -> (type)index */
9542 if (integer_zerop (arg0))
9543 return non_lvalue (fold_convert (type, arg1));
9545 /* PTR +p 0 -> PTR */
9546 if (integer_zerop (arg1))
9547 return non_lvalue (fold_convert (type, arg0));
9549 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9550 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9551 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9552 return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
9553 fold_convert (sizetype, arg1),
9554 fold_convert (sizetype, arg0)));
9556 /* index +p PTR -> PTR +p index */
9557 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9558 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9559 return fold_build2 (POINTER_PLUS_EXPR, type,
9560 fold_convert (type, arg1),
9561 fold_convert (sizetype, arg0));
9563 /* (PTR +p B) +p A -> PTR +p (B + A) */
9564 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9567 tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
9568 tree arg00 = TREE_OPERAND (arg0, 0);
9569 inner = fold_build2 (PLUS_EXPR, sizetype,
9570 arg01, fold_convert (sizetype, arg1));
9571 return fold_convert (type,
9572 fold_build2 (POINTER_PLUS_EXPR,
9573 TREE_TYPE (arg00), arg00, inner));
9576 /* PTR_CST +p CST -> CST1 */
9577 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9578 return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
9580 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9581 of the array. Loop optimizer sometimes produce this type of
9583 if (TREE_CODE (arg0) == ADDR_EXPR)
9585 tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
9587 return fold_convert (type, tem);
9593 /* PTR + INT -> (INT)(PTR p+ INT) */
9594 if (POINTER_TYPE_P (TREE_TYPE (arg0))
9595 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9596 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9599 fold_convert (sizetype, arg1)));
9600 /* INT + PTR -> (INT)(PTR p+ INT) */
9601 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9602 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9603 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9606 fold_convert (sizetype, arg0)));
9607 /* A + (-B) -> A - B */
9608 if (TREE_CODE (arg1) == NEGATE_EXPR)
9609 return fold_build2 (MINUS_EXPR, type,
9610 fold_convert (type, arg0),
9611 fold_convert (type, TREE_OPERAND (arg1, 0)));
9612 /* (-A) + B -> B - A */
9613 if (TREE_CODE (arg0) == NEGATE_EXPR
9614 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9615 return fold_build2 (MINUS_EXPR, type,
9616 fold_convert (type, arg1),
9617 fold_convert (type, TREE_OPERAND (arg0, 0)));
9619 if (INTEGRAL_TYPE_P (type))
9621 /* Convert ~A + 1 to -A. */
9622 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9623 && integer_onep (arg1))
9624 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
9627 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9628 && !TYPE_OVERFLOW_TRAPS (type))
9630 tree tem = TREE_OPERAND (arg0, 0);
9633 if (operand_equal_p (tem, arg1, 0))
9635 t1 = build_int_cst_type (type, -1);
9636 return omit_one_operand (type, t1, arg1);
9641 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9642 && !TYPE_OVERFLOW_TRAPS (type))
9644 tree tem = TREE_OPERAND (arg1, 0);
9647 if (operand_equal_p (arg0, tem, 0))
9649 t1 = build_int_cst_type (type, -1);
9650 return omit_one_operand (type, t1, arg0);
9655 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9656 same or one. Make sure type is not saturating.
9657 fold_plusminus_mult_expr will re-associate. */
9658 if ((TREE_CODE (arg0) == MULT_EXPR
9659 || TREE_CODE (arg1) == MULT_EXPR)
9660 && !TYPE_SATURATING (type)
9661 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9663 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9668 if (! FLOAT_TYPE_P (type))
9670 if (integer_zerop (arg1))
9671 return non_lvalue (fold_convert (type, arg0));
9673 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9674 with a constant, and the two constants have no bits in common,
9675 we should treat this as a BIT_IOR_EXPR since this may produce more
9677 if (TREE_CODE (arg0) == BIT_AND_EXPR
9678 && TREE_CODE (arg1) == BIT_AND_EXPR
9679 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9680 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9681 && integer_zerop (const_binop (BIT_AND_EXPR,
9682 TREE_OPERAND (arg0, 1),
9683 TREE_OPERAND (arg1, 1), 0)))
9685 code = BIT_IOR_EXPR;
9689 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9690 (plus (plus (mult) (mult)) (foo)) so that we can
9691 take advantage of the factoring cases below. */
9692 if (((TREE_CODE (arg0) == PLUS_EXPR
9693 || TREE_CODE (arg0) == MINUS_EXPR)
9694 && TREE_CODE (arg1) == MULT_EXPR)
9695 || ((TREE_CODE (arg1) == PLUS_EXPR
9696 || TREE_CODE (arg1) == MINUS_EXPR)
9697 && TREE_CODE (arg0) == MULT_EXPR))
9699 tree parg0, parg1, parg, marg;
9700 enum tree_code pcode;
9702 if (TREE_CODE (arg1) == MULT_EXPR)
9703 parg = arg0, marg = arg1;
9705 parg = arg1, marg = arg0;
9706 pcode = TREE_CODE (parg);
9707 parg0 = TREE_OPERAND (parg, 0);
9708 parg1 = TREE_OPERAND (parg, 1);
9712 if (TREE_CODE (parg0) == MULT_EXPR
9713 && TREE_CODE (parg1) != MULT_EXPR)
9714 return fold_build2 (pcode, type,
9715 fold_build2 (PLUS_EXPR, type,
9716 fold_convert (type, parg0),
9717 fold_convert (type, marg)),
9718 fold_convert (type, parg1));
9719 if (TREE_CODE (parg0) != MULT_EXPR
9720 && TREE_CODE (parg1) == MULT_EXPR)
9721 return fold_build2 (PLUS_EXPR, type,
9722 fold_convert (type, parg0),
9723 fold_build2 (pcode, type,
9724 fold_convert (type, marg),
9731 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9732 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
9733 return non_lvalue (fold_convert (type, arg0));
9735 /* Likewise if the operands are reversed. */
9736 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9737 return non_lvalue (fold_convert (type, arg1));
9739 /* Convert X + -C into X - C. */
9740 if (TREE_CODE (arg1) == REAL_CST
9741 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
9743 tem = fold_negate_const (arg1, type);
9744 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
9745 return fold_build2 (MINUS_EXPR, type,
9746 fold_convert (type, arg0),
9747 fold_convert (type, tem));
9750 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9751 to __complex__ ( x, y ). This is not the same for SNaNs or
9752 if signed zeros are involved. */
9753 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9754 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9755 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9757 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9758 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9759 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9760 bool arg0rz = false, arg0iz = false;
9761 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9762 || (arg0i && (arg0iz = real_zerop (arg0i))))
9764 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9765 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9766 if (arg0rz && arg1i && real_zerop (arg1i))
9768 tree rp = arg1r ? arg1r
9769 : build1 (REALPART_EXPR, rtype, arg1);
9770 tree ip = arg0i ? arg0i
9771 : build1 (IMAGPART_EXPR, rtype, arg0);
9772 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9774 else if (arg0iz && arg1r && real_zerop (arg1r))
9776 tree rp = arg0r ? arg0r
9777 : build1 (REALPART_EXPR, rtype, arg0);
9778 tree ip = arg1i ? arg1i
9779 : build1 (IMAGPART_EXPR, rtype, arg1);
9780 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9785 if (flag_unsafe_math_optimizations
9786 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9787 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9788 && (tem = distribute_real_division (code, type, arg0, arg1)))
9791 /* Convert x+x into x*2.0. */
9792 if (operand_equal_p (arg0, arg1, 0)
9793 && SCALAR_FLOAT_TYPE_P (type))
9794 return fold_build2 (MULT_EXPR, type, arg0,
9795 build_real (type, dconst2));
9797 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
9798 We associate floats only if the user has specified
9799 -fassociative-math. */
9800 if (flag_associative_math
9801 && TREE_CODE (arg1) == PLUS_EXPR
9802 && TREE_CODE (arg0) != MULT_EXPR)
9804 tree tree10 = TREE_OPERAND (arg1, 0);
9805 tree tree11 = TREE_OPERAND (arg1, 1);
9806 if (TREE_CODE (tree11) == MULT_EXPR
9807 && TREE_CODE (tree10) == MULT_EXPR)
9810 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
9811 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
9814 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
9815 We associate floats only if the user has specified
9816 -fassociative-math. */
9817 if (flag_associative_math
9818 && TREE_CODE (arg0) == PLUS_EXPR
9819 && TREE_CODE (arg1) != MULT_EXPR)
9821 tree tree00 = TREE_OPERAND (arg0, 0);
9822 tree tree01 = TREE_OPERAND (arg0, 1);
9823 if (TREE_CODE (tree01) == MULT_EXPR
9824 && TREE_CODE (tree00) == MULT_EXPR)
9827 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
9828 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
9834 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9835 is a rotate of A by C1 bits. */
9836 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9837 is a rotate of A by B bits. */
9839 enum tree_code code0, code1;
9840 code0 = TREE_CODE (arg0);
9841 code1 = TREE_CODE (arg1);
9842 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
9843 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
9844 && operand_equal_p (TREE_OPERAND (arg0, 0),
9845 TREE_OPERAND (arg1, 0), 0)
9846 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
9848 tree tree01, tree11;
9849 enum tree_code code01, code11;
9851 tree01 = TREE_OPERAND (arg0, 1);
9852 tree11 = TREE_OPERAND (arg1, 1);
9853 STRIP_NOPS (tree01);
9854 STRIP_NOPS (tree11);
9855 code01 = TREE_CODE (tree01);
9856 code11 = TREE_CODE (tree11);
9857 if (code01 == INTEGER_CST
9858 && code11 == INTEGER_CST
9859 && TREE_INT_CST_HIGH (tree01) == 0
9860 && TREE_INT_CST_HIGH (tree11) == 0
9861 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
9862 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
9863 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
9864 code0 == LSHIFT_EXPR ? tree01 : tree11);
9865 else if (code11 == MINUS_EXPR)
9867 tree tree110, tree111;
9868 tree110 = TREE_OPERAND (tree11, 0);
9869 tree111 = TREE_OPERAND (tree11, 1);
9870 STRIP_NOPS (tree110);
9871 STRIP_NOPS (tree111);
9872 if (TREE_CODE (tree110) == INTEGER_CST
9873 && 0 == compare_tree_int (tree110,
9875 (TREE_TYPE (TREE_OPERAND
9877 && operand_equal_p (tree01, tree111, 0))
9878 return build2 ((code0 == LSHIFT_EXPR
9881 type, TREE_OPERAND (arg0, 0), tree01);
9883 else if (code01 == MINUS_EXPR)
9885 tree tree010, tree011;
9886 tree010 = TREE_OPERAND (tree01, 0);
9887 tree011 = TREE_OPERAND (tree01, 1);
9888 STRIP_NOPS (tree010);
9889 STRIP_NOPS (tree011);
9890 if (TREE_CODE (tree010) == INTEGER_CST
9891 && 0 == compare_tree_int (tree010,
9893 (TREE_TYPE (TREE_OPERAND
9895 && operand_equal_p (tree11, tree011, 0))
9896 return build2 ((code0 != LSHIFT_EXPR
9899 type, TREE_OPERAND (arg0, 0), tree11);
9905 /* In most languages, can't associate operations on floats through
9906 parentheses. Rather than remember where the parentheses were, we
9907 don't associate floats at all, unless the user has specified
9909 And, we need to make sure type is not saturating. */
9911 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
9912 && !TYPE_SATURATING (type))
9914 tree var0, con0, lit0, minus_lit0;
9915 tree var1, con1, lit1, minus_lit1;
9918 /* Split both trees into variables, constants, and literals. Then
9919 associate each group together, the constants with literals,
9920 then the result with variables. This increases the chances of
9921 literals being recombined later and of generating relocatable
9922 expressions for the sum of a constant and literal. */
9923 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
9924 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
9925 code == MINUS_EXPR);
9927 /* With undefined overflow we can only associate constants
9928 with one variable. */
9929 if ((POINTER_TYPE_P (type)
9930 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
9936 if (TREE_CODE (tmp0) == NEGATE_EXPR)
9937 tmp0 = TREE_OPERAND (tmp0, 0);
9938 if (TREE_CODE (tmp1) == NEGATE_EXPR)
9939 tmp1 = TREE_OPERAND (tmp1, 0);
9940 /* The only case we can still associate with two variables
9941 is if they are the same, modulo negation. */
9942 if (!operand_equal_p (tmp0, tmp1, 0))
9946 /* Only do something if we found more than two objects. Otherwise,
9947 nothing has changed and we risk infinite recursion. */
9949 && (2 < ((var0 != 0) + (var1 != 0)
9950 + (con0 != 0) + (con1 != 0)
9951 + (lit0 != 0) + (lit1 != 0)
9952 + (minus_lit0 != 0) + (minus_lit1 != 0))))
9954 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9955 if (code == MINUS_EXPR)
9958 var0 = associate_trees (var0, var1, code, type);
9959 con0 = associate_trees (con0, con1, code, type);
9960 lit0 = associate_trees (lit0, lit1, code, type);
9961 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
9963 /* Preserve the MINUS_EXPR if the negative part of the literal is
9964 greater than the positive part. Otherwise, the multiplicative
9965 folding code (i.e extract_muldiv) may be fooled in case
9966 unsigned constants are subtracted, like in the following
9967 example: ((X*2 + 4) - 8U)/2. */
9968 if (minus_lit0 && lit0)
9970 if (TREE_CODE (lit0) == INTEGER_CST
9971 && TREE_CODE (minus_lit0) == INTEGER_CST
9972 && tree_int_cst_lt (lit0, minus_lit0))
9974 minus_lit0 = associate_trees (minus_lit0, lit0,
9980 lit0 = associate_trees (lit0, minus_lit0,
9988 return fold_convert (type,
9989 associate_trees (var0, minus_lit0,
9993 con0 = associate_trees (con0, minus_lit0,
9995 return fold_convert (type,
9996 associate_trees (var0, con0,
10001 con0 = associate_trees (con0, lit0, code, type);
10002 return fold_convert (type, associate_trees (var0, con0,
10010 /* Pointer simplifications for subtraction, simple reassociations. */
10011 if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
10013 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
10014 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
10015 && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
10017 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10018 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10019 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10020 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10021 return fold_build2 (PLUS_EXPR, type,
10022 fold_build2 (MINUS_EXPR, type, arg00, arg10),
10023 fold_build2 (MINUS_EXPR, type, arg01, arg11));
10025 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
10026 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
10028 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10029 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10030 tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
10032 return fold_build2 (PLUS_EXPR, type, tmp, arg01);
10035 /* A - (-B) -> A + B */
10036 if (TREE_CODE (arg1) == NEGATE_EXPR)
10037 return fold_build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0));
10038 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
10039 if (TREE_CODE (arg0) == NEGATE_EXPR
10040 && (FLOAT_TYPE_P (type)
10041 || INTEGRAL_TYPE_P (type))
10042 && negate_expr_p (arg1)
10043 && reorder_operands_p (arg0, arg1))
10044 return fold_build2 (MINUS_EXPR, type, negate_expr (arg1),
10045 TREE_OPERAND (arg0, 0));
10046 /* Convert -A - 1 to ~A. */
10047 if (INTEGRAL_TYPE_P (type)
10048 && TREE_CODE (arg0) == NEGATE_EXPR
10049 && integer_onep (arg1)
10050 && !TYPE_OVERFLOW_TRAPS (type))
10051 return fold_build1 (BIT_NOT_EXPR, type,
10052 fold_convert (type, TREE_OPERAND (arg0, 0)));
10054 /* Convert -1 - A to ~A. */
10055 if (INTEGRAL_TYPE_P (type)
10056 && integer_all_onesp (arg0))
10057 return fold_build1 (BIT_NOT_EXPR, type, op1);
10059 if (! FLOAT_TYPE_P (type))
10061 if (integer_zerop (arg0))
10062 return negate_expr (fold_convert (type, arg1));
10063 if (integer_zerop (arg1))
10064 return non_lvalue (fold_convert (type, arg0));
10066 /* Fold A - (A & B) into ~B & A. */
10067 if (!TREE_SIDE_EFFECTS (arg0)
10068 && TREE_CODE (arg1) == BIT_AND_EXPR)
10070 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
10072 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10073 return fold_build2 (BIT_AND_EXPR, type,
10074 fold_build1 (BIT_NOT_EXPR, type, arg10),
10075 fold_convert (type, arg0));
10077 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10079 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10080 return fold_build2 (BIT_AND_EXPR, type,
10081 fold_build1 (BIT_NOT_EXPR, type, arg11),
10082 fold_convert (type, arg0));
10086 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
10087 any power of 2 minus 1. */
10088 if (TREE_CODE (arg0) == BIT_AND_EXPR
10089 && TREE_CODE (arg1) == BIT_AND_EXPR
10090 && operand_equal_p (TREE_OPERAND (arg0, 0),
10091 TREE_OPERAND (arg1, 0), 0))
10093 tree mask0 = TREE_OPERAND (arg0, 1);
10094 tree mask1 = TREE_OPERAND (arg1, 1);
10095 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
10097 if (operand_equal_p (tem, mask1, 0))
10099 tem = fold_build2 (BIT_XOR_EXPR, type,
10100 TREE_OPERAND (arg0, 0), mask1);
10101 return fold_build2 (MINUS_EXPR, type, tem, mask1);
10106 /* See if ARG1 is zero and X - ARG1 reduces to X. */
10107 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
10108 return non_lvalue (fold_convert (type, arg0));
10110 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
10111 ARG0 is zero and X + ARG0 reduces to X, since that would mean
10112 (-ARG1 + ARG0) reduces to -ARG1. */
10113 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
10114 return negate_expr (fold_convert (type, arg1));
10116 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
10117 __complex__ ( x, -y ). This is not the same for SNaNs or if
10118 signed zeros are involved. */
10119 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10120 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10121 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10123 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10124 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10125 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10126 bool arg0rz = false, arg0iz = false;
10127 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10128 || (arg0i && (arg0iz = real_zerop (arg0i))))
10130 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10131 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10132 if (arg0rz && arg1i && real_zerop (arg1i))
10134 tree rp = fold_build1 (NEGATE_EXPR, rtype,
10136 : build1 (REALPART_EXPR, rtype, arg1));
10137 tree ip = arg0i ? arg0i
10138 : build1 (IMAGPART_EXPR, rtype, arg0);
10139 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10141 else if (arg0iz && arg1r && real_zerop (arg1r))
10143 tree rp = arg0r ? arg0r
10144 : build1 (REALPART_EXPR, rtype, arg0);
10145 tree ip = fold_build1 (NEGATE_EXPR, rtype,
10147 : build1 (IMAGPART_EXPR, rtype, arg1));
10148 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10153 /* Fold &x - &x. This can happen from &x.foo - &x.
10154 This is unsafe for certain floats even in non-IEEE formats.
10155 In IEEE, it is unsafe because it does wrong for NaNs.
10156 Also note that operand_equal_p is always false if an operand
10159 if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
10160 && operand_equal_p (arg0, arg1, 0))
10161 return fold_convert (type, integer_zero_node);
10163 /* A - B -> A + (-B) if B is easily negatable. */
10164 if (negate_expr_p (arg1)
10165 && ((FLOAT_TYPE_P (type)
10166 /* Avoid this transformation if B is a positive REAL_CST. */
10167 && (TREE_CODE (arg1) != REAL_CST
10168 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
10169 || INTEGRAL_TYPE_P (type)))
10170 return fold_build2 (PLUS_EXPR, type,
10171 fold_convert (type, arg0),
10172 fold_convert (type, negate_expr (arg1)));
10174 /* Try folding difference of addresses. */
10176 HOST_WIDE_INT diff;
10178 if ((TREE_CODE (arg0) == ADDR_EXPR
10179 || TREE_CODE (arg1) == ADDR_EXPR)
10180 && ptr_difference_const (arg0, arg1, &diff))
10181 return build_int_cst_type (type, diff);
10184 /* Fold &a[i] - &a[j] to i-j. */
10185 if (TREE_CODE (arg0) == ADDR_EXPR
10186 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
10187 && TREE_CODE (arg1) == ADDR_EXPR
10188 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
10190 tree aref0 = TREE_OPERAND (arg0, 0);
10191 tree aref1 = TREE_OPERAND (arg1, 0);
10192 if (operand_equal_p (TREE_OPERAND (aref0, 0),
10193 TREE_OPERAND (aref1, 0), 0))
10195 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
10196 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
10197 tree esz = array_ref_element_size (aref0);
10198 tree diff = build2 (MINUS_EXPR, type, op0, op1);
10199 return fold_build2 (MULT_EXPR, type, diff,
10200 fold_convert (type, esz));
10205 if (flag_unsafe_math_optimizations
10206 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10207 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10208 && (tem = distribute_real_division (code, type, arg0, arg1)))
10211 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
10212 same or one. Make sure type is not saturating.
10213 fold_plusminus_mult_expr will re-associate. */
10214 if ((TREE_CODE (arg0) == MULT_EXPR
10215 || TREE_CODE (arg1) == MULT_EXPR)
10216 && !TYPE_SATURATING (type)
10217 && (!FLOAT_TYPE_P (type) || flag_associative_math))
10219 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
10227 /* (-A) * (-B) -> A * B */
10228 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10229 return fold_build2 (MULT_EXPR, type,
10230 fold_convert (type, TREE_OPERAND (arg0, 0)),
10231 fold_convert (type, negate_expr (arg1)));
10232 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10233 return fold_build2 (MULT_EXPR, type,
10234 fold_convert (type, negate_expr (arg0)),
10235 fold_convert (type, TREE_OPERAND (arg1, 0)));
10237 if (! FLOAT_TYPE_P (type))
10239 if (integer_zerop (arg1))
10240 return omit_one_operand (type, arg1, arg0);
10241 if (integer_onep (arg1))
10242 return non_lvalue (fold_convert (type, arg0));
10243 /* Transform x * -1 into -x. */
10244 if (integer_all_onesp (arg1))
10245 return fold_convert (type, negate_expr (arg0));
10246 /* Transform x * -C into -x * C if x is easily negatable. */
10247 if (TREE_CODE (arg1) == INTEGER_CST
10248 && tree_int_cst_sgn (arg1) == -1
10249 && negate_expr_p (arg0)
10250 && (tem = negate_expr (arg1)) != arg1
10251 && !TREE_OVERFLOW (tem))
10252 return fold_build2 (MULT_EXPR, type,
10253 negate_expr (arg0), tem);
10255 /* (a * (1 << b)) is (a << b) */
10256 if (TREE_CODE (arg1) == LSHIFT_EXPR
10257 && integer_onep (TREE_OPERAND (arg1, 0)))
10258 return fold_build2 (LSHIFT_EXPR, type, arg0,
10259 TREE_OPERAND (arg1, 1));
10260 if (TREE_CODE (arg0) == LSHIFT_EXPR
10261 && integer_onep (TREE_OPERAND (arg0, 0)))
10262 return fold_build2 (LSHIFT_EXPR, type, arg1,
10263 TREE_OPERAND (arg0, 1));
10265 strict_overflow_p = false;
10266 if (TREE_CODE (arg1) == INTEGER_CST
10267 && 0 != (tem = extract_muldiv (op0,
10268 fold_convert (type, arg1),
10270 &strict_overflow_p)))
10272 if (strict_overflow_p)
10273 fold_overflow_warning (("assuming signed overflow does not "
10274 "occur when simplifying "
10276 WARN_STRICT_OVERFLOW_MISC);
10277 return fold_convert (type, tem);
10280 /* Optimize z * conj(z) for integer complex numbers. */
10281 if (TREE_CODE (arg0) == CONJ_EXPR
10282 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10283 return fold_mult_zconjz (type, arg1);
10284 if (TREE_CODE (arg1) == CONJ_EXPR
10285 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10286 return fold_mult_zconjz (type, arg0);
10290 /* Maybe fold x * 0 to 0. The expressions aren't the same
10291 when x is NaN, since x * 0 is also NaN. Nor are they the
10292 same in modes with signed zeros, since multiplying a
10293 negative value by 0 gives -0, not +0. */
10294 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10295 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10296 && real_zerop (arg1))
10297 return omit_one_operand (type, arg1, arg0);
10298 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
10299 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10300 && real_onep (arg1))
10301 return non_lvalue (fold_convert (type, arg0));
10303 /* Transform x * -1.0 into -x. */
10304 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10305 && real_minus_onep (arg1))
10306 return fold_convert (type, negate_expr (arg0));
10308 /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
10309 the result for floating point types due to rounding so it is applied
10310 only if -fassociative-math was specify. */
10311 if (flag_associative_math
10312 && TREE_CODE (arg0) == RDIV_EXPR
10313 && TREE_CODE (arg1) == REAL_CST
10314 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
10316 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
10319 return fold_build2 (RDIV_EXPR, type, tem,
10320 TREE_OPERAND (arg0, 1));
10323 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10324 if (operand_equal_p (arg0, arg1, 0))
10326 tree tem = fold_strip_sign_ops (arg0);
10327 if (tem != NULL_TREE)
10329 tem = fold_convert (type, tem);
10330 return fold_build2 (MULT_EXPR, type, tem, tem);
10334 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10335 This is not the same for NaNs or if signed zeros are
10337 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10338 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10339 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10340 && TREE_CODE (arg1) == COMPLEX_CST
10341 && real_zerop (TREE_REALPART (arg1)))
10343 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10344 if (real_onep (TREE_IMAGPART (arg1)))
10345 return fold_build2 (COMPLEX_EXPR, type,
10346 negate_expr (fold_build1 (IMAGPART_EXPR,
10348 fold_build1 (REALPART_EXPR, rtype, arg0));
10349 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10350 return fold_build2 (COMPLEX_EXPR, type,
10351 fold_build1 (IMAGPART_EXPR, rtype, arg0),
10352 negate_expr (fold_build1 (REALPART_EXPR,
10356 /* Optimize z * conj(z) for floating point complex numbers.
10357 Guarded by flag_unsafe_math_optimizations as non-finite
10358 imaginary components don't produce scalar results. */
10359 if (flag_unsafe_math_optimizations
10360 && TREE_CODE (arg0) == CONJ_EXPR
10361 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10362 return fold_mult_zconjz (type, arg1);
10363 if (flag_unsafe_math_optimizations
10364 && TREE_CODE (arg1) == CONJ_EXPR
10365 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10366 return fold_mult_zconjz (type, arg0);
10368 if (flag_unsafe_math_optimizations)
10370 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10371 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10373 /* Optimizations of root(...)*root(...). */
10374 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
10377 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10378 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10380 /* Optimize sqrt(x)*sqrt(x) as x. */
10381 if (BUILTIN_SQRT_P (fcode0)
10382 && operand_equal_p (arg00, arg10, 0)
10383 && ! HONOR_SNANS (TYPE_MODE (type)))
10386 /* Optimize root(x)*root(y) as root(x*y). */
10387 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10388 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10389 return build_call_expr (rootfn, 1, arg);
10392 /* Optimize expN(x)*expN(y) as expN(x+y). */
10393 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
10395 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10396 tree arg = fold_build2 (PLUS_EXPR, type,
10397 CALL_EXPR_ARG (arg0, 0),
10398 CALL_EXPR_ARG (arg1, 0));
10399 return build_call_expr (expfn, 1, arg);
10402 /* Optimizations of pow(...)*pow(...). */
10403 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
10404 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
10405 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
10407 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10408 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10409 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10410 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10412 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10413 if (operand_equal_p (arg01, arg11, 0))
10415 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10416 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10417 return build_call_expr (powfn, 2, arg, arg01);
10420 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10421 if (operand_equal_p (arg00, arg10, 0))
10423 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10424 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
10425 return build_call_expr (powfn, 2, arg00, arg);
10429 /* Optimize tan(x)*cos(x) as sin(x). */
10430 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
10431 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
10432 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
10433 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
10434 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
10435 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
10436 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10437 CALL_EXPR_ARG (arg1, 0), 0))
10439 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
10441 if (sinfn != NULL_TREE)
10442 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
10445 /* Optimize x*pow(x,c) as pow(x,c+1). */
10446 if (fcode1 == BUILT_IN_POW
10447 || fcode1 == BUILT_IN_POWF
10448 || fcode1 == BUILT_IN_POWL)
10450 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10451 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10452 if (TREE_CODE (arg11) == REAL_CST
10453 && !TREE_OVERFLOW (arg11)
10454 && operand_equal_p (arg0, arg10, 0))
10456 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10460 c = TREE_REAL_CST (arg11);
10461 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10462 arg = build_real (type, c);
10463 return build_call_expr (powfn, 2, arg0, arg);
10467 /* Optimize pow(x,c)*x as pow(x,c+1). */
10468 if (fcode0 == BUILT_IN_POW
10469 || fcode0 == BUILT_IN_POWF
10470 || fcode0 == BUILT_IN_POWL)
10472 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10473 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10474 if (TREE_CODE (arg01) == REAL_CST
10475 && !TREE_OVERFLOW (arg01)
10476 && operand_equal_p (arg1, arg00, 0))
10478 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10482 c = TREE_REAL_CST (arg01);
10483 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10484 arg = build_real (type, c);
10485 return build_call_expr (powfn, 2, arg1, arg);
10489 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10490 if (! optimize_size
10491 && operand_equal_p (arg0, arg1, 0))
10493 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
10497 tree arg = build_real (type, dconst2);
10498 return build_call_expr (powfn, 2, arg0, arg);
10507 if (integer_all_onesp (arg1))
10508 return omit_one_operand (type, arg1, arg0);
10509 if (integer_zerop (arg1))
10510 return non_lvalue (fold_convert (type, arg0));
10511 if (operand_equal_p (arg0, arg1, 0))
10512 return non_lvalue (fold_convert (type, arg0));
10514 /* ~X | X is -1. */
10515 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10516 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10518 t1 = fold_convert (type, integer_zero_node);
10519 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10520 return omit_one_operand (type, t1, arg1);
10523 /* X | ~X is -1. */
10524 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10525 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10527 t1 = fold_convert (type, integer_zero_node);
10528 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10529 return omit_one_operand (type, t1, arg0);
10532 /* Canonicalize (X & C1) | C2. */
10533 if (TREE_CODE (arg0) == BIT_AND_EXPR
10534 && TREE_CODE (arg1) == INTEGER_CST
10535 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10537 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, mlo, mhi;
10538 int width = TYPE_PRECISION (type);
10539 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10540 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10541 hi2 = TREE_INT_CST_HIGH (arg1);
10542 lo2 = TREE_INT_CST_LOW (arg1);
10544 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10545 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10546 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10548 if (width > HOST_BITS_PER_WIDE_INT)
10550 mhi = (unsigned HOST_WIDE_INT) -1
10551 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10557 mlo = (unsigned HOST_WIDE_INT) -1
10558 >> (HOST_BITS_PER_WIDE_INT - width);
10561 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10562 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10563 return fold_build2 (BIT_IOR_EXPR, type,
10564 TREE_OPERAND (arg0, 0), arg1);
10566 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2. */
10569 if ((hi1 & ~hi2) != hi1 || (lo1 & ~lo2) != lo1)
10570 return fold_build2 (BIT_IOR_EXPR, type,
10571 fold_build2 (BIT_AND_EXPR, type,
10572 TREE_OPERAND (arg0, 0),
10573 build_int_cst_wide (type,
10579 /* (X & Y) | Y is (X, Y). */
10580 if (TREE_CODE (arg0) == BIT_AND_EXPR
10581 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10582 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10583 /* (X & Y) | X is (Y, X). */
10584 if (TREE_CODE (arg0) == BIT_AND_EXPR
10585 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10586 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10587 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10588 /* X | (X & Y) is (Y, X). */
10589 if (TREE_CODE (arg1) == BIT_AND_EXPR
10590 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10591 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10592 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10593 /* X | (Y & X) is (Y, X). */
10594 if (TREE_CODE (arg1) == BIT_AND_EXPR
10595 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10596 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10597 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10599 t1 = distribute_bit_expr (code, type, arg0, arg1);
10600 if (t1 != NULL_TREE)
10603 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10605 This results in more efficient code for machines without a NAND
10606 instruction. Combine will canonicalize to the first form
10607 which will allow use of NAND instructions provided by the
10608 backend if they exist. */
10609 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10610 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10612 return fold_build1 (BIT_NOT_EXPR, type,
10613 build2 (BIT_AND_EXPR, type,
10614 TREE_OPERAND (arg0, 0),
10615 TREE_OPERAND (arg1, 0)));
10618 /* See if this can be simplified into a rotate first. If that
10619 is unsuccessful continue in the association code. */
10623 if (integer_zerop (arg1))
10624 return non_lvalue (fold_convert (type, arg0));
10625 if (integer_all_onesp (arg1))
10626 return fold_build1 (BIT_NOT_EXPR, type, op0);
10627 if (operand_equal_p (arg0, arg1, 0))
10628 return omit_one_operand (type, integer_zero_node, arg0);
10630 /* ~X ^ X is -1. */
10631 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10632 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10634 t1 = fold_convert (type, integer_zero_node);
10635 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10636 return omit_one_operand (type, t1, arg1);
10639 /* X ^ ~X is -1. */
10640 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10641 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10643 t1 = fold_convert (type, integer_zero_node);
10644 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10645 return omit_one_operand (type, t1, arg0);
10648 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10649 with a constant, and the two constants have no bits in common,
10650 we should treat this as a BIT_IOR_EXPR since this may produce more
10651 simplifications. */
10652 if (TREE_CODE (arg0) == BIT_AND_EXPR
10653 && TREE_CODE (arg1) == BIT_AND_EXPR
10654 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10655 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10656 && integer_zerop (const_binop (BIT_AND_EXPR,
10657 TREE_OPERAND (arg0, 1),
10658 TREE_OPERAND (arg1, 1), 0)))
10660 code = BIT_IOR_EXPR;
10664 /* (X | Y) ^ X -> Y & ~ X*/
10665 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10666 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10668 tree t2 = TREE_OPERAND (arg0, 1);
10669 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10671 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10672 fold_convert (type, t1));
10676 /* (Y | X) ^ X -> Y & ~ X*/
10677 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10678 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10680 tree t2 = TREE_OPERAND (arg0, 0);
10681 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10683 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10684 fold_convert (type, t1));
10688 /* X ^ (X | Y) -> Y & ~ X*/
10689 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10690 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
10692 tree t2 = TREE_OPERAND (arg1, 1);
10693 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10695 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10696 fold_convert (type, t1));
10700 /* X ^ (Y | X) -> Y & ~ X*/
10701 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10702 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
10704 tree t2 = TREE_OPERAND (arg1, 0);
10705 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10707 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10708 fold_convert (type, t1));
10712 /* Convert ~X ^ ~Y to X ^ Y. */
10713 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10714 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10715 return fold_build2 (code, type,
10716 fold_convert (type, TREE_OPERAND (arg0, 0)),
10717 fold_convert (type, TREE_OPERAND (arg1, 0)));
10719 /* Convert ~X ^ C to X ^ ~C. */
10720 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10721 && TREE_CODE (arg1) == INTEGER_CST)
10722 return fold_build2 (code, type,
10723 fold_convert (type, TREE_OPERAND (arg0, 0)),
10724 fold_build1 (BIT_NOT_EXPR, type, arg1));
10726 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10727 if (TREE_CODE (arg0) == BIT_AND_EXPR
10728 && integer_onep (TREE_OPERAND (arg0, 1))
10729 && integer_onep (arg1))
10730 return fold_build2 (EQ_EXPR, type, arg0,
10731 build_int_cst (TREE_TYPE (arg0), 0));
10733 /* Fold (X & Y) ^ Y as ~X & Y. */
10734 if (TREE_CODE (arg0) == BIT_AND_EXPR
10735 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10737 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10738 return fold_build2 (BIT_AND_EXPR, type,
10739 fold_build1 (BIT_NOT_EXPR, type, tem),
10740 fold_convert (type, arg1));
10742 /* Fold (X & Y) ^ X as ~Y & X. */
10743 if (TREE_CODE (arg0) == BIT_AND_EXPR
10744 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10745 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10747 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10748 return fold_build2 (BIT_AND_EXPR, type,
10749 fold_build1 (BIT_NOT_EXPR, type, tem),
10750 fold_convert (type, arg1));
10752 /* Fold X ^ (X & Y) as X & ~Y. */
10753 if (TREE_CODE (arg1) == BIT_AND_EXPR
10754 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10756 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10757 return fold_build2 (BIT_AND_EXPR, type,
10758 fold_convert (type, arg0),
10759 fold_build1 (BIT_NOT_EXPR, type, tem));
10761 /* Fold X ^ (Y & X) as ~Y & X. */
10762 if (TREE_CODE (arg1) == BIT_AND_EXPR
10763 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10764 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10766 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10767 return fold_build2 (BIT_AND_EXPR, type,
10768 fold_build1 (BIT_NOT_EXPR, type, tem),
10769 fold_convert (type, arg0));
10772 /* See if this can be simplified into a rotate first. If that
10773 is unsuccessful continue in the association code. */
10777 if (integer_all_onesp (arg1))
10778 return non_lvalue (fold_convert (type, arg0));
10779 if (integer_zerop (arg1))
10780 return omit_one_operand (type, arg1, arg0);
10781 if (operand_equal_p (arg0, arg1, 0))
10782 return non_lvalue (fold_convert (type, arg0));
10784 /* ~X & X is always zero. */
10785 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10786 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10787 return omit_one_operand (type, integer_zero_node, arg1);
10789 /* X & ~X is always zero. */
10790 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10791 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10792 return omit_one_operand (type, integer_zero_node, arg0);
10794 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
10795 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10796 && TREE_CODE (arg1) == INTEGER_CST
10797 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10798 return fold_build2 (BIT_IOR_EXPR, type,
10799 fold_build2 (BIT_AND_EXPR, type,
10800 TREE_OPERAND (arg0, 0), arg1),
10801 fold_build2 (BIT_AND_EXPR, type,
10802 TREE_OPERAND (arg0, 1), arg1));
10804 /* (X | Y) & Y is (X, Y). */
10805 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10806 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10807 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10808 /* (X | Y) & X is (Y, X). */
10809 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10810 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10811 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10812 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10813 /* X & (X | Y) is (Y, X). */
10814 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10815 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10816 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10817 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10818 /* X & (Y | X) is (Y, X). */
10819 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10820 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10821 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10822 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10824 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10825 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10826 && integer_onep (TREE_OPERAND (arg0, 1))
10827 && integer_onep (arg1))
10829 tem = TREE_OPERAND (arg0, 0);
10830 return fold_build2 (EQ_EXPR, type,
10831 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10832 build_int_cst (TREE_TYPE (tem), 1)),
10833 build_int_cst (TREE_TYPE (tem), 0));
10835 /* Fold ~X & 1 as (X & 1) == 0. */
10836 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10837 && integer_onep (arg1))
10839 tem = TREE_OPERAND (arg0, 0);
10840 return fold_build2 (EQ_EXPR, type,
10841 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10842 build_int_cst (TREE_TYPE (tem), 1)),
10843 build_int_cst (TREE_TYPE (tem), 0));
10846 /* Fold (X ^ Y) & Y as ~X & Y. */
10847 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10848 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10850 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10851 return fold_build2 (BIT_AND_EXPR, type,
10852 fold_build1 (BIT_NOT_EXPR, type, tem),
10853 fold_convert (type, arg1));
10855 /* Fold (X ^ Y) & X as ~Y & X. */
10856 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10857 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10858 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10860 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10861 return fold_build2 (BIT_AND_EXPR, type,
10862 fold_build1 (BIT_NOT_EXPR, type, tem),
10863 fold_convert (type, arg1));
10865 /* Fold X & (X ^ Y) as X & ~Y. */
10866 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10867 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10869 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10870 return fold_build2 (BIT_AND_EXPR, type,
10871 fold_convert (type, arg0),
10872 fold_build1 (BIT_NOT_EXPR, type, tem));
10874 /* Fold X & (Y ^ X) as ~Y & X. */
10875 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10876 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10877 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10879 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10880 return fold_build2 (BIT_AND_EXPR, type,
10881 fold_build1 (BIT_NOT_EXPR, type, tem),
10882 fold_convert (type, arg0));
10885 t1 = distribute_bit_expr (code, type, arg0, arg1);
10886 if (t1 != NULL_TREE)
10888 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10889 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
10890 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
10893 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
10895 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
10896 && (~TREE_INT_CST_LOW (arg1)
10897 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
10898 return fold_convert (type, TREE_OPERAND (arg0, 0));
10901 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
10903 This results in more efficient code for machines without a NOR
10904 instruction. Combine will canonicalize to the first form
10905 which will allow use of NOR instructions provided by the
10906 backend if they exist. */
10907 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10908 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10910 return fold_build1 (BIT_NOT_EXPR, type,
10911 build2 (BIT_IOR_EXPR, type,
10912 TREE_OPERAND (arg0, 0),
10913 TREE_OPERAND (arg1, 0)));
10919 /* Don't touch a floating-point divide by zero unless the mode
10920 of the constant can represent infinity. */
10921 if (TREE_CODE (arg1) == REAL_CST
10922 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
10923 && real_zerop (arg1))
10926 /* Optimize A / A to 1.0 if we don't care about
10927 NaNs or Infinities. Skip the transformation
10928 for non-real operands. */
10929 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
10930 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10931 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
10932 && operand_equal_p (arg0, arg1, 0))
10934 tree r = build_real (TREE_TYPE (arg0), dconst1);
10936 return omit_two_operands (type, r, arg0, arg1);
10939 /* The complex version of the above A / A optimization. */
10940 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10941 && operand_equal_p (arg0, arg1, 0))
10943 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
10944 if (! HONOR_NANS (TYPE_MODE (elem_type))
10945 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
10947 tree r = build_real (elem_type, dconst1);
10948 /* omit_two_operands will call fold_convert for us. */
10949 return omit_two_operands (type, r, arg0, arg1);
10953 /* (-A) / (-B) -> A / B */
10954 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10955 return fold_build2 (RDIV_EXPR, type,
10956 TREE_OPERAND (arg0, 0),
10957 negate_expr (arg1));
10958 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10959 return fold_build2 (RDIV_EXPR, type,
10960 negate_expr (arg0),
10961 TREE_OPERAND (arg1, 0));
10963 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
10964 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10965 && real_onep (arg1))
10966 return non_lvalue (fold_convert (type, arg0));
10968 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
10969 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10970 && real_minus_onep (arg1))
10971 return non_lvalue (fold_convert (type, negate_expr (arg0)));
10973 /* If ARG1 is a constant, we can convert this to a multiply by the
10974 reciprocal. This does not have the same rounding properties,
10975 so only do this if -freciprocal-math. We can actually
10976 always safely do it if ARG1 is a power of two, but it's hard to
10977 tell if it is or not in a portable manner. */
10978 if (TREE_CODE (arg1) == REAL_CST)
10980 if (flag_reciprocal_math
10981 && 0 != (tem = const_binop (code, build_real (type, dconst1),
10983 return fold_build2 (MULT_EXPR, type, arg0, tem);
10984 /* Find the reciprocal if optimizing and the result is exact. */
10988 r = TREE_REAL_CST (arg1);
10989 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
10991 tem = build_real (type, r);
10992 return fold_build2 (MULT_EXPR, type,
10993 fold_convert (type, arg0), tem);
10997 /* Convert A/B/C to A/(B*C). */
10998 if (flag_reciprocal_math
10999 && TREE_CODE (arg0) == RDIV_EXPR)
11000 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
11001 fold_build2 (MULT_EXPR, type,
11002 TREE_OPERAND (arg0, 1), arg1));
11004 /* Convert A/(B/C) to (A/B)*C. */
11005 if (flag_reciprocal_math
11006 && TREE_CODE (arg1) == RDIV_EXPR)
11007 return fold_build2 (MULT_EXPR, type,
11008 fold_build2 (RDIV_EXPR, type, arg0,
11009 TREE_OPERAND (arg1, 0)),
11010 TREE_OPERAND (arg1, 1));
11012 /* Convert C1/(X*C2) into (C1/C2)/X. */
11013 if (flag_reciprocal_math
11014 && TREE_CODE (arg1) == MULT_EXPR
11015 && TREE_CODE (arg0) == REAL_CST
11016 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
11018 tree tem = const_binop (RDIV_EXPR, arg0,
11019 TREE_OPERAND (arg1, 1), 0);
11021 return fold_build2 (RDIV_EXPR, type, tem,
11022 TREE_OPERAND (arg1, 0));
11025 if (flag_unsafe_math_optimizations)
11027 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
11028 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
11030 /* Optimize sin(x)/cos(x) as tan(x). */
11031 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
11032 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
11033 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
11034 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11035 CALL_EXPR_ARG (arg1, 0), 0))
11037 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11039 if (tanfn != NULL_TREE)
11040 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11043 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
11044 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
11045 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
11046 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
11047 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11048 CALL_EXPR_ARG (arg1, 0), 0))
11050 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11052 if (tanfn != NULL_TREE)
11054 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11055 return fold_build2 (RDIV_EXPR, type,
11056 build_real (type, dconst1), tmp);
11060 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
11061 NaNs or Infinities. */
11062 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
11063 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
11064 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
11066 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11067 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11069 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11070 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11071 && operand_equal_p (arg00, arg01, 0))
11073 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11075 if (cosfn != NULL_TREE)
11076 return build_call_expr (cosfn, 1, arg00);
11080 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11081 NaNs or Infinities. */
11082 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
11083 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
11084 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
11086 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11087 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11089 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11090 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11091 && operand_equal_p (arg00, arg01, 0))
11093 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11095 if (cosfn != NULL_TREE)
11097 tree tmp = build_call_expr (cosfn, 1, arg00);
11098 return fold_build2 (RDIV_EXPR, type,
11099 build_real (type, dconst1),
11105 /* Optimize pow(x,c)/x as pow(x,c-1). */
11106 if (fcode0 == BUILT_IN_POW
11107 || fcode0 == BUILT_IN_POWF
11108 || fcode0 == BUILT_IN_POWL)
11110 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11111 tree arg01 = CALL_EXPR_ARG (arg0, 1);
11112 if (TREE_CODE (arg01) == REAL_CST
11113 && !TREE_OVERFLOW (arg01)
11114 && operand_equal_p (arg1, arg00, 0))
11116 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
11120 c = TREE_REAL_CST (arg01);
11121 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
11122 arg = build_real (type, c);
11123 return build_call_expr (powfn, 2, arg1, arg);
11127 /* Optimize a/root(b/c) into a*root(c/b). */
11128 if (BUILTIN_ROOT_P (fcode1))
11130 tree rootarg = CALL_EXPR_ARG (arg1, 0);
11132 if (TREE_CODE (rootarg) == RDIV_EXPR)
11134 tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11135 tree b = TREE_OPERAND (rootarg, 0);
11136 tree c = TREE_OPERAND (rootarg, 1);
11138 tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
11140 tmp = build_call_expr (rootfn, 1, tmp);
11141 return fold_build2 (MULT_EXPR, type, arg0, tmp);
11145 /* Optimize x/expN(y) into x*expN(-y). */
11146 if (BUILTIN_EXPONENT_P (fcode1))
11148 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11149 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
11150 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
11151 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11154 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11155 if (fcode1 == BUILT_IN_POW
11156 || fcode1 == BUILT_IN_POWF
11157 || fcode1 == BUILT_IN_POWL)
11159 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11160 tree arg10 = CALL_EXPR_ARG (arg1, 0);
11161 tree arg11 = CALL_EXPR_ARG (arg1, 1);
11162 tree neg11 = fold_convert (type, negate_expr (arg11));
11163 arg1 = build_call_expr (powfn, 2, arg10, neg11);
11164 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11169 case TRUNC_DIV_EXPR:
11170 case FLOOR_DIV_EXPR:
11171 /* Simplify A / (B << N) where A and B are positive and B is
11172 a power of 2, to A >> (N + log2(B)). */
11173 strict_overflow_p = false;
11174 if (TREE_CODE (arg1) == LSHIFT_EXPR
11175 && (TYPE_UNSIGNED (type)
11176 || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
11178 tree sval = TREE_OPERAND (arg1, 0);
11179 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
11181 tree sh_cnt = TREE_OPERAND (arg1, 1);
11182 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
11184 if (strict_overflow_p)
11185 fold_overflow_warning (("assuming signed overflow does not "
11186 "occur when simplifying A / (B << N)"),
11187 WARN_STRICT_OVERFLOW_MISC);
11189 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
11190 sh_cnt, build_int_cst (NULL_TREE, pow2));
11191 return fold_build2 (RSHIFT_EXPR, type,
11192 fold_convert (type, arg0), sh_cnt);
11197 case ROUND_DIV_EXPR:
11198 case CEIL_DIV_EXPR:
11199 case EXACT_DIV_EXPR:
11200 if (integer_onep (arg1))
11201 return non_lvalue (fold_convert (type, arg0));
11202 if (integer_zerop (arg1))
11204 /* X / -1 is -X. */
11205 if (!TYPE_UNSIGNED (type)
11206 && TREE_CODE (arg1) == INTEGER_CST
11207 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11208 && TREE_INT_CST_HIGH (arg1) == -1)
11209 return fold_convert (type, negate_expr (arg0));
11211 /* Convert -A / -B to A / B when the type is signed and overflow is
11213 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11214 && TREE_CODE (arg0) == NEGATE_EXPR
11215 && negate_expr_p (arg1))
11217 if (INTEGRAL_TYPE_P (type))
11218 fold_overflow_warning (("assuming signed overflow does not occur "
11219 "when distributing negation across "
11221 WARN_STRICT_OVERFLOW_MISC);
11222 return fold_build2 (code, type,
11223 fold_convert (type, TREE_OPERAND (arg0, 0)),
11224 negate_expr (arg1));
11226 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11227 && TREE_CODE (arg1) == NEGATE_EXPR
11228 && negate_expr_p (arg0))
11230 if (INTEGRAL_TYPE_P (type))
11231 fold_overflow_warning (("assuming signed overflow does not occur "
11232 "when distributing negation across "
11234 WARN_STRICT_OVERFLOW_MISC);
11235 return fold_build2 (code, type, negate_expr (arg0),
11236 TREE_OPERAND (arg1, 0));
11239 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11240 operation, EXACT_DIV_EXPR.
11242 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11243 At one time others generated faster code, it's not clear if they do
11244 after the last round to changes to the DIV code in expmed.c. */
11245 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
11246 && multiple_of_p (type, arg0, arg1))
11247 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
11249 strict_overflow_p = false;
11250 if (TREE_CODE (arg1) == INTEGER_CST
11251 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11252 &strict_overflow_p)))
11254 if (strict_overflow_p)
11255 fold_overflow_warning (("assuming signed overflow does not occur "
11256 "when simplifying division"),
11257 WARN_STRICT_OVERFLOW_MISC);
11258 return fold_convert (type, tem);
11263 case CEIL_MOD_EXPR:
11264 case FLOOR_MOD_EXPR:
11265 case ROUND_MOD_EXPR:
11266 case TRUNC_MOD_EXPR:
11267 /* X % 1 is always zero, but be sure to preserve any side
11269 if (integer_onep (arg1))
11270 return omit_one_operand (type, integer_zero_node, arg0);
11272 /* X % 0, return X % 0 unchanged so that we can get the
11273 proper warnings and errors. */
11274 if (integer_zerop (arg1))
11277 /* 0 % X is always zero, but be sure to preserve any side
11278 effects in X. Place this after checking for X == 0. */
11279 if (integer_zerop (arg0))
11280 return omit_one_operand (type, integer_zero_node, arg1);
11282 /* X % -1 is zero. */
11283 if (!TYPE_UNSIGNED (type)
11284 && TREE_CODE (arg1) == INTEGER_CST
11285 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11286 && TREE_INT_CST_HIGH (arg1) == -1)
11287 return omit_one_operand (type, integer_zero_node, arg0);
11289 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11290 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11291 strict_overflow_p = false;
11292 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
11293 && (TYPE_UNSIGNED (type)
11294 || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
11297 /* Also optimize A % (C << N) where C is a power of 2,
11298 to A & ((C << N) - 1). */
11299 if (TREE_CODE (arg1) == LSHIFT_EXPR)
11300 c = TREE_OPERAND (arg1, 0);
11302 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
11304 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
11305 build_int_cst (TREE_TYPE (arg1), 1));
11306 if (strict_overflow_p)
11307 fold_overflow_warning (("assuming signed overflow does not "
11308 "occur when simplifying "
11309 "X % (power of two)"),
11310 WARN_STRICT_OVERFLOW_MISC);
11311 return fold_build2 (BIT_AND_EXPR, type,
11312 fold_convert (type, arg0),
11313 fold_convert (type, mask));
11317 /* X % -C is the same as X % C. */
11318 if (code == TRUNC_MOD_EXPR
11319 && !TYPE_UNSIGNED (type)
11320 && TREE_CODE (arg1) == INTEGER_CST
11321 && !TREE_OVERFLOW (arg1)
11322 && TREE_INT_CST_HIGH (arg1) < 0
11323 && !TYPE_OVERFLOW_TRAPS (type)
11324 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11325 && !sign_bit_p (arg1, arg1))
11326 return fold_build2 (code, type, fold_convert (type, arg0),
11327 fold_convert (type, negate_expr (arg1)));
11329 /* X % -Y is the same as X % Y. */
11330 if (code == TRUNC_MOD_EXPR
11331 && !TYPE_UNSIGNED (type)
11332 && TREE_CODE (arg1) == NEGATE_EXPR
11333 && !TYPE_OVERFLOW_TRAPS (type))
11334 return fold_build2 (code, type, fold_convert (type, arg0),
11335 fold_convert (type, TREE_OPERAND (arg1, 0)));
11337 if (TREE_CODE (arg1) == INTEGER_CST
11338 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11339 &strict_overflow_p)))
11341 if (strict_overflow_p)
11342 fold_overflow_warning (("assuming signed overflow does not occur "
11343 "when simplifying modulos"),
11344 WARN_STRICT_OVERFLOW_MISC);
11345 return fold_convert (type, tem);
11352 if (integer_all_onesp (arg0))
11353 return omit_one_operand (type, arg0, arg1);
11357 /* Optimize -1 >> x for arithmetic right shifts. */
11358 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
11359 return omit_one_operand (type, arg0, arg1);
11360 /* ... fall through ... */
11364 if (integer_zerop (arg1))
11365 return non_lvalue (fold_convert (type, arg0));
11366 if (integer_zerop (arg0))
11367 return omit_one_operand (type, arg0, arg1);
11369 /* Since negative shift count is not well-defined,
11370 don't try to compute it in the compiler. */
11371 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
11374 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11375 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
11376 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11377 && host_integerp (TREE_OPERAND (arg0, 1), false)
11378 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11380 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
11381 + TREE_INT_CST_LOW (arg1));
11383 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11384 being well defined. */
11385 if (low >= TYPE_PRECISION (type))
11387 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
11388 low = low % TYPE_PRECISION (type);
11389 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
11390 return build_int_cst (type, 0);
11392 low = TYPE_PRECISION (type) - 1;
11395 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11396 build_int_cst (type, low));
11399 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11400 into x & ((unsigned)-1 >> c) for unsigned types. */
11401 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
11402 || (TYPE_UNSIGNED (type)
11403 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
11404 && host_integerp (arg1, false)
11405 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11406 && host_integerp (TREE_OPERAND (arg0, 1), false)
11407 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11409 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
11410 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
11416 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
11418 lshift = build_int_cst (type, -1);
11419 lshift = int_const_binop (code, lshift, arg1, 0);
11421 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
11425 /* Rewrite an LROTATE_EXPR by a constant into an
11426 RROTATE_EXPR by a new constant. */
11427 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
11429 tree tem = build_int_cst (TREE_TYPE (arg1),
11430 GET_MODE_BITSIZE (TYPE_MODE (type)));
11431 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
11432 return fold_build2 (RROTATE_EXPR, type, arg0, tem);
11435 /* If we have a rotate of a bit operation with the rotate count and
11436 the second operand of the bit operation both constant,
11437 permute the two operations. */
11438 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11439 && (TREE_CODE (arg0) == BIT_AND_EXPR
11440 || TREE_CODE (arg0) == BIT_IOR_EXPR
11441 || TREE_CODE (arg0) == BIT_XOR_EXPR)
11442 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11443 return fold_build2 (TREE_CODE (arg0), type,
11444 fold_build2 (code, type,
11445 TREE_OPERAND (arg0, 0), arg1),
11446 fold_build2 (code, type,
11447 TREE_OPERAND (arg0, 1), arg1));
11449 /* Two consecutive rotates adding up to the width of the mode can
11451 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11452 && TREE_CODE (arg0) == RROTATE_EXPR
11453 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11454 && TREE_INT_CST_HIGH (arg1) == 0
11455 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
11456 && ((TREE_INT_CST_LOW (arg1)
11457 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
11458 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
11459 return TREE_OPERAND (arg0, 0);
11464 if (operand_equal_p (arg0, arg1, 0))
11465 return omit_one_operand (type, arg0, arg1);
11466 if (INTEGRAL_TYPE_P (type)
11467 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
11468 return omit_one_operand (type, arg1, arg0);
11469 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
11475 if (operand_equal_p (arg0, arg1, 0))
11476 return omit_one_operand (type, arg0, arg1);
11477 if (INTEGRAL_TYPE_P (type)
11478 && TYPE_MAX_VALUE (type)
11479 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
11480 return omit_one_operand (type, arg1, arg0);
11481 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
11486 case TRUTH_ANDIF_EXPR:
11487 /* Note that the operands of this must be ints
11488 and their values must be 0 or 1.
11489 ("true" is a fixed value perhaps depending on the language.) */
11490 /* If first arg is constant zero, return it. */
11491 if (integer_zerop (arg0))
11492 return fold_convert (type, arg0);
11493 case TRUTH_AND_EXPR:
11494 /* If either arg is constant true, drop it. */
11495 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11496 return non_lvalue (fold_convert (type, arg1));
11497 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
11498 /* Preserve sequence points. */
11499 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11500 return non_lvalue (fold_convert (type, arg0));
11501 /* If second arg is constant zero, result is zero, but first arg
11502 must be evaluated. */
11503 if (integer_zerop (arg1))
11504 return omit_one_operand (type, arg1, arg0);
11505 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11506 case will be handled here. */
11507 if (integer_zerop (arg0))
11508 return omit_one_operand (type, arg0, arg1);
11510 /* !X && X is always false. */
11511 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11512 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11513 return omit_one_operand (type, integer_zero_node, arg1);
11514 /* X && !X is always false. */
11515 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11516 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11517 return omit_one_operand (type, integer_zero_node, arg0);
11519 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
11520 means A >= Y && A != MAX, but in this case we know that
11523 if (!TREE_SIDE_EFFECTS (arg0)
11524 && !TREE_SIDE_EFFECTS (arg1))
11526 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
11527 if (tem && !operand_equal_p (tem, arg0, 0))
11528 return fold_build2 (code, type, tem, arg1);
11530 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
11531 if (tem && !operand_equal_p (tem, arg1, 0))
11532 return fold_build2 (code, type, arg0, tem);
11536 /* We only do these simplifications if we are optimizing. */
11540 /* Check for things like (A || B) && (A || C). We can convert this
11541 to A || (B && C). Note that either operator can be any of the four
11542 truth and/or operations and the transformation will still be
11543 valid. Also note that we only care about order for the
11544 ANDIF and ORIF operators. If B contains side effects, this
11545 might change the truth-value of A. */
11546 if (TREE_CODE (arg0) == TREE_CODE (arg1)
11547 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
11548 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
11549 || TREE_CODE (arg0) == TRUTH_AND_EXPR
11550 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
11551 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
11553 tree a00 = TREE_OPERAND (arg0, 0);
11554 tree a01 = TREE_OPERAND (arg0, 1);
11555 tree a10 = TREE_OPERAND (arg1, 0);
11556 tree a11 = TREE_OPERAND (arg1, 1);
11557 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
11558 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
11559 && (code == TRUTH_AND_EXPR
11560 || code == TRUTH_OR_EXPR));
11562 if (operand_equal_p (a00, a10, 0))
11563 return fold_build2 (TREE_CODE (arg0), type, a00,
11564 fold_build2 (code, type, a01, a11));
11565 else if (commutative && operand_equal_p (a00, a11, 0))
11566 return fold_build2 (TREE_CODE (arg0), type, a00,
11567 fold_build2 (code, type, a01, a10));
11568 else if (commutative && operand_equal_p (a01, a10, 0))
11569 return fold_build2 (TREE_CODE (arg0), type, a01,
11570 fold_build2 (code, type, a00, a11));
11572 /* This case if tricky because we must either have commutative
11573 operators or else A10 must not have side-effects. */
11575 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
11576 && operand_equal_p (a01, a11, 0))
11577 return fold_build2 (TREE_CODE (arg0), type,
11578 fold_build2 (code, type, a00, a10),
11582 /* See if we can build a range comparison. */
11583 if (0 != (tem = fold_range_test (code, type, op0, op1)))
11586 /* Check for the possibility of merging component references. If our
11587 lhs is another similar operation, try to merge its rhs with our
11588 rhs. Then try to merge our lhs and rhs. */
11589 if (TREE_CODE (arg0) == code
11590 && 0 != (tem = fold_truthop (code, type,
11591 TREE_OPERAND (arg0, 1), arg1)))
11592 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11594 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
11599 case TRUTH_ORIF_EXPR:
11600 /* Note that the operands of this must be ints
11601 and their values must be 0 or true.
11602 ("true" is a fixed value perhaps depending on the language.) */
11603 /* If first arg is constant true, return it. */
11604 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11605 return fold_convert (type, arg0);
11606 case TRUTH_OR_EXPR:
11607 /* If either arg is constant zero, drop it. */
11608 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
11609 return non_lvalue (fold_convert (type, arg1));
11610 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
11611 /* Preserve sequence points. */
11612 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11613 return non_lvalue (fold_convert (type, arg0));
11614 /* If second arg is constant true, result is true, but we must
11615 evaluate first arg. */
11616 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
11617 return omit_one_operand (type, arg1, arg0);
11618 /* Likewise for first arg, but note this only occurs here for
11620 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11621 return omit_one_operand (type, arg0, arg1);
11623 /* !X || X is always true. */
11624 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11625 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11626 return omit_one_operand (type, integer_one_node, arg1);
11627 /* X || !X is always true. */
11628 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11629 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11630 return omit_one_operand (type, integer_one_node, arg0);
11634 case TRUTH_XOR_EXPR:
11635 /* If the second arg is constant zero, drop it. */
11636 if (integer_zerop (arg1))
11637 return non_lvalue (fold_convert (type, arg0));
11638 /* If the second arg is constant true, this is a logical inversion. */
11639 if (integer_onep (arg1))
11641 /* Only call invert_truthvalue if operand is a truth value. */
11642 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
11643 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
11645 tem = invert_truthvalue (arg0);
11646 return non_lvalue (fold_convert (type, tem));
11648 /* Identical arguments cancel to zero. */
11649 if (operand_equal_p (arg0, arg1, 0))
11650 return omit_one_operand (type, integer_zero_node, arg0);
11652 /* !X ^ X is always true. */
11653 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11654 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11655 return omit_one_operand (type, integer_one_node, arg1);
11657 /* X ^ !X is always true. */
11658 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11659 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11660 return omit_one_operand (type, integer_one_node, arg0);
11666 tem = fold_comparison (code, type, op0, op1);
11667 if (tem != NULL_TREE)
11670 /* bool_var != 0 becomes bool_var. */
11671 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11672 && code == NE_EXPR)
11673 return non_lvalue (fold_convert (type, arg0));
11675 /* bool_var == 1 becomes bool_var. */
11676 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11677 && code == EQ_EXPR)
11678 return non_lvalue (fold_convert (type, arg0));
11680 /* bool_var != 1 becomes !bool_var. */
11681 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11682 && code == NE_EXPR)
11683 return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
11685 /* bool_var == 0 becomes !bool_var. */
11686 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11687 && code == EQ_EXPR)
11688 return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
11690 /* If this is an equality comparison of the address of two non-weak,
11691 unaliased symbols neither of which are extern (since we do not
11692 have access to attributes for externs), then we know the result. */
11693 if (TREE_CODE (arg0) == ADDR_EXPR
11694 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
11695 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
11696 && ! lookup_attribute ("alias",
11697 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
11698 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
11699 && TREE_CODE (arg1) == ADDR_EXPR
11700 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
11701 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
11702 && ! lookup_attribute ("alias",
11703 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
11704 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
11706 /* We know that we're looking at the address of two
11707 non-weak, unaliased, static _DECL nodes.
11709 It is both wasteful and incorrect to call operand_equal_p
11710 to compare the two ADDR_EXPR nodes. It is wasteful in that
11711 all we need to do is test pointer equality for the arguments
11712 to the two ADDR_EXPR nodes. It is incorrect to use
11713 operand_equal_p as that function is NOT equivalent to a
11714 C equality test. It can in fact return false for two
11715 objects which would test as equal using the C equality
11717 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
11718 return constant_boolean_node (equal
11719 ? code == EQ_EXPR : code != EQ_EXPR,
11723 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
11724 a MINUS_EXPR of a constant, we can convert it into a comparison with
11725 a revised constant as long as no overflow occurs. */
11726 if (TREE_CODE (arg1) == INTEGER_CST
11727 && (TREE_CODE (arg0) == PLUS_EXPR
11728 || TREE_CODE (arg0) == MINUS_EXPR)
11729 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11730 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
11731 ? MINUS_EXPR : PLUS_EXPR,
11732 fold_convert (TREE_TYPE (arg0), arg1),
11733 TREE_OPERAND (arg0, 1), 0))
11734 && !TREE_OVERFLOW (tem))
11735 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11737 /* Similarly for a NEGATE_EXPR. */
11738 if (TREE_CODE (arg0) == NEGATE_EXPR
11739 && TREE_CODE (arg1) == INTEGER_CST
11740 && 0 != (tem = negate_expr (arg1))
11741 && TREE_CODE (tem) == INTEGER_CST
11742 && !TREE_OVERFLOW (tem))
11743 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11745 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
11746 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11747 && TREE_CODE (arg1) == INTEGER_CST
11748 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11749 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11750 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
11751 fold_convert (TREE_TYPE (arg0), arg1),
11752 TREE_OPERAND (arg0, 1)));
11754 /* Transform comparisons of the form X +- C CMP X. */
11755 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11756 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11757 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11758 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
11759 || POINTER_TYPE_P (TREE_TYPE (arg0))))
11761 tree cst = TREE_OPERAND (arg0, 1);
11763 if (code == EQ_EXPR
11764 && !integer_zerop (cst))
11765 return omit_two_operands (type, boolean_false_node,
11766 TREE_OPERAND (arg0, 0), arg1);
11768 return omit_two_operands (type, boolean_true_node,
11769 TREE_OPERAND (arg0, 0), arg1);
11772 /* If we have X - Y == 0, we can convert that to X == Y and similarly
11773 for !=. Don't do this for ordered comparisons due to overflow. */
11774 if (TREE_CODE (arg0) == MINUS_EXPR
11775 && integer_zerop (arg1))
11776 return fold_build2 (code, type,
11777 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
11779 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
11780 if (TREE_CODE (arg0) == ABS_EXPR
11781 && (integer_zerop (arg1) || real_zerop (arg1)))
11782 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
11784 /* If this is an EQ or NE comparison with zero and ARG0 is
11785 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
11786 two operations, but the latter can be done in one less insn
11787 on machines that have only two-operand insns or on which a
11788 constant cannot be the first operand. */
11789 if (TREE_CODE (arg0) == BIT_AND_EXPR
11790 && integer_zerop (arg1))
11792 tree arg00 = TREE_OPERAND (arg0, 0);
11793 tree arg01 = TREE_OPERAND (arg0, 1);
11794 if (TREE_CODE (arg00) == LSHIFT_EXPR
11795 && integer_onep (TREE_OPERAND (arg00, 0)))
11797 fold_build2 (code, type,
11798 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11799 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
11800 arg01, TREE_OPERAND (arg00, 1)),
11801 fold_convert (TREE_TYPE (arg0),
11802 integer_one_node)),
11804 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
11805 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
11807 fold_build2 (code, type,
11808 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11809 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
11810 arg00, TREE_OPERAND (arg01, 1)),
11811 fold_convert (TREE_TYPE (arg0),
11812 integer_one_node)),
11816 /* If this is an NE or EQ comparison of zero against the result of a
11817 signed MOD operation whose second operand is a power of 2, make
11818 the MOD operation unsigned since it is simpler and equivalent. */
11819 if (integer_zerop (arg1)
11820 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
11821 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
11822 || TREE_CODE (arg0) == CEIL_MOD_EXPR
11823 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
11824 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
11825 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11827 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
11828 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
11829 fold_convert (newtype,
11830 TREE_OPERAND (arg0, 0)),
11831 fold_convert (newtype,
11832 TREE_OPERAND (arg0, 1)));
11834 return fold_build2 (code, type, newmod,
11835 fold_convert (newtype, arg1));
11838 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
11839 C1 is a valid shift constant, and C2 is a power of two, i.e.
11841 if (TREE_CODE (arg0) == BIT_AND_EXPR
11842 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
11843 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
11845 && integer_pow2p (TREE_OPERAND (arg0, 1))
11846 && integer_zerop (arg1))
11848 tree itype = TREE_TYPE (arg0);
11849 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
11850 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
11852 /* Check for a valid shift count. */
11853 if (TREE_INT_CST_HIGH (arg001) == 0
11854 && TREE_INT_CST_LOW (arg001) < prec)
11856 tree arg01 = TREE_OPERAND (arg0, 1);
11857 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11858 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
11859 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
11860 can be rewritten as (X & (C2 << C1)) != 0. */
11861 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
11863 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
11864 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
11865 return fold_build2 (code, type, tem, arg1);
11867 /* Otherwise, for signed (arithmetic) shifts,
11868 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
11869 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
11870 else if (!TYPE_UNSIGNED (itype))
11871 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
11872 arg000, build_int_cst (itype, 0));
11873 /* Otherwise, of unsigned (logical) shifts,
11874 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
11875 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
11877 return omit_one_operand (type,
11878 code == EQ_EXPR ? integer_one_node
11879 : integer_zero_node,
11884 /* If this is an NE comparison of zero with an AND of one, remove the
11885 comparison since the AND will give the correct value. */
11886 if (code == NE_EXPR
11887 && integer_zerop (arg1)
11888 && TREE_CODE (arg0) == BIT_AND_EXPR
11889 && integer_onep (TREE_OPERAND (arg0, 1)))
11890 return fold_convert (type, arg0);
11892 /* If we have (A & C) == C where C is a power of 2, convert this into
11893 (A & C) != 0. Similarly for NE_EXPR. */
11894 if (TREE_CODE (arg0) == BIT_AND_EXPR
11895 && integer_pow2p (TREE_OPERAND (arg0, 1))
11896 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11897 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11898 arg0, fold_convert (TREE_TYPE (arg0),
11899 integer_zero_node));
11901 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
11902 bit, then fold the expression into A < 0 or A >= 0. */
11903 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
11907 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
11908 Similarly for NE_EXPR. */
11909 if (TREE_CODE (arg0) == BIT_AND_EXPR
11910 && TREE_CODE (arg1) == INTEGER_CST
11911 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11913 tree notc = fold_build1 (BIT_NOT_EXPR,
11914 TREE_TYPE (TREE_OPERAND (arg0, 1)),
11915 TREE_OPERAND (arg0, 1));
11916 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11918 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11919 if (integer_nonzerop (dandnotc))
11920 return omit_one_operand (type, rslt, arg0);
11923 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
11924 Similarly for NE_EXPR. */
11925 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11926 && TREE_CODE (arg1) == INTEGER_CST
11927 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11929 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
11930 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11931 TREE_OPERAND (arg0, 1), notd);
11932 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11933 if (integer_nonzerop (candnotd))
11934 return omit_one_operand (type, rslt, arg0);
11937 /* If this is a comparison of a field, we may be able to simplify it. */
11938 if ((TREE_CODE (arg0) == COMPONENT_REF
11939 || TREE_CODE (arg0) == BIT_FIELD_REF)
11940 /* Handle the constant case even without -O
11941 to make sure the warnings are given. */
11942 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
11944 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
11949 /* Optimize comparisons of strlen vs zero to a compare of the
11950 first character of the string vs zero. To wit,
11951 strlen(ptr) == 0 => *ptr == 0
11952 strlen(ptr) != 0 => *ptr != 0
11953 Other cases should reduce to one of these two (or a constant)
11954 due to the return value of strlen being unsigned. */
11955 if (TREE_CODE (arg0) == CALL_EXPR
11956 && integer_zerop (arg1))
11958 tree fndecl = get_callee_fndecl (arg0);
11961 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
11962 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
11963 && call_expr_nargs (arg0) == 1
11964 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
11966 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
11967 return fold_build2 (code, type, iref,
11968 build_int_cst (TREE_TYPE (iref), 0));
11972 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
11973 of X. Similarly fold (X >> C) == 0 into X >= 0. */
11974 if (TREE_CODE (arg0) == RSHIFT_EXPR
11975 && integer_zerop (arg1)
11976 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11978 tree arg00 = TREE_OPERAND (arg0, 0);
11979 tree arg01 = TREE_OPERAND (arg0, 1);
11980 tree itype = TREE_TYPE (arg00);
11981 if (TREE_INT_CST_HIGH (arg01) == 0
11982 && TREE_INT_CST_LOW (arg01)
11983 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
11985 if (TYPE_UNSIGNED (itype))
11987 itype = signed_type_for (itype);
11988 arg00 = fold_convert (itype, arg00);
11990 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
11991 type, arg00, build_int_cst (itype, 0));
11995 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
11996 if (integer_zerop (arg1)
11997 && TREE_CODE (arg0) == BIT_XOR_EXPR)
11998 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11999 TREE_OPERAND (arg0, 1));
12001 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
12002 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12003 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12004 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12005 build_int_cst (TREE_TYPE (arg1), 0));
12006 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
12007 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12008 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12009 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
12010 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
12011 build_int_cst (TREE_TYPE (arg1), 0));
12013 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
12014 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12015 && TREE_CODE (arg1) == INTEGER_CST
12016 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12017 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12018 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
12019 TREE_OPERAND (arg0, 1), arg1));
12021 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
12022 (X & C) == 0 when C is a single bit. */
12023 if (TREE_CODE (arg0) == BIT_AND_EXPR
12024 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
12025 && integer_zerop (arg1)
12026 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12028 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12029 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
12030 TREE_OPERAND (arg0, 1));
12031 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
12035 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12036 constant C is a power of two, i.e. a single bit. */
12037 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12038 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12039 && integer_zerop (arg1)
12040 && integer_pow2p (TREE_OPERAND (arg0, 1))
12041 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12042 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12044 tree arg00 = TREE_OPERAND (arg0, 0);
12045 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12046 arg00, build_int_cst (TREE_TYPE (arg00), 0));
12049 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12050 when is C is a power of two, i.e. a single bit. */
12051 if (TREE_CODE (arg0) == BIT_AND_EXPR
12052 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
12053 && integer_zerop (arg1)
12054 && integer_pow2p (TREE_OPERAND (arg0, 1))
12055 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12056 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12058 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12059 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
12060 arg000, TREE_OPERAND (arg0, 1));
12061 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12062 tem, build_int_cst (TREE_TYPE (tem), 0));
12065 if (integer_zerop (arg1)
12066 && tree_expr_nonzero_p (arg0))
12068 tree res = constant_boolean_node (code==NE_EXPR, type);
12069 return omit_one_operand (type, res, arg0);
12072 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12073 if (TREE_CODE (arg0) == NEGATE_EXPR
12074 && TREE_CODE (arg1) == NEGATE_EXPR)
12075 return fold_build2 (code, type,
12076 TREE_OPERAND (arg0, 0),
12077 TREE_OPERAND (arg1, 0));
12079 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12080 if (TREE_CODE (arg0) == BIT_AND_EXPR
12081 && TREE_CODE (arg1) == BIT_AND_EXPR)
12083 tree arg00 = TREE_OPERAND (arg0, 0);
12084 tree arg01 = TREE_OPERAND (arg0, 1);
12085 tree arg10 = TREE_OPERAND (arg1, 0);
12086 tree arg11 = TREE_OPERAND (arg1, 1);
12087 tree itype = TREE_TYPE (arg0);
12089 if (operand_equal_p (arg01, arg11, 0))
12090 return fold_build2 (code, type,
12091 fold_build2 (BIT_AND_EXPR, itype,
12092 fold_build2 (BIT_XOR_EXPR, itype,
12095 build_int_cst (itype, 0));
12097 if (operand_equal_p (arg01, arg10, 0))
12098 return fold_build2 (code, type,
12099 fold_build2 (BIT_AND_EXPR, itype,
12100 fold_build2 (BIT_XOR_EXPR, itype,
12103 build_int_cst (itype, 0));
12105 if (operand_equal_p (arg00, arg11, 0))
12106 return fold_build2 (code, type,
12107 fold_build2 (BIT_AND_EXPR, itype,
12108 fold_build2 (BIT_XOR_EXPR, itype,
12111 build_int_cst (itype, 0));
12113 if (operand_equal_p (arg00, arg10, 0))
12114 return fold_build2 (code, type,
12115 fold_build2 (BIT_AND_EXPR, itype,
12116 fold_build2 (BIT_XOR_EXPR, itype,
12119 build_int_cst (itype, 0));
12122 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12123 && TREE_CODE (arg1) == BIT_XOR_EXPR)
12125 tree arg00 = TREE_OPERAND (arg0, 0);
12126 tree arg01 = TREE_OPERAND (arg0, 1);
12127 tree arg10 = TREE_OPERAND (arg1, 0);
12128 tree arg11 = TREE_OPERAND (arg1, 1);
12129 tree itype = TREE_TYPE (arg0);
12131 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12132 operand_equal_p guarantees no side-effects so we don't need
12133 to use omit_one_operand on Z. */
12134 if (operand_equal_p (arg01, arg11, 0))
12135 return fold_build2 (code, type, arg00, arg10);
12136 if (operand_equal_p (arg01, arg10, 0))
12137 return fold_build2 (code, type, arg00, arg11);
12138 if (operand_equal_p (arg00, arg11, 0))
12139 return fold_build2 (code, type, arg01, arg10);
12140 if (operand_equal_p (arg00, arg10, 0))
12141 return fold_build2 (code, type, arg01, arg11);
12143 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12144 if (TREE_CODE (arg01) == INTEGER_CST
12145 && TREE_CODE (arg11) == INTEGER_CST)
12146 return fold_build2 (code, type,
12147 fold_build2 (BIT_XOR_EXPR, itype, arg00,
12148 fold_build2 (BIT_XOR_EXPR, itype,
12153 /* Attempt to simplify equality/inequality comparisons of complex
12154 values. Only lower the comparison if the result is known or
12155 can be simplified to a single scalar comparison. */
12156 if ((TREE_CODE (arg0) == COMPLEX_EXPR
12157 || TREE_CODE (arg0) == COMPLEX_CST)
12158 && (TREE_CODE (arg1) == COMPLEX_EXPR
12159 || TREE_CODE (arg1) == COMPLEX_CST))
12161 tree real0, imag0, real1, imag1;
12164 if (TREE_CODE (arg0) == COMPLEX_EXPR)
12166 real0 = TREE_OPERAND (arg0, 0);
12167 imag0 = TREE_OPERAND (arg0, 1);
12171 real0 = TREE_REALPART (arg0);
12172 imag0 = TREE_IMAGPART (arg0);
12175 if (TREE_CODE (arg1) == COMPLEX_EXPR)
12177 real1 = TREE_OPERAND (arg1, 0);
12178 imag1 = TREE_OPERAND (arg1, 1);
12182 real1 = TREE_REALPART (arg1);
12183 imag1 = TREE_IMAGPART (arg1);
12186 rcond = fold_binary (code, type, real0, real1);
12187 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
12189 if (integer_zerop (rcond))
12191 if (code == EQ_EXPR)
12192 return omit_two_operands (type, boolean_false_node,
12194 return fold_build2 (NE_EXPR, type, imag0, imag1);
12198 if (code == NE_EXPR)
12199 return omit_two_operands (type, boolean_true_node,
12201 return fold_build2 (EQ_EXPR, type, imag0, imag1);
12205 icond = fold_binary (code, type, imag0, imag1);
12206 if (icond && TREE_CODE (icond) == INTEGER_CST)
12208 if (integer_zerop (icond))
12210 if (code == EQ_EXPR)
12211 return omit_two_operands (type, boolean_false_node,
12213 return fold_build2 (NE_EXPR, type, real0, real1);
12217 if (code == NE_EXPR)
12218 return omit_two_operands (type, boolean_true_node,
12220 return fold_build2 (EQ_EXPR, type, real0, real1);
12231 tem = fold_comparison (code, type, op0, op1);
12232 if (tem != NULL_TREE)
12235 /* Transform comparisons of the form X +- C CMP X. */
12236 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12237 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12238 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
12239 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
12240 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12241 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
12243 tree arg01 = TREE_OPERAND (arg0, 1);
12244 enum tree_code code0 = TREE_CODE (arg0);
12247 if (TREE_CODE (arg01) == REAL_CST)
12248 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
12250 is_positive = tree_int_cst_sgn (arg01);
12252 /* (X - c) > X becomes false. */
12253 if (code == GT_EXPR
12254 && ((code0 == MINUS_EXPR && is_positive >= 0)
12255 || (code0 == PLUS_EXPR && is_positive <= 0)))
12257 if (TREE_CODE (arg01) == INTEGER_CST
12258 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12259 fold_overflow_warning (("assuming signed overflow does not "
12260 "occur when assuming that (X - c) > X "
12261 "is always false"),
12262 WARN_STRICT_OVERFLOW_ALL);
12263 return constant_boolean_node (0, type);
12266 /* Likewise (X + c) < X becomes false. */
12267 if (code == LT_EXPR
12268 && ((code0 == PLUS_EXPR && is_positive >= 0)
12269 || (code0 == MINUS_EXPR && is_positive <= 0)))
12271 if (TREE_CODE (arg01) == INTEGER_CST
12272 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12273 fold_overflow_warning (("assuming signed overflow does not "
12274 "occur when assuming that "
12275 "(X + c) < X is always false"),
12276 WARN_STRICT_OVERFLOW_ALL);
12277 return constant_boolean_node (0, type);
12280 /* Convert (X - c) <= X to true. */
12281 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12283 && ((code0 == MINUS_EXPR && is_positive >= 0)
12284 || (code0 == PLUS_EXPR && is_positive <= 0)))
12286 if (TREE_CODE (arg01) == INTEGER_CST
12287 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12288 fold_overflow_warning (("assuming signed overflow does not "
12289 "occur when assuming that "
12290 "(X - c) <= X is always true"),
12291 WARN_STRICT_OVERFLOW_ALL);
12292 return constant_boolean_node (1, type);
12295 /* Convert (X + c) >= X to true. */
12296 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12298 && ((code0 == PLUS_EXPR && is_positive >= 0)
12299 || (code0 == MINUS_EXPR && is_positive <= 0)))
12301 if (TREE_CODE (arg01) == INTEGER_CST
12302 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12303 fold_overflow_warning (("assuming signed overflow does not "
12304 "occur when assuming that "
12305 "(X + c) >= X is always true"),
12306 WARN_STRICT_OVERFLOW_ALL);
12307 return constant_boolean_node (1, type);
12310 if (TREE_CODE (arg01) == INTEGER_CST)
12312 /* Convert X + c > X and X - c < X to true for integers. */
12313 if (code == GT_EXPR
12314 && ((code0 == PLUS_EXPR && is_positive > 0)
12315 || (code0 == MINUS_EXPR && is_positive < 0)))
12317 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12318 fold_overflow_warning (("assuming signed overflow does "
12319 "not occur when assuming that "
12320 "(X + c) > X is always true"),
12321 WARN_STRICT_OVERFLOW_ALL);
12322 return constant_boolean_node (1, type);
12325 if (code == LT_EXPR
12326 && ((code0 == MINUS_EXPR && is_positive > 0)
12327 || (code0 == PLUS_EXPR && is_positive < 0)))
12329 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12330 fold_overflow_warning (("assuming signed overflow does "
12331 "not occur when assuming that "
12332 "(X - c) < X is always true"),
12333 WARN_STRICT_OVERFLOW_ALL);
12334 return constant_boolean_node (1, type);
12337 /* Convert X + c <= X and X - c >= X to false for integers. */
12338 if (code == LE_EXPR
12339 && ((code0 == PLUS_EXPR && is_positive > 0)
12340 || (code0 == MINUS_EXPR && is_positive < 0)))
12342 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12343 fold_overflow_warning (("assuming signed overflow does "
12344 "not occur when assuming that "
12345 "(X + c) <= X is always false"),
12346 WARN_STRICT_OVERFLOW_ALL);
12347 return constant_boolean_node (0, type);
12350 if (code == GE_EXPR
12351 && ((code0 == MINUS_EXPR && is_positive > 0)
12352 || (code0 == PLUS_EXPR && is_positive < 0)))
12354 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12355 fold_overflow_warning (("assuming signed overflow does "
12356 "not occur when assuming that "
12357 "(X - c) >= X is always false"),
12358 WARN_STRICT_OVERFLOW_ALL);
12359 return constant_boolean_node (0, type);
12364 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
12365 This transformation affects the cases which are handled in later
12366 optimizations involving comparisons with non-negative constants. */
12367 if (TREE_CODE (arg1) == INTEGER_CST
12368 && TREE_CODE (arg0) != INTEGER_CST
12369 && tree_int_cst_sgn (arg1) > 0)
12371 if (code == GE_EXPR)
12373 arg1 = const_binop (MINUS_EXPR, arg1,
12374 build_int_cst (TREE_TYPE (arg1), 1), 0);
12375 return fold_build2 (GT_EXPR, type, arg0,
12376 fold_convert (TREE_TYPE (arg0), arg1));
12378 if (code == LT_EXPR)
12380 arg1 = const_binop (MINUS_EXPR, arg1,
12381 build_int_cst (TREE_TYPE (arg1), 1), 0);
12382 return fold_build2 (LE_EXPR, type, arg0,
12383 fold_convert (TREE_TYPE (arg0), arg1));
12387 /* Comparisons with the highest or lowest possible integer of
12388 the specified precision will have known values. */
12390 tree arg1_type = TREE_TYPE (arg1);
12391 unsigned int width = TYPE_PRECISION (arg1_type);
12393 if (TREE_CODE (arg1) == INTEGER_CST
12394 && !TREE_OVERFLOW (arg1)
12395 && width <= 2 * HOST_BITS_PER_WIDE_INT
12396 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
12398 HOST_WIDE_INT signed_max_hi;
12399 unsigned HOST_WIDE_INT signed_max_lo;
12400 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
12402 if (width <= HOST_BITS_PER_WIDE_INT)
12404 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12409 if (TYPE_UNSIGNED (arg1_type))
12411 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12417 max_lo = signed_max_lo;
12418 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12424 width -= HOST_BITS_PER_WIDE_INT;
12425 signed_max_lo = -1;
12426 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12431 if (TYPE_UNSIGNED (arg1_type))
12433 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12438 max_hi = signed_max_hi;
12439 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12443 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
12444 && TREE_INT_CST_LOW (arg1) == max_lo)
12448 return omit_one_operand (type, integer_zero_node, arg0);
12451 return fold_build2 (EQ_EXPR, type, op0, op1);
12454 return omit_one_operand (type, integer_one_node, arg0);
12457 return fold_build2 (NE_EXPR, type, op0, op1);
12459 /* The GE_EXPR and LT_EXPR cases above are not normally
12460 reached because of previous transformations. */
12465 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12467 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
12471 arg1 = const_binop (PLUS_EXPR, arg1,
12472 build_int_cst (TREE_TYPE (arg1), 1), 0);
12473 return fold_build2 (EQ_EXPR, type,
12474 fold_convert (TREE_TYPE (arg1), arg0),
12477 arg1 = const_binop (PLUS_EXPR, arg1,
12478 build_int_cst (TREE_TYPE (arg1), 1), 0);
12479 return fold_build2 (NE_EXPR, type,
12480 fold_convert (TREE_TYPE (arg1), arg0),
12485 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12487 && TREE_INT_CST_LOW (arg1) == min_lo)
12491 return omit_one_operand (type, integer_zero_node, arg0);
12494 return fold_build2 (EQ_EXPR, type, op0, op1);
12497 return omit_one_operand (type, integer_one_node, arg0);
12500 return fold_build2 (NE_EXPR, type, op0, op1);
12505 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12507 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
12511 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12512 return fold_build2 (NE_EXPR, type,
12513 fold_convert (TREE_TYPE (arg1), arg0),
12516 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12517 return fold_build2 (EQ_EXPR, type,
12518 fold_convert (TREE_TYPE (arg1), arg0),
12524 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
12525 && TREE_INT_CST_LOW (arg1) == signed_max_lo
12526 && TYPE_UNSIGNED (arg1_type)
12527 /* We will flip the signedness of the comparison operator
12528 associated with the mode of arg1, so the sign bit is
12529 specified by this mode. Check that arg1 is the signed
12530 max associated with this sign bit. */
12531 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
12532 /* signed_type does not work on pointer types. */
12533 && INTEGRAL_TYPE_P (arg1_type))
12535 /* The following case also applies to X < signed_max+1
12536 and X >= signed_max+1 because previous transformations. */
12537 if (code == LE_EXPR || code == GT_EXPR)
12540 st = signed_type_for (TREE_TYPE (arg1));
12541 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
12542 type, fold_convert (st, arg0),
12543 build_int_cst (st, 0));
12549 /* If we are comparing an ABS_EXPR with a constant, we can
12550 convert all the cases into explicit comparisons, but they may
12551 well not be faster than doing the ABS and one comparison.
12552 But ABS (X) <= C is a range comparison, which becomes a subtraction
12553 and a comparison, and is probably faster. */
12554 if (code == LE_EXPR
12555 && TREE_CODE (arg1) == INTEGER_CST
12556 && TREE_CODE (arg0) == ABS_EXPR
12557 && ! TREE_SIDE_EFFECTS (arg0)
12558 && (0 != (tem = negate_expr (arg1)))
12559 && TREE_CODE (tem) == INTEGER_CST
12560 && !TREE_OVERFLOW (tem))
12561 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12562 build2 (GE_EXPR, type,
12563 TREE_OPERAND (arg0, 0), tem),
12564 build2 (LE_EXPR, type,
12565 TREE_OPERAND (arg0, 0), arg1));
12567 /* Convert ABS_EXPR<x> >= 0 to true. */
12568 strict_overflow_p = false;
12569 if (code == GE_EXPR
12570 && (integer_zerop (arg1)
12571 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
12572 && real_zerop (arg1)))
12573 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12575 if (strict_overflow_p)
12576 fold_overflow_warning (("assuming signed overflow does not occur "
12577 "when simplifying comparison of "
12578 "absolute value and zero"),
12579 WARN_STRICT_OVERFLOW_CONDITIONAL);
12580 return omit_one_operand (type, integer_one_node, arg0);
12583 /* Convert ABS_EXPR<x> < 0 to false. */
12584 strict_overflow_p = false;
12585 if (code == LT_EXPR
12586 && (integer_zerop (arg1) || real_zerop (arg1))
12587 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12589 if (strict_overflow_p)
12590 fold_overflow_warning (("assuming signed overflow does not occur "
12591 "when simplifying comparison of "
12592 "absolute value and zero"),
12593 WARN_STRICT_OVERFLOW_CONDITIONAL);
12594 return omit_one_operand (type, integer_zero_node, arg0);
12597 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
12598 and similarly for >= into !=. */
12599 if ((code == LT_EXPR || code == GE_EXPR)
12600 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12601 && TREE_CODE (arg1) == LSHIFT_EXPR
12602 && integer_onep (TREE_OPERAND (arg1, 0)))
12603 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12604 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12605 TREE_OPERAND (arg1, 1)),
12606 build_int_cst (TREE_TYPE (arg0), 0));
12608 if ((code == LT_EXPR || code == GE_EXPR)
12609 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12610 && (TREE_CODE (arg1) == NOP_EXPR
12611 || TREE_CODE (arg1) == CONVERT_EXPR)
12612 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
12613 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
12615 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12616 fold_convert (TREE_TYPE (arg0),
12617 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12618 TREE_OPERAND (TREE_OPERAND (arg1, 0),
12620 build_int_cst (TREE_TYPE (arg0), 0));
12624 case UNORDERED_EXPR:
12632 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
12634 t1 = fold_relational_const (code, type, arg0, arg1);
12635 if (t1 != NULL_TREE)
12639 /* If the first operand is NaN, the result is constant. */
12640 if (TREE_CODE (arg0) == REAL_CST
12641 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
12642 && (code != LTGT_EXPR || ! flag_trapping_math))
12644 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12645 ? integer_zero_node
12646 : integer_one_node;
12647 return omit_one_operand (type, t1, arg1);
12650 /* If the second operand is NaN, the result is constant. */
12651 if (TREE_CODE (arg1) == REAL_CST
12652 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
12653 && (code != LTGT_EXPR || ! flag_trapping_math))
12655 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12656 ? integer_zero_node
12657 : integer_one_node;
12658 return omit_one_operand (type, t1, arg0);
12661 /* Simplify unordered comparison of something with itself. */
12662 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
12663 && operand_equal_p (arg0, arg1, 0))
12664 return constant_boolean_node (1, type);
12666 if (code == LTGT_EXPR
12667 && !flag_trapping_math
12668 && operand_equal_p (arg0, arg1, 0))
12669 return constant_boolean_node (0, type);
12671 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12673 tree targ0 = strip_float_extensions (arg0);
12674 tree targ1 = strip_float_extensions (arg1);
12675 tree newtype = TREE_TYPE (targ0);
12677 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
12678 newtype = TREE_TYPE (targ1);
12680 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
12681 return fold_build2 (code, type, fold_convert (newtype, targ0),
12682 fold_convert (newtype, targ1));
12687 case COMPOUND_EXPR:
12688 /* When pedantic, a compound expression can be neither an lvalue
12689 nor an integer constant expression. */
12690 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
12692 /* Don't let (0, 0) be null pointer constant. */
12693 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
12694 : fold_convert (type, arg1);
12695 return pedantic_non_lvalue (tem);
12698 if ((TREE_CODE (arg0) == REAL_CST
12699 && TREE_CODE (arg1) == REAL_CST)
12700 || (TREE_CODE (arg0) == INTEGER_CST
12701 && TREE_CODE (arg1) == INTEGER_CST))
12702 return build_complex (type, arg0, arg1);
12706 /* An ASSERT_EXPR should never be passed to fold_binary. */
12707 gcc_unreachable ();
12711 } /* switch (code) */
12714 /* Callback for walk_tree, looking for LABEL_EXPR.
12715 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
12716 Do not check the sub-tree of GOTO_EXPR. */
12719 contains_label_1 (tree *tp,
12720 int *walk_subtrees,
12721 void *data ATTRIBUTE_UNUSED)
12723 switch (TREE_CODE (*tp))
12728 *walk_subtrees = 0;
12735 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
12736 accessible from outside the sub-tree. Returns NULL_TREE if no
12737 addressable label is found. */
12740 contains_label_p (tree st)
12742 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
12745 /* Fold a ternary expression of code CODE and type TYPE with operands
12746 OP0, OP1, and OP2. Return the folded expression if folding is
12747 successful. Otherwise, return NULL_TREE. */
12750 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
12753 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
12754 enum tree_code_class kind = TREE_CODE_CLASS (code);
12756 gcc_assert (IS_EXPR_CODE_CLASS (kind)
12757 && TREE_CODE_LENGTH (code) == 3);
12759 /* Strip any conversions that don't change the mode. This is safe
12760 for every expression, except for a comparison expression because
12761 its signedness is derived from its operands. So, in the latter
12762 case, only strip conversions that don't change the signedness.
12764 Note that this is done as an internal manipulation within the
12765 constant folder, in order to find the simplest representation of
12766 the arguments so that their form can be studied. In any cases,
12767 the appropriate type conversions should be put back in the tree
12768 that will get out of the constant folder. */
12783 case COMPONENT_REF:
12784 if (TREE_CODE (arg0) == CONSTRUCTOR
12785 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
12787 unsigned HOST_WIDE_INT idx;
12789 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
12796 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
12797 so all simple results must be passed through pedantic_non_lvalue. */
12798 if (TREE_CODE (arg0) == INTEGER_CST)
12800 tree unused_op = integer_zerop (arg0) ? op1 : op2;
12801 tem = integer_zerop (arg0) ? op2 : op1;
12802 /* Only optimize constant conditions when the selected branch
12803 has the same type as the COND_EXPR. This avoids optimizing
12804 away "c ? x : throw", where the throw has a void type.
12805 Avoid throwing away that operand which contains label. */
12806 if ((!TREE_SIDE_EFFECTS (unused_op)
12807 || !contains_label_p (unused_op))
12808 && (! VOID_TYPE_P (TREE_TYPE (tem))
12809 || VOID_TYPE_P (type)))
12810 return pedantic_non_lvalue (tem);
12813 if (operand_equal_p (arg1, op2, 0))
12814 return pedantic_omit_one_operand (type, arg1, arg0);
12816 /* If we have A op B ? A : C, we may be able to convert this to a
12817 simpler expression, depending on the operation and the values
12818 of B and C. Signed zeros prevent all of these transformations,
12819 for reasons given above each one.
12821 Also try swapping the arguments and inverting the conditional. */
12822 if (COMPARISON_CLASS_P (arg0)
12823 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12824 arg1, TREE_OPERAND (arg0, 1))
12825 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
12827 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
12832 if (COMPARISON_CLASS_P (arg0)
12833 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12835 TREE_OPERAND (arg0, 1))
12836 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
12838 tem = fold_truth_not_expr (arg0);
12839 if (tem && COMPARISON_CLASS_P (tem))
12841 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
12847 /* If the second operand is simpler than the third, swap them
12848 since that produces better jump optimization results. */
12849 if (truth_value_p (TREE_CODE (arg0))
12850 && tree_swap_operands_p (op1, op2, false))
12852 /* See if this can be inverted. If it can't, possibly because
12853 it was a floating-point inequality comparison, don't do
12855 tem = fold_truth_not_expr (arg0);
12857 return fold_build3 (code, type, tem, op2, op1);
12860 /* Convert A ? 1 : 0 to simply A. */
12861 if (integer_onep (op1)
12862 && integer_zerop (op2)
12863 /* If we try to convert OP0 to our type, the
12864 call to fold will try to move the conversion inside
12865 a COND, which will recurse. In that case, the COND_EXPR
12866 is probably the best choice, so leave it alone. */
12867 && type == TREE_TYPE (arg0))
12868 return pedantic_non_lvalue (arg0);
12870 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
12871 over COND_EXPR in cases such as floating point comparisons. */
12872 if (integer_zerop (op1)
12873 && integer_onep (op2)
12874 && truth_value_p (TREE_CODE (arg0)))
12875 return pedantic_non_lvalue (fold_convert (type,
12876 invert_truthvalue (arg0)));
12878 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
12879 if (TREE_CODE (arg0) == LT_EXPR
12880 && integer_zerop (TREE_OPERAND (arg0, 1))
12881 && integer_zerop (op2)
12882 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
12884 /* sign_bit_p only checks ARG1 bits within A's precision.
12885 If <sign bit of A> has wider type than A, bits outside
12886 of A's precision in <sign bit of A> need to be checked.
12887 If they are all 0, this optimization needs to be done
12888 in unsigned A's type, if they are all 1 in signed A's type,
12889 otherwise this can't be done. */
12890 if (TYPE_PRECISION (TREE_TYPE (tem))
12891 < TYPE_PRECISION (TREE_TYPE (arg1))
12892 && TYPE_PRECISION (TREE_TYPE (tem))
12893 < TYPE_PRECISION (type))
12895 unsigned HOST_WIDE_INT mask_lo;
12896 HOST_WIDE_INT mask_hi;
12897 int inner_width, outer_width;
12900 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
12901 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
12902 if (outer_width > TYPE_PRECISION (type))
12903 outer_width = TYPE_PRECISION (type);
12905 if (outer_width > HOST_BITS_PER_WIDE_INT)
12907 mask_hi = ((unsigned HOST_WIDE_INT) -1
12908 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
12914 mask_lo = ((unsigned HOST_WIDE_INT) -1
12915 >> (HOST_BITS_PER_WIDE_INT - outer_width));
12917 if (inner_width > HOST_BITS_PER_WIDE_INT)
12919 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
12920 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12924 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
12925 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12927 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
12928 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
12930 tem_type = signed_type_for (TREE_TYPE (tem));
12931 tem = fold_convert (tem_type, tem);
12933 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
12934 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
12936 tem_type = unsigned_type_for (TREE_TYPE (tem));
12937 tem = fold_convert (tem_type, tem);
12944 return fold_convert (type,
12945 fold_build2 (BIT_AND_EXPR,
12946 TREE_TYPE (tem), tem,
12947 fold_convert (TREE_TYPE (tem),
12951 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
12952 already handled above. */
12953 if (TREE_CODE (arg0) == BIT_AND_EXPR
12954 && integer_onep (TREE_OPERAND (arg0, 1))
12955 && integer_zerop (op2)
12956 && integer_pow2p (arg1))
12958 tree tem = TREE_OPERAND (arg0, 0);
12960 if (TREE_CODE (tem) == RSHIFT_EXPR
12961 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
12962 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
12963 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
12964 return fold_build2 (BIT_AND_EXPR, type,
12965 TREE_OPERAND (tem, 0), arg1);
12968 /* A & N ? N : 0 is simply A & N if N is a power of two. This
12969 is probably obsolete because the first operand should be a
12970 truth value (that's why we have the two cases above), but let's
12971 leave it in until we can confirm this for all front-ends. */
12972 if (integer_zerop (op2)
12973 && TREE_CODE (arg0) == NE_EXPR
12974 && integer_zerop (TREE_OPERAND (arg0, 1))
12975 && integer_pow2p (arg1)
12976 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12977 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12978 arg1, OEP_ONLY_CONST))
12979 return pedantic_non_lvalue (fold_convert (type,
12980 TREE_OPERAND (arg0, 0)));
12982 /* Convert A ? B : 0 into A && B if A and B are truth values. */
12983 if (integer_zerop (op2)
12984 && truth_value_p (TREE_CODE (arg0))
12985 && truth_value_p (TREE_CODE (arg1)))
12986 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12987 fold_convert (type, arg0),
12990 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
12991 if (integer_onep (op2)
12992 && truth_value_p (TREE_CODE (arg0))
12993 && truth_value_p (TREE_CODE (arg1)))
12995 /* Only perform transformation if ARG0 is easily inverted. */
12996 tem = fold_truth_not_expr (arg0);
12998 return fold_build2 (TRUTH_ORIF_EXPR, type,
12999 fold_convert (type, tem),
13003 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
13004 if (integer_zerop (arg1)
13005 && truth_value_p (TREE_CODE (arg0))
13006 && truth_value_p (TREE_CODE (op2)))
13008 /* Only perform transformation if ARG0 is easily inverted. */
13009 tem = fold_truth_not_expr (arg0);
13011 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13012 fold_convert (type, tem),
13016 /* Convert A ? 1 : B into A || B if A and B are truth values. */
13017 if (integer_onep (arg1)
13018 && truth_value_p (TREE_CODE (arg0))
13019 && truth_value_p (TREE_CODE (op2)))
13020 return fold_build2 (TRUTH_ORIF_EXPR, type,
13021 fold_convert (type, arg0),
13027 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
13028 of fold_ternary on them. */
13029 gcc_unreachable ();
13031 case BIT_FIELD_REF:
13032 if ((TREE_CODE (arg0) == VECTOR_CST
13033 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
13034 && type == TREE_TYPE (TREE_TYPE (arg0))
13035 && host_integerp (arg1, 1)
13036 && host_integerp (op2, 1))
13038 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
13039 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
13042 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
13043 && (idx % width) == 0
13044 && (idx = idx / width)
13045 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
13047 tree elements = NULL_TREE;
13049 if (TREE_CODE (arg0) == VECTOR_CST)
13050 elements = TREE_VECTOR_CST_ELTS (arg0);
13053 unsigned HOST_WIDE_INT idx;
13056 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
13057 elements = tree_cons (NULL_TREE, value, elements);
13059 while (idx-- > 0 && elements)
13060 elements = TREE_CHAIN (elements);
13062 return TREE_VALUE (elements);
13064 return fold_convert (type, integer_zero_node);
13071 } /* switch (code) */
13074 /* Perform constant folding and related simplification of EXPR.
13075 The related simplifications include x*1 => x, x*0 => 0, etc.,
13076 and application of the associative law.
13077 NOP_EXPR conversions may be removed freely (as long as we
13078 are careful not to change the type of the overall expression).
13079 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13080 but we can constant-fold them if they have constant operands. */
13082 #ifdef ENABLE_FOLD_CHECKING
13083 # define fold(x) fold_1 (x)
13084 static tree fold_1 (tree);
13090 const tree t = expr;
13091 enum tree_code code = TREE_CODE (t);
13092 enum tree_code_class kind = TREE_CODE_CLASS (code);
13095 /* Return right away if a constant. */
13096 if (kind == tcc_constant)
13099 /* CALL_EXPR-like objects with variable numbers of operands are
13100 treated specially. */
13101 if (kind == tcc_vl_exp)
13103 if (code == CALL_EXPR)
13105 tem = fold_call_expr (expr, false);
13106 return tem ? tem : expr;
13111 if (IS_EXPR_CODE_CLASS (kind)
13112 || IS_GIMPLE_STMT_CODE_CLASS (kind))
13114 tree type = TREE_TYPE (t);
13115 tree op0, op1, op2;
13117 switch (TREE_CODE_LENGTH (code))
13120 op0 = TREE_OPERAND (t, 0);
13121 tem = fold_unary (code, type, op0);
13122 return tem ? tem : expr;
13124 op0 = TREE_OPERAND (t, 0);
13125 op1 = TREE_OPERAND (t, 1);
13126 tem = fold_binary (code, type, op0, op1);
13127 return tem ? tem : expr;
13129 op0 = TREE_OPERAND (t, 0);
13130 op1 = TREE_OPERAND (t, 1);
13131 op2 = TREE_OPERAND (t, 2);
13132 tem = fold_ternary (code, type, op0, op1, op2);
13133 return tem ? tem : expr;
13142 return fold (DECL_INITIAL (t));
13146 } /* switch (code) */
13149 #ifdef ENABLE_FOLD_CHECKING
13152 static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
13153 static void fold_check_failed (const_tree, const_tree);
13154 void print_fold_checksum (const_tree);
13156 /* When --enable-checking=fold, compute a digest of expr before
13157 and after actual fold call to see if fold did not accidentally
13158 change original expr. */
13164 struct md5_ctx ctx;
13165 unsigned char checksum_before[16], checksum_after[16];
13168 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13169 md5_init_ctx (&ctx);
13170 fold_checksum_tree (expr, &ctx, ht);
13171 md5_finish_ctx (&ctx, checksum_before);
13174 ret = fold_1 (expr);
13176 md5_init_ctx (&ctx);
13177 fold_checksum_tree (expr, &ctx, ht);
13178 md5_finish_ctx (&ctx, checksum_after);
13181 if (memcmp (checksum_before, checksum_after, 16))
13182 fold_check_failed (expr, ret);
13188 print_fold_checksum (const_tree expr)
13190 struct md5_ctx ctx;
13191 unsigned char checksum[16], cnt;
13194 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13195 md5_init_ctx (&ctx);
13196 fold_checksum_tree (expr, &ctx, ht);
13197 md5_finish_ctx (&ctx, checksum);
13199 for (cnt = 0; cnt < 16; ++cnt)
13200 fprintf (stderr, "%02x", checksum[cnt]);
13201 putc ('\n', stderr);
13205 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
13207 internal_error ("fold check: original tree changed by fold");
13211 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
13214 enum tree_code code;
13215 struct tree_function_decl buf;
13220 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
13221 <= sizeof (struct tree_function_decl))
13222 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
13225 slot = (const void **) htab_find_slot (ht, expr, INSERT);
13229 code = TREE_CODE (expr);
13230 if (TREE_CODE_CLASS (code) == tcc_declaration
13231 && DECL_ASSEMBLER_NAME_SET_P (expr))
13233 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13234 memcpy ((char *) &buf, expr, tree_size (expr));
13235 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
13236 expr = (tree) &buf;
13238 else if (TREE_CODE_CLASS (code) == tcc_type
13239 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
13240 || TYPE_CACHED_VALUES_P (expr)
13241 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
13243 /* Allow these fields to be modified. */
13245 memcpy ((char *) &buf, expr, tree_size (expr));
13246 expr = tmp = (tree) &buf;
13247 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
13248 TYPE_POINTER_TO (tmp) = NULL;
13249 TYPE_REFERENCE_TO (tmp) = NULL;
13250 if (TYPE_CACHED_VALUES_P (tmp))
13252 TYPE_CACHED_VALUES_P (tmp) = 0;
13253 TYPE_CACHED_VALUES (tmp) = NULL;
13256 md5_process_bytes (expr, tree_size (expr), ctx);
13257 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
13258 if (TREE_CODE_CLASS (code) != tcc_type
13259 && TREE_CODE_CLASS (code) != tcc_declaration
13260 && code != TREE_LIST
13261 && code != SSA_NAME)
13262 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
13263 switch (TREE_CODE_CLASS (code))
13269 md5_process_bytes (TREE_STRING_POINTER (expr),
13270 TREE_STRING_LENGTH (expr), ctx);
13273 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
13274 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
13277 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
13283 case tcc_exceptional:
13287 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
13288 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
13289 expr = TREE_CHAIN (expr);
13290 goto recursive_label;
13293 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
13294 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
13300 case tcc_expression:
13301 case tcc_reference:
13302 case tcc_comparison:
13305 case tcc_statement:
13307 len = TREE_OPERAND_LENGTH (expr);
13308 for (i = 0; i < len; ++i)
13309 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
13311 case tcc_declaration:
13312 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
13313 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
13314 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
13316 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
13317 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
13318 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
13319 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
13320 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
13322 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
13323 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
13325 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
13327 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
13328 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
13329 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
13333 if (TREE_CODE (expr) == ENUMERAL_TYPE)
13334 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
13335 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
13336 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
13337 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
13338 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
13339 if (INTEGRAL_TYPE_P (expr)
13340 || SCALAR_FLOAT_TYPE_P (expr))
13342 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
13343 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
13345 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
13346 if (TREE_CODE (expr) == RECORD_TYPE
13347 || TREE_CODE (expr) == UNION_TYPE
13348 || TREE_CODE (expr) == QUAL_UNION_TYPE)
13349 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
13350 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
13357 /* Helper function for outputting the checksum of a tree T. When
13358 debugging with gdb, you can "define mynext" to be "next" followed
13359 by "call debug_fold_checksum (op0)", then just trace down till the
13363 debug_fold_checksum (const_tree t)
13366 unsigned char checksum[16];
13367 struct md5_ctx ctx;
13368 htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13370 md5_init_ctx (&ctx);
13371 fold_checksum_tree (t, &ctx, ht);
13372 md5_finish_ctx (&ctx, checksum);
13375 for (i = 0; i < 16; i++)
13376 fprintf (stderr, "%d ", checksum[i]);
13378 fprintf (stderr, "\n");
13383 /* Fold a unary tree expression with code CODE of type TYPE with an
13384 operand OP0. Return a folded expression if successful. Otherwise,
13385 return a tree expression with code CODE of type TYPE with an
13389 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
13392 #ifdef ENABLE_FOLD_CHECKING
13393 unsigned char checksum_before[16], checksum_after[16];
13394 struct md5_ctx ctx;
13397 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13398 md5_init_ctx (&ctx);
13399 fold_checksum_tree (op0, &ctx, ht);
13400 md5_finish_ctx (&ctx, checksum_before);
13404 tem = fold_unary (code, type, op0);
13406 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
13408 #ifdef ENABLE_FOLD_CHECKING
13409 md5_init_ctx (&ctx);
13410 fold_checksum_tree (op0, &ctx, ht);
13411 md5_finish_ctx (&ctx, checksum_after);
13414 if (memcmp (checksum_before, checksum_after, 16))
13415 fold_check_failed (op0, tem);
13420 /* Fold a binary tree expression with code CODE of type TYPE with
13421 operands OP0 and OP1. Return a folded expression if successful.
13422 Otherwise, return a tree expression with code CODE of type TYPE
13423 with operands OP0 and OP1. */
13426 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
13430 #ifdef ENABLE_FOLD_CHECKING
13431 unsigned char checksum_before_op0[16],
13432 checksum_before_op1[16],
13433 checksum_after_op0[16],
13434 checksum_after_op1[16];
13435 struct md5_ctx ctx;
13438 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13439 md5_init_ctx (&ctx);
13440 fold_checksum_tree (op0, &ctx, ht);
13441 md5_finish_ctx (&ctx, checksum_before_op0);
13444 md5_init_ctx (&ctx);
13445 fold_checksum_tree (op1, &ctx, ht);
13446 md5_finish_ctx (&ctx, checksum_before_op1);
13450 tem = fold_binary (code, type, op0, op1);
13452 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
13454 #ifdef ENABLE_FOLD_CHECKING
13455 md5_init_ctx (&ctx);
13456 fold_checksum_tree (op0, &ctx, ht);
13457 md5_finish_ctx (&ctx, checksum_after_op0);
13460 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13461 fold_check_failed (op0, tem);
13463 md5_init_ctx (&ctx);
13464 fold_checksum_tree (op1, &ctx, ht);
13465 md5_finish_ctx (&ctx, checksum_after_op1);
13468 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13469 fold_check_failed (op1, tem);
13474 /* Fold a ternary tree expression with code CODE of type TYPE with
13475 operands OP0, OP1, and OP2. Return a folded expression if
13476 successful. Otherwise, return a tree expression with code CODE of
13477 type TYPE with operands OP0, OP1, and OP2. */
13480 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
13484 #ifdef ENABLE_FOLD_CHECKING
13485 unsigned char checksum_before_op0[16],
13486 checksum_before_op1[16],
13487 checksum_before_op2[16],
13488 checksum_after_op0[16],
13489 checksum_after_op1[16],
13490 checksum_after_op2[16];
13491 struct md5_ctx ctx;
13494 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13495 md5_init_ctx (&ctx);
13496 fold_checksum_tree (op0, &ctx, ht);
13497 md5_finish_ctx (&ctx, checksum_before_op0);
13500 md5_init_ctx (&ctx);
13501 fold_checksum_tree (op1, &ctx, ht);
13502 md5_finish_ctx (&ctx, checksum_before_op1);
13505 md5_init_ctx (&ctx);
13506 fold_checksum_tree (op2, &ctx, ht);
13507 md5_finish_ctx (&ctx, checksum_before_op2);
13511 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
13512 tem = fold_ternary (code, type, op0, op1, op2);
13514 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
13516 #ifdef ENABLE_FOLD_CHECKING
13517 md5_init_ctx (&ctx);
13518 fold_checksum_tree (op0, &ctx, ht);
13519 md5_finish_ctx (&ctx, checksum_after_op0);
13522 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13523 fold_check_failed (op0, tem);
13525 md5_init_ctx (&ctx);
13526 fold_checksum_tree (op1, &ctx, ht);
13527 md5_finish_ctx (&ctx, checksum_after_op1);
13530 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13531 fold_check_failed (op1, tem);
13533 md5_init_ctx (&ctx);
13534 fold_checksum_tree (op2, &ctx, ht);
13535 md5_finish_ctx (&ctx, checksum_after_op2);
13538 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
13539 fold_check_failed (op2, tem);
13544 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
13545 arguments in ARGARRAY, and a null static chain.
13546 Return a folded expression if successful. Otherwise, return a CALL_EXPR
13547 of type TYPE from the given operands as constructed by build_call_array. */
13550 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
13553 #ifdef ENABLE_FOLD_CHECKING
13554 unsigned char checksum_before_fn[16],
13555 checksum_before_arglist[16],
13556 checksum_after_fn[16],
13557 checksum_after_arglist[16];
13558 struct md5_ctx ctx;
13562 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13563 md5_init_ctx (&ctx);
13564 fold_checksum_tree (fn, &ctx, ht);
13565 md5_finish_ctx (&ctx, checksum_before_fn);
13568 md5_init_ctx (&ctx);
13569 for (i = 0; i < nargs; i++)
13570 fold_checksum_tree (argarray[i], &ctx, ht);
13571 md5_finish_ctx (&ctx, checksum_before_arglist);
13575 tem = fold_builtin_call_array (type, fn, nargs, argarray);
13577 #ifdef ENABLE_FOLD_CHECKING
13578 md5_init_ctx (&ctx);
13579 fold_checksum_tree (fn, &ctx, ht);
13580 md5_finish_ctx (&ctx, checksum_after_fn);
13583 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
13584 fold_check_failed (fn, tem);
13586 md5_init_ctx (&ctx);
13587 for (i = 0; i < nargs; i++)
13588 fold_checksum_tree (argarray[i], &ctx, ht);
13589 md5_finish_ctx (&ctx, checksum_after_arglist);
13592 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
13593 fold_check_failed (NULL_TREE, tem);
13598 /* Perform constant folding and related simplification of initializer
13599 expression EXPR. These behave identically to "fold_buildN" but ignore
13600 potential run-time traps and exceptions that fold must preserve. */
13602 #define START_FOLD_INIT \
13603 int saved_signaling_nans = flag_signaling_nans;\
13604 int saved_trapping_math = flag_trapping_math;\
13605 int saved_rounding_math = flag_rounding_math;\
13606 int saved_trapv = flag_trapv;\
13607 int saved_folding_initializer = folding_initializer;\
13608 flag_signaling_nans = 0;\
13609 flag_trapping_math = 0;\
13610 flag_rounding_math = 0;\
13612 folding_initializer = 1;
13614 #define END_FOLD_INIT \
13615 flag_signaling_nans = saved_signaling_nans;\
13616 flag_trapping_math = saved_trapping_math;\
13617 flag_rounding_math = saved_rounding_math;\
13618 flag_trapv = saved_trapv;\
13619 folding_initializer = saved_folding_initializer;
13622 fold_build1_initializer (enum tree_code code, tree type, tree op)
13627 result = fold_build1 (code, type, op);
13634 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
13639 result = fold_build2 (code, type, op0, op1);
13646 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
13652 result = fold_build3 (code, type, op0, op1, op2);
13659 fold_build_call_array_initializer (tree type, tree fn,
13660 int nargs, tree *argarray)
13665 result = fold_build_call_array (type, fn, nargs, argarray);
13671 #undef START_FOLD_INIT
13672 #undef END_FOLD_INIT
13674 /* Determine if first argument is a multiple of second argument. Return 0 if
13675 it is not, or we cannot easily determined it to be.
13677 An example of the sort of thing we care about (at this point; this routine
13678 could surely be made more general, and expanded to do what the *_DIV_EXPR's
13679 fold cases do now) is discovering that
13681 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13687 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
13689 This code also handles discovering that
13691 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13693 is a multiple of 8 so we don't have to worry about dealing with a
13694 possible remainder.
13696 Note that we *look* inside a SAVE_EXPR only to determine how it was
13697 calculated; it is not safe for fold to do much of anything else with the
13698 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
13699 at run time. For example, the latter example above *cannot* be implemented
13700 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
13701 evaluation time of the original SAVE_EXPR is not necessarily the same at
13702 the time the new expression is evaluated. The only optimization of this
13703 sort that would be valid is changing
13705 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
13709 SAVE_EXPR (I) * SAVE_EXPR (J)
13711 (where the same SAVE_EXPR (J) is used in the original and the
13712 transformed version). */
13715 multiple_of_p (tree type, const_tree top, const_tree bottom)
13717 if (operand_equal_p (top, bottom, 0))
13720 if (TREE_CODE (type) != INTEGER_TYPE)
13723 switch (TREE_CODE (top))
13726 /* Bitwise and provides a power of two multiple. If the mask is
13727 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
13728 if (!integer_pow2p (bottom))
13733 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13734 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13738 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13739 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13742 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
13746 op1 = TREE_OPERAND (top, 1);
13747 /* const_binop may not detect overflow correctly,
13748 so check for it explicitly here. */
13749 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
13750 > TREE_INT_CST_LOW (op1)
13751 && TREE_INT_CST_HIGH (op1) == 0
13752 && 0 != (t1 = fold_convert (type,
13753 const_binop (LSHIFT_EXPR,
13756 && !TREE_OVERFLOW (t1))
13757 return multiple_of_p (type, t1, bottom);
13762 /* Can't handle conversions from non-integral or wider integral type. */
13763 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
13764 || (TYPE_PRECISION (type)
13765 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
13768 /* .. fall through ... */
13771 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
13774 if (TREE_CODE (bottom) != INTEGER_CST
13775 || integer_zerop (bottom)
13776 || (TYPE_UNSIGNED (type)
13777 && (tree_int_cst_sgn (top) < 0
13778 || tree_int_cst_sgn (bottom) < 0)))
13780 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
13788 /* Return true if `t' is known to be non-negative. If the return
13789 value is based on the assumption that signed overflow is undefined,
13790 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13791 *STRICT_OVERFLOW_P. */
13794 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
13796 if (t == error_mark_node)
13799 if (TYPE_UNSIGNED (TREE_TYPE (t)))
13802 switch (TREE_CODE (t))
13805 /* Query VRP to see if it has recorded any information about
13806 the range of this object. */
13807 return ssa_name_nonnegative_p (t);
13810 /* We can't return 1 if flag_wrapv is set because
13811 ABS_EXPR<INT_MIN> = INT_MIN. */
13812 if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
13814 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
13816 *strict_overflow_p = true;
13822 return tree_int_cst_sgn (t) >= 0;
13825 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
13828 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
13830 case POINTER_PLUS_EXPR:
13832 if (FLOAT_TYPE_P (TREE_TYPE (t)))
13833 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13835 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13836 strict_overflow_p));
13838 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
13839 both unsigned and at least 2 bits shorter than the result. */
13840 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
13841 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
13842 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
13844 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
13845 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
13846 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13847 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13849 unsigned int prec = MAX (TYPE_PRECISION (inner1),
13850 TYPE_PRECISION (inner2)) + 1;
13851 return prec < TYPE_PRECISION (TREE_TYPE (t));
13857 if (FLOAT_TYPE_P (TREE_TYPE (t)))
13859 /* x * x for floating point x is always non-negative. */
13860 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
13862 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13864 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13865 strict_overflow_p));
13868 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
13869 both unsigned and their total bits is shorter than the result. */
13870 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
13871 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
13872 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
13874 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
13875 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
13876 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13877 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13878 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
13879 < TYPE_PRECISION (TREE_TYPE (t));
13885 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13887 || tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13888 strict_overflow_p));
13894 case TRUNC_DIV_EXPR:
13895 case CEIL_DIV_EXPR:
13896 case FLOOR_DIV_EXPR:
13897 case ROUND_DIV_EXPR:
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 case TRUNC_MOD_EXPR:
13904 case CEIL_MOD_EXPR:
13905 case FLOOR_MOD_EXPR:
13906 case ROUND_MOD_EXPR:
13908 case NON_LVALUE_EXPR:
13910 case FIX_TRUNC_EXPR:
13911 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13912 strict_overflow_p);
13914 case COMPOUND_EXPR:
13916 case GIMPLE_MODIFY_STMT:
13917 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
13918 strict_overflow_p);
13921 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
13922 strict_overflow_p);
13925 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13927 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
13928 strict_overflow_p));
13932 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
13933 tree outer_type = TREE_TYPE (t);
13935 if (TREE_CODE (outer_type) == REAL_TYPE)
13937 if (TREE_CODE (inner_type) == REAL_TYPE)
13938 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13939 strict_overflow_p);
13940 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13942 if (TYPE_UNSIGNED (inner_type))
13944 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
13945 strict_overflow_p);
13948 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
13950 if (TREE_CODE (inner_type) == REAL_TYPE)
13951 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t,0),
13952 strict_overflow_p);
13953 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13954 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
13955 && TYPE_UNSIGNED (inner_type);
13962 tree temp = TARGET_EXPR_SLOT (t);
13963 t = TARGET_EXPR_INITIAL (t);
13965 /* If the initializer is non-void, then it's a normal expression
13966 that will be assigned to the slot. */
13967 if (!VOID_TYPE_P (t))
13968 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
13970 /* Otherwise, the initializer sets the slot in some way. One common
13971 way is an assignment statement at the end of the initializer. */
13974 if (TREE_CODE (t) == BIND_EXPR)
13975 t = expr_last (BIND_EXPR_BODY (t));
13976 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
13977 || TREE_CODE (t) == TRY_CATCH_EXPR)
13978 t = expr_last (TREE_OPERAND (t, 0));
13979 else if (TREE_CODE (t) == STATEMENT_LIST)
13984 if ((TREE_CODE (t) == MODIFY_EXPR
13985 || TREE_CODE (t) == GIMPLE_MODIFY_STMT)
13986 && GENERIC_TREE_OPERAND (t, 0) == temp)
13987 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
13988 strict_overflow_p);
13995 tree fndecl = get_callee_fndecl (t);
13996 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
13997 switch (DECL_FUNCTION_CODE (fndecl))
13999 CASE_FLT_FN (BUILT_IN_ACOS):
14000 CASE_FLT_FN (BUILT_IN_ACOSH):
14001 CASE_FLT_FN (BUILT_IN_CABS):
14002 CASE_FLT_FN (BUILT_IN_COSH):
14003 CASE_FLT_FN (BUILT_IN_ERFC):
14004 CASE_FLT_FN (BUILT_IN_EXP):
14005 CASE_FLT_FN (BUILT_IN_EXP10):
14006 CASE_FLT_FN (BUILT_IN_EXP2):
14007 CASE_FLT_FN (BUILT_IN_FABS):
14008 CASE_FLT_FN (BUILT_IN_FDIM):
14009 CASE_FLT_FN (BUILT_IN_HYPOT):
14010 CASE_FLT_FN (BUILT_IN_POW10):
14011 CASE_INT_FN (BUILT_IN_FFS):
14012 CASE_INT_FN (BUILT_IN_PARITY):
14013 CASE_INT_FN (BUILT_IN_POPCOUNT):
14014 case BUILT_IN_BSWAP32:
14015 case BUILT_IN_BSWAP64:
14019 CASE_FLT_FN (BUILT_IN_SQRT):
14020 /* sqrt(-0.0) is -0.0. */
14021 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
14023 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14024 strict_overflow_p);
14026 CASE_FLT_FN (BUILT_IN_ASINH):
14027 CASE_FLT_FN (BUILT_IN_ATAN):
14028 CASE_FLT_FN (BUILT_IN_ATANH):
14029 CASE_FLT_FN (BUILT_IN_CBRT):
14030 CASE_FLT_FN (BUILT_IN_CEIL):
14031 CASE_FLT_FN (BUILT_IN_ERF):
14032 CASE_FLT_FN (BUILT_IN_EXPM1):
14033 CASE_FLT_FN (BUILT_IN_FLOOR):
14034 CASE_FLT_FN (BUILT_IN_FMOD):
14035 CASE_FLT_FN (BUILT_IN_FREXP):
14036 CASE_FLT_FN (BUILT_IN_LCEIL):
14037 CASE_FLT_FN (BUILT_IN_LDEXP):
14038 CASE_FLT_FN (BUILT_IN_LFLOOR):
14039 CASE_FLT_FN (BUILT_IN_LLCEIL):
14040 CASE_FLT_FN (BUILT_IN_LLFLOOR):
14041 CASE_FLT_FN (BUILT_IN_LLRINT):
14042 CASE_FLT_FN (BUILT_IN_LLROUND):
14043 CASE_FLT_FN (BUILT_IN_LRINT):
14044 CASE_FLT_FN (BUILT_IN_LROUND):
14045 CASE_FLT_FN (BUILT_IN_MODF):
14046 CASE_FLT_FN (BUILT_IN_NEARBYINT):
14047 CASE_FLT_FN (BUILT_IN_RINT):
14048 CASE_FLT_FN (BUILT_IN_ROUND):
14049 CASE_FLT_FN (BUILT_IN_SCALB):
14050 CASE_FLT_FN (BUILT_IN_SCALBLN):
14051 CASE_FLT_FN (BUILT_IN_SCALBN):
14052 CASE_FLT_FN (BUILT_IN_SIGNBIT):
14053 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
14054 CASE_FLT_FN (BUILT_IN_SINH):
14055 CASE_FLT_FN (BUILT_IN_TANH):
14056 CASE_FLT_FN (BUILT_IN_TRUNC):
14057 /* True if the 1st argument is nonnegative. */
14058 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14059 strict_overflow_p);
14061 CASE_FLT_FN (BUILT_IN_FMAX):
14062 /* True if the 1st OR 2nd arguments are nonnegative. */
14063 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14065 || (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14066 strict_overflow_p)));
14068 CASE_FLT_FN (BUILT_IN_FMIN):
14069 /* True if the 1st AND 2nd arguments are nonnegative. */
14070 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14072 && (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14073 strict_overflow_p)));
14075 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14076 /* True if the 2nd argument is nonnegative. */
14077 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14078 strict_overflow_p);
14080 CASE_FLT_FN (BUILT_IN_POWI):
14081 /* True if the 1st argument is nonnegative or the second
14082 argument is an even integer. */
14083 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == INTEGER_CST)
14085 tree arg1 = CALL_EXPR_ARG (t, 1);
14086 if ((TREE_INT_CST_LOW (arg1) & 1) == 0)
14089 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14090 strict_overflow_p);
14092 CASE_FLT_FN (BUILT_IN_POW):
14093 /* True if the 1st argument is nonnegative or the second
14094 argument is an even integer valued real. */
14095 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == REAL_CST)
14100 c = TREE_REAL_CST (CALL_EXPR_ARG (t, 1));
14101 n = real_to_integer (&c);
14104 REAL_VALUE_TYPE cint;
14105 real_from_integer (&cint, VOIDmode, n,
14106 n < 0 ? -1 : 0, 0);
14107 if (real_identical (&c, &cint))
14111 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14112 strict_overflow_p);
14119 /* ... fall through ... */
14123 tree type = TREE_TYPE (t);
14124 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
14125 && truth_value_p (TREE_CODE (t)))
14126 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
14127 have a signed:1 type (where the value is -1 and 0). */
14132 /* We don't know sign of `t', so be conservative and return false. */
14136 /* Return true if `t' is known to be non-negative. Handle warnings
14137 about undefined signed overflow. */
14140 tree_expr_nonnegative_p (tree t)
14142 bool ret, strict_overflow_p;
14144 strict_overflow_p = false;
14145 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
14146 if (strict_overflow_p)
14147 fold_overflow_warning (("assuming signed overflow does not occur when "
14148 "determining that expression is always "
14150 WARN_STRICT_OVERFLOW_MISC);
14154 /* Return true when T is an address and is known to be nonzero.
14155 For floating point we further ensure that T is not denormal.
14156 Similar logic is present in nonzero_address in rtlanal.h.
14158 If the return value is based on the assumption that signed overflow
14159 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14160 change *STRICT_OVERFLOW_P. */
14163 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14165 tree type = TREE_TYPE (t);
14166 bool sub_strict_overflow_p;
14168 /* Doing something useful for floating point would need more work. */
14169 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
14172 switch (TREE_CODE (t))
14175 /* Query VRP to see if it has recorded any information about
14176 the range of this object. */
14177 return ssa_name_nonzero_p (t);
14180 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14181 strict_overflow_p);
14184 return !integer_zerop (t);
14186 case POINTER_PLUS_EXPR:
14188 if (TYPE_OVERFLOW_UNDEFINED (type))
14190 /* With the presence of negative values it is hard
14191 to say something. */
14192 sub_strict_overflow_p = false;
14193 if (!tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14194 &sub_strict_overflow_p)
14195 || !tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14196 &sub_strict_overflow_p))
14198 /* One of operands must be positive and the other non-negative. */
14199 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14200 overflows, on a twos-complement machine the sum of two
14201 nonnegative numbers can never be zero. */
14202 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14204 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14205 strict_overflow_p));
14210 if (TYPE_OVERFLOW_UNDEFINED (type))
14212 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14214 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14215 strict_overflow_p))
14217 *strict_overflow_p = true;
14225 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
14226 tree outer_type = TREE_TYPE (t);
14228 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
14229 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14230 strict_overflow_p));
14236 tree base = get_base_address (TREE_OPERAND (t, 0));
14241 /* Weak declarations may link to NULL. */
14242 if (VAR_OR_FUNCTION_DECL_P (base))
14243 return !DECL_WEAK (base);
14245 /* Constants are never weak. */
14246 if (CONSTANT_CLASS_P (base))
14253 sub_strict_overflow_p = false;
14254 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14255 &sub_strict_overflow_p)
14256 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
14257 &sub_strict_overflow_p))
14259 if (sub_strict_overflow_p)
14260 *strict_overflow_p = true;
14266 sub_strict_overflow_p = false;
14267 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14268 &sub_strict_overflow_p)
14269 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14270 &sub_strict_overflow_p))
14272 if (sub_strict_overflow_p)
14273 *strict_overflow_p = true;
14278 sub_strict_overflow_p = false;
14279 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14280 &sub_strict_overflow_p))
14282 if (sub_strict_overflow_p)
14283 *strict_overflow_p = true;
14285 /* When both operands are nonzero, then MAX must be too. */
14286 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14287 strict_overflow_p))
14290 /* MAX where operand 0 is positive is positive. */
14291 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14292 strict_overflow_p);
14294 /* MAX where operand 1 is positive is positive. */
14295 else if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14296 &sub_strict_overflow_p)
14297 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14298 &sub_strict_overflow_p))
14300 if (sub_strict_overflow_p)
14301 *strict_overflow_p = true;
14306 case COMPOUND_EXPR:
14308 case GIMPLE_MODIFY_STMT:
14310 return tree_expr_nonzero_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14311 strict_overflow_p);
14314 case NON_LVALUE_EXPR:
14315 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14316 strict_overflow_p);
14319 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14321 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14322 strict_overflow_p));
14325 return alloca_call_p (t);
14333 /* Return true when T is an address and is known to be nonzero.
14334 Handle warnings about undefined signed overflow. */
14337 tree_expr_nonzero_p (tree t)
14339 bool ret, strict_overflow_p;
14341 strict_overflow_p = false;
14342 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
14343 if (strict_overflow_p)
14344 fold_overflow_warning (("assuming signed overflow does not occur when "
14345 "determining that expression is always "
14347 WARN_STRICT_OVERFLOW_MISC);
14351 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
14352 attempt to fold the expression to a constant without modifying TYPE,
14355 If the expression could be simplified to a constant, then return
14356 the constant. If the expression would not be simplified to a
14357 constant, then return NULL_TREE. */
14360 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
14362 tree tem = fold_binary (code, type, op0, op1);
14363 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14366 /* Given the components of a unary expression CODE, TYPE and OP0,
14367 attempt to fold the expression to a constant without modifying
14370 If the expression could be simplified to a constant, then return
14371 the constant. If the expression would not be simplified to a
14372 constant, then return NULL_TREE. */
14375 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
14377 tree tem = fold_unary (code, type, op0);
14378 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14381 /* If EXP represents referencing an element in a constant string
14382 (either via pointer arithmetic or array indexing), return the
14383 tree representing the value accessed, otherwise return NULL. */
14386 fold_read_from_constant_string (tree exp)
14388 if ((TREE_CODE (exp) == INDIRECT_REF
14389 || TREE_CODE (exp) == ARRAY_REF)
14390 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
14392 tree exp1 = TREE_OPERAND (exp, 0);
14396 if (TREE_CODE (exp) == INDIRECT_REF)
14397 string = string_constant (exp1, &index);
14400 tree low_bound = array_ref_low_bound (exp);
14401 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
14403 /* Optimize the special-case of a zero lower bound.
14405 We convert the low_bound to sizetype to avoid some problems
14406 with constant folding. (E.g. suppose the lower bound is 1,
14407 and its mode is QI. Without the conversion,l (ARRAY
14408 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
14409 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
14410 if (! integer_zerop (low_bound))
14411 index = size_diffop (index, fold_convert (sizetype, low_bound));
14417 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
14418 && TREE_CODE (string) == STRING_CST
14419 && TREE_CODE (index) == INTEGER_CST
14420 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
14421 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
14423 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
14424 return build_int_cst_type (TREE_TYPE (exp),
14425 (TREE_STRING_POINTER (string)
14426 [TREE_INT_CST_LOW (index)]));
14431 /* Return the tree for neg (ARG0) when ARG0 is known to be either
14432 an integer constant, real, or fixed-point constant.
14434 TYPE is the type of the result. */
14437 fold_negate_const (tree arg0, tree type)
14439 tree t = NULL_TREE;
14441 switch (TREE_CODE (arg0))
14445 unsigned HOST_WIDE_INT low;
14446 HOST_WIDE_INT high;
14447 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14448 TREE_INT_CST_HIGH (arg0),
14450 t = force_fit_type_double (type, low, high, 1,
14451 (overflow | TREE_OVERFLOW (arg0))
14452 && !TYPE_UNSIGNED (type));
14457 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14462 FIXED_VALUE_TYPE f;
14463 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
14464 &(TREE_FIXED_CST (arg0)), NULL,
14465 TYPE_SATURATING (type));
14466 t = build_fixed (type, f);
14467 /* Propagate overflow flags. */
14468 if (overflow_p | TREE_OVERFLOW (arg0))
14470 TREE_OVERFLOW (t) = 1;
14471 TREE_CONSTANT_OVERFLOW (t) = 1;
14473 else if (TREE_CONSTANT_OVERFLOW (arg0))
14474 TREE_CONSTANT_OVERFLOW (t) = 1;
14479 gcc_unreachable ();
14485 /* Return the tree for abs (ARG0) when ARG0 is known to be either
14486 an integer constant or real constant.
14488 TYPE is the type of the result. */
14491 fold_abs_const (tree arg0, tree type)
14493 tree t = NULL_TREE;
14495 switch (TREE_CODE (arg0))
14498 /* If the value is unsigned, then the absolute value is
14499 the same as the ordinary value. */
14500 if (TYPE_UNSIGNED (type))
14502 /* Similarly, if the value is non-negative. */
14503 else if (INT_CST_LT (integer_minus_one_node, arg0))
14505 /* If the value is negative, then the absolute value is
14509 unsigned HOST_WIDE_INT low;
14510 HOST_WIDE_INT high;
14511 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14512 TREE_INT_CST_HIGH (arg0),
14514 t = force_fit_type_double (type, low, high, -1,
14515 overflow | TREE_OVERFLOW (arg0));
14520 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
14521 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14527 gcc_unreachable ();
14533 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
14534 constant. TYPE is the type of the result. */
14537 fold_not_const (tree arg0, tree type)
14539 tree t = NULL_TREE;
14541 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
14543 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
14544 ~TREE_INT_CST_HIGH (arg0), 0,
14545 TREE_OVERFLOW (arg0));
14550 /* Given CODE, a relational operator, the target type, TYPE and two
14551 constant operands OP0 and OP1, return the result of the
14552 relational operation. If the result is not a compile time
14553 constant, then return NULL_TREE. */
14556 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
14558 int result, invert;
14560 /* From here on, the only cases we handle are when the result is
14561 known to be a constant. */
14563 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
14565 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
14566 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
14568 /* Handle the cases where either operand is a NaN. */
14569 if (real_isnan (c0) || real_isnan (c1))
14579 case UNORDERED_EXPR:
14593 if (flag_trapping_math)
14599 gcc_unreachable ();
14602 return constant_boolean_node (result, type);
14605 return constant_boolean_node (real_compare (code, c0, c1), type);
14608 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
14610 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
14611 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
14612 return constant_boolean_node (fixed_compare (code, c0, c1), type);
14615 /* Handle equality/inequality of complex constants. */
14616 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
14618 tree rcond = fold_relational_const (code, type,
14619 TREE_REALPART (op0),
14620 TREE_REALPART (op1));
14621 tree icond = fold_relational_const (code, type,
14622 TREE_IMAGPART (op0),
14623 TREE_IMAGPART (op1));
14624 if (code == EQ_EXPR)
14625 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
14626 else if (code == NE_EXPR)
14627 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
14632 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14634 To compute GT, swap the arguments and do LT.
14635 To compute GE, do LT and invert the result.
14636 To compute LE, swap the arguments, do LT and invert the result.
14637 To compute NE, do EQ and invert the result.
14639 Therefore, the code below must handle only EQ and LT. */
14641 if (code == LE_EXPR || code == GT_EXPR)
14646 code = swap_tree_comparison (code);
14649 /* Note that it is safe to invert for real values here because we
14650 have already handled the one case that it matters. */
14653 if (code == NE_EXPR || code == GE_EXPR)
14656 code = invert_tree_comparison (code, false);
14659 /* Compute a result for LT or EQ if args permit;
14660 Otherwise return T. */
14661 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
14663 if (code == EQ_EXPR)
14664 result = tree_int_cst_equal (op0, op1);
14665 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
14666 result = INT_CST_LT_UNSIGNED (op0, op1);
14668 result = INT_CST_LT (op0, op1);
14675 return constant_boolean_node (result, type);
14678 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
14679 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
14683 fold_build_cleanup_point_expr (tree type, tree expr)
14685 /* If the expression does not have side effects then we don't have to wrap
14686 it with a cleanup point expression. */
14687 if (!TREE_SIDE_EFFECTS (expr))
14690 /* If the expression is a return, check to see if the expression inside the
14691 return has no side effects or the right hand side of the modify expression
14692 inside the return. If either don't have side effects set we don't need to
14693 wrap the expression in a cleanup point expression. Note we don't check the
14694 left hand side of the modify because it should always be a return decl. */
14695 if (TREE_CODE (expr) == RETURN_EXPR)
14697 tree op = TREE_OPERAND (expr, 0);
14698 if (!op || !TREE_SIDE_EFFECTS (op))
14700 op = TREE_OPERAND (op, 1);
14701 if (!TREE_SIDE_EFFECTS (op))
14705 return build1 (CLEANUP_POINT_EXPR, type, expr);
14708 /* Given a pointer value OP0 and a type TYPE, return a simplified version
14709 of an indirection through OP0, or NULL_TREE if no simplification is
14713 fold_indirect_ref_1 (tree type, tree op0)
14719 subtype = TREE_TYPE (sub);
14720 if (!POINTER_TYPE_P (subtype))
14723 if (TREE_CODE (sub) == ADDR_EXPR)
14725 tree op = TREE_OPERAND (sub, 0);
14726 tree optype = TREE_TYPE (op);
14727 /* *&CONST_DECL -> to the value of the const decl. */
14728 if (TREE_CODE (op) == CONST_DECL)
14729 return DECL_INITIAL (op);
14730 /* *&p => p; make sure to handle *&"str"[cst] here. */
14731 if (type == optype)
14733 tree fop = fold_read_from_constant_string (op);
14739 /* *(foo *)&fooarray => fooarray[0] */
14740 else if (TREE_CODE (optype) == ARRAY_TYPE
14741 && type == TREE_TYPE (optype))
14743 tree type_domain = TYPE_DOMAIN (optype);
14744 tree min_val = size_zero_node;
14745 if (type_domain && TYPE_MIN_VALUE (type_domain))
14746 min_val = TYPE_MIN_VALUE (type_domain);
14747 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
14749 /* *(foo *)&complexfoo => __real__ complexfoo */
14750 else if (TREE_CODE (optype) == COMPLEX_TYPE
14751 && type == TREE_TYPE (optype))
14752 return fold_build1 (REALPART_EXPR, type, op);
14753 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
14754 else if (TREE_CODE (optype) == VECTOR_TYPE
14755 && type == TREE_TYPE (optype))
14757 tree part_width = TYPE_SIZE (type);
14758 tree index = bitsize_int (0);
14759 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
14763 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
14764 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
14765 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
14767 tree op00 = TREE_OPERAND (sub, 0);
14768 tree op01 = TREE_OPERAND (sub, 1);
14772 op00type = TREE_TYPE (op00);
14773 if (TREE_CODE (op00) == ADDR_EXPR
14774 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
14775 && type == TREE_TYPE (TREE_TYPE (op00type)))
14777 tree size = TYPE_SIZE_UNIT (type);
14778 if (tree_int_cst_equal (size, op01))
14779 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
14783 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
14784 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
14785 && type == TREE_TYPE (TREE_TYPE (subtype)))
14788 tree min_val = size_zero_node;
14789 sub = build_fold_indirect_ref (sub);
14790 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
14791 if (type_domain && TYPE_MIN_VALUE (type_domain))
14792 min_val = TYPE_MIN_VALUE (type_domain);
14793 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
14799 /* Builds an expression for an indirection through T, simplifying some
14803 build_fold_indirect_ref (tree t)
14805 tree type = TREE_TYPE (TREE_TYPE (t));
14806 tree sub = fold_indirect_ref_1 (type, t);
14811 return build1 (INDIRECT_REF, type, t);
14814 /* Given an INDIRECT_REF T, return either T or a simplified version. */
14817 fold_indirect_ref (tree t)
14819 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
14827 /* Strip non-trapping, non-side-effecting tree nodes from an expression
14828 whose result is ignored. The type of the returned tree need not be
14829 the same as the original expression. */
14832 fold_ignored_result (tree t)
14834 if (!TREE_SIDE_EFFECTS (t))
14835 return integer_zero_node;
14838 switch (TREE_CODE_CLASS (TREE_CODE (t)))
14841 t = TREE_OPERAND (t, 0);
14845 case tcc_comparison:
14846 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
14847 t = TREE_OPERAND (t, 0);
14848 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
14849 t = TREE_OPERAND (t, 1);
14854 case tcc_expression:
14855 switch (TREE_CODE (t))
14857 case COMPOUND_EXPR:
14858 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
14860 t = TREE_OPERAND (t, 0);
14864 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
14865 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
14867 t = TREE_OPERAND (t, 0);
14880 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
14881 This can only be applied to objects of a sizetype. */
14884 round_up (tree value, int divisor)
14886 tree div = NULL_TREE;
14888 gcc_assert (divisor > 0);
14892 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14893 have to do anything. Only do this when we are not given a const,
14894 because in that case, this check is more expensive than just
14896 if (TREE_CODE (value) != INTEGER_CST)
14898 div = build_int_cst (TREE_TYPE (value), divisor);
14900 if (multiple_of_p (TREE_TYPE (value), value, div))
14904 /* If divisor is a power of two, simplify this to bit manipulation. */
14905 if (divisor == (divisor & -divisor))
14907 if (TREE_CODE (value) == INTEGER_CST)
14909 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
14910 unsigned HOST_WIDE_INT high;
14913 if ((low & (divisor - 1)) == 0)
14916 overflow_p = TREE_OVERFLOW (value);
14917 high = TREE_INT_CST_HIGH (value);
14918 low &= ~(divisor - 1);
14927 return force_fit_type_double (TREE_TYPE (value), low, high,
14934 t = build_int_cst (TREE_TYPE (value), divisor - 1);
14935 value = size_binop (PLUS_EXPR, value, t);
14936 t = build_int_cst (TREE_TYPE (value), -divisor);
14937 value = size_binop (BIT_AND_EXPR, value, t);
14943 div = build_int_cst (TREE_TYPE (value), divisor);
14944 value = size_binop (CEIL_DIV_EXPR, value, div);
14945 value = size_binop (MULT_EXPR, value, div);
14951 /* Likewise, but round down. */
14954 round_down (tree value, int divisor)
14956 tree div = NULL_TREE;
14958 gcc_assert (divisor > 0);
14962 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
14963 have to do anything. Only do this when we are not given a const,
14964 because in that case, this check is more expensive than just
14966 if (TREE_CODE (value) != INTEGER_CST)
14968 div = build_int_cst (TREE_TYPE (value), divisor);
14970 if (multiple_of_p (TREE_TYPE (value), value, div))
14974 /* If divisor is a power of two, simplify this to bit manipulation. */
14975 if (divisor == (divisor & -divisor))
14979 t = build_int_cst (TREE_TYPE (value), -divisor);
14980 value = size_binop (BIT_AND_EXPR, value, t);
14985 div = build_int_cst (TREE_TYPE (value), divisor);
14986 value = size_binop (FLOOR_DIV_EXPR, value, div);
14987 value = size_binop (MULT_EXPR, value, div);
14993 /* Returns the pointer to the base of the object addressed by EXP and
14994 extracts the information about the offset of the access, storing it
14995 to PBITPOS and POFFSET. */
14998 split_address_to_core_and_offset (tree exp,
14999 HOST_WIDE_INT *pbitpos, tree *poffset)
15002 enum machine_mode mode;
15003 int unsignedp, volatilep;
15004 HOST_WIDE_INT bitsize;
15006 if (TREE_CODE (exp) == ADDR_EXPR)
15008 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
15009 poffset, &mode, &unsignedp, &volatilep,
15011 core = fold_addr_expr (core);
15017 *poffset = NULL_TREE;
15023 /* Returns true if addresses of E1 and E2 differ by a constant, false
15024 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15027 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
15030 HOST_WIDE_INT bitpos1, bitpos2;
15031 tree toffset1, toffset2, tdiff, type;
15033 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
15034 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
15036 if (bitpos1 % BITS_PER_UNIT != 0
15037 || bitpos2 % BITS_PER_UNIT != 0
15038 || !operand_equal_p (core1, core2, 0))
15041 if (toffset1 && toffset2)
15043 type = TREE_TYPE (toffset1);
15044 if (type != TREE_TYPE (toffset2))
15045 toffset2 = fold_convert (type, toffset2);
15047 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
15048 if (!cst_and_fits_in_hwi (tdiff))
15051 *diff = int_cst_value (tdiff);
15053 else if (toffset1 || toffset2)
15055 /* If only one of the offsets is non-constant, the difference cannot
15062 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
15066 /* Simplify the floating point expression EXP when the sign of the
15067 result is not significant. Return NULL_TREE if no simplification
15071 fold_strip_sign_ops (tree exp)
15075 switch (TREE_CODE (exp))
15079 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15080 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
15084 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
15086 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15087 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15088 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
15089 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
15090 arg0 ? arg0 : TREE_OPERAND (exp, 0),
15091 arg1 ? arg1 : TREE_OPERAND (exp, 1));
15094 case COMPOUND_EXPR:
15095 arg0 = TREE_OPERAND (exp, 0);
15096 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15098 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
15102 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15103 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
15105 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
15106 arg0 ? arg0 : TREE_OPERAND (exp, 1),
15107 arg1 ? arg1 : TREE_OPERAND (exp, 2));
15112 const enum built_in_function fcode = builtin_mathfn_code (exp);
15115 CASE_FLT_FN (BUILT_IN_COPYSIGN):
15116 /* Strip copysign function call, return the 1st argument. */
15117 arg0 = CALL_EXPR_ARG (exp, 0);
15118 arg1 = CALL_EXPR_ARG (exp, 1);
15119 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
15122 /* Strip sign ops from the argument of "odd" math functions. */
15123 if (negate_mathfn_p (fcode))
15125 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
15127 return build_call_expr (get_callee_fndecl (exp), 1, arg0);