1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
31 and force_fit_type_double.
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type_double takes a constant, an overflowable flag and a
43 prior overflow indicator. It forces the value to fit the type and
46 Note: Since the folders get called on non-gimple code as well as
47 gimple code, we need to handle GIMPLE tuples as well as their
48 corresponding tree equivalents. */
52 #include "coretypes.h"
57 #include "fixed-value.h"
65 #include "langhooks.h"
68 /* Nonzero if we are folding constants inside an initializer; zero
70 int folding_initializer = 0;
72 /* The following constants represent a bit based encoding of GCC's
73 comparison operators. This encoding simplifies transformations
74 on relational comparison operators, such as AND and OR. */
75 enum comparison_code {
94 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
95 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
96 static bool negate_mathfn_p (enum built_in_function);
97 static bool negate_expr_p (tree);
98 static tree negate_expr (tree);
99 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
100 static tree associate_trees (tree, tree, enum tree_code, tree);
101 static tree const_binop (enum tree_code, tree, tree, int);
102 static enum comparison_code comparison_to_compcode (enum tree_code);
103 static enum tree_code compcode_to_comparison (enum comparison_code);
104 static tree combine_comparisons (enum tree_code, enum tree_code,
105 enum tree_code, tree, tree, tree);
106 static int truth_value_p (enum tree_code);
107 static int operand_equal_for_comparison_p (tree, tree, tree);
108 static int twoval_comparison_p (tree, tree *, tree *, int *);
109 static tree eval_subst (tree, tree, tree, tree, tree);
110 static tree pedantic_omit_one_operand (tree, tree, tree);
111 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
112 static tree make_bit_field_ref (tree, tree, int, int, int);
113 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
114 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
115 enum machine_mode *, int *, int *,
117 static int all_ones_mask_p (const_tree, int);
118 static tree sign_bit_p (tree, const_tree);
119 static int simple_operand_p (const_tree);
120 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
121 static tree range_predecessor (tree);
122 static tree range_successor (tree);
123 static tree make_range (tree, int *, tree *, tree *, bool *);
124 static tree build_range_check (tree, tree, int, tree, tree);
125 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
127 static tree fold_range_test (enum tree_code, tree, tree, tree);
128 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
129 static tree unextend (tree, int, int, tree);
130 static tree fold_truthop (enum tree_code, tree, tree, tree);
131 static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
132 static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
133 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
134 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
137 static bool fold_real_zero_addition_p (const_tree, const_tree, int);
138 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
140 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
141 static tree fold_div_compare (enum tree_code, tree, tree, tree);
142 static bool reorder_operands_p (const_tree, const_tree);
143 static tree fold_negate_const (tree, tree);
144 static tree fold_not_const (tree, tree);
145 static tree fold_relational_const (enum tree_code, tree, tree, tree);
148 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
149 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
150 and SUM1. Then this yields nonzero if overflow occurred during the
153 Overflow occurs if A and B have the same sign, but A and SUM differ in
154 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
156 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
158 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
159 We do that by representing the two-word integer in 4 words, with only
160 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
161 number. The value of the word is LOWPART + HIGHPART * BASE. */
164 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
165 #define HIGHPART(x) \
166 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
167 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
169 /* Unpack a two-word integer into 4 words.
170 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
171 WORDS points to the array of HOST_WIDE_INTs. */
174 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
176 words[0] = LOWPART (low);
177 words[1] = HIGHPART (low);
178 words[2] = LOWPART (hi);
179 words[3] = HIGHPART (hi);
182 /* Pack an array of 4 words into a two-word integer.
183 WORDS points to the array of words.
184 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
187 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
190 *low = words[0] + words[1] * BASE;
191 *hi = words[2] + words[3] * BASE;
194 /* Force the double-word integer L1, H1 to be within the range of the
195 integer type TYPE. Stores the properly truncated and sign-extended
196 double-word integer in *LV, *HV. Returns true if the operation
197 overflows, that is, argument and result are different. */
200 fit_double_type (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
201 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, const_tree type)
203 unsigned HOST_WIDE_INT low0 = l1;
204 HOST_WIDE_INT high0 = h1;
206 int sign_extended_type;
208 if (POINTER_TYPE_P (type)
209 || TREE_CODE (type) == OFFSET_TYPE)
212 prec = TYPE_PRECISION (type);
214 /* Size types *are* sign extended. */
215 sign_extended_type = (!TYPE_UNSIGNED (type)
216 || (TREE_CODE (type) == INTEGER_TYPE
217 && TYPE_IS_SIZETYPE (type)));
219 /* First clear all bits that are beyond the type's precision. */
220 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
222 else if (prec > HOST_BITS_PER_WIDE_INT)
223 h1 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
227 if (prec < HOST_BITS_PER_WIDE_INT)
228 l1 &= ~((HOST_WIDE_INT) (-1) << prec);
231 /* Then do sign extension if necessary. */
232 if (!sign_extended_type)
233 /* No sign extension */;
234 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
235 /* Correct width already. */;
236 else if (prec > HOST_BITS_PER_WIDE_INT)
238 /* Sign extend top half? */
239 if (h1 & ((unsigned HOST_WIDE_INT)1
240 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
241 h1 |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
243 else if (prec == HOST_BITS_PER_WIDE_INT)
245 if ((HOST_WIDE_INT)l1 < 0)
250 /* Sign extend bottom half? */
251 if (l1 & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
254 l1 |= (HOST_WIDE_INT)(-1) << prec;
261 /* If the value didn't fit, signal overflow. */
262 return l1 != low0 || h1 != high0;
265 /* We force the double-int HIGH:LOW to the range of the type TYPE by
266 sign or zero extending it.
267 OVERFLOWABLE indicates if we are interested
268 in overflow of the value, when >0 we are only interested in signed
269 overflow, for <0 we are interested in any overflow. OVERFLOWED
270 indicates whether overflow has already occurred. CONST_OVERFLOWED
271 indicates whether constant overflow has already occurred. We force
272 T's value to be within range of T's type (by setting to 0 or 1 all
273 the bits outside the type's range). We set TREE_OVERFLOWED if,
274 OVERFLOWED is nonzero,
275 or OVERFLOWABLE is >0 and signed overflow occurs
276 or OVERFLOWABLE is <0 and any overflow occurs
277 We return a new tree node for the extended double-int. The node
278 is shared if no overflow flags are set. */
281 force_fit_type_double (tree type, unsigned HOST_WIDE_INT low,
282 HOST_WIDE_INT high, int overflowable,
285 int sign_extended_type;
288 /* Size types *are* sign extended. */
289 sign_extended_type = (!TYPE_UNSIGNED (type)
290 || (TREE_CODE (type) == INTEGER_TYPE
291 && TYPE_IS_SIZETYPE (type)));
293 overflow = fit_double_type (low, high, &low, &high, type);
295 /* If we need to set overflow flags, return a new unshared node. */
296 if (overflowed || overflow)
300 || (overflowable > 0 && sign_extended_type))
302 tree t = make_node (INTEGER_CST);
303 TREE_INT_CST_LOW (t) = low;
304 TREE_INT_CST_HIGH (t) = high;
305 TREE_TYPE (t) = type;
306 TREE_OVERFLOW (t) = 1;
311 /* Else build a shared node. */
312 return build_int_cst_wide (type, low, high);
315 /* Add two doubleword integers with doubleword result.
316 Return nonzero if the operation overflows according to UNSIGNED_P.
317 Each argument is given as two `HOST_WIDE_INT' pieces.
318 One argument is L1 and H1; the other, L2 and H2.
319 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
322 add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
323 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
324 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
327 unsigned HOST_WIDE_INT l;
331 h = h1 + h2 + (l < l1);
337 return (unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1;
339 return OVERFLOW_SUM_SIGN (h1, h2, h);
342 /* Negate a doubleword integer with doubleword result.
343 Return nonzero if the operation overflows, assuming it's signed.
344 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
345 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
348 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
349 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
355 return (*hv & h1) < 0;
365 /* Multiply two doubleword integers with doubleword result.
366 Return nonzero if the operation overflows according to UNSIGNED_P.
367 Each argument is given as two `HOST_WIDE_INT' pieces.
368 One argument is L1 and H1; the other, L2 and H2.
369 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
372 mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
373 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
374 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
377 HOST_WIDE_INT arg1[4];
378 HOST_WIDE_INT arg2[4];
379 HOST_WIDE_INT prod[4 * 2];
380 unsigned HOST_WIDE_INT carry;
382 unsigned HOST_WIDE_INT toplow, neglow;
383 HOST_WIDE_INT tophigh, neghigh;
385 encode (arg1, l1, h1);
386 encode (arg2, l2, h2);
388 memset (prod, 0, sizeof prod);
390 for (i = 0; i < 4; i++)
393 for (j = 0; j < 4; j++)
396 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
397 carry += arg1[i] * arg2[j];
398 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
400 prod[k] = LOWPART (carry);
401 carry = HIGHPART (carry);
406 decode (prod, lv, hv);
407 decode (prod + 4, &toplow, &tophigh);
409 /* Unsigned overflow is immediate. */
411 return (toplow | tophigh) != 0;
413 /* Check for signed overflow by calculating the signed representation of the
414 top half of the result; it should agree with the low half's sign bit. */
417 neg_double (l2, h2, &neglow, &neghigh);
418 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
422 neg_double (l1, h1, &neglow, &neghigh);
423 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
425 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
428 /* Shift the doubleword integer in L1, H1 left by COUNT places
429 keeping only PREC bits of result.
430 Shift right if COUNT is negative.
431 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
432 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
435 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
436 HOST_WIDE_INT count, unsigned int prec,
437 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
439 unsigned HOST_WIDE_INT signmask;
443 rshift_double (l1, h1, -count, prec, lv, hv, arith);
447 if (SHIFT_COUNT_TRUNCATED)
450 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
452 /* Shifting by the host word size is undefined according to the
453 ANSI standard, so we must handle this as a special case. */
457 else if (count >= HOST_BITS_PER_WIDE_INT)
459 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
464 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
465 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
469 /* Sign extend all bits that are beyond the precision. */
471 signmask = -((prec > HOST_BITS_PER_WIDE_INT
472 ? ((unsigned HOST_WIDE_INT) *hv
473 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
474 : (*lv >> (prec - 1))) & 1);
476 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
478 else if (prec >= HOST_BITS_PER_WIDE_INT)
480 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
481 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
486 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
487 *lv |= signmask << prec;
491 /* Shift the doubleword integer in L1, H1 right by COUNT places
492 keeping only PREC bits of result. COUNT must be positive.
493 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
494 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
497 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
498 HOST_WIDE_INT count, unsigned int prec,
499 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
502 unsigned HOST_WIDE_INT signmask;
505 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
508 if (SHIFT_COUNT_TRUNCATED)
511 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
513 /* Shifting by the host word size is undefined according to the
514 ANSI standard, so we must handle this as a special case. */
518 else if (count >= HOST_BITS_PER_WIDE_INT)
521 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
525 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
527 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
530 /* Zero / sign extend all bits that are beyond the precision. */
532 if (count >= (HOST_WIDE_INT)prec)
537 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
539 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
541 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
542 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
547 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
548 *lv |= signmask << (prec - count);
552 /* Rotate the doubleword integer in L1, H1 left by COUNT places
553 keeping only PREC bits of result.
554 Rotate right if COUNT is negative.
555 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
558 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
559 HOST_WIDE_INT count, unsigned int prec,
560 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
562 unsigned HOST_WIDE_INT s1l, s2l;
563 HOST_WIDE_INT s1h, s2h;
569 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
570 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
575 /* Rotate the doubleword integer in L1, H1 left by COUNT places
576 keeping only PREC bits of result. COUNT must be positive.
577 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
580 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
581 HOST_WIDE_INT count, unsigned int prec,
582 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
584 unsigned HOST_WIDE_INT s1l, s2l;
585 HOST_WIDE_INT s1h, s2h;
591 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
592 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
597 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
598 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
599 CODE is a tree code for a kind of division, one of
600 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
602 It controls how the quotient is rounded to an integer.
603 Return nonzero if the operation overflows.
604 UNS nonzero says do unsigned division. */
607 div_and_round_double (enum tree_code code, int uns,
608 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
609 HOST_WIDE_INT hnum_orig,
610 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
611 HOST_WIDE_INT hden_orig,
612 unsigned HOST_WIDE_INT *lquo,
613 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
617 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
618 HOST_WIDE_INT den[4], quo[4];
620 unsigned HOST_WIDE_INT work;
621 unsigned HOST_WIDE_INT carry = 0;
622 unsigned HOST_WIDE_INT lnum = lnum_orig;
623 HOST_WIDE_INT hnum = hnum_orig;
624 unsigned HOST_WIDE_INT lden = lden_orig;
625 HOST_WIDE_INT hden = hden_orig;
628 if (hden == 0 && lden == 0)
629 overflow = 1, lden = 1;
631 /* Calculate quotient sign and convert operands to unsigned. */
637 /* (minimum integer) / (-1) is the only overflow case. */
638 if (neg_double (lnum, hnum, &lnum, &hnum)
639 && ((HOST_WIDE_INT) lden & hden) == -1)
645 neg_double (lden, hden, &lden, &hden);
649 if (hnum == 0 && hden == 0)
650 { /* single precision */
652 /* This unsigned division rounds toward zero. */
658 { /* trivial case: dividend < divisor */
659 /* hden != 0 already checked. */
666 memset (quo, 0, sizeof quo);
668 memset (num, 0, sizeof num); /* to zero 9th element */
669 memset (den, 0, sizeof den);
671 encode (num, lnum, hnum);
672 encode (den, lden, hden);
674 /* Special code for when the divisor < BASE. */
675 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
677 /* hnum != 0 already checked. */
678 for (i = 4 - 1; i >= 0; i--)
680 work = num[i] + carry * BASE;
681 quo[i] = work / lden;
687 /* Full double precision division,
688 with thanks to Don Knuth's "Seminumerical Algorithms". */
689 int num_hi_sig, den_hi_sig;
690 unsigned HOST_WIDE_INT quo_est, scale;
692 /* Find the highest nonzero divisor digit. */
693 for (i = 4 - 1;; i--)
700 /* Insure that the first digit of the divisor is at least BASE/2.
701 This is required by the quotient digit estimation algorithm. */
703 scale = BASE / (den[den_hi_sig] + 1);
705 { /* scale divisor and dividend */
707 for (i = 0; i <= 4 - 1; i++)
709 work = (num[i] * scale) + carry;
710 num[i] = LOWPART (work);
711 carry = HIGHPART (work);
716 for (i = 0; i <= 4 - 1; i++)
718 work = (den[i] * scale) + carry;
719 den[i] = LOWPART (work);
720 carry = HIGHPART (work);
721 if (den[i] != 0) den_hi_sig = i;
728 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
730 /* Guess the next quotient digit, quo_est, by dividing the first
731 two remaining dividend digits by the high order quotient digit.
732 quo_est is never low and is at most 2 high. */
733 unsigned HOST_WIDE_INT tmp;
735 num_hi_sig = i + den_hi_sig + 1;
736 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
737 if (num[num_hi_sig] != den[den_hi_sig])
738 quo_est = work / den[den_hi_sig];
742 /* Refine quo_est so it's usually correct, and at most one high. */
743 tmp = work - quo_est * den[den_hi_sig];
745 && (den[den_hi_sig - 1] * quo_est
746 > (tmp * BASE + num[num_hi_sig - 2])))
749 /* Try QUO_EST as the quotient digit, by multiplying the
750 divisor by QUO_EST and subtracting from the remaining dividend.
751 Keep in mind that QUO_EST is the I - 1st digit. */
754 for (j = 0; j <= den_hi_sig; j++)
756 work = quo_est * den[j] + carry;
757 carry = HIGHPART (work);
758 work = num[i + j] - LOWPART (work);
759 num[i + j] = LOWPART (work);
760 carry += HIGHPART (work) != 0;
763 /* If quo_est was high by one, then num[i] went negative and
764 we need to correct things. */
765 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
768 carry = 0; /* add divisor back in */
769 for (j = 0; j <= den_hi_sig; j++)
771 work = num[i + j] + den[j] + carry;
772 carry = HIGHPART (work);
773 num[i + j] = LOWPART (work);
776 num [num_hi_sig] += carry;
779 /* Store the quotient digit. */
784 decode (quo, lquo, hquo);
787 /* If result is negative, make it so. */
789 neg_double (*lquo, *hquo, lquo, hquo);
791 /* Compute trial remainder: rem = num - (quo * den) */
792 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
793 neg_double (*lrem, *hrem, lrem, hrem);
794 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
799 case TRUNC_MOD_EXPR: /* round toward zero */
800 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
804 case FLOOR_MOD_EXPR: /* round toward negative infinity */
805 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
808 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
816 case CEIL_MOD_EXPR: /* round toward positive infinity */
817 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
819 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
827 case ROUND_MOD_EXPR: /* round to closest integer */
829 unsigned HOST_WIDE_INT labs_rem = *lrem;
830 HOST_WIDE_INT habs_rem = *hrem;
831 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
832 HOST_WIDE_INT habs_den = hden, htwice;
834 /* Get absolute values. */
836 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
838 neg_double (lden, hden, &labs_den, &habs_den);
840 /* If (2 * abs (lrem) >= abs (lden)) */
841 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
842 labs_rem, habs_rem, <wice, &htwice);
844 if (((unsigned HOST_WIDE_INT) habs_den
845 < (unsigned HOST_WIDE_INT) htwice)
846 || (((unsigned HOST_WIDE_INT) habs_den
847 == (unsigned HOST_WIDE_INT) htwice)
848 && (labs_den < ltwice)))
852 add_double (*lquo, *hquo,
853 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
856 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
868 /* Compute true remainder: rem = num - (quo * den) */
869 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
870 neg_double (*lrem, *hrem, lrem, hrem);
871 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
875 /* If ARG2 divides ARG1 with zero remainder, carries out the division
876 of type CODE and returns the quotient.
877 Otherwise returns NULL_TREE. */
880 div_if_zero_remainder (enum tree_code code, const_tree arg1, const_tree arg2)
882 unsigned HOST_WIDE_INT int1l, int2l;
883 HOST_WIDE_INT int1h, int2h;
884 unsigned HOST_WIDE_INT quol, reml;
885 HOST_WIDE_INT quoh, remh;
886 tree type = TREE_TYPE (arg1);
887 int uns = TYPE_UNSIGNED (type);
889 int1l = TREE_INT_CST_LOW (arg1);
890 int1h = TREE_INT_CST_HIGH (arg1);
891 /* &obj[0] + -128 really should be compiled as &obj[-8] rather than
892 &obj[some_exotic_number]. */
893 if (POINTER_TYPE_P (type))
896 type = signed_type_for (type);
897 fit_double_type (int1l, int1h, &int1l, &int1h,
901 fit_double_type (int1l, int1h, &int1l, &int1h, type);
902 int2l = TREE_INT_CST_LOW (arg2);
903 int2h = TREE_INT_CST_HIGH (arg2);
905 div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
906 &quol, &quoh, &reml, &remh);
907 if (remh != 0 || reml != 0)
910 return build_int_cst_wide (type, quol, quoh);
913 /* This is nonzero if we should defer warnings about undefined
914 overflow. This facility exists because these warnings are a
915 special case. The code to estimate loop iterations does not want
916 to issue any warnings, since it works with expressions which do not
917 occur in user code. Various bits of cleanup code call fold(), but
918 only use the result if it has certain characteristics (e.g., is a
919 constant); that code only wants to issue a warning if the result is
922 static int fold_deferring_overflow_warnings;
924 /* If a warning about undefined overflow is deferred, this is the
925 warning. Note that this may cause us to turn two warnings into
926 one, but that is fine since it is sufficient to only give one
927 warning per expression. */
929 static const char* fold_deferred_overflow_warning;
931 /* If a warning about undefined overflow is deferred, this is the
932 level at which the warning should be emitted. */
934 static enum warn_strict_overflow_code fold_deferred_overflow_code;
936 /* Start deferring overflow warnings. We could use a stack here to
937 permit nested calls, but at present it is not necessary. */
940 fold_defer_overflow_warnings (void)
942 ++fold_deferring_overflow_warnings;
945 /* Stop deferring overflow warnings. If there is a pending warning,
946 and ISSUE is true, then issue the warning if appropriate. STMT is
947 the statement with which the warning should be associated (used for
948 location information); STMT may be NULL. CODE is the level of the
949 warning--a warn_strict_overflow_code value. This function will use
950 the smaller of CODE and the deferred code when deciding whether to
951 issue the warning. CODE may be zero to mean to always use the
955 fold_undefer_overflow_warnings (bool issue, const_tree stmt, int code)
960 gcc_assert (fold_deferring_overflow_warnings > 0);
961 --fold_deferring_overflow_warnings;
962 if (fold_deferring_overflow_warnings > 0)
964 if (fold_deferred_overflow_warning != NULL
966 && code < (int) fold_deferred_overflow_code)
967 fold_deferred_overflow_code = code;
971 warnmsg = fold_deferred_overflow_warning;
972 fold_deferred_overflow_warning = NULL;
974 if (!issue || warnmsg == NULL)
977 if (stmt != NULL_TREE && TREE_NO_WARNING (stmt))
980 /* Use the smallest code level when deciding to issue the
982 if (code == 0 || code > (int) fold_deferred_overflow_code)
983 code = fold_deferred_overflow_code;
985 if (!issue_strict_overflow_warning (code))
988 if (stmt == NULL_TREE || !expr_has_location (stmt))
989 locus = input_location;
991 locus = expr_location (stmt);
992 warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
995 /* Stop deferring overflow warnings, ignoring any deferred
999 fold_undefer_and_ignore_overflow_warnings (void)
1001 fold_undefer_overflow_warnings (false, NULL_TREE, 0);
1004 /* Whether we are deferring overflow warnings. */
1007 fold_deferring_overflow_warnings_p (void)
1009 return fold_deferring_overflow_warnings > 0;
1012 /* This is called when we fold something based on the fact that signed
1013 overflow is undefined. */
1016 fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
1018 gcc_assert (!flag_wrapv && !flag_trapv);
1019 if (fold_deferring_overflow_warnings > 0)
1021 if (fold_deferred_overflow_warning == NULL
1022 || wc < fold_deferred_overflow_code)
1024 fold_deferred_overflow_warning = gmsgid;
1025 fold_deferred_overflow_code = wc;
1028 else if (issue_strict_overflow_warning (wc))
1029 warning (OPT_Wstrict_overflow, gmsgid);
1032 /* Return true if the built-in mathematical function specified by CODE
1033 is odd, i.e. -f(x) == f(-x). */
1036 negate_mathfn_p (enum built_in_function code)
1040 CASE_FLT_FN (BUILT_IN_ASIN):
1041 CASE_FLT_FN (BUILT_IN_ASINH):
1042 CASE_FLT_FN (BUILT_IN_ATAN):
1043 CASE_FLT_FN (BUILT_IN_ATANH):
1044 CASE_FLT_FN (BUILT_IN_CASIN):
1045 CASE_FLT_FN (BUILT_IN_CASINH):
1046 CASE_FLT_FN (BUILT_IN_CATAN):
1047 CASE_FLT_FN (BUILT_IN_CATANH):
1048 CASE_FLT_FN (BUILT_IN_CBRT):
1049 CASE_FLT_FN (BUILT_IN_CPROJ):
1050 CASE_FLT_FN (BUILT_IN_CSIN):
1051 CASE_FLT_FN (BUILT_IN_CSINH):
1052 CASE_FLT_FN (BUILT_IN_CTAN):
1053 CASE_FLT_FN (BUILT_IN_CTANH):
1054 CASE_FLT_FN (BUILT_IN_ERF):
1055 CASE_FLT_FN (BUILT_IN_LLROUND):
1056 CASE_FLT_FN (BUILT_IN_LROUND):
1057 CASE_FLT_FN (BUILT_IN_ROUND):
1058 CASE_FLT_FN (BUILT_IN_SIN):
1059 CASE_FLT_FN (BUILT_IN_SINH):
1060 CASE_FLT_FN (BUILT_IN_TAN):
1061 CASE_FLT_FN (BUILT_IN_TANH):
1062 CASE_FLT_FN (BUILT_IN_TRUNC):
1065 CASE_FLT_FN (BUILT_IN_LLRINT):
1066 CASE_FLT_FN (BUILT_IN_LRINT):
1067 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1068 CASE_FLT_FN (BUILT_IN_RINT):
1069 return !flag_rounding_math;
1077 /* Check whether we may negate an integer constant T without causing
1081 may_negate_without_overflow_p (const_tree t)
1083 unsigned HOST_WIDE_INT val;
1087 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1089 type = TREE_TYPE (t);
1090 if (TYPE_UNSIGNED (type))
1093 prec = TYPE_PRECISION (type);
1094 if (prec > HOST_BITS_PER_WIDE_INT)
1096 if (TREE_INT_CST_LOW (t) != 0)
1098 prec -= HOST_BITS_PER_WIDE_INT;
1099 val = TREE_INT_CST_HIGH (t);
1102 val = TREE_INT_CST_LOW (t);
1103 if (prec < HOST_BITS_PER_WIDE_INT)
1104 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1105 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1108 /* Determine whether an expression T can be cheaply negated using
1109 the function negate_expr without introducing undefined overflow. */
1112 negate_expr_p (tree t)
1119 type = TREE_TYPE (t);
1121 STRIP_SIGN_NOPS (t);
1122 switch (TREE_CODE (t))
1125 if (TYPE_OVERFLOW_WRAPS (type))
1128 /* Check that -CST will not overflow type. */
1129 return may_negate_without_overflow_p (t);
1131 return (INTEGRAL_TYPE_P (type)
1132 && TYPE_OVERFLOW_WRAPS (type));
1140 return negate_expr_p (TREE_REALPART (t))
1141 && negate_expr_p (TREE_IMAGPART (t));
1144 return negate_expr_p (TREE_OPERAND (t, 0))
1145 && negate_expr_p (TREE_OPERAND (t, 1));
1148 return negate_expr_p (TREE_OPERAND (t, 0));
1151 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1152 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1154 /* -(A + B) -> (-B) - A. */
1155 if (negate_expr_p (TREE_OPERAND (t, 1))
1156 && reorder_operands_p (TREE_OPERAND (t, 0),
1157 TREE_OPERAND (t, 1)))
1159 /* -(A + B) -> (-A) - B. */
1160 return negate_expr_p (TREE_OPERAND (t, 0));
1163 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1164 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1165 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1166 && reorder_operands_p (TREE_OPERAND (t, 0),
1167 TREE_OPERAND (t, 1));
1170 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1176 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1177 return negate_expr_p (TREE_OPERAND (t, 1))
1178 || negate_expr_p (TREE_OPERAND (t, 0));
1181 case TRUNC_DIV_EXPR:
1182 case ROUND_DIV_EXPR:
1183 case FLOOR_DIV_EXPR:
1185 case EXACT_DIV_EXPR:
1186 /* In general we can't negate A / B, because if A is INT_MIN and
1187 B is 1, we may turn this into INT_MIN / -1 which is undefined
1188 and actually traps on some architectures. But if overflow is
1189 undefined, we can negate, because - (INT_MIN / 1) is an
1191 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1192 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1194 return negate_expr_p (TREE_OPERAND (t, 1))
1195 || negate_expr_p (TREE_OPERAND (t, 0));
1198 /* Negate -((double)float) as (double)(-float). */
1199 if (TREE_CODE (type) == REAL_TYPE)
1201 tree tem = strip_float_extensions (t);
1203 return negate_expr_p (tem);
1208 /* Negate -f(x) as f(-x). */
1209 if (negate_mathfn_p (builtin_mathfn_code (t)))
1210 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1214 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1215 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1217 tree op1 = TREE_OPERAND (t, 1);
1218 if (TREE_INT_CST_HIGH (op1) == 0
1219 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1220 == TREE_INT_CST_LOW (op1))
1231 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1232 simplification is possible.
1233 If negate_expr_p would return true for T, NULL_TREE will never be
1237 fold_negate_expr (tree t)
1239 tree type = TREE_TYPE (t);
1242 switch (TREE_CODE (t))
1244 /* Convert - (~A) to A + 1. */
1246 if (INTEGRAL_TYPE_P (type))
1247 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1248 build_int_cst (type, 1));
1252 tem = fold_negate_const (t, type);
1253 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1254 || !TYPE_OVERFLOW_TRAPS (type))
1259 tem = fold_negate_const (t, type);
1260 /* Two's complement FP formats, such as c4x, may overflow. */
1261 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1266 tem = fold_negate_const (t, type);
1271 tree rpart = negate_expr (TREE_REALPART (t));
1272 tree ipart = negate_expr (TREE_IMAGPART (t));
1274 if ((TREE_CODE (rpart) == REAL_CST
1275 && TREE_CODE (ipart) == REAL_CST)
1276 || (TREE_CODE (rpart) == INTEGER_CST
1277 && TREE_CODE (ipart) == INTEGER_CST))
1278 return build_complex (type, rpart, ipart);
1283 if (negate_expr_p (t))
1284 return fold_build2 (COMPLEX_EXPR, type,
1285 fold_negate_expr (TREE_OPERAND (t, 0)),
1286 fold_negate_expr (TREE_OPERAND (t, 1)));
1290 if (negate_expr_p (t))
1291 return fold_build1 (CONJ_EXPR, type,
1292 fold_negate_expr (TREE_OPERAND (t, 0)));
1296 return TREE_OPERAND (t, 0);
1299 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1300 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1302 /* -(A + B) -> (-B) - A. */
1303 if (negate_expr_p (TREE_OPERAND (t, 1))
1304 && reorder_operands_p (TREE_OPERAND (t, 0),
1305 TREE_OPERAND (t, 1)))
1307 tem = negate_expr (TREE_OPERAND (t, 1));
1308 return fold_build2 (MINUS_EXPR, type,
1309 tem, TREE_OPERAND (t, 0));
1312 /* -(A + B) -> (-A) - B. */
1313 if (negate_expr_p (TREE_OPERAND (t, 0)))
1315 tem = negate_expr (TREE_OPERAND (t, 0));
1316 return fold_build2 (MINUS_EXPR, type,
1317 tem, TREE_OPERAND (t, 1));
1323 /* - (A - B) -> B - A */
1324 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1325 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1326 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1327 return fold_build2 (MINUS_EXPR, type,
1328 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1332 if (TYPE_UNSIGNED (type))
1338 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1340 tem = TREE_OPERAND (t, 1);
1341 if (negate_expr_p (tem))
1342 return fold_build2 (TREE_CODE (t), type,
1343 TREE_OPERAND (t, 0), negate_expr (tem));
1344 tem = TREE_OPERAND (t, 0);
1345 if (negate_expr_p (tem))
1346 return fold_build2 (TREE_CODE (t), type,
1347 negate_expr (tem), TREE_OPERAND (t, 1));
1351 case TRUNC_DIV_EXPR:
1352 case ROUND_DIV_EXPR:
1353 case FLOOR_DIV_EXPR:
1355 case EXACT_DIV_EXPR:
1356 /* In general we can't negate A / B, because if A is INT_MIN and
1357 B is 1, we may turn this into INT_MIN / -1 which is undefined
1358 and actually traps on some architectures. But if overflow is
1359 undefined, we can negate, because - (INT_MIN / 1) is an
1361 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1363 const char * const warnmsg = G_("assuming signed overflow does not "
1364 "occur when negating a division");
1365 tem = TREE_OPERAND (t, 1);
1366 if (negate_expr_p (tem))
1368 if (INTEGRAL_TYPE_P (type)
1369 && (TREE_CODE (tem) != INTEGER_CST
1370 || integer_onep (tem)))
1371 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1372 return fold_build2 (TREE_CODE (t), type,
1373 TREE_OPERAND (t, 0), negate_expr (tem));
1375 tem = TREE_OPERAND (t, 0);
1376 if (negate_expr_p (tem))
1378 if (INTEGRAL_TYPE_P (type)
1379 && (TREE_CODE (tem) != INTEGER_CST
1380 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1381 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1382 return fold_build2 (TREE_CODE (t), type,
1383 negate_expr (tem), TREE_OPERAND (t, 1));
1389 /* Convert -((double)float) into (double)(-float). */
1390 if (TREE_CODE (type) == REAL_TYPE)
1392 tem = strip_float_extensions (t);
1393 if (tem != t && negate_expr_p (tem))
1394 return fold_convert (type, negate_expr (tem));
1399 /* Negate -f(x) as f(-x). */
1400 if (negate_mathfn_p (builtin_mathfn_code (t))
1401 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1405 fndecl = get_callee_fndecl (t);
1406 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1407 return build_call_expr (fndecl, 1, arg);
1412 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1413 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1415 tree op1 = TREE_OPERAND (t, 1);
1416 if (TREE_INT_CST_HIGH (op1) == 0
1417 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1418 == TREE_INT_CST_LOW (op1))
1420 tree ntype = TYPE_UNSIGNED (type)
1421 ? signed_type_for (type)
1422 : unsigned_type_for (type);
1423 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1424 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1425 return fold_convert (type, temp);
1437 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1438 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1439 return NULL_TREE. */
1442 negate_expr (tree t)
1449 type = TREE_TYPE (t);
1450 STRIP_SIGN_NOPS (t);
1452 tem = fold_negate_expr (t);
1454 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1455 return fold_convert (type, tem);
1458 /* Split a tree IN into a constant, literal and variable parts that could be
1459 combined with CODE to make IN. "constant" means an expression with
1460 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1461 commutative arithmetic operation. Store the constant part into *CONP,
1462 the literal in *LITP and return the variable part. If a part isn't
1463 present, set it to null. If the tree does not decompose in this way,
1464 return the entire tree as the variable part and the other parts as null.
1466 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1467 case, we negate an operand that was subtracted. Except if it is a
1468 literal for which we use *MINUS_LITP instead.
1470 If NEGATE_P is true, we are negating all of IN, again except a literal
1471 for which we use *MINUS_LITP instead.
1473 If IN is itself a literal or constant, return it as appropriate.
1475 Note that we do not guarantee that any of the three values will be the
1476 same type as IN, but they will have the same signedness and mode. */
1479 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1480 tree *minus_litp, int negate_p)
1488 /* Strip any conversions that don't change the machine mode or signedness. */
1489 STRIP_SIGN_NOPS (in);
1491 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
1492 || TREE_CODE (in) == FIXED_CST)
1494 else if (TREE_CODE (in) == code
1495 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1496 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
1497 /* We can associate addition and subtraction together (even
1498 though the C standard doesn't say so) for integers because
1499 the value is not affected. For reals, the value might be
1500 affected, so we can't. */
1501 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1502 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1504 tree op0 = TREE_OPERAND (in, 0);
1505 tree op1 = TREE_OPERAND (in, 1);
1506 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1507 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1509 /* First see if either of the operands is a literal, then a constant. */
1510 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
1511 || TREE_CODE (op0) == FIXED_CST)
1512 *litp = op0, op0 = 0;
1513 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
1514 || TREE_CODE (op1) == FIXED_CST)
1515 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1517 if (op0 != 0 && TREE_CONSTANT (op0))
1518 *conp = op0, op0 = 0;
1519 else if (op1 != 0 && TREE_CONSTANT (op1))
1520 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1522 /* If we haven't dealt with either operand, this is not a case we can
1523 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1524 if (op0 != 0 && op1 != 0)
1529 var = op1, neg_var_p = neg1_p;
1531 /* Now do any needed negations. */
1533 *minus_litp = *litp, *litp = 0;
1535 *conp = negate_expr (*conp);
1537 var = negate_expr (var);
1539 else if (TREE_CONSTANT (in))
1547 *minus_litp = *litp, *litp = 0;
1548 else if (*minus_litp)
1549 *litp = *minus_litp, *minus_litp = 0;
1550 *conp = negate_expr (*conp);
1551 var = negate_expr (var);
1557 /* Re-associate trees split by the above function. T1 and T2 are either
1558 expressions to associate or null. Return the new expression, if any. If
1559 we build an operation, do it in TYPE and with CODE. */
1562 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1569 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1570 try to fold this since we will have infinite recursion. But do
1571 deal with any NEGATE_EXPRs. */
1572 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1573 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1575 if (code == PLUS_EXPR)
1577 if (TREE_CODE (t1) == NEGATE_EXPR)
1578 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1579 fold_convert (type, TREE_OPERAND (t1, 0)));
1580 else if (TREE_CODE (t2) == NEGATE_EXPR)
1581 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1582 fold_convert (type, TREE_OPERAND (t2, 0)));
1583 else if (integer_zerop (t2))
1584 return fold_convert (type, t1);
1586 else if (code == MINUS_EXPR)
1588 if (integer_zerop (t2))
1589 return fold_convert (type, t1);
1592 return build2 (code, type, fold_convert (type, t1),
1593 fold_convert (type, t2));
1596 return fold_build2 (code, type, fold_convert (type, t1),
1597 fold_convert (type, t2));
1600 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1601 for use in int_const_binop, size_binop and size_diffop. */
1604 int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
1606 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1608 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1623 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1624 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1625 && TYPE_MODE (type1) == TYPE_MODE (type2);
1629 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1630 to produce a new constant. Return NULL_TREE if we don't know how
1631 to evaluate CODE at compile-time.
1633 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1636 int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2, int notrunc)
1638 unsigned HOST_WIDE_INT int1l, int2l;
1639 HOST_WIDE_INT int1h, int2h;
1640 unsigned HOST_WIDE_INT low;
1642 unsigned HOST_WIDE_INT garbagel;
1643 HOST_WIDE_INT garbageh;
1645 tree type = TREE_TYPE (arg1);
1646 int uns = TYPE_UNSIGNED (type);
1648 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1651 int1l = TREE_INT_CST_LOW (arg1);
1652 int1h = TREE_INT_CST_HIGH (arg1);
1653 int2l = TREE_INT_CST_LOW (arg2);
1654 int2h = TREE_INT_CST_HIGH (arg2);
1659 low = int1l | int2l, hi = int1h | int2h;
1663 low = int1l ^ int2l, hi = int1h ^ int2h;
1667 low = int1l & int2l, hi = int1h & int2h;
1673 /* It's unclear from the C standard whether shifts can overflow.
1674 The following code ignores overflow; perhaps a C standard
1675 interpretation ruling is needed. */
1676 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1683 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1688 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1692 neg_double (int2l, int2h, &low, &hi);
1693 add_double (int1l, int1h, low, hi, &low, &hi);
1694 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1698 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1701 case TRUNC_DIV_EXPR:
1702 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1703 case EXACT_DIV_EXPR:
1704 /* This is a shortcut for a common special case. */
1705 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1706 && !TREE_OVERFLOW (arg1)
1707 && !TREE_OVERFLOW (arg2)
1708 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1710 if (code == CEIL_DIV_EXPR)
1713 low = int1l / int2l, hi = 0;
1717 /* ... fall through ... */
1719 case ROUND_DIV_EXPR:
1720 if (int2h == 0 && int2l == 0)
1722 if (int2h == 0 && int2l == 1)
1724 low = int1l, hi = int1h;
1727 if (int1l == int2l && int1h == int2h
1728 && ! (int1l == 0 && int1h == 0))
1733 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1734 &low, &hi, &garbagel, &garbageh);
1737 case TRUNC_MOD_EXPR:
1738 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1739 /* This is a shortcut for a common special case. */
1740 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1741 && !TREE_OVERFLOW (arg1)
1742 && !TREE_OVERFLOW (arg2)
1743 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1745 if (code == CEIL_MOD_EXPR)
1747 low = int1l % int2l, hi = 0;
1751 /* ... fall through ... */
1753 case ROUND_MOD_EXPR:
1754 if (int2h == 0 && int2l == 0)
1756 overflow = div_and_round_double (code, uns,
1757 int1l, int1h, int2l, int2h,
1758 &garbagel, &garbageh, &low, &hi);
1764 low = (((unsigned HOST_WIDE_INT) int1h
1765 < (unsigned HOST_WIDE_INT) int2h)
1766 || (((unsigned HOST_WIDE_INT) int1h
1767 == (unsigned HOST_WIDE_INT) int2h)
1770 low = (int1h < int2h
1771 || (int1h == int2h && int1l < int2l));
1773 if (low == (code == MIN_EXPR))
1774 low = int1l, hi = int1h;
1776 low = int2l, hi = int2h;
1785 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1787 /* Propagate overflow flags ourselves. */
1788 if (((!uns || is_sizetype) && overflow)
1789 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1792 TREE_OVERFLOW (t) = 1;
1796 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1797 ((!uns || is_sizetype) && overflow)
1798 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1803 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1804 constant. We assume ARG1 and ARG2 have the same data type, or at least
1805 are the same kind of constant and the same machine mode. Return zero if
1806 combining the constants is not allowed in the current operating mode.
1808 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1811 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1813 /* Sanity check for the recursive cases. */
1820 if (TREE_CODE (arg1) == INTEGER_CST)
1821 return int_const_binop (code, arg1, arg2, notrunc);
1823 if (TREE_CODE (arg1) == REAL_CST)
1825 enum machine_mode mode;
1828 REAL_VALUE_TYPE value;
1829 REAL_VALUE_TYPE result;
1833 /* The following codes are handled by real_arithmetic. */
1848 d1 = TREE_REAL_CST (arg1);
1849 d2 = TREE_REAL_CST (arg2);
1851 type = TREE_TYPE (arg1);
1852 mode = TYPE_MODE (type);
1854 /* Don't perform operation if we honor signaling NaNs and
1855 either operand is a NaN. */
1856 if (HONOR_SNANS (mode)
1857 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1860 /* Don't perform operation if it would raise a division
1861 by zero exception. */
1862 if (code == RDIV_EXPR
1863 && REAL_VALUES_EQUAL (d2, dconst0)
1864 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1867 /* If either operand is a NaN, just return it. Otherwise, set up
1868 for floating-point trap; we return an overflow. */
1869 if (REAL_VALUE_ISNAN (d1))
1871 else if (REAL_VALUE_ISNAN (d2))
1874 inexact = real_arithmetic (&value, code, &d1, &d2);
1875 real_convert (&result, mode, &value);
1877 /* Don't constant fold this floating point operation if
1878 the result has overflowed and flag_trapping_math. */
1879 if (flag_trapping_math
1880 && MODE_HAS_INFINITIES (mode)
1881 && REAL_VALUE_ISINF (result)
1882 && !REAL_VALUE_ISINF (d1)
1883 && !REAL_VALUE_ISINF (d2))
1886 /* Don't constant fold this floating point operation if the
1887 result may dependent upon the run-time rounding mode and
1888 flag_rounding_math is set, or if GCC's software emulation
1889 is unable to accurately represent the result. */
1890 if ((flag_rounding_math
1891 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1892 && !flag_unsafe_math_optimizations))
1893 && (inexact || !real_identical (&result, &value)))
1896 t = build_real (type, result);
1898 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1902 if (TREE_CODE (arg1) == FIXED_CST)
1904 FIXED_VALUE_TYPE f1;
1905 FIXED_VALUE_TYPE f2;
1906 FIXED_VALUE_TYPE result;
1911 /* The following codes are handled by fixed_arithmetic. */
1917 case TRUNC_DIV_EXPR:
1918 f2 = TREE_FIXED_CST (arg2);
1923 f2.data.high = TREE_INT_CST_HIGH (arg2);
1924 f2.data.low = TREE_INT_CST_LOW (arg2);
1932 f1 = TREE_FIXED_CST (arg1);
1933 type = TREE_TYPE (arg1);
1934 sat_p = TYPE_SATURATING (type);
1935 overflow_p = fixed_arithmetic (&result, code, &f1, &f2, sat_p);
1936 t = build_fixed (type, result);
1937 /* Propagate overflow flags. */
1938 if (overflow_p | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1940 TREE_OVERFLOW (t) = 1;
1941 TREE_CONSTANT_OVERFLOW (t) = 1;
1943 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1944 TREE_CONSTANT_OVERFLOW (t) = 1;
1948 if (TREE_CODE (arg1) == COMPLEX_CST)
1950 tree type = TREE_TYPE (arg1);
1951 tree r1 = TREE_REALPART (arg1);
1952 tree i1 = TREE_IMAGPART (arg1);
1953 tree r2 = TREE_REALPART (arg2);
1954 tree i2 = TREE_IMAGPART (arg2);
1961 real = const_binop (code, r1, r2, notrunc);
1962 imag = const_binop (code, i1, i2, notrunc);
1966 real = const_binop (MINUS_EXPR,
1967 const_binop (MULT_EXPR, r1, r2, notrunc),
1968 const_binop (MULT_EXPR, i1, i2, notrunc),
1970 imag = const_binop (PLUS_EXPR,
1971 const_binop (MULT_EXPR, r1, i2, notrunc),
1972 const_binop (MULT_EXPR, i1, r2, notrunc),
1979 = const_binop (PLUS_EXPR,
1980 const_binop (MULT_EXPR, r2, r2, notrunc),
1981 const_binop (MULT_EXPR, i2, i2, notrunc),
1984 = const_binop (PLUS_EXPR,
1985 const_binop (MULT_EXPR, r1, r2, notrunc),
1986 const_binop (MULT_EXPR, i1, i2, notrunc),
1989 = const_binop (MINUS_EXPR,
1990 const_binop (MULT_EXPR, i1, r2, notrunc),
1991 const_binop (MULT_EXPR, r1, i2, notrunc),
1994 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1995 code = TRUNC_DIV_EXPR;
1997 real = const_binop (code, t1, magsquared, notrunc);
1998 imag = const_binop (code, t2, magsquared, notrunc);
2007 return build_complex (type, real, imag);
2013 /* Create a size type INT_CST node with NUMBER sign extended. KIND
2014 indicates which particular sizetype to create. */
2017 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
2019 return build_int_cst (sizetype_tab[(int) kind], number);
2022 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2023 is a tree code. The type of the result is taken from the operands.
2024 Both must be equivalent integer types, ala int_binop_types_match_p.
2025 If the operands are constant, so is the result. */
2028 size_binop (enum tree_code code, tree arg0, tree arg1)
2030 tree type = TREE_TYPE (arg0);
2032 if (arg0 == error_mark_node || arg1 == error_mark_node)
2033 return error_mark_node;
2035 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
2038 /* Handle the special case of two integer constants faster. */
2039 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
2041 /* And some specific cases even faster than that. */
2042 if (code == PLUS_EXPR)
2044 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
2046 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2049 else if (code == MINUS_EXPR)
2051 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2054 else if (code == MULT_EXPR)
2056 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
2060 /* Handle general case of two integer constants. */
2061 return int_const_binop (code, arg0, arg1, 0);
2064 return fold_build2 (code, type, arg0, arg1);
2067 /* Given two values, either both of sizetype or both of bitsizetype,
2068 compute the difference between the two values. Return the value
2069 in signed type corresponding to the type of the operands. */
2072 size_diffop (tree arg0, tree arg1)
2074 tree type = TREE_TYPE (arg0);
2077 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
2080 /* If the type is already signed, just do the simple thing. */
2081 if (!TYPE_UNSIGNED (type))
2082 return size_binop (MINUS_EXPR, arg0, arg1);
2084 if (type == sizetype)
2086 else if (type == bitsizetype)
2087 ctype = sbitsizetype;
2089 ctype = signed_type_for (type);
2091 /* If either operand is not a constant, do the conversions to the signed
2092 type and subtract. The hardware will do the right thing with any
2093 overflow in the subtraction. */
2094 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2095 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
2096 fold_convert (ctype, arg1));
2098 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2099 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2100 overflow) and negate (which can't either). Special-case a result
2101 of zero while we're here. */
2102 if (tree_int_cst_equal (arg0, arg1))
2103 return build_int_cst (ctype, 0);
2104 else if (tree_int_cst_lt (arg1, arg0))
2105 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2107 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
2108 fold_convert (ctype, size_binop (MINUS_EXPR,
2112 /* A subroutine of fold_convert_const handling conversions of an
2113 INTEGER_CST to another integer type. */
2116 fold_convert_const_int_from_int (tree type, const_tree arg1)
2120 /* Given an integer constant, make new constant with new type,
2121 appropriately sign-extended or truncated. */
2122 t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
2123 TREE_INT_CST_HIGH (arg1),
2124 /* Don't set the overflow when
2125 converting a pointer */
2126 !POINTER_TYPE_P (TREE_TYPE (arg1)),
2127 (TREE_INT_CST_HIGH (arg1) < 0
2128 && (TYPE_UNSIGNED (type)
2129 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2130 | TREE_OVERFLOW (arg1));
2135 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2136 to an integer type. */
2139 fold_convert_const_int_from_real (enum tree_code code, tree type, const_tree arg1)
2144 /* The following code implements the floating point to integer
2145 conversion rules required by the Java Language Specification,
2146 that IEEE NaNs are mapped to zero and values that overflow
2147 the target precision saturate, i.e. values greater than
2148 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2149 are mapped to INT_MIN. These semantics are allowed by the
2150 C and C++ standards that simply state that the behavior of
2151 FP-to-integer conversion is unspecified upon overflow. */
2153 HOST_WIDE_INT high, low;
2155 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2159 case FIX_TRUNC_EXPR:
2160 real_trunc (&r, VOIDmode, &x);
2167 /* If R is NaN, return zero and show we have an overflow. */
2168 if (REAL_VALUE_ISNAN (r))
2175 /* See if R is less than the lower bound or greater than the
2180 tree lt = TYPE_MIN_VALUE (type);
2181 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2182 if (REAL_VALUES_LESS (r, l))
2185 high = TREE_INT_CST_HIGH (lt);
2186 low = TREE_INT_CST_LOW (lt);
2192 tree ut = TYPE_MAX_VALUE (type);
2195 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2196 if (REAL_VALUES_LESS (u, r))
2199 high = TREE_INT_CST_HIGH (ut);
2200 low = TREE_INT_CST_LOW (ut);
2206 REAL_VALUE_TO_INT (&low, &high, r);
2208 t = force_fit_type_double (type, low, high, -1,
2209 overflow | TREE_OVERFLOW (arg1));
2213 /* A subroutine of fold_convert_const handling conversions of a
2214 FIXED_CST to an integer type. */
2217 fold_convert_const_int_from_fixed (tree type, const_tree arg1)
2220 double_int temp, temp_trunc;
2223 /* Right shift FIXED_CST to temp by fbit. */
2224 temp = TREE_FIXED_CST (arg1).data;
2225 mode = TREE_FIXED_CST (arg1).mode;
2226 if (GET_MODE_FBIT (mode) < 2 * HOST_BITS_PER_WIDE_INT)
2228 lshift_double (temp.low, temp.high,
2229 - GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2230 &temp.low, &temp.high, SIGNED_FIXED_POINT_MODE_P (mode));
2232 /* Left shift temp to temp_trunc by fbit. */
2233 lshift_double (temp.low, temp.high,
2234 GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2235 &temp_trunc.low, &temp_trunc.high,
2236 SIGNED_FIXED_POINT_MODE_P (mode));
2243 temp_trunc.high = 0;
2246 /* If FIXED_CST is negative, we need to round the value toward 0.
2247 By checking if the fractional bits are not zero to add 1 to temp. */
2248 if (SIGNED_FIXED_POINT_MODE_P (mode) && temp_trunc.high < 0
2249 && !double_int_equal_p (TREE_FIXED_CST (arg1).data, temp_trunc))
2254 temp = double_int_add (temp, one);
2257 /* Given a fixed-point constant, make new constant with new type,
2258 appropriately sign-extended or truncated. */
2259 t = force_fit_type_double (type, temp.low, temp.high, -1,
2261 && (TYPE_UNSIGNED (type)
2262 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2263 | TREE_OVERFLOW (arg1));
2268 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2269 to another floating point type. */
2272 fold_convert_const_real_from_real (tree type, const_tree arg1)
2274 REAL_VALUE_TYPE value;
2277 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2278 t = build_real (type, value);
2280 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2284 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2285 to a floating point type. */
2288 fold_convert_const_real_from_fixed (tree type, const_tree arg1)
2290 REAL_VALUE_TYPE value;
2293 real_convert_from_fixed (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1));
2294 t = build_real (type, value);
2296 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2297 TREE_CONSTANT_OVERFLOW (t)
2298 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2302 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2303 to another fixed-point type. */
2306 fold_convert_const_fixed_from_fixed (tree type, const_tree arg1)
2308 FIXED_VALUE_TYPE value;
2312 overflow_p = fixed_convert (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1),
2313 TYPE_SATURATING (type));
2314 t = build_fixed (type, value);
2316 /* Propagate overflow flags. */
2317 if (overflow_p | TREE_OVERFLOW (arg1))
2319 TREE_OVERFLOW (t) = 1;
2320 TREE_CONSTANT_OVERFLOW (t) = 1;
2322 else if (TREE_CONSTANT_OVERFLOW (arg1))
2323 TREE_CONSTANT_OVERFLOW (t) = 1;
2327 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2328 to a fixed-point type. */
2331 fold_convert_const_fixed_from_int (tree type, const_tree arg1)
2333 FIXED_VALUE_TYPE value;
2337 overflow_p = fixed_convert_from_int (&value, TYPE_MODE (type),
2338 TREE_INT_CST (arg1),
2339 TYPE_UNSIGNED (TREE_TYPE (arg1)),
2340 TYPE_SATURATING (type));
2341 t = build_fixed (type, value);
2343 /* Propagate overflow flags. */
2344 if (overflow_p | TREE_OVERFLOW (arg1))
2346 TREE_OVERFLOW (t) = 1;
2347 TREE_CONSTANT_OVERFLOW (t) = 1;
2349 else if (TREE_CONSTANT_OVERFLOW (arg1))
2350 TREE_CONSTANT_OVERFLOW (t) = 1;
2354 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2355 to a fixed-point type. */
2358 fold_convert_const_fixed_from_real (tree type, const_tree arg1)
2360 FIXED_VALUE_TYPE value;
2364 overflow_p = fixed_convert_from_real (&value, TYPE_MODE (type),
2365 &TREE_REAL_CST (arg1),
2366 TYPE_SATURATING (type));
2367 t = build_fixed (type, value);
2369 /* Propagate overflow flags. */
2370 if (overflow_p | TREE_OVERFLOW (arg1))
2372 TREE_OVERFLOW (t) = 1;
2373 TREE_CONSTANT_OVERFLOW (t) = 1;
2375 else if (TREE_CONSTANT_OVERFLOW (arg1))
2376 TREE_CONSTANT_OVERFLOW (t) = 1;
2380 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2381 type TYPE. If no simplification can be done return NULL_TREE. */
2384 fold_convert_const (enum tree_code code, tree type, tree arg1)
2386 if (TREE_TYPE (arg1) == type)
2389 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2391 if (TREE_CODE (arg1) == INTEGER_CST)
2392 return fold_convert_const_int_from_int (type, arg1);
2393 else if (TREE_CODE (arg1) == REAL_CST)
2394 return fold_convert_const_int_from_real (code, type, arg1);
2395 else if (TREE_CODE (arg1) == FIXED_CST)
2396 return fold_convert_const_int_from_fixed (type, arg1);
2398 else if (TREE_CODE (type) == REAL_TYPE)
2400 if (TREE_CODE (arg1) == INTEGER_CST)
2401 return build_real_from_int_cst (type, arg1);
2402 else if (TREE_CODE (arg1) == REAL_CST)
2403 return fold_convert_const_real_from_real (type, arg1);
2404 else if (TREE_CODE (arg1) == FIXED_CST)
2405 return fold_convert_const_real_from_fixed (type, arg1);
2407 else if (TREE_CODE (type) == FIXED_POINT_TYPE)
2409 if (TREE_CODE (arg1) == FIXED_CST)
2410 return fold_convert_const_fixed_from_fixed (type, arg1);
2411 else if (TREE_CODE (arg1) == INTEGER_CST)
2412 return fold_convert_const_fixed_from_int (type, arg1);
2413 else if (TREE_CODE (arg1) == REAL_CST)
2414 return fold_convert_const_fixed_from_real (type, arg1);
2419 /* Construct a vector of zero elements of vector type TYPE. */
2422 build_zero_vector (tree type)
2427 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2428 units = TYPE_VECTOR_SUBPARTS (type);
2431 for (i = 0; i < units; i++)
2432 list = tree_cons (NULL_TREE, elem, list);
2433 return build_vector (type, list);
2436 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2439 fold_convertible_p (const_tree type, const_tree arg)
2441 tree orig = TREE_TYPE (arg);
2446 if (TREE_CODE (arg) == ERROR_MARK
2447 || TREE_CODE (type) == ERROR_MARK
2448 || TREE_CODE (orig) == ERROR_MARK)
2451 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2454 switch (TREE_CODE (type))
2456 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2457 case POINTER_TYPE: case REFERENCE_TYPE:
2459 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2460 || TREE_CODE (orig) == OFFSET_TYPE)
2462 return (TREE_CODE (orig) == VECTOR_TYPE
2463 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2466 return TREE_CODE (type) == TREE_CODE (orig);
2470 /* Convert expression ARG to type TYPE. Used by the middle-end for
2471 simple conversions in preference to calling the front-end's convert. */
2474 fold_convert (tree type, tree arg)
2476 tree orig = TREE_TYPE (arg);
2482 if (TREE_CODE (arg) == ERROR_MARK
2483 || TREE_CODE (type) == ERROR_MARK
2484 || TREE_CODE (orig) == ERROR_MARK)
2485 return error_mark_node;
2487 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2488 return fold_build1 (NOP_EXPR, type, arg);
2490 switch (TREE_CODE (type))
2492 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2493 case POINTER_TYPE: case REFERENCE_TYPE:
2495 if (TREE_CODE (arg) == INTEGER_CST)
2497 tem = fold_convert_const (NOP_EXPR, type, arg);
2498 if (tem != NULL_TREE)
2501 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2502 || TREE_CODE (orig) == OFFSET_TYPE)
2503 return fold_build1 (NOP_EXPR, type, arg);
2504 if (TREE_CODE (orig) == COMPLEX_TYPE)
2506 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2507 return fold_convert (type, tem);
2509 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2510 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2511 return fold_build1 (NOP_EXPR, type, arg);
2514 if (TREE_CODE (arg) == INTEGER_CST)
2516 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2517 if (tem != NULL_TREE)
2520 else if (TREE_CODE (arg) == REAL_CST)
2522 tem = fold_convert_const (NOP_EXPR, type, arg);
2523 if (tem != NULL_TREE)
2526 else if (TREE_CODE (arg) == FIXED_CST)
2528 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2529 if (tem != NULL_TREE)
2533 switch (TREE_CODE (orig))
2536 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2537 case POINTER_TYPE: case REFERENCE_TYPE:
2538 return fold_build1 (FLOAT_EXPR, type, arg);
2541 return fold_build1 (NOP_EXPR, type, arg);
2543 case FIXED_POINT_TYPE:
2544 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2547 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2548 return fold_convert (type, tem);
2554 case FIXED_POINT_TYPE:
2555 if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
2556 || TREE_CODE (arg) == REAL_CST)
2558 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2559 if (tem != NULL_TREE)
2563 switch (TREE_CODE (orig))
2565 case FIXED_POINT_TYPE:
2570 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2573 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2574 return fold_convert (type, tem);
2581 switch (TREE_CODE (orig))
2584 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2585 case POINTER_TYPE: case REFERENCE_TYPE:
2587 case FIXED_POINT_TYPE:
2588 return build2 (COMPLEX_EXPR, type,
2589 fold_convert (TREE_TYPE (type), arg),
2590 fold_convert (TREE_TYPE (type), integer_zero_node));
2595 if (TREE_CODE (arg) == COMPLEX_EXPR)
2597 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2598 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2599 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2602 arg = save_expr (arg);
2603 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2604 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2605 rpart = fold_convert (TREE_TYPE (type), rpart);
2606 ipart = fold_convert (TREE_TYPE (type), ipart);
2607 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2615 if (integer_zerop (arg))
2616 return build_zero_vector (type);
2617 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2618 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2619 || TREE_CODE (orig) == VECTOR_TYPE);
2620 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2623 tem = fold_ignored_result (arg);
2624 if (TREE_CODE (tem) == GIMPLE_MODIFY_STMT)
2626 return fold_build1 (NOP_EXPR, type, tem);
2633 /* Return false if expr can be assumed not to be an lvalue, true
2637 maybe_lvalue_p (const_tree x)
2639 /* We only need to wrap lvalue tree codes. */
2640 switch (TREE_CODE (x))
2651 case ALIGN_INDIRECT_REF:
2652 case MISALIGNED_INDIRECT_REF:
2654 case ARRAY_RANGE_REF:
2660 case PREINCREMENT_EXPR:
2661 case PREDECREMENT_EXPR:
2663 case TRY_CATCH_EXPR:
2664 case WITH_CLEANUP_EXPR:
2667 case GIMPLE_MODIFY_STMT:
2676 /* Assume the worst for front-end tree codes. */
2677 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2685 /* Return an expr equal to X but certainly not valid as an lvalue. */
2690 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2695 if (! maybe_lvalue_p (x))
2697 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2700 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2701 Zero means allow extended lvalues. */
2703 int pedantic_lvalues;
2705 /* When pedantic, return an expr equal to X but certainly not valid as a
2706 pedantic lvalue. Otherwise, return X. */
2709 pedantic_non_lvalue (tree x)
2711 if (pedantic_lvalues)
2712 return non_lvalue (x);
2717 /* Given a tree comparison code, return the code that is the logical inverse
2718 of the given code. It is not safe to do this for floating-point
2719 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2720 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2723 invert_tree_comparison (enum tree_code code, bool honor_nans)
2725 if (honor_nans && flag_trapping_math)
2735 return honor_nans ? UNLE_EXPR : LE_EXPR;
2737 return honor_nans ? UNLT_EXPR : LT_EXPR;
2739 return honor_nans ? UNGE_EXPR : GE_EXPR;
2741 return honor_nans ? UNGT_EXPR : GT_EXPR;
2755 return UNORDERED_EXPR;
2756 case UNORDERED_EXPR:
2757 return ORDERED_EXPR;
2763 /* Similar, but return the comparison that results if the operands are
2764 swapped. This is safe for floating-point. */
2767 swap_tree_comparison (enum tree_code code)
2774 case UNORDERED_EXPR:
2800 /* Convert a comparison tree code from an enum tree_code representation
2801 into a compcode bit-based encoding. This function is the inverse of
2802 compcode_to_comparison. */
2804 static enum comparison_code
2805 comparison_to_compcode (enum tree_code code)
2822 return COMPCODE_ORD;
2823 case UNORDERED_EXPR:
2824 return COMPCODE_UNORD;
2826 return COMPCODE_UNLT;
2828 return COMPCODE_UNEQ;
2830 return COMPCODE_UNLE;
2832 return COMPCODE_UNGT;
2834 return COMPCODE_LTGT;
2836 return COMPCODE_UNGE;
2842 /* Convert a compcode bit-based encoding of a comparison operator back
2843 to GCC's enum tree_code representation. This function is the
2844 inverse of comparison_to_compcode. */
2846 static enum tree_code
2847 compcode_to_comparison (enum comparison_code code)
2864 return ORDERED_EXPR;
2865 case COMPCODE_UNORD:
2866 return UNORDERED_EXPR;
2884 /* Return a tree for the comparison which is the combination of
2885 doing the AND or OR (depending on CODE) of the two operations LCODE
2886 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2887 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2888 if this makes the transformation invalid. */
2891 combine_comparisons (enum tree_code code, enum tree_code lcode,
2892 enum tree_code rcode, tree truth_type,
2893 tree ll_arg, tree lr_arg)
2895 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2896 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2897 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2898 enum comparison_code compcode;
2902 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2903 compcode = lcompcode & rcompcode;
2906 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2907 compcode = lcompcode | rcompcode;
2916 /* Eliminate unordered comparisons, as well as LTGT and ORD
2917 which are not used unless the mode has NaNs. */
2918 compcode &= ~COMPCODE_UNORD;
2919 if (compcode == COMPCODE_LTGT)
2920 compcode = COMPCODE_NE;
2921 else if (compcode == COMPCODE_ORD)
2922 compcode = COMPCODE_TRUE;
2924 else if (flag_trapping_math)
2926 /* Check that the original operation and the optimized ones will trap
2927 under the same condition. */
2928 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2929 && (lcompcode != COMPCODE_EQ)
2930 && (lcompcode != COMPCODE_ORD);
2931 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2932 && (rcompcode != COMPCODE_EQ)
2933 && (rcompcode != COMPCODE_ORD);
2934 bool trap = (compcode & COMPCODE_UNORD) == 0
2935 && (compcode != COMPCODE_EQ)
2936 && (compcode != COMPCODE_ORD);
2938 /* In a short-circuited boolean expression the LHS might be
2939 such that the RHS, if evaluated, will never trap. For
2940 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2941 if neither x nor y is NaN. (This is a mixed blessing: for
2942 example, the expression above will never trap, hence
2943 optimizing it to x < y would be invalid). */
2944 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2945 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2948 /* If the comparison was short-circuited, and only the RHS
2949 trapped, we may now generate a spurious trap. */
2951 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2954 /* If we changed the conditions that cause a trap, we lose. */
2955 if ((ltrap || rtrap) != trap)
2959 if (compcode == COMPCODE_TRUE)
2960 return constant_boolean_node (true, truth_type);
2961 else if (compcode == COMPCODE_FALSE)
2962 return constant_boolean_node (false, truth_type);
2964 return fold_build2 (compcode_to_comparison (compcode),
2965 truth_type, ll_arg, lr_arg);
2968 /* Return nonzero if CODE is a tree code that represents a truth value. */
2971 truth_value_p (enum tree_code code)
2973 return (TREE_CODE_CLASS (code) == tcc_comparison
2974 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2975 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2976 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2979 /* Return nonzero if two operands (typically of the same tree node)
2980 are necessarily equal. If either argument has side-effects this
2981 function returns zero. FLAGS modifies behavior as follows:
2983 If OEP_ONLY_CONST is set, only return nonzero for constants.
2984 This function tests whether the operands are indistinguishable;
2985 it does not test whether they are equal using C's == operation.
2986 The distinction is important for IEEE floating point, because
2987 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2988 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2990 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2991 even though it may hold multiple values during a function.
2992 This is because a GCC tree node guarantees that nothing else is
2993 executed between the evaluation of its "operands" (which may often
2994 be evaluated in arbitrary order). Hence if the operands themselves
2995 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2996 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2997 unset means assuming isochronic (or instantaneous) tree equivalence.
2998 Unless comparing arbitrary expression trees, such as from different
2999 statements, this flag can usually be left unset.
3001 If OEP_PURE_SAME is set, then pure functions with identical arguments
3002 are considered the same. It is used when the caller has other ways
3003 to ensure that global memory is unchanged in between. */
3006 operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
3008 /* If either is ERROR_MARK, they aren't equal. */
3009 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
3012 /* If both types don't have the same signedness, then we can't consider
3013 them equal. We must check this before the STRIP_NOPS calls
3014 because they may change the signedness of the arguments. */
3015 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3018 /* If both types don't have the same precision, then it is not safe
3020 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
3026 /* In case both args are comparisons but with different comparison
3027 code, try to swap the comparison operands of one arg to produce
3028 a match and compare that variant. */
3029 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3030 && COMPARISON_CLASS_P (arg0)
3031 && COMPARISON_CLASS_P (arg1))
3033 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
3035 if (TREE_CODE (arg0) == swap_code)
3036 return operand_equal_p (TREE_OPERAND (arg0, 0),
3037 TREE_OPERAND (arg1, 1), flags)
3038 && operand_equal_p (TREE_OPERAND (arg0, 1),
3039 TREE_OPERAND (arg1, 0), flags);
3042 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3043 /* This is needed for conversions and for COMPONENT_REF.
3044 Might as well play it safe and always test this. */
3045 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
3046 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
3047 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
3050 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3051 We don't care about side effects in that case because the SAVE_EXPR
3052 takes care of that for us. In all other cases, two expressions are
3053 equal if they have no side effects. If we have two identical
3054 expressions with side effects that should be treated the same due
3055 to the only side effects being identical SAVE_EXPR's, that will
3056 be detected in the recursive calls below. */
3057 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
3058 && (TREE_CODE (arg0) == SAVE_EXPR
3059 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
3062 /* Next handle constant cases, those for which we can return 1 even
3063 if ONLY_CONST is set. */
3064 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
3065 switch (TREE_CODE (arg0))
3068 return tree_int_cst_equal (arg0, arg1);
3071 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
3072 TREE_FIXED_CST (arg1));
3075 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
3076 TREE_REAL_CST (arg1)))
3080 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
3082 /* If we do not distinguish between signed and unsigned zero,
3083 consider them equal. */
3084 if (real_zerop (arg0) && real_zerop (arg1))
3093 v1 = TREE_VECTOR_CST_ELTS (arg0);
3094 v2 = TREE_VECTOR_CST_ELTS (arg1);
3097 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
3100 v1 = TREE_CHAIN (v1);
3101 v2 = TREE_CHAIN (v2);
3108 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
3110 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
3114 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
3115 && ! memcmp (TREE_STRING_POINTER (arg0),
3116 TREE_STRING_POINTER (arg1),
3117 TREE_STRING_LENGTH (arg0)));
3120 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
3126 if (flags & OEP_ONLY_CONST)
3129 /* Define macros to test an operand from arg0 and arg1 for equality and a
3130 variant that allows null and views null as being different from any
3131 non-null value. In the latter case, if either is null, the both
3132 must be; otherwise, do the normal comparison. */
3133 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3134 TREE_OPERAND (arg1, N), flags)
3136 #define OP_SAME_WITH_NULL(N) \
3137 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3138 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3140 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
3143 /* Two conversions are equal only if signedness and modes match. */
3144 switch (TREE_CODE (arg0))
3148 case FIX_TRUNC_EXPR:
3149 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
3150 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3160 case tcc_comparison:
3162 if (OP_SAME (0) && OP_SAME (1))
3165 /* For commutative ops, allow the other order. */
3166 return (commutative_tree_code (TREE_CODE (arg0))
3167 && operand_equal_p (TREE_OPERAND (arg0, 0),
3168 TREE_OPERAND (arg1, 1), flags)
3169 && operand_equal_p (TREE_OPERAND (arg0, 1),
3170 TREE_OPERAND (arg1, 0), flags));
3173 /* If either of the pointer (or reference) expressions we are
3174 dereferencing contain a side effect, these cannot be equal. */
3175 if (TREE_SIDE_EFFECTS (arg0)
3176 || TREE_SIDE_EFFECTS (arg1))
3179 switch (TREE_CODE (arg0))
3182 case ALIGN_INDIRECT_REF:
3183 case MISALIGNED_INDIRECT_REF:
3189 case ARRAY_RANGE_REF:
3190 /* Operands 2 and 3 may be null.
3191 Compare the array index by value if it is constant first as we
3192 may have different types but same value here. */
3194 && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
3195 TREE_OPERAND (arg1, 1))
3197 && OP_SAME_WITH_NULL (2)
3198 && OP_SAME_WITH_NULL (3));
3201 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3202 may be NULL when we're called to compare MEM_EXPRs. */
3203 return OP_SAME_WITH_NULL (0)
3205 && OP_SAME_WITH_NULL (2);
3208 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3214 case tcc_expression:
3215 switch (TREE_CODE (arg0))
3218 case TRUTH_NOT_EXPR:
3221 case TRUTH_ANDIF_EXPR:
3222 case TRUTH_ORIF_EXPR:
3223 return OP_SAME (0) && OP_SAME (1);
3225 case TRUTH_AND_EXPR:
3227 case TRUTH_XOR_EXPR:
3228 if (OP_SAME (0) && OP_SAME (1))
3231 /* Otherwise take into account this is a commutative operation. */
3232 return (operand_equal_p (TREE_OPERAND (arg0, 0),
3233 TREE_OPERAND (arg1, 1), flags)
3234 && operand_equal_p (TREE_OPERAND (arg0, 1),
3235 TREE_OPERAND (arg1, 0), flags));
3242 switch (TREE_CODE (arg0))
3245 /* If the CALL_EXPRs call different functions, then they
3246 clearly can not be equal. */
3247 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
3252 unsigned int cef = call_expr_flags (arg0);
3253 if (flags & OEP_PURE_SAME)
3254 cef &= ECF_CONST | ECF_PURE;
3261 /* Now see if all the arguments are the same. */
3263 const_call_expr_arg_iterator iter0, iter1;
3265 for (a0 = first_const_call_expr_arg (arg0, &iter0),
3266 a1 = first_const_call_expr_arg (arg1, &iter1);
3268 a0 = next_const_call_expr_arg (&iter0),
3269 a1 = next_const_call_expr_arg (&iter1))
3270 if (! operand_equal_p (a0, a1, flags))
3273 /* If we get here and both argument lists are exhausted
3274 then the CALL_EXPRs are equal. */
3275 return ! (a0 || a1);
3281 case tcc_declaration:
3282 /* Consider __builtin_sqrt equal to sqrt. */
3283 return (TREE_CODE (arg0) == FUNCTION_DECL
3284 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
3285 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
3286 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
3293 #undef OP_SAME_WITH_NULL
3296 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3297 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3299 When in doubt, return 0. */
3302 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
3304 int unsignedp1, unsignedpo;
3305 tree primarg0, primarg1, primother;
3306 unsigned int correct_width;
3308 if (operand_equal_p (arg0, arg1, 0))
3311 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3312 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3315 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3316 and see if the inner values are the same. This removes any
3317 signedness comparison, which doesn't matter here. */
3318 primarg0 = arg0, primarg1 = arg1;
3319 STRIP_NOPS (primarg0);
3320 STRIP_NOPS (primarg1);
3321 if (operand_equal_p (primarg0, primarg1, 0))
3324 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3325 actual comparison operand, ARG0.
3327 First throw away any conversions to wider types
3328 already present in the operands. */
3330 primarg1 = get_narrower (arg1, &unsignedp1);
3331 primother = get_narrower (other, &unsignedpo);
3333 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3334 if (unsignedp1 == unsignedpo
3335 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3336 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3338 tree type = TREE_TYPE (arg0);
3340 /* Make sure shorter operand is extended the right way
3341 to match the longer operand. */
3342 primarg1 = fold_convert (signed_or_unsigned_type_for
3343 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3345 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3352 /* See if ARG is an expression that is either a comparison or is performing
3353 arithmetic on comparisons. The comparisons must only be comparing
3354 two different values, which will be stored in *CVAL1 and *CVAL2; if
3355 they are nonzero it means that some operands have already been found.
3356 No variables may be used anywhere else in the expression except in the
3357 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3358 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3360 If this is true, return 1. Otherwise, return zero. */
3363 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3365 enum tree_code code = TREE_CODE (arg);
3366 enum tree_code_class class = TREE_CODE_CLASS (code);
3368 /* We can handle some of the tcc_expression cases here. */
3369 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3371 else if (class == tcc_expression
3372 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3373 || code == COMPOUND_EXPR))
3376 else if (class == tcc_expression && code == SAVE_EXPR
3377 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3379 /* If we've already found a CVAL1 or CVAL2, this expression is
3380 two complex to handle. */
3381 if (*cval1 || *cval2)
3391 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3394 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3395 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3396 cval1, cval2, save_p));
3401 case tcc_expression:
3402 if (code == COND_EXPR)
3403 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3404 cval1, cval2, save_p)
3405 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3406 cval1, cval2, save_p)
3407 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3408 cval1, cval2, save_p));
3411 case tcc_comparison:
3412 /* First see if we can handle the first operand, then the second. For
3413 the second operand, we know *CVAL1 can't be zero. It must be that
3414 one side of the comparison is each of the values; test for the
3415 case where this isn't true by failing if the two operands
3418 if (operand_equal_p (TREE_OPERAND (arg, 0),
3419 TREE_OPERAND (arg, 1), 0))
3423 *cval1 = TREE_OPERAND (arg, 0);
3424 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3426 else if (*cval2 == 0)
3427 *cval2 = TREE_OPERAND (arg, 0);
3428 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3433 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3435 else if (*cval2 == 0)
3436 *cval2 = TREE_OPERAND (arg, 1);
3437 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3449 /* ARG is a tree that is known to contain just arithmetic operations and
3450 comparisons. Evaluate the operations in the tree substituting NEW0 for
3451 any occurrence of OLD0 as an operand of a comparison and likewise for
3455 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3457 tree type = TREE_TYPE (arg);
3458 enum tree_code code = TREE_CODE (arg);
3459 enum tree_code_class class = TREE_CODE_CLASS (code);
3461 /* We can handle some of the tcc_expression cases here. */
3462 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3464 else if (class == tcc_expression
3465 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3471 return fold_build1 (code, type,
3472 eval_subst (TREE_OPERAND (arg, 0),
3473 old0, new0, old1, new1));
3476 return fold_build2 (code, type,
3477 eval_subst (TREE_OPERAND (arg, 0),
3478 old0, new0, old1, new1),
3479 eval_subst (TREE_OPERAND (arg, 1),
3480 old0, new0, old1, new1));
3482 case tcc_expression:
3486 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3489 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3492 return fold_build3 (code, type,
3493 eval_subst (TREE_OPERAND (arg, 0),
3494 old0, new0, old1, new1),
3495 eval_subst (TREE_OPERAND (arg, 1),
3496 old0, new0, old1, new1),
3497 eval_subst (TREE_OPERAND (arg, 2),
3498 old0, new0, old1, new1));
3502 /* Fall through - ??? */
3504 case tcc_comparison:
3506 tree arg0 = TREE_OPERAND (arg, 0);
3507 tree arg1 = TREE_OPERAND (arg, 1);
3509 /* We need to check both for exact equality and tree equality. The
3510 former will be true if the operand has a side-effect. In that
3511 case, we know the operand occurred exactly once. */
3513 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3515 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3518 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3520 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3523 return fold_build2 (code, type, arg0, arg1);
3531 /* Return a tree for the case when the result of an expression is RESULT
3532 converted to TYPE and OMITTED was previously an operand of the expression
3533 but is now not needed (e.g., we folded OMITTED * 0).
3535 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3536 the conversion of RESULT to TYPE. */
3539 omit_one_operand (tree type, tree result, tree omitted)
3541 tree t = fold_convert (type, result);
3543 /* If the resulting operand is an empty statement, just return the omitted
3544 statement casted to void. */
3545 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3546 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3548 if (TREE_SIDE_EFFECTS (omitted))
3549 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3551 return non_lvalue (t);
3554 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3557 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3559 tree t = fold_convert (type, result);
3561 /* If the resulting operand is an empty statement, just return the omitted
3562 statement casted to void. */
3563 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3564 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3566 if (TREE_SIDE_EFFECTS (omitted))
3567 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3569 return pedantic_non_lvalue (t);
3572 /* Return a tree for the case when the result of an expression is RESULT
3573 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3574 of the expression but are now not needed.
3576 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3577 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3578 evaluated before OMITTED2. Otherwise, if neither has side effects,
3579 just do the conversion of RESULT to TYPE. */
3582 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3584 tree t = fold_convert (type, result);
3586 if (TREE_SIDE_EFFECTS (omitted2))
3587 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3588 if (TREE_SIDE_EFFECTS (omitted1))
3589 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3591 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3595 /* Return a simplified tree node for the truth-negation of ARG. This
3596 never alters ARG itself. We assume that ARG is an operation that
3597 returns a truth value (0 or 1).
3599 FIXME: one would think we would fold the result, but it causes
3600 problems with the dominator optimizer. */
3603 fold_truth_not_expr (tree arg)
3605 tree type = TREE_TYPE (arg);
3606 enum tree_code code = TREE_CODE (arg);
3608 /* If this is a comparison, we can simply invert it, except for
3609 floating-point non-equality comparisons, in which case we just
3610 enclose a TRUTH_NOT_EXPR around what we have. */
3612 if (TREE_CODE_CLASS (code) == tcc_comparison)
3614 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3615 if (FLOAT_TYPE_P (op_type)
3616 && flag_trapping_math
3617 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3618 && code != NE_EXPR && code != EQ_EXPR)
3622 code = invert_tree_comparison (code,
3623 HONOR_NANS (TYPE_MODE (op_type)));
3624 if (code == ERROR_MARK)
3627 return build2 (code, type,
3628 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3635 return constant_boolean_node (integer_zerop (arg), type);
3637 case TRUTH_AND_EXPR:
3638 return build2 (TRUTH_OR_EXPR, type,
3639 invert_truthvalue (TREE_OPERAND (arg, 0)),
3640 invert_truthvalue (TREE_OPERAND (arg, 1)));
3643 return build2 (TRUTH_AND_EXPR, type,
3644 invert_truthvalue (TREE_OPERAND (arg, 0)),
3645 invert_truthvalue (TREE_OPERAND (arg, 1)));
3647 case TRUTH_XOR_EXPR:
3648 /* Here we can invert either operand. We invert the first operand
3649 unless the second operand is a TRUTH_NOT_EXPR in which case our
3650 result is the XOR of the first operand with the inside of the
3651 negation of the second operand. */
3653 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3654 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3655 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3657 return build2 (TRUTH_XOR_EXPR, type,
3658 invert_truthvalue (TREE_OPERAND (arg, 0)),
3659 TREE_OPERAND (arg, 1));
3661 case TRUTH_ANDIF_EXPR:
3662 return build2 (TRUTH_ORIF_EXPR, type,
3663 invert_truthvalue (TREE_OPERAND (arg, 0)),
3664 invert_truthvalue (TREE_OPERAND (arg, 1)));
3666 case TRUTH_ORIF_EXPR:
3667 return build2 (TRUTH_ANDIF_EXPR, type,
3668 invert_truthvalue (TREE_OPERAND (arg, 0)),
3669 invert_truthvalue (TREE_OPERAND (arg, 1)));
3671 case TRUTH_NOT_EXPR:
3672 return TREE_OPERAND (arg, 0);
3676 tree arg1 = TREE_OPERAND (arg, 1);
3677 tree arg2 = TREE_OPERAND (arg, 2);
3678 /* A COND_EXPR may have a throw as one operand, which
3679 then has void type. Just leave void operands
3681 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3682 VOID_TYPE_P (TREE_TYPE (arg1))
3683 ? arg1 : invert_truthvalue (arg1),
3684 VOID_TYPE_P (TREE_TYPE (arg2))
3685 ? arg2 : invert_truthvalue (arg2));
3689 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3690 invert_truthvalue (TREE_OPERAND (arg, 1)));
3692 case NON_LVALUE_EXPR:
3693 return invert_truthvalue (TREE_OPERAND (arg, 0));
3696 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3697 return build1 (TRUTH_NOT_EXPR, type, arg);
3701 return build1 (TREE_CODE (arg), type,
3702 invert_truthvalue (TREE_OPERAND (arg, 0)));
3705 if (!integer_onep (TREE_OPERAND (arg, 1)))
3707 return build2 (EQ_EXPR, type, arg,
3708 build_int_cst (type, 0));
3711 return build1 (TRUTH_NOT_EXPR, type, arg);
3713 case CLEANUP_POINT_EXPR:
3714 return build1 (CLEANUP_POINT_EXPR, type,
3715 invert_truthvalue (TREE_OPERAND (arg, 0)));
3724 /* Return a simplified tree node for the truth-negation of ARG. This
3725 never alters ARG itself. We assume that ARG is an operation that
3726 returns a truth value (0 or 1).
3728 FIXME: one would think we would fold the result, but it causes
3729 problems with the dominator optimizer. */
3732 invert_truthvalue (tree arg)
3736 if (TREE_CODE (arg) == ERROR_MARK)
3739 tem = fold_truth_not_expr (arg);
3741 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3746 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3747 operands are another bit-wise operation with a common input. If so,
3748 distribute the bit operations to save an operation and possibly two if
3749 constants are involved. For example, convert
3750 (A | B) & (A | C) into A | (B & C)
3751 Further simplification will occur if B and C are constants.
3753 If this optimization cannot be done, 0 will be returned. */
3756 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3761 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3762 || TREE_CODE (arg0) == code
3763 || (TREE_CODE (arg0) != BIT_AND_EXPR
3764 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3767 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3769 common = TREE_OPERAND (arg0, 0);
3770 left = TREE_OPERAND (arg0, 1);
3771 right = TREE_OPERAND (arg1, 1);
3773 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3775 common = TREE_OPERAND (arg0, 0);
3776 left = TREE_OPERAND (arg0, 1);
3777 right = TREE_OPERAND (arg1, 0);
3779 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3781 common = TREE_OPERAND (arg0, 1);
3782 left = TREE_OPERAND (arg0, 0);
3783 right = TREE_OPERAND (arg1, 1);
3785 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3787 common = TREE_OPERAND (arg0, 1);
3788 left = TREE_OPERAND (arg0, 0);
3789 right = TREE_OPERAND (arg1, 0);
3794 return fold_build2 (TREE_CODE (arg0), type, common,
3795 fold_build2 (code, type, left, right));
3798 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3799 with code CODE. This optimization is unsafe. */
3801 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3803 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3804 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3806 /* (A / C) +- (B / C) -> (A +- B) / C. */
3808 && operand_equal_p (TREE_OPERAND (arg0, 1),
3809 TREE_OPERAND (arg1, 1), 0))
3810 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3811 fold_build2 (code, type,
3812 TREE_OPERAND (arg0, 0),
3813 TREE_OPERAND (arg1, 0)),
3814 TREE_OPERAND (arg0, 1));
3816 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3817 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3818 TREE_OPERAND (arg1, 0), 0)
3819 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3820 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3822 REAL_VALUE_TYPE r0, r1;
3823 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3824 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3826 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3828 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3829 real_arithmetic (&r0, code, &r0, &r1);
3830 return fold_build2 (MULT_EXPR, type,
3831 TREE_OPERAND (arg0, 0),
3832 build_real (type, r0));
3838 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3839 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3842 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3849 tree size = TYPE_SIZE (TREE_TYPE (inner));
3850 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3851 || POINTER_TYPE_P (TREE_TYPE (inner)))
3852 && host_integerp (size, 0)
3853 && tree_low_cst (size, 0) == bitsize)
3854 return fold_convert (type, inner);
3857 result = build3 (BIT_FIELD_REF, type, inner,
3858 size_int (bitsize), bitsize_int (bitpos));
3860 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3865 /* Optimize a bit-field compare.
3867 There are two cases: First is a compare against a constant and the
3868 second is a comparison of two items where the fields are at the same
3869 bit position relative to the start of a chunk (byte, halfword, word)
3870 large enough to contain it. In these cases we can avoid the shift
3871 implicit in bitfield extractions.
3873 For constants, we emit a compare of the shifted constant with the
3874 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3875 compared. For two fields at the same position, we do the ANDs with the
3876 similar mask and compare the result of the ANDs.
3878 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3879 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3880 are the left and right operands of the comparison, respectively.
3882 If the optimization described above can be done, we return the resulting
3883 tree. Otherwise we return zero. */
3886 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3889 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3890 tree type = TREE_TYPE (lhs);
3891 tree signed_type, unsigned_type;
3892 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3893 enum machine_mode lmode, rmode, nmode;
3894 int lunsignedp, runsignedp;
3895 int lvolatilep = 0, rvolatilep = 0;
3896 tree linner, rinner = NULL_TREE;
3900 /* Get all the information about the extractions being done. If the bit size
3901 if the same as the size of the underlying object, we aren't doing an
3902 extraction at all and so can do nothing. We also don't want to
3903 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3904 then will no longer be able to replace it. */
3905 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3906 &lunsignedp, &lvolatilep, false);
3907 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3908 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3913 /* If this is not a constant, we can only do something if bit positions,
3914 sizes, and signedness are the same. */
3915 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3916 &runsignedp, &rvolatilep, false);
3918 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3919 || lunsignedp != runsignedp || offset != 0
3920 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3924 /* See if we can find a mode to refer to this field. We should be able to,
3925 but fail if we can't. */
3926 nmode = get_best_mode (lbitsize, lbitpos,
3927 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3928 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3929 TYPE_ALIGN (TREE_TYPE (rinner))),
3930 word_mode, lvolatilep || rvolatilep);
3931 if (nmode == VOIDmode)
3934 /* Set signed and unsigned types of the precision of this mode for the
3936 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3937 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3939 /* Compute the bit position and size for the new reference and our offset
3940 within it. If the new reference is the same size as the original, we
3941 won't optimize anything, so return zero. */
3942 nbitsize = GET_MODE_BITSIZE (nmode);
3943 nbitpos = lbitpos & ~ (nbitsize - 1);
3945 if (nbitsize == lbitsize)
3948 if (BYTES_BIG_ENDIAN)
3949 lbitpos = nbitsize - lbitsize - lbitpos;
3951 /* Make the mask to be used against the extracted field. */
3952 mask = build_int_cst_type (unsigned_type, -1);
3953 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3954 mask = const_binop (RSHIFT_EXPR, mask,
3955 size_int (nbitsize - lbitsize - lbitpos), 0);
3958 /* If not comparing with constant, just rework the comparison
3960 return fold_build2 (code, compare_type,
3961 fold_build2 (BIT_AND_EXPR, unsigned_type,
3962 make_bit_field_ref (linner,
3967 fold_build2 (BIT_AND_EXPR, unsigned_type,
3968 make_bit_field_ref (rinner,
3974 /* Otherwise, we are handling the constant case. See if the constant is too
3975 big for the field. Warn and return a tree of for 0 (false) if so. We do
3976 this not only for its own sake, but to avoid having to test for this
3977 error case below. If we didn't, we might generate wrong code.
3979 For unsigned fields, the constant shifted right by the field length should
3980 be all zero. For signed fields, the high-order bits should agree with
3985 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3986 fold_convert (unsigned_type, rhs),
3987 size_int (lbitsize), 0)))
3989 warning (0, "comparison is always %d due to width of bit-field",
3991 return constant_boolean_node (code == NE_EXPR, compare_type);
3996 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3997 size_int (lbitsize - 1), 0);
3998 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
4000 warning (0, "comparison is always %d due to width of bit-field",
4002 return constant_boolean_node (code == NE_EXPR, compare_type);
4006 /* Single-bit compares should always be against zero. */
4007 if (lbitsize == 1 && ! integer_zerop (rhs))
4009 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
4010 rhs = build_int_cst (type, 0);
4013 /* Make a new bitfield reference, shift the constant over the
4014 appropriate number of bits and mask it with the computed mask
4015 (in case this was a signed field). If we changed it, make a new one. */
4016 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
4019 TREE_SIDE_EFFECTS (lhs) = 1;
4020 TREE_THIS_VOLATILE (lhs) = 1;
4023 rhs = const_binop (BIT_AND_EXPR,
4024 const_binop (LSHIFT_EXPR,
4025 fold_convert (unsigned_type, rhs),
4026 size_int (lbitpos), 0),
4029 return build2 (code, compare_type,
4030 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
4034 /* Subroutine for fold_truthop: decode a field reference.
4036 If EXP is a comparison reference, we return the innermost reference.
4038 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
4039 set to the starting bit number.
4041 If the innermost field can be completely contained in a mode-sized
4042 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
4044 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
4045 otherwise it is not changed.
4047 *PUNSIGNEDP is set to the signedness of the field.
4049 *PMASK is set to the mask used. This is either contained in a
4050 BIT_AND_EXPR or derived from the width of the field.
4052 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
4054 Return 0 if this is not a component reference or is one that we can't
4055 do anything with. */
4058 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
4059 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
4060 int *punsignedp, int *pvolatilep,
4061 tree *pmask, tree *pand_mask)
4063 tree outer_type = 0;
4065 tree mask, inner, offset;
4067 unsigned int precision;
4069 /* All the optimizations using this function assume integer fields.
4070 There are problems with FP fields since the type_for_size call
4071 below can fail for, e.g., XFmode. */
4072 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
4075 /* We are interested in the bare arrangement of bits, so strip everything
4076 that doesn't affect the machine mode. However, record the type of the
4077 outermost expression if it may matter below. */
4078 if (TREE_CODE (exp) == NOP_EXPR
4079 || TREE_CODE (exp) == CONVERT_EXPR
4080 || TREE_CODE (exp) == NON_LVALUE_EXPR)
4081 outer_type = TREE_TYPE (exp);
4084 if (TREE_CODE (exp) == BIT_AND_EXPR)
4086 and_mask = TREE_OPERAND (exp, 1);
4087 exp = TREE_OPERAND (exp, 0);
4088 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
4089 if (TREE_CODE (and_mask) != INTEGER_CST)
4093 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
4094 punsignedp, pvolatilep, false);
4095 if ((inner == exp && and_mask == 0)
4096 || *pbitsize < 0 || offset != 0
4097 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
4100 /* If the number of bits in the reference is the same as the bitsize of
4101 the outer type, then the outer type gives the signedness. Otherwise
4102 (in case of a small bitfield) the signedness is unchanged. */
4103 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
4104 *punsignedp = TYPE_UNSIGNED (outer_type);
4106 /* Compute the mask to access the bitfield. */
4107 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
4108 precision = TYPE_PRECISION (unsigned_type);
4110 mask = build_int_cst_type (unsigned_type, -1);
4112 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4113 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4115 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
4117 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
4118 fold_convert (unsigned_type, and_mask), mask);
4121 *pand_mask = and_mask;
4125 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
4129 all_ones_mask_p (const_tree mask, int size)
4131 tree type = TREE_TYPE (mask);
4132 unsigned int precision = TYPE_PRECISION (type);
4135 tmask = build_int_cst_type (signed_type_for (type), -1);
4138 tree_int_cst_equal (mask,
4139 const_binop (RSHIFT_EXPR,
4140 const_binop (LSHIFT_EXPR, tmask,
4141 size_int (precision - size),
4143 size_int (precision - size), 0));
4146 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
4147 represents the sign bit of EXP's type. If EXP represents a sign
4148 or zero extension, also test VAL against the unextended type.
4149 The return value is the (sub)expression whose sign bit is VAL,
4150 or NULL_TREE otherwise. */
4153 sign_bit_p (tree exp, const_tree val)
4155 unsigned HOST_WIDE_INT mask_lo, lo;
4156 HOST_WIDE_INT mask_hi, hi;
4160 /* Tree EXP must have an integral type. */
4161 t = TREE_TYPE (exp);
4162 if (! INTEGRAL_TYPE_P (t))
4165 /* Tree VAL must be an integer constant. */
4166 if (TREE_CODE (val) != INTEGER_CST
4167 || TREE_OVERFLOW (val))
4170 width = TYPE_PRECISION (t);
4171 if (width > HOST_BITS_PER_WIDE_INT)
4173 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
4176 mask_hi = ((unsigned HOST_WIDE_INT) -1
4177 >> (2 * HOST_BITS_PER_WIDE_INT - width));
4183 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
4186 mask_lo = ((unsigned HOST_WIDE_INT) -1
4187 >> (HOST_BITS_PER_WIDE_INT - width));
4190 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
4191 treat VAL as if it were unsigned. */
4192 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
4193 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
4196 /* Handle extension from a narrower type. */
4197 if (TREE_CODE (exp) == NOP_EXPR
4198 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
4199 return sign_bit_p (TREE_OPERAND (exp, 0), val);
4204 /* Subroutine for fold_truthop: determine if an operand is simple enough
4205 to be evaluated unconditionally. */
4208 simple_operand_p (const_tree exp)
4210 /* Strip any conversions that don't change the machine mode. */
4213 return (CONSTANT_CLASS_P (exp)
4214 || TREE_CODE (exp) == SSA_NAME
4216 && ! TREE_ADDRESSABLE (exp)
4217 && ! TREE_THIS_VOLATILE (exp)
4218 && ! DECL_NONLOCAL (exp)
4219 /* Don't regard global variables as simple. They may be
4220 allocated in ways unknown to the compiler (shared memory,
4221 #pragma weak, etc). */
4222 && ! TREE_PUBLIC (exp)
4223 && ! DECL_EXTERNAL (exp)
4224 /* Loading a static variable is unduly expensive, but global
4225 registers aren't expensive. */
4226 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
4229 /* The following functions are subroutines to fold_range_test and allow it to
4230 try to change a logical combination of comparisons into a range test.
4233 X == 2 || X == 3 || X == 4 || X == 5
4237 (unsigned) (X - 2) <= 3
4239 We describe each set of comparisons as being either inside or outside
4240 a range, using a variable named like IN_P, and then describe the
4241 range with a lower and upper bound. If one of the bounds is omitted,
4242 it represents either the highest or lowest value of the type.
4244 In the comments below, we represent a range by two numbers in brackets
4245 preceded by a "+" to designate being inside that range, or a "-" to
4246 designate being outside that range, so the condition can be inverted by
4247 flipping the prefix. An omitted bound is represented by a "-". For
4248 example, "- [-, 10]" means being outside the range starting at the lowest
4249 possible value and ending at 10, in other words, being greater than 10.
4250 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4253 We set up things so that the missing bounds are handled in a consistent
4254 manner so neither a missing bound nor "true" and "false" need to be
4255 handled using a special case. */
4257 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4258 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4259 and UPPER1_P are nonzero if the respective argument is an upper bound
4260 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4261 must be specified for a comparison. ARG1 will be converted to ARG0's
4262 type if both are specified. */
4265 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
4266 tree arg1, int upper1_p)
4272 /* If neither arg represents infinity, do the normal operation.
4273 Else, if not a comparison, return infinity. Else handle the special
4274 comparison rules. Note that most of the cases below won't occur, but
4275 are handled for consistency. */
4277 if (arg0 != 0 && arg1 != 0)
4279 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
4280 arg0, fold_convert (TREE_TYPE (arg0), arg1));
4282 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
4285 if (TREE_CODE_CLASS (code) != tcc_comparison)
4288 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4289 for neither. In real maths, we cannot assume open ended ranges are
4290 the same. But, this is computer arithmetic, where numbers are finite.
4291 We can therefore make the transformation of any unbounded range with
4292 the value Z, Z being greater than any representable number. This permits
4293 us to treat unbounded ranges as equal. */
4294 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
4295 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
4299 result = sgn0 == sgn1;
4302 result = sgn0 != sgn1;
4305 result = sgn0 < sgn1;
4308 result = sgn0 <= sgn1;
4311 result = sgn0 > sgn1;
4314 result = sgn0 >= sgn1;
4320 return constant_boolean_node (result, type);
4323 /* Given EXP, a logical expression, set the range it is testing into
4324 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4325 actually being tested. *PLOW and *PHIGH will be made of the same
4326 type as the returned expression. If EXP is not a comparison, we
4327 will most likely not be returning a useful value and range. Set
4328 *STRICT_OVERFLOW_P to true if the return value is only valid
4329 because signed overflow is undefined; otherwise, do not change
4330 *STRICT_OVERFLOW_P. */
4333 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4334 bool *strict_overflow_p)
4336 enum tree_code code;
4337 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4338 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4340 tree low, high, n_low, n_high;
4342 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4343 and see if we can refine the range. Some of the cases below may not
4344 happen, but it doesn't seem worth worrying about this. We "continue"
4345 the outer loop when we've changed something; otherwise we "break"
4346 the switch, which will "break" the while. */
4349 low = high = build_int_cst (TREE_TYPE (exp), 0);
4353 code = TREE_CODE (exp);
4354 exp_type = TREE_TYPE (exp);
4356 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4358 if (TREE_OPERAND_LENGTH (exp) > 0)
4359 arg0 = TREE_OPERAND (exp, 0);
4360 if (TREE_CODE_CLASS (code) == tcc_comparison
4361 || TREE_CODE_CLASS (code) == tcc_unary
4362 || TREE_CODE_CLASS (code) == tcc_binary)
4363 arg0_type = TREE_TYPE (arg0);
4364 if (TREE_CODE_CLASS (code) == tcc_binary
4365 || TREE_CODE_CLASS (code) == tcc_comparison
4366 || (TREE_CODE_CLASS (code) == tcc_expression
4367 && TREE_OPERAND_LENGTH (exp) > 1))
4368 arg1 = TREE_OPERAND (exp, 1);
4373 case TRUTH_NOT_EXPR:
4374 in_p = ! in_p, exp = arg0;
4377 case EQ_EXPR: case NE_EXPR:
4378 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4379 /* We can only do something if the range is testing for zero
4380 and if the second operand is an integer constant. Note that
4381 saying something is "in" the range we make is done by
4382 complementing IN_P since it will set in the initial case of
4383 being not equal to zero; "out" is leaving it alone. */
4384 if (low == 0 || high == 0
4385 || ! integer_zerop (low) || ! integer_zerop (high)
4386 || TREE_CODE (arg1) != INTEGER_CST)
4391 case NE_EXPR: /* - [c, c] */
4394 case EQ_EXPR: /* + [c, c] */
4395 in_p = ! in_p, low = high = arg1;
4397 case GT_EXPR: /* - [-, c] */
4398 low = 0, high = arg1;
4400 case GE_EXPR: /* + [c, -] */
4401 in_p = ! in_p, low = arg1, high = 0;
4403 case LT_EXPR: /* - [c, -] */
4404 low = arg1, high = 0;
4406 case LE_EXPR: /* + [-, c] */
4407 in_p = ! in_p, low = 0, high = arg1;
4413 /* If this is an unsigned comparison, we also know that EXP is
4414 greater than or equal to zero. We base the range tests we make
4415 on that fact, so we record it here so we can parse existing
4416 range tests. We test arg0_type since often the return type
4417 of, e.g. EQ_EXPR, is boolean. */
4418 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4420 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4422 build_int_cst (arg0_type, 0),
4426 in_p = n_in_p, low = n_low, high = n_high;
4428 /* If the high bound is missing, but we have a nonzero low
4429 bound, reverse the range so it goes from zero to the low bound
4431 if (high == 0 && low && ! integer_zerop (low))
4434 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4435 integer_one_node, 0);
4436 low = build_int_cst (arg0_type, 0);
4444 /* (-x) IN [a,b] -> x in [-b, -a] */
4445 n_low = range_binop (MINUS_EXPR, exp_type,
4446 build_int_cst (exp_type, 0),
4448 n_high = range_binop (MINUS_EXPR, exp_type,
4449 build_int_cst (exp_type, 0),
4451 low = n_low, high = n_high;
4457 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4458 build_int_cst (exp_type, 1));
4461 case PLUS_EXPR: case MINUS_EXPR:
4462 if (TREE_CODE (arg1) != INTEGER_CST)
4465 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4466 move a constant to the other side. */
4467 if (!TYPE_UNSIGNED (arg0_type)
4468 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4471 /* If EXP is signed, any overflow in the computation is undefined,
4472 so we don't worry about it so long as our computations on
4473 the bounds don't overflow. For unsigned, overflow is defined
4474 and this is exactly the right thing. */
4475 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4476 arg0_type, low, 0, arg1, 0);
4477 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4478 arg0_type, high, 1, arg1, 0);
4479 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4480 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4483 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4484 *strict_overflow_p = true;
4486 /* Check for an unsigned range which has wrapped around the maximum
4487 value thus making n_high < n_low, and normalize it. */
4488 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4490 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4491 integer_one_node, 0);
4492 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4493 integer_one_node, 0);
4495 /* If the range is of the form +/- [ x+1, x ], we won't
4496 be able to normalize it. But then, it represents the
4497 whole range or the empty set, so make it
4499 if (tree_int_cst_equal (n_low, low)
4500 && tree_int_cst_equal (n_high, high))
4506 low = n_low, high = n_high;
4511 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
4512 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4515 if (! INTEGRAL_TYPE_P (arg0_type)
4516 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4517 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4520 n_low = low, n_high = high;
4523 n_low = fold_convert (arg0_type, n_low);
4526 n_high = fold_convert (arg0_type, n_high);
4529 /* If we're converting arg0 from an unsigned type, to exp,
4530 a signed type, we will be doing the comparison as unsigned.
4531 The tests above have already verified that LOW and HIGH
4534 So we have to ensure that we will handle large unsigned
4535 values the same way that the current signed bounds treat
4538 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4542 /* For fixed-point modes, we need to pass the saturating flag
4543 as the 2nd parameter. */
4544 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
4545 equiv_type = lang_hooks.types.type_for_mode
4546 (TYPE_MODE (arg0_type),
4547 TYPE_SATURATING (arg0_type));
4549 equiv_type = lang_hooks.types.type_for_mode
4550 (TYPE_MODE (arg0_type), 1);
4552 /* A range without an upper bound is, naturally, unbounded.
4553 Since convert would have cropped a very large value, use
4554 the max value for the destination type. */
4556 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4557 : TYPE_MAX_VALUE (arg0_type);
4559 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4560 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4561 fold_convert (arg0_type,
4563 build_int_cst (arg0_type, 1));
4565 /* If the low bound is specified, "and" the range with the
4566 range for which the original unsigned value will be
4570 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4571 1, n_low, n_high, 1,
4572 fold_convert (arg0_type,
4577 in_p = (n_in_p == in_p);
4581 /* Otherwise, "or" the range with the range of the input
4582 that will be interpreted as negative. */
4583 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4584 0, n_low, n_high, 1,
4585 fold_convert (arg0_type,
4590 in_p = (in_p != n_in_p);
4595 low = n_low, high = n_high;
4605 /* If EXP is a constant, we can evaluate whether this is true or false. */
4606 if (TREE_CODE (exp) == INTEGER_CST)
4608 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4610 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4616 *pin_p = in_p, *plow = low, *phigh = high;
4620 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4621 type, TYPE, return an expression to test if EXP is in (or out of, depending
4622 on IN_P) the range. Return 0 if the test couldn't be created. */
4625 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4627 tree etype = TREE_TYPE (exp);
4630 #ifdef HAVE_canonicalize_funcptr_for_compare
4631 /* Disable this optimization for function pointer expressions
4632 on targets that require function pointer canonicalization. */
4633 if (HAVE_canonicalize_funcptr_for_compare
4634 && TREE_CODE (etype) == POINTER_TYPE
4635 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4641 value = build_range_check (type, exp, 1, low, high);
4643 return invert_truthvalue (value);
4648 if (low == 0 && high == 0)
4649 return build_int_cst (type, 1);
4652 return fold_build2 (LE_EXPR, type, exp,
4653 fold_convert (etype, high));
4656 return fold_build2 (GE_EXPR, type, exp,
4657 fold_convert (etype, low));
4659 if (operand_equal_p (low, high, 0))
4660 return fold_build2 (EQ_EXPR, type, exp,
4661 fold_convert (etype, low));
4663 if (integer_zerop (low))
4665 if (! TYPE_UNSIGNED (etype))
4667 etype = unsigned_type_for (etype);
4668 high = fold_convert (etype, high);
4669 exp = fold_convert (etype, exp);
4671 return build_range_check (type, exp, 1, 0, high);
4674 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4675 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4677 unsigned HOST_WIDE_INT lo;
4681 prec = TYPE_PRECISION (etype);
4682 if (prec <= HOST_BITS_PER_WIDE_INT)
4685 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4689 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4690 lo = (unsigned HOST_WIDE_INT) -1;
4693 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4695 if (TYPE_UNSIGNED (etype))
4697 etype = signed_type_for (etype);
4698 exp = fold_convert (etype, exp);
4700 return fold_build2 (GT_EXPR, type, exp,
4701 build_int_cst (etype, 0));
4705 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4706 This requires wrap-around arithmetics for the type of the expression. */
4707 switch (TREE_CODE (etype))
4710 /* There is no requirement that LOW be within the range of ETYPE
4711 if the latter is a subtype. It must, however, be within the base
4712 type of ETYPE. So be sure we do the subtraction in that type. */
4713 if (TREE_TYPE (etype))
4714 etype = TREE_TYPE (etype);
4719 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4720 TYPE_UNSIGNED (etype));
4727 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4728 if (TREE_CODE (etype) == INTEGER_TYPE
4729 && !TYPE_OVERFLOW_WRAPS (etype))
4731 tree utype, minv, maxv;
4733 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4734 for the type in question, as we rely on this here. */
4735 utype = unsigned_type_for (etype);
4736 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4737 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4738 integer_one_node, 1);
4739 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4741 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4748 high = fold_convert (etype, high);
4749 low = fold_convert (etype, low);
4750 exp = fold_convert (etype, exp);
4752 value = const_binop (MINUS_EXPR, high, low, 0);
4755 if (POINTER_TYPE_P (etype))
4757 if (value != 0 && !TREE_OVERFLOW (value))
4759 low = fold_convert (sizetype, low);
4760 low = fold_build1 (NEGATE_EXPR, sizetype, low);
4761 return build_range_check (type,
4762 fold_build2 (POINTER_PLUS_EXPR, etype, exp, low),
4763 1, build_int_cst (etype, 0), value);
4768 if (value != 0 && !TREE_OVERFLOW (value))
4769 return build_range_check (type,
4770 fold_build2 (MINUS_EXPR, etype, exp, low),
4771 1, build_int_cst (etype, 0), value);
4776 /* Return the predecessor of VAL in its type, handling the infinite case. */
4779 range_predecessor (tree val)
4781 tree type = TREE_TYPE (val);
4783 if (INTEGRAL_TYPE_P (type)
4784 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4787 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4790 /* Return the successor of VAL in its type, handling the infinite case. */
4793 range_successor (tree val)
4795 tree type = TREE_TYPE (val);
4797 if (INTEGRAL_TYPE_P (type)
4798 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4801 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4804 /* Given two ranges, see if we can merge them into one. Return 1 if we
4805 can, 0 if we can't. Set the output range into the specified parameters. */
4808 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4809 tree high0, int in1_p, tree low1, tree high1)
4817 int lowequal = ((low0 == 0 && low1 == 0)
4818 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4819 low0, 0, low1, 0)));
4820 int highequal = ((high0 == 0 && high1 == 0)
4821 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4822 high0, 1, high1, 1)));
4824 /* Make range 0 be the range that starts first, or ends last if they
4825 start at the same value. Swap them if it isn't. */
4826 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4829 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4830 high1, 1, high0, 1))))
4832 temp = in0_p, in0_p = in1_p, in1_p = temp;
4833 tem = low0, low0 = low1, low1 = tem;
4834 tem = high0, high0 = high1, high1 = tem;
4837 /* Now flag two cases, whether the ranges are disjoint or whether the
4838 second range is totally subsumed in the first. Note that the tests
4839 below are simplified by the ones above. */
4840 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4841 high0, 1, low1, 0));
4842 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4843 high1, 1, high0, 1));
4845 /* We now have four cases, depending on whether we are including or
4846 excluding the two ranges. */
4849 /* If they don't overlap, the result is false. If the second range
4850 is a subset it is the result. Otherwise, the range is from the start
4851 of the second to the end of the first. */
4853 in_p = 0, low = high = 0;
4855 in_p = 1, low = low1, high = high1;
4857 in_p = 1, low = low1, high = high0;
4860 else if (in0_p && ! in1_p)
4862 /* If they don't overlap, the result is the first range. If they are
4863 equal, the result is false. If the second range is a subset of the
4864 first, and the ranges begin at the same place, we go from just after
4865 the end of the second range to the end of the first. If the second
4866 range is not a subset of the first, or if it is a subset and both
4867 ranges end at the same place, the range starts at the start of the
4868 first range and ends just before the second range.
4869 Otherwise, we can't describe this as a single range. */
4871 in_p = 1, low = low0, high = high0;
4872 else if (lowequal && highequal)
4873 in_p = 0, low = high = 0;
4874 else if (subset && lowequal)
4876 low = range_successor (high1);
4881 /* We are in the weird situation where high0 > high1 but
4882 high1 has no successor. Punt. */
4886 else if (! subset || highequal)
4889 high = range_predecessor (low1);
4893 /* low0 < low1 but low1 has no predecessor. Punt. */
4901 else if (! in0_p && in1_p)
4903 /* If they don't overlap, the result is the second range. If the second
4904 is a subset of the first, the result is false. Otherwise,
4905 the range starts just after the first range and ends at the
4906 end of the second. */
4908 in_p = 1, low = low1, high = high1;
4909 else if (subset || highequal)
4910 in_p = 0, low = high = 0;
4913 low = range_successor (high0);
4918 /* high1 > high0 but high0 has no successor. Punt. */
4926 /* The case where we are excluding both ranges. Here the complex case
4927 is if they don't overlap. In that case, the only time we have a
4928 range is if they are adjacent. If the second is a subset of the
4929 first, the result is the first. Otherwise, the range to exclude
4930 starts at the beginning of the first range and ends at the end of the
4934 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4935 range_successor (high0),
4937 in_p = 0, low = low0, high = high1;
4940 /* Canonicalize - [min, x] into - [-, x]. */
4941 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4942 switch (TREE_CODE (TREE_TYPE (low0)))
4945 if (TYPE_PRECISION (TREE_TYPE (low0))
4946 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4950 if (tree_int_cst_equal (low0,
4951 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4955 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4956 && integer_zerop (low0))
4963 /* Canonicalize - [x, max] into - [x, -]. */
4964 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4965 switch (TREE_CODE (TREE_TYPE (high1)))
4968 if (TYPE_PRECISION (TREE_TYPE (high1))
4969 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4973 if (tree_int_cst_equal (high1,
4974 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4978 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4979 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4981 integer_one_node, 1)))
4988 /* The ranges might be also adjacent between the maximum and
4989 minimum values of the given type. For
4990 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4991 return + [x + 1, y - 1]. */
4992 if (low0 == 0 && high1 == 0)
4994 low = range_successor (high0);
4995 high = range_predecessor (low1);
4996 if (low == 0 || high == 0)
5006 in_p = 0, low = low0, high = high0;
5008 in_p = 0, low = low0, high = high1;
5011 *pin_p = in_p, *plow = low, *phigh = high;
5016 /* Subroutine of fold, looking inside expressions of the form
5017 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
5018 of the COND_EXPR. This function is being used also to optimize
5019 A op B ? C : A, by reversing the comparison first.
5021 Return a folded expression whose code is not a COND_EXPR
5022 anymore, or NULL_TREE if no folding opportunity is found. */
5025 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
5027 enum tree_code comp_code = TREE_CODE (arg0);
5028 tree arg00 = TREE_OPERAND (arg0, 0);
5029 tree arg01 = TREE_OPERAND (arg0, 1);
5030 tree arg1_type = TREE_TYPE (arg1);
5036 /* If we have A op 0 ? A : -A, consider applying the following
5039 A == 0? A : -A same as -A
5040 A != 0? A : -A same as A
5041 A >= 0? A : -A same as abs (A)
5042 A > 0? A : -A same as abs (A)
5043 A <= 0? A : -A same as -abs (A)
5044 A < 0? A : -A same as -abs (A)
5046 None of these transformations work for modes with signed
5047 zeros. If A is +/-0, the first two transformations will
5048 change the sign of the result (from +0 to -0, or vice
5049 versa). The last four will fix the sign of the result,
5050 even though the original expressions could be positive or
5051 negative, depending on the sign of A.
5053 Note that all these transformations are correct if A is
5054 NaN, since the two alternatives (A and -A) are also NaNs. */
5055 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
5056 ? real_zerop (arg01)
5057 : integer_zerop (arg01))
5058 && ((TREE_CODE (arg2) == NEGATE_EXPR
5059 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
5060 /* In the case that A is of the form X-Y, '-A' (arg2) may
5061 have already been folded to Y-X, check for that. */
5062 || (TREE_CODE (arg1) == MINUS_EXPR
5063 && TREE_CODE (arg2) == MINUS_EXPR
5064 && operand_equal_p (TREE_OPERAND (arg1, 0),
5065 TREE_OPERAND (arg2, 1), 0)
5066 && operand_equal_p (TREE_OPERAND (arg1, 1),
5067 TREE_OPERAND (arg2, 0), 0))))
5072 tem = fold_convert (arg1_type, arg1);
5073 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
5076 return pedantic_non_lvalue (fold_convert (type, arg1));
5079 if (flag_trapping_math)
5084 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5085 arg1 = fold_convert (signed_type_for
5086 (TREE_TYPE (arg1)), arg1);
5087 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5088 return pedantic_non_lvalue (fold_convert (type, tem));
5091 if (flag_trapping_math)
5095 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5096 arg1 = fold_convert (signed_type_for
5097 (TREE_TYPE (arg1)), arg1);
5098 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5099 return negate_expr (fold_convert (type, tem));
5101 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5105 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
5106 A == 0 ? A : 0 is always 0 unless A is -0. Note that
5107 both transformations are correct when A is NaN: A != 0
5108 is then true, and A == 0 is false. */
5110 if (integer_zerop (arg01) && integer_zerop (arg2))
5112 if (comp_code == NE_EXPR)
5113 return pedantic_non_lvalue (fold_convert (type, arg1));
5114 else if (comp_code == EQ_EXPR)
5115 return build_int_cst (type, 0);
5118 /* Try some transformations of A op B ? A : B.
5120 A == B? A : B same as B
5121 A != B? A : B same as A
5122 A >= B? A : B same as max (A, B)
5123 A > B? A : B same as max (B, A)
5124 A <= B? A : B same as min (A, B)
5125 A < B? A : B same as min (B, A)
5127 As above, these transformations don't work in the presence
5128 of signed zeros. For example, if A and B are zeros of
5129 opposite sign, the first two transformations will change
5130 the sign of the result. In the last four, the original
5131 expressions give different results for (A=+0, B=-0) and
5132 (A=-0, B=+0), but the transformed expressions do not.
5134 The first two transformations are correct if either A or B
5135 is a NaN. In the first transformation, the condition will
5136 be false, and B will indeed be chosen. In the case of the
5137 second transformation, the condition A != B will be true,
5138 and A will be chosen.
5140 The conversions to max() and min() are not correct if B is
5141 a number and A is not. The conditions in the original
5142 expressions will be false, so all four give B. The min()
5143 and max() versions would give a NaN instead. */
5144 if (operand_equal_for_comparison_p (arg01, arg2, arg00)
5145 /* Avoid these transformations if the COND_EXPR may be used
5146 as an lvalue in the C++ front-end. PR c++/19199. */
5148 || (strcmp (lang_hooks.name, "GNU C++") != 0
5149 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
5150 || ! maybe_lvalue_p (arg1)
5151 || ! maybe_lvalue_p (arg2)))
5153 tree comp_op0 = arg00;
5154 tree comp_op1 = arg01;
5155 tree comp_type = TREE_TYPE (comp_op0);
5157 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
5158 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
5168 return pedantic_non_lvalue (fold_convert (type, arg2));
5170 return pedantic_non_lvalue (fold_convert (type, arg1));
5175 /* In C++ a ?: expression can be an lvalue, so put the
5176 operand which will be used if they are equal first
5177 so that we can convert this back to the
5178 corresponding COND_EXPR. */
5179 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5181 comp_op0 = fold_convert (comp_type, comp_op0);
5182 comp_op1 = fold_convert (comp_type, comp_op1);
5183 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
5184 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
5185 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
5186 return pedantic_non_lvalue (fold_convert (type, tem));
5193 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5195 comp_op0 = fold_convert (comp_type, comp_op0);
5196 comp_op1 = fold_convert (comp_type, comp_op1);
5197 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
5198 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
5199 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
5200 return pedantic_non_lvalue (fold_convert (type, tem));
5204 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5205 return pedantic_non_lvalue (fold_convert (type, arg2));
5208 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5209 return pedantic_non_lvalue (fold_convert (type, arg1));
5212 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5217 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
5218 we might still be able to simplify this. For example,
5219 if C1 is one less or one more than C2, this might have started
5220 out as a MIN or MAX and been transformed by this function.
5221 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
5223 if (INTEGRAL_TYPE_P (type)
5224 && TREE_CODE (arg01) == INTEGER_CST
5225 && TREE_CODE (arg2) == INTEGER_CST)
5229 /* We can replace A with C1 in this case. */
5230 arg1 = fold_convert (type, arg01);
5231 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
5234 /* If C1 is C2 + 1, this is min(A, C2). */
5235 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5237 && operand_equal_p (arg01,
5238 const_binop (PLUS_EXPR, arg2,
5239 build_int_cst (type, 1), 0),
5241 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5243 fold_convert (type, arg1),
5248 /* If C1 is C2 - 1, this is min(A, C2). */
5249 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5251 && operand_equal_p (arg01,
5252 const_binop (MINUS_EXPR, arg2,
5253 build_int_cst (type, 1), 0),
5255 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5257 fold_convert (type, arg1),
5262 /* If C1 is C2 - 1, this is max(A, C2). */
5263 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5265 && operand_equal_p (arg01,
5266 const_binop (MINUS_EXPR, arg2,
5267 build_int_cst (type, 1), 0),
5269 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5271 fold_convert (type, arg1),
5276 /* If C1 is C2 + 1, this is max(A, C2). */
5277 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5279 && operand_equal_p (arg01,
5280 const_binop (PLUS_EXPR, arg2,
5281 build_int_cst (type, 1), 0),
5283 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5285 fold_convert (type, arg1),
5299 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5300 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
5303 /* EXP is some logical combination of boolean tests. See if we can
5304 merge it into some range test. Return the new tree if so. */
5307 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
5309 int or_op = (code == TRUTH_ORIF_EXPR
5310 || code == TRUTH_OR_EXPR);
5311 int in0_p, in1_p, in_p;
5312 tree low0, low1, low, high0, high1, high;
5313 bool strict_overflow_p = false;
5314 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
5315 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
5317 const char * const warnmsg = G_("assuming signed overflow does not occur "
5318 "when simplifying range test");
5320 /* If this is an OR operation, invert both sides; we will invert
5321 again at the end. */
5323 in0_p = ! in0_p, in1_p = ! in1_p;
5325 /* If both expressions are the same, if we can merge the ranges, and we
5326 can build the range test, return it or it inverted. If one of the
5327 ranges is always true or always false, consider it to be the same
5328 expression as the other. */
5329 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
5330 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
5332 && 0 != (tem = (build_range_check (type,
5334 : rhs != 0 ? rhs : integer_zero_node,
5337 if (strict_overflow_p)
5338 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
5339 return or_op ? invert_truthvalue (tem) : tem;
5342 /* On machines where the branch cost is expensive, if this is a
5343 short-circuited branch and the underlying object on both sides
5344 is the same, make a non-short-circuit operation. */
5345 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5346 && lhs != 0 && rhs != 0
5347 && (code == TRUTH_ANDIF_EXPR
5348 || code == TRUTH_ORIF_EXPR)
5349 && operand_equal_p (lhs, rhs, 0))
5351 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5352 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5353 which cases we can't do this. */
5354 if (simple_operand_p (lhs))
5355 return build2 (code == TRUTH_ANDIF_EXPR
5356 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5359 else if (lang_hooks.decls.global_bindings_p () == 0
5360 && ! CONTAINS_PLACEHOLDER_P (lhs))
5362 tree common = save_expr (lhs);
5364 if (0 != (lhs = build_range_check (type, common,
5365 or_op ? ! in0_p : in0_p,
5367 && (0 != (rhs = build_range_check (type, common,
5368 or_op ? ! in1_p : in1_p,
5371 if (strict_overflow_p)
5372 fold_overflow_warning (warnmsg,
5373 WARN_STRICT_OVERFLOW_COMPARISON);
5374 return build2 (code == TRUTH_ANDIF_EXPR
5375 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5384 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5385 bit value. Arrange things so the extra bits will be set to zero if and
5386 only if C is signed-extended to its full width. If MASK is nonzero,
5387 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5390 unextend (tree c, int p, int unsignedp, tree mask)
5392 tree type = TREE_TYPE (c);
5393 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5396 if (p == modesize || unsignedp)
5399 /* We work by getting just the sign bit into the low-order bit, then
5400 into the high-order bit, then sign-extend. We then XOR that value
5402 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5403 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5405 /* We must use a signed type in order to get an arithmetic right shift.
5406 However, we must also avoid introducing accidental overflows, so that
5407 a subsequent call to integer_zerop will work. Hence we must
5408 do the type conversion here. At this point, the constant is either
5409 zero or one, and the conversion to a signed type can never overflow.
5410 We could get an overflow if this conversion is done anywhere else. */
5411 if (TYPE_UNSIGNED (type))
5412 temp = fold_convert (signed_type_for (type), temp);
5414 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5415 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5417 temp = const_binop (BIT_AND_EXPR, temp,
5418 fold_convert (TREE_TYPE (c), mask), 0);
5419 /* If necessary, convert the type back to match the type of C. */
5420 if (TYPE_UNSIGNED (type))
5421 temp = fold_convert (type, temp);
5423 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5426 /* Find ways of folding logical expressions of LHS and RHS:
5427 Try to merge two comparisons to the same innermost item.
5428 Look for range tests like "ch >= '0' && ch <= '9'".
5429 Look for combinations of simple terms on machines with expensive branches
5430 and evaluate the RHS unconditionally.
5432 For example, if we have p->a == 2 && p->b == 4 and we can make an
5433 object large enough to span both A and B, we can do this with a comparison
5434 against the object ANDed with the a mask.
5436 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5437 operations to do this with one comparison.
5439 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5440 function and the one above.
5442 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5443 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5445 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5448 We return the simplified tree or 0 if no optimization is possible. */
5451 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5453 /* If this is the "or" of two comparisons, we can do something if
5454 the comparisons are NE_EXPR. If this is the "and", we can do something
5455 if the comparisons are EQ_EXPR. I.e.,
5456 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5458 WANTED_CODE is this operation code. For single bit fields, we can
5459 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5460 comparison for one-bit fields. */
5462 enum tree_code wanted_code;
5463 enum tree_code lcode, rcode;
5464 tree ll_arg, lr_arg, rl_arg, rr_arg;
5465 tree ll_inner, lr_inner, rl_inner, rr_inner;
5466 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5467 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5468 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
5469 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
5470 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5471 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5472 enum machine_mode lnmode, rnmode;
5473 tree ll_mask, lr_mask, rl_mask, rr_mask;
5474 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5475 tree l_const, r_const;
5476 tree lntype, rntype, result;
5477 int first_bit, end_bit;
5479 tree orig_lhs = lhs, orig_rhs = rhs;
5480 enum tree_code orig_code = code;
5482 /* Start by getting the comparison codes. Fail if anything is volatile.
5483 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5484 it were surrounded with a NE_EXPR. */
5486 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5489 lcode = TREE_CODE (lhs);
5490 rcode = TREE_CODE (rhs);
5492 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5494 lhs = build2 (NE_EXPR, truth_type, lhs,
5495 build_int_cst (TREE_TYPE (lhs), 0));
5499 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5501 rhs = build2 (NE_EXPR, truth_type, rhs,
5502 build_int_cst (TREE_TYPE (rhs), 0));
5506 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5507 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5510 ll_arg = TREE_OPERAND (lhs, 0);
5511 lr_arg = TREE_OPERAND (lhs, 1);
5512 rl_arg = TREE_OPERAND (rhs, 0);
5513 rr_arg = TREE_OPERAND (rhs, 1);
5515 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5516 if (simple_operand_p (ll_arg)
5517 && simple_operand_p (lr_arg))
5520 if (operand_equal_p (ll_arg, rl_arg, 0)
5521 && operand_equal_p (lr_arg, rr_arg, 0))
5523 result = combine_comparisons (code, lcode, rcode,
5524 truth_type, ll_arg, lr_arg);
5528 else if (operand_equal_p (ll_arg, rr_arg, 0)
5529 && operand_equal_p (lr_arg, rl_arg, 0))
5531 result = combine_comparisons (code, lcode,
5532 swap_tree_comparison (rcode),
5533 truth_type, ll_arg, lr_arg);
5539 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5540 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5542 /* If the RHS can be evaluated unconditionally and its operands are
5543 simple, it wins to evaluate the RHS unconditionally on machines
5544 with expensive branches. In this case, this isn't a comparison
5545 that can be merged. Avoid doing this if the RHS is a floating-point
5546 comparison since those can trap. */
5548 if (BRANCH_COST >= 2
5549 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5550 && simple_operand_p (rl_arg)
5551 && simple_operand_p (rr_arg))
5553 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5554 if (code == TRUTH_OR_EXPR
5555 && lcode == NE_EXPR && integer_zerop (lr_arg)
5556 && rcode == NE_EXPR && integer_zerop (rr_arg)
5557 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5558 return build2 (NE_EXPR, truth_type,
5559 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5561 build_int_cst (TREE_TYPE (ll_arg), 0));
5563 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5564 if (code == TRUTH_AND_EXPR
5565 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5566 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5567 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
5568 return build2 (EQ_EXPR, truth_type,
5569 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5571 build_int_cst (TREE_TYPE (ll_arg), 0));
5573 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5575 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5576 return build2 (code, truth_type, lhs, rhs);
5581 /* See if the comparisons can be merged. Then get all the parameters for
5584 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5585 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5589 ll_inner = decode_field_reference (ll_arg,
5590 &ll_bitsize, &ll_bitpos, &ll_mode,
5591 &ll_unsignedp, &volatilep, &ll_mask,
5593 lr_inner = decode_field_reference (lr_arg,
5594 &lr_bitsize, &lr_bitpos, &lr_mode,
5595 &lr_unsignedp, &volatilep, &lr_mask,
5597 rl_inner = decode_field_reference (rl_arg,
5598 &rl_bitsize, &rl_bitpos, &rl_mode,
5599 &rl_unsignedp, &volatilep, &rl_mask,
5601 rr_inner = decode_field_reference (rr_arg,
5602 &rr_bitsize, &rr_bitpos, &rr_mode,
5603 &rr_unsignedp, &volatilep, &rr_mask,
5606 /* It must be true that the inner operation on the lhs of each
5607 comparison must be the same if we are to be able to do anything.
5608 Then see if we have constants. If not, the same must be true for
5610 if (volatilep || ll_inner == 0 || rl_inner == 0
5611 || ! operand_equal_p (ll_inner, rl_inner, 0))
5614 if (TREE_CODE (lr_arg) == INTEGER_CST
5615 && TREE_CODE (rr_arg) == INTEGER_CST)
5616 l_const = lr_arg, r_const = rr_arg;
5617 else if (lr_inner == 0 || rr_inner == 0
5618 || ! operand_equal_p (lr_inner, rr_inner, 0))
5621 l_const = r_const = 0;
5623 /* If either comparison code is not correct for our logical operation,
5624 fail. However, we can convert a one-bit comparison against zero into
5625 the opposite comparison against that bit being set in the field. */
5627 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5628 if (lcode != wanted_code)
5630 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5632 /* Make the left operand unsigned, since we are only interested
5633 in the value of one bit. Otherwise we are doing the wrong
5642 /* This is analogous to the code for l_const above. */
5643 if (rcode != wanted_code)
5645 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5654 /* See if we can find a mode that contains both fields being compared on
5655 the left. If we can't, fail. Otherwise, update all constants and masks
5656 to be relative to a field of that size. */
5657 first_bit = MIN (ll_bitpos, rl_bitpos);
5658 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5659 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5660 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5662 if (lnmode == VOIDmode)
5665 lnbitsize = GET_MODE_BITSIZE (lnmode);
5666 lnbitpos = first_bit & ~ (lnbitsize - 1);
5667 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5668 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5670 if (BYTES_BIG_ENDIAN)
5672 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5673 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5676 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5677 size_int (xll_bitpos), 0);
5678 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5679 size_int (xrl_bitpos), 0);
5683 l_const = fold_convert (lntype, l_const);
5684 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5685 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5686 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5687 fold_build1 (BIT_NOT_EXPR,
5691 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5693 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5698 r_const = fold_convert (lntype, r_const);
5699 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5700 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5701 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5702 fold_build1 (BIT_NOT_EXPR,
5706 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5708 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5712 /* If the right sides are not constant, do the same for it. Also,
5713 disallow this optimization if a size or signedness mismatch occurs
5714 between the left and right sides. */
5717 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
5718 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
5719 /* Make sure the two fields on the right
5720 correspond to the left without being swapped. */
5721 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
5724 first_bit = MIN (lr_bitpos, rr_bitpos);
5725 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
5726 rnmode = get_best_mode (end_bit - first_bit, first_bit,
5727 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
5729 if (rnmode == VOIDmode)
5732 rnbitsize = GET_MODE_BITSIZE (rnmode);
5733 rnbitpos = first_bit & ~ (rnbitsize - 1);
5734 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
5735 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
5737 if (BYTES_BIG_ENDIAN)
5739 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
5740 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
5743 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
5744 size_int (xlr_bitpos), 0);
5745 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
5746 size_int (xrr_bitpos), 0);
5748 /* Make a mask that corresponds to both fields being compared.
5749 Do this for both items being compared. If the operands are the
5750 same size and the bits being compared are in the same position
5751 then we can do this by masking both and comparing the masked
5753 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5754 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
5755 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
5757 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5758 ll_unsignedp || rl_unsignedp);
5759 if (! all_ones_mask_p (ll_mask, lnbitsize))
5760 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
5762 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
5763 lr_unsignedp || rr_unsignedp);
5764 if (! all_ones_mask_p (lr_mask, rnbitsize))
5765 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
5767 return build2 (wanted_code, truth_type, lhs, rhs);
5770 /* There is still another way we can do something: If both pairs of
5771 fields being compared are adjacent, we may be able to make a wider
5772 field containing them both.
5774 Note that we still must mask the lhs/rhs expressions. Furthermore,
5775 the mask must be shifted to account for the shift done by
5776 make_bit_field_ref. */
5777 if ((ll_bitsize + ll_bitpos == rl_bitpos
5778 && lr_bitsize + lr_bitpos == rr_bitpos)
5779 || (ll_bitpos == rl_bitpos + rl_bitsize
5780 && lr_bitpos == rr_bitpos + rr_bitsize))
5784 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
5785 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
5786 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
5787 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
5789 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
5790 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
5791 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
5792 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
5794 /* Convert to the smaller type before masking out unwanted bits. */
5796 if (lntype != rntype)
5798 if (lnbitsize > rnbitsize)
5800 lhs = fold_convert (rntype, lhs);
5801 ll_mask = fold_convert (rntype, ll_mask);
5804 else if (lnbitsize < rnbitsize)
5806 rhs = fold_convert (lntype, rhs);
5807 lr_mask = fold_convert (lntype, lr_mask);
5812 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
5813 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
5815 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
5816 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
5818 return build2 (wanted_code, truth_type, lhs, rhs);
5824 /* Handle the case of comparisons with constants. If there is something in
5825 common between the masks, those bits of the constants must be the same.
5826 If not, the condition is always false. Test for this to avoid generating
5827 incorrect code below. */
5828 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5829 if (! integer_zerop (result)
5830 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5831 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5833 if (wanted_code == NE_EXPR)
5835 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5836 return constant_boolean_node (true, truth_type);
5840 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5841 return constant_boolean_node (false, truth_type);
5845 /* Construct the expression we will return. First get the component
5846 reference we will make. Unless the mask is all ones the width of
5847 that field, perform the mask operation. Then compare with the
5849 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5850 ll_unsignedp || rl_unsignedp);
5852 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5853 if (! all_ones_mask_p (ll_mask, lnbitsize))
5854 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
5856 return build2 (wanted_code, truth_type, result,
5857 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
5860 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5864 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5867 enum tree_code op_code;
5868 tree comp_const = op1;
5870 int consts_equal, consts_lt;
5873 STRIP_SIGN_NOPS (arg0);
5875 op_code = TREE_CODE (arg0);
5876 minmax_const = TREE_OPERAND (arg0, 1);
5877 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5878 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5879 inner = TREE_OPERAND (arg0, 0);
5881 /* If something does not permit us to optimize, return the original tree. */
5882 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5883 || TREE_CODE (comp_const) != INTEGER_CST
5884 || TREE_OVERFLOW (comp_const)
5885 || TREE_CODE (minmax_const) != INTEGER_CST
5886 || TREE_OVERFLOW (minmax_const))
5889 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5890 and GT_EXPR, doing the rest with recursive calls using logical
5894 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5896 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5899 return invert_truthvalue (tem);
5905 fold_build2 (TRUTH_ORIF_EXPR, type,
5906 optimize_minmax_comparison
5907 (EQ_EXPR, type, arg0, comp_const),
5908 optimize_minmax_comparison
5909 (GT_EXPR, type, arg0, comp_const));
5912 if (op_code == MAX_EXPR && consts_equal)
5913 /* MAX (X, 0) == 0 -> X <= 0 */
5914 return fold_build2 (LE_EXPR, type, inner, comp_const);
5916 else if (op_code == MAX_EXPR && consts_lt)
5917 /* MAX (X, 0) == 5 -> X == 5 */
5918 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5920 else if (op_code == MAX_EXPR)
5921 /* MAX (X, 0) == -1 -> false */
5922 return omit_one_operand (type, integer_zero_node, inner);
5924 else if (consts_equal)
5925 /* MIN (X, 0) == 0 -> X >= 0 */
5926 return fold_build2 (GE_EXPR, type, inner, comp_const);
5929 /* MIN (X, 0) == 5 -> false */
5930 return omit_one_operand (type, integer_zero_node, inner);
5933 /* MIN (X, 0) == -1 -> X == -1 */
5934 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5937 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5938 /* MAX (X, 0) > 0 -> X > 0
5939 MAX (X, 0) > 5 -> X > 5 */
5940 return fold_build2 (GT_EXPR, type, inner, comp_const);
5942 else if (op_code == MAX_EXPR)
5943 /* MAX (X, 0) > -1 -> true */
5944 return omit_one_operand (type, integer_one_node, inner);
5946 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5947 /* MIN (X, 0) > 0 -> false
5948 MIN (X, 0) > 5 -> false */
5949 return omit_one_operand (type, integer_zero_node, inner);
5952 /* MIN (X, 0) > -1 -> X > -1 */
5953 return fold_build2 (GT_EXPR, type, inner, comp_const);
5960 /* T is an integer expression that is being multiplied, divided, or taken a
5961 modulus (CODE says which and what kind of divide or modulus) by a
5962 constant C. See if we can eliminate that operation by folding it with
5963 other operations already in T. WIDE_TYPE, if non-null, is a type that
5964 should be used for the computation if wider than our type.
5966 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5967 (X * 2) + (Y * 4). We must, however, be assured that either the original
5968 expression would not overflow or that overflow is undefined for the type
5969 in the language in question.
5971 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5972 the machine has a multiply-accumulate insn or that this is part of an
5973 addressing calculation.
5975 If we return a non-null expression, it is an equivalent form of the
5976 original computation, but need not be in the original type.
5978 We set *STRICT_OVERFLOW_P to true if the return values depends on
5979 signed overflow being undefined. Otherwise we do not change
5980 *STRICT_OVERFLOW_P. */
5983 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
5984 bool *strict_overflow_p)
5986 /* To avoid exponential search depth, refuse to allow recursion past
5987 three levels. Beyond that (1) it's highly unlikely that we'll find
5988 something interesting and (2) we've probably processed it before
5989 when we built the inner expression. */
5998 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
6005 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
6006 bool *strict_overflow_p)
6008 tree type = TREE_TYPE (t);
6009 enum tree_code tcode = TREE_CODE (t);
6010 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
6011 > GET_MODE_SIZE (TYPE_MODE (type)))
6012 ? wide_type : type);
6014 int same_p = tcode == code;
6015 tree op0 = NULL_TREE, op1 = NULL_TREE;
6016 bool sub_strict_overflow_p;
6018 /* Don't deal with constants of zero here; they confuse the code below. */
6019 if (integer_zerop (c))
6022 if (TREE_CODE_CLASS (tcode) == tcc_unary)
6023 op0 = TREE_OPERAND (t, 0);
6025 if (TREE_CODE_CLASS (tcode) == tcc_binary)
6026 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
6028 /* Note that we need not handle conditional operations here since fold
6029 already handles those cases. So just do arithmetic here. */
6033 /* For a constant, we can always simplify if we are a multiply
6034 or (for divide and modulus) if it is a multiple of our constant. */
6035 if (code == MULT_EXPR
6036 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
6037 return const_binop (code, fold_convert (ctype, t),
6038 fold_convert (ctype, c), 0);
6041 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
6042 /* If op0 is an expression ... */
6043 if ((COMPARISON_CLASS_P (op0)
6044 || UNARY_CLASS_P (op0)
6045 || BINARY_CLASS_P (op0)
6046 || VL_EXP_CLASS_P (op0)
6047 || EXPRESSION_CLASS_P (op0))
6048 /* ... and is unsigned, and its type is smaller than ctype,
6049 then we cannot pass through as widening. */
6050 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
6051 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
6052 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
6053 && (GET_MODE_SIZE (TYPE_MODE (ctype))
6054 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
6055 /* ... or this is a truncation (t is narrower than op0),
6056 then we cannot pass through this narrowing. */
6057 || (GET_MODE_SIZE (TYPE_MODE (type))
6058 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
6059 /* ... or signedness changes for division or modulus,
6060 then we cannot pass through this conversion. */
6061 || (code != MULT_EXPR
6062 && (TYPE_UNSIGNED (ctype)
6063 != TYPE_UNSIGNED (TREE_TYPE (op0))))
6064 /* ... or has undefined overflow while the converted to
6065 type has not, we cannot do the operation in the inner type
6066 as that would introduce undefined overflow. */
6067 || (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))
6068 && !TYPE_OVERFLOW_UNDEFINED (type))))
6071 /* Pass the constant down and see if we can make a simplification. If
6072 we can, replace this expression with the inner simplification for
6073 possible later conversion to our or some other type. */
6074 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
6075 && TREE_CODE (t2) == INTEGER_CST
6076 && !TREE_OVERFLOW (t2)
6077 && (0 != (t1 = extract_muldiv (op0, t2, code,
6079 ? ctype : NULL_TREE,
6080 strict_overflow_p))))
6085 /* If widening the type changes it from signed to unsigned, then we
6086 must avoid building ABS_EXPR itself as unsigned. */
6087 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
6089 tree cstype = (*signed_type_for) (ctype);
6090 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
6093 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
6094 return fold_convert (ctype, t1);
6098 /* If the constant is negative, we cannot simplify this. */
6099 if (tree_int_cst_sgn (c) == -1)
6103 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
6105 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
6108 case MIN_EXPR: case MAX_EXPR:
6109 /* If widening the type changes the signedness, then we can't perform
6110 this optimization as that changes the result. */
6111 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
6114 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
6115 sub_strict_overflow_p = false;
6116 if ((t1 = extract_muldiv (op0, c, code, wide_type,
6117 &sub_strict_overflow_p)) != 0
6118 && (t2 = extract_muldiv (op1, c, code, wide_type,
6119 &sub_strict_overflow_p)) != 0)
6121 if (tree_int_cst_sgn (c) < 0)
6122 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
6123 if (sub_strict_overflow_p)
6124 *strict_overflow_p = true;
6125 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6126 fold_convert (ctype, t2));
6130 case LSHIFT_EXPR: case RSHIFT_EXPR:
6131 /* If the second operand is constant, this is a multiplication
6132 or floor division, by a power of two, so we can treat it that
6133 way unless the multiplier or divisor overflows. Signed
6134 left-shift overflow is implementation-defined rather than
6135 undefined in C90, so do not convert signed left shift into
6137 if (TREE_CODE (op1) == INTEGER_CST
6138 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
6139 /* const_binop may not detect overflow correctly,
6140 so check for it explicitly here. */
6141 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
6142 && TREE_INT_CST_HIGH (op1) == 0
6143 && 0 != (t1 = fold_convert (ctype,
6144 const_binop (LSHIFT_EXPR,
6147 && !TREE_OVERFLOW (t1))
6148 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
6149 ? MULT_EXPR : FLOOR_DIV_EXPR,
6150 ctype, fold_convert (ctype, op0), t1),
6151 c, code, wide_type, strict_overflow_p);
6154 case PLUS_EXPR: case MINUS_EXPR:
6155 /* See if we can eliminate the operation on both sides. If we can, we
6156 can return a new PLUS or MINUS. If we can't, the only remaining
6157 cases where we can do anything are if the second operand is a
6159 sub_strict_overflow_p = false;
6160 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
6161 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
6162 if (t1 != 0 && t2 != 0
6163 && (code == MULT_EXPR
6164 /* If not multiplication, we can only do this if both operands
6165 are divisible by c. */
6166 || (multiple_of_p (ctype, op0, c)
6167 && multiple_of_p (ctype, op1, c))))
6169 if (sub_strict_overflow_p)
6170 *strict_overflow_p = true;
6171 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6172 fold_convert (ctype, t2));
6175 /* If this was a subtraction, negate OP1 and set it to be an addition.
6176 This simplifies the logic below. */
6177 if (tcode == MINUS_EXPR)
6178 tcode = PLUS_EXPR, op1 = negate_expr (op1);
6180 if (TREE_CODE (op1) != INTEGER_CST)
6183 /* If either OP1 or C are negative, this optimization is not safe for
6184 some of the division and remainder types while for others we need
6185 to change the code. */
6186 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
6188 if (code == CEIL_DIV_EXPR)
6189 code = FLOOR_DIV_EXPR;
6190 else if (code == FLOOR_DIV_EXPR)
6191 code = CEIL_DIV_EXPR;
6192 else if (code != MULT_EXPR
6193 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
6197 /* If it's a multiply or a division/modulus operation of a multiple
6198 of our constant, do the operation and verify it doesn't overflow. */
6199 if (code == MULT_EXPR
6200 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6202 op1 = const_binop (code, fold_convert (ctype, op1),
6203 fold_convert (ctype, c), 0);
6204 /* We allow the constant to overflow with wrapping semantics. */
6206 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
6212 /* If we have an unsigned type is not a sizetype, we cannot widen
6213 the operation since it will change the result if the original
6214 computation overflowed. */
6215 if (TYPE_UNSIGNED (ctype)
6216 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
6220 /* If we were able to eliminate our operation from the first side,
6221 apply our operation to the second side and reform the PLUS. */
6222 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
6223 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
6225 /* The last case is if we are a multiply. In that case, we can
6226 apply the distributive law to commute the multiply and addition
6227 if the multiplication of the constants doesn't overflow. */
6228 if (code == MULT_EXPR)
6229 return fold_build2 (tcode, ctype,
6230 fold_build2 (code, ctype,
6231 fold_convert (ctype, op0),
6232 fold_convert (ctype, c)),
6238 /* We have a special case here if we are doing something like
6239 (C * 8) % 4 since we know that's zero. */
6240 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
6241 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
6242 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
6243 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6244 return omit_one_operand (type, integer_zero_node, op0);
6246 /* ... fall through ... */
6248 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
6249 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
6250 /* If we can extract our operation from the LHS, do so and return a
6251 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
6252 do something only if the second operand is a constant. */
6254 && (t1 = extract_muldiv (op0, c, code, wide_type,
6255 strict_overflow_p)) != 0)
6256 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6257 fold_convert (ctype, op1));
6258 else if (tcode == MULT_EXPR && code == MULT_EXPR
6259 && (t1 = extract_muldiv (op1, c, code, wide_type,
6260 strict_overflow_p)) != 0)
6261 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6262 fold_convert (ctype, t1));
6263 else if (TREE_CODE (op1) != INTEGER_CST)
6266 /* If these are the same operation types, we can associate them
6267 assuming no overflow. */
6269 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
6270 fold_convert (ctype, c), 0))
6271 && !TREE_OVERFLOW (t1))
6272 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
6274 /* If these operations "cancel" each other, we have the main
6275 optimizations of this pass, which occur when either constant is a
6276 multiple of the other, in which case we replace this with either an
6277 operation or CODE or TCODE.
6279 If we have an unsigned type that is not a sizetype, we cannot do
6280 this since it will change the result if the original computation
6282 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
6283 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
6284 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
6285 || (tcode == MULT_EXPR
6286 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
6287 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
6288 && code != MULT_EXPR)))
6290 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6292 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6293 *strict_overflow_p = true;
6294 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6295 fold_convert (ctype,
6296 const_binop (TRUNC_DIV_EXPR,
6299 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
6301 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6302 *strict_overflow_p = true;
6303 return fold_build2 (code, ctype, fold_convert (ctype, op0),
6304 fold_convert (ctype,
6305 const_binop (TRUNC_DIV_EXPR,
6318 /* Return a node which has the indicated constant VALUE (either 0 or
6319 1), and is of the indicated TYPE. */
6322 constant_boolean_node (int value, tree type)
6324 if (type == integer_type_node)
6325 return value ? integer_one_node : integer_zero_node;
6326 else if (type == boolean_type_node)
6327 return value ? boolean_true_node : boolean_false_node;
6329 return build_int_cst (type, value);
6333 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6334 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6335 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6336 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6337 COND is the first argument to CODE; otherwise (as in the example
6338 given here), it is the second argument. TYPE is the type of the
6339 original expression. Return NULL_TREE if no simplification is
6343 fold_binary_op_with_conditional_arg (enum tree_code code,
6344 tree type, tree op0, tree op1,
6345 tree cond, tree arg, int cond_first_p)
6347 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6348 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6349 tree test, true_value, false_value;
6350 tree lhs = NULL_TREE;
6351 tree rhs = NULL_TREE;
6353 /* This transformation is only worthwhile if we don't have to wrap
6354 arg in a SAVE_EXPR, and the operation can be simplified on at least
6355 one of the branches once its pushed inside the COND_EXPR. */
6356 if (!TREE_CONSTANT (arg))
6359 if (TREE_CODE (cond) == COND_EXPR)
6361 test = TREE_OPERAND (cond, 0);
6362 true_value = TREE_OPERAND (cond, 1);
6363 false_value = TREE_OPERAND (cond, 2);
6364 /* If this operand throws an expression, then it does not make
6365 sense to try to perform a logical or arithmetic operation
6367 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6369 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6374 tree testtype = TREE_TYPE (cond);
6376 true_value = constant_boolean_node (true, testtype);
6377 false_value = constant_boolean_node (false, testtype);
6380 arg = fold_convert (arg_type, arg);
6383 true_value = fold_convert (cond_type, true_value);
6385 lhs = fold_build2 (code, type, true_value, arg);
6387 lhs = fold_build2 (code, type, arg, true_value);
6391 false_value = fold_convert (cond_type, false_value);
6393 rhs = fold_build2 (code, type, false_value, arg);
6395 rhs = fold_build2 (code, type, arg, false_value);
6398 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6399 return fold_convert (type, test);
6403 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6405 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6406 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6407 ADDEND is the same as X.
6409 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6410 and finite. The problematic cases are when X is zero, and its mode
6411 has signed zeros. In the case of rounding towards -infinity,
6412 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6413 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6416 fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
6418 if (!real_zerop (addend))
6421 /* Don't allow the fold with -fsignaling-nans. */
6422 if (HONOR_SNANS (TYPE_MODE (type)))
6425 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6426 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6429 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6430 if (TREE_CODE (addend) == REAL_CST
6431 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6434 /* The mode has signed zeros, and we have to honor their sign.
6435 In this situation, there is only one case we can return true for.
6436 X - 0 is the same as X unless rounding towards -infinity is
6438 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6441 /* Subroutine of fold() that checks comparisons of built-in math
6442 functions against real constants.
6444 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6445 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6446 is the type of the result and ARG0 and ARG1 are the operands of the
6447 comparison. ARG1 must be a TREE_REAL_CST.
6449 The function returns the constant folded tree if a simplification
6450 can be made, and NULL_TREE otherwise. */
6453 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6454 tree type, tree arg0, tree arg1)
6458 if (BUILTIN_SQRT_P (fcode))
6460 tree arg = CALL_EXPR_ARG (arg0, 0);
6461 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6463 c = TREE_REAL_CST (arg1);
6464 if (REAL_VALUE_NEGATIVE (c))
6466 /* sqrt(x) < y is always false, if y is negative. */
6467 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6468 return omit_one_operand (type, integer_zero_node, arg);
6470 /* sqrt(x) > y is always true, if y is negative and we
6471 don't care about NaNs, i.e. negative values of x. */
6472 if (code == NE_EXPR || !HONOR_NANS (mode))
6473 return omit_one_operand (type, integer_one_node, arg);
6475 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6476 return fold_build2 (GE_EXPR, type, arg,
6477 build_real (TREE_TYPE (arg), dconst0));
6479 else if (code == GT_EXPR || code == GE_EXPR)
6483 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6484 real_convert (&c2, mode, &c2);
6486 if (REAL_VALUE_ISINF (c2))
6488 /* sqrt(x) > y is x == +Inf, when y is very large. */
6489 if (HONOR_INFINITIES (mode))
6490 return fold_build2 (EQ_EXPR, type, arg,
6491 build_real (TREE_TYPE (arg), c2));
6493 /* sqrt(x) > y is always false, when y is very large
6494 and we don't care about infinities. */
6495 return omit_one_operand (type, integer_zero_node, arg);
6498 /* sqrt(x) > c is the same as x > c*c. */
6499 return fold_build2 (code, type, arg,
6500 build_real (TREE_TYPE (arg), c2));
6502 else if (code == LT_EXPR || code == LE_EXPR)
6506 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6507 real_convert (&c2, mode, &c2);
6509 if (REAL_VALUE_ISINF (c2))
6511 /* sqrt(x) < y is always true, when y is a very large
6512 value and we don't care about NaNs or Infinities. */
6513 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6514 return omit_one_operand (type, integer_one_node, arg);
6516 /* sqrt(x) < y is x != +Inf when y is very large and we
6517 don't care about NaNs. */
6518 if (! HONOR_NANS (mode))
6519 return fold_build2 (NE_EXPR, type, arg,
6520 build_real (TREE_TYPE (arg), c2));
6522 /* sqrt(x) < y is x >= 0 when y is very large and we
6523 don't care about Infinities. */
6524 if (! HONOR_INFINITIES (mode))
6525 return fold_build2 (GE_EXPR, type, arg,
6526 build_real (TREE_TYPE (arg), dconst0));
6528 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6529 if (lang_hooks.decls.global_bindings_p () != 0
6530 || CONTAINS_PLACEHOLDER_P (arg))
6533 arg = save_expr (arg);
6534 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6535 fold_build2 (GE_EXPR, type, arg,
6536 build_real (TREE_TYPE (arg),
6538 fold_build2 (NE_EXPR, type, arg,
6539 build_real (TREE_TYPE (arg),
6543 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6544 if (! HONOR_NANS (mode))
6545 return fold_build2 (code, type, arg,
6546 build_real (TREE_TYPE (arg), c2));
6548 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6549 if (lang_hooks.decls.global_bindings_p () == 0
6550 && ! CONTAINS_PLACEHOLDER_P (arg))
6552 arg = save_expr (arg);
6553 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6554 fold_build2 (GE_EXPR, type, arg,
6555 build_real (TREE_TYPE (arg),
6557 fold_build2 (code, type, arg,
6558 build_real (TREE_TYPE (arg),
6567 /* Subroutine of fold() that optimizes comparisons against Infinities,
6568 either +Inf or -Inf.
6570 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6571 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6572 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6574 The function returns the constant folded tree if a simplification
6575 can be made, and NULL_TREE otherwise. */
6578 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6580 enum machine_mode mode;
6581 REAL_VALUE_TYPE max;
6585 mode = TYPE_MODE (TREE_TYPE (arg0));
6587 /* For negative infinity swap the sense of the comparison. */
6588 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6590 code = swap_tree_comparison (code);
6595 /* x > +Inf is always false, if with ignore sNANs. */
6596 if (HONOR_SNANS (mode))
6598 return omit_one_operand (type, integer_zero_node, arg0);
6601 /* x <= +Inf is always true, if we don't case about NaNs. */
6602 if (! HONOR_NANS (mode))
6603 return omit_one_operand (type, integer_one_node, arg0);
6605 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6606 if (lang_hooks.decls.global_bindings_p () == 0
6607 && ! CONTAINS_PLACEHOLDER_P (arg0))
6609 arg0 = save_expr (arg0);
6610 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6616 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6617 real_maxval (&max, neg, mode);
6618 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6619 arg0, build_real (TREE_TYPE (arg0), max));
6622 /* x < +Inf is always equal to x <= DBL_MAX. */
6623 real_maxval (&max, neg, mode);
6624 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6625 arg0, build_real (TREE_TYPE (arg0), max));
6628 /* x != +Inf is always equal to !(x > DBL_MAX). */
6629 real_maxval (&max, neg, mode);
6630 if (! HONOR_NANS (mode))
6631 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6632 arg0, build_real (TREE_TYPE (arg0), max));
6634 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6635 arg0, build_real (TREE_TYPE (arg0), max));
6636 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6645 /* Subroutine of fold() that optimizes comparisons of a division by
6646 a nonzero integer constant against an integer constant, i.e.
6649 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6650 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6651 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6653 The function returns the constant folded tree if a simplification
6654 can be made, and NULL_TREE otherwise. */
6657 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6659 tree prod, tmp, hi, lo;
6660 tree arg00 = TREE_OPERAND (arg0, 0);
6661 tree arg01 = TREE_OPERAND (arg0, 1);
6662 unsigned HOST_WIDE_INT lpart;
6663 HOST_WIDE_INT hpart;
6664 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6668 /* We have to do this the hard way to detect unsigned overflow.
6669 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6670 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6671 TREE_INT_CST_HIGH (arg01),
6672 TREE_INT_CST_LOW (arg1),
6673 TREE_INT_CST_HIGH (arg1),
6674 &lpart, &hpart, unsigned_p);
6675 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6677 neg_overflow = false;
6681 tmp = int_const_binop (MINUS_EXPR, arg01,
6682 build_int_cst (TREE_TYPE (arg01), 1), 0);
6685 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6686 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6687 TREE_INT_CST_HIGH (prod),
6688 TREE_INT_CST_LOW (tmp),
6689 TREE_INT_CST_HIGH (tmp),
6690 &lpart, &hpart, unsigned_p);
6691 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6692 -1, overflow | TREE_OVERFLOW (prod));
6694 else if (tree_int_cst_sgn (arg01) >= 0)
6696 tmp = int_const_binop (MINUS_EXPR, arg01,
6697 build_int_cst (TREE_TYPE (arg01), 1), 0);
6698 switch (tree_int_cst_sgn (arg1))
6701 neg_overflow = true;
6702 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6707 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6712 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6722 /* A negative divisor reverses the relational operators. */
6723 code = swap_tree_comparison (code);
6725 tmp = int_const_binop (PLUS_EXPR, arg01,
6726 build_int_cst (TREE_TYPE (arg01), 1), 0);
6727 switch (tree_int_cst_sgn (arg1))
6730 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6735 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6740 neg_overflow = true;
6741 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6753 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6754 return omit_one_operand (type, integer_zero_node, arg00);
6755 if (TREE_OVERFLOW (hi))
6756 return fold_build2 (GE_EXPR, type, arg00, lo);
6757 if (TREE_OVERFLOW (lo))
6758 return fold_build2 (LE_EXPR, type, arg00, hi);
6759 return build_range_check (type, arg00, 1, lo, hi);
6762 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6763 return omit_one_operand (type, integer_one_node, arg00);
6764 if (TREE_OVERFLOW (hi))
6765 return fold_build2 (LT_EXPR, type, arg00, lo);
6766 if (TREE_OVERFLOW (lo))
6767 return fold_build2 (GT_EXPR, type, arg00, hi);
6768 return build_range_check (type, arg00, 0, lo, hi);
6771 if (TREE_OVERFLOW (lo))
6773 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6774 return omit_one_operand (type, tmp, arg00);
6776 return fold_build2 (LT_EXPR, type, arg00, lo);
6779 if (TREE_OVERFLOW (hi))
6781 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6782 return omit_one_operand (type, tmp, arg00);
6784 return fold_build2 (LE_EXPR, type, arg00, hi);
6787 if (TREE_OVERFLOW (hi))
6789 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6790 return omit_one_operand (type, tmp, arg00);
6792 return fold_build2 (GT_EXPR, type, arg00, hi);
6795 if (TREE_OVERFLOW (lo))
6797 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6798 return omit_one_operand (type, tmp, arg00);
6800 return fold_build2 (GE_EXPR, type, arg00, lo);
6810 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6811 equality/inequality test, then return a simplified form of the test
6812 using a sign testing. Otherwise return NULL. TYPE is the desired
6816 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6819 /* If this is testing a single bit, we can optimize the test. */
6820 if ((code == NE_EXPR || code == EQ_EXPR)
6821 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6822 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6824 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6825 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6826 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6828 if (arg00 != NULL_TREE
6829 /* This is only a win if casting to a signed type is cheap,
6830 i.e. when arg00's type is not a partial mode. */
6831 && TYPE_PRECISION (TREE_TYPE (arg00))
6832 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6834 tree stype = signed_type_for (TREE_TYPE (arg00));
6835 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6836 result_type, fold_convert (stype, arg00),
6837 build_int_cst (stype, 0));
6844 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6845 equality/inequality test, then return a simplified form of
6846 the test using shifts and logical operations. Otherwise return
6847 NULL. TYPE is the desired result type. */
6850 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6853 /* If this is testing a single bit, we can optimize the test. */
6854 if ((code == NE_EXPR || code == EQ_EXPR)
6855 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6856 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6858 tree inner = TREE_OPERAND (arg0, 0);
6859 tree type = TREE_TYPE (arg0);
6860 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6861 enum machine_mode operand_mode = TYPE_MODE (type);
6863 tree signed_type, unsigned_type, intermediate_type;
6866 /* First, see if we can fold the single bit test into a sign-bit
6868 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6873 /* Otherwise we have (A & C) != 0 where C is a single bit,
6874 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6875 Similarly for (A & C) == 0. */
6877 /* If INNER is a right shift of a constant and it plus BITNUM does
6878 not overflow, adjust BITNUM and INNER. */
6879 if (TREE_CODE (inner) == RSHIFT_EXPR
6880 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6881 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6882 && bitnum < TYPE_PRECISION (type)
6883 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6884 bitnum - TYPE_PRECISION (type)))
6886 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6887 inner = TREE_OPERAND (inner, 0);
6890 /* If we are going to be able to omit the AND below, we must do our
6891 operations as unsigned. If we must use the AND, we have a choice.
6892 Normally unsigned is faster, but for some machines signed is. */
6893 #ifdef LOAD_EXTEND_OP
6894 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6895 && !flag_syntax_only) ? 0 : 1;
6900 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6901 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6902 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6903 inner = fold_convert (intermediate_type, inner);
6906 inner = build2 (RSHIFT_EXPR, intermediate_type,
6907 inner, size_int (bitnum));
6909 one = build_int_cst (intermediate_type, 1);
6911 if (code == EQ_EXPR)
6912 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6914 /* Put the AND last so it can combine with more things. */
6915 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6917 /* Make sure to return the proper type. */
6918 inner = fold_convert (result_type, inner);
6925 /* Check whether we are allowed to reorder operands arg0 and arg1,
6926 such that the evaluation of arg1 occurs before arg0. */
6929 reorder_operands_p (const_tree arg0, const_tree arg1)
6931 if (! flag_evaluation_order)
6933 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6935 return ! TREE_SIDE_EFFECTS (arg0)
6936 && ! TREE_SIDE_EFFECTS (arg1);
6939 /* Test whether it is preferable two swap two operands, ARG0 and
6940 ARG1, for example because ARG0 is an integer constant and ARG1
6941 isn't. If REORDER is true, only recommend swapping if we can
6942 evaluate the operands in reverse order. */
6945 tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
6947 STRIP_SIGN_NOPS (arg0);
6948 STRIP_SIGN_NOPS (arg1);
6950 if (TREE_CODE (arg1) == INTEGER_CST)
6952 if (TREE_CODE (arg0) == INTEGER_CST)
6955 if (TREE_CODE (arg1) == REAL_CST)
6957 if (TREE_CODE (arg0) == REAL_CST)
6960 if (TREE_CODE (arg1) == FIXED_CST)
6962 if (TREE_CODE (arg0) == FIXED_CST)
6965 if (TREE_CODE (arg1) == COMPLEX_CST)
6967 if (TREE_CODE (arg0) == COMPLEX_CST)
6970 if (TREE_CONSTANT (arg1))
6972 if (TREE_CONSTANT (arg0))
6978 if (reorder && flag_evaluation_order
6979 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6982 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6983 for commutative and comparison operators. Ensuring a canonical
6984 form allows the optimizers to find additional redundancies without
6985 having to explicitly check for both orderings. */
6986 if (TREE_CODE (arg0) == SSA_NAME
6987 && TREE_CODE (arg1) == SSA_NAME
6988 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6991 /* Put SSA_NAMEs last. */
6992 if (TREE_CODE (arg1) == SSA_NAME)
6994 if (TREE_CODE (arg0) == SSA_NAME)
6997 /* Put variables last. */
7006 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
7007 ARG0 is extended to a wider type. */
7010 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
7012 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
7014 tree shorter_type, outer_type;
7018 if (arg0_unw == arg0)
7020 shorter_type = TREE_TYPE (arg0_unw);
7022 #ifdef HAVE_canonicalize_funcptr_for_compare
7023 /* Disable this optimization if we're casting a function pointer
7024 type on targets that require function pointer canonicalization. */
7025 if (HAVE_canonicalize_funcptr_for_compare
7026 && TREE_CODE (shorter_type) == POINTER_TYPE
7027 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
7031 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
7034 arg1_unw = get_unwidened (arg1, shorter_type);
7036 /* If possible, express the comparison in the shorter mode. */
7037 if ((code == EQ_EXPR || code == NE_EXPR
7038 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
7039 && (TREE_TYPE (arg1_unw) == shorter_type
7040 || (TREE_CODE (arg1_unw) == INTEGER_CST
7041 && (TREE_CODE (shorter_type) == INTEGER_TYPE
7042 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
7043 && int_fits_type_p (arg1_unw, shorter_type))))
7044 return fold_build2 (code, type, arg0_unw,
7045 fold_convert (shorter_type, arg1_unw));
7047 if (TREE_CODE (arg1_unw) != INTEGER_CST
7048 || TREE_CODE (shorter_type) != INTEGER_TYPE
7049 || !int_fits_type_p (arg1_unw, shorter_type))
7052 /* If we are comparing with the integer that does not fit into the range
7053 of the shorter type, the result is known. */
7054 outer_type = TREE_TYPE (arg1_unw);
7055 min = lower_bound_in_type (outer_type, shorter_type);
7056 max = upper_bound_in_type (outer_type, shorter_type);
7058 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7060 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7067 return omit_one_operand (type, integer_zero_node, arg0);
7072 return omit_one_operand (type, integer_one_node, arg0);
7078 return omit_one_operand (type, integer_one_node, arg0);
7080 return omit_one_operand (type, integer_zero_node, arg0);
7085 return omit_one_operand (type, integer_zero_node, arg0);
7087 return omit_one_operand (type, integer_one_node, arg0);
7096 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
7097 ARG0 just the signedness is changed. */
7100 fold_sign_changed_comparison (enum tree_code code, tree type,
7101 tree arg0, tree arg1)
7104 tree inner_type, outer_type;
7106 if (TREE_CODE (arg0) != NOP_EXPR
7107 && TREE_CODE (arg0) != CONVERT_EXPR)
7110 outer_type = TREE_TYPE (arg0);
7111 arg0_inner = TREE_OPERAND (arg0, 0);
7112 inner_type = TREE_TYPE (arg0_inner);
7114 #ifdef HAVE_canonicalize_funcptr_for_compare
7115 /* Disable this optimization if we're casting a function pointer
7116 type on targets that require function pointer canonicalization. */
7117 if (HAVE_canonicalize_funcptr_for_compare
7118 && TREE_CODE (inner_type) == POINTER_TYPE
7119 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
7123 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
7126 if (TREE_CODE (arg1) != INTEGER_CST
7127 && !((TREE_CODE (arg1) == NOP_EXPR
7128 || TREE_CODE (arg1) == CONVERT_EXPR)
7129 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
7132 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
7137 if (TREE_CODE (arg1) == INTEGER_CST)
7138 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
7139 TREE_INT_CST_HIGH (arg1), 0,
7140 TREE_OVERFLOW (arg1));
7142 arg1 = fold_convert (inner_type, arg1);
7144 return fold_build2 (code, type, arg0_inner, arg1);
7147 /* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
7148 step of the array. Reconstructs s and delta in the case of s * delta
7149 being an integer constant (and thus already folded).
7150 ADDR is the address. MULT is the multiplicative expression.
7151 If the function succeeds, the new address expression is returned. Otherwise
7152 NULL_TREE is returned. */
7155 try_move_mult_to_index (tree addr, tree op1)
7157 tree s, delta, step;
7158 tree ref = TREE_OPERAND (addr, 0), pref;
7163 /* Strip the nops that might be added when converting op1 to sizetype. */
7166 /* Canonicalize op1 into a possibly non-constant delta
7167 and an INTEGER_CST s. */
7168 if (TREE_CODE (op1) == MULT_EXPR)
7170 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
7175 if (TREE_CODE (arg0) == INTEGER_CST)
7180 else if (TREE_CODE (arg1) == INTEGER_CST)
7188 else if (TREE_CODE (op1) == INTEGER_CST)
7195 /* Simulate we are delta * 1. */
7197 s = integer_one_node;
7200 for (;; ref = TREE_OPERAND (ref, 0))
7202 if (TREE_CODE (ref) == ARRAY_REF)
7204 /* Remember if this was a multi-dimensional array. */
7205 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
7208 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
7212 step = array_ref_element_size (ref);
7213 if (TREE_CODE (step) != INTEGER_CST)
7218 if (! tree_int_cst_equal (step, s))
7223 /* Try if delta is a multiple of step. */
7224 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
7230 /* Only fold here if we can verify we do not overflow one
7231 dimension of a multi-dimensional array. */
7236 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
7237 || !INTEGRAL_TYPE_P (itype)
7238 || !TYPE_MAX_VALUE (itype)
7239 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
7242 tmp = fold_binary (PLUS_EXPR, itype,
7243 fold_convert (itype,
7244 TREE_OPERAND (ref, 1)),
7245 fold_convert (itype, delta));
7247 || TREE_CODE (tmp) != INTEGER_CST
7248 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
7257 if (!handled_component_p (ref))
7261 /* We found the suitable array reference. So copy everything up to it,
7262 and replace the index. */
7264 pref = TREE_OPERAND (addr, 0);
7265 ret = copy_node (pref);
7270 pref = TREE_OPERAND (pref, 0);
7271 TREE_OPERAND (pos, 0) = copy_node (pref);
7272 pos = TREE_OPERAND (pos, 0);
7275 TREE_OPERAND (pos, 1) = fold_build2 (PLUS_EXPR, itype,
7276 fold_convert (itype,
7277 TREE_OPERAND (pos, 1)),
7278 fold_convert (itype, delta));
7280 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
7284 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
7285 means A >= Y && A != MAX, but in this case we know that
7286 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
7289 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
7291 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
7293 if (TREE_CODE (bound) == LT_EXPR)
7294 a = TREE_OPERAND (bound, 0);
7295 else if (TREE_CODE (bound) == GT_EXPR)
7296 a = TREE_OPERAND (bound, 1);
7300 typea = TREE_TYPE (a);
7301 if (!INTEGRAL_TYPE_P (typea)
7302 && !POINTER_TYPE_P (typea))
7305 if (TREE_CODE (ineq) == LT_EXPR)
7307 a1 = TREE_OPERAND (ineq, 1);
7308 y = TREE_OPERAND (ineq, 0);
7310 else if (TREE_CODE (ineq) == GT_EXPR)
7312 a1 = TREE_OPERAND (ineq, 0);
7313 y = TREE_OPERAND (ineq, 1);
7318 if (TREE_TYPE (a1) != typea)
7321 if (POINTER_TYPE_P (typea))
7323 /* Convert the pointer types into integer before taking the difference. */
7324 tree ta = fold_convert (ssizetype, a);
7325 tree ta1 = fold_convert (ssizetype, a1);
7326 diff = fold_binary (MINUS_EXPR, ssizetype, ta1, ta);
7329 diff = fold_binary (MINUS_EXPR, typea, a1, a);
7331 if (!diff || !integer_onep (diff))
7334 return fold_build2 (GE_EXPR, type, a, y);
7337 /* Fold a sum or difference of at least one multiplication.
7338 Returns the folded tree or NULL if no simplification could be made. */
7341 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7343 tree arg00, arg01, arg10, arg11;
7344 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7346 /* (A * C) +- (B * C) -> (A+-B) * C.
7347 (A * C) +- A -> A * (C+-1).
7348 We are most concerned about the case where C is a constant,
7349 but other combinations show up during loop reduction. Since
7350 it is not difficult, try all four possibilities. */
7352 if (TREE_CODE (arg0) == MULT_EXPR)
7354 arg00 = TREE_OPERAND (arg0, 0);
7355 arg01 = TREE_OPERAND (arg0, 1);
7357 else if (TREE_CODE (arg0) == INTEGER_CST)
7359 arg00 = build_one_cst (type);
7364 /* We cannot generate constant 1 for fract. */
7365 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7368 arg01 = build_one_cst (type);
7370 if (TREE_CODE (arg1) == MULT_EXPR)
7372 arg10 = TREE_OPERAND (arg1, 0);
7373 arg11 = TREE_OPERAND (arg1, 1);
7375 else if (TREE_CODE (arg1) == INTEGER_CST)
7377 arg10 = build_one_cst (type);
7382 /* We cannot generate constant 1 for fract. */
7383 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7386 arg11 = build_one_cst (type);
7390 if (operand_equal_p (arg01, arg11, 0))
7391 same = arg01, alt0 = arg00, alt1 = arg10;
7392 else if (operand_equal_p (arg00, arg10, 0))
7393 same = arg00, alt0 = arg01, alt1 = arg11;
7394 else if (operand_equal_p (arg00, arg11, 0))
7395 same = arg00, alt0 = arg01, alt1 = arg10;
7396 else if (operand_equal_p (arg01, arg10, 0))
7397 same = arg01, alt0 = arg00, alt1 = arg11;
7399 /* No identical multiplicands; see if we can find a common
7400 power-of-two factor in non-power-of-two multiplies. This
7401 can help in multi-dimensional array access. */
7402 else if (host_integerp (arg01, 0)
7403 && host_integerp (arg11, 0))
7405 HOST_WIDE_INT int01, int11, tmp;
7408 int01 = TREE_INT_CST_LOW (arg01);
7409 int11 = TREE_INT_CST_LOW (arg11);
7411 /* Move min of absolute values to int11. */
7412 if ((int01 >= 0 ? int01 : -int01)
7413 < (int11 >= 0 ? int11 : -int11))
7415 tmp = int01, int01 = int11, int11 = tmp;
7416 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7423 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
7425 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7426 build_int_cst (TREE_TYPE (arg00),
7431 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7436 return fold_build2 (MULT_EXPR, type,
7437 fold_build2 (code, type,
7438 fold_convert (type, alt0),
7439 fold_convert (type, alt1)),
7440 fold_convert (type, same));
7445 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7446 specified by EXPR into the buffer PTR of length LEN bytes.
7447 Return the number of bytes placed in the buffer, or zero
7451 native_encode_int (const_tree expr, unsigned char *ptr, int len)
7453 tree type = TREE_TYPE (expr);
7454 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7455 int byte, offset, word, words;
7456 unsigned char value;
7458 if (total_bytes > len)
7460 words = total_bytes / UNITS_PER_WORD;
7462 for (byte = 0; byte < total_bytes; byte++)
7464 int bitpos = byte * BITS_PER_UNIT;
7465 if (bitpos < HOST_BITS_PER_WIDE_INT)
7466 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7468 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7469 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7471 if (total_bytes > UNITS_PER_WORD)
7473 word = byte / UNITS_PER_WORD;
7474 if (WORDS_BIG_ENDIAN)
7475 word = (words - 1) - word;
7476 offset = word * UNITS_PER_WORD;
7477 if (BYTES_BIG_ENDIAN)
7478 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7480 offset += byte % UNITS_PER_WORD;
7483 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7484 ptr[offset] = value;
7490 /* Subroutine of native_encode_expr. Encode the REAL_CST
7491 specified by EXPR into the buffer PTR of length LEN bytes.
7492 Return the number of bytes placed in the buffer, or zero
7496 native_encode_real (const_tree expr, unsigned char *ptr, int len)
7498 tree type = TREE_TYPE (expr);
7499 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7500 int byte, offset, word, words, bitpos;
7501 unsigned char value;
7503 /* There are always 32 bits in each long, no matter the size of
7504 the hosts long. We handle floating point representations with
7508 if (total_bytes > len)
7510 words = 32 / UNITS_PER_WORD;
7512 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7514 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7515 bitpos += BITS_PER_UNIT)
7517 byte = (bitpos / BITS_PER_UNIT) & 3;
7518 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7520 if (UNITS_PER_WORD < 4)
7522 word = byte / UNITS_PER_WORD;
7523 if (WORDS_BIG_ENDIAN)
7524 word = (words - 1) - word;
7525 offset = word * UNITS_PER_WORD;
7526 if (BYTES_BIG_ENDIAN)
7527 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7529 offset += byte % UNITS_PER_WORD;
7532 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7533 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7538 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7539 specified by EXPR into the buffer PTR of length LEN bytes.
7540 Return the number of bytes placed in the buffer, or zero
7544 native_encode_complex (const_tree expr, unsigned char *ptr, int len)
7549 part = TREE_REALPART (expr);
7550 rsize = native_encode_expr (part, ptr, len);
7553 part = TREE_IMAGPART (expr);
7554 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7557 return rsize + isize;
7561 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7562 specified by EXPR into the buffer PTR of length LEN bytes.
7563 Return the number of bytes placed in the buffer, or zero
7567 native_encode_vector (const_tree expr, unsigned char *ptr, int len)
7569 int i, size, offset, count;
7570 tree itype, elem, elements;
7573 elements = TREE_VECTOR_CST_ELTS (expr);
7574 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7575 itype = TREE_TYPE (TREE_TYPE (expr));
7576 size = GET_MODE_SIZE (TYPE_MODE (itype));
7577 for (i = 0; i < count; i++)
7581 elem = TREE_VALUE (elements);
7582 elements = TREE_CHAIN (elements);
7589 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7594 if (offset + size > len)
7596 memset (ptr+offset, 0, size);
7604 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7605 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7606 buffer PTR of length LEN bytes. Return the number of bytes
7607 placed in the buffer, or zero upon failure. */
7610 native_encode_expr (const_tree expr, unsigned char *ptr, int len)
7612 switch (TREE_CODE (expr))
7615 return native_encode_int (expr, ptr, len);
7618 return native_encode_real (expr, ptr, len);
7621 return native_encode_complex (expr, ptr, len);
7624 return native_encode_vector (expr, ptr, len);
7632 /* Subroutine of native_interpret_expr. Interpret the contents of
7633 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7634 If the buffer cannot be interpreted, return NULL_TREE. */
7637 native_interpret_int (tree type, const unsigned char *ptr, int len)
7639 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7640 int byte, offset, word, words;
7641 unsigned char value;
7642 unsigned int HOST_WIDE_INT lo = 0;
7643 HOST_WIDE_INT hi = 0;
7645 if (total_bytes > len)
7647 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7649 words = total_bytes / UNITS_PER_WORD;
7651 for (byte = 0; byte < total_bytes; byte++)
7653 int bitpos = byte * BITS_PER_UNIT;
7654 if (total_bytes > UNITS_PER_WORD)
7656 word = byte / UNITS_PER_WORD;
7657 if (WORDS_BIG_ENDIAN)
7658 word = (words - 1) - word;
7659 offset = word * UNITS_PER_WORD;
7660 if (BYTES_BIG_ENDIAN)
7661 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7663 offset += byte % UNITS_PER_WORD;
7666 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7667 value = ptr[offset];
7669 if (bitpos < HOST_BITS_PER_WIDE_INT)
7670 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7672 hi |= (unsigned HOST_WIDE_INT) value
7673 << (bitpos - HOST_BITS_PER_WIDE_INT);
7676 return build_int_cst_wide_type (type, lo, hi);
7680 /* Subroutine of native_interpret_expr. Interpret the contents of
7681 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7682 If the buffer cannot be interpreted, return NULL_TREE. */
7685 native_interpret_real (tree type, const unsigned char *ptr, int len)
7687 enum machine_mode mode = TYPE_MODE (type);
7688 int total_bytes = GET_MODE_SIZE (mode);
7689 int byte, offset, word, words, bitpos;
7690 unsigned char value;
7691 /* There are always 32 bits in each long, no matter the size of
7692 the hosts long. We handle floating point representations with
7697 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7698 if (total_bytes > len || total_bytes > 24)
7700 words = 32 / UNITS_PER_WORD;
7702 memset (tmp, 0, sizeof (tmp));
7703 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7704 bitpos += BITS_PER_UNIT)
7706 byte = (bitpos / BITS_PER_UNIT) & 3;
7707 if (UNITS_PER_WORD < 4)
7709 word = byte / UNITS_PER_WORD;
7710 if (WORDS_BIG_ENDIAN)
7711 word = (words - 1) - word;
7712 offset = word * UNITS_PER_WORD;
7713 if (BYTES_BIG_ENDIAN)
7714 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7716 offset += byte % UNITS_PER_WORD;
7719 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7720 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7722 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7725 real_from_target (&r, tmp, mode);
7726 return build_real (type, r);
7730 /* Subroutine of native_interpret_expr. Interpret the contents of
7731 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7732 If the buffer cannot be interpreted, return NULL_TREE. */
7735 native_interpret_complex (tree type, const unsigned char *ptr, int len)
7737 tree etype, rpart, ipart;
7740 etype = TREE_TYPE (type);
7741 size = GET_MODE_SIZE (TYPE_MODE (etype));
7744 rpart = native_interpret_expr (etype, ptr, size);
7747 ipart = native_interpret_expr (etype, ptr+size, size);
7750 return build_complex (type, rpart, ipart);
7754 /* Subroutine of native_interpret_expr. Interpret the contents of
7755 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7756 If the buffer cannot be interpreted, return NULL_TREE. */
7759 native_interpret_vector (tree type, const unsigned char *ptr, int len)
7761 tree etype, elem, elements;
7764 etype = TREE_TYPE (type);
7765 size = GET_MODE_SIZE (TYPE_MODE (etype));
7766 count = TYPE_VECTOR_SUBPARTS (type);
7767 if (size * count > len)
7770 elements = NULL_TREE;
7771 for (i = count - 1; i >= 0; i--)
7773 elem = native_interpret_expr (etype, ptr+(i*size), size);
7776 elements = tree_cons (NULL_TREE, elem, elements);
7778 return build_vector (type, elements);
7782 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7783 the buffer PTR of length LEN as a constant of type TYPE. For
7784 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7785 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7786 return NULL_TREE. */
7789 native_interpret_expr (tree type, const unsigned char *ptr, int len)
7791 switch (TREE_CODE (type))
7796 return native_interpret_int (type, ptr, len);
7799 return native_interpret_real (type, ptr, len);
7802 return native_interpret_complex (type, ptr, len);
7805 return native_interpret_vector (type, ptr, len);
7813 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7814 TYPE at compile-time. If we're unable to perform the conversion
7815 return NULL_TREE. */
7818 fold_view_convert_expr (tree type, tree expr)
7820 /* We support up to 512-bit values (for V8DFmode). */
7821 unsigned char buffer[64];
7824 /* Check that the host and target are sane. */
7825 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7828 len = native_encode_expr (expr, buffer, sizeof (buffer));
7832 return native_interpret_expr (type, buffer, len);
7835 /* Build an expression for the address of T. Folds away INDIRECT_REF
7836 to avoid confusing the gimplify process. When IN_FOLD is true
7837 avoid modifications of T. */
7840 build_fold_addr_expr_with_type_1 (tree t, tree ptrtype, bool in_fold)
7842 /* The size of the object is not relevant when talking about its address. */
7843 if (TREE_CODE (t) == WITH_SIZE_EXPR)
7844 t = TREE_OPERAND (t, 0);
7846 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
7847 if (TREE_CODE (t) == INDIRECT_REF
7848 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
7850 t = TREE_OPERAND (t, 0);
7852 if (TREE_TYPE (t) != ptrtype)
7853 t = build1 (NOP_EXPR, ptrtype, t);
7859 while (handled_component_p (base))
7860 base = TREE_OPERAND (base, 0);
7863 TREE_ADDRESSABLE (base) = 1;
7865 t = build1 (ADDR_EXPR, ptrtype, t);
7868 t = build1 (ADDR_EXPR, ptrtype, t);
7873 /* Build an expression for the address of T with type PTRTYPE. This
7874 function modifies the input parameter 'T' by sometimes setting the
7875 TREE_ADDRESSABLE flag. */
7878 build_fold_addr_expr_with_type (tree t, tree ptrtype)
7880 return build_fold_addr_expr_with_type_1 (t, ptrtype, false);
7883 /* Build an expression for the address of T. This function modifies
7884 the input parameter 'T' by sometimes setting the TREE_ADDRESSABLE
7885 flag. When called from fold functions, use fold_addr_expr instead. */
7888 build_fold_addr_expr (tree t)
7890 return build_fold_addr_expr_with_type_1 (t,
7891 build_pointer_type (TREE_TYPE (t)),
7895 /* Same as build_fold_addr_expr, builds an expression for the address
7896 of T, but avoids touching the input node 't'. Fold functions
7897 should use this version. */
7900 fold_addr_expr (tree t)
7902 tree ptrtype = build_pointer_type (TREE_TYPE (t));
7904 return build_fold_addr_expr_with_type_1 (t, ptrtype, true);
7907 /* Fold a unary expression of code CODE and type TYPE with operand
7908 OP0. Return the folded expression if folding is successful.
7909 Otherwise, return NULL_TREE. */
7912 fold_unary (enum tree_code code, tree type, tree op0)
7916 enum tree_code_class kind = TREE_CODE_CLASS (code);
7918 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7919 && TREE_CODE_LENGTH (code) == 1);
7924 if (code == NOP_EXPR || code == CONVERT_EXPR
7925 || code == FLOAT_EXPR || code == ABS_EXPR)
7927 /* Don't use STRIP_NOPS, because signedness of argument type
7929 STRIP_SIGN_NOPS (arg0);
7933 /* Strip any conversions that don't change the mode. This
7934 is safe for every expression, except for a comparison
7935 expression because its signedness is derived from its
7938 Note that this is done as an internal manipulation within
7939 the constant folder, in order to find the simplest
7940 representation of the arguments so that their form can be
7941 studied. In any cases, the appropriate type conversions
7942 should be put back in the tree that will get out of the
7948 if (TREE_CODE_CLASS (code) == tcc_unary)
7950 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7951 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7952 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
7953 else if (TREE_CODE (arg0) == COND_EXPR)
7955 tree arg01 = TREE_OPERAND (arg0, 1);
7956 tree arg02 = TREE_OPERAND (arg0, 2);
7957 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7958 arg01 = fold_build1 (code, type, arg01);
7959 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7960 arg02 = fold_build1 (code, type, arg02);
7961 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
7964 /* If this was a conversion, and all we did was to move into
7965 inside the COND_EXPR, bring it back out. But leave it if
7966 it is a conversion from integer to integer and the
7967 result precision is no wider than a word since such a
7968 conversion is cheap and may be optimized away by combine,
7969 while it couldn't if it were outside the COND_EXPR. Then return
7970 so we don't get into an infinite recursion loop taking the
7971 conversion out and then back in. */
7973 if ((code == NOP_EXPR || code == CONVERT_EXPR
7974 || code == NON_LVALUE_EXPR)
7975 && TREE_CODE (tem) == COND_EXPR
7976 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7977 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7978 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7979 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7980 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7981 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7982 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7984 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7985 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7986 || flag_syntax_only))
7987 tem = build1 (code, type,
7989 TREE_TYPE (TREE_OPERAND
7990 (TREE_OPERAND (tem, 1), 0)),
7991 TREE_OPERAND (tem, 0),
7992 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7993 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
7996 else if (COMPARISON_CLASS_P (arg0))
7998 if (TREE_CODE (type) == BOOLEAN_TYPE)
8000 arg0 = copy_node (arg0);
8001 TREE_TYPE (arg0) = type;
8004 else if (TREE_CODE (type) != INTEGER_TYPE)
8005 return fold_build3 (COND_EXPR, type, arg0,
8006 fold_build1 (code, type,
8008 fold_build1 (code, type,
8009 integer_zero_node));
8018 case FIX_TRUNC_EXPR:
8019 if (TREE_TYPE (op0) == type)
8022 /* If we have (type) (a CMP b) and type is an integral type, return
8023 new expression involving the new type. */
8024 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
8025 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
8026 TREE_OPERAND (op0, 1));
8028 /* Handle cases of two conversions in a row. */
8029 if (TREE_CODE (op0) == NOP_EXPR
8030 || TREE_CODE (op0) == CONVERT_EXPR)
8032 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
8033 tree inter_type = TREE_TYPE (op0);
8034 int inside_int = INTEGRAL_TYPE_P (inside_type);
8035 int inside_ptr = POINTER_TYPE_P (inside_type);
8036 int inside_float = FLOAT_TYPE_P (inside_type);
8037 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
8038 unsigned int inside_prec = TYPE_PRECISION (inside_type);
8039 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
8040 int inter_int = INTEGRAL_TYPE_P (inter_type);
8041 int inter_ptr = POINTER_TYPE_P (inter_type);
8042 int inter_float = FLOAT_TYPE_P (inter_type);
8043 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
8044 unsigned int inter_prec = TYPE_PRECISION (inter_type);
8045 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
8046 int final_int = INTEGRAL_TYPE_P (type);
8047 int final_ptr = POINTER_TYPE_P (type);
8048 int final_float = FLOAT_TYPE_P (type);
8049 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
8050 unsigned int final_prec = TYPE_PRECISION (type);
8051 int final_unsignedp = TYPE_UNSIGNED (type);
8053 /* In addition to the cases of two conversions in a row
8054 handled below, if we are converting something to its own
8055 type via an object of identical or wider precision, neither
8056 conversion is needed. */
8057 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
8058 && (((inter_int || inter_ptr) && final_int)
8059 || (inter_float && final_float))
8060 && inter_prec >= final_prec)
8061 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8063 /* Likewise, if the intermediate and final types are either both
8064 float or both integer, we don't need the middle conversion if
8065 it is wider than the final type and doesn't change the signedness
8066 (for integers). Avoid this if the final type is a pointer
8067 since then we sometimes need the inner conversion. Likewise if
8068 the outer has a precision not equal to the size of its mode. */
8069 if (((inter_int && inside_int)
8070 || (inter_float && inside_float)
8071 || (inter_vec && inside_vec))
8072 && inter_prec >= inside_prec
8073 && (inter_float || inter_vec
8074 || inter_unsignedp == inside_unsignedp)
8075 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
8076 && TYPE_MODE (type) == TYPE_MODE (inter_type))
8078 && (! final_vec || inter_prec == inside_prec))
8079 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8081 /* If we have a sign-extension of a zero-extended value, we can
8082 replace that by a single zero-extension. */
8083 if (inside_int && inter_int && final_int
8084 && inside_prec < inter_prec && inter_prec < final_prec
8085 && inside_unsignedp && !inter_unsignedp)
8086 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8088 /* Two conversions in a row are not needed unless:
8089 - some conversion is floating-point (overstrict for now), or
8090 - some conversion is a vector (overstrict for now), or
8091 - the intermediate type is narrower than both initial and
8093 - the intermediate type and innermost type differ in signedness,
8094 and the outermost type is wider than the intermediate, or
8095 - the initial type is a pointer type and the precisions of the
8096 intermediate and final types differ, or
8097 - the final type is a pointer type and the precisions of the
8098 initial and intermediate types differ.
8099 - the initial type is a pointer to an array and the final type
8101 if (! inside_float && ! inter_float && ! final_float
8102 && ! inside_vec && ! inter_vec && ! final_vec
8103 && (inter_prec >= inside_prec || inter_prec >= final_prec)
8104 && ! (inside_int && inter_int
8105 && inter_unsignedp != inside_unsignedp
8106 && inter_prec < final_prec)
8107 && ((inter_unsignedp && inter_prec > inside_prec)
8108 == (final_unsignedp && final_prec > inter_prec))
8109 && ! (inside_ptr && inter_prec != final_prec)
8110 && ! (final_ptr && inside_prec != inter_prec)
8111 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
8112 && TYPE_MODE (type) == TYPE_MODE (inter_type))
8113 && ! (inside_ptr && final_ptr
8114 && TREE_CODE (TREE_TYPE (inside_type)) == ARRAY_TYPE
8115 && TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
8116 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8119 /* Handle (T *)&A.B.C for A being of type T and B and C
8120 living at offset zero. This occurs frequently in
8121 C++ upcasting and then accessing the base. */
8122 if (TREE_CODE (op0) == ADDR_EXPR
8123 && POINTER_TYPE_P (type)
8124 && handled_component_p (TREE_OPERAND (op0, 0)))
8126 HOST_WIDE_INT bitsize, bitpos;
8128 enum machine_mode mode;
8129 int unsignedp, volatilep;
8130 tree base = TREE_OPERAND (op0, 0);
8131 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
8132 &mode, &unsignedp, &volatilep, false);
8133 /* If the reference was to a (constant) zero offset, we can use
8134 the address of the base if it has the same base type
8135 as the result type. */
8136 if (! offset && bitpos == 0
8137 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
8138 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
8139 return fold_convert (type, fold_addr_expr (base));
8142 if ((TREE_CODE (op0) == MODIFY_EXPR
8143 || TREE_CODE (op0) == GIMPLE_MODIFY_STMT)
8144 && TREE_CONSTANT (GENERIC_TREE_OPERAND (op0, 1))
8145 /* Detect assigning a bitfield. */
8146 && !(TREE_CODE (GENERIC_TREE_OPERAND (op0, 0)) == COMPONENT_REF
8148 (TREE_OPERAND (GENERIC_TREE_OPERAND (op0, 0), 1))))
8150 /* Don't leave an assignment inside a conversion
8151 unless assigning a bitfield. */
8152 tem = fold_build1 (code, type, GENERIC_TREE_OPERAND (op0, 1));
8153 /* First do the assignment, then return converted constant. */
8154 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
8155 TREE_NO_WARNING (tem) = 1;
8156 TREE_USED (tem) = 1;
8160 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
8161 constants (if x has signed type, the sign bit cannot be set
8162 in c). This folds extension into the BIT_AND_EXPR. */
8163 if (INTEGRAL_TYPE_P (type)
8164 && TREE_CODE (type) != BOOLEAN_TYPE
8165 && TREE_CODE (op0) == BIT_AND_EXPR
8166 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
8169 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
8172 if (TYPE_UNSIGNED (TREE_TYPE (and))
8173 || (TYPE_PRECISION (type)
8174 <= TYPE_PRECISION (TREE_TYPE (and))))
8176 else if (TYPE_PRECISION (TREE_TYPE (and1))
8177 <= HOST_BITS_PER_WIDE_INT
8178 && host_integerp (and1, 1))
8180 unsigned HOST_WIDE_INT cst;
8182 cst = tree_low_cst (and1, 1);
8183 cst &= (HOST_WIDE_INT) -1
8184 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
8185 change = (cst == 0);
8186 #ifdef LOAD_EXTEND_OP
8188 && !flag_syntax_only
8189 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
8192 tree uns = unsigned_type_for (TREE_TYPE (and0));
8193 and0 = fold_convert (uns, and0);
8194 and1 = fold_convert (uns, and1);
8200 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
8201 TREE_INT_CST_HIGH (and1), 0,
8202 TREE_OVERFLOW (and1));
8203 return fold_build2 (BIT_AND_EXPR, type,
8204 fold_convert (type, and0), tem);
8208 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
8209 when one of the new casts will fold away. Conservatively we assume
8210 that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
8211 if (POINTER_TYPE_P (type)
8212 && TREE_CODE (arg0) == POINTER_PLUS_EXPR
8213 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8214 || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
8215 || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
8217 tree arg00 = TREE_OPERAND (arg0, 0);
8218 tree arg01 = TREE_OPERAND (arg0, 1);
8220 return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
8221 fold_convert (sizetype, arg01));
8224 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
8225 of the same precision, and X is an integer type not narrower than
8226 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
8227 if (INTEGRAL_TYPE_P (type)
8228 && TREE_CODE (op0) == BIT_NOT_EXPR
8229 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
8230 && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
8231 || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
8232 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
8234 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
8235 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
8236 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
8237 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
8240 tem = fold_convert_const (code, type, op0);
8241 return tem ? tem : NULL_TREE;
8243 case FIXED_CONVERT_EXPR:
8244 tem = fold_convert_const (code, type, arg0);
8245 return tem ? tem : NULL_TREE;
8247 case VIEW_CONVERT_EXPR:
8248 if (TREE_TYPE (op0) == type)
8250 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR
8251 || (TREE_CODE (op0) == NOP_EXPR
8252 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
8253 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
8254 && TYPE_PRECISION (TREE_TYPE (op0))
8255 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
8256 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
8257 return fold_view_convert_expr (type, op0);
8260 tem = fold_negate_expr (arg0);
8262 return fold_convert (type, tem);
8266 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
8267 return fold_abs_const (arg0, type);
8268 else if (TREE_CODE (arg0) == NEGATE_EXPR)
8269 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
8270 /* Convert fabs((double)float) into (double)fabsf(float). */
8271 else if (TREE_CODE (arg0) == NOP_EXPR
8272 && TREE_CODE (type) == REAL_TYPE)
8274 tree targ0 = strip_float_extensions (arg0);
8276 return fold_convert (type, fold_build1 (ABS_EXPR,
8280 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
8281 else if (TREE_CODE (arg0) == ABS_EXPR)
8283 else if (tree_expr_nonnegative_p (arg0))
8286 /* Strip sign ops from argument. */
8287 if (TREE_CODE (type) == REAL_TYPE)
8289 tem = fold_strip_sign_ops (arg0);
8291 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
8296 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8297 return fold_convert (type, arg0);
8298 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8300 tree itype = TREE_TYPE (type);
8301 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
8302 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
8303 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
8305 if (TREE_CODE (arg0) == COMPLEX_CST)
8307 tree itype = TREE_TYPE (type);
8308 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
8309 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
8310 return build_complex (type, rpart, negate_expr (ipart));
8312 if (TREE_CODE (arg0) == CONJ_EXPR)
8313 return fold_convert (type, TREE_OPERAND (arg0, 0));
8317 if (TREE_CODE (arg0) == INTEGER_CST)
8318 return fold_not_const (arg0, type);
8319 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
8320 return TREE_OPERAND (op0, 0);
8321 /* Convert ~ (-A) to A - 1. */
8322 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
8323 return fold_build2 (MINUS_EXPR, type,
8324 fold_convert (type, TREE_OPERAND (arg0, 0)),
8325 build_int_cst (type, 1));
8326 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
8327 else if (INTEGRAL_TYPE_P (type)
8328 && ((TREE_CODE (arg0) == MINUS_EXPR
8329 && integer_onep (TREE_OPERAND (arg0, 1)))
8330 || (TREE_CODE (arg0) == PLUS_EXPR
8331 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
8332 return fold_build1 (NEGATE_EXPR, type,
8333 fold_convert (type, TREE_OPERAND (arg0, 0)));
8334 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8335 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8336 && (tem = fold_unary (BIT_NOT_EXPR, type,
8338 TREE_OPERAND (arg0, 0)))))
8339 return fold_build2 (BIT_XOR_EXPR, type, tem,
8340 fold_convert (type, TREE_OPERAND (arg0, 1)));
8341 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8342 && (tem = fold_unary (BIT_NOT_EXPR, type,
8344 TREE_OPERAND (arg0, 1)))))
8345 return fold_build2 (BIT_XOR_EXPR, type,
8346 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
8347 /* Perform BIT_NOT_EXPR on each element individually. */
8348 else if (TREE_CODE (arg0) == VECTOR_CST)
8350 tree elements = TREE_VECTOR_CST_ELTS (arg0), elem, list = NULL_TREE;
8351 int count = TYPE_VECTOR_SUBPARTS (type), i;
8353 for (i = 0; i < count; i++)
8357 elem = TREE_VALUE (elements);
8358 elem = fold_unary (BIT_NOT_EXPR, TREE_TYPE (type), elem);
8359 if (elem == NULL_TREE)
8361 elements = TREE_CHAIN (elements);
8364 elem = build_int_cst (TREE_TYPE (type), -1);
8365 list = tree_cons (NULL_TREE, elem, list);
8368 return build_vector (type, nreverse (list));
8373 case TRUTH_NOT_EXPR:
8374 /* The argument to invert_truthvalue must have Boolean type. */
8375 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8376 arg0 = fold_convert (boolean_type_node, arg0);
8378 /* Note that the operand of this must be an int
8379 and its values must be 0 or 1.
8380 ("true" is a fixed value perhaps depending on the language,
8381 but we don't handle values other than 1 correctly yet.) */
8382 tem = fold_truth_not_expr (arg0);
8385 return fold_convert (type, tem);
8388 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8389 return fold_convert (type, arg0);
8390 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8391 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8392 TREE_OPERAND (arg0, 1));
8393 if (TREE_CODE (arg0) == COMPLEX_CST)
8394 return fold_convert (type, TREE_REALPART (arg0));
8395 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8397 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8398 tem = fold_build2 (TREE_CODE (arg0), itype,
8399 fold_build1 (REALPART_EXPR, itype,
8400 TREE_OPERAND (arg0, 0)),
8401 fold_build1 (REALPART_EXPR, itype,
8402 TREE_OPERAND (arg0, 1)));
8403 return fold_convert (type, tem);
8405 if (TREE_CODE (arg0) == CONJ_EXPR)
8407 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8408 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8409 return fold_convert (type, tem);
8411 if (TREE_CODE (arg0) == CALL_EXPR)
8413 tree fn = get_callee_fndecl (arg0);
8414 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8415 switch (DECL_FUNCTION_CODE (fn))
8417 CASE_FLT_FN (BUILT_IN_CEXPI):
8418 fn = mathfn_built_in (type, BUILT_IN_COS);
8420 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8430 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8431 return fold_convert (type, integer_zero_node);
8432 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8433 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8434 TREE_OPERAND (arg0, 0));
8435 if (TREE_CODE (arg0) == COMPLEX_CST)
8436 return fold_convert (type, TREE_IMAGPART (arg0));
8437 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8439 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8440 tem = fold_build2 (TREE_CODE (arg0), itype,
8441 fold_build1 (IMAGPART_EXPR, itype,
8442 TREE_OPERAND (arg0, 0)),
8443 fold_build1 (IMAGPART_EXPR, itype,
8444 TREE_OPERAND (arg0, 1)));
8445 return fold_convert (type, tem);
8447 if (TREE_CODE (arg0) == CONJ_EXPR)
8449 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8450 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8451 return fold_convert (type, negate_expr (tem));
8453 if (TREE_CODE (arg0) == CALL_EXPR)
8455 tree fn = get_callee_fndecl (arg0);
8456 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8457 switch (DECL_FUNCTION_CODE (fn))
8459 CASE_FLT_FN (BUILT_IN_CEXPI):
8460 fn = mathfn_built_in (type, BUILT_IN_SIN);
8462 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8473 } /* switch (code) */
8476 /* Fold a binary expression of code CODE and type TYPE with operands
8477 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8478 Return the folded expression if folding is successful. Otherwise,
8479 return NULL_TREE. */
8482 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8484 enum tree_code compl_code;
8486 if (code == MIN_EXPR)
8487 compl_code = MAX_EXPR;
8488 else if (code == MAX_EXPR)
8489 compl_code = MIN_EXPR;
8493 /* MIN (MAX (a, b), b) == b. */
8494 if (TREE_CODE (op0) == compl_code
8495 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8496 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8498 /* MIN (MAX (b, a), b) == b. */
8499 if (TREE_CODE (op0) == compl_code
8500 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8501 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8502 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8504 /* MIN (a, MAX (a, b)) == a. */
8505 if (TREE_CODE (op1) == compl_code
8506 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8507 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8508 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8510 /* MIN (a, MAX (b, a)) == a. */
8511 if (TREE_CODE (op1) == compl_code
8512 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8513 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8514 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8519 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8520 by changing CODE to reduce the magnitude of constants involved in
8521 ARG0 of the comparison.
8522 Returns a canonicalized comparison tree if a simplification was
8523 possible, otherwise returns NULL_TREE.
8524 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8525 valid if signed overflow is undefined. */
8528 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8529 tree arg0, tree arg1,
8530 bool *strict_overflow_p)
8532 enum tree_code code0 = TREE_CODE (arg0);
8533 tree t, cst0 = NULL_TREE;
8537 /* Match A +- CST code arg1 and CST code arg1. */
8538 if (!(((code0 == MINUS_EXPR
8539 || code0 == PLUS_EXPR)
8540 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8541 || code0 == INTEGER_CST))
8544 /* Identify the constant in arg0 and its sign. */
8545 if (code0 == INTEGER_CST)
8548 cst0 = TREE_OPERAND (arg0, 1);
8549 sgn0 = tree_int_cst_sgn (cst0);
8551 /* Overflowed constants and zero will cause problems. */
8552 if (integer_zerop (cst0)
8553 || TREE_OVERFLOW (cst0))
8556 /* See if we can reduce the magnitude of the constant in
8557 arg0 by changing the comparison code. */
8558 if (code0 == INTEGER_CST)
8560 /* CST <= arg1 -> CST-1 < arg1. */
8561 if (code == LE_EXPR && sgn0 == 1)
8563 /* -CST < arg1 -> -CST-1 <= arg1. */
8564 else if (code == LT_EXPR && sgn0 == -1)
8566 /* CST > arg1 -> CST-1 >= arg1. */
8567 else if (code == GT_EXPR && sgn0 == 1)
8569 /* -CST >= arg1 -> -CST-1 > arg1. */
8570 else if (code == GE_EXPR && sgn0 == -1)
8574 /* arg1 code' CST' might be more canonical. */
8579 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8581 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8583 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8584 else if (code == GT_EXPR
8585 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8587 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8588 else if (code == LE_EXPR
8589 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8591 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8592 else if (code == GE_EXPR
8593 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8597 *strict_overflow_p = true;
8600 /* Now build the constant reduced in magnitude. */
8601 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8602 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8603 if (code0 != INTEGER_CST)
8604 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8606 /* If swapping might yield to a more canonical form, do so. */
8608 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8610 return fold_build2 (code, type, t, arg1);
8613 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8614 overflow further. Try to decrease the magnitude of constants involved
8615 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8616 and put sole constants at the second argument position.
8617 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8620 maybe_canonicalize_comparison (enum tree_code code, tree type,
8621 tree arg0, tree arg1)
8624 bool strict_overflow_p;
8625 const char * const warnmsg = G_("assuming signed overflow does not occur "
8626 "when reducing constant in comparison");
8628 /* In principle pointers also have undefined overflow behavior,
8629 but that causes problems elsewhere. */
8630 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8631 || POINTER_TYPE_P (TREE_TYPE (arg0)))
8634 /* Try canonicalization by simplifying arg0. */
8635 strict_overflow_p = false;
8636 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8637 &strict_overflow_p);
8640 if (strict_overflow_p)
8641 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8645 /* Try canonicalization by simplifying arg1 using the swapped
8647 code = swap_tree_comparison (code);
8648 strict_overflow_p = false;
8649 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8650 &strict_overflow_p);
8651 if (t && strict_overflow_p)
8652 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8656 /* Subroutine of fold_binary. This routine performs all of the
8657 transformations that are common to the equality/inequality
8658 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8659 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8660 fold_binary should call fold_binary. Fold a comparison with
8661 tree code CODE and type TYPE with operands OP0 and OP1. Return
8662 the folded comparison or NULL_TREE. */
8665 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8667 tree arg0, arg1, tem;
8672 STRIP_SIGN_NOPS (arg0);
8673 STRIP_SIGN_NOPS (arg1);
8675 tem = fold_relational_const (code, type, arg0, arg1);
8676 if (tem != NULL_TREE)
8679 /* If one arg is a real or integer constant, put it last. */
8680 if (tree_swap_operands_p (arg0, arg1, true))
8681 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8683 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8684 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8685 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8686 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8687 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8688 && (TREE_CODE (arg1) == INTEGER_CST
8689 && !TREE_OVERFLOW (arg1)))
8691 tree const1 = TREE_OPERAND (arg0, 1);
8693 tree variable = TREE_OPERAND (arg0, 0);
8696 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8698 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8699 TREE_TYPE (arg1), const2, const1);
8701 /* If the constant operation overflowed this can be
8702 simplified as a comparison against INT_MAX/INT_MIN. */
8703 if (TREE_CODE (lhs) == INTEGER_CST
8704 && TREE_OVERFLOW (lhs))
8706 int const1_sgn = tree_int_cst_sgn (const1);
8707 enum tree_code code2 = code;
8709 /* Get the sign of the constant on the lhs if the
8710 operation were VARIABLE + CONST1. */
8711 if (TREE_CODE (arg0) == MINUS_EXPR)
8712 const1_sgn = -const1_sgn;
8714 /* The sign of the constant determines if we overflowed
8715 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8716 Canonicalize to the INT_MIN overflow by swapping the comparison
8718 if (const1_sgn == -1)
8719 code2 = swap_tree_comparison (code);
8721 /* We now can look at the canonicalized case
8722 VARIABLE + 1 CODE2 INT_MIN
8723 and decide on the result. */
8724 if (code2 == LT_EXPR
8726 || code2 == EQ_EXPR)
8727 return omit_one_operand (type, boolean_false_node, variable);
8728 else if (code2 == NE_EXPR
8730 || code2 == GT_EXPR)
8731 return omit_one_operand (type, boolean_true_node, variable);
8734 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8735 && (TREE_CODE (lhs) != INTEGER_CST
8736 || !TREE_OVERFLOW (lhs)))
8738 fold_overflow_warning (("assuming signed overflow does not occur "
8739 "when changing X +- C1 cmp C2 to "
8741 WARN_STRICT_OVERFLOW_COMPARISON);
8742 return fold_build2 (code, type, variable, lhs);
8746 /* For comparisons of pointers we can decompose it to a compile time
8747 comparison of the base objects and the offsets into the object.
8748 This requires at least one operand being an ADDR_EXPR or a
8749 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8750 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8751 && (TREE_CODE (arg0) == ADDR_EXPR
8752 || TREE_CODE (arg1) == ADDR_EXPR
8753 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
8754 || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
8756 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8757 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8758 enum machine_mode mode;
8759 int volatilep, unsignedp;
8760 bool indirect_base0 = false;
8762 /* Get base and offset for the access. Strip ADDR_EXPR for
8763 get_inner_reference, but put it back by stripping INDIRECT_REF
8764 off the base object if possible. */
8766 if (TREE_CODE (arg0) == ADDR_EXPR)
8768 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8769 &bitsize, &bitpos0, &offset0, &mode,
8770 &unsignedp, &volatilep, false);
8771 if (TREE_CODE (base0) == INDIRECT_REF)
8772 base0 = TREE_OPERAND (base0, 0);
8774 indirect_base0 = true;
8776 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
8778 base0 = TREE_OPERAND (arg0, 0);
8779 offset0 = TREE_OPERAND (arg0, 1);
8783 if (TREE_CODE (arg1) == ADDR_EXPR)
8785 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8786 &bitsize, &bitpos1, &offset1, &mode,
8787 &unsignedp, &volatilep, false);
8788 /* We have to make sure to have an indirect/non-indirect base1
8789 just the same as we did for base0. */
8790 if (TREE_CODE (base1) == INDIRECT_REF
8792 base1 = TREE_OPERAND (base1, 0);
8793 else if (!indirect_base0)
8796 else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
8798 base1 = TREE_OPERAND (arg1, 0);
8799 offset1 = TREE_OPERAND (arg1, 1);
8801 else if (indirect_base0)
8804 /* If we have equivalent bases we might be able to simplify. */
8806 && operand_equal_p (base0, base1, 0))
8808 /* We can fold this expression to a constant if the non-constant
8809 offset parts are equal. */
8810 if (offset0 == offset1
8811 || (offset0 && offset1
8812 && operand_equal_p (offset0, offset1, 0)))
8817 return build_int_cst (boolean_type_node, bitpos0 == bitpos1);
8819 return build_int_cst (boolean_type_node, bitpos0 != bitpos1);
8821 return build_int_cst (boolean_type_node, bitpos0 < bitpos1);
8823 return build_int_cst (boolean_type_node, bitpos0 <= bitpos1);
8825 return build_int_cst (boolean_type_node, bitpos0 >= bitpos1);
8827 return build_int_cst (boolean_type_node, bitpos0 > bitpos1);
8831 /* We can simplify the comparison to a comparison of the variable
8832 offset parts if the constant offset parts are equal.
8833 Be careful to use signed size type here because otherwise we
8834 mess with array offsets in the wrong way. This is possible
8835 because pointer arithmetic is restricted to retain within an
8836 object and overflow on pointer differences is undefined as of
8837 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8838 else if (bitpos0 == bitpos1)
8840 tree signed_size_type_node;
8841 signed_size_type_node = signed_type_for (size_type_node);
8843 /* By converting to signed size type we cover middle-end pointer
8844 arithmetic which operates on unsigned pointer types of size
8845 type size and ARRAY_REF offsets which are properly sign or
8846 zero extended from their type in case it is narrower than
8848 if (offset0 == NULL_TREE)
8849 offset0 = build_int_cst (signed_size_type_node, 0);
8851 offset0 = fold_convert (signed_size_type_node, offset0);
8852 if (offset1 == NULL_TREE)
8853 offset1 = build_int_cst (signed_size_type_node, 0);
8855 offset1 = fold_convert (signed_size_type_node, offset1);
8857 return fold_build2 (code, type, offset0, offset1);
8862 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8863 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8864 the resulting offset is smaller in absolute value than the
8866 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8867 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8868 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8869 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8870 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
8871 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8872 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
8874 tree const1 = TREE_OPERAND (arg0, 1);
8875 tree const2 = TREE_OPERAND (arg1, 1);
8876 tree variable1 = TREE_OPERAND (arg0, 0);
8877 tree variable2 = TREE_OPERAND (arg1, 0);
8879 const char * const warnmsg = G_("assuming signed overflow does not "
8880 "occur when combining constants around "
8883 /* Put the constant on the side where it doesn't overflow and is
8884 of lower absolute value than before. */
8885 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8886 ? MINUS_EXPR : PLUS_EXPR,
8888 if (!TREE_OVERFLOW (cst)
8889 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
8891 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8892 return fold_build2 (code, type,
8894 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
8898 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8899 ? MINUS_EXPR : PLUS_EXPR,
8901 if (!TREE_OVERFLOW (cst)
8902 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
8904 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8905 return fold_build2 (code, type,
8906 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
8912 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
8913 signed arithmetic case. That form is created by the compiler
8914 often enough for folding it to be of value. One example is in
8915 computing loop trip counts after Operator Strength Reduction. */
8916 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8917 && TREE_CODE (arg0) == MULT_EXPR
8918 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8919 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8920 && integer_zerop (arg1))
8922 tree const1 = TREE_OPERAND (arg0, 1);
8923 tree const2 = arg1; /* zero */
8924 tree variable1 = TREE_OPERAND (arg0, 0);
8925 enum tree_code cmp_code = code;
8927 gcc_assert (!integer_zerop (const1));
8929 fold_overflow_warning (("assuming signed overflow does not occur when "
8930 "eliminating multiplication in comparison "
8932 WARN_STRICT_OVERFLOW_COMPARISON);
8934 /* If const1 is negative we swap the sense of the comparison. */
8935 if (tree_int_cst_sgn (const1) < 0)
8936 cmp_code = swap_tree_comparison (cmp_code);
8938 return fold_build2 (cmp_code, type, variable1, const2);
8941 tem = maybe_canonicalize_comparison (code, type, op0, op1);
8945 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8947 tree targ0 = strip_float_extensions (arg0);
8948 tree targ1 = strip_float_extensions (arg1);
8949 tree newtype = TREE_TYPE (targ0);
8951 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8952 newtype = TREE_TYPE (targ1);
8954 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8955 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8956 return fold_build2 (code, type, fold_convert (newtype, targ0),
8957 fold_convert (newtype, targ1));
8959 /* (-a) CMP (-b) -> b CMP a */
8960 if (TREE_CODE (arg0) == NEGATE_EXPR
8961 && TREE_CODE (arg1) == NEGATE_EXPR)
8962 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8963 TREE_OPERAND (arg0, 0));
8965 if (TREE_CODE (arg1) == REAL_CST)
8967 REAL_VALUE_TYPE cst;
8968 cst = TREE_REAL_CST (arg1);
8970 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8971 if (TREE_CODE (arg0) == NEGATE_EXPR)
8972 return fold_build2 (swap_tree_comparison (code), type,
8973 TREE_OPERAND (arg0, 0),
8974 build_real (TREE_TYPE (arg1),
8975 REAL_VALUE_NEGATE (cst)));
8977 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8978 /* a CMP (-0) -> a CMP 0 */
8979 if (REAL_VALUE_MINUS_ZERO (cst))
8980 return fold_build2 (code, type, arg0,
8981 build_real (TREE_TYPE (arg1), dconst0));
8983 /* x != NaN is always true, other ops are always false. */
8984 if (REAL_VALUE_ISNAN (cst)
8985 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8987 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8988 return omit_one_operand (type, tem, arg0);
8991 /* Fold comparisons against infinity. */
8992 if (REAL_VALUE_ISINF (cst))
8994 tem = fold_inf_compare (code, type, arg0, arg1);
8995 if (tem != NULL_TREE)
9000 /* If this is a comparison of a real constant with a PLUS_EXPR
9001 or a MINUS_EXPR of a real constant, we can convert it into a
9002 comparison with a revised real constant as long as no overflow
9003 occurs when unsafe_math_optimizations are enabled. */
9004 if (flag_unsafe_math_optimizations
9005 && TREE_CODE (arg1) == REAL_CST
9006 && (TREE_CODE (arg0) == PLUS_EXPR
9007 || TREE_CODE (arg0) == MINUS_EXPR)
9008 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
9009 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9010 ? MINUS_EXPR : PLUS_EXPR,
9011 arg1, TREE_OPERAND (arg0, 1), 0))
9012 && !TREE_OVERFLOW (tem))
9013 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9015 /* Likewise, we can simplify a comparison of a real constant with
9016 a MINUS_EXPR whose first operand is also a real constant, i.e.
9017 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
9018 floating-point types only if -fassociative-math is set. */
9019 if (flag_associative_math
9020 && TREE_CODE (arg1) == REAL_CST
9021 && TREE_CODE (arg0) == MINUS_EXPR
9022 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
9023 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
9025 && !TREE_OVERFLOW (tem))
9026 return fold_build2 (swap_tree_comparison (code), type,
9027 TREE_OPERAND (arg0, 1), tem);
9029 /* Fold comparisons against built-in math functions. */
9030 if (TREE_CODE (arg1) == REAL_CST
9031 && flag_unsafe_math_optimizations
9032 && ! flag_errno_math)
9034 enum built_in_function fcode = builtin_mathfn_code (arg0);
9036 if (fcode != END_BUILTINS)
9038 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
9039 if (tem != NULL_TREE)
9045 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
9046 && (TREE_CODE (arg0) == NOP_EXPR
9047 || TREE_CODE (arg0) == CONVERT_EXPR))
9049 /* If we are widening one operand of an integer comparison,
9050 see if the other operand is similarly being widened. Perhaps we
9051 can do the comparison in the narrower type. */
9052 tem = fold_widened_comparison (code, type, arg0, arg1);
9056 /* Or if we are changing signedness. */
9057 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
9062 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9063 constant, we can simplify it. */
9064 if (TREE_CODE (arg1) == INTEGER_CST
9065 && (TREE_CODE (arg0) == MIN_EXPR
9066 || TREE_CODE (arg0) == MAX_EXPR)
9067 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9069 tem = optimize_minmax_comparison (code, type, op0, op1);
9074 /* Simplify comparison of something with itself. (For IEEE
9075 floating-point, we can only do some of these simplifications.) */
9076 if (operand_equal_p (arg0, arg1, 0))
9081 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9082 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9083 return constant_boolean_node (1, type);
9088 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9089 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9090 return constant_boolean_node (1, type);
9091 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9094 /* For NE, we can only do this simplification if integer
9095 or we don't honor IEEE floating point NaNs. */
9096 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
9097 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9099 /* ... fall through ... */
9102 return constant_boolean_node (0, type);
9108 /* If we are comparing an expression that just has comparisons
9109 of two integer values, arithmetic expressions of those comparisons,
9110 and constants, we can simplify it. There are only three cases
9111 to check: the two values can either be equal, the first can be
9112 greater, or the second can be greater. Fold the expression for
9113 those three values. Since each value must be 0 or 1, we have
9114 eight possibilities, each of which corresponds to the constant 0
9115 or 1 or one of the six possible comparisons.
9117 This handles common cases like (a > b) == 0 but also handles
9118 expressions like ((x > y) - (y > x)) > 0, which supposedly
9119 occur in macroized code. */
9121 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
9123 tree cval1 = 0, cval2 = 0;
9126 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
9127 /* Don't handle degenerate cases here; they should already
9128 have been handled anyway. */
9129 && cval1 != 0 && cval2 != 0
9130 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
9131 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
9132 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
9133 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
9134 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
9135 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
9136 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9138 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9139 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9141 /* We can't just pass T to eval_subst in case cval1 or cval2
9142 was the same as ARG1. */
9145 = fold_build2 (code, type,
9146 eval_subst (arg0, cval1, maxval,
9150 = fold_build2 (code, type,
9151 eval_subst (arg0, cval1, maxval,
9155 = fold_build2 (code, type,
9156 eval_subst (arg0, cval1, minval,
9160 /* All three of these results should be 0 or 1. Confirm they are.
9161 Then use those values to select the proper code to use. */
9163 if (TREE_CODE (high_result) == INTEGER_CST
9164 && TREE_CODE (equal_result) == INTEGER_CST
9165 && TREE_CODE (low_result) == INTEGER_CST)
9167 /* Make a 3-bit mask with the high-order bit being the
9168 value for `>', the next for '=', and the low for '<'. */
9169 switch ((integer_onep (high_result) * 4)
9170 + (integer_onep (equal_result) * 2)
9171 + integer_onep (low_result))
9175 return omit_one_operand (type, integer_zero_node, arg0);
9196 return omit_one_operand (type, integer_one_node, arg0);
9200 return save_expr (build2 (code, type, cval1, cval2));
9201 return fold_build2 (code, type, cval1, cval2);
9206 /* Fold a comparison of the address of COMPONENT_REFs with the same
9207 type and component to a comparison of the address of the base
9208 object. In short, &x->a OP &y->a to x OP y and
9209 &x->a OP &y.a to x OP &y */
9210 if (TREE_CODE (arg0) == ADDR_EXPR
9211 && TREE_CODE (TREE_OPERAND (arg0, 0)) == COMPONENT_REF
9212 && TREE_CODE (arg1) == ADDR_EXPR
9213 && TREE_CODE (TREE_OPERAND (arg1, 0)) == COMPONENT_REF)
9215 tree cref0 = TREE_OPERAND (arg0, 0);
9216 tree cref1 = TREE_OPERAND (arg1, 0);
9217 if (TREE_OPERAND (cref0, 1) == TREE_OPERAND (cref1, 1))
9219 tree op0 = TREE_OPERAND (cref0, 0);
9220 tree op1 = TREE_OPERAND (cref1, 0);
9221 return fold_build2 (code, type,
9222 fold_addr_expr (op0),
9223 fold_addr_expr (op1));
9227 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9228 into a single range test. */
9229 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9230 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9231 && TREE_CODE (arg1) == INTEGER_CST
9232 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9233 && !integer_zerop (TREE_OPERAND (arg0, 1))
9234 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9235 && !TREE_OVERFLOW (arg1))
9237 tem = fold_div_compare (code, type, arg0, arg1);
9238 if (tem != NULL_TREE)
9242 /* Fold ~X op ~Y as Y op X. */
9243 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9244 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9246 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9247 return fold_build2 (code, type,
9248 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
9249 TREE_OPERAND (arg0, 0));
9252 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
9253 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9254 && TREE_CODE (arg1) == INTEGER_CST)
9256 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9257 return fold_build2 (swap_tree_comparison (code), type,
9258 TREE_OPERAND (arg0, 0),
9259 fold_build1 (BIT_NOT_EXPR, cmp_type,
9260 fold_convert (cmp_type, arg1)));
9267 /* Subroutine of fold_binary. Optimize complex multiplications of the
9268 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9269 argument EXPR represents the expression "z" of type TYPE. */
9272 fold_mult_zconjz (tree type, tree expr)
9274 tree itype = TREE_TYPE (type);
9275 tree rpart, ipart, tem;
9277 if (TREE_CODE (expr) == COMPLEX_EXPR)
9279 rpart = TREE_OPERAND (expr, 0);
9280 ipart = TREE_OPERAND (expr, 1);
9282 else if (TREE_CODE (expr) == COMPLEX_CST)
9284 rpart = TREE_REALPART (expr);
9285 ipart = TREE_IMAGPART (expr);
9289 expr = save_expr (expr);
9290 rpart = fold_build1 (REALPART_EXPR, itype, expr);
9291 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
9294 rpart = save_expr (rpart);
9295 ipart = save_expr (ipart);
9296 tem = fold_build2 (PLUS_EXPR, itype,
9297 fold_build2 (MULT_EXPR, itype, rpart, rpart),
9298 fold_build2 (MULT_EXPR, itype, ipart, ipart));
9299 return fold_build2 (COMPLEX_EXPR, type, tem,
9300 fold_convert (itype, integer_zero_node));
9304 /* Subroutine of fold_binary. If P is the value of EXPR, computes
9305 power-of-two M and (arbitrary) N such that M divides (P-N). This condition
9306 guarantees that P and N have the same least significant log2(M) bits.
9307 N is not otherwise constrained. In particular, N is not normalized to
9308 0 <= N < M as is common. In general, the precise value of P is unknown.
9309 M is chosen as large as possible such that constant N can be determined.
9311 Returns M and sets *RESIDUE to N. */
9313 static unsigned HOST_WIDE_INT
9314 get_pointer_modulus_and_residue (tree expr, unsigned HOST_WIDE_INT *residue)
9316 enum tree_code code;
9320 code = TREE_CODE (expr);
9321 if (code == ADDR_EXPR)
9323 expr = TREE_OPERAND (expr, 0);
9324 if (handled_component_p (expr))
9326 HOST_WIDE_INT bitsize, bitpos;
9328 enum machine_mode mode;
9329 int unsignedp, volatilep;
9331 expr = get_inner_reference (expr, &bitsize, &bitpos, &offset,
9332 &mode, &unsignedp, &volatilep, false);
9333 *residue = bitpos / BITS_PER_UNIT;
9336 if (TREE_CODE (offset) == INTEGER_CST)
9337 *residue += TREE_INT_CST_LOW (offset);
9339 /* We don't handle more complicated offset expressions. */
9345 return DECL_ALIGN_UNIT (expr);
9347 else if (code == POINTER_PLUS_EXPR)
9350 unsigned HOST_WIDE_INT modulus;
9351 enum tree_code inner_code;
9353 op0 = TREE_OPERAND (expr, 0);
9355 modulus = get_pointer_modulus_and_residue (op0, residue);
9357 op1 = TREE_OPERAND (expr, 1);
9359 inner_code = TREE_CODE (op1);
9360 if (inner_code == INTEGER_CST)
9362 *residue += TREE_INT_CST_LOW (op1);
9365 else if (inner_code == MULT_EXPR)
9367 op1 = TREE_OPERAND (op1, 1);
9368 if (TREE_CODE (op1) == INTEGER_CST)
9370 unsigned HOST_WIDE_INT align;
9372 /* Compute the greatest power-of-2 divisor of op1. */
9373 align = TREE_INT_CST_LOW (op1);
9376 /* If align is non-zero and less than *modulus, replace
9377 *modulus with align., If align is 0, then either op1 is 0
9378 or the greatest power-of-2 divisor of op1 doesn't fit in an
9379 unsigned HOST_WIDE_INT. In either case, no additional
9380 constraint is imposed. */
9382 modulus = MIN (modulus, align);
9389 /* If we get here, we were unable to determine anything useful about the
9395 /* Fold a binary expression of code CODE and type TYPE with operands
9396 OP0 and OP1. Return the folded expression if folding is
9397 successful. Otherwise, return NULL_TREE. */
9400 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
9402 enum tree_code_class kind = TREE_CODE_CLASS (code);
9403 tree arg0, arg1, tem;
9404 tree t1 = NULL_TREE;
9405 bool strict_overflow_p;
9407 gcc_assert ((IS_EXPR_CODE_CLASS (kind)
9408 || IS_GIMPLE_STMT_CODE_CLASS (kind))
9409 && TREE_CODE_LENGTH (code) == 2
9411 && op1 != NULL_TREE);
9416 /* Strip any conversions that don't change the mode. This is
9417 safe for every expression, except for a comparison expression
9418 because its signedness is derived from its operands. So, in
9419 the latter case, only strip conversions that don't change the
9422 Note that this is done as an internal manipulation within the
9423 constant folder, in order to find the simplest representation
9424 of the arguments so that their form can be studied. In any
9425 cases, the appropriate type conversions should be put back in
9426 the tree that will get out of the constant folder. */
9428 if (kind == tcc_comparison)
9430 STRIP_SIGN_NOPS (arg0);
9431 STRIP_SIGN_NOPS (arg1);
9439 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9440 constant but we can't do arithmetic on them. */
9441 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9442 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9443 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == FIXED_CST)
9444 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == INTEGER_CST)
9445 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9446 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9448 if (kind == tcc_binary)
9450 /* Make sure type and arg0 have the same saturating flag. */
9451 gcc_assert (TYPE_SATURATING (type)
9452 == TYPE_SATURATING (TREE_TYPE (arg0)));
9453 tem = const_binop (code, arg0, arg1, 0);
9455 else if (kind == tcc_comparison)
9456 tem = fold_relational_const (code, type, arg0, arg1);
9460 if (tem != NULL_TREE)
9462 if (TREE_TYPE (tem) != type)
9463 tem = fold_convert (type, tem);
9468 /* If this is a commutative operation, and ARG0 is a constant, move it
9469 to ARG1 to reduce the number of tests below. */
9470 if (commutative_tree_code (code)
9471 && tree_swap_operands_p (arg0, arg1, true))
9472 return fold_build2 (code, type, op1, op0);
9474 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9476 First check for cases where an arithmetic operation is applied to a
9477 compound, conditional, or comparison operation. Push the arithmetic
9478 operation inside the compound or conditional to see if any folding
9479 can then be done. Convert comparison to conditional for this purpose.
9480 The also optimizes non-constant cases that used to be done in
9483 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9484 one of the operands is a comparison and the other is a comparison, a
9485 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9486 code below would make the expression more complex. Change it to a
9487 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9488 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9490 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9491 || code == EQ_EXPR || code == NE_EXPR)
9492 && ((truth_value_p (TREE_CODE (arg0))
9493 && (truth_value_p (TREE_CODE (arg1))
9494 || (TREE_CODE (arg1) == BIT_AND_EXPR
9495 && integer_onep (TREE_OPERAND (arg1, 1)))))
9496 || (truth_value_p (TREE_CODE (arg1))
9497 && (truth_value_p (TREE_CODE (arg0))
9498 || (TREE_CODE (arg0) == BIT_AND_EXPR
9499 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9501 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9502 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9505 fold_convert (boolean_type_node, arg0),
9506 fold_convert (boolean_type_node, arg1));
9508 if (code == EQ_EXPR)
9509 tem = invert_truthvalue (tem);
9511 return fold_convert (type, tem);
9514 if (TREE_CODE_CLASS (code) == tcc_binary
9515 || TREE_CODE_CLASS (code) == tcc_comparison)
9517 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9518 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9519 fold_build2 (code, type,
9520 fold_convert (TREE_TYPE (op0),
9521 TREE_OPERAND (arg0, 1)),
9523 if (TREE_CODE (arg1) == COMPOUND_EXPR
9524 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9525 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9526 fold_build2 (code, type, op0,
9527 fold_convert (TREE_TYPE (op1),
9528 TREE_OPERAND (arg1, 1))));
9530 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9532 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9534 /*cond_first_p=*/1);
9535 if (tem != NULL_TREE)
9539 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9541 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9543 /*cond_first_p=*/0);
9544 if (tem != NULL_TREE)
9551 case POINTER_PLUS_EXPR:
9552 /* 0 +p index -> (type)index */
9553 if (integer_zerop (arg0))
9554 return non_lvalue (fold_convert (type, arg1));
9556 /* PTR +p 0 -> PTR */
9557 if (integer_zerop (arg1))
9558 return non_lvalue (fold_convert (type, arg0));
9560 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9561 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9562 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9563 return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
9564 fold_convert (sizetype, arg1),
9565 fold_convert (sizetype, arg0)));
9567 /* index +p PTR -> PTR +p index */
9568 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9569 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9570 return fold_build2 (POINTER_PLUS_EXPR, type,
9571 fold_convert (type, arg1),
9572 fold_convert (sizetype, arg0));
9574 /* (PTR +p B) +p A -> PTR +p (B + A) */
9575 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9578 tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
9579 tree arg00 = TREE_OPERAND (arg0, 0);
9580 inner = fold_build2 (PLUS_EXPR, sizetype,
9581 arg01, fold_convert (sizetype, arg1));
9582 return fold_convert (type,
9583 fold_build2 (POINTER_PLUS_EXPR,
9584 TREE_TYPE (arg00), arg00, inner));
9587 /* PTR_CST +p CST -> CST1 */
9588 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9589 return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
9591 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9592 of the array. Loop optimizer sometimes produce this type of
9594 if (TREE_CODE (arg0) == ADDR_EXPR)
9596 tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
9598 return fold_convert (type, tem);
9604 /* PTR + INT -> (INT)(PTR p+ INT) */
9605 if (POINTER_TYPE_P (TREE_TYPE (arg0))
9606 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9607 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9610 fold_convert (sizetype, arg1)));
9611 /* INT + PTR -> (INT)(PTR p+ INT) */
9612 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9613 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9614 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9617 fold_convert (sizetype, arg0)));
9618 /* A + (-B) -> A - B */
9619 if (TREE_CODE (arg1) == NEGATE_EXPR)
9620 return fold_build2 (MINUS_EXPR, type,
9621 fold_convert (type, arg0),
9622 fold_convert (type, TREE_OPERAND (arg1, 0)));
9623 /* (-A) + B -> B - A */
9624 if (TREE_CODE (arg0) == NEGATE_EXPR
9625 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9626 return fold_build2 (MINUS_EXPR, type,
9627 fold_convert (type, arg1),
9628 fold_convert (type, TREE_OPERAND (arg0, 0)));
9630 if (INTEGRAL_TYPE_P (type))
9632 /* Convert ~A + 1 to -A. */
9633 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9634 && integer_onep (arg1))
9635 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
9638 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9639 && !TYPE_OVERFLOW_TRAPS (type))
9641 tree tem = TREE_OPERAND (arg0, 0);
9644 if (operand_equal_p (tem, arg1, 0))
9646 t1 = build_int_cst_type (type, -1);
9647 return omit_one_operand (type, t1, arg1);
9652 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9653 && !TYPE_OVERFLOW_TRAPS (type))
9655 tree tem = TREE_OPERAND (arg1, 0);
9658 if (operand_equal_p (arg0, tem, 0))
9660 t1 = build_int_cst_type (type, -1);
9661 return omit_one_operand (type, t1, arg0);
9665 /* X + (X / CST) * -CST is X % CST. */
9666 if (TREE_CODE (arg1) == MULT_EXPR
9667 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9668 && operand_equal_p (arg0,
9669 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
9671 tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
9672 tree cst1 = TREE_OPERAND (arg1, 1);
9673 tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
9674 if (sum && integer_zerop (sum))
9675 return fold_convert (type,
9676 fold_build2 (TRUNC_MOD_EXPR,
9677 TREE_TYPE (arg0), arg0, cst0));
9681 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9682 same or one. Make sure type is not saturating.
9683 fold_plusminus_mult_expr will re-associate. */
9684 if ((TREE_CODE (arg0) == MULT_EXPR
9685 || TREE_CODE (arg1) == MULT_EXPR)
9686 && !TYPE_SATURATING (type)
9687 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9689 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9694 if (! FLOAT_TYPE_P (type))
9696 if (integer_zerop (arg1))
9697 return non_lvalue (fold_convert (type, arg0));
9699 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9700 with a constant, and the two constants have no bits in common,
9701 we should treat this as a BIT_IOR_EXPR since this may produce more
9703 if (TREE_CODE (arg0) == BIT_AND_EXPR
9704 && TREE_CODE (arg1) == BIT_AND_EXPR
9705 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9706 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9707 && integer_zerop (const_binop (BIT_AND_EXPR,
9708 TREE_OPERAND (arg0, 1),
9709 TREE_OPERAND (arg1, 1), 0)))
9711 code = BIT_IOR_EXPR;
9715 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9716 (plus (plus (mult) (mult)) (foo)) so that we can
9717 take advantage of the factoring cases below. */
9718 if (((TREE_CODE (arg0) == PLUS_EXPR
9719 || TREE_CODE (arg0) == MINUS_EXPR)
9720 && TREE_CODE (arg1) == MULT_EXPR)
9721 || ((TREE_CODE (arg1) == PLUS_EXPR
9722 || TREE_CODE (arg1) == MINUS_EXPR)
9723 && TREE_CODE (arg0) == MULT_EXPR))
9725 tree parg0, parg1, parg, marg;
9726 enum tree_code pcode;
9728 if (TREE_CODE (arg1) == MULT_EXPR)
9729 parg = arg0, marg = arg1;
9731 parg = arg1, marg = arg0;
9732 pcode = TREE_CODE (parg);
9733 parg0 = TREE_OPERAND (parg, 0);
9734 parg1 = TREE_OPERAND (parg, 1);
9738 if (TREE_CODE (parg0) == MULT_EXPR
9739 && TREE_CODE (parg1) != MULT_EXPR)
9740 return fold_build2 (pcode, type,
9741 fold_build2 (PLUS_EXPR, type,
9742 fold_convert (type, parg0),
9743 fold_convert (type, marg)),
9744 fold_convert (type, parg1));
9745 if (TREE_CODE (parg0) != MULT_EXPR
9746 && TREE_CODE (parg1) == MULT_EXPR)
9747 return fold_build2 (PLUS_EXPR, type,
9748 fold_convert (type, parg0),
9749 fold_build2 (pcode, type,
9750 fold_convert (type, marg),
9757 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9758 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
9759 return non_lvalue (fold_convert (type, arg0));
9761 /* Likewise if the operands are reversed. */
9762 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9763 return non_lvalue (fold_convert (type, arg1));
9765 /* Convert X + -C into X - C. */
9766 if (TREE_CODE (arg1) == REAL_CST
9767 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
9769 tem = fold_negate_const (arg1, type);
9770 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
9771 return fold_build2 (MINUS_EXPR, type,
9772 fold_convert (type, arg0),
9773 fold_convert (type, tem));
9776 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9777 to __complex__ ( x, y ). This is not the same for SNaNs or
9778 if signed zeros are involved. */
9779 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9780 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9781 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9783 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9784 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9785 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9786 bool arg0rz = false, arg0iz = false;
9787 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9788 || (arg0i && (arg0iz = real_zerop (arg0i))))
9790 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9791 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9792 if (arg0rz && arg1i && real_zerop (arg1i))
9794 tree rp = arg1r ? arg1r
9795 : build1 (REALPART_EXPR, rtype, arg1);
9796 tree ip = arg0i ? arg0i
9797 : build1 (IMAGPART_EXPR, rtype, arg0);
9798 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9800 else if (arg0iz && arg1r && real_zerop (arg1r))
9802 tree rp = arg0r ? arg0r
9803 : build1 (REALPART_EXPR, rtype, arg0);
9804 tree ip = arg1i ? arg1i
9805 : build1 (IMAGPART_EXPR, rtype, arg1);
9806 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9811 if (flag_unsafe_math_optimizations
9812 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9813 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9814 && (tem = distribute_real_division (code, type, arg0, arg1)))
9817 /* Convert x+x into x*2.0. */
9818 if (operand_equal_p (arg0, arg1, 0)
9819 && SCALAR_FLOAT_TYPE_P (type))
9820 return fold_build2 (MULT_EXPR, type, arg0,
9821 build_real (type, dconst2));
9823 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
9824 We associate floats only if the user has specified
9825 -fassociative-math. */
9826 if (flag_associative_math
9827 && TREE_CODE (arg1) == PLUS_EXPR
9828 && TREE_CODE (arg0) != MULT_EXPR)
9830 tree tree10 = TREE_OPERAND (arg1, 0);
9831 tree tree11 = TREE_OPERAND (arg1, 1);
9832 if (TREE_CODE (tree11) == MULT_EXPR
9833 && TREE_CODE (tree10) == MULT_EXPR)
9836 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
9837 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
9840 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
9841 We associate floats only if the user has specified
9842 -fassociative-math. */
9843 if (flag_associative_math
9844 && TREE_CODE (arg0) == PLUS_EXPR
9845 && TREE_CODE (arg1) != MULT_EXPR)
9847 tree tree00 = TREE_OPERAND (arg0, 0);
9848 tree tree01 = TREE_OPERAND (arg0, 1);
9849 if (TREE_CODE (tree01) == MULT_EXPR
9850 && TREE_CODE (tree00) == MULT_EXPR)
9853 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
9854 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
9860 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9861 is a rotate of A by C1 bits. */
9862 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9863 is a rotate of A by B bits. */
9865 enum tree_code code0, code1;
9866 code0 = TREE_CODE (arg0);
9867 code1 = TREE_CODE (arg1);
9868 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
9869 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
9870 && operand_equal_p (TREE_OPERAND (arg0, 0),
9871 TREE_OPERAND (arg1, 0), 0)
9872 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
9874 tree tree01, tree11;
9875 enum tree_code code01, code11;
9877 tree01 = TREE_OPERAND (arg0, 1);
9878 tree11 = TREE_OPERAND (arg1, 1);
9879 STRIP_NOPS (tree01);
9880 STRIP_NOPS (tree11);
9881 code01 = TREE_CODE (tree01);
9882 code11 = TREE_CODE (tree11);
9883 if (code01 == INTEGER_CST
9884 && code11 == INTEGER_CST
9885 && TREE_INT_CST_HIGH (tree01) == 0
9886 && TREE_INT_CST_HIGH (tree11) == 0
9887 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
9888 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
9889 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
9890 code0 == LSHIFT_EXPR ? tree01 : tree11);
9891 else if (code11 == MINUS_EXPR)
9893 tree tree110, tree111;
9894 tree110 = TREE_OPERAND (tree11, 0);
9895 tree111 = TREE_OPERAND (tree11, 1);
9896 STRIP_NOPS (tree110);
9897 STRIP_NOPS (tree111);
9898 if (TREE_CODE (tree110) == INTEGER_CST
9899 && 0 == compare_tree_int (tree110,
9901 (TREE_TYPE (TREE_OPERAND
9903 && operand_equal_p (tree01, tree111, 0))
9904 return build2 ((code0 == LSHIFT_EXPR
9907 type, TREE_OPERAND (arg0, 0), tree01);
9909 else if (code01 == MINUS_EXPR)
9911 tree tree010, tree011;
9912 tree010 = TREE_OPERAND (tree01, 0);
9913 tree011 = TREE_OPERAND (tree01, 1);
9914 STRIP_NOPS (tree010);
9915 STRIP_NOPS (tree011);
9916 if (TREE_CODE (tree010) == INTEGER_CST
9917 && 0 == compare_tree_int (tree010,
9919 (TREE_TYPE (TREE_OPERAND
9921 && operand_equal_p (tree11, tree011, 0))
9922 return build2 ((code0 != LSHIFT_EXPR
9925 type, TREE_OPERAND (arg0, 0), tree11);
9931 /* In most languages, can't associate operations on floats through
9932 parentheses. Rather than remember where the parentheses were, we
9933 don't associate floats at all, unless the user has specified
9935 And, we need to make sure type is not saturating. */
9937 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
9938 && !TYPE_SATURATING (type))
9940 tree var0, con0, lit0, minus_lit0;
9941 tree var1, con1, lit1, minus_lit1;
9944 /* Split both trees into variables, constants, and literals. Then
9945 associate each group together, the constants with literals,
9946 then the result with variables. This increases the chances of
9947 literals being recombined later and of generating relocatable
9948 expressions for the sum of a constant and literal. */
9949 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
9950 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
9951 code == MINUS_EXPR);
9953 /* With undefined overflow we can only associate constants
9954 with one variable. */
9955 if ((POINTER_TYPE_P (type)
9956 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
9962 if (TREE_CODE (tmp0) == NEGATE_EXPR)
9963 tmp0 = TREE_OPERAND (tmp0, 0);
9964 if (TREE_CODE (tmp1) == NEGATE_EXPR)
9965 tmp1 = TREE_OPERAND (tmp1, 0);
9966 /* The only case we can still associate with two variables
9967 is if they are the same, modulo negation. */
9968 if (!operand_equal_p (tmp0, tmp1, 0))
9972 /* Only do something if we found more than two objects. Otherwise,
9973 nothing has changed and we risk infinite recursion. */
9975 && (2 < ((var0 != 0) + (var1 != 0)
9976 + (con0 != 0) + (con1 != 0)
9977 + (lit0 != 0) + (lit1 != 0)
9978 + (minus_lit0 != 0) + (minus_lit1 != 0))))
9980 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9981 if (code == MINUS_EXPR)
9984 var0 = associate_trees (var0, var1, code, type);
9985 con0 = associate_trees (con0, con1, code, type);
9986 lit0 = associate_trees (lit0, lit1, code, type);
9987 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
9989 /* Preserve the MINUS_EXPR if the negative part of the literal is
9990 greater than the positive part. Otherwise, the multiplicative
9991 folding code (i.e extract_muldiv) may be fooled in case
9992 unsigned constants are subtracted, like in the following
9993 example: ((X*2 + 4) - 8U)/2. */
9994 if (minus_lit0 && lit0)
9996 if (TREE_CODE (lit0) == INTEGER_CST
9997 && TREE_CODE (minus_lit0) == INTEGER_CST
9998 && tree_int_cst_lt (lit0, minus_lit0))
10000 minus_lit0 = associate_trees (minus_lit0, lit0,
10006 lit0 = associate_trees (lit0, minus_lit0,
10014 return fold_convert (type,
10015 associate_trees (var0, minus_lit0,
10016 MINUS_EXPR, type));
10019 con0 = associate_trees (con0, minus_lit0,
10021 return fold_convert (type,
10022 associate_trees (var0, con0,
10027 con0 = associate_trees (con0, lit0, code, type);
10028 return fold_convert (type, associate_trees (var0, con0,
10036 /* Pointer simplifications for subtraction, simple reassociations. */
10037 if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
10039 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
10040 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
10041 && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
10043 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10044 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10045 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10046 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10047 return fold_build2 (PLUS_EXPR, type,
10048 fold_build2 (MINUS_EXPR, type, arg00, arg10),
10049 fold_build2 (MINUS_EXPR, type, arg01, arg11));
10051 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
10052 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
10054 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10055 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10056 tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
10058 return fold_build2 (PLUS_EXPR, type, tmp, arg01);
10061 /* A - (-B) -> A + B */
10062 if (TREE_CODE (arg1) == NEGATE_EXPR)
10063 return fold_build2 (PLUS_EXPR, type, op0,
10064 fold_convert (type, TREE_OPERAND (arg1, 0)));
10065 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
10066 if (TREE_CODE (arg0) == NEGATE_EXPR
10067 && (FLOAT_TYPE_P (type)
10068 || INTEGRAL_TYPE_P (type))
10069 && negate_expr_p (arg1)
10070 && reorder_operands_p (arg0, arg1))
10071 return fold_build2 (MINUS_EXPR, type,
10072 fold_convert (type, negate_expr (arg1)),
10073 fold_convert (type, TREE_OPERAND (arg0, 0)));
10074 /* Convert -A - 1 to ~A. */
10075 if (INTEGRAL_TYPE_P (type)
10076 && TREE_CODE (arg0) == NEGATE_EXPR
10077 && integer_onep (arg1)
10078 && !TYPE_OVERFLOW_TRAPS (type))
10079 return fold_build1 (BIT_NOT_EXPR, type,
10080 fold_convert (type, TREE_OPERAND (arg0, 0)));
10082 /* Convert -1 - A to ~A. */
10083 if (INTEGRAL_TYPE_P (type)
10084 && integer_all_onesp (arg0))
10085 return fold_build1 (BIT_NOT_EXPR, type, op1);
10088 /* X - (X / CST) * CST is X % CST. */
10089 if (INTEGRAL_TYPE_P (type)
10090 && TREE_CODE (arg1) == MULT_EXPR
10091 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
10092 && operand_equal_p (arg0,
10093 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
10094 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
10095 TREE_OPERAND (arg1, 1), 0))
10096 return fold_convert (type,
10097 fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
10098 arg0, TREE_OPERAND (arg1, 1)));
10100 if (! FLOAT_TYPE_P (type))
10102 if (integer_zerop (arg0))
10103 return negate_expr (fold_convert (type, arg1));
10104 if (integer_zerop (arg1))
10105 return non_lvalue (fold_convert (type, arg0));
10107 /* Fold A - (A & B) into ~B & A. */
10108 if (!TREE_SIDE_EFFECTS (arg0)
10109 && TREE_CODE (arg1) == BIT_AND_EXPR)
10111 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
10113 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10114 return fold_build2 (BIT_AND_EXPR, type,
10115 fold_build1 (BIT_NOT_EXPR, type, arg10),
10116 fold_convert (type, arg0));
10118 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10120 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10121 return fold_build2 (BIT_AND_EXPR, type,
10122 fold_build1 (BIT_NOT_EXPR, type, arg11),
10123 fold_convert (type, arg0));
10127 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
10128 any power of 2 minus 1. */
10129 if (TREE_CODE (arg0) == BIT_AND_EXPR
10130 && TREE_CODE (arg1) == BIT_AND_EXPR
10131 && operand_equal_p (TREE_OPERAND (arg0, 0),
10132 TREE_OPERAND (arg1, 0), 0))
10134 tree mask0 = TREE_OPERAND (arg0, 1);
10135 tree mask1 = TREE_OPERAND (arg1, 1);
10136 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
10138 if (operand_equal_p (tem, mask1, 0))
10140 tem = fold_build2 (BIT_XOR_EXPR, type,
10141 TREE_OPERAND (arg0, 0), mask1);
10142 return fold_build2 (MINUS_EXPR, type, tem, mask1);
10147 /* See if ARG1 is zero and X - ARG1 reduces to X. */
10148 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
10149 return non_lvalue (fold_convert (type, arg0));
10151 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
10152 ARG0 is zero and X + ARG0 reduces to X, since that would mean
10153 (-ARG1 + ARG0) reduces to -ARG1. */
10154 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
10155 return negate_expr (fold_convert (type, arg1));
10157 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
10158 __complex__ ( x, -y ). This is not the same for SNaNs or if
10159 signed zeros are involved. */
10160 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10161 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10162 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10164 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10165 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10166 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10167 bool arg0rz = false, arg0iz = false;
10168 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10169 || (arg0i && (arg0iz = real_zerop (arg0i))))
10171 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10172 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10173 if (arg0rz && arg1i && real_zerop (arg1i))
10175 tree rp = fold_build1 (NEGATE_EXPR, rtype,
10177 : build1 (REALPART_EXPR, rtype, arg1));
10178 tree ip = arg0i ? arg0i
10179 : build1 (IMAGPART_EXPR, rtype, arg0);
10180 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10182 else if (arg0iz && arg1r && real_zerop (arg1r))
10184 tree rp = arg0r ? arg0r
10185 : build1 (REALPART_EXPR, rtype, arg0);
10186 tree ip = fold_build1 (NEGATE_EXPR, rtype,
10188 : build1 (IMAGPART_EXPR, rtype, arg1));
10189 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10194 /* Fold &x - &x. This can happen from &x.foo - &x.
10195 This is unsafe for certain floats even in non-IEEE formats.
10196 In IEEE, it is unsafe because it does wrong for NaNs.
10197 Also note that operand_equal_p is always false if an operand
10200 if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
10201 && operand_equal_p (arg0, arg1, 0))
10202 return fold_convert (type, integer_zero_node);
10204 /* A - B -> A + (-B) if B is easily negatable. */
10205 if (negate_expr_p (arg1)
10206 && ((FLOAT_TYPE_P (type)
10207 /* Avoid this transformation if B is a positive REAL_CST. */
10208 && (TREE_CODE (arg1) != REAL_CST
10209 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
10210 || INTEGRAL_TYPE_P (type)))
10211 return fold_build2 (PLUS_EXPR, type,
10212 fold_convert (type, arg0),
10213 fold_convert (type, negate_expr (arg1)));
10215 /* Try folding difference of addresses. */
10217 HOST_WIDE_INT diff;
10219 if ((TREE_CODE (arg0) == ADDR_EXPR
10220 || TREE_CODE (arg1) == ADDR_EXPR)
10221 && ptr_difference_const (arg0, arg1, &diff))
10222 return build_int_cst_type (type, diff);
10225 /* Fold &a[i] - &a[j] to i-j. */
10226 if (TREE_CODE (arg0) == ADDR_EXPR
10227 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
10228 && TREE_CODE (arg1) == ADDR_EXPR
10229 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
10231 tree aref0 = TREE_OPERAND (arg0, 0);
10232 tree aref1 = TREE_OPERAND (arg1, 0);
10233 if (operand_equal_p (TREE_OPERAND (aref0, 0),
10234 TREE_OPERAND (aref1, 0), 0))
10236 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
10237 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
10238 tree esz = array_ref_element_size (aref0);
10239 tree diff = build2 (MINUS_EXPR, type, op0, op1);
10240 return fold_build2 (MULT_EXPR, type, diff,
10241 fold_convert (type, esz));
10246 if (flag_unsafe_math_optimizations
10247 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10248 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10249 && (tem = distribute_real_division (code, type, arg0, arg1)))
10252 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
10253 same or one. Make sure type is not saturating.
10254 fold_plusminus_mult_expr will re-associate. */
10255 if ((TREE_CODE (arg0) == MULT_EXPR
10256 || TREE_CODE (arg1) == MULT_EXPR)
10257 && !TYPE_SATURATING (type)
10258 && (!FLOAT_TYPE_P (type) || flag_associative_math))
10260 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
10268 /* (-A) * (-B) -> A * B */
10269 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10270 return fold_build2 (MULT_EXPR, type,
10271 fold_convert (type, TREE_OPERAND (arg0, 0)),
10272 fold_convert (type, negate_expr (arg1)));
10273 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10274 return fold_build2 (MULT_EXPR, type,
10275 fold_convert (type, negate_expr (arg0)),
10276 fold_convert (type, TREE_OPERAND (arg1, 0)));
10278 if (! FLOAT_TYPE_P (type))
10280 if (integer_zerop (arg1))
10281 return omit_one_operand (type, arg1, arg0);
10282 if (integer_onep (arg1))
10283 return non_lvalue (fold_convert (type, arg0));
10284 /* Transform x * -1 into -x. Make sure to do the negation
10285 on the original operand with conversions not stripped
10286 because we can only strip non-sign-changing conversions. */
10287 if (integer_all_onesp (arg1))
10288 return fold_convert (type, negate_expr (op0));
10289 /* Transform x * -C into -x * C if x is easily negatable. */
10290 if (TREE_CODE (arg1) == INTEGER_CST
10291 && tree_int_cst_sgn (arg1) == -1
10292 && negate_expr_p (arg0)
10293 && (tem = negate_expr (arg1)) != arg1
10294 && !TREE_OVERFLOW (tem))
10295 return fold_build2 (MULT_EXPR, type,
10296 fold_convert (type, negate_expr (arg0)), tem);
10298 /* (a * (1 << b)) is (a << b) */
10299 if (TREE_CODE (arg1) == LSHIFT_EXPR
10300 && integer_onep (TREE_OPERAND (arg1, 0)))
10301 return fold_build2 (LSHIFT_EXPR, type, op0,
10302 TREE_OPERAND (arg1, 1));
10303 if (TREE_CODE (arg0) == LSHIFT_EXPR
10304 && integer_onep (TREE_OPERAND (arg0, 0)))
10305 return fold_build2 (LSHIFT_EXPR, type, op1,
10306 TREE_OPERAND (arg0, 1));
10308 strict_overflow_p = false;
10309 if (TREE_CODE (arg1) == INTEGER_CST
10310 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10311 &strict_overflow_p)))
10313 if (strict_overflow_p)
10314 fold_overflow_warning (("assuming signed overflow does not "
10315 "occur when simplifying "
10317 WARN_STRICT_OVERFLOW_MISC);
10318 return fold_convert (type, tem);
10321 /* Optimize z * conj(z) for integer complex numbers. */
10322 if (TREE_CODE (arg0) == CONJ_EXPR
10323 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10324 return fold_mult_zconjz (type, arg1);
10325 if (TREE_CODE (arg1) == CONJ_EXPR
10326 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10327 return fold_mult_zconjz (type, arg0);
10331 /* Maybe fold x * 0 to 0. The expressions aren't the same
10332 when x is NaN, since x * 0 is also NaN. Nor are they the
10333 same in modes with signed zeros, since multiplying a
10334 negative value by 0 gives -0, not +0. */
10335 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10336 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10337 && real_zerop (arg1))
10338 return omit_one_operand (type, arg1, arg0);
10339 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
10340 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10341 && real_onep (arg1))
10342 return non_lvalue (fold_convert (type, arg0));
10344 /* Transform x * -1.0 into -x. */
10345 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10346 && real_minus_onep (arg1))
10347 return fold_convert (type, negate_expr (arg0));
10349 /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
10350 the result for floating point types due to rounding so it is applied
10351 only if -fassociative-math was specify. */
10352 if (flag_associative_math
10353 && TREE_CODE (arg0) == RDIV_EXPR
10354 && TREE_CODE (arg1) == REAL_CST
10355 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
10357 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
10360 return fold_build2 (RDIV_EXPR, type, tem,
10361 TREE_OPERAND (arg0, 1));
10364 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10365 if (operand_equal_p (arg0, arg1, 0))
10367 tree tem = fold_strip_sign_ops (arg0);
10368 if (tem != NULL_TREE)
10370 tem = fold_convert (type, tem);
10371 return fold_build2 (MULT_EXPR, type, tem, tem);
10375 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10376 This is not the same for NaNs or if signed zeros are
10378 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10379 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10380 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10381 && TREE_CODE (arg1) == COMPLEX_CST
10382 && real_zerop (TREE_REALPART (arg1)))
10384 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10385 if (real_onep (TREE_IMAGPART (arg1)))
10386 return fold_build2 (COMPLEX_EXPR, type,
10387 negate_expr (fold_build1 (IMAGPART_EXPR,
10389 fold_build1 (REALPART_EXPR, rtype, arg0));
10390 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10391 return fold_build2 (COMPLEX_EXPR, type,
10392 fold_build1 (IMAGPART_EXPR, rtype, arg0),
10393 negate_expr (fold_build1 (REALPART_EXPR,
10397 /* Optimize z * conj(z) for floating point complex numbers.
10398 Guarded by flag_unsafe_math_optimizations as non-finite
10399 imaginary components don't produce scalar results. */
10400 if (flag_unsafe_math_optimizations
10401 && TREE_CODE (arg0) == CONJ_EXPR
10402 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10403 return fold_mult_zconjz (type, arg1);
10404 if (flag_unsafe_math_optimizations
10405 && TREE_CODE (arg1) == CONJ_EXPR
10406 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10407 return fold_mult_zconjz (type, arg0);
10409 if (flag_unsafe_math_optimizations)
10411 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10412 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10414 /* Optimizations of root(...)*root(...). */
10415 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
10418 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10419 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10421 /* Optimize sqrt(x)*sqrt(x) as x. */
10422 if (BUILTIN_SQRT_P (fcode0)
10423 && operand_equal_p (arg00, arg10, 0)
10424 && ! HONOR_SNANS (TYPE_MODE (type)))
10427 /* Optimize root(x)*root(y) as root(x*y). */
10428 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10429 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10430 return build_call_expr (rootfn, 1, arg);
10433 /* Optimize expN(x)*expN(y) as expN(x+y). */
10434 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
10436 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10437 tree arg = fold_build2 (PLUS_EXPR, type,
10438 CALL_EXPR_ARG (arg0, 0),
10439 CALL_EXPR_ARG (arg1, 0));
10440 return build_call_expr (expfn, 1, arg);
10443 /* Optimizations of pow(...)*pow(...). */
10444 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
10445 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
10446 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
10448 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10449 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10450 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10451 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10453 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10454 if (operand_equal_p (arg01, arg11, 0))
10456 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10457 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10458 return build_call_expr (powfn, 2, arg, arg01);
10461 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10462 if (operand_equal_p (arg00, arg10, 0))
10464 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10465 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
10466 return build_call_expr (powfn, 2, arg00, arg);
10470 /* Optimize tan(x)*cos(x) as sin(x). */
10471 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
10472 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
10473 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
10474 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
10475 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
10476 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
10477 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10478 CALL_EXPR_ARG (arg1, 0), 0))
10480 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
10482 if (sinfn != NULL_TREE)
10483 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
10486 /* Optimize x*pow(x,c) as pow(x,c+1). */
10487 if (fcode1 == BUILT_IN_POW
10488 || fcode1 == BUILT_IN_POWF
10489 || fcode1 == BUILT_IN_POWL)
10491 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10492 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10493 if (TREE_CODE (arg11) == REAL_CST
10494 && !TREE_OVERFLOW (arg11)
10495 && operand_equal_p (arg0, arg10, 0))
10497 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10501 c = TREE_REAL_CST (arg11);
10502 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10503 arg = build_real (type, c);
10504 return build_call_expr (powfn, 2, arg0, arg);
10508 /* Optimize pow(x,c)*x as pow(x,c+1). */
10509 if (fcode0 == BUILT_IN_POW
10510 || fcode0 == BUILT_IN_POWF
10511 || fcode0 == BUILT_IN_POWL)
10513 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10514 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10515 if (TREE_CODE (arg01) == REAL_CST
10516 && !TREE_OVERFLOW (arg01)
10517 && operand_equal_p (arg1, arg00, 0))
10519 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10523 c = TREE_REAL_CST (arg01);
10524 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10525 arg = build_real (type, c);
10526 return build_call_expr (powfn, 2, arg1, arg);
10530 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10531 if (! optimize_size
10532 && operand_equal_p (arg0, arg1, 0))
10534 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
10538 tree arg = build_real (type, dconst2);
10539 return build_call_expr (powfn, 2, arg0, arg);
10548 if (integer_all_onesp (arg1))
10549 return omit_one_operand (type, arg1, arg0);
10550 if (integer_zerop (arg1))
10551 return non_lvalue (fold_convert (type, arg0));
10552 if (operand_equal_p (arg0, arg1, 0))
10553 return non_lvalue (fold_convert (type, arg0));
10555 /* ~X | X is -1. */
10556 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10557 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10559 t1 = fold_convert (type, integer_zero_node);
10560 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10561 return omit_one_operand (type, t1, arg1);
10564 /* X | ~X is -1. */
10565 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10566 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10568 t1 = fold_convert (type, integer_zero_node);
10569 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10570 return omit_one_operand (type, t1, arg0);
10573 /* Canonicalize (X & C1) | C2. */
10574 if (TREE_CODE (arg0) == BIT_AND_EXPR
10575 && TREE_CODE (arg1) == INTEGER_CST
10576 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10578 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, hi3, lo3, mlo, mhi;
10579 int width = TYPE_PRECISION (type), w;
10580 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10581 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10582 hi2 = TREE_INT_CST_HIGH (arg1);
10583 lo2 = TREE_INT_CST_LOW (arg1);
10585 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10586 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10587 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10589 if (width > HOST_BITS_PER_WIDE_INT)
10591 mhi = (unsigned HOST_WIDE_INT) -1
10592 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10598 mlo = (unsigned HOST_WIDE_INT) -1
10599 >> (HOST_BITS_PER_WIDE_INT - width);
10602 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10603 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10604 return fold_build2 (BIT_IOR_EXPR, type,
10605 TREE_OPERAND (arg0, 0), arg1);
10607 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
10608 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
10609 mode which allows further optimizations. */
10616 for (w = BITS_PER_UNIT;
10617 w <= width && w <= HOST_BITS_PER_WIDE_INT;
10620 unsigned HOST_WIDE_INT mask
10621 = (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
10622 if (((lo1 | lo2) & mask) == mask
10623 && (lo1 & ~mask) == 0 && hi1 == 0)
10630 if (hi3 != hi1 || lo3 != lo1)
10631 return fold_build2 (BIT_IOR_EXPR, type,
10632 fold_build2 (BIT_AND_EXPR, type,
10633 TREE_OPERAND (arg0, 0),
10634 build_int_cst_wide (type,
10639 /* (X & Y) | Y is (X, Y). */
10640 if (TREE_CODE (arg0) == BIT_AND_EXPR
10641 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10642 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10643 /* (X & Y) | X is (Y, X). */
10644 if (TREE_CODE (arg0) == BIT_AND_EXPR
10645 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10646 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10647 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10648 /* X | (X & Y) is (Y, X). */
10649 if (TREE_CODE (arg1) == BIT_AND_EXPR
10650 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10651 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10652 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10653 /* X | (Y & X) is (Y, X). */
10654 if (TREE_CODE (arg1) == BIT_AND_EXPR
10655 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10656 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10657 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10659 t1 = distribute_bit_expr (code, type, arg0, arg1);
10660 if (t1 != NULL_TREE)
10663 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10665 This results in more efficient code for machines without a NAND
10666 instruction. Combine will canonicalize to the first form
10667 which will allow use of NAND instructions provided by the
10668 backend if they exist. */
10669 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10670 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10672 return fold_build1 (BIT_NOT_EXPR, type,
10673 build2 (BIT_AND_EXPR, type,
10674 TREE_OPERAND (arg0, 0),
10675 TREE_OPERAND (arg1, 0)));
10678 /* See if this can be simplified into a rotate first. If that
10679 is unsuccessful continue in the association code. */
10683 if (integer_zerop (arg1))
10684 return non_lvalue (fold_convert (type, arg0));
10685 if (integer_all_onesp (arg1))
10686 return fold_build1 (BIT_NOT_EXPR, type, op0);
10687 if (operand_equal_p (arg0, arg1, 0))
10688 return omit_one_operand (type, integer_zero_node, arg0);
10690 /* ~X ^ X is -1. */
10691 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10692 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10694 t1 = fold_convert (type, integer_zero_node);
10695 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10696 return omit_one_operand (type, t1, arg1);
10699 /* X ^ ~X is -1. */
10700 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10701 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10703 t1 = fold_convert (type, integer_zero_node);
10704 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10705 return omit_one_operand (type, t1, arg0);
10708 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10709 with a constant, and the two constants have no bits in common,
10710 we should treat this as a BIT_IOR_EXPR since this may produce more
10711 simplifications. */
10712 if (TREE_CODE (arg0) == BIT_AND_EXPR
10713 && TREE_CODE (arg1) == BIT_AND_EXPR
10714 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10715 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10716 && integer_zerop (const_binop (BIT_AND_EXPR,
10717 TREE_OPERAND (arg0, 1),
10718 TREE_OPERAND (arg1, 1), 0)))
10720 code = BIT_IOR_EXPR;
10724 /* (X | Y) ^ X -> Y & ~ X*/
10725 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10726 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10728 tree t2 = TREE_OPERAND (arg0, 1);
10729 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10731 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10732 fold_convert (type, t1));
10736 /* (Y | X) ^ X -> Y & ~ X*/
10737 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10738 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10740 tree t2 = TREE_OPERAND (arg0, 0);
10741 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10743 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10744 fold_convert (type, t1));
10748 /* X ^ (X | Y) -> Y & ~ X*/
10749 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10750 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
10752 tree t2 = TREE_OPERAND (arg1, 1);
10753 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10755 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10756 fold_convert (type, t1));
10760 /* X ^ (Y | X) -> Y & ~ X*/
10761 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10762 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
10764 tree t2 = TREE_OPERAND (arg1, 0);
10765 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10767 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10768 fold_convert (type, t1));
10772 /* Convert ~X ^ ~Y to X ^ Y. */
10773 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10774 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10775 return fold_build2 (code, type,
10776 fold_convert (type, TREE_OPERAND (arg0, 0)),
10777 fold_convert (type, TREE_OPERAND (arg1, 0)));
10779 /* Convert ~X ^ C to X ^ ~C. */
10780 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10781 && TREE_CODE (arg1) == INTEGER_CST)
10782 return fold_build2 (code, type,
10783 fold_convert (type, TREE_OPERAND (arg0, 0)),
10784 fold_build1 (BIT_NOT_EXPR, type, arg1));
10786 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10787 if (TREE_CODE (arg0) == BIT_AND_EXPR
10788 && integer_onep (TREE_OPERAND (arg0, 1))
10789 && integer_onep (arg1))
10790 return fold_build2 (EQ_EXPR, type, arg0,
10791 build_int_cst (TREE_TYPE (arg0), 0));
10793 /* Fold (X & Y) ^ Y as ~X & Y. */
10794 if (TREE_CODE (arg0) == BIT_AND_EXPR
10795 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10797 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10798 return fold_build2 (BIT_AND_EXPR, type,
10799 fold_build1 (BIT_NOT_EXPR, type, tem),
10800 fold_convert (type, arg1));
10802 /* Fold (X & Y) ^ X as ~Y & X. */
10803 if (TREE_CODE (arg0) == BIT_AND_EXPR
10804 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10805 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10807 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10808 return fold_build2 (BIT_AND_EXPR, type,
10809 fold_build1 (BIT_NOT_EXPR, type, tem),
10810 fold_convert (type, arg1));
10812 /* Fold X ^ (X & Y) as X & ~Y. */
10813 if (TREE_CODE (arg1) == BIT_AND_EXPR
10814 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10816 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10817 return fold_build2 (BIT_AND_EXPR, type,
10818 fold_convert (type, arg0),
10819 fold_build1 (BIT_NOT_EXPR, type, tem));
10821 /* Fold X ^ (Y & X) as ~Y & X. */
10822 if (TREE_CODE (arg1) == BIT_AND_EXPR
10823 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10824 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10826 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10827 return fold_build2 (BIT_AND_EXPR, type,
10828 fold_build1 (BIT_NOT_EXPR, type, tem),
10829 fold_convert (type, arg0));
10832 /* See if this can be simplified into a rotate first. If that
10833 is unsuccessful continue in the association code. */
10837 if (integer_all_onesp (arg1))
10838 return non_lvalue (fold_convert (type, arg0));
10839 if (integer_zerop (arg1))
10840 return omit_one_operand (type, arg1, arg0);
10841 if (operand_equal_p (arg0, arg1, 0))
10842 return non_lvalue (fold_convert (type, arg0));
10844 /* ~X & X is always zero. */
10845 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10846 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10847 return omit_one_operand (type, integer_zero_node, arg1);
10849 /* X & ~X is always zero. */
10850 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10851 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10852 return omit_one_operand (type, integer_zero_node, arg0);
10854 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
10855 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10856 && TREE_CODE (arg1) == INTEGER_CST
10857 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10859 tree tmp1 = fold_convert (TREE_TYPE (arg0), arg1);
10860 tree tmp2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10861 TREE_OPERAND (arg0, 0), tmp1);
10862 tree tmp3 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10863 TREE_OPERAND (arg0, 1), tmp1);
10864 return fold_convert (type,
10865 fold_build2 (BIT_IOR_EXPR, TREE_TYPE (arg0),
10869 /* (X | Y) & Y is (X, Y). */
10870 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10871 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10872 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10873 /* (X | Y) & X is (Y, X). */
10874 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10875 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10876 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10877 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10878 /* X & (X | Y) is (Y, X). */
10879 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10880 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10881 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10882 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10883 /* X & (Y | X) is (Y, X). */
10884 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10885 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10886 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10887 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10889 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10890 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10891 && integer_onep (TREE_OPERAND (arg0, 1))
10892 && integer_onep (arg1))
10894 tem = TREE_OPERAND (arg0, 0);
10895 return fold_build2 (EQ_EXPR, type,
10896 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10897 build_int_cst (TREE_TYPE (tem), 1)),
10898 build_int_cst (TREE_TYPE (tem), 0));
10900 /* Fold ~X & 1 as (X & 1) == 0. */
10901 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10902 && integer_onep (arg1))
10904 tem = TREE_OPERAND (arg0, 0);
10905 return fold_build2 (EQ_EXPR, type,
10906 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10907 build_int_cst (TREE_TYPE (tem), 1)),
10908 build_int_cst (TREE_TYPE (tem), 0));
10911 /* Fold (X ^ Y) & Y as ~X & Y. */
10912 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10913 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10915 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10916 return fold_build2 (BIT_AND_EXPR, type,
10917 fold_build1 (BIT_NOT_EXPR, type, tem),
10918 fold_convert (type, arg1));
10920 /* Fold (X ^ Y) & X as ~Y & X. */
10921 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10922 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10923 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10925 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10926 return fold_build2 (BIT_AND_EXPR, type,
10927 fold_build1 (BIT_NOT_EXPR, type, tem),
10928 fold_convert (type, arg1));
10930 /* Fold X & (X ^ Y) as X & ~Y. */
10931 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10932 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10934 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10935 return fold_build2 (BIT_AND_EXPR, type,
10936 fold_convert (type, arg0),
10937 fold_build1 (BIT_NOT_EXPR, type, tem));
10939 /* Fold X & (Y ^ X) as ~Y & X. */
10940 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10941 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10942 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10944 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10945 return fold_build2 (BIT_AND_EXPR, type,
10946 fold_build1 (BIT_NOT_EXPR, type, tem),
10947 fold_convert (type, arg0));
10950 t1 = distribute_bit_expr (code, type, arg0, arg1);
10951 if (t1 != NULL_TREE)
10953 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10954 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
10955 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
10958 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
10960 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
10961 && (~TREE_INT_CST_LOW (arg1)
10962 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
10963 return fold_convert (type, TREE_OPERAND (arg0, 0));
10966 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
10968 This results in more efficient code for machines without a NOR
10969 instruction. Combine will canonicalize to the first form
10970 which will allow use of NOR instructions provided by the
10971 backend if they exist. */
10972 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10973 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10975 return fold_build1 (BIT_NOT_EXPR, type,
10976 build2 (BIT_IOR_EXPR, type,
10977 fold_convert (type,
10978 TREE_OPERAND (arg0, 0)),
10979 fold_convert (type,
10980 TREE_OPERAND (arg1, 0))));
10983 /* If arg0 is derived from the address of an object or function, we may
10984 be able to fold this expression using the object or function's
10986 if (POINTER_TYPE_P (TREE_TYPE (arg0)) && host_integerp (arg1, 1))
10988 unsigned HOST_WIDE_INT modulus, residue;
10989 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (arg1);
10991 modulus = get_pointer_modulus_and_residue (arg0, &residue);
10993 /* This works because modulus is a power of 2. If this weren't the
10994 case, we'd have to replace it by its greatest power-of-2
10995 divisor: modulus & -modulus. */
10997 return build_int_cst (type, residue & low);
11000 /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
11001 (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
11002 if the new mask might be further optimized. */
11003 if ((TREE_CODE (arg0) == LSHIFT_EXPR
11004 || TREE_CODE (arg0) == RSHIFT_EXPR)
11005 && host_integerp (TREE_OPERAND (arg0, 1), 1)
11006 && host_integerp (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)))
11007 && tree_low_cst (TREE_OPERAND (arg0, 1), 1)
11008 < TYPE_PRECISION (TREE_TYPE (arg0))
11009 && TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
11010 && tree_low_cst (TREE_OPERAND (arg0, 1), 1) > 0)
11012 unsigned int shiftc = tree_low_cst (TREE_OPERAND (arg0, 1), 1);
11013 unsigned HOST_WIDE_INT mask
11014 = tree_low_cst (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)));
11015 unsigned HOST_WIDE_INT newmask, zerobits = 0;
11016 tree shift_type = TREE_TYPE (arg0);
11018 if (TREE_CODE (arg0) == LSHIFT_EXPR)
11019 zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
11020 else if (TREE_CODE (arg0) == RSHIFT_EXPR
11021 && TYPE_PRECISION (TREE_TYPE (arg0))
11022 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg0))))
11024 unsigned int prec = TYPE_PRECISION (TREE_TYPE (arg0));
11025 tree arg00 = TREE_OPERAND (arg0, 0);
11026 /* See if more bits can be proven as zero because of
11028 if (TREE_CODE (arg00) == NOP_EXPR
11029 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
11031 tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
11032 if (TYPE_PRECISION (inner_type)
11033 == GET_MODE_BITSIZE (TYPE_MODE (inner_type))
11034 && TYPE_PRECISION (inner_type) < prec)
11036 prec = TYPE_PRECISION (inner_type);
11037 /* See if we can shorten the right shift. */
11039 shift_type = inner_type;
11042 zerobits = ~(unsigned HOST_WIDE_INT) 0;
11043 zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
11044 zerobits <<= prec - shiftc;
11045 /* For arithmetic shift if sign bit could be set, zerobits
11046 can contain actually sign bits, so no transformation is
11047 possible, unless MASK masks them all away. In that
11048 case the shift needs to be converted into logical shift. */
11049 if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
11050 && prec == TYPE_PRECISION (TREE_TYPE (arg0)))
11052 if ((mask & zerobits) == 0)
11053 shift_type = unsigned_type_for (TREE_TYPE (arg0));
11059 /* ((X << 16) & 0xff00) is (X, 0). */
11060 if ((mask & zerobits) == mask)
11061 return omit_one_operand (type, build_int_cst (type, 0), arg0);
11063 newmask = mask | zerobits;
11064 if (newmask != mask && (newmask & (newmask + 1)) == 0)
11068 /* Only do the transformation if NEWMASK is some integer
11070 for (prec = BITS_PER_UNIT;
11071 prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
11072 if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
11074 if (prec < HOST_BITS_PER_WIDE_INT
11075 || newmask == ~(unsigned HOST_WIDE_INT) 0)
11077 if (shift_type != TREE_TYPE (arg0))
11079 tem = fold_build2 (TREE_CODE (arg0), shift_type,
11080 fold_convert (shift_type,
11081 TREE_OPERAND (arg0, 0)),
11082 TREE_OPERAND (arg0, 1));
11083 tem = fold_convert (type, tem);
11087 return fold_build2 (BIT_AND_EXPR, type, tem,
11088 build_int_cst_type (TREE_TYPE (op1),
11097 /* Don't touch a floating-point divide by zero unless the mode
11098 of the constant can represent infinity. */
11099 if (TREE_CODE (arg1) == REAL_CST
11100 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
11101 && real_zerop (arg1))
11104 /* Optimize A / A to 1.0 if we don't care about
11105 NaNs or Infinities. Skip the transformation
11106 for non-real operands. */
11107 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
11108 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
11109 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
11110 && operand_equal_p (arg0, arg1, 0))
11112 tree r = build_real (TREE_TYPE (arg0), dconst1);
11114 return omit_two_operands (type, r, arg0, arg1);
11117 /* The complex version of the above A / A optimization. */
11118 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
11119 && operand_equal_p (arg0, arg1, 0))
11121 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
11122 if (! HONOR_NANS (TYPE_MODE (elem_type))
11123 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
11125 tree r = build_real (elem_type, dconst1);
11126 /* omit_two_operands will call fold_convert for us. */
11127 return omit_two_operands (type, r, arg0, arg1);
11131 /* (-A) / (-B) -> A / B */
11132 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
11133 return fold_build2 (RDIV_EXPR, type,
11134 TREE_OPERAND (arg0, 0),
11135 negate_expr (arg1));
11136 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
11137 return fold_build2 (RDIV_EXPR, type,
11138 negate_expr (arg0),
11139 TREE_OPERAND (arg1, 0));
11141 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
11142 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11143 && real_onep (arg1))
11144 return non_lvalue (fold_convert (type, arg0));
11146 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
11147 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11148 && real_minus_onep (arg1))
11149 return non_lvalue (fold_convert (type, negate_expr (arg0)));
11151 /* If ARG1 is a constant, we can convert this to a multiply by the
11152 reciprocal. This does not have the same rounding properties,
11153 so only do this if -freciprocal-math. We can actually
11154 always safely do it if ARG1 is a power of two, but it's hard to
11155 tell if it is or not in a portable manner. */
11156 if (TREE_CODE (arg1) == REAL_CST)
11158 if (flag_reciprocal_math
11159 && 0 != (tem = const_binop (code, build_real (type, dconst1),
11161 return fold_build2 (MULT_EXPR, type, arg0, tem);
11162 /* Find the reciprocal if optimizing and the result is exact. */
11166 r = TREE_REAL_CST (arg1);
11167 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
11169 tem = build_real (type, r);
11170 return fold_build2 (MULT_EXPR, type,
11171 fold_convert (type, arg0), tem);
11175 /* Convert A/B/C to A/(B*C). */
11176 if (flag_reciprocal_math
11177 && TREE_CODE (arg0) == RDIV_EXPR)
11178 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
11179 fold_build2 (MULT_EXPR, type,
11180 TREE_OPERAND (arg0, 1), arg1));
11182 /* Convert A/(B/C) to (A/B)*C. */
11183 if (flag_reciprocal_math
11184 && TREE_CODE (arg1) == RDIV_EXPR)
11185 return fold_build2 (MULT_EXPR, type,
11186 fold_build2 (RDIV_EXPR, type, arg0,
11187 TREE_OPERAND (arg1, 0)),
11188 TREE_OPERAND (arg1, 1));
11190 /* Convert C1/(X*C2) into (C1/C2)/X. */
11191 if (flag_reciprocal_math
11192 && TREE_CODE (arg1) == MULT_EXPR
11193 && TREE_CODE (arg0) == REAL_CST
11194 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
11196 tree tem = const_binop (RDIV_EXPR, arg0,
11197 TREE_OPERAND (arg1, 1), 0);
11199 return fold_build2 (RDIV_EXPR, type, tem,
11200 TREE_OPERAND (arg1, 0));
11203 if (flag_unsafe_math_optimizations)
11205 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
11206 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
11208 /* Optimize sin(x)/cos(x) as tan(x). */
11209 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
11210 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
11211 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
11212 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11213 CALL_EXPR_ARG (arg1, 0), 0))
11215 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11217 if (tanfn != NULL_TREE)
11218 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11221 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
11222 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
11223 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
11224 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
11225 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11226 CALL_EXPR_ARG (arg1, 0), 0))
11228 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11230 if (tanfn != NULL_TREE)
11232 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11233 return fold_build2 (RDIV_EXPR, type,
11234 build_real (type, dconst1), tmp);
11238 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
11239 NaNs or Infinities. */
11240 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
11241 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
11242 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
11244 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11245 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11247 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11248 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11249 && operand_equal_p (arg00, arg01, 0))
11251 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11253 if (cosfn != NULL_TREE)
11254 return build_call_expr (cosfn, 1, arg00);
11258 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11259 NaNs or Infinities. */
11260 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
11261 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
11262 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
11264 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11265 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11267 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11268 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11269 && operand_equal_p (arg00, arg01, 0))
11271 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11273 if (cosfn != NULL_TREE)
11275 tree tmp = build_call_expr (cosfn, 1, arg00);
11276 return fold_build2 (RDIV_EXPR, type,
11277 build_real (type, dconst1),
11283 /* Optimize pow(x,c)/x as pow(x,c-1). */
11284 if (fcode0 == BUILT_IN_POW
11285 || fcode0 == BUILT_IN_POWF
11286 || fcode0 == BUILT_IN_POWL)
11288 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11289 tree arg01 = CALL_EXPR_ARG (arg0, 1);
11290 if (TREE_CODE (arg01) == REAL_CST
11291 && !TREE_OVERFLOW (arg01)
11292 && operand_equal_p (arg1, arg00, 0))
11294 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
11298 c = TREE_REAL_CST (arg01);
11299 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
11300 arg = build_real (type, c);
11301 return build_call_expr (powfn, 2, arg1, arg);
11305 /* Optimize a/root(b/c) into a*root(c/b). */
11306 if (BUILTIN_ROOT_P (fcode1))
11308 tree rootarg = CALL_EXPR_ARG (arg1, 0);
11310 if (TREE_CODE (rootarg) == RDIV_EXPR)
11312 tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11313 tree b = TREE_OPERAND (rootarg, 0);
11314 tree c = TREE_OPERAND (rootarg, 1);
11316 tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
11318 tmp = build_call_expr (rootfn, 1, tmp);
11319 return fold_build2 (MULT_EXPR, type, arg0, tmp);
11323 /* Optimize x/expN(y) into x*expN(-y). */
11324 if (BUILTIN_EXPONENT_P (fcode1))
11326 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11327 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
11328 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
11329 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11332 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11333 if (fcode1 == BUILT_IN_POW
11334 || fcode1 == BUILT_IN_POWF
11335 || fcode1 == BUILT_IN_POWL)
11337 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11338 tree arg10 = CALL_EXPR_ARG (arg1, 0);
11339 tree arg11 = CALL_EXPR_ARG (arg1, 1);
11340 tree neg11 = fold_convert (type, negate_expr (arg11));
11341 arg1 = build_call_expr (powfn, 2, arg10, neg11);
11342 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11347 case TRUNC_DIV_EXPR:
11348 case FLOOR_DIV_EXPR:
11349 /* Simplify A / (B << N) where A and B are positive and B is
11350 a power of 2, to A >> (N + log2(B)). */
11351 strict_overflow_p = false;
11352 if (TREE_CODE (arg1) == LSHIFT_EXPR
11353 && (TYPE_UNSIGNED (type)
11354 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11356 tree sval = TREE_OPERAND (arg1, 0);
11357 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
11359 tree sh_cnt = TREE_OPERAND (arg1, 1);
11360 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
11362 if (strict_overflow_p)
11363 fold_overflow_warning (("assuming signed overflow does not "
11364 "occur when simplifying A / (B << N)"),
11365 WARN_STRICT_OVERFLOW_MISC);
11367 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
11368 sh_cnt, build_int_cst (NULL_TREE, pow2));
11369 return fold_build2 (RSHIFT_EXPR, type,
11370 fold_convert (type, arg0), sh_cnt);
11374 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
11375 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
11376 if (INTEGRAL_TYPE_P (type)
11377 && TYPE_UNSIGNED (type)
11378 && code == FLOOR_DIV_EXPR)
11379 return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
11383 case ROUND_DIV_EXPR:
11384 case CEIL_DIV_EXPR:
11385 case EXACT_DIV_EXPR:
11386 if (integer_onep (arg1))
11387 return non_lvalue (fold_convert (type, arg0));
11388 if (integer_zerop (arg1))
11390 /* X / -1 is -X. */
11391 if (!TYPE_UNSIGNED (type)
11392 && TREE_CODE (arg1) == INTEGER_CST
11393 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11394 && TREE_INT_CST_HIGH (arg1) == -1)
11395 return fold_convert (type, negate_expr (arg0));
11397 /* Convert -A / -B to A / B when the type is signed and overflow is
11399 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11400 && TREE_CODE (arg0) == NEGATE_EXPR
11401 && negate_expr_p (arg1))
11403 if (INTEGRAL_TYPE_P (type))
11404 fold_overflow_warning (("assuming signed overflow does not occur "
11405 "when distributing negation across "
11407 WARN_STRICT_OVERFLOW_MISC);
11408 return fold_build2 (code, type,
11409 fold_convert (type, TREE_OPERAND (arg0, 0)),
11410 negate_expr (arg1));
11412 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11413 && TREE_CODE (arg1) == NEGATE_EXPR
11414 && negate_expr_p (arg0))
11416 if (INTEGRAL_TYPE_P (type))
11417 fold_overflow_warning (("assuming signed overflow does not occur "
11418 "when distributing negation across "
11420 WARN_STRICT_OVERFLOW_MISC);
11421 return fold_build2 (code, type, negate_expr (arg0),
11422 TREE_OPERAND (arg1, 0));
11425 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11426 operation, EXACT_DIV_EXPR.
11428 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11429 At one time others generated faster code, it's not clear if they do
11430 after the last round to changes to the DIV code in expmed.c. */
11431 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
11432 && multiple_of_p (type, arg0, arg1))
11433 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
11435 strict_overflow_p = false;
11436 if (TREE_CODE (arg1) == INTEGER_CST
11437 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11438 &strict_overflow_p)))
11440 if (strict_overflow_p)
11441 fold_overflow_warning (("assuming signed overflow does not occur "
11442 "when simplifying division"),
11443 WARN_STRICT_OVERFLOW_MISC);
11444 return fold_convert (type, tem);
11449 case CEIL_MOD_EXPR:
11450 case FLOOR_MOD_EXPR:
11451 case ROUND_MOD_EXPR:
11452 case TRUNC_MOD_EXPR:
11453 /* X % 1 is always zero, but be sure to preserve any side
11455 if (integer_onep (arg1))
11456 return omit_one_operand (type, integer_zero_node, arg0);
11458 /* X % 0, return X % 0 unchanged so that we can get the
11459 proper warnings and errors. */
11460 if (integer_zerop (arg1))
11463 /* 0 % X is always zero, but be sure to preserve any side
11464 effects in X. Place this after checking for X == 0. */
11465 if (integer_zerop (arg0))
11466 return omit_one_operand (type, integer_zero_node, arg1);
11468 /* X % -1 is zero. */
11469 if (!TYPE_UNSIGNED (type)
11470 && TREE_CODE (arg1) == INTEGER_CST
11471 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11472 && TREE_INT_CST_HIGH (arg1) == -1)
11473 return omit_one_operand (type, integer_zero_node, arg0);
11475 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11476 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11477 strict_overflow_p = false;
11478 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
11479 && (TYPE_UNSIGNED (type)
11480 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11483 /* Also optimize A % (C << N) where C is a power of 2,
11484 to A & ((C << N) - 1). */
11485 if (TREE_CODE (arg1) == LSHIFT_EXPR)
11486 c = TREE_OPERAND (arg1, 0);
11488 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
11490 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
11491 build_int_cst (TREE_TYPE (arg1), 1));
11492 if (strict_overflow_p)
11493 fold_overflow_warning (("assuming signed overflow does not "
11494 "occur when simplifying "
11495 "X % (power of two)"),
11496 WARN_STRICT_OVERFLOW_MISC);
11497 return fold_build2 (BIT_AND_EXPR, type,
11498 fold_convert (type, arg0),
11499 fold_convert (type, mask));
11503 /* X % -C is the same as X % C. */
11504 if (code == TRUNC_MOD_EXPR
11505 && !TYPE_UNSIGNED (type)
11506 && TREE_CODE (arg1) == INTEGER_CST
11507 && !TREE_OVERFLOW (arg1)
11508 && TREE_INT_CST_HIGH (arg1) < 0
11509 && !TYPE_OVERFLOW_TRAPS (type)
11510 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11511 && !sign_bit_p (arg1, arg1))
11512 return fold_build2 (code, type, fold_convert (type, arg0),
11513 fold_convert (type, negate_expr (arg1)));
11515 /* X % -Y is the same as X % Y. */
11516 if (code == TRUNC_MOD_EXPR
11517 && !TYPE_UNSIGNED (type)
11518 && TREE_CODE (arg1) == NEGATE_EXPR
11519 && !TYPE_OVERFLOW_TRAPS (type))
11520 return fold_build2 (code, type, fold_convert (type, arg0),
11521 fold_convert (type, TREE_OPERAND (arg1, 0)));
11523 if (TREE_CODE (arg1) == INTEGER_CST
11524 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11525 &strict_overflow_p)))
11527 if (strict_overflow_p)
11528 fold_overflow_warning (("assuming signed overflow does not occur "
11529 "when simplifying modulos"),
11530 WARN_STRICT_OVERFLOW_MISC);
11531 return fold_convert (type, tem);
11538 if (integer_all_onesp (arg0))
11539 return omit_one_operand (type, arg0, arg1);
11543 /* Optimize -1 >> x for arithmetic right shifts. */
11544 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
11545 return omit_one_operand (type, arg0, arg1);
11546 /* ... fall through ... */
11550 if (integer_zerop (arg1))
11551 return non_lvalue (fold_convert (type, arg0));
11552 if (integer_zerop (arg0))
11553 return omit_one_operand (type, arg0, arg1);
11555 /* Since negative shift count is not well-defined,
11556 don't try to compute it in the compiler. */
11557 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
11560 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11561 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
11562 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11563 && host_integerp (TREE_OPERAND (arg0, 1), false)
11564 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11566 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
11567 + TREE_INT_CST_LOW (arg1));
11569 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11570 being well defined. */
11571 if (low >= TYPE_PRECISION (type))
11573 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
11574 low = low % TYPE_PRECISION (type);
11575 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
11576 return build_int_cst (type, 0);
11578 low = TYPE_PRECISION (type) - 1;
11581 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11582 build_int_cst (type, low));
11585 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11586 into x & ((unsigned)-1 >> c) for unsigned types. */
11587 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
11588 || (TYPE_UNSIGNED (type)
11589 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
11590 && host_integerp (arg1, false)
11591 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11592 && host_integerp (TREE_OPERAND (arg0, 1), false)
11593 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11595 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
11596 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
11602 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
11604 lshift = build_int_cst (type, -1);
11605 lshift = int_const_binop (code, lshift, arg1, 0);
11607 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
11611 /* Rewrite an LROTATE_EXPR by a constant into an
11612 RROTATE_EXPR by a new constant. */
11613 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
11615 tree tem = build_int_cst (TREE_TYPE (arg1),
11616 GET_MODE_BITSIZE (TYPE_MODE (type)));
11617 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
11618 return fold_build2 (RROTATE_EXPR, type, op0, tem);
11621 /* If we have a rotate of a bit operation with the rotate count and
11622 the second operand of the bit operation both constant,
11623 permute the two operations. */
11624 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11625 && (TREE_CODE (arg0) == BIT_AND_EXPR
11626 || TREE_CODE (arg0) == BIT_IOR_EXPR
11627 || TREE_CODE (arg0) == BIT_XOR_EXPR)
11628 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11629 return fold_build2 (TREE_CODE (arg0), type,
11630 fold_build2 (code, type,
11631 TREE_OPERAND (arg0, 0), arg1),
11632 fold_build2 (code, type,
11633 TREE_OPERAND (arg0, 1), arg1));
11635 /* Two consecutive rotates adding up to the width of the mode can
11637 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11638 && TREE_CODE (arg0) == RROTATE_EXPR
11639 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11640 && TREE_INT_CST_HIGH (arg1) == 0
11641 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
11642 && ((TREE_INT_CST_LOW (arg1)
11643 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
11644 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
11645 return TREE_OPERAND (arg0, 0);
11647 /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
11648 (X & C2) >> C1 into (X >> C1) & (C2 >> C1)
11649 if the latter can be further optimized. */
11650 if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
11651 && TREE_CODE (arg0) == BIT_AND_EXPR
11652 && TREE_CODE (arg1) == INTEGER_CST
11653 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11655 tree mask = fold_build2 (code, type,
11656 fold_convert (type, TREE_OPERAND (arg0, 1)),
11658 tree shift = fold_build2 (code, type,
11659 fold_convert (type, TREE_OPERAND (arg0, 0)),
11661 tem = fold_binary (BIT_AND_EXPR, type, shift, mask);
11669 if (operand_equal_p (arg0, arg1, 0))
11670 return omit_one_operand (type, arg0, arg1);
11671 if (INTEGRAL_TYPE_P (type)
11672 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
11673 return omit_one_operand (type, arg1, arg0);
11674 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
11680 if (operand_equal_p (arg0, arg1, 0))
11681 return omit_one_operand (type, arg0, arg1);
11682 if (INTEGRAL_TYPE_P (type)
11683 && TYPE_MAX_VALUE (type)
11684 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
11685 return omit_one_operand (type, arg1, arg0);
11686 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
11691 case TRUTH_ANDIF_EXPR:
11692 /* Note that the operands of this must be ints
11693 and their values must be 0 or 1.
11694 ("true" is a fixed value perhaps depending on the language.) */
11695 /* If first arg is constant zero, return it. */
11696 if (integer_zerop (arg0))
11697 return fold_convert (type, arg0);
11698 case TRUTH_AND_EXPR:
11699 /* If either arg is constant true, drop it. */
11700 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11701 return non_lvalue (fold_convert (type, arg1));
11702 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
11703 /* Preserve sequence points. */
11704 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11705 return non_lvalue (fold_convert (type, arg0));
11706 /* If second arg is constant zero, result is zero, but first arg
11707 must be evaluated. */
11708 if (integer_zerop (arg1))
11709 return omit_one_operand (type, arg1, arg0);
11710 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11711 case will be handled here. */
11712 if (integer_zerop (arg0))
11713 return omit_one_operand (type, arg0, arg1);
11715 /* !X && X is always false. */
11716 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11717 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11718 return omit_one_operand (type, integer_zero_node, arg1);
11719 /* X && !X is always false. */
11720 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11721 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11722 return omit_one_operand (type, integer_zero_node, arg0);
11724 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
11725 means A >= Y && A != MAX, but in this case we know that
11728 if (!TREE_SIDE_EFFECTS (arg0)
11729 && !TREE_SIDE_EFFECTS (arg1))
11731 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
11732 if (tem && !operand_equal_p (tem, arg0, 0))
11733 return fold_build2 (code, type, tem, arg1);
11735 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
11736 if (tem && !operand_equal_p (tem, arg1, 0))
11737 return fold_build2 (code, type, arg0, tem);
11741 /* We only do these simplifications if we are optimizing. */
11745 /* Check for things like (A || B) && (A || C). We can convert this
11746 to A || (B && C). Note that either operator can be any of the four
11747 truth and/or operations and the transformation will still be
11748 valid. Also note that we only care about order for the
11749 ANDIF and ORIF operators. If B contains side effects, this
11750 might change the truth-value of A. */
11751 if (TREE_CODE (arg0) == TREE_CODE (arg1)
11752 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
11753 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
11754 || TREE_CODE (arg0) == TRUTH_AND_EXPR
11755 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
11756 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
11758 tree a00 = TREE_OPERAND (arg0, 0);
11759 tree a01 = TREE_OPERAND (arg0, 1);
11760 tree a10 = TREE_OPERAND (arg1, 0);
11761 tree a11 = TREE_OPERAND (arg1, 1);
11762 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
11763 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
11764 && (code == TRUTH_AND_EXPR
11765 || code == TRUTH_OR_EXPR));
11767 if (operand_equal_p (a00, a10, 0))
11768 return fold_build2 (TREE_CODE (arg0), type, a00,
11769 fold_build2 (code, type, a01, a11));
11770 else if (commutative && operand_equal_p (a00, a11, 0))
11771 return fold_build2 (TREE_CODE (arg0), type, a00,
11772 fold_build2 (code, type, a01, a10));
11773 else if (commutative && operand_equal_p (a01, a10, 0))
11774 return fold_build2 (TREE_CODE (arg0), type, a01,
11775 fold_build2 (code, type, a00, a11));
11777 /* This case if tricky because we must either have commutative
11778 operators or else A10 must not have side-effects. */
11780 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
11781 && operand_equal_p (a01, a11, 0))
11782 return fold_build2 (TREE_CODE (arg0), type,
11783 fold_build2 (code, type, a00, a10),
11787 /* See if we can build a range comparison. */
11788 if (0 != (tem = fold_range_test (code, type, op0, op1)))
11791 /* Check for the possibility of merging component references. If our
11792 lhs is another similar operation, try to merge its rhs with our
11793 rhs. Then try to merge our lhs and rhs. */
11794 if (TREE_CODE (arg0) == code
11795 && 0 != (tem = fold_truthop (code, type,
11796 TREE_OPERAND (arg0, 1), arg1)))
11797 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11799 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
11804 case TRUTH_ORIF_EXPR:
11805 /* Note that the operands of this must be ints
11806 and their values must be 0 or true.
11807 ("true" is a fixed value perhaps depending on the language.) */
11808 /* If first arg is constant true, return it. */
11809 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11810 return fold_convert (type, arg0);
11811 case TRUTH_OR_EXPR:
11812 /* If either arg is constant zero, drop it. */
11813 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
11814 return non_lvalue (fold_convert (type, arg1));
11815 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
11816 /* Preserve sequence points. */
11817 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11818 return non_lvalue (fold_convert (type, arg0));
11819 /* If second arg is constant true, result is true, but we must
11820 evaluate first arg. */
11821 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
11822 return omit_one_operand (type, arg1, arg0);
11823 /* Likewise for first arg, but note this only occurs here for
11825 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11826 return omit_one_operand (type, arg0, arg1);
11828 /* !X || X is always true. */
11829 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11830 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11831 return omit_one_operand (type, integer_one_node, arg1);
11832 /* X || !X is always true. */
11833 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11834 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11835 return omit_one_operand (type, integer_one_node, arg0);
11839 case TRUTH_XOR_EXPR:
11840 /* If the second arg is constant zero, drop it. */
11841 if (integer_zerop (arg1))
11842 return non_lvalue (fold_convert (type, arg0));
11843 /* If the second arg is constant true, this is a logical inversion. */
11844 if (integer_onep (arg1))
11846 /* Only call invert_truthvalue if operand is a truth value. */
11847 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
11848 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
11850 tem = invert_truthvalue (arg0);
11851 return non_lvalue (fold_convert (type, tem));
11853 /* Identical arguments cancel to zero. */
11854 if (operand_equal_p (arg0, arg1, 0))
11855 return omit_one_operand (type, integer_zero_node, arg0);
11857 /* !X ^ X is always true. */
11858 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11859 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11860 return omit_one_operand (type, integer_one_node, arg1);
11862 /* X ^ !X is always true. */
11863 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11864 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11865 return omit_one_operand (type, integer_one_node, arg0);
11871 tem = fold_comparison (code, type, op0, op1);
11872 if (tem != NULL_TREE)
11875 /* bool_var != 0 becomes bool_var. */
11876 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11877 && code == NE_EXPR)
11878 return non_lvalue (fold_convert (type, arg0));
11880 /* bool_var == 1 becomes bool_var. */
11881 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11882 && code == EQ_EXPR)
11883 return non_lvalue (fold_convert (type, arg0));
11885 /* bool_var != 1 becomes !bool_var. */
11886 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11887 && code == NE_EXPR)
11888 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11890 /* bool_var == 0 becomes !bool_var. */
11891 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11892 && code == EQ_EXPR)
11893 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11895 /* If this is an equality comparison of the address of two non-weak,
11896 unaliased symbols neither of which are extern (since we do not
11897 have access to attributes for externs), then we know the result. */
11898 if (TREE_CODE (arg0) == ADDR_EXPR
11899 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
11900 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
11901 && ! lookup_attribute ("alias",
11902 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
11903 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
11904 && TREE_CODE (arg1) == ADDR_EXPR
11905 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
11906 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
11907 && ! lookup_attribute ("alias",
11908 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
11909 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
11911 /* We know that we're looking at the address of two
11912 non-weak, unaliased, static _DECL nodes.
11914 It is both wasteful and incorrect to call operand_equal_p
11915 to compare the two ADDR_EXPR nodes. It is wasteful in that
11916 all we need to do is test pointer equality for the arguments
11917 to the two ADDR_EXPR nodes. It is incorrect to use
11918 operand_equal_p as that function is NOT equivalent to a
11919 C equality test. It can in fact return false for two
11920 objects which would test as equal using the C equality
11922 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
11923 return constant_boolean_node (equal
11924 ? code == EQ_EXPR : code != EQ_EXPR,
11928 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
11929 a MINUS_EXPR of a constant, we can convert it into a comparison with
11930 a revised constant as long as no overflow occurs. */
11931 if (TREE_CODE (arg1) == INTEGER_CST
11932 && (TREE_CODE (arg0) == PLUS_EXPR
11933 || TREE_CODE (arg0) == MINUS_EXPR)
11934 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11935 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
11936 ? MINUS_EXPR : PLUS_EXPR,
11937 fold_convert (TREE_TYPE (arg0), arg1),
11938 TREE_OPERAND (arg0, 1), 0))
11939 && !TREE_OVERFLOW (tem))
11940 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11942 /* Similarly for a NEGATE_EXPR. */
11943 if (TREE_CODE (arg0) == NEGATE_EXPR
11944 && TREE_CODE (arg1) == INTEGER_CST
11945 && 0 != (tem = negate_expr (arg1))
11946 && TREE_CODE (tem) == INTEGER_CST
11947 && !TREE_OVERFLOW (tem))
11948 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11950 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
11951 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11952 && TREE_CODE (arg1) == INTEGER_CST
11953 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11954 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11955 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
11956 fold_convert (TREE_TYPE (arg0), arg1),
11957 TREE_OPERAND (arg0, 1)));
11959 /* Transform comparisons of the form X +- C CMP X. */
11960 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11961 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11962 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11963 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
11964 || POINTER_TYPE_P (TREE_TYPE (arg0))))
11966 tree cst = TREE_OPERAND (arg0, 1);
11968 if (code == EQ_EXPR
11969 && !integer_zerop (cst))
11970 return omit_two_operands (type, boolean_false_node,
11971 TREE_OPERAND (arg0, 0), arg1);
11973 return omit_two_operands (type, boolean_true_node,
11974 TREE_OPERAND (arg0, 0), arg1);
11977 /* If we have X - Y == 0, we can convert that to X == Y and similarly
11978 for !=. Don't do this for ordered comparisons due to overflow. */
11979 if (TREE_CODE (arg0) == MINUS_EXPR
11980 && integer_zerop (arg1))
11981 return fold_build2 (code, type,
11982 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
11984 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
11985 if (TREE_CODE (arg0) == ABS_EXPR
11986 && (integer_zerop (arg1) || real_zerop (arg1)))
11987 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
11989 /* If this is an EQ or NE comparison with zero and ARG0 is
11990 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
11991 two operations, but the latter can be done in one less insn
11992 on machines that have only two-operand insns or on which a
11993 constant cannot be the first operand. */
11994 if (TREE_CODE (arg0) == BIT_AND_EXPR
11995 && integer_zerop (arg1))
11997 tree arg00 = TREE_OPERAND (arg0, 0);
11998 tree arg01 = TREE_OPERAND (arg0, 1);
11999 if (TREE_CODE (arg00) == LSHIFT_EXPR
12000 && integer_onep (TREE_OPERAND (arg00, 0)))
12002 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
12003 arg01, TREE_OPERAND (arg00, 1));
12004 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
12005 build_int_cst (TREE_TYPE (arg0), 1));
12006 return fold_build2 (code, type,
12007 fold_convert (TREE_TYPE (arg1), tem), arg1);
12009 else if (TREE_CODE (arg01) == LSHIFT_EXPR
12010 && integer_onep (TREE_OPERAND (arg01, 0)))
12012 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
12013 arg00, TREE_OPERAND (arg01, 1));
12014 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
12015 build_int_cst (TREE_TYPE (arg0), 1));
12016 return fold_build2 (code, type,
12017 fold_convert (TREE_TYPE (arg1), tem), arg1);
12021 /* If this is an NE or EQ comparison of zero against the result of a
12022 signed MOD operation whose second operand is a power of 2, make
12023 the MOD operation unsigned since it is simpler and equivalent. */
12024 if (integer_zerop (arg1)
12025 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
12026 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
12027 || TREE_CODE (arg0) == CEIL_MOD_EXPR
12028 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
12029 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
12030 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12032 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
12033 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
12034 fold_convert (newtype,
12035 TREE_OPERAND (arg0, 0)),
12036 fold_convert (newtype,
12037 TREE_OPERAND (arg0, 1)));
12039 return fold_build2 (code, type, newmod,
12040 fold_convert (newtype, arg1));
12043 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
12044 C1 is a valid shift constant, and C2 is a power of two, i.e.
12046 if (TREE_CODE (arg0) == BIT_AND_EXPR
12047 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
12048 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
12050 && integer_pow2p (TREE_OPERAND (arg0, 1))
12051 && integer_zerop (arg1))
12053 tree itype = TREE_TYPE (arg0);
12054 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
12055 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
12057 /* Check for a valid shift count. */
12058 if (TREE_INT_CST_HIGH (arg001) == 0
12059 && TREE_INT_CST_LOW (arg001) < prec)
12061 tree arg01 = TREE_OPERAND (arg0, 1);
12062 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12063 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
12064 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
12065 can be rewritten as (X & (C2 << C1)) != 0. */
12066 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
12068 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
12069 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
12070 return fold_build2 (code, type, tem, arg1);
12072 /* Otherwise, for signed (arithmetic) shifts,
12073 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
12074 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
12075 else if (!TYPE_UNSIGNED (itype))
12076 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
12077 arg000, build_int_cst (itype, 0));
12078 /* Otherwise, of unsigned (logical) shifts,
12079 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
12080 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
12082 return omit_one_operand (type,
12083 code == EQ_EXPR ? integer_one_node
12084 : integer_zero_node,
12089 /* If this is an NE comparison of zero with an AND of one, remove the
12090 comparison since the AND will give the correct value. */
12091 if (code == NE_EXPR
12092 && integer_zerop (arg1)
12093 && TREE_CODE (arg0) == BIT_AND_EXPR
12094 && integer_onep (TREE_OPERAND (arg0, 1)))
12095 return fold_convert (type, arg0);
12097 /* If we have (A & C) == C where C is a power of 2, convert this into
12098 (A & C) != 0. Similarly for NE_EXPR. */
12099 if (TREE_CODE (arg0) == BIT_AND_EXPR
12100 && integer_pow2p (TREE_OPERAND (arg0, 1))
12101 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12102 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12103 arg0, fold_convert (TREE_TYPE (arg0),
12104 integer_zero_node));
12106 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
12107 bit, then fold the expression into A < 0 or A >= 0. */
12108 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
12112 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
12113 Similarly for NE_EXPR. */
12114 if (TREE_CODE (arg0) == BIT_AND_EXPR
12115 && TREE_CODE (arg1) == INTEGER_CST
12116 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12118 tree notc = fold_build1 (BIT_NOT_EXPR,
12119 TREE_TYPE (TREE_OPERAND (arg0, 1)),
12120 TREE_OPERAND (arg0, 1));
12121 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12123 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
12124 if (integer_nonzerop (dandnotc))
12125 return omit_one_operand (type, rslt, arg0);
12128 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
12129 Similarly for NE_EXPR. */
12130 if (TREE_CODE (arg0) == BIT_IOR_EXPR
12131 && TREE_CODE (arg1) == INTEGER_CST
12132 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12134 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
12135 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12136 TREE_OPERAND (arg0, 1), notd);
12137 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
12138 if (integer_nonzerop (candnotd))
12139 return omit_one_operand (type, rslt, arg0);
12142 /* If this is a comparison of a field, we may be able to simplify it. */
12143 if ((TREE_CODE (arg0) == COMPONENT_REF
12144 || TREE_CODE (arg0) == BIT_FIELD_REF)
12145 /* Handle the constant case even without -O
12146 to make sure the warnings are given. */
12147 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
12149 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
12154 /* Optimize comparisons of strlen vs zero to a compare of the
12155 first character of the string vs zero. To wit,
12156 strlen(ptr) == 0 => *ptr == 0
12157 strlen(ptr) != 0 => *ptr != 0
12158 Other cases should reduce to one of these two (or a constant)
12159 due to the return value of strlen being unsigned. */
12160 if (TREE_CODE (arg0) == CALL_EXPR
12161 && integer_zerop (arg1))
12163 tree fndecl = get_callee_fndecl (arg0);
12166 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
12167 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
12168 && call_expr_nargs (arg0) == 1
12169 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
12171 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
12172 return fold_build2 (code, type, iref,
12173 build_int_cst (TREE_TYPE (iref), 0));
12177 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
12178 of X. Similarly fold (X >> C) == 0 into X >= 0. */
12179 if (TREE_CODE (arg0) == RSHIFT_EXPR
12180 && integer_zerop (arg1)
12181 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12183 tree arg00 = TREE_OPERAND (arg0, 0);
12184 tree arg01 = TREE_OPERAND (arg0, 1);
12185 tree itype = TREE_TYPE (arg00);
12186 if (TREE_INT_CST_HIGH (arg01) == 0
12187 && TREE_INT_CST_LOW (arg01)
12188 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
12190 if (TYPE_UNSIGNED (itype))
12192 itype = signed_type_for (itype);
12193 arg00 = fold_convert (itype, arg00);
12195 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
12196 type, arg00, build_int_cst (itype, 0));
12200 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
12201 if (integer_zerop (arg1)
12202 && TREE_CODE (arg0) == BIT_XOR_EXPR)
12203 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12204 TREE_OPERAND (arg0, 1));
12206 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
12207 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12208 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12209 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12210 build_int_cst (TREE_TYPE (arg1), 0));
12211 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
12212 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12213 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12214 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
12215 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
12216 build_int_cst (TREE_TYPE (arg1), 0));
12218 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
12219 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12220 && TREE_CODE (arg1) == INTEGER_CST
12221 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12222 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12223 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
12224 TREE_OPERAND (arg0, 1), arg1));
12226 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
12227 (X & C) == 0 when C is a single bit. */
12228 if (TREE_CODE (arg0) == BIT_AND_EXPR
12229 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
12230 && integer_zerop (arg1)
12231 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12233 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12234 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
12235 TREE_OPERAND (arg0, 1));
12236 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
12240 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12241 constant C is a power of two, i.e. a single bit. */
12242 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12243 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12244 && integer_zerop (arg1)
12245 && integer_pow2p (TREE_OPERAND (arg0, 1))
12246 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12247 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12249 tree arg00 = TREE_OPERAND (arg0, 0);
12250 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12251 arg00, build_int_cst (TREE_TYPE (arg00), 0));
12254 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12255 when is C is a power of two, i.e. a single bit. */
12256 if (TREE_CODE (arg0) == BIT_AND_EXPR
12257 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
12258 && integer_zerop (arg1)
12259 && integer_pow2p (TREE_OPERAND (arg0, 1))
12260 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12261 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12263 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12264 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
12265 arg000, TREE_OPERAND (arg0, 1));
12266 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12267 tem, build_int_cst (TREE_TYPE (tem), 0));
12270 if (integer_zerop (arg1)
12271 && tree_expr_nonzero_p (arg0))
12273 tree res = constant_boolean_node (code==NE_EXPR, type);
12274 return omit_one_operand (type, res, arg0);
12277 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12278 if (TREE_CODE (arg0) == NEGATE_EXPR
12279 && TREE_CODE (arg1) == NEGATE_EXPR)
12280 return fold_build2 (code, type,
12281 TREE_OPERAND (arg0, 0),
12282 TREE_OPERAND (arg1, 0));
12284 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12285 if (TREE_CODE (arg0) == BIT_AND_EXPR
12286 && TREE_CODE (arg1) == BIT_AND_EXPR)
12288 tree arg00 = TREE_OPERAND (arg0, 0);
12289 tree arg01 = TREE_OPERAND (arg0, 1);
12290 tree arg10 = TREE_OPERAND (arg1, 0);
12291 tree arg11 = TREE_OPERAND (arg1, 1);
12292 tree itype = TREE_TYPE (arg0);
12294 if (operand_equal_p (arg01, arg11, 0))
12295 return fold_build2 (code, type,
12296 fold_build2 (BIT_AND_EXPR, itype,
12297 fold_build2 (BIT_XOR_EXPR, itype,
12300 build_int_cst (itype, 0));
12302 if (operand_equal_p (arg01, arg10, 0))
12303 return fold_build2 (code, type,
12304 fold_build2 (BIT_AND_EXPR, itype,
12305 fold_build2 (BIT_XOR_EXPR, itype,
12308 build_int_cst (itype, 0));
12310 if (operand_equal_p (arg00, arg11, 0))
12311 return fold_build2 (code, type,
12312 fold_build2 (BIT_AND_EXPR, itype,
12313 fold_build2 (BIT_XOR_EXPR, itype,
12316 build_int_cst (itype, 0));
12318 if (operand_equal_p (arg00, arg10, 0))
12319 return fold_build2 (code, type,
12320 fold_build2 (BIT_AND_EXPR, itype,
12321 fold_build2 (BIT_XOR_EXPR, itype,
12324 build_int_cst (itype, 0));
12327 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12328 && TREE_CODE (arg1) == BIT_XOR_EXPR)
12330 tree arg00 = TREE_OPERAND (arg0, 0);
12331 tree arg01 = TREE_OPERAND (arg0, 1);
12332 tree arg10 = TREE_OPERAND (arg1, 0);
12333 tree arg11 = TREE_OPERAND (arg1, 1);
12334 tree itype = TREE_TYPE (arg0);
12336 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12337 operand_equal_p guarantees no side-effects so we don't need
12338 to use omit_one_operand on Z. */
12339 if (operand_equal_p (arg01, arg11, 0))
12340 return fold_build2 (code, type, arg00, arg10);
12341 if (operand_equal_p (arg01, arg10, 0))
12342 return fold_build2 (code, type, arg00, arg11);
12343 if (operand_equal_p (arg00, arg11, 0))
12344 return fold_build2 (code, type, arg01, arg10);
12345 if (operand_equal_p (arg00, arg10, 0))
12346 return fold_build2 (code, type, arg01, arg11);
12348 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12349 if (TREE_CODE (arg01) == INTEGER_CST
12350 && TREE_CODE (arg11) == INTEGER_CST)
12351 return fold_build2 (code, type,
12352 fold_build2 (BIT_XOR_EXPR, itype, arg00,
12353 fold_build2 (BIT_XOR_EXPR, itype,
12358 /* Attempt to simplify equality/inequality comparisons of complex
12359 values. Only lower the comparison if the result is known or
12360 can be simplified to a single scalar comparison. */
12361 if ((TREE_CODE (arg0) == COMPLEX_EXPR
12362 || TREE_CODE (arg0) == COMPLEX_CST)
12363 && (TREE_CODE (arg1) == COMPLEX_EXPR
12364 || TREE_CODE (arg1) == COMPLEX_CST))
12366 tree real0, imag0, real1, imag1;
12369 if (TREE_CODE (arg0) == COMPLEX_EXPR)
12371 real0 = TREE_OPERAND (arg0, 0);
12372 imag0 = TREE_OPERAND (arg0, 1);
12376 real0 = TREE_REALPART (arg0);
12377 imag0 = TREE_IMAGPART (arg0);
12380 if (TREE_CODE (arg1) == COMPLEX_EXPR)
12382 real1 = TREE_OPERAND (arg1, 0);
12383 imag1 = TREE_OPERAND (arg1, 1);
12387 real1 = TREE_REALPART (arg1);
12388 imag1 = TREE_IMAGPART (arg1);
12391 rcond = fold_binary (code, type, real0, real1);
12392 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
12394 if (integer_zerop (rcond))
12396 if (code == EQ_EXPR)
12397 return omit_two_operands (type, boolean_false_node,
12399 return fold_build2 (NE_EXPR, type, imag0, imag1);
12403 if (code == NE_EXPR)
12404 return omit_two_operands (type, boolean_true_node,
12406 return fold_build2 (EQ_EXPR, type, imag0, imag1);
12410 icond = fold_binary (code, type, imag0, imag1);
12411 if (icond && TREE_CODE (icond) == INTEGER_CST)
12413 if (integer_zerop (icond))
12415 if (code == EQ_EXPR)
12416 return omit_two_operands (type, boolean_false_node,
12418 return fold_build2 (NE_EXPR, type, real0, real1);
12422 if (code == NE_EXPR)
12423 return omit_two_operands (type, boolean_true_node,
12425 return fold_build2 (EQ_EXPR, type, real0, real1);
12436 tem = fold_comparison (code, type, op0, op1);
12437 if (tem != NULL_TREE)
12440 /* Transform comparisons of the form X +- C CMP X. */
12441 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12442 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12443 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
12444 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
12445 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12446 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
12448 tree arg01 = TREE_OPERAND (arg0, 1);
12449 enum tree_code code0 = TREE_CODE (arg0);
12452 if (TREE_CODE (arg01) == REAL_CST)
12453 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
12455 is_positive = tree_int_cst_sgn (arg01);
12457 /* (X - c) > X becomes false. */
12458 if (code == GT_EXPR
12459 && ((code0 == MINUS_EXPR && is_positive >= 0)
12460 || (code0 == PLUS_EXPR && is_positive <= 0)))
12462 if (TREE_CODE (arg01) == INTEGER_CST
12463 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12464 fold_overflow_warning (("assuming signed overflow does not "
12465 "occur when assuming that (X - c) > X "
12466 "is always false"),
12467 WARN_STRICT_OVERFLOW_ALL);
12468 return constant_boolean_node (0, type);
12471 /* Likewise (X + c) < X becomes false. */
12472 if (code == LT_EXPR
12473 && ((code0 == PLUS_EXPR && is_positive >= 0)
12474 || (code0 == MINUS_EXPR && is_positive <= 0)))
12476 if (TREE_CODE (arg01) == INTEGER_CST
12477 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12478 fold_overflow_warning (("assuming signed overflow does not "
12479 "occur when assuming that "
12480 "(X + c) < X is always false"),
12481 WARN_STRICT_OVERFLOW_ALL);
12482 return constant_boolean_node (0, type);
12485 /* Convert (X - c) <= X to true. */
12486 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12488 && ((code0 == MINUS_EXPR && is_positive >= 0)
12489 || (code0 == PLUS_EXPR && is_positive <= 0)))
12491 if (TREE_CODE (arg01) == INTEGER_CST
12492 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12493 fold_overflow_warning (("assuming signed overflow does not "
12494 "occur when assuming that "
12495 "(X - c) <= X is always true"),
12496 WARN_STRICT_OVERFLOW_ALL);
12497 return constant_boolean_node (1, type);
12500 /* Convert (X + c) >= X to true. */
12501 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12503 && ((code0 == PLUS_EXPR && is_positive >= 0)
12504 || (code0 == MINUS_EXPR && is_positive <= 0)))
12506 if (TREE_CODE (arg01) == INTEGER_CST
12507 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12508 fold_overflow_warning (("assuming signed overflow does not "
12509 "occur when assuming that "
12510 "(X + c) >= X is always true"),
12511 WARN_STRICT_OVERFLOW_ALL);
12512 return constant_boolean_node (1, type);
12515 if (TREE_CODE (arg01) == INTEGER_CST)
12517 /* Convert X + c > X and X - c < X to true for integers. */
12518 if (code == GT_EXPR
12519 && ((code0 == PLUS_EXPR && is_positive > 0)
12520 || (code0 == MINUS_EXPR && is_positive < 0)))
12522 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12523 fold_overflow_warning (("assuming signed overflow does "
12524 "not occur when assuming that "
12525 "(X + c) > X is always true"),
12526 WARN_STRICT_OVERFLOW_ALL);
12527 return constant_boolean_node (1, type);
12530 if (code == LT_EXPR
12531 && ((code0 == MINUS_EXPR && is_positive > 0)
12532 || (code0 == PLUS_EXPR && is_positive < 0)))
12534 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12535 fold_overflow_warning (("assuming signed overflow does "
12536 "not occur when assuming that "
12537 "(X - c) < X is always true"),
12538 WARN_STRICT_OVERFLOW_ALL);
12539 return constant_boolean_node (1, type);
12542 /* Convert X + c <= X and X - c >= X to false for integers. */
12543 if (code == LE_EXPR
12544 && ((code0 == PLUS_EXPR && is_positive > 0)
12545 || (code0 == MINUS_EXPR && is_positive < 0)))
12547 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12548 fold_overflow_warning (("assuming signed overflow does "
12549 "not occur when assuming that "
12550 "(X + c) <= X is always false"),
12551 WARN_STRICT_OVERFLOW_ALL);
12552 return constant_boolean_node (0, type);
12555 if (code == GE_EXPR
12556 && ((code0 == MINUS_EXPR && is_positive > 0)
12557 || (code0 == PLUS_EXPR && is_positive < 0)))
12559 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12560 fold_overflow_warning (("assuming signed overflow does "
12561 "not occur when assuming that "
12562 "(X - c) >= X is always false"),
12563 WARN_STRICT_OVERFLOW_ALL);
12564 return constant_boolean_node (0, type);
12569 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
12570 This transformation affects the cases which are handled in later
12571 optimizations involving comparisons with non-negative constants. */
12572 if (TREE_CODE (arg1) == INTEGER_CST
12573 && TREE_CODE (arg0) != INTEGER_CST
12574 && tree_int_cst_sgn (arg1) > 0)
12576 if (code == GE_EXPR)
12578 arg1 = const_binop (MINUS_EXPR, arg1,
12579 build_int_cst (TREE_TYPE (arg1), 1), 0);
12580 return fold_build2 (GT_EXPR, type, arg0,
12581 fold_convert (TREE_TYPE (arg0), arg1));
12583 if (code == LT_EXPR)
12585 arg1 = const_binop (MINUS_EXPR, arg1,
12586 build_int_cst (TREE_TYPE (arg1), 1), 0);
12587 return fold_build2 (LE_EXPR, type, arg0,
12588 fold_convert (TREE_TYPE (arg0), arg1));
12592 /* Comparisons with the highest or lowest possible integer of
12593 the specified precision will have known values. */
12595 tree arg1_type = TREE_TYPE (arg1);
12596 unsigned int width = TYPE_PRECISION (arg1_type);
12598 if (TREE_CODE (arg1) == INTEGER_CST
12599 && !TREE_OVERFLOW (arg1)
12600 && width <= 2 * HOST_BITS_PER_WIDE_INT
12601 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
12603 HOST_WIDE_INT signed_max_hi;
12604 unsigned HOST_WIDE_INT signed_max_lo;
12605 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
12607 if (width <= HOST_BITS_PER_WIDE_INT)
12609 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12614 if (TYPE_UNSIGNED (arg1_type))
12616 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12622 max_lo = signed_max_lo;
12623 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12629 width -= HOST_BITS_PER_WIDE_INT;
12630 signed_max_lo = -1;
12631 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12636 if (TYPE_UNSIGNED (arg1_type))
12638 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12643 max_hi = signed_max_hi;
12644 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12648 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
12649 && TREE_INT_CST_LOW (arg1) == max_lo)
12653 return omit_one_operand (type, integer_zero_node, arg0);
12656 return fold_build2 (EQ_EXPR, type, op0, op1);
12659 return omit_one_operand (type, integer_one_node, arg0);
12662 return fold_build2 (NE_EXPR, type, op0, op1);
12664 /* The GE_EXPR and LT_EXPR cases above are not normally
12665 reached because of previous transformations. */
12670 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12672 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
12676 arg1 = const_binop (PLUS_EXPR, arg1,
12677 build_int_cst (TREE_TYPE (arg1), 1), 0);
12678 return fold_build2 (EQ_EXPR, type,
12679 fold_convert (TREE_TYPE (arg1), arg0),
12682 arg1 = const_binop (PLUS_EXPR, arg1,
12683 build_int_cst (TREE_TYPE (arg1), 1), 0);
12684 return fold_build2 (NE_EXPR, type,
12685 fold_convert (TREE_TYPE (arg1), arg0),
12690 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12692 && TREE_INT_CST_LOW (arg1) == min_lo)
12696 return omit_one_operand (type, integer_zero_node, arg0);
12699 return fold_build2 (EQ_EXPR, type, op0, op1);
12702 return omit_one_operand (type, integer_one_node, arg0);
12705 return fold_build2 (NE_EXPR, type, op0, op1);
12710 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12712 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
12716 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12717 return fold_build2 (NE_EXPR, type,
12718 fold_convert (TREE_TYPE (arg1), arg0),
12721 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12722 return fold_build2 (EQ_EXPR, type,
12723 fold_convert (TREE_TYPE (arg1), arg0),
12729 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
12730 && TREE_INT_CST_LOW (arg1) == signed_max_lo
12731 && TYPE_UNSIGNED (arg1_type)
12732 /* We will flip the signedness of the comparison operator
12733 associated with the mode of arg1, so the sign bit is
12734 specified by this mode. Check that arg1 is the signed
12735 max associated with this sign bit. */
12736 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
12737 /* signed_type does not work on pointer types. */
12738 && INTEGRAL_TYPE_P (arg1_type))
12740 /* The following case also applies to X < signed_max+1
12741 and X >= signed_max+1 because previous transformations. */
12742 if (code == LE_EXPR || code == GT_EXPR)
12745 st = signed_type_for (TREE_TYPE (arg1));
12746 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
12747 type, fold_convert (st, arg0),
12748 build_int_cst (st, 0));
12754 /* If we are comparing an ABS_EXPR with a constant, we can
12755 convert all the cases into explicit comparisons, but they may
12756 well not be faster than doing the ABS and one comparison.
12757 But ABS (X) <= C is a range comparison, which becomes a subtraction
12758 and a comparison, and is probably faster. */
12759 if (code == LE_EXPR
12760 && TREE_CODE (arg1) == INTEGER_CST
12761 && TREE_CODE (arg0) == ABS_EXPR
12762 && ! TREE_SIDE_EFFECTS (arg0)
12763 && (0 != (tem = negate_expr (arg1)))
12764 && TREE_CODE (tem) == INTEGER_CST
12765 && !TREE_OVERFLOW (tem))
12766 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12767 build2 (GE_EXPR, type,
12768 TREE_OPERAND (arg0, 0), tem),
12769 build2 (LE_EXPR, type,
12770 TREE_OPERAND (arg0, 0), arg1));
12772 /* Convert ABS_EXPR<x> >= 0 to true. */
12773 strict_overflow_p = false;
12774 if (code == GE_EXPR
12775 && (integer_zerop (arg1)
12776 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
12777 && real_zerop (arg1)))
12778 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12780 if (strict_overflow_p)
12781 fold_overflow_warning (("assuming signed overflow does not occur "
12782 "when simplifying comparison of "
12783 "absolute value and zero"),
12784 WARN_STRICT_OVERFLOW_CONDITIONAL);
12785 return omit_one_operand (type, integer_one_node, arg0);
12788 /* Convert ABS_EXPR<x> < 0 to false. */
12789 strict_overflow_p = false;
12790 if (code == LT_EXPR
12791 && (integer_zerop (arg1) || real_zerop (arg1))
12792 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12794 if (strict_overflow_p)
12795 fold_overflow_warning (("assuming signed overflow does not occur "
12796 "when simplifying comparison of "
12797 "absolute value and zero"),
12798 WARN_STRICT_OVERFLOW_CONDITIONAL);
12799 return omit_one_operand (type, integer_zero_node, arg0);
12802 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
12803 and similarly for >= into !=. */
12804 if ((code == LT_EXPR || code == GE_EXPR)
12805 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12806 && TREE_CODE (arg1) == LSHIFT_EXPR
12807 && integer_onep (TREE_OPERAND (arg1, 0)))
12808 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12809 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12810 TREE_OPERAND (arg1, 1)),
12811 build_int_cst (TREE_TYPE (arg0), 0));
12813 if ((code == LT_EXPR || code == GE_EXPR)
12814 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12815 && (TREE_CODE (arg1) == NOP_EXPR
12816 || TREE_CODE (arg1) == CONVERT_EXPR)
12817 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
12818 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
12820 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12821 fold_convert (TREE_TYPE (arg0),
12822 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12823 TREE_OPERAND (TREE_OPERAND (arg1, 0),
12825 build_int_cst (TREE_TYPE (arg0), 0));
12829 case UNORDERED_EXPR:
12837 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
12839 t1 = fold_relational_const (code, type, arg0, arg1);
12840 if (t1 != NULL_TREE)
12844 /* If the first operand is NaN, the result is constant. */
12845 if (TREE_CODE (arg0) == REAL_CST
12846 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
12847 && (code != LTGT_EXPR || ! flag_trapping_math))
12849 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12850 ? integer_zero_node
12851 : integer_one_node;
12852 return omit_one_operand (type, t1, arg1);
12855 /* If the second operand is NaN, the result is constant. */
12856 if (TREE_CODE (arg1) == REAL_CST
12857 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
12858 && (code != LTGT_EXPR || ! flag_trapping_math))
12860 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12861 ? integer_zero_node
12862 : integer_one_node;
12863 return omit_one_operand (type, t1, arg0);
12866 /* Simplify unordered comparison of something with itself. */
12867 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
12868 && operand_equal_p (arg0, arg1, 0))
12869 return constant_boolean_node (1, type);
12871 if (code == LTGT_EXPR
12872 && !flag_trapping_math
12873 && operand_equal_p (arg0, arg1, 0))
12874 return constant_boolean_node (0, type);
12876 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12878 tree targ0 = strip_float_extensions (arg0);
12879 tree targ1 = strip_float_extensions (arg1);
12880 tree newtype = TREE_TYPE (targ0);
12882 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
12883 newtype = TREE_TYPE (targ1);
12885 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
12886 return fold_build2 (code, type, fold_convert (newtype, targ0),
12887 fold_convert (newtype, targ1));
12892 case COMPOUND_EXPR:
12893 /* When pedantic, a compound expression can be neither an lvalue
12894 nor an integer constant expression. */
12895 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
12897 /* Don't let (0, 0) be null pointer constant. */
12898 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
12899 : fold_convert (type, arg1);
12900 return pedantic_non_lvalue (tem);
12903 if ((TREE_CODE (arg0) == REAL_CST
12904 && TREE_CODE (arg1) == REAL_CST)
12905 || (TREE_CODE (arg0) == INTEGER_CST
12906 && TREE_CODE (arg1) == INTEGER_CST))
12907 return build_complex (type, arg0, arg1);
12911 /* An ASSERT_EXPR should never be passed to fold_binary. */
12912 gcc_unreachable ();
12916 } /* switch (code) */
12919 /* Callback for walk_tree, looking for LABEL_EXPR.
12920 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
12921 Do not check the sub-tree of GOTO_EXPR. */
12924 contains_label_1 (tree *tp,
12925 int *walk_subtrees,
12926 void *data ATTRIBUTE_UNUSED)
12928 switch (TREE_CODE (*tp))
12933 *walk_subtrees = 0;
12940 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
12941 accessible from outside the sub-tree. Returns NULL_TREE if no
12942 addressable label is found. */
12945 contains_label_p (tree st)
12947 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
12950 /* Fold a ternary expression of code CODE and type TYPE with operands
12951 OP0, OP1, and OP2. Return the folded expression if folding is
12952 successful. Otherwise, return NULL_TREE. */
12955 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
12958 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
12959 enum tree_code_class kind = TREE_CODE_CLASS (code);
12961 gcc_assert (IS_EXPR_CODE_CLASS (kind)
12962 && TREE_CODE_LENGTH (code) == 3);
12964 /* Strip any conversions that don't change the mode. This is safe
12965 for every expression, except for a comparison expression because
12966 its signedness is derived from its operands. So, in the latter
12967 case, only strip conversions that don't change the signedness.
12969 Note that this is done as an internal manipulation within the
12970 constant folder, in order to find the simplest representation of
12971 the arguments so that their form can be studied. In any cases,
12972 the appropriate type conversions should be put back in the tree
12973 that will get out of the constant folder. */
12988 case COMPONENT_REF:
12989 if (TREE_CODE (arg0) == CONSTRUCTOR
12990 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
12992 unsigned HOST_WIDE_INT idx;
12994 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
13001 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
13002 so all simple results must be passed through pedantic_non_lvalue. */
13003 if (TREE_CODE (arg0) == INTEGER_CST)
13005 tree unused_op = integer_zerop (arg0) ? op1 : op2;
13006 tem = integer_zerop (arg0) ? op2 : op1;
13007 /* Only optimize constant conditions when the selected branch
13008 has the same type as the COND_EXPR. This avoids optimizing
13009 away "c ? x : throw", where the throw has a void type.
13010 Avoid throwing away that operand which contains label. */
13011 if ((!TREE_SIDE_EFFECTS (unused_op)
13012 || !contains_label_p (unused_op))
13013 && (! VOID_TYPE_P (TREE_TYPE (tem))
13014 || VOID_TYPE_P (type)))
13015 return pedantic_non_lvalue (tem);
13018 if (operand_equal_p (arg1, op2, 0))
13019 return pedantic_omit_one_operand (type, arg1, arg0);
13021 /* If we have A op B ? A : C, we may be able to convert this to a
13022 simpler expression, depending on the operation and the values
13023 of B and C. Signed zeros prevent all of these transformations,
13024 for reasons given above each one.
13026 Also try swapping the arguments and inverting the conditional. */
13027 if (COMPARISON_CLASS_P (arg0)
13028 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
13029 arg1, TREE_OPERAND (arg0, 1))
13030 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
13032 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
13037 if (COMPARISON_CLASS_P (arg0)
13038 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
13040 TREE_OPERAND (arg0, 1))
13041 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
13043 tem = fold_truth_not_expr (arg0);
13044 if (tem && COMPARISON_CLASS_P (tem))
13046 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
13052 /* If the second operand is simpler than the third, swap them
13053 since that produces better jump optimization results. */
13054 if (truth_value_p (TREE_CODE (arg0))
13055 && tree_swap_operands_p (op1, op2, false))
13057 /* See if this can be inverted. If it can't, possibly because
13058 it was a floating-point inequality comparison, don't do
13060 tem = fold_truth_not_expr (arg0);
13062 return fold_build3 (code, type, tem, op2, op1);
13065 /* Convert A ? 1 : 0 to simply A. */
13066 if (integer_onep (op1)
13067 && integer_zerop (op2)
13068 /* If we try to convert OP0 to our type, the
13069 call to fold will try to move the conversion inside
13070 a COND, which will recurse. In that case, the COND_EXPR
13071 is probably the best choice, so leave it alone. */
13072 && type == TREE_TYPE (arg0))
13073 return pedantic_non_lvalue (arg0);
13075 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
13076 over COND_EXPR in cases such as floating point comparisons. */
13077 if (integer_zerop (op1)
13078 && integer_onep (op2)
13079 && truth_value_p (TREE_CODE (arg0)))
13080 return pedantic_non_lvalue (fold_convert (type,
13081 invert_truthvalue (arg0)));
13083 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
13084 if (TREE_CODE (arg0) == LT_EXPR
13085 && integer_zerop (TREE_OPERAND (arg0, 1))
13086 && integer_zerop (op2)
13087 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
13089 /* sign_bit_p only checks ARG1 bits within A's precision.
13090 If <sign bit of A> has wider type than A, bits outside
13091 of A's precision in <sign bit of A> need to be checked.
13092 If they are all 0, this optimization needs to be done
13093 in unsigned A's type, if they are all 1 in signed A's type,
13094 otherwise this can't be done. */
13095 if (TYPE_PRECISION (TREE_TYPE (tem))
13096 < TYPE_PRECISION (TREE_TYPE (arg1))
13097 && TYPE_PRECISION (TREE_TYPE (tem))
13098 < TYPE_PRECISION (type))
13100 unsigned HOST_WIDE_INT mask_lo;
13101 HOST_WIDE_INT mask_hi;
13102 int inner_width, outer_width;
13105 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
13106 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
13107 if (outer_width > TYPE_PRECISION (type))
13108 outer_width = TYPE_PRECISION (type);
13110 if (outer_width > HOST_BITS_PER_WIDE_INT)
13112 mask_hi = ((unsigned HOST_WIDE_INT) -1
13113 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
13119 mask_lo = ((unsigned HOST_WIDE_INT) -1
13120 >> (HOST_BITS_PER_WIDE_INT - outer_width));
13122 if (inner_width > HOST_BITS_PER_WIDE_INT)
13124 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
13125 >> (HOST_BITS_PER_WIDE_INT - inner_width));
13129 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
13130 >> (HOST_BITS_PER_WIDE_INT - inner_width));
13132 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
13133 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
13135 tem_type = signed_type_for (TREE_TYPE (tem));
13136 tem = fold_convert (tem_type, tem);
13138 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
13139 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
13141 tem_type = unsigned_type_for (TREE_TYPE (tem));
13142 tem = fold_convert (tem_type, tem);
13149 return fold_convert (type,
13150 fold_build2 (BIT_AND_EXPR,
13151 TREE_TYPE (tem), tem,
13152 fold_convert (TREE_TYPE (tem),
13156 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
13157 already handled above. */
13158 if (TREE_CODE (arg0) == BIT_AND_EXPR
13159 && integer_onep (TREE_OPERAND (arg0, 1))
13160 && integer_zerop (op2)
13161 && integer_pow2p (arg1))
13163 tree tem = TREE_OPERAND (arg0, 0);
13165 if (TREE_CODE (tem) == RSHIFT_EXPR
13166 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
13167 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
13168 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
13169 return fold_build2 (BIT_AND_EXPR, type,
13170 TREE_OPERAND (tem, 0), arg1);
13173 /* A & N ? N : 0 is simply A & N if N is a power of two. This
13174 is probably obsolete because the first operand should be a
13175 truth value (that's why we have the two cases above), but let's
13176 leave it in until we can confirm this for all front-ends. */
13177 if (integer_zerop (op2)
13178 && TREE_CODE (arg0) == NE_EXPR
13179 && integer_zerop (TREE_OPERAND (arg0, 1))
13180 && integer_pow2p (arg1)
13181 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
13182 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
13183 arg1, OEP_ONLY_CONST))
13184 return pedantic_non_lvalue (fold_convert (type,
13185 TREE_OPERAND (arg0, 0)));
13187 /* Convert A ? B : 0 into A && B if A and B are truth values. */
13188 if (integer_zerop (op2)
13189 && truth_value_p (TREE_CODE (arg0))
13190 && truth_value_p (TREE_CODE (arg1)))
13191 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13192 fold_convert (type, arg0),
13195 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
13196 if (integer_onep (op2)
13197 && truth_value_p (TREE_CODE (arg0))
13198 && truth_value_p (TREE_CODE (arg1)))
13200 /* Only perform transformation if ARG0 is easily inverted. */
13201 tem = fold_truth_not_expr (arg0);
13203 return fold_build2 (TRUTH_ORIF_EXPR, type,
13204 fold_convert (type, tem),
13208 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
13209 if (integer_zerop (arg1)
13210 && truth_value_p (TREE_CODE (arg0))
13211 && truth_value_p (TREE_CODE (op2)))
13213 /* Only perform transformation if ARG0 is easily inverted. */
13214 tem = fold_truth_not_expr (arg0);
13216 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13217 fold_convert (type, tem),
13221 /* Convert A ? 1 : B into A || B if A and B are truth values. */
13222 if (integer_onep (arg1)
13223 && truth_value_p (TREE_CODE (arg0))
13224 && truth_value_p (TREE_CODE (op2)))
13225 return fold_build2 (TRUTH_ORIF_EXPR, type,
13226 fold_convert (type, arg0),
13232 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
13233 of fold_ternary on them. */
13234 gcc_unreachable ();
13236 case BIT_FIELD_REF:
13237 if ((TREE_CODE (arg0) == VECTOR_CST
13238 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
13239 && type == TREE_TYPE (TREE_TYPE (arg0))
13240 && host_integerp (arg1, 1)
13241 && host_integerp (op2, 1))
13243 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
13244 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
13247 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
13248 && (idx % width) == 0
13249 && (idx = idx / width)
13250 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
13252 tree elements = NULL_TREE;
13254 if (TREE_CODE (arg0) == VECTOR_CST)
13255 elements = TREE_VECTOR_CST_ELTS (arg0);
13258 unsigned HOST_WIDE_INT idx;
13261 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
13262 elements = tree_cons (NULL_TREE, value, elements);
13264 while (idx-- > 0 && elements)
13265 elements = TREE_CHAIN (elements);
13267 return TREE_VALUE (elements);
13269 return fold_convert (type, integer_zero_node);
13276 } /* switch (code) */
13279 /* Perform constant folding and related simplification of EXPR.
13280 The related simplifications include x*1 => x, x*0 => 0, etc.,
13281 and application of the associative law.
13282 NOP_EXPR conversions may be removed freely (as long as we
13283 are careful not to change the type of the overall expression).
13284 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13285 but we can constant-fold them if they have constant operands. */
13287 #ifdef ENABLE_FOLD_CHECKING
13288 # define fold(x) fold_1 (x)
13289 static tree fold_1 (tree);
13295 const tree t = expr;
13296 enum tree_code code = TREE_CODE (t);
13297 enum tree_code_class kind = TREE_CODE_CLASS (code);
13300 /* Return right away if a constant. */
13301 if (kind == tcc_constant)
13304 /* CALL_EXPR-like objects with variable numbers of operands are
13305 treated specially. */
13306 if (kind == tcc_vl_exp)
13308 if (code == CALL_EXPR)
13310 tem = fold_call_expr (expr, false);
13311 return tem ? tem : expr;
13316 if (IS_EXPR_CODE_CLASS (kind)
13317 || IS_GIMPLE_STMT_CODE_CLASS (kind))
13319 tree type = TREE_TYPE (t);
13320 tree op0, op1, op2;
13322 switch (TREE_CODE_LENGTH (code))
13325 op0 = TREE_OPERAND (t, 0);
13326 tem = fold_unary (code, type, op0);
13327 return tem ? tem : expr;
13329 op0 = TREE_OPERAND (t, 0);
13330 op1 = TREE_OPERAND (t, 1);
13331 tem = fold_binary (code, type, op0, op1);
13332 return tem ? tem : expr;
13334 op0 = TREE_OPERAND (t, 0);
13335 op1 = TREE_OPERAND (t, 1);
13336 op2 = TREE_OPERAND (t, 2);
13337 tem = fold_ternary (code, type, op0, op1, op2);
13338 return tem ? tem : expr;
13347 return fold (DECL_INITIAL (t));
13351 } /* switch (code) */
13354 #ifdef ENABLE_FOLD_CHECKING
13357 static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
13358 static void fold_check_failed (const_tree, const_tree);
13359 void print_fold_checksum (const_tree);
13361 /* When --enable-checking=fold, compute a digest of expr before
13362 and after actual fold call to see if fold did not accidentally
13363 change original expr. */
13369 struct md5_ctx ctx;
13370 unsigned char checksum_before[16], checksum_after[16];
13373 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13374 md5_init_ctx (&ctx);
13375 fold_checksum_tree (expr, &ctx, ht);
13376 md5_finish_ctx (&ctx, checksum_before);
13379 ret = fold_1 (expr);
13381 md5_init_ctx (&ctx);
13382 fold_checksum_tree (expr, &ctx, ht);
13383 md5_finish_ctx (&ctx, checksum_after);
13386 if (memcmp (checksum_before, checksum_after, 16))
13387 fold_check_failed (expr, ret);
13393 print_fold_checksum (const_tree expr)
13395 struct md5_ctx ctx;
13396 unsigned char checksum[16], cnt;
13399 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13400 md5_init_ctx (&ctx);
13401 fold_checksum_tree (expr, &ctx, ht);
13402 md5_finish_ctx (&ctx, checksum);
13404 for (cnt = 0; cnt < 16; ++cnt)
13405 fprintf (stderr, "%02x", checksum[cnt]);
13406 putc ('\n', stderr);
13410 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
13412 internal_error ("fold check: original tree changed by fold");
13416 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
13419 enum tree_code code;
13420 struct tree_function_decl buf;
13425 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
13426 <= sizeof (struct tree_function_decl))
13427 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
13430 slot = (const void **) htab_find_slot (ht, expr, INSERT);
13434 code = TREE_CODE (expr);
13435 if (TREE_CODE_CLASS (code) == tcc_declaration
13436 && DECL_ASSEMBLER_NAME_SET_P (expr))
13438 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13439 memcpy ((char *) &buf, expr, tree_size (expr));
13440 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
13441 expr = (tree) &buf;
13443 else if (TREE_CODE_CLASS (code) == tcc_type
13444 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
13445 || TYPE_CACHED_VALUES_P (expr)
13446 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
13448 /* Allow these fields to be modified. */
13450 memcpy ((char *) &buf, expr, tree_size (expr));
13451 expr = tmp = (tree) &buf;
13452 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
13453 TYPE_POINTER_TO (tmp) = NULL;
13454 TYPE_REFERENCE_TO (tmp) = NULL;
13455 if (TYPE_CACHED_VALUES_P (tmp))
13457 TYPE_CACHED_VALUES_P (tmp) = 0;
13458 TYPE_CACHED_VALUES (tmp) = NULL;
13461 md5_process_bytes (expr, tree_size (expr), ctx);
13462 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
13463 if (TREE_CODE_CLASS (code) != tcc_type
13464 && TREE_CODE_CLASS (code) != tcc_declaration
13465 && code != TREE_LIST
13466 && code != SSA_NAME)
13467 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
13468 switch (TREE_CODE_CLASS (code))
13474 md5_process_bytes (TREE_STRING_POINTER (expr),
13475 TREE_STRING_LENGTH (expr), ctx);
13478 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
13479 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
13482 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
13488 case tcc_exceptional:
13492 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
13493 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
13494 expr = TREE_CHAIN (expr);
13495 goto recursive_label;
13498 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
13499 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
13505 case tcc_expression:
13506 case tcc_reference:
13507 case tcc_comparison:
13510 case tcc_statement:
13512 len = TREE_OPERAND_LENGTH (expr);
13513 for (i = 0; i < len; ++i)
13514 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
13516 case tcc_declaration:
13517 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
13518 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
13519 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
13521 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
13522 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
13523 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
13524 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
13525 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
13527 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
13528 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
13530 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
13532 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
13533 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
13534 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
13538 if (TREE_CODE (expr) == ENUMERAL_TYPE)
13539 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
13540 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
13541 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
13542 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
13543 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
13544 if (INTEGRAL_TYPE_P (expr)
13545 || SCALAR_FLOAT_TYPE_P (expr))
13547 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
13548 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
13550 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
13551 if (TREE_CODE (expr) == RECORD_TYPE
13552 || TREE_CODE (expr) == UNION_TYPE
13553 || TREE_CODE (expr) == QUAL_UNION_TYPE)
13554 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
13555 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
13562 /* Helper function for outputting the checksum of a tree T. When
13563 debugging with gdb, you can "define mynext" to be "next" followed
13564 by "call debug_fold_checksum (op0)", then just trace down till the
13568 debug_fold_checksum (const_tree t)
13571 unsigned char checksum[16];
13572 struct md5_ctx ctx;
13573 htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13575 md5_init_ctx (&ctx);
13576 fold_checksum_tree (t, &ctx, ht);
13577 md5_finish_ctx (&ctx, checksum);
13580 for (i = 0; i < 16; i++)
13581 fprintf (stderr, "%d ", checksum[i]);
13583 fprintf (stderr, "\n");
13588 /* Fold a unary tree expression with code CODE of type TYPE with an
13589 operand OP0. Return a folded expression if successful. Otherwise,
13590 return a tree expression with code CODE of type TYPE with an
13594 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
13597 #ifdef ENABLE_FOLD_CHECKING
13598 unsigned char checksum_before[16], checksum_after[16];
13599 struct md5_ctx ctx;
13602 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13603 md5_init_ctx (&ctx);
13604 fold_checksum_tree (op0, &ctx, ht);
13605 md5_finish_ctx (&ctx, checksum_before);
13609 tem = fold_unary (code, type, op0);
13611 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
13613 #ifdef ENABLE_FOLD_CHECKING
13614 md5_init_ctx (&ctx);
13615 fold_checksum_tree (op0, &ctx, ht);
13616 md5_finish_ctx (&ctx, checksum_after);
13619 if (memcmp (checksum_before, checksum_after, 16))
13620 fold_check_failed (op0, tem);
13625 /* Fold a binary tree expression with code CODE of type TYPE with
13626 operands OP0 and OP1. Return a folded expression if successful.
13627 Otherwise, return a tree expression with code CODE of type TYPE
13628 with operands OP0 and OP1. */
13631 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
13635 #ifdef ENABLE_FOLD_CHECKING
13636 unsigned char checksum_before_op0[16],
13637 checksum_before_op1[16],
13638 checksum_after_op0[16],
13639 checksum_after_op1[16];
13640 struct md5_ctx ctx;
13643 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13644 md5_init_ctx (&ctx);
13645 fold_checksum_tree (op0, &ctx, ht);
13646 md5_finish_ctx (&ctx, checksum_before_op0);
13649 md5_init_ctx (&ctx);
13650 fold_checksum_tree (op1, &ctx, ht);
13651 md5_finish_ctx (&ctx, checksum_before_op1);
13655 tem = fold_binary (code, type, op0, op1);
13657 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
13659 #ifdef ENABLE_FOLD_CHECKING
13660 md5_init_ctx (&ctx);
13661 fold_checksum_tree (op0, &ctx, ht);
13662 md5_finish_ctx (&ctx, checksum_after_op0);
13665 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13666 fold_check_failed (op0, tem);
13668 md5_init_ctx (&ctx);
13669 fold_checksum_tree (op1, &ctx, ht);
13670 md5_finish_ctx (&ctx, checksum_after_op1);
13673 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13674 fold_check_failed (op1, tem);
13679 /* Fold a ternary tree expression with code CODE of type TYPE with
13680 operands OP0, OP1, and OP2. Return a folded expression if
13681 successful. Otherwise, return a tree expression with code CODE of
13682 type TYPE with operands OP0, OP1, and OP2. */
13685 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
13689 #ifdef ENABLE_FOLD_CHECKING
13690 unsigned char checksum_before_op0[16],
13691 checksum_before_op1[16],
13692 checksum_before_op2[16],
13693 checksum_after_op0[16],
13694 checksum_after_op1[16],
13695 checksum_after_op2[16];
13696 struct md5_ctx ctx;
13699 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13700 md5_init_ctx (&ctx);
13701 fold_checksum_tree (op0, &ctx, ht);
13702 md5_finish_ctx (&ctx, checksum_before_op0);
13705 md5_init_ctx (&ctx);
13706 fold_checksum_tree (op1, &ctx, ht);
13707 md5_finish_ctx (&ctx, checksum_before_op1);
13710 md5_init_ctx (&ctx);
13711 fold_checksum_tree (op2, &ctx, ht);
13712 md5_finish_ctx (&ctx, checksum_before_op2);
13716 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
13717 tem = fold_ternary (code, type, op0, op1, op2);
13719 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
13721 #ifdef ENABLE_FOLD_CHECKING
13722 md5_init_ctx (&ctx);
13723 fold_checksum_tree (op0, &ctx, ht);
13724 md5_finish_ctx (&ctx, checksum_after_op0);
13727 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13728 fold_check_failed (op0, tem);
13730 md5_init_ctx (&ctx);
13731 fold_checksum_tree (op1, &ctx, ht);
13732 md5_finish_ctx (&ctx, checksum_after_op1);
13735 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13736 fold_check_failed (op1, tem);
13738 md5_init_ctx (&ctx);
13739 fold_checksum_tree (op2, &ctx, ht);
13740 md5_finish_ctx (&ctx, checksum_after_op2);
13743 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
13744 fold_check_failed (op2, tem);
13749 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
13750 arguments in ARGARRAY, and a null static chain.
13751 Return a folded expression if successful. Otherwise, return a CALL_EXPR
13752 of type TYPE from the given operands as constructed by build_call_array. */
13755 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
13758 #ifdef ENABLE_FOLD_CHECKING
13759 unsigned char checksum_before_fn[16],
13760 checksum_before_arglist[16],
13761 checksum_after_fn[16],
13762 checksum_after_arglist[16];
13763 struct md5_ctx ctx;
13767 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13768 md5_init_ctx (&ctx);
13769 fold_checksum_tree (fn, &ctx, ht);
13770 md5_finish_ctx (&ctx, checksum_before_fn);
13773 md5_init_ctx (&ctx);
13774 for (i = 0; i < nargs; i++)
13775 fold_checksum_tree (argarray[i], &ctx, ht);
13776 md5_finish_ctx (&ctx, checksum_before_arglist);
13780 tem = fold_builtin_call_array (type, fn, nargs, argarray);
13782 #ifdef ENABLE_FOLD_CHECKING
13783 md5_init_ctx (&ctx);
13784 fold_checksum_tree (fn, &ctx, ht);
13785 md5_finish_ctx (&ctx, checksum_after_fn);
13788 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
13789 fold_check_failed (fn, tem);
13791 md5_init_ctx (&ctx);
13792 for (i = 0; i < nargs; i++)
13793 fold_checksum_tree (argarray[i], &ctx, ht);
13794 md5_finish_ctx (&ctx, checksum_after_arglist);
13797 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
13798 fold_check_failed (NULL_TREE, tem);
13803 /* Perform constant folding and related simplification of initializer
13804 expression EXPR. These behave identically to "fold_buildN" but ignore
13805 potential run-time traps and exceptions that fold must preserve. */
13807 #define START_FOLD_INIT \
13808 int saved_signaling_nans = flag_signaling_nans;\
13809 int saved_trapping_math = flag_trapping_math;\
13810 int saved_rounding_math = flag_rounding_math;\
13811 int saved_trapv = flag_trapv;\
13812 int saved_folding_initializer = folding_initializer;\
13813 flag_signaling_nans = 0;\
13814 flag_trapping_math = 0;\
13815 flag_rounding_math = 0;\
13817 folding_initializer = 1;
13819 #define END_FOLD_INIT \
13820 flag_signaling_nans = saved_signaling_nans;\
13821 flag_trapping_math = saved_trapping_math;\
13822 flag_rounding_math = saved_rounding_math;\
13823 flag_trapv = saved_trapv;\
13824 folding_initializer = saved_folding_initializer;
13827 fold_build1_initializer (enum tree_code code, tree type, tree op)
13832 result = fold_build1 (code, type, op);
13839 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
13844 result = fold_build2 (code, type, op0, op1);
13851 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
13857 result = fold_build3 (code, type, op0, op1, op2);
13864 fold_build_call_array_initializer (tree type, tree fn,
13865 int nargs, tree *argarray)
13870 result = fold_build_call_array (type, fn, nargs, argarray);
13876 #undef START_FOLD_INIT
13877 #undef END_FOLD_INIT
13879 /* Determine if first argument is a multiple of second argument. Return 0 if
13880 it is not, or we cannot easily determined it to be.
13882 An example of the sort of thing we care about (at this point; this routine
13883 could surely be made more general, and expanded to do what the *_DIV_EXPR's
13884 fold cases do now) is discovering that
13886 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13892 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
13894 This code also handles discovering that
13896 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13898 is a multiple of 8 so we don't have to worry about dealing with a
13899 possible remainder.
13901 Note that we *look* inside a SAVE_EXPR only to determine how it was
13902 calculated; it is not safe for fold to do much of anything else with the
13903 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
13904 at run time. For example, the latter example above *cannot* be implemented
13905 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
13906 evaluation time of the original SAVE_EXPR is not necessarily the same at
13907 the time the new expression is evaluated. The only optimization of this
13908 sort that would be valid is changing
13910 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
13914 SAVE_EXPR (I) * SAVE_EXPR (J)
13916 (where the same SAVE_EXPR (J) is used in the original and the
13917 transformed version). */
13920 multiple_of_p (tree type, const_tree top, const_tree bottom)
13922 if (operand_equal_p (top, bottom, 0))
13925 if (TREE_CODE (type) != INTEGER_TYPE)
13928 switch (TREE_CODE (top))
13931 /* Bitwise and provides a power of two multiple. If the mask is
13932 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
13933 if (!integer_pow2p (bottom))
13938 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13939 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13943 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13944 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13947 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
13951 op1 = TREE_OPERAND (top, 1);
13952 /* const_binop may not detect overflow correctly,
13953 so check for it explicitly here. */
13954 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
13955 > TREE_INT_CST_LOW (op1)
13956 && TREE_INT_CST_HIGH (op1) == 0
13957 && 0 != (t1 = fold_convert (type,
13958 const_binop (LSHIFT_EXPR,
13961 && !TREE_OVERFLOW (t1))
13962 return multiple_of_p (type, t1, bottom);
13967 /* Can't handle conversions from non-integral or wider integral type. */
13968 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
13969 || (TYPE_PRECISION (type)
13970 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
13973 /* .. fall through ... */
13976 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
13979 if (TREE_CODE (bottom) != INTEGER_CST
13980 || integer_zerop (bottom)
13981 || (TYPE_UNSIGNED (type)
13982 && (tree_int_cst_sgn (top) < 0
13983 || tree_int_cst_sgn (bottom) < 0)))
13985 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
13993 /* Return true if `t' is known to be non-negative. If the return
13994 value is based on the assumption that signed overflow is undefined,
13995 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13996 *STRICT_OVERFLOW_P. */
13999 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14001 if (t == error_mark_node)
14004 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14007 switch (TREE_CODE (t))
14010 /* Query VRP to see if it has recorded any information about
14011 the range of this object. */
14012 return ssa_name_nonnegative_p (t);
14015 /* We can't return 1 if flag_wrapv is set because
14016 ABS_EXPR<INT_MIN> = INT_MIN. */
14017 if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
14019 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
14021 *strict_overflow_p = true;
14027 return tree_int_cst_sgn (t) >= 0;
14030 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
14033 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
14035 case POINTER_PLUS_EXPR:
14037 if (FLOAT_TYPE_P (TREE_TYPE (t)))
14038 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14040 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14041 strict_overflow_p));
14043 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
14044 both unsigned and at least 2 bits shorter than the result. */
14045 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
14046 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
14047 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
14049 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
14050 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
14051 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
14052 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
14054 unsigned int prec = MAX (TYPE_PRECISION (inner1),
14055 TYPE_PRECISION (inner2)) + 1;
14056 return prec < TYPE_PRECISION (TREE_TYPE (t));
14062 if (FLOAT_TYPE_P (TREE_TYPE (t)))
14064 /* x * x for floating point x is always non-negative. */
14065 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
14067 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14069 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14070 strict_overflow_p));
14073 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
14074 both unsigned and their total bits is shorter than the result. */
14075 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
14076 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
14077 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
14079 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
14080 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
14081 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
14082 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
14083 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
14084 < TYPE_PRECISION (TREE_TYPE (t));
14090 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14092 || tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14093 strict_overflow_p));
14099 case TRUNC_DIV_EXPR:
14100 case CEIL_DIV_EXPR:
14101 case FLOOR_DIV_EXPR:
14102 case ROUND_DIV_EXPR:
14103 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14105 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14106 strict_overflow_p));
14108 case TRUNC_MOD_EXPR:
14109 case CEIL_MOD_EXPR:
14110 case FLOOR_MOD_EXPR:
14111 case ROUND_MOD_EXPR:
14113 case NON_LVALUE_EXPR:
14115 case FIX_TRUNC_EXPR:
14116 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14117 strict_overflow_p);
14119 case COMPOUND_EXPR:
14121 case GIMPLE_MODIFY_STMT:
14122 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14123 strict_overflow_p);
14126 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
14127 strict_overflow_p);
14130 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14132 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
14133 strict_overflow_p));
14137 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
14138 tree outer_type = TREE_TYPE (t);
14140 if (TREE_CODE (outer_type) == REAL_TYPE)
14142 if (TREE_CODE (inner_type) == REAL_TYPE)
14143 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14144 strict_overflow_p);
14145 if (TREE_CODE (inner_type) == INTEGER_TYPE)
14147 if (TYPE_UNSIGNED (inner_type))
14149 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14150 strict_overflow_p);
14153 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
14155 if (TREE_CODE (inner_type) == REAL_TYPE)
14156 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t,0),
14157 strict_overflow_p);
14158 if (TREE_CODE (inner_type) == INTEGER_TYPE)
14159 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
14160 && TYPE_UNSIGNED (inner_type);
14167 tree temp = TARGET_EXPR_SLOT (t);
14168 t = TARGET_EXPR_INITIAL (t);
14170 /* If the initializer is non-void, then it's a normal expression
14171 that will be assigned to the slot. */
14172 if (!VOID_TYPE_P (t))
14173 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
14175 /* Otherwise, the initializer sets the slot in some way. One common
14176 way is an assignment statement at the end of the initializer. */
14179 if (TREE_CODE (t) == BIND_EXPR)
14180 t = expr_last (BIND_EXPR_BODY (t));
14181 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
14182 || TREE_CODE (t) == TRY_CATCH_EXPR)
14183 t = expr_last (TREE_OPERAND (t, 0));
14184 else if (TREE_CODE (t) == STATEMENT_LIST)
14189 if ((TREE_CODE (t) == MODIFY_EXPR
14190 || TREE_CODE (t) == GIMPLE_MODIFY_STMT)
14191 && GENERIC_TREE_OPERAND (t, 0) == temp)
14192 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14193 strict_overflow_p);
14200 tree fndecl = get_callee_fndecl (t);
14201 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
14202 switch (DECL_FUNCTION_CODE (fndecl))
14204 CASE_FLT_FN (BUILT_IN_ACOS):
14205 CASE_FLT_FN (BUILT_IN_ACOSH):
14206 CASE_FLT_FN (BUILT_IN_CABS):
14207 CASE_FLT_FN (BUILT_IN_COSH):
14208 CASE_FLT_FN (BUILT_IN_ERFC):
14209 CASE_FLT_FN (BUILT_IN_EXP):
14210 CASE_FLT_FN (BUILT_IN_EXP10):
14211 CASE_FLT_FN (BUILT_IN_EXP2):
14212 CASE_FLT_FN (BUILT_IN_FABS):
14213 CASE_FLT_FN (BUILT_IN_FDIM):
14214 CASE_FLT_FN (BUILT_IN_HYPOT):
14215 CASE_FLT_FN (BUILT_IN_POW10):
14216 CASE_INT_FN (BUILT_IN_FFS):
14217 CASE_INT_FN (BUILT_IN_PARITY):
14218 CASE_INT_FN (BUILT_IN_POPCOUNT):
14219 case BUILT_IN_BSWAP32:
14220 case BUILT_IN_BSWAP64:
14224 CASE_FLT_FN (BUILT_IN_SQRT):
14225 /* sqrt(-0.0) is -0.0. */
14226 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
14228 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14229 strict_overflow_p);
14231 CASE_FLT_FN (BUILT_IN_ASINH):
14232 CASE_FLT_FN (BUILT_IN_ATAN):
14233 CASE_FLT_FN (BUILT_IN_ATANH):
14234 CASE_FLT_FN (BUILT_IN_CBRT):
14235 CASE_FLT_FN (BUILT_IN_CEIL):
14236 CASE_FLT_FN (BUILT_IN_ERF):
14237 CASE_FLT_FN (BUILT_IN_EXPM1):
14238 CASE_FLT_FN (BUILT_IN_FLOOR):
14239 CASE_FLT_FN (BUILT_IN_FMOD):
14240 CASE_FLT_FN (BUILT_IN_FREXP):
14241 CASE_FLT_FN (BUILT_IN_LCEIL):
14242 CASE_FLT_FN (BUILT_IN_LDEXP):
14243 CASE_FLT_FN (BUILT_IN_LFLOOR):
14244 CASE_FLT_FN (BUILT_IN_LLCEIL):
14245 CASE_FLT_FN (BUILT_IN_LLFLOOR):
14246 CASE_FLT_FN (BUILT_IN_LLRINT):
14247 CASE_FLT_FN (BUILT_IN_LLROUND):
14248 CASE_FLT_FN (BUILT_IN_LRINT):
14249 CASE_FLT_FN (BUILT_IN_LROUND):
14250 CASE_FLT_FN (BUILT_IN_MODF):
14251 CASE_FLT_FN (BUILT_IN_NEARBYINT):
14252 CASE_FLT_FN (BUILT_IN_RINT):
14253 CASE_FLT_FN (BUILT_IN_ROUND):
14254 CASE_FLT_FN (BUILT_IN_SCALB):
14255 CASE_FLT_FN (BUILT_IN_SCALBLN):
14256 CASE_FLT_FN (BUILT_IN_SCALBN):
14257 CASE_FLT_FN (BUILT_IN_SIGNBIT):
14258 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
14259 CASE_FLT_FN (BUILT_IN_SINH):
14260 CASE_FLT_FN (BUILT_IN_TANH):
14261 CASE_FLT_FN (BUILT_IN_TRUNC):
14262 /* True if the 1st argument is nonnegative. */
14263 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14264 strict_overflow_p);
14266 CASE_FLT_FN (BUILT_IN_FMAX):
14267 /* True if the 1st OR 2nd arguments are nonnegative. */
14268 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14270 || (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14271 strict_overflow_p)));
14273 CASE_FLT_FN (BUILT_IN_FMIN):
14274 /* True if the 1st AND 2nd arguments are nonnegative. */
14275 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14277 && (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14278 strict_overflow_p)));
14280 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14281 /* True if the 2nd argument is nonnegative. */
14282 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14283 strict_overflow_p);
14285 CASE_FLT_FN (BUILT_IN_POWI):
14286 /* True if the 1st argument is nonnegative or the second
14287 argument is an even integer. */
14288 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == INTEGER_CST)
14290 tree arg1 = CALL_EXPR_ARG (t, 1);
14291 if ((TREE_INT_CST_LOW (arg1) & 1) == 0)
14294 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14295 strict_overflow_p);
14297 CASE_FLT_FN (BUILT_IN_POW):
14298 /* True if the 1st argument is nonnegative or the second
14299 argument is an even integer valued real. */
14300 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == REAL_CST)
14305 c = TREE_REAL_CST (CALL_EXPR_ARG (t, 1));
14306 n = real_to_integer (&c);
14309 REAL_VALUE_TYPE cint;
14310 real_from_integer (&cint, VOIDmode, n,
14311 n < 0 ? -1 : 0, 0);
14312 if (real_identical (&c, &cint))
14316 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14317 strict_overflow_p);
14324 /* ... fall through ... */
14328 tree type = TREE_TYPE (t);
14329 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
14330 && truth_value_p (TREE_CODE (t)))
14331 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
14332 have a signed:1 type (where the value is -1 and 0). */
14337 /* We don't know sign of `t', so be conservative and return false. */
14341 /* Return true if `t' is known to be non-negative. Handle warnings
14342 about undefined signed overflow. */
14345 tree_expr_nonnegative_p (tree t)
14347 bool ret, strict_overflow_p;
14349 strict_overflow_p = false;
14350 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
14351 if (strict_overflow_p)
14352 fold_overflow_warning (("assuming signed overflow does not occur when "
14353 "determining that expression is always "
14355 WARN_STRICT_OVERFLOW_MISC);
14359 /* Return true when T is an address and is known to be nonzero.
14360 For floating point we further ensure that T is not denormal.
14361 Similar logic is present in nonzero_address in rtlanal.h.
14363 If the return value is based on the assumption that signed overflow
14364 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14365 change *STRICT_OVERFLOW_P. */
14368 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14370 tree type = TREE_TYPE (t);
14371 bool sub_strict_overflow_p;
14373 /* Doing something useful for floating point would need more work. */
14374 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
14377 switch (TREE_CODE (t))
14380 /* Query VRP to see if it has recorded any information about
14381 the range of this object. */
14382 return ssa_name_nonzero_p (t);
14385 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14386 strict_overflow_p);
14389 return !integer_zerop (t);
14391 case POINTER_PLUS_EXPR:
14393 if (TYPE_OVERFLOW_UNDEFINED (type))
14395 /* With the presence of negative values it is hard
14396 to say something. */
14397 sub_strict_overflow_p = false;
14398 if (!tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14399 &sub_strict_overflow_p)
14400 || !tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14401 &sub_strict_overflow_p))
14403 /* One of operands must be positive and the other non-negative. */
14404 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14405 overflows, on a twos-complement machine the sum of two
14406 nonnegative numbers can never be zero. */
14407 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14409 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14410 strict_overflow_p));
14415 if (TYPE_OVERFLOW_UNDEFINED (type))
14417 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14419 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14420 strict_overflow_p))
14422 *strict_overflow_p = true;
14430 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
14431 tree outer_type = TREE_TYPE (t);
14433 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
14434 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14435 strict_overflow_p));
14441 tree base = get_base_address (TREE_OPERAND (t, 0));
14446 /* Weak declarations may link to NULL. */
14447 if (VAR_OR_FUNCTION_DECL_P (base))
14448 return !DECL_WEAK (base);
14450 /* Constants are never weak. */
14451 if (CONSTANT_CLASS_P (base))
14458 sub_strict_overflow_p = false;
14459 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14460 &sub_strict_overflow_p)
14461 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
14462 &sub_strict_overflow_p))
14464 if (sub_strict_overflow_p)
14465 *strict_overflow_p = true;
14471 sub_strict_overflow_p = false;
14472 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14473 &sub_strict_overflow_p)
14474 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14475 &sub_strict_overflow_p))
14477 if (sub_strict_overflow_p)
14478 *strict_overflow_p = true;
14483 sub_strict_overflow_p = false;
14484 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14485 &sub_strict_overflow_p))
14487 if (sub_strict_overflow_p)
14488 *strict_overflow_p = true;
14490 /* When both operands are nonzero, then MAX must be too. */
14491 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14492 strict_overflow_p))
14495 /* MAX where operand 0 is positive is positive. */
14496 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14497 strict_overflow_p);
14499 /* MAX where operand 1 is positive is positive. */
14500 else if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14501 &sub_strict_overflow_p)
14502 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14503 &sub_strict_overflow_p))
14505 if (sub_strict_overflow_p)
14506 *strict_overflow_p = true;
14511 case COMPOUND_EXPR:
14513 case GIMPLE_MODIFY_STMT:
14515 return tree_expr_nonzero_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14516 strict_overflow_p);
14519 case NON_LVALUE_EXPR:
14520 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14521 strict_overflow_p);
14524 return (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14526 || tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14527 strict_overflow_p));
14530 return alloca_call_p (t);
14538 /* Return true when T is an address and is known to be nonzero.
14539 Handle warnings about undefined signed overflow. */
14542 tree_expr_nonzero_p (tree t)
14544 bool ret, strict_overflow_p;
14546 strict_overflow_p = false;
14547 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
14548 if (strict_overflow_p)
14549 fold_overflow_warning (("assuming signed overflow does not occur when "
14550 "determining that expression is always "
14552 WARN_STRICT_OVERFLOW_MISC);
14556 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
14557 attempt to fold the expression to a constant without modifying TYPE,
14560 If the expression could be simplified to a constant, then return
14561 the constant. If the expression would not be simplified to a
14562 constant, then return NULL_TREE. */
14565 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
14567 tree tem = fold_binary (code, type, op0, op1);
14568 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14571 /* Given the components of a unary expression CODE, TYPE and OP0,
14572 attempt to fold the expression to a constant without modifying
14575 If the expression could be simplified to a constant, then return
14576 the constant. If the expression would not be simplified to a
14577 constant, then return NULL_TREE. */
14580 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
14582 tree tem = fold_unary (code, type, op0);
14583 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14586 /* If EXP represents referencing an element in a constant string
14587 (either via pointer arithmetic or array indexing), return the
14588 tree representing the value accessed, otherwise return NULL. */
14591 fold_read_from_constant_string (tree exp)
14593 if ((TREE_CODE (exp) == INDIRECT_REF
14594 || TREE_CODE (exp) == ARRAY_REF)
14595 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
14597 tree exp1 = TREE_OPERAND (exp, 0);
14601 if (TREE_CODE (exp) == INDIRECT_REF)
14602 string = string_constant (exp1, &index);
14605 tree low_bound = array_ref_low_bound (exp);
14606 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
14608 /* Optimize the special-case of a zero lower bound.
14610 We convert the low_bound to sizetype to avoid some problems
14611 with constant folding. (E.g. suppose the lower bound is 1,
14612 and its mode is QI. Without the conversion,l (ARRAY
14613 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
14614 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
14615 if (! integer_zerop (low_bound))
14616 index = size_diffop (index, fold_convert (sizetype, low_bound));
14622 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
14623 && TREE_CODE (string) == STRING_CST
14624 && TREE_CODE (index) == INTEGER_CST
14625 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
14626 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
14628 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
14629 return build_int_cst_type (TREE_TYPE (exp),
14630 (TREE_STRING_POINTER (string)
14631 [TREE_INT_CST_LOW (index)]));
14636 /* Return the tree for neg (ARG0) when ARG0 is known to be either
14637 an integer constant, real, or fixed-point constant.
14639 TYPE is the type of the result. */
14642 fold_negate_const (tree arg0, tree type)
14644 tree t = NULL_TREE;
14646 switch (TREE_CODE (arg0))
14650 unsigned HOST_WIDE_INT low;
14651 HOST_WIDE_INT high;
14652 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14653 TREE_INT_CST_HIGH (arg0),
14655 t = force_fit_type_double (type, low, high, 1,
14656 (overflow | TREE_OVERFLOW (arg0))
14657 && !TYPE_UNSIGNED (type));
14662 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14667 FIXED_VALUE_TYPE f;
14668 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
14669 &(TREE_FIXED_CST (arg0)), NULL,
14670 TYPE_SATURATING (type));
14671 t = build_fixed (type, f);
14672 /* Propagate overflow flags. */
14673 if (overflow_p | TREE_OVERFLOW (arg0))
14675 TREE_OVERFLOW (t) = 1;
14676 TREE_CONSTANT_OVERFLOW (t) = 1;
14678 else if (TREE_CONSTANT_OVERFLOW (arg0))
14679 TREE_CONSTANT_OVERFLOW (t) = 1;
14684 gcc_unreachable ();
14690 /* Return the tree for abs (ARG0) when ARG0 is known to be either
14691 an integer constant or real constant.
14693 TYPE is the type of the result. */
14696 fold_abs_const (tree arg0, tree type)
14698 tree t = NULL_TREE;
14700 switch (TREE_CODE (arg0))
14703 /* If the value is unsigned, then the absolute value is
14704 the same as the ordinary value. */
14705 if (TYPE_UNSIGNED (type))
14707 /* Similarly, if the value is non-negative. */
14708 else if (INT_CST_LT (integer_minus_one_node, arg0))
14710 /* If the value is negative, then the absolute value is
14714 unsigned HOST_WIDE_INT low;
14715 HOST_WIDE_INT high;
14716 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14717 TREE_INT_CST_HIGH (arg0),
14719 t = force_fit_type_double (type, low, high, -1,
14720 overflow | TREE_OVERFLOW (arg0));
14725 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
14726 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14732 gcc_unreachable ();
14738 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
14739 constant. TYPE is the type of the result. */
14742 fold_not_const (tree arg0, tree type)
14744 tree t = NULL_TREE;
14746 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
14748 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
14749 ~TREE_INT_CST_HIGH (arg0), 0,
14750 TREE_OVERFLOW (arg0));
14755 /* Given CODE, a relational operator, the target type, TYPE and two
14756 constant operands OP0 and OP1, return the result of the
14757 relational operation. If the result is not a compile time
14758 constant, then return NULL_TREE. */
14761 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
14763 int result, invert;
14765 /* From here on, the only cases we handle are when the result is
14766 known to be a constant. */
14768 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
14770 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
14771 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
14773 /* Handle the cases where either operand is a NaN. */
14774 if (real_isnan (c0) || real_isnan (c1))
14784 case UNORDERED_EXPR:
14798 if (flag_trapping_math)
14804 gcc_unreachable ();
14807 return constant_boolean_node (result, type);
14810 return constant_boolean_node (real_compare (code, c0, c1), type);
14813 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
14815 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
14816 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
14817 return constant_boolean_node (fixed_compare (code, c0, c1), type);
14820 /* Handle equality/inequality of complex constants. */
14821 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
14823 tree rcond = fold_relational_const (code, type,
14824 TREE_REALPART (op0),
14825 TREE_REALPART (op1));
14826 tree icond = fold_relational_const (code, type,
14827 TREE_IMAGPART (op0),
14828 TREE_IMAGPART (op1));
14829 if (code == EQ_EXPR)
14830 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
14831 else if (code == NE_EXPR)
14832 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
14837 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14839 To compute GT, swap the arguments and do LT.
14840 To compute GE, do LT and invert the result.
14841 To compute LE, swap the arguments, do LT and invert the result.
14842 To compute NE, do EQ and invert the result.
14844 Therefore, the code below must handle only EQ and LT. */
14846 if (code == LE_EXPR || code == GT_EXPR)
14851 code = swap_tree_comparison (code);
14854 /* Note that it is safe to invert for real values here because we
14855 have already handled the one case that it matters. */
14858 if (code == NE_EXPR || code == GE_EXPR)
14861 code = invert_tree_comparison (code, false);
14864 /* Compute a result for LT or EQ if args permit;
14865 Otherwise return T. */
14866 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
14868 if (code == EQ_EXPR)
14869 result = tree_int_cst_equal (op0, op1);
14870 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
14871 result = INT_CST_LT_UNSIGNED (op0, op1);
14873 result = INT_CST_LT (op0, op1);
14880 return constant_boolean_node (result, type);
14883 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
14884 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
14888 fold_build_cleanup_point_expr (tree type, tree expr)
14890 /* If the expression does not have side effects then we don't have to wrap
14891 it with a cleanup point expression. */
14892 if (!TREE_SIDE_EFFECTS (expr))
14895 /* If the expression is a return, check to see if the expression inside the
14896 return has no side effects or the right hand side of the modify expression
14897 inside the return. If either don't have side effects set we don't need to
14898 wrap the expression in a cleanup point expression. Note we don't check the
14899 left hand side of the modify because it should always be a return decl. */
14900 if (TREE_CODE (expr) == RETURN_EXPR)
14902 tree op = TREE_OPERAND (expr, 0);
14903 if (!op || !TREE_SIDE_EFFECTS (op))
14905 op = TREE_OPERAND (op, 1);
14906 if (!TREE_SIDE_EFFECTS (op))
14910 return build1 (CLEANUP_POINT_EXPR, type, expr);
14913 /* Given a pointer value OP0 and a type TYPE, return a simplified version
14914 of an indirection through OP0, or NULL_TREE if no simplification is
14918 fold_indirect_ref_1 (tree type, tree op0)
14924 subtype = TREE_TYPE (sub);
14925 if (!POINTER_TYPE_P (subtype))
14928 if (TREE_CODE (sub) == ADDR_EXPR)
14930 tree op = TREE_OPERAND (sub, 0);
14931 tree optype = TREE_TYPE (op);
14932 /* *&CONST_DECL -> to the value of the const decl. */
14933 if (TREE_CODE (op) == CONST_DECL)
14934 return DECL_INITIAL (op);
14935 /* *&p => p; make sure to handle *&"str"[cst] here. */
14936 if (type == optype)
14938 tree fop = fold_read_from_constant_string (op);
14944 /* *(foo *)&fooarray => fooarray[0] */
14945 else if (TREE_CODE (optype) == ARRAY_TYPE
14946 && type == TREE_TYPE (optype))
14948 tree type_domain = TYPE_DOMAIN (optype);
14949 tree min_val = size_zero_node;
14950 if (type_domain && TYPE_MIN_VALUE (type_domain))
14951 min_val = TYPE_MIN_VALUE (type_domain);
14952 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
14954 /* *(foo *)&complexfoo => __real__ complexfoo */
14955 else if (TREE_CODE (optype) == COMPLEX_TYPE
14956 && type == TREE_TYPE (optype))
14957 return fold_build1 (REALPART_EXPR, type, op);
14958 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
14959 else if (TREE_CODE (optype) == VECTOR_TYPE
14960 && type == TREE_TYPE (optype))
14962 tree part_width = TYPE_SIZE (type);
14963 tree index = bitsize_int (0);
14964 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
14968 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
14969 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
14970 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
14972 tree op00 = TREE_OPERAND (sub, 0);
14973 tree op01 = TREE_OPERAND (sub, 1);
14977 op00type = TREE_TYPE (op00);
14978 if (TREE_CODE (op00) == ADDR_EXPR
14979 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
14980 && type == TREE_TYPE (TREE_TYPE (op00type)))
14982 tree size = TYPE_SIZE_UNIT (type);
14983 if (tree_int_cst_equal (size, op01))
14984 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
14988 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
14989 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
14990 && type == TREE_TYPE (TREE_TYPE (subtype)))
14993 tree min_val = size_zero_node;
14994 sub = build_fold_indirect_ref (sub);
14995 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
14996 if (type_domain && TYPE_MIN_VALUE (type_domain))
14997 min_val = TYPE_MIN_VALUE (type_domain);
14998 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
15004 /* Builds an expression for an indirection through T, simplifying some
15008 build_fold_indirect_ref (tree t)
15010 tree type = TREE_TYPE (TREE_TYPE (t));
15011 tree sub = fold_indirect_ref_1 (type, t);
15016 return build1 (INDIRECT_REF, type, t);
15019 /* Given an INDIRECT_REF T, return either T or a simplified version. */
15022 fold_indirect_ref (tree t)
15024 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
15032 /* Strip non-trapping, non-side-effecting tree nodes from an expression
15033 whose result is ignored. The type of the returned tree need not be
15034 the same as the original expression. */
15037 fold_ignored_result (tree t)
15039 if (!TREE_SIDE_EFFECTS (t))
15040 return integer_zero_node;
15043 switch (TREE_CODE_CLASS (TREE_CODE (t)))
15046 t = TREE_OPERAND (t, 0);
15050 case tcc_comparison:
15051 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15052 t = TREE_OPERAND (t, 0);
15053 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
15054 t = TREE_OPERAND (t, 1);
15059 case tcc_expression:
15060 switch (TREE_CODE (t))
15062 case COMPOUND_EXPR:
15063 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15065 t = TREE_OPERAND (t, 0);
15069 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
15070 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
15072 t = TREE_OPERAND (t, 0);
15085 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
15086 This can only be applied to objects of a sizetype. */
15089 round_up (tree value, int divisor)
15091 tree div = NULL_TREE;
15093 gcc_assert (divisor > 0);
15097 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15098 have to do anything. Only do this when we are not given a const,
15099 because in that case, this check is more expensive than just
15101 if (TREE_CODE (value) != INTEGER_CST)
15103 div = build_int_cst (TREE_TYPE (value), divisor);
15105 if (multiple_of_p (TREE_TYPE (value), value, div))
15109 /* If divisor is a power of two, simplify this to bit manipulation. */
15110 if (divisor == (divisor & -divisor))
15112 if (TREE_CODE (value) == INTEGER_CST)
15114 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
15115 unsigned HOST_WIDE_INT high;
15118 if ((low & (divisor - 1)) == 0)
15121 overflow_p = TREE_OVERFLOW (value);
15122 high = TREE_INT_CST_HIGH (value);
15123 low &= ~(divisor - 1);
15132 return force_fit_type_double (TREE_TYPE (value), low, high,
15139 t = build_int_cst (TREE_TYPE (value), divisor - 1);
15140 value = size_binop (PLUS_EXPR, value, t);
15141 t = build_int_cst (TREE_TYPE (value), -divisor);
15142 value = size_binop (BIT_AND_EXPR, value, t);
15148 div = build_int_cst (TREE_TYPE (value), divisor);
15149 value = size_binop (CEIL_DIV_EXPR, value, div);
15150 value = size_binop (MULT_EXPR, value, div);
15156 /* Likewise, but round down. */
15159 round_down (tree value, int divisor)
15161 tree div = NULL_TREE;
15163 gcc_assert (divisor > 0);
15167 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15168 have to do anything. Only do this when we are not given a const,
15169 because in that case, this check is more expensive than just
15171 if (TREE_CODE (value) != INTEGER_CST)
15173 div = build_int_cst (TREE_TYPE (value), divisor);
15175 if (multiple_of_p (TREE_TYPE (value), value, div))
15179 /* If divisor is a power of two, simplify this to bit manipulation. */
15180 if (divisor == (divisor & -divisor))
15184 t = build_int_cst (TREE_TYPE (value), -divisor);
15185 value = size_binop (BIT_AND_EXPR, value, t);
15190 div = build_int_cst (TREE_TYPE (value), divisor);
15191 value = size_binop (FLOOR_DIV_EXPR, value, div);
15192 value = size_binop (MULT_EXPR, value, div);
15198 /* Returns the pointer to the base of the object addressed by EXP and
15199 extracts the information about the offset of the access, storing it
15200 to PBITPOS and POFFSET. */
15203 split_address_to_core_and_offset (tree exp,
15204 HOST_WIDE_INT *pbitpos, tree *poffset)
15207 enum machine_mode mode;
15208 int unsignedp, volatilep;
15209 HOST_WIDE_INT bitsize;
15211 if (TREE_CODE (exp) == ADDR_EXPR)
15213 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
15214 poffset, &mode, &unsignedp, &volatilep,
15216 core = fold_addr_expr (core);
15222 *poffset = NULL_TREE;
15228 /* Returns true if addresses of E1 and E2 differ by a constant, false
15229 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15232 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
15235 HOST_WIDE_INT bitpos1, bitpos2;
15236 tree toffset1, toffset2, tdiff, type;
15238 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
15239 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
15241 if (bitpos1 % BITS_PER_UNIT != 0
15242 || bitpos2 % BITS_PER_UNIT != 0
15243 || !operand_equal_p (core1, core2, 0))
15246 if (toffset1 && toffset2)
15248 type = TREE_TYPE (toffset1);
15249 if (type != TREE_TYPE (toffset2))
15250 toffset2 = fold_convert (type, toffset2);
15252 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
15253 if (!cst_and_fits_in_hwi (tdiff))
15256 *diff = int_cst_value (tdiff);
15258 else if (toffset1 || toffset2)
15260 /* If only one of the offsets is non-constant, the difference cannot
15267 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
15271 /* Simplify the floating point expression EXP when the sign of the
15272 result is not significant. Return NULL_TREE if no simplification
15276 fold_strip_sign_ops (tree exp)
15280 switch (TREE_CODE (exp))
15284 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15285 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
15289 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
15291 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15292 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15293 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
15294 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
15295 arg0 ? arg0 : TREE_OPERAND (exp, 0),
15296 arg1 ? arg1 : TREE_OPERAND (exp, 1));
15299 case COMPOUND_EXPR:
15300 arg0 = TREE_OPERAND (exp, 0);
15301 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15303 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
15307 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15308 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
15310 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
15311 arg0 ? arg0 : TREE_OPERAND (exp, 1),
15312 arg1 ? arg1 : TREE_OPERAND (exp, 2));
15317 const enum built_in_function fcode = builtin_mathfn_code (exp);
15320 CASE_FLT_FN (BUILT_IN_COPYSIGN):
15321 /* Strip copysign function call, return the 1st argument. */
15322 arg0 = CALL_EXPR_ARG (exp, 0);
15323 arg1 = CALL_EXPR_ARG (exp, 1);
15324 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
15327 /* Strip sign ops from the argument of "odd" math functions. */
15328 if (negate_mathfn_p (fcode))
15330 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
15332 return build_call_expr (get_callee_fndecl (exp), 1, arg0);