1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
31 and force_fit_type_double.
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type_double takes a constant, an overflowable flag and a
43 prior overflow indicator. It forces the value to fit the type and
46 Note: Since the folders get called on non-gimple code as well as
47 gimple code, we need to handle GIMPLE tuples as well as their
48 corresponding tree equivalents. */
52 #include "coretypes.h"
57 #include "fixed-value.h"
66 #include "langhooks.h"
70 /* Nonzero if we are folding constants inside an initializer; zero
72 int folding_initializer = 0;
74 /* The following constants represent a bit based encoding of GCC's
75 comparison operators. This encoding simplifies transformations
76 on relational comparison operators, such as AND and OR. */
77 enum comparison_code {
96 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
97 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
98 static bool negate_mathfn_p (enum built_in_function);
99 static bool negate_expr_p (tree);
100 static tree negate_expr (tree);
101 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
102 static tree associate_trees (tree, tree, enum tree_code, tree);
103 static tree const_binop (enum tree_code, tree, tree, int);
104 static enum comparison_code comparison_to_compcode (enum tree_code);
105 static enum tree_code compcode_to_comparison (enum comparison_code);
106 static int operand_equal_for_comparison_p (tree, tree, tree);
107 static int twoval_comparison_p (tree, tree *, tree *, int *);
108 static tree eval_subst (tree, tree, tree, tree, tree);
109 static tree pedantic_omit_one_operand (tree, tree, tree);
110 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
111 static tree make_bit_field_ref (tree, tree, HOST_WIDE_INT, HOST_WIDE_INT, int);
112 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
113 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
114 enum machine_mode *, int *, int *,
116 static int all_ones_mask_p (const_tree, int);
117 static tree sign_bit_p (tree, const_tree);
118 static int simple_operand_p (const_tree);
119 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
120 static tree range_predecessor (tree);
121 static tree range_successor (tree);
122 static tree make_range (tree, int *, tree *, tree *, bool *);
123 static tree build_range_check (tree, tree, int, tree, tree);
124 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
126 static tree fold_range_test (enum tree_code, tree, tree, tree);
127 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
128 static tree unextend (tree, int, int, tree);
129 static tree fold_truthop (enum tree_code, tree, tree, tree);
130 static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
131 static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
132 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
133 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
136 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
138 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
139 static tree fold_div_compare (enum tree_code, tree, tree, tree);
140 static bool reorder_operands_p (const_tree, const_tree);
141 static tree fold_negate_const (tree, tree);
142 static tree fold_not_const (tree, tree);
143 static tree fold_relational_const (enum tree_code, tree, tree, tree);
146 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
147 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
148 and SUM1. Then this yields nonzero if overflow occurred during the
151 Overflow occurs if A and B have the same sign, but A and SUM differ in
152 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
154 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
156 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
157 We do that by representing the two-word integer in 4 words, with only
158 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
159 number. The value of the word is LOWPART + HIGHPART * BASE. */
162 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
163 #define HIGHPART(x) \
164 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
165 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
167 /* Unpack a two-word integer into 4 words.
168 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
169 WORDS points to the array of HOST_WIDE_INTs. */
172 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
174 words[0] = LOWPART (low);
175 words[1] = HIGHPART (low);
176 words[2] = LOWPART (hi);
177 words[3] = HIGHPART (hi);
180 /* Pack an array of 4 words into a two-word integer.
181 WORDS points to the array of words.
182 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
185 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
188 *low = words[0] + words[1] * BASE;
189 *hi = words[2] + words[3] * BASE;
192 /* Force the double-word integer L1, H1 to be within the range of the
193 integer type TYPE. Stores the properly truncated and sign-extended
194 double-word integer in *LV, *HV. Returns true if the operation
195 overflows, that is, argument and result are different. */
198 fit_double_type (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
199 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, const_tree type)
201 unsigned HOST_WIDE_INT low0 = l1;
202 HOST_WIDE_INT high0 = h1;
204 int sign_extended_type;
206 if (POINTER_TYPE_P (type)
207 || TREE_CODE (type) == OFFSET_TYPE)
210 prec = TYPE_PRECISION (type);
212 /* Size types *are* sign extended. */
213 sign_extended_type = (!TYPE_UNSIGNED (type)
214 || (TREE_CODE (type) == INTEGER_TYPE
215 && TYPE_IS_SIZETYPE (type)));
217 /* First clear all bits that are beyond the type's precision. */
218 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
220 else if (prec > HOST_BITS_PER_WIDE_INT)
221 h1 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
225 if (prec < HOST_BITS_PER_WIDE_INT)
226 l1 &= ~((HOST_WIDE_INT) (-1) << prec);
229 /* Then do sign extension if necessary. */
230 if (!sign_extended_type)
231 /* No sign extension */;
232 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
233 /* Correct width already. */;
234 else if (prec > HOST_BITS_PER_WIDE_INT)
236 /* Sign extend top half? */
237 if (h1 & ((unsigned HOST_WIDE_INT)1
238 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
239 h1 |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
241 else if (prec == HOST_BITS_PER_WIDE_INT)
243 if ((HOST_WIDE_INT)l1 < 0)
248 /* Sign extend bottom half? */
249 if (l1 & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
252 l1 |= (HOST_WIDE_INT)(-1) << prec;
259 /* If the value didn't fit, signal overflow. */
260 return l1 != low0 || h1 != high0;
263 /* We force the double-int HIGH:LOW to the range of the type TYPE by
264 sign or zero extending it.
265 OVERFLOWABLE indicates if we are interested
266 in overflow of the value, when >0 we are only interested in signed
267 overflow, for <0 we are interested in any overflow. OVERFLOWED
268 indicates whether overflow has already occurred. CONST_OVERFLOWED
269 indicates whether constant overflow has already occurred. We force
270 T's value to be within range of T's type (by setting to 0 or 1 all
271 the bits outside the type's range). We set TREE_OVERFLOWED if,
272 OVERFLOWED is nonzero,
273 or OVERFLOWABLE is >0 and signed overflow occurs
274 or OVERFLOWABLE is <0 and any overflow occurs
275 We return a new tree node for the extended double-int. The node
276 is shared if no overflow flags are set. */
279 force_fit_type_double (tree type, unsigned HOST_WIDE_INT low,
280 HOST_WIDE_INT high, int overflowable,
283 int sign_extended_type;
286 /* Size types *are* sign extended. */
287 sign_extended_type = (!TYPE_UNSIGNED (type)
288 || (TREE_CODE (type) == INTEGER_TYPE
289 && TYPE_IS_SIZETYPE (type)));
291 overflow = fit_double_type (low, high, &low, &high, type);
293 /* If we need to set overflow flags, return a new unshared node. */
294 if (overflowed || overflow)
298 || (overflowable > 0 && sign_extended_type))
300 tree t = make_node (INTEGER_CST);
301 TREE_INT_CST_LOW (t) = low;
302 TREE_INT_CST_HIGH (t) = high;
303 TREE_TYPE (t) = type;
304 TREE_OVERFLOW (t) = 1;
309 /* Else build a shared node. */
310 return build_int_cst_wide (type, low, high);
313 /* Add two doubleword integers with doubleword result.
314 Return nonzero if the operation overflows according to UNSIGNED_P.
315 Each argument is given as two `HOST_WIDE_INT' pieces.
316 One argument is L1 and H1; the other, L2 and H2.
317 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
320 add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
321 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
322 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
325 unsigned HOST_WIDE_INT l;
329 h = h1 + h2 + (l < l1);
335 return (unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1;
337 return OVERFLOW_SUM_SIGN (h1, h2, h);
340 /* Negate a doubleword integer with doubleword result.
341 Return nonzero if the operation overflows, assuming it's signed.
342 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
343 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
346 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
347 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
353 return (*hv & h1) < 0;
363 /* Multiply two doubleword integers with doubleword result.
364 Return nonzero if the operation overflows according to UNSIGNED_P.
365 Each argument is given as two `HOST_WIDE_INT' pieces.
366 One argument is L1 and H1; the other, L2 and H2.
367 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
370 mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
371 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
372 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
375 HOST_WIDE_INT arg1[4];
376 HOST_WIDE_INT arg2[4];
377 HOST_WIDE_INT prod[4 * 2];
378 unsigned HOST_WIDE_INT carry;
380 unsigned HOST_WIDE_INT toplow, neglow;
381 HOST_WIDE_INT tophigh, neghigh;
383 encode (arg1, l1, h1);
384 encode (arg2, l2, h2);
386 memset (prod, 0, sizeof prod);
388 for (i = 0; i < 4; i++)
391 for (j = 0; j < 4; j++)
394 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
395 carry += arg1[i] * arg2[j];
396 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
398 prod[k] = LOWPART (carry);
399 carry = HIGHPART (carry);
404 decode (prod, lv, hv);
405 decode (prod + 4, &toplow, &tophigh);
407 /* Unsigned overflow is immediate. */
409 return (toplow | tophigh) != 0;
411 /* Check for signed overflow by calculating the signed representation of the
412 top half of the result; it should agree with the low half's sign bit. */
415 neg_double (l2, h2, &neglow, &neghigh);
416 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
420 neg_double (l1, h1, &neglow, &neghigh);
421 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
423 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
426 /* Shift the doubleword integer in L1, H1 left by COUNT places
427 keeping only PREC bits of result.
428 Shift right if COUNT is negative.
429 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
430 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
433 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
434 HOST_WIDE_INT count, unsigned int prec,
435 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
437 unsigned HOST_WIDE_INT signmask;
441 rshift_double (l1, h1, -count, prec, lv, hv, arith);
445 if (SHIFT_COUNT_TRUNCATED)
448 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
450 /* Shifting by the host word size is undefined according to the
451 ANSI standard, so we must handle this as a special case. */
455 else if (count >= HOST_BITS_PER_WIDE_INT)
457 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
462 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
463 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
467 /* Sign extend all bits that are beyond the precision. */
469 signmask = -((prec > HOST_BITS_PER_WIDE_INT
470 ? ((unsigned HOST_WIDE_INT) *hv
471 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
472 : (*lv >> (prec - 1))) & 1);
474 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
476 else if (prec >= HOST_BITS_PER_WIDE_INT)
478 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
479 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
484 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
485 *lv |= signmask << prec;
489 /* Shift the doubleword integer in L1, H1 right by COUNT places
490 keeping only PREC bits of result. COUNT must be positive.
491 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
492 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
495 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
496 HOST_WIDE_INT count, unsigned int prec,
497 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
500 unsigned HOST_WIDE_INT signmask;
503 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
506 if (SHIFT_COUNT_TRUNCATED)
509 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
511 /* Shifting by the host word size is undefined according to the
512 ANSI standard, so we must handle this as a special case. */
516 else if (count >= HOST_BITS_PER_WIDE_INT)
519 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
523 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
525 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
528 /* Zero / sign extend all bits that are beyond the precision. */
530 if (count >= (HOST_WIDE_INT)prec)
535 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
537 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
539 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
540 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
545 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
546 *lv |= signmask << (prec - count);
550 /* Rotate the doubleword integer in L1, H1 left by COUNT places
551 keeping only PREC bits of result.
552 Rotate right if COUNT is negative.
553 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
556 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
557 HOST_WIDE_INT count, unsigned int prec,
558 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
560 unsigned HOST_WIDE_INT s1l, s2l;
561 HOST_WIDE_INT s1h, s2h;
567 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
568 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
573 /* Rotate the doubleword integer in L1, H1 left by COUNT places
574 keeping only PREC bits of result. COUNT must be positive.
575 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
578 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
579 HOST_WIDE_INT count, unsigned int prec,
580 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
582 unsigned HOST_WIDE_INT s1l, s2l;
583 HOST_WIDE_INT s1h, s2h;
589 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
590 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
595 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
596 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
597 CODE is a tree code for a kind of division, one of
598 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
600 It controls how the quotient is rounded to an integer.
601 Return nonzero if the operation overflows.
602 UNS nonzero says do unsigned division. */
605 div_and_round_double (enum tree_code code, int uns,
606 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
607 HOST_WIDE_INT hnum_orig,
608 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
609 HOST_WIDE_INT hden_orig,
610 unsigned HOST_WIDE_INT *lquo,
611 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
615 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
616 HOST_WIDE_INT den[4], quo[4];
618 unsigned HOST_WIDE_INT work;
619 unsigned HOST_WIDE_INT carry = 0;
620 unsigned HOST_WIDE_INT lnum = lnum_orig;
621 HOST_WIDE_INT hnum = hnum_orig;
622 unsigned HOST_WIDE_INT lden = lden_orig;
623 HOST_WIDE_INT hden = hden_orig;
626 if (hden == 0 && lden == 0)
627 overflow = 1, lden = 1;
629 /* Calculate quotient sign and convert operands to unsigned. */
635 /* (minimum integer) / (-1) is the only overflow case. */
636 if (neg_double (lnum, hnum, &lnum, &hnum)
637 && ((HOST_WIDE_INT) lden & hden) == -1)
643 neg_double (lden, hden, &lden, &hden);
647 if (hnum == 0 && hden == 0)
648 { /* single precision */
650 /* This unsigned division rounds toward zero. */
656 { /* trivial case: dividend < divisor */
657 /* hden != 0 already checked. */
664 memset (quo, 0, sizeof quo);
666 memset (num, 0, sizeof num); /* to zero 9th element */
667 memset (den, 0, sizeof den);
669 encode (num, lnum, hnum);
670 encode (den, lden, hden);
672 /* Special code for when the divisor < BASE. */
673 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
675 /* hnum != 0 already checked. */
676 for (i = 4 - 1; i >= 0; i--)
678 work = num[i] + carry * BASE;
679 quo[i] = work / lden;
685 /* Full double precision division,
686 with thanks to Don Knuth's "Seminumerical Algorithms". */
687 int num_hi_sig, den_hi_sig;
688 unsigned HOST_WIDE_INT quo_est, scale;
690 /* Find the highest nonzero divisor digit. */
691 for (i = 4 - 1;; i--)
698 /* Insure that the first digit of the divisor is at least BASE/2.
699 This is required by the quotient digit estimation algorithm. */
701 scale = BASE / (den[den_hi_sig] + 1);
703 { /* scale divisor and dividend */
705 for (i = 0; i <= 4 - 1; i++)
707 work = (num[i] * scale) + carry;
708 num[i] = LOWPART (work);
709 carry = HIGHPART (work);
714 for (i = 0; i <= 4 - 1; i++)
716 work = (den[i] * scale) + carry;
717 den[i] = LOWPART (work);
718 carry = HIGHPART (work);
719 if (den[i] != 0) den_hi_sig = i;
726 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
728 /* Guess the next quotient digit, quo_est, by dividing the first
729 two remaining dividend digits by the high order quotient digit.
730 quo_est is never low and is at most 2 high. */
731 unsigned HOST_WIDE_INT tmp;
733 num_hi_sig = i + den_hi_sig + 1;
734 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
735 if (num[num_hi_sig] != den[den_hi_sig])
736 quo_est = work / den[den_hi_sig];
740 /* Refine quo_est so it's usually correct, and at most one high. */
741 tmp = work - quo_est * den[den_hi_sig];
743 && (den[den_hi_sig - 1] * quo_est
744 > (tmp * BASE + num[num_hi_sig - 2])))
747 /* Try QUO_EST as the quotient digit, by multiplying the
748 divisor by QUO_EST and subtracting from the remaining dividend.
749 Keep in mind that QUO_EST is the I - 1st digit. */
752 for (j = 0; j <= den_hi_sig; j++)
754 work = quo_est * den[j] + carry;
755 carry = HIGHPART (work);
756 work = num[i + j] - LOWPART (work);
757 num[i + j] = LOWPART (work);
758 carry += HIGHPART (work) != 0;
761 /* If quo_est was high by one, then num[i] went negative and
762 we need to correct things. */
763 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
766 carry = 0; /* add divisor back in */
767 for (j = 0; j <= den_hi_sig; j++)
769 work = num[i + j] + den[j] + carry;
770 carry = HIGHPART (work);
771 num[i + j] = LOWPART (work);
774 num [num_hi_sig] += carry;
777 /* Store the quotient digit. */
782 decode (quo, lquo, hquo);
785 /* If result is negative, make it so. */
787 neg_double (*lquo, *hquo, lquo, hquo);
789 /* Compute trial remainder: rem = num - (quo * den) */
790 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
791 neg_double (*lrem, *hrem, lrem, hrem);
792 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
797 case TRUNC_MOD_EXPR: /* round toward zero */
798 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
802 case FLOOR_MOD_EXPR: /* round toward negative infinity */
803 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
806 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
814 case CEIL_MOD_EXPR: /* round toward positive infinity */
815 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
817 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
825 case ROUND_MOD_EXPR: /* round to closest integer */
827 unsigned HOST_WIDE_INT labs_rem = *lrem;
828 HOST_WIDE_INT habs_rem = *hrem;
829 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
830 HOST_WIDE_INT habs_den = hden, htwice;
832 /* Get absolute values. */
834 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
836 neg_double (lden, hden, &labs_den, &habs_den);
838 /* If (2 * abs (lrem) >= abs (lden)), adjust the quotient. */
839 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
840 labs_rem, habs_rem, <wice, &htwice);
842 if (((unsigned HOST_WIDE_INT) habs_den
843 < (unsigned HOST_WIDE_INT) htwice)
844 || (((unsigned HOST_WIDE_INT) habs_den
845 == (unsigned HOST_WIDE_INT) htwice)
846 && (labs_den <= ltwice)))
850 add_double (*lquo, *hquo,
851 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
854 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
866 /* Compute true remainder: rem = num - (quo * den) */
867 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
868 neg_double (*lrem, *hrem, lrem, hrem);
869 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
873 /* If ARG2 divides ARG1 with zero remainder, carries out the division
874 of type CODE and returns the quotient.
875 Otherwise returns NULL_TREE. */
878 div_if_zero_remainder (enum tree_code code, const_tree arg1, const_tree arg2)
880 unsigned HOST_WIDE_INT int1l, int2l;
881 HOST_WIDE_INT int1h, int2h;
882 unsigned HOST_WIDE_INT quol, reml;
883 HOST_WIDE_INT quoh, remh;
884 tree type = TREE_TYPE (arg1);
885 int uns = TYPE_UNSIGNED (type);
887 int1l = TREE_INT_CST_LOW (arg1);
888 int1h = TREE_INT_CST_HIGH (arg1);
889 /* &obj[0] + -128 really should be compiled as &obj[-8] rather than
890 &obj[some_exotic_number]. */
891 if (POINTER_TYPE_P (type))
894 type = signed_type_for (type);
895 fit_double_type (int1l, int1h, &int1l, &int1h,
899 fit_double_type (int1l, int1h, &int1l, &int1h, type);
900 int2l = TREE_INT_CST_LOW (arg2);
901 int2h = TREE_INT_CST_HIGH (arg2);
903 div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
904 &quol, &quoh, &reml, &remh);
905 if (remh != 0 || reml != 0)
908 return build_int_cst_wide (type, quol, quoh);
911 /* This is nonzero if we should defer warnings about undefined
912 overflow. This facility exists because these warnings are a
913 special case. The code to estimate loop iterations does not want
914 to issue any warnings, since it works with expressions which do not
915 occur in user code. Various bits of cleanup code call fold(), but
916 only use the result if it has certain characteristics (e.g., is a
917 constant); that code only wants to issue a warning if the result is
920 static int fold_deferring_overflow_warnings;
922 /* If a warning about undefined overflow is deferred, this is the
923 warning. Note that this may cause us to turn two warnings into
924 one, but that is fine since it is sufficient to only give one
925 warning per expression. */
927 static const char* fold_deferred_overflow_warning;
929 /* If a warning about undefined overflow is deferred, this is the
930 level at which the warning should be emitted. */
932 static enum warn_strict_overflow_code fold_deferred_overflow_code;
934 /* Start deferring overflow warnings. We could use a stack here to
935 permit nested calls, but at present it is not necessary. */
938 fold_defer_overflow_warnings (void)
940 ++fold_deferring_overflow_warnings;
943 /* Stop deferring overflow warnings. If there is a pending warning,
944 and ISSUE is true, then issue the warning if appropriate. STMT is
945 the statement with which the warning should be associated (used for
946 location information); STMT may be NULL. CODE is the level of the
947 warning--a warn_strict_overflow_code value. This function will use
948 the smaller of CODE and the deferred code when deciding whether to
949 issue the warning. CODE may be zero to mean to always use the
953 fold_undefer_overflow_warnings (bool issue, const_gimple stmt, int code)
958 gcc_assert (fold_deferring_overflow_warnings > 0);
959 --fold_deferring_overflow_warnings;
960 if (fold_deferring_overflow_warnings > 0)
962 if (fold_deferred_overflow_warning != NULL
964 && code < (int) fold_deferred_overflow_code)
965 fold_deferred_overflow_code = code;
969 warnmsg = fold_deferred_overflow_warning;
970 fold_deferred_overflow_warning = NULL;
972 if (!issue || warnmsg == NULL)
975 if (gimple_no_warning_p (stmt))
978 /* Use the smallest code level when deciding to issue the
980 if (code == 0 || code > (int) fold_deferred_overflow_code)
981 code = fold_deferred_overflow_code;
983 if (!issue_strict_overflow_warning (code))
987 locus = input_location;
989 locus = gimple_location (stmt);
990 warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
993 /* Stop deferring overflow warnings, ignoring any deferred
997 fold_undefer_and_ignore_overflow_warnings (void)
999 fold_undefer_overflow_warnings (false, NULL, 0);
1002 /* Whether we are deferring overflow warnings. */
1005 fold_deferring_overflow_warnings_p (void)
1007 return fold_deferring_overflow_warnings > 0;
1010 /* This is called when we fold something based on the fact that signed
1011 overflow is undefined. */
1014 fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
1016 if (fold_deferring_overflow_warnings > 0)
1018 if (fold_deferred_overflow_warning == NULL
1019 || wc < fold_deferred_overflow_code)
1021 fold_deferred_overflow_warning = gmsgid;
1022 fold_deferred_overflow_code = wc;
1025 else if (issue_strict_overflow_warning (wc))
1026 warning (OPT_Wstrict_overflow, gmsgid);
1029 /* Return true if the built-in mathematical function specified by CODE
1030 is odd, i.e. -f(x) == f(-x). */
1033 negate_mathfn_p (enum built_in_function code)
1037 CASE_FLT_FN (BUILT_IN_ASIN):
1038 CASE_FLT_FN (BUILT_IN_ASINH):
1039 CASE_FLT_FN (BUILT_IN_ATAN):
1040 CASE_FLT_FN (BUILT_IN_ATANH):
1041 CASE_FLT_FN (BUILT_IN_CASIN):
1042 CASE_FLT_FN (BUILT_IN_CASINH):
1043 CASE_FLT_FN (BUILT_IN_CATAN):
1044 CASE_FLT_FN (BUILT_IN_CATANH):
1045 CASE_FLT_FN (BUILT_IN_CBRT):
1046 CASE_FLT_FN (BUILT_IN_CPROJ):
1047 CASE_FLT_FN (BUILT_IN_CSIN):
1048 CASE_FLT_FN (BUILT_IN_CSINH):
1049 CASE_FLT_FN (BUILT_IN_CTAN):
1050 CASE_FLT_FN (BUILT_IN_CTANH):
1051 CASE_FLT_FN (BUILT_IN_ERF):
1052 CASE_FLT_FN (BUILT_IN_LLROUND):
1053 CASE_FLT_FN (BUILT_IN_LROUND):
1054 CASE_FLT_FN (BUILT_IN_ROUND):
1055 CASE_FLT_FN (BUILT_IN_SIN):
1056 CASE_FLT_FN (BUILT_IN_SINH):
1057 CASE_FLT_FN (BUILT_IN_TAN):
1058 CASE_FLT_FN (BUILT_IN_TANH):
1059 CASE_FLT_FN (BUILT_IN_TRUNC):
1062 CASE_FLT_FN (BUILT_IN_LLRINT):
1063 CASE_FLT_FN (BUILT_IN_LRINT):
1064 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1065 CASE_FLT_FN (BUILT_IN_RINT):
1066 return !flag_rounding_math;
1074 /* Check whether we may negate an integer constant T without causing
1078 may_negate_without_overflow_p (const_tree t)
1080 unsigned HOST_WIDE_INT val;
1084 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1086 type = TREE_TYPE (t);
1087 if (TYPE_UNSIGNED (type))
1090 prec = TYPE_PRECISION (type);
1091 if (prec > HOST_BITS_PER_WIDE_INT)
1093 if (TREE_INT_CST_LOW (t) != 0)
1095 prec -= HOST_BITS_PER_WIDE_INT;
1096 val = TREE_INT_CST_HIGH (t);
1099 val = TREE_INT_CST_LOW (t);
1100 if (prec < HOST_BITS_PER_WIDE_INT)
1101 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1102 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1105 /* Determine whether an expression T can be cheaply negated using
1106 the function negate_expr without introducing undefined overflow. */
1109 negate_expr_p (tree t)
1116 type = TREE_TYPE (t);
1118 STRIP_SIGN_NOPS (t);
1119 switch (TREE_CODE (t))
1122 if (TYPE_OVERFLOW_WRAPS (type))
1125 /* Check that -CST will not overflow type. */
1126 return may_negate_without_overflow_p (t);
1128 return (INTEGRAL_TYPE_P (type)
1129 && TYPE_OVERFLOW_WRAPS (type));
1137 return negate_expr_p (TREE_REALPART (t))
1138 && negate_expr_p (TREE_IMAGPART (t));
1141 return negate_expr_p (TREE_OPERAND (t, 0))
1142 && negate_expr_p (TREE_OPERAND (t, 1));
1145 return negate_expr_p (TREE_OPERAND (t, 0));
1148 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1149 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1151 /* -(A + B) -> (-B) - A. */
1152 if (negate_expr_p (TREE_OPERAND (t, 1))
1153 && reorder_operands_p (TREE_OPERAND (t, 0),
1154 TREE_OPERAND (t, 1)))
1156 /* -(A + B) -> (-A) - B. */
1157 return negate_expr_p (TREE_OPERAND (t, 0));
1160 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1161 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1162 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1163 && reorder_operands_p (TREE_OPERAND (t, 0),
1164 TREE_OPERAND (t, 1));
1167 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1173 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1174 return negate_expr_p (TREE_OPERAND (t, 1))
1175 || negate_expr_p (TREE_OPERAND (t, 0));
1178 case TRUNC_DIV_EXPR:
1179 case ROUND_DIV_EXPR:
1180 case FLOOR_DIV_EXPR:
1182 case EXACT_DIV_EXPR:
1183 /* In general we can't negate A / B, because if A is INT_MIN and
1184 B is 1, we may turn this into INT_MIN / -1 which is undefined
1185 and actually traps on some architectures. But if overflow is
1186 undefined, we can negate, because - (INT_MIN / 1) is an
1188 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1189 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1191 return negate_expr_p (TREE_OPERAND (t, 1))
1192 || negate_expr_p (TREE_OPERAND (t, 0));
1195 /* Negate -((double)float) as (double)(-float). */
1196 if (TREE_CODE (type) == REAL_TYPE)
1198 tree tem = strip_float_extensions (t);
1200 return negate_expr_p (tem);
1205 /* Negate -f(x) as f(-x). */
1206 if (negate_mathfn_p (builtin_mathfn_code (t)))
1207 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1211 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1212 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1214 tree op1 = TREE_OPERAND (t, 1);
1215 if (TREE_INT_CST_HIGH (op1) == 0
1216 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1217 == TREE_INT_CST_LOW (op1))
1228 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1229 simplification is possible.
1230 If negate_expr_p would return true for T, NULL_TREE will never be
1234 fold_negate_expr (tree t)
1236 tree type = TREE_TYPE (t);
1239 switch (TREE_CODE (t))
1241 /* Convert - (~A) to A + 1. */
1243 if (INTEGRAL_TYPE_P (type))
1244 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1245 build_int_cst (type, 1));
1249 tem = fold_negate_const (t, type);
1250 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1251 || !TYPE_OVERFLOW_TRAPS (type))
1256 tem = fold_negate_const (t, type);
1257 /* Two's complement FP formats, such as c4x, may overflow. */
1258 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1263 tem = fold_negate_const (t, type);
1268 tree rpart = negate_expr (TREE_REALPART (t));
1269 tree ipart = negate_expr (TREE_IMAGPART (t));
1271 if ((TREE_CODE (rpart) == REAL_CST
1272 && TREE_CODE (ipart) == REAL_CST)
1273 || (TREE_CODE (rpart) == INTEGER_CST
1274 && TREE_CODE (ipart) == INTEGER_CST))
1275 return build_complex (type, rpart, ipart);
1280 if (negate_expr_p (t))
1281 return fold_build2 (COMPLEX_EXPR, type,
1282 fold_negate_expr (TREE_OPERAND (t, 0)),
1283 fold_negate_expr (TREE_OPERAND (t, 1)));
1287 if (negate_expr_p (t))
1288 return fold_build1 (CONJ_EXPR, type,
1289 fold_negate_expr (TREE_OPERAND (t, 0)));
1293 return TREE_OPERAND (t, 0);
1296 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1297 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1299 /* -(A + B) -> (-B) - A. */
1300 if (negate_expr_p (TREE_OPERAND (t, 1))
1301 && reorder_operands_p (TREE_OPERAND (t, 0),
1302 TREE_OPERAND (t, 1)))
1304 tem = negate_expr (TREE_OPERAND (t, 1));
1305 return fold_build2 (MINUS_EXPR, type,
1306 tem, TREE_OPERAND (t, 0));
1309 /* -(A + B) -> (-A) - B. */
1310 if (negate_expr_p (TREE_OPERAND (t, 0)))
1312 tem = negate_expr (TREE_OPERAND (t, 0));
1313 return fold_build2 (MINUS_EXPR, type,
1314 tem, TREE_OPERAND (t, 1));
1320 /* - (A - B) -> B - A */
1321 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1322 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1323 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1324 return fold_build2 (MINUS_EXPR, type,
1325 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1329 if (TYPE_UNSIGNED (type))
1335 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1337 tem = TREE_OPERAND (t, 1);
1338 if (negate_expr_p (tem))
1339 return fold_build2 (TREE_CODE (t), type,
1340 TREE_OPERAND (t, 0), negate_expr (tem));
1341 tem = TREE_OPERAND (t, 0);
1342 if (negate_expr_p (tem))
1343 return fold_build2 (TREE_CODE (t), type,
1344 negate_expr (tem), TREE_OPERAND (t, 1));
1348 case TRUNC_DIV_EXPR:
1349 case ROUND_DIV_EXPR:
1350 case FLOOR_DIV_EXPR:
1352 case EXACT_DIV_EXPR:
1353 /* In general we can't negate A / B, because if A is INT_MIN and
1354 B is 1, we may turn this into INT_MIN / -1 which is undefined
1355 and actually traps on some architectures. But if overflow is
1356 undefined, we can negate, because - (INT_MIN / 1) is an
1358 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1360 const char * const warnmsg = G_("assuming signed overflow does not "
1361 "occur when negating a division");
1362 tem = TREE_OPERAND (t, 1);
1363 if (negate_expr_p (tem))
1365 if (INTEGRAL_TYPE_P (type)
1366 && (TREE_CODE (tem) != INTEGER_CST
1367 || integer_onep (tem)))
1368 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1369 return fold_build2 (TREE_CODE (t), type,
1370 TREE_OPERAND (t, 0), negate_expr (tem));
1372 tem = TREE_OPERAND (t, 0);
1373 if (negate_expr_p (tem))
1375 if (INTEGRAL_TYPE_P (type)
1376 && (TREE_CODE (tem) != INTEGER_CST
1377 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1378 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1379 return fold_build2 (TREE_CODE (t), type,
1380 negate_expr (tem), TREE_OPERAND (t, 1));
1386 /* Convert -((double)float) into (double)(-float). */
1387 if (TREE_CODE (type) == REAL_TYPE)
1389 tem = strip_float_extensions (t);
1390 if (tem != t && negate_expr_p (tem))
1391 return fold_convert (type, negate_expr (tem));
1396 /* Negate -f(x) as f(-x). */
1397 if (negate_mathfn_p (builtin_mathfn_code (t))
1398 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1402 fndecl = get_callee_fndecl (t);
1403 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1404 return build_call_expr (fndecl, 1, arg);
1409 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1410 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1412 tree op1 = TREE_OPERAND (t, 1);
1413 if (TREE_INT_CST_HIGH (op1) == 0
1414 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1415 == TREE_INT_CST_LOW (op1))
1417 tree ntype = TYPE_UNSIGNED (type)
1418 ? signed_type_for (type)
1419 : unsigned_type_for (type);
1420 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1421 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1422 return fold_convert (type, temp);
1434 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1435 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1436 return NULL_TREE. */
1439 negate_expr (tree t)
1446 type = TREE_TYPE (t);
1447 STRIP_SIGN_NOPS (t);
1449 tem = fold_negate_expr (t);
1451 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1452 return fold_convert (type, tem);
1455 /* Split a tree IN into a constant, literal and variable parts that could be
1456 combined with CODE to make IN. "constant" means an expression with
1457 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1458 commutative arithmetic operation. Store the constant part into *CONP,
1459 the literal in *LITP and return the variable part. If a part isn't
1460 present, set it to null. If the tree does not decompose in this way,
1461 return the entire tree as the variable part and the other parts as null.
1463 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1464 case, we negate an operand that was subtracted. Except if it is a
1465 literal for which we use *MINUS_LITP instead.
1467 If NEGATE_P is true, we are negating all of IN, again except a literal
1468 for which we use *MINUS_LITP instead.
1470 If IN is itself a literal or constant, return it as appropriate.
1472 Note that we do not guarantee that any of the three values will be the
1473 same type as IN, but they will have the same signedness and mode. */
1476 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1477 tree *minus_litp, int negate_p)
1485 /* Strip any conversions that don't change the machine mode or signedness. */
1486 STRIP_SIGN_NOPS (in);
1488 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
1489 || TREE_CODE (in) == FIXED_CST)
1491 else if (TREE_CODE (in) == code
1492 || ((! FLOAT_TYPE_P (TREE_TYPE (in)) || flag_associative_math)
1493 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
1494 /* We can associate addition and subtraction together (even
1495 though the C standard doesn't say so) for integers because
1496 the value is not affected. For reals, the value might be
1497 affected, so we can't. */
1498 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1499 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1501 tree op0 = TREE_OPERAND (in, 0);
1502 tree op1 = TREE_OPERAND (in, 1);
1503 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1504 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1506 /* First see if either of the operands is a literal, then a constant. */
1507 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
1508 || TREE_CODE (op0) == FIXED_CST)
1509 *litp = op0, op0 = 0;
1510 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
1511 || TREE_CODE (op1) == FIXED_CST)
1512 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1514 if (op0 != 0 && TREE_CONSTANT (op0))
1515 *conp = op0, op0 = 0;
1516 else if (op1 != 0 && TREE_CONSTANT (op1))
1517 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1519 /* If we haven't dealt with either operand, this is not a case we can
1520 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1521 if (op0 != 0 && op1 != 0)
1526 var = op1, neg_var_p = neg1_p;
1528 /* Now do any needed negations. */
1530 *minus_litp = *litp, *litp = 0;
1532 *conp = negate_expr (*conp);
1534 var = negate_expr (var);
1536 else if (TREE_CONSTANT (in))
1544 *minus_litp = *litp, *litp = 0;
1545 else if (*minus_litp)
1546 *litp = *minus_litp, *minus_litp = 0;
1547 *conp = negate_expr (*conp);
1548 var = negate_expr (var);
1554 /* Re-associate trees split by the above function. T1 and T2 are either
1555 expressions to associate or null. Return the new expression, if any. If
1556 we build an operation, do it in TYPE and with CODE. */
1559 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1566 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1567 try to fold this since we will have infinite recursion. But do
1568 deal with any NEGATE_EXPRs. */
1569 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1570 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1572 if (code == PLUS_EXPR)
1574 if (TREE_CODE (t1) == NEGATE_EXPR)
1575 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1576 fold_convert (type, TREE_OPERAND (t1, 0)));
1577 else if (TREE_CODE (t2) == NEGATE_EXPR)
1578 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1579 fold_convert (type, TREE_OPERAND (t2, 0)));
1580 else if (integer_zerop (t2))
1581 return fold_convert (type, t1);
1583 else if (code == MINUS_EXPR)
1585 if (integer_zerop (t2))
1586 return fold_convert (type, t1);
1589 return build2 (code, type, fold_convert (type, t1),
1590 fold_convert (type, t2));
1593 return fold_build2 (code, type, fold_convert (type, t1),
1594 fold_convert (type, t2));
1597 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1598 for use in int_const_binop, size_binop and size_diffop. */
1601 int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
1603 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1605 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1620 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1621 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1622 && TYPE_MODE (type1) == TYPE_MODE (type2);
1626 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1627 to produce a new constant. Return NULL_TREE if we don't know how
1628 to evaluate CODE at compile-time.
1630 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1633 int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2, int notrunc)
1635 unsigned HOST_WIDE_INT int1l, int2l;
1636 HOST_WIDE_INT int1h, int2h;
1637 unsigned HOST_WIDE_INT low;
1639 unsigned HOST_WIDE_INT garbagel;
1640 HOST_WIDE_INT garbageh;
1642 tree type = TREE_TYPE (arg1);
1643 int uns = TYPE_UNSIGNED (type);
1645 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1648 int1l = TREE_INT_CST_LOW (arg1);
1649 int1h = TREE_INT_CST_HIGH (arg1);
1650 int2l = TREE_INT_CST_LOW (arg2);
1651 int2h = TREE_INT_CST_HIGH (arg2);
1656 low = int1l | int2l, hi = int1h | int2h;
1660 low = int1l ^ int2l, hi = int1h ^ int2h;
1664 low = int1l & int2l, hi = int1h & int2h;
1670 /* It's unclear from the C standard whether shifts can overflow.
1671 The following code ignores overflow; perhaps a C standard
1672 interpretation ruling is needed. */
1673 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1680 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1685 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1689 neg_double (int2l, int2h, &low, &hi);
1690 add_double (int1l, int1h, low, hi, &low, &hi);
1691 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1695 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1698 case TRUNC_DIV_EXPR:
1699 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1700 case EXACT_DIV_EXPR:
1701 /* This is a shortcut for a common special case. */
1702 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1703 && !TREE_OVERFLOW (arg1)
1704 && !TREE_OVERFLOW (arg2)
1705 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1707 if (code == CEIL_DIV_EXPR)
1710 low = int1l / int2l, hi = 0;
1714 /* ... fall through ... */
1716 case ROUND_DIV_EXPR:
1717 if (int2h == 0 && int2l == 0)
1719 if (int2h == 0 && int2l == 1)
1721 low = int1l, hi = int1h;
1724 if (int1l == int2l && int1h == int2h
1725 && ! (int1l == 0 && int1h == 0))
1730 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1731 &low, &hi, &garbagel, &garbageh);
1734 case TRUNC_MOD_EXPR:
1735 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1736 /* This is a shortcut for a common special case. */
1737 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1738 && !TREE_OVERFLOW (arg1)
1739 && !TREE_OVERFLOW (arg2)
1740 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1742 if (code == CEIL_MOD_EXPR)
1744 low = int1l % int2l, hi = 0;
1748 /* ... fall through ... */
1750 case ROUND_MOD_EXPR:
1751 if (int2h == 0 && int2l == 0)
1753 overflow = div_and_round_double (code, uns,
1754 int1l, int1h, int2l, int2h,
1755 &garbagel, &garbageh, &low, &hi);
1761 low = (((unsigned HOST_WIDE_INT) int1h
1762 < (unsigned HOST_WIDE_INT) int2h)
1763 || (((unsigned HOST_WIDE_INT) int1h
1764 == (unsigned HOST_WIDE_INT) int2h)
1767 low = (int1h < int2h
1768 || (int1h == int2h && int1l < int2l));
1770 if (low == (code == MIN_EXPR))
1771 low = int1l, hi = int1h;
1773 low = int2l, hi = int2h;
1782 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1784 /* Propagate overflow flags ourselves. */
1785 if (((!uns || is_sizetype) && overflow)
1786 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1789 TREE_OVERFLOW (t) = 1;
1793 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1794 ((!uns || is_sizetype) && overflow)
1795 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1800 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1801 constant. We assume ARG1 and ARG2 have the same data type, or at least
1802 are the same kind of constant and the same machine mode. Return zero if
1803 combining the constants is not allowed in the current operating mode.
1805 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1808 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1810 /* Sanity check for the recursive cases. */
1817 if (TREE_CODE (arg1) == INTEGER_CST)
1818 return int_const_binop (code, arg1, arg2, notrunc);
1820 if (TREE_CODE (arg1) == REAL_CST)
1822 enum machine_mode mode;
1825 REAL_VALUE_TYPE value;
1826 REAL_VALUE_TYPE result;
1830 /* The following codes are handled by real_arithmetic. */
1845 d1 = TREE_REAL_CST (arg1);
1846 d2 = TREE_REAL_CST (arg2);
1848 type = TREE_TYPE (arg1);
1849 mode = TYPE_MODE (type);
1851 /* Don't perform operation if we honor signaling NaNs and
1852 either operand is a NaN. */
1853 if (HONOR_SNANS (mode)
1854 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1857 /* Don't perform operation if it would raise a division
1858 by zero exception. */
1859 if (code == RDIV_EXPR
1860 && REAL_VALUES_EQUAL (d2, dconst0)
1861 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1864 /* If either operand is a NaN, just return it. Otherwise, set up
1865 for floating-point trap; we return an overflow. */
1866 if (REAL_VALUE_ISNAN (d1))
1868 else if (REAL_VALUE_ISNAN (d2))
1871 inexact = real_arithmetic (&value, code, &d1, &d2);
1872 real_convert (&result, mode, &value);
1874 /* Don't constant fold this floating point operation if
1875 the result has overflowed and flag_trapping_math. */
1876 if (flag_trapping_math
1877 && MODE_HAS_INFINITIES (mode)
1878 && REAL_VALUE_ISINF (result)
1879 && !REAL_VALUE_ISINF (d1)
1880 && !REAL_VALUE_ISINF (d2))
1883 /* Don't constant fold this floating point operation if the
1884 result may dependent upon the run-time rounding mode and
1885 flag_rounding_math is set, or if GCC's software emulation
1886 is unable to accurately represent the result. */
1887 if ((flag_rounding_math
1888 || (MODE_COMPOSITE_P (mode) && !flag_unsafe_math_optimizations))
1889 && (inexact || !real_identical (&result, &value)))
1892 t = build_real (type, result);
1894 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1898 if (TREE_CODE (arg1) == FIXED_CST)
1900 FIXED_VALUE_TYPE f1;
1901 FIXED_VALUE_TYPE f2;
1902 FIXED_VALUE_TYPE result;
1907 /* The following codes are handled by fixed_arithmetic. */
1913 case TRUNC_DIV_EXPR:
1914 f2 = TREE_FIXED_CST (arg2);
1919 f2.data.high = TREE_INT_CST_HIGH (arg2);
1920 f2.data.low = TREE_INT_CST_LOW (arg2);
1928 f1 = TREE_FIXED_CST (arg1);
1929 type = TREE_TYPE (arg1);
1930 sat_p = TYPE_SATURATING (type);
1931 overflow_p = fixed_arithmetic (&result, code, &f1, &f2, sat_p);
1932 t = build_fixed (type, result);
1933 /* Propagate overflow flags. */
1934 if (overflow_p | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1936 TREE_OVERFLOW (t) = 1;
1937 TREE_CONSTANT_OVERFLOW (t) = 1;
1939 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1940 TREE_CONSTANT_OVERFLOW (t) = 1;
1944 if (TREE_CODE (arg1) == COMPLEX_CST)
1946 tree type = TREE_TYPE (arg1);
1947 tree r1 = TREE_REALPART (arg1);
1948 tree i1 = TREE_IMAGPART (arg1);
1949 tree r2 = TREE_REALPART (arg2);
1950 tree i2 = TREE_IMAGPART (arg2);
1957 real = const_binop (code, r1, r2, notrunc);
1958 imag = const_binop (code, i1, i2, notrunc);
1962 real = const_binop (MINUS_EXPR,
1963 const_binop (MULT_EXPR, r1, r2, notrunc),
1964 const_binop (MULT_EXPR, i1, i2, notrunc),
1966 imag = const_binop (PLUS_EXPR,
1967 const_binop (MULT_EXPR, r1, i2, notrunc),
1968 const_binop (MULT_EXPR, i1, r2, notrunc),
1975 = const_binop (PLUS_EXPR,
1976 const_binop (MULT_EXPR, r2, r2, notrunc),
1977 const_binop (MULT_EXPR, i2, i2, notrunc),
1980 = const_binop (PLUS_EXPR,
1981 const_binop (MULT_EXPR, r1, r2, notrunc),
1982 const_binop (MULT_EXPR, i1, i2, notrunc),
1985 = const_binop (MINUS_EXPR,
1986 const_binop (MULT_EXPR, i1, r2, notrunc),
1987 const_binop (MULT_EXPR, r1, i2, notrunc),
1990 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1991 code = TRUNC_DIV_EXPR;
1993 real = const_binop (code, t1, magsquared, notrunc);
1994 imag = const_binop (code, t2, magsquared, notrunc);
2003 return build_complex (type, real, imag);
2009 /* Create a size type INT_CST node with NUMBER sign extended. KIND
2010 indicates which particular sizetype to create. */
2013 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
2015 return build_int_cst (sizetype_tab[(int) kind], number);
2018 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2019 is a tree code. The type of the result is taken from the operands.
2020 Both must be equivalent integer types, ala int_binop_types_match_p.
2021 If the operands are constant, so is the result. */
2024 size_binop (enum tree_code code, tree arg0, tree arg1)
2026 tree type = TREE_TYPE (arg0);
2028 if (arg0 == error_mark_node || arg1 == error_mark_node)
2029 return error_mark_node;
2031 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
2034 /* Handle the special case of two integer constants faster. */
2035 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
2037 /* And some specific cases even faster than that. */
2038 if (code == PLUS_EXPR)
2040 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
2042 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2045 else if (code == MINUS_EXPR)
2047 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2050 else if (code == MULT_EXPR)
2052 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
2056 /* Handle general case of two integer constants. */
2057 return int_const_binop (code, arg0, arg1, 0);
2060 return fold_build2 (code, type, arg0, arg1);
2063 /* Given two values, either both of sizetype or both of bitsizetype,
2064 compute the difference between the two values. Return the value
2065 in signed type corresponding to the type of the operands. */
2068 size_diffop (tree arg0, tree arg1)
2070 tree type = TREE_TYPE (arg0);
2073 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
2076 /* If the type is already signed, just do the simple thing. */
2077 if (!TYPE_UNSIGNED (type))
2078 return size_binop (MINUS_EXPR, arg0, arg1);
2080 if (type == sizetype)
2082 else if (type == bitsizetype)
2083 ctype = sbitsizetype;
2085 ctype = signed_type_for (type);
2087 /* If either operand is not a constant, do the conversions to the signed
2088 type and subtract. The hardware will do the right thing with any
2089 overflow in the subtraction. */
2090 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2091 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
2092 fold_convert (ctype, arg1));
2094 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2095 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2096 overflow) and negate (which can't either). Special-case a result
2097 of zero while we're here. */
2098 if (tree_int_cst_equal (arg0, arg1))
2099 return build_int_cst (ctype, 0);
2100 else if (tree_int_cst_lt (arg1, arg0))
2101 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2103 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
2104 fold_convert (ctype, size_binop (MINUS_EXPR,
2108 /* A subroutine of fold_convert_const handling conversions of an
2109 INTEGER_CST to another integer type. */
2112 fold_convert_const_int_from_int (tree type, const_tree arg1)
2116 /* Given an integer constant, make new constant with new type,
2117 appropriately sign-extended or truncated. */
2118 t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
2119 TREE_INT_CST_HIGH (arg1),
2120 /* Don't set the overflow when
2121 converting from a pointer, */
2122 !POINTER_TYPE_P (TREE_TYPE (arg1))
2123 /* or to a sizetype with same signedness
2124 and the precision is unchanged.
2125 ??? sizetype is always sign-extended,
2126 but its signedness depends on the
2127 frontend. Thus we see spurious overflows
2128 here if we do not check this. */
2129 && !((TYPE_PRECISION (TREE_TYPE (arg1))
2130 == TYPE_PRECISION (type))
2131 && (TYPE_UNSIGNED (TREE_TYPE (arg1))
2132 == TYPE_UNSIGNED (type))
2133 && ((TREE_CODE (TREE_TYPE (arg1)) == INTEGER_TYPE
2134 && TYPE_IS_SIZETYPE (TREE_TYPE (arg1)))
2135 || (TREE_CODE (type) == INTEGER_TYPE
2136 && TYPE_IS_SIZETYPE (type)))),
2137 (TREE_INT_CST_HIGH (arg1) < 0
2138 && (TYPE_UNSIGNED (type)
2139 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2140 | TREE_OVERFLOW (arg1));
2145 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2146 to an integer type. */
2149 fold_convert_const_int_from_real (enum tree_code code, tree type, const_tree arg1)
2154 /* The following code implements the floating point to integer
2155 conversion rules required by the Java Language Specification,
2156 that IEEE NaNs are mapped to zero and values that overflow
2157 the target precision saturate, i.e. values greater than
2158 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2159 are mapped to INT_MIN. These semantics are allowed by the
2160 C and C++ standards that simply state that the behavior of
2161 FP-to-integer conversion is unspecified upon overflow. */
2163 HOST_WIDE_INT high, low;
2165 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2169 case FIX_TRUNC_EXPR:
2170 real_trunc (&r, VOIDmode, &x);
2177 /* If R is NaN, return zero and show we have an overflow. */
2178 if (REAL_VALUE_ISNAN (r))
2185 /* See if R is less than the lower bound or greater than the
2190 tree lt = TYPE_MIN_VALUE (type);
2191 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2192 if (REAL_VALUES_LESS (r, l))
2195 high = TREE_INT_CST_HIGH (lt);
2196 low = TREE_INT_CST_LOW (lt);
2202 tree ut = TYPE_MAX_VALUE (type);
2205 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2206 if (REAL_VALUES_LESS (u, r))
2209 high = TREE_INT_CST_HIGH (ut);
2210 low = TREE_INT_CST_LOW (ut);
2216 REAL_VALUE_TO_INT (&low, &high, r);
2218 t = force_fit_type_double (type, low, high, -1,
2219 overflow | TREE_OVERFLOW (arg1));
2223 /* A subroutine of fold_convert_const handling conversions of a
2224 FIXED_CST to an integer type. */
2227 fold_convert_const_int_from_fixed (tree type, const_tree arg1)
2230 double_int temp, temp_trunc;
2233 /* Right shift FIXED_CST to temp by fbit. */
2234 temp = TREE_FIXED_CST (arg1).data;
2235 mode = TREE_FIXED_CST (arg1).mode;
2236 if (GET_MODE_FBIT (mode) < 2 * HOST_BITS_PER_WIDE_INT)
2238 lshift_double (temp.low, temp.high,
2239 - GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2240 &temp.low, &temp.high, SIGNED_FIXED_POINT_MODE_P (mode));
2242 /* Left shift temp to temp_trunc by fbit. */
2243 lshift_double (temp.low, temp.high,
2244 GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2245 &temp_trunc.low, &temp_trunc.high,
2246 SIGNED_FIXED_POINT_MODE_P (mode));
2253 temp_trunc.high = 0;
2256 /* If FIXED_CST is negative, we need to round the value toward 0.
2257 By checking if the fractional bits are not zero to add 1 to temp. */
2258 if (SIGNED_FIXED_POINT_MODE_P (mode) && temp_trunc.high < 0
2259 && !double_int_equal_p (TREE_FIXED_CST (arg1).data, temp_trunc))
2264 temp = double_int_add (temp, one);
2267 /* Given a fixed-point constant, make new constant with new type,
2268 appropriately sign-extended or truncated. */
2269 t = force_fit_type_double (type, temp.low, temp.high, -1,
2271 && (TYPE_UNSIGNED (type)
2272 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2273 | TREE_OVERFLOW (arg1));
2278 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2279 to another floating point type. */
2282 fold_convert_const_real_from_real (tree type, const_tree arg1)
2284 REAL_VALUE_TYPE value;
2287 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2288 t = build_real (type, value);
2290 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2294 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2295 to a floating point type. */
2298 fold_convert_const_real_from_fixed (tree type, const_tree arg1)
2300 REAL_VALUE_TYPE value;
2303 real_convert_from_fixed (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1));
2304 t = build_real (type, value);
2306 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2307 TREE_CONSTANT_OVERFLOW (t)
2308 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2312 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2313 to another fixed-point type. */
2316 fold_convert_const_fixed_from_fixed (tree type, const_tree arg1)
2318 FIXED_VALUE_TYPE value;
2322 overflow_p = fixed_convert (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1),
2323 TYPE_SATURATING (type));
2324 t = build_fixed (type, value);
2326 /* Propagate overflow flags. */
2327 if (overflow_p | TREE_OVERFLOW (arg1))
2329 TREE_OVERFLOW (t) = 1;
2330 TREE_CONSTANT_OVERFLOW (t) = 1;
2332 else if (TREE_CONSTANT_OVERFLOW (arg1))
2333 TREE_CONSTANT_OVERFLOW (t) = 1;
2337 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2338 to a fixed-point type. */
2341 fold_convert_const_fixed_from_int (tree type, const_tree arg1)
2343 FIXED_VALUE_TYPE value;
2347 overflow_p = fixed_convert_from_int (&value, TYPE_MODE (type),
2348 TREE_INT_CST (arg1),
2349 TYPE_UNSIGNED (TREE_TYPE (arg1)),
2350 TYPE_SATURATING (type));
2351 t = build_fixed (type, value);
2353 /* Propagate overflow flags. */
2354 if (overflow_p | TREE_OVERFLOW (arg1))
2356 TREE_OVERFLOW (t) = 1;
2357 TREE_CONSTANT_OVERFLOW (t) = 1;
2359 else if (TREE_CONSTANT_OVERFLOW (arg1))
2360 TREE_CONSTANT_OVERFLOW (t) = 1;
2364 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2365 to a fixed-point type. */
2368 fold_convert_const_fixed_from_real (tree type, const_tree arg1)
2370 FIXED_VALUE_TYPE value;
2374 overflow_p = fixed_convert_from_real (&value, TYPE_MODE (type),
2375 &TREE_REAL_CST (arg1),
2376 TYPE_SATURATING (type));
2377 t = build_fixed (type, value);
2379 /* Propagate overflow flags. */
2380 if (overflow_p | TREE_OVERFLOW (arg1))
2382 TREE_OVERFLOW (t) = 1;
2383 TREE_CONSTANT_OVERFLOW (t) = 1;
2385 else if (TREE_CONSTANT_OVERFLOW (arg1))
2386 TREE_CONSTANT_OVERFLOW (t) = 1;
2390 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2391 type TYPE. If no simplification can be done return NULL_TREE. */
2394 fold_convert_const (enum tree_code code, tree type, tree arg1)
2396 if (TREE_TYPE (arg1) == type)
2399 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type)
2400 || TREE_CODE (type) == OFFSET_TYPE)
2402 if (TREE_CODE (arg1) == INTEGER_CST)
2403 return fold_convert_const_int_from_int (type, arg1);
2404 else if (TREE_CODE (arg1) == REAL_CST)
2405 return fold_convert_const_int_from_real (code, type, arg1);
2406 else if (TREE_CODE (arg1) == FIXED_CST)
2407 return fold_convert_const_int_from_fixed (type, arg1);
2409 else if (TREE_CODE (type) == REAL_TYPE)
2411 if (TREE_CODE (arg1) == INTEGER_CST)
2412 return build_real_from_int_cst (type, arg1);
2413 else if (TREE_CODE (arg1) == REAL_CST)
2414 return fold_convert_const_real_from_real (type, arg1);
2415 else if (TREE_CODE (arg1) == FIXED_CST)
2416 return fold_convert_const_real_from_fixed (type, arg1);
2418 else if (TREE_CODE (type) == FIXED_POINT_TYPE)
2420 if (TREE_CODE (arg1) == FIXED_CST)
2421 return fold_convert_const_fixed_from_fixed (type, arg1);
2422 else if (TREE_CODE (arg1) == INTEGER_CST)
2423 return fold_convert_const_fixed_from_int (type, arg1);
2424 else if (TREE_CODE (arg1) == REAL_CST)
2425 return fold_convert_const_fixed_from_real (type, arg1);
2430 /* Construct a vector of zero elements of vector type TYPE. */
2433 build_zero_vector (tree type)
2438 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2439 units = TYPE_VECTOR_SUBPARTS (type);
2442 for (i = 0; i < units; i++)
2443 list = tree_cons (NULL_TREE, elem, list);
2444 return build_vector (type, list);
2447 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2450 fold_convertible_p (const_tree type, const_tree arg)
2452 tree orig = TREE_TYPE (arg);
2457 if (TREE_CODE (arg) == ERROR_MARK
2458 || TREE_CODE (type) == ERROR_MARK
2459 || TREE_CODE (orig) == ERROR_MARK)
2462 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2465 switch (TREE_CODE (type))
2467 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2468 case POINTER_TYPE: case REFERENCE_TYPE:
2470 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2471 || TREE_CODE (orig) == OFFSET_TYPE)
2473 return (TREE_CODE (orig) == VECTOR_TYPE
2474 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2477 case FIXED_POINT_TYPE:
2481 return TREE_CODE (type) == TREE_CODE (orig);
2488 /* Convert expression ARG to type TYPE. Used by the middle-end for
2489 simple conversions in preference to calling the front-end's convert. */
2492 fold_convert (tree type, tree arg)
2494 tree orig = TREE_TYPE (arg);
2500 if (TREE_CODE (arg) == ERROR_MARK
2501 || TREE_CODE (type) == ERROR_MARK
2502 || TREE_CODE (orig) == ERROR_MARK)
2503 return error_mark_node;
2505 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2506 return fold_build1 (NOP_EXPR, type, arg);
2508 switch (TREE_CODE (type))
2510 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2511 case POINTER_TYPE: case REFERENCE_TYPE:
2513 if (TREE_CODE (arg) == INTEGER_CST)
2515 tem = fold_convert_const (NOP_EXPR, type, arg);
2516 if (tem != NULL_TREE)
2519 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2520 || TREE_CODE (orig) == OFFSET_TYPE)
2521 return fold_build1 (NOP_EXPR, type, arg);
2522 if (TREE_CODE (orig) == COMPLEX_TYPE)
2524 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2525 return fold_convert (type, tem);
2527 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2528 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2529 return fold_build1 (NOP_EXPR, type, arg);
2532 if (TREE_CODE (arg) == INTEGER_CST)
2534 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2535 if (tem != NULL_TREE)
2538 else if (TREE_CODE (arg) == REAL_CST)
2540 tem = fold_convert_const (NOP_EXPR, type, arg);
2541 if (tem != NULL_TREE)
2544 else if (TREE_CODE (arg) == FIXED_CST)
2546 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2547 if (tem != NULL_TREE)
2551 switch (TREE_CODE (orig))
2554 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2555 case POINTER_TYPE: case REFERENCE_TYPE:
2556 return fold_build1 (FLOAT_EXPR, type, arg);
2559 return fold_build1 (NOP_EXPR, type, arg);
2561 case FIXED_POINT_TYPE:
2562 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2565 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2566 return fold_convert (type, tem);
2572 case FIXED_POINT_TYPE:
2573 if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
2574 || TREE_CODE (arg) == REAL_CST)
2576 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2577 if (tem != NULL_TREE)
2581 switch (TREE_CODE (orig))
2583 case FIXED_POINT_TYPE:
2588 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2591 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2592 return fold_convert (type, tem);
2599 switch (TREE_CODE (orig))
2602 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2603 case POINTER_TYPE: case REFERENCE_TYPE:
2605 case FIXED_POINT_TYPE:
2606 return build2 (COMPLEX_EXPR, type,
2607 fold_convert (TREE_TYPE (type), arg),
2608 fold_convert (TREE_TYPE (type), integer_zero_node));
2613 if (TREE_CODE (arg) == COMPLEX_EXPR)
2615 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2616 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2617 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2620 arg = save_expr (arg);
2621 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2622 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2623 rpart = fold_convert (TREE_TYPE (type), rpart);
2624 ipart = fold_convert (TREE_TYPE (type), ipart);
2625 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2633 if (integer_zerop (arg))
2634 return build_zero_vector (type);
2635 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2636 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2637 || TREE_CODE (orig) == VECTOR_TYPE);
2638 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2641 tem = fold_ignored_result (arg);
2642 if (TREE_CODE (tem) == MODIFY_EXPR)
2644 return fold_build1 (NOP_EXPR, type, tem);
2651 /* Return false if expr can be assumed not to be an lvalue, true
2655 maybe_lvalue_p (const_tree x)
2657 /* We only need to wrap lvalue tree codes. */
2658 switch (TREE_CODE (x))
2669 case ALIGN_INDIRECT_REF:
2670 case MISALIGNED_INDIRECT_REF:
2672 case ARRAY_RANGE_REF:
2678 case PREINCREMENT_EXPR:
2679 case PREDECREMENT_EXPR:
2681 case TRY_CATCH_EXPR:
2682 case WITH_CLEANUP_EXPR:
2693 /* Assume the worst for front-end tree codes. */
2694 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2702 /* Return an expr equal to X but certainly not valid as an lvalue. */
2707 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2712 if (! maybe_lvalue_p (x))
2714 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2717 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2718 Zero means allow extended lvalues. */
2720 int pedantic_lvalues;
2722 /* When pedantic, return an expr equal to X but certainly not valid as a
2723 pedantic lvalue. Otherwise, return X. */
2726 pedantic_non_lvalue (tree x)
2728 if (pedantic_lvalues)
2729 return non_lvalue (x);
2734 /* Given a tree comparison code, return the code that is the logical inverse
2735 of the given code. It is not safe to do this for floating-point
2736 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2737 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2740 invert_tree_comparison (enum tree_code code, bool honor_nans)
2742 if (honor_nans && flag_trapping_math)
2752 return honor_nans ? UNLE_EXPR : LE_EXPR;
2754 return honor_nans ? UNLT_EXPR : LT_EXPR;
2756 return honor_nans ? UNGE_EXPR : GE_EXPR;
2758 return honor_nans ? UNGT_EXPR : GT_EXPR;
2772 return UNORDERED_EXPR;
2773 case UNORDERED_EXPR:
2774 return ORDERED_EXPR;
2780 /* Similar, but return the comparison that results if the operands are
2781 swapped. This is safe for floating-point. */
2784 swap_tree_comparison (enum tree_code code)
2791 case UNORDERED_EXPR:
2817 /* Convert a comparison tree code from an enum tree_code representation
2818 into a compcode bit-based encoding. This function is the inverse of
2819 compcode_to_comparison. */
2821 static enum comparison_code
2822 comparison_to_compcode (enum tree_code code)
2839 return COMPCODE_ORD;
2840 case UNORDERED_EXPR:
2841 return COMPCODE_UNORD;
2843 return COMPCODE_UNLT;
2845 return COMPCODE_UNEQ;
2847 return COMPCODE_UNLE;
2849 return COMPCODE_UNGT;
2851 return COMPCODE_LTGT;
2853 return COMPCODE_UNGE;
2859 /* Convert a compcode bit-based encoding of a comparison operator back
2860 to GCC's enum tree_code representation. This function is the
2861 inverse of comparison_to_compcode. */
2863 static enum tree_code
2864 compcode_to_comparison (enum comparison_code code)
2881 return ORDERED_EXPR;
2882 case COMPCODE_UNORD:
2883 return UNORDERED_EXPR;
2901 /* Return a tree for the comparison which is the combination of
2902 doing the AND or OR (depending on CODE) of the two operations LCODE
2903 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2904 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2905 if this makes the transformation invalid. */
2908 combine_comparisons (enum tree_code code, enum tree_code lcode,
2909 enum tree_code rcode, tree truth_type,
2910 tree ll_arg, tree lr_arg)
2912 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2913 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2914 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2915 enum comparison_code compcode;
2919 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2920 compcode = lcompcode & rcompcode;
2923 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2924 compcode = lcompcode | rcompcode;
2933 /* Eliminate unordered comparisons, as well as LTGT and ORD
2934 which are not used unless the mode has NaNs. */
2935 compcode &= ~COMPCODE_UNORD;
2936 if (compcode == COMPCODE_LTGT)
2937 compcode = COMPCODE_NE;
2938 else if (compcode == COMPCODE_ORD)
2939 compcode = COMPCODE_TRUE;
2941 else if (flag_trapping_math)
2943 /* Check that the original operation and the optimized ones will trap
2944 under the same condition. */
2945 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2946 && (lcompcode != COMPCODE_EQ)
2947 && (lcompcode != COMPCODE_ORD);
2948 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2949 && (rcompcode != COMPCODE_EQ)
2950 && (rcompcode != COMPCODE_ORD);
2951 bool trap = (compcode & COMPCODE_UNORD) == 0
2952 && (compcode != COMPCODE_EQ)
2953 && (compcode != COMPCODE_ORD);
2955 /* In a short-circuited boolean expression the LHS might be
2956 such that the RHS, if evaluated, will never trap. For
2957 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2958 if neither x nor y is NaN. (This is a mixed blessing: for
2959 example, the expression above will never trap, hence
2960 optimizing it to x < y would be invalid). */
2961 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2962 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2965 /* If the comparison was short-circuited, and only the RHS
2966 trapped, we may now generate a spurious trap. */
2968 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2971 /* If we changed the conditions that cause a trap, we lose. */
2972 if ((ltrap || rtrap) != trap)
2976 if (compcode == COMPCODE_TRUE)
2977 return constant_boolean_node (true, truth_type);
2978 else if (compcode == COMPCODE_FALSE)
2979 return constant_boolean_node (false, truth_type);
2981 return fold_build2 (compcode_to_comparison (compcode),
2982 truth_type, ll_arg, lr_arg);
2985 /* Return nonzero if two operands (typically of the same tree node)
2986 are necessarily equal. If either argument has side-effects this
2987 function returns zero. FLAGS modifies behavior as follows:
2989 If OEP_ONLY_CONST is set, only return nonzero for constants.
2990 This function tests whether the operands are indistinguishable;
2991 it does not test whether they are equal using C's == operation.
2992 The distinction is important for IEEE floating point, because
2993 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2994 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2996 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2997 even though it may hold multiple values during a function.
2998 This is because a GCC tree node guarantees that nothing else is
2999 executed between the evaluation of its "operands" (which may often
3000 be evaluated in arbitrary order). Hence if the operands themselves
3001 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
3002 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
3003 unset means assuming isochronic (or instantaneous) tree equivalence.
3004 Unless comparing arbitrary expression trees, such as from different
3005 statements, this flag can usually be left unset.
3007 If OEP_PURE_SAME is set, then pure functions with identical arguments
3008 are considered the same. It is used when the caller has other ways
3009 to ensure that global memory is unchanged in between. */
3012 operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
3014 /* If either is ERROR_MARK, they aren't equal. */
3015 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
3018 /* Check equality of integer constants before bailing out due to
3019 precision differences. */
3020 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
3021 return tree_int_cst_equal (arg0, arg1);
3023 /* If both types don't have the same signedness, then we can't consider
3024 them equal. We must check this before the STRIP_NOPS calls
3025 because they may change the signedness of the arguments. As pointers
3026 strictly don't have a signedness, require either two pointers or
3027 two non-pointers as well. */
3028 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1))
3029 || POINTER_TYPE_P (TREE_TYPE (arg0)) != POINTER_TYPE_P (TREE_TYPE (arg1)))
3032 /* If both types don't have the same precision, then it is not safe
3034 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
3040 /* In case both args are comparisons but with different comparison
3041 code, try to swap the comparison operands of one arg to produce
3042 a match and compare that variant. */
3043 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3044 && COMPARISON_CLASS_P (arg0)
3045 && COMPARISON_CLASS_P (arg1))
3047 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
3049 if (TREE_CODE (arg0) == swap_code)
3050 return operand_equal_p (TREE_OPERAND (arg0, 0),
3051 TREE_OPERAND (arg1, 1), flags)
3052 && operand_equal_p (TREE_OPERAND (arg0, 1),
3053 TREE_OPERAND (arg1, 0), flags);
3056 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3057 /* This is needed for conversions and for COMPONENT_REF.
3058 Might as well play it safe and always test this. */
3059 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
3060 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
3061 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
3064 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3065 We don't care about side effects in that case because the SAVE_EXPR
3066 takes care of that for us. In all other cases, two expressions are
3067 equal if they have no side effects. If we have two identical
3068 expressions with side effects that should be treated the same due
3069 to the only side effects being identical SAVE_EXPR's, that will
3070 be detected in the recursive calls below. */
3071 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
3072 && (TREE_CODE (arg0) == SAVE_EXPR
3073 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
3076 /* Next handle constant cases, those for which we can return 1 even
3077 if ONLY_CONST is set. */
3078 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
3079 switch (TREE_CODE (arg0))
3082 return tree_int_cst_equal (arg0, arg1);
3085 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
3086 TREE_FIXED_CST (arg1));
3089 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
3090 TREE_REAL_CST (arg1)))
3094 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
3096 /* If we do not distinguish between signed and unsigned zero,
3097 consider them equal. */
3098 if (real_zerop (arg0) && real_zerop (arg1))
3107 v1 = TREE_VECTOR_CST_ELTS (arg0);
3108 v2 = TREE_VECTOR_CST_ELTS (arg1);
3111 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
3114 v1 = TREE_CHAIN (v1);
3115 v2 = TREE_CHAIN (v2);
3122 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
3124 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
3128 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
3129 && ! memcmp (TREE_STRING_POINTER (arg0),
3130 TREE_STRING_POINTER (arg1),
3131 TREE_STRING_LENGTH (arg0)));
3134 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
3140 if (flags & OEP_ONLY_CONST)
3143 /* Define macros to test an operand from arg0 and arg1 for equality and a
3144 variant that allows null and views null as being different from any
3145 non-null value. In the latter case, if either is null, the both
3146 must be; otherwise, do the normal comparison. */
3147 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3148 TREE_OPERAND (arg1, N), flags)
3150 #define OP_SAME_WITH_NULL(N) \
3151 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3152 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3154 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
3157 /* Two conversions are equal only if signedness and modes match. */
3158 switch (TREE_CODE (arg0))
3161 case FIX_TRUNC_EXPR:
3162 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
3163 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3173 case tcc_comparison:
3175 if (OP_SAME (0) && OP_SAME (1))
3178 /* For commutative ops, allow the other order. */
3179 return (commutative_tree_code (TREE_CODE (arg0))
3180 && operand_equal_p (TREE_OPERAND (arg0, 0),
3181 TREE_OPERAND (arg1, 1), flags)
3182 && operand_equal_p (TREE_OPERAND (arg0, 1),
3183 TREE_OPERAND (arg1, 0), flags));
3186 /* If either of the pointer (or reference) expressions we are
3187 dereferencing contain a side effect, these cannot be equal. */
3188 if (TREE_SIDE_EFFECTS (arg0)
3189 || TREE_SIDE_EFFECTS (arg1))
3192 switch (TREE_CODE (arg0))
3195 case ALIGN_INDIRECT_REF:
3196 case MISALIGNED_INDIRECT_REF:
3202 case ARRAY_RANGE_REF:
3203 /* Operands 2 and 3 may be null.
3204 Compare the array index by value if it is constant first as we
3205 may have different types but same value here. */
3207 && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
3208 TREE_OPERAND (arg1, 1))
3210 && OP_SAME_WITH_NULL (2)
3211 && OP_SAME_WITH_NULL (3));
3214 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3215 may be NULL when we're called to compare MEM_EXPRs. */
3216 return OP_SAME_WITH_NULL (0)
3218 && OP_SAME_WITH_NULL (2);
3221 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3227 case tcc_expression:
3228 switch (TREE_CODE (arg0))
3231 case TRUTH_NOT_EXPR:
3234 case TRUTH_ANDIF_EXPR:
3235 case TRUTH_ORIF_EXPR:
3236 return OP_SAME (0) && OP_SAME (1);
3238 case TRUTH_AND_EXPR:
3240 case TRUTH_XOR_EXPR:
3241 if (OP_SAME (0) && OP_SAME (1))
3244 /* Otherwise take into account this is a commutative operation. */
3245 return (operand_equal_p (TREE_OPERAND (arg0, 0),
3246 TREE_OPERAND (arg1, 1), flags)
3247 && operand_equal_p (TREE_OPERAND (arg0, 1),
3248 TREE_OPERAND (arg1, 0), flags));
3251 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3258 switch (TREE_CODE (arg0))
3261 /* If the CALL_EXPRs call different functions, then they
3262 clearly can not be equal. */
3263 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
3268 unsigned int cef = call_expr_flags (arg0);
3269 if (flags & OEP_PURE_SAME)
3270 cef &= ECF_CONST | ECF_PURE;
3277 /* Now see if all the arguments are the same. */
3279 const_call_expr_arg_iterator iter0, iter1;
3281 for (a0 = first_const_call_expr_arg (arg0, &iter0),
3282 a1 = first_const_call_expr_arg (arg1, &iter1);
3284 a0 = next_const_call_expr_arg (&iter0),
3285 a1 = next_const_call_expr_arg (&iter1))
3286 if (! operand_equal_p (a0, a1, flags))
3289 /* If we get here and both argument lists are exhausted
3290 then the CALL_EXPRs are equal. */
3291 return ! (a0 || a1);
3297 case tcc_declaration:
3298 /* Consider __builtin_sqrt equal to sqrt. */
3299 return (TREE_CODE (arg0) == FUNCTION_DECL
3300 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
3301 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
3302 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
3309 #undef OP_SAME_WITH_NULL
3312 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3313 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3315 When in doubt, return 0. */
3318 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
3320 int unsignedp1, unsignedpo;
3321 tree primarg0, primarg1, primother;
3322 unsigned int correct_width;
3324 if (operand_equal_p (arg0, arg1, 0))
3327 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3328 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3331 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3332 and see if the inner values are the same. This removes any
3333 signedness comparison, which doesn't matter here. */
3334 primarg0 = arg0, primarg1 = arg1;
3335 STRIP_NOPS (primarg0);
3336 STRIP_NOPS (primarg1);
3337 if (operand_equal_p (primarg0, primarg1, 0))
3340 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3341 actual comparison operand, ARG0.
3343 First throw away any conversions to wider types
3344 already present in the operands. */
3346 primarg1 = get_narrower (arg1, &unsignedp1);
3347 primother = get_narrower (other, &unsignedpo);
3349 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3350 if (unsignedp1 == unsignedpo
3351 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3352 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3354 tree type = TREE_TYPE (arg0);
3356 /* Make sure shorter operand is extended the right way
3357 to match the longer operand. */
3358 primarg1 = fold_convert (signed_or_unsigned_type_for
3359 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3361 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3368 /* See if ARG is an expression that is either a comparison or is performing
3369 arithmetic on comparisons. The comparisons must only be comparing
3370 two different values, which will be stored in *CVAL1 and *CVAL2; if
3371 they are nonzero it means that some operands have already been found.
3372 No variables may be used anywhere else in the expression except in the
3373 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3374 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3376 If this is true, return 1. Otherwise, return zero. */
3379 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3381 enum tree_code code = TREE_CODE (arg);
3382 enum tree_code_class tclass = TREE_CODE_CLASS (code);
3384 /* We can handle some of the tcc_expression cases here. */
3385 if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
3387 else if (tclass == tcc_expression
3388 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3389 || code == COMPOUND_EXPR))
3390 tclass = tcc_binary;
3392 else if (tclass == tcc_expression && code == SAVE_EXPR
3393 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3395 /* If we've already found a CVAL1 or CVAL2, this expression is
3396 two complex to handle. */
3397 if (*cval1 || *cval2)
3407 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3410 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3411 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3412 cval1, cval2, save_p));
3417 case tcc_expression:
3418 if (code == COND_EXPR)
3419 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3420 cval1, cval2, save_p)
3421 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3422 cval1, cval2, save_p)
3423 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3424 cval1, cval2, save_p));
3427 case tcc_comparison:
3428 /* First see if we can handle the first operand, then the second. For
3429 the second operand, we know *CVAL1 can't be zero. It must be that
3430 one side of the comparison is each of the values; test for the
3431 case where this isn't true by failing if the two operands
3434 if (operand_equal_p (TREE_OPERAND (arg, 0),
3435 TREE_OPERAND (arg, 1), 0))
3439 *cval1 = TREE_OPERAND (arg, 0);
3440 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3442 else if (*cval2 == 0)
3443 *cval2 = TREE_OPERAND (arg, 0);
3444 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3449 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3451 else if (*cval2 == 0)
3452 *cval2 = TREE_OPERAND (arg, 1);
3453 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3465 /* ARG is a tree that is known to contain just arithmetic operations and
3466 comparisons. Evaluate the operations in the tree substituting NEW0 for
3467 any occurrence of OLD0 as an operand of a comparison and likewise for
3471 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3473 tree type = TREE_TYPE (arg);
3474 enum tree_code code = TREE_CODE (arg);
3475 enum tree_code_class tclass = TREE_CODE_CLASS (code);
3477 /* We can handle some of the tcc_expression cases here. */
3478 if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
3480 else if (tclass == tcc_expression
3481 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3482 tclass = tcc_binary;
3487 return fold_build1 (code, type,
3488 eval_subst (TREE_OPERAND (arg, 0),
3489 old0, new0, old1, new1));
3492 return fold_build2 (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));
3498 case tcc_expression:
3502 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3505 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3508 return fold_build3 (code, type,
3509 eval_subst (TREE_OPERAND (arg, 0),
3510 old0, new0, old1, new1),
3511 eval_subst (TREE_OPERAND (arg, 1),
3512 old0, new0, old1, new1),
3513 eval_subst (TREE_OPERAND (arg, 2),
3514 old0, new0, old1, new1));
3518 /* Fall through - ??? */
3520 case tcc_comparison:
3522 tree arg0 = TREE_OPERAND (arg, 0);
3523 tree arg1 = TREE_OPERAND (arg, 1);
3525 /* We need to check both for exact equality and tree equality. The
3526 former will be true if the operand has a side-effect. In that
3527 case, we know the operand occurred exactly once. */
3529 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3531 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3534 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3536 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3539 return fold_build2 (code, type, arg0, arg1);
3547 /* Return a tree for the case when the result of an expression is RESULT
3548 converted to TYPE and OMITTED was previously an operand of the expression
3549 but is now not needed (e.g., we folded OMITTED * 0).
3551 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3552 the conversion of RESULT to TYPE. */
3555 omit_one_operand (tree type, tree result, tree omitted)
3557 tree t = fold_convert (type, result);
3559 /* If the resulting operand is an empty statement, just return the omitted
3560 statement casted to void. */
3561 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3562 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3564 if (TREE_SIDE_EFFECTS (omitted))
3565 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3567 return non_lvalue (t);
3570 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3573 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3575 tree t = fold_convert (type, result);
3577 /* If the resulting operand is an empty statement, just return the omitted
3578 statement casted to void. */
3579 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3580 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3582 if (TREE_SIDE_EFFECTS (omitted))
3583 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3585 return pedantic_non_lvalue (t);
3588 /* Return a tree for the case when the result of an expression is RESULT
3589 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3590 of the expression but are now not needed.
3592 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3593 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3594 evaluated before OMITTED2. Otherwise, if neither has side effects,
3595 just do the conversion of RESULT to TYPE. */
3598 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3600 tree t = fold_convert (type, result);
3602 if (TREE_SIDE_EFFECTS (omitted2))
3603 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3604 if (TREE_SIDE_EFFECTS (omitted1))
3605 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3607 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3611 /* Return a simplified tree node for the truth-negation of ARG. This
3612 never alters ARG itself. We assume that ARG is an operation that
3613 returns a truth value (0 or 1).
3615 FIXME: one would think we would fold the result, but it causes
3616 problems with the dominator optimizer. */
3619 fold_truth_not_expr (tree arg)
3621 tree type = TREE_TYPE (arg);
3622 enum tree_code code = TREE_CODE (arg);
3624 /* If this is a comparison, we can simply invert it, except for
3625 floating-point non-equality comparisons, in which case we just
3626 enclose a TRUTH_NOT_EXPR around what we have. */
3628 if (TREE_CODE_CLASS (code) == tcc_comparison)
3630 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3631 if (FLOAT_TYPE_P (op_type)
3632 && flag_trapping_math
3633 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3634 && code != NE_EXPR && code != EQ_EXPR)
3638 code = invert_tree_comparison (code,
3639 HONOR_NANS (TYPE_MODE (op_type)));
3640 if (code == ERROR_MARK)
3643 return build2 (code, type,
3644 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3651 return constant_boolean_node (integer_zerop (arg), type);
3653 case TRUTH_AND_EXPR:
3654 return build2 (TRUTH_OR_EXPR, type,
3655 invert_truthvalue (TREE_OPERAND (arg, 0)),
3656 invert_truthvalue (TREE_OPERAND (arg, 1)));
3659 return build2 (TRUTH_AND_EXPR, type,
3660 invert_truthvalue (TREE_OPERAND (arg, 0)),
3661 invert_truthvalue (TREE_OPERAND (arg, 1)));
3663 case TRUTH_XOR_EXPR:
3664 /* Here we can invert either operand. We invert the first operand
3665 unless the second operand is a TRUTH_NOT_EXPR in which case our
3666 result is the XOR of the first operand with the inside of the
3667 negation of the second operand. */
3669 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3670 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3671 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3673 return build2 (TRUTH_XOR_EXPR, type,
3674 invert_truthvalue (TREE_OPERAND (arg, 0)),
3675 TREE_OPERAND (arg, 1));
3677 case TRUTH_ANDIF_EXPR:
3678 return build2 (TRUTH_ORIF_EXPR, type,
3679 invert_truthvalue (TREE_OPERAND (arg, 0)),
3680 invert_truthvalue (TREE_OPERAND (arg, 1)));
3682 case TRUTH_ORIF_EXPR:
3683 return build2 (TRUTH_ANDIF_EXPR, type,
3684 invert_truthvalue (TREE_OPERAND (arg, 0)),
3685 invert_truthvalue (TREE_OPERAND (arg, 1)));
3687 case TRUTH_NOT_EXPR:
3688 return TREE_OPERAND (arg, 0);
3692 tree arg1 = TREE_OPERAND (arg, 1);
3693 tree arg2 = TREE_OPERAND (arg, 2);
3694 /* A COND_EXPR may have a throw as one operand, which
3695 then has void type. Just leave void operands
3697 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3698 VOID_TYPE_P (TREE_TYPE (arg1))
3699 ? arg1 : invert_truthvalue (arg1),
3700 VOID_TYPE_P (TREE_TYPE (arg2))
3701 ? arg2 : invert_truthvalue (arg2));
3705 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3706 invert_truthvalue (TREE_OPERAND (arg, 1)));
3708 case NON_LVALUE_EXPR:
3709 return invert_truthvalue (TREE_OPERAND (arg, 0));
3712 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3713 return build1 (TRUTH_NOT_EXPR, type, arg);
3717 return build1 (TREE_CODE (arg), type,
3718 invert_truthvalue (TREE_OPERAND (arg, 0)));
3721 if (!integer_onep (TREE_OPERAND (arg, 1)))
3723 return build2 (EQ_EXPR, type, arg,
3724 build_int_cst (type, 0));
3727 return build1 (TRUTH_NOT_EXPR, type, arg);
3729 case CLEANUP_POINT_EXPR:
3730 return build1 (CLEANUP_POINT_EXPR, type,
3731 invert_truthvalue (TREE_OPERAND (arg, 0)));
3740 /* Return a simplified tree node for the truth-negation of ARG. This
3741 never alters ARG itself. We assume that ARG is an operation that
3742 returns a truth value (0 or 1).
3744 FIXME: one would think we would fold the result, but it causes
3745 problems with the dominator optimizer. */
3748 invert_truthvalue (tree arg)
3752 if (TREE_CODE (arg) == ERROR_MARK)
3755 tem = fold_truth_not_expr (arg);
3757 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3762 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3763 operands are another bit-wise operation with a common input. If so,
3764 distribute the bit operations to save an operation and possibly two if
3765 constants are involved. For example, convert
3766 (A | B) & (A | C) into A | (B & C)
3767 Further simplification will occur if B and C are constants.
3769 If this optimization cannot be done, 0 will be returned. */
3772 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3777 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3778 || TREE_CODE (arg0) == code
3779 || (TREE_CODE (arg0) != BIT_AND_EXPR
3780 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3783 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3785 common = TREE_OPERAND (arg0, 0);
3786 left = TREE_OPERAND (arg0, 1);
3787 right = TREE_OPERAND (arg1, 1);
3789 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3791 common = TREE_OPERAND (arg0, 0);
3792 left = TREE_OPERAND (arg0, 1);
3793 right = TREE_OPERAND (arg1, 0);
3795 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3797 common = TREE_OPERAND (arg0, 1);
3798 left = TREE_OPERAND (arg0, 0);
3799 right = TREE_OPERAND (arg1, 1);
3801 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3803 common = TREE_OPERAND (arg0, 1);
3804 left = TREE_OPERAND (arg0, 0);
3805 right = TREE_OPERAND (arg1, 0);
3810 common = fold_convert (type, common);
3811 left = fold_convert (type, left);
3812 right = fold_convert (type, right);
3813 return fold_build2 (TREE_CODE (arg0), type, common,
3814 fold_build2 (code, type, left, right));
3817 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3818 with code CODE. This optimization is unsafe. */
3820 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3822 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3823 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3825 /* (A / C) +- (B / C) -> (A +- B) / C. */
3827 && operand_equal_p (TREE_OPERAND (arg0, 1),
3828 TREE_OPERAND (arg1, 1), 0))
3829 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3830 fold_build2 (code, type,
3831 TREE_OPERAND (arg0, 0),
3832 TREE_OPERAND (arg1, 0)),
3833 TREE_OPERAND (arg0, 1));
3835 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3836 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3837 TREE_OPERAND (arg1, 0), 0)
3838 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3839 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3841 REAL_VALUE_TYPE r0, r1;
3842 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3843 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3845 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3847 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3848 real_arithmetic (&r0, code, &r0, &r1);
3849 return fold_build2 (MULT_EXPR, type,
3850 TREE_OPERAND (arg0, 0),
3851 build_real (type, r0));
3857 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3858 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3861 make_bit_field_ref (tree inner, tree type, HOST_WIDE_INT bitsize,
3862 HOST_WIDE_INT bitpos, int unsignedp)
3864 tree result, bftype;
3868 tree size = TYPE_SIZE (TREE_TYPE (inner));
3869 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3870 || POINTER_TYPE_P (TREE_TYPE (inner)))
3871 && host_integerp (size, 0)
3872 && tree_low_cst (size, 0) == bitsize)
3873 return fold_convert (type, inner);
3877 if (TYPE_PRECISION (bftype) != bitsize
3878 || TYPE_UNSIGNED (bftype) == !unsignedp)
3879 bftype = build_nonstandard_integer_type (bitsize, 0);
3881 result = build3 (BIT_FIELD_REF, bftype, inner,
3882 size_int (bitsize), bitsize_int (bitpos));
3885 result = fold_convert (type, result);
3890 /* Optimize a bit-field compare.
3892 There are two cases: First is a compare against a constant and the
3893 second is a comparison of two items where the fields are at the same
3894 bit position relative to the start of a chunk (byte, halfword, word)
3895 large enough to contain it. In these cases we can avoid the shift
3896 implicit in bitfield extractions.
3898 For constants, we emit a compare of the shifted constant with the
3899 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3900 compared. For two fields at the same position, we do the ANDs with the
3901 similar mask and compare the result of the ANDs.
3903 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3904 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3905 are the left and right operands of the comparison, respectively.
3907 If the optimization described above can be done, we return the resulting
3908 tree. Otherwise we return zero. */
3911 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3914 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3915 tree type = TREE_TYPE (lhs);
3916 tree signed_type, unsigned_type;
3917 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3918 enum machine_mode lmode, rmode, nmode;
3919 int lunsignedp, runsignedp;
3920 int lvolatilep = 0, rvolatilep = 0;
3921 tree linner, rinner = NULL_TREE;
3925 /* Get all the information about the extractions being done. If the bit size
3926 if the same as the size of the underlying object, we aren't doing an
3927 extraction at all and so can do nothing. We also don't want to
3928 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3929 then will no longer be able to replace it. */
3930 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3931 &lunsignedp, &lvolatilep, false);
3932 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3933 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3938 /* If this is not a constant, we can only do something if bit positions,
3939 sizes, and signedness are the same. */
3940 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3941 &runsignedp, &rvolatilep, false);
3943 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3944 || lunsignedp != runsignedp || offset != 0
3945 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3949 /* See if we can find a mode to refer to this field. We should be able to,
3950 but fail if we can't. */
3951 nmode = get_best_mode (lbitsize, lbitpos,
3952 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3953 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3954 TYPE_ALIGN (TREE_TYPE (rinner))),
3955 word_mode, lvolatilep || rvolatilep);
3956 if (nmode == VOIDmode)
3959 /* Set signed and unsigned types of the precision of this mode for the
3961 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3962 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3964 /* Compute the bit position and size for the new reference and our offset
3965 within it. If the new reference is the same size as the original, we
3966 won't optimize anything, so return zero. */
3967 nbitsize = GET_MODE_BITSIZE (nmode);
3968 nbitpos = lbitpos & ~ (nbitsize - 1);
3970 if (nbitsize == lbitsize)
3973 if (BYTES_BIG_ENDIAN)
3974 lbitpos = nbitsize - lbitsize - lbitpos;
3976 /* Make the mask to be used against the extracted field. */
3977 mask = build_int_cst_type (unsigned_type, -1);
3978 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3979 mask = const_binop (RSHIFT_EXPR, mask,
3980 size_int (nbitsize - lbitsize - lbitpos), 0);
3983 /* If not comparing with constant, just rework the comparison
3985 return fold_build2 (code, compare_type,
3986 fold_build2 (BIT_AND_EXPR, unsigned_type,
3987 make_bit_field_ref (linner,
3992 fold_build2 (BIT_AND_EXPR, unsigned_type,
3993 make_bit_field_ref (rinner,
3999 /* Otherwise, we are handling the constant case. See if the constant is too
4000 big for the field. Warn and return a tree of for 0 (false) if so. We do
4001 this not only for its own sake, but to avoid having to test for this
4002 error case below. If we didn't, we might generate wrong code.
4004 For unsigned fields, the constant shifted right by the field length should
4005 be all zero. For signed fields, the high-order bits should agree with
4010 if (! integer_zerop (const_binop (RSHIFT_EXPR,
4011 fold_convert (unsigned_type, rhs),
4012 size_int (lbitsize), 0)))
4014 warning (0, "comparison is always %d due to width of bit-field",
4016 return constant_boolean_node (code == NE_EXPR, compare_type);
4021 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
4022 size_int (lbitsize - 1), 0);
4023 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
4025 warning (0, "comparison is always %d due to width of bit-field",
4027 return constant_boolean_node (code == NE_EXPR, compare_type);
4031 /* Single-bit compares should always be against zero. */
4032 if (lbitsize == 1 && ! integer_zerop (rhs))
4034 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
4035 rhs = build_int_cst (type, 0);
4038 /* Make a new bitfield reference, shift the constant over the
4039 appropriate number of bits and mask it with the computed mask
4040 (in case this was a signed field). If we changed it, make a new one. */
4041 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
4044 TREE_SIDE_EFFECTS (lhs) = 1;
4045 TREE_THIS_VOLATILE (lhs) = 1;
4048 rhs = const_binop (BIT_AND_EXPR,
4049 const_binop (LSHIFT_EXPR,
4050 fold_convert (unsigned_type, rhs),
4051 size_int (lbitpos), 0),
4054 return build2 (code, compare_type,
4055 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
4059 /* Subroutine for fold_truthop: decode a field reference.
4061 If EXP is a comparison reference, we return the innermost reference.
4063 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
4064 set to the starting bit number.
4066 If the innermost field can be completely contained in a mode-sized
4067 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
4069 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
4070 otherwise it is not changed.
4072 *PUNSIGNEDP is set to the signedness of the field.
4074 *PMASK is set to the mask used. This is either contained in a
4075 BIT_AND_EXPR or derived from the width of the field.
4077 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
4079 Return 0 if this is not a component reference or is one that we can't
4080 do anything with. */
4083 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
4084 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
4085 int *punsignedp, int *pvolatilep,
4086 tree *pmask, tree *pand_mask)
4088 tree outer_type = 0;
4090 tree mask, inner, offset;
4092 unsigned int precision;
4094 /* All the optimizations using this function assume integer fields.
4095 There are problems with FP fields since the type_for_size call
4096 below can fail for, e.g., XFmode. */
4097 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
4100 /* We are interested in the bare arrangement of bits, so strip everything
4101 that doesn't affect the machine mode. However, record the type of the
4102 outermost expression if it may matter below. */
4103 if (CONVERT_EXPR_P (exp)
4104 || TREE_CODE (exp) == NON_LVALUE_EXPR)
4105 outer_type = TREE_TYPE (exp);
4108 if (TREE_CODE (exp) == BIT_AND_EXPR)
4110 and_mask = TREE_OPERAND (exp, 1);
4111 exp = TREE_OPERAND (exp, 0);
4112 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
4113 if (TREE_CODE (and_mask) != INTEGER_CST)
4117 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
4118 punsignedp, pvolatilep, false);
4119 if ((inner == exp && and_mask == 0)
4120 || *pbitsize < 0 || offset != 0
4121 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
4124 /* If the number of bits in the reference is the same as the bitsize of
4125 the outer type, then the outer type gives the signedness. Otherwise
4126 (in case of a small bitfield) the signedness is unchanged. */
4127 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
4128 *punsignedp = TYPE_UNSIGNED (outer_type);
4130 /* Compute the mask to access the bitfield. */
4131 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
4132 precision = TYPE_PRECISION (unsigned_type);
4134 mask = build_int_cst_type (unsigned_type, -1);
4136 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4137 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
4139 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
4141 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
4142 fold_convert (unsigned_type, and_mask), mask);
4145 *pand_mask = and_mask;
4149 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
4153 all_ones_mask_p (const_tree mask, int size)
4155 tree type = TREE_TYPE (mask);
4156 unsigned int precision = TYPE_PRECISION (type);
4159 tmask = build_int_cst_type (signed_type_for (type), -1);
4162 tree_int_cst_equal (mask,
4163 const_binop (RSHIFT_EXPR,
4164 const_binop (LSHIFT_EXPR, tmask,
4165 size_int (precision - size),
4167 size_int (precision - size), 0));
4170 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
4171 represents the sign bit of EXP's type. If EXP represents a sign
4172 or zero extension, also test VAL against the unextended type.
4173 The return value is the (sub)expression whose sign bit is VAL,
4174 or NULL_TREE otherwise. */
4177 sign_bit_p (tree exp, const_tree val)
4179 unsigned HOST_WIDE_INT mask_lo, lo;
4180 HOST_WIDE_INT mask_hi, hi;
4184 /* Tree EXP must have an integral type. */
4185 t = TREE_TYPE (exp);
4186 if (! INTEGRAL_TYPE_P (t))
4189 /* Tree VAL must be an integer constant. */
4190 if (TREE_CODE (val) != INTEGER_CST
4191 || TREE_OVERFLOW (val))
4194 width = TYPE_PRECISION (t);
4195 if (width > HOST_BITS_PER_WIDE_INT)
4197 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
4200 mask_hi = ((unsigned HOST_WIDE_INT) -1
4201 >> (2 * HOST_BITS_PER_WIDE_INT - width));
4207 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
4210 mask_lo = ((unsigned HOST_WIDE_INT) -1
4211 >> (HOST_BITS_PER_WIDE_INT - width));
4214 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
4215 treat VAL as if it were unsigned. */
4216 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
4217 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
4220 /* Handle extension from a narrower type. */
4221 if (TREE_CODE (exp) == NOP_EXPR
4222 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
4223 return sign_bit_p (TREE_OPERAND (exp, 0), val);
4228 /* Subroutine for fold_truthop: determine if an operand is simple enough
4229 to be evaluated unconditionally. */
4232 simple_operand_p (const_tree exp)
4234 /* Strip any conversions that don't change the machine mode. */
4237 return (CONSTANT_CLASS_P (exp)
4238 || TREE_CODE (exp) == SSA_NAME
4240 && ! TREE_ADDRESSABLE (exp)
4241 && ! TREE_THIS_VOLATILE (exp)
4242 && ! DECL_NONLOCAL (exp)
4243 /* Don't regard global variables as simple. They may be
4244 allocated in ways unknown to the compiler (shared memory,
4245 #pragma weak, etc). */
4246 && ! TREE_PUBLIC (exp)
4247 && ! DECL_EXTERNAL (exp)
4248 /* Loading a static variable is unduly expensive, but global
4249 registers aren't expensive. */
4250 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
4253 /* The following functions are subroutines to fold_range_test and allow it to
4254 try to change a logical combination of comparisons into a range test.
4257 X == 2 || X == 3 || X == 4 || X == 5
4261 (unsigned) (X - 2) <= 3
4263 We describe each set of comparisons as being either inside or outside
4264 a range, using a variable named like IN_P, and then describe the
4265 range with a lower and upper bound. If one of the bounds is omitted,
4266 it represents either the highest or lowest value of the type.
4268 In the comments below, we represent a range by two numbers in brackets
4269 preceded by a "+" to designate being inside that range, or a "-" to
4270 designate being outside that range, so the condition can be inverted by
4271 flipping the prefix. An omitted bound is represented by a "-". For
4272 example, "- [-, 10]" means being outside the range starting at the lowest
4273 possible value and ending at 10, in other words, being greater than 10.
4274 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4277 We set up things so that the missing bounds are handled in a consistent
4278 manner so neither a missing bound nor "true" and "false" need to be
4279 handled using a special case. */
4281 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4282 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4283 and UPPER1_P are nonzero if the respective argument is an upper bound
4284 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4285 must be specified for a comparison. ARG1 will be converted to ARG0's
4286 type if both are specified. */
4289 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
4290 tree arg1, int upper1_p)
4296 /* If neither arg represents infinity, do the normal operation.
4297 Else, if not a comparison, return infinity. Else handle the special
4298 comparison rules. Note that most of the cases below won't occur, but
4299 are handled for consistency. */
4301 if (arg0 != 0 && arg1 != 0)
4303 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
4304 arg0, fold_convert (TREE_TYPE (arg0), arg1));
4306 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
4309 if (TREE_CODE_CLASS (code) != tcc_comparison)
4312 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4313 for neither. In real maths, we cannot assume open ended ranges are
4314 the same. But, this is computer arithmetic, where numbers are finite.
4315 We can therefore make the transformation of any unbounded range with
4316 the value Z, Z being greater than any representable number. This permits
4317 us to treat unbounded ranges as equal. */
4318 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
4319 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
4323 result = sgn0 == sgn1;
4326 result = sgn0 != sgn1;
4329 result = sgn0 < sgn1;
4332 result = sgn0 <= sgn1;
4335 result = sgn0 > sgn1;
4338 result = sgn0 >= sgn1;
4344 return constant_boolean_node (result, type);
4347 /* Given EXP, a logical expression, set the range it is testing into
4348 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4349 actually being tested. *PLOW and *PHIGH will be made of the same
4350 type as the returned expression. If EXP is not a comparison, we
4351 will most likely not be returning a useful value and range. Set
4352 *STRICT_OVERFLOW_P to true if the return value is only valid
4353 because signed overflow is undefined; otherwise, do not change
4354 *STRICT_OVERFLOW_P. */
4357 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4358 bool *strict_overflow_p)
4360 enum tree_code code;
4361 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4362 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4364 tree low, high, n_low, n_high;
4366 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4367 and see if we can refine the range. Some of the cases below may not
4368 happen, but it doesn't seem worth worrying about this. We "continue"
4369 the outer loop when we've changed something; otherwise we "break"
4370 the switch, which will "break" the while. */
4373 low = high = build_int_cst (TREE_TYPE (exp), 0);
4377 code = TREE_CODE (exp);
4378 exp_type = TREE_TYPE (exp);
4380 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4382 if (TREE_OPERAND_LENGTH (exp) > 0)
4383 arg0 = TREE_OPERAND (exp, 0);
4384 if (TREE_CODE_CLASS (code) == tcc_comparison
4385 || TREE_CODE_CLASS (code) == tcc_unary
4386 || TREE_CODE_CLASS (code) == tcc_binary)
4387 arg0_type = TREE_TYPE (arg0);
4388 if (TREE_CODE_CLASS (code) == tcc_binary
4389 || TREE_CODE_CLASS (code) == tcc_comparison
4390 || (TREE_CODE_CLASS (code) == tcc_expression
4391 && TREE_OPERAND_LENGTH (exp) > 1))
4392 arg1 = TREE_OPERAND (exp, 1);
4397 case TRUTH_NOT_EXPR:
4398 in_p = ! in_p, exp = arg0;
4401 case EQ_EXPR: case NE_EXPR:
4402 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4403 /* We can only do something if the range is testing for zero
4404 and if the second operand is an integer constant. Note that
4405 saying something is "in" the range we make is done by
4406 complementing IN_P since it will set in the initial case of
4407 being not equal to zero; "out" is leaving it alone. */
4408 if (low == 0 || high == 0
4409 || ! integer_zerop (low) || ! integer_zerop (high)
4410 || TREE_CODE (arg1) != INTEGER_CST)
4415 case NE_EXPR: /* - [c, c] */
4418 case EQ_EXPR: /* + [c, c] */
4419 in_p = ! in_p, low = high = arg1;
4421 case GT_EXPR: /* - [-, c] */
4422 low = 0, high = arg1;
4424 case GE_EXPR: /* + [c, -] */
4425 in_p = ! in_p, low = arg1, high = 0;
4427 case LT_EXPR: /* - [c, -] */
4428 low = arg1, high = 0;
4430 case LE_EXPR: /* + [-, c] */
4431 in_p = ! in_p, low = 0, high = arg1;
4437 /* If this is an unsigned comparison, we also know that EXP is
4438 greater than or equal to zero. We base the range tests we make
4439 on that fact, so we record it here so we can parse existing
4440 range tests. We test arg0_type since often the return type
4441 of, e.g. EQ_EXPR, is boolean. */
4442 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4444 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4446 build_int_cst (arg0_type, 0),
4450 in_p = n_in_p, low = n_low, high = n_high;
4452 /* If the high bound is missing, but we have a nonzero low
4453 bound, reverse the range so it goes from zero to the low bound
4455 if (high == 0 && low && ! integer_zerop (low))
4458 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4459 integer_one_node, 0);
4460 low = build_int_cst (arg0_type, 0);
4468 /* (-x) IN [a,b] -> x in [-b, -a] */
4469 n_low = range_binop (MINUS_EXPR, exp_type,
4470 build_int_cst (exp_type, 0),
4472 n_high = range_binop (MINUS_EXPR, exp_type,
4473 build_int_cst (exp_type, 0),
4475 low = n_low, high = n_high;
4481 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4482 build_int_cst (exp_type, 1));
4485 case PLUS_EXPR: case MINUS_EXPR:
4486 if (TREE_CODE (arg1) != INTEGER_CST)
4489 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4490 move a constant to the other side. */
4491 if (!TYPE_UNSIGNED (arg0_type)
4492 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4495 /* If EXP is signed, any overflow in the computation is undefined,
4496 so we don't worry about it so long as our computations on
4497 the bounds don't overflow. For unsigned, overflow is defined
4498 and this is exactly the right thing. */
4499 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4500 arg0_type, low, 0, arg1, 0);
4501 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4502 arg0_type, high, 1, arg1, 0);
4503 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4504 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4507 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4508 *strict_overflow_p = true;
4510 /* Check for an unsigned range which has wrapped around the maximum
4511 value thus making n_high < n_low, and normalize it. */
4512 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4514 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4515 integer_one_node, 0);
4516 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4517 integer_one_node, 0);
4519 /* If the range is of the form +/- [ x+1, x ], we won't
4520 be able to normalize it. But then, it represents the
4521 whole range or the empty set, so make it
4523 if (tree_int_cst_equal (n_low, low)
4524 && tree_int_cst_equal (n_high, high))
4530 low = n_low, high = n_high;
4535 CASE_CONVERT: case NON_LVALUE_EXPR:
4536 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4539 if (! INTEGRAL_TYPE_P (arg0_type)
4540 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4541 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4544 n_low = low, n_high = high;
4547 n_low = fold_convert (arg0_type, n_low);
4550 n_high = fold_convert (arg0_type, n_high);
4553 /* If we're converting arg0 from an unsigned type, to exp,
4554 a signed type, we will be doing the comparison as unsigned.
4555 The tests above have already verified that LOW and HIGH
4558 So we have to ensure that we will handle large unsigned
4559 values the same way that the current signed bounds treat
4562 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4566 /* For fixed-point modes, we need to pass the saturating flag
4567 as the 2nd parameter. */
4568 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
4569 equiv_type = lang_hooks.types.type_for_mode
4570 (TYPE_MODE (arg0_type),
4571 TYPE_SATURATING (arg0_type));
4573 equiv_type = lang_hooks.types.type_for_mode
4574 (TYPE_MODE (arg0_type), 1);
4576 /* A range without an upper bound is, naturally, unbounded.
4577 Since convert would have cropped a very large value, use
4578 the max value for the destination type. */
4580 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4581 : TYPE_MAX_VALUE (arg0_type);
4583 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4584 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4585 fold_convert (arg0_type,
4587 build_int_cst (arg0_type, 1));
4589 /* If the low bound is specified, "and" the range with the
4590 range for which the original unsigned value will be
4594 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4595 1, n_low, n_high, 1,
4596 fold_convert (arg0_type,
4601 in_p = (n_in_p == in_p);
4605 /* Otherwise, "or" the range with the range of the input
4606 that will be interpreted as negative. */
4607 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4608 0, n_low, n_high, 1,
4609 fold_convert (arg0_type,
4614 in_p = (in_p != n_in_p);
4619 low = n_low, high = n_high;
4629 /* If EXP is a constant, we can evaluate whether this is true or false. */
4630 if (TREE_CODE (exp) == INTEGER_CST)
4632 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4634 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4640 *pin_p = in_p, *plow = low, *phigh = high;
4644 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4645 type, TYPE, return an expression to test if EXP is in (or out of, depending
4646 on IN_P) the range. Return 0 if the test couldn't be created. */
4649 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4651 tree etype = TREE_TYPE (exp);
4654 #ifdef HAVE_canonicalize_funcptr_for_compare
4655 /* Disable this optimization for function pointer expressions
4656 on targets that require function pointer canonicalization. */
4657 if (HAVE_canonicalize_funcptr_for_compare
4658 && TREE_CODE (etype) == POINTER_TYPE
4659 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4665 value = build_range_check (type, exp, 1, low, high);
4667 return invert_truthvalue (value);
4672 if (low == 0 && high == 0)
4673 return build_int_cst (type, 1);
4676 return fold_build2 (LE_EXPR, type, exp,
4677 fold_convert (etype, high));
4680 return fold_build2 (GE_EXPR, type, exp,
4681 fold_convert (etype, low));
4683 if (operand_equal_p (low, high, 0))
4684 return fold_build2 (EQ_EXPR, type, exp,
4685 fold_convert (etype, low));
4687 if (integer_zerop (low))
4689 if (! TYPE_UNSIGNED (etype))
4691 etype = unsigned_type_for (etype);
4692 high = fold_convert (etype, high);
4693 exp = fold_convert (etype, exp);
4695 return build_range_check (type, exp, 1, 0, high);
4698 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4699 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4701 unsigned HOST_WIDE_INT lo;
4705 prec = TYPE_PRECISION (etype);
4706 if (prec <= HOST_BITS_PER_WIDE_INT)
4709 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4713 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4714 lo = (unsigned HOST_WIDE_INT) -1;
4717 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4719 if (TYPE_UNSIGNED (etype))
4721 tree signed_etype = signed_type_for (etype);
4722 if (TYPE_PRECISION (signed_etype) != TYPE_PRECISION (etype))
4724 = build_nonstandard_integer_type (TYPE_PRECISION (etype), 0);
4726 etype = signed_etype;
4727 exp = fold_convert (etype, exp);
4729 return fold_build2 (GT_EXPR, type, exp,
4730 build_int_cst (etype, 0));
4734 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4735 This requires wrap-around arithmetics for the type of the expression. */
4736 switch (TREE_CODE (etype))
4739 /* There is no requirement that LOW be within the range of ETYPE
4740 if the latter is a subtype. It must, however, be within the base
4741 type of ETYPE. So be sure we do the subtraction in that type. */
4742 if (TREE_TYPE (etype))
4743 etype = TREE_TYPE (etype);
4748 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4749 TYPE_UNSIGNED (etype));
4756 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4757 if (TREE_CODE (etype) == INTEGER_TYPE
4758 && !TYPE_OVERFLOW_WRAPS (etype))
4760 tree utype, minv, maxv;
4762 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4763 for the type in question, as we rely on this here. */
4764 utype = unsigned_type_for (etype);
4765 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4766 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4767 integer_one_node, 1);
4768 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4770 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4777 high = fold_convert (etype, high);
4778 low = fold_convert (etype, low);
4779 exp = fold_convert (etype, exp);
4781 value = const_binop (MINUS_EXPR, high, low, 0);
4784 if (POINTER_TYPE_P (etype))
4786 if (value != 0 && !TREE_OVERFLOW (value))
4788 low = fold_convert (sizetype, low);
4789 low = fold_build1 (NEGATE_EXPR, sizetype, low);
4790 return build_range_check (type,
4791 fold_build2 (POINTER_PLUS_EXPR, etype, exp, low),
4792 1, build_int_cst (etype, 0), value);
4797 if (value != 0 && !TREE_OVERFLOW (value))
4798 return build_range_check (type,
4799 fold_build2 (MINUS_EXPR, etype, exp, low),
4800 1, build_int_cst (etype, 0), value);
4805 /* Return the predecessor of VAL in its type, handling the infinite case. */
4808 range_predecessor (tree val)
4810 tree type = TREE_TYPE (val);
4812 if (INTEGRAL_TYPE_P (type)
4813 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4816 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4819 /* Return the successor of VAL in its type, handling the infinite case. */
4822 range_successor (tree val)
4824 tree type = TREE_TYPE (val);
4826 if (INTEGRAL_TYPE_P (type)
4827 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4830 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4833 /* Given two ranges, see if we can merge them into one. Return 1 if we
4834 can, 0 if we can't. Set the output range into the specified parameters. */
4837 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4838 tree high0, int in1_p, tree low1, tree high1)
4846 int lowequal = ((low0 == 0 && low1 == 0)
4847 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4848 low0, 0, low1, 0)));
4849 int highequal = ((high0 == 0 && high1 == 0)
4850 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4851 high0, 1, high1, 1)));
4853 /* Make range 0 be the range that starts first, or ends last if they
4854 start at the same value. Swap them if it isn't. */
4855 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4858 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4859 high1, 1, high0, 1))))
4861 temp = in0_p, in0_p = in1_p, in1_p = temp;
4862 tem = low0, low0 = low1, low1 = tem;
4863 tem = high0, high0 = high1, high1 = tem;
4866 /* Now flag two cases, whether the ranges are disjoint or whether the
4867 second range is totally subsumed in the first. Note that the tests
4868 below are simplified by the ones above. */
4869 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4870 high0, 1, low1, 0));
4871 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4872 high1, 1, high0, 1));
4874 /* We now have four cases, depending on whether we are including or
4875 excluding the two ranges. */
4878 /* If they don't overlap, the result is false. If the second range
4879 is a subset it is the result. Otherwise, the range is from the start
4880 of the second to the end of the first. */
4882 in_p = 0, low = high = 0;
4884 in_p = 1, low = low1, high = high1;
4886 in_p = 1, low = low1, high = high0;
4889 else if (in0_p && ! in1_p)
4891 /* If they don't overlap, the result is the first range. If they are
4892 equal, the result is false. If the second range is a subset of the
4893 first, and the ranges begin at the same place, we go from just after
4894 the end of the second range to the end of the first. If the second
4895 range is not a subset of the first, or if it is a subset and both
4896 ranges end at the same place, the range starts at the start of the
4897 first range and ends just before the second range.
4898 Otherwise, we can't describe this as a single range. */
4900 in_p = 1, low = low0, high = high0;
4901 else if (lowequal && highequal)
4902 in_p = 0, low = high = 0;
4903 else if (subset && lowequal)
4905 low = range_successor (high1);
4910 /* We are in the weird situation where high0 > high1 but
4911 high1 has no successor. Punt. */
4915 else if (! subset || highequal)
4918 high = range_predecessor (low1);
4922 /* low0 < low1 but low1 has no predecessor. Punt. */
4930 else if (! in0_p && in1_p)
4932 /* If they don't overlap, the result is the second range. If the second
4933 is a subset of the first, the result is false. Otherwise,
4934 the range starts just after the first range and ends at the
4935 end of the second. */
4937 in_p = 1, low = low1, high = high1;
4938 else if (subset || highequal)
4939 in_p = 0, low = high = 0;
4942 low = range_successor (high0);
4947 /* high1 > high0 but high0 has no successor. Punt. */
4955 /* The case where we are excluding both ranges. Here the complex case
4956 is if they don't overlap. In that case, the only time we have a
4957 range is if they are adjacent. If the second is a subset of the
4958 first, the result is the first. Otherwise, the range to exclude
4959 starts at the beginning of the first range and ends at the end of the
4963 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4964 range_successor (high0),
4966 in_p = 0, low = low0, high = high1;
4969 /* Canonicalize - [min, x] into - [-, x]. */
4970 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4971 switch (TREE_CODE (TREE_TYPE (low0)))
4974 if (TYPE_PRECISION (TREE_TYPE (low0))
4975 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4979 if (tree_int_cst_equal (low0,
4980 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4984 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4985 && integer_zerop (low0))
4992 /* Canonicalize - [x, max] into - [x, -]. */
4993 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4994 switch (TREE_CODE (TREE_TYPE (high1)))
4997 if (TYPE_PRECISION (TREE_TYPE (high1))
4998 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
5002 if (tree_int_cst_equal (high1,
5003 TYPE_MAX_VALUE (TREE_TYPE (high1))))
5007 if (TYPE_UNSIGNED (TREE_TYPE (high1))
5008 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
5010 integer_one_node, 1)))
5017 /* The ranges might be also adjacent between the maximum and
5018 minimum values of the given type. For
5019 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
5020 return + [x + 1, y - 1]. */
5021 if (low0 == 0 && high1 == 0)
5023 low = range_successor (high0);
5024 high = range_predecessor (low1);
5025 if (low == 0 || high == 0)
5035 in_p = 0, low = low0, high = high0;
5037 in_p = 0, low = low0, high = high1;
5040 *pin_p = in_p, *plow = low, *phigh = high;
5045 /* Subroutine of fold, looking inside expressions of the form
5046 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
5047 of the COND_EXPR. This function is being used also to optimize
5048 A op B ? C : A, by reversing the comparison first.
5050 Return a folded expression whose code is not a COND_EXPR
5051 anymore, or NULL_TREE if no folding opportunity is found. */
5054 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
5056 enum tree_code comp_code = TREE_CODE (arg0);
5057 tree arg00 = TREE_OPERAND (arg0, 0);
5058 tree arg01 = TREE_OPERAND (arg0, 1);
5059 tree arg1_type = TREE_TYPE (arg1);
5065 /* If we have A op 0 ? A : -A, consider applying the following
5068 A == 0? A : -A same as -A
5069 A != 0? A : -A same as A
5070 A >= 0? A : -A same as abs (A)
5071 A > 0? A : -A same as abs (A)
5072 A <= 0? A : -A same as -abs (A)
5073 A < 0? A : -A same as -abs (A)
5075 None of these transformations work for modes with signed
5076 zeros. If A is +/-0, the first two transformations will
5077 change the sign of the result (from +0 to -0, or vice
5078 versa). The last four will fix the sign of the result,
5079 even though the original expressions could be positive or
5080 negative, depending on the sign of A.
5082 Note that all these transformations are correct if A is
5083 NaN, since the two alternatives (A and -A) are also NaNs. */
5084 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
5085 && (FLOAT_TYPE_P (TREE_TYPE (arg01))
5086 ? real_zerop (arg01)
5087 : integer_zerop (arg01))
5088 && ((TREE_CODE (arg2) == NEGATE_EXPR
5089 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
5090 /* In the case that A is of the form X-Y, '-A' (arg2) may
5091 have already been folded to Y-X, check for that. */
5092 || (TREE_CODE (arg1) == MINUS_EXPR
5093 && TREE_CODE (arg2) == MINUS_EXPR
5094 && operand_equal_p (TREE_OPERAND (arg1, 0),
5095 TREE_OPERAND (arg2, 1), 0)
5096 && operand_equal_p (TREE_OPERAND (arg1, 1),
5097 TREE_OPERAND (arg2, 0), 0))))
5102 tem = fold_convert (arg1_type, arg1);
5103 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
5106 return pedantic_non_lvalue (fold_convert (type, arg1));
5109 if (flag_trapping_math)
5114 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5115 arg1 = fold_convert (signed_type_for
5116 (TREE_TYPE (arg1)), arg1);
5117 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5118 return pedantic_non_lvalue (fold_convert (type, tem));
5121 if (flag_trapping_math)
5125 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
5126 arg1 = fold_convert (signed_type_for
5127 (TREE_TYPE (arg1)), arg1);
5128 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
5129 return negate_expr (fold_convert (type, tem));
5131 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5135 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
5136 A == 0 ? A : 0 is always 0 unless A is -0. Note that
5137 both transformations are correct when A is NaN: A != 0
5138 is then true, and A == 0 is false. */
5140 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
5141 && integer_zerop (arg01) && integer_zerop (arg2))
5143 if (comp_code == NE_EXPR)
5144 return pedantic_non_lvalue (fold_convert (type, arg1));
5145 else if (comp_code == EQ_EXPR)
5146 return build_int_cst (type, 0);
5149 /* Try some transformations of A op B ? A : B.
5151 A == B? A : B same as B
5152 A != B? A : B same as A
5153 A >= B? A : B same as max (A, B)
5154 A > B? A : B same as max (B, A)
5155 A <= B? A : B same as min (A, B)
5156 A < B? A : B same as min (B, A)
5158 As above, these transformations don't work in the presence
5159 of signed zeros. For example, if A and B are zeros of
5160 opposite sign, the first two transformations will change
5161 the sign of the result. In the last four, the original
5162 expressions give different results for (A=+0, B=-0) and
5163 (A=-0, B=+0), but the transformed expressions do not.
5165 The first two transformations are correct if either A or B
5166 is a NaN. In the first transformation, the condition will
5167 be false, and B will indeed be chosen. In the case of the
5168 second transformation, the condition A != B will be true,
5169 and A will be chosen.
5171 The conversions to max() and min() are not correct if B is
5172 a number and A is not. The conditions in the original
5173 expressions will be false, so all four give B. The min()
5174 and max() versions would give a NaN instead. */
5175 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
5176 && operand_equal_for_comparison_p (arg01, arg2, arg00)
5177 /* Avoid these transformations if the COND_EXPR may be used
5178 as an lvalue in the C++ front-end. PR c++/19199. */
5180 || (strcmp (lang_hooks.name, "GNU C++") != 0
5181 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
5182 || ! maybe_lvalue_p (arg1)
5183 || ! maybe_lvalue_p (arg2)))
5185 tree comp_op0 = arg00;
5186 tree comp_op1 = arg01;
5187 tree comp_type = TREE_TYPE (comp_op0);
5189 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
5190 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
5200 return pedantic_non_lvalue (fold_convert (type, arg2));
5202 return pedantic_non_lvalue (fold_convert (type, arg1));
5207 /* In C++ a ?: expression can be an lvalue, so put the
5208 operand which will be used if they are equal first
5209 so that we can convert this back to the
5210 corresponding COND_EXPR. */
5211 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5213 comp_op0 = fold_convert (comp_type, comp_op0);
5214 comp_op1 = fold_convert (comp_type, comp_op1);
5215 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
5216 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
5217 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
5218 return pedantic_non_lvalue (fold_convert (type, tem));
5225 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5227 comp_op0 = fold_convert (comp_type, comp_op0);
5228 comp_op1 = fold_convert (comp_type, comp_op1);
5229 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
5230 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
5231 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
5232 return pedantic_non_lvalue (fold_convert (type, tem));
5236 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5237 return pedantic_non_lvalue (fold_convert (type, arg2));
5240 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5241 return pedantic_non_lvalue (fold_convert (type, arg1));
5244 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5249 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
5250 we might still be able to simplify this. For example,
5251 if C1 is one less or one more than C2, this might have started
5252 out as a MIN or MAX and been transformed by this function.
5253 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
5255 if (INTEGRAL_TYPE_P (type)
5256 && TREE_CODE (arg01) == INTEGER_CST
5257 && TREE_CODE (arg2) == INTEGER_CST)
5261 /* We can replace A with C1 in this case. */
5262 arg1 = fold_convert (type, arg01);
5263 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
5266 /* If C1 is C2 + 1, this is min(A, C2). */
5267 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5269 && operand_equal_p (arg01,
5270 const_binop (PLUS_EXPR, arg2,
5271 build_int_cst (type, 1), 0),
5273 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5275 fold_convert (type, arg1),
5280 /* If C1 is C2 - 1, this is min(A, C2). */
5281 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5283 && operand_equal_p (arg01,
5284 const_binop (MINUS_EXPR, arg2,
5285 build_int_cst (type, 1), 0),
5287 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5289 fold_convert (type, arg1),
5294 /* If C1 is C2 - 1, this is max(A, C2). */
5295 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5297 && operand_equal_p (arg01,
5298 const_binop (MINUS_EXPR, arg2,
5299 build_int_cst (type, 1), 0),
5301 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5303 fold_convert (type, arg1),
5308 /* If C1 is C2 + 1, this is max(A, C2). */
5309 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5311 && operand_equal_p (arg01,
5312 const_binop (PLUS_EXPR, arg2,
5313 build_int_cst (type, 1), 0),
5315 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5317 fold_convert (type, arg1),
5331 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5332 #define LOGICAL_OP_NON_SHORT_CIRCUIT \
5333 (BRANCH_COST (optimize_function_for_speed_p (cfun), \
5337 /* EXP is some logical combination of boolean tests. See if we can
5338 merge it into some range test. Return the new tree if so. */
5341 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
5343 int or_op = (code == TRUTH_ORIF_EXPR
5344 || code == TRUTH_OR_EXPR);
5345 int in0_p, in1_p, in_p;
5346 tree low0, low1, low, high0, high1, high;
5347 bool strict_overflow_p = false;
5348 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
5349 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
5351 const char * const warnmsg = G_("assuming signed overflow does not occur "
5352 "when simplifying range test");
5354 /* If this is an OR operation, invert both sides; we will invert
5355 again at the end. */
5357 in0_p = ! in0_p, in1_p = ! in1_p;
5359 /* If both expressions are the same, if we can merge the ranges, and we
5360 can build the range test, return it or it inverted. If one of the
5361 ranges is always true or always false, consider it to be the same
5362 expression as the other. */
5363 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
5364 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
5366 && 0 != (tem = (build_range_check (type,
5368 : rhs != 0 ? rhs : integer_zero_node,
5371 if (strict_overflow_p)
5372 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
5373 return or_op ? invert_truthvalue (tem) : tem;
5376 /* On machines where the branch cost is expensive, if this is a
5377 short-circuited branch and the underlying object on both sides
5378 is the same, make a non-short-circuit operation. */
5379 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5380 && lhs != 0 && rhs != 0
5381 && (code == TRUTH_ANDIF_EXPR
5382 || code == TRUTH_ORIF_EXPR)
5383 && operand_equal_p (lhs, rhs, 0))
5385 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5386 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5387 which cases we can't do this. */
5388 if (simple_operand_p (lhs))
5389 return build2 (code == TRUTH_ANDIF_EXPR
5390 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5393 else if (lang_hooks.decls.global_bindings_p () == 0
5394 && ! CONTAINS_PLACEHOLDER_P (lhs))
5396 tree common = save_expr (lhs);
5398 if (0 != (lhs = build_range_check (type, common,
5399 or_op ? ! in0_p : in0_p,
5401 && (0 != (rhs = build_range_check (type, common,
5402 or_op ? ! in1_p : in1_p,
5405 if (strict_overflow_p)
5406 fold_overflow_warning (warnmsg,
5407 WARN_STRICT_OVERFLOW_COMPARISON);
5408 return build2 (code == TRUTH_ANDIF_EXPR
5409 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5418 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5419 bit value. Arrange things so the extra bits will be set to zero if and
5420 only if C is signed-extended to its full width. If MASK is nonzero,
5421 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5424 unextend (tree c, int p, int unsignedp, tree mask)
5426 tree type = TREE_TYPE (c);
5427 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5430 if (p == modesize || unsignedp)
5433 /* We work by getting just the sign bit into the low-order bit, then
5434 into the high-order bit, then sign-extend. We then XOR that value
5436 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5437 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5439 /* We must use a signed type in order to get an arithmetic right shift.
5440 However, we must also avoid introducing accidental overflows, so that
5441 a subsequent call to integer_zerop will work. Hence we must
5442 do the type conversion here. At this point, the constant is either
5443 zero or one, and the conversion to a signed type can never overflow.
5444 We could get an overflow if this conversion is done anywhere else. */
5445 if (TYPE_UNSIGNED (type))
5446 temp = fold_convert (signed_type_for (type), temp);
5448 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5449 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5451 temp = const_binop (BIT_AND_EXPR, temp,
5452 fold_convert (TREE_TYPE (c), mask), 0);
5453 /* If necessary, convert the type back to match the type of C. */
5454 if (TYPE_UNSIGNED (type))
5455 temp = fold_convert (type, temp);
5457 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5460 /* Find ways of folding logical expressions of LHS and RHS:
5461 Try to merge two comparisons to the same innermost item.
5462 Look for range tests like "ch >= '0' && ch <= '9'".
5463 Look for combinations of simple terms on machines with expensive branches
5464 and evaluate the RHS unconditionally.
5466 For example, if we have p->a == 2 && p->b == 4 and we can make an
5467 object large enough to span both A and B, we can do this with a comparison
5468 against the object ANDed with the a mask.
5470 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5471 operations to do this with one comparison.
5473 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5474 function and the one above.
5476 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5477 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5479 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5482 We return the simplified tree or 0 if no optimization is possible. */
5485 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5487 /* If this is the "or" of two comparisons, we can do something if
5488 the comparisons are NE_EXPR. If this is the "and", we can do something
5489 if the comparisons are EQ_EXPR. I.e.,
5490 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5492 WANTED_CODE is this operation code. For single bit fields, we can
5493 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5494 comparison for one-bit fields. */
5496 enum tree_code wanted_code;
5497 enum tree_code lcode, rcode;
5498 tree ll_arg, lr_arg, rl_arg, rr_arg;
5499 tree ll_inner, lr_inner, rl_inner, rr_inner;
5500 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5501 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5502 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
5503 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
5504 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5505 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5506 enum machine_mode lnmode, rnmode;
5507 tree ll_mask, lr_mask, rl_mask, rr_mask;
5508 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5509 tree l_const, r_const;
5510 tree lntype, rntype, result;
5511 HOST_WIDE_INT first_bit, end_bit;
5513 tree orig_lhs = lhs, orig_rhs = rhs;
5514 enum tree_code orig_code = code;
5516 /* Start by getting the comparison codes. Fail if anything is volatile.
5517 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5518 it were surrounded with a NE_EXPR. */
5520 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5523 lcode = TREE_CODE (lhs);
5524 rcode = TREE_CODE (rhs);
5526 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5528 lhs = build2 (NE_EXPR, truth_type, lhs,
5529 build_int_cst (TREE_TYPE (lhs), 0));
5533 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5535 rhs = build2 (NE_EXPR, truth_type, rhs,
5536 build_int_cst (TREE_TYPE (rhs), 0));
5540 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5541 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5544 ll_arg = TREE_OPERAND (lhs, 0);
5545 lr_arg = TREE_OPERAND (lhs, 1);
5546 rl_arg = TREE_OPERAND (rhs, 0);
5547 rr_arg = TREE_OPERAND (rhs, 1);
5549 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5550 if (simple_operand_p (ll_arg)
5551 && simple_operand_p (lr_arg))
5554 if (operand_equal_p (ll_arg, rl_arg, 0)
5555 && operand_equal_p (lr_arg, rr_arg, 0))
5557 result = combine_comparisons (code, lcode, rcode,
5558 truth_type, ll_arg, lr_arg);
5562 else if (operand_equal_p (ll_arg, rr_arg, 0)
5563 && operand_equal_p (lr_arg, rl_arg, 0))
5565 result = combine_comparisons (code, lcode,
5566 swap_tree_comparison (rcode),
5567 truth_type, ll_arg, lr_arg);
5573 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5574 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5576 /* If the RHS can be evaluated unconditionally and its operands are
5577 simple, it wins to evaluate the RHS unconditionally on machines
5578 with expensive branches. In this case, this isn't a comparison
5579 that can be merged. Avoid doing this if the RHS is a floating-point
5580 comparison since those can trap. */
5582 if (BRANCH_COST (optimize_function_for_speed_p (cfun),
5584 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5585 && simple_operand_p (rl_arg)
5586 && simple_operand_p (rr_arg))
5588 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5589 if (code == TRUTH_OR_EXPR
5590 && lcode == NE_EXPR && integer_zerop (lr_arg)
5591 && rcode == NE_EXPR && integer_zerop (rr_arg)
5592 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5593 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5594 return build2 (NE_EXPR, truth_type,
5595 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5597 build_int_cst (TREE_TYPE (ll_arg), 0));
5599 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5600 if (code == TRUTH_AND_EXPR
5601 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5602 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5603 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5604 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5605 return build2 (EQ_EXPR, truth_type,
5606 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5608 build_int_cst (TREE_TYPE (ll_arg), 0));
5610 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5612 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5613 return build2 (code, truth_type, lhs, rhs);
5618 /* See if the comparisons can be merged. Then get all the parameters for
5621 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5622 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5626 ll_inner = decode_field_reference (ll_arg,
5627 &ll_bitsize, &ll_bitpos, &ll_mode,
5628 &ll_unsignedp, &volatilep, &ll_mask,
5630 lr_inner = decode_field_reference (lr_arg,
5631 &lr_bitsize, &lr_bitpos, &lr_mode,
5632 &lr_unsignedp, &volatilep, &lr_mask,
5634 rl_inner = decode_field_reference (rl_arg,
5635 &rl_bitsize, &rl_bitpos, &rl_mode,
5636 &rl_unsignedp, &volatilep, &rl_mask,
5638 rr_inner = decode_field_reference (rr_arg,
5639 &rr_bitsize, &rr_bitpos, &rr_mode,
5640 &rr_unsignedp, &volatilep, &rr_mask,
5643 /* It must be true that the inner operation on the lhs of each
5644 comparison must be the same if we are to be able to do anything.
5645 Then see if we have constants. If not, the same must be true for
5647 if (volatilep || ll_inner == 0 || rl_inner == 0
5648 || ! operand_equal_p (ll_inner, rl_inner, 0))
5651 if (TREE_CODE (lr_arg) == INTEGER_CST
5652 && TREE_CODE (rr_arg) == INTEGER_CST)
5653 l_const = lr_arg, r_const = rr_arg;
5654 else if (lr_inner == 0 || rr_inner == 0
5655 || ! operand_equal_p (lr_inner, rr_inner, 0))
5658 l_const = r_const = 0;
5660 /* If either comparison code is not correct for our logical operation,
5661 fail. However, we can convert a one-bit comparison against zero into
5662 the opposite comparison against that bit being set in the field. */
5664 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5665 if (lcode != wanted_code)
5667 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5669 /* Make the left operand unsigned, since we are only interested
5670 in the value of one bit. Otherwise we are doing the wrong
5679 /* This is analogous to the code for l_const above. */
5680 if (rcode != wanted_code)
5682 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5691 /* See if we can find a mode that contains both fields being compared on
5692 the left. If we can't, fail. Otherwise, update all constants and masks
5693 to be relative to a field of that size. */
5694 first_bit = MIN (ll_bitpos, rl_bitpos);
5695 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5696 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5697 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5699 if (lnmode == VOIDmode)
5702 lnbitsize = GET_MODE_BITSIZE (lnmode);
5703 lnbitpos = first_bit & ~ (lnbitsize - 1);
5704 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5705 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5707 if (BYTES_BIG_ENDIAN)
5709 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5710 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5713 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5714 size_int (xll_bitpos), 0);
5715 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5716 size_int (xrl_bitpos), 0);
5720 l_const = fold_convert (lntype, l_const);
5721 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5722 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5723 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5724 fold_build1 (BIT_NOT_EXPR,
5728 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5730 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5735 r_const = fold_convert (lntype, r_const);
5736 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5737 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5738 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5739 fold_build1 (BIT_NOT_EXPR,
5743 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5745 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5749 /* If the right sides are not constant, do the same for it. Also,
5750 disallow this optimization if a size or signedness mismatch occurs
5751 between the left and right sides. */
5754 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
5755 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
5756 /* Make sure the two fields on the right
5757 correspond to the left without being swapped. */
5758 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
5761 first_bit = MIN (lr_bitpos, rr_bitpos);
5762 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
5763 rnmode = get_best_mode (end_bit - first_bit, first_bit,
5764 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
5766 if (rnmode == VOIDmode)
5769 rnbitsize = GET_MODE_BITSIZE (rnmode);
5770 rnbitpos = first_bit & ~ (rnbitsize - 1);
5771 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
5772 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
5774 if (BYTES_BIG_ENDIAN)
5776 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
5777 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
5780 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
5781 size_int (xlr_bitpos), 0);
5782 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
5783 size_int (xrr_bitpos), 0);
5785 /* Make a mask that corresponds to both fields being compared.
5786 Do this for both items being compared. If the operands are the
5787 same size and the bits being compared are in the same position
5788 then we can do this by masking both and comparing the masked
5790 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5791 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
5792 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
5794 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5795 ll_unsignedp || rl_unsignedp);
5796 if (! all_ones_mask_p (ll_mask, lnbitsize))
5797 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
5799 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
5800 lr_unsignedp || rr_unsignedp);
5801 if (! all_ones_mask_p (lr_mask, rnbitsize))
5802 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
5804 return build2 (wanted_code, truth_type, lhs, rhs);
5807 /* There is still another way we can do something: If both pairs of
5808 fields being compared are adjacent, we may be able to make a wider
5809 field containing them both.
5811 Note that we still must mask the lhs/rhs expressions. Furthermore,
5812 the mask must be shifted to account for the shift done by
5813 make_bit_field_ref. */
5814 if ((ll_bitsize + ll_bitpos == rl_bitpos
5815 && lr_bitsize + lr_bitpos == rr_bitpos)
5816 || (ll_bitpos == rl_bitpos + rl_bitsize
5817 && lr_bitpos == rr_bitpos + rr_bitsize))
5821 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
5822 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
5823 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
5824 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
5826 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
5827 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
5828 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
5829 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
5831 /* Convert to the smaller type before masking out unwanted bits. */
5833 if (lntype != rntype)
5835 if (lnbitsize > rnbitsize)
5837 lhs = fold_convert (rntype, lhs);
5838 ll_mask = fold_convert (rntype, ll_mask);
5841 else if (lnbitsize < rnbitsize)
5843 rhs = fold_convert (lntype, rhs);
5844 lr_mask = fold_convert (lntype, lr_mask);
5849 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
5850 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
5852 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
5853 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
5855 return build2 (wanted_code, truth_type, lhs, rhs);
5861 /* Handle the case of comparisons with constants. If there is something in
5862 common between the masks, those bits of the constants must be the same.
5863 If not, the condition is always false. Test for this to avoid generating
5864 incorrect code below. */
5865 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5866 if (! integer_zerop (result)
5867 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5868 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5870 if (wanted_code == NE_EXPR)
5872 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5873 return constant_boolean_node (true, truth_type);
5877 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5878 return constant_boolean_node (false, truth_type);
5882 /* Construct the expression we will return. First get the component
5883 reference we will make. Unless the mask is all ones the width of
5884 that field, perform the mask operation. Then compare with the
5886 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
5887 ll_unsignedp || rl_unsignedp);
5889 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5890 if (! all_ones_mask_p (ll_mask, lnbitsize))
5891 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
5893 return build2 (wanted_code, truth_type, result,
5894 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
5897 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5901 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5904 enum tree_code op_code;
5907 int consts_equal, consts_lt;
5910 STRIP_SIGN_NOPS (arg0);
5912 op_code = TREE_CODE (arg0);
5913 minmax_const = TREE_OPERAND (arg0, 1);
5914 comp_const = fold_convert (TREE_TYPE (arg0), op1);
5915 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5916 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5917 inner = TREE_OPERAND (arg0, 0);
5919 /* If something does not permit us to optimize, return the original tree. */
5920 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5921 || TREE_CODE (comp_const) != INTEGER_CST
5922 || TREE_OVERFLOW (comp_const)
5923 || TREE_CODE (minmax_const) != INTEGER_CST
5924 || TREE_OVERFLOW (minmax_const))
5927 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5928 and GT_EXPR, doing the rest with recursive calls using logical
5932 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5934 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5937 return invert_truthvalue (tem);
5943 fold_build2 (TRUTH_ORIF_EXPR, type,
5944 optimize_minmax_comparison
5945 (EQ_EXPR, type, arg0, comp_const),
5946 optimize_minmax_comparison
5947 (GT_EXPR, type, arg0, comp_const));
5950 if (op_code == MAX_EXPR && consts_equal)
5951 /* MAX (X, 0) == 0 -> X <= 0 */
5952 return fold_build2 (LE_EXPR, type, inner, comp_const);
5954 else if (op_code == MAX_EXPR && consts_lt)
5955 /* MAX (X, 0) == 5 -> X == 5 */
5956 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5958 else if (op_code == MAX_EXPR)
5959 /* MAX (X, 0) == -1 -> false */
5960 return omit_one_operand (type, integer_zero_node, inner);
5962 else if (consts_equal)
5963 /* MIN (X, 0) == 0 -> X >= 0 */
5964 return fold_build2 (GE_EXPR, type, inner, comp_const);
5967 /* MIN (X, 0) == 5 -> false */
5968 return omit_one_operand (type, integer_zero_node, inner);
5971 /* MIN (X, 0) == -1 -> X == -1 */
5972 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5975 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5976 /* MAX (X, 0) > 0 -> X > 0
5977 MAX (X, 0) > 5 -> X > 5 */
5978 return fold_build2 (GT_EXPR, type, inner, comp_const);
5980 else if (op_code == MAX_EXPR)
5981 /* MAX (X, 0) > -1 -> true */
5982 return omit_one_operand (type, integer_one_node, inner);
5984 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5985 /* MIN (X, 0) > 0 -> false
5986 MIN (X, 0) > 5 -> false */
5987 return omit_one_operand (type, integer_zero_node, inner);
5990 /* MIN (X, 0) > -1 -> X > -1 */
5991 return fold_build2 (GT_EXPR, type, inner, comp_const);
5998 /* T is an integer expression that is being multiplied, divided, or taken a
5999 modulus (CODE says which and what kind of divide or modulus) by a
6000 constant C. See if we can eliminate that operation by folding it with
6001 other operations already in T. WIDE_TYPE, if non-null, is a type that
6002 should be used for the computation if wider than our type.
6004 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
6005 (X * 2) + (Y * 4). We must, however, be assured that either the original
6006 expression would not overflow or that overflow is undefined for the type
6007 in the language in question.
6009 If we return a non-null expression, it is an equivalent form of the
6010 original computation, but need not be in the original type.
6012 We set *STRICT_OVERFLOW_P to true if the return values depends on
6013 signed overflow being undefined. Otherwise we do not change
6014 *STRICT_OVERFLOW_P. */
6017 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
6018 bool *strict_overflow_p)
6020 /* To avoid exponential search depth, refuse to allow recursion past
6021 three levels. Beyond that (1) it's highly unlikely that we'll find
6022 something interesting and (2) we've probably processed it before
6023 when we built the inner expression. */
6032 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
6039 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
6040 bool *strict_overflow_p)
6042 tree type = TREE_TYPE (t);
6043 enum tree_code tcode = TREE_CODE (t);
6044 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
6045 > GET_MODE_SIZE (TYPE_MODE (type)))
6046 ? wide_type : type);
6048 int same_p = tcode == code;
6049 tree op0 = NULL_TREE, op1 = NULL_TREE;
6050 bool sub_strict_overflow_p;
6052 /* Don't deal with constants of zero here; they confuse the code below. */
6053 if (integer_zerop (c))
6056 if (TREE_CODE_CLASS (tcode) == tcc_unary)
6057 op0 = TREE_OPERAND (t, 0);
6059 if (TREE_CODE_CLASS (tcode) == tcc_binary)
6060 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
6062 /* Note that we need not handle conditional operations here since fold
6063 already handles those cases. So just do arithmetic here. */
6067 /* For a constant, we can always simplify if we are a multiply
6068 or (for divide and modulus) if it is a multiple of our constant. */
6069 if (code == MULT_EXPR
6070 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
6071 return const_binop (code, fold_convert (ctype, t),
6072 fold_convert (ctype, c), 0);
6075 CASE_CONVERT: case NON_LVALUE_EXPR:
6076 /* If op0 is an expression ... */
6077 if ((COMPARISON_CLASS_P (op0)
6078 || UNARY_CLASS_P (op0)
6079 || BINARY_CLASS_P (op0)
6080 || VL_EXP_CLASS_P (op0)
6081 || EXPRESSION_CLASS_P (op0))
6082 /* ... and has wrapping overflow, and its type is smaller
6083 than ctype, then we cannot pass through as widening. */
6084 && ((TYPE_OVERFLOW_WRAPS (TREE_TYPE (op0))
6085 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
6086 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
6087 && (TYPE_PRECISION (ctype)
6088 > TYPE_PRECISION (TREE_TYPE (op0))))
6089 /* ... or this is a truncation (t is narrower than op0),
6090 then we cannot pass through this narrowing. */
6091 || (TYPE_PRECISION (type)
6092 < TYPE_PRECISION (TREE_TYPE (op0)))
6093 /* ... or signedness changes for division or modulus,
6094 then we cannot pass through this conversion. */
6095 || (code != MULT_EXPR
6096 && (TYPE_UNSIGNED (ctype)
6097 != TYPE_UNSIGNED (TREE_TYPE (op0))))
6098 /* ... or has undefined overflow while the converted to
6099 type has not, we cannot do the operation in the inner type
6100 as that would introduce undefined overflow. */
6101 || (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))
6102 && !TYPE_OVERFLOW_UNDEFINED (type))))
6105 /* Pass the constant down and see if we can make a simplification. If
6106 we can, replace this expression with the inner simplification for
6107 possible later conversion to our or some other type. */
6108 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
6109 && TREE_CODE (t2) == INTEGER_CST
6110 && !TREE_OVERFLOW (t2)
6111 && (0 != (t1 = extract_muldiv (op0, t2, code,
6113 ? ctype : NULL_TREE,
6114 strict_overflow_p))))
6119 /* If widening the type changes it from signed to unsigned, then we
6120 must avoid building ABS_EXPR itself as unsigned. */
6121 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
6123 tree cstype = (*signed_type_for) (ctype);
6124 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
6127 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
6128 return fold_convert (ctype, t1);
6132 /* If the constant is negative, we cannot simplify this. */
6133 if (tree_int_cst_sgn (c) == -1)
6137 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
6139 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
6142 case MIN_EXPR: case MAX_EXPR:
6143 /* If widening the type changes the signedness, then we can't perform
6144 this optimization as that changes the result. */
6145 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
6148 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
6149 sub_strict_overflow_p = false;
6150 if ((t1 = extract_muldiv (op0, c, code, wide_type,
6151 &sub_strict_overflow_p)) != 0
6152 && (t2 = extract_muldiv (op1, c, code, wide_type,
6153 &sub_strict_overflow_p)) != 0)
6155 if (tree_int_cst_sgn (c) < 0)
6156 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
6157 if (sub_strict_overflow_p)
6158 *strict_overflow_p = true;
6159 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6160 fold_convert (ctype, t2));
6164 case LSHIFT_EXPR: case RSHIFT_EXPR:
6165 /* If the second operand is constant, this is a multiplication
6166 or floor division, by a power of two, so we can treat it that
6167 way unless the multiplier or divisor overflows. Signed
6168 left-shift overflow is implementation-defined rather than
6169 undefined in C90, so do not convert signed left shift into
6171 if (TREE_CODE (op1) == INTEGER_CST
6172 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
6173 /* const_binop may not detect overflow correctly,
6174 so check for it explicitly here. */
6175 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
6176 && TREE_INT_CST_HIGH (op1) == 0
6177 && 0 != (t1 = fold_convert (ctype,
6178 const_binop (LSHIFT_EXPR,
6181 && !TREE_OVERFLOW (t1))
6182 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
6183 ? MULT_EXPR : FLOOR_DIV_EXPR,
6184 ctype, fold_convert (ctype, op0), t1),
6185 c, code, wide_type, strict_overflow_p);
6188 case PLUS_EXPR: case MINUS_EXPR:
6189 /* See if we can eliminate the operation on both sides. If we can, we
6190 can return a new PLUS or MINUS. If we can't, the only remaining
6191 cases where we can do anything are if the second operand is a
6193 sub_strict_overflow_p = false;
6194 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
6195 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
6196 if (t1 != 0 && t2 != 0
6197 && (code == MULT_EXPR
6198 /* If not multiplication, we can only do this if both operands
6199 are divisible by c. */
6200 || (multiple_of_p (ctype, op0, c)
6201 && multiple_of_p (ctype, op1, c))))
6203 if (sub_strict_overflow_p)
6204 *strict_overflow_p = true;
6205 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6206 fold_convert (ctype, t2));
6209 /* If this was a subtraction, negate OP1 and set it to be an addition.
6210 This simplifies the logic below. */
6211 if (tcode == MINUS_EXPR)
6212 tcode = PLUS_EXPR, op1 = negate_expr (op1);
6214 if (TREE_CODE (op1) != INTEGER_CST)
6217 /* If either OP1 or C are negative, this optimization is not safe for
6218 some of the division and remainder types while for others we need
6219 to change the code. */
6220 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
6222 if (code == CEIL_DIV_EXPR)
6223 code = FLOOR_DIV_EXPR;
6224 else if (code == FLOOR_DIV_EXPR)
6225 code = CEIL_DIV_EXPR;
6226 else if (code != MULT_EXPR
6227 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
6231 /* If it's a multiply or a division/modulus operation of a multiple
6232 of our constant, do the operation and verify it doesn't overflow. */
6233 if (code == MULT_EXPR
6234 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6236 op1 = const_binop (code, fold_convert (ctype, op1),
6237 fold_convert (ctype, c), 0);
6238 /* We allow the constant to overflow with wrapping semantics. */
6240 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
6246 /* If we have an unsigned type is not a sizetype, we cannot widen
6247 the operation since it will change the result if the original
6248 computation overflowed. */
6249 if (TYPE_UNSIGNED (ctype)
6250 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
6254 /* If we were able to eliminate our operation from the first side,
6255 apply our operation to the second side and reform the PLUS. */
6256 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
6257 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
6259 /* The last case is if we are a multiply. In that case, we can
6260 apply the distributive law to commute the multiply and addition
6261 if the multiplication of the constants doesn't overflow. */
6262 if (code == MULT_EXPR)
6263 return fold_build2 (tcode, ctype,
6264 fold_build2 (code, ctype,
6265 fold_convert (ctype, op0),
6266 fold_convert (ctype, c)),
6272 /* We have a special case here if we are doing something like
6273 (C * 8) % 4 since we know that's zero. */
6274 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
6275 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
6276 /* If the multiplication can overflow we cannot optimize this.
6277 ??? Until we can properly mark individual operations as
6278 not overflowing we need to treat sizetype special here as
6279 stor-layout relies on this opimization to make
6280 DECL_FIELD_BIT_OFFSET always a constant. */
6281 && (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t))
6282 || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
6283 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
6284 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
6285 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6287 *strict_overflow_p = true;
6288 return omit_one_operand (type, integer_zero_node, op0);
6291 /* ... fall through ... */
6293 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
6294 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
6295 /* If we can extract our operation from the LHS, do so and return a
6296 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
6297 do something only if the second operand is a constant. */
6299 && (t1 = extract_muldiv (op0, c, code, wide_type,
6300 strict_overflow_p)) != 0)
6301 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
6302 fold_convert (ctype, op1));
6303 else if (tcode == MULT_EXPR && code == MULT_EXPR
6304 && (t1 = extract_muldiv (op1, c, code, wide_type,
6305 strict_overflow_p)) != 0)
6306 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6307 fold_convert (ctype, t1));
6308 else if (TREE_CODE (op1) != INTEGER_CST)
6311 /* If these are the same operation types, we can associate them
6312 assuming no overflow. */
6314 && 0 != (t1 = int_const_binop (MULT_EXPR, fold_convert (ctype, op1),
6315 fold_convert (ctype, c), 1))
6316 && 0 != (t1 = force_fit_type_double (ctype, TREE_INT_CST_LOW (t1),
6317 TREE_INT_CST_HIGH (t1),
6318 (TYPE_UNSIGNED (ctype)
6319 && tcode != MULT_EXPR) ? -1 : 1,
6320 TREE_OVERFLOW (t1)))
6321 && !TREE_OVERFLOW (t1))
6322 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
6324 /* If these operations "cancel" each other, we have the main
6325 optimizations of this pass, which occur when either constant is a
6326 multiple of the other, in which case we replace this with either an
6327 operation or CODE or TCODE.
6329 If we have an unsigned type that is not a sizetype, we cannot do
6330 this since it will change the result if the original computation
6332 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
6333 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
6334 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
6335 || (tcode == MULT_EXPR
6336 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
6337 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
6338 && code != MULT_EXPR)))
6340 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
6342 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6343 *strict_overflow_p = true;
6344 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
6345 fold_convert (ctype,
6346 const_binop (TRUNC_DIV_EXPR,
6349 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
6351 if (TYPE_OVERFLOW_UNDEFINED (ctype))
6352 *strict_overflow_p = true;
6353 return fold_build2 (code, ctype, fold_convert (ctype, op0),
6354 fold_convert (ctype,
6355 const_binop (TRUNC_DIV_EXPR,
6368 /* Return a node which has the indicated constant VALUE (either 0 or
6369 1), and is of the indicated TYPE. */
6372 constant_boolean_node (int value, tree type)
6374 if (type == integer_type_node)
6375 return value ? integer_one_node : integer_zero_node;
6376 else if (type == boolean_type_node)
6377 return value ? boolean_true_node : boolean_false_node;
6379 return build_int_cst (type, value);
6383 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6384 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6385 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6386 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6387 COND is the first argument to CODE; otherwise (as in the example
6388 given here), it is the second argument. TYPE is the type of the
6389 original expression. Return NULL_TREE if no simplification is
6393 fold_binary_op_with_conditional_arg (enum tree_code code,
6394 tree type, tree op0, tree op1,
6395 tree cond, tree arg, int cond_first_p)
6397 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6398 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6399 tree test, true_value, false_value;
6400 tree lhs = NULL_TREE;
6401 tree rhs = NULL_TREE;
6403 /* This transformation is only worthwhile if we don't have to wrap
6404 arg in a SAVE_EXPR, and the operation can be simplified on at least
6405 one of the branches once its pushed inside the COND_EXPR. */
6406 if (!TREE_CONSTANT (arg))
6409 if (TREE_CODE (cond) == COND_EXPR)
6411 test = TREE_OPERAND (cond, 0);
6412 true_value = TREE_OPERAND (cond, 1);
6413 false_value = TREE_OPERAND (cond, 2);
6414 /* If this operand throws an expression, then it does not make
6415 sense to try to perform a logical or arithmetic operation
6417 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6419 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6424 tree testtype = TREE_TYPE (cond);
6426 true_value = constant_boolean_node (true, testtype);
6427 false_value = constant_boolean_node (false, testtype);
6430 arg = fold_convert (arg_type, arg);
6433 true_value = fold_convert (cond_type, true_value);
6435 lhs = fold_build2 (code, type, true_value, arg);
6437 lhs = fold_build2 (code, type, arg, true_value);
6441 false_value = fold_convert (cond_type, false_value);
6443 rhs = fold_build2 (code, type, false_value, arg);
6445 rhs = fold_build2 (code, type, arg, false_value);
6448 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6449 return fold_convert (type, test);
6453 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6455 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6456 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6457 ADDEND is the same as X.
6459 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6460 and finite. The problematic cases are when X is zero, and its mode
6461 has signed zeros. In the case of rounding towards -infinity,
6462 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6463 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6466 fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
6468 if (!real_zerop (addend))
6471 /* Don't allow the fold with -fsignaling-nans. */
6472 if (HONOR_SNANS (TYPE_MODE (type)))
6475 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6476 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6479 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6480 if (TREE_CODE (addend) == REAL_CST
6481 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6484 /* The mode has signed zeros, and we have to honor their sign.
6485 In this situation, there is only one case we can return true for.
6486 X - 0 is the same as X unless rounding towards -infinity is
6488 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6491 /* Subroutine of fold() that checks comparisons of built-in math
6492 functions against real constants.
6494 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6495 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6496 is the type of the result and ARG0 and ARG1 are the operands of the
6497 comparison. ARG1 must be a TREE_REAL_CST.
6499 The function returns the constant folded tree if a simplification
6500 can be made, and NULL_TREE otherwise. */
6503 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6504 tree type, tree arg0, tree arg1)
6508 if (BUILTIN_SQRT_P (fcode))
6510 tree arg = CALL_EXPR_ARG (arg0, 0);
6511 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6513 c = TREE_REAL_CST (arg1);
6514 if (REAL_VALUE_NEGATIVE (c))
6516 /* sqrt(x) < y is always false, if y is negative. */
6517 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6518 return omit_one_operand (type, integer_zero_node, arg);
6520 /* sqrt(x) > y is always true, if y is negative and we
6521 don't care about NaNs, i.e. negative values of x. */
6522 if (code == NE_EXPR || !HONOR_NANS (mode))
6523 return omit_one_operand (type, integer_one_node, arg);
6525 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6526 return fold_build2 (GE_EXPR, type, arg,
6527 build_real (TREE_TYPE (arg), dconst0));
6529 else if (code == GT_EXPR || code == GE_EXPR)
6533 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6534 real_convert (&c2, mode, &c2);
6536 if (REAL_VALUE_ISINF (c2))
6538 /* sqrt(x) > y is x == +Inf, when y is very large. */
6539 if (HONOR_INFINITIES (mode))
6540 return fold_build2 (EQ_EXPR, type, arg,
6541 build_real (TREE_TYPE (arg), c2));
6543 /* sqrt(x) > y is always false, when y is very large
6544 and we don't care about infinities. */
6545 return omit_one_operand (type, integer_zero_node, arg);
6548 /* sqrt(x) > c is the same as x > c*c. */
6549 return fold_build2 (code, type, arg,
6550 build_real (TREE_TYPE (arg), c2));
6552 else if (code == LT_EXPR || code == LE_EXPR)
6556 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6557 real_convert (&c2, mode, &c2);
6559 if (REAL_VALUE_ISINF (c2))
6561 /* sqrt(x) < y is always true, when y is a very large
6562 value and we don't care about NaNs or Infinities. */
6563 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6564 return omit_one_operand (type, integer_one_node, arg);
6566 /* sqrt(x) < y is x != +Inf when y is very large and we
6567 don't care about NaNs. */
6568 if (! HONOR_NANS (mode))
6569 return fold_build2 (NE_EXPR, type, arg,
6570 build_real (TREE_TYPE (arg), c2));
6572 /* sqrt(x) < y is x >= 0 when y is very large and we
6573 don't care about Infinities. */
6574 if (! HONOR_INFINITIES (mode))
6575 return fold_build2 (GE_EXPR, type, arg,
6576 build_real (TREE_TYPE (arg), dconst0));
6578 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6579 if (lang_hooks.decls.global_bindings_p () != 0
6580 || CONTAINS_PLACEHOLDER_P (arg))
6583 arg = save_expr (arg);
6584 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6585 fold_build2 (GE_EXPR, type, arg,
6586 build_real (TREE_TYPE (arg),
6588 fold_build2 (NE_EXPR, type, arg,
6589 build_real (TREE_TYPE (arg),
6593 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6594 if (! HONOR_NANS (mode))
6595 return fold_build2 (code, type, arg,
6596 build_real (TREE_TYPE (arg), c2));
6598 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6599 if (lang_hooks.decls.global_bindings_p () == 0
6600 && ! CONTAINS_PLACEHOLDER_P (arg))
6602 arg = save_expr (arg);
6603 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6604 fold_build2 (GE_EXPR, type, arg,
6605 build_real (TREE_TYPE (arg),
6607 fold_build2 (code, type, arg,
6608 build_real (TREE_TYPE (arg),
6617 /* Subroutine of fold() that optimizes comparisons against Infinities,
6618 either +Inf or -Inf.
6620 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6621 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6622 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6624 The function returns the constant folded tree if a simplification
6625 can be made, and NULL_TREE otherwise. */
6628 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6630 enum machine_mode mode;
6631 REAL_VALUE_TYPE max;
6635 mode = TYPE_MODE (TREE_TYPE (arg0));
6637 /* For negative infinity swap the sense of the comparison. */
6638 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6640 code = swap_tree_comparison (code);
6645 /* x > +Inf is always false, if with ignore sNANs. */
6646 if (HONOR_SNANS (mode))
6648 return omit_one_operand (type, integer_zero_node, arg0);
6651 /* x <= +Inf is always true, if we don't case about NaNs. */
6652 if (! HONOR_NANS (mode))
6653 return omit_one_operand (type, integer_one_node, arg0);
6655 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6656 if (lang_hooks.decls.global_bindings_p () == 0
6657 && ! CONTAINS_PLACEHOLDER_P (arg0))
6659 arg0 = save_expr (arg0);
6660 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6666 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6667 real_maxval (&max, neg, mode);
6668 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6669 arg0, build_real (TREE_TYPE (arg0), max));
6672 /* x < +Inf is always equal to x <= DBL_MAX. */
6673 real_maxval (&max, neg, mode);
6674 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6675 arg0, build_real (TREE_TYPE (arg0), max));
6678 /* x != +Inf is always equal to !(x > DBL_MAX). */
6679 real_maxval (&max, neg, mode);
6680 if (! HONOR_NANS (mode))
6681 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6682 arg0, build_real (TREE_TYPE (arg0), max));
6684 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6685 arg0, build_real (TREE_TYPE (arg0), max));
6686 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6695 /* Subroutine of fold() that optimizes comparisons of a division by
6696 a nonzero integer constant against an integer constant, i.e.
6699 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6700 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6701 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6703 The function returns the constant folded tree if a simplification
6704 can be made, and NULL_TREE otherwise. */
6707 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6709 tree prod, tmp, hi, lo;
6710 tree arg00 = TREE_OPERAND (arg0, 0);
6711 tree arg01 = TREE_OPERAND (arg0, 1);
6712 unsigned HOST_WIDE_INT lpart;
6713 HOST_WIDE_INT hpart;
6714 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6718 /* We have to do this the hard way to detect unsigned overflow.
6719 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6720 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6721 TREE_INT_CST_HIGH (arg01),
6722 TREE_INT_CST_LOW (arg1),
6723 TREE_INT_CST_HIGH (arg1),
6724 &lpart, &hpart, unsigned_p);
6725 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6727 neg_overflow = false;
6731 tmp = int_const_binop (MINUS_EXPR, arg01,
6732 build_int_cst (TREE_TYPE (arg01), 1), 0);
6735 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6736 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6737 TREE_INT_CST_HIGH (prod),
6738 TREE_INT_CST_LOW (tmp),
6739 TREE_INT_CST_HIGH (tmp),
6740 &lpart, &hpart, unsigned_p);
6741 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6742 -1, overflow | TREE_OVERFLOW (prod));
6744 else if (tree_int_cst_sgn (arg01) >= 0)
6746 tmp = int_const_binop (MINUS_EXPR, arg01,
6747 build_int_cst (TREE_TYPE (arg01), 1), 0);
6748 switch (tree_int_cst_sgn (arg1))
6751 neg_overflow = true;
6752 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6757 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6762 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6772 /* A negative divisor reverses the relational operators. */
6773 code = swap_tree_comparison (code);
6775 tmp = int_const_binop (PLUS_EXPR, arg01,
6776 build_int_cst (TREE_TYPE (arg01), 1), 0);
6777 switch (tree_int_cst_sgn (arg1))
6780 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6785 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6790 neg_overflow = true;
6791 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6803 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6804 return omit_one_operand (type, integer_zero_node, arg00);
6805 if (TREE_OVERFLOW (hi))
6806 return fold_build2 (GE_EXPR, type, arg00, lo);
6807 if (TREE_OVERFLOW (lo))
6808 return fold_build2 (LE_EXPR, type, arg00, hi);
6809 return build_range_check (type, arg00, 1, lo, hi);
6812 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6813 return omit_one_operand (type, integer_one_node, arg00);
6814 if (TREE_OVERFLOW (hi))
6815 return fold_build2 (LT_EXPR, type, arg00, lo);
6816 if (TREE_OVERFLOW (lo))
6817 return fold_build2 (GT_EXPR, type, arg00, hi);
6818 return build_range_check (type, arg00, 0, lo, hi);
6821 if (TREE_OVERFLOW (lo))
6823 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6824 return omit_one_operand (type, tmp, arg00);
6826 return fold_build2 (LT_EXPR, type, arg00, lo);
6829 if (TREE_OVERFLOW (hi))
6831 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6832 return omit_one_operand (type, tmp, arg00);
6834 return fold_build2 (LE_EXPR, type, arg00, hi);
6837 if (TREE_OVERFLOW (hi))
6839 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6840 return omit_one_operand (type, tmp, arg00);
6842 return fold_build2 (GT_EXPR, type, arg00, hi);
6845 if (TREE_OVERFLOW (lo))
6847 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6848 return omit_one_operand (type, tmp, arg00);
6850 return fold_build2 (GE_EXPR, type, arg00, lo);
6860 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6861 equality/inequality test, then return a simplified form of the test
6862 using a sign testing. Otherwise return NULL. TYPE is the desired
6866 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6869 /* If this is testing a single bit, we can optimize the test. */
6870 if ((code == NE_EXPR || code == EQ_EXPR)
6871 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6872 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6874 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6875 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6876 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6878 if (arg00 != NULL_TREE
6879 /* This is only a win if casting to a signed type is cheap,
6880 i.e. when arg00's type is not a partial mode. */
6881 && TYPE_PRECISION (TREE_TYPE (arg00))
6882 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6884 tree stype = signed_type_for (TREE_TYPE (arg00));
6885 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6886 result_type, fold_convert (stype, arg00),
6887 build_int_cst (stype, 0));
6894 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6895 equality/inequality test, then return a simplified form of
6896 the test using shifts and logical operations. Otherwise return
6897 NULL. TYPE is the desired result type. */
6900 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6903 /* If this is testing a single bit, we can optimize the test. */
6904 if ((code == NE_EXPR || code == EQ_EXPR)
6905 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6906 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6908 tree inner = TREE_OPERAND (arg0, 0);
6909 tree type = TREE_TYPE (arg0);
6910 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6911 enum machine_mode operand_mode = TYPE_MODE (type);
6913 tree signed_type, unsigned_type, intermediate_type;
6916 /* First, see if we can fold the single bit test into a sign-bit
6918 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6923 /* Otherwise we have (A & C) != 0 where C is a single bit,
6924 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6925 Similarly for (A & C) == 0. */
6927 /* If INNER is a right shift of a constant and it plus BITNUM does
6928 not overflow, adjust BITNUM and INNER. */
6929 if (TREE_CODE (inner) == RSHIFT_EXPR
6930 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6931 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6932 && bitnum < TYPE_PRECISION (type)
6933 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6934 bitnum - TYPE_PRECISION (type)))
6936 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6937 inner = TREE_OPERAND (inner, 0);
6940 /* If we are going to be able to omit the AND below, we must do our
6941 operations as unsigned. If we must use the AND, we have a choice.
6942 Normally unsigned is faster, but for some machines signed is. */
6943 #ifdef LOAD_EXTEND_OP
6944 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6945 && !flag_syntax_only) ? 0 : 1;
6950 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6951 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6952 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6953 inner = fold_convert (intermediate_type, inner);
6956 inner = build2 (RSHIFT_EXPR, intermediate_type,
6957 inner, size_int (bitnum));
6959 one = build_int_cst (intermediate_type, 1);
6961 if (code == EQ_EXPR)
6962 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6964 /* Put the AND last so it can combine with more things. */
6965 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6967 /* Make sure to return the proper type. */
6968 inner = fold_convert (result_type, inner);
6975 /* Check whether we are allowed to reorder operands arg0 and arg1,
6976 such that the evaluation of arg1 occurs before arg0. */
6979 reorder_operands_p (const_tree arg0, const_tree arg1)
6981 if (! flag_evaluation_order)
6983 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6985 return ! TREE_SIDE_EFFECTS (arg0)
6986 && ! TREE_SIDE_EFFECTS (arg1);
6989 /* Test whether it is preferable two swap two operands, ARG0 and
6990 ARG1, for example because ARG0 is an integer constant and ARG1
6991 isn't. If REORDER is true, only recommend swapping if we can
6992 evaluate the operands in reverse order. */
6995 tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
6997 STRIP_SIGN_NOPS (arg0);
6998 STRIP_SIGN_NOPS (arg1);
7000 if (TREE_CODE (arg1) == INTEGER_CST)
7002 if (TREE_CODE (arg0) == INTEGER_CST)
7005 if (TREE_CODE (arg1) == REAL_CST)
7007 if (TREE_CODE (arg0) == REAL_CST)
7010 if (TREE_CODE (arg1) == FIXED_CST)
7012 if (TREE_CODE (arg0) == FIXED_CST)
7015 if (TREE_CODE (arg1) == COMPLEX_CST)
7017 if (TREE_CODE (arg0) == COMPLEX_CST)
7020 if (TREE_CONSTANT (arg1))
7022 if (TREE_CONSTANT (arg0))
7025 if (optimize_function_for_size_p (cfun))
7028 if (reorder && flag_evaluation_order
7029 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
7032 /* It is preferable to swap two SSA_NAME to ensure a canonical form
7033 for commutative and comparison operators. Ensuring a canonical
7034 form allows the optimizers to find additional redundancies without
7035 having to explicitly check for both orderings. */
7036 if (TREE_CODE (arg0) == SSA_NAME
7037 && TREE_CODE (arg1) == SSA_NAME
7038 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
7041 /* Put SSA_NAMEs last. */
7042 if (TREE_CODE (arg1) == SSA_NAME)
7044 if (TREE_CODE (arg0) == SSA_NAME)
7047 /* Put variables last. */
7056 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
7057 ARG0 is extended to a wider type. */
7060 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
7062 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
7064 tree shorter_type, outer_type;
7068 if (arg0_unw == arg0)
7070 shorter_type = TREE_TYPE (arg0_unw);
7072 #ifdef HAVE_canonicalize_funcptr_for_compare
7073 /* Disable this optimization if we're casting a function pointer
7074 type on targets that require function pointer canonicalization. */
7075 if (HAVE_canonicalize_funcptr_for_compare
7076 && TREE_CODE (shorter_type) == POINTER_TYPE
7077 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
7081 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
7084 arg1_unw = get_unwidened (arg1, NULL_TREE);
7086 /* If possible, express the comparison in the shorter mode. */
7087 if ((code == EQ_EXPR || code == NE_EXPR
7088 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
7089 && (TREE_TYPE (arg1_unw) == shorter_type
7090 || ((TYPE_PRECISION (shorter_type)
7091 >= TYPE_PRECISION (TREE_TYPE (arg1_unw)))
7092 && (TYPE_UNSIGNED (shorter_type)
7093 == TYPE_UNSIGNED (TREE_TYPE (arg1_unw))))
7094 || (TREE_CODE (arg1_unw) == INTEGER_CST
7095 && (TREE_CODE (shorter_type) == INTEGER_TYPE
7096 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
7097 && int_fits_type_p (arg1_unw, shorter_type))))
7098 return fold_build2 (code, type, arg0_unw,
7099 fold_convert (shorter_type, arg1_unw));
7101 if (TREE_CODE (arg1_unw) != INTEGER_CST
7102 || TREE_CODE (shorter_type) != INTEGER_TYPE
7103 || !int_fits_type_p (arg1_unw, shorter_type))
7106 /* If we are comparing with the integer that does not fit into the range
7107 of the shorter type, the result is known. */
7108 outer_type = TREE_TYPE (arg1_unw);
7109 min = lower_bound_in_type (outer_type, shorter_type);
7110 max = upper_bound_in_type (outer_type, shorter_type);
7112 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7114 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
7121 return omit_one_operand (type, integer_zero_node, arg0);
7126 return omit_one_operand (type, integer_one_node, arg0);
7132 return omit_one_operand (type, integer_one_node, arg0);
7134 return omit_one_operand (type, integer_zero_node, arg0);
7139 return omit_one_operand (type, integer_zero_node, arg0);
7141 return omit_one_operand (type, integer_one_node, arg0);
7150 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
7151 ARG0 just the signedness is changed. */
7154 fold_sign_changed_comparison (enum tree_code code, tree type,
7155 tree arg0, tree arg1)
7158 tree inner_type, outer_type;
7160 if (!CONVERT_EXPR_P (arg0))
7163 outer_type = TREE_TYPE (arg0);
7164 arg0_inner = TREE_OPERAND (arg0, 0);
7165 inner_type = TREE_TYPE (arg0_inner);
7167 #ifdef HAVE_canonicalize_funcptr_for_compare
7168 /* Disable this optimization if we're casting a function pointer
7169 type on targets that require function pointer canonicalization. */
7170 if (HAVE_canonicalize_funcptr_for_compare
7171 && TREE_CODE (inner_type) == POINTER_TYPE
7172 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
7176 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
7179 /* If the conversion is from an integral subtype to its basetype
7181 if (TREE_TYPE (inner_type) == outer_type)
7184 if (TREE_CODE (arg1) != INTEGER_CST
7185 && !(CONVERT_EXPR_P (arg1)
7186 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
7189 if ((TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
7190 || POINTER_TYPE_P (inner_type) != POINTER_TYPE_P (outer_type))
7195 if (TREE_CODE (arg1) == INTEGER_CST)
7196 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
7197 TREE_INT_CST_HIGH (arg1), 0,
7198 TREE_OVERFLOW (arg1));
7200 arg1 = fold_convert (inner_type, arg1);
7202 return fold_build2 (code, type, arg0_inner, arg1);
7205 /* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
7206 step of the array. Reconstructs s and delta in the case of s * delta
7207 being an integer constant (and thus already folded).
7208 ADDR is the address. MULT is the multiplicative expression.
7209 If the function succeeds, the new address expression is returned. Otherwise
7210 NULL_TREE is returned. */
7213 try_move_mult_to_index (tree addr, tree op1)
7215 tree s, delta, step;
7216 tree ref = TREE_OPERAND (addr, 0), pref;
7221 /* Strip the nops that might be added when converting op1 to sizetype. */
7224 /* Canonicalize op1 into a possibly non-constant delta
7225 and an INTEGER_CST s. */
7226 if (TREE_CODE (op1) == MULT_EXPR)
7228 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
7233 if (TREE_CODE (arg0) == INTEGER_CST)
7238 else if (TREE_CODE (arg1) == INTEGER_CST)
7246 else if (TREE_CODE (op1) == INTEGER_CST)
7253 /* Simulate we are delta * 1. */
7255 s = integer_one_node;
7258 for (;; ref = TREE_OPERAND (ref, 0))
7260 if (TREE_CODE (ref) == ARRAY_REF)
7262 /* Remember if this was a multi-dimensional array. */
7263 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
7266 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
7270 step = array_ref_element_size (ref);
7271 if (TREE_CODE (step) != INTEGER_CST)
7276 if (! tree_int_cst_equal (step, s))
7281 /* Try if delta is a multiple of step. */
7282 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, op1, step);
7288 /* Only fold here if we can verify we do not overflow one
7289 dimension of a multi-dimensional array. */
7294 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
7295 || !INTEGRAL_TYPE_P (itype)
7296 || !TYPE_MAX_VALUE (itype)
7297 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
7300 tmp = fold_binary (PLUS_EXPR, itype,
7301 fold_convert (itype,
7302 TREE_OPERAND (ref, 1)),
7303 fold_convert (itype, delta));
7305 || TREE_CODE (tmp) != INTEGER_CST
7306 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
7315 if (!handled_component_p (ref))
7319 /* We found the suitable array reference. So copy everything up to it,
7320 and replace the index. */
7322 pref = TREE_OPERAND (addr, 0);
7323 ret = copy_node (pref);
7328 pref = TREE_OPERAND (pref, 0);
7329 TREE_OPERAND (pos, 0) = copy_node (pref);
7330 pos = TREE_OPERAND (pos, 0);
7333 TREE_OPERAND (pos, 1) = fold_build2 (PLUS_EXPR, itype,
7334 fold_convert (itype,
7335 TREE_OPERAND (pos, 1)),
7336 fold_convert (itype, delta));
7338 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
7342 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
7343 means A >= Y && A != MAX, but in this case we know that
7344 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
7347 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
7349 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
7351 if (TREE_CODE (bound) == LT_EXPR)
7352 a = TREE_OPERAND (bound, 0);
7353 else if (TREE_CODE (bound) == GT_EXPR)
7354 a = TREE_OPERAND (bound, 1);
7358 typea = TREE_TYPE (a);
7359 if (!INTEGRAL_TYPE_P (typea)
7360 && !POINTER_TYPE_P (typea))
7363 if (TREE_CODE (ineq) == LT_EXPR)
7365 a1 = TREE_OPERAND (ineq, 1);
7366 y = TREE_OPERAND (ineq, 0);
7368 else if (TREE_CODE (ineq) == GT_EXPR)
7370 a1 = TREE_OPERAND (ineq, 0);
7371 y = TREE_OPERAND (ineq, 1);
7376 if (TREE_TYPE (a1) != typea)
7379 if (POINTER_TYPE_P (typea))
7381 /* Convert the pointer types into integer before taking the difference. */
7382 tree ta = fold_convert (ssizetype, a);
7383 tree ta1 = fold_convert (ssizetype, a1);
7384 diff = fold_binary (MINUS_EXPR, ssizetype, ta1, ta);
7387 diff = fold_binary (MINUS_EXPR, typea, a1, a);
7389 if (!diff || !integer_onep (diff))
7392 return fold_build2 (GE_EXPR, type, a, y);
7395 /* Fold a sum or difference of at least one multiplication.
7396 Returns the folded tree or NULL if no simplification could be made. */
7399 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7401 tree arg00, arg01, arg10, arg11;
7402 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7404 /* (A * C) +- (B * C) -> (A+-B) * C.
7405 (A * C) +- A -> A * (C+-1).
7406 We are most concerned about the case where C is a constant,
7407 but other combinations show up during loop reduction. Since
7408 it is not difficult, try all four possibilities. */
7410 if (TREE_CODE (arg0) == MULT_EXPR)
7412 arg00 = TREE_OPERAND (arg0, 0);
7413 arg01 = TREE_OPERAND (arg0, 1);
7415 else if (TREE_CODE (arg0) == INTEGER_CST)
7417 arg00 = build_one_cst (type);
7422 /* We cannot generate constant 1 for fract. */
7423 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7426 arg01 = build_one_cst (type);
7428 if (TREE_CODE (arg1) == MULT_EXPR)
7430 arg10 = TREE_OPERAND (arg1, 0);
7431 arg11 = TREE_OPERAND (arg1, 1);
7433 else if (TREE_CODE (arg1) == INTEGER_CST)
7435 arg10 = build_one_cst (type);
7436 /* As we canonicalize A - 2 to A + -2 get rid of that sign for
7437 the purpose of this canonicalization. */
7438 if (TREE_INT_CST_HIGH (arg1) == -1
7439 && negate_expr_p (arg1)
7440 && code == PLUS_EXPR)
7442 arg11 = negate_expr (arg1);
7450 /* We cannot generate constant 1 for fract. */
7451 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7454 arg11 = build_one_cst (type);
7458 if (operand_equal_p (arg01, arg11, 0))
7459 same = arg01, alt0 = arg00, alt1 = arg10;
7460 else if (operand_equal_p (arg00, arg10, 0))
7461 same = arg00, alt0 = arg01, alt1 = arg11;
7462 else if (operand_equal_p (arg00, arg11, 0))
7463 same = arg00, alt0 = arg01, alt1 = arg10;
7464 else if (operand_equal_p (arg01, arg10, 0))
7465 same = arg01, alt0 = arg00, alt1 = arg11;
7467 /* No identical multiplicands; see if we can find a common
7468 power-of-two factor in non-power-of-two multiplies. This
7469 can help in multi-dimensional array access. */
7470 else if (host_integerp (arg01, 0)
7471 && host_integerp (arg11, 0))
7473 HOST_WIDE_INT int01, int11, tmp;
7476 int01 = TREE_INT_CST_LOW (arg01);
7477 int11 = TREE_INT_CST_LOW (arg11);
7479 /* Move min of absolute values to int11. */
7480 if ((int01 >= 0 ? int01 : -int01)
7481 < (int11 >= 0 ? int11 : -int11))
7483 tmp = int01, int01 = int11, int11 = tmp;
7484 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7491 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
7493 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7494 build_int_cst (TREE_TYPE (arg00),
7499 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7504 return fold_build2 (MULT_EXPR, type,
7505 fold_build2 (code, type,
7506 fold_convert (type, alt0),
7507 fold_convert (type, alt1)),
7508 fold_convert (type, same));
7513 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7514 specified by EXPR into the buffer PTR of length LEN bytes.
7515 Return the number of bytes placed in the buffer, or zero
7519 native_encode_int (const_tree expr, unsigned char *ptr, int len)
7521 tree type = TREE_TYPE (expr);
7522 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7523 int byte, offset, word, words;
7524 unsigned char value;
7526 if (total_bytes > len)
7528 words = total_bytes / UNITS_PER_WORD;
7530 for (byte = 0; byte < total_bytes; byte++)
7532 int bitpos = byte * BITS_PER_UNIT;
7533 if (bitpos < HOST_BITS_PER_WIDE_INT)
7534 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7536 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7537 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7539 if (total_bytes > UNITS_PER_WORD)
7541 word = byte / UNITS_PER_WORD;
7542 if (WORDS_BIG_ENDIAN)
7543 word = (words - 1) - word;
7544 offset = word * UNITS_PER_WORD;
7545 if (BYTES_BIG_ENDIAN)
7546 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7548 offset += byte % UNITS_PER_WORD;
7551 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7552 ptr[offset] = value;
7558 /* Subroutine of native_encode_expr. Encode the REAL_CST
7559 specified by EXPR into the buffer PTR of length LEN bytes.
7560 Return the number of bytes placed in the buffer, or zero
7564 native_encode_real (const_tree expr, unsigned char *ptr, int len)
7566 tree type = TREE_TYPE (expr);
7567 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7568 int byte, offset, word, words, bitpos;
7569 unsigned char value;
7571 /* There are always 32 bits in each long, no matter the size of
7572 the hosts long. We handle floating point representations with
7576 if (total_bytes > len)
7578 words = (32 / BITS_PER_UNIT) / UNITS_PER_WORD;
7580 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7582 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7583 bitpos += BITS_PER_UNIT)
7585 byte = (bitpos / BITS_PER_UNIT) & 3;
7586 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7588 if (UNITS_PER_WORD < 4)
7590 word = byte / UNITS_PER_WORD;
7591 if (WORDS_BIG_ENDIAN)
7592 word = (words - 1) - word;
7593 offset = word * UNITS_PER_WORD;
7594 if (BYTES_BIG_ENDIAN)
7595 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7597 offset += byte % UNITS_PER_WORD;
7600 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7601 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7606 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7607 specified by EXPR into the buffer PTR of length LEN bytes.
7608 Return the number of bytes placed in the buffer, or zero
7612 native_encode_complex (const_tree expr, unsigned char *ptr, int len)
7617 part = TREE_REALPART (expr);
7618 rsize = native_encode_expr (part, ptr, len);
7621 part = TREE_IMAGPART (expr);
7622 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7625 return rsize + isize;
7629 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7630 specified by EXPR into the buffer PTR of length LEN bytes.
7631 Return the number of bytes placed in the buffer, or zero
7635 native_encode_vector (const_tree expr, unsigned char *ptr, int len)
7637 int i, size, offset, count;
7638 tree itype, elem, elements;
7641 elements = TREE_VECTOR_CST_ELTS (expr);
7642 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7643 itype = TREE_TYPE (TREE_TYPE (expr));
7644 size = GET_MODE_SIZE (TYPE_MODE (itype));
7645 for (i = 0; i < count; i++)
7649 elem = TREE_VALUE (elements);
7650 elements = TREE_CHAIN (elements);
7657 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7662 if (offset + size > len)
7664 memset (ptr+offset, 0, size);
7672 /* Subroutine of native_encode_expr. Encode the STRING_CST
7673 specified by EXPR into the buffer PTR of length LEN bytes.
7674 Return the number of bytes placed in the buffer, or zero
7678 native_encode_string (const_tree expr, unsigned char *ptr, int len)
7680 tree type = TREE_TYPE (expr);
7681 HOST_WIDE_INT total_bytes;
7683 if (TREE_CODE (type) != ARRAY_TYPE
7684 || TREE_CODE (TREE_TYPE (type)) != INTEGER_TYPE
7685 || GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) != BITS_PER_UNIT
7686 || !host_integerp (TYPE_SIZE_UNIT (type), 0))
7688 total_bytes = tree_low_cst (TYPE_SIZE_UNIT (type), 0);
7689 if (total_bytes > len)
7691 if (TREE_STRING_LENGTH (expr) < total_bytes)
7693 memcpy (ptr, TREE_STRING_POINTER (expr), TREE_STRING_LENGTH (expr));
7694 memset (ptr + TREE_STRING_LENGTH (expr), 0,
7695 total_bytes - TREE_STRING_LENGTH (expr));
7698 memcpy (ptr, TREE_STRING_POINTER (expr), total_bytes);
7703 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7704 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7705 buffer PTR of length LEN bytes. Return the number of bytes
7706 placed in the buffer, or zero upon failure. */
7709 native_encode_expr (const_tree expr, unsigned char *ptr, int len)
7711 switch (TREE_CODE (expr))
7714 return native_encode_int (expr, ptr, len);
7717 return native_encode_real (expr, ptr, len);
7720 return native_encode_complex (expr, ptr, len);
7723 return native_encode_vector (expr, ptr, len);
7726 return native_encode_string (expr, ptr, len);
7734 /* Subroutine of native_interpret_expr. Interpret the contents of
7735 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7736 If the buffer cannot be interpreted, return NULL_TREE. */
7739 native_interpret_int (tree type, const unsigned char *ptr, int len)
7741 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7742 int byte, offset, word, words;
7743 unsigned char value;
7744 unsigned int HOST_WIDE_INT lo = 0;
7745 HOST_WIDE_INT hi = 0;
7747 if (total_bytes > len)
7749 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7751 words = total_bytes / UNITS_PER_WORD;
7753 for (byte = 0; byte < total_bytes; byte++)
7755 int bitpos = byte * BITS_PER_UNIT;
7756 if (total_bytes > UNITS_PER_WORD)
7758 word = byte / UNITS_PER_WORD;
7759 if (WORDS_BIG_ENDIAN)
7760 word = (words - 1) - word;
7761 offset = word * UNITS_PER_WORD;
7762 if (BYTES_BIG_ENDIAN)
7763 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7765 offset += byte % UNITS_PER_WORD;
7768 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7769 value = ptr[offset];
7771 if (bitpos < HOST_BITS_PER_WIDE_INT)
7772 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7774 hi |= (unsigned HOST_WIDE_INT) value
7775 << (bitpos - HOST_BITS_PER_WIDE_INT);
7778 return build_int_cst_wide_type (type, lo, hi);
7782 /* Subroutine of native_interpret_expr. Interpret the contents of
7783 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7784 If the buffer cannot be interpreted, return NULL_TREE. */
7787 native_interpret_real (tree type, const unsigned char *ptr, int len)
7789 enum machine_mode mode = TYPE_MODE (type);
7790 int total_bytes = GET_MODE_SIZE (mode);
7791 int byte, offset, word, words, bitpos;
7792 unsigned char value;
7793 /* There are always 32 bits in each long, no matter the size of
7794 the hosts long. We handle floating point representations with
7799 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7800 if (total_bytes > len || total_bytes > 24)
7802 words = (32 / BITS_PER_UNIT) / UNITS_PER_WORD;
7804 memset (tmp, 0, sizeof (tmp));
7805 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7806 bitpos += BITS_PER_UNIT)
7808 byte = (bitpos / BITS_PER_UNIT) & 3;
7809 if (UNITS_PER_WORD < 4)
7811 word = byte / UNITS_PER_WORD;
7812 if (WORDS_BIG_ENDIAN)
7813 word = (words - 1) - word;
7814 offset = word * UNITS_PER_WORD;
7815 if (BYTES_BIG_ENDIAN)
7816 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7818 offset += byte % UNITS_PER_WORD;
7821 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7822 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7824 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7827 real_from_target (&r, tmp, mode);
7828 return build_real (type, r);
7832 /* Subroutine of native_interpret_expr. Interpret the contents of
7833 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7834 If the buffer cannot be interpreted, return NULL_TREE. */
7837 native_interpret_complex (tree type, const unsigned char *ptr, int len)
7839 tree etype, rpart, ipart;
7842 etype = TREE_TYPE (type);
7843 size = GET_MODE_SIZE (TYPE_MODE (etype));
7846 rpart = native_interpret_expr (etype, ptr, size);
7849 ipart = native_interpret_expr (etype, ptr+size, size);
7852 return build_complex (type, rpart, ipart);
7856 /* Subroutine of native_interpret_expr. Interpret the contents of
7857 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7858 If the buffer cannot be interpreted, return NULL_TREE. */
7861 native_interpret_vector (tree type, const unsigned char *ptr, int len)
7863 tree etype, elem, elements;
7866 etype = TREE_TYPE (type);
7867 size = GET_MODE_SIZE (TYPE_MODE (etype));
7868 count = TYPE_VECTOR_SUBPARTS (type);
7869 if (size * count > len)
7872 elements = NULL_TREE;
7873 for (i = count - 1; i >= 0; i--)
7875 elem = native_interpret_expr (etype, ptr+(i*size), size);
7878 elements = tree_cons (NULL_TREE, elem, elements);
7880 return build_vector (type, elements);
7884 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7885 the buffer PTR of length LEN as a constant of type TYPE. For
7886 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7887 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7888 return NULL_TREE. */
7891 native_interpret_expr (tree type, const unsigned char *ptr, int len)
7893 switch (TREE_CODE (type))
7898 return native_interpret_int (type, ptr, len);
7901 return native_interpret_real (type, ptr, len);
7904 return native_interpret_complex (type, ptr, len);
7907 return native_interpret_vector (type, ptr, len);
7915 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7916 TYPE at compile-time. If we're unable to perform the conversion
7917 return NULL_TREE. */
7920 fold_view_convert_expr (tree type, tree expr)
7922 /* We support up to 512-bit values (for V8DFmode). */
7923 unsigned char buffer[64];
7926 /* Check that the host and target are sane. */
7927 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7930 len = native_encode_expr (expr, buffer, sizeof (buffer));
7934 return native_interpret_expr (type, buffer, len);
7937 /* Build an expression for the address of T. Folds away INDIRECT_REF
7938 to avoid confusing the gimplify process. */
7941 build_fold_addr_expr_with_type (tree t, tree ptrtype)
7943 /* The size of the object is not relevant when talking about its address. */
7944 if (TREE_CODE (t) == WITH_SIZE_EXPR)
7945 t = TREE_OPERAND (t, 0);
7947 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
7948 if (TREE_CODE (t) == INDIRECT_REF
7949 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
7951 t = TREE_OPERAND (t, 0);
7953 if (TREE_TYPE (t) != ptrtype)
7954 t = build1 (NOP_EXPR, ptrtype, t);
7957 t = build1 (ADDR_EXPR, ptrtype, t);
7962 /* Build an expression for the address of T. */
7965 build_fold_addr_expr (tree t)
7967 tree ptrtype = build_pointer_type (TREE_TYPE (t));
7969 return build_fold_addr_expr_with_type (t, ptrtype);
7972 /* Fold a unary expression of code CODE and type TYPE with operand
7973 OP0. Return the folded expression if folding is successful.
7974 Otherwise, return NULL_TREE. */
7977 fold_unary (enum tree_code code, tree type, tree op0)
7981 enum tree_code_class kind = TREE_CODE_CLASS (code);
7983 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7984 && TREE_CODE_LENGTH (code) == 1);
7989 if (CONVERT_EXPR_CODE_P (code)
7990 || code == FLOAT_EXPR || code == ABS_EXPR)
7992 /* Don't use STRIP_NOPS, because signedness of argument type
7994 STRIP_SIGN_NOPS (arg0);
7998 /* Strip any conversions that don't change the mode. This
7999 is safe for every expression, except for a comparison
8000 expression because its signedness is derived from its
8003 Note that this is done as an internal manipulation within
8004 the constant folder, in order to find the simplest
8005 representation of the arguments so that their form can be
8006 studied. In any cases, the appropriate type conversions
8007 should be put back in the tree that will get out of the
8013 if (TREE_CODE_CLASS (code) == tcc_unary)
8015 if (TREE_CODE (arg0) == COMPOUND_EXPR)
8016 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
8017 fold_build1 (code, type,
8018 fold_convert (TREE_TYPE (op0),
8019 TREE_OPERAND (arg0, 1))));
8020 else if (TREE_CODE (arg0) == COND_EXPR)
8022 tree arg01 = TREE_OPERAND (arg0, 1);
8023 tree arg02 = TREE_OPERAND (arg0, 2);
8024 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
8025 arg01 = fold_build1 (code, type,
8026 fold_convert (TREE_TYPE (op0), arg01));
8027 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
8028 arg02 = fold_build1 (code, type,
8029 fold_convert (TREE_TYPE (op0), arg02));
8030 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
8033 /* If this was a conversion, and all we did was to move into
8034 inside the COND_EXPR, bring it back out. But leave it if
8035 it is a conversion from integer to integer and the
8036 result precision is no wider than a word since such a
8037 conversion is cheap and may be optimized away by combine,
8038 while it couldn't if it were outside the COND_EXPR. Then return
8039 so we don't get into an infinite recursion loop taking the
8040 conversion out and then back in. */
8042 if ((CONVERT_EXPR_CODE_P (code)
8043 || code == NON_LVALUE_EXPR)
8044 && TREE_CODE (tem) == COND_EXPR
8045 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
8046 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
8047 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
8048 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
8049 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
8050 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
8051 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
8053 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
8054 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
8055 || flag_syntax_only))
8056 tem = build1 (code, type,
8058 TREE_TYPE (TREE_OPERAND
8059 (TREE_OPERAND (tem, 1), 0)),
8060 TREE_OPERAND (tem, 0),
8061 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
8062 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
8065 else if (COMPARISON_CLASS_P (arg0))
8067 if (TREE_CODE (type) == BOOLEAN_TYPE)
8069 arg0 = copy_node (arg0);
8070 TREE_TYPE (arg0) = type;
8073 else if (TREE_CODE (type) != INTEGER_TYPE)
8074 return fold_build3 (COND_EXPR, type, arg0,
8075 fold_build1 (code, type,
8077 fold_build1 (code, type,
8078 integer_zero_node));
8085 /* Re-association barriers around constants and other re-association
8086 barriers can be removed. */
8087 if (CONSTANT_CLASS_P (op0)
8088 || TREE_CODE (op0) == PAREN_EXPR)
8089 return fold_convert (type, op0);
8094 case FIX_TRUNC_EXPR:
8095 if (TREE_TYPE (op0) == type)
8098 /* If we have (type) (a CMP b) and type is an integral type, return
8099 new expression involving the new type. */
8100 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
8101 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
8102 TREE_OPERAND (op0, 1));
8104 /* Handle cases of two conversions in a row. */
8105 if (CONVERT_EXPR_P (op0))
8107 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
8108 tree inter_type = TREE_TYPE (op0);
8109 int inside_int = INTEGRAL_TYPE_P (inside_type);
8110 int inside_ptr = POINTER_TYPE_P (inside_type);
8111 int inside_float = FLOAT_TYPE_P (inside_type);
8112 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
8113 unsigned int inside_prec = TYPE_PRECISION (inside_type);
8114 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
8115 int inter_int = INTEGRAL_TYPE_P (inter_type);
8116 int inter_ptr = POINTER_TYPE_P (inter_type);
8117 int inter_float = FLOAT_TYPE_P (inter_type);
8118 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
8119 unsigned int inter_prec = TYPE_PRECISION (inter_type);
8120 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
8121 int final_int = INTEGRAL_TYPE_P (type);
8122 int final_ptr = POINTER_TYPE_P (type);
8123 int final_float = FLOAT_TYPE_P (type);
8124 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
8125 unsigned int final_prec = TYPE_PRECISION (type);
8126 int final_unsignedp = TYPE_UNSIGNED (type);
8128 /* In addition to the cases of two conversions in a row
8129 handled below, if we are converting something to its own
8130 type via an object of identical or wider precision, neither
8131 conversion is needed. */
8132 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
8133 && (((inter_int || inter_ptr) && final_int)
8134 || (inter_float && final_float))
8135 && inter_prec >= final_prec)
8136 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8138 /* Likewise, if the intermediate and initial types are either both
8139 float or both integer, we don't need the middle conversion if the
8140 former is wider than the latter and doesn't change the signedness
8141 (for integers). Avoid this if the final type is a pointer since
8142 then we sometimes need the middle conversion. Likewise if the
8143 final type has a precision not equal to the size of its mode. */
8144 if (((inter_int && inside_int)
8145 || (inter_float && inside_float)
8146 || (inter_vec && inside_vec))
8147 && inter_prec >= inside_prec
8148 && (inter_float || inter_vec
8149 || inter_unsignedp == inside_unsignedp)
8150 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
8151 && TYPE_MODE (type) == TYPE_MODE (inter_type))
8153 && (! final_vec || inter_prec == inside_prec))
8154 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8156 /* If we have a sign-extension of a zero-extended value, we can
8157 replace that by a single zero-extension. */
8158 if (inside_int && inter_int && final_int
8159 && inside_prec < inter_prec && inter_prec < final_prec
8160 && inside_unsignedp && !inter_unsignedp)
8161 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8163 /* Two conversions in a row are not needed unless:
8164 - some conversion is floating-point (overstrict for now), or
8165 - some conversion is a vector (overstrict for now), or
8166 - the intermediate type is narrower than both initial and
8168 - the intermediate type and innermost type differ in signedness,
8169 and the outermost type is wider than the intermediate, or
8170 - the initial type is a pointer type and the precisions of the
8171 intermediate and final types differ, or
8172 - the final type is a pointer type and the precisions of the
8173 initial and intermediate types differ. */
8174 if (! inside_float && ! inter_float && ! final_float
8175 && ! inside_vec && ! inter_vec && ! final_vec
8176 && (inter_prec >= inside_prec || inter_prec >= final_prec)
8177 && ! (inside_int && inter_int
8178 && inter_unsignedp != inside_unsignedp
8179 && inter_prec < final_prec)
8180 && ((inter_unsignedp && inter_prec > inside_prec)
8181 == (final_unsignedp && final_prec > inter_prec))
8182 && ! (inside_ptr && inter_prec != final_prec)
8183 && ! (final_ptr && inside_prec != inter_prec)
8184 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
8185 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
8186 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
8189 /* Handle (T *)&A.B.C for A being of type T and B and C
8190 living at offset zero. This occurs frequently in
8191 C++ upcasting and then accessing the base. */
8192 if (TREE_CODE (op0) == ADDR_EXPR
8193 && POINTER_TYPE_P (type)
8194 && handled_component_p (TREE_OPERAND (op0, 0)))
8196 HOST_WIDE_INT bitsize, bitpos;
8198 enum machine_mode mode;
8199 int unsignedp, volatilep;
8200 tree base = TREE_OPERAND (op0, 0);
8201 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
8202 &mode, &unsignedp, &volatilep, false);
8203 /* If the reference was to a (constant) zero offset, we can use
8204 the address of the base if it has the same base type
8205 as the result type. */
8206 if (! offset && bitpos == 0
8207 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
8208 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
8209 return fold_convert (type, build_fold_addr_expr (base));
8212 if (TREE_CODE (op0) == MODIFY_EXPR
8213 && TREE_CONSTANT (TREE_OPERAND (op0, 1))
8214 /* Detect assigning a bitfield. */
8215 && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
8217 (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
8219 /* Don't leave an assignment inside a conversion
8220 unless assigning a bitfield. */
8221 tem = fold_build1 (code, type, TREE_OPERAND (op0, 1));
8222 /* First do the assignment, then return converted constant. */
8223 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
8224 TREE_NO_WARNING (tem) = 1;
8225 TREE_USED (tem) = 1;
8229 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
8230 constants (if x has signed type, the sign bit cannot be set
8231 in c). This folds extension into the BIT_AND_EXPR.
8232 ??? We don't do it for BOOLEAN_TYPE or ENUMERAL_TYPE because they
8233 very likely don't have maximal range for their precision and this
8234 transformation effectively doesn't preserve non-maximal ranges. */
8235 if (TREE_CODE (type) == INTEGER_TYPE
8236 && TREE_CODE (op0) == BIT_AND_EXPR
8237 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST
8238 /* Not if the conversion is to the sub-type. */
8239 && TREE_TYPE (type) != TREE_TYPE (op0))
8242 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
8245 if (TYPE_UNSIGNED (TREE_TYPE (and))
8246 || (TYPE_PRECISION (type)
8247 <= TYPE_PRECISION (TREE_TYPE (and))))
8249 else if (TYPE_PRECISION (TREE_TYPE (and1))
8250 <= HOST_BITS_PER_WIDE_INT
8251 && host_integerp (and1, 1))
8253 unsigned HOST_WIDE_INT cst;
8255 cst = tree_low_cst (and1, 1);
8256 cst &= (HOST_WIDE_INT) -1
8257 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
8258 change = (cst == 0);
8259 #ifdef LOAD_EXTEND_OP
8261 && !flag_syntax_only
8262 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
8265 tree uns = unsigned_type_for (TREE_TYPE (and0));
8266 and0 = fold_convert (uns, and0);
8267 and1 = fold_convert (uns, and1);
8273 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
8274 TREE_INT_CST_HIGH (and1), 0,
8275 TREE_OVERFLOW (and1));
8276 return fold_build2 (BIT_AND_EXPR, type,
8277 fold_convert (type, and0), tem);
8281 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
8282 when one of the new casts will fold away. Conservatively we assume
8283 that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
8284 if (POINTER_TYPE_P (type)
8285 && TREE_CODE (arg0) == POINTER_PLUS_EXPR
8286 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8287 || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
8288 || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
8290 tree arg00 = TREE_OPERAND (arg0, 0);
8291 tree arg01 = TREE_OPERAND (arg0, 1);
8293 return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
8294 fold_convert (sizetype, arg01));
8297 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
8298 of the same precision, and X is an integer type not narrower than
8299 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
8300 if (INTEGRAL_TYPE_P (type)
8301 && TREE_CODE (op0) == BIT_NOT_EXPR
8302 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
8303 && CONVERT_EXPR_P (TREE_OPERAND (op0, 0))
8304 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
8306 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
8307 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
8308 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
8309 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
8312 /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the
8313 type of X and Y (integer types only). */
8314 if (INTEGRAL_TYPE_P (type)
8315 && TREE_CODE (op0) == MULT_EXPR
8316 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
8317 && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (op0)))
8319 /* Be careful not to introduce new overflows. */
8321 if (TYPE_OVERFLOW_WRAPS (type))
8324 mult_type = unsigned_type_for (type);
8326 if (TYPE_PRECISION (mult_type) < TYPE_PRECISION (TREE_TYPE (op0)))
8328 tem = fold_build2 (MULT_EXPR, mult_type,
8329 fold_convert (mult_type,
8330 TREE_OPERAND (op0, 0)),
8331 fold_convert (mult_type,
8332 TREE_OPERAND (op0, 1)));
8333 return fold_convert (type, tem);
8337 tem = fold_convert_const (code, type, op0);
8338 return tem ? tem : NULL_TREE;
8340 case FIXED_CONVERT_EXPR:
8341 tem = fold_convert_const (code, type, arg0);
8342 return tem ? tem : NULL_TREE;
8344 case VIEW_CONVERT_EXPR:
8345 if (TREE_TYPE (op0) == type)
8347 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
8348 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
8350 /* For integral conversions with the same precision or pointer
8351 conversions use a NOP_EXPR instead. */
8352 if ((INTEGRAL_TYPE_P (type)
8353 || POINTER_TYPE_P (type))
8354 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
8355 || POINTER_TYPE_P (TREE_TYPE (op0)))
8356 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0))
8357 /* Do not muck with VIEW_CONVERT_EXPRs that convert from
8358 a sub-type to its base type as generated by the Ada FE. */
8359 && !(INTEGRAL_TYPE_P (TREE_TYPE (op0))
8360 && TREE_TYPE (TREE_TYPE (op0))))
8361 return fold_convert (type, op0);
8363 /* Strip inner integral conversions that do not change the precision. */
8364 if (CONVERT_EXPR_P (op0)
8365 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
8366 || POINTER_TYPE_P (TREE_TYPE (op0)))
8367 && (INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
8368 || POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0))))
8369 && (TYPE_PRECISION (TREE_TYPE (op0))
8370 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
8371 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
8373 return fold_view_convert_expr (type, op0);
8376 tem = fold_negate_expr (arg0);
8378 return fold_convert (type, tem);
8382 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
8383 return fold_abs_const (arg0, type);
8384 else if (TREE_CODE (arg0) == NEGATE_EXPR)
8385 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
8386 /* Convert fabs((double)float) into (double)fabsf(float). */
8387 else if (TREE_CODE (arg0) == NOP_EXPR
8388 && TREE_CODE (type) == REAL_TYPE)
8390 tree targ0 = strip_float_extensions (arg0);
8392 return fold_convert (type, fold_build1 (ABS_EXPR,
8396 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
8397 else if (TREE_CODE (arg0) == ABS_EXPR)
8399 else if (tree_expr_nonnegative_p (arg0))
8402 /* Strip sign ops from argument. */
8403 if (TREE_CODE (type) == REAL_TYPE)
8405 tem = fold_strip_sign_ops (arg0);
8407 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
8412 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8413 return fold_convert (type, arg0);
8414 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8416 tree itype = TREE_TYPE (type);
8417 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
8418 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
8419 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
8421 if (TREE_CODE (arg0) == COMPLEX_CST)
8423 tree itype = TREE_TYPE (type);
8424 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
8425 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
8426 return build_complex (type, rpart, negate_expr (ipart));
8428 if (TREE_CODE (arg0) == CONJ_EXPR)
8429 return fold_convert (type, TREE_OPERAND (arg0, 0));
8433 if (TREE_CODE (arg0) == INTEGER_CST)
8434 return fold_not_const (arg0, type);
8435 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
8436 return fold_convert (type, TREE_OPERAND (arg0, 0));
8437 /* Convert ~ (-A) to A - 1. */
8438 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
8439 return fold_build2 (MINUS_EXPR, type,
8440 fold_convert (type, TREE_OPERAND (arg0, 0)),
8441 build_int_cst (type, 1));
8442 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
8443 else if (INTEGRAL_TYPE_P (type)
8444 && ((TREE_CODE (arg0) == MINUS_EXPR
8445 && integer_onep (TREE_OPERAND (arg0, 1)))
8446 || (TREE_CODE (arg0) == PLUS_EXPR
8447 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
8448 return fold_build1 (NEGATE_EXPR, type,
8449 fold_convert (type, TREE_OPERAND (arg0, 0)));
8450 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8451 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8452 && (tem = fold_unary (BIT_NOT_EXPR, type,
8454 TREE_OPERAND (arg0, 0)))))
8455 return fold_build2 (BIT_XOR_EXPR, type, tem,
8456 fold_convert (type, TREE_OPERAND (arg0, 1)));
8457 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8458 && (tem = fold_unary (BIT_NOT_EXPR, type,
8460 TREE_OPERAND (arg0, 1)))))
8461 return fold_build2 (BIT_XOR_EXPR, type,
8462 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
8463 /* Perform BIT_NOT_EXPR on each element individually. */
8464 else if (TREE_CODE (arg0) == VECTOR_CST)
8466 tree elements = TREE_VECTOR_CST_ELTS (arg0), elem, list = NULL_TREE;
8467 int count = TYPE_VECTOR_SUBPARTS (type), i;
8469 for (i = 0; i < count; i++)
8473 elem = TREE_VALUE (elements);
8474 elem = fold_unary (BIT_NOT_EXPR, TREE_TYPE (type), elem);
8475 if (elem == NULL_TREE)
8477 elements = TREE_CHAIN (elements);
8480 elem = build_int_cst (TREE_TYPE (type), -1);
8481 list = tree_cons (NULL_TREE, elem, list);
8484 return build_vector (type, nreverse (list));
8489 case TRUTH_NOT_EXPR:
8490 /* The argument to invert_truthvalue must have Boolean type. */
8491 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8492 arg0 = fold_convert (boolean_type_node, arg0);
8494 /* Note that the operand of this must be an int
8495 and its values must be 0 or 1.
8496 ("true" is a fixed value perhaps depending on the language,
8497 but we don't handle values other than 1 correctly yet.) */
8498 tem = fold_truth_not_expr (arg0);
8501 return fold_convert (type, tem);
8504 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8505 return fold_convert (type, arg0);
8506 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8507 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8508 TREE_OPERAND (arg0, 1));
8509 if (TREE_CODE (arg0) == COMPLEX_CST)
8510 return fold_convert (type, TREE_REALPART (arg0));
8511 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8513 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8514 tem = fold_build2 (TREE_CODE (arg0), itype,
8515 fold_build1 (REALPART_EXPR, itype,
8516 TREE_OPERAND (arg0, 0)),
8517 fold_build1 (REALPART_EXPR, itype,
8518 TREE_OPERAND (arg0, 1)));
8519 return fold_convert (type, tem);
8521 if (TREE_CODE (arg0) == CONJ_EXPR)
8523 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8524 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8525 return fold_convert (type, tem);
8527 if (TREE_CODE (arg0) == CALL_EXPR)
8529 tree fn = get_callee_fndecl (arg0);
8530 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8531 switch (DECL_FUNCTION_CODE (fn))
8533 CASE_FLT_FN (BUILT_IN_CEXPI):
8534 fn = mathfn_built_in (type, BUILT_IN_COS);
8536 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8546 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8547 return fold_convert (type, integer_zero_node);
8548 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8549 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8550 TREE_OPERAND (arg0, 0));
8551 if (TREE_CODE (arg0) == COMPLEX_CST)
8552 return fold_convert (type, TREE_IMAGPART (arg0));
8553 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8555 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8556 tem = fold_build2 (TREE_CODE (arg0), itype,
8557 fold_build1 (IMAGPART_EXPR, itype,
8558 TREE_OPERAND (arg0, 0)),
8559 fold_build1 (IMAGPART_EXPR, itype,
8560 TREE_OPERAND (arg0, 1)));
8561 return fold_convert (type, tem);
8563 if (TREE_CODE (arg0) == CONJ_EXPR)
8565 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8566 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8567 return fold_convert (type, negate_expr (tem));
8569 if (TREE_CODE (arg0) == CALL_EXPR)
8571 tree fn = get_callee_fndecl (arg0);
8572 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8573 switch (DECL_FUNCTION_CODE (fn))
8575 CASE_FLT_FN (BUILT_IN_CEXPI):
8576 fn = mathfn_built_in (type, BUILT_IN_SIN);
8578 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8589 } /* switch (code) */
8593 /* If the operation was a conversion do _not_ mark a resulting constant
8594 with TREE_OVERFLOW if the original constant was not. These conversions
8595 have implementation defined behavior and retaining the TREE_OVERFLOW
8596 flag here would confuse later passes such as VRP. */
8598 fold_unary_ignore_overflow (enum tree_code code, tree type, tree op0)
8600 tree res = fold_unary (code, type, op0);
8602 && TREE_CODE (res) == INTEGER_CST
8603 && TREE_CODE (op0) == INTEGER_CST
8604 && CONVERT_EXPR_CODE_P (code))
8605 TREE_OVERFLOW (res) = TREE_OVERFLOW (op0);
8610 /* Fold a binary expression of code CODE and type TYPE with operands
8611 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8612 Return the folded expression if folding is successful. Otherwise,
8613 return NULL_TREE. */
8616 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8618 enum tree_code compl_code;
8620 if (code == MIN_EXPR)
8621 compl_code = MAX_EXPR;
8622 else if (code == MAX_EXPR)
8623 compl_code = MIN_EXPR;
8627 /* MIN (MAX (a, b), b) == b. */
8628 if (TREE_CODE (op0) == compl_code
8629 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8630 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8632 /* MIN (MAX (b, a), b) == b. */
8633 if (TREE_CODE (op0) == compl_code
8634 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8635 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8636 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8638 /* MIN (a, MAX (a, b)) == a. */
8639 if (TREE_CODE (op1) == compl_code
8640 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8641 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8642 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8644 /* MIN (a, MAX (b, a)) == a. */
8645 if (TREE_CODE (op1) == compl_code
8646 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8647 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8648 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8653 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8654 by changing CODE to reduce the magnitude of constants involved in
8655 ARG0 of the comparison.
8656 Returns a canonicalized comparison tree if a simplification was
8657 possible, otherwise returns NULL_TREE.
8658 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8659 valid if signed overflow is undefined. */
8662 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8663 tree arg0, tree arg1,
8664 bool *strict_overflow_p)
8666 enum tree_code code0 = TREE_CODE (arg0);
8667 tree t, cst0 = NULL_TREE;
8671 /* Match A +- CST code arg1 and CST code arg1. We can change the
8672 first form only if overflow is undefined. */
8673 if (!((TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8674 /* In principle pointers also have undefined overflow behavior,
8675 but that causes problems elsewhere. */
8676 && !POINTER_TYPE_P (TREE_TYPE (arg0))
8677 && (code0 == MINUS_EXPR
8678 || code0 == PLUS_EXPR)
8679 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8680 || code0 == INTEGER_CST))
8683 /* Identify the constant in arg0 and its sign. */
8684 if (code0 == INTEGER_CST)
8687 cst0 = TREE_OPERAND (arg0, 1);
8688 sgn0 = tree_int_cst_sgn (cst0);
8690 /* Overflowed constants and zero will cause problems. */
8691 if (integer_zerop (cst0)
8692 || TREE_OVERFLOW (cst0))
8695 /* See if we can reduce the magnitude of the constant in
8696 arg0 by changing the comparison code. */
8697 if (code0 == INTEGER_CST)
8699 /* CST <= arg1 -> CST-1 < arg1. */
8700 if (code == LE_EXPR && sgn0 == 1)
8702 /* -CST < arg1 -> -CST-1 <= arg1. */
8703 else if (code == LT_EXPR && sgn0 == -1)
8705 /* CST > arg1 -> CST-1 >= arg1. */
8706 else if (code == GT_EXPR && sgn0 == 1)
8708 /* -CST >= arg1 -> -CST-1 > arg1. */
8709 else if (code == GE_EXPR && sgn0 == -1)
8713 /* arg1 code' CST' might be more canonical. */
8718 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8720 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8722 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8723 else if (code == GT_EXPR
8724 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8726 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8727 else if (code == LE_EXPR
8728 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8730 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8731 else if (code == GE_EXPR
8732 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8736 *strict_overflow_p = true;
8739 /* Now build the constant reduced in magnitude. But not if that
8740 would produce one outside of its types range. */
8741 if (INTEGRAL_TYPE_P (TREE_TYPE (cst0))
8743 && TYPE_MIN_VALUE (TREE_TYPE (cst0))
8744 && tree_int_cst_equal (cst0, TYPE_MIN_VALUE (TREE_TYPE (cst0))))
8746 && TYPE_MAX_VALUE (TREE_TYPE (cst0))
8747 && tree_int_cst_equal (cst0, TYPE_MAX_VALUE (TREE_TYPE (cst0))))))
8748 /* We cannot swap the comparison here as that would cause us to
8749 endlessly recurse. */
8752 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8753 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8754 if (code0 != INTEGER_CST)
8755 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8757 /* If swapping might yield to a more canonical form, do so. */
8759 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8761 return fold_build2 (code, type, t, arg1);
8764 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8765 overflow further. Try to decrease the magnitude of constants involved
8766 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8767 and put sole constants at the second argument position.
8768 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8771 maybe_canonicalize_comparison (enum tree_code code, tree type,
8772 tree arg0, tree arg1)
8775 bool strict_overflow_p;
8776 const char * const warnmsg = G_("assuming signed overflow does not occur "
8777 "when reducing constant in comparison");
8779 /* Try canonicalization by simplifying arg0. */
8780 strict_overflow_p = false;
8781 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8782 &strict_overflow_p);
8785 if (strict_overflow_p)
8786 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8790 /* Try canonicalization by simplifying arg1 using the swapped
8792 code = swap_tree_comparison (code);
8793 strict_overflow_p = false;
8794 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8795 &strict_overflow_p);
8796 if (t && strict_overflow_p)
8797 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8801 /* Return whether BASE + OFFSET + BITPOS may wrap around the address
8802 space. This is used to avoid issuing overflow warnings for
8803 expressions like &p->x which can not wrap. */
8806 pointer_may_wrap_p (tree base, tree offset, HOST_WIDE_INT bitpos)
8808 unsigned HOST_WIDE_INT offset_low, total_low;
8809 HOST_WIDE_INT size, offset_high, total_high;
8811 if (!POINTER_TYPE_P (TREE_TYPE (base)))
8817 if (offset == NULL_TREE)
8822 else if (TREE_CODE (offset) != INTEGER_CST || TREE_OVERFLOW (offset))
8826 offset_low = TREE_INT_CST_LOW (offset);
8827 offset_high = TREE_INT_CST_HIGH (offset);
8830 if (add_double_with_sign (offset_low, offset_high,
8831 bitpos / BITS_PER_UNIT, 0,
8832 &total_low, &total_high,
8836 if (total_high != 0)
8839 size = int_size_in_bytes (TREE_TYPE (TREE_TYPE (base)));
8843 /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
8845 if (TREE_CODE (base) == ADDR_EXPR)
8847 HOST_WIDE_INT base_size;
8849 base_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (base, 0)));
8850 if (base_size > 0 && size < base_size)
8854 return total_low > (unsigned HOST_WIDE_INT) size;
8857 /* Subroutine of fold_binary. This routine performs all of the
8858 transformations that are common to the equality/inequality
8859 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8860 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8861 fold_binary should call fold_binary. Fold a comparison with
8862 tree code CODE and type TYPE with operands OP0 and OP1. Return
8863 the folded comparison or NULL_TREE. */
8866 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8868 tree arg0, arg1, tem;
8873 STRIP_SIGN_NOPS (arg0);
8874 STRIP_SIGN_NOPS (arg1);
8876 tem = fold_relational_const (code, type, arg0, arg1);
8877 if (tem != NULL_TREE)
8880 /* If one arg is a real or integer constant, put it last. */
8881 if (tree_swap_operands_p (arg0, arg1, true))
8882 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8884 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8885 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8886 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8887 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8888 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8889 && (TREE_CODE (arg1) == INTEGER_CST
8890 && !TREE_OVERFLOW (arg1)))
8892 tree const1 = TREE_OPERAND (arg0, 1);
8894 tree variable = TREE_OPERAND (arg0, 0);
8897 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8899 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8900 TREE_TYPE (arg1), const2, const1);
8902 /* If the constant operation overflowed this can be
8903 simplified as a comparison against INT_MAX/INT_MIN. */
8904 if (TREE_CODE (lhs) == INTEGER_CST
8905 && TREE_OVERFLOW (lhs))
8907 int const1_sgn = tree_int_cst_sgn (const1);
8908 enum tree_code code2 = code;
8910 /* Get the sign of the constant on the lhs if the
8911 operation were VARIABLE + CONST1. */
8912 if (TREE_CODE (arg0) == MINUS_EXPR)
8913 const1_sgn = -const1_sgn;
8915 /* The sign of the constant determines if we overflowed
8916 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8917 Canonicalize to the INT_MIN overflow by swapping the comparison
8919 if (const1_sgn == -1)
8920 code2 = swap_tree_comparison (code);
8922 /* We now can look at the canonicalized case
8923 VARIABLE + 1 CODE2 INT_MIN
8924 and decide on the result. */
8925 if (code2 == LT_EXPR
8927 || code2 == EQ_EXPR)
8928 return omit_one_operand (type, boolean_false_node, variable);
8929 else if (code2 == NE_EXPR
8931 || code2 == GT_EXPR)
8932 return omit_one_operand (type, boolean_true_node, variable);
8935 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8936 && (TREE_CODE (lhs) != INTEGER_CST
8937 || !TREE_OVERFLOW (lhs)))
8939 fold_overflow_warning (("assuming signed overflow does not occur "
8940 "when changing X +- C1 cmp C2 to "
8942 WARN_STRICT_OVERFLOW_COMPARISON);
8943 return fold_build2 (code, type, variable, lhs);
8947 /* For comparisons of pointers we can decompose it to a compile time
8948 comparison of the base objects and the offsets into the object.
8949 This requires at least one operand being an ADDR_EXPR or a
8950 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8951 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8952 && (TREE_CODE (arg0) == ADDR_EXPR
8953 || TREE_CODE (arg1) == ADDR_EXPR
8954 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
8955 || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
8957 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8958 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8959 enum machine_mode mode;
8960 int volatilep, unsignedp;
8961 bool indirect_base0 = false, indirect_base1 = false;
8963 /* Get base and offset for the access. Strip ADDR_EXPR for
8964 get_inner_reference, but put it back by stripping INDIRECT_REF
8965 off the base object if possible. indirect_baseN will be true
8966 if baseN is not an address but refers to the object itself. */
8968 if (TREE_CODE (arg0) == ADDR_EXPR)
8970 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8971 &bitsize, &bitpos0, &offset0, &mode,
8972 &unsignedp, &volatilep, false);
8973 if (TREE_CODE (base0) == INDIRECT_REF)
8974 base0 = TREE_OPERAND (base0, 0);
8976 indirect_base0 = true;
8978 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
8980 base0 = TREE_OPERAND (arg0, 0);
8981 offset0 = TREE_OPERAND (arg0, 1);
8985 if (TREE_CODE (arg1) == ADDR_EXPR)
8987 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8988 &bitsize, &bitpos1, &offset1, &mode,
8989 &unsignedp, &volatilep, false);
8990 if (TREE_CODE (base1) == INDIRECT_REF)
8991 base1 = TREE_OPERAND (base1, 0);
8993 indirect_base1 = true;
8995 else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
8997 base1 = TREE_OPERAND (arg1, 0);
8998 offset1 = TREE_OPERAND (arg1, 1);
9001 /* If we have equivalent bases we might be able to simplify. */
9002 if (indirect_base0 == indirect_base1
9003 && operand_equal_p (base0, base1, 0))
9005 /* We can fold this expression to a constant if the non-constant
9006 offset parts are equal. */
9007 if ((offset0 == offset1
9008 || (offset0 && offset1
9009 && operand_equal_p (offset0, offset1, 0)))
9012 || POINTER_TYPE_OVERFLOW_UNDEFINED))
9017 && bitpos0 != bitpos1
9018 && (pointer_may_wrap_p (base0, offset0, bitpos0)
9019 || pointer_may_wrap_p (base1, offset1, bitpos1)))
9020 fold_overflow_warning (("assuming pointer wraparound does not "
9021 "occur when comparing P +- C1 with "
9023 WARN_STRICT_OVERFLOW_CONDITIONAL);
9028 return constant_boolean_node (bitpos0 == bitpos1, type);
9030 return constant_boolean_node (bitpos0 != bitpos1, type);
9032 return constant_boolean_node (bitpos0 < bitpos1, type);
9034 return constant_boolean_node (bitpos0 <= bitpos1, type);
9036 return constant_boolean_node (bitpos0 >= bitpos1, type);
9038 return constant_boolean_node (bitpos0 > bitpos1, type);
9042 /* We can simplify the comparison to a comparison of the variable
9043 offset parts if the constant offset parts are equal.
9044 Be careful to use signed size type here because otherwise we
9045 mess with array offsets in the wrong way. This is possible
9046 because pointer arithmetic is restricted to retain within an
9047 object and overflow on pointer differences is undefined as of
9048 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
9049 else if (bitpos0 == bitpos1
9050 && ((code == EQ_EXPR || code == NE_EXPR)
9051 || POINTER_TYPE_OVERFLOW_UNDEFINED))
9053 tree signed_size_type_node;
9054 signed_size_type_node = signed_type_for (size_type_node);
9056 /* By converting to signed size type we cover middle-end pointer
9057 arithmetic which operates on unsigned pointer types of size
9058 type size and ARRAY_REF offsets which are properly sign or
9059 zero extended from their type in case it is narrower than
9061 if (offset0 == NULL_TREE)
9062 offset0 = build_int_cst (signed_size_type_node, 0);
9064 offset0 = fold_convert (signed_size_type_node, offset0);
9065 if (offset1 == NULL_TREE)
9066 offset1 = build_int_cst (signed_size_type_node, 0);
9068 offset1 = fold_convert (signed_size_type_node, offset1);
9072 && (pointer_may_wrap_p (base0, offset0, bitpos0)
9073 || pointer_may_wrap_p (base1, offset1, bitpos1)))
9074 fold_overflow_warning (("assuming pointer wraparound does not "
9075 "occur when comparing P +- C1 with "
9077 WARN_STRICT_OVERFLOW_COMPARISON);
9079 return fold_build2 (code, type, offset0, offset1);
9082 /* For non-equal bases we can simplify if they are addresses
9083 of local binding decls or constants. */
9084 else if (indirect_base0 && indirect_base1
9085 /* We know that !operand_equal_p (base0, base1, 0)
9086 because the if condition was false. But make
9087 sure two decls are not the same. */
9089 && TREE_CODE (arg0) == ADDR_EXPR
9090 && TREE_CODE (arg1) == ADDR_EXPR
9091 && (((TREE_CODE (base0) == VAR_DECL
9092 || TREE_CODE (base0) == PARM_DECL)
9093 && (targetm.binds_local_p (base0)
9094 || CONSTANT_CLASS_P (base1)))
9095 || CONSTANT_CLASS_P (base0))
9096 && (((TREE_CODE (base1) == VAR_DECL
9097 || TREE_CODE (base1) == PARM_DECL)
9098 && (targetm.binds_local_p (base1)
9099 || CONSTANT_CLASS_P (base0)))
9100 || CONSTANT_CLASS_P (base1)))
9102 if (code == EQ_EXPR)
9103 return omit_two_operands (type, boolean_false_node, arg0, arg1);
9104 else if (code == NE_EXPR)
9105 return omit_two_operands (type, boolean_true_node, arg0, arg1);
9107 /* For equal offsets we can simplify to a comparison of the
9109 else if (bitpos0 == bitpos1
9111 ? base0 != TREE_OPERAND (arg0, 0) : base0 != arg0)
9113 ? base1 != TREE_OPERAND (arg1, 0) : base1 != arg1)
9114 && ((offset0 == offset1)
9115 || (offset0 && offset1
9116 && operand_equal_p (offset0, offset1, 0))))
9119 base0 = build_fold_addr_expr (base0);
9121 base1 = build_fold_addr_expr (base1);
9122 return fold_build2 (code, type, base0, base1);
9126 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
9127 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
9128 the resulting offset is smaller in absolute value than the
9130 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
9131 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
9132 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9133 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
9134 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
9135 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9136 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
9138 tree const1 = TREE_OPERAND (arg0, 1);
9139 tree const2 = TREE_OPERAND (arg1, 1);
9140 tree variable1 = TREE_OPERAND (arg0, 0);
9141 tree variable2 = TREE_OPERAND (arg1, 0);
9143 const char * const warnmsg = G_("assuming signed overflow does not "
9144 "occur when combining constants around "
9147 /* Put the constant on the side where it doesn't overflow and is
9148 of lower absolute value than before. */
9149 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
9150 ? MINUS_EXPR : PLUS_EXPR,
9152 if (!TREE_OVERFLOW (cst)
9153 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
9155 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
9156 return fold_build2 (code, type,
9158 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
9162 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
9163 ? MINUS_EXPR : PLUS_EXPR,
9165 if (!TREE_OVERFLOW (cst)
9166 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
9168 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
9169 return fold_build2 (code, type,
9170 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
9176 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
9177 signed arithmetic case. That form is created by the compiler
9178 often enough for folding it to be of value. One example is in
9179 computing loop trip counts after Operator Strength Reduction. */
9180 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
9181 && TREE_CODE (arg0) == MULT_EXPR
9182 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9183 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
9184 && integer_zerop (arg1))
9186 tree const1 = TREE_OPERAND (arg0, 1);
9187 tree const2 = arg1; /* zero */
9188 tree variable1 = TREE_OPERAND (arg0, 0);
9189 enum tree_code cmp_code = code;
9191 gcc_assert (!integer_zerop (const1));
9193 fold_overflow_warning (("assuming signed overflow does not occur when "
9194 "eliminating multiplication in comparison "
9196 WARN_STRICT_OVERFLOW_COMPARISON);
9198 /* If const1 is negative we swap the sense of the comparison. */
9199 if (tree_int_cst_sgn (const1) < 0)
9200 cmp_code = swap_tree_comparison (cmp_code);
9202 return fold_build2 (cmp_code, type, variable1, const2);
9205 tem = maybe_canonicalize_comparison (code, type, op0, op1);
9209 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
9211 tree targ0 = strip_float_extensions (arg0);
9212 tree targ1 = strip_float_extensions (arg1);
9213 tree newtype = TREE_TYPE (targ0);
9215 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
9216 newtype = TREE_TYPE (targ1);
9218 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9219 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
9220 return fold_build2 (code, type, fold_convert (newtype, targ0),
9221 fold_convert (newtype, targ1));
9223 /* (-a) CMP (-b) -> b CMP a */
9224 if (TREE_CODE (arg0) == NEGATE_EXPR
9225 && TREE_CODE (arg1) == NEGATE_EXPR)
9226 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
9227 TREE_OPERAND (arg0, 0));
9229 if (TREE_CODE (arg1) == REAL_CST)
9231 REAL_VALUE_TYPE cst;
9232 cst = TREE_REAL_CST (arg1);
9234 /* (-a) CMP CST -> a swap(CMP) (-CST) */
9235 if (TREE_CODE (arg0) == NEGATE_EXPR)
9236 return fold_build2 (swap_tree_comparison (code), type,
9237 TREE_OPERAND (arg0, 0),
9238 build_real (TREE_TYPE (arg1),
9239 REAL_VALUE_NEGATE (cst)));
9241 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
9242 /* a CMP (-0) -> a CMP 0 */
9243 if (REAL_VALUE_MINUS_ZERO (cst))
9244 return fold_build2 (code, type, arg0,
9245 build_real (TREE_TYPE (arg1), dconst0));
9247 /* x != NaN is always true, other ops are always false. */
9248 if (REAL_VALUE_ISNAN (cst)
9249 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
9251 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
9252 return omit_one_operand (type, tem, arg0);
9255 /* Fold comparisons against infinity. */
9256 if (REAL_VALUE_ISINF (cst)
9257 && MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1))))
9259 tem = fold_inf_compare (code, type, arg0, arg1);
9260 if (tem != NULL_TREE)
9265 /* If this is a comparison of a real constant with a PLUS_EXPR
9266 or a MINUS_EXPR of a real constant, we can convert it into a
9267 comparison with a revised real constant as long as no overflow
9268 occurs when unsafe_math_optimizations are enabled. */
9269 if (flag_unsafe_math_optimizations
9270 && TREE_CODE (arg1) == REAL_CST
9271 && (TREE_CODE (arg0) == PLUS_EXPR
9272 || TREE_CODE (arg0) == MINUS_EXPR)
9273 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
9274 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9275 ? MINUS_EXPR : PLUS_EXPR,
9276 arg1, TREE_OPERAND (arg0, 1), 0))
9277 && !TREE_OVERFLOW (tem))
9278 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9280 /* Likewise, we can simplify a comparison of a real constant with
9281 a MINUS_EXPR whose first operand is also a real constant, i.e.
9282 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
9283 floating-point types only if -fassociative-math is set. */
9284 if (flag_associative_math
9285 && TREE_CODE (arg1) == REAL_CST
9286 && TREE_CODE (arg0) == MINUS_EXPR
9287 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
9288 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
9290 && !TREE_OVERFLOW (tem))
9291 return fold_build2 (swap_tree_comparison (code), type,
9292 TREE_OPERAND (arg0, 1), tem);
9294 /* Fold comparisons against built-in math functions. */
9295 if (TREE_CODE (arg1) == REAL_CST
9296 && flag_unsafe_math_optimizations
9297 && ! flag_errno_math)
9299 enum built_in_function fcode = builtin_mathfn_code (arg0);
9301 if (fcode != END_BUILTINS)
9303 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
9304 if (tem != NULL_TREE)
9310 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
9311 && CONVERT_EXPR_P (arg0))
9313 /* If we are widening one operand of an integer comparison,
9314 see if the other operand is similarly being widened. Perhaps we
9315 can do the comparison in the narrower type. */
9316 tem = fold_widened_comparison (code, type, arg0, arg1);
9320 /* Or if we are changing signedness. */
9321 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
9326 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9327 constant, we can simplify it. */
9328 if (TREE_CODE (arg1) == INTEGER_CST
9329 && (TREE_CODE (arg0) == MIN_EXPR
9330 || TREE_CODE (arg0) == MAX_EXPR)
9331 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9333 tem = optimize_minmax_comparison (code, type, op0, op1);
9338 /* Simplify comparison of something with itself. (For IEEE
9339 floating-point, we can only do some of these simplifications.) */
9340 if (operand_equal_p (arg0, arg1, 0))
9345 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9346 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9347 return constant_boolean_node (1, type);
9352 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9353 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9354 return constant_boolean_node (1, type);
9355 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9358 /* For NE, we can only do this simplification if integer
9359 or we don't honor IEEE floating point NaNs. */
9360 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
9361 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9363 /* ... fall through ... */
9366 return constant_boolean_node (0, type);
9372 /* If we are comparing an expression that just has comparisons
9373 of two integer values, arithmetic expressions of those comparisons,
9374 and constants, we can simplify it. There are only three cases
9375 to check: the two values can either be equal, the first can be
9376 greater, or the second can be greater. Fold the expression for
9377 those three values. Since each value must be 0 or 1, we have
9378 eight possibilities, each of which corresponds to the constant 0
9379 or 1 or one of the six possible comparisons.
9381 This handles common cases like (a > b) == 0 but also handles
9382 expressions like ((x > y) - (y > x)) > 0, which supposedly
9383 occur in macroized code. */
9385 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
9387 tree cval1 = 0, cval2 = 0;
9390 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
9391 /* Don't handle degenerate cases here; they should already
9392 have been handled anyway. */
9393 && cval1 != 0 && cval2 != 0
9394 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
9395 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
9396 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
9397 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
9398 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
9399 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
9400 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9402 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9403 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9405 /* We can't just pass T to eval_subst in case cval1 or cval2
9406 was the same as ARG1. */
9409 = fold_build2 (code, type,
9410 eval_subst (arg0, cval1, maxval,
9414 = fold_build2 (code, type,
9415 eval_subst (arg0, cval1, maxval,
9419 = fold_build2 (code, type,
9420 eval_subst (arg0, cval1, minval,
9424 /* All three of these results should be 0 or 1. Confirm they are.
9425 Then use those values to select the proper code to use. */
9427 if (TREE_CODE (high_result) == INTEGER_CST
9428 && TREE_CODE (equal_result) == INTEGER_CST
9429 && TREE_CODE (low_result) == INTEGER_CST)
9431 /* Make a 3-bit mask with the high-order bit being the
9432 value for `>', the next for '=', and the low for '<'. */
9433 switch ((integer_onep (high_result) * 4)
9434 + (integer_onep (equal_result) * 2)
9435 + integer_onep (low_result))
9439 return omit_one_operand (type, integer_zero_node, arg0);
9460 return omit_one_operand (type, integer_one_node, arg0);
9464 return save_expr (build2 (code, type, cval1, cval2));
9465 return fold_build2 (code, type, cval1, cval2);
9470 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9471 into a single range test. */
9472 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9473 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9474 && TREE_CODE (arg1) == INTEGER_CST
9475 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9476 && !integer_zerop (TREE_OPERAND (arg0, 1))
9477 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9478 && !TREE_OVERFLOW (arg1))
9480 tem = fold_div_compare (code, type, arg0, arg1);
9481 if (tem != NULL_TREE)
9485 /* Fold ~X op ~Y as Y op X. */
9486 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9487 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9489 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9490 return fold_build2 (code, type,
9491 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
9492 TREE_OPERAND (arg0, 0));
9495 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
9496 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9497 && TREE_CODE (arg1) == INTEGER_CST)
9499 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9500 return fold_build2 (swap_tree_comparison (code), type,
9501 TREE_OPERAND (arg0, 0),
9502 fold_build1 (BIT_NOT_EXPR, cmp_type,
9503 fold_convert (cmp_type, arg1)));
9510 /* Subroutine of fold_binary. Optimize complex multiplications of the
9511 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9512 argument EXPR represents the expression "z" of type TYPE. */
9515 fold_mult_zconjz (tree type, tree expr)
9517 tree itype = TREE_TYPE (type);
9518 tree rpart, ipart, tem;
9520 if (TREE_CODE (expr) == COMPLEX_EXPR)
9522 rpart = TREE_OPERAND (expr, 0);
9523 ipart = TREE_OPERAND (expr, 1);
9525 else if (TREE_CODE (expr) == COMPLEX_CST)
9527 rpart = TREE_REALPART (expr);
9528 ipart = TREE_IMAGPART (expr);
9532 expr = save_expr (expr);
9533 rpart = fold_build1 (REALPART_EXPR, itype, expr);
9534 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
9537 rpart = save_expr (rpart);
9538 ipart = save_expr (ipart);
9539 tem = fold_build2 (PLUS_EXPR, itype,
9540 fold_build2 (MULT_EXPR, itype, rpart, rpart),
9541 fold_build2 (MULT_EXPR, itype, ipart, ipart));
9542 return fold_build2 (COMPLEX_EXPR, type, tem,
9543 fold_convert (itype, integer_zero_node));
9547 /* Subroutine of fold_binary. If P is the value of EXPR, computes
9548 power-of-two M and (arbitrary) N such that M divides (P-N). This condition
9549 guarantees that P and N have the same least significant log2(M) bits.
9550 N is not otherwise constrained. In particular, N is not normalized to
9551 0 <= N < M as is common. In general, the precise value of P is unknown.
9552 M is chosen as large as possible such that constant N can be determined.
9554 Returns M and sets *RESIDUE to N.
9556 If ALLOW_FUNC_ALIGN is true, do take functions' DECL_ALIGN_UNIT into
9557 account. This is not always possible due to PR 35705.
9560 static unsigned HOST_WIDE_INT
9561 get_pointer_modulus_and_residue (tree expr, unsigned HOST_WIDE_INT *residue,
9562 bool allow_func_align)
9564 enum tree_code code;
9568 code = TREE_CODE (expr);
9569 if (code == ADDR_EXPR)
9571 expr = TREE_OPERAND (expr, 0);
9572 if (handled_component_p (expr))
9574 HOST_WIDE_INT bitsize, bitpos;
9576 enum machine_mode mode;
9577 int unsignedp, volatilep;
9579 expr = get_inner_reference (expr, &bitsize, &bitpos, &offset,
9580 &mode, &unsignedp, &volatilep, false);
9581 *residue = bitpos / BITS_PER_UNIT;
9584 if (TREE_CODE (offset) == INTEGER_CST)
9585 *residue += TREE_INT_CST_LOW (offset);
9587 /* We don't handle more complicated offset expressions. */
9593 && (allow_func_align || TREE_CODE (expr) != FUNCTION_DECL))
9594 return DECL_ALIGN_UNIT (expr);
9596 else if (code == POINTER_PLUS_EXPR)
9599 unsigned HOST_WIDE_INT modulus;
9600 enum tree_code inner_code;
9602 op0 = TREE_OPERAND (expr, 0);
9604 modulus = get_pointer_modulus_and_residue (op0, residue,
9607 op1 = TREE_OPERAND (expr, 1);
9609 inner_code = TREE_CODE (op1);
9610 if (inner_code == INTEGER_CST)
9612 *residue += TREE_INT_CST_LOW (op1);
9615 else if (inner_code == MULT_EXPR)
9617 op1 = TREE_OPERAND (op1, 1);
9618 if (TREE_CODE (op1) == INTEGER_CST)
9620 unsigned HOST_WIDE_INT align;
9622 /* Compute the greatest power-of-2 divisor of op1. */
9623 align = TREE_INT_CST_LOW (op1);
9626 /* If align is non-zero and less than *modulus, replace
9627 *modulus with align., If align is 0, then either op1 is 0
9628 or the greatest power-of-2 divisor of op1 doesn't fit in an
9629 unsigned HOST_WIDE_INT. In either case, no additional
9630 constraint is imposed. */
9632 modulus = MIN (modulus, align);
9639 /* If we get here, we were unable to determine anything useful about the
9645 /* Fold a binary expression of code CODE and type TYPE with operands
9646 OP0 and OP1. Return the folded expression if folding is
9647 successful. Otherwise, return NULL_TREE. */
9650 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
9652 enum tree_code_class kind = TREE_CODE_CLASS (code);
9653 tree arg0, arg1, tem;
9654 tree t1 = NULL_TREE;
9655 bool strict_overflow_p;
9657 gcc_assert (IS_EXPR_CODE_CLASS (kind)
9658 && TREE_CODE_LENGTH (code) == 2
9660 && op1 != NULL_TREE);
9665 /* Strip any conversions that don't change the mode. This is
9666 safe for every expression, except for a comparison expression
9667 because its signedness is derived from its operands. So, in
9668 the latter case, only strip conversions that don't change the
9669 signedness. MIN_EXPR/MAX_EXPR also need signedness of arguments
9672 Note that this is done as an internal manipulation within the
9673 constant folder, in order to find the simplest representation
9674 of the arguments so that their form can be studied. In any
9675 cases, the appropriate type conversions should be put back in
9676 the tree that will get out of the constant folder. */
9678 if (kind == tcc_comparison || code == MIN_EXPR || code == MAX_EXPR)
9680 STRIP_SIGN_NOPS (arg0);
9681 STRIP_SIGN_NOPS (arg1);
9689 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9690 constant but we can't do arithmetic on them. */
9691 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9692 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9693 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == FIXED_CST)
9694 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == INTEGER_CST)
9695 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9696 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9698 if (kind == tcc_binary)
9700 /* Make sure type and arg0 have the same saturating flag. */
9701 gcc_assert (TYPE_SATURATING (type)
9702 == TYPE_SATURATING (TREE_TYPE (arg0)));
9703 tem = const_binop (code, arg0, arg1, 0);
9705 else if (kind == tcc_comparison)
9706 tem = fold_relational_const (code, type, arg0, arg1);
9710 if (tem != NULL_TREE)
9712 if (TREE_TYPE (tem) != type)
9713 tem = fold_convert (type, tem);
9718 /* If this is a commutative operation, and ARG0 is a constant, move it
9719 to ARG1 to reduce the number of tests below. */
9720 if (commutative_tree_code (code)
9721 && tree_swap_operands_p (arg0, arg1, true))
9722 return fold_build2 (code, type, op1, op0);
9724 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9726 First check for cases where an arithmetic operation is applied to a
9727 compound, conditional, or comparison operation. Push the arithmetic
9728 operation inside the compound or conditional to see if any folding
9729 can then be done. Convert comparison to conditional for this purpose.
9730 The also optimizes non-constant cases that used to be done in
9733 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9734 one of the operands is a comparison and the other is a comparison, a
9735 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9736 code below would make the expression more complex. Change it to a
9737 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9738 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9740 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9741 || code == EQ_EXPR || code == NE_EXPR)
9742 && ((truth_value_p (TREE_CODE (arg0))
9743 && (truth_value_p (TREE_CODE (arg1))
9744 || (TREE_CODE (arg1) == BIT_AND_EXPR
9745 && integer_onep (TREE_OPERAND (arg1, 1)))))
9746 || (truth_value_p (TREE_CODE (arg1))
9747 && (truth_value_p (TREE_CODE (arg0))
9748 || (TREE_CODE (arg0) == BIT_AND_EXPR
9749 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9751 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9752 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9755 fold_convert (boolean_type_node, arg0),
9756 fold_convert (boolean_type_node, arg1));
9758 if (code == EQ_EXPR)
9759 tem = invert_truthvalue (tem);
9761 return fold_convert (type, tem);
9764 if (TREE_CODE_CLASS (code) == tcc_binary
9765 || TREE_CODE_CLASS (code) == tcc_comparison)
9767 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9768 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9769 fold_build2 (code, type,
9770 fold_convert (TREE_TYPE (op0),
9771 TREE_OPERAND (arg0, 1)),
9773 if (TREE_CODE (arg1) == COMPOUND_EXPR
9774 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9775 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9776 fold_build2 (code, type, op0,
9777 fold_convert (TREE_TYPE (op1),
9778 TREE_OPERAND (arg1, 1))));
9780 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9782 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9784 /*cond_first_p=*/1);
9785 if (tem != NULL_TREE)
9789 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9791 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9793 /*cond_first_p=*/0);
9794 if (tem != NULL_TREE)
9801 case POINTER_PLUS_EXPR:
9802 /* 0 +p index -> (type)index */
9803 if (integer_zerop (arg0))
9804 return non_lvalue (fold_convert (type, arg1));
9806 /* PTR +p 0 -> PTR */
9807 if (integer_zerop (arg1))
9808 return non_lvalue (fold_convert (type, arg0));
9810 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9811 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9812 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9813 return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
9814 fold_convert (sizetype, arg1),
9815 fold_convert (sizetype, arg0)));
9817 /* index +p PTR -> PTR +p index */
9818 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9819 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9820 return fold_build2 (POINTER_PLUS_EXPR, type,
9821 fold_convert (type, arg1),
9822 fold_convert (sizetype, arg0));
9824 /* (PTR +p B) +p A -> PTR +p (B + A) */
9825 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9828 tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
9829 tree arg00 = TREE_OPERAND (arg0, 0);
9830 inner = fold_build2 (PLUS_EXPR, sizetype,
9831 arg01, fold_convert (sizetype, arg1));
9832 return fold_convert (type,
9833 fold_build2 (POINTER_PLUS_EXPR,
9834 TREE_TYPE (arg00), arg00, inner));
9837 /* PTR_CST +p CST -> CST1 */
9838 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9839 return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
9841 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9842 of the array. Loop optimizer sometimes produce this type of
9844 if (TREE_CODE (arg0) == ADDR_EXPR)
9846 tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
9848 return fold_convert (type, tem);
9854 /* A + (-B) -> A - B */
9855 if (TREE_CODE (arg1) == NEGATE_EXPR)
9856 return fold_build2 (MINUS_EXPR, type,
9857 fold_convert (type, arg0),
9858 fold_convert (type, TREE_OPERAND (arg1, 0)));
9859 /* (-A) + B -> B - A */
9860 if (TREE_CODE (arg0) == NEGATE_EXPR
9861 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9862 return fold_build2 (MINUS_EXPR, type,
9863 fold_convert (type, arg1),
9864 fold_convert (type, TREE_OPERAND (arg0, 0)));
9866 if (INTEGRAL_TYPE_P (type))
9868 /* Convert ~A + 1 to -A. */
9869 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9870 && integer_onep (arg1))
9871 return fold_build1 (NEGATE_EXPR, type,
9872 fold_convert (type, TREE_OPERAND (arg0, 0)));
9875 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9876 && !TYPE_OVERFLOW_TRAPS (type))
9878 tree tem = TREE_OPERAND (arg0, 0);
9881 if (operand_equal_p (tem, arg1, 0))
9883 t1 = build_int_cst_type (type, -1);
9884 return omit_one_operand (type, t1, arg1);
9889 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9890 && !TYPE_OVERFLOW_TRAPS (type))
9892 tree tem = TREE_OPERAND (arg1, 0);
9895 if (operand_equal_p (arg0, tem, 0))
9897 t1 = build_int_cst_type (type, -1);
9898 return omit_one_operand (type, t1, arg0);
9902 /* X + (X / CST) * -CST is X % CST. */
9903 if (TREE_CODE (arg1) == MULT_EXPR
9904 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9905 && operand_equal_p (arg0,
9906 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
9908 tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
9909 tree cst1 = TREE_OPERAND (arg1, 1);
9910 tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
9911 if (sum && integer_zerop (sum))
9912 return fold_convert (type,
9913 fold_build2 (TRUNC_MOD_EXPR,
9914 TREE_TYPE (arg0), arg0, cst0));
9918 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9919 same or one. Make sure type is not saturating.
9920 fold_plusminus_mult_expr will re-associate. */
9921 if ((TREE_CODE (arg0) == MULT_EXPR
9922 || TREE_CODE (arg1) == MULT_EXPR)
9923 && !TYPE_SATURATING (type)
9924 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9926 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9931 if (! FLOAT_TYPE_P (type))
9933 if (integer_zerop (arg1))
9934 return non_lvalue (fold_convert (type, arg0));
9936 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9937 with a constant, and the two constants have no bits in common,
9938 we should treat this as a BIT_IOR_EXPR since this may produce more
9940 if (TREE_CODE (arg0) == BIT_AND_EXPR
9941 && TREE_CODE (arg1) == BIT_AND_EXPR
9942 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9943 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9944 && integer_zerop (const_binop (BIT_AND_EXPR,
9945 TREE_OPERAND (arg0, 1),
9946 TREE_OPERAND (arg1, 1), 0)))
9948 code = BIT_IOR_EXPR;
9952 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9953 (plus (plus (mult) (mult)) (foo)) so that we can
9954 take advantage of the factoring cases below. */
9955 if (((TREE_CODE (arg0) == PLUS_EXPR
9956 || TREE_CODE (arg0) == MINUS_EXPR)
9957 && TREE_CODE (arg1) == MULT_EXPR)
9958 || ((TREE_CODE (arg1) == PLUS_EXPR
9959 || TREE_CODE (arg1) == MINUS_EXPR)
9960 && TREE_CODE (arg0) == MULT_EXPR))
9962 tree parg0, parg1, parg, marg;
9963 enum tree_code pcode;
9965 if (TREE_CODE (arg1) == MULT_EXPR)
9966 parg = arg0, marg = arg1;
9968 parg = arg1, marg = arg0;
9969 pcode = TREE_CODE (parg);
9970 parg0 = TREE_OPERAND (parg, 0);
9971 parg1 = TREE_OPERAND (parg, 1);
9975 if (TREE_CODE (parg0) == MULT_EXPR
9976 && TREE_CODE (parg1) != MULT_EXPR)
9977 return fold_build2 (pcode, type,
9978 fold_build2 (PLUS_EXPR, type,
9979 fold_convert (type, parg0),
9980 fold_convert (type, marg)),
9981 fold_convert (type, parg1));
9982 if (TREE_CODE (parg0) != MULT_EXPR
9983 && TREE_CODE (parg1) == MULT_EXPR)
9984 return fold_build2 (PLUS_EXPR, type,
9985 fold_convert (type, parg0),
9986 fold_build2 (pcode, type,
9987 fold_convert (type, marg),
9994 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9995 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
9996 return non_lvalue (fold_convert (type, arg0));
9998 /* Likewise if the operands are reversed. */
9999 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
10000 return non_lvalue (fold_convert (type, arg1));
10002 /* Convert X + -C into X - C. */
10003 if (TREE_CODE (arg1) == REAL_CST
10004 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
10006 tem = fold_negate_const (arg1, type);
10007 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
10008 return fold_build2 (MINUS_EXPR, type,
10009 fold_convert (type, arg0),
10010 fold_convert (type, tem));
10013 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
10014 to __complex__ ( x, y ). This is not the same for SNaNs or
10015 if signed zeros are involved. */
10016 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10017 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10018 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10020 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10021 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10022 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10023 bool arg0rz = false, arg0iz = false;
10024 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10025 || (arg0i && (arg0iz = real_zerop (arg0i))))
10027 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10028 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10029 if (arg0rz && arg1i && real_zerop (arg1i))
10031 tree rp = arg1r ? arg1r
10032 : build1 (REALPART_EXPR, rtype, arg1);
10033 tree ip = arg0i ? arg0i
10034 : build1 (IMAGPART_EXPR, rtype, arg0);
10035 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10037 else if (arg0iz && arg1r && real_zerop (arg1r))
10039 tree rp = arg0r ? arg0r
10040 : build1 (REALPART_EXPR, rtype, arg0);
10041 tree ip = arg1i ? arg1i
10042 : build1 (IMAGPART_EXPR, rtype, arg1);
10043 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10048 if (flag_unsafe_math_optimizations
10049 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10050 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10051 && (tem = distribute_real_division (code, type, arg0, arg1)))
10054 /* Convert x+x into x*2.0. */
10055 if (operand_equal_p (arg0, arg1, 0)
10056 && SCALAR_FLOAT_TYPE_P (type))
10057 return fold_build2 (MULT_EXPR, type, arg0,
10058 build_real (type, dconst2));
10060 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
10061 We associate floats only if the user has specified
10062 -fassociative-math. */
10063 if (flag_associative_math
10064 && TREE_CODE (arg1) == PLUS_EXPR
10065 && TREE_CODE (arg0) != MULT_EXPR)
10067 tree tree10 = TREE_OPERAND (arg1, 0);
10068 tree tree11 = TREE_OPERAND (arg1, 1);
10069 if (TREE_CODE (tree11) == MULT_EXPR
10070 && TREE_CODE (tree10) == MULT_EXPR)
10073 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
10074 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
10077 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
10078 We associate floats only if the user has specified
10079 -fassociative-math. */
10080 if (flag_associative_math
10081 && TREE_CODE (arg0) == PLUS_EXPR
10082 && TREE_CODE (arg1) != MULT_EXPR)
10084 tree tree00 = TREE_OPERAND (arg0, 0);
10085 tree tree01 = TREE_OPERAND (arg0, 1);
10086 if (TREE_CODE (tree01) == MULT_EXPR
10087 && TREE_CODE (tree00) == MULT_EXPR)
10090 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
10091 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
10097 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
10098 is a rotate of A by C1 bits. */
10099 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
10100 is a rotate of A by B bits. */
10102 enum tree_code code0, code1;
10104 code0 = TREE_CODE (arg0);
10105 code1 = TREE_CODE (arg1);
10106 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
10107 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
10108 && operand_equal_p (TREE_OPERAND (arg0, 0),
10109 TREE_OPERAND (arg1, 0), 0)
10110 && (rtype = TREE_TYPE (TREE_OPERAND (arg0, 0)),
10111 TYPE_UNSIGNED (rtype))
10112 /* Only create rotates in complete modes. Other cases are not
10113 expanded properly. */
10114 && TYPE_PRECISION (rtype) == GET_MODE_PRECISION (TYPE_MODE (rtype)))
10116 tree tree01, tree11;
10117 enum tree_code code01, code11;
10119 tree01 = TREE_OPERAND (arg0, 1);
10120 tree11 = TREE_OPERAND (arg1, 1);
10121 STRIP_NOPS (tree01);
10122 STRIP_NOPS (tree11);
10123 code01 = TREE_CODE (tree01);
10124 code11 = TREE_CODE (tree11);
10125 if (code01 == INTEGER_CST
10126 && code11 == INTEGER_CST
10127 && TREE_INT_CST_HIGH (tree01) == 0
10128 && TREE_INT_CST_HIGH (tree11) == 0
10129 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
10130 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
10131 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
10132 code0 == LSHIFT_EXPR ? tree01 : tree11);
10133 else if (code11 == MINUS_EXPR)
10135 tree tree110, tree111;
10136 tree110 = TREE_OPERAND (tree11, 0);
10137 tree111 = TREE_OPERAND (tree11, 1);
10138 STRIP_NOPS (tree110);
10139 STRIP_NOPS (tree111);
10140 if (TREE_CODE (tree110) == INTEGER_CST
10141 && 0 == compare_tree_int (tree110,
10143 (TREE_TYPE (TREE_OPERAND
10145 && operand_equal_p (tree01, tree111, 0))
10146 return build2 ((code0 == LSHIFT_EXPR
10149 type, TREE_OPERAND (arg0, 0), tree01);
10151 else if (code01 == MINUS_EXPR)
10153 tree tree010, tree011;
10154 tree010 = TREE_OPERAND (tree01, 0);
10155 tree011 = TREE_OPERAND (tree01, 1);
10156 STRIP_NOPS (tree010);
10157 STRIP_NOPS (tree011);
10158 if (TREE_CODE (tree010) == INTEGER_CST
10159 && 0 == compare_tree_int (tree010,
10161 (TREE_TYPE (TREE_OPERAND
10163 && operand_equal_p (tree11, tree011, 0))
10164 return build2 ((code0 != LSHIFT_EXPR
10167 type, TREE_OPERAND (arg0, 0), tree11);
10173 /* In most languages, can't associate operations on floats through
10174 parentheses. Rather than remember where the parentheses were, we
10175 don't associate floats at all, unless the user has specified
10176 -fassociative-math.
10177 And, we need to make sure type is not saturating. */
10179 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
10180 && !TYPE_SATURATING (type))
10182 tree var0, con0, lit0, minus_lit0;
10183 tree var1, con1, lit1, minus_lit1;
10186 /* Split both trees into variables, constants, and literals. Then
10187 associate each group together, the constants with literals,
10188 then the result with variables. This increases the chances of
10189 literals being recombined later and of generating relocatable
10190 expressions for the sum of a constant and literal. */
10191 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
10192 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
10193 code == MINUS_EXPR);
10195 /* With undefined overflow we can only associate constants
10196 with one variable. */
10197 if (((POINTER_TYPE_P (type) && POINTER_TYPE_OVERFLOW_UNDEFINED)
10198 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
10204 if (TREE_CODE (tmp0) == NEGATE_EXPR)
10205 tmp0 = TREE_OPERAND (tmp0, 0);
10206 if (TREE_CODE (tmp1) == NEGATE_EXPR)
10207 tmp1 = TREE_OPERAND (tmp1, 0);
10208 /* The only case we can still associate with two variables
10209 is if they are the same, modulo negation. */
10210 if (!operand_equal_p (tmp0, tmp1, 0))
10214 /* Only do something if we found more than two objects. Otherwise,
10215 nothing has changed and we risk infinite recursion. */
10217 && (2 < ((var0 != 0) + (var1 != 0)
10218 + (con0 != 0) + (con1 != 0)
10219 + (lit0 != 0) + (lit1 != 0)
10220 + (minus_lit0 != 0) + (minus_lit1 != 0))))
10222 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
10223 if (code == MINUS_EXPR)
10226 var0 = associate_trees (var0, var1, code, type);
10227 con0 = associate_trees (con0, con1, code, type);
10228 lit0 = associate_trees (lit0, lit1, code, type);
10229 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
10231 /* Preserve the MINUS_EXPR if the negative part of the literal is
10232 greater than the positive part. Otherwise, the multiplicative
10233 folding code (i.e extract_muldiv) may be fooled in case
10234 unsigned constants are subtracted, like in the following
10235 example: ((X*2 + 4) - 8U)/2. */
10236 if (minus_lit0 && lit0)
10238 if (TREE_CODE (lit0) == INTEGER_CST
10239 && TREE_CODE (minus_lit0) == INTEGER_CST
10240 && tree_int_cst_lt (lit0, minus_lit0))
10242 minus_lit0 = associate_trees (minus_lit0, lit0,
10248 lit0 = associate_trees (lit0, minus_lit0,
10256 return fold_convert (type,
10257 associate_trees (var0, minus_lit0,
10258 MINUS_EXPR, type));
10261 con0 = associate_trees (con0, minus_lit0,
10263 return fold_convert (type,
10264 associate_trees (var0, con0,
10269 con0 = associate_trees (con0, lit0, code, type);
10270 return fold_convert (type, associate_trees (var0, con0,
10278 /* Pointer simplifications for subtraction, simple reassociations. */
10279 if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
10281 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
10282 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
10283 && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
10285 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10286 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10287 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10288 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10289 return fold_build2 (PLUS_EXPR, type,
10290 fold_build2 (MINUS_EXPR, type, arg00, arg10),
10291 fold_build2 (MINUS_EXPR, type, arg01, arg11));
10293 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
10294 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
10296 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
10297 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
10298 tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
10300 return fold_build2 (PLUS_EXPR, type, tmp, arg01);
10303 /* A - (-B) -> A + B */
10304 if (TREE_CODE (arg1) == NEGATE_EXPR)
10305 return fold_build2 (PLUS_EXPR, type, op0,
10306 fold_convert (type, TREE_OPERAND (arg1, 0)));
10307 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
10308 if (TREE_CODE (arg0) == NEGATE_EXPR
10309 && (FLOAT_TYPE_P (type)
10310 || INTEGRAL_TYPE_P (type))
10311 && negate_expr_p (arg1)
10312 && reorder_operands_p (arg0, arg1))
10313 return fold_build2 (MINUS_EXPR, type,
10314 fold_convert (type, negate_expr (arg1)),
10315 fold_convert (type, TREE_OPERAND (arg0, 0)));
10316 /* Convert -A - 1 to ~A. */
10317 if (INTEGRAL_TYPE_P (type)
10318 && TREE_CODE (arg0) == NEGATE_EXPR
10319 && integer_onep (arg1)
10320 && !TYPE_OVERFLOW_TRAPS (type))
10321 return fold_build1 (BIT_NOT_EXPR, type,
10322 fold_convert (type, TREE_OPERAND (arg0, 0)));
10324 /* Convert -1 - A to ~A. */
10325 if (INTEGRAL_TYPE_P (type)
10326 && integer_all_onesp (arg0))
10327 return fold_build1 (BIT_NOT_EXPR, type, op1);
10330 /* X - (X / CST) * CST is X % CST. */
10331 if (INTEGRAL_TYPE_P (type)
10332 && TREE_CODE (arg1) == MULT_EXPR
10333 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
10334 && operand_equal_p (arg0,
10335 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
10336 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
10337 TREE_OPERAND (arg1, 1), 0))
10338 return fold_convert (type,
10339 fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
10340 arg0, TREE_OPERAND (arg1, 1)));
10342 if (! FLOAT_TYPE_P (type))
10344 if (integer_zerop (arg0))
10345 return negate_expr (fold_convert (type, arg1));
10346 if (integer_zerop (arg1))
10347 return non_lvalue (fold_convert (type, arg0));
10349 /* Fold A - (A & B) into ~B & A. */
10350 if (!TREE_SIDE_EFFECTS (arg0)
10351 && TREE_CODE (arg1) == BIT_AND_EXPR)
10353 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
10355 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
10356 return fold_build2 (BIT_AND_EXPR, type,
10357 fold_build1 (BIT_NOT_EXPR, type, arg10),
10358 fold_convert (type, arg0));
10360 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10362 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
10363 return fold_build2 (BIT_AND_EXPR, type,
10364 fold_build1 (BIT_NOT_EXPR, type, arg11),
10365 fold_convert (type, arg0));
10369 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
10370 any power of 2 minus 1. */
10371 if (TREE_CODE (arg0) == BIT_AND_EXPR
10372 && TREE_CODE (arg1) == BIT_AND_EXPR
10373 && operand_equal_p (TREE_OPERAND (arg0, 0),
10374 TREE_OPERAND (arg1, 0), 0))
10376 tree mask0 = TREE_OPERAND (arg0, 1);
10377 tree mask1 = TREE_OPERAND (arg1, 1);
10378 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
10380 if (operand_equal_p (tem, mask1, 0))
10382 tem = fold_build2 (BIT_XOR_EXPR, type,
10383 TREE_OPERAND (arg0, 0), mask1);
10384 return fold_build2 (MINUS_EXPR, type, tem, mask1);
10389 /* See if ARG1 is zero and X - ARG1 reduces to X. */
10390 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
10391 return non_lvalue (fold_convert (type, arg0));
10393 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
10394 ARG0 is zero and X + ARG0 reduces to X, since that would mean
10395 (-ARG1 + ARG0) reduces to -ARG1. */
10396 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
10397 return negate_expr (fold_convert (type, arg1));
10399 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
10400 __complex__ ( x, -y ). This is not the same for SNaNs or if
10401 signed zeros are involved. */
10402 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10403 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10404 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10406 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10407 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10408 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10409 bool arg0rz = false, arg0iz = false;
10410 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10411 || (arg0i && (arg0iz = real_zerop (arg0i))))
10413 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10414 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10415 if (arg0rz && arg1i && real_zerop (arg1i))
10417 tree rp = fold_build1 (NEGATE_EXPR, rtype,
10419 : build1 (REALPART_EXPR, rtype, arg1));
10420 tree ip = arg0i ? arg0i
10421 : build1 (IMAGPART_EXPR, rtype, arg0);
10422 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10424 else if (arg0iz && arg1r && real_zerop (arg1r))
10426 tree rp = arg0r ? arg0r
10427 : build1 (REALPART_EXPR, rtype, arg0);
10428 tree ip = fold_build1 (NEGATE_EXPR, rtype,
10430 : build1 (IMAGPART_EXPR, rtype, arg1));
10431 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10436 /* Fold &x - &x. This can happen from &x.foo - &x.
10437 This is unsafe for certain floats even in non-IEEE formats.
10438 In IEEE, it is unsafe because it does wrong for NaNs.
10439 Also note that operand_equal_p is always false if an operand
10442 if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
10443 && operand_equal_p (arg0, arg1, 0))
10444 return fold_convert (type, integer_zero_node);
10446 /* A - B -> A + (-B) if B is easily negatable. */
10447 if (negate_expr_p (arg1)
10448 && ((FLOAT_TYPE_P (type)
10449 /* Avoid this transformation if B is a positive REAL_CST. */
10450 && (TREE_CODE (arg1) != REAL_CST
10451 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
10452 || INTEGRAL_TYPE_P (type)))
10453 return fold_build2 (PLUS_EXPR, type,
10454 fold_convert (type, arg0),
10455 fold_convert (type, negate_expr (arg1)));
10457 /* Try folding difference of addresses. */
10459 HOST_WIDE_INT diff;
10461 if ((TREE_CODE (arg0) == ADDR_EXPR
10462 || TREE_CODE (arg1) == ADDR_EXPR)
10463 && ptr_difference_const (arg0, arg1, &diff))
10464 return build_int_cst_type (type, diff);
10467 /* Fold &a[i] - &a[j] to i-j. */
10468 if (TREE_CODE (arg0) == ADDR_EXPR
10469 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
10470 && TREE_CODE (arg1) == ADDR_EXPR
10471 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
10473 tree aref0 = TREE_OPERAND (arg0, 0);
10474 tree aref1 = TREE_OPERAND (arg1, 0);
10475 if (operand_equal_p (TREE_OPERAND (aref0, 0),
10476 TREE_OPERAND (aref1, 0), 0))
10478 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
10479 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
10480 tree esz = array_ref_element_size (aref0);
10481 tree diff = build2 (MINUS_EXPR, type, op0, op1);
10482 return fold_build2 (MULT_EXPR, type, diff,
10483 fold_convert (type, esz));
10488 if (flag_unsafe_math_optimizations
10489 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10490 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10491 && (tem = distribute_real_division (code, type, arg0, arg1)))
10494 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
10495 same or one. Make sure type is not saturating.
10496 fold_plusminus_mult_expr will re-associate. */
10497 if ((TREE_CODE (arg0) == MULT_EXPR
10498 || TREE_CODE (arg1) == MULT_EXPR)
10499 && !TYPE_SATURATING (type)
10500 && (!FLOAT_TYPE_P (type) || flag_associative_math))
10502 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
10510 /* (-A) * (-B) -> A * B */
10511 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10512 return fold_build2 (MULT_EXPR, type,
10513 fold_convert (type, TREE_OPERAND (arg0, 0)),
10514 fold_convert (type, negate_expr (arg1)));
10515 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10516 return fold_build2 (MULT_EXPR, type,
10517 fold_convert (type, negate_expr (arg0)),
10518 fold_convert (type, TREE_OPERAND (arg1, 0)));
10520 if (! FLOAT_TYPE_P (type))
10522 if (integer_zerop (arg1))
10523 return omit_one_operand (type, arg1, arg0);
10524 if (integer_onep (arg1))
10525 return non_lvalue (fold_convert (type, arg0));
10526 /* Transform x * -1 into -x. Make sure to do the negation
10527 on the original operand with conversions not stripped
10528 because we can only strip non-sign-changing conversions. */
10529 if (integer_all_onesp (arg1))
10530 return fold_convert (type, negate_expr (op0));
10531 /* Transform x * -C into -x * C if x is easily negatable. */
10532 if (TREE_CODE (arg1) == INTEGER_CST
10533 && tree_int_cst_sgn (arg1) == -1
10534 && negate_expr_p (arg0)
10535 && (tem = negate_expr (arg1)) != arg1
10536 && !TREE_OVERFLOW (tem))
10537 return fold_build2 (MULT_EXPR, type,
10538 fold_convert (type, negate_expr (arg0)), tem);
10540 /* (a * (1 << b)) is (a << b) */
10541 if (TREE_CODE (arg1) == LSHIFT_EXPR
10542 && integer_onep (TREE_OPERAND (arg1, 0)))
10543 return fold_build2 (LSHIFT_EXPR, type, op0,
10544 TREE_OPERAND (arg1, 1));
10545 if (TREE_CODE (arg0) == LSHIFT_EXPR
10546 && integer_onep (TREE_OPERAND (arg0, 0)))
10547 return fold_build2 (LSHIFT_EXPR, type, op1,
10548 TREE_OPERAND (arg0, 1));
10550 /* (A + A) * C -> A * 2 * C */
10551 if (TREE_CODE (arg0) == PLUS_EXPR
10552 && TREE_CODE (arg1) == INTEGER_CST
10553 && operand_equal_p (TREE_OPERAND (arg0, 0),
10554 TREE_OPERAND (arg0, 1), 0))
10555 return fold_build2 (MULT_EXPR, type,
10556 omit_one_operand (type, TREE_OPERAND (arg0, 0),
10557 TREE_OPERAND (arg0, 1)),
10558 fold_build2 (MULT_EXPR, type,
10559 build_int_cst (type, 2) , arg1));
10561 strict_overflow_p = false;
10562 if (TREE_CODE (arg1) == INTEGER_CST
10563 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10564 &strict_overflow_p)))
10566 if (strict_overflow_p)
10567 fold_overflow_warning (("assuming signed overflow does not "
10568 "occur when simplifying "
10570 WARN_STRICT_OVERFLOW_MISC);
10571 return fold_convert (type, tem);
10574 /* Optimize z * conj(z) for integer complex numbers. */
10575 if (TREE_CODE (arg0) == CONJ_EXPR
10576 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10577 return fold_mult_zconjz (type, arg1);
10578 if (TREE_CODE (arg1) == CONJ_EXPR
10579 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10580 return fold_mult_zconjz (type, arg0);
10584 /* Maybe fold x * 0 to 0. The expressions aren't the same
10585 when x is NaN, since x * 0 is also NaN. Nor are they the
10586 same in modes with signed zeros, since multiplying a
10587 negative value by 0 gives -0, not +0. */
10588 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10589 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10590 && real_zerop (arg1))
10591 return omit_one_operand (type, arg1, arg0);
10592 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
10593 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10594 && real_onep (arg1))
10595 return non_lvalue (fold_convert (type, arg0));
10597 /* Transform x * -1.0 into -x. */
10598 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10599 && real_minus_onep (arg1))
10600 return fold_convert (type, negate_expr (arg0));
10602 /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
10603 the result for floating point types due to rounding so it is applied
10604 only if -fassociative-math was specify. */
10605 if (flag_associative_math
10606 && TREE_CODE (arg0) == RDIV_EXPR
10607 && TREE_CODE (arg1) == REAL_CST
10608 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
10610 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
10613 return fold_build2 (RDIV_EXPR, type, tem,
10614 TREE_OPERAND (arg0, 1));
10617 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10618 if (operand_equal_p (arg0, arg1, 0))
10620 tree tem = fold_strip_sign_ops (arg0);
10621 if (tem != NULL_TREE)
10623 tem = fold_convert (type, tem);
10624 return fold_build2 (MULT_EXPR, type, tem, tem);
10628 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10629 This is not the same for NaNs or if signed zeros are
10631 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10632 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10633 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10634 && TREE_CODE (arg1) == COMPLEX_CST
10635 && real_zerop (TREE_REALPART (arg1)))
10637 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10638 if (real_onep (TREE_IMAGPART (arg1)))
10639 return fold_build2 (COMPLEX_EXPR, type,
10640 negate_expr (fold_build1 (IMAGPART_EXPR,
10642 fold_build1 (REALPART_EXPR, rtype, arg0));
10643 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10644 return fold_build2 (COMPLEX_EXPR, type,
10645 fold_build1 (IMAGPART_EXPR, rtype, arg0),
10646 negate_expr (fold_build1 (REALPART_EXPR,
10650 /* Optimize z * conj(z) for floating point complex numbers.
10651 Guarded by flag_unsafe_math_optimizations as non-finite
10652 imaginary components don't produce scalar results. */
10653 if (flag_unsafe_math_optimizations
10654 && TREE_CODE (arg0) == CONJ_EXPR
10655 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10656 return fold_mult_zconjz (type, arg1);
10657 if (flag_unsafe_math_optimizations
10658 && TREE_CODE (arg1) == CONJ_EXPR
10659 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10660 return fold_mult_zconjz (type, arg0);
10662 if (flag_unsafe_math_optimizations)
10664 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10665 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10667 /* Optimizations of root(...)*root(...). */
10668 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
10671 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10672 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10674 /* Optimize sqrt(x)*sqrt(x) as x. */
10675 if (BUILTIN_SQRT_P (fcode0)
10676 && operand_equal_p (arg00, arg10, 0)
10677 && ! HONOR_SNANS (TYPE_MODE (type)))
10680 /* Optimize root(x)*root(y) as root(x*y). */
10681 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10682 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10683 return build_call_expr (rootfn, 1, arg);
10686 /* Optimize expN(x)*expN(y) as expN(x+y). */
10687 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
10689 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10690 tree arg = fold_build2 (PLUS_EXPR, type,
10691 CALL_EXPR_ARG (arg0, 0),
10692 CALL_EXPR_ARG (arg1, 0));
10693 return build_call_expr (expfn, 1, arg);
10696 /* Optimizations of pow(...)*pow(...). */
10697 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
10698 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
10699 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
10701 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10702 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10703 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10704 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10706 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10707 if (operand_equal_p (arg01, arg11, 0))
10709 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10710 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10711 return build_call_expr (powfn, 2, arg, arg01);
10714 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10715 if (operand_equal_p (arg00, arg10, 0))
10717 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10718 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
10719 return build_call_expr (powfn, 2, arg00, arg);
10723 /* Optimize tan(x)*cos(x) as sin(x). */
10724 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
10725 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
10726 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
10727 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
10728 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
10729 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
10730 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10731 CALL_EXPR_ARG (arg1, 0), 0))
10733 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
10735 if (sinfn != NULL_TREE)
10736 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
10739 /* Optimize x*pow(x,c) as pow(x,c+1). */
10740 if (fcode1 == BUILT_IN_POW
10741 || fcode1 == BUILT_IN_POWF
10742 || fcode1 == BUILT_IN_POWL)
10744 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10745 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10746 if (TREE_CODE (arg11) == REAL_CST
10747 && !TREE_OVERFLOW (arg11)
10748 && operand_equal_p (arg0, arg10, 0))
10750 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10754 c = TREE_REAL_CST (arg11);
10755 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10756 arg = build_real (type, c);
10757 return build_call_expr (powfn, 2, arg0, arg);
10761 /* Optimize pow(x,c)*x as pow(x,c+1). */
10762 if (fcode0 == BUILT_IN_POW
10763 || fcode0 == BUILT_IN_POWF
10764 || fcode0 == BUILT_IN_POWL)
10766 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10767 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10768 if (TREE_CODE (arg01) == REAL_CST
10769 && !TREE_OVERFLOW (arg01)
10770 && operand_equal_p (arg1, arg00, 0))
10772 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10776 c = TREE_REAL_CST (arg01);
10777 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10778 arg = build_real (type, c);
10779 return build_call_expr (powfn, 2, arg1, arg);
10783 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10784 if (optimize_function_for_speed_p (cfun)
10785 && operand_equal_p (arg0, arg1, 0))
10787 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
10791 tree arg = build_real (type, dconst2);
10792 return build_call_expr (powfn, 2, arg0, arg);
10801 if (integer_all_onesp (arg1))
10802 return omit_one_operand (type, arg1, arg0);
10803 if (integer_zerop (arg1))
10804 return non_lvalue (fold_convert (type, arg0));
10805 if (operand_equal_p (arg0, arg1, 0))
10806 return non_lvalue (fold_convert (type, arg0));
10808 /* ~X | X is -1. */
10809 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10810 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10812 t1 = fold_convert (type, integer_zero_node);
10813 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10814 return omit_one_operand (type, t1, arg1);
10817 /* X | ~X is -1. */
10818 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10819 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10821 t1 = fold_convert (type, integer_zero_node);
10822 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10823 return omit_one_operand (type, t1, arg0);
10826 /* Canonicalize (X & C1) | C2. */
10827 if (TREE_CODE (arg0) == BIT_AND_EXPR
10828 && TREE_CODE (arg1) == INTEGER_CST
10829 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10831 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, hi3, lo3, mlo, mhi;
10832 int width = TYPE_PRECISION (type), w;
10833 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10834 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10835 hi2 = TREE_INT_CST_HIGH (arg1);
10836 lo2 = TREE_INT_CST_LOW (arg1);
10838 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10839 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10840 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10842 if (width > HOST_BITS_PER_WIDE_INT)
10844 mhi = (unsigned HOST_WIDE_INT) -1
10845 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10851 mlo = (unsigned HOST_WIDE_INT) -1
10852 >> (HOST_BITS_PER_WIDE_INT - width);
10855 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10856 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10857 return fold_build2 (BIT_IOR_EXPR, type,
10858 TREE_OPERAND (arg0, 0), arg1);
10860 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
10861 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
10862 mode which allows further optimizations. */
10869 for (w = BITS_PER_UNIT;
10870 w <= width && w <= HOST_BITS_PER_WIDE_INT;
10873 unsigned HOST_WIDE_INT mask
10874 = (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
10875 if (((lo1 | lo2) & mask) == mask
10876 && (lo1 & ~mask) == 0 && hi1 == 0)
10883 if (hi3 != hi1 || lo3 != lo1)
10884 return fold_build2 (BIT_IOR_EXPR, type,
10885 fold_build2 (BIT_AND_EXPR, type,
10886 TREE_OPERAND (arg0, 0),
10887 build_int_cst_wide (type,
10892 /* (X & Y) | Y is (X, Y). */
10893 if (TREE_CODE (arg0) == BIT_AND_EXPR
10894 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10895 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10896 /* (X & Y) | X is (Y, X). */
10897 if (TREE_CODE (arg0) == BIT_AND_EXPR
10898 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10899 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10900 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10901 /* X | (X & Y) is (Y, X). */
10902 if (TREE_CODE (arg1) == BIT_AND_EXPR
10903 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10904 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10905 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10906 /* X | (Y & X) is (Y, X). */
10907 if (TREE_CODE (arg1) == BIT_AND_EXPR
10908 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10909 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10910 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10912 t1 = distribute_bit_expr (code, type, arg0, arg1);
10913 if (t1 != NULL_TREE)
10916 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10918 This results in more efficient code for machines without a NAND
10919 instruction. Combine will canonicalize to the first form
10920 which will allow use of NAND instructions provided by the
10921 backend if they exist. */
10922 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10923 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10925 return fold_build1 (BIT_NOT_EXPR, type,
10926 build2 (BIT_AND_EXPR, type,
10927 fold_convert (type,
10928 TREE_OPERAND (arg0, 0)),
10929 fold_convert (type,
10930 TREE_OPERAND (arg1, 0))));
10933 /* See if this can be simplified into a rotate first. If that
10934 is unsuccessful continue in the association code. */
10938 if (integer_zerop (arg1))
10939 return non_lvalue (fold_convert (type, arg0));
10940 if (integer_all_onesp (arg1))
10941 return fold_build1 (BIT_NOT_EXPR, type, op0);
10942 if (operand_equal_p (arg0, arg1, 0))
10943 return omit_one_operand (type, integer_zero_node, arg0);
10945 /* ~X ^ X is -1. */
10946 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10947 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10949 t1 = fold_convert (type, integer_zero_node);
10950 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10951 return omit_one_operand (type, t1, arg1);
10954 /* X ^ ~X is -1. */
10955 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10956 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10958 t1 = fold_convert (type, integer_zero_node);
10959 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10960 return omit_one_operand (type, t1, arg0);
10963 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10964 with a constant, and the two constants have no bits in common,
10965 we should treat this as a BIT_IOR_EXPR since this may produce more
10966 simplifications. */
10967 if (TREE_CODE (arg0) == BIT_AND_EXPR
10968 && TREE_CODE (arg1) == BIT_AND_EXPR
10969 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10970 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10971 && integer_zerop (const_binop (BIT_AND_EXPR,
10972 TREE_OPERAND (arg0, 1),
10973 TREE_OPERAND (arg1, 1), 0)))
10975 code = BIT_IOR_EXPR;
10979 /* (X | Y) ^ X -> Y & ~ X*/
10980 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10981 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10983 tree t2 = TREE_OPERAND (arg0, 1);
10984 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10986 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10987 fold_convert (type, t1));
10991 /* (Y | X) ^ X -> Y & ~ X*/
10992 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10993 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10995 tree t2 = TREE_OPERAND (arg0, 0);
10996 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10998 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10999 fold_convert (type, t1));
11003 /* X ^ (X | Y) -> Y & ~ X*/
11004 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11005 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
11007 tree t2 = TREE_OPERAND (arg1, 1);
11008 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
11010 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
11011 fold_convert (type, t1));
11015 /* X ^ (Y | X) -> Y & ~ X*/
11016 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11017 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
11019 tree t2 = TREE_OPERAND (arg1, 0);
11020 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
11022 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
11023 fold_convert (type, t1));
11027 /* Convert ~X ^ ~Y to X ^ Y. */
11028 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11029 && TREE_CODE (arg1) == BIT_NOT_EXPR)
11030 return fold_build2 (code, type,
11031 fold_convert (type, TREE_OPERAND (arg0, 0)),
11032 fold_convert (type, TREE_OPERAND (arg1, 0)));
11034 /* Convert ~X ^ C to X ^ ~C. */
11035 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11036 && TREE_CODE (arg1) == INTEGER_CST)
11037 return fold_build2 (code, type,
11038 fold_convert (type, TREE_OPERAND (arg0, 0)),
11039 fold_build1 (BIT_NOT_EXPR, type, arg1));
11041 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
11042 if (TREE_CODE (arg0) == BIT_AND_EXPR
11043 && integer_onep (TREE_OPERAND (arg0, 1))
11044 && integer_onep (arg1))
11045 return fold_build2 (EQ_EXPR, type, arg0,
11046 build_int_cst (TREE_TYPE (arg0), 0));
11048 /* Fold (X & Y) ^ Y as ~X & Y. */
11049 if (TREE_CODE (arg0) == BIT_AND_EXPR
11050 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11052 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
11053 return fold_build2 (BIT_AND_EXPR, type,
11054 fold_build1 (BIT_NOT_EXPR, type, tem),
11055 fold_convert (type, arg1));
11057 /* Fold (X & Y) ^ X as ~Y & X. */
11058 if (TREE_CODE (arg0) == BIT_AND_EXPR
11059 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11060 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11062 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
11063 return fold_build2 (BIT_AND_EXPR, type,
11064 fold_build1 (BIT_NOT_EXPR, type, tem),
11065 fold_convert (type, arg1));
11067 /* Fold X ^ (X & Y) as X & ~Y. */
11068 if (TREE_CODE (arg1) == BIT_AND_EXPR
11069 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11071 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
11072 return fold_build2 (BIT_AND_EXPR, type,
11073 fold_convert (type, arg0),
11074 fold_build1 (BIT_NOT_EXPR, type, tem));
11076 /* Fold X ^ (Y & X) as ~Y & X. */
11077 if (TREE_CODE (arg1) == BIT_AND_EXPR
11078 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
11079 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
11081 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
11082 return fold_build2 (BIT_AND_EXPR, type,
11083 fold_build1 (BIT_NOT_EXPR, type, tem),
11084 fold_convert (type, arg0));
11087 /* See if this can be simplified into a rotate first. If that
11088 is unsuccessful continue in the association code. */
11092 if (integer_all_onesp (arg1))
11093 return non_lvalue (fold_convert (type, arg0));
11094 if (integer_zerop (arg1))
11095 return omit_one_operand (type, arg1, arg0);
11096 if (operand_equal_p (arg0, arg1, 0))
11097 return non_lvalue (fold_convert (type, arg0));
11099 /* ~X & X is always zero. */
11100 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11101 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11102 return omit_one_operand (type, integer_zero_node, arg1);
11104 /* X & ~X is always zero. */
11105 if (TREE_CODE (arg1) == BIT_NOT_EXPR
11106 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11107 return omit_one_operand (type, integer_zero_node, arg0);
11109 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
11110 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11111 && TREE_CODE (arg1) == INTEGER_CST
11112 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11114 tree tmp1 = fold_convert (type, arg1);
11115 tree tmp2 = fold_convert (type, TREE_OPERAND (arg0, 0));
11116 tree tmp3 = fold_convert (type, TREE_OPERAND (arg0, 1));
11117 tmp2 = fold_build2 (BIT_AND_EXPR, type, tmp2, tmp1);
11118 tmp3 = fold_build2 (BIT_AND_EXPR, type, tmp3, tmp1);
11119 return fold_convert (type,
11120 fold_build2 (BIT_IOR_EXPR, type, tmp2, tmp3));
11123 /* (X | Y) & Y is (X, Y). */
11124 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11125 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11126 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
11127 /* (X | Y) & X is (Y, X). */
11128 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11129 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11130 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11131 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
11132 /* X & (X | Y) is (Y, X). */
11133 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11134 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
11135 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
11136 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
11137 /* X & (Y | X) is (Y, X). */
11138 if (TREE_CODE (arg1) == BIT_IOR_EXPR
11139 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
11140 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
11141 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
11143 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
11144 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11145 && integer_onep (TREE_OPERAND (arg0, 1))
11146 && integer_onep (arg1))
11148 tem = TREE_OPERAND (arg0, 0);
11149 return fold_build2 (EQ_EXPR, type,
11150 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
11151 build_int_cst (TREE_TYPE (tem), 1)),
11152 build_int_cst (TREE_TYPE (tem), 0));
11154 /* Fold ~X & 1 as (X & 1) == 0. */
11155 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11156 && integer_onep (arg1))
11158 tem = TREE_OPERAND (arg0, 0);
11159 return fold_build2 (EQ_EXPR, type,
11160 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
11161 build_int_cst (TREE_TYPE (tem), 1)),
11162 build_int_cst (TREE_TYPE (tem), 0));
11165 /* Fold (X ^ Y) & Y as ~X & Y. */
11166 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11167 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11169 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
11170 return fold_build2 (BIT_AND_EXPR, type,
11171 fold_build1 (BIT_NOT_EXPR, type, tem),
11172 fold_convert (type, arg1));
11174 /* Fold (X ^ Y) & X as ~Y & X. */
11175 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11176 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11177 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11179 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
11180 return fold_build2 (BIT_AND_EXPR, type,
11181 fold_build1 (BIT_NOT_EXPR, type, tem),
11182 fold_convert (type, arg1));
11184 /* Fold X & (X ^ Y) as X & ~Y. */
11185 if (TREE_CODE (arg1) == BIT_XOR_EXPR
11186 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11188 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
11189 return fold_build2 (BIT_AND_EXPR, type,
11190 fold_convert (type, arg0),
11191 fold_build1 (BIT_NOT_EXPR, type, tem));
11193 /* Fold X & (Y ^ X) as ~Y & X. */
11194 if (TREE_CODE (arg1) == BIT_XOR_EXPR
11195 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
11196 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
11198 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
11199 return fold_build2 (BIT_AND_EXPR, type,
11200 fold_build1 (BIT_NOT_EXPR, type, tem),
11201 fold_convert (type, arg0));
11204 t1 = distribute_bit_expr (code, type, arg0, arg1);
11205 if (t1 != NULL_TREE)
11207 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
11208 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
11209 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
11212 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
11214 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
11215 && (~TREE_INT_CST_LOW (arg1)
11216 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
11217 return fold_convert (type, TREE_OPERAND (arg0, 0));
11220 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
11222 This results in more efficient code for machines without a NOR
11223 instruction. Combine will canonicalize to the first form
11224 which will allow use of NOR instructions provided by the
11225 backend if they exist. */
11226 if (TREE_CODE (arg0) == BIT_NOT_EXPR
11227 && TREE_CODE (arg1) == BIT_NOT_EXPR)
11229 return fold_build1 (BIT_NOT_EXPR, type,
11230 build2 (BIT_IOR_EXPR, type,
11231 fold_convert (type,
11232 TREE_OPERAND (arg0, 0)),
11233 fold_convert (type,
11234 TREE_OPERAND (arg1, 0))));
11237 /* If arg0 is derived from the address of an object or function, we may
11238 be able to fold this expression using the object or function's
11240 if (POINTER_TYPE_P (TREE_TYPE (arg0)) && host_integerp (arg1, 1))
11242 unsigned HOST_WIDE_INT modulus, residue;
11243 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (arg1);
11245 modulus = get_pointer_modulus_and_residue (arg0, &residue,
11246 integer_onep (arg1));
11248 /* This works because modulus is a power of 2. If this weren't the
11249 case, we'd have to replace it by its greatest power-of-2
11250 divisor: modulus & -modulus. */
11252 return build_int_cst (type, residue & low);
11255 /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
11256 (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
11257 if the new mask might be further optimized. */
11258 if ((TREE_CODE (arg0) == LSHIFT_EXPR
11259 || TREE_CODE (arg0) == RSHIFT_EXPR)
11260 && host_integerp (TREE_OPERAND (arg0, 1), 1)
11261 && host_integerp (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)))
11262 && tree_low_cst (TREE_OPERAND (arg0, 1), 1)
11263 < TYPE_PRECISION (TREE_TYPE (arg0))
11264 && TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
11265 && tree_low_cst (TREE_OPERAND (arg0, 1), 1) > 0)
11267 unsigned int shiftc = tree_low_cst (TREE_OPERAND (arg0, 1), 1);
11268 unsigned HOST_WIDE_INT mask
11269 = tree_low_cst (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)));
11270 unsigned HOST_WIDE_INT newmask, zerobits = 0;
11271 tree shift_type = TREE_TYPE (arg0);
11273 if (TREE_CODE (arg0) == LSHIFT_EXPR)
11274 zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
11275 else if (TREE_CODE (arg0) == RSHIFT_EXPR
11276 && TYPE_PRECISION (TREE_TYPE (arg0))
11277 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg0))))
11279 unsigned int prec = TYPE_PRECISION (TREE_TYPE (arg0));
11280 tree arg00 = TREE_OPERAND (arg0, 0);
11281 /* See if more bits can be proven as zero because of
11283 if (TREE_CODE (arg00) == NOP_EXPR
11284 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
11286 tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
11287 if (TYPE_PRECISION (inner_type)
11288 == GET_MODE_BITSIZE (TYPE_MODE (inner_type))
11289 && TYPE_PRECISION (inner_type) < prec)
11291 prec = TYPE_PRECISION (inner_type);
11292 /* See if we can shorten the right shift. */
11294 shift_type = inner_type;
11297 zerobits = ~(unsigned HOST_WIDE_INT) 0;
11298 zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
11299 zerobits <<= prec - shiftc;
11300 /* For arithmetic shift if sign bit could be set, zerobits
11301 can contain actually sign bits, so no transformation is
11302 possible, unless MASK masks them all away. In that
11303 case the shift needs to be converted into logical shift. */
11304 if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
11305 && prec == TYPE_PRECISION (TREE_TYPE (arg0)))
11307 if ((mask & zerobits) == 0)
11308 shift_type = unsigned_type_for (TREE_TYPE (arg0));
11314 /* ((X << 16) & 0xff00) is (X, 0). */
11315 if ((mask & zerobits) == mask)
11316 return omit_one_operand (type, build_int_cst (type, 0), arg0);
11318 newmask = mask | zerobits;
11319 if (newmask != mask && (newmask & (newmask + 1)) == 0)
11323 /* Only do the transformation if NEWMASK is some integer
11325 for (prec = BITS_PER_UNIT;
11326 prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
11327 if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
11329 if (prec < HOST_BITS_PER_WIDE_INT
11330 || newmask == ~(unsigned HOST_WIDE_INT) 0)
11332 if (shift_type != TREE_TYPE (arg0))
11334 tem = fold_build2 (TREE_CODE (arg0), shift_type,
11335 fold_convert (shift_type,
11336 TREE_OPERAND (arg0, 0)),
11337 TREE_OPERAND (arg0, 1));
11338 tem = fold_convert (type, tem);
11342 return fold_build2 (BIT_AND_EXPR, type, tem,
11343 build_int_cst_type (TREE_TYPE (op1),
11352 /* Don't touch a floating-point divide by zero unless the mode
11353 of the constant can represent infinity. */
11354 if (TREE_CODE (arg1) == REAL_CST
11355 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
11356 && real_zerop (arg1))
11359 /* Optimize A / A to 1.0 if we don't care about
11360 NaNs or Infinities. Skip the transformation
11361 for non-real operands. */
11362 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
11363 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
11364 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
11365 && operand_equal_p (arg0, arg1, 0))
11367 tree r = build_real (TREE_TYPE (arg0), dconst1);
11369 return omit_two_operands (type, r, arg0, arg1);
11372 /* The complex version of the above A / A optimization. */
11373 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
11374 && operand_equal_p (arg0, arg1, 0))
11376 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
11377 if (! HONOR_NANS (TYPE_MODE (elem_type))
11378 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
11380 tree r = build_real (elem_type, dconst1);
11381 /* omit_two_operands will call fold_convert for us. */
11382 return omit_two_operands (type, r, arg0, arg1);
11386 /* (-A) / (-B) -> A / B */
11387 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
11388 return fold_build2 (RDIV_EXPR, type,
11389 TREE_OPERAND (arg0, 0),
11390 negate_expr (arg1));
11391 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
11392 return fold_build2 (RDIV_EXPR, type,
11393 negate_expr (arg0),
11394 TREE_OPERAND (arg1, 0));
11396 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
11397 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11398 && real_onep (arg1))
11399 return non_lvalue (fold_convert (type, arg0));
11401 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
11402 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11403 && real_minus_onep (arg1))
11404 return non_lvalue (fold_convert (type, negate_expr (arg0)));
11406 /* If ARG1 is a constant, we can convert this to a multiply by the
11407 reciprocal. This does not have the same rounding properties,
11408 so only do this if -freciprocal-math. We can actually
11409 always safely do it if ARG1 is a power of two, but it's hard to
11410 tell if it is or not in a portable manner. */
11411 if (TREE_CODE (arg1) == REAL_CST)
11413 if (flag_reciprocal_math
11414 && 0 != (tem = const_binop (code, build_real (type, dconst1),
11416 return fold_build2 (MULT_EXPR, type, arg0, tem);
11417 /* Find the reciprocal if optimizing and the result is exact. */
11421 r = TREE_REAL_CST (arg1);
11422 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
11424 tem = build_real (type, r);
11425 return fold_build2 (MULT_EXPR, type,
11426 fold_convert (type, arg0), tem);
11430 /* Convert A/B/C to A/(B*C). */
11431 if (flag_reciprocal_math
11432 && TREE_CODE (arg0) == RDIV_EXPR)
11433 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
11434 fold_build2 (MULT_EXPR, type,
11435 TREE_OPERAND (arg0, 1), arg1));
11437 /* Convert A/(B/C) to (A/B)*C. */
11438 if (flag_reciprocal_math
11439 && TREE_CODE (arg1) == RDIV_EXPR)
11440 return fold_build2 (MULT_EXPR, type,
11441 fold_build2 (RDIV_EXPR, type, arg0,
11442 TREE_OPERAND (arg1, 0)),
11443 TREE_OPERAND (arg1, 1));
11445 /* Convert C1/(X*C2) into (C1/C2)/X. */
11446 if (flag_reciprocal_math
11447 && TREE_CODE (arg1) == MULT_EXPR
11448 && TREE_CODE (arg0) == REAL_CST
11449 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
11451 tree tem = const_binop (RDIV_EXPR, arg0,
11452 TREE_OPERAND (arg1, 1), 0);
11454 return fold_build2 (RDIV_EXPR, type, tem,
11455 TREE_OPERAND (arg1, 0));
11458 if (flag_unsafe_math_optimizations)
11460 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
11461 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
11463 /* Optimize sin(x)/cos(x) as tan(x). */
11464 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
11465 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
11466 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
11467 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11468 CALL_EXPR_ARG (arg1, 0), 0))
11470 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11472 if (tanfn != NULL_TREE)
11473 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11476 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
11477 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
11478 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
11479 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
11480 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11481 CALL_EXPR_ARG (arg1, 0), 0))
11483 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11485 if (tanfn != NULL_TREE)
11487 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11488 return fold_build2 (RDIV_EXPR, type,
11489 build_real (type, dconst1), tmp);
11493 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
11494 NaNs or Infinities. */
11495 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
11496 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
11497 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
11499 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11500 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11502 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11503 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11504 && operand_equal_p (arg00, arg01, 0))
11506 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11508 if (cosfn != NULL_TREE)
11509 return build_call_expr (cosfn, 1, arg00);
11513 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11514 NaNs or Infinities. */
11515 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
11516 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
11517 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
11519 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11520 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11522 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11523 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11524 && operand_equal_p (arg00, arg01, 0))
11526 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11528 if (cosfn != NULL_TREE)
11530 tree tmp = build_call_expr (cosfn, 1, arg00);
11531 return fold_build2 (RDIV_EXPR, type,
11532 build_real (type, dconst1),
11538 /* Optimize pow(x,c)/x as pow(x,c-1). */
11539 if (fcode0 == BUILT_IN_POW
11540 || fcode0 == BUILT_IN_POWF
11541 || fcode0 == BUILT_IN_POWL)
11543 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11544 tree arg01 = CALL_EXPR_ARG (arg0, 1);
11545 if (TREE_CODE (arg01) == REAL_CST
11546 && !TREE_OVERFLOW (arg01)
11547 && operand_equal_p (arg1, arg00, 0))
11549 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
11553 c = TREE_REAL_CST (arg01);
11554 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
11555 arg = build_real (type, c);
11556 return build_call_expr (powfn, 2, arg1, arg);
11560 /* Optimize a/root(b/c) into a*root(c/b). */
11561 if (BUILTIN_ROOT_P (fcode1))
11563 tree rootarg = CALL_EXPR_ARG (arg1, 0);
11565 if (TREE_CODE (rootarg) == RDIV_EXPR)
11567 tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11568 tree b = TREE_OPERAND (rootarg, 0);
11569 tree c = TREE_OPERAND (rootarg, 1);
11571 tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
11573 tmp = build_call_expr (rootfn, 1, tmp);
11574 return fold_build2 (MULT_EXPR, type, arg0, tmp);
11578 /* Optimize x/expN(y) into x*expN(-y). */
11579 if (BUILTIN_EXPONENT_P (fcode1))
11581 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11582 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
11583 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
11584 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11587 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11588 if (fcode1 == BUILT_IN_POW
11589 || fcode1 == BUILT_IN_POWF
11590 || fcode1 == BUILT_IN_POWL)
11592 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11593 tree arg10 = CALL_EXPR_ARG (arg1, 0);
11594 tree arg11 = CALL_EXPR_ARG (arg1, 1);
11595 tree neg11 = fold_convert (type, negate_expr (arg11));
11596 arg1 = build_call_expr (powfn, 2, arg10, neg11);
11597 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11602 case TRUNC_DIV_EXPR:
11603 case FLOOR_DIV_EXPR:
11604 /* Simplify A / (B << N) where A and B are positive and B is
11605 a power of 2, to A >> (N + log2(B)). */
11606 strict_overflow_p = false;
11607 if (TREE_CODE (arg1) == LSHIFT_EXPR
11608 && (TYPE_UNSIGNED (type)
11609 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11611 tree sval = TREE_OPERAND (arg1, 0);
11612 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
11614 tree sh_cnt = TREE_OPERAND (arg1, 1);
11615 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
11617 if (strict_overflow_p)
11618 fold_overflow_warning (("assuming signed overflow does not "
11619 "occur when simplifying A / (B << N)"),
11620 WARN_STRICT_OVERFLOW_MISC);
11622 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
11623 sh_cnt, build_int_cst (NULL_TREE, pow2));
11624 return fold_build2 (RSHIFT_EXPR, type,
11625 fold_convert (type, arg0), sh_cnt);
11629 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
11630 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
11631 if (INTEGRAL_TYPE_P (type)
11632 && TYPE_UNSIGNED (type)
11633 && code == FLOOR_DIV_EXPR)
11634 return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
11638 case ROUND_DIV_EXPR:
11639 case CEIL_DIV_EXPR:
11640 case EXACT_DIV_EXPR:
11641 if (integer_onep (arg1))
11642 return non_lvalue (fold_convert (type, arg0));
11643 if (integer_zerop (arg1))
11645 /* X / -1 is -X. */
11646 if (!TYPE_UNSIGNED (type)
11647 && TREE_CODE (arg1) == INTEGER_CST
11648 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11649 && TREE_INT_CST_HIGH (arg1) == -1)
11650 return fold_convert (type, negate_expr (arg0));
11652 /* Convert -A / -B to A / B when the type is signed and overflow is
11654 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11655 && TREE_CODE (arg0) == NEGATE_EXPR
11656 && negate_expr_p (arg1))
11658 if (INTEGRAL_TYPE_P (type))
11659 fold_overflow_warning (("assuming signed overflow does not occur "
11660 "when distributing negation across "
11662 WARN_STRICT_OVERFLOW_MISC);
11663 return fold_build2 (code, type,
11664 fold_convert (type, TREE_OPERAND (arg0, 0)),
11665 fold_convert (type, negate_expr (arg1)));
11667 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11668 && TREE_CODE (arg1) == NEGATE_EXPR
11669 && negate_expr_p (arg0))
11671 if (INTEGRAL_TYPE_P (type))
11672 fold_overflow_warning (("assuming signed overflow does not occur "
11673 "when distributing negation across "
11675 WARN_STRICT_OVERFLOW_MISC);
11676 return fold_build2 (code, type,
11677 fold_convert (type, negate_expr (arg0)),
11678 fold_convert (type, TREE_OPERAND (arg1, 0)));
11681 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11682 operation, EXACT_DIV_EXPR.
11684 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11685 At one time others generated faster code, it's not clear if they do
11686 after the last round to changes to the DIV code in expmed.c. */
11687 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
11688 && multiple_of_p (type, arg0, arg1))
11689 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
11691 strict_overflow_p = false;
11692 if (TREE_CODE (arg1) == INTEGER_CST
11693 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11694 &strict_overflow_p)))
11696 if (strict_overflow_p)
11697 fold_overflow_warning (("assuming signed overflow does not occur "
11698 "when simplifying division"),
11699 WARN_STRICT_OVERFLOW_MISC);
11700 return fold_convert (type, tem);
11705 case CEIL_MOD_EXPR:
11706 case FLOOR_MOD_EXPR:
11707 case ROUND_MOD_EXPR:
11708 case TRUNC_MOD_EXPR:
11709 /* X % 1 is always zero, but be sure to preserve any side
11711 if (integer_onep (arg1))
11712 return omit_one_operand (type, integer_zero_node, arg0);
11714 /* X % 0, return X % 0 unchanged so that we can get the
11715 proper warnings and errors. */
11716 if (integer_zerop (arg1))
11719 /* 0 % X is always zero, but be sure to preserve any side
11720 effects in X. Place this after checking for X == 0. */
11721 if (integer_zerop (arg0))
11722 return omit_one_operand (type, integer_zero_node, arg1);
11724 /* X % -1 is zero. */
11725 if (!TYPE_UNSIGNED (type)
11726 && TREE_CODE (arg1) == INTEGER_CST
11727 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11728 && TREE_INT_CST_HIGH (arg1) == -1)
11729 return omit_one_operand (type, integer_zero_node, arg0);
11731 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11732 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11733 strict_overflow_p = false;
11734 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
11735 && (TYPE_UNSIGNED (type)
11736 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11739 /* Also optimize A % (C << N) where C is a power of 2,
11740 to A & ((C << N) - 1). */
11741 if (TREE_CODE (arg1) == LSHIFT_EXPR)
11742 c = TREE_OPERAND (arg1, 0);
11744 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
11746 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
11747 build_int_cst (TREE_TYPE (arg1), 1));
11748 if (strict_overflow_p)
11749 fold_overflow_warning (("assuming signed overflow does not "
11750 "occur when simplifying "
11751 "X % (power of two)"),
11752 WARN_STRICT_OVERFLOW_MISC);
11753 return fold_build2 (BIT_AND_EXPR, type,
11754 fold_convert (type, arg0),
11755 fold_convert (type, mask));
11759 /* X % -C is the same as X % C. */
11760 if (code == TRUNC_MOD_EXPR
11761 && !TYPE_UNSIGNED (type)
11762 && TREE_CODE (arg1) == INTEGER_CST
11763 && !TREE_OVERFLOW (arg1)
11764 && TREE_INT_CST_HIGH (arg1) < 0
11765 && !TYPE_OVERFLOW_TRAPS (type)
11766 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11767 && !sign_bit_p (arg1, arg1))
11768 return fold_build2 (code, type, fold_convert (type, arg0),
11769 fold_convert (type, negate_expr (arg1)));
11771 /* X % -Y is the same as X % Y. */
11772 if (code == TRUNC_MOD_EXPR
11773 && !TYPE_UNSIGNED (type)
11774 && TREE_CODE (arg1) == NEGATE_EXPR
11775 && !TYPE_OVERFLOW_TRAPS (type))
11776 return fold_build2 (code, type, fold_convert (type, arg0),
11777 fold_convert (type, TREE_OPERAND (arg1, 0)));
11779 if (TREE_CODE (arg1) == INTEGER_CST
11780 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11781 &strict_overflow_p)))
11783 if (strict_overflow_p)
11784 fold_overflow_warning (("assuming signed overflow does not occur "
11785 "when simplifying modulus"),
11786 WARN_STRICT_OVERFLOW_MISC);
11787 return fold_convert (type, tem);
11794 if (integer_all_onesp (arg0))
11795 return omit_one_operand (type, arg0, arg1);
11799 /* Optimize -1 >> x for arithmetic right shifts. */
11800 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type)
11801 && tree_expr_nonnegative_p (arg1))
11802 return omit_one_operand (type, arg0, arg1);
11803 /* ... fall through ... */
11807 if (integer_zerop (arg1))
11808 return non_lvalue (fold_convert (type, arg0));
11809 if (integer_zerop (arg0))
11810 return omit_one_operand (type, arg0, arg1);
11812 /* Since negative shift count is not well-defined,
11813 don't try to compute it in the compiler. */
11814 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
11817 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11818 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
11819 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11820 && host_integerp (TREE_OPERAND (arg0, 1), false)
11821 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11823 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
11824 + TREE_INT_CST_LOW (arg1));
11826 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11827 being well defined. */
11828 if (low >= TYPE_PRECISION (type))
11830 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
11831 low = low % TYPE_PRECISION (type);
11832 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
11833 return build_int_cst (type, 0);
11835 low = TYPE_PRECISION (type) - 1;
11838 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11839 build_int_cst (type, low));
11842 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11843 into x & ((unsigned)-1 >> c) for unsigned types. */
11844 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
11845 || (TYPE_UNSIGNED (type)
11846 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
11847 && host_integerp (arg1, false)
11848 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11849 && host_integerp (TREE_OPERAND (arg0, 1), false)
11850 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11852 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
11853 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
11859 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
11861 lshift = build_int_cst (type, -1);
11862 lshift = int_const_binop (code, lshift, arg1, 0);
11864 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
11868 /* Rewrite an LROTATE_EXPR by a constant into an
11869 RROTATE_EXPR by a new constant. */
11870 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
11872 tree tem = build_int_cst (TREE_TYPE (arg1),
11873 TYPE_PRECISION (type));
11874 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
11875 return fold_build2 (RROTATE_EXPR, type, op0, tem);
11878 /* If we have a rotate of a bit operation with the rotate count and
11879 the second operand of the bit operation both constant,
11880 permute the two operations. */
11881 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11882 && (TREE_CODE (arg0) == BIT_AND_EXPR
11883 || TREE_CODE (arg0) == BIT_IOR_EXPR
11884 || TREE_CODE (arg0) == BIT_XOR_EXPR)
11885 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11886 return fold_build2 (TREE_CODE (arg0), type,
11887 fold_build2 (code, type,
11888 TREE_OPERAND (arg0, 0), arg1),
11889 fold_build2 (code, type,
11890 TREE_OPERAND (arg0, 1), arg1));
11892 /* Two consecutive rotates adding up to the precision of the
11893 type can be ignored. */
11894 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11895 && TREE_CODE (arg0) == RROTATE_EXPR
11896 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11897 && TREE_INT_CST_HIGH (arg1) == 0
11898 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
11899 && ((TREE_INT_CST_LOW (arg1)
11900 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
11901 == (unsigned int) TYPE_PRECISION (type)))
11902 return TREE_OPERAND (arg0, 0);
11904 /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
11905 (X & C2) >> C1 into (X >> C1) & (C2 >> C1)
11906 if the latter can be further optimized. */
11907 if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
11908 && TREE_CODE (arg0) == BIT_AND_EXPR
11909 && TREE_CODE (arg1) == INTEGER_CST
11910 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11912 tree mask = fold_build2 (code, type,
11913 fold_convert (type, TREE_OPERAND (arg0, 1)),
11915 tree shift = fold_build2 (code, type,
11916 fold_convert (type, TREE_OPERAND (arg0, 0)),
11918 tem = fold_binary (BIT_AND_EXPR, type, shift, mask);
11926 if (operand_equal_p (arg0, arg1, 0))
11927 return omit_one_operand (type, arg0, arg1);
11928 if (INTEGRAL_TYPE_P (type)
11929 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
11930 return omit_one_operand (type, arg1, arg0);
11931 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
11937 if (operand_equal_p (arg0, arg1, 0))
11938 return omit_one_operand (type, arg0, arg1);
11939 if (INTEGRAL_TYPE_P (type)
11940 && TYPE_MAX_VALUE (type)
11941 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
11942 return omit_one_operand (type, arg1, arg0);
11943 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
11948 case TRUTH_ANDIF_EXPR:
11949 /* Note that the operands of this must be ints
11950 and their values must be 0 or 1.
11951 ("true" is a fixed value perhaps depending on the language.) */
11952 /* If first arg is constant zero, return it. */
11953 if (integer_zerop (arg0))
11954 return fold_convert (type, arg0);
11955 case TRUTH_AND_EXPR:
11956 /* If either arg is constant true, drop it. */
11957 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11958 return non_lvalue (fold_convert (type, arg1));
11959 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
11960 /* Preserve sequence points. */
11961 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11962 return non_lvalue (fold_convert (type, arg0));
11963 /* If second arg is constant zero, result is zero, but first arg
11964 must be evaluated. */
11965 if (integer_zerop (arg1))
11966 return omit_one_operand (type, arg1, arg0);
11967 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11968 case will be handled here. */
11969 if (integer_zerop (arg0))
11970 return omit_one_operand (type, arg0, arg1);
11972 /* !X && X is always false. */
11973 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11974 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11975 return omit_one_operand (type, integer_zero_node, arg1);
11976 /* X && !X is always false. */
11977 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11978 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11979 return omit_one_operand (type, integer_zero_node, arg0);
11981 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
11982 means A >= Y && A != MAX, but in this case we know that
11985 if (!TREE_SIDE_EFFECTS (arg0)
11986 && !TREE_SIDE_EFFECTS (arg1))
11988 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
11989 if (tem && !operand_equal_p (tem, arg0, 0))
11990 return fold_build2 (code, type, tem, arg1);
11992 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
11993 if (tem && !operand_equal_p (tem, arg1, 0))
11994 return fold_build2 (code, type, arg0, tem);
11998 /* We only do these simplifications if we are optimizing. */
12002 /* Check for things like (A || B) && (A || C). We can convert this
12003 to A || (B && C). Note that either operator can be any of the four
12004 truth and/or operations and the transformation will still be
12005 valid. Also note that we only care about order for the
12006 ANDIF and ORIF operators. If B contains side effects, this
12007 might change the truth-value of A. */
12008 if (TREE_CODE (arg0) == TREE_CODE (arg1)
12009 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
12010 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
12011 || TREE_CODE (arg0) == TRUTH_AND_EXPR
12012 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
12013 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
12015 tree a00 = TREE_OPERAND (arg0, 0);
12016 tree a01 = TREE_OPERAND (arg0, 1);
12017 tree a10 = TREE_OPERAND (arg1, 0);
12018 tree a11 = TREE_OPERAND (arg1, 1);
12019 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
12020 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
12021 && (code == TRUTH_AND_EXPR
12022 || code == TRUTH_OR_EXPR));
12024 if (operand_equal_p (a00, a10, 0))
12025 return fold_build2 (TREE_CODE (arg0), type, a00,
12026 fold_build2 (code, type, a01, a11));
12027 else if (commutative && operand_equal_p (a00, a11, 0))
12028 return fold_build2 (TREE_CODE (arg0), type, a00,
12029 fold_build2 (code, type, a01, a10));
12030 else if (commutative && operand_equal_p (a01, a10, 0))
12031 return fold_build2 (TREE_CODE (arg0), type, a01,
12032 fold_build2 (code, type, a00, a11));
12034 /* This case if tricky because we must either have commutative
12035 operators or else A10 must not have side-effects. */
12037 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
12038 && operand_equal_p (a01, a11, 0))
12039 return fold_build2 (TREE_CODE (arg0), type,
12040 fold_build2 (code, type, a00, a10),
12044 /* See if we can build a range comparison. */
12045 if (0 != (tem = fold_range_test (code, type, op0, op1)))
12048 /* Check for the possibility of merging component references. If our
12049 lhs is another similar operation, try to merge its rhs with our
12050 rhs. Then try to merge our lhs and rhs. */
12051 if (TREE_CODE (arg0) == code
12052 && 0 != (tem = fold_truthop (code, type,
12053 TREE_OPERAND (arg0, 1), arg1)))
12054 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
12056 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
12061 case TRUTH_ORIF_EXPR:
12062 /* Note that the operands of this must be ints
12063 and their values must be 0 or true.
12064 ("true" is a fixed value perhaps depending on the language.) */
12065 /* If first arg is constant true, return it. */
12066 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
12067 return fold_convert (type, arg0);
12068 case TRUTH_OR_EXPR:
12069 /* If either arg is constant zero, drop it. */
12070 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
12071 return non_lvalue (fold_convert (type, arg1));
12072 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
12073 /* Preserve sequence points. */
12074 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
12075 return non_lvalue (fold_convert (type, arg0));
12076 /* If second arg is constant true, result is true, but we must
12077 evaluate first arg. */
12078 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
12079 return omit_one_operand (type, arg1, arg0);
12080 /* Likewise for first arg, but note this only occurs here for
12082 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
12083 return omit_one_operand (type, arg0, arg1);
12085 /* !X || X is always true. */
12086 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
12087 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
12088 return omit_one_operand (type, integer_one_node, arg1);
12089 /* X || !X is always true. */
12090 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
12091 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
12092 return omit_one_operand (type, integer_one_node, arg0);
12096 case TRUTH_XOR_EXPR:
12097 /* If the second arg is constant zero, drop it. */
12098 if (integer_zerop (arg1))
12099 return non_lvalue (fold_convert (type, arg0));
12100 /* If the second arg is constant true, this is a logical inversion. */
12101 if (integer_onep (arg1))
12103 /* Only call invert_truthvalue if operand is a truth value. */
12104 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
12105 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
12107 tem = invert_truthvalue (arg0);
12108 return non_lvalue (fold_convert (type, tem));
12110 /* Identical arguments cancel to zero. */
12111 if (operand_equal_p (arg0, arg1, 0))
12112 return omit_one_operand (type, integer_zero_node, arg0);
12114 /* !X ^ X is always true. */
12115 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
12116 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
12117 return omit_one_operand (type, integer_one_node, arg1);
12119 /* X ^ !X is always true. */
12120 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
12121 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
12122 return omit_one_operand (type, integer_one_node, arg0);
12128 tem = fold_comparison (code, type, op0, op1);
12129 if (tem != NULL_TREE)
12132 /* bool_var != 0 becomes bool_var. */
12133 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
12134 && code == NE_EXPR)
12135 return non_lvalue (fold_convert (type, arg0));
12137 /* bool_var == 1 becomes bool_var. */
12138 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
12139 && code == EQ_EXPR)
12140 return non_lvalue (fold_convert (type, arg0));
12142 /* bool_var != 1 becomes !bool_var. */
12143 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
12144 && code == NE_EXPR)
12145 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
12147 /* bool_var == 0 becomes !bool_var. */
12148 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
12149 && code == EQ_EXPR)
12150 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
12152 /* If this is an equality comparison of the address of two non-weak,
12153 unaliased symbols neither of which are extern (since we do not
12154 have access to attributes for externs), then we know the result. */
12155 if (TREE_CODE (arg0) == ADDR_EXPR
12156 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
12157 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
12158 && ! lookup_attribute ("alias",
12159 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
12160 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
12161 && TREE_CODE (arg1) == ADDR_EXPR
12162 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
12163 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
12164 && ! lookup_attribute ("alias",
12165 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
12166 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
12168 /* We know that we're looking at the address of two
12169 non-weak, unaliased, static _DECL nodes.
12171 It is both wasteful and incorrect to call operand_equal_p
12172 to compare the two ADDR_EXPR nodes. It is wasteful in that
12173 all we need to do is test pointer equality for the arguments
12174 to the two ADDR_EXPR nodes. It is incorrect to use
12175 operand_equal_p as that function is NOT equivalent to a
12176 C equality test. It can in fact return false for two
12177 objects which would test as equal using the C equality
12179 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
12180 return constant_boolean_node (equal
12181 ? code == EQ_EXPR : code != EQ_EXPR,
12185 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
12186 a MINUS_EXPR of a constant, we can convert it into a comparison with
12187 a revised constant as long as no overflow occurs. */
12188 if (TREE_CODE (arg1) == INTEGER_CST
12189 && (TREE_CODE (arg0) == PLUS_EXPR
12190 || TREE_CODE (arg0) == MINUS_EXPR)
12191 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12192 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
12193 ? MINUS_EXPR : PLUS_EXPR,
12194 fold_convert (TREE_TYPE (arg0), arg1),
12195 TREE_OPERAND (arg0, 1), 0))
12196 && !TREE_OVERFLOW (tem))
12197 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
12199 /* Similarly for a NEGATE_EXPR. */
12200 if (TREE_CODE (arg0) == NEGATE_EXPR
12201 && TREE_CODE (arg1) == INTEGER_CST
12202 && 0 != (tem = negate_expr (arg1))
12203 && TREE_CODE (tem) == INTEGER_CST
12204 && !TREE_OVERFLOW (tem))
12205 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
12207 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
12208 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12209 && TREE_CODE (arg1) == INTEGER_CST
12210 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12211 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12212 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
12213 fold_convert (TREE_TYPE (arg0), arg1),
12214 TREE_OPERAND (arg0, 1)));
12216 /* Transform comparisons of the form X +- C CMP X. */
12217 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12218 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12219 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12220 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
12221 || POINTER_TYPE_P (TREE_TYPE (arg0))))
12223 tree cst = TREE_OPERAND (arg0, 1);
12225 if (code == EQ_EXPR
12226 && !integer_zerop (cst))
12227 return omit_two_operands (type, boolean_false_node,
12228 TREE_OPERAND (arg0, 0), arg1);
12230 return omit_two_operands (type, boolean_true_node,
12231 TREE_OPERAND (arg0, 0), arg1);
12234 /* If we have X - Y == 0, we can convert that to X == Y and similarly
12235 for !=. Don't do this for ordered comparisons due to overflow. */
12236 if (TREE_CODE (arg0) == MINUS_EXPR
12237 && integer_zerop (arg1))
12238 return fold_build2 (code, type,
12239 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
12241 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
12242 if (TREE_CODE (arg0) == ABS_EXPR
12243 && (integer_zerop (arg1) || real_zerop (arg1)))
12244 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
12246 /* If this is an EQ or NE comparison with zero and ARG0 is
12247 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
12248 two operations, but the latter can be done in one less insn
12249 on machines that have only two-operand insns or on which a
12250 constant cannot be the first operand. */
12251 if (TREE_CODE (arg0) == BIT_AND_EXPR
12252 && integer_zerop (arg1))
12254 tree arg00 = TREE_OPERAND (arg0, 0);
12255 tree arg01 = TREE_OPERAND (arg0, 1);
12256 if (TREE_CODE (arg00) == LSHIFT_EXPR
12257 && integer_onep (TREE_OPERAND (arg00, 0)))
12259 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
12260 arg01, TREE_OPERAND (arg00, 1));
12261 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
12262 build_int_cst (TREE_TYPE (arg0), 1));
12263 return fold_build2 (code, type,
12264 fold_convert (TREE_TYPE (arg1), tem), arg1);
12266 else if (TREE_CODE (arg01) == LSHIFT_EXPR
12267 && integer_onep (TREE_OPERAND (arg01, 0)))
12269 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
12270 arg00, TREE_OPERAND (arg01, 1));
12271 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
12272 build_int_cst (TREE_TYPE (arg0), 1));
12273 return fold_build2 (code, type,
12274 fold_convert (TREE_TYPE (arg1), tem), arg1);
12278 /* If this is an NE or EQ comparison of zero against the result of a
12279 signed MOD operation whose second operand is a power of 2, make
12280 the MOD operation unsigned since it is simpler and equivalent. */
12281 if (integer_zerop (arg1)
12282 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
12283 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
12284 || TREE_CODE (arg0) == CEIL_MOD_EXPR
12285 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
12286 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
12287 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12289 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
12290 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
12291 fold_convert (newtype,
12292 TREE_OPERAND (arg0, 0)),
12293 fold_convert (newtype,
12294 TREE_OPERAND (arg0, 1)));
12296 return fold_build2 (code, type, newmod,
12297 fold_convert (newtype, arg1));
12300 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
12301 C1 is a valid shift constant, and C2 is a power of two, i.e.
12303 if (TREE_CODE (arg0) == BIT_AND_EXPR
12304 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
12305 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
12307 && integer_pow2p (TREE_OPERAND (arg0, 1))
12308 && integer_zerop (arg1))
12310 tree itype = TREE_TYPE (arg0);
12311 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
12312 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
12314 /* Check for a valid shift count. */
12315 if (TREE_INT_CST_HIGH (arg001) == 0
12316 && TREE_INT_CST_LOW (arg001) < prec)
12318 tree arg01 = TREE_OPERAND (arg0, 1);
12319 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12320 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
12321 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
12322 can be rewritten as (X & (C2 << C1)) != 0. */
12323 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
12325 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
12326 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
12327 return fold_build2 (code, type, tem, arg1);
12329 /* Otherwise, for signed (arithmetic) shifts,
12330 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
12331 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
12332 else if (!TYPE_UNSIGNED (itype))
12333 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
12334 arg000, build_int_cst (itype, 0));
12335 /* Otherwise, of unsigned (logical) shifts,
12336 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
12337 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
12339 return omit_one_operand (type,
12340 code == EQ_EXPR ? integer_one_node
12341 : integer_zero_node,
12346 /* If this is an NE comparison of zero with an AND of one, remove the
12347 comparison since the AND will give the correct value. */
12348 if (code == NE_EXPR
12349 && integer_zerop (arg1)
12350 && TREE_CODE (arg0) == BIT_AND_EXPR
12351 && integer_onep (TREE_OPERAND (arg0, 1)))
12352 return fold_convert (type, arg0);
12354 /* If we have (A & C) == C where C is a power of 2, convert this into
12355 (A & C) != 0. Similarly for NE_EXPR. */
12356 if (TREE_CODE (arg0) == BIT_AND_EXPR
12357 && integer_pow2p (TREE_OPERAND (arg0, 1))
12358 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12359 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12360 arg0, fold_convert (TREE_TYPE (arg0),
12361 integer_zero_node));
12363 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
12364 bit, then fold the expression into A < 0 or A >= 0. */
12365 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
12369 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
12370 Similarly for NE_EXPR. */
12371 if (TREE_CODE (arg0) == BIT_AND_EXPR
12372 && TREE_CODE (arg1) == INTEGER_CST
12373 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12375 tree notc = fold_build1 (BIT_NOT_EXPR,
12376 TREE_TYPE (TREE_OPERAND (arg0, 1)),
12377 TREE_OPERAND (arg0, 1));
12378 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12380 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
12381 if (integer_nonzerop (dandnotc))
12382 return omit_one_operand (type, rslt, arg0);
12385 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
12386 Similarly for NE_EXPR. */
12387 if (TREE_CODE (arg0) == BIT_IOR_EXPR
12388 && TREE_CODE (arg1) == INTEGER_CST
12389 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12391 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
12392 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12393 TREE_OPERAND (arg0, 1), notd);
12394 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
12395 if (integer_nonzerop (candnotd))
12396 return omit_one_operand (type, rslt, arg0);
12399 /* If this is a comparison of a field, we may be able to simplify it. */
12400 if ((TREE_CODE (arg0) == COMPONENT_REF
12401 || TREE_CODE (arg0) == BIT_FIELD_REF)
12402 /* Handle the constant case even without -O
12403 to make sure the warnings are given. */
12404 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
12406 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
12411 /* Optimize comparisons of strlen vs zero to a compare of the
12412 first character of the string vs zero. To wit,
12413 strlen(ptr) == 0 => *ptr == 0
12414 strlen(ptr) != 0 => *ptr != 0
12415 Other cases should reduce to one of these two (or a constant)
12416 due to the return value of strlen being unsigned. */
12417 if (TREE_CODE (arg0) == CALL_EXPR
12418 && integer_zerop (arg1))
12420 tree fndecl = get_callee_fndecl (arg0);
12423 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
12424 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
12425 && call_expr_nargs (arg0) == 1
12426 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
12428 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
12429 return fold_build2 (code, type, iref,
12430 build_int_cst (TREE_TYPE (iref), 0));
12434 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
12435 of X. Similarly fold (X >> C) == 0 into X >= 0. */
12436 if (TREE_CODE (arg0) == RSHIFT_EXPR
12437 && integer_zerop (arg1)
12438 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12440 tree arg00 = TREE_OPERAND (arg0, 0);
12441 tree arg01 = TREE_OPERAND (arg0, 1);
12442 tree itype = TREE_TYPE (arg00);
12443 if (TREE_INT_CST_HIGH (arg01) == 0
12444 && TREE_INT_CST_LOW (arg01)
12445 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
12447 if (TYPE_UNSIGNED (itype))
12449 itype = signed_type_for (itype);
12450 arg00 = fold_convert (itype, arg00);
12452 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
12453 type, arg00, build_int_cst (itype, 0));
12457 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
12458 if (integer_zerop (arg1)
12459 && TREE_CODE (arg0) == BIT_XOR_EXPR)
12460 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12461 TREE_OPERAND (arg0, 1));
12463 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
12464 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12465 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12466 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12467 build_int_cst (TREE_TYPE (arg1), 0));
12468 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
12469 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12470 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12471 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
12472 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
12473 build_int_cst (TREE_TYPE (arg1), 0));
12475 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
12476 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12477 && TREE_CODE (arg1) == INTEGER_CST
12478 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12479 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12480 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
12481 TREE_OPERAND (arg0, 1), arg1));
12483 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
12484 (X & C) == 0 when C is a single bit. */
12485 if (TREE_CODE (arg0) == BIT_AND_EXPR
12486 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
12487 && integer_zerop (arg1)
12488 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12490 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12491 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
12492 TREE_OPERAND (arg0, 1));
12493 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
12497 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12498 constant C is a power of two, i.e. a single bit. */
12499 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12500 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12501 && integer_zerop (arg1)
12502 && integer_pow2p (TREE_OPERAND (arg0, 1))
12503 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12504 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12506 tree arg00 = TREE_OPERAND (arg0, 0);
12507 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12508 arg00, build_int_cst (TREE_TYPE (arg00), 0));
12511 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12512 when is C is a power of two, i.e. a single bit. */
12513 if (TREE_CODE (arg0) == BIT_AND_EXPR
12514 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
12515 && integer_zerop (arg1)
12516 && integer_pow2p (TREE_OPERAND (arg0, 1))
12517 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12518 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12520 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12521 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
12522 arg000, TREE_OPERAND (arg0, 1));
12523 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12524 tem, build_int_cst (TREE_TYPE (tem), 0));
12527 if (integer_zerop (arg1)
12528 && tree_expr_nonzero_p (arg0))
12530 tree res = constant_boolean_node (code==NE_EXPR, type);
12531 return omit_one_operand (type, res, arg0);
12534 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12535 if (TREE_CODE (arg0) == NEGATE_EXPR
12536 && TREE_CODE (arg1) == NEGATE_EXPR)
12537 return fold_build2 (code, type,
12538 TREE_OPERAND (arg0, 0),
12539 TREE_OPERAND (arg1, 0));
12541 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12542 if (TREE_CODE (arg0) == BIT_AND_EXPR
12543 && TREE_CODE (arg1) == BIT_AND_EXPR)
12545 tree arg00 = TREE_OPERAND (arg0, 0);
12546 tree arg01 = TREE_OPERAND (arg0, 1);
12547 tree arg10 = TREE_OPERAND (arg1, 0);
12548 tree arg11 = TREE_OPERAND (arg1, 1);
12549 tree itype = TREE_TYPE (arg0);
12551 if (operand_equal_p (arg01, arg11, 0))
12552 return fold_build2 (code, type,
12553 fold_build2 (BIT_AND_EXPR, itype,
12554 fold_build2 (BIT_XOR_EXPR, itype,
12557 build_int_cst (itype, 0));
12559 if (operand_equal_p (arg01, arg10, 0))
12560 return fold_build2 (code, type,
12561 fold_build2 (BIT_AND_EXPR, itype,
12562 fold_build2 (BIT_XOR_EXPR, itype,
12565 build_int_cst (itype, 0));
12567 if (operand_equal_p (arg00, arg11, 0))
12568 return fold_build2 (code, type,
12569 fold_build2 (BIT_AND_EXPR, itype,
12570 fold_build2 (BIT_XOR_EXPR, itype,
12573 build_int_cst (itype, 0));
12575 if (operand_equal_p (arg00, arg10, 0))
12576 return fold_build2 (code, type,
12577 fold_build2 (BIT_AND_EXPR, itype,
12578 fold_build2 (BIT_XOR_EXPR, itype,
12581 build_int_cst (itype, 0));
12584 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12585 && TREE_CODE (arg1) == BIT_XOR_EXPR)
12587 tree arg00 = TREE_OPERAND (arg0, 0);
12588 tree arg01 = TREE_OPERAND (arg0, 1);
12589 tree arg10 = TREE_OPERAND (arg1, 0);
12590 tree arg11 = TREE_OPERAND (arg1, 1);
12591 tree itype = TREE_TYPE (arg0);
12593 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12594 operand_equal_p guarantees no side-effects so we don't need
12595 to use omit_one_operand on Z. */
12596 if (operand_equal_p (arg01, arg11, 0))
12597 return fold_build2 (code, type, arg00, arg10);
12598 if (operand_equal_p (arg01, arg10, 0))
12599 return fold_build2 (code, type, arg00, arg11);
12600 if (operand_equal_p (arg00, arg11, 0))
12601 return fold_build2 (code, type, arg01, arg10);
12602 if (operand_equal_p (arg00, arg10, 0))
12603 return fold_build2 (code, type, arg01, arg11);
12605 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12606 if (TREE_CODE (arg01) == INTEGER_CST
12607 && TREE_CODE (arg11) == INTEGER_CST)
12608 return fold_build2 (code, type,
12609 fold_build2 (BIT_XOR_EXPR, itype, arg00,
12610 fold_build2 (BIT_XOR_EXPR, itype,
12615 /* Attempt to simplify equality/inequality comparisons of complex
12616 values. Only lower the comparison if the result is known or
12617 can be simplified to a single scalar comparison. */
12618 if ((TREE_CODE (arg0) == COMPLEX_EXPR
12619 || TREE_CODE (arg0) == COMPLEX_CST)
12620 && (TREE_CODE (arg1) == COMPLEX_EXPR
12621 || TREE_CODE (arg1) == COMPLEX_CST))
12623 tree real0, imag0, real1, imag1;
12626 if (TREE_CODE (arg0) == COMPLEX_EXPR)
12628 real0 = TREE_OPERAND (arg0, 0);
12629 imag0 = TREE_OPERAND (arg0, 1);
12633 real0 = TREE_REALPART (arg0);
12634 imag0 = TREE_IMAGPART (arg0);
12637 if (TREE_CODE (arg1) == COMPLEX_EXPR)
12639 real1 = TREE_OPERAND (arg1, 0);
12640 imag1 = TREE_OPERAND (arg1, 1);
12644 real1 = TREE_REALPART (arg1);
12645 imag1 = TREE_IMAGPART (arg1);
12648 rcond = fold_binary (code, type, real0, real1);
12649 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
12651 if (integer_zerop (rcond))
12653 if (code == EQ_EXPR)
12654 return omit_two_operands (type, boolean_false_node,
12656 return fold_build2 (NE_EXPR, type, imag0, imag1);
12660 if (code == NE_EXPR)
12661 return omit_two_operands (type, boolean_true_node,
12663 return fold_build2 (EQ_EXPR, type, imag0, imag1);
12667 icond = fold_binary (code, type, imag0, imag1);
12668 if (icond && TREE_CODE (icond) == INTEGER_CST)
12670 if (integer_zerop (icond))
12672 if (code == EQ_EXPR)
12673 return omit_two_operands (type, boolean_false_node,
12675 return fold_build2 (NE_EXPR, type, real0, real1);
12679 if (code == NE_EXPR)
12680 return omit_two_operands (type, boolean_true_node,
12682 return fold_build2 (EQ_EXPR, type, real0, real1);
12693 tem = fold_comparison (code, type, op0, op1);
12694 if (tem != NULL_TREE)
12697 /* Transform comparisons of the form X +- C CMP X. */
12698 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12699 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12700 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
12701 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
12702 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12703 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
12705 tree arg01 = TREE_OPERAND (arg0, 1);
12706 enum tree_code code0 = TREE_CODE (arg0);
12709 if (TREE_CODE (arg01) == REAL_CST)
12710 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
12712 is_positive = tree_int_cst_sgn (arg01);
12714 /* (X - c) > X becomes false. */
12715 if (code == GT_EXPR
12716 && ((code0 == MINUS_EXPR && is_positive >= 0)
12717 || (code0 == PLUS_EXPR && is_positive <= 0)))
12719 if (TREE_CODE (arg01) == INTEGER_CST
12720 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12721 fold_overflow_warning (("assuming signed overflow does not "
12722 "occur when assuming that (X - c) > X "
12723 "is always false"),
12724 WARN_STRICT_OVERFLOW_ALL);
12725 return constant_boolean_node (0, type);
12728 /* Likewise (X + c) < X becomes false. */
12729 if (code == LT_EXPR
12730 && ((code0 == PLUS_EXPR && is_positive >= 0)
12731 || (code0 == MINUS_EXPR && is_positive <= 0)))
12733 if (TREE_CODE (arg01) == INTEGER_CST
12734 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12735 fold_overflow_warning (("assuming signed overflow does not "
12736 "occur when assuming that "
12737 "(X + c) < X is always false"),
12738 WARN_STRICT_OVERFLOW_ALL);
12739 return constant_boolean_node (0, type);
12742 /* Convert (X - c) <= X to true. */
12743 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12745 && ((code0 == MINUS_EXPR && is_positive >= 0)
12746 || (code0 == PLUS_EXPR && is_positive <= 0)))
12748 if (TREE_CODE (arg01) == INTEGER_CST
12749 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12750 fold_overflow_warning (("assuming signed overflow does not "
12751 "occur when assuming that "
12752 "(X - c) <= X is always true"),
12753 WARN_STRICT_OVERFLOW_ALL);
12754 return constant_boolean_node (1, type);
12757 /* Convert (X + c) >= X to true. */
12758 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12760 && ((code0 == PLUS_EXPR && is_positive >= 0)
12761 || (code0 == MINUS_EXPR && is_positive <= 0)))
12763 if (TREE_CODE (arg01) == INTEGER_CST
12764 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12765 fold_overflow_warning (("assuming signed overflow does not "
12766 "occur when assuming that "
12767 "(X + c) >= X is always true"),
12768 WARN_STRICT_OVERFLOW_ALL);
12769 return constant_boolean_node (1, type);
12772 if (TREE_CODE (arg01) == INTEGER_CST)
12774 /* Convert X + c > X and X - c < X to true for integers. */
12775 if (code == GT_EXPR
12776 && ((code0 == PLUS_EXPR && is_positive > 0)
12777 || (code0 == MINUS_EXPR && is_positive < 0)))
12779 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12780 fold_overflow_warning (("assuming signed overflow does "
12781 "not occur when assuming that "
12782 "(X + c) > X is always true"),
12783 WARN_STRICT_OVERFLOW_ALL);
12784 return constant_boolean_node (1, type);
12787 if (code == LT_EXPR
12788 && ((code0 == MINUS_EXPR && is_positive > 0)
12789 || (code0 == PLUS_EXPR && is_positive < 0)))
12791 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12792 fold_overflow_warning (("assuming signed overflow does "
12793 "not occur when assuming that "
12794 "(X - c) < X is always true"),
12795 WARN_STRICT_OVERFLOW_ALL);
12796 return constant_boolean_node (1, type);
12799 /* Convert X + c <= X and X - c >= X to false for integers. */
12800 if (code == LE_EXPR
12801 && ((code0 == PLUS_EXPR && is_positive > 0)
12802 || (code0 == MINUS_EXPR && is_positive < 0)))
12804 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12805 fold_overflow_warning (("assuming signed overflow does "
12806 "not occur when assuming that "
12807 "(X + c) <= X is always false"),
12808 WARN_STRICT_OVERFLOW_ALL);
12809 return constant_boolean_node (0, type);
12812 if (code == GE_EXPR
12813 && ((code0 == MINUS_EXPR && is_positive > 0)
12814 || (code0 == PLUS_EXPR && is_positive < 0)))
12816 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12817 fold_overflow_warning (("assuming signed overflow does "
12818 "not occur when assuming that "
12819 "(X - c) >= X is always false"),
12820 WARN_STRICT_OVERFLOW_ALL);
12821 return constant_boolean_node (0, type);
12826 /* Comparisons with the highest or lowest possible integer of
12827 the specified precision will have known values. */
12829 tree arg1_type = TREE_TYPE (arg1);
12830 unsigned int width = TYPE_PRECISION (arg1_type);
12832 if (TREE_CODE (arg1) == INTEGER_CST
12833 && width <= 2 * HOST_BITS_PER_WIDE_INT
12834 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
12836 HOST_WIDE_INT signed_max_hi;
12837 unsigned HOST_WIDE_INT signed_max_lo;
12838 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
12840 if (width <= HOST_BITS_PER_WIDE_INT)
12842 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12847 if (TYPE_UNSIGNED (arg1_type))
12849 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12855 max_lo = signed_max_lo;
12856 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12862 width -= HOST_BITS_PER_WIDE_INT;
12863 signed_max_lo = -1;
12864 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12869 if (TYPE_UNSIGNED (arg1_type))
12871 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12876 max_hi = signed_max_hi;
12877 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12881 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
12882 && TREE_INT_CST_LOW (arg1) == max_lo)
12886 return omit_one_operand (type, integer_zero_node, arg0);
12889 return fold_build2 (EQ_EXPR, type, op0, op1);
12892 return omit_one_operand (type, integer_one_node, arg0);
12895 return fold_build2 (NE_EXPR, type, op0, op1);
12897 /* The GE_EXPR and LT_EXPR cases above are not normally
12898 reached because of previous transformations. */
12903 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12905 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
12909 arg1 = const_binop (PLUS_EXPR, arg1,
12910 build_int_cst (TREE_TYPE (arg1), 1), 0);
12911 return fold_build2 (EQ_EXPR, type,
12912 fold_convert (TREE_TYPE (arg1), arg0),
12915 arg1 = const_binop (PLUS_EXPR, arg1,
12916 build_int_cst (TREE_TYPE (arg1), 1), 0);
12917 return fold_build2 (NE_EXPR, type,
12918 fold_convert (TREE_TYPE (arg1), arg0),
12923 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12925 && TREE_INT_CST_LOW (arg1) == min_lo)
12929 return omit_one_operand (type, integer_zero_node, arg0);
12932 return fold_build2 (EQ_EXPR, type, op0, op1);
12935 return omit_one_operand (type, integer_one_node, arg0);
12938 return fold_build2 (NE_EXPR, type, op0, op1);
12943 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12945 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
12949 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12950 return fold_build2 (NE_EXPR, type,
12951 fold_convert (TREE_TYPE (arg1), arg0),
12954 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12955 return fold_build2 (EQ_EXPR, type,
12956 fold_convert (TREE_TYPE (arg1), arg0),
12962 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
12963 && TREE_INT_CST_LOW (arg1) == signed_max_lo
12964 && TYPE_UNSIGNED (arg1_type)
12965 /* We will flip the signedness of the comparison operator
12966 associated with the mode of arg1, so the sign bit is
12967 specified by this mode. Check that arg1 is the signed
12968 max associated with this sign bit. */
12969 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
12970 /* signed_type does not work on pointer types. */
12971 && INTEGRAL_TYPE_P (arg1_type))
12973 /* The following case also applies to X < signed_max+1
12974 and X >= signed_max+1 because previous transformations. */
12975 if (code == LE_EXPR || code == GT_EXPR)
12978 st = signed_type_for (TREE_TYPE (arg1));
12979 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
12980 type, fold_convert (st, arg0),
12981 build_int_cst (st, 0));
12987 /* If we are comparing an ABS_EXPR with a constant, we can
12988 convert all the cases into explicit comparisons, but they may
12989 well not be faster than doing the ABS and one comparison.
12990 But ABS (X) <= C is a range comparison, which becomes a subtraction
12991 and a comparison, and is probably faster. */
12992 if (code == LE_EXPR
12993 && TREE_CODE (arg1) == INTEGER_CST
12994 && TREE_CODE (arg0) == ABS_EXPR
12995 && ! TREE_SIDE_EFFECTS (arg0)
12996 && (0 != (tem = negate_expr (arg1)))
12997 && TREE_CODE (tem) == INTEGER_CST
12998 && !TREE_OVERFLOW (tem))
12999 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13000 build2 (GE_EXPR, type,
13001 TREE_OPERAND (arg0, 0), tem),
13002 build2 (LE_EXPR, type,
13003 TREE_OPERAND (arg0, 0), arg1));
13005 /* Convert ABS_EXPR<x> >= 0 to true. */
13006 strict_overflow_p = false;
13007 if (code == GE_EXPR
13008 && (integer_zerop (arg1)
13009 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
13010 && real_zerop (arg1)))
13011 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
13013 if (strict_overflow_p)
13014 fold_overflow_warning (("assuming signed overflow does not occur "
13015 "when simplifying comparison of "
13016 "absolute value and zero"),
13017 WARN_STRICT_OVERFLOW_CONDITIONAL);
13018 return omit_one_operand (type, integer_one_node, arg0);
13021 /* Convert ABS_EXPR<x> < 0 to false. */
13022 strict_overflow_p = false;
13023 if (code == LT_EXPR
13024 && (integer_zerop (arg1) || real_zerop (arg1))
13025 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
13027 if (strict_overflow_p)
13028 fold_overflow_warning (("assuming signed overflow does not occur "
13029 "when simplifying comparison of "
13030 "absolute value and zero"),
13031 WARN_STRICT_OVERFLOW_CONDITIONAL);
13032 return omit_one_operand (type, integer_zero_node, arg0);
13035 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
13036 and similarly for >= into !=. */
13037 if ((code == LT_EXPR || code == GE_EXPR)
13038 && TYPE_UNSIGNED (TREE_TYPE (arg0))
13039 && TREE_CODE (arg1) == LSHIFT_EXPR
13040 && integer_onep (TREE_OPERAND (arg1, 0)))
13041 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
13042 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
13043 TREE_OPERAND (arg1, 1)),
13044 build_int_cst (TREE_TYPE (arg0), 0));
13046 if ((code == LT_EXPR || code == GE_EXPR)
13047 && TYPE_UNSIGNED (TREE_TYPE (arg0))
13048 && CONVERT_EXPR_P (arg1)
13049 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
13050 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
13052 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
13053 fold_convert (TREE_TYPE (arg0),
13054 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
13055 TREE_OPERAND (TREE_OPERAND (arg1, 0),
13057 build_int_cst (TREE_TYPE (arg0), 0));
13061 case UNORDERED_EXPR:
13069 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
13071 t1 = fold_relational_const (code, type, arg0, arg1);
13072 if (t1 != NULL_TREE)
13076 /* If the first operand is NaN, the result is constant. */
13077 if (TREE_CODE (arg0) == REAL_CST
13078 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
13079 && (code != LTGT_EXPR || ! flag_trapping_math))
13081 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
13082 ? integer_zero_node
13083 : integer_one_node;
13084 return omit_one_operand (type, t1, arg1);
13087 /* If the second operand is NaN, the result is constant. */
13088 if (TREE_CODE (arg1) == REAL_CST
13089 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
13090 && (code != LTGT_EXPR || ! flag_trapping_math))
13092 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
13093 ? integer_zero_node
13094 : integer_one_node;
13095 return omit_one_operand (type, t1, arg0);
13098 /* Simplify unordered comparison of something with itself. */
13099 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
13100 && operand_equal_p (arg0, arg1, 0))
13101 return constant_boolean_node (1, type);
13103 if (code == LTGT_EXPR
13104 && !flag_trapping_math
13105 && operand_equal_p (arg0, arg1, 0))
13106 return constant_boolean_node (0, type);
13108 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
13110 tree targ0 = strip_float_extensions (arg0);
13111 tree targ1 = strip_float_extensions (arg1);
13112 tree newtype = TREE_TYPE (targ0);
13114 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
13115 newtype = TREE_TYPE (targ1);
13117 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
13118 return fold_build2 (code, type, fold_convert (newtype, targ0),
13119 fold_convert (newtype, targ1));
13124 case COMPOUND_EXPR:
13125 /* When pedantic, a compound expression can be neither an lvalue
13126 nor an integer constant expression. */
13127 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
13129 /* Don't let (0, 0) be null pointer constant. */
13130 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
13131 : fold_convert (type, arg1);
13132 return pedantic_non_lvalue (tem);
13135 if ((TREE_CODE (arg0) == REAL_CST
13136 && TREE_CODE (arg1) == REAL_CST)
13137 || (TREE_CODE (arg0) == INTEGER_CST
13138 && TREE_CODE (arg1) == INTEGER_CST))
13139 return build_complex (type, arg0, arg1);
13143 /* An ASSERT_EXPR should never be passed to fold_binary. */
13144 gcc_unreachable ();
13148 } /* switch (code) */
13151 /* Callback for walk_tree, looking for LABEL_EXPR.
13152 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
13153 Do not check the sub-tree of GOTO_EXPR. */
13156 contains_label_1 (tree *tp,
13157 int *walk_subtrees,
13158 void *data ATTRIBUTE_UNUSED)
13160 switch (TREE_CODE (*tp))
13165 *walk_subtrees = 0;
13172 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
13173 accessible from outside the sub-tree. Returns NULL_TREE if no
13174 addressable label is found. */
13177 contains_label_p (tree st)
13179 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
13182 /* Fold a ternary expression of code CODE and type TYPE with operands
13183 OP0, OP1, and OP2. Return the folded expression if folding is
13184 successful. Otherwise, return NULL_TREE. */
13187 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
13190 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
13191 enum tree_code_class kind = TREE_CODE_CLASS (code);
13193 gcc_assert (IS_EXPR_CODE_CLASS (kind)
13194 && TREE_CODE_LENGTH (code) == 3);
13196 /* Strip any conversions that don't change the mode. This is safe
13197 for every expression, except for a comparison expression because
13198 its signedness is derived from its operands. So, in the latter
13199 case, only strip conversions that don't change the signedness.
13201 Note that this is done as an internal manipulation within the
13202 constant folder, in order to find the simplest representation of
13203 the arguments so that their form can be studied. In any cases,
13204 the appropriate type conversions should be put back in the tree
13205 that will get out of the constant folder. */
13220 case COMPONENT_REF:
13221 if (TREE_CODE (arg0) == CONSTRUCTOR
13222 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
13224 unsigned HOST_WIDE_INT idx;
13226 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
13233 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
13234 so all simple results must be passed through pedantic_non_lvalue. */
13235 if (TREE_CODE (arg0) == INTEGER_CST)
13237 tree unused_op = integer_zerop (arg0) ? op1 : op2;
13238 tem = integer_zerop (arg0) ? op2 : op1;
13239 /* Only optimize constant conditions when the selected branch
13240 has the same type as the COND_EXPR. This avoids optimizing
13241 away "c ? x : throw", where the throw has a void type.
13242 Avoid throwing away that operand which contains label. */
13243 if ((!TREE_SIDE_EFFECTS (unused_op)
13244 || !contains_label_p (unused_op))
13245 && (! VOID_TYPE_P (TREE_TYPE (tem))
13246 || VOID_TYPE_P (type)))
13247 return pedantic_non_lvalue (tem);
13250 if (operand_equal_p (arg1, op2, 0))
13251 return pedantic_omit_one_operand (type, arg1, arg0);
13253 /* If we have A op B ? A : C, we may be able to convert this to a
13254 simpler expression, depending on the operation and the values
13255 of B and C. Signed zeros prevent all of these transformations,
13256 for reasons given above each one.
13258 Also try swapping the arguments and inverting the conditional. */
13259 if (COMPARISON_CLASS_P (arg0)
13260 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
13261 arg1, TREE_OPERAND (arg0, 1))
13262 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
13264 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
13269 if (COMPARISON_CLASS_P (arg0)
13270 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
13272 TREE_OPERAND (arg0, 1))
13273 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
13275 tem = fold_truth_not_expr (arg0);
13276 if (tem && COMPARISON_CLASS_P (tem))
13278 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
13284 /* If the second operand is simpler than the third, swap them
13285 since that produces better jump optimization results. */
13286 if (truth_value_p (TREE_CODE (arg0))
13287 && tree_swap_operands_p (op1, op2, false))
13289 /* See if this can be inverted. If it can't, possibly because
13290 it was a floating-point inequality comparison, don't do
13292 tem = fold_truth_not_expr (arg0);
13294 return fold_build3 (code, type, tem, op2, op1);
13297 /* Convert A ? 1 : 0 to simply A. */
13298 if (integer_onep (op1)
13299 && integer_zerop (op2)
13300 /* If we try to convert OP0 to our type, the
13301 call to fold will try to move the conversion inside
13302 a COND, which will recurse. In that case, the COND_EXPR
13303 is probably the best choice, so leave it alone. */
13304 && type == TREE_TYPE (arg0))
13305 return pedantic_non_lvalue (arg0);
13307 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
13308 over COND_EXPR in cases such as floating point comparisons. */
13309 if (integer_zerop (op1)
13310 && integer_onep (op2)
13311 && truth_value_p (TREE_CODE (arg0)))
13312 return pedantic_non_lvalue (fold_convert (type,
13313 invert_truthvalue (arg0)));
13315 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
13316 if (TREE_CODE (arg0) == LT_EXPR
13317 && integer_zerop (TREE_OPERAND (arg0, 1))
13318 && integer_zerop (op2)
13319 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
13321 /* sign_bit_p only checks ARG1 bits within A's precision.
13322 If <sign bit of A> has wider type than A, bits outside
13323 of A's precision in <sign bit of A> need to be checked.
13324 If they are all 0, this optimization needs to be done
13325 in unsigned A's type, if they are all 1 in signed A's type,
13326 otherwise this can't be done. */
13327 if (TYPE_PRECISION (TREE_TYPE (tem))
13328 < TYPE_PRECISION (TREE_TYPE (arg1))
13329 && TYPE_PRECISION (TREE_TYPE (tem))
13330 < TYPE_PRECISION (type))
13332 unsigned HOST_WIDE_INT mask_lo;
13333 HOST_WIDE_INT mask_hi;
13334 int inner_width, outer_width;
13337 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
13338 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
13339 if (outer_width > TYPE_PRECISION (type))
13340 outer_width = TYPE_PRECISION (type);
13342 if (outer_width > HOST_BITS_PER_WIDE_INT)
13344 mask_hi = ((unsigned HOST_WIDE_INT) -1
13345 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
13351 mask_lo = ((unsigned HOST_WIDE_INT) -1
13352 >> (HOST_BITS_PER_WIDE_INT - outer_width));
13354 if (inner_width > HOST_BITS_PER_WIDE_INT)
13356 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
13357 >> (HOST_BITS_PER_WIDE_INT - inner_width));
13361 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
13362 >> (HOST_BITS_PER_WIDE_INT - inner_width));
13364 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
13365 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
13367 tem_type = signed_type_for (TREE_TYPE (tem));
13368 tem = fold_convert (tem_type, tem);
13370 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
13371 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
13373 tem_type = unsigned_type_for (TREE_TYPE (tem));
13374 tem = fold_convert (tem_type, tem);
13381 return fold_convert (type,
13382 fold_build2 (BIT_AND_EXPR,
13383 TREE_TYPE (tem), tem,
13384 fold_convert (TREE_TYPE (tem),
13388 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
13389 already handled above. */
13390 if (TREE_CODE (arg0) == BIT_AND_EXPR
13391 && integer_onep (TREE_OPERAND (arg0, 1))
13392 && integer_zerop (op2)
13393 && integer_pow2p (arg1))
13395 tree tem = TREE_OPERAND (arg0, 0);
13397 if (TREE_CODE (tem) == RSHIFT_EXPR
13398 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
13399 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
13400 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
13401 return fold_build2 (BIT_AND_EXPR, type,
13402 TREE_OPERAND (tem, 0), arg1);
13405 /* A & N ? N : 0 is simply A & N if N is a power of two. This
13406 is probably obsolete because the first operand should be a
13407 truth value (that's why we have the two cases above), but let's
13408 leave it in until we can confirm this for all front-ends. */
13409 if (integer_zerop (op2)
13410 && TREE_CODE (arg0) == NE_EXPR
13411 && integer_zerop (TREE_OPERAND (arg0, 1))
13412 && integer_pow2p (arg1)
13413 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
13414 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
13415 arg1, OEP_ONLY_CONST))
13416 return pedantic_non_lvalue (fold_convert (type,
13417 TREE_OPERAND (arg0, 0)));
13419 /* Convert A ? B : 0 into A && B if A and B are truth values. */
13420 if (integer_zerop (op2)
13421 && truth_value_p (TREE_CODE (arg0))
13422 && truth_value_p (TREE_CODE (arg1)))
13423 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13424 fold_convert (type, arg0),
13427 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
13428 if (integer_onep (op2)
13429 && truth_value_p (TREE_CODE (arg0))
13430 && truth_value_p (TREE_CODE (arg1)))
13432 /* Only perform transformation if ARG0 is easily inverted. */
13433 tem = fold_truth_not_expr (arg0);
13435 return fold_build2 (TRUTH_ORIF_EXPR, type,
13436 fold_convert (type, tem),
13440 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
13441 if (integer_zerop (arg1)
13442 && truth_value_p (TREE_CODE (arg0))
13443 && truth_value_p (TREE_CODE (op2)))
13445 /* Only perform transformation if ARG0 is easily inverted. */
13446 tem = fold_truth_not_expr (arg0);
13448 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13449 fold_convert (type, tem),
13453 /* Convert A ? 1 : B into A || B if A and B are truth values. */
13454 if (integer_onep (arg1)
13455 && truth_value_p (TREE_CODE (arg0))
13456 && truth_value_p (TREE_CODE (op2)))
13457 return fold_build2 (TRUTH_ORIF_EXPR, type,
13458 fold_convert (type, arg0),
13464 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
13465 of fold_ternary on them. */
13466 gcc_unreachable ();
13468 case BIT_FIELD_REF:
13469 if ((TREE_CODE (arg0) == VECTOR_CST
13470 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
13471 && type == TREE_TYPE (TREE_TYPE (arg0)))
13473 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
13474 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
13477 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
13478 && (idx % width) == 0
13479 && (idx = idx / width)
13480 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
13482 tree elements = NULL_TREE;
13484 if (TREE_CODE (arg0) == VECTOR_CST)
13485 elements = TREE_VECTOR_CST_ELTS (arg0);
13488 unsigned HOST_WIDE_INT idx;
13491 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
13492 elements = tree_cons (NULL_TREE, value, elements);
13494 while (idx-- > 0 && elements)
13495 elements = TREE_CHAIN (elements);
13497 return TREE_VALUE (elements);
13499 return fold_convert (type, integer_zero_node);
13503 /* A bit-field-ref that referenced the full argument can be stripped. */
13504 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
13505 && TYPE_PRECISION (TREE_TYPE (arg0)) == tree_low_cst (arg1, 1)
13506 && integer_zerop (op2))
13507 return fold_convert (type, arg0);
13513 } /* switch (code) */
13516 /* Perform constant folding and related simplification of EXPR.
13517 The related simplifications include x*1 => x, x*0 => 0, etc.,
13518 and application of the associative law.
13519 NOP_EXPR conversions may be removed freely (as long as we
13520 are careful not to change the type of the overall expression).
13521 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13522 but we can constant-fold them if they have constant operands. */
13524 #ifdef ENABLE_FOLD_CHECKING
13525 # define fold(x) fold_1 (x)
13526 static tree fold_1 (tree);
13532 const tree t = expr;
13533 enum tree_code code = TREE_CODE (t);
13534 enum tree_code_class kind = TREE_CODE_CLASS (code);
13537 /* Return right away if a constant. */
13538 if (kind == tcc_constant)
13541 /* CALL_EXPR-like objects with variable numbers of operands are
13542 treated specially. */
13543 if (kind == tcc_vl_exp)
13545 if (code == CALL_EXPR)
13547 tem = fold_call_expr (expr, false);
13548 return tem ? tem : expr;
13553 if (IS_EXPR_CODE_CLASS (kind))
13555 tree type = TREE_TYPE (t);
13556 tree op0, op1, op2;
13558 switch (TREE_CODE_LENGTH (code))
13561 op0 = TREE_OPERAND (t, 0);
13562 tem = fold_unary (code, type, op0);
13563 return tem ? tem : expr;
13565 op0 = TREE_OPERAND (t, 0);
13566 op1 = TREE_OPERAND (t, 1);
13567 tem = fold_binary (code, type, op0, op1);
13568 return tem ? tem : expr;
13570 op0 = TREE_OPERAND (t, 0);
13571 op1 = TREE_OPERAND (t, 1);
13572 op2 = TREE_OPERAND (t, 2);
13573 tem = fold_ternary (code, type, op0, op1, op2);
13574 return tem ? tem : expr;
13584 tree op0 = TREE_OPERAND (t, 0);
13585 tree op1 = TREE_OPERAND (t, 1);
13587 if (TREE_CODE (op1) == INTEGER_CST
13588 && TREE_CODE (op0) == CONSTRUCTOR
13589 && ! type_contains_placeholder_p (TREE_TYPE (op0)))
13591 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (op0);
13592 unsigned HOST_WIDE_INT end = VEC_length (constructor_elt, elts);
13593 unsigned HOST_WIDE_INT begin = 0;
13595 /* Find a matching index by means of a binary search. */
13596 while (begin != end)
13598 unsigned HOST_WIDE_INT middle = (begin + end) / 2;
13599 tree index = VEC_index (constructor_elt, elts, middle)->index;
13601 if (TREE_CODE (index) == INTEGER_CST
13602 && tree_int_cst_lt (index, op1))
13603 begin = middle + 1;
13604 else if (TREE_CODE (index) == INTEGER_CST
13605 && tree_int_cst_lt (op1, index))
13607 else if (TREE_CODE (index) == RANGE_EXPR
13608 && tree_int_cst_lt (TREE_OPERAND (index, 1), op1))
13609 begin = middle + 1;
13610 else if (TREE_CODE (index) == RANGE_EXPR
13611 && tree_int_cst_lt (op1, TREE_OPERAND (index, 0)))
13614 return VEC_index (constructor_elt, elts, middle)->value;
13622 return fold (DECL_INITIAL (t));
13626 } /* switch (code) */
13629 #ifdef ENABLE_FOLD_CHECKING
13632 static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
13633 static void fold_check_failed (const_tree, const_tree);
13634 void print_fold_checksum (const_tree);
13636 /* When --enable-checking=fold, compute a digest of expr before
13637 and after actual fold call to see if fold did not accidentally
13638 change original expr. */
13644 struct md5_ctx ctx;
13645 unsigned char checksum_before[16], checksum_after[16];
13648 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13649 md5_init_ctx (&ctx);
13650 fold_checksum_tree (expr, &ctx, ht);
13651 md5_finish_ctx (&ctx, checksum_before);
13654 ret = fold_1 (expr);
13656 md5_init_ctx (&ctx);
13657 fold_checksum_tree (expr, &ctx, ht);
13658 md5_finish_ctx (&ctx, checksum_after);
13661 if (memcmp (checksum_before, checksum_after, 16))
13662 fold_check_failed (expr, ret);
13668 print_fold_checksum (const_tree expr)
13670 struct md5_ctx ctx;
13671 unsigned char checksum[16], cnt;
13674 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13675 md5_init_ctx (&ctx);
13676 fold_checksum_tree (expr, &ctx, ht);
13677 md5_finish_ctx (&ctx, checksum);
13679 for (cnt = 0; cnt < 16; ++cnt)
13680 fprintf (stderr, "%02x", checksum[cnt]);
13681 putc ('\n', stderr);
13685 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
13687 internal_error ("fold check: original tree changed by fold");
13691 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
13694 enum tree_code code;
13695 union tree_node buf;
13700 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
13701 <= sizeof (struct tree_function_decl))
13702 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
13705 slot = (const void **) htab_find_slot (ht, expr, INSERT);
13709 code = TREE_CODE (expr);
13710 if (TREE_CODE_CLASS (code) == tcc_declaration
13711 && DECL_ASSEMBLER_NAME_SET_P (expr))
13713 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13714 memcpy ((char *) &buf, expr, tree_size (expr));
13715 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
13716 expr = (tree) &buf;
13718 else if (TREE_CODE_CLASS (code) == tcc_type
13719 && (TYPE_POINTER_TO (expr)
13720 || TYPE_REFERENCE_TO (expr)
13721 || TYPE_CACHED_VALUES_P (expr)
13722 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)
13723 || TYPE_NEXT_VARIANT (expr)))
13725 /* Allow these fields to be modified. */
13727 memcpy ((char *) &buf, expr, tree_size (expr));
13728 expr = tmp = (tree) &buf;
13729 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
13730 TYPE_POINTER_TO (tmp) = NULL;
13731 TYPE_REFERENCE_TO (tmp) = NULL;
13732 TYPE_NEXT_VARIANT (tmp) = NULL;
13733 if (TYPE_CACHED_VALUES_P (tmp))
13735 TYPE_CACHED_VALUES_P (tmp) = 0;
13736 TYPE_CACHED_VALUES (tmp) = NULL;
13739 md5_process_bytes (expr, tree_size (expr), ctx);
13740 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
13741 if (TREE_CODE_CLASS (code) != tcc_type
13742 && TREE_CODE_CLASS (code) != tcc_declaration
13743 && code != TREE_LIST
13744 && code != SSA_NAME)
13745 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
13746 switch (TREE_CODE_CLASS (code))
13752 md5_process_bytes (TREE_STRING_POINTER (expr),
13753 TREE_STRING_LENGTH (expr), ctx);
13756 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
13757 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
13760 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
13766 case tcc_exceptional:
13770 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
13771 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
13772 expr = TREE_CHAIN (expr);
13773 goto recursive_label;
13776 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
13777 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
13783 case tcc_expression:
13784 case tcc_reference:
13785 case tcc_comparison:
13788 case tcc_statement:
13790 len = TREE_OPERAND_LENGTH (expr);
13791 for (i = 0; i < len; ++i)
13792 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
13794 case tcc_declaration:
13795 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
13796 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
13797 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
13799 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
13800 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
13801 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
13802 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
13803 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
13805 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
13806 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
13808 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
13810 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
13811 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
13812 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
13816 if (TREE_CODE (expr) == ENUMERAL_TYPE)
13817 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
13818 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
13819 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
13820 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
13821 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
13822 if (INTEGRAL_TYPE_P (expr)
13823 || SCALAR_FLOAT_TYPE_P (expr))
13825 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
13826 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
13828 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
13829 if (TREE_CODE (expr) == RECORD_TYPE
13830 || TREE_CODE (expr) == UNION_TYPE
13831 || TREE_CODE (expr) == QUAL_UNION_TYPE)
13832 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
13833 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
13840 /* Helper function for outputting the checksum of a tree T. When
13841 debugging with gdb, you can "define mynext" to be "next" followed
13842 by "call debug_fold_checksum (op0)", then just trace down till the
13846 debug_fold_checksum (const_tree t)
13849 unsigned char checksum[16];
13850 struct md5_ctx ctx;
13851 htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13853 md5_init_ctx (&ctx);
13854 fold_checksum_tree (t, &ctx, ht);
13855 md5_finish_ctx (&ctx, checksum);
13858 for (i = 0; i < 16; i++)
13859 fprintf (stderr, "%d ", checksum[i]);
13861 fprintf (stderr, "\n");
13866 /* Fold a unary tree expression with code CODE of type TYPE with an
13867 operand OP0. Return a folded expression if successful. Otherwise,
13868 return a tree expression with code CODE of type TYPE with an
13872 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
13875 #ifdef ENABLE_FOLD_CHECKING
13876 unsigned char checksum_before[16], checksum_after[16];
13877 struct md5_ctx ctx;
13880 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13881 md5_init_ctx (&ctx);
13882 fold_checksum_tree (op0, &ctx, ht);
13883 md5_finish_ctx (&ctx, checksum_before);
13887 tem = fold_unary (code, type, op0);
13889 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
13891 #ifdef ENABLE_FOLD_CHECKING
13892 md5_init_ctx (&ctx);
13893 fold_checksum_tree (op0, &ctx, ht);
13894 md5_finish_ctx (&ctx, checksum_after);
13897 if (memcmp (checksum_before, checksum_after, 16))
13898 fold_check_failed (op0, tem);
13903 /* Fold a binary tree expression with code CODE of type TYPE with
13904 operands OP0 and OP1. Return a folded expression if successful.
13905 Otherwise, return a tree expression with code CODE of type TYPE
13906 with operands OP0 and OP1. */
13909 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
13913 #ifdef ENABLE_FOLD_CHECKING
13914 unsigned char checksum_before_op0[16],
13915 checksum_before_op1[16],
13916 checksum_after_op0[16],
13917 checksum_after_op1[16];
13918 struct md5_ctx ctx;
13921 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13922 md5_init_ctx (&ctx);
13923 fold_checksum_tree (op0, &ctx, ht);
13924 md5_finish_ctx (&ctx, checksum_before_op0);
13927 md5_init_ctx (&ctx);
13928 fold_checksum_tree (op1, &ctx, ht);
13929 md5_finish_ctx (&ctx, checksum_before_op1);
13933 tem = fold_binary (code, type, op0, op1);
13935 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
13937 #ifdef ENABLE_FOLD_CHECKING
13938 md5_init_ctx (&ctx);
13939 fold_checksum_tree (op0, &ctx, ht);
13940 md5_finish_ctx (&ctx, checksum_after_op0);
13943 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13944 fold_check_failed (op0, tem);
13946 md5_init_ctx (&ctx);
13947 fold_checksum_tree (op1, &ctx, ht);
13948 md5_finish_ctx (&ctx, checksum_after_op1);
13951 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13952 fold_check_failed (op1, tem);
13957 /* Fold a ternary tree expression with code CODE of type TYPE with
13958 operands OP0, OP1, and OP2. Return a folded expression if
13959 successful. Otherwise, return a tree expression with code CODE of
13960 type TYPE with operands OP0, OP1, and OP2. */
13963 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
13967 #ifdef ENABLE_FOLD_CHECKING
13968 unsigned char checksum_before_op0[16],
13969 checksum_before_op1[16],
13970 checksum_before_op2[16],
13971 checksum_after_op0[16],
13972 checksum_after_op1[16],
13973 checksum_after_op2[16];
13974 struct md5_ctx ctx;
13977 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13978 md5_init_ctx (&ctx);
13979 fold_checksum_tree (op0, &ctx, ht);
13980 md5_finish_ctx (&ctx, checksum_before_op0);
13983 md5_init_ctx (&ctx);
13984 fold_checksum_tree (op1, &ctx, ht);
13985 md5_finish_ctx (&ctx, checksum_before_op1);
13988 md5_init_ctx (&ctx);
13989 fold_checksum_tree (op2, &ctx, ht);
13990 md5_finish_ctx (&ctx, checksum_before_op2);
13994 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
13995 tem = fold_ternary (code, type, op0, op1, op2);
13997 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
13999 #ifdef ENABLE_FOLD_CHECKING
14000 md5_init_ctx (&ctx);
14001 fold_checksum_tree (op0, &ctx, ht);
14002 md5_finish_ctx (&ctx, checksum_after_op0);
14005 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
14006 fold_check_failed (op0, tem);
14008 md5_init_ctx (&ctx);
14009 fold_checksum_tree (op1, &ctx, ht);
14010 md5_finish_ctx (&ctx, checksum_after_op1);
14013 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
14014 fold_check_failed (op1, tem);
14016 md5_init_ctx (&ctx);
14017 fold_checksum_tree (op2, &ctx, ht);
14018 md5_finish_ctx (&ctx, checksum_after_op2);
14021 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
14022 fold_check_failed (op2, tem);
14027 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
14028 arguments in ARGARRAY, and a null static chain.
14029 Return a folded expression if successful. Otherwise, return a CALL_EXPR
14030 of type TYPE from the given operands as constructed by build_call_array. */
14033 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
14036 #ifdef ENABLE_FOLD_CHECKING
14037 unsigned char checksum_before_fn[16],
14038 checksum_before_arglist[16],
14039 checksum_after_fn[16],
14040 checksum_after_arglist[16];
14041 struct md5_ctx ctx;
14045 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
14046 md5_init_ctx (&ctx);
14047 fold_checksum_tree (fn, &ctx, ht);
14048 md5_finish_ctx (&ctx, checksum_before_fn);
14051 md5_init_ctx (&ctx);
14052 for (i = 0; i < nargs; i++)
14053 fold_checksum_tree (argarray[i], &ctx, ht);
14054 md5_finish_ctx (&ctx, checksum_before_arglist);
14058 tem = fold_builtin_call_array (type, fn, nargs, argarray);
14060 #ifdef ENABLE_FOLD_CHECKING
14061 md5_init_ctx (&ctx);
14062 fold_checksum_tree (fn, &ctx, ht);
14063 md5_finish_ctx (&ctx, checksum_after_fn);
14066 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
14067 fold_check_failed (fn, tem);
14069 md5_init_ctx (&ctx);
14070 for (i = 0; i < nargs; i++)
14071 fold_checksum_tree (argarray[i], &ctx, ht);
14072 md5_finish_ctx (&ctx, checksum_after_arglist);
14075 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
14076 fold_check_failed (NULL_TREE, tem);
14081 /* Perform constant folding and related simplification of initializer
14082 expression EXPR. These behave identically to "fold_buildN" but ignore
14083 potential run-time traps and exceptions that fold must preserve. */
14085 #define START_FOLD_INIT \
14086 int saved_signaling_nans = flag_signaling_nans;\
14087 int saved_trapping_math = flag_trapping_math;\
14088 int saved_rounding_math = flag_rounding_math;\
14089 int saved_trapv = flag_trapv;\
14090 int saved_folding_initializer = folding_initializer;\
14091 flag_signaling_nans = 0;\
14092 flag_trapping_math = 0;\
14093 flag_rounding_math = 0;\
14095 folding_initializer = 1;
14097 #define END_FOLD_INIT \
14098 flag_signaling_nans = saved_signaling_nans;\
14099 flag_trapping_math = saved_trapping_math;\
14100 flag_rounding_math = saved_rounding_math;\
14101 flag_trapv = saved_trapv;\
14102 folding_initializer = saved_folding_initializer;
14105 fold_build1_initializer (enum tree_code code, tree type, tree op)
14110 result = fold_build1 (code, type, op);
14117 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
14122 result = fold_build2 (code, type, op0, op1);
14129 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
14135 result = fold_build3 (code, type, op0, op1, op2);
14142 fold_build_call_array_initializer (tree type, tree fn,
14143 int nargs, tree *argarray)
14148 result = fold_build_call_array (type, fn, nargs, argarray);
14154 #undef START_FOLD_INIT
14155 #undef END_FOLD_INIT
14157 /* Determine if first argument is a multiple of second argument. Return 0 if
14158 it is not, or we cannot easily determined it to be.
14160 An example of the sort of thing we care about (at this point; this routine
14161 could surely be made more general, and expanded to do what the *_DIV_EXPR's
14162 fold cases do now) is discovering that
14164 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
14170 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
14172 This code also handles discovering that
14174 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
14176 is a multiple of 8 so we don't have to worry about dealing with a
14177 possible remainder.
14179 Note that we *look* inside a SAVE_EXPR only to determine how it was
14180 calculated; it is not safe for fold to do much of anything else with the
14181 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
14182 at run time. For example, the latter example above *cannot* be implemented
14183 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
14184 evaluation time of the original SAVE_EXPR is not necessarily the same at
14185 the time the new expression is evaluated. The only optimization of this
14186 sort that would be valid is changing
14188 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
14192 SAVE_EXPR (I) * SAVE_EXPR (J)
14194 (where the same SAVE_EXPR (J) is used in the original and the
14195 transformed version). */
14198 multiple_of_p (tree type, const_tree top, const_tree bottom)
14200 if (operand_equal_p (top, bottom, 0))
14203 if (TREE_CODE (type) != INTEGER_TYPE)
14206 switch (TREE_CODE (top))
14209 /* Bitwise and provides a power of two multiple. If the mask is
14210 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
14211 if (!integer_pow2p (bottom))
14216 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
14217 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
14221 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
14222 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
14225 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
14229 op1 = TREE_OPERAND (top, 1);
14230 /* const_binop may not detect overflow correctly,
14231 so check for it explicitly here. */
14232 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
14233 > TREE_INT_CST_LOW (op1)
14234 && TREE_INT_CST_HIGH (op1) == 0
14235 && 0 != (t1 = fold_convert (type,
14236 const_binop (LSHIFT_EXPR,
14239 && !TREE_OVERFLOW (t1))
14240 return multiple_of_p (type, t1, bottom);
14245 /* Can't handle conversions from non-integral or wider integral type. */
14246 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
14247 || (TYPE_PRECISION (type)
14248 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
14251 /* .. fall through ... */
14254 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
14257 if (TREE_CODE (bottom) != INTEGER_CST
14258 || integer_zerop (bottom)
14259 || (TYPE_UNSIGNED (type)
14260 && (tree_int_cst_sgn (top) < 0
14261 || tree_int_cst_sgn (bottom) < 0)))
14263 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
14271 /* Return true if CODE or TYPE is known to be non-negative. */
14274 tree_simple_nonnegative_warnv_p (enum tree_code code, tree type)
14276 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
14277 && truth_value_p (code))
14278 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
14279 have a signed:1 type (where the value is -1 and 0). */
14284 /* Return true if (CODE OP0) is known to be non-negative. If the return
14285 value is based on the assumption that signed overflow is undefined,
14286 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14287 *STRICT_OVERFLOW_P. */
14290 tree_unary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
14291 bool *strict_overflow_p)
14293 if (TYPE_UNSIGNED (type))
14299 /* We can't return 1 if flag_wrapv is set because
14300 ABS_EXPR<INT_MIN> = INT_MIN. */
14301 if (!INTEGRAL_TYPE_P (type))
14303 if (TYPE_OVERFLOW_UNDEFINED (type))
14305 *strict_overflow_p = true;
14310 case NON_LVALUE_EXPR:
14312 case FIX_TRUNC_EXPR:
14313 return tree_expr_nonnegative_warnv_p (op0,
14314 strict_overflow_p);
14318 tree inner_type = TREE_TYPE (op0);
14319 tree outer_type = type;
14321 if (TREE_CODE (outer_type) == REAL_TYPE)
14323 if (TREE_CODE (inner_type) == REAL_TYPE)
14324 return tree_expr_nonnegative_warnv_p (op0,
14325 strict_overflow_p);
14326 if (TREE_CODE (inner_type) == INTEGER_TYPE)
14328 if (TYPE_UNSIGNED (inner_type))
14330 return tree_expr_nonnegative_warnv_p (op0,
14331 strict_overflow_p);
14334 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
14336 if (TREE_CODE (inner_type) == REAL_TYPE)
14337 return tree_expr_nonnegative_warnv_p (op0,
14338 strict_overflow_p);
14339 if (TREE_CODE (inner_type) == INTEGER_TYPE)
14340 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
14341 && TYPE_UNSIGNED (inner_type);
14347 return tree_simple_nonnegative_warnv_p (code, type);
14350 /* We don't know sign of `t', so be conservative and return false. */
14354 /* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
14355 value is based on the assumption that signed overflow is undefined,
14356 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14357 *STRICT_OVERFLOW_P. */
14360 tree_binary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
14361 tree op1, bool *strict_overflow_p)
14363 if (TYPE_UNSIGNED (type))
14368 case POINTER_PLUS_EXPR:
14370 if (FLOAT_TYPE_P (type))
14371 return (tree_expr_nonnegative_warnv_p (op0,
14373 && tree_expr_nonnegative_warnv_p (op1,
14374 strict_overflow_p));
14376 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
14377 both unsigned and at least 2 bits shorter than the result. */
14378 if (TREE_CODE (type) == INTEGER_TYPE
14379 && TREE_CODE (op0) == NOP_EXPR
14380 && TREE_CODE (op1) == NOP_EXPR)
14382 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
14383 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
14384 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
14385 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
14387 unsigned int prec = MAX (TYPE_PRECISION (inner1),
14388 TYPE_PRECISION (inner2)) + 1;
14389 return prec < TYPE_PRECISION (type);
14395 if (FLOAT_TYPE_P (type))
14397 /* x * x for floating point x is always non-negative. */
14398 if (operand_equal_p (op0, op1, 0))
14400 return (tree_expr_nonnegative_warnv_p (op0,
14402 && tree_expr_nonnegative_warnv_p (op1,
14403 strict_overflow_p));
14406 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
14407 both unsigned and their total bits is shorter than the result. */
14408 if (TREE_CODE (type) == INTEGER_TYPE
14409 && (TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == INTEGER_CST)
14410 && (TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == INTEGER_CST))
14412 tree inner0 = (TREE_CODE (op0) == NOP_EXPR)
14413 ? TREE_TYPE (TREE_OPERAND (op0, 0))
14415 tree inner1 = (TREE_CODE (op1) == NOP_EXPR)
14416 ? TREE_TYPE (TREE_OPERAND (op1, 0))
14419 bool unsigned0 = TYPE_UNSIGNED (inner0);
14420 bool unsigned1 = TYPE_UNSIGNED (inner1);
14422 if (TREE_CODE (op0) == INTEGER_CST)
14423 unsigned0 = unsigned0 || tree_int_cst_sgn (op0) >= 0;
14425 if (TREE_CODE (op1) == INTEGER_CST)
14426 unsigned1 = unsigned1 || tree_int_cst_sgn (op1) >= 0;
14428 if (TREE_CODE (inner0) == INTEGER_TYPE && unsigned0
14429 && TREE_CODE (inner1) == INTEGER_TYPE && unsigned1)
14431 unsigned int precision0 = (TREE_CODE (op0) == INTEGER_CST)
14432 ? tree_int_cst_min_precision (op0, /*unsignedp=*/true)
14433 : TYPE_PRECISION (inner0);
14435 unsigned int precision1 = (TREE_CODE (op1) == INTEGER_CST)
14436 ? tree_int_cst_min_precision (op1, /*unsignedp=*/true)
14437 : TYPE_PRECISION (inner1);
14439 return precision0 + precision1 < TYPE_PRECISION (type);
14446 return (tree_expr_nonnegative_warnv_p (op0,
14448 || tree_expr_nonnegative_warnv_p (op1,
14449 strict_overflow_p));
14455 case TRUNC_DIV_EXPR:
14456 case CEIL_DIV_EXPR:
14457 case FLOOR_DIV_EXPR:
14458 case ROUND_DIV_EXPR:
14459 return (tree_expr_nonnegative_warnv_p (op0,
14461 && tree_expr_nonnegative_warnv_p (op1,
14462 strict_overflow_p));
14464 case TRUNC_MOD_EXPR:
14465 case CEIL_MOD_EXPR:
14466 case FLOOR_MOD_EXPR:
14467 case ROUND_MOD_EXPR:
14468 return tree_expr_nonnegative_warnv_p (op0,
14469 strict_overflow_p);
14471 return tree_simple_nonnegative_warnv_p (code, type);
14474 /* We don't know sign of `t', so be conservative and return false. */
14478 /* Return true if T is known to be non-negative. If the return
14479 value is based on the assumption that signed overflow is undefined,
14480 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14481 *STRICT_OVERFLOW_P. */
14484 tree_single_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14486 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14489 switch (TREE_CODE (t))
14492 return tree_int_cst_sgn (t) >= 0;
14495 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
14498 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
14501 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14503 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
14504 strict_overflow_p));
14506 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14509 /* We don't know sign of `t', so be conservative and return false. */
14513 /* Return true if T is known to be non-negative. If the return
14514 value is based on the assumption that signed overflow is undefined,
14515 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14516 *STRICT_OVERFLOW_P. */
14519 tree_call_nonnegative_warnv_p (tree type, tree fndecl,
14520 tree arg0, tree arg1, bool *strict_overflow_p)
14522 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
14523 switch (DECL_FUNCTION_CODE (fndecl))
14525 CASE_FLT_FN (BUILT_IN_ACOS):
14526 CASE_FLT_FN (BUILT_IN_ACOSH):
14527 CASE_FLT_FN (BUILT_IN_CABS):
14528 CASE_FLT_FN (BUILT_IN_COSH):
14529 CASE_FLT_FN (BUILT_IN_ERFC):
14530 CASE_FLT_FN (BUILT_IN_EXP):
14531 CASE_FLT_FN (BUILT_IN_EXP10):
14532 CASE_FLT_FN (BUILT_IN_EXP2):
14533 CASE_FLT_FN (BUILT_IN_FABS):
14534 CASE_FLT_FN (BUILT_IN_FDIM):
14535 CASE_FLT_FN (BUILT_IN_HYPOT):
14536 CASE_FLT_FN (BUILT_IN_POW10):
14537 CASE_INT_FN (BUILT_IN_FFS):
14538 CASE_INT_FN (BUILT_IN_PARITY):
14539 CASE_INT_FN (BUILT_IN_POPCOUNT):
14540 case BUILT_IN_BSWAP32:
14541 case BUILT_IN_BSWAP64:
14545 CASE_FLT_FN (BUILT_IN_SQRT):
14546 /* sqrt(-0.0) is -0.0. */
14547 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
14549 return tree_expr_nonnegative_warnv_p (arg0,
14550 strict_overflow_p);
14552 CASE_FLT_FN (BUILT_IN_ASINH):
14553 CASE_FLT_FN (BUILT_IN_ATAN):
14554 CASE_FLT_FN (BUILT_IN_ATANH):
14555 CASE_FLT_FN (BUILT_IN_CBRT):
14556 CASE_FLT_FN (BUILT_IN_CEIL):
14557 CASE_FLT_FN (BUILT_IN_ERF):
14558 CASE_FLT_FN (BUILT_IN_EXPM1):
14559 CASE_FLT_FN (BUILT_IN_FLOOR):
14560 CASE_FLT_FN (BUILT_IN_FMOD):
14561 CASE_FLT_FN (BUILT_IN_FREXP):
14562 CASE_FLT_FN (BUILT_IN_LCEIL):
14563 CASE_FLT_FN (BUILT_IN_LDEXP):
14564 CASE_FLT_FN (BUILT_IN_LFLOOR):
14565 CASE_FLT_FN (BUILT_IN_LLCEIL):
14566 CASE_FLT_FN (BUILT_IN_LLFLOOR):
14567 CASE_FLT_FN (BUILT_IN_LLRINT):
14568 CASE_FLT_FN (BUILT_IN_LLROUND):
14569 CASE_FLT_FN (BUILT_IN_LRINT):
14570 CASE_FLT_FN (BUILT_IN_LROUND):
14571 CASE_FLT_FN (BUILT_IN_MODF):
14572 CASE_FLT_FN (BUILT_IN_NEARBYINT):
14573 CASE_FLT_FN (BUILT_IN_RINT):
14574 CASE_FLT_FN (BUILT_IN_ROUND):
14575 CASE_FLT_FN (BUILT_IN_SCALB):
14576 CASE_FLT_FN (BUILT_IN_SCALBLN):
14577 CASE_FLT_FN (BUILT_IN_SCALBN):
14578 CASE_FLT_FN (BUILT_IN_SIGNBIT):
14579 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
14580 CASE_FLT_FN (BUILT_IN_SINH):
14581 CASE_FLT_FN (BUILT_IN_TANH):
14582 CASE_FLT_FN (BUILT_IN_TRUNC):
14583 /* True if the 1st argument is nonnegative. */
14584 return tree_expr_nonnegative_warnv_p (arg0,
14585 strict_overflow_p);
14587 CASE_FLT_FN (BUILT_IN_FMAX):
14588 /* True if the 1st OR 2nd arguments are nonnegative. */
14589 return (tree_expr_nonnegative_warnv_p (arg0,
14591 || (tree_expr_nonnegative_warnv_p (arg1,
14592 strict_overflow_p)));
14594 CASE_FLT_FN (BUILT_IN_FMIN):
14595 /* True if the 1st AND 2nd arguments are nonnegative. */
14596 return (tree_expr_nonnegative_warnv_p (arg0,
14598 && (tree_expr_nonnegative_warnv_p (arg1,
14599 strict_overflow_p)));
14601 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14602 /* True if the 2nd argument is nonnegative. */
14603 return tree_expr_nonnegative_warnv_p (arg1,
14604 strict_overflow_p);
14606 CASE_FLT_FN (BUILT_IN_POWI):
14607 /* True if the 1st argument is nonnegative or the second
14608 argument is an even integer. */
14609 if (TREE_CODE (arg1) == INTEGER_CST
14610 && (TREE_INT_CST_LOW (arg1) & 1) == 0)
14612 return tree_expr_nonnegative_warnv_p (arg0,
14613 strict_overflow_p);
14615 CASE_FLT_FN (BUILT_IN_POW):
14616 /* True if the 1st argument is nonnegative or the second
14617 argument is an even integer valued real. */
14618 if (TREE_CODE (arg1) == REAL_CST)
14623 c = TREE_REAL_CST (arg1);
14624 n = real_to_integer (&c);
14627 REAL_VALUE_TYPE cint;
14628 real_from_integer (&cint, VOIDmode, n,
14629 n < 0 ? -1 : 0, 0);
14630 if (real_identical (&c, &cint))
14634 return tree_expr_nonnegative_warnv_p (arg0,
14635 strict_overflow_p);
14640 return tree_simple_nonnegative_warnv_p (CALL_EXPR,
14644 /* Return true if T is known to be non-negative. If the return
14645 value is based on the assumption that signed overflow is undefined,
14646 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14647 *STRICT_OVERFLOW_P. */
14650 tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14652 enum tree_code code = TREE_CODE (t);
14653 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14660 tree temp = TARGET_EXPR_SLOT (t);
14661 t = TARGET_EXPR_INITIAL (t);
14663 /* If the initializer is non-void, then it's a normal expression
14664 that will be assigned to the slot. */
14665 if (!VOID_TYPE_P (t))
14666 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
14668 /* Otherwise, the initializer sets the slot in some way. One common
14669 way is an assignment statement at the end of the initializer. */
14672 if (TREE_CODE (t) == BIND_EXPR)
14673 t = expr_last (BIND_EXPR_BODY (t));
14674 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
14675 || TREE_CODE (t) == TRY_CATCH_EXPR)
14676 t = expr_last (TREE_OPERAND (t, 0));
14677 else if (TREE_CODE (t) == STATEMENT_LIST)
14682 if (TREE_CODE (t) == MODIFY_EXPR
14683 && TREE_OPERAND (t, 0) == temp)
14684 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14685 strict_overflow_p);
14692 tree arg0 = call_expr_nargs (t) > 0 ? CALL_EXPR_ARG (t, 0) : NULL_TREE;
14693 tree arg1 = call_expr_nargs (t) > 1 ? CALL_EXPR_ARG (t, 1) : NULL_TREE;
14695 return tree_call_nonnegative_warnv_p (TREE_TYPE (t),
14696 get_callee_fndecl (t),
14699 strict_overflow_p);
14701 case COMPOUND_EXPR:
14703 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14704 strict_overflow_p);
14706 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
14707 strict_overflow_p);
14709 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14710 strict_overflow_p);
14713 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14717 /* We don't know sign of `t', so be conservative and return false. */
14721 /* Return true if T is known to be non-negative. If the return
14722 value is based on the assumption that signed overflow is undefined,
14723 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14724 *STRICT_OVERFLOW_P. */
14727 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14729 enum tree_code code;
14730 if (t == error_mark_node)
14733 code = TREE_CODE (t);
14734 switch (TREE_CODE_CLASS (code))
14737 case tcc_comparison:
14738 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14740 TREE_OPERAND (t, 0),
14741 TREE_OPERAND (t, 1),
14742 strict_overflow_p);
14745 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14747 TREE_OPERAND (t, 0),
14748 strict_overflow_p);
14751 case tcc_declaration:
14752 case tcc_reference:
14753 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14761 case TRUTH_AND_EXPR:
14762 case TRUTH_OR_EXPR:
14763 case TRUTH_XOR_EXPR:
14764 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14766 TREE_OPERAND (t, 0),
14767 TREE_OPERAND (t, 1),
14768 strict_overflow_p);
14769 case TRUTH_NOT_EXPR:
14770 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14772 TREE_OPERAND (t, 0),
14773 strict_overflow_p);
14780 case WITH_SIZE_EXPR:
14784 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14787 return tree_invalid_nonnegative_warnv_p (t, strict_overflow_p);
14791 /* Return true if `t' is known to be non-negative. Handle warnings
14792 about undefined signed overflow. */
14795 tree_expr_nonnegative_p (tree t)
14797 bool ret, strict_overflow_p;
14799 strict_overflow_p = false;
14800 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
14801 if (strict_overflow_p)
14802 fold_overflow_warning (("assuming signed overflow does not occur when "
14803 "determining that expression is always "
14805 WARN_STRICT_OVERFLOW_MISC);
14810 /* Return true when (CODE OP0) is an address and is known to be nonzero.
14811 For floating point we further ensure that T is not denormal.
14812 Similar logic is present in nonzero_address in rtlanal.h.
14814 If the return value is based on the assumption that signed overflow
14815 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14816 change *STRICT_OVERFLOW_P. */
14819 tree_unary_nonzero_warnv_p (enum tree_code code, tree type, tree op0,
14820 bool *strict_overflow_p)
14825 return tree_expr_nonzero_warnv_p (op0,
14826 strict_overflow_p);
14830 tree inner_type = TREE_TYPE (op0);
14831 tree outer_type = type;
14833 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
14834 && tree_expr_nonzero_warnv_p (op0,
14835 strict_overflow_p));
14839 case NON_LVALUE_EXPR:
14840 return tree_expr_nonzero_warnv_p (op0,
14841 strict_overflow_p);
14850 /* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
14851 For floating point we further ensure that T is not denormal.
14852 Similar logic is present in nonzero_address in rtlanal.h.
14854 If the return value is based on the assumption that signed overflow
14855 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14856 change *STRICT_OVERFLOW_P. */
14859 tree_binary_nonzero_warnv_p (enum tree_code code,
14862 tree op1, bool *strict_overflow_p)
14864 bool sub_strict_overflow_p;
14867 case POINTER_PLUS_EXPR:
14869 if (TYPE_OVERFLOW_UNDEFINED (type))
14871 /* With the presence of negative values it is hard
14872 to say something. */
14873 sub_strict_overflow_p = false;
14874 if (!tree_expr_nonnegative_warnv_p (op0,
14875 &sub_strict_overflow_p)
14876 || !tree_expr_nonnegative_warnv_p (op1,
14877 &sub_strict_overflow_p))
14879 /* One of operands must be positive and the other non-negative. */
14880 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14881 overflows, on a twos-complement machine the sum of two
14882 nonnegative numbers can never be zero. */
14883 return (tree_expr_nonzero_warnv_p (op0,
14885 || tree_expr_nonzero_warnv_p (op1,
14886 strict_overflow_p));
14891 if (TYPE_OVERFLOW_UNDEFINED (type))
14893 if (tree_expr_nonzero_warnv_p (op0,
14895 && tree_expr_nonzero_warnv_p (op1,
14896 strict_overflow_p))
14898 *strict_overflow_p = true;
14905 sub_strict_overflow_p = false;
14906 if (tree_expr_nonzero_warnv_p (op0,
14907 &sub_strict_overflow_p)
14908 && tree_expr_nonzero_warnv_p (op1,
14909 &sub_strict_overflow_p))
14911 if (sub_strict_overflow_p)
14912 *strict_overflow_p = true;
14917 sub_strict_overflow_p = false;
14918 if (tree_expr_nonzero_warnv_p (op0,
14919 &sub_strict_overflow_p))
14921 if (sub_strict_overflow_p)
14922 *strict_overflow_p = true;
14924 /* When both operands are nonzero, then MAX must be too. */
14925 if (tree_expr_nonzero_warnv_p (op1,
14926 strict_overflow_p))
14929 /* MAX where operand 0 is positive is positive. */
14930 return tree_expr_nonnegative_warnv_p (op0,
14931 strict_overflow_p);
14933 /* MAX where operand 1 is positive is positive. */
14934 else if (tree_expr_nonzero_warnv_p (op1,
14935 &sub_strict_overflow_p)
14936 && tree_expr_nonnegative_warnv_p (op1,
14937 &sub_strict_overflow_p))
14939 if (sub_strict_overflow_p)
14940 *strict_overflow_p = true;
14946 return (tree_expr_nonzero_warnv_p (op1,
14948 || tree_expr_nonzero_warnv_p (op0,
14949 strict_overflow_p));
14958 /* Return true when T is an address and is known to be nonzero.
14959 For floating point we further ensure that T is not denormal.
14960 Similar logic is present in nonzero_address in rtlanal.h.
14962 If the return value is based on the assumption that signed overflow
14963 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14964 change *STRICT_OVERFLOW_P. */
14967 tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14969 bool sub_strict_overflow_p;
14970 switch (TREE_CODE (t))
14973 return !integer_zerop (t);
14977 tree base = get_base_address (TREE_OPERAND (t, 0));
14982 /* Weak declarations may link to NULL. */
14983 if (VAR_OR_FUNCTION_DECL_P (base))
14984 return !DECL_WEAK (base);
14986 /* Constants are never weak. */
14987 if (CONSTANT_CLASS_P (base))
14994 sub_strict_overflow_p = false;
14995 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14996 &sub_strict_overflow_p)
14997 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
14998 &sub_strict_overflow_p))
15000 if (sub_strict_overflow_p)
15001 *strict_overflow_p = true;
15012 /* Return true when T is an address and is known to be nonzero.
15013 For floating point we further ensure that T is not denormal.
15014 Similar logic is present in nonzero_address in rtlanal.h.
15016 If the return value is based on the assumption that signed overflow
15017 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
15018 change *STRICT_OVERFLOW_P. */
15021 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
15023 tree type = TREE_TYPE (t);
15024 enum tree_code code;
15026 /* Doing something useful for floating point would need more work. */
15027 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
15030 code = TREE_CODE (t);
15031 switch (TREE_CODE_CLASS (code))
15034 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
15035 strict_overflow_p);
15037 case tcc_comparison:
15038 return tree_binary_nonzero_warnv_p (code, type,
15039 TREE_OPERAND (t, 0),
15040 TREE_OPERAND (t, 1),
15041 strict_overflow_p);
15043 case tcc_declaration:
15044 case tcc_reference:
15045 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
15053 case TRUTH_NOT_EXPR:
15054 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
15055 strict_overflow_p);
15057 case TRUTH_AND_EXPR:
15058 case TRUTH_OR_EXPR:
15059 case TRUTH_XOR_EXPR:
15060 return tree_binary_nonzero_warnv_p (code, type,
15061 TREE_OPERAND (t, 0),
15062 TREE_OPERAND (t, 1),
15063 strict_overflow_p);
15070 case WITH_SIZE_EXPR:
15074 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
15076 case COMPOUND_EXPR:
15079 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
15080 strict_overflow_p);
15083 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
15084 strict_overflow_p);
15087 return alloca_call_p (t);
15095 /* Return true when T is an address and is known to be nonzero.
15096 Handle warnings about undefined signed overflow. */
15099 tree_expr_nonzero_p (tree t)
15101 bool ret, strict_overflow_p;
15103 strict_overflow_p = false;
15104 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
15105 if (strict_overflow_p)
15106 fold_overflow_warning (("assuming signed overflow does not occur when "
15107 "determining that expression is always "
15109 WARN_STRICT_OVERFLOW_MISC);
15113 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
15114 attempt to fold the expression to a constant without modifying TYPE,
15117 If the expression could be simplified to a constant, then return
15118 the constant. If the expression would not be simplified to a
15119 constant, then return NULL_TREE. */
15122 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
15124 tree tem = fold_binary (code, type, op0, op1);
15125 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
15128 /* Given the components of a unary expression CODE, TYPE and OP0,
15129 attempt to fold the expression to a constant without modifying
15132 If the expression could be simplified to a constant, then return
15133 the constant. If the expression would not be simplified to a
15134 constant, then return NULL_TREE. */
15137 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
15139 tree tem = fold_unary (code, type, op0);
15140 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
15143 /* If EXP represents referencing an element in a constant string
15144 (either via pointer arithmetic or array indexing), return the
15145 tree representing the value accessed, otherwise return NULL. */
15148 fold_read_from_constant_string (tree exp)
15150 if ((TREE_CODE (exp) == INDIRECT_REF
15151 || TREE_CODE (exp) == ARRAY_REF)
15152 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
15154 tree exp1 = TREE_OPERAND (exp, 0);
15158 if (TREE_CODE (exp) == INDIRECT_REF)
15159 string = string_constant (exp1, &index);
15162 tree low_bound = array_ref_low_bound (exp);
15163 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
15165 /* Optimize the special-case of a zero lower bound.
15167 We convert the low_bound to sizetype to avoid some problems
15168 with constant folding. (E.g. suppose the lower bound is 1,
15169 and its mode is QI. Without the conversion,l (ARRAY
15170 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
15171 +INDEX), which becomes (ARRAY+255+INDEX). Oops!) */
15172 if (! integer_zerop (low_bound))
15173 index = size_diffop (index, fold_convert (sizetype, low_bound));
15179 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
15180 && TREE_CODE (string) == STRING_CST
15181 && TREE_CODE (index) == INTEGER_CST
15182 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
15183 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
15185 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
15186 return build_int_cst_type (TREE_TYPE (exp),
15187 (TREE_STRING_POINTER (string)
15188 [TREE_INT_CST_LOW (index)]));
15193 /* Return the tree for neg (ARG0) when ARG0 is known to be either
15194 an integer constant, real, or fixed-point constant.
15196 TYPE is the type of the result. */
15199 fold_negate_const (tree arg0, tree type)
15201 tree t = NULL_TREE;
15203 switch (TREE_CODE (arg0))
15207 unsigned HOST_WIDE_INT low;
15208 HOST_WIDE_INT high;
15209 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
15210 TREE_INT_CST_HIGH (arg0),
15212 t = force_fit_type_double (type, low, high, 1,
15213 (overflow | TREE_OVERFLOW (arg0))
15214 && !TYPE_UNSIGNED (type));
15219 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
15224 FIXED_VALUE_TYPE f;
15225 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
15226 &(TREE_FIXED_CST (arg0)), NULL,
15227 TYPE_SATURATING (type));
15228 t = build_fixed (type, f);
15229 /* Propagate overflow flags. */
15230 if (overflow_p | TREE_OVERFLOW (arg0))
15232 TREE_OVERFLOW (t) = 1;
15233 TREE_CONSTANT_OVERFLOW (t) = 1;
15235 else if (TREE_CONSTANT_OVERFLOW (arg0))
15236 TREE_CONSTANT_OVERFLOW (t) = 1;
15241 gcc_unreachable ();
15247 /* Return the tree for abs (ARG0) when ARG0 is known to be either
15248 an integer constant or real constant.
15250 TYPE is the type of the result. */
15253 fold_abs_const (tree arg0, tree type)
15255 tree t = NULL_TREE;
15257 switch (TREE_CODE (arg0))
15260 /* If the value is unsigned, then the absolute value is
15261 the same as the ordinary value. */
15262 if (TYPE_UNSIGNED (type))
15264 /* Similarly, if the value is non-negative. */
15265 else if (INT_CST_LT (integer_minus_one_node, arg0))
15267 /* If the value is negative, then the absolute value is
15271 unsigned HOST_WIDE_INT low;
15272 HOST_WIDE_INT high;
15273 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
15274 TREE_INT_CST_HIGH (arg0),
15276 t = force_fit_type_double (type, low, high, -1,
15277 overflow | TREE_OVERFLOW (arg0));
15282 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
15283 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
15289 gcc_unreachable ();
15295 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
15296 constant. TYPE is the type of the result. */
15299 fold_not_const (tree arg0, tree type)
15301 tree t = NULL_TREE;
15303 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
15305 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
15306 ~TREE_INT_CST_HIGH (arg0), 0,
15307 TREE_OVERFLOW (arg0));
15312 /* Given CODE, a relational operator, the target type, TYPE and two
15313 constant operands OP0 and OP1, return the result of the
15314 relational operation. If the result is not a compile time
15315 constant, then return NULL_TREE. */
15318 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
15320 int result, invert;
15322 /* From here on, the only cases we handle are when the result is
15323 known to be a constant. */
15325 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
15327 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
15328 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
15330 /* Handle the cases where either operand is a NaN. */
15331 if (real_isnan (c0) || real_isnan (c1))
15341 case UNORDERED_EXPR:
15355 if (flag_trapping_math)
15361 gcc_unreachable ();
15364 return constant_boolean_node (result, type);
15367 return constant_boolean_node (real_compare (code, c0, c1), type);
15370 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
15372 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
15373 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
15374 return constant_boolean_node (fixed_compare (code, c0, c1), type);
15377 /* Handle equality/inequality of complex constants. */
15378 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
15380 tree rcond = fold_relational_const (code, type,
15381 TREE_REALPART (op0),
15382 TREE_REALPART (op1));
15383 tree icond = fold_relational_const (code, type,
15384 TREE_IMAGPART (op0),
15385 TREE_IMAGPART (op1));
15386 if (code == EQ_EXPR)
15387 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
15388 else if (code == NE_EXPR)
15389 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
15394 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
15396 To compute GT, swap the arguments and do LT.
15397 To compute GE, do LT and invert the result.
15398 To compute LE, swap the arguments, do LT and invert the result.
15399 To compute NE, do EQ and invert the result.
15401 Therefore, the code below must handle only EQ and LT. */
15403 if (code == LE_EXPR || code == GT_EXPR)
15408 code = swap_tree_comparison (code);
15411 /* Note that it is safe to invert for real values here because we
15412 have already handled the one case that it matters. */
15415 if (code == NE_EXPR || code == GE_EXPR)
15418 code = invert_tree_comparison (code, false);
15421 /* Compute a result for LT or EQ if args permit;
15422 Otherwise return T. */
15423 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
15425 if (code == EQ_EXPR)
15426 result = tree_int_cst_equal (op0, op1);
15427 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
15428 result = INT_CST_LT_UNSIGNED (op0, op1);
15430 result = INT_CST_LT (op0, op1);
15437 return constant_boolean_node (result, type);
15440 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
15441 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
15445 fold_build_cleanup_point_expr (tree type, tree expr)
15447 /* If the expression does not have side effects then we don't have to wrap
15448 it with a cleanup point expression. */
15449 if (!TREE_SIDE_EFFECTS (expr))
15452 /* If the expression is a return, check to see if the expression inside the
15453 return has no side effects or the right hand side of the modify expression
15454 inside the return. If either don't have side effects set we don't need to
15455 wrap the expression in a cleanup point expression. Note we don't check the
15456 left hand side of the modify because it should always be a return decl. */
15457 if (TREE_CODE (expr) == RETURN_EXPR)
15459 tree op = TREE_OPERAND (expr, 0);
15460 if (!op || !TREE_SIDE_EFFECTS (op))
15462 op = TREE_OPERAND (op, 1);
15463 if (!TREE_SIDE_EFFECTS (op))
15467 return build1 (CLEANUP_POINT_EXPR, type, expr);
15470 /* Given a pointer value OP0 and a type TYPE, return a simplified version
15471 of an indirection through OP0, or NULL_TREE if no simplification is
15475 fold_indirect_ref_1 (tree type, tree op0)
15481 subtype = TREE_TYPE (sub);
15482 if (!POINTER_TYPE_P (subtype))
15485 if (TREE_CODE (sub) == ADDR_EXPR)
15487 tree op = TREE_OPERAND (sub, 0);
15488 tree optype = TREE_TYPE (op);
15489 /* *&CONST_DECL -> to the value of the const decl. */
15490 if (TREE_CODE (op) == CONST_DECL)
15491 return DECL_INITIAL (op);
15492 /* *&p => p; make sure to handle *&"str"[cst] here. */
15493 if (type == optype)
15495 tree fop = fold_read_from_constant_string (op);
15501 /* *(foo *)&fooarray => fooarray[0] */
15502 else if (TREE_CODE (optype) == ARRAY_TYPE
15503 && type == TREE_TYPE (optype))
15505 tree type_domain = TYPE_DOMAIN (optype);
15506 tree min_val = size_zero_node;
15507 if (type_domain && TYPE_MIN_VALUE (type_domain))
15508 min_val = TYPE_MIN_VALUE (type_domain);
15509 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
15511 /* *(foo *)&complexfoo => __real__ complexfoo */
15512 else if (TREE_CODE (optype) == COMPLEX_TYPE
15513 && type == TREE_TYPE (optype))
15514 return fold_build1 (REALPART_EXPR, type, op);
15515 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
15516 else if (TREE_CODE (optype) == VECTOR_TYPE
15517 && type == TREE_TYPE (optype))
15519 tree part_width = TYPE_SIZE (type);
15520 tree index = bitsize_int (0);
15521 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
15525 /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
15526 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15527 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15529 tree op00 = TREE_OPERAND (sub, 0);
15530 tree op01 = TREE_OPERAND (sub, 1);
15534 op00type = TREE_TYPE (op00);
15535 if (TREE_CODE (op00) == ADDR_EXPR
15536 && TREE_CODE (TREE_TYPE (op00type)) == VECTOR_TYPE
15537 && type == TREE_TYPE (TREE_TYPE (op00type)))
15539 HOST_WIDE_INT offset = tree_low_cst (op01, 0);
15540 tree part_width = TYPE_SIZE (type);
15541 unsigned HOST_WIDE_INT part_widthi = tree_low_cst (part_width, 0)/BITS_PER_UNIT;
15542 unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
15543 tree index = bitsize_int (indexi);
15545 if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (op00type)))
15546 return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (op00, 0),
15547 part_width, index);
15553 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
15554 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15555 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15557 tree op00 = TREE_OPERAND (sub, 0);
15558 tree op01 = TREE_OPERAND (sub, 1);
15562 op00type = TREE_TYPE (op00);
15563 if (TREE_CODE (op00) == ADDR_EXPR
15564 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
15565 && type == TREE_TYPE (TREE_TYPE (op00type)))
15567 tree size = TYPE_SIZE_UNIT (type);
15568 if (tree_int_cst_equal (size, op01))
15569 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
15573 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
15574 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
15575 && type == TREE_TYPE (TREE_TYPE (subtype)))
15578 tree min_val = size_zero_node;
15579 sub = build_fold_indirect_ref (sub);
15580 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
15581 if (type_domain && TYPE_MIN_VALUE (type_domain))
15582 min_val = TYPE_MIN_VALUE (type_domain);
15583 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
15589 /* Builds an expression for an indirection through T, simplifying some
15593 build_fold_indirect_ref (tree t)
15595 tree type = TREE_TYPE (TREE_TYPE (t));
15596 tree sub = fold_indirect_ref_1 (type, t);
15601 return build1 (INDIRECT_REF, type, t);
15604 /* Given an INDIRECT_REF T, return either T or a simplified version. */
15607 fold_indirect_ref (tree t)
15609 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
15617 /* Strip non-trapping, non-side-effecting tree nodes from an expression
15618 whose result is ignored. The type of the returned tree need not be
15619 the same as the original expression. */
15622 fold_ignored_result (tree t)
15624 if (!TREE_SIDE_EFFECTS (t))
15625 return integer_zero_node;
15628 switch (TREE_CODE_CLASS (TREE_CODE (t)))
15631 t = TREE_OPERAND (t, 0);
15635 case tcc_comparison:
15636 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15637 t = TREE_OPERAND (t, 0);
15638 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
15639 t = TREE_OPERAND (t, 1);
15644 case tcc_expression:
15645 switch (TREE_CODE (t))
15647 case COMPOUND_EXPR:
15648 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15650 t = TREE_OPERAND (t, 0);
15654 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
15655 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
15657 t = TREE_OPERAND (t, 0);
15670 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
15671 This can only be applied to objects of a sizetype. */
15674 round_up (tree value, int divisor)
15676 tree div = NULL_TREE;
15678 gcc_assert (divisor > 0);
15682 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15683 have to do anything. Only do this when we are not given a const,
15684 because in that case, this check is more expensive than just
15686 if (TREE_CODE (value) != INTEGER_CST)
15688 div = build_int_cst (TREE_TYPE (value), divisor);
15690 if (multiple_of_p (TREE_TYPE (value), value, div))
15694 /* If divisor is a power of two, simplify this to bit manipulation. */
15695 if (divisor == (divisor & -divisor))
15697 if (TREE_CODE (value) == INTEGER_CST)
15699 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
15700 unsigned HOST_WIDE_INT high;
15703 if ((low & (divisor - 1)) == 0)
15706 overflow_p = TREE_OVERFLOW (value);
15707 high = TREE_INT_CST_HIGH (value);
15708 low &= ~(divisor - 1);
15717 return force_fit_type_double (TREE_TYPE (value), low, high,
15724 t = build_int_cst (TREE_TYPE (value), divisor - 1);
15725 value = size_binop (PLUS_EXPR, value, t);
15726 t = build_int_cst (TREE_TYPE (value), -divisor);
15727 value = size_binop (BIT_AND_EXPR, value, t);
15733 div = build_int_cst (TREE_TYPE (value), divisor);
15734 value = size_binop (CEIL_DIV_EXPR, value, div);
15735 value = size_binop (MULT_EXPR, value, div);
15741 /* Likewise, but round down. */
15744 round_down (tree value, int divisor)
15746 tree div = NULL_TREE;
15748 gcc_assert (divisor > 0);
15752 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15753 have to do anything. Only do this when we are not given a const,
15754 because in that case, this check is more expensive than just
15756 if (TREE_CODE (value) != INTEGER_CST)
15758 div = build_int_cst (TREE_TYPE (value), divisor);
15760 if (multiple_of_p (TREE_TYPE (value), value, div))
15764 /* If divisor is a power of two, simplify this to bit manipulation. */
15765 if (divisor == (divisor & -divisor))
15769 t = build_int_cst (TREE_TYPE (value), -divisor);
15770 value = size_binop (BIT_AND_EXPR, value, t);
15775 div = build_int_cst (TREE_TYPE (value), divisor);
15776 value = size_binop (FLOOR_DIV_EXPR, value, div);
15777 value = size_binop (MULT_EXPR, value, div);
15783 /* Returns the pointer to the base of the object addressed by EXP and
15784 extracts the information about the offset of the access, storing it
15785 to PBITPOS and POFFSET. */
15788 split_address_to_core_and_offset (tree exp,
15789 HOST_WIDE_INT *pbitpos, tree *poffset)
15792 enum machine_mode mode;
15793 int unsignedp, volatilep;
15794 HOST_WIDE_INT bitsize;
15796 if (TREE_CODE (exp) == ADDR_EXPR)
15798 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
15799 poffset, &mode, &unsignedp, &volatilep,
15801 core = build_fold_addr_expr (core);
15807 *poffset = NULL_TREE;
15813 /* Returns true if addresses of E1 and E2 differ by a constant, false
15814 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15817 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
15820 HOST_WIDE_INT bitpos1, bitpos2;
15821 tree toffset1, toffset2, tdiff, type;
15823 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
15824 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
15826 if (bitpos1 % BITS_PER_UNIT != 0
15827 || bitpos2 % BITS_PER_UNIT != 0
15828 || !operand_equal_p (core1, core2, 0))
15831 if (toffset1 && toffset2)
15833 type = TREE_TYPE (toffset1);
15834 if (type != TREE_TYPE (toffset2))
15835 toffset2 = fold_convert (type, toffset2);
15837 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
15838 if (!cst_and_fits_in_hwi (tdiff))
15841 *diff = int_cst_value (tdiff);
15843 else if (toffset1 || toffset2)
15845 /* If only one of the offsets is non-constant, the difference cannot
15852 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
15856 /* Simplify the floating point expression EXP when the sign of the
15857 result is not significant. Return NULL_TREE if no simplification
15861 fold_strip_sign_ops (tree exp)
15865 switch (TREE_CODE (exp))
15869 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15870 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
15874 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
15876 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15877 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15878 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
15879 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
15880 arg0 ? arg0 : TREE_OPERAND (exp, 0),
15881 arg1 ? arg1 : TREE_OPERAND (exp, 1));
15884 case COMPOUND_EXPR:
15885 arg0 = TREE_OPERAND (exp, 0);
15886 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15888 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
15892 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15893 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
15895 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
15896 arg0 ? arg0 : TREE_OPERAND (exp, 1),
15897 arg1 ? arg1 : TREE_OPERAND (exp, 2));
15902 const enum built_in_function fcode = builtin_mathfn_code (exp);
15905 CASE_FLT_FN (BUILT_IN_COPYSIGN):
15906 /* Strip copysign function call, return the 1st argument. */
15907 arg0 = CALL_EXPR_ARG (exp, 0);
15908 arg1 = CALL_EXPR_ARG (exp, 1);
15909 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
15912 /* Strip sign ops from the argument of "odd" math functions. */
15913 if (negate_mathfn_p (fcode))
15915 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
15917 return build_call_expr (get_callee_fndecl (exp), 1, arg0);