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 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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
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 takes a constant, an overflowable flag and prior
43 overflow indicators. It forces the value to fit the type and sets
44 TREE_OVERFLOW and TREE_CONSTANT_OVERFLOW as appropriate. */
48 #include "coretypes.h"
59 #include "langhooks.h"
62 /* The following constants represent a bit based encoding of GCC's
63 comparison operators. This encoding simplifies transformations
64 on relational comparison operators, such as AND and OR. */
65 enum comparison_code {
84 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
85 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
86 static bool negate_mathfn_p (enum built_in_function);
87 static bool negate_expr_p (tree);
88 static tree negate_expr (tree);
89 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
90 static tree associate_trees (tree, tree, enum tree_code, tree);
91 static tree const_binop (enum tree_code, tree, tree, int);
92 static enum tree_code invert_tree_comparison (enum tree_code, bool);
93 static enum comparison_code comparison_to_compcode (enum tree_code);
94 static enum tree_code compcode_to_comparison (enum comparison_code);
95 static tree combine_comparisons (enum tree_code, enum tree_code,
96 enum tree_code, tree, tree, tree);
97 static int truth_value_p (enum tree_code);
98 static int operand_equal_for_comparison_p (tree, tree, tree);
99 static int twoval_comparison_p (tree, tree *, tree *, int *);
100 static tree eval_subst (tree, tree, tree, tree, tree);
101 static tree pedantic_omit_one_operand (tree, tree, tree);
102 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
103 static tree make_bit_field_ref (tree, tree, int, int, int);
104 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
105 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
106 enum machine_mode *, int *, int *,
108 static int all_ones_mask_p (tree, int);
109 static tree sign_bit_p (tree, tree);
110 static int simple_operand_p (tree);
111 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
112 static tree make_range (tree, int *, tree *, tree *);
113 static tree build_range_check (tree, tree, int, tree, tree);
114 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
116 static tree fold_range_test (tree);
117 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
118 static tree unextend (tree, int, int, tree);
119 static tree fold_truthop (enum tree_code, tree, tree, tree);
120 static tree optimize_minmax_comparison (tree);
121 static tree extract_muldiv (tree, tree, enum tree_code, tree);
122 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
123 static int multiple_of_p (tree, tree, tree);
124 static tree fold_binary_op_with_conditional_arg (tree, enum tree_code,
126 static bool fold_real_zero_addition_p (tree, tree, int);
127 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
129 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
130 static tree fold_div_compare (enum tree_code, tree, tree, tree);
131 static bool reorder_operands_p (tree, tree);
132 static tree fold_negate_const (tree, tree);
133 static tree fold_not_const (tree, tree);
134 static tree fold_relational_const (enum tree_code, tree, tree, tree);
135 static tree fold_relational_hi_lo (enum tree_code *, const tree,
137 static bool tree_expr_nonzero_p (tree);
139 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
140 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
141 and SUM1. Then this yields nonzero if overflow occurred during the
144 Overflow occurs if A and B have the same sign, but A and SUM differ in
145 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
147 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
149 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
150 We do that by representing the two-word integer in 4 words, with only
151 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
152 number. The value of the word is LOWPART + HIGHPART * BASE. */
155 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
156 #define HIGHPART(x) \
157 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
158 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
160 /* Unpack a two-word integer into 4 words.
161 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
162 WORDS points to the array of HOST_WIDE_INTs. */
165 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
167 words[0] = LOWPART (low);
168 words[1] = HIGHPART (low);
169 words[2] = LOWPART (hi);
170 words[3] = HIGHPART (hi);
173 /* Pack an array of 4 words into a two-word integer.
174 WORDS points to the array of words.
175 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
178 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
181 *low = words[0] + words[1] * BASE;
182 *hi = words[2] + words[3] * BASE;
185 /* T is an INT_CST node. OVERFLOWABLE indicates if we are interested
186 in overflow of the value, when >0 we are only interested in signed
187 overflow, for <0 we are interested in any overflow. OVERFLOWED
188 indicates whether overflow has already occurred. CONST_OVERFLOWED
189 indicates whether constant overflow has already occurred. We force
190 T's value to be within range of T's type (by setting to 0 or 1 all
191 the bits outside the type's range). We set TREE_OVERFLOWED if,
192 OVERFLOWED is nonzero,
193 or OVERFLOWABLE is >0 and signed overflow occurs
194 or OVERFLOWABLE is <0 and any overflow occurs
195 We set TREE_CONSTANT_OVERFLOWED if,
196 CONST_OVERFLOWED is nonzero
197 or we set TREE_OVERFLOWED.
198 We return either the original T, or a copy. */
201 force_fit_type (tree t, int overflowable,
202 bool overflowed, bool overflowed_const)
204 unsigned HOST_WIDE_INT low;
207 int sign_extended_type;
209 gcc_assert (TREE_CODE (t) == INTEGER_CST);
211 low = TREE_INT_CST_LOW (t);
212 high = TREE_INT_CST_HIGH (t);
214 if (POINTER_TYPE_P (TREE_TYPE (t))
215 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
218 prec = TYPE_PRECISION (TREE_TYPE (t));
219 /* Size types *are* sign extended. */
220 sign_extended_type = (!TYPE_UNSIGNED (TREE_TYPE (t))
221 || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
222 && TYPE_IS_SIZETYPE (TREE_TYPE (t))));
224 /* First clear all bits that are beyond the type's precision. */
226 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
228 else if (prec > HOST_BITS_PER_WIDE_INT)
229 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
233 if (prec < HOST_BITS_PER_WIDE_INT)
234 low &= ~((HOST_WIDE_INT) (-1) << prec);
237 if (!sign_extended_type)
238 /* No sign extension */;
239 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
240 /* Correct width already. */;
241 else if (prec > HOST_BITS_PER_WIDE_INT)
243 /* Sign extend top half? */
244 if (high & ((unsigned HOST_WIDE_INT)1
245 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
246 high |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
248 else if (prec == HOST_BITS_PER_WIDE_INT)
250 if ((HOST_WIDE_INT)low < 0)
255 /* Sign extend bottom half? */
256 if (low & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
259 low |= (HOST_WIDE_INT)(-1) << prec;
263 /* If the value changed, return a new node. */
264 if (overflowed || overflowed_const
265 || low != TREE_INT_CST_LOW (t) || high != TREE_INT_CST_HIGH (t))
267 t = build_int_cst_wide (TREE_TYPE (t), low, high);
271 || (overflowable > 0 && sign_extended_type))
274 TREE_OVERFLOW (t) = 1;
275 TREE_CONSTANT_OVERFLOW (t) = 1;
277 else if (overflowed_const)
280 TREE_CONSTANT_OVERFLOW (t) = 1;
287 /* Add two doubleword integers with doubleword result.
288 Each argument is given as two `HOST_WIDE_INT' pieces.
289 One argument is L1 and H1; the other, L2 and H2.
290 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
293 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
294 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
295 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
297 unsigned HOST_WIDE_INT l;
301 h = h1 + h2 + (l < l1);
305 return OVERFLOW_SUM_SIGN (h1, h2, h);
308 /* Negate a doubleword integer with doubleword result.
309 Return nonzero if the operation overflows, assuming it's signed.
310 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
311 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
314 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
315 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
321 return (*hv & h1) < 0;
331 /* Multiply two doubleword integers with doubleword result.
332 Return nonzero if the operation overflows, assuming it's signed.
333 Each argument is given as two `HOST_WIDE_INT' pieces.
334 One argument is L1 and H1; the other, L2 and H2.
335 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
338 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
339 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
340 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
342 HOST_WIDE_INT arg1[4];
343 HOST_WIDE_INT arg2[4];
344 HOST_WIDE_INT prod[4 * 2];
345 unsigned HOST_WIDE_INT carry;
347 unsigned HOST_WIDE_INT toplow, neglow;
348 HOST_WIDE_INT tophigh, neghigh;
350 encode (arg1, l1, h1);
351 encode (arg2, l2, h2);
353 memset (prod, 0, sizeof prod);
355 for (i = 0; i < 4; i++)
358 for (j = 0; j < 4; j++)
361 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
362 carry += arg1[i] * arg2[j];
363 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
365 prod[k] = LOWPART (carry);
366 carry = HIGHPART (carry);
371 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
373 /* Check for overflow by calculating the top half of the answer in full;
374 it should agree with the low half's sign bit. */
375 decode (prod + 4, &toplow, &tophigh);
378 neg_double (l2, h2, &neglow, &neghigh);
379 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
383 neg_double (l1, h1, &neglow, &neghigh);
384 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
386 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
389 /* Shift the doubleword integer in L1, H1 left by COUNT places
390 keeping only PREC bits of result.
391 Shift right if COUNT is negative.
392 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
393 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
396 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
397 HOST_WIDE_INT count, unsigned int prec,
398 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
400 unsigned HOST_WIDE_INT signmask;
404 rshift_double (l1, h1, -count, prec, lv, hv, arith);
408 if (SHIFT_COUNT_TRUNCATED)
411 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
413 /* Shifting by the host word size is undefined according to the
414 ANSI standard, so we must handle this as a special case. */
418 else if (count >= HOST_BITS_PER_WIDE_INT)
420 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
425 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
426 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
430 /* Sign extend all bits that are beyond the precision. */
432 signmask = -((prec > HOST_BITS_PER_WIDE_INT
433 ? ((unsigned HOST_WIDE_INT) *hv
434 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
435 : (*lv >> (prec - 1))) & 1);
437 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
439 else if (prec >= HOST_BITS_PER_WIDE_INT)
441 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
442 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
447 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
448 *lv |= signmask << prec;
452 /* Shift the doubleword integer in L1, H1 right by COUNT places
453 keeping only PREC bits of result. COUNT must be positive.
454 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
455 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
458 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
459 HOST_WIDE_INT count, unsigned int prec,
460 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
463 unsigned HOST_WIDE_INT signmask;
466 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
469 if (SHIFT_COUNT_TRUNCATED)
472 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
474 /* Shifting by the host word size is undefined according to the
475 ANSI standard, so we must handle this as a special case. */
479 else if (count >= HOST_BITS_PER_WIDE_INT)
482 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
486 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
488 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
491 /* Zero / sign extend all bits that are beyond the precision. */
493 if (count >= (HOST_WIDE_INT)prec)
498 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
500 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
502 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
503 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
508 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
509 *lv |= signmask << (prec - count);
513 /* Rotate the doubleword integer in L1, H1 left by COUNT places
514 keeping only PREC bits of result.
515 Rotate right if COUNT is negative.
516 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
519 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
520 HOST_WIDE_INT count, unsigned int prec,
521 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
523 unsigned HOST_WIDE_INT s1l, s2l;
524 HOST_WIDE_INT s1h, s2h;
530 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
531 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
536 /* Rotate the doubleword integer in L1, H1 left by COUNT places
537 keeping only PREC bits of result. COUNT must be positive.
538 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
541 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
542 HOST_WIDE_INT count, unsigned int prec,
543 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
545 unsigned HOST_WIDE_INT s1l, s2l;
546 HOST_WIDE_INT s1h, s2h;
552 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
553 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
558 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
559 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
560 CODE is a tree code for a kind of division, one of
561 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
563 It controls how the quotient is rounded to an integer.
564 Return nonzero if the operation overflows.
565 UNS nonzero says do unsigned division. */
568 div_and_round_double (enum tree_code code, int uns,
569 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
570 HOST_WIDE_INT hnum_orig,
571 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
572 HOST_WIDE_INT hden_orig,
573 unsigned HOST_WIDE_INT *lquo,
574 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
578 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
579 HOST_WIDE_INT den[4], quo[4];
581 unsigned HOST_WIDE_INT work;
582 unsigned HOST_WIDE_INT carry = 0;
583 unsigned HOST_WIDE_INT lnum = lnum_orig;
584 HOST_WIDE_INT hnum = hnum_orig;
585 unsigned HOST_WIDE_INT lden = lden_orig;
586 HOST_WIDE_INT hden = hden_orig;
589 if (hden == 0 && lden == 0)
590 overflow = 1, lden = 1;
592 /* Calculate quotient sign and convert operands to unsigned. */
598 /* (minimum integer) / (-1) is the only overflow case. */
599 if (neg_double (lnum, hnum, &lnum, &hnum)
600 && ((HOST_WIDE_INT) lden & hden) == -1)
606 neg_double (lden, hden, &lden, &hden);
610 if (hnum == 0 && hden == 0)
611 { /* single precision */
613 /* This unsigned division rounds toward zero. */
619 { /* trivial case: dividend < divisor */
620 /* hden != 0 already checked. */
627 memset (quo, 0, sizeof quo);
629 memset (num, 0, sizeof num); /* to zero 9th element */
630 memset (den, 0, sizeof den);
632 encode (num, lnum, hnum);
633 encode (den, lden, hden);
635 /* Special code for when the divisor < BASE. */
636 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
638 /* hnum != 0 already checked. */
639 for (i = 4 - 1; i >= 0; i--)
641 work = num[i] + carry * BASE;
642 quo[i] = work / lden;
648 /* Full double precision division,
649 with thanks to Don Knuth's "Seminumerical Algorithms". */
650 int num_hi_sig, den_hi_sig;
651 unsigned HOST_WIDE_INT quo_est, scale;
653 /* Find the highest nonzero divisor digit. */
654 for (i = 4 - 1;; i--)
661 /* Insure that the first digit of the divisor is at least BASE/2.
662 This is required by the quotient digit estimation algorithm. */
664 scale = BASE / (den[den_hi_sig] + 1);
666 { /* scale divisor and dividend */
668 for (i = 0; i <= 4 - 1; i++)
670 work = (num[i] * scale) + carry;
671 num[i] = LOWPART (work);
672 carry = HIGHPART (work);
677 for (i = 0; i <= 4 - 1; i++)
679 work = (den[i] * scale) + carry;
680 den[i] = LOWPART (work);
681 carry = HIGHPART (work);
682 if (den[i] != 0) den_hi_sig = i;
689 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
691 /* Guess the next quotient digit, quo_est, by dividing the first
692 two remaining dividend digits by the high order quotient digit.
693 quo_est is never low and is at most 2 high. */
694 unsigned HOST_WIDE_INT tmp;
696 num_hi_sig = i + den_hi_sig + 1;
697 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
698 if (num[num_hi_sig] != den[den_hi_sig])
699 quo_est = work / den[den_hi_sig];
703 /* Refine quo_est so it's usually correct, and at most one high. */
704 tmp = work - quo_est * den[den_hi_sig];
706 && (den[den_hi_sig - 1] * quo_est
707 > (tmp * BASE + num[num_hi_sig - 2])))
710 /* Try QUO_EST as the quotient digit, by multiplying the
711 divisor by QUO_EST and subtracting from the remaining dividend.
712 Keep in mind that QUO_EST is the I - 1st digit. */
715 for (j = 0; j <= den_hi_sig; j++)
717 work = quo_est * den[j] + carry;
718 carry = HIGHPART (work);
719 work = num[i + j] - LOWPART (work);
720 num[i + j] = LOWPART (work);
721 carry += HIGHPART (work) != 0;
724 /* If quo_est was high by one, then num[i] went negative and
725 we need to correct things. */
726 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
729 carry = 0; /* add divisor back in */
730 for (j = 0; j <= den_hi_sig; j++)
732 work = num[i + j] + den[j] + carry;
733 carry = HIGHPART (work);
734 num[i + j] = LOWPART (work);
737 num [num_hi_sig] += carry;
740 /* Store the quotient digit. */
745 decode (quo, lquo, hquo);
748 /* If result is negative, make it so. */
750 neg_double (*lquo, *hquo, lquo, hquo);
752 /* Compute trial remainder: rem = num - (quo * den) */
753 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
754 neg_double (*lrem, *hrem, lrem, hrem);
755 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
760 case TRUNC_MOD_EXPR: /* round toward zero */
761 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
765 case FLOOR_MOD_EXPR: /* round toward negative infinity */
766 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
769 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
777 case CEIL_MOD_EXPR: /* round toward positive infinity */
778 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
780 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
788 case ROUND_MOD_EXPR: /* round to closest integer */
790 unsigned HOST_WIDE_INT labs_rem = *lrem;
791 HOST_WIDE_INT habs_rem = *hrem;
792 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
793 HOST_WIDE_INT habs_den = hden, htwice;
795 /* Get absolute values. */
797 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
799 neg_double (lden, hden, &labs_den, &habs_den);
801 /* If (2 * abs (lrem) >= abs (lden)) */
802 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
803 labs_rem, habs_rem, <wice, &htwice);
805 if (((unsigned HOST_WIDE_INT) habs_den
806 < (unsigned HOST_WIDE_INT) htwice)
807 || (((unsigned HOST_WIDE_INT) habs_den
808 == (unsigned HOST_WIDE_INT) htwice)
809 && (labs_den < ltwice)))
813 add_double (*lquo, *hquo,
814 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
817 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
829 /* Compute true remainder: rem = num - (quo * den) */
830 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
831 neg_double (*lrem, *hrem, lrem, hrem);
832 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
836 /* Return true if built-in mathematical function specified by CODE
837 preserves the sign of it argument, i.e. -f(x) == f(-x). */
840 negate_mathfn_p (enum built_in_function code)
864 /* Check whether we may negate an integer constant T without causing
868 may_negate_without_overflow_p (tree t)
870 unsigned HOST_WIDE_INT val;
874 gcc_assert (TREE_CODE (t) == INTEGER_CST);
876 type = TREE_TYPE (t);
877 if (TYPE_UNSIGNED (type))
880 prec = TYPE_PRECISION (type);
881 if (prec > HOST_BITS_PER_WIDE_INT)
883 if (TREE_INT_CST_LOW (t) != 0)
885 prec -= HOST_BITS_PER_WIDE_INT;
886 val = TREE_INT_CST_HIGH (t);
889 val = TREE_INT_CST_LOW (t);
890 if (prec < HOST_BITS_PER_WIDE_INT)
891 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
892 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
895 /* Determine whether an expression T can be cheaply negated using
896 the function negate_expr. */
899 negate_expr_p (tree t)
906 type = TREE_TYPE (t);
909 switch (TREE_CODE (t))
912 if (TYPE_UNSIGNED (type) || ! flag_trapv)
915 /* Check that -CST will not overflow type. */
916 return may_negate_without_overflow_p (t);
923 return negate_expr_p (TREE_REALPART (t))
924 && negate_expr_p (TREE_IMAGPART (t));
927 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
929 /* -(A + B) -> (-B) - A. */
930 if (negate_expr_p (TREE_OPERAND (t, 1))
931 && reorder_operands_p (TREE_OPERAND (t, 0),
932 TREE_OPERAND (t, 1)))
934 /* -(A + B) -> (-A) - B. */
935 return negate_expr_p (TREE_OPERAND (t, 0));
938 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
939 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
940 && reorder_operands_p (TREE_OPERAND (t, 0),
941 TREE_OPERAND (t, 1));
944 if (TYPE_UNSIGNED (TREE_TYPE (t)))
950 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
951 return negate_expr_p (TREE_OPERAND (t, 1))
952 || negate_expr_p (TREE_OPERAND (t, 0));
956 /* Negate -((double)float) as (double)(-float). */
957 if (TREE_CODE (type) == REAL_TYPE)
959 tree tem = strip_float_extensions (t);
961 return negate_expr_p (tem);
966 /* Negate -f(x) as f(-x). */
967 if (negate_mathfn_p (builtin_mathfn_code (t)))
968 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
972 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
973 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
975 tree op1 = TREE_OPERAND (t, 1);
976 if (TREE_INT_CST_HIGH (op1) == 0
977 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
978 == TREE_INT_CST_LOW (op1))
989 /* Given T, an expression, return the negation of T. Allow for T to be
990 null, in which case return null. */
1001 type = TREE_TYPE (t);
1002 STRIP_SIGN_NOPS (t);
1004 switch (TREE_CODE (t))
1007 tem = fold_negate_const (t, type);
1008 if (! TREE_OVERFLOW (tem)
1009 || TYPE_UNSIGNED (type)
1015 tem = fold_negate_const (t, type);
1016 /* Two's complement FP formats, such as c4x, may overflow. */
1017 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
1018 return fold_convert (type, tem);
1023 tree rpart = negate_expr (TREE_REALPART (t));
1024 tree ipart = negate_expr (TREE_IMAGPART (t));
1026 if ((TREE_CODE (rpart) == REAL_CST
1027 && TREE_CODE (ipart) == REAL_CST)
1028 || (TREE_CODE (rpart) == INTEGER_CST
1029 && TREE_CODE (ipart) == INTEGER_CST))
1030 return build_complex (type, rpart, ipart);
1035 return fold_convert (type, TREE_OPERAND (t, 0));
1038 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1040 /* -(A + B) -> (-B) - A. */
1041 if (negate_expr_p (TREE_OPERAND (t, 1))
1042 && reorder_operands_p (TREE_OPERAND (t, 0),
1043 TREE_OPERAND (t, 1)))
1045 tem = negate_expr (TREE_OPERAND (t, 1));
1046 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1047 tem, TREE_OPERAND (t, 0)));
1048 return fold_convert (type, tem);
1051 /* -(A + B) -> (-A) - B. */
1052 if (negate_expr_p (TREE_OPERAND (t, 0)))
1054 tem = negate_expr (TREE_OPERAND (t, 0));
1055 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1056 tem, TREE_OPERAND (t, 1)));
1057 return fold_convert (type, tem);
1063 /* - (A - B) -> B - A */
1064 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1065 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1066 return fold_convert (type,
1067 fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1068 TREE_OPERAND (t, 1),
1069 TREE_OPERAND (t, 0))));
1073 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1079 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1081 tem = TREE_OPERAND (t, 1);
1082 if (negate_expr_p (tem))
1083 return fold_convert (type,
1084 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1085 TREE_OPERAND (t, 0),
1086 negate_expr (tem))));
1087 tem = TREE_OPERAND (t, 0);
1088 if (negate_expr_p (tem))
1089 return fold_convert (type,
1090 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1092 TREE_OPERAND (t, 1))));
1097 /* Convert -((double)float) into (double)(-float). */
1098 if (TREE_CODE (type) == REAL_TYPE)
1100 tem = strip_float_extensions (t);
1101 if (tem != t && negate_expr_p (tem))
1102 return fold_convert (type, negate_expr (tem));
1107 /* Negate -f(x) as f(-x). */
1108 if (negate_mathfn_p (builtin_mathfn_code (t))
1109 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1111 tree fndecl, arg, arglist;
1113 fndecl = get_callee_fndecl (t);
1114 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1115 arglist = build_tree_list (NULL_TREE, arg);
1116 return build_function_call_expr (fndecl, arglist);
1121 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1122 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1124 tree op1 = TREE_OPERAND (t, 1);
1125 if (TREE_INT_CST_HIGH (op1) == 0
1126 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1127 == TREE_INT_CST_LOW (op1))
1129 tree ntype = TYPE_UNSIGNED (type)
1130 ? lang_hooks.types.signed_type (type)
1131 : lang_hooks.types.unsigned_type (type);
1132 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1133 temp = fold (build2 (RSHIFT_EXPR, ntype, temp, op1));
1134 return fold_convert (type, temp);
1143 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1144 return fold_convert (type, tem);
1147 /* Split a tree IN into a constant, literal and variable parts that could be
1148 combined with CODE to make IN. "constant" means an expression with
1149 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1150 commutative arithmetic operation. Store the constant part into *CONP,
1151 the literal in *LITP and return the variable part. If a part isn't
1152 present, set it to null. If the tree does not decompose in this way,
1153 return the entire tree as the variable part and the other parts as null.
1155 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1156 case, we negate an operand that was subtracted. Except if it is a
1157 literal for which we use *MINUS_LITP instead.
1159 If NEGATE_P is true, we are negating all of IN, again except a literal
1160 for which we use *MINUS_LITP instead.
1162 If IN is itself a literal or constant, return it as appropriate.
1164 Note that we do not guarantee that any of the three values will be the
1165 same type as IN, but they will have the same signedness and mode. */
1168 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1169 tree *minus_litp, int negate_p)
1177 /* Strip any conversions that don't change the machine mode or signedness. */
1178 STRIP_SIGN_NOPS (in);
1180 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1182 else if (TREE_CODE (in) == code
1183 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1184 /* We can associate addition and subtraction together (even
1185 though the C standard doesn't say so) for integers because
1186 the value is not affected. For reals, the value might be
1187 affected, so we can't. */
1188 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1189 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1191 tree op0 = TREE_OPERAND (in, 0);
1192 tree op1 = TREE_OPERAND (in, 1);
1193 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1194 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1196 /* First see if either of the operands is a literal, then a constant. */
1197 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1198 *litp = op0, op0 = 0;
1199 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1200 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1202 if (op0 != 0 && TREE_CONSTANT (op0))
1203 *conp = op0, op0 = 0;
1204 else if (op1 != 0 && TREE_CONSTANT (op1))
1205 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1207 /* If we haven't dealt with either operand, this is not a case we can
1208 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1209 if (op0 != 0 && op1 != 0)
1214 var = op1, neg_var_p = neg1_p;
1216 /* Now do any needed negations. */
1218 *minus_litp = *litp, *litp = 0;
1220 *conp = negate_expr (*conp);
1222 var = negate_expr (var);
1224 else if (TREE_CONSTANT (in))
1232 *minus_litp = *litp, *litp = 0;
1233 else if (*minus_litp)
1234 *litp = *minus_litp, *minus_litp = 0;
1235 *conp = negate_expr (*conp);
1236 var = negate_expr (var);
1242 /* Re-associate trees split by the above function. T1 and T2 are either
1243 expressions to associate or null. Return the new expression, if any. If
1244 we build an operation, do it in TYPE and with CODE. */
1247 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1254 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1255 try to fold this since we will have infinite recursion. But do
1256 deal with any NEGATE_EXPRs. */
1257 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1258 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1260 if (code == PLUS_EXPR)
1262 if (TREE_CODE (t1) == NEGATE_EXPR)
1263 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1264 fold_convert (type, TREE_OPERAND (t1, 0)));
1265 else if (TREE_CODE (t2) == NEGATE_EXPR)
1266 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1267 fold_convert (type, TREE_OPERAND (t2, 0)));
1268 else if (integer_zerop (t2))
1269 return fold_convert (type, t1);
1271 else if (code == MINUS_EXPR)
1273 if (integer_zerop (t2))
1274 return fold_convert (type, t1);
1277 return build2 (code, type, fold_convert (type, t1),
1278 fold_convert (type, t2));
1281 return fold (build2 (code, type, fold_convert (type, t1),
1282 fold_convert (type, t2)));
1285 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1286 to produce a new constant.
1288 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1291 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1293 unsigned HOST_WIDE_INT int1l, int2l;
1294 HOST_WIDE_INT int1h, int2h;
1295 unsigned HOST_WIDE_INT low;
1297 unsigned HOST_WIDE_INT garbagel;
1298 HOST_WIDE_INT garbageh;
1300 tree type = TREE_TYPE (arg1);
1301 int uns = TYPE_UNSIGNED (type);
1303 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1305 int no_overflow = 0;
1307 int1l = TREE_INT_CST_LOW (arg1);
1308 int1h = TREE_INT_CST_HIGH (arg1);
1309 int2l = TREE_INT_CST_LOW (arg2);
1310 int2h = TREE_INT_CST_HIGH (arg2);
1315 low = int1l | int2l, hi = int1h | int2h;
1319 low = int1l ^ int2l, hi = int1h ^ int2h;
1323 low = int1l & int2l, hi = int1h & int2h;
1329 /* It's unclear from the C standard whether shifts can overflow.
1330 The following code ignores overflow; perhaps a C standard
1331 interpretation ruling is needed. */
1332 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1340 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1345 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1349 neg_double (int2l, int2h, &low, &hi);
1350 add_double (int1l, int1h, low, hi, &low, &hi);
1351 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1355 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1358 case TRUNC_DIV_EXPR:
1359 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1360 case EXACT_DIV_EXPR:
1361 /* This is a shortcut for a common special case. */
1362 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1363 && ! TREE_CONSTANT_OVERFLOW (arg1)
1364 && ! TREE_CONSTANT_OVERFLOW (arg2)
1365 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1367 if (code == CEIL_DIV_EXPR)
1370 low = int1l / int2l, hi = 0;
1374 /* ... fall through ... */
1376 case ROUND_DIV_EXPR:
1377 if (int2h == 0 && int2l == 1)
1379 low = int1l, hi = int1h;
1382 if (int1l == int2l && int1h == int2h
1383 && ! (int1l == 0 && int1h == 0))
1388 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1389 &low, &hi, &garbagel, &garbageh);
1392 case TRUNC_MOD_EXPR:
1393 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1394 /* This is a shortcut for a common special case. */
1395 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1396 && ! TREE_CONSTANT_OVERFLOW (arg1)
1397 && ! TREE_CONSTANT_OVERFLOW (arg2)
1398 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1400 if (code == CEIL_MOD_EXPR)
1402 low = int1l % int2l, hi = 0;
1406 /* ... fall through ... */
1408 case ROUND_MOD_EXPR:
1409 overflow = div_and_round_double (code, uns,
1410 int1l, int1h, int2l, int2h,
1411 &garbagel, &garbageh, &low, &hi);
1417 low = (((unsigned HOST_WIDE_INT) int1h
1418 < (unsigned HOST_WIDE_INT) int2h)
1419 || (((unsigned HOST_WIDE_INT) int1h
1420 == (unsigned HOST_WIDE_INT) int2h)
1423 low = (int1h < int2h
1424 || (int1h == int2h && int1l < int2l));
1426 if (low == (code == MIN_EXPR))
1427 low = int1l, hi = int1h;
1429 low = int2l, hi = int2h;
1436 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1440 /* Propagate overflow flags ourselves. */
1441 if (((!uns || is_sizetype) && overflow)
1442 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1445 TREE_OVERFLOW (t) = 1;
1446 TREE_CONSTANT_OVERFLOW (t) = 1;
1448 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1451 TREE_CONSTANT_OVERFLOW (t) = 1;
1455 t = force_fit_type (t, 1,
1456 ((!uns || is_sizetype) && overflow)
1457 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2),
1458 TREE_CONSTANT_OVERFLOW (arg1)
1459 | TREE_CONSTANT_OVERFLOW (arg2));
1464 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1465 constant. We assume ARG1 and ARG2 have the same data type, or at least
1466 are the same kind of constant and the same machine mode.
1468 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1471 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1476 if (TREE_CODE (arg1) == INTEGER_CST)
1477 return int_const_binop (code, arg1, arg2, notrunc);
1479 if (TREE_CODE (arg1) == REAL_CST)
1481 enum machine_mode mode;
1484 REAL_VALUE_TYPE value;
1485 REAL_VALUE_TYPE result;
1489 d1 = TREE_REAL_CST (arg1);
1490 d2 = TREE_REAL_CST (arg2);
1492 type = TREE_TYPE (arg1);
1493 mode = TYPE_MODE (type);
1495 /* Don't perform operation if we honor signaling NaNs and
1496 either operand is a NaN. */
1497 if (HONOR_SNANS (mode)
1498 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1501 /* Don't perform operation if it would raise a division
1502 by zero exception. */
1503 if (code == RDIV_EXPR
1504 && REAL_VALUES_EQUAL (d2, dconst0)
1505 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1508 /* If either operand is a NaN, just return it. Otherwise, set up
1509 for floating-point trap; we return an overflow. */
1510 if (REAL_VALUE_ISNAN (d1))
1512 else if (REAL_VALUE_ISNAN (d2))
1515 inexact = real_arithmetic (&value, code, &d1, &d2);
1516 real_convert (&result, mode, &value);
1518 /* Don't constant fold this floating point operation if the
1519 result may dependent upon the run-time rounding mode and
1520 flag_rounding_math is set, or if GCC's software emulation
1521 is unable to accurately represent the result. */
1523 if ((flag_rounding_math
1524 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1525 && !flag_unsafe_math_optimizations))
1526 && (inexact || !real_identical (&result, &value)))
1529 t = build_real (type, result);
1531 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1532 TREE_CONSTANT_OVERFLOW (t)
1534 | TREE_CONSTANT_OVERFLOW (arg1)
1535 | TREE_CONSTANT_OVERFLOW (arg2);
1538 if (TREE_CODE (arg1) == COMPLEX_CST)
1540 tree type = TREE_TYPE (arg1);
1541 tree r1 = TREE_REALPART (arg1);
1542 tree i1 = TREE_IMAGPART (arg1);
1543 tree r2 = TREE_REALPART (arg2);
1544 tree i2 = TREE_IMAGPART (arg2);
1550 t = build_complex (type,
1551 const_binop (PLUS_EXPR, r1, r2, notrunc),
1552 const_binop (PLUS_EXPR, i1, i2, notrunc));
1556 t = build_complex (type,
1557 const_binop (MINUS_EXPR, r1, r2, notrunc),
1558 const_binop (MINUS_EXPR, i1, i2, notrunc));
1562 t = build_complex (type,
1563 const_binop (MINUS_EXPR,
1564 const_binop (MULT_EXPR,
1566 const_binop (MULT_EXPR,
1569 const_binop (PLUS_EXPR,
1570 const_binop (MULT_EXPR,
1572 const_binop (MULT_EXPR,
1580 = const_binop (PLUS_EXPR,
1581 const_binop (MULT_EXPR, r2, r2, notrunc),
1582 const_binop (MULT_EXPR, i2, i2, notrunc),
1585 t = build_complex (type,
1587 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1588 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1589 const_binop (PLUS_EXPR,
1590 const_binop (MULT_EXPR, r1, r2,
1592 const_binop (MULT_EXPR, i1, i2,
1595 magsquared, notrunc),
1597 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1598 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1599 const_binop (MINUS_EXPR,
1600 const_binop (MULT_EXPR, i1, r2,
1602 const_binop (MULT_EXPR, r1, i2,
1605 magsquared, notrunc));
1617 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1618 indicates which particular sizetype to create. */
1621 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
1623 return build_int_cst (sizetype_tab[(int) kind], number);
1626 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1627 is a tree code. The type of the result is taken from the operands.
1628 Both must be the same type integer type and it must be a size type.
1629 If the operands are constant, so is the result. */
1632 size_binop (enum tree_code code, tree arg0, tree arg1)
1634 tree type = TREE_TYPE (arg0);
1636 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1637 && type == TREE_TYPE (arg1));
1639 /* Handle the special case of two integer constants faster. */
1640 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1642 /* And some specific cases even faster than that. */
1643 if (code == PLUS_EXPR && integer_zerop (arg0))
1645 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1646 && integer_zerop (arg1))
1648 else if (code == MULT_EXPR && integer_onep (arg0))
1651 /* Handle general case of two integer constants. */
1652 return int_const_binop (code, arg0, arg1, 0);
1655 if (arg0 == error_mark_node || arg1 == error_mark_node)
1656 return error_mark_node;
1658 return fold (build2 (code, type, arg0, arg1));
1661 /* Given two values, either both of sizetype or both of bitsizetype,
1662 compute the difference between the two values. Return the value
1663 in signed type corresponding to the type of the operands. */
1666 size_diffop (tree arg0, tree arg1)
1668 tree type = TREE_TYPE (arg0);
1671 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1672 && type == TREE_TYPE (arg1));
1674 /* If the type is already signed, just do the simple thing. */
1675 if (!TYPE_UNSIGNED (type))
1676 return size_binop (MINUS_EXPR, arg0, arg1);
1678 ctype = type == bitsizetype ? sbitsizetype : ssizetype;
1680 /* If either operand is not a constant, do the conversions to the signed
1681 type and subtract. The hardware will do the right thing with any
1682 overflow in the subtraction. */
1683 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1684 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1685 fold_convert (ctype, arg1));
1687 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1688 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1689 overflow) and negate (which can't either). Special-case a result
1690 of zero while we're here. */
1691 if (tree_int_cst_equal (arg0, arg1))
1692 return fold_convert (ctype, integer_zero_node);
1693 else if (tree_int_cst_lt (arg1, arg0))
1694 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1696 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1697 fold_convert (ctype, size_binop (MINUS_EXPR,
1701 /* A subroutine of fold_convert_const handling conversions of an
1702 INTEGER_CST to another integer type. */
1705 fold_convert_const_int_from_int (tree type, tree arg1)
1709 /* Given an integer constant, make new constant with new type,
1710 appropriately sign-extended or truncated. */
1711 t = build_int_cst_wide (type, TREE_INT_CST_LOW (arg1),
1712 TREE_INT_CST_HIGH (arg1));
1714 t = force_fit_type (t,
1715 /* Don't set the overflow when
1716 converting a pointer */
1717 !POINTER_TYPE_P (TREE_TYPE (arg1)),
1718 (TREE_INT_CST_HIGH (arg1) < 0
1719 && (TYPE_UNSIGNED (type)
1720 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
1721 | TREE_OVERFLOW (arg1),
1722 TREE_CONSTANT_OVERFLOW (arg1));
1727 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1728 to an integer type. */
1731 fold_convert_const_int_from_real (enum tree_code code, tree type, tree arg1)
1736 /* The following code implements the floating point to integer
1737 conversion rules required by the Java Language Specification,
1738 that IEEE NaNs are mapped to zero and values that overflow
1739 the target precision saturate, i.e. values greater than
1740 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1741 are mapped to INT_MIN. These semantics are allowed by the
1742 C and C++ standards that simply state that the behavior of
1743 FP-to-integer conversion is unspecified upon overflow. */
1745 HOST_WIDE_INT high, low;
1747 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1751 case FIX_TRUNC_EXPR:
1752 real_trunc (&r, VOIDmode, &x);
1756 real_ceil (&r, VOIDmode, &x);
1759 case FIX_FLOOR_EXPR:
1760 real_floor (&r, VOIDmode, &x);
1763 case FIX_ROUND_EXPR:
1764 real_round (&r, VOIDmode, &x);
1771 /* If R is NaN, return zero and show we have an overflow. */
1772 if (REAL_VALUE_ISNAN (r))
1779 /* See if R is less than the lower bound or greater than the
1784 tree lt = TYPE_MIN_VALUE (type);
1785 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1786 if (REAL_VALUES_LESS (r, l))
1789 high = TREE_INT_CST_HIGH (lt);
1790 low = TREE_INT_CST_LOW (lt);
1796 tree ut = TYPE_MAX_VALUE (type);
1799 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1800 if (REAL_VALUES_LESS (u, r))
1803 high = TREE_INT_CST_HIGH (ut);
1804 low = TREE_INT_CST_LOW (ut);
1810 REAL_VALUE_TO_INT (&low, &high, r);
1812 t = build_int_cst_wide (type, low, high);
1814 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg1),
1815 TREE_CONSTANT_OVERFLOW (arg1));
1819 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1820 to another floating point type. */
1823 fold_convert_const_real_from_real (tree type, tree arg1)
1825 REAL_VALUE_TYPE value;
1828 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
1829 t = build_real (type, value);
1831 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
1832 TREE_CONSTANT_OVERFLOW (t)
1833 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1837 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1838 type TYPE. If no simplification can be done return NULL_TREE. */
1841 fold_convert_const (enum tree_code code, tree type, tree arg1)
1843 if (TREE_TYPE (arg1) == type)
1846 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1848 if (TREE_CODE (arg1) == INTEGER_CST)
1849 return fold_convert_const_int_from_int (type, arg1);
1850 else if (TREE_CODE (arg1) == REAL_CST)
1851 return fold_convert_const_int_from_real (code, type, arg1);
1853 else if (TREE_CODE (type) == REAL_TYPE)
1855 if (TREE_CODE (arg1) == INTEGER_CST)
1856 return build_real_from_int_cst (type, arg1);
1857 if (TREE_CODE (arg1) == REAL_CST)
1858 return fold_convert_const_real_from_real (type, arg1);
1863 /* Construct a vector of zero elements of vector type TYPE. */
1866 build_zero_vector (tree type)
1871 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
1872 units = TYPE_VECTOR_SUBPARTS (type);
1875 for (i = 0; i < units; i++)
1876 list = tree_cons (NULL_TREE, elem, list);
1877 return build_vector (type, list);
1880 /* Convert expression ARG to type TYPE. Used by the middle-end for
1881 simple conversions in preference to calling the front-end's convert. */
1884 fold_convert (tree type, tree arg)
1886 tree orig = TREE_TYPE (arg);
1892 if (TREE_CODE (arg) == ERROR_MARK
1893 || TREE_CODE (type) == ERROR_MARK
1894 || TREE_CODE (orig) == ERROR_MARK)
1895 return error_mark_node;
1897 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
1898 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
1899 TYPE_MAIN_VARIANT (orig)))
1900 return fold (build1 (NOP_EXPR, type, arg));
1902 switch (TREE_CODE (type))
1904 case INTEGER_TYPE: case CHAR_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1905 case POINTER_TYPE: case REFERENCE_TYPE:
1907 if (TREE_CODE (arg) == INTEGER_CST)
1909 tem = fold_convert_const (NOP_EXPR, type, arg);
1910 if (tem != NULL_TREE)
1913 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1914 || TREE_CODE (orig) == OFFSET_TYPE)
1915 return fold (build1 (NOP_EXPR, type, arg));
1916 if (TREE_CODE (orig) == COMPLEX_TYPE)
1918 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1919 return fold_convert (type, tem);
1921 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
1922 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1923 return fold (build1 (NOP_EXPR, type, arg));
1926 if (TREE_CODE (arg) == INTEGER_CST)
1928 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1929 if (tem != NULL_TREE)
1932 else if (TREE_CODE (arg) == REAL_CST)
1934 tem = fold_convert_const (NOP_EXPR, type, arg);
1935 if (tem != NULL_TREE)
1939 switch (TREE_CODE (orig))
1941 case INTEGER_TYPE: case CHAR_TYPE:
1942 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1943 case POINTER_TYPE: case REFERENCE_TYPE:
1944 return fold (build1 (FLOAT_EXPR, type, arg));
1947 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1951 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1952 return fold_convert (type, tem);
1959 switch (TREE_CODE (orig))
1961 case INTEGER_TYPE: case CHAR_TYPE:
1962 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1963 case POINTER_TYPE: case REFERENCE_TYPE:
1965 return build2 (COMPLEX_EXPR, type,
1966 fold_convert (TREE_TYPE (type), arg),
1967 fold_convert (TREE_TYPE (type), integer_zero_node));
1972 if (TREE_CODE (arg) == COMPLEX_EXPR)
1974 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1975 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1976 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1979 arg = save_expr (arg);
1980 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1981 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1982 rpart = fold_convert (TREE_TYPE (type), rpart);
1983 ipart = fold_convert (TREE_TYPE (type), ipart);
1984 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1992 if (integer_zerop (arg))
1993 return build_zero_vector (type);
1994 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1995 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1996 || TREE_CODE (orig) == VECTOR_TYPE);
1997 return fold (build1 (NOP_EXPR, type, arg));
2000 return fold (build1 (CONVERT_EXPR, type, fold_ignored_result (arg)));
2007 /* Return an expr equal to X but certainly not valid as an lvalue. */
2012 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2017 /* We only need to wrap lvalue tree codes. */
2018 switch (TREE_CODE (x))
2029 case ALIGN_INDIRECT_REF:
2030 case MISALIGNED_INDIRECT_REF:
2032 case ARRAY_RANGE_REF:
2038 case PREINCREMENT_EXPR:
2039 case PREDECREMENT_EXPR:
2041 case TRY_CATCH_EXPR:
2042 case WITH_CLEANUP_EXPR:
2053 /* Assume the worst for front-end tree codes. */
2054 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2058 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2061 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2062 Zero means allow extended lvalues. */
2064 int pedantic_lvalues;
2066 /* When pedantic, return an expr equal to X but certainly not valid as a
2067 pedantic lvalue. Otherwise, return X. */
2070 pedantic_non_lvalue (tree x)
2072 if (pedantic_lvalues)
2073 return non_lvalue (x);
2078 /* Given a tree comparison code, return the code that is the logical inverse
2079 of the given code. It is not safe to do this for floating-point
2080 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2081 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2083 static enum tree_code
2084 invert_tree_comparison (enum tree_code code, bool honor_nans)
2086 if (honor_nans && flag_trapping_math)
2096 return honor_nans ? UNLE_EXPR : LE_EXPR;
2098 return honor_nans ? UNLT_EXPR : LT_EXPR;
2100 return honor_nans ? UNGE_EXPR : GE_EXPR;
2102 return honor_nans ? UNGT_EXPR : GT_EXPR;
2116 return UNORDERED_EXPR;
2117 case UNORDERED_EXPR:
2118 return ORDERED_EXPR;
2124 /* Similar, but return the comparison that results if the operands are
2125 swapped. This is safe for floating-point. */
2128 swap_tree_comparison (enum tree_code code)
2149 /* Convert a comparison tree code from an enum tree_code representation
2150 into a compcode bit-based encoding. This function is the inverse of
2151 compcode_to_comparison. */
2153 static enum comparison_code
2154 comparison_to_compcode (enum tree_code code)
2171 return COMPCODE_ORD;
2172 case UNORDERED_EXPR:
2173 return COMPCODE_UNORD;
2175 return COMPCODE_UNLT;
2177 return COMPCODE_UNEQ;
2179 return COMPCODE_UNLE;
2181 return COMPCODE_UNGT;
2183 return COMPCODE_LTGT;
2185 return COMPCODE_UNGE;
2191 /* Convert a compcode bit-based encoding of a comparison operator back
2192 to GCC's enum tree_code representation. This function is the
2193 inverse of comparison_to_compcode. */
2195 static enum tree_code
2196 compcode_to_comparison (enum comparison_code code)
2213 return ORDERED_EXPR;
2214 case COMPCODE_UNORD:
2215 return UNORDERED_EXPR;
2233 /* Return a tree for the comparison which is the combination of
2234 doing the AND or OR (depending on CODE) of the two operations LCODE
2235 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2236 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2237 if this makes the transformation invalid. */
2240 combine_comparisons (enum tree_code code, enum tree_code lcode,
2241 enum tree_code rcode, tree truth_type,
2242 tree ll_arg, tree lr_arg)
2244 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2245 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2246 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2247 enum comparison_code compcode;
2251 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2252 compcode = lcompcode & rcompcode;
2255 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2256 compcode = lcompcode | rcompcode;
2265 /* Eliminate unordered comparisons, as well as LTGT and ORD
2266 which are not used unless the mode has NaNs. */
2267 compcode &= ~COMPCODE_UNORD;
2268 if (compcode == COMPCODE_LTGT)
2269 compcode = COMPCODE_NE;
2270 else if (compcode == COMPCODE_ORD)
2271 compcode = COMPCODE_TRUE;
2273 else if (flag_trapping_math)
2275 /* Check that the original operation and the optimized ones will trap
2276 under the same condition. */
2277 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2278 && (lcompcode != COMPCODE_EQ)
2279 && (lcompcode != COMPCODE_ORD);
2280 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2281 && (rcompcode != COMPCODE_EQ)
2282 && (rcompcode != COMPCODE_ORD);
2283 bool trap = (compcode & COMPCODE_UNORD) == 0
2284 && (compcode != COMPCODE_EQ)
2285 && (compcode != COMPCODE_ORD);
2287 /* In a short-circuited boolean expression the LHS might be
2288 such that the RHS, if evaluated, will never trap. For
2289 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2290 if neither x nor y is NaN. (This is a mixed blessing: for
2291 example, the expression above will never trap, hence
2292 optimizing it to x < y would be invalid). */
2293 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2294 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2297 /* If the comparison was short-circuited, and only the RHS
2298 trapped, we may now generate a spurious trap. */
2300 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2303 /* If we changed the conditions that cause a trap, we lose. */
2304 if ((ltrap || rtrap) != trap)
2308 if (compcode == COMPCODE_TRUE)
2309 return constant_boolean_node (true, truth_type);
2310 else if (compcode == COMPCODE_FALSE)
2311 return constant_boolean_node (false, truth_type);
2313 return fold (build2 (compcode_to_comparison (compcode),
2314 truth_type, ll_arg, lr_arg));
2317 /* Return nonzero if CODE is a tree code that represents a truth value. */
2320 truth_value_p (enum tree_code code)
2322 return (TREE_CODE_CLASS (code) == tcc_comparison
2323 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2324 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2325 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2328 /* Return nonzero if two operands (typically of the same tree node)
2329 are necessarily equal. If either argument has side-effects this
2330 function returns zero. FLAGS modifies behavior as follows:
2332 If OEP_ONLY_CONST is set, only return nonzero for constants.
2333 This function tests whether the operands are indistinguishable;
2334 it does not test whether they are equal using C's == operation.
2335 The distinction is important for IEEE floating point, because
2336 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2337 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2339 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2340 even though it may hold multiple values during a function.
2341 This is because a GCC tree node guarantees that nothing else is
2342 executed between the evaluation of its "operands" (which may often
2343 be evaluated in arbitrary order). Hence if the operands themselves
2344 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2345 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2346 unset means assuming isochronic (or instantaneous) tree equivalence.
2347 Unless comparing arbitrary expression trees, such as from different
2348 statements, this flag can usually be left unset.
2350 If OEP_PURE_SAME is set, then pure functions with identical arguments
2351 are considered the same. It is used when the caller has other ways
2352 to ensure that global memory is unchanged in between. */
2355 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2357 /* If either is ERROR_MARK, they aren't equal. */
2358 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2361 /* If both types don't have the same signedness, then we can't consider
2362 them equal. We must check this before the STRIP_NOPS calls
2363 because they may change the signedness of the arguments. */
2364 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2370 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2371 /* This is needed for conversions and for COMPONENT_REF.
2372 Might as well play it safe and always test this. */
2373 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2374 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2375 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2378 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2379 We don't care about side effects in that case because the SAVE_EXPR
2380 takes care of that for us. In all other cases, two expressions are
2381 equal if they have no side effects. If we have two identical
2382 expressions with side effects that should be treated the same due
2383 to the only side effects being identical SAVE_EXPR's, that will
2384 be detected in the recursive calls below. */
2385 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2386 && (TREE_CODE (arg0) == SAVE_EXPR
2387 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2390 /* Next handle constant cases, those for which we can return 1 even
2391 if ONLY_CONST is set. */
2392 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2393 switch (TREE_CODE (arg0))
2396 return (! TREE_CONSTANT_OVERFLOW (arg0)
2397 && ! TREE_CONSTANT_OVERFLOW (arg1)
2398 && tree_int_cst_equal (arg0, arg1));
2401 return (! TREE_CONSTANT_OVERFLOW (arg0)
2402 && ! TREE_CONSTANT_OVERFLOW (arg1)
2403 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2404 TREE_REAL_CST (arg1)));
2410 if (TREE_CONSTANT_OVERFLOW (arg0)
2411 || TREE_CONSTANT_OVERFLOW (arg1))
2414 v1 = TREE_VECTOR_CST_ELTS (arg0);
2415 v2 = TREE_VECTOR_CST_ELTS (arg1);
2418 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2421 v1 = TREE_CHAIN (v1);
2422 v2 = TREE_CHAIN (v2);
2429 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2431 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2435 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2436 && ! memcmp (TREE_STRING_POINTER (arg0),
2437 TREE_STRING_POINTER (arg1),
2438 TREE_STRING_LENGTH (arg0)));
2441 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2447 if (flags & OEP_ONLY_CONST)
2450 /* Define macros to test an operand from arg0 and arg1 for equality and a
2451 variant that allows null and views null as being different from any
2452 non-null value. In the latter case, if either is null, the both
2453 must be; otherwise, do the normal comparison. */
2454 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
2455 TREE_OPERAND (arg1, N), flags)
2457 #define OP_SAME_WITH_NULL(N) \
2458 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
2459 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
2461 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2464 /* Two conversions are equal only if signedness and modes match. */
2465 switch (TREE_CODE (arg0))
2470 case FIX_TRUNC_EXPR:
2471 case FIX_FLOOR_EXPR:
2472 case FIX_ROUND_EXPR:
2473 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
2474 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2484 case tcc_comparison:
2486 if (OP_SAME (0) && OP_SAME (1))
2489 /* For commutative ops, allow the other order. */
2490 return (commutative_tree_code (TREE_CODE (arg0))
2491 && operand_equal_p (TREE_OPERAND (arg0, 0),
2492 TREE_OPERAND (arg1, 1), flags)
2493 && operand_equal_p (TREE_OPERAND (arg0, 1),
2494 TREE_OPERAND (arg1, 0), flags));
2497 /* If either of the pointer (or reference) expressions we are
2498 dereferencing contain a side effect, these cannot be equal. */
2499 if (TREE_SIDE_EFFECTS (arg0)
2500 || TREE_SIDE_EFFECTS (arg1))
2503 switch (TREE_CODE (arg0))
2506 case ALIGN_INDIRECT_REF:
2507 case MISALIGNED_INDIRECT_REF:
2513 case ARRAY_RANGE_REF:
2514 /* Operands 2 and 3 may be null. */
2517 && OP_SAME_WITH_NULL (2)
2518 && OP_SAME_WITH_NULL (3));
2521 /* Handle operand 2 the same as for ARRAY_REF. */
2522 return OP_SAME (0) && OP_SAME (1) && OP_SAME_WITH_NULL (2);
2525 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
2531 case tcc_expression:
2532 switch (TREE_CODE (arg0))
2535 case TRUTH_NOT_EXPR:
2538 case TRUTH_ANDIF_EXPR:
2539 case TRUTH_ORIF_EXPR:
2540 return OP_SAME (0) && OP_SAME (1);
2542 case TRUTH_AND_EXPR:
2544 case TRUTH_XOR_EXPR:
2545 if (OP_SAME (0) && OP_SAME (1))
2548 /* Otherwise take into account this is a commutative operation. */
2549 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2550 TREE_OPERAND (arg1, 1), flags)
2551 && operand_equal_p (TREE_OPERAND (arg0, 1),
2552 TREE_OPERAND (arg1, 0), flags));
2555 /* If the CALL_EXPRs call different functions, then they
2556 clearly can not be equal. */
2561 unsigned int cef = call_expr_flags (arg0);
2562 if (flags & OEP_PURE_SAME)
2563 cef &= ECF_CONST | ECF_PURE;
2570 /* Now see if all the arguments are the same. operand_equal_p
2571 does not handle TREE_LIST, so we walk the operands here
2572 feeding them to operand_equal_p. */
2573 arg0 = TREE_OPERAND (arg0, 1);
2574 arg1 = TREE_OPERAND (arg1, 1);
2575 while (arg0 && arg1)
2577 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2581 arg0 = TREE_CHAIN (arg0);
2582 arg1 = TREE_CHAIN (arg1);
2585 /* If we get here and both argument lists are exhausted
2586 then the CALL_EXPRs are equal. */
2587 return ! (arg0 || arg1);
2593 case tcc_declaration:
2594 /* Consider __builtin_sqrt equal to sqrt. */
2595 return (TREE_CODE (arg0) == FUNCTION_DECL
2596 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2597 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2598 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2605 #undef OP_SAME_WITH_NULL
2608 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2609 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2611 When in doubt, return 0. */
2614 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2616 int unsignedp1, unsignedpo;
2617 tree primarg0, primarg1, primother;
2618 unsigned int correct_width;
2620 if (operand_equal_p (arg0, arg1, 0))
2623 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2624 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2627 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2628 and see if the inner values are the same. This removes any
2629 signedness comparison, which doesn't matter here. */
2630 primarg0 = arg0, primarg1 = arg1;
2631 STRIP_NOPS (primarg0);
2632 STRIP_NOPS (primarg1);
2633 if (operand_equal_p (primarg0, primarg1, 0))
2636 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2637 actual comparison operand, ARG0.
2639 First throw away any conversions to wider types
2640 already present in the operands. */
2642 primarg1 = get_narrower (arg1, &unsignedp1);
2643 primother = get_narrower (other, &unsignedpo);
2645 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2646 if (unsignedp1 == unsignedpo
2647 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2648 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2650 tree type = TREE_TYPE (arg0);
2652 /* Make sure shorter operand is extended the right way
2653 to match the longer operand. */
2654 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2655 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2657 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2664 /* See if ARG is an expression that is either a comparison or is performing
2665 arithmetic on comparisons. The comparisons must only be comparing
2666 two different values, which will be stored in *CVAL1 and *CVAL2; if
2667 they are nonzero it means that some operands have already been found.
2668 No variables may be used anywhere else in the expression except in the
2669 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2670 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2672 If this is true, return 1. Otherwise, return zero. */
2675 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2677 enum tree_code code = TREE_CODE (arg);
2678 enum tree_code_class class = TREE_CODE_CLASS (code);
2680 /* We can handle some of the tcc_expression cases here. */
2681 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2683 else if (class == tcc_expression
2684 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2685 || code == COMPOUND_EXPR))
2688 else if (class == tcc_expression && code == SAVE_EXPR
2689 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2691 /* If we've already found a CVAL1 or CVAL2, this expression is
2692 two complex to handle. */
2693 if (*cval1 || *cval2)
2703 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2706 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2707 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2708 cval1, cval2, save_p));
2713 case tcc_expression:
2714 if (code == COND_EXPR)
2715 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2716 cval1, cval2, save_p)
2717 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2718 cval1, cval2, save_p)
2719 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2720 cval1, cval2, save_p));
2723 case tcc_comparison:
2724 /* First see if we can handle the first operand, then the second. For
2725 the second operand, we know *CVAL1 can't be zero. It must be that
2726 one side of the comparison is each of the values; test for the
2727 case where this isn't true by failing if the two operands
2730 if (operand_equal_p (TREE_OPERAND (arg, 0),
2731 TREE_OPERAND (arg, 1), 0))
2735 *cval1 = TREE_OPERAND (arg, 0);
2736 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2738 else if (*cval2 == 0)
2739 *cval2 = TREE_OPERAND (arg, 0);
2740 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2745 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2747 else if (*cval2 == 0)
2748 *cval2 = TREE_OPERAND (arg, 1);
2749 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2761 /* ARG is a tree that is known to contain just arithmetic operations and
2762 comparisons. Evaluate the operations in the tree substituting NEW0 for
2763 any occurrence of OLD0 as an operand of a comparison and likewise for
2767 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2769 tree type = TREE_TYPE (arg);
2770 enum tree_code code = TREE_CODE (arg);
2771 enum tree_code_class class = TREE_CODE_CLASS (code);
2773 /* We can handle some of the tcc_expression cases here. */
2774 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2776 else if (class == tcc_expression
2777 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2783 return fold (build1 (code, type,
2784 eval_subst (TREE_OPERAND (arg, 0),
2785 old0, new0, old1, new1)));
2788 return fold (build2 (code, type,
2789 eval_subst (TREE_OPERAND (arg, 0),
2790 old0, new0, old1, new1),
2791 eval_subst (TREE_OPERAND (arg, 1),
2792 old0, new0, old1, new1)));
2794 case tcc_expression:
2798 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2801 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2804 return fold (build3 (code, type,
2805 eval_subst (TREE_OPERAND (arg, 0),
2806 old0, new0, old1, new1),
2807 eval_subst (TREE_OPERAND (arg, 1),
2808 old0, new0, old1, new1),
2809 eval_subst (TREE_OPERAND (arg, 2),
2810 old0, new0, old1, new1)));
2814 /* Fall through - ??? */
2816 case tcc_comparison:
2818 tree arg0 = TREE_OPERAND (arg, 0);
2819 tree arg1 = TREE_OPERAND (arg, 1);
2821 /* We need to check both for exact equality and tree equality. The
2822 former will be true if the operand has a side-effect. In that
2823 case, we know the operand occurred exactly once. */
2825 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2827 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2830 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2832 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2835 return fold (build2 (code, type, arg0, arg1));
2843 /* Return a tree for the case when the result of an expression is RESULT
2844 converted to TYPE and OMITTED was previously an operand of the expression
2845 but is now not needed (e.g., we folded OMITTED * 0).
2847 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2848 the conversion of RESULT to TYPE. */
2851 omit_one_operand (tree type, tree result, tree omitted)
2853 tree t = fold_convert (type, result);
2855 if (TREE_SIDE_EFFECTS (omitted))
2856 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2858 return non_lvalue (t);
2861 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2864 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2866 tree t = fold_convert (type, result);
2868 if (TREE_SIDE_EFFECTS (omitted))
2869 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2871 return pedantic_non_lvalue (t);
2874 /* Return a tree for the case when the result of an expression is RESULT
2875 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2876 of the expression but are now not needed.
2878 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2879 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
2880 evaluated before OMITTED2. Otherwise, if neither has side effects,
2881 just do the conversion of RESULT to TYPE. */
2884 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
2886 tree t = fold_convert (type, result);
2888 if (TREE_SIDE_EFFECTS (omitted2))
2889 t = build2 (COMPOUND_EXPR, type, omitted2, t);
2890 if (TREE_SIDE_EFFECTS (omitted1))
2891 t = build2 (COMPOUND_EXPR, type, omitted1, t);
2893 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
2897 /* Return a simplified tree node for the truth-negation of ARG. This
2898 never alters ARG itself. We assume that ARG is an operation that
2899 returns a truth value (0 or 1).
2901 FIXME: one would think we would fold the result, but it causes
2902 problems with the dominator optimizer. */
2904 invert_truthvalue (tree arg)
2906 tree type = TREE_TYPE (arg);
2907 enum tree_code code = TREE_CODE (arg);
2909 if (code == ERROR_MARK)
2912 /* If this is a comparison, we can simply invert it, except for
2913 floating-point non-equality comparisons, in which case we just
2914 enclose a TRUTH_NOT_EXPR around what we have. */
2916 if (TREE_CODE_CLASS (code) == tcc_comparison)
2918 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
2919 if (FLOAT_TYPE_P (op_type)
2920 && flag_trapping_math
2921 && code != ORDERED_EXPR && code != UNORDERED_EXPR
2922 && code != NE_EXPR && code != EQ_EXPR)
2923 return build1 (TRUTH_NOT_EXPR, type, arg);
2926 code = invert_tree_comparison (code,
2927 HONOR_NANS (TYPE_MODE (op_type)));
2928 if (code == ERROR_MARK)
2929 return build1 (TRUTH_NOT_EXPR, type, arg);
2931 return build2 (code, type,
2932 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2939 return constant_boolean_node (integer_zerop (arg), type);
2941 case TRUTH_AND_EXPR:
2942 return build2 (TRUTH_OR_EXPR, type,
2943 invert_truthvalue (TREE_OPERAND (arg, 0)),
2944 invert_truthvalue (TREE_OPERAND (arg, 1)));
2947 return build2 (TRUTH_AND_EXPR, type,
2948 invert_truthvalue (TREE_OPERAND (arg, 0)),
2949 invert_truthvalue (TREE_OPERAND (arg, 1)));
2951 case TRUTH_XOR_EXPR:
2952 /* Here we can invert either operand. We invert the first operand
2953 unless the second operand is a TRUTH_NOT_EXPR in which case our
2954 result is the XOR of the first operand with the inside of the
2955 negation of the second operand. */
2957 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2958 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2959 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2961 return build2 (TRUTH_XOR_EXPR, type,
2962 invert_truthvalue (TREE_OPERAND (arg, 0)),
2963 TREE_OPERAND (arg, 1));
2965 case TRUTH_ANDIF_EXPR:
2966 return build2 (TRUTH_ORIF_EXPR, type,
2967 invert_truthvalue (TREE_OPERAND (arg, 0)),
2968 invert_truthvalue (TREE_OPERAND (arg, 1)));
2970 case TRUTH_ORIF_EXPR:
2971 return build2 (TRUTH_ANDIF_EXPR, type,
2972 invert_truthvalue (TREE_OPERAND (arg, 0)),
2973 invert_truthvalue (TREE_OPERAND (arg, 1)));
2975 case TRUTH_NOT_EXPR:
2976 return TREE_OPERAND (arg, 0);
2979 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
2980 invert_truthvalue (TREE_OPERAND (arg, 1)),
2981 invert_truthvalue (TREE_OPERAND (arg, 2)));
2984 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2985 invert_truthvalue (TREE_OPERAND (arg, 1)));
2987 case NON_LVALUE_EXPR:
2988 return invert_truthvalue (TREE_OPERAND (arg, 0));
2991 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2996 return build1 (TREE_CODE (arg), type,
2997 invert_truthvalue (TREE_OPERAND (arg, 0)));
3000 if (!integer_onep (TREE_OPERAND (arg, 1)))
3002 return build2 (EQ_EXPR, type, arg,
3003 fold_convert (type, integer_zero_node));
3006 return build1 (TRUTH_NOT_EXPR, type, arg);
3008 case CLEANUP_POINT_EXPR:
3009 return build1 (CLEANUP_POINT_EXPR, type,
3010 invert_truthvalue (TREE_OPERAND (arg, 0)));
3015 gcc_assert (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE);
3016 return build1 (TRUTH_NOT_EXPR, type, arg);
3019 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3020 operands are another bit-wise operation with a common input. If so,
3021 distribute the bit operations to save an operation and possibly two if
3022 constants are involved. For example, convert
3023 (A | B) & (A | C) into A | (B & C)
3024 Further simplification will occur if B and C are constants.
3026 If this optimization cannot be done, 0 will be returned. */
3029 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3034 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3035 || TREE_CODE (arg0) == code
3036 || (TREE_CODE (arg0) != BIT_AND_EXPR
3037 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3040 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3042 common = TREE_OPERAND (arg0, 0);
3043 left = TREE_OPERAND (arg0, 1);
3044 right = TREE_OPERAND (arg1, 1);
3046 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3048 common = TREE_OPERAND (arg0, 0);
3049 left = TREE_OPERAND (arg0, 1);
3050 right = TREE_OPERAND (arg1, 0);
3052 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3054 common = TREE_OPERAND (arg0, 1);
3055 left = TREE_OPERAND (arg0, 0);
3056 right = TREE_OPERAND (arg1, 1);
3058 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3060 common = TREE_OPERAND (arg0, 1);
3061 left = TREE_OPERAND (arg0, 0);
3062 right = TREE_OPERAND (arg1, 0);
3067 return fold (build2 (TREE_CODE (arg0), type, common,
3068 fold (build2 (code, type, left, right))));
3071 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3072 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3075 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3082 tree size = TYPE_SIZE (TREE_TYPE (inner));
3083 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3084 || POINTER_TYPE_P (TREE_TYPE (inner)))
3085 && host_integerp (size, 0)
3086 && tree_low_cst (size, 0) == bitsize)
3087 return fold_convert (type, inner);
3090 result = build3 (BIT_FIELD_REF, type, inner,
3091 size_int (bitsize), bitsize_int (bitpos));
3093 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3098 /* Optimize a bit-field compare.
3100 There are two cases: First is a compare against a constant and the
3101 second is a comparison of two items where the fields are at the same
3102 bit position relative to the start of a chunk (byte, halfword, word)
3103 large enough to contain it. In these cases we can avoid the shift
3104 implicit in bitfield extractions.
3106 For constants, we emit a compare of the shifted constant with the
3107 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3108 compared. For two fields at the same position, we do the ANDs with the
3109 similar mask and compare the result of the ANDs.
3111 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3112 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3113 are the left and right operands of the comparison, respectively.
3115 If the optimization described above can be done, we return the resulting
3116 tree. Otherwise we return zero. */
3119 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3122 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3123 tree type = TREE_TYPE (lhs);
3124 tree signed_type, unsigned_type;
3125 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3126 enum machine_mode lmode, rmode, nmode;
3127 int lunsignedp, runsignedp;
3128 int lvolatilep = 0, rvolatilep = 0;
3129 tree linner, rinner = NULL_TREE;
3133 /* Get all the information about the extractions being done. If the bit size
3134 if the same as the size of the underlying object, we aren't doing an
3135 extraction at all and so can do nothing. We also don't want to
3136 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3137 then will no longer be able to replace it. */
3138 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3139 &lunsignedp, &lvolatilep, false);
3140 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3141 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3146 /* If this is not a constant, we can only do something if bit positions,
3147 sizes, and signedness are the same. */
3148 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3149 &runsignedp, &rvolatilep, false);
3151 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3152 || lunsignedp != runsignedp || offset != 0
3153 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3157 /* See if we can find a mode to refer to this field. We should be able to,
3158 but fail if we can't. */
3159 nmode = get_best_mode (lbitsize, lbitpos,
3160 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3161 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3162 TYPE_ALIGN (TREE_TYPE (rinner))),
3163 word_mode, lvolatilep || rvolatilep);
3164 if (nmode == VOIDmode)
3167 /* Set signed and unsigned types of the precision of this mode for the
3169 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3170 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3172 /* Compute the bit position and size for the new reference and our offset
3173 within it. If the new reference is the same size as the original, we
3174 won't optimize anything, so return zero. */
3175 nbitsize = GET_MODE_BITSIZE (nmode);
3176 nbitpos = lbitpos & ~ (nbitsize - 1);
3178 if (nbitsize == lbitsize)
3181 if (BYTES_BIG_ENDIAN)
3182 lbitpos = nbitsize - lbitsize - lbitpos;
3184 /* Make the mask to be used against the extracted field. */
3185 mask = build_int_cst (unsigned_type, -1);
3186 mask = force_fit_type (mask, 0, false, false);
3187 mask = fold_convert (unsigned_type, mask);
3188 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3189 mask = const_binop (RSHIFT_EXPR, mask,
3190 size_int (nbitsize - lbitsize - lbitpos), 0);
3193 /* If not comparing with constant, just rework the comparison
3195 return build2 (code, compare_type,
3196 build2 (BIT_AND_EXPR, unsigned_type,
3197 make_bit_field_ref (linner, unsigned_type,
3198 nbitsize, nbitpos, 1),
3200 build2 (BIT_AND_EXPR, unsigned_type,
3201 make_bit_field_ref (rinner, unsigned_type,
3202 nbitsize, nbitpos, 1),
3205 /* Otherwise, we are handling the constant case. See if the constant is too
3206 big for the field. Warn and return a tree of for 0 (false) if so. We do
3207 this not only for its own sake, but to avoid having to test for this
3208 error case below. If we didn't, we might generate wrong code.
3210 For unsigned fields, the constant shifted right by the field length should
3211 be all zero. For signed fields, the high-order bits should agree with
3216 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3217 fold_convert (unsigned_type, rhs),
3218 size_int (lbitsize), 0)))
3220 warning ("comparison is always %d due to width of bit-field",
3222 return constant_boolean_node (code == NE_EXPR, compare_type);
3227 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3228 size_int (lbitsize - 1), 0);
3229 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3231 warning ("comparison is always %d due to width of bit-field",
3233 return constant_boolean_node (code == NE_EXPR, compare_type);
3237 /* Single-bit compares should always be against zero. */
3238 if (lbitsize == 1 && ! integer_zerop (rhs))
3240 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3241 rhs = fold_convert (type, integer_zero_node);
3244 /* Make a new bitfield reference, shift the constant over the
3245 appropriate number of bits and mask it with the computed mask
3246 (in case this was a signed field). If we changed it, make a new one. */
3247 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3250 TREE_SIDE_EFFECTS (lhs) = 1;
3251 TREE_THIS_VOLATILE (lhs) = 1;
3254 rhs = fold (const_binop (BIT_AND_EXPR,
3255 const_binop (LSHIFT_EXPR,
3256 fold_convert (unsigned_type, rhs),
3257 size_int (lbitpos), 0),
3260 return build2 (code, compare_type,
3261 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3265 /* Subroutine for fold_truthop: decode a field reference.
3267 If EXP is a comparison reference, we return the innermost reference.
3269 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3270 set to the starting bit number.
3272 If the innermost field can be completely contained in a mode-sized
3273 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3275 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3276 otherwise it is not changed.
3278 *PUNSIGNEDP is set to the signedness of the field.
3280 *PMASK is set to the mask used. This is either contained in a
3281 BIT_AND_EXPR or derived from the width of the field.
3283 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3285 Return 0 if this is not a component reference or is one that we can't
3286 do anything with. */
3289 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3290 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3291 int *punsignedp, int *pvolatilep,
3292 tree *pmask, tree *pand_mask)
3294 tree outer_type = 0;
3296 tree mask, inner, offset;
3298 unsigned int precision;
3300 /* All the optimizations using this function assume integer fields.
3301 There are problems with FP fields since the type_for_size call
3302 below can fail for, e.g., XFmode. */
3303 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3306 /* We are interested in the bare arrangement of bits, so strip everything
3307 that doesn't affect the machine mode. However, record the type of the
3308 outermost expression if it may matter below. */
3309 if (TREE_CODE (exp) == NOP_EXPR
3310 || TREE_CODE (exp) == CONVERT_EXPR
3311 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3312 outer_type = TREE_TYPE (exp);
3315 if (TREE_CODE (exp) == BIT_AND_EXPR)
3317 and_mask = TREE_OPERAND (exp, 1);
3318 exp = TREE_OPERAND (exp, 0);
3319 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3320 if (TREE_CODE (and_mask) != INTEGER_CST)
3324 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3325 punsignedp, pvolatilep, false);
3326 if ((inner == exp && and_mask == 0)
3327 || *pbitsize < 0 || offset != 0
3328 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3331 /* If the number of bits in the reference is the same as the bitsize of
3332 the outer type, then the outer type gives the signedness. Otherwise
3333 (in case of a small bitfield) the signedness is unchanged. */
3334 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3335 *punsignedp = TYPE_UNSIGNED (outer_type);
3337 /* Compute the mask to access the bitfield. */
3338 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3339 precision = TYPE_PRECISION (unsigned_type);
3341 mask = build_int_cst (unsigned_type, -1);
3342 mask = force_fit_type (mask, 0, false, false);
3344 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3345 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3347 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3349 mask = fold (build2 (BIT_AND_EXPR, unsigned_type,
3350 fold_convert (unsigned_type, and_mask), mask));
3353 *pand_mask = and_mask;
3357 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3361 all_ones_mask_p (tree mask, int size)
3363 tree type = TREE_TYPE (mask);
3364 unsigned int precision = TYPE_PRECISION (type);
3367 tmask = build_int_cst (lang_hooks.types.signed_type (type), -1);
3368 tmask = force_fit_type (tmask, 0, false, false);
3371 tree_int_cst_equal (mask,
3372 const_binop (RSHIFT_EXPR,
3373 const_binop (LSHIFT_EXPR, tmask,
3374 size_int (precision - size),
3376 size_int (precision - size), 0));
3379 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3380 represents the sign bit of EXP's type. If EXP represents a sign
3381 or zero extension, also test VAL against the unextended type.
3382 The return value is the (sub)expression whose sign bit is VAL,
3383 or NULL_TREE otherwise. */
3386 sign_bit_p (tree exp, tree val)
3388 unsigned HOST_WIDE_INT mask_lo, lo;
3389 HOST_WIDE_INT mask_hi, hi;
3393 /* Tree EXP must have an integral type. */
3394 t = TREE_TYPE (exp);
3395 if (! INTEGRAL_TYPE_P (t))
3398 /* Tree VAL must be an integer constant. */
3399 if (TREE_CODE (val) != INTEGER_CST
3400 || TREE_CONSTANT_OVERFLOW (val))
3403 width = TYPE_PRECISION (t);
3404 if (width > HOST_BITS_PER_WIDE_INT)
3406 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3409 mask_hi = ((unsigned HOST_WIDE_INT) -1
3410 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3416 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3419 mask_lo = ((unsigned HOST_WIDE_INT) -1
3420 >> (HOST_BITS_PER_WIDE_INT - width));
3423 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3424 treat VAL as if it were unsigned. */
3425 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3426 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3429 /* Handle extension from a narrower type. */
3430 if (TREE_CODE (exp) == NOP_EXPR
3431 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3432 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3437 /* Subroutine for fold_truthop: determine if an operand is simple enough
3438 to be evaluated unconditionally. */
3441 simple_operand_p (tree exp)
3443 /* Strip any conversions that don't change the machine mode. */
3446 return (CONSTANT_CLASS_P (exp)
3447 || TREE_CODE (exp) == SSA_NAME
3449 && ! TREE_ADDRESSABLE (exp)
3450 && ! TREE_THIS_VOLATILE (exp)
3451 && ! DECL_NONLOCAL (exp)
3452 /* Don't regard global variables as simple. They may be
3453 allocated in ways unknown to the compiler (shared memory,
3454 #pragma weak, etc). */
3455 && ! TREE_PUBLIC (exp)
3456 && ! DECL_EXTERNAL (exp)
3457 /* Loading a static variable is unduly expensive, but global
3458 registers aren't expensive. */
3459 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3462 /* The following functions are subroutines to fold_range_test and allow it to
3463 try to change a logical combination of comparisons into a range test.
3466 X == 2 || X == 3 || X == 4 || X == 5
3470 (unsigned) (X - 2) <= 3
3472 We describe each set of comparisons as being either inside or outside
3473 a range, using a variable named like IN_P, and then describe the
3474 range with a lower and upper bound. If one of the bounds is omitted,
3475 it represents either the highest or lowest value of the type.
3477 In the comments below, we represent a range by two numbers in brackets
3478 preceded by a "+" to designate being inside that range, or a "-" to
3479 designate being outside that range, so the condition can be inverted by
3480 flipping the prefix. An omitted bound is represented by a "-". For
3481 example, "- [-, 10]" means being outside the range starting at the lowest
3482 possible value and ending at 10, in other words, being greater than 10.
3483 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3486 We set up things so that the missing bounds are handled in a consistent
3487 manner so neither a missing bound nor "true" and "false" need to be
3488 handled using a special case. */
3490 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3491 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3492 and UPPER1_P are nonzero if the respective argument is an upper bound
3493 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3494 must be specified for a comparison. ARG1 will be converted to ARG0's
3495 type if both are specified. */
3498 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3499 tree arg1, int upper1_p)
3505 /* If neither arg represents infinity, do the normal operation.
3506 Else, if not a comparison, return infinity. Else handle the special
3507 comparison rules. Note that most of the cases below won't occur, but
3508 are handled for consistency. */
3510 if (arg0 != 0 && arg1 != 0)
3512 tem = fold (build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3513 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3515 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3518 if (TREE_CODE_CLASS (code) != tcc_comparison)
3521 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3522 for neither. In real maths, we cannot assume open ended ranges are
3523 the same. But, this is computer arithmetic, where numbers are finite.
3524 We can therefore make the transformation of any unbounded range with
3525 the value Z, Z being greater than any representable number. This permits
3526 us to treat unbounded ranges as equal. */
3527 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3528 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3532 result = sgn0 == sgn1;
3535 result = sgn0 != sgn1;
3538 result = sgn0 < sgn1;
3541 result = sgn0 <= sgn1;
3544 result = sgn0 > sgn1;
3547 result = sgn0 >= sgn1;
3553 return constant_boolean_node (result, type);
3556 /* Given EXP, a logical expression, set the range it is testing into
3557 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3558 actually being tested. *PLOW and *PHIGH will be made of the same type
3559 as the returned expression. If EXP is not a comparison, we will most
3560 likely not be returning a useful value and range. */
3563 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3565 enum tree_code code;
3566 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
3567 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
3569 tree low, high, n_low, n_high;
3571 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3572 and see if we can refine the range. Some of the cases below may not
3573 happen, but it doesn't seem worth worrying about this. We "continue"
3574 the outer loop when we've changed something; otherwise we "break"
3575 the switch, which will "break" the while. */
3578 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3582 code = TREE_CODE (exp);
3583 exp_type = TREE_TYPE (exp);
3585 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3587 if (TREE_CODE_LENGTH (code) > 0)
3588 arg0 = TREE_OPERAND (exp, 0);
3589 if (TREE_CODE_CLASS (code) == tcc_comparison
3590 || TREE_CODE_CLASS (code) == tcc_unary
3591 || TREE_CODE_CLASS (code) == tcc_binary)
3592 arg0_type = TREE_TYPE (arg0);
3593 if (TREE_CODE_CLASS (code) == tcc_binary
3594 || TREE_CODE_CLASS (code) == tcc_comparison
3595 || (TREE_CODE_CLASS (code) == tcc_expression
3596 && TREE_CODE_LENGTH (code) > 1))
3597 arg1 = TREE_OPERAND (exp, 1);
3602 case TRUTH_NOT_EXPR:
3603 in_p = ! in_p, exp = arg0;
3606 case EQ_EXPR: case NE_EXPR:
3607 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3608 /* We can only do something if the range is testing for zero
3609 and if the second operand is an integer constant. Note that
3610 saying something is "in" the range we make is done by
3611 complementing IN_P since it will set in the initial case of
3612 being not equal to zero; "out" is leaving it alone. */
3613 if (low == 0 || high == 0
3614 || ! integer_zerop (low) || ! integer_zerop (high)
3615 || TREE_CODE (arg1) != INTEGER_CST)
3620 case NE_EXPR: /* - [c, c] */
3623 case EQ_EXPR: /* + [c, c] */
3624 in_p = ! in_p, low = high = arg1;
3626 case GT_EXPR: /* - [-, c] */
3627 low = 0, high = arg1;
3629 case GE_EXPR: /* + [c, -] */
3630 in_p = ! in_p, low = arg1, high = 0;
3632 case LT_EXPR: /* - [c, -] */
3633 low = arg1, high = 0;
3635 case LE_EXPR: /* + [-, c] */
3636 in_p = ! in_p, low = 0, high = arg1;
3642 /* If this is an unsigned comparison, we also know that EXP is
3643 greater than or equal to zero. We base the range tests we make
3644 on that fact, so we record it here so we can parse existing
3645 range tests. We test arg0_type since often the return type
3646 of, e.g. EQ_EXPR, is boolean. */
3647 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
3649 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3651 fold_convert (arg0_type, integer_zero_node),
3655 in_p = n_in_p, low = n_low, high = n_high;
3657 /* If the high bound is missing, but we have a nonzero low
3658 bound, reverse the range so it goes from zero to the low bound
3660 if (high == 0 && low && ! integer_zerop (low))
3663 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3664 integer_one_node, 0);
3665 low = fold_convert (arg0_type, integer_zero_node);
3673 /* (-x) IN [a,b] -> x in [-b, -a] */
3674 n_low = range_binop (MINUS_EXPR, exp_type,
3675 fold_convert (exp_type, integer_zero_node),
3677 n_high = range_binop (MINUS_EXPR, exp_type,
3678 fold_convert (exp_type, integer_zero_node),
3680 low = n_low, high = n_high;
3686 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
3687 fold_convert (exp_type, integer_one_node));
3690 case PLUS_EXPR: case MINUS_EXPR:
3691 if (TREE_CODE (arg1) != INTEGER_CST)
3694 /* If EXP is signed, any overflow in the computation is undefined,
3695 so we don't worry about it so long as our computations on
3696 the bounds don't overflow. For unsigned, overflow is defined
3697 and this is exactly the right thing. */
3698 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3699 arg0_type, low, 0, arg1, 0);
3700 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3701 arg0_type, high, 1, arg1, 0);
3702 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3703 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3706 /* Check for an unsigned range which has wrapped around the maximum
3707 value thus making n_high < n_low, and normalize it. */
3708 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3710 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
3711 integer_one_node, 0);
3712 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
3713 integer_one_node, 0);
3715 /* If the range is of the form +/- [ x+1, x ], we won't
3716 be able to normalize it. But then, it represents the
3717 whole range or the empty set, so make it
3719 if (tree_int_cst_equal (n_low, low)
3720 && tree_int_cst_equal (n_high, high))
3726 low = n_low, high = n_high;
3731 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3732 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
3735 if (! INTEGRAL_TYPE_P (arg0_type)
3736 || (low != 0 && ! int_fits_type_p (low, arg0_type))
3737 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
3740 n_low = low, n_high = high;
3743 n_low = fold_convert (arg0_type, n_low);
3746 n_high = fold_convert (arg0_type, n_high);
3749 /* If we're converting arg0 from an unsigned type, to exp,
3750 a signed type, we will be doing the comparison as unsigned.
3751 The tests above have already verified that LOW and HIGH
3754 So we have to ensure that we will handle large unsigned
3755 values the same way that the current signed bounds treat
3758 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
3761 tree equiv_type = lang_hooks.types.type_for_mode
3762 (TYPE_MODE (arg0_type), 1);
3764 /* A range without an upper bound is, naturally, unbounded.
3765 Since convert would have cropped a very large value, use
3766 the max value for the destination type. */
3768 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3769 : TYPE_MAX_VALUE (arg0_type);
3771 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
3772 high_positive = fold (build2 (RSHIFT_EXPR, arg0_type,
3773 fold_convert (arg0_type,
3775 fold_convert (arg0_type,
3776 integer_one_node)));
3778 /* If the low bound is specified, "and" the range with the
3779 range for which the original unsigned value will be
3783 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3784 1, n_low, n_high, 1,
3785 fold_convert (arg0_type,
3790 in_p = (n_in_p == in_p);
3794 /* Otherwise, "or" the range with the range of the input
3795 that will be interpreted as negative. */
3796 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3797 0, n_low, n_high, 1,
3798 fold_convert (arg0_type,
3803 in_p = (in_p != n_in_p);
3808 low = n_low, high = n_high;
3818 /* If EXP is a constant, we can evaluate whether this is true or false. */
3819 if (TREE_CODE (exp) == INTEGER_CST)
3821 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3823 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3829 *pin_p = in_p, *plow = low, *phigh = high;
3833 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3834 type, TYPE, return an expression to test if EXP is in (or out of, depending
3835 on IN_P) the range. Return 0 if the test couldn't be created. */
3838 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3840 tree etype = TREE_TYPE (exp);
3845 value = build_range_check (type, exp, 1, low, high);
3847 return invert_truthvalue (value);
3852 if (low == 0 && high == 0)
3853 return fold_convert (type, integer_one_node);
3856 return fold (build2 (LE_EXPR, type, exp, high));
3859 return fold (build2 (GE_EXPR, type, exp, low));
3861 if (operand_equal_p (low, high, 0))
3862 return fold (build2 (EQ_EXPR, type, exp, low));
3864 if (integer_zerop (low))
3866 if (! TYPE_UNSIGNED (etype))
3868 etype = lang_hooks.types.unsigned_type (etype);
3869 high = fold_convert (etype, high);
3870 exp = fold_convert (etype, exp);
3872 return build_range_check (type, exp, 1, 0, high);
3875 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3876 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3878 unsigned HOST_WIDE_INT lo;
3882 prec = TYPE_PRECISION (etype);
3883 if (prec <= HOST_BITS_PER_WIDE_INT)
3886 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3890 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3891 lo = (unsigned HOST_WIDE_INT) -1;
3894 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3896 if (TYPE_UNSIGNED (etype))
3898 etype = lang_hooks.types.signed_type (etype);
3899 exp = fold_convert (etype, exp);
3901 return fold (build2 (GT_EXPR, type, exp,
3902 fold_convert (etype, integer_zero_node)));
3906 value = const_binop (MINUS_EXPR, high, low, 0);
3907 if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
3909 tree utype, minv, maxv;
3911 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
3912 for the type in question, as we rely on this here. */
3913 switch (TREE_CODE (etype))
3918 utype = lang_hooks.types.unsigned_type (etype);
3919 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
3920 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
3921 integer_one_node, 1);
3922 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
3923 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
3927 high = fold_convert (etype, high);
3928 low = fold_convert (etype, low);
3929 exp = fold_convert (etype, exp);
3930 value = const_binop (MINUS_EXPR, high, low, 0);
3938 if (value != 0 && ! TREE_OVERFLOW (value))
3939 return build_range_check (type,
3940 fold (build2 (MINUS_EXPR, etype, exp, low)),
3941 1, fold_convert (etype, integer_zero_node),
3947 /* Given two ranges, see if we can merge them into one. Return 1 if we
3948 can, 0 if we can't. Set the output range into the specified parameters. */
3951 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3952 tree high0, int in1_p, tree low1, tree high1)
3960 int lowequal = ((low0 == 0 && low1 == 0)
3961 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3962 low0, 0, low1, 0)));
3963 int highequal = ((high0 == 0 && high1 == 0)
3964 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3965 high0, 1, high1, 1)));
3967 /* Make range 0 be the range that starts first, or ends last if they
3968 start at the same value. Swap them if it isn't. */
3969 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3972 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3973 high1, 1, high0, 1))))
3975 temp = in0_p, in0_p = in1_p, in1_p = temp;
3976 tem = low0, low0 = low1, low1 = tem;
3977 tem = high0, high0 = high1, high1 = tem;
3980 /* Now flag two cases, whether the ranges are disjoint or whether the
3981 second range is totally subsumed in the first. Note that the tests
3982 below are simplified by the ones above. */
3983 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3984 high0, 1, low1, 0));
3985 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3986 high1, 1, high0, 1));
3988 /* We now have four cases, depending on whether we are including or
3989 excluding the two ranges. */
3992 /* If they don't overlap, the result is false. If the second range
3993 is a subset it is the result. Otherwise, the range is from the start
3994 of the second to the end of the first. */
3996 in_p = 0, low = high = 0;
3998 in_p = 1, low = low1, high = high1;
4000 in_p = 1, low = low1, high = high0;
4003 else if (in0_p && ! in1_p)
4005 /* If they don't overlap, the result is the first range. If they are
4006 equal, the result is false. If the second range is a subset of the
4007 first, and the ranges begin at the same place, we go from just after
4008 the end of the first range to the end of the second. If the second
4009 range is not a subset of the first, or if it is a subset and both
4010 ranges end at the same place, the range starts at the start of the
4011 first range and ends just before the second range.
4012 Otherwise, we can't describe this as a single range. */
4014 in_p = 1, low = low0, high = high0;
4015 else if (lowequal && highequal)
4016 in_p = 0, low = high = 0;
4017 else if (subset && lowequal)
4019 in_p = 1, high = high0;
4020 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
4021 integer_one_node, 0);
4023 else if (! subset || highequal)
4025 in_p = 1, low = low0;
4026 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4027 integer_one_node, 0);
4033 else if (! in0_p && in1_p)
4035 /* If they don't overlap, the result is the second range. If the second
4036 is a subset of the first, the result is false. Otherwise,
4037 the range starts just after the first range and ends at the
4038 end of the second. */
4040 in_p = 1, low = low1, high = high1;
4041 else if (subset || highequal)
4042 in_p = 0, low = high = 0;
4045 in_p = 1, high = high1;
4046 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4047 integer_one_node, 0);
4053 /* The case where we are excluding both ranges. Here the complex case
4054 is if they don't overlap. In that case, the only time we have a
4055 range is if they are adjacent. If the second is a subset of the
4056 first, the result is the first. Otherwise, the range to exclude
4057 starts at the beginning of the first range and ends at the end of the
4061 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4062 range_binop (PLUS_EXPR, NULL_TREE,
4064 integer_one_node, 1),
4066 in_p = 0, low = low0, high = high1;
4069 /* Canonicalize - [min, x] into - [-, x]. */
4070 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4071 switch (TREE_CODE (TREE_TYPE (low0)))
4074 if (TYPE_PRECISION (TREE_TYPE (low0))
4075 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4080 if (tree_int_cst_equal (low0,
4081 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4085 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4086 && integer_zerop (low0))
4093 /* Canonicalize - [x, max] into - [x, -]. */
4094 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4095 switch (TREE_CODE (TREE_TYPE (high1)))
4098 if (TYPE_PRECISION (TREE_TYPE (high1))
4099 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4104 if (tree_int_cst_equal (high1,
4105 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4109 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4110 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4112 integer_one_node, 1)))
4119 /* The ranges might be also adjacent between the maximum and
4120 minimum values of the given type. For
4121 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4122 return + [x + 1, y - 1]. */
4123 if (low0 == 0 && high1 == 0)
4125 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4126 integer_one_node, 1);
4127 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4128 integer_one_node, 0);
4129 if (low == 0 || high == 0)
4139 in_p = 0, low = low0, high = high0;
4141 in_p = 0, low = low0, high = high1;
4144 *pin_p = in_p, *plow = low, *phigh = high;
4149 /* Subroutine of fold, looking inside expressions of the form
4150 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4151 of the COND_EXPR. This function is being used also to optimize
4152 A op B ? C : A, by reversing the comparison first.
4154 Return a folded expression whose code is not a COND_EXPR
4155 anymore, or NULL_TREE if no folding opportunity is found. */
4158 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4160 enum tree_code comp_code = TREE_CODE (arg0);
4161 tree arg00 = TREE_OPERAND (arg0, 0);
4162 tree arg01 = TREE_OPERAND (arg0, 1);
4163 tree arg1_type = TREE_TYPE (arg1);
4169 /* If we have A op 0 ? A : -A, consider applying the following
4172 A == 0? A : -A same as -A
4173 A != 0? A : -A same as A
4174 A >= 0? A : -A same as abs (A)
4175 A > 0? A : -A same as abs (A)
4176 A <= 0? A : -A same as -abs (A)
4177 A < 0? A : -A same as -abs (A)
4179 None of these transformations work for modes with signed
4180 zeros. If A is +/-0, the first two transformations will
4181 change the sign of the result (from +0 to -0, or vice
4182 versa). The last four will fix the sign of the result,
4183 even though the original expressions could be positive or
4184 negative, depending on the sign of A.
4186 Note that all these transformations are correct if A is
4187 NaN, since the two alternatives (A and -A) are also NaNs. */
4188 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4189 ? real_zerop (arg01)
4190 : integer_zerop (arg01))
4191 && TREE_CODE (arg2) == NEGATE_EXPR
4192 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4197 tem = fold_convert (arg1_type, arg1);
4198 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4201 return pedantic_non_lvalue (fold_convert (type, arg1));
4204 if (flag_trapping_math)
4209 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4210 arg1 = fold_convert (lang_hooks.types.signed_type
4211 (TREE_TYPE (arg1)), arg1);
4212 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4213 return pedantic_non_lvalue (fold_convert (type, tem));
4216 if (flag_trapping_math)
4220 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4221 arg1 = fold_convert (lang_hooks.types.signed_type
4222 (TREE_TYPE (arg1)), arg1);
4223 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4224 return negate_expr (fold_convert (type, tem));
4226 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4230 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4231 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4232 both transformations are correct when A is NaN: A != 0
4233 is then true, and A == 0 is false. */
4235 if (integer_zerop (arg01) && integer_zerop (arg2))
4237 if (comp_code == NE_EXPR)
4238 return pedantic_non_lvalue (fold_convert (type, arg1));
4239 else if (comp_code == EQ_EXPR)
4240 return fold_convert (type, integer_zero_node);
4243 /* Try some transformations of A op B ? A : B.
4245 A == B? A : B same as B
4246 A != B? A : B same as A
4247 A >= B? A : B same as max (A, B)
4248 A > B? A : B same as max (B, A)
4249 A <= B? A : B same as min (A, B)
4250 A < B? A : B same as min (B, A)
4252 As above, these transformations don't work in the presence
4253 of signed zeros. For example, if A and B are zeros of
4254 opposite sign, the first two transformations will change
4255 the sign of the result. In the last four, the original
4256 expressions give different results for (A=+0, B=-0) and
4257 (A=-0, B=+0), but the transformed expressions do not.
4259 The first two transformations are correct if either A or B
4260 is a NaN. In the first transformation, the condition will
4261 be false, and B will indeed be chosen. In the case of the
4262 second transformation, the condition A != B will be true,
4263 and A will be chosen.
4265 The conversions to max() and min() are not correct if B is
4266 a number and A is not. The conditions in the original
4267 expressions will be false, so all four give B. The min()
4268 and max() versions would give a NaN instead. */
4269 if (operand_equal_for_comparison_p (arg01, arg2, arg00))
4271 tree comp_op0 = arg00;
4272 tree comp_op1 = arg01;
4273 tree comp_type = TREE_TYPE (comp_op0);
4275 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4276 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4286 return pedantic_non_lvalue (fold_convert (type, arg2));
4288 return pedantic_non_lvalue (fold_convert (type, arg1));
4293 /* In C++ a ?: expression can be an lvalue, so put the
4294 operand which will be used if they are equal first
4295 so that we can convert this back to the
4296 corresponding COND_EXPR. */
4297 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4299 comp_op0 = fold_convert (comp_type, comp_op0);
4300 comp_op1 = fold_convert (comp_type, comp_op1);
4301 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4302 ? fold (build2 (MIN_EXPR, comp_type, comp_op0, comp_op1))
4303 : fold (build2 (MIN_EXPR, comp_type, comp_op1, comp_op0));
4304 return pedantic_non_lvalue (fold_convert (type, tem));
4311 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4313 comp_op0 = fold_convert (comp_type, comp_op0);
4314 comp_op1 = fold_convert (comp_type, comp_op1);
4315 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
4316 ? fold (build2 (MAX_EXPR, comp_type, comp_op0, comp_op1))
4317 : fold (build2 (MAX_EXPR, comp_type, comp_op1, comp_op0));
4318 return pedantic_non_lvalue (fold_convert (type, tem));
4322 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4323 return pedantic_non_lvalue (fold_convert (type, arg2));
4326 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4327 return pedantic_non_lvalue (fold_convert (type, arg1));
4330 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4335 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4336 we might still be able to simplify this. For example,
4337 if C1 is one less or one more than C2, this might have started
4338 out as a MIN or MAX and been transformed by this function.
4339 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4341 if (INTEGRAL_TYPE_P (type)
4342 && TREE_CODE (arg01) == INTEGER_CST
4343 && TREE_CODE (arg2) == INTEGER_CST)
4347 /* We can replace A with C1 in this case. */
4348 arg1 = fold_convert (type, arg01);
4349 return fold (build3 (COND_EXPR, type, arg0, arg1, arg2));
4352 /* If C1 is C2 + 1, this is min(A, C2). */
4353 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4355 && operand_equal_p (arg01,
4356 const_binop (PLUS_EXPR, arg2,
4357 integer_one_node, 0),
4359 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4360 type, arg1, arg2)));
4364 /* If C1 is C2 - 1, this is min(A, C2). */
4365 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4367 && operand_equal_p (arg01,
4368 const_binop (MINUS_EXPR, arg2,
4369 integer_one_node, 0),
4371 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4372 type, arg1, arg2)));
4376 /* If C1 is C2 - 1, this is max(A, C2). */
4377 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4379 && operand_equal_p (arg01,
4380 const_binop (MINUS_EXPR, arg2,
4381 integer_one_node, 0),
4383 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4384 type, arg1, arg2)));
4388 /* If C1 is C2 + 1, this is max(A, C2). */
4389 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4391 && operand_equal_p (arg01,
4392 const_binop (PLUS_EXPR, arg2,
4393 integer_one_node, 0),
4395 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4396 type, arg1, arg2)));
4409 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
4410 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4413 /* EXP is some logical combination of boolean tests. See if we can
4414 merge it into some range test. Return the new tree if so. */
4417 fold_range_test (tree exp)
4419 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
4420 || TREE_CODE (exp) == TRUTH_OR_EXPR);
4421 int in0_p, in1_p, in_p;
4422 tree low0, low1, low, high0, high1, high;
4423 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
4424 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
4427 /* If this is an OR operation, invert both sides; we will invert
4428 again at the end. */
4430 in0_p = ! in0_p, in1_p = ! in1_p;
4432 /* If both expressions are the same, if we can merge the ranges, and we
4433 can build the range test, return it or it inverted. If one of the
4434 ranges is always true or always false, consider it to be the same
4435 expression as the other. */
4436 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4437 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4439 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
4441 : rhs != 0 ? rhs : integer_zero_node,
4443 return or_op ? invert_truthvalue (tem) : tem;
4445 /* On machines where the branch cost is expensive, if this is a
4446 short-circuited branch and the underlying object on both sides
4447 is the same, make a non-short-circuit operation. */
4448 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
4449 && lhs != 0 && rhs != 0
4450 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4451 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
4452 && operand_equal_p (lhs, rhs, 0))
4454 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4455 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4456 which cases we can't do this. */
4457 if (simple_operand_p (lhs))
4458 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4459 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4460 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
4461 TREE_OPERAND (exp, 1));
4463 else if (lang_hooks.decls.global_bindings_p () == 0
4464 && ! CONTAINS_PLACEHOLDER_P (lhs))
4466 tree common = save_expr (lhs);
4468 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
4469 or_op ? ! in0_p : in0_p,
4471 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
4472 or_op ? ! in1_p : in1_p,
4474 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4475 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4476 TREE_TYPE (exp), lhs, rhs);
4483 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4484 bit value. Arrange things so the extra bits will be set to zero if and
4485 only if C is signed-extended to its full width. If MASK is nonzero,
4486 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4489 unextend (tree c, int p, int unsignedp, tree mask)
4491 tree type = TREE_TYPE (c);
4492 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4495 if (p == modesize || unsignedp)
4498 /* We work by getting just the sign bit into the low-order bit, then
4499 into the high-order bit, then sign-extend. We then XOR that value
4501 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4502 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
4504 /* We must use a signed type in order to get an arithmetic right shift.
4505 However, we must also avoid introducing accidental overflows, so that
4506 a subsequent call to integer_zerop will work. Hence we must
4507 do the type conversion here. At this point, the constant is either
4508 zero or one, and the conversion to a signed type can never overflow.
4509 We could get an overflow if this conversion is done anywhere else. */
4510 if (TYPE_UNSIGNED (type))
4511 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
4513 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4514 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
4516 temp = const_binop (BIT_AND_EXPR, temp,
4517 fold_convert (TREE_TYPE (c), mask), 0);
4518 /* If necessary, convert the type back to match the type of C. */
4519 if (TYPE_UNSIGNED (type))
4520 temp = fold_convert (type, temp);
4522 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
4525 /* Find ways of folding logical expressions of LHS and RHS:
4526 Try to merge two comparisons to the same innermost item.
4527 Look for range tests like "ch >= '0' && ch <= '9'".
4528 Look for combinations of simple terms on machines with expensive branches
4529 and evaluate the RHS unconditionally.
4531 For example, if we have p->a == 2 && p->b == 4 and we can make an
4532 object large enough to span both A and B, we can do this with a comparison
4533 against the object ANDed with the a mask.
4535 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4536 operations to do this with one comparison.
4538 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4539 function and the one above.
4541 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4542 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4544 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4547 We return the simplified tree or 0 if no optimization is possible. */
4550 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
4552 /* If this is the "or" of two comparisons, we can do something if
4553 the comparisons are NE_EXPR. If this is the "and", we can do something
4554 if the comparisons are EQ_EXPR. I.e.,
4555 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4557 WANTED_CODE is this operation code. For single bit fields, we can
4558 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4559 comparison for one-bit fields. */
4561 enum tree_code wanted_code;
4562 enum tree_code lcode, rcode;
4563 tree ll_arg, lr_arg, rl_arg, rr_arg;
4564 tree ll_inner, lr_inner, rl_inner, rr_inner;
4565 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
4566 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
4567 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
4568 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
4569 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
4570 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
4571 enum machine_mode lnmode, rnmode;
4572 tree ll_mask, lr_mask, rl_mask, rr_mask;
4573 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
4574 tree l_const, r_const;
4575 tree lntype, rntype, result;
4576 int first_bit, end_bit;
4579 /* Start by getting the comparison codes. Fail if anything is volatile.
4580 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4581 it were surrounded with a NE_EXPR. */
4583 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
4586 lcode = TREE_CODE (lhs);
4587 rcode = TREE_CODE (rhs);
4589 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
4591 lhs = build2 (NE_EXPR, truth_type, lhs,
4592 fold_convert (TREE_TYPE (lhs), integer_zero_node));
4596 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
4598 rhs = build2 (NE_EXPR, truth_type, rhs,
4599 fold_convert (TREE_TYPE (rhs), integer_zero_node));
4603 if (TREE_CODE_CLASS (lcode) != tcc_comparison
4604 || TREE_CODE_CLASS (rcode) != tcc_comparison)
4607 ll_arg = TREE_OPERAND (lhs, 0);
4608 lr_arg = TREE_OPERAND (lhs, 1);
4609 rl_arg = TREE_OPERAND (rhs, 0);
4610 rr_arg = TREE_OPERAND (rhs, 1);
4612 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4613 if (simple_operand_p (ll_arg)
4614 && simple_operand_p (lr_arg))
4617 if (operand_equal_p (ll_arg, rl_arg, 0)
4618 && operand_equal_p (lr_arg, rr_arg, 0))
4620 result = combine_comparisons (code, lcode, rcode,
4621 truth_type, ll_arg, lr_arg);
4625 else if (operand_equal_p (ll_arg, rr_arg, 0)
4626 && operand_equal_p (lr_arg, rl_arg, 0))
4628 result = combine_comparisons (code, lcode,
4629 swap_tree_comparison (rcode),
4630 truth_type, ll_arg, lr_arg);
4636 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4637 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4639 /* If the RHS can be evaluated unconditionally and its operands are
4640 simple, it wins to evaluate the RHS unconditionally on machines
4641 with expensive branches. In this case, this isn't a comparison
4642 that can be merged. Avoid doing this if the RHS is a floating-point
4643 comparison since those can trap. */
4645 if (BRANCH_COST >= 2
4646 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4647 && simple_operand_p (rl_arg)
4648 && simple_operand_p (rr_arg))
4650 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4651 if (code == TRUTH_OR_EXPR
4652 && lcode == NE_EXPR && integer_zerop (lr_arg)
4653 && rcode == NE_EXPR && integer_zerop (rr_arg)
4654 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4655 return build2 (NE_EXPR, truth_type,
4656 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4658 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4660 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4661 if (code == TRUTH_AND_EXPR
4662 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4663 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4664 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4665 return build2 (EQ_EXPR, truth_type,
4666 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4668 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4670 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
4671 return build2 (code, truth_type, lhs, rhs);
4674 /* See if the comparisons can be merged. Then get all the parameters for
4677 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4678 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4682 ll_inner = decode_field_reference (ll_arg,
4683 &ll_bitsize, &ll_bitpos, &ll_mode,
4684 &ll_unsignedp, &volatilep, &ll_mask,
4686 lr_inner = decode_field_reference (lr_arg,
4687 &lr_bitsize, &lr_bitpos, &lr_mode,
4688 &lr_unsignedp, &volatilep, &lr_mask,
4690 rl_inner = decode_field_reference (rl_arg,
4691 &rl_bitsize, &rl_bitpos, &rl_mode,
4692 &rl_unsignedp, &volatilep, &rl_mask,
4694 rr_inner = decode_field_reference (rr_arg,
4695 &rr_bitsize, &rr_bitpos, &rr_mode,
4696 &rr_unsignedp, &volatilep, &rr_mask,
4699 /* It must be true that the inner operation on the lhs of each
4700 comparison must be the same if we are to be able to do anything.
4701 Then see if we have constants. If not, the same must be true for
4703 if (volatilep || ll_inner == 0 || rl_inner == 0
4704 || ! operand_equal_p (ll_inner, rl_inner, 0))
4707 if (TREE_CODE (lr_arg) == INTEGER_CST
4708 && TREE_CODE (rr_arg) == INTEGER_CST)
4709 l_const = lr_arg, r_const = rr_arg;
4710 else if (lr_inner == 0 || rr_inner == 0
4711 || ! operand_equal_p (lr_inner, rr_inner, 0))
4714 l_const = r_const = 0;
4716 /* If either comparison code is not correct for our logical operation,
4717 fail. However, we can convert a one-bit comparison against zero into
4718 the opposite comparison against that bit being set in the field. */
4720 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4721 if (lcode != wanted_code)
4723 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4725 /* Make the left operand unsigned, since we are only interested
4726 in the value of one bit. Otherwise we are doing the wrong
4735 /* This is analogous to the code for l_const above. */
4736 if (rcode != wanted_code)
4738 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4747 /* After this point all optimizations will generate bit-field
4748 references, which we might not want. */
4749 if (! lang_hooks.can_use_bit_fields_p ())
4752 /* See if we can find a mode that contains both fields being compared on
4753 the left. If we can't, fail. Otherwise, update all constants and masks
4754 to be relative to a field of that size. */
4755 first_bit = MIN (ll_bitpos, rl_bitpos);
4756 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4757 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4758 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4760 if (lnmode == VOIDmode)
4763 lnbitsize = GET_MODE_BITSIZE (lnmode);
4764 lnbitpos = first_bit & ~ (lnbitsize - 1);
4765 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4766 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4768 if (BYTES_BIG_ENDIAN)
4770 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4771 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4774 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4775 size_int (xll_bitpos), 0);
4776 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4777 size_int (xrl_bitpos), 0);
4781 l_const = fold_convert (lntype, l_const);
4782 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4783 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4784 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4785 fold (build1 (BIT_NOT_EXPR,
4789 warning ("comparison is always %d", wanted_code == NE_EXPR);
4791 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4796 r_const = fold_convert (lntype, r_const);
4797 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4798 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4799 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4800 fold (build1 (BIT_NOT_EXPR,
4804 warning ("comparison is always %d", wanted_code == NE_EXPR);
4806 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4810 /* If the right sides are not constant, do the same for it. Also,
4811 disallow this optimization if a size or signedness mismatch occurs
4812 between the left and right sides. */
4815 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4816 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4817 /* Make sure the two fields on the right
4818 correspond to the left without being swapped. */
4819 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4822 first_bit = MIN (lr_bitpos, rr_bitpos);
4823 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4824 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4825 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4827 if (rnmode == VOIDmode)
4830 rnbitsize = GET_MODE_BITSIZE (rnmode);
4831 rnbitpos = first_bit & ~ (rnbitsize - 1);
4832 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4833 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4835 if (BYTES_BIG_ENDIAN)
4837 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4838 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4841 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4842 size_int (xlr_bitpos), 0);
4843 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4844 size_int (xrr_bitpos), 0);
4846 /* Make a mask that corresponds to both fields being compared.
4847 Do this for both items being compared. If the operands are the
4848 same size and the bits being compared are in the same position
4849 then we can do this by masking both and comparing the masked
4851 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4852 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4853 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4855 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4856 ll_unsignedp || rl_unsignedp);
4857 if (! all_ones_mask_p (ll_mask, lnbitsize))
4858 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
4860 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4861 lr_unsignedp || rr_unsignedp);
4862 if (! all_ones_mask_p (lr_mask, rnbitsize))
4863 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
4865 return build2 (wanted_code, truth_type, lhs, rhs);
4868 /* There is still another way we can do something: If both pairs of
4869 fields being compared are adjacent, we may be able to make a wider
4870 field containing them both.
4872 Note that we still must mask the lhs/rhs expressions. Furthermore,
4873 the mask must be shifted to account for the shift done by
4874 make_bit_field_ref. */
4875 if ((ll_bitsize + ll_bitpos == rl_bitpos
4876 && lr_bitsize + lr_bitpos == rr_bitpos)
4877 || (ll_bitpos == rl_bitpos + rl_bitsize
4878 && lr_bitpos == rr_bitpos + rr_bitsize))
4882 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4883 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4884 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4885 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4887 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4888 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4889 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4890 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4892 /* Convert to the smaller type before masking out unwanted bits. */
4894 if (lntype != rntype)
4896 if (lnbitsize > rnbitsize)
4898 lhs = fold_convert (rntype, lhs);
4899 ll_mask = fold_convert (rntype, ll_mask);
4902 else if (lnbitsize < rnbitsize)
4904 rhs = fold_convert (lntype, rhs);
4905 lr_mask = fold_convert (lntype, lr_mask);
4910 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4911 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
4913 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4914 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
4916 return build2 (wanted_code, truth_type, lhs, rhs);
4922 /* Handle the case of comparisons with constants. If there is something in
4923 common between the masks, those bits of the constants must be the same.
4924 If not, the condition is always false. Test for this to avoid generating
4925 incorrect code below. */
4926 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4927 if (! integer_zerop (result)
4928 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4929 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4931 if (wanted_code == NE_EXPR)
4933 warning ("%<or%> of unmatched not-equal tests is always 1");
4934 return constant_boolean_node (true, truth_type);
4938 warning ("%<and%> of mutually exclusive equal-tests is always 0");
4939 return constant_boolean_node (false, truth_type);
4943 /* Construct the expression we will return. First get the component
4944 reference we will make. Unless the mask is all ones the width of
4945 that field, perform the mask operation. Then compare with the
4947 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4948 ll_unsignedp || rl_unsignedp);
4950 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4951 if (! all_ones_mask_p (ll_mask, lnbitsize))
4952 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
4954 return build2 (wanted_code, truth_type, result,
4955 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4958 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4962 optimize_minmax_comparison (tree t)
4964 tree type = TREE_TYPE (t);
4965 tree arg0 = TREE_OPERAND (t, 0);
4966 enum tree_code op_code;
4967 tree comp_const = TREE_OPERAND (t, 1);
4969 int consts_equal, consts_lt;
4972 STRIP_SIGN_NOPS (arg0);
4974 op_code = TREE_CODE (arg0);
4975 minmax_const = TREE_OPERAND (arg0, 1);
4976 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4977 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4978 inner = TREE_OPERAND (arg0, 0);
4980 /* If something does not permit us to optimize, return the original tree. */
4981 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4982 || TREE_CODE (comp_const) != INTEGER_CST
4983 || TREE_CONSTANT_OVERFLOW (comp_const)
4984 || TREE_CODE (minmax_const) != INTEGER_CST
4985 || TREE_CONSTANT_OVERFLOW (minmax_const))
4988 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4989 and GT_EXPR, doing the rest with recursive calls using logical
4991 switch (TREE_CODE (t))
4993 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4995 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4999 fold (build2 (TRUTH_ORIF_EXPR, type,
5000 optimize_minmax_comparison
5001 (build2 (EQ_EXPR, type, arg0, comp_const)),
5002 optimize_minmax_comparison
5003 (build2 (GT_EXPR, type, arg0, comp_const))));
5006 if (op_code == MAX_EXPR && consts_equal)
5007 /* MAX (X, 0) == 0 -> X <= 0 */
5008 return fold (build2 (LE_EXPR, type, inner, comp_const));
5010 else if (op_code == MAX_EXPR && consts_lt)
5011 /* MAX (X, 0) == 5 -> X == 5 */
5012 return fold (build2 (EQ_EXPR, type, inner, comp_const));
5014 else if (op_code == MAX_EXPR)
5015 /* MAX (X, 0) == -1 -> false */
5016 return omit_one_operand (type, integer_zero_node, inner);
5018 else if (consts_equal)
5019 /* MIN (X, 0) == 0 -> X >= 0 */
5020 return fold (build2 (GE_EXPR, type, inner, comp_const));
5023 /* MIN (X, 0) == 5 -> false */
5024 return omit_one_operand (type, integer_zero_node, inner);
5027 /* MIN (X, 0) == -1 -> X == -1 */
5028 return fold (build2 (EQ_EXPR, type, inner, comp_const));
5031 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5032 /* MAX (X, 0) > 0 -> X > 0
5033 MAX (X, 0) > 5 -> X > 5 */
5034 return fold (build2 (GT_EXPR, type, inner, comp_const));
5036 else if (op_code == MAX_EXPR)
5037 /* MAX (X, 0) > -1 -> true */
5038 return omit_one_operand (type, integer_one_node, inner);
5040 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5041 /* MIN (X, 0) > 0 -> false
5042 MIN (X, 0) > 5 -> false */
5043 return omit_one_operand (type, integer_zero_node, inner);
5046 /* MIN (X, 0) > -1 -> X > -1 */
5047 return fold (build2 (GT_EXPR, type, inner, comp_const));
5054 /* T is an integer expression that is being multiplied, divided, or taken a
5055 modulus (CODE says which and what kind of divide or modulus) by a
5056 constant C. See if we can eliminate that operation by folding it with
5057 other operations already in T. WIDE_TYPE, if non-null, is a type that
5058 should be used for the computation if wider than our type.
5060 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5061 (X * 2) + (Y * 4). We must, however, be assured that either the original
5062 expression would not overflow or that overflow is undefined for the type
5063 in the language in question.
5065 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5066 the machine has a multiply-accumulate insn or that this is part of an
5067 addressing calculation.
5069 If we return a non-null expression, it is an equivalent form of the
5070 original computation, but need not be in the original type. */
5073 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
5075 /* To avoid exponential search depth, refuse to allow recursion past
5076 three levels. Beyond that (1) it's highly unlikely that we'll find
5077 something interesting and (2) we've probably processed it before
5078 when we built the inner expression. */
5087 ret = extract_muldiv_1 (t, c, code, wide_type);
5094 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
5096 tree type = TREE_TYPE (t);
5097 enum tree_code tcode = TREE_CODE (t);
5098 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5099 > GET_MODE_SIZE (TYPE_MODE (type)))
5100 ? wide_type : type);
5102 int same_p = tcode == code;
5103 tree op0 = NULL_TREE, op1 = NULL_TREE;
5105 /* Don't deal with constants of zero here; they confuse the code below. */
5106 if (integer_zerop (c))
5109 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5110 op0 = TREE_OPERAND (t, 0);
5112 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5113 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5115 /* Note that we need not handle conditional operations here since fold
5116 already handles those cases. So just do arithmetic here. */
5120 /* For a constant, we can always simplify if we are a multiply
5121 or (for divide and modulus) if it is a multiple of our constant. */
5122 if (code == MULT_EXPR
5123 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5124 return const_binop (code, fold_convert (ctype, t),
5125 fold_convert (ctype, c), 0);
5128 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5129 /* If op0 is an expression ... */
5130 if ((COMPARISON_CLASS_P (op0)
5131 || UNARY_CLASS_P (op0)
5132 || BINARY_CLASS_P (op0)
5133 || EXPRESSION_CLASS_P (op0))
5134 /* ... and is unsigned, and its type is smaller than ctype,
5135 then we cannot pass through as widening. */
5136 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5137 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5138 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5139 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5140 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5141 /* ... or this is a truncation (t is narrower than op0),
5142 then we cannot pass through this narrowing. */
5143 || (GET_MODE_SIZE (TYPE_MODE (type))
5144 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5145 /* ... or signedness changes for division or modulus,
5146 then we cannot pass through this conversion. */
5147 || (code != MULT_EXPR
5148 && (TYPE_UNSIGNED (ctype)
5149 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5152 /* Pass the constant down and see if we can make a simplification. If
5153 we can, replace this expression with the inner simplification for
5154 possible later conversion to our or some other type. */
5155 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5156 && TREE_CODE (t2) == INTEGER_CST
5157 && ! TREE_CONSTANT_OVERFLOW (t2)
5158 && (0 != (t1 = extract_muldiv (op0, t2, code,
5160 ? ctype : NULL_TREE))))
5165 /* If widening the type changes it from signed to unsigned, then we
5166 must avoid building ABS_EXPR itself as unsigned. */
5167 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5169 tree cstype = (*lang_hooks.types.signed_type) (ctype);
5170 if ((t1 = extract_muldiv (op0, c, code, cstype)) != 0)
5172 t1 = fold (build1 (tcode, cstype, fold_convert (cstype, t1)));
5173 return fold_convert (ctype, t1);
5179 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5180 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
5183 case MIN_EXPR: case MAX_EXPR:
5184 /* If widening the type changes the signedness, then we can't perform
5185 this optimization as that changes the result. */
5186 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5189 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5190 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
5191 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
5193 if (tree_int_cst_sgn (c) < 0)
5194 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5196 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5197 fold_convert (ctype, t2)));
5201 case LSHIFT_EXPR: case RSHIFT_EXPR:
5202 /* If the second operand is constant, this is a multiplication
5203 or floor division, by a power of two, so we can treat it that
5204 way unless the multiplier or divisor overflows. Signed
5205 left-shift overflow is implementation-defined rather than
5206 undefined in C90, so do not convert signed left shift into
5208 if (TREE_CODE (op1) == INTEGER_CST
5209 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5210 /* const_binop may not detect overflow correctly,
5211 so check for it explicitly here. */
5212 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5213 && TREE_INT_CST_HIGH (op1) == 0
5214 && 0 != (t1 = fold_convert (ctype,
5215 const_binop (LSHIFT_EXPR,
5218 && ! TREE_OVERFLOW (t1))
5219 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5220 ? MULT_EXPR : FLOOR_DIV_EXPR,
5221 ctype, fold_convert (ctype, op0), t1),
5222 c, code, wide_type);
5225 case PLUS_EXPR: case MINUS_EXPR:
5226 /* See if we can eliminate the operation on both sides. If we can, we
5227 can return a new PLUS or MINUS. If we can't, the only remaining
5228 cases where we can do anything are if the second operand is a
5230 t1 = extract_muldiv (op0, c, code, wide_type);
5231 t2 = extract_muldiv (op1, c, code, wide_type);
5232 if (t1 != 0 && t2 != 0
5233 && (code == MULT_EXPR
5234 /* If not multiplication, we can only do this if both operands
5235 are divisible by c. */
5236 || (multiple_of_p (ctype, op0, c)
5237 && multiple_of_p (ctype, op1, c))))
5238 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5239 fold_convert (ctype, t2)));
5241 /* If this was a subtraction, negate OP1 and set it to be an addition.
5242 This simplifies the logic below. */
5243 if (tcode == MINUS_EXPR)
5244 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5246 if (TREE_CODE (op1) != INTEGER_CST)
5249 /* If either OP1 or C are negative, this optimization is not safe for
5250 some of the division and remainder types while for others we need
5251 to change the code. */
5252 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5254 if (code == CEIL_DIV_EXPR)
5255 code = FLOOR_DIV_EXPR;
5256 else if (code == FLOOR_DIV_EXPR)
5257 code = CEIL_DIV_EXPR;
5258 else if (code != MULT_EXPR
5259 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5263 /* If it's a multiply or a division/modulus operation of a multiple
5264 of our constant, do the operation and verify it doesn't overflow. */
5265 if (code == MULT_EXPR
5266 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5268 op1 = const_binop (code, fold_convert (ctype, op1),
5269 fold_convert (ctype, c), 0);
5270 /* We allow the constant to overflow with wrapping semantics. */
5272 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
5278 /* If we have an unsigned type is not a sizetype, we cannot widen
5279 the operation since it will change the result if the original
5280 computation overflowed. */
5281 if (TYPE_UNSIGNED (ctype)
5282 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5286 /* If we were able to eliminate our operation from the first side,
5287 apply our operation to the second side and reform the PLUS. */
5288 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5289 return fold (build2 (tcode, ctype, fold_convert (ctype, t1), op1));
5291 /* The last case is if we are a multiply. In that case, we can
5292 apply the distributive law to commute the multiply and addition
5293 if the multiplication of the constants doesn't overflow. */
5294 if (code == MULT_EXPR)
5295 return fold (build2 (tcode, ctype,
5296 fold (build2 (code, ctype,
5297 fold_convert (ctype, op0),
5298 fold_convert (ctype, c))),
5304 /* We have a special case here if we are doing something like
5305 (C * 8) % 4 since we know that's zero. */
5306 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5307 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5308 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5309 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5310 return omit_one_operand (type, integer_zero_node, op0);
5312 /* ... fall through ... */
5314 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5315 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5316 /* If we can extract our operation from the LHS, do so and return a
5317 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5318 do something only if the second operand is a constant. */
5320 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5321 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5322 fold_convert (ctype, op1)));
5323 else if (tcode == MULT_EXPR && code == MULT_EXPR
5324 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
5325 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5326 fold_convert (ctype, t1)));
5327 else if (TREE_CODE (op1) != INTEGER_CST)
5330 /* If these are the same operation types, we can associate them
5331 assuming no overflow. */
5333 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5334 fold_convert (ctype, c), 0))
5335 && ! TREE_OVERFLOW (t1))
5336 return fold (build2 (tcode, ctype, fold_convert (ctype, op0), t1));
5338 /* If these operations "cancel" each other, we have the main
5339 optimizations of this pass, which occur when either constant is a
5340 multiple of the other, in which case we replace this with either an
5341 operation or CODE or TCODE.
5343 If we have an unsigned type that is not a sizetype, we cannot do
5344 this since it will change the result if the original computation
5346 if ((! TYPE_UNSIGNED (ctype)
5347 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5349 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5350 || (tcode == MULT_EXPR
5351 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5352 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5354 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5355 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5356 fold_convert (ctype,
5357 const_binop (TRUNC_DIV_EXPR,
5359 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5360 return fold (build2 (code, ctype, fold_convert (ctype, op0),
5361 fold_convert (ctype,
5362 const_binop (TRUNC_DIV_EXPR,
5374 /* Return a node which has the indicated constant VALUE (either 0 or
5375 1), and is of the indicated TYPE. */
5378 constant_boolean_node (int value, tree type)
5380 if (type == integer_type_node)
5381 return value ? integer_one_node : integer_zero_node;
5382 else if (type == boolean_type_node)
5383 return value ? boolean_true_node : boolean_false_node;
5385 return build_int_cst (type, value);
5389 /* Return true if expr looks like an ARRAY_REF and set base and
5390 offset to the appropriate trees. If there is no offset,
5391 offset is set to NULL_TREE. */
5394 extract_array_ref (tree expr, tree *base, tree *offset)
5396 /* We have to be careful with stripping nops as with the
5397 base type the meaning of the offset can change. */
5398 tree inner_expr = expr;
5399 STRIP_NOPS (inner_expr);
5400 /* One canonical form is a PLUS_EXPR with the first
5401 argument being an ADDR_EXPR with a possible NOP_EXPR
5403 if (TREE_CODE (expr) == PLUS_EXPR)
5405 tree op0 = TREE_OPERAND (expr, 0);
5407 if (TREE_CODE (op0) == ADDR_EXPR)
5409 *base = TREE_OPERAND (expr, 0);
5410 *offset = TREE_OPERAND (expr, 1);
5414 /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
5415 which we transform into an ADDR_EXPR with appropriate
5416 offset. For other arguments to the ADDR_EXPR we assume
5417 zero offset and as such do not care about the ADDR_EXPR
5418 type and strip possible nops from it. */
5419 else if (TREE_CODE (inner_expr) == ADDR_EXPR)
5421 tree op0 = TREE_OPERAND (inner_expr, 0);
5422 if (TREE_CODE (op0) == ARRAY_REF)
5424 *base = build_fold_addr_expr (TREE_OPERAND (op0, 0));
5425 *offset = TREE_OPERAND (op0, 1);
5430 *offset = NULL_TREE;
5439 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5440 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5441 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5442 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5443 COND is the first argument to CODE; otherwise (as in the example
5444 given here), it is the second argument. TYPE is the type of the
5445 original expression. Return NULL_TREE if no simplification is
5449 fold_binary_op_with_conditional_arg (tree t, enum tree_code code, tree cond,
5450 tree arg, int cond_first_p)
5452 const tree type = TREE_TYPE (t);
5453 tree cond_type = cond_first_p ? TREE_TYPE (TREE_OPERAND (t, 0))
5454 : TREE_TYPE (TREE_OPERAND (t, 1));
5455 tree arg_type = cond_first_p ? TREE_TYPE (TREE_OPERAND (t, 1))
5456 : TREE_TYPE (TREE_OPERAND (t, 0));
5457 tree test, true_value, false_value;
5458 tree lhs = NULL_TREE;
5459 tree rhs = NULL_TREE;
5461 /* This transformation is only worthwhile if we don't have to wrap
5462 arg in a SAVE_EXPR, and the operation can be simplified on at least
5463 one of the branches once its pushed inside the COND_EXPR. */
5464 if (!TREE_CONSTANT (arg))
5467 if (TREE_CODE (cond) == COND_EXPR)
5469 test = TREE_OPERAND (cond, 0);
5470 true_value = TREE_OPERAND (cond, 1);
5471 false_value = TREE_OPERAND (cond, 2);
5472 /* If this operand throws an expression, then it does not make
5473 sense to try to perform a logical or arithmetic operation
5475 if (VOID_TYPE_P (TREE_TYPE (true_value)))
5477 if (VOID_TYPE_P (TREE_TYPE (false_value)))
5482 tree testtype = TREE_TYPE (cond);
5484 true_value = constant_boolean_node (true, testtype);
5485 false_value = constant_boolean_node (false, testtype);
5488 arg = fold_convert (arg_type, arg);
5491 true_value = fold_convert (cond_type, true_value);
5492 lhs = fold (cond_first_p ? build2 (code, type, true_value, arg)
5493 : build2 (code, type, arg, true_value));
5497 false_value = fold_convert (cond_type, false_value);
5498 rhs = fold (cond_first_p ? build2 (code, type, false_value, arg)
5499 : build2 (code, type, arg, false_value));
5502 test = fold (build3 (COND_EXPR, type, test, lhs, rhs));
5503 return fold_convert (type, test);
5507 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5509 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5510 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5511 ADDEND is the same as X.
5513 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5514 and finite. The problematic cases are when X is zero, and its mode
5515 has signed zeros. In the case of rounding towards -infinity,
5516 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5517 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5520 fold_real_zero_addition_p (tree type, tree addend, int negate)
5522 if (!real_zerop (addend))
5525 /* Don't allow the fold with -fsignaling-nans. */
5526 if (HONOR_SNANS (TYPE_MODE (type)))
5529 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5530 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5533 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5534 if (TREE_CODE (addend) == REAL_CST
5535 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5538 /* The mode has signed zeros, and we have to honor their sign.
5539 In this situation, there is only one case we can return true for.
5540 X - 0 is the same as X unless rounding towards -infinity is
5542 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5545 /* Subroutine of fold() that checks comparisons of built-in math
5546 functions against real constants.
5548 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5549 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5550 is the type of the result and ARG0 and ARG1 are the operands of the
5551 comparison. ARG1 must be a TREE_REAL_CST.
5553 The function returns the constant folded tree if a simplification
5554 can be made, and NULL_TREE otherwise. */
5557 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5558 tree type, tree arg0, tree arg1)
5562 if (BUILTIN_SQRT_P (fcode))
5564 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5565 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5567 c = TREE_REAL_CST (arg1);
5568 if (REAL_VALUE_NEGATIVE (c))
5570 /* sqrt(x) < y is always false, if y is negative. */
5571 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5572 return omit_one_operand (type, integer_zero_node, arg);
5574 /* sqrt(x) > y is always true, if y is negative and we
5575 don't care about NaNs, i.e. negative values of x. */
5576 if (code == NE_EXPR || !HONOR_NANS (mode))
5577 return omit_one_operand (type, integer_one_node, arg);
5579 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5580 return fold (build2 (GE_EXPR, type, arg,
5581 build_real (TREE_TYPE (arg), dconst0)));
5583 else if (code == GT_EXPR || code == GE_EXPR)
5587 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5588 real_convert (&c2, mode, &c2);
5590 if (REAL_VALUE_ISINF (c2))
5592 /* sqrt(x) > y is x == +Inf, when y is very large. */
5593 if (HONOR_INFINITIES (mode))
5594 return fold (build2 (EQ_EXPR, type, arg,
5595 build_real (TREE_TYPE (arg), c2)));
5597 /* sqrt(x) > y is always false, when y is very large
5598 and we don't care about infinities. */
5599 return omit_one_operand (type, integer_zero_node, arg);
5602 /* sqrt(x) > c is the same as x > c*c. */
5603 return fold (build2 (code, type, arg,
5604 build_real (TREE_TYPE (arg), c2)));
5606 else if (code == LT_EXPR || code == LE_EXPR)
5610 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5611 real_convert (&c2, mode, &c2);
5613 if (REAL_VALUE_ISINF (c2))
5615 /* sqrt(x) < y is always true, when y is a very large
5616 value and we don't care about NaNs or Infinities. */
5617 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5618 return omit_one_operand (type, integer_one_node, arg);
5620 /* sqrt(x) < y is x != +Inf when y is very large and we
5621 don't care about NaNs. */
5622 if (! HONOR_NANS (mode))
5623 return fold (build2 (NE_EXPR, type, arg,
5624 build_real (TREE_TYPE (arg), c2)));
5626 /* sqrt(x) < y is x >= 0 when y is very large and we
5627 don't care about Infinities. */
5628 if (! HONOR_INFINITIES (mode))
5629 return fold (build2 (GE_EXPR, type, arg,
5630 build_real (TREE_TYPE (arg), dconst0)));
5632 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5633 if (lang_hooks.decls.global_bindings_p () != 0
5634 || CONTAINS_PLACEHOLDER_P (arg))
5637 arg = save_expr (arg);
5638 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5639 fold (build2 (GE_EXPR, type, arg,
5640 build_real (TREE_TYPE (arg),
5642 fold (build2 (NE_EXPR, type, arg,
5643 build_real (TREE_TYPE (arg),
5647 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5648 if (! HONOR_NANS (mode))
5649 return fold (build2 (code, type, arg,
5650 build_real (TREE_TYPE (arg), c2)));
5652 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5653 if (lang_hooks.decls.global_bindings_p () == 0
5654 && ! CONTAINS_PLACEHOLDER_P (arg))
5656 arg = save_expr (arg);
5657 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5658 fold (build2 (GE_EXPR, type, arg,
5659 build_real (TREE_TYPE (arg),
5661 fold (build2 (code, type, arg,
5662 build_real (TREE_TYPE (arg),
5671 /* Subroutine of fold() that optimizes comparisons against Infinities,
5672 either +Inf or -Inf.
5674 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5675 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5676 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5678 The function returns the constant folded tree if a simplification
5679 can be made, and NULL_TREE otherwise. */
5682 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5684 enum machine_mode mode;
5685 REAL_VALUE_TYPE max;
5689 mode = TYPE_MODE (TREE_TYPE (arg0));
5691 /* For negative infinity swap the sense of the comparison. */
5692 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5694 code = swap_tree_comparison (code);
5699 /* x > +Inf is always false, if with ignore sNANs. */
5700 if (HONOR_SNANS (mode))
5702 return omit_one_operand (type, integer_zero_node, arg0);
5705 /* x <= +Inf is always true, if we don't case about NaNs. */
5706 if (! HONOR_NANS (mode))
5707 return omit_one_operand (type, integer_one_node, arg0);
5709 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5710 if (lang_hooks.decls.global_bindings_p () == 0
5711 && ! CONTAINS_PLACEHOLDER_P (arg0))
5713 arg0 = save_expr (arg0);
5714 return fold (build2 (EQ_EXPR, type, arg0, arg0));
5720 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5721 real_maxval (&max, neg, mode);
5722 return fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5723 arg0, build_real (TREE_TYPE (arg0), max)));
5726 /* x < +Inf is always equal to x <= DBL_MAX. */
5727 real_maxval (&max, neg, mode);
5728 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5729 arg0, build_real (TREE_TYPE (arg0), max)));
5732 /* x != +Inf is always equal to !(x > DBL_MAX). */
5733 real_maxval (&max, neg, mode);
5734 if (! HONOR_NANS (mode))
5735 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5736 arg0, build_real (TREE_TYPE (arg0), max)));
5738 /* The transformation below creates non-gimple code and thus is
5739 not appropriate if we are in gimple form. */
5743 temp = fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5744 arg0, build_real (TREE_TYPE (arg0), max)));
5745 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5754 /* Subroutine of fold() that optimizes comparisons of a division by
5755 a nonzero integer constant against an integer constant, i.e.
5758 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5759 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5760 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5762 The function returns the constant folded tree if a simplification
5763 can be made, and NULL_TREE otherwise. */
5766 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5768 tree prod, tmp, hi, lo;
5769 tree arg00 = TREE_OPERAND (arg0, 0);
5770 tree arg01 = TREE_OPERAND (arg0, 1);
5771 unsigned HOST_WIDE_INT lpart;
5772 HOST_WIDE_INT hpart;
5775 /* We have to do this the hard way to detect unsigned overflow.
5776 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5777 overflow = mul_double (TREE_INT_CST_LOW (arg01),
5778 TREE_INT_CST_HIGH (arg01),
5779 TREE_INT_CST_LOW (arg1),
5780 TREE_INT_CST_HIGH (arg1), &lpart, &hpart);
5781 prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5782 prod = force_fit_type (prod, -1, overflow, false);
5784 if (TYPE_UNSIGNED (TREE_TYPE (arg0)))
5786 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5789 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5790 overflow = add_double (TREE_INT_CST_LOW (prod),
5791 TREE_INT_CST_HIGH (prod),
5792 TREE_INT_CST_LOW (tmp),
5793 TREE_INT_CST_HIGH (tmp),
5795 hi = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5796 hi = force_fit_type (hi, -1, overflow | TREE_OVERFLOW (prod),
5797 TREE_CONSTANT_OVERFLOW (prod));
5799 else if (tree_int_cst_sgn (arg01) >= 0)
5801 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5802 switch (tree_int_cst_sgn (arg1))
5805 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5810 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
5815 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5825 /* A negative divisor reverses the relational operators. */
5826 code = swap_tree_comparison (code);
5828 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
5829 switch (tree_int_cst_sgn (arg1))
5832 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5837 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
5842 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5854 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5855 return omit_one_operand (type, integer_zero_node, arg00);
5856 if (TREE_OVERFLOW (hi))
5857 return fold (build2 (GE_EXPR, type, arg00, lo));
5858 if (TREE_OVERFLOW (lo))
5859 return fold (build2 (LE_EXPR, type, arg00, hi));
5860 return build_range_check (type, arg00, 1, lo, hi);
5863 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5864 return omit_one_operand (type, integer_one_node, arg00);
5865 if (TREE_OVERFLOW (hi))
5866 return fold (build2 (LT_EXPR, type, arg00, lo));
5867 if (TREE_OVERFLOW (lo))
5868 return fold (build2 (GT_EXPR, type, arg00, hi));
5869 return build_range_check (type, arg00, 0, lo, hi);
5872 if (TREE_OVERFLOW (lo))
5873 return omit_one_operand (type, integer_zero_node, arg00);
5874 return fold (build2 (LT_EXPR, type, arg00, lo));
5877 if (TREE_OVERFLOW (hi))
5878 return omit_one_operand (type, integer_one_node, arg00);
5879 return fold (build2 (LE_EXPR, type, arg00, hi));
5882 if (TREE_OVERFLOW (hi))
5883 return omit_one_operand (type, integer_zero_node, arg00);
5884 return fold (build2 (GT_EXPR, type, arg00, hi));
5887 if (TREE_OVERFLOW (lo))
5888 return omit_one_operand (type, integer_one_node, arg00);
5889 return fold (build2 (GE_EXPR, type, arg00, lo));
5899 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5900 equality/inequality test, then return a simplified form of
5901 the test using shifts and logical operations. Otherwise return
5902 NULL. TYPE is the desired result type. */
5905 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5908 /* If this is testing a single bit, we can optimize the test. */
5909 if ((code == NE_EXPR || code == EQ_EXPR)
5910 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5911 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5913 tree inner = TREE_OPERAND (arg0, 0);
5914 tree type = TREE_TYPE (arg0);
5915 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5916 enum machine_mode operand_mode = TYPE_MODE (type);
5918 tree signed_type, unsigned_type, intermediate_type;
5921 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5922 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5923 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5924 if (arg00 != NULL_TREE
5925 /* This is only a win if casting to a signed type is cheap,
5926 i.e. when arg00's type is not a partial mode. */
5927 && TYPE_PRECISION (TREE_TYPE (arg00))
5928 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
5930 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5931 return fold (build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
5932 result_type, fold_convert (stype, arg00),
5933 fold_convert (stype, integer_zero_node)));
5936 /* Otherwise we have (A & C) != 0 where C is a single bit,
5937 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5938 Similarly for (A & C) == 0. */
5940 /* If INNER is a right shift of a constant and it plus BITNUM does
5941 not overflow, adjust BITNUM and INNER. */
5942 if (TREE_CODE (inner) == RSHIFT_EXPR
5943 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5944 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5945 && bitnum < TYPE_PRECISION (type)
5946 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5947 bitnum - TYPE_PRECISION (type)))
5949 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5950 inner = TREE_OPERAND (inner, 0);
5953 /* If we are going to be able to omit the AND below, we must do our
5954 operations as unsigned. If we must use the AND, we have a choice.
5955 Normally unsigned is faster, but for some machines signed is. */
5956 #ifdef LOAD_EXTEND_OP
5957 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
5958 && !flag_syntax_only) ? 0 : 1;
5963 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5964 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5965 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5966 inner = fold_convert (intermediate_type, inner);
5969 inner = build2 (RSHIFT_EXPR, intermediate_type,
5970 inner, size_int (bitnum));
5972 if (code == EQ_EXPR)
5973 inner = fold (build2 (BIT_XOR_EXPR, intermediate_type,
5974 inner, integer_one_node));
5976 /* Put the AND last so it can combine with more things. */
5977 inner = build2 (BIT_AND_EXPR, intermediate_type,
5978 inner, integer_one_node);
5980 /* Make sure to return the proper type. */
5981 inner = fold_convert (result_type, inner);
5988 /* Check whether we are allowed to reorder operands arg0 and arg1,
5989 such that the evaluation of arg1 occurs before arg0. */
5992 reorder_operands_p (tree arg0, tree arg1)
5994 if (! flag_evaluation_order)
5996 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5998 return ! TREE_SIDE_EFFECTS (arg0)
5999 && ! TREE_SIDE_EFFECTS (arg1);
6002 /* Test whether it is preferable two swap two operands, ARG0 and
6003 ARG1, for example because ARG0 is an integer constant and ARG1
6004 isn't. If REORDER is true, only recommend swapping if we can
6005 evaluate the operands in reverse order. */
6008 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
6010 STRIP_SIGN_NOPS (arg0);
6011 STRIP_SIGN_NOPS (arg1);
6013 if (TREE_CODE (arg1) == INTEGER_CST)
6015 if (TREE_CODE (arg0) == INTEGER_CST)
6018 if (TREE_CODE (arg1) == REAL_CST)
6020 if (TREE_CODE (arg0) == REAL_CST)
6023 if (TREE_CODE (arg1) == COMPLEX_CST)
6025 if (TREE_CODE (arg0) == COMPLEX_CST)
6028 if (TREE_CONSTANT (arg1))
6030 if (TREE_CONSTANT (arg0))
6036 if (reorder && flag_evaluation_order
6037 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6045 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6046 for commutative and comparison operators. Ensuring a canonical
6047 form allows the optimizers to find additional redundancies without
6048 having to explicitly check for both orderings. */
6049 if (TREE_CODE (arg0) == SSA_NAME
6050 && TREE_CODE (arg1) == SSA_NAME
6051 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6057 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6058 ARG0 is extended to a wider type. */
6061 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6063 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6065 tree shorter_type, outer_type;
6069 if (arg0_unw == arg0)
6071 shorter_type = TREE_TYPE (arg0_unw);
6073 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6076 arg1_unw = get_unwidened (arg1, shorter_type);
6080 /* If possible, express the comparison in the shorter mode. */
6081 if ((code == EQ_EXPR || code == NE_EXPR
6082 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6083 && (TREE_TYPE (arg1_unw) == shorter_type
6084 || (TREE_CODE (arg1_unw) == INTEGER_CST
6085 && TREE_CODE (shorter_type) == INTEGER_TYPE
6086 && int_fits_type_p (arg1_unw, shorter_type))))
6087 return fold (build (code, type, arg0_unw,
6088 fold_convert (shorter_type, arg1_unw)));
6090 if (TREE_CODE (arg1_unw) != INTEGER_CST)
6093 /* If we are comparing with the integer that does not fit into the range
6094 of the shorter type, the result is known. */
6095 outer_type = TREE_TYPE (arg1_unw);
6096 min = lower_bound_in_type (outer_type, shorter_type);
6097 max = upper_bound_in_type (outer_type, shorter_type);
6099 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6101 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6108 return omit_one_operand (type, integer_zero_node, arg0);
6113 return omit_one_operand (type, integer_one_node, arg0);
6119 return omit_one_operand (type, integer_one_node, arg0);
6121 return omit_one_operand (type, integer_zero_node, arg0);
6126 return omit_one_operand (type, integer_zero_node, arg0);
6128 return omit_one_operand (type, integer_one_node, arg0);
6137 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6138 ARG0 just the signedness is changed. */
6141 fold_sign_changed_comparison (enum tree_code code, tree type,
6142 tree arg0, tree arg1)
6144 tree arg0_inner, tmp;
6145 tree inner_type, outer_type;
6147 if (TREE_CODE (arg0) != NOP_EXPR)
6150 outer_type = TREE_TYPE (arg0);
6151 arg0_inner = TREE_OPERAND (arg0, 0);
6152 inner_type = TREE_TYPE (arg0_inner);
6154 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6157 if (TREE_CODE (arg1) != INTEGER_CST
6158 && !(TREE_CODE (arg1) == NOP_EXPR
6159 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6162 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6167 if (TREE_CODE (arg1) == INTEGER_CST)
6169 tmp = build_int_cst_wide (inner_type,
6170 TREE_INT_CST_LOW (arg1),
6171 TREE_INT_CST_HIGH (arg1));
6172 arg1 = force_fit_type (tmp, 0,
6173 TREE_OVERFLOW (arg1),
6174 TREE_CONSTANT_OVERFLOW (arg1));
6177 arg1 = fold_convert (inner_type, arg1);
6179 return fold (build (code, type, arg0_inner, arg1));
6182 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6183 step of the array. ADDR is the address. MULT is the multiplicative expression.
6184 If the function succeeds, the new address expression is returned. Otherwise
6185 NULL_TREE is returned. */
6188 try_move_mult_to_index (enum tree_code code, tree addr, tree mult)
6190 tree s, delta, step;
6191 tree arg0 = TREE_OPERAND (mult, 0), arg1 = TREE_OPERAND (mult, 1);
6192 tree ref = TREE_OPERAND (addr, 0), pref;
6199 if (TREE_CODE (arg0) == INTEGER_CST)
6204 else if (TREE_CODE (arg1) == INTEGER_CST)
6212 for (;; ref = TREE_OPERAND (ref, 0))
6214 if (TREE_CODE (ref) == ARRAY_REF)
6216 step = array_ref_element_size (ref);
6218 if (TREE_CODE (step) != INTEGER_CST)
6221 itype = TREE_TYPE (step);
6223 /* If the type sizes do not match, we might run into problems
6224 when one of them would overflow. */
6225 if (TYPE_PRECISION (itype) != TYPE_PRECISION (TREE_TYPE (s)))
6228 if (!operand_equal_p (step, fold_convert (itype, s), 0))
6231 delta = fold_convert (itype, delta);
6235 if (!handled_component_p (ref))
6239 /* We found the suitable array reference. So copy everything up to it,
6240 and replace the index. */
6242 pref = TREE_OPERAND (addr, 0);
6243 ret = copy_node (pref);
6248 pref = TREE_OPERAND (pref, 0);
6249 TREE_OPERAND (pos, 0) = copy_node (pref);
6250 pos = TREE_OPERAND (pos, 0);
6253 TREE_OPERAND (pos, 1) = fold (build2 (code, itype,
6254 TREE_OPERAND (pos, 1),
6257 return build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6261 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6262 means A >= Y && A != MAX, but in this case we know that
6263 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6266 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6268 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6270 if (TREE_CODE (bound) == LT_EXPR)
6271 a = TREE_OPERAND (bound, 0);
6272 else if (TREE_CODE (bound) == GT_EXPR)
6273 a = TREE_OPERAND (bound, 1);
6277 typea = TREE_TYPE (a);
6278 if (!INTEGRAL_TYPE_P (typea)
6279 && !POINTER_TYPE_P (typea))
6282 if (TREE_CODE (ineq) == LT_EXPR)
6284 a1 = TREE_OPERAND (ineq, 1);
6285 y = TREE_OPERAND (ineq, 0);
6287 else if (TREE_CODE (ineq) == GT_EXPR)
6289 a1 = TREE_OPERAND (ineq, 0);
6290 y = TREE_OPERAND (ineq, 1);
6295 if (TREE_TYPE (a1) != typea)
6298 diff = fold (build2 (MINUS_EXPR, typea, a1, a));
6299 if (!integer_onep (diff))
6302 return fold (build2 (GE_EXPR, type, a, y));
6305 /* Fold complex addition when both components are accessible by parts.
6306 Return non-null if successful. CODE should be PLUS_EXPR for addition,
6307 or MINUS_EXPR for subtraction. */
6310 fold_complex_add (tree type, tree ac, tree bc, enum tree_code code)
6312 tree ar, ai, br, bi, rr, ri, inner_type;
6314 if (TREE_CODE (ac) == COMPLEX_EXPR)
6315 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6316 else if (TREE_CODE (ac) == COMPLEX_CST)
6317 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6321 if (TREE_CODE (bc) == COMPLEX_EXPR)
6322 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6323 else if (TREE_CODE (bc) == COMPLEX_CST)
6324 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6328 inner_type = TREE_TYPE (type);
6330 rr = fold (build2 (code, inner_type, ar, br));
6331 ri = fold (build2 (code, inner_type, ai, bi));
6333 return fold (build2 (COMPLEX_EXPR, type, rr, ri));
6336 /* Perform some simplifications of complex multiplication when one or more
6337 of the components are constants or zeros. Return non-null if successful. */
6340 fold_complex_mult_parts (tree type, tree ar, tree ai, tree br, tree bi)
6342 tree rr, ri, inner_type, zero;
6343 bool ar0, ai0, br0, bi0, bi1;
6345 inner_type = TREE_TYPE (type);
6348 if (SCALAR_FLOAT_TYPE_P (inner_type))
6350 ar0 = ai0 = br0 = bi0 = bi1 = false;
6352 /* We're only interested in +0.0 here, thus we don't use real_zerop. */
6354 if (TREE_CODE (ar) == REAL_CST
6355 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ar), dconst0))
6356 ar0 = true, zero = ar;
6358 if (TREE_CODE (ai) == REAL_CST
6359 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ai), dconst0))
6360 ai0 = true, zero = ai;
6362 if (TREE_CODE (br) == REAL_CST
6363 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (br), dconst0))
6364 br0 = true, zero = br;
6366 if (TREE_CODE (bi) == REAL_CST)
6368 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst0))
6369 bi0 = true, zero = bi;
6370 else if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst1))
6376 ar0 = integer_zerop (ar);
6379 ai0 = integer_zerop (ai);
6382 br0 = integer_zerop (br);
6385 bi0 = integer_zerop (bi);
6392 bi1 = integer_onep (bi);
6395 /* We won't optimize anything below unless something is zero. */
6399 if (ai0 && br0 && bi1)
6404 else if (ai0 && bi0)
6406 rr = fold (build2 (MULT_EXPR, inner_type, ar, br));
6409 else if (ai0 && br0)
6412 ri = fold (build2 (MULT_EXPR, inner_type, ar, bi));
6414 else if (ar0 && bi0)
6417 ri = fold (build2 (MULT_EXPR, inner_type, ai, br));
6419 else if (ar0 && br0)
6421 rr = fold (build2 (MULT_EXPR, inner_type, ai, bi));
6422 rr = fold (build1 (NEGATE_EXPR, inner_type, rr));
6427 rr = fold (build2 (MULT_EXPR, inner_type, ar, br));
6428 ri = fold (build2 (MULT_EXPR, inner_type, ai, br));
6432 rr = fold (build2 (MULT_EXPR, inner_type, ar, br));
6433 ri = fold (build2 (MULT_EXPR, inner_type, ar, bi));
6437 rr = fold (build2 (MULT_EXPR, inner_type, ai, bi));
6438 rr = fold (build1 (NEGATE_EXPR, inner_type, rr));
6439 ri = fold (build2 (MULT_EXPR, inner_type, ar, bi));
6443 rr = fold (build2 (MULT_EXPR, inner_type, ai, bi));
6444 rr = fold (build1 (NEGATE_EXPR, inner_type, rr));
6445 ri = fold (build2 (MULT_EXPR, inner_type, ai, br));
6450 return fold (build2 (COMPLEX_EXPR, type, rr, ri));
6454 fold_complex_mult (tree type, tree ac, tree bc)
6456 tree ar, ai, br, bi;
6458 if (TREE_CODE (ac) == COMPLEX_EXPR)
6459 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6460 else if (TREE_CODE (ac) == COMPLEX_CST)
6461 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6465 if (TREE_CODE (bc) == COMPLEX_EXPR)
6466 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6467 else if (TREE_CODE (bc) == COMPLEX_CST)
6468 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6472 return fold_complex_mult_parts (type, ar, ai, br, bi);
6475 /* Perform some simplifications of complex division when one or more of
6476 the components are constants or zeros. Return non-null if successful. */
6479 fold_complex_div_parts (tree type, tree ar, tree ai, tree br, tree bi,
6480 enum tree_code code)
6482 tree rr, ri, inner_type, zero;
6483 bool ar0, ai0, br0, bi0, bi1;
6485 inner_type = TREE_TYPE (type);
6488 if (SCALAR_FLOAT_TYPE_P (inner_type))
6490 ar0 = ai0 = br0 = bi0 = bi1 = false;
6492 /* We're only interested in +0.0 here, thus we don't use real_zerop. */
6494 if (TREE_CODE (ar) == REAL_CST
6495 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ar), dconst0))
6496 ar0 = true, zero = ar;
6498 if (TREE_CODE (ai) == REAL_CST
6499 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ai), dconst0))
6500 ai0 = true, zero = ai;
6502 if (TREE_CODE (br) == REAL_CST
6503 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (br), dconst0))
6504 br0 = true, zero = br;
6506 if (TREE_CODE (bi) == REAL_CST)
6508 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst0))
6509 bi0 = true, zero = bi;
6510 else if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst1))
6516 ar0 = integer_zerop (ar);
6519 ai0 = integer_zerop (ai);
6522 br0 = integer_zerop (br);
6525 bi0 = integer_zerop (bi);
6532 bi1 = integer_onep (bi);
6535 /* We won't optimize anything below unless something is zero. */
6541 rr = fold (build2 (code, inner_type, ar, br));
6544 else if (ai0 && br0)
6547 ri = fold (build2 (code, inner_type, ar, bi));
6548 ri = fold (build1 (NEGATE_EXPR, inner_type, ri));
6550 else if (ar0 && bi0)
6553 ri = fold (build2 (code, inner_type, ai, br));
6555 else if (ar0 && br0)
6557 rr = fold (build2 (code, inner_type, ai, bi));
6562 rr = fold (build2 (code, inner_type, ar, br));
6563 ri = fold (build2 (code, inner_type, ai, br));
6567 rr = fold (build2 (code, inner_type, ai, bi));
6568 ri = fold (build2 (code, inner_type, ar, bi));
6569 ri = fold (build1 (NEGATE_EXPR, inner_type, ri));
6574 return fold (build2 (COMPLEX_EXPR, type, rr, ri));
6578 fold_complex_div (tree type, tree ac, tree bc, enum tree_code code)
6580 tree ar, ai, br, bi;
6582 if (TREE_CODE (ac) == COMPLEX_EXPR)
6583 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6584 else if (TREE_CODE (ac) == COMPLEX_CST)
6585 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6589 if (TREE_CODE (bc) == COMPLEX_EXPR)
6590 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6591 else if (TREE_CODE (bc) == COMPLEX_CST)
6592 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6596 return fold_complex_div_parts (type, ar, ai, br, bi, code);
6599 /* Fold a unary expression EXPR. Return the folded expression if
6600 folding is successful. Otherwise, return the original
6604 fold_unary (tree expr)
6606 const tree t = expr;
6607 const tree type = TREE_TYPE (expr);
6610 enum tree_code code = TREE_CODE (t);
6611 enum tree_code_class kind = TREE_CODE_CLASS (code);
6613 gcc_assert (IS_EXPR_CODE_CLASS (kind)
6614 && TREE_CODE_LENGTH (code) == 1);
6617 arg0 = op0 = TREE_OPERAND (t, 0);
6620 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
6622 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
6623 STRIP_SIGN_NOPS (arg0);
6627 /* Strip any conversions that don't change the mode. This
6628 is safe for every expression, except for a comparison
6629 expression because its signedness is derived from its
6632 Note that this is done as an internal manipulation within
6633 the constant folder, in order to find the simplest
6634 representation of the arguments so that their form can be
6635 studied. In any cases, the appropriate type conversions
6636 should be put back in the tree that will get out of the
6642 if (TREE_CODE_CLASS (code) == tcc_unary)
6644 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6645 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6646 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
6647 else if (TREE_CODE (arg0) == COND_EXPR)
6649 tree arg01 = TREE_OPERAND (arg0, 1);
6650 tree arg02 = TREE_OPERAND (arg0, 2);
6651 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6652 arg01 = fold (build1 (code, type, arg01));
6653 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6654 arg02 = fold (build1 (code, type, arg02));
6655 tem = fold (build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6658 /* If this was a conversion, and all we did was to move into
6659 inside the COND_EXPR, bring it back out. But leave it if
6660 it is a conversion from integer to integer and the
6661 result precision is no wider than a word since such a
6662 conversion is cheap and may be optimized away by combine,
6663 while it couldn't if it were outside the COND_EXPR. Then return
6664 so we don't get into an infinite recursion loop taking the
6665 conversion out and then back in. */
6667 if ((code == NOP_EXPR || code == CONVERT_EXPR
6668 || code == NON_LVALUE_EXPR)
6669 && TREE_CODE (tem) == COND_EXPR
6670 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6671 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6672 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6673 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6674 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6675 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6676 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6678 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6679 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
6680 || flag_syntax_only))
6681 tem = build1 (code, type,
6683 TREE_TYPE (TREE_OPERAND
6684 (TREE_OPERAND (tem, 1), 0)),
6685 TREE_OPERAND (tem, 0),
6686 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6687 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6690 else if (COMPARISON_CLASS_P (arg0))
6692 if (TREE_CODE (type) == BOOLEAN_TYPE)
6694 arg0 = copy_node (arg0);
6695 TREE_TYPE (arg0) = type;
6698 else if (TREE_CODE (type) != INTEGER_TYPE)
6699 return fold (build3 (COND_EXPR, type, arg0,
6700 fold (build1 (code, type,
6702 fold (build1 (code, type,
6703 integer_zero_node))));
6712 case FIX_TRUNC_EXPR:
6714 case FIX_FLOOR_EXPR:
6715 case FIX_ROUND_EXPR:
6716 if (TREE_TYPE (op0) == type)
6719 /* Handle cases of two conversions in a row. */
6720 if (TREE_CODE (op0) == NOP_EXPR
6721 || TREE_CODE (op0) == CONVERT_EXPR)
6723 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
6724 tree inter_type = TREE_TYPE (op0);
6725 int inside_int = INTEGRAL_TYPE_P (inside_type);
6726 int inside_ptr = POINTER_TYPE_P (inside_type);
6727 int inside_float = FLOAT_TYPE_P (inside_type);
6728 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6729 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6730 int inter_int = INTEGRAL_TYPE_P (inter_type);
6731 int inter_ptr = POINTER_TYPE_P (inter_type);
6732 int inter_float = FLOAT_TYPE_P (inter_type);
6733 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6734 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6735 int final_int = INTEGRAL_TYPE_P (type);
6736 int final_ptr = POINTER_TYPE_P (type);
6737 int final_float = FLOAT_TYPE_P (type);
6738 unsigned int final_prec = TYPE_PRECISION (type);
6739 int final_unsignedp = TYPE_UNSIGNED (type);
6741 /* In addition to the cases of two conversions in a row
6742 handled below, if we are converting something to its own
6743 type via an object of identical or wider precision, neither
6744 conversion is needed. */
6745 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6746 && ((inter_int && final_int) || (inter_float && final_float))
6747 && inter_prec >= final_prec)
6748 return fold (build1 (code, type, TREE_OPERAND (op0, 0)));
6750 /* Likewise, if the intermediate and final types are either both
6751 float or both integer, we don't need the middle conversion if
6752 it is wider than the final type and doesn't change the signedness
6753 (for integers). Avoid this if the final type is a pointer
6754 since then we sometimes need the inner conversion. Likewise if
6755 the outer has a precision not equal to the size of its mode. */
6756 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6757 || (inter_float && inside_float))
6758 && inter_prec >= inside_prec
6759 && (inter_float || inter_unsignedp == inside_unsignedp)
6760 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6761 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6763 return fold (build1 (code, type, TREE_OPERAND (op0, 0)));
6765 /* If we have a sign-extension of a zero-extended value, we can
6766 replace that by a single zero-extension. */
6767 if (inside_int && inter_int && final_int
6768 && inside_prec < inter_prec && inter_prec < final_prec
6769 && inside_unsignedp && !inter_unsignedp)
6770 return fold (build1 (code, type, TREE_OPERAND (op0, 0)));
6772 /* Two conversions in a row are not needed unless:
6773 - some conversion is floating-point (overstrict for now), or
6774 - the intermediate type is narrower than both initial and
6776 - the intermediate type and innermost type differ in signedness,
6777 and the outermost type is wider than the intermediate, or
6778 - the initial type is a pointer type and the precisions of the
6779 intermediate and final types differ, or
6780 - the final type is a pointer type and the precisions of the
6781 initial and intermediate types differ. */
6782 if (! inside_float && ! inter_float && ! final_float
6783 && (inter_prec > inside_prec || inter_prec > final_prec)
6784 && ! (inside_int && inter_int
6785 && inter_unsignedp != inside_unsignedp
6786 && inter_prec < final_prec)
6787 && ((inter_unsignedp && inter_prec > inside_prec)
6788 == (final_unsignedp && final_prec > inter_prec))
6789 && ! (inside_ptr && inter_prec != final_prec)
6790 && ! (final_ptr && inside_prec != inter_prec)
6791 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6792 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6794 return fold (build1 (code, type, TREE_OPERAND (op0, 0)));
6797 if (TREE_CODE (op0) == MODIFY_EXPR
6798 && TREE_CONSTANT (TREE_OPERAND (op0, 1))
6799 /* Detect assigning a bitfield. */
6800 && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
6801 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
6803 /* Don't leave an assignment inside a conversion
6804 unless assigning a bitfield. */
6805 tem = copy_node (t);
6806 TREE_OPERAND (tem, 0) = TREE_OPERAND (op0, 1);
6807 /* First do the assignment, then return converted constant. */
6808 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, fold (tem));
6809 TREE_NO_WARNING (tem) = 1;
6810 TREE_USED (tem) = 1;
6814 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6815 constants (if x has signed type, the sign bit cannot be set
6816 in c). This folds extension into the BIT_AND_EXPR. */
6817 if (INTEGRAL_TYPE_P (type)
6818 && TREE_CODE (type) != BOOLEAN_TYPE
6819 && TREE_CODE (op0) == BIT_AND_EXPR
6820 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
6823 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6826 if (TYPE_UNSIGNED (TREE_TYPE (and))
6827 || (TYPE_PRECISION (type)
6828 <= TYPE_PRECISION (TREE_TYPE (and))))
6830 else if (TYPE_PRECISION (TREE_TYPE (and1))
6831 <= HOST_BITS_PER_WIDE_INT
6832 && host_integerp (and1, 1))
6834 unsigned HOST_WIDE_INT cst;
6836 cst = tree_low_cst (and1, 1);
6837 cst &= (HOST_WIDE_INT) -1
6838 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6839 change = (cst == 0);
6840 #ifdef LOAD_EXTEND_OP
6842 && !flag_syntax_only
6843 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6846 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6847 and0 = fold_convert (uns, and0);
6848 and1 = fold_convert (uns, and1);
6854 tem = build_int_cst_wide (type, TREE_INT_CST_LOW (and1),
6855 TREE_INT_CST_HIGH (and1));
6856 tem = force_fit_type (tem, 0, TREE_OVERFLOW (and1),
6857 TREE_CONSTANT_OVERFLOW (and1));
6858 return fold (build2 (BIT_AND_EXPR, type,
6859 fold_convert (type, and0), tem));
6863 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6864 T2 being pointers to types of the same size. */
6865 if (POINTER_TYPE_P (type)
6866 && BINARY_CLASS_P (arg0)
6867 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6868 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6870 tree arg00 = TREE_OPERAND (arg0, 0);
6872 tree t1 = TREE_TYPE (arg00);
6873 tree tt0 = TREE_TYPE (t0);
6874 tree tt1 = TREE_TYPE (t1);
6875 tree s0 = TYPE_SIZE (tt0);
6876 tree s1 = TYPE_SIZE (tt1);
6878 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6879 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6880 TREE_OPERAND (arg0, 1));
6883 tem = fold_convert_const (code, type, arg0);
6884 return tem ? tem : t;
6886 case VIEW_CONVERT_EXPR:
6887 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
6888 return build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
6892 if (negate_expr_p (arg0))
6893 return fold_convert (type, negate_expr (arg0));
6894 /* Convert - (~A) to A + 1. */
6895 if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == BIT_NOT_EXPR)
6896 return fold (build2 (PLUS_EXPR, type, TREE_OPERAND (arg0, 0),
6897 build_int_cst (type, 1)));
6901 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
6902 return fold_abs_const (arg0, type);
6903 else if (TREE_CODE (arg0) == NEGATE_EXPR)
6904 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
6905 /* Convert fabs((double)float) into (double)fabsf(float). */
6906 else if (TREE_CODE (arg0) == NOP_EXPR
6907 && TREE_CODE (type) == REAL_TYPE)
6909 tree targ0 = strip_float_extensions (arg0);
6911 return fold_convert (type, fold (build1 (ABS_EXPR,
6915 else if (tree_expr_nonnegative_p (arg0))
6918 /* Strip sign ops from argument. */
6919 if (TREE_CODE (type) == REAL_TYPE)
6921 tem = fold_strip_sign_ops (arg0);
6923 return fold (build1 (ABS_EXPR, type, fold_convert (type, tem)));
6928 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6929 return fold_convert (type, arg0);
6930 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6931 return build2 (COMPLEX_EXPR, type,
6932 TREE_OPERAND (arg0, 0),
6933 negate_expr (TREE_OPERAND (arg0, 1)));
6934 else if (TREE_CODE (arg0) == COMPLEX_CST)
6935 return build_complex (type, TREE_REALPART (arg0),
6936 negate_expr (TREE_IMAGPART (arg0)));
6937 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6938 return fold (build2 (TREE_CODE (arg0), type,
6939 fold (build1 (CONJ_EXPR, type,
6940 TREE_OPERAND (arg0, 0))),
6941 fold (build1 (CONJ_EXPR, type,
6942 TREE_OPERAND (arg0, 1)))));
6943 else if (TREE_CODE (arg0) == CONJ_EXPR)
6944 return TREE_OPERAND (arg0, 0);
6948 if (TREE_CODE (arg0) == INTEGER_CST)
6949 return fold_not_const (arg0, type);
6950 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
6951 return TREE_OPERAND (arg0, 0);
6952 /* Convert ~ (-A) to A - 1. */
6953 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
6954 return fold (build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
6955 build_int_cst (type, 1)));
6956 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
6957 else if (INTEGRAL_TYPE_P (type)
6958 && ((TREE_CODE (arg0) == MINUS_EXPR
6959 && integer_onep (TREE_OPERAND (arg0, 1)))
6960 || (TREE_CODE (arg0) == PLUS_EXPR
6961 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
6962 return fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0)));
6965 case TRUTH_NOT_EXPR:
6966 /* The argument to invert_truthvalue must have Boolean type. */
6967 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
6968 arg0 = fold_convert (boolean_type_node, arg0);
6970 /* Note that the operand of this must be an int
6971 and its values must be 0 or 1.
6972 ("true" is a fixed value perhaps depending on the language,
6973 but we don't handle values other than 1 correctly yet.) */
6974 tem = invert_truthvalue (arg0);
6975 /* Avoid infinite recursion. */
6976 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6978 return fold_convert (type, tem);
6981 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6983 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6984 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
6985 TREE_OPERAND (arg0, 1));
6986 else if (TREE_CODE (arg0) == COMPLEX_CST)
6987 return TREE_REALPART (arg0);
6988 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6989 return fold (build2 (TREE_CODE (arg0), type,
6990 fold (build1 (REALPART_EXPR, type,
6991 TREE_OPERAND (arg0, 0))),
6992 fold (build1 (REALPART_EXPR, type,
6993 TREE_OPERAND (arg0, 1)))));
6997 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6998 return fold_convert (type, integer_zero_node);
6999 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7000 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7001 TREE_OPERAND (arg0, 0));
7002 else if (TREE_CODE (arg0) == COMPLEX_CST)
7003 return TREE_IMAGPART (arg0);
7004 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7005 return fold (build2 (TREE_CODE (arg0), type,
7006 fold (build1 (IMAGPART_EXPR, type,
7007 TREE_OPERAND (arg0, 0))),
7008 fold (build1 (IMAGPART_EXPR, type,
7009 TREE_OPERAND (arg0, 1)))));
7014 } /* switch (code) */
7017 /* Fold a binary expression EXPR. Return the folded expression if
7018 folding is successful. Otherwise, return the original
7022 fold_binary (tree expr)
7024 const tree t = expr;
7025 const tree type = TREE_TYPE (expr);
7026 tree t1 = NULL_TREE;
7029 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
7030 enum tree_code code = TREE_CODE (t);
7031 enum tree_code_class kind = TREE_CODE_CLASS (code);
7033 /* WINS will be nonzero when the switch is done
7034 if all operands are constant. */
7038 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7039 && TREE_CODE_LENGTH (code) == 2);
7041 op0 = TREE_OPERAND (t, 0);
7042 op1 = TREE_OPERAND (t, 1);
7043 for (i = 0; i < 2; i++)
7045 tree op = TREE_OPERAND (t, i);
7049 continue; /* Valid for CALL_EXPR, at least. */
7051 /* Strip any conversions that don't change the mode. This is
7052 safe for every expression, except for a comparison expression
7053 because its signedness is derived from its operands. So, in
7054 the latter case, only strip conversions that don't change the
7057 Note that this is done as an internal manipulation within the
7058 constant folder, in order to find the simplest representation
7059 of the arguments so that their form can be studied. In any
7060 cases, the appropriate type conversions should be put back in
7061 the tree that will get out of the constant folder. */
7062 if (kind == tcc_comparison)
7063 STRIP_SIGN_NOPS (op);
7067 if (TREE_CODE (op) == COMPLEX_CST)
7068 subop = TREE_REALPART (op);
7072 if (TREE_CODE (subop) != INTEGER_CST
7073 && TREE_CODE (subop) != REAL_CST)
7074 /* Note that TREE_CONSTANT isn't enough:
7075 static var addresses are constant but we can't
7076 do arithmetic on them. */
7085 /* If this is a commutative operation, and ARG0 is a constant, move it
7086 to ARG1 to reduce the number of tests below. */
7087 if (commutative_tree_code (code)
7088 && tree_swap_operands_p (arg0, arg1, true))
7089 return fold (build2 (code, type, op1, op0));
7091 /* Now WINS is set as described above,
7092 ARG0 is the first operand of EXPR,
7093 and ARG1 is the second operand (if it has more than one operand).
7095 First check for cases where an arithmetic operation is applied to a
7096 compound, conditional, or comparison operation. Push the arithmetic
7097 operation inside the compound or conditional to see if any folding
7098 can then be done. Convert comparison to conditional for this purpose.
7099 The also optimizes non-constant cases that used to be done in
7102 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
7103 one of the operands is a comparison and the other is a comparison, a
7104 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
7105 code below would make the expression more complex. Change it to a
7106 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
7107 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
7109 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
7110 || code == EQ_EXPR || code == NE_EXPR)
7111 && ((truth_value_p (TREE_CODE (arg0))
7112 && (truth_value_p (TREE_CODE (arg1))
7113 || (TREE_CODE (arg1) == BIT_AND_EXPR
7114 && integer_onep (TREE_OPERAND (arg1, 1)))))
7115 || (truth_value_p (TREE_CODE (arg1))
7116 && (truth_value_p (TREE_CODE (arg0))
7117 || (TREE_CODE (arg0) == BIT_AND_EXPR
7118 && integer_onep (TREE_OPERAND (arg0, 1)))))))
7120 tem = fold (build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
7121 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
7123 type, fold_convert (boolean_type_node, arg0),
7124 fold_convert (boolean_type_node, arg1)));
7126 if (code == EQ_EXPR)
7127 tem = invert_truthvalue (tem);
7132 if (TREE_CODE_CLASS (code) == tcc_comparison
7133 && TREE_CODE (arg0) == COMPOUND_EXPR)
7134 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7135 fold (build2 (code, type, TREE_OPERAND (arg0, 1), arg1)));
7136 else if (TREE_CODE_CLASS (code) == tcc_comparison
7137 && TREE_CODE (arg1) == COMPOUND_EXPR)
7138 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
7139 fold (build2 (code, type, arg0, TREE_OPERAND (arg1, 1))));
7140 else if (TREE_CODE_CLASS (code) == tcc_binary
7141 || TREE_CODE_CLASS (code) == tcc_comparison)
7143 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7144 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7145 fold (build2 (code, type, TREE_OPERAND (arg0, 1),
7147 if (TREE_CODE (arg1) == COMPOUND_EXPR
7148 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
7149 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
7150 fold (build2 (code, type,
7151 arg0, TREE_OPERAND (arg1, 1))));
7153 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
7155 tem = fold_binary_op_with_conditional_arg (t, code, arg0, arg1,
7156 /*cond_first_p=*/1);
7157 if (tem != NULL_TREE)
7161 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
7163 tem = fold_binary_op_with_conditional_arg (t, code, arg1, arg0,
7164 /*cond_first_p=*/0);
7165 if (tem != NULL_TREE)
7173 if (TREE_CONSTANT (t) != wins)
7175 tem = copy_node (t);
7176 TREE_CONSTANT (tem) = wins;
7177 TREE_INVARIANT (tem) = wins;
7183 /* A + (-B) -> A - B */
7184 if (TREE_CODE (arg1) == NEGATE_EXPR)
7185 return fold (build2 (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
7186 /* (-A) + B -> B - A */
7187 if (TREE_CODE (arg0) == NEGATE_EXPR
7188 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
7189 return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
7191 if (TREE_CODE (type) == COMPLEX_TYPE)
7193 tem = fold_complex_add (type, arg0, arg1, PLUS_EXPR);
7198 if (! FLOAT_TYPE_P (type))
7200 if (integer_zerop (arg1))
7201 return non_lvalue (fold_convert (type, arg0));
7203 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
7204 with a constant, and the two constants have no bits in common,
7205 we should treat this as a BIT_IOR_EXPR since this may produce more
7207 if (TREE_CODE (arg0) == BIT_AND_EXPR
7208 && TREE_CODE (arg1) == BIT_AND_EXPR
7209 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7210 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7211 && integer_zerop (const_binop (BIT_AND_EXPR,
7212 TREE_OPERAND (arg0, 1),
7213 TREE_OPERAND (arg1, 1), 0)))
7215 code = BIT_IOR_EXPR;
7219 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
7220 (plus (plus (mult) (mult)) (foo)) so that we can
7221 take advantage of the factoring cases below. */
7222 if (((TREE_CODE (arg0) == PLUS_EXPR
7223 || TREE_CODE (arg0) == MINUS_EXPR)
7224 && TREE_CODE (arg1) == MULT_EXPR)
7225 || ((TREE_CODE (arg1) == PLUS_EXPR
7226 || TREE_CODE (arg1) == MINUS_EXPR)
7227 && TREE_CODE (arg0) == MULT_EXPR))
7229 tree parg0, parg1, parg, marg;
7230 enum tree_code pcode;
7232 if (TREE_CODE (arg1) == MULT_EXPR)
7233 parg = arg0, marg = arg1;
7235 parg = arg1, marg = arg0;
7236 pcode = TREE_CODE (parg);
7237 parg0 = TREE_OPERAND (parg, 0);
7238 parg1 = TREE_OPERAND (parg, 1);
7242 if (TREE_CODE (parg0) == MULT_EXPR
7243 && TREE_CODE (parg1) != MULT_EXPR)
7244 return fold (build2 (pcode, type,
7245 fold (build2 (PLUS_EXPR, type,
7246 fold_convert (type, parg0),
7247 fold_convert (type, marg))),
7248 fold_convert (type, parg1)));
7249 if (TREE_CODE (parg0) != MULT_EXPR
7250 && TREE_CODE (parg1) == MULT_EXPR)
7251 return fold (build2 (PLUS_EXPR, type,
7252 fold_convert (type, parg0),
7253 fold (build2 (pcode, type,
7254 fold_convert (type, marg),
7259 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
7261 tree arg00, arg01, arg10, arg11;
7262 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7264 /* (A * C) + (B * C) -> (A+B) * C.
7265 We are most concerned about the case where C is a constant,
7266 but other combinations show up during loop reduction. Since
7267 it is not difficult, try all four possibilities. */
7269 arg00 = TREE_OPERAND (arg0, 0);
7270 arg01 = TREE_OPERAND (arg0, 1);
7271 arg10 = TREE_OPERAND (arg1, 0);
7272 arg11 = TREE_OPERAND (arg1, 1);
7275 if (operand_equal_p (arg01, arg11, 0))
7276 same = arg01, alt0 = arg00, alt1 = arg10;
7277 else if (operand_equal_p (arg00, arg10, 0))
7278 same = arg00, alt0 = arg01, alt1 = arg11;
7279 else if (operand_equal_p (arg00, arg11, 0))
7280 same = arg00, alt0 = arg01, alt1 = arg10;
7281 else if (operand_equal_p (arg01, arg10, 0))
7282 same = arg01, alt0 = arg00, alt1 = arg11;
7284 /* No identical multiplicands; see if we can find a common
7285 power-of-two factor in non-power-of-two multiplies. This
7286 can help in multi-dimensional array access. */
7287 else if (TREE_CODE (arg01) == INTEGER_CST
7288 && TREE_CODE (arg11) == INTEGER_CST
7289 && TREE_INT_CST_HIGH (arg01) == 0
7290 && TREE_INT_CST_HIGH (arg11) == 0)
7292 HOST_WIDE_INT int01, int11, tmp;
7293 int01 = TREE_INT_CST_LOW (arg01);
7294 int11 = TREE_INT_CST_LOW (arg11);
7296 /* Move min of absolute values to int11. */
7297 if ((int01 >= 0 ? int01 : -int01)
7298 < (int11 >= 0 ? int11 : -int11))
7300 tmp = int01, int01 = int11, int11 = tmp;
7301 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7302 alt0 = arg01, arg01 = arg11, arg11 = alt0;
7305 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
7307 alt0 = fold (build2 (MULT_EXPR, type, arg00,
7308 build_int_cst (NULL_TREE,
7316 return fold (build2 (MULT_EXPR, type,
7317 fold (build2 (PLUS_EXPR, type,
7318 fold_convert (type, alt0),
7319 fold_convert (type, alt1))),
7323 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
7324 of the array. Loop optimizer sometimes produce this type of
7326 if (TREE_CODE (arg0) == ADDR_EXPR
7327 && TREE_CODE (arg1) == MULT_EXPR)
7329 tem = try_move_mult_to_index (PLUS_EXPR, arg0, arg1);
7331 return fold_convert (type, fold (tem));
7333 else if (TREE_CODE (arg1) == ADDR_EXPR
7334 && TREE_CODE (arg0) == MULT_EXPR)
7336 tem = try_move_mult_to_index (PLUS_EXPR, arg1, arg0);
7338 return fold_convert (type, fold (tem));
7343 /* See if ARG1 is zero and X + ARG1 reduces to X. */
7344 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
7345 return non_lvalue (fold_convert (type, arg0));
7347 /* Likewise if the operands are reversed. */
7348 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7349 return non_lvalue (fold_convert (type, arg1));
7351 /* Convert X + -C into X - C. */
7352 if (TREE_CODE (arg1) == REAL_CST
7353 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
7355 tem = fold_negate_const (arg1, type);
7356 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
7357 return fold (build2 (MINUS_EXPR, type,
7358 fold_convert (type, arg0),
7359 fold_convert (type, tem)));
7362 /* Convert x+x into x*2.0. */
7363 if (operand_equal_p (arg0, arg1, 0)
7364 && SCALAR_FLOAT_TYPE_P (type))
7365 return fold (build2 (MULT_EXPR, type, arg0,
7366 build_real (type, dconst2)));
7368 /* Convert x*c+x into x*(c+1). */
7369 if (flag_unsafe_math_optimizations
7370 && TREE_CODE (arg0) == MULT_EXPR
7371 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7372 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
7373 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7377 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
7378 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7379 return fold (build2 (MULT_EXPR, type, arg1,
7380 build_real (type, c)));
7383 /* Convert x+x*c into x*(c+1). */
7384 if (flag_unsafe_math_optimizations
7385 && TREE_CODE (arg1) == MULT_EXPR
7386 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
7387 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
7388 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
7392 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
7393 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7394 return fold (build2 (MULT_EXPR, type, arg0,
7395 build_real (type, c)));
7398 /* Convert x*c1+x*c2 into x*(c1+c2). */
7399 if (flag_unsafe_math_optimizations
7400 && TREE_CODE (arg0) == MULT_EXPR
7401 && TREE_CODE (arg1) == MULT_EXPR
7402 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7403 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
7404 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
7405 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
7406 && operand_equal_p (TREE_OPERAND (arg0, 0),
7407 TREE_OPERAND (arg1, 0), 0))
7409 REAL_VALUE_TYPE c1, c2;
7411 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
7412 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
7413 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
7414 return fold (build2 (MULT_EXPR, type,
7415 TREE_OPERAND (arg0, 0),
7416 build_real (type, c1)));
7418 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
7419 if (flag_unsafe_math_optimizations
7420 && TREE_CODE (arg1) == PLUS_EXPR
7421 && TREE_CODE (arg0) != MULT_EXPR)
7423 tree tree10 = TREE_OPERAND (arg1, 0);
7424 tree tree11 = TREE_OPERAND (arg1, 1);
7425 if (TREE_CODE (tree11) == MULT_EXPR
7426 && TREE_CODE (tree10) == MULT_EXPR)
7429 tree0 = fold (build2 (PLUS_EXPR, type, arg0, tree10));
7430 return fold (build2 (PLUS_EXPR, type, tree0, tree11));
7433 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
7434 if (flag_unsafe_math_optimizations
7435 && TREE_CODE (arg0) == PLUS_EXPR
7436 && TREE_CODE (arg1) != MULT_EXPR)
7438 tree tree00 = TREE_OPERAND (arg0, 0);
7439 tree tree01 = TREE_OPERAND (arg0, 1);
7440 if (TREE_CODE (tree01) == MULT_EXPR
7441 && TREE_CODE (tree00) == MULT_EXPR)
7444 tree0 = fold (build2 (PLUS_EXPR, type, tree01, arg1));
7445 return fold (build2 (PLUS_EXPR, type, tree00, tree0));
7451 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
7452 is a rotate of A by C1 bits. */
7453 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
7454 is a rotate of A by B bits. */
7456 enum tree_code code0, code1;
7457 code0 = TREE_CODE (arg0);
7458 code1 = TREE_CODE (arg1);
7459 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
7460 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
7461 && operand_equal_p (TREE_OPERAND (arg0, 0),
7462 TREE_OPERAND (arg1, 0), 0)
7463 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7465 tree tree01, tree11;
7466 enum tree_code code01, code11;
7468 tree01 = TREE_OPERAND (arg0, 1);
7469 tree11 = TREE_OPERAND (arg1, 1);
7470 STRIP_NOPS (tree01);
7471 STRIP_NOPS (tree11);
7472 code01 = TREE_CODE (tree01);
7473 code11 = TREE_CODE (tree11);
7474 if (code01 == INTEGER_CST
7475 && code11 == INTEGER_CST
7476 && TREE_INT_CST_HIGH (tree01) == 0
7477 && TREE_INT_CST_HIGH (tree11) == 0
7478 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
7479 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
7480 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
7481 code0 == LSHIFT_EXPR ? tree01 : tree11);
7482 else if (code11 == MINUS_EXPR)
7484 tree tree110, tree111;
7485 tree110 = TREE_OPERAND (tree11, 0);
7486 tree111 = TREE_OPERAND (tree11, 1);
7487 STRIP_NOPS (tree110);
7488 STRIP_NOPS (tree111);
7489 if (TREE_CODE (tree110) == INTEGER_CST
7490 && 0 == compare_tree_int (tree110,
7492 (TREE_TYPE (TREE_OPERAND
7494 && operand_equal_p (tree01, tree111, 0))
7495 return build2 ((code0 == LSHIFT_EXPR
7498 type, TREE_OPERAND (arg0, 0), tree01);
7500 else if (code01 == MINUS_EXPR)
7502 tree tree010, tree011;
7503 tree010 = TREE_OPERAND (tree01, 0);
7504 tree011 = TREE_OPERAND (tree01, 1);
7505 STRIP_NOPS (tree010);
7506 STRIP_NOPS (tree011);
7507 if (TREE_CODE (tree010) == INTEGER_CST
7508 && 0 == compare_tree_int (tree010,
7510 (TREE_TYPE (TREE_OPERAND
7512 && operand_equal_p (tree11, tree011, 0))
7513 return build2 ((code0 != LSHIFT_EXPR
7516 type, TREE_OPERAND (arg0, 0), tree11);
7522 /* In most languages, can't associate operations on floats through
7523 parentheses. Rather than remember where the parentheses were, we
7524 don't associate floats at all, unless the user has specified
7525 -funsafe-math-optimizations. */
7528 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7530 tree var0, con0, lit0, minus_lit0;
7531 tree var1, con1, lit1, minus_lit1;
7533 /* Split both trees into variables, constants, and literals. Then
7534 associate each group together, the constants with literals,
7535 then the result with variables. This increases the chances of
7536 literals being recombined later and of generating relocatable
7537 expressions for the sum of a constant and literal. */
7538 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
7539 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
7540 code == MINUS_EXPR);
7542 /* Only do something if we found more than two objects. Otherwise,
7543 nothing has changed and we risk infinite recursion. */
7544 if (2 < ((var0 != 0) + (var1 != 0)
7545 + (con0 != 0) + (con1 != 0)
7546 + (lit0 != 0) + (lit1 != 0)
7547 + (minus_lit0 != 0) + (minus_lit1 != 0)))
7549 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
7550 if (code == MINUS_EXPR)
7553 var0 = associate_trees (var0, var1, code, type);
7554 con0 = associate_trees (con0, con1, code, type);
7555 lit0 = associate_trees (lit0, lit1, code, type);
7556 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
7558 /* Preserve the MINUS_EXPR if the negative part of the literal is
7559 greater than the positive part. Otherwise, the multiplicative
7560 folding code (i.e extract_muldiv) may be fooled in case
7561 unsigned constants are subtracted, like in the following
7562 example: ((X*2 + 4) - 8U)/2. */
7563 if (minus_lit0 && lit0)
7565 if (TREE_CODE (lit0) == INTEGER_CST
7566 && TREE_CODE (minus_lit0) == INTEGER_CST
7567 && tree_int_cst_lt (lit0, minus_lit0))
7569 minus_lit0 = associate_trees (minus_lit0, lit0,
7575 lit0 = associate_trees (lit0, minus_lit0,
7583 return fold_convert (type,
7584 associate_trees (var0, minus_lit0,
7588 con0 = associate_trees (con0, minus_lit0,
7590 return fold_convert (type,
7591 associate_trees (var0, con0,
7596 con0 = associate_trees (con0, lit0, code, type);
7597 return fold_convert (type, associate_trees (var0, con0,
7604 t1 = const_binop (code, arg0, arg1, 0);
7605 if (t1 != NULL_TREE)
7607 /* The return value should always have
7608 the same type as the original expression. */
7609 if (TREE_TYPE (t1) != type)
7610 t1 = fold_convert (type, t1);
7617 /* A - (-B) -> A + B */
7618 if (TREE_CODE (arg1) == NEGATE_EXPR)
7619 return fold (build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
7620 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
7621 if (TREE_CODE (arg0) == NEGATE_EXPR
7622 && (FLOAT_TYPE_P (type)
7623 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
7624 && negate_expr_p (arg1)
7625 && reorder_operands_p (arg0, arg1))
7626 return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
7627 TREE_OPERAND (arg0, 0)));
7629 if (TREE_CODE (type) == COMPLEX_TYPE)
7631 tem = fold_complex_add (type, arg0, arg1, MINUS_EXPR);
7636 if (! FLOAT_TYPE_P (type))
7638 if (! wins && integer_zerop (arg0))
7639 return negate_expr (fold_convert (type, arg1));
7640 if (integer_zerop (arg1))
7641 return non_lvalue (fold_convert (type, arg0));
7643 /* Fold A - (A & B) into ~B & A. */
7644 if (!TREE_SIDE_EFFECTS (arg0)
7645 && TREE_CODE (arg1) == BIT_AND_EXPR)
7647 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
7648 return fold (build2 (BIT_AND_EXPR, type,
7649 fold (build1 (BIT_NOT_EXPR, type,
7650 TREE_OPERAND (arg1, 0))),
7652 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7653 return fold (build2 (BIT_AND_EXPR, type,
7654 fold (build1 (BIT_NOT_EXPR, type,
7655 TREE_OPERAND (arg1, 1))),
7659 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
7660 any power of 2 minus 1. */
7661 if (TREE_CODE (arg0) == BIT_AND_EXPR
7662 && TREE_CODE (arg1) == BIT_AND_EXPR
7663 && operand_equal_p (TREE_OPERAND (arg0, 0),
7664 TREE_OPERAND (arg1, 0), 0))
7666 tree mask0 = TREE_OPERAND (arg0, 1);
7667 tree mask1 = TREE_OPERAND (arg1, 1);
7668 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
7670 if (operand_equal_p (tem, mask1, 0))
7672 tem = fold (build2 (BIT_XOR_EXPR, type,
7673 TREE_OPERAND (arg0, 0), mask1));
7674 return fold (build2 (MINUS_EXPR, type, tem, mask1));
7679 /* See if ARG1 is zero and X - ARG1 reduces to X. */
7680 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
7681 return non_lvalue (fold_convert (type, arg0));
7683 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
7684 ARG0 is zero and X + ARG0 reduces to X, since that would mean
7685 (-ARG1 + ARG0) reduces to -ARG1. */
7686 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7687 return negate_expr (fold_convert (type, arg1));
7689 /* Fold &x - &x. This can happen from &x.foo - &x.
7690 This is unsafe for certain floats even in non-IEEE formats.
7691 In IEEE, it is unsafe because it does wrong for NaNs.
7692 Also note that operand_equal_p is always false if an operand
7695 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
7696 && operand_equal_p (arg0, arg1, 0))
7697 return fold_convert (type, integer_zero_node);
7699 /* A - B -> A + (-B) if B is easily negatable. */
7700 if (!wins && negate_expr_p (arg1)
7701 && ((FLOAT_TYPE_P (type)
7702 /* Avoid this transformation if B is a positive REAL_CST. */
7703 && (TREE_CODE (arg1) != REAL_CST
7704 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
7705 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
7706 return fold (build2 (PLUS_EXPR, type, arg0, negate_expr (arg1)));
7708 /* Try folding difference of addresses. */
7712 if ((TREE_CODE (arg0) == ADDR_EXPR
7713 || TREE_CODE (arg1) == ADDR_EXPR)
7714 && ptr_difference_const (arg0, arg1, &diff))
7715 return build_int_cst_type (type, diff);
7718 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
7719 of the array. Loop optimizer sometimes produce this type of
7721 if (TREE_CODE (arg0) == ADDR_EXPR
7722 && TREE_CODE (arg1) == MULT_EXPR)
7724 tem = try_move_mult_to_index (MINUS_EXPR, arg0, arg1);
7726 return fold_convert (type, fold (tem));
7729 if (TREE_CODE (arg0) == MULT_EXPR
7730 && TREE_CODE (arg1) == MULT_EXPR
7731 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7733 /* (A * C) - (B * C) -> (A-B) * C. */
7734 if (operand_equal_p (TREE_OPERAND (arg0, 1),
7735 TREE_OPERAND (arg1, 1), 0))
7736 return fold (build2 (MULT_EXPR, type,
7737 fold (build2 (MINUS_EXPR, type,
7738 TREE_OPERAND (arg0, 0),
7739 TREE_OPERAND (arg1, 0))),
7740 TREE_OPERAND (arg0, 1)));
7741 /* (A * C1) - (A * C2) -> A * (C1-C2). */
7742 if (operand_equal_p (TREE_OPERAND (arg0, 0),
7743 TREE_OPERAND (arg1, 0), 0))
7744 return fold (build2 (MULT_EXPR, type,
7745 TREE_OPERAND (arg0, 0),
7746 fold (build2 (MINUS_EXPR, type,
7747 TREE_OPERAND (arg0, 1),
7748 TREE_OPERAND (arg1, 1)))));
7754 /* (-A) * (-B) -> A * B */
7755 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7756 return fold (build2 (MULT_EXPR, type,
7757 TREE_OPERAND (arg0, 0),
7758 negate_expr (arg1)));
7759 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7760 return fold (build2 (MULT_EXPR, type,
7762 TREE_OPERAND (arg1, 0)));
7764 if (TREE_CODE (type) == COMPLEX_TYPE)
7766 tem = fold_complex_mult (type, arg0, arg1);
7771 if (! FLOAT_TYPE_P (type))
7773 if (integer_zerop (arg1))
7774 return omit_one_operand (type, arg1, arg0);
7775 if (integer_onep (arg1))
7776 return non_lvalue (fold_convert (type, arg0));
7778 /* (a * (1 << b)) is (a << b) */
7779 if (TREE_CODE (arg1) == LSHIFT_EXPR
7780 && integer_onep (TREE_OPERAND (arg1, 0)))
7781 return fold (build2 (LSHIFT_EXPR, type, arg0,
7782 TREE_OPERAND (arg1, 1)));
7783 if (TREE_CODE (arg0) == LSHIFT_EXPR
7784 && integer_onep (TREE_OPERAND (arg0, 0)))
7785 return fold (build2 (LSHIFT_EXPR, type, arg1,
7786 TREE_OPERAND (arg0, 1)));
7788 if (TREE_CODE (arg1) == INTEGER_CST
7789 && 0 != (tem = extract_muldiv (op0,
7790 fold_convert (type, arg1),
7792 return fold_convert (type, tem);
7797 /* Maybe fold x * 0 to 0. The expressions aren't the same
7798 when x is NaN, since x * 0 is also NaN. Nor are they the
7799 same in modes with signed zeros, since multiplying a
7800 negative value by 0 gives -0, not +0. */
7801 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
7802 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
7803 && real_zerop (arg1))
7804 return omit_one_operand (type, arg1, arg0);
7805 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7806 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7807 && real_onep (arg1))
7808 return non_lvalue (fold_convert (type, arg0));
7810 /* Transform x * -1.0 into -x. */
7811 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7812 && real_minus_onep (arg1))
7813 return fold_convert (type, negate_expr (arg0));
7815 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7816 if (flag_unsafe_math_optimizations
7817 && TREE_CODE (arg0) == RDIV_EXPR
7818 && TREE_CODE (arg1) == REAL_CST
7819 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
7821 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
7824 return fold (build2 (RDIV_EXPR, type, tem,
7825 TREE_OPERAND (arg0, 1)));
7828 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
7829 if (operand_equal_p (arg0, arg1, 0))
7831 tree tem = fold_strip_sign_ops (arg0);
7832 if (tem != NULL_TREE)
7834 tem = fold_convert (type, tem);
7835 return fold (build2 (MULT_EXPR, type, tem, tem));
7839 if (flag_unsafe_math_optimizations)
7841 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7842 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7844 /* Optimizations of root(...)*root(...). */
7845 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
7847 tree rootfn, arg, arglist;
7848 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7849 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7851 /* Optimize sqrt(x)*sqrt(x) as x. */
7852 if (BUILTIN_SQRT_P (fcode0)
7853 && operand_equal_p (arg00, arg10, 0)
7854 && ! HONOR_SNANS (TYPE_MODE (type)))
7857 /* Optimize root(x)*root(y) as root(x*y). */
7858 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7859 arg = fold (build2 (MULT_EXPR, type, arg00, arg10));
7860 arglist = build_tree_list (NULL_TREE, arg);
7861 return build_function_call_expr (rootfn, arglist);
7864 /* Optimize expN(x)*expN(y) as expN(x+y). */
7865 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
7867 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7868 tree arg = build2 (PLUS_EXPR, type,
7869 TREE_VALUE (TREE_OPERAND (arg0, 1)),
7870 TREE_VALUE (TREE_OPERAND (arg1, 1)));
7871 tree arglist = build_tree_list (NULL_TREE, fold (arg));
7872 return build_function_call_expr (expfn, arglist);
7875 /* Optimizations of pow(...)*pow(...). */
7876 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
7877 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
7878 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
7880 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7881 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7883 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7884 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7887 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7888 if (operand_equal_p (arg01, arg11, 0))
7890 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7891 tree arg = build2 (MULT_EXPR, type, arg00, arg10);
7892 tree arglist = tree_cons (NULL_TREE, fold (arg),
7893 build_tree_list (NULL_TREE,
7895 return build_function_call_expr (powfn, arglist);
7898 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7899 if (operand_equal_p (arg00, arg10, 0))
7901 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7902 tree arg = fold (build2 (PLUS_EXPR, type, arg01, arg11));
7903 tree arglist = tree_cons (NULL_TREE, arg00,
7904 build_tree_list (NULL_TREE,
7906 return build_function_call_expr (powfn, arglist);
7910 /* Optimize tan(x)*cos(x) as sin(x). */
7911 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
7912 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
7913 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
7914 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
7915 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
7916 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
7917 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7918 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7920 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
7922 if (sinfn != NULL_TREE)
7923 return build_function_call_expr (sinfn,
7924 TREE_OPERAND (arg0, 1));
7927 /* Optimize x*pow(x,c) as pow(x,c+1). */
7928 if (fcode1 == BUILT_IN_POW
7929 || fcode1 == BUILT_IN_POWF
7930 || fcode1 == BUILT_IN_POWL)
7932 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7933 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7935 if (TREE_CODE (arg11) == REAL_CST
7936 && ! TREE_CONSTANT_OVERFLOW (arg11)
7937 && operand_equal_p (arg0, arg10, 0))
7939 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7943 c = TREE_REAL_CST (arg11);
7944 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7945 arg = build_real (type, c);
7946 arglist = build_tree_list (NULL_TREE, arg);
7947 arglist = tree_cons (NULL_TREE, arg0, arglist);
7948 return build_function_call_expr (powfn, arglist);
7952 /* Optimize pow(x,c)*x as pow(x,c+1). */
7953 if (fcode0 == BUILT_IN_POW
7954 || fcode0 == BUILT_IN_POWF
7955 || fcode0 == BUILT_IN_POWL)
7957 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7958 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7960 if (TREE_CODE (arg01) == REAL_CST
7961 && ! TREE_CONSTANT_OVERFLOW (arg01)
7962 && operand_equal_p (arg1, arg00, 0))
7964 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7968 c = TREE_REAL_CST (arg01);
7969 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7970 arg = build_real (type, c);
7971 arglist = build_tree_list (NULL_TREE, arg);
7972 arglist = tree_cons (NULL_TREE, arg1, arglist);
7973 return build_function_call_expr (powfn, arglist);
7977 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
7979 && operand_equal_p (arg0, arg1, 0))
7981 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
7985 tree arg = build_real (type, dconst2);
7986 tree arglist = build_tree_list (NULL_TREE, arg);
7987 arglist = tree_cons (NULL_TREE, arg0, arglist);
7988 return build_function_call_expr (powfn, arglist);
7997 if (integer_all_onesp (arg1))
7998 return omit_one_operand (type, arg1, arg0);
7999 if (integer_zerop (arg1))
8000 return non_lvalue (fold_convert (type, arg0));
8001 if (operand_equal_p (arg0, arg1, 0))
8002 return non_lvalue (fold_convert (type, arg0));
8005 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8006 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8008 t1 = build_int_cst (type, -1);
8009 t1 = force_fit_type (t1, 0, false, false);
8010 return omit_one_operand (type, t1, arg1);
8014 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8015 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8017 t1 = build_int_cst (type, -1);
8018 t1 = force_fit_type (t1, 0, false, false);
8019 return omit_one_operand (type, t1, arg0);
8022 t1 = distribute_bit_expr (code, type, arg0, arg1);
8023 if (t1 != NULL_TREE)
8026 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
8028 This results in more efficient code for machines without a NAND
8029 instruction. Combine will canonicalize to the first form
8030 which will allow use of NAND instructions provided by the
8031 backend if they exist. */
8032 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8033 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8035 return fold (build1 (BIT_NOT_EXPR, type,
8036 build2 (BIT_AND_EXPR, type,
8037 TREE_OPERAND (arg0, 0),
8038 TREE_OPERAND (arg1, 0))));
8041 /* See if this can be simplified into a rotate first. If that
8042 is unsuccessful continue in the association code. */
8046 if (integer_zerop (arg1))
8047 return non_lvalue (fold_convert (type, arg0));
8048 if (integer_all_onesp (arg1))
8049 return fold (build1 (BIT_NOT_EXPR, type, arg0));
8050 if (operand_equal_p (arg0, arg1, 0))
8051 return omit_one_operand (type, integer_zero_node, arg0);
8054 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8055 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8057 t1 = build_int_cst (type, -1);
8058 t1 = force_fit_type (t1, 0, false, false);
8059 return omit_one_operand (type, t1, arg1);
8063 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8064 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8066 t1 = build_int_cst (type, -1);
8067 t1 = force_fit_type (t1, 0, false, false);
8068 return omit_one_operand (type, t1, arg0);
8071 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
8072 with a constant, and the two constants have no bits in common,
8073 we should treat this as a BIT_IOR_EXPR since this may produce more
8075 if (TREE_CODE (arg0) == BIT_AND_EXPR
8076 && TREE_CODE (arg1) == BIT_AND_EXPR
8077 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8078 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8079 && integer_zerop (const_binop (BIT_AND_EXPR,
8080 TREE_OPERAND (arg0, 1),
8081 TREE_OPERAND (arg1, 1), 0)))
8083 code = BIT_IOR_EXPR;
8087 /* See if this can be simplified into a rotate first. If that
8088 is unsuccessful continue in the association code. */
8092 if (integer_all_onesp (arg1))
8093 return non_lvalue (fold_convert (type, arg0));
8094 if (integer_zerop (arg1))
8095 return omit_one_operand (type, arg1, arg0);
8096 if (operand_equal_p (arg0, arg1, 0))
8097 return non_lvalue (fold_convert (type, arg0));
8099 /* ~X & X is always zero. */
8100 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8101 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8102 return omit_one_operand (type, integer_zero_node, arg1);
8104 /* X & ~X is always zero. */
8105 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8106 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8107 return omit_one_operand (type, integer_zero_node, arg0);
8109 t1 = distribute_bit_expr (code, type, arg0, arg1);
8110 if (t1 != NULL_TREE)
8112 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
8113 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
8114 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
8117 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
8119 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
8120 && (~TREE_INT_CST_LOW (arg1)
8121 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
8122 return fold_convert (type, TREE_OPERAND (arg0, 0));
8125 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
8127 This results in more efficient code for machines without a NOR
8128 instruction. Combine will canonicalize to the first form
8129 which will allow use of NOR instructions provided by the
8130 backend if they exist. */
8131 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8132 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8134 return fold (build1 (BIT_NOT_EXPR, type,
8135 build2 (BIT_IOR_EXPR, type,
8136 TREE_OPERAND (arg0, 0),
8137 TREE_OPERAND (arg1, 0))));
8143 /* Don't touch a floating-point divide by zero unless the mode
8144 of the constant can represent infinity. */
8145 if (TREE_CODE (arg1) == REAL_CST
8146 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
8147 && real_zerop (arg1))
8150 /* (-A) / (-B) -> A / B */
8151 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
8152 return fold (build2 (RDIV_EXPR, type,
8153 TREE_OPERAND (arg0, 0),
8154 negate_expr (arg1)));
8155 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
8156 return fold (build2 (RDIV_EXPR, type,
8158 TREE_OPERAND (arg1, 0)));
8160 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
8161 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
8162 && real_onep (arg1))
8163 return non_lvalue (fold_convert (type, arg0));
8165 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
8166 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
8167 && real_minus_onep (arg1))
8168 return non_lvalue (fold_convert (type, negate_expr (arg0)));
8170 /* If ARG1 is a constant, we can convert this to a multiply by the
8171 reciprocal. This does not have the same rounding properties,
8172 so only do this if -funsafe-math-optimizations. We can actually
8173 always safely do it if ARG1 is a power of two, but it's hard to
8174 tell if it is or not in a portable manner. */
8175 if (TREE_CODE (arg1) == REAL_CST)
8177 if (flag_unsafe_math_optimizations
8178 && 0 != (tem = const_binop (code, build_real (type, dconst1),
8180 return fold (build2 (MULT_EXPR, type, arg0, tem));
8181 /* Find the reciprocal if optimizing and the result is exact. */
8185 r = TREE_REAL_CST (arg1);
8186 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
8188 tem = build_real (type, r);
8189 return fold (build2 (MULT_EXPR, type, arg0, tem));
8193 /* Convert A/B/C to A/(B*C). */
8194 if (flag_unsafe_math_optimizations
8195 && TREE_CODE (arg0) == RDIV_EXPR)
8196 return fold (build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
8197 fold (build2 (MULT_EXPR, type,
8198 TREE_OPERAND (arg0, 1), arg1))));
8200 /* Convert A/(B/C) to (A/B)*C. */
8201 if (flag_unsafe_math_optimizations
8202 && TREE_CODE (arg1) == RDIV_EXPR)
8203 return fold (build2 (MULT_EXPR, type,
8204 fold (build2 (RDIV_EXPR, type, arg0,
8205 TREE_OPERAND (arg1, 0))),
8206 TREE_OPERAND (arg1, 1)));
8208 /* Convert C1/(X*C2) into (C1/C2)/X. */
8209 if (flag_unsafe_math_optimizations
8210 && TREE_CODE (arg1) == MULT_EXPR
8211 && TREE_CODE (arg0) == REAL_CST
8212 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
8214 tree tem = const_binop (RDIV_EXPR, arg0,
8215 TREE_OPERAND (arg1, 1), 0);
8217 return fold (build2 (RDIV_EXPR, type, tem,
8218 TREE_OPERAND (arg1, 0)));
8221 if (TREE_CODE (type) == COMPLEX_TYPE)
8223 tem = fold_complex_div (type, arg0, arg1, code);
8228 if (flag_unsafe_math_optimizations)
8230 enum built_in_function fcode = builtin_mathfn_code (arg1);
8231 /* Optimize x/expN(y) into x*expN(-y). */
8232 if (BUILTIN_EXPONENT_P (fcode))
8234 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8235 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
8236 tree arglist = build_tree_list (NULL_TREE,
8237 fold_convert (type, arg));
8238 arg1 = build_function_call_expr (expfn, arglist);
8239 return fold (build2 (MULT_EXPR, type, arg0, arg1));
8242 /* Optimize x/pow(y,z) into x*pow(y,-z). */
8243 if (fcode == BUILT_IN_POW
8244 || fcode == BUILT_IN_POWF
8245 || fcode == BUILT_IN_POWL)
8247 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8248 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
8249 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
8250 tree neg11 = fold_convert (type, negate_expr (arg11));
8251 tree arglist = tree_cons(NULL_TREE, arg10,
8252 build_tree_list (NULL_TREE, neg11));
8253 arg1 = build_function_call_expr (powfn, arglist);
8254 return fold (build2 (MULT_EXPR, type, arg0, arg1));
8258 if (flag_unsafe_math_optimizations)
8260 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
8261 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
8263 /* Optimize sin(x)/cos(x) as tan(x). */
8264 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
8265 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
8266 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
8267 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8268 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8270 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
8272 if (tanfn != NULL_TREE)
8273 return build_function_call_expr (tanfn,
8274 TREE_OPERAND (arg0, 1));
8277 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
8278 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
8279 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
8280 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
8281 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8282 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8284 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
8286 if (tanfn != NULL_TREE)
8288 tree tmp = TREE_OPERAND (arg0, 1);
8289 tmp = build_function_call_expr (tanfn, tmp);
8290 return fold (build2 (RDIV_EXPR, type,
8291 build_real (type, dconst1), tmp));
8295 /* Optimize pow(x,c)/x as pow(x,c-1). */
8296 if (fcode0 == BUILT_IN_POW
8297 || fcode0 == BUILT_IN_POWF
8298 || fcode0 == BUILT_IN_POWL)
8300 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
8301 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
8302 if (TREE_CODE (arg01) == REAL_CST
8303 && ! TREE_CONSTANT_OVERFLOW (arg01)
8304 && operand_equal_p (arg1, arg00, 0))
8306 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8310 c = TREE_REAL_CST (arg01);
8311 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
8312 arg = build_real (type, c);
8313 arglist = build_tree_list (NULL_TREE, arg);
8314 arglist = tree_cons (NULL_TREE, arg1, arglist);
8315 return build_function_call_expr (powfn, arglist);
8321 case TRUNC_DIV_EXPR:
8322 case ROUND_DIV_EXPR:
8323 case FLOOR_DIV_EXPR:
8325 case EXACT_DIV_EXPR:
8326 if (integer_onep (arg1))
8327 return non_lvalue (fold_convert (type, arg0));
8328 if (integer_zerop (arg1))
8331 if (!TYPE_UNSIGNED (type)
8332 && TREE_CODE (arg1) == INTEGER_CST
8333 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
8334 && TREE_INT_CST_HIGH (arg1) == -1)
8335 return fold_convert (type, negate_expr (arg0));
8337 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
8338 operation, EXACT_DIV_EXPR.
8340 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
8341 At one time others generated faster code, it's not clear if they do
8342 after the last round to changes to the DIV code in expmed.c. */
8343 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
8344 && multiple_of_p (type, arg0, arg1))
8345 return fold (build2 (EXACT_DIV_EXPR, type, arg0, arg1));
8347 if (TREE_CODE (arg1) == INTEGER_CST
8348 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE)))
8349 return fold_convert (type, tem);
8351 if (TREE_CODE (type) == COMPLEX_TYPE)
8353 tem = fold_complex_div (type, arg0, arg1, code);
8360 case FLOOR_MOD_EXPR:
8361 case ROUND_MOD_EXPR:
8362 case TRUNC_MOD_EXPR:
8363 /* X % 1 is always zero, but be sure to preserve any side
8365 if (integer_onep (arg1))
8366 return omit_one_operand (type, integer_zero_node, arg0);
8368 /* X % 0, return X % 0 unchanged so that we can get the
8369 proper warnings and errors. */
8370 if (integer_zerop (arg1))
8373 /* 0 % X is always zero, but be sure to preserve any side
8374 effects in X. Place this after checking for X == 0. */
8375 if (integer_zerop (arg0))
8376 return omit_one_operand (type, integer_zero_node, arg1);
8378 /* X % -1 is zero. */
8379 if (!TYPE_UNSIGNED (type)
8380 && TREE_CODE (arg1) == INTEGER_CST
8381 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
8382 && TREE_INT_CST_HIGH (arg1) == -1)
8383 return omit_one_operand (type, integer_zero_node, arg0);
8385 /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
8386 BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
8387 if (code == TRUNC_MOD_EXPR
8388 && TYPE_UNSIGNED (type)
8389 && integer_pow2p (arg1))
8391 unsigned HOST_WIDE_INT high, low;
8395 l = tree_log2 (arg1);
8396 if (l >= HOST_BITS_PER_WIDE_INT)
8398 high = ((unsigned HOST_WIDE_INT) 1
8399 << (l - HOST_BITS_PER_WIDE_INT)) - 1;
8405 low = ((unsigned HOST_WIDE_INT) 1 << l) - 1;
8408 mask = build_int_cst_wide (type, low, high);
8409 return fold (build2 (BIT_AND_EXPR, type,
8410 fold_convert (type, arg0), mask));
8413 /* X % -C is the same as X % C. */
8414 if (code == TRUNC_MOD_EXPR
8415 && !TYPE_UNSIGNED (type)
8416 && TREE_CODE (arg1) == INTEGER_CST
8417 && TREE_INT_CST_HIGH (arg1) < 0
8419 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
8420 && !sign_bit_p (arg1, arg1))
8421 return fold (build2 (code, type, fold_convert (type, arg0),
8422 fold_convert (type, negate_expr (arg1))));
8424 /* X % -Y is the same as X % Y. */
8425 if (code == TRUNC_MOD_EXPR
8426 && !TYPE_UNSIGNED (type)
8427 && TREE_CODE (arg1) == NEGATE_EXPR
8429 return fold (build2 (code, type, fold_convert (type, arg0),
8430 fold_convert (type, TREE_OPERAND (arg1, 0))));
8432 if (TREE_CODE (arg1) == INTEGER_CST
8433 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE)))
8434 return fold_convert (type, tem);
8440 if (integer_all_onesp (arg0))
8441 return omit_one_operand (type, arg0, arg1);
8445 /* Optimize -1 >> x for arithmetic right shifts. */
8446 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
8447 return omit_one_operand (type, arg0, arg1);
8448 /* ... fall through ... */
8452 if (integer_zerop (arg1))
8453 return non_lvalue (fold_convert (type, arg0));
8454 if (integer_zerop (arg0))
8455 return omit_one_operand (type, arg0, arg1);
8457 /* Since negative shift count is not well-defined,
8458 don't try to compute it in the compiler. */
8459 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
8461 /* Rewrite an LROTATE_EXPR by a constant into an
8462 RROTATE_EXPR by a new constant. */
8463 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
8465 tree tem = build_int_cst (NULL_TREE,
8466 GET_MODE_BITSIZE (TYPE_MODE (type)));
8467 tem = fold_convert (TREE_TYPE (arg1), tem);
8468 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
8469 return fold (build2 (RROTATE_EXPR, type, arg0, tem));
8472 /* If we have a rotate of a bit operation with the rotate count and
8473 the second operand of the bit operation both constant,
8474 permute the two operations. */
8475 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8476 && (TREE_CODE (arg0) == BIT_AND_EXPR
8477 || TREE_CODE (arg0) == BIT_IOR_EXPR
8478 || TREE_CODE (arg0) == BIT_XOR_EXPR)
8479 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8480 return fold (build2 (TREE_CODE (arg0), type,
8481 fold (build2 (code, type,
8482 TREE_OPERAND (arg0, 0), arg1)),
8483 fold (build2 (code, type,
8484 TREE_OPERAND (arg0, 1), arg1))));
8486 /* Two consecutive rotates adding up to the width of the mode can
8488 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8489 && TREE_CODE (arg0) == RROTATE_EXPR
8490 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8491 && TREE_INT_CST_HIGH (arg1) == 0
8492 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
8493 && ((TREE_INT_CST_LOW (arg1)
8494 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
8495 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
8496 return TREE_OPERAND (arg0, 0);
8501 if (operand_equal_p (arg0, arg1, 0))
8502 return omit_one_operand (type, arg0, arg1);
8503 if (INTEGRAL_TYPE_P (type)
8504 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
8505 return omit_one_operand (type, arg1, arg0);
8509 if (operand_equal_p (arg0, arg1, 0))
8510 return omit_one_operand (type, arg0, arg1);
8511 if (INTEGRAL_TYPE_P (type)
8512 && TYPE_MAX_VALUE (type)
8513 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
8514 return omit_one_operand (type, arg1, arg0);
8517 case TRUTH_ANDIF_EXPR:
8518 /* Note that the operands of this must be ints
8519 and their values must be 0 or 1.
8520 ("true" is a fixed value perhaps depending on the language.) */
8521 /* If first arg is constant zero, return it. */
8522 if (integer_zerop (arg0))
8523 return fold_convert (type, arg0);
8524 case TRUTH_AND_EXPR:
8525 /* If either arg is constant true, drop it. */
8526 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8527 return non_lvalue (fold_convert (type, arg1));
8528 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
8529 /* Preserve sequence points. */
8530 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8531 return non_lvalue (fold_convert (type, arg0));
8532 /* If second arg is constant zero, result is zero, but first arg
8533 must be evaluated. */
8534 if (integer_zerop (arg1))
8535 return omit_one_operand (type, arg1, arg0);
8536 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
8537 case will be handled here. */
8538 if (integer_zerop (arg0))
8539 return omit_one_operand (type, arg0, arg1);
8541 /* !X && X is always false. */
8542 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8543 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8544 return omit_one_operand (type, integer_zero_node, arg1);
8545 /* X && !X is always false. */
8546 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8547 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8548 return omit_one_operand (type, integer_zero_node, arg0);
8550 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
8551 means A >= Y && A != MAX, but in this case we know that
8554 if (!TREE_SIDE_EFFECTS (arg0)
8555 && !TREE_SIDE_EFFECTS (arg1))
8557 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
8559 return fold (build2 (code, type, tem, arg1));
8561 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
8563 return fold (build2 (code, type, arg0, tem));
8567 /* We only do these simplifications if we are optimizing. */
8571 /* Check for things like (A || B) && (A || C). We can convert this
8572 to A || (B && C). Note that either operator can be any of the four
8573 truth and/or operations and the transformation will still be
8574 valid. Also note that we only care about order for the
8575 ANDIF and ORIF operators. If B contains side effects, this
8576 might change the truth-value of A. */
8577 if (TREE_CODE (arg0) == TREE_CODE (arg1)
8578 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
8579 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
8580 || TREE_CODE (arg0) == TRUTH_AND_EXPR
8581 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
8582 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
8584 tree a00 = TREE_OPERAND (arg0, 0);
8585 tree a01 = TREE_OPERAND (arg0, 1);
8586 tree a10 = TREE_OPERAND (arg1, 0);
8587 tree a11 = TREE_OPERAND (arg1, 1);
8588 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
8589 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
8590 && (code == TRUTH_AND_EXPR
8591 || code == TRUTH_OR_EXPR));
8593 if (operand_equal_p (a00, a10, 0))
8594 return fold (build2 (TREE_CODE (arg0), type, a00,
8595 fold (build2 (code, type, a01, a11))));
8596 else if (commutative && operand_equal_p (a00, a11, 0))
8597 return fold (build2 (TREE_CODE (arg0), type, a00,
8598 fold (build2 (code, type, a01, a10))));
8599 else if (commutative && operand_equal_p (a01, a10, 0))
8600 return fold (build2 (TREE_CODE (arg0), type, a01,
8601 fold (build2 (code, type, a00, a11))));
8603 /* This case if tricky because we must either have commutative
8604 operators or else A10 must not have side-effects. */
8606 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
8607 && operand_equal_p (a01, a11, 0))
8608 return fold (build2 (TREE_CODE (arg0), type,
8609 fold (build2 (code, type, a00, a10)),
8613 /* See if we can build a range comparison. */
8614 if (0 != (tem = fold_range_test (t)))
8617 /* Check for the possibility of merging component references. If our
8618 lhs is another similar operation, try to merge its rhs with our
8619 rhs. Then try to merge our lhs and rhs. */
8620 if (TREE_CODE (arg0) == code
8621 && 0 != (tem = fold_truthop (code, type,
8622 TREE_OPERAND (arg0, 1), arg1)))
8623 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8625 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
8630 case TRUTH_ORIF_EXPR:
8631 /* Note that the operands of this must be ints
8632 and their values must be 0 or true.
8633 ("true" is a fixed value perhaps depending on the language.) */
8634 /* If first arg is constant true, return it. */
8635 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8636 return fold_convert (type, arg0);
8638 /* If either arg is constant zero, drop it. */
8639 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
8640 return non_lvalue (fold_convert (type, arg1));
8641 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
8642 /* Preserve sequence points. */
8643 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8644 return non_lvalue (fold_convert (type, arg0));
8645 /* If second arg is constant true, result is true, but we must
8646 evaluate first arg. */
8647 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
8648 return omit_one_operand (type, arg1, arg0);
8649 /* Likewise for first arg, but note this only occurs here for
8651 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8652 return omit_one_operand (type, arg0, arg1);
8654 /* !X || X is always true. */
8655 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8656 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8657 return omit_one_operand (type, integer_one_node, arg1);
8658 /* X || !X is always true. */
8659 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8660 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8661 return omit_one_operand (type, integer_one_node, arg0);
8665 case TRUTH_XOR_EXPR:
8666 /* If the second arg is constant zero, drop it. */
8667 if (integer_zerop (arg1))
8668 return non_lvalue (fold_convert (type, arg0));
8669 /* If the second arg is constant true, this is a logical inversion. */
8670 if (integer_onep (arg1))
8671 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
8672 /* Identical arguments cancel to zero. */
8673 if (operand_equal_p (arg0, arg1, 0))
8674 return omit_one_operand (type, integer_zero_node, arg0);
8676 /* !X ^ X is always true. */
8677 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8678 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8679 return omit_one_operand (type, integer_one_node, arg1);
8681 /* X ^ !X is always true. */
8682 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8683 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8684 return omit_one_operand (type, integer_one_node, arg0);
8694 /* If one arg is a real or integer constant, put it last. */
8695 if (tree_swap_operands_p (arg0, arg1, true))
8696 return fold (build2 (swap_tree_comparison (code), type, arg1, arg0));
8698 /* If this is an equality comparison of the address of a non-weak
8699 object against zero, then we know the result. */
8700 if ((code == EQ_EXPR || code == NE_EXPR)
8701 && TREE_CODE (arg0) == ADDR_EXPR
8702 && DECL_P (TREE_OPERAND (arg0, 0))
8703 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8704 && integer_zerop (arg1))
8705 return constant_boolean_node (code != EQ_EXPR, type);
8707 /* If this is an equality comparison of the address of two non-weak,
8708 unaliased symbols neither of which are extern (since we do not
8709 have access to attributes for externs), then we know the result. */
8710 if ((code == EQ_EXPR || code == NE_EXPR)
8711 && TREE_CODE (arg0) == ADDR_EXPR
8712 && DECL_P (TREE_OPERAND (arg0, 0))
8713 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8714 && ! lookup_attribute ("alias",
8715 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
8716 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
8717 && TREE_CODE (arg1) == ADDR_EXPR
8718 && DECL_P (TREE_OPERAND (arg1, 0))
8719 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
8720 && ! lookup_attribute ("alias",
8721 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
8722 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
8723 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
8724 ? code == EQ_EXPR : code != EQ_EXPR,
8727 /* If this is a comparison of two exprs that look like an
8728 ARRAY_REF of the same object, then we can fold this to a
8729 comparison of the two offsets. */
8730 if (COMPARISON_CLASS_P (t))
8732 tree base0, offset0, base1, offset1;
8734 if (extract_array_ref (arg0, &base0, &offset0)
8735 && extract_array_ref (arg1, &base1, &offset1)
8736 && operand_equal_p (base0, base1, 0))
8738 if (offset0 == NULL_TREE
8739 && offset1 == NULL_TREE)
8741 offset0 = integer_zero_node;
8742 offset1 = integer_zero_node;
8744 else if (offset0 == NULL_TREE)
8745 offset0 = build_int_cst (TREE_TYPE (offset1), 0);
8746 else if (offset1 == NULL_TREE)
8747 offset1 = build_int_cst (TREE_TYPE (offset0), 0);
8749 if (TREE_TYPE (offset0) == TREE_TYPE (offset1))
8750 return fold (build2 (code, type, offset0, offset1));
8754 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8756 tree targ0 = strip_float_extensions (arg0);
8757 tree targ1 = strip_float_extensions (arg1);
8758 tree newtype = TREE_TYPE (targ0);
8760 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8761 newtype = TREE_TYPE (targ1);
8763 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8764 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8765 return fold (build2 (code, type, fold_convert (newtype, targ0),
8766 fold_convert (newtype, targ1)));
8768 /* (-a) CMP (-b) -> b CMP a */
8769 if (TREE_CODE (arg0) == NEGATE_EXPR
8770 && TREE_CODE (arg1) == NEGATE_EXPR)
8771 return fold (build2 (code, type, TREE_OPERAND (arg1, 0),
8772 TREE_OPERAND (arg0, 0)));
8774 if (TREE_CODE (arg1) == REAL_CST)
8776 REAL_VALUE_TYPE cst;
8777 cst = TREE_REAL_CST (arg1);
8779 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8780 if (TREE_CODE (arg0) == NEGATE_EXPR)
8782 fold (build2 (swap_tree_comparison (code), type,
8783 TREE_OPERAND (arg0, 0),
8784 build_real (TREE_TYPE (arg1),
8785 REAL_VALUE_NEGATE (cst))));
8787 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8788 /* a CMP (-0) -> a CMP 0 */
8789 if (REAL_VALUE_MINUS_ZERO (cst))
8790 return fold (build2 (code, type, arg0,
8791 build_real (TREE_TYPE (arg1), dconst0)));
8793 /* x != NaN is always true, other ops are always false. */
8794 if (REAL_VALUE_ISNAN (cst)
8795 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8797 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8798 return omit_one_operand (type, tem, arg0);
8801 /* Fold comparisons against infinity. */
8802 if (REAL_VALUE_ISINF (cst))
8804 tem = fold_inf_compare (code, type, arg0, arg1);
8805 if (tem != NULL_TREE)
8810 /* If this is a comparison of a real constant with a PLUS_EXPR
8811 or a MINUS_EXPR of a real constant, we can convert it into a
8812 comparison with a revised real constant as long as no overflow
8813 occurs when unsafe_math_optimizations are enabled. */
8814 if (flag_unsafe_math_optimizations
8815 && TREE_CODE (arg1) == REAL_CST
8816 && (TREE_CODE (arg0) == PLUS_EXPR
8817 || TREE_CODE (arg0) == MINUS_EXPR)
8818 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8819 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8820 ? MINUS_EXPR : PLUS_EXPR,
8821 arg1, TREE_OPERAND (arg0, 1), 0))
8822 && ! TREE_CONSTANT_OVERFLOW (tem))
8823 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8825 /* Likewise, we can simplify a comparison of a real constant with
8826 a MINUS_EXPR whose first operand is also a real constant, i.e.
8827 (c1 - x) < c2 becomes x > c1-c2. */
8828 if (flag_unsafe_math_optimizations
8829 && TREE_CODE (arg1) == REAL_CST
8830 && TREE_CODE (arg0) == MINUS_EXPR
8831 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8832 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8834 && ! TREE_CONSTANT_OVERFLOW (tem))
8835 return fold (build2 (swap_tree_comparison (code), type,
8836 TREE_OPERAND (arg0, 1), tem));
8838 /* Fold comparisons against built-in math functions. */
8839 if (TREE_CODE (arg1) == REAL_CST
8840 && flag_unsafe_math_optimizations
8841 && ! flag_errno_math)
8843 enum built_in_function fcode = builtin_mathfn_code (arg0);
8845 if (fcode != END_BUILTINS)
8847 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8848 if (tem != NULL_TREE)
8854 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8855 if (TREE_CONSTANT (arg1)
8856 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8857 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8858 /* This optimization is invalid for ordered comparisons
8859 if CONST+INCR overflows or if foo+incr might overflow.
8860 This optimization is invalid for floating point due to rounding.
8861 For pointer types we assume overflow doesn't happen. */
8862 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8863 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8864 && (code == EQ_EXPR || code == NE_EXPR))))
8866 tree varop, newconst;
8868 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8870 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
8871 arg1, TREE_OPERAND (arg0, 1)));
8872 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8873 TREE_OPERAND (arg0, 0),
8874 TREE_OPERAND (arg0, 1));
8878 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
8879 arg1, TREE_OPERAND (arg0, 1)));
8880 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8881 TREE_OPERAND (arg0, 0),
8882 TREE_OPERAND (arg0, 1));
8886 /* If VAROP is a reference to a bitfield, we must mask
8887 the constant by the width of the field. */
8888 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8889 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8890 && host_integerp (DECL_SIZE (TREE_OPERAND
8891 (TREE_OPERAND (varop, 0), 1)), 1))
8893 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8894 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8895 tree folded_compare, shift;
8897 /* First check whether the comparison would come out
8898 always the same. If we don't do that we would
8899 change the meaning with the masking. */
8900 folded_compare = fold (build2 (code, type,
8901 TREE_OPERAND (varop, 0), arg1));
8902 if (integer_zerop (folded_compare)
8903 || integer_onep (folded_compare))
8904 return omit_one_operand (type, folded_compare, varop);
8906 shift = build_int_cst (NULL_TREE,
8907 TYPE_PRECISION (TREE_TYPE (varop)) - size);
8908 shift = fold_convert (TREE_TYPE (varop), shift);
8909 newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8911 newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8915 return fold (build2 (code, type, varop, newconst));
8918 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
8919 This transformation affects the cases which are handled in later
8920 optimizations involving comparisons with non-negative constants. */
8921 if (TREE_CODE (arg1) == INTEGER_CST
8922 && TREE_CODE (arg0) != INTEGER_CST
8923 && tree_int_cst_sgn (arg1) > 0)
8928 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8929 return fold (build2 (GT_EXPR, type, arg0, arg1));
8932 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8933 return fold (build2 (LE_EXPR, type, arg0, arg1));
8940 /* Comparisons with the highest or lowest possible integer of
8941 the specified size will have known values.
8943 This is quite similar to fold_relational_hi_lo, however,
8944 attempts to share the code have been nothing but trouble. */
8946 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
8948 if (TREE_CODE (arg1) == INTEGER_CST
8949 && ! TREE_CONSTANT_OVERFLOW (arg1)
8950 && width <= 2 * HOST_BITS_PER_WIDE_INT
8951 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
8952 || POINTER_TYPE_P (TREE_TYPE (arg1))))
8954 HOST_WIDE_INT signed_max_hi;
8955 unsigned HOST_WIDE_INT signed_max_lo;
8956 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
8958 if (width <= HOST_BITS_PER_WIDE_INT)
8960 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
8965 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
8967 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
8973 max_lo = signed_max_lo;
8974 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
8980 width -= HOST_BITS_PER_WIDE_INT;
8982 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
8987 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
8989 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
8994 max_hi = signed_max_hi;
8995 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
8999 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
9000 && TREE_INT_CST_LOW (arg1) == max_lo)
9004 return omit_one_operand (type, integer_zero_node, arg0);
9007 return fold (build2 (EQ_EXPR, type, arg0, arg1));
9010 return omit_one_operand (type, integer_one_node, arg0);
9013 return fold (build2 (NE_EXPR, type, arg0, arg1));
9015 /* The GE_EXPR and LT_EXPR cases above are not normally
9016 reached because of previous transformations. */
9021 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9023 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
9027 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
9028 return fold (build2 (EQ_EXPR, type, arg0, arg1));
9030 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
9031 return fold (build2 (NE_EXPR, type, arg0, arg1));
9035 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9037 && TREE_INT_CST_LOW (arg1) == min_lo)
9041 return omit_one_operand (type, integer_zero_node, arg0);
9044 return fold (build2 (EQ_EXPR, type, arg0, arg1));
9047 return omit_one_operand (type, integer_one_node, arg0);
9050 return fold (build2 (NE_EXPR, type, arg0, arg1));
9055 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9057 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
9061 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9062 return fold (build2 (NE_EXPR, type, arg0, arg1));
9064 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9065 return fold (build2 (EQ_EXPR, type, arg0, arg1));
9070 else if (!in_gimple_form
9071 && TREE_INT_CST_HIGH (arg1) == signed_max_hi
9072 && TREE_INT_CST_LOW (arg1) == signed_max_lo
9073 && TYPE_UNSIGNED (TREE_TYPE (arg1))
9074 /* signed_type does not work on pointer types. */
9075 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9077 /* The following case also applies to X < signed_max+1
9078 and X >= signed_max+1 because previous transformations. */
9079 if (code == LE_EXPR || code == GT_EXPR)
9082 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
9083 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
9085 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
9086 type, fold_convert (st0, arg0),
9087 fold_convert (st1, integer_zero_node)));
9093 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
9094 a MINUS_EXPR of a constant, we can convert it into a comparison with
9095 a revised constant as long as no overflow occurs. */
9096 if ((code == EQ_EXPR || code == NE_EXPR)
9097 && TREE_CODE (arg1) == INTEGER_CST
9098 && (TREE_CODE (arg0) == PLUS_EXPR
9099 || TREE_CODE (arg0) == MINUS_EXPR)
9100 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9101 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9102 ? MINUS_EXPR : PLUS_EXPR,
9103 arg1, TREE_OPERAND (arg0, 1), 0))
9104 && ! TREE_CONSTANT_OVERFLOW (tem))
9105 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
9107 /* Similarly for a NEGATE_EXPR. */
9108 else if ((code == EQ_EXPR || code == NE_EXPR)
9109 && TREE_CODE (arg0) == NEGATE_EXPR
9110 && TREE_CODE (arg1) == INTEGER_CST
9111 && 0 != (tem = negate_expr (arg1))
9112 && TREE_CODE (tem) == INTEGER_CST
9113 && ! TREE_CONSTANT_OVERFLOW (tem))
9114 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
9116 /* If we have X - Y == 0, we can convert that to X == Y and similarly
9117 for !=. Don't do this for ordered comparisons due to overflow. */
9118 else if ((code == NE_EXPR || code == EQ_EXPR)
9119 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
9120 return fold (build2 (code, type,
9121 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
9123 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
9124 && TREE_CODE (arg0) == NOP_EXPR)
9126 /* If we are widening one operand of an integer comparison,
9127 see if the other operand is similarly being widened. Perhaps we
9128 can do the comparison in the narrower type. */
9129 tem = fold_widened_comparison (code, type, arg0, arg1);
9133 /* Or if we are changing signedness. */
9134 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
9139 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9140 constant, we can simplify it. */
9141 else if (TREE_CODE (arg1) == INTEGER_CST
9142 && (TREE_CODE (arg0) == MIN_EXPR
9143 || TREE_CODE (arg0) == MAX_EXPR)
9144 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9145 return optimize_minmax_comparison (t);
9147 /* If we are comparing an ABS_EXPR with a constant, we can
9148 convert all the cases into explicit comparisons, but they may
9149 well not be faster than doing the ABS and one comparison.
9150 But ABS (X) <= C is a range comparison, which becomes a subtraction
9151 and a comparison, and is probably faster. */
9152 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
9153 && TREE_CODE (arg0) == ABS_EXPR
9154 && ! TREE_SIDE_EFFECTS (arg0)
9155 && (0 != (tem = negate_expr (arg1)))
9156 && TREE_CODE (tem) == INTEGER_CST
9157 && ! TREE_CONSTANT_OVERFLOW (tem))
9158 return fold (build2 (TRUTH_ANDIF_EXPR, type,
9159 build2 (GE_EXPR, type,
9160 TREE_OPERAND (arg0, 0), tem),
9161 build2 (LE_EXPR, type,
9162 TREE_OPERAND (arg0, 0), arg1)));
9164 /* Convert ABS_EXPR<x> >= 0 to true. */
9165 else if (code == GE_EXPR
9166 && tree_expr_nonnegative_p (arg0)
9167 && (integer_zerop (arg1)
9168 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9169 && real_zerop (arg1))))
9170 return omit_one_operand (type, integer_one_node, arg0);
9172 /* Convert ABS_EXPR<x> < 0 to false. */
9173 else if (code == LT_EXPR
9174 && tree_expr_nonnegative_p (arg0)
9175 && (integer_zerop (arg1) || real_zerop (arg1)))
9176 return omit_one_operand (type, integer_zero_node, arg0);
9178 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
9179 else if ((code == EQ_EXPR || code == NE_EXPR)
9180 && TREE_CODE (arg0) == ABS_EXPR
9181 && (integer_zerop (arg1) || real_zerop (arg1)))
9182 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), arg1));
9184 /* If this is an EQ or NE comparison with zero and ARG0 is
9185 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
9186 two operations, but the latter can be done in one less insn
9187 on machines that have only two-operand insns or on which a
9188 constant cannot be the first operand. */
9189 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
9190 && TREE_CODE (arg0) == BIT_AND_EXPR)
9192 tree arg00 = TREE_OPERAND (arg0, 0);
9193 tree arg01 = TREE_OPERAND (arg0, 1);
9194 if (TREE_CODE (arg00) == LSHIFT_EXPR
9195 && integer_onep (TREE_OPERAND (arg00, 0)))
9197 fold (build2 (code, type,
9198 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9199 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
9200 arg01, TREE_OPERAND (arg00, 1)),
9201 fold_convert (TREE_TYPE (arg0),
9204 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
9205 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
9207 fold (build2 (code, type,
9208 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9209 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
9210 arg00, TREE_OPERAND (arg01, 1)),
9211 fold_convert (TREE_TYPE (arg0),
9216 /* If this is an NE or EQ comparison of zero against the result of a
9217 signed MOD operation whose second operand is a power of 2, make
9218 the MOD operation unsigned since it is simpler and equivalent. */
9219 if ((code == NE_EXPR || code == EQ_EXPR)
9220 && integer_zerop (arg1)
9221 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
9222 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
9223 || TREE_CODE (arg0) == CEIL_MOD_EXPR
9224 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
9225 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
9226 && integer_pow2p (TREE_OPERAND (arg0, 1)))
9228 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
9229 tree newmod = fold (build2 (TREE_CODE (arg0), newtype,
9230 fold_convert (newtype,
9231 TREE_OPERAND (arg0, 0)),
9232 fold_convert (newtype,
9233 TREE_OPERAND (arg0, 1))));
9235 return fold (build2 (code, type, newmod,
9236 fold_convert (newtype, arg1)));
9239 /* If this is an NE comparison of zero with an AND of one, remove the
9240 comparison since the AND will give the correct value. */
9241 if (code == NE_EXPR && integer_zerop (arg1)
9242 && TREE_CODE (arg0) == BIT_AND_EXPR
9243 && integer_onep (TREE_OPERAND (arg0, 1)))
9244 return fold_convert (type, arg0);
9246 /* If we have (A & C) == C where C is a power of 2, convert this into
9247 (A & C) != 0. Similarly for NE_EXPR. */
9248 if ((code == EQ_EXPR || code == NE_EXPR)
9249 && TREE_CODE (arg0) == BIT_AND_EXPR
9250 && integer_pow2p (TREE_OPERAND (arg0, 1))
9251 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9252 return fold (build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
9253 arg0, fold_convert (TREE_TYPE (arg0),
9254 integer_zero_node)));
9256 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
9257 2, then fold the expression into shifts and logical operations. */
9258 tem = fold_single_bit_test (code, arg0, arg1, type);
9262 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
9263 Similarly for NE_EXPR. */
9264 if ((code == EQ_EXPR || code == NE_EXPR)
9265 && TREE_CODE (arg0) == BIT_AND_EXPR
9266 && TREE_CODE (arg1) == INTEGER_CST
9267 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9269 tree notc = fold (build1 (BIT_NOT_EXPR,
9270 TREE_TYPE (TREE_OPERAND (arg0, 1)),
9271 TREE_OPERAND (arg0, 1)));
9272 tree dandnotc = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9274 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
9275 if (integer_nonzerop (dandnotc))
9276 return omit_one_operand (type, rslt, arg0);
9279 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
9280 Similarly for NE_EXPR. */
9281 if ((code == EQ_EXPR || code == NE_EXPR)
9282 && TREE_CODE (arg0) == BIT_IOR_EXPR
9283 && TREE_CODE (arg1) == INTEGER_CST
9284 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9286 tree notd = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1));
9287 tree candnotd = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9288 TREE_OPERAND (arg0, 1), notd));
9289 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
9290 if (integer_nonzerop (candnotd))
9291 return omit_one_operand (type, rslt, arg0);
9294 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
9295 and similarly for >= into !=. */
9296 if ((code == LT_EXPR || code == GE_EXPR)
9297 && TYPE_UNSIGNED (TREE_TYPE (arg0))
9298 && TREE_CODE (arg1) == LSHIFT_EXPR
9299 && integer_onep (TREE_OPERAND (arg1, 0)))
9300 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
9301 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
9302 TREE_OPERAND (arg1, 1)),
9303 fold_convert (TREE_TYPE (arg0), integer_zero_node));
9305 else if ((code == LT_EXPR || code == GE_EXPR)
9306 && TYPE_UNSIGNED (TREE_TYPE (arg0))
9307 && (TREE_CODE (arg1) == NOP_EXPR
9308 || TREE_CODE (arg1) == CONVERT_EXPR)
9309 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
9310 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
9312 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
9313 fold_convert (TREE_TYPE (arg0),
9314 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
9315 TREE_OPERAND (TREE_OPERAND (arg1, 0),
9317 fold_convert (TREE_TYPE (arg0), integer_zero_node));
9319 /* Simplify comparison of something with itself. (For IEEE
9320 floating-point, we can only do some of these simplifications.) */
9321 if (operand_equal_p (arg0, arg1, 0))
9326 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9327 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9328 return constant_boolean_node (1, type);
9333 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9334 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9335 return constant_boolean_node (1, type);
9336 return fold (build2 (EQ_EXPR, type, arg0, arg1));
9339 /* For NE, we can only do this simplification if integer
9340 or we don't honor IEEE floating point NaNs. */
9341 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
9342 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9344 /* ... fall through ... */
9347 return constant_boolean_node (0, type);
9353 /* If we are comparing an expression that just has comparisons
9354 of two integer values, arithmetic expressions of those comparisons,
9355 and constants, we can simplify it. There are only three cases
9356 to check: the two values can either be equal, the first can be
9357 greater, or the second can be greater. Fold the expression for
9358 those three values. Since each value must be 0 or 1, we have
9359 eight possibilities, each of which corresponds to the constant 0
9360 or 1 or one of the six possible comparisons.
9362 This handles common cases like (a > b) == 0 but also handles
9363 expressions like ((x > y) - (y > x)) > 0, which supposedly
9364 occur in macroized code. */
9366 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
9368 tree cval1 = 0, cval2 = 0;
9371 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
9372 /* Don't handle degenerate cases here; they should already
9373 have been handled anyway. */
9374 && cval1 != 0 && cval2 != 0
9375 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
9376 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
9377 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
9378 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
9379 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
9380 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
9381 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9383 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9384 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9386 /* We can't just pass T to eval_subst in case cval1 or cval2
9387 was the same as ARG1. */
9390 = fold (build2 (code, type,
9391 eval_subst (arg0, cval1, maxval,
9395 = fold (build2 (code, type,
9396 eval_subst (arg0, cval1, maxval,
9400 = fold (build2 (code, type,
9401 eval_subst (arg0, cval1, minval,
9405 /* All three of these results should be 0 or 1. Confirm they
9406 are. Then use those values to select the proper code
9409 if ((integer_zerop (high_result)
9410 || integer_onep (high_result))
9411 && (integer_zerop (equal_result)
9412 || integer_onep (equal_result))
9413 && (integer_zerop (low_result)
9414 || integer_onep (low_result)))
9416 /* Make a 3-bit mask with the high-order bit being the
9417 value for `>', the next for '=', and the low for '<'. */
9418 switch ((integer_onep (high_result) * 4)
9419 + (integer_onep (equal_result) * 2)
9420 + integer_onep (low_result))
9424 return omit_one_operand (type, integer_zero_node, arg0);
9445 return omit_one_operand (type, integer_one_node, arg0);
9448 tem = build2 (code, type, cval1, cval2);
9450 return save_expr (tem);
9457 /* If this is a comparison of a field, we may be able to simplify it. */
9458 if (((TREE_CODE (arg0) == COMPONENT_REF
9459 && lang_hooks.can_use_bit_fields_p ())
9460 || TREE_CODE (arg0) == BIT_FIELD_REF)
9461 && (code == EQ_EXPR || code == NE_EXPR)
9462 /* Handle the constant case even without -O
9463 to make sure the warnings are given. */
9464 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
9466 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
9471 /* If this is a comparison of complex values and either or both sides
9472 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
9473 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
9474 This may prevent needless evaluations. */
9475 if ((code == EQ_EXPR || code == NE_EXPR)
9476 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
9477 && (TREE_CODE (arg0) == COMPLEX_EXPR
9478 || TREE_CODE (arg1) == COMPLEX_EXPR
9479 || TREE_CODE (arg0) == COMPLEX_CST
9480 || TREE_CODE (arg1) == COMPLEX_CST))
9482 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
9483 tree real0, imag0, real1, imag1;
9485 arg0 = save_expr (arg0);
9486 arg1 = save_expr (arg1);
9487 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
9488 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
9489 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
9490 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
9492 return fold (build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
9495 fold (build2 (code, type, real0, real1)),
9496 fold (build2 (code, type, imag0, imag1))));
9499 /* Optimize comparisons of strlen vs zero to a compare of the
9500 first character of the string vs zero. To wit,
9501 strlen(ptr) == 0 => *ptr == 0
9502 strlen(ptr) != 0 => *ptr != 0
9503 Other cases should reduce to one of these two (or a constant)
9504 due to the return value of strlen being unsigned. */
9505 if ((code == EQ_EXPR || code == NE_EXPR)
9506 && integer_zerop (arg1)
9507 && TREE_CODE (arg0) == CALL_EXPR)
9509 tree fndecl = get_callee_fndecl (arg0);
9513 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
9514 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
9515 && (arglist = TREE_OPERAND (arg0, 1))
9516 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
9517 && ! TREE_CHAIN (arglist))
9518 return fold (build2 (code, type,
9519 build1 (INDIRECT_REF, char_type_node,
9520 TREE_VALUE (arglist)),
9521 fold_convert (char_type_node,
9522 integer_zero_node)));
9525 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9526 into a single range test. */
9527 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9528 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9529 && TREE_CODE (arg1) == INTEGER_CST
9530 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9531 && !integer_zerop (TREE_OPERAND (arg0, 1))
9532 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9533 && !TREE_OVERFLOW (arg1))
9535 t1 = fold_div_compare (code, type, arg0, arg1);
9536 if (t1 != NULL_TREE)
9540 if ((code == EQ_EXPR || code == NE_EXPR)
9541 && !TREE_SIDE_EFFECTS (arg0)
9542 && integer_zerop (arg1)
9543 && tree_expr_nonzero_p (arg0))
9544 return constant_boolean_node (code==NE_EXPR, type);
9546 t1 = fold_relational_const (code, type, arg0, arg1);
9547 return t1 == NULL_TREE ? t : t1;
9549 case UNORDERED_EXPR:
9557 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9559 t1 = fold_relational_const (code, type, arg0, arg1);
9560 if (t1 != NULL_TREE)
9564 /* If the first operand is NaN, the result is constant. */
9565 if (TREE_CODE (arg0) == REAL_CST
9566 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
9567 && (code != LTGT_EXPR || ! flag_trapping_math))
9569 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9572 return omit_one_operand (type, t1, arg1);
9575 /* If the second operand is NaN, the result is constant. */
9576 if (TREE_CODE (arg1) == REAL_CST
9577 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
9578 && (code != LTGT_EXPR || ! flag_trapping_math))
9580 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9583 return omit_one_operand (type, t1, arg0);
9586 /* Simplify unordered comparison of something with itself. */
9587 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
9588 && operand_equal_p (arg0, arg1, 0))
9589 return constant_boolean_node (1, type);
9591 if (code == LTGT_EXPR
9592 && !flag_trapping_math
9593 && operand_equal_p (arg0, arg1, 0))
9594 return constant_boolean_node (0, type);
9596 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9598 tree targ0 = strip_float_extensions (arg0);
9599 tree targ1 = strip_float_extensions (arg1);
9600 tree newtype = TREE_TYPE (targ0);
9602 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
9603 newtype = TREE_TYPE (targ1);
9605 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
9606 return fold (build2 (code, type, fold_convert (newtype, targ0),
9607 fold_convert (newtype, targ1)));
9613 /* When pedantic, a compound expression can be neither an lvalue
9614 nor an integer constant expression. */
9615 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
9617 /* Don't let (0, 0) be null pointer constant. */
9618 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
9619 : fold_convert (type, arg1);
9620 return pedantic_non_lvalue (tem);
9624 return build_complex (type, arg0, arg1);
9629 } /* switch (code) */
9632 /* Fold a ternary expression EXPR. Return the folded expression if
9633 folding is successful. Otherwise, return the original
9637 fold_ternary (tree expr)
9639 const tree t = expr;
9640 const tree type = TREE_TYPE (expr);
9643 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
9644 enum tree_code code = TREE_CODE (t);
9645 enum tree_code_class kind = TREE_CODE_CLASS (code);
9647 gcc_assert (IS_EXPR_CODE_CLASS (kind)
9648 && TREE_CODE_LENGTH (code) == 3);
9650 op0 = TREE_OPERAND (t, 0);
9651 op1 = TREE_OPERAND (t, 1);
9652 op2 = TREE_OPERAND (t, 2);
9654 /* Strip any conversions that don't change the mode. This is safe
9655 for every expression, except for a comparison expression because
9656 its signedness is derived from its operands. So, in the latter
9657 case, only strip conversions that don't change the signedness.
9659 Note that this is done as an internal manipulation within the
9660 constant folder, in order to find the simplest representation of
9661 the arguments so that their form can be studied. In any cases,
9662 the appropriate type conversions should be put back in the tree
9663 that will get out of the constant folder. */
9679 if (TREE_CODE (arg0) == CONSTRUCTOR
9680 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
9682 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
9684 return TREE_VALUE (m);
9689 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
9690 so all simple results must be passed through pedantic_non_lvalue. */
9691 if (TREE_CODE (arg0) == INTEGER_CST)
9693 tem = integer_zerop (arg0) ? op2 : op1;
9694 /* Only optimize constant conditions when the selected branch
9695 has the same type as the COND_EXPR. This avoids optimizing
9696 away "c ? x : throw", where the throw has a void type. */
9697 if (! VOID_TYPE_P (TREE_TYPE (tem))
9698 || VOID_TYPE_P (type))
9699 return pedantic_non_lvalue (tem);
9702 if (operand_equal_p (arg1, op2, 0))
9703 return pedantic_omit_one_operand (type, arg1, arg0);
9705 /* If we have A op B ? A : C, we may be able to convert this to a
9706 simpler expression, depending on the operation and the values
9707 of B and C. Signed zeros prevent all of these transformations,
9708 for reasons given above each one.
9710 Also try swapping the arguments and inverting the conditional. */
9711 if (COMPARISON_CLASS_P (arg0)
9712 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
9713 arg1, TREE_OPERAND (arg0, 1))
9714 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
9716 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
9721 if (COMPARISON_CLASS_P (arg0)
9722 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
9724 TREE_OPERAND (arg0, 1))
9725 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
9727 tem = invert_truthvalue (arg0);
9728 if (COMPARISON_CLASS_P (tem))
9730 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
9736 /* If the second operand is simpler than the third, swap them
9737 since that produces better jump optimization results. */
9738 if (tree_swap_operands_p (op1, op2, false))
9740 /* See if this can be inverted. If it can't, possibly because
9741 it was a floating-point inequality comparison, don't do
9743 tem = invert_truthvalue (arg0);
9745 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9746 return fold (build3 (code, type, tem, op2, op1));
9749 /* Convert A ? 1 : 0 to simply A. */
9750 if (integer_onep (op1)
9751 && integer_zerop (op2)
9752 /* If we try to convert OP0 to our type, the
9753 call to fold will try to move the conversion inside
9754 a COND, which will recurse. In that case, the COND_EXPR
9755 is probably the best choice, so leave it alone. */
9756 && type == TREE_TYPE (arg0))
9757 return pedantic_non_lvalue (arg0);
9759 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
9760 over COND_EXPR in cases such as floating point comparisons. */
9761 if (integer_zerop (op1)
9762 && integer_onep (op2)
9763 && truth_value_p (TREE_CODE (arg0)))
9764 return pedantic_non_lvalue (fold_convert (type,
9765 invert_truthvalue (arg0)));
9767 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
9768 if (TREE_CODE (arg0) == LT_EXPR
9769 && integer_zerop (TREE_OPERAND (arg0, 1))
9770 && integer_zerop (op2)
9771 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
9772 return fold_convert (type, fold (build2 (BIT_AND_EXPR,
9773 TREE_TYPE (tem), tem, arg1)));
9775 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
9776 already handled above. */
9777 if (TREE_CODE (arg0) == BIT_AND_EXPR
9778 && integer_onep (TREE_OPERAND (arg0, 1))
9779 && integer_zerop (op2)
9780 && integer_pow2p (arg1))
9782 tree tem = TREE_OPERAND (arg0, 0);
9784 if (TREE_CODE (tem) == RSHIFT_EXPR
9785 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
9786 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
9787 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
9788 return fold (build2 (BIT_AND_EXPR, type,
9789 TREE_OPERAND (tem, 0), arg1));
9792 /* A & N ? N : 0 is simply A & N if N is a power of two. This
9793 is probably obsolete because the first operand should be a
9794 truth value (that's why we have the two cases above), but let's
9795 leave it in until we can confirm this for all front-ends. */
9796 if (integer_zerop (op2)
9797 && TREE_CODE (arg0) == NE_EXPR
9798 && integer_zerop (TREE_OPERAND (arg0, 1))
9799 && integer_pow2p (arg1)
9800 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
9801 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
9802 arg1, OEP_ONLY_CONST))
9803 return pedantic_non_lvalue (fold_convert (type,
9804 TREE_OPERAND (arg0, 0)));
9806 /* Convert A ? B : 0 into A && B if A and B are truth values. */
9807 if (integer_zerop (op2)
9808 && truth_value_p (TREE_CODE (arg0))
9809 && truth_value_p (TREE_CODE (arg1)))
9810 return fold (build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1));
9812 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
9813 if (integer_onep (op2)
9814 && truth_value_p (TREE_CODE (arg0))
9815 && truth_value_p (TREE_CODE (arg1)))
9817 /* Only perform transformation if ARG0 is easily inverted. */
9818 tem = invert_truthvalue (arg0);
9819 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9820 return fold (build2 (TRUTH_ORIF_EXPR, type, tem, arg1));
9823 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
9824 if (integer_zerop (arg1)
9825 && truth_value_p (TREE_CODE (arg0))
9826 && truth_value_p (TREE_CODE (op2)))
9828 /* Only perform transformation if ARG0 is easily inverted. */
9829 tem = invert_truthvalue (arg0);
9830 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9831 return fold (build2 (TRUTH_ANDIF_EXPR, type, tem, op2));
9834 /* Convert A ? 1 : B into A || B if A and B are truth values. */
9835 if (integer_onep (arg1)
9836 && truth_value_p (TREE_CODE (arg0))
9837 && truth_value_p (TREE_CODE (op2)))
9838 return fold (build2 (TRUTH_ORIF_EXPR, type, arg0, op2));
9843 /* Check for a built-in function. */
9844 if (TREE_CODE (op0) == ADDR_EXPR
9845 && TREE_CODE (TREE_OPERAND (op0, 0)) == FUNCTION_DECL
9846 && DECL_BUILT_IN (TREE_OPERAND (op0, 0)))
9848 tree tmp = fold_builtin (t, false);
9856 } /* switch (code) */
9859 /* Perform constant folding and related simplification of EXPR.
9860 The related simplifications include x*1 => x, x*0 => 0, etc.,
9861 and application of the associative law.
9862 NOP_EXPR conversions may be removed freely (as long as we
9863 are careful not to change the type of the overall expression).
9864 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
9865 but we can constant-fold them if they have constant operands. */
9867 #ifdef ENABLE_FOLD_CHECKING
9868 # define fold(x) fold_1 (x)
9869 static tree fold_1 (tree);
9875 const tree t = expr;
9876 enum tree_code code = TREE_CODE (t);
9877 enum tree_code_class kind = TREE_CODE_CLASS (code);
9879 /* Return right away if a constant. */
9880 if (kind == tcc_constant)
9883 if (IS_EXPR_CODE_CLASS (kind))
9885 switch (TREE_CODE_LENGTH (code))
9888 return fold_unary (expr);
9890 return fold_binary (expr);
9892 return fold_ternary (expr);
9901 return fold (DECL_INITIAL (t));
9905 } /* switch (code) */
9908 #ifdef ENABLE_FOLD_CHECKING
9911 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
9912 static void fold_check_failed (tree, tree);
9913 void print_fold_checksum (tree);
9915 /* When --enable-checking=fold, compute a digest of expr before
9916 and after actual fold call to see if fold did not accidentally
9917 change original expr. */
9924 unsigned char checksum_before[16], checksum_after[16];
9927 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9928 md5_init_ctx (&ctx);
9929 fold_checksum_tree (expr, &ctx, ht);
9930 md5_finish_ctx (&ctx, checksum_before);
9933 ret = fold_1 (expr);
9935 md5_init_ctx (&ctx);
9936 fold_checksum_tree (expr, &ctx, ht);
9937 md5_finish_ctx (&ctx, checksum_after);
9940 if (memcmp (checksum_before, checksum_after, 16))
9941 fold_check_failed (expr, ret);
9947 print_fold_checksum (tree expr)
9950 unsigned char checksum[16], cnt;
9953 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9954 md5_init_ctx (&ctx);
9955 fold_checksum_tree (expr, &ctx, ht);
9956 md5_finish_ctx (&ctx, checksum);
9958 for (cnt = 0; cnt < 16; ++cnt)
9959 fprintf (stderr, "%02x", checksum[cnt]);
9960 putc ('\n', stderr);
9964 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
9966 internal_error ("fold check: original tree changed by fold");
9970 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
9973 enum tree_code code;
9974 char buf[sizeof (struct tree_decl)];
9977 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
9978 <= sizeof (struct tree_decl))
9979 && sizeof (struct tree_type) <= sizeof (struct tree_decl));
9982 slot = htab_find_slot (ht, expr, INSERT);
9986 code = TREE_CODE (expr);
9987 if (TREE_CODE_CLASS (code) == tcc_declaration
9988 && DECL_ASSEMBLER_NAME_SET_P (expr))
9990 /* Allow DECL_ASSEMBLER_NAME to be modified. */
9991 memcpy (buf, expr, tree_size (expr));
9993 SET_DECL_ASSEMBLER_NAME (expr, NULL);
9995 else if (TREE_CODE_CLASS (code) == tcc_type
9996 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
9997 || TYPE_CACHED_VALUES_P (expr)))
9999 /* Allow these fields to be modified. */
10000 memcpy (buf, expr, tree_size (expr));
10002 TYPE_POINTER_TO (expr) = NULL;
10003 TYPE_REFERENCE_TO (expr) = NULL;
10004 TYPE_CACHED_VALUES_P (expr) = 0;
10005 TYPE_CACHED_VALUES (expr) = NULL;
10007 md5_process_bytes (expr, tree_size (expr), ctx);
10008 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
10009 if (TREE_CODE_CLASS (code) != tcc_type
10010 && TREE_CODE_CLASS (code) != tcc_declaration)
10011 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
10012 switch (TREE_CODE_CLASS (code))
10018 md5_process_bytes (TREE_STRING_POINTER (expr),
10019 TREE_STRING_LENGTH (expr), ctx);
10022 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
10023 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
10026 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
10032 case tcc_exceptional:
10036 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
10037 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
10040 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
10041 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
10047 case tcc_expression:
10048 case tcc_reference:
10049 case tcc_comparison:
10052 case tcc_statement:
10053 len = TREE_CODE_LENGTH (code);
10054 for (i = 0; i < len; ++i)
10055 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
10057 case tcc_declaration:
10058 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
10059 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
10060 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
10061 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
10062 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
10063 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
10064 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
10065 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
10066 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
10067 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
10068 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
10071 if (TREE_CODE (expr) == ENUMERAL_TYPE)
10072 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
10073 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
10074 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
10075 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
10076 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
10077 if (INTEGRAL_TYPE_P (expr)
10078 || SCALAR_FLOAT_TYPE_P (expr))
10080 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
10081 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
10083 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
10084 if (TREE_CODE (expr) == RECORD_TYPE
10085 || TREE_CODE (expr) == UNION_TYPE
10086 || TREE_CODE (expr) == QUAL_UNION_TYPE)
10087 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
10088 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
10097 /* Perform constant folding and related simplification of initializer
10098 expression EXPR. This behaves identically to "fold" but ignores
10099 potential run-time traps and exceptions that fold must preserve. */
10102 fold_initializer (tree expr)
10104 int saved_signaling_nans = flag_signaling_nans;
10105 int saved_trapping_math = flag_trapping_math;
10106 int saved_rounding_math = flag_rounding_math;
10107 int saved_trapv = flag_trapv;
10110 flag_signaling_nans = 0;
10111 flag_trapping_math = 0;
10112 flag_rounding_math = 0;
10115 result = fold (expr);
10117 flag_signaling_nans = saved_signaling_nans;
10118 flag_trapping_math = saved_trapping_math;
10119 flag_rounding_math = saved_rounding_math;
10120 flag_trapv = saved_trapv;
10125 /* Determine if first argument is a multiple of second argument. Return 0 if
10126 it is not, or we cannot easily determined it to be.
10128 An example of the sort of thing we care about (at this point; this routine
10129 could surely be made more general, and expanded to do what the *_DIV_EXPR's
10130 fold cases do now) is discovering that
10132 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
10138 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
10140 This code also handles discovering that
10142 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
10144 is a multiple of 8 so we don't have to worry about dealing with a
10145 possible remainder.
10147 Note that we *look* inside a SAVE_EXPR only to determine how it was
10148 calculated; it is not safe for fold to do much of anything else with the
10149 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
10150 at run time. For example, the latter example above *cannot* be implemented
10151 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
10152 evaluation time of the original SAVE_EXPR is not necessarily the same at
10153 the time the new expression is evaluated. The only optimization of this
10154 sort that would be valid is changing
10156 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
10160 SAVE_EXPR (I) * SAVE_EXPR (J)
10162 (where the same SAVE_EXPR (J) is used in the original and the
10163 transformed version). */
10166 multiple_of_p (tree type, tree top, tree bottom)
10168 if (operand_equal_p (top, bottom, 0))
10171 if (TREE_CODE (type) != INTEGER_TYPE)
10174 switch (TREE_CODE (top))
10177 /* Bitwise and provides a power of two multiple. If the mask is
10178 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
10179 if (!integer_pow2p (bottom))
10184 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
10185 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
10189 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
10190 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
10193 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
10197 op1 = TREE_OPERAND (top, 1);
10198 /* const_binop may not detect overflow correctly,
10199 so check for it explicitly here. */
10200 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
10201 > TREE_INT_CST_LOW (op1)
10202 && TREE_INT_CST_HIGH (op1) == 0
10203 && 0 != (t1 = fold_convert (type,
10204 const_binop (LSHIFT_EXPR,
10207 && ! TREE_OVERFLOW (t1))
10208 return multiple_of_p (type, t1, bottom);
10213 /* Can't handle conversions from non-integral or wider integral type. */
10214 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
10215 || (TYPE_PRECISION (type)
10216 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
10219 /* .. fall through ... */
10222 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
10225 if (TREE_CODE (bottom) != INTEGER_CST
10226 || (TYPE_UNSIGNED (type)
10227 && (tree_int_cst_sgn (top) < 0
10228 || tree_int_cst_sgn (bottom) < 0)))
10230 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
10238 /* Return true if `t' is known to be non-negative. */
10241 tree_expr_nonnegative_p (tree t)
10243 switch (TREE_CODE (t))
10249 return tree_int_cst_sgn (t) >= 0;
10252 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
10255 if (FLOAT_TYPE_P (TREE_TYPE (t)))
10256 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10257 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10259 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
10260 both unsigned and at least 2 bits shorter than the result. */
10261 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
10262 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
10263 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
10265 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
10266 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
10267 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
10268 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
10270 unsigned int prec = MAX (TYPE_PRECISION (inner1),
10271 TYPE_PRECISION (inner2)) + 1;
10272 return prec < TYPE_PRECISION (TREE_TYPE (t));
10278 if (FLOAT_TYPE_P (TREE_TYPE (t)))
10280 /* x * x for floating point x is always non-negative. */
10281 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
10283 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10284 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10287 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
10288 both unsigned and their total bits is shorter than the result. */
10289 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
10290 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
10291 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
10293 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
10294 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
10295 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
10296 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
10297 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
10298 < TYPE_PRECISION (TREE_TYPE (t));
10302 case TRUNC_DIV_EXPR:
10303 case CEIL_DIV_EXPR:
10304 case FLOOR_DIV_EXPR:
10305 case ROUND_DIV_EXPR:
10306 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10307 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10309 case TRUNC_MOD_EXPR:
10310 case CEIL_MOD_EXPR:
10311 case FLOOR_MOD_EXPR:
10312 case ROUND_MOD_EXPR:
10313 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10316 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10317 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10320 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
10321 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10324 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10325 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10329 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
10330 tree outer_type = TREE_TYPE (t);
10332 if (TREE_CODE (outer_type) == REAL_TYPE)
10334 if (TREE_CODE (inner_type) == REAL_TYPE)
10335 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10336 if (TREE_CODE (inner_type) == INTEGER_TYPE)
10338 if (TYPE_UNSIGNED (inner_type))
10340 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10343 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
10345 if (TREE_CODE (inner_type) == REAL_TYPE)
10346 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
10347 if (TREE_CODE (inner_type) == INTEGER_TYPE)
10348 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
10349 && TYPE_UNSIGNED (inner_type);
10355 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
10356 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
10357 case COMPOUND_EXPR:
10358 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10360 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10361 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10363 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10364 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10366 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10368 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
10370 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10371 case NON_LVALUE_EXPR:
10372 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10374 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10378 tree temp = TARGET_EXPR_SLOT (t);
10379 t = TARGET_EXPR_INITIAL (t);
10381 /* If the initializer is non-void, then it's a normal expression
10382 that will be assigned to the slot. */
10383 if (!VOID_TYPE_P (t))
10384 return tree_expr_nonnegative_p (t);
10386 /* Otherwise, the initializer sets the slot in some way. One common
10387 way is an assignment statement at the end of the initializer. */
10390 if (TREE_CODE (t) == BIND_EXPR)
10391 t = expr_last (BIND_EXPR_BODY (t));
10392 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
10393 || TREE_CODE (t) == TRY_CATCH_EXPR)
10394 t = expr_last (TREE_OPERAND (t, 0));
10395 else if (TREE_CODE (t) == STATEMENT_LIST)
10400 if (TREE_CODE (t) == MODIFY_EXPR
10401 && TREE_OPERAND (t, 0) == temp)
10402 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10409 tree fndecl = get_callee_fndecl (t);
10410 tree arglist = TREE_OPERAND (t, 1);
10411 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
10412 switch (DECL_FUNCTION_CODE (fndecl))
10414 #define CASE_BUILTIN_F(BUILT_IN_FN) \
10415 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
10416 #define CASE_BUILTIN_I(BUILT_IN_FN) \
10417 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
10419 CASE_BUILTIN_F (BUILT_IN_ACOS)
10420 CASE_BUILTIN_F (BUILT_IN_ACOSH)
10421 CASE_BUILTIN_F (BUILT_IN_CABS)
10422 CASE_BUILTIN_F (BUILT_IN_COSH)
10423 CASE_BUILTIN_F (BUILT_IN_ERFC)
10424 CASE_BUILTIN_F (BUILT_IN_EXP)
10425 CASE_BUILTIN_F (BUILT_IN_EXP10)
10426 CASE_BUILTIN_F (BUILT_IN_EXP2)
10427 CASE_BUILTIN_F (BUILT_IN_FABS)
10428 CASE_BUILTIN_F (BUILT_IN_FDIM)
10429 CASE_BUILTIN_F (BUILT_IN_FREXP)
10430 CASE_BUILTIN_F (BUILT_IN_HYPOT)
10431 CASE_BUILTIN_F (BUILT_IN_POW10)
10432 CASE_BUILTIN_I (BUILT_IN_FFS)
10433 CASE_BUILTIN_I (BUILT_IN_PARITY)
10434 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
10438 CASE_BUILTIN_F (BUILT_IN_SQRT)
10439 /* sqrt(-0.0) is -0.0. */
10440 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
10442 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
10444 CASE_BUILTIN_F (BUILT_IN_ASINH)
10445 CASE_BUILTIN_F (BUILT_IN_ATAN)
10446 CASE_BUILTIN_F (BUILT_IN_ATANH)
10447 CASE_BUILTIN_F (BUILT_IN_CBRT)
10448 CASE_BUILTIN_F (BUILT_IN_CEIL)
10449 CASE_BUILTIN_F (BUILT_IN_ERF)
10450 CASE_BUILTIN_F (BUILT_IN_EXPM1)
10451 CASE_BUILTIN_F (BUILT_IN_FLOOR)
10452 CASE_BUILTIN_F (BUILT_IN_FMOD)
10453 CASE_BUILTIN_F (BUILT_IN_LDEXP)
10454 CASE_BUILTIN_F (BUILT_IN_LLRINT)
10455 CASE_BUILTIN_F (BUILT_IN_LLROUND)
10456 CASE_BUILTIN_F (BUILT_IN_LRINT)
10457 CASE_BUILTIN_F (BUILT_IN_LROUND)
10458 CASE_BUILTIN_F (BUILT_IN_MODF)
10459 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
10460 CASE_BUILTIN_F (BUILT_IN_POW)
10461 CASE_BUILTIN_F (BUILT_IN_RINT)
10462 CASE_BUILTIN_F (BUILT_IN_ROUND)
10463 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
10464 CASE_BUILTIN_F (BUILT_IN_SINH)
10465 CASE_BUILTIN_F (BUILT_IN_TANH)
10466 CASE_BUILTIN_F (BUILT_IN_TRUNC)
10467 /* True if the 1st argument is nonnegative. */
10468 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
10470 CASE_BUILTIN_F (BUILT_IN_FMAX)
10471 /* True if the 1st OR 2nd arguments are nonnegative. */
10472 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
10473 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10475 CASE_BUILTIN_F (BUILT_IN_FMIN)
10476 /* True if the 1st AND 2nd arguments are nonnegative. */
10477 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
10478 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10480 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
10481 /* True if the 2nd argument is nonnegative. */
10482 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10486 #undef CASE_BUILTIN_F
10487 #undef CASE_BUILTIN_I
10491 /* ... fall through ... */
10494 if (truth_value_p (TREE_CODE (t)))
10495 /* Truth values evaluate to 0 or 1, which is nonnegative. */
10499 /* We don't know sign of `t', so be conservative and return false. */
10503 /* Return true when T is an address and is known to be nonzero.
10504 For floating point we further ensure that T is not denormal.
10505 Similar logic is present in nonzero_address in rtlanal.h. */
10508 tree_expr_nonzero_p (tree t)
10510 tree type = TREE_TYPE (t);
10512 /* Doing something useful for floating point would need more work. */
10513 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
10516 switch (TREE_CODE (t))
10519 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10520 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10523 /* We used to test for !integer_zerop here. This does not work correctly
10524 if TREE_CONSTANT_OVERFLOW (t). */
10525 return (TREE_INT_CST_LOW (t) != 0
10526 || TREE_INT_CST_HIGH (t) != 0);
10529 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10531 /* With the presence of negative values it is hard
10532 to say something. */
10533 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10534 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
10536 /* One of operands must be positive and the other non-negative. */
10537 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10538 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10543 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10545 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10546 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10552 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
10553 tree outer_type = TREE_TYPE (t);
10555 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
10556 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
10562 tree base = get_base_address (TREE_OPERAND (t, 0));
10567 /* Weak declarations may link to NULL. */
10569 return !DECL_WEAK (base);
10571 /* Constants are never weak. */
10572 if (CONSTANT_CLASS_P (base))
10579 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10580 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
10583 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10584 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10587 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
10589 /* When both operands are nonzero, then MAX must be too. */
10590 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
10593 /* MAX where operand 0 is positive is positive. */
10594 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10596 /* MAX where operand 1 is positive is positive. */
10597 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10598 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
10602 case COMPOUND_EXPR:
10605 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
10608 case NON_LVALUE_EXPR:
10609 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10612 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10613 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10621 /* See if we are applying CODE, a relational to the highest or lowest
10622 possible integer of TYPE. If so, then the result is a compile
10626 fold_relational_hi_lo (enum tree_code *code_p, const tree type, tree *op0_p,
10631 enum tree_code code = *code_p;
10632 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (op1)));
10634 if (TREE_CODE (op1) == INTEGER_CST
10635 && ! TREE_CONSTANT_OVERFLOW (op1)
10636 && width <= HOST_BITS_PER_WIDE_INT
10637 && (INTEGRAL_TYPE_P (TREE_TYPE (op1))
10638 || POINTER_TYPE_P (TREE_TYPE (op1))))
10640 unsigned HOST_WIDE_INT signed_max;
10641 unsigned HOST_WIDE_INT max, min;
10643 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
10645 if (TYPE_UNSIGNED (TREE_TYPE (op1)))
10647 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
10653 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
10656 if (TREE_INT_CST_HIGH (op1) == 0
10657 && TREE_INT_CST_LOW (op1) == max)
10661 return omit_one_operand (type, integer_zero_node, op0);
10667 return omit_one_operand (type, integer_one_node, op0);
10673 /* The GE_EXPR and LT_EXPR cases above are not normally
10674 reached because of previous transformations. */
10679 else if (TREE_INT_CST_HIGH (op1) == 0
10680 && TREE_INT_CST_LOW (op1) == max - 1)
10685 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
10689 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
10694 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
10695 && TREE_INT_CST_LOW (op1) == min)
10699 return omit_one_operand (type, integer_zero_node, op0);
10706 return omit_one_operand (type, integer_one_node, op0);
10715 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
10716 && TREE_INT_CST_LOW (op1) == min + 1)
10721 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10725 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10731 else if (TREE_INT_CST_HIGH (op1) == 0
10732 && TREE_INT_CST_LOW (op1) == signed_max
10733 && TYPE_UNSIGNED (TREE_TYPE (op1))
10734 /* signed_type does not work on pointer types. */
10735 && INTEGRAL_TYPE_P (TREE_TYPE (op1)))
10737 /* The following case also applies to X < signed_max+1
10738 and X >= signed_max+1 because previous transformations. */
10739 if (code == LE_EXPR || code == GT_EXPR)
10741 tree st0, st1, exp, retval;
10742 st0 = lang_hooks.types.signed_type (TREE_TYPE (op0));
10743 st1 = lang_hooks.types.signed_type (TREE_TYPE (op1));
10745 exp = build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
10747 fold_convert (st0, op0),
10748 fold_convert (st1, integer_zero_node));
10750 retval = fold_binary_to_constant (TREE_CODE (exp),
10752 TREE_OPERAND (exp, 0),
10753 TREE_OPERAND (exp, 1));
10755 /* If we are in gimple form, then returning EXP would create
10756 non-gimple expressions. Clearing it is safe and insures
10757 we do not allow a non-gimple expression to escape. */
10758 if (in_gimple_form)
10761 return (retval ? retval : exp);
10770 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
10771 attempt to fold the expression to a constant without modifying TYPE,
10774 If the expression could be simplified to a constant, then return
10775 the constant. If the expression would not be simplified to a
10776 constant, then return NULL_TREE.
10778 Note this is primarily designed to be called after gimplification
10779 of the tree structures and when at least one operand is a constant.
10780 As a result of those simplifying assumptions this routine is far
10781 simpler than the generic fold routine. */
10784 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
10791 /* If this is a commutative operation, and ARG0 is a constant, move it
10792 to ARG1 to reduce the number of tests below. */
10793 if (commutative_tree_code (code)
10794 && (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST))
10801 /* If either operand is a complex type, extract its real component. */
10802 if (TREE_CODE (op0) == COMPLEX_CST)
10803 subop0 = TREE_REALPART (op0);
10807 if (TREE_CODE (op1) == COMPLEX_CST)
10808 subop1 = TREE_REALPART (op1);
10812 /* Note if either argument is not a real or integer constant.
10813 With a few exceptions, simplification is limited to cases
10814 where both arguments are constants. */
10815 if ((TREE_CODE (subop0) != INTEGER_CST
10816 && TREE_CODE (subop0) != REAL_CST)
10817 || (TREE_CODE (subop1) != INTEGER_CST
10818 && TREE_CODE (subop1) != REAL_CST))
10824 /* (plus (address) (const_int)) is a constant. */
10825 if (TREE_CODE (op0) == PLUS_EXPR
10826 && TREE_CODE (op1) == INTEGER_CST
10827 && (TREE_CODE (TREE_OPERAND (op0, 0)) == ADDR_EXPR
10828 || (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
10829 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (op0, 0), 0))
10831 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
10833 return build2 (PLUS_EXPR, type, TREE_OPERAND (op0, 0),
10834 const_binop (PLUS_EXPR, op1,
10835 TREE_OPERAND (op0, 1), 0));
10843 /* Both arguments are constants. Simplify. */
10844 tem = const_binop (code, op0, op1, 0);
10845 if (tem != NULL_TREE)
10847 /* The return value should always have the same type as
10848 the original expression. */
10849 if (TREE_TYPE (tem) != type)
10850 tem = fold_convert (type, tem);
10857 /* Fold &x - &x. This can happen from &x.foo - &x.
10858 This is unsafe for certain floats even in non-IEEE formats.
10859 In IEEE, it is unsafe because it does wrong for NaNs.
10860 Also note that operand_equal_p is always false if an
10861 operand is volatile. */
10862 if (! FLOAT_TYPE_P (type) && operand_equal_p (op0, op1, 0))
10863 return fold_convert (type, integer_zero_node);
10869 /* Special case multiplication or bitwise AND where one argument
10871 if (! FLOAT_TYPE_P (type) && integer_zerop (op1))
10872 return omit_one_operand (type, op1, op0);
10874 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (op0)))
10875 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op0)))
10876 && real_zerop (op1))
10877 return omit_one_operand (type, op1, op0);
10882 /* Special case when we know the result will be all ones. */
10883 if (integer_all_onesp (op1))
10884 return omit_one_operand (type, op1, op0);
10888 case TRUNC_DIV_EXPR:
10889 case ROUND_DIV_EXPR:
10890 case FLOOR_DIV_EXPR:
10891 case CEIL_DIV_EXPR:
10892 case EXACT_DIV_EXPR:
10893 case TRUNC_MOD_EXPR:
10894 case ROUND_MOD_EXPR:
10895 case FLOOR_MOD_EXPR:
10896 case CEIL_MOD_EXPR:
10898 /* Division by zero is undefined. */
10899 if (integer_zerop (op1))
10902 if (TREE_CODE (op1) == REAL_CST
10903 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (op1)))
10904 && real_zerop (op1))
10910 if (INTEGRAL_TYPE_P (type)
10911 && operand_equal_p (op1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
10912 return omit_one_operand (type, op1, op0);
10917 if (INTEGRAL_TYPE_P (type)
10918 && TYPE_MAX_VALUE (type)
10919 && operand_equal_p (op1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
10920 return omit_one_operand (type, op1, op0);
10925 /* Optimize -1 >> x for arithmetic right shifts. */
10926 if (integer_all_onesp (op0) && ! TYPE_UNSIGNED (type))
10927 return omit_one_operand (type, op0, op1);
10928 /* ... fall through ... */
10931 if (integer_zerop (op0))
10932 return omit_one_operand (type, op0, op1);
10934 /* Since negative shift count is not well-defined, don't
10935 try to compute it in the compiler. */
10936 if (TREE_CODE (op1) == INTEGER_CST && tree_int_cst_sgn (op1) < 0)
10943 /* -1 rotated either direction by any amount is still -1. */
10944 if (integer_all_onesp (op0))
10945 return omit_one_operand (type, op0, op1);
10947 /* 0 rotated either direction by any amount is still zero. */
10948 if (integer_zerop (op0))
10949 return omit_one_operand (type, op0, op1);
10955 return build_complex (type, op0, op1);
10964 /* If one arg is a real or integer constant, put it last. */
10965 if ((TREE_CODE (op0) == INTEGER_CST
10966 && TREE_CODE (op1) != INTEGER_CST)
10967 || (TREE_CODE (op0) == REAL_CST
10968 && TREE_CODE (op0) != REAL_CST))
10975 code = swap_tree_comparison (code);
10978 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
10979 This transformation affects the cases which are handled in later
10980 optimizations involving comparisons with non-negative constants. */
10981 if (TREE_CODE (op1) == INTEGER_CST
10982 && TREE_CODE (op0) != INTEGER_CST
10983 && tree_int_cst_sgn (op1) > 0)
10989 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10994 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
11002 tem = fold_relational_hi_lo (&code, type, &op0, &op1);
11006 /* Fall through. */
11009 case UNORDERED_EXPR:
11019 return fold_relational_const (code, type, op0, op1);
11022 /* This could probably be handled. */
11025 case TRUTH_AND_EXPR:
11026 /* If second arg is constant zero, result is zero, but first arg
11027 must be evaluated. */
11028 if (integer_zerop (op1))
11029 return omit_one_operand (type, op1, op0);
11030 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11031 case will be handled here. */
11032 if (integer_zerop (op0))
11033 return omit_one_operand (type, op0, op1);
11034 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
11035 return constant_boolean_node (true, type);
11038 case TRUTH_OR_EXPR:
11039 /* If second arg is constant true, result is true, but we must
11040 evaluate first arg. */
11041 if (TREE_CODE (op1) == INTEGER_CST && ! integer_zerop (op1))
11042 return omit_one_operand (type, op1, op0);
11043 /* Likewise for first arg, but note this only occurs here for
11045 if (TREE_CODE (op0) == INTEGER_CST && ! integer_zerop (op0))
11046 return omit_one_operand (type, op0, op1);
11047 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
11048 return constant_boolean_node (false, type);
11051 case TRUTH_XOR_EXPR:
11052 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
11054 int x = ! integer_zerop (op0) ^ ! integer_zerop (op1);
11055 return constant_boolean_node (x, type);
11064 /* Given the components of a unary expression CODE, TYPE and OP0,
11065 attempt to fold the expression to a constant without modifying
11068 If the expression could be simplified to a constant, then return
11069 the constant. If the expression would not be simplified to a
11070 constant, then return NULL_TREE.
11072 Note this is primarily designed to be called after gimplification
11073 of the tree structures and when op0 is a constant. As a result
11074 of those simplifying assumptions this routine is far simpler than
11075 the generic fold routine. */
11078 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
11080 /* Make sure we have a suitable constant argument. */
11081 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
11085 if (TREE_CODE (op0) == COMPLEX_CST)
11086 subop = TREE_REALPART (op0);
11090 if (TREE_CODE (subop) != INTEGER_CST && TREE_CODE (subop) != REAL_CST)
11099 case FIX_TRUNC_EXPR:
11100 case FIX_FLOOR_EXPR:
11101 case FIX_CEIL_EXPR:
11102 return fold_convert_const (code, type, op0);
11105 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
11106 return fold_negate_const (op0, type);
11111 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
11112 return fold_abs_const (op0, type);
11117 if (TREE_CODE (op0) == INTEGER_CST)
11118 return fold_not_const (op0, type);
11122 case REALPART_EXPR:
11123 if (TREE_CODE (op0) == COMPLEX_CST)
11124 return TREE_REALPART (op0);
11128 case IMAGPART_EXPR:
11129 if (TREE_CODE (op0) == COMPLEX_CST)
11130 return TREE_IMAGPART (op0);
11135 if (TREE_CODE (op0) == COMPLEX_CST
11136 && TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
11137 return build_complex (type, TREE_REALPART (op0),
11138 negate_expr (TREE_IMAGPART (op0)));
11146 /* If EXP represents referencing an element in a constant string
11147 (either via pointer arithmetic or array indexing), return the
11148 tree representing the value accessed, otherwise return NULL. */
11151 fold_read_from_constant_string (tree exp)
11153 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
11155 tree exp1 = TREE_OPERAND (exp, 0);
11159 if (TREE_CODE (exp) == INDIRECT_REF)
11160 string = string_constant (exp1, &index);
11163 tree low_bound = array_ref_low_bound (exp);
11164 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
11166 /* Optimize the special-case of a zero lower bound.
11168 We convert the low_bound to sizetype to avoid some problems
11169 with constant folding. (E.g. suppose the lower bound is 1,
11170 and its mode is QI. Without the conversion,l (ARRAY
11171 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
11172 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
11173 if (! integer_zerop (low_bound))
11174 index = size_diffop (index, fold_convert (sizetype, low_bound));
11180 && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
11181 && TREE_CODE (string) == STRING_CST
11182 && TREE_CODE (index) == INTEGER_CST
11183 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
11184 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
11186 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
11187 return fold_convert (TREE_TYPE (exp),
11188 build_int_cst (NULL_TREE,
11189 (TREE_STRING_POINTER (string)
11190 [TREE_INT_CST_LOW (index)])));
11195 /* Return the tree for neg (ARG0) when ARG0 is known to be either
11196 an integer constant or real constant.
11198 TYPE is the type of the result. */
11201 fold_negate_const (tree arg0, tree type)
11203 tree t = NULL_TREE;
11205 switch (TREE_CODE (arg0))
11209 unsigned HOST_WIDE_INT low;
11210 HOST_WIDE_INT high;
11211 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
11212 TREE_INT_CST_HIGH (arg0),
11214 t = build_int_cst_wide (type, low, high);
11215 t = force_fit_type (t, 1,
11216 (overflow | TREE_OVERFLOW (arg0))
11217 && !TYPE_UNSIGNED (type),
11218 TREE_CONSTANT_OVERFLOW (arg0));
11223 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
11227 gcc_unreachable ();
11233 /* Return the tree for abs (ARG0) when ARG0 is known to be either
11234 an integer constant or real constant.
11236 TYPE is the type of the result. */
11239 fold_abs_const (tree arg0, tree type)
11241 tree t = NULL_TREE;
11243 switch (TREE_CODE (arg0))
11246 /* If the value is unsigned, then the absolute value is
11247 the same as the ordinary value. */
11248 if (TYPE_UNSIGNED (type))
11250 /* Similarly, if the value is non-negative. */
11251 else if (INT_CST_LT (integer_minus_one_node, arg0))
11253 /* If the value is negative, then the absolute value is
11257 unsigned HOST_WIDE_INT low;
11258 HOST_WIDE_INT high;
11259 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
11260 TREE_INT_CST_HIGH (arg0),
11262 t = build_int_cst_wide (type, low, high);
11263 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
11264 TREE_CONSTANT_OVERFLOW (arg0));
11269 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
11270 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
11276 gcc_unreachable ();
11282 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
11283 constant. TYPE is the type of the result. */
11286 fold_not_const (tree arg0, tree type)
11288 tree t = NULL_TREE;
11290 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
11292 t = build_int_cst_wide (type,
11293 ~ TREE_INT_CST_LOW (arg0),
11294 ~ TREE_INT_CST_HIGH (arg0));
11295 t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
11296 TREE_CONSTANT_OVERFLOW (arg0));
11301 /* Given CODE, a relational operator, the target type, TYPE and two
11302 constant operands OP0 and OP1, return the result of the
11303 relational operation. If the result is not a compile time
11304 constant, then return NULL_TREE. */
11307 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
11309 int result, invert;
11311 /* From here on, the only cases we handle are when the result is
11312 known to be a constant. */
11314 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
11316 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
11317 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
11319 /* Handle the cases where either operand is a NaN. */
11320 if (real_isnan (c0) || real_isnan (c1))
11330 case UNORDERED_EXPR:
11344 if (flag_trapping_math)
11350 gcc_unreachable ();
11353 return constant_boolean_node (result, type);
11356 return constant_boolean_node (real_compare (code, c0, c1), type);
11359 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
11361 To compute GT, swap the arguments and do LT.
11362 To compute GE, do LT and invert the result.
11363 To compute LE, swap the arguments, do LT and invert the result.
11364 To compute NE, do EQ and invert the result.
11366 Therefore, the code below must handle only EQ and LT. */
11368 if (code == LE_EXPR || code == GT_EXPR)
11373 code = swap_tree_comparison (code);
11376 /* Note that it is safe to invert for real values here because we
11377 have already handled the one case that it matters. */
11380 if (code == NE_EXPR || code == GE_EXPR)
11383 code = invert_tree_comparison (code, false);
11386 /* Compute a result for LT or EQ if args permit;
11387 Otherwise return T. */
11388 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
11390 if (code == EQ_EXPR)
11391 result = tree_int_cst_equal (op0, op1);
11392 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
11393 result = INT_CST_LT_UNSIGNED (op0, op1);
11395 result = INT_CST_LT (op0, op1);
11402 return constant_boolean_node (result, type);
11405 /* Build an expression for the a clean point containing EXPR with type TYPE.
11406 Don't build a cleanup point expression for EXPR which don't have side
11410 fold_build_cleanup_point_expr (tree type, tree expr)
11412 /* If the expression does not have side effects then we don't have to wrap
11413 it with a cleanup point expression. */
11414 if (!TREE_SIDE_EFFECTS (expr))
11417 /* If the expression is a return, check to see if the expression inside the
11418 return has no side effects or the right hand side of the modify expression
11419 inside the return. If either don't have side effects set we don't need to
11420 wrap the expression in a cleanup point expression. Note we don't check the
11421 left hand side of the modify because it should always be a return decl. */
11422 if (TREE_CODE (expr) == RETURN_EXPR)
11424 tree op = TREE_OPERAND (expr, 0);
11425 if (!op || !TREE_SIDE_EFFECTS (op))
11427 op = TREE_OPERAND (op, 1);
11428 if (!TREE_SIDE_EFFECTS (op))
11432 return build1 (CLEANUP_POINT_EXPR, type, expr);
11435 /* Build an expression for the address of T. Folds away INDIRECT_REF to
11436 avoid confusing the gimplify process. */
11439 build_fold_addr_expr_with_type (tree t, tree ptrtype)
11441 /* The size of the object is not relevant when talking about its address. */
11442 if (TREE_CODE (t) == WITH_SIZE_EXPR)
11443 t = TREE_OPERAND (t, 0);
11445 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
11446 if (TREE_CODE (t) == INDIRECT_REF
11447 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
11449 t = TREE_OPERAND (t, 0);
11450 if (TREE_TYPE (t) != ptrtype)
11451 t = build1 (NOP_EXPR, ptrtype, t);
11457 while (handled_component_p (base))
11458 base = TREE_OPERAND (base, 0);
11460 TREE_ADDRESSABLE (base) = 1;
11462 t = build1 (ADDR_EXPR, ptrtype, t);
11469 build_fold_addr_expr (tree t)
11471 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
11474 /* Given a pointer value T, return a simplified version of an indirection
11475 through T, or NULL_TREE if no simplification is possible. */
11478 fold_indirect_ref_1 (tree t)
11480 tree type = TREE_TYPE (TREE_TYPE (t));
11485 subtype = TREE_TYPE (sub);
11486 if (!POINTER_TYPE_P (subtype))
11489 if (TREE_CODE (sub) == ADDR_EXPR)
11491 tree op = TREE_OPERAND (sub, 0);
11492 tree optype = TREE_TYPE (op);
11494 if (lang_hooks.types_compatible_p (type, optype))
11496 /* *(foo *)&fooarray => fooarray[0] */
11497 else if (TREE_CODE (optype) == ARRAY_TYPE
11498 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
11500 tree type_domain = TYPE_DOMAIN (optype);
11501 tree min_val = size_zero_node;
11502 if (type_domain && TYPE_MIN_VALUE (type_domain))
11503 min_val = TYPE_MIN_VALUE (type_domain);
11504 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
11508 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
11509 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
11510 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
11513 tree min_val = size_zero_node;
11514 sub = build_fold_indirect_ref (sub);
11515 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
11516 if (type_domain && TYPE_MIN_VALUE (type_domain))
11517 min_val = TYPE_MIN_VALUE (type_domain);
11518 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
11524 /* Builds an expression for an indirection through T, simplifying some
11528 build_fold_indirect_ref (tree t)
11530 tree sub = fold_indirect_ref_1 (t);
11535 return build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (t)), t);
11538 /* Given an INDIRECT_REF T, return either T or a simplified version. */
11541 fold_indirect_ref (tree t)
11543 tree sub = fold_indirect_ref_1 (TREE_OPERAND (t, 0));
11551 /* Strip non-trapping, non-side-effecting tree nodes from an expression
11552 whose result is ignored. The type of the returned tree need not be
11553 the same as the original expression. */
11556 fold_ignored_result (tree t)
11558 if (!TREE_SIDE_EFFECTS (t))
11559 return integer_zero_node;
11562 switch (TREE_CODE_CLASS (TREE_CODE (t)))
11565 t = TREE_OPERAND (t, 0);
11569 case tcc_comparison:
11570 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
11571 t = TREE_OPERAND (t, 0);
11572 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
11573 t = TREE_OPERAND (t, 1);
11578 case tcc_expression:
11579 switch (TREE_CODE (t))
11581 case COMPOUND_EXPR:
11582 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
11584 t = TREE_OPERAND (t, 0);
11588 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
11589 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
11591 t = TREE_OPERAND (t, 0);
11604 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
11605 This can only be applied to objects of a sizetype. */
11608 round_up (tree value, int divisor)
11610 tree div = NULL_TREE;
11612 gcc_assert (divisor > 0);
11616 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11617 have to do anything. Only do this when we are not given a const,
11618 because in that case, this check is more expensive than just
11620 if (TREE_CODE (value) != INTEGER_CST)
11622 div = build_int_cst (TREE_TYPE (value), divisor);
11624 if (multiple_of_p (TREE_TYPE (value), value, div))
11628 /* If divisor is a power of two, simplify this to bit manipulation. */
11629 if (divisor == (divisor & -divisor))
11633 t = build_int_cst (TREE_TYPE (value), divisor - 1);
11634 value = size_binop (PLUS_EXPR, value, t);
11635 t = build_int_cst (TREE_TYPE (value), -divisor);
11636 value = size_binop (BIT_AND_EXPR, value, t);
11641 div = build_int_cst (TREE_TYPE (value), divisor);
11642 value = size_binop (CEIL_DIV_EXPR, value, div);
11643 value = size_binop (MULT_EXPR, value, div);
11649 /* Likewise, but round down. */
11652 round_down (tree value, int divisor)
11654 tree div = NULL_TREE;
11656 gcc_assert (divisor > 0);
11660 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11661 have to do anything. Only do this when we are not given a const,
11662 because in that case, this check is more expensive than just
11664 if (TREE_CODE (value) != INTEGER_CST)
11666 div = build_int_cst (TREE_TYPE (value), divisor);
11668 if (multiple_of_p (TREE_TYPE (value), value, div))
11672 /* If divisor is a power of two, simplify this to bit manipulation. */
11673 if (divisor == (divisor & -divisor))
11677 t = build_int_cst (TREE_TYPE (value), -divisor);
11678 value = size_binop (BIT_AND_EXPR, value, t);
11683 div = build_int_cst (TREE_TYPE (value), divisor);
11684 value = size_binop (FLOOR_DIV_EXPR, value, div);
11685 value = size_binop (MULT_EXPR, value, div);
11691 /* Returns the pointer to the base of the object addressed by EXP and
11692 extracts the information about the offset of the access, storing it
11693 to PBITPOS and POFFSET. */
11696 split_address_to_core_and_offset (tree exp,
11697 HOST_WIDE_INT *pbitpos, tree *poffset)
11700 enum machine_mode mode;
11701 int unsignedp, volatilep;
11702 HOST_WIDE_INT bitsize;
11704 if (TREE_CODE (exp) == ADDR_EXPR)
11706 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
11707 poffset, &mode, &unsignedp, &volatilep,
11710 if (TREE_CODE (core) == INDIRECT_REF)
11711 core = TREE_OPERAND (core, 0);
11717 *poffset = NULL_TREE;
11723 /* Returns true if addresses of E1 and E2 differ by a constant, false
11724 otherwise. If they do, E1 - E2 is stored in *DIFF. */
11727 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
11730 HOST_WIDE_INT bitpos1, bitpos2;
11731 tree toffset1, toffset2, tdiff, type;
11733 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
11734 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
11736 if (bitpos1 % BITS_PER_UNIT != 0
11737 || bitpos2 % BITS_PER_UNIT != 0
11738 || !operand_equal_p (core1, core2, 0))
11741 if (toffset1 && toffset2)
11743 type = TREE_TYPE (toffset1);
11744 if (type != TREE_TYPE (toffset2))
11745 toffset2 = fold_convert (type, toffset2);
11747 tdiff = fold (build2 (MINUS_EXPR, type, toffset1, toffset2));
11748 if (!host_integerp (tdiff, 0))
11751 *diff = tree_low_cst (tdiff, 0);
11753 else if (toffset1 || toffset2)
11755 /* If only one of the offsets is non-constant, the difference cannot
11762 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
11766 /* Simplify the floating point expression EXP when the sign of the
11767 result is not significant. Return NULL_TREE if no simplification
11771 fold_strip_sign_ops (tree exp)
11775 switch (TREE_CODE (exp))
11779 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
11780 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
11784 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
11786 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
11787 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
11788 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
11789 return fold (build2 (TREE_CODE (exp), TREE_TYPE (exp),
11790 arg0 ? arg0 : TREE_OPERAND (exp, 0),
11791 arg1 ? arg1 : TREE_OPERAND (exp, 1)));