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;
5384 else if (TREE_CODE (type) == BOOLEAN_TYPE)
5385 return lang_hooks.truthvalue_conversion (value ? integer_one_node
5386 : integer_zero_node);
5388 return build_int_cst (type, value);
5392 /* Return true if expr looks like an ARRAY_REF and set base and
5393 offset to the appropriate trees. If there is no offset,
5394 offset is set to NULL_TREE. */
5397 extract_array_ref (tree expr, tree *base, tree *offset)
5399 /* We have to be careful with stripping nops as with the
5400 base type the meaning of the offset can change. */
5401 tree inner_expr = expr;
5402 STRIP_NOPS (inner_expr);
5403 /* One canonical form is a PLUS_EXPR with the first
5404 argument being an ADDR_EXPR with a possible NOP_EXPR
5406 if (TREE_CODE (expr) == PLUS_EXPR)
5408 tree op0 = TREE_OPERAND (expr, 0);
5410 if (TREE_CODE (op0) == ADDR_EXPR)
5412 *base = TREE_OPERAND (expr, 0);
5413 *offset = TREE_OPERAND (expr, 1);
5417 /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
5418 which we transform into an ADDR_EXPR with appropriate
5419 offset. For other arguments to the ADDR_EXPR we assume
5420 zero offset and as such do not care about the ADDR_EXPR
5421 type and strip possible nops from it. */
5422 else if (TREE_CODE (inner_expr) == ADDR_EXPR)
5424 tree op0 = TREE_OPERAND (inner_expr, 0);
5425 if (TREE_CODE (op0) == ARRAY_REF)
5427 *base = build_fold_addr_expr (TREE_OPERAND (op0, 0));
5428 *offset = TREE_OPERAND (op0, 1);
5433 *offset = NULL_TREE;
5442 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5443 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5444 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5445 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5446 COND is the first argument to CODE; otherwise (as in the example
5447 given here), it is the second argument. TYPE is the type of the
5448 original expression. Return NULL_TREE if no simplification is
5452 fold_binary_op_with_conditional_arg (tree t, enum tree_code code, tree cond,
5453 tree arg, int cond_first_p)
5455 const tree type = TREE_TYPE (t);
5456 tree cond_type = cond_first_p ? TREE_TYPE (TREE_OPERAND (t, 0))
5457 : TREE_TYPE (TREE_OPERAND (t, 1));
5458 tree arg_type = cond_first_p ? TREE_TYPE (TREE_OPERAND (t, 1))
5459 : TREE_TYPE (TREE_OPERAND (t, 0));
5460 tree test, true_value, false_value;
5461 tree lhs = NULL_TREE;
5462 tree rhs = NULL_TREE;
5464 /* This transformation is only worthwhile if we don't have to wrap
5465 arg in a SAVE_EXPR, and the operation can be simplified on at least
5466 one of the branches once its pushed inside the COND_EXPR. */
5467 if (!TREE_CONSTANT (arg))
5470 if (TREE_CODE (cond) == COND_EXPR)
5472 test = TREE_OPERAND (cond, 0);
5473 true_value = TREE_OPERAND (cond, 1);
5474 false_value = TREE_OPERAND (cond, 2);
5475 /* If this operand throws an expression, then it does not make
5476 sense to try to perform a logical or arithmetic operation
5478 if (VOID_TYPE_P (TREE_TYPE (true_value)))
5480 if (VOID_TYPE_P (TREE_TYPE (false_value)))
5485 tree testtype = TREE_TYPE (cond);
5487 true_value = constant_boolean_node (true, testtype);
5488 false_value = constant_boolean_node (false, testtype);
5491 arg = fold_convert (arg_type, arg);
5494 true_value = fold_convert (cond_type, true_value);
5495 lhs = fold (cond_first_p ? build2 (code, type, true_value, arg)
5496 : build2 (code, type, arg, true_value));
5500 false_value = fold_convert (cond_type, false_value);
5501 rhs = fold (cond_first_p ? build2 (code, type, false_value, arg)
5502 : build2 (code, type, arg, false_value));
5505 test = fold (build3 (COND_EXPR, type, test, lhs, rhs));
5506 return fold_convert (type, test);
5510 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5512 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5513 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5514 ADDEND is the same as X.
5516 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5517 and finite. The problematic cases are when X is zero, and its mode
5518 has signed zeros. In the case of rounding towards -infinity,
5519 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5520 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5523 fold_real_zero_addition_p (tree type, tree addend, int negate)
5525 if (!real_zerop (addend))
5528 /* Don't allow the fold with -fsignaling-nans. */
5529 if (HONOR_SNANS (TYPE_MODE (type)))
5532 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5533 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5536 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5537 if (TREE_CODE (addend) == REAL_CST
5538 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5541 /* The mode has signed zeros, and we have to honor their sign.
5542 In this situation, there is only one case we can return true for.
5543 X - 0 is the same as X unless rounding towards -infinity is
5545 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5548 /* Subroutine of fold() that checks comparisons of built-in math
5549 functions against real constants.
5551 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5552 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5553 is the type of the result and ARG0 and ARG1 are the operands of the
5554 comparison. ARG1 must be a TREE_REAL_CST.
5556 The function returns the constant folded tree if a simplification
5557 can be made, and NULL_TREE otherwise. */
5560 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5561 tree type, tree arg0, tree arg1)
5565 if (BUILTIN_SQRT_P (fcode))
5567 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5568 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5570 c = TREE_REAL_CST (arg1);
5571 if (REAL_VALUE_NEGATIVE (c))
5573 /* sqrt(x) < y is always false, if y is negative. */
5574 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5575 return omit_one_operand (type, integer_zero_node, arg);
5577 /* sqrt(x) > y is always true, if y is negative and we
5578 don't care about NaNs, i.e. negative values of x. */
5579 if (code == NE_EXPR || !HONOR_NANS (mode))
5580 return omit_one_operand (type, integer_one_node, arg);
5582 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5583 return fold (build2 (GE_EXPR, type, arg,
5584 build_real (TREE_TYPE (arg), dconst0)));
5586 else if (code == GT_EXPR || code == GE_EXPR)
5590 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5591 real_convert (&c2, mode, &c2);
5593 if (REAL_VALUE_ISINF (c2))
5595 /* sqrt(x) > y is x == +Inf, when y is very large. */
5596 if (HONOR_INFINITIES (mode))
5597 return fold (build2 (EQ_EXPR, type, arg,
5598 build_real (TREE_TYPE (arg), c2)));
5600 /* sqrt(x) > y is always false, when y is very large
5601 and we don't care about infinities. */
5602 return omit_one_operand (type, integer_zero_node, arg);
5605 /* sqrt(x) > c is the same as x > c*c. */
5606 return fold (build2 (code, type, arg,
5607 build_real (TREE_TYPE (arg), c2)));
5609 else if (code == LT_EXPR || code == LE_EXPR)
5613 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5614 real_convert (&c2, mode, &c2);
5616 if (REAL_VALUE_ISINF (c2))
5618 /* sqrt(x) < y is always true, when y is a very large
5619 value and we don't care about NaNs or Infinities. */
5620 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5621 return omit_one_operand (type, integer_one_node, arg);
5623 /* sqrt(x) < y is x != +Inf when y is very large and we
5624 don't care about NaNs. */
5625 if (! HONOR_NANS (mode))
5626 return fold (build2 (NE_EXPR, type, arg,
5627 build_real (TREE_TYPE (arg), c2)));
5629 /* sqrt(x) < y is x >= 0 when y is very large and we
5630 don't care about Infinities. */
5631 if (! HONOR_INFINITIES (mode))
5632 return fold (build2 (GE_EXPR, type, arg,
5633 build_real (TREE_TYPE (arg), dconst0)));
5635 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5636 if (lang_hooks.decls.global_bindings_p () != 0
5637 || CONTAINS_PLACEHOLDER_P (arg))
5640 arg = save_expr (arg);
5641 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5642 fold (build2 (GE_EXPR, type, arg,
5643 build_real (TREE_TYPE (arg),
5645 fold (build2 (NE_EXPR, type, arg,
5646 build_real (TREE_TYPE (arg),
5650 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5651 if (! HONOR_NANS (mode))
5652 return fold (build2 (code, type, arg,
5653 build_real (TREE_TYPE (arg), c2)));
5655 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5656 if (lang_hooks.decls.global_bindings_p () == 0
5657 && ! CONTAINS_PLACEHOLDER_P (arg))
5659 arg = save_expr (arg);
5660 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5661 fold (build2 (GE_EXPR, type, arg,
5662 build_real (TREE_TYPE (arg),
5664 fold (build2 (code, type, arg,
5665 build_real (TREE_TYPE (arg),
5674 /* Subroutine of fold() that optimizes comparisons against Infinities,
5675 either +Inf or -Inf.
5677 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5678 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5679 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5681 The function returns the constant folded tree if a simplification
5682 can be made, and NULL_TREE otherwise. */
5685 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5687 enum machine_mode mode;
5688 REAL_VALUE_TYPE max;
5692 mode = TYPE_MODE (TREE_TYPE (arg0));
5694 /* For negative infinity swap the sense of the comparison. */
5695 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5697 code = swap_tree_comparison (code);
5702 /* x > +Inf is always false, if with ignore sNANs. */
5703 if (HONOR_SNANS (mode))
5705 return omit_one_operand (type, integer_zero_node, arg0);
5708 /* x <= +Inf is always true, if we don't case about NaNs. */
5709 if (! HONOR_NANS (mode))
5710 return omit_one_operand (type, integer_one_node, arg0);
5712 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5713 if (lang_hooks.decls.global_bindings_p () == 0
5714 && ! CONTAINS_PLACEHOLDER_P (arg0))
5716 arg0 = save_expr (arg0);
5717 return fold (build2 (EQ_EXPR, type, arg0, arg0));
5723 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5724 real_maxval (&max, neg, mode);
5725 return fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5726 arg0, build_real (TREE_TYPE (arg0), max)));
5729 /* x < +Inf is always equal to x <= DBL_MAX. */
5730 real_maxval (&max, neg, mode);
5731 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5732 arg0, build_real (TREE_TYPE (arg0), max)));
5735 /* x != +Inf is always equal to !(x > DBL_MAX). */
5736 real_maxval (&max, neg, mode);
5737 if (! HONOR_NANS (mode))
5738 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5739 arg0, build_real (TREE_TYPE (arg0), max)));
5741 /* The transformation below creates non-gimple code and thus is
5742 not appropriate if we are in gimple form. */
5746 temp = fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5747 arg0, build_real (TREE_TYPE (arg0), max)));
5748 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5757 /* Subroutine of fold() that optimizes comparisons of a division by
5758 a nonzero integer constant against an integer constant, i.e.
5761 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5762 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5763 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5765 The function returns the constant folded tree if a simplification
5766 can be made, and NULL_TREE otherwise. */
5769 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5771 tree prod, tmp, hi, lo;
5772 tree arg00 = TREE_OPERAND (arg0, 0);
5773 tree arg01 = TREE_OPERAND (arg0, 1);
5774 unsigned HOST_WIDE_INT lpart;
5775 HOST_WIDE_INT hpart;
5778 /* We have to do this the hard way to detect unsigned overflow.
5779 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5780 overflow = mul_double (TREE_INT_CST_LOW (arg01),
5781 TREE_INT_CST_HIGH (arg01),
5782 TREE_INT_CST_LOW (arg1),
5783 TREE_INT_CST_HIGH (arg1), &lpart, &hpart);
5784 prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5785 prod = force_fit_type (prod, -1, overflow, false);
5787 if (TYPE_UNSIGNED (TREE_TYPE (arg0)))
5789 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5792 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5793 overflow = add_double (TREE_INT_CST_LOW (prod),
5794 TREE_INT_CST_HIGH (prod),
5795 TREE_INT_CST_LOW (tmp),
5796 TREE_INT_CST_HIGH (tmp),
5798 hi = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5799 hi = force_fit_type (hi, -1, overflow | TREE_OVERFLOW (prod),
5800 TREE_CONSTANT_OVERFLOW (prod));
5802 else if (tree_int_cst_sgn (arg01) >= 0)
5804 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5805 switch (tree_int_cst_sgn (arg1))
5808 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5813 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
5818 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5828 /* A negative divisor reverses the relational operators. */
5829 code = swap_tree_comparison (code);
5831 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
5832 switch (tree_int_cst_sgn (arg1))
5835 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5840 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
5845 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5857 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5858 return omit_one_operand (type, integer_zero_node, arg00);
5859 if (TREE_OVERFLOW (hi))
5860 return fold (build2 (GE_EXPR, type, arg00, lo));
5861 if (TREE_OVERFLOW (lo))
5862 return fold (build2 (LE_EXPR, type, arg00, hi));
5863 return build_range_check (type, arg00, 1, lo, hi);
5866 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5867 return omit_one_operand (type, integer_one_node, arg00);
5868 if (TREE_OVERFLOW (hi))
5869 return fold (build2 (LT_EXPR, type, arg00, lo));
5870 if (TREE_OVERFLOW (lo))
5871 return fold (build2 (GT_EXPR, type, arg00, hi));
5872 return build_range_check (type, arg00, 0, lo, hi);
5875 if (TREE_OVERFLOW (lo))
5876 return omit_one_operand (type, integer_zero_node, arg00);
5877 return fold (build2 (LT_EXPR, type, arg00, lo));
5880 if (TREE_OVERFLOW (hi))
5881 return omit_one_operand (type, integer_one_node, arg00);
5882 return fold (build2 (LE_EXPR, type, arg00, hi));
5885 if (TREE_OVERFLOW (hi))
5886 return omit_one_operand (type, integer_zero_node, arg00);
5887 return fold (build2 (GT_EXPR, type, arg00, hi));
5890 if (TREE_OVERFLOW (lo))
5891 return omit_one_operand (type, integer_one_node, arg00);
5892 return fold (build2 (GE_EXPR, type, arg00, lo));
5902 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5903 equality/inequality test, then return a simplified form of
5904 the test using shifts and logical operations. Otherwise return
5905 NULL. TYPE is the desired result type. */
5908 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5911 /* If this is testing a single bit, we can optimize the test. */
5912 if ((code == NE_EXPR || code == EQ_EXPR)
5913 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5914 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5916 tree inner = TREE_OPERAND (arg0, 0);
5917 tree type = TREE_TYPE (arg0);
5918 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5919 enum machine_mode operand_mode = TYPE_MODE (type);
5921 tree signed_type, unsigned_type, intermediate_type;
5924 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5925 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5926 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5927 if (arg00 != NULL_TREE
5928 /* This is only a win if casting to a signed type is cheap,
5929 i.e. when arg00's type is not a partial mode. */
5930 && TYPE_PRECISION (TREE_TYPE (arg00))
5931 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
5933 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5934 return fold (build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
5935 result_type, fold_convert (stype, arg00),
5936 fold_convert (stype, integer_zero_node)));
5939 /* Otherwise we have (A & C) != 0 where C is a single bit,
5940 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5941 Similarly for (A & C) == 0. */
5943 /* If INNER is a right shift of a constant and it plus BITNUM does
5944 not overflow, adjust BITNUM and INNER. */
5945 if (TREE_CODE (inner) == RSHIFT_EXPR
5946 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5947 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5948 && bitnum < TYPE_PRECISION (type)
5949 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5950 bitnum - TYPE_PRECISION (type)))
5952 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5953 inner = TREE_OPERAND (inner, 0);
5956 /* If we are going to be able to omit the AND below, we must do our
5957 operations as unsigned. If we must use the AND, we have a choice.
5958 Normally unsigned is faster, but for some machines signed is. */
5959 #ifdef LOAD_EXTEND_OP
5960 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
5961 && !flag_syntax_only) ? 0 : 1;
5966 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5967 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5968 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5969 inner = fold_convert (intermediate_type, inner);
5972 inner = build2 (RSHIFT_EXPR, intermediate_type,
5973 inner, size_int (bitnum));
5975 if (code == EQ_EXPR)
5976 inner = fold (build2 (BIT_XOR_EXPR, intermediate_type,
5977 inner, integer_one_node));
5979 /* Put the AND last so it can combine with more things. */
5980 inner = build2 (BIT_AND_EXPR, intermediate_type,
5981 inner, integer_one_node);
5983 /* Make sure to return the proper type. */
5984 inner = fold_convert (result_type, inner);
5991 /* Check whether we are allowed to reorder operands arg0 and arg1,
5992 such that the evaluation of arg1 occurs before arg0. */
5995 reorder_operands_p (tree arg0, tree arg1)
5997 if (! flag_evaluation_order)
5999 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6001 return ! TREE_SIDE_EFFECTS (arg0)
6002 && ! TREE_SIDE_EFFECTS (arg1);
6005 /* Test whether it is preferable two swap two operands, ARG0 and
6006 ARG1, for example because ARG0 is an integer constant and ARG1
6007 isn't. If REORDER is true, only recommend swapping if we can
6008 evaluate the operands in reverse order. */
6011 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
6013 STRIP_SIGN_NOPS (arg0);
6014 STRIP_SIGN_NOPS (arg1);
6016 if (TREE_CODE (arg1) == INTEGER_CST)
6018 if (TREE_CODE (arg0) == INTEGER_CST)
6021 if (TREE_CODE (arg1) == REAL_CST)
6023 if (TREE_CODE (arg0) == REAL_CST)
6026 if (TREE_CODE (arg1) == COMPLEX_CST)
6028 if (TREE_CODE (arg0) == COMPLEX_CST)
6031 if (TREE_CONSTANT (arg1))
6033 if (TREE_CONSTANT (arg0))
6039 if (reorder && flag_evaluation_order
6040 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6048 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6049 for commutative and comparison operators. Ensuring a canonical
6050 form allows the optimizers to find additional redundancies without
6051 having to explicitly check for both orderings. */
6052 if (TREE_CODE (arg0) == SSA_NAME
6053 && TREE_CODE (arg1) == SSA_NAME
6054 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6060 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6061 ARG0 is extended to a wider type. */
6064 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6066 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6068 tree shorter_type, outer_type;
6072 if (arg0_unw == arg0)
6074 shorter_type = TREE_TYPE (arg0_unw);
6076 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6079 arg1_unw = get_unwidened (arg1, shorter_type);
6083 /* If possible, express the comparison in the shorter mode. */
6084 if ((code == EQ_EXPR || code == NE_EXPR
6085 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6086 && (TREE_TYPE (arg1_unw) == shorter_type
6087 || (TREE_CODE (arg1_unw) == INTEGER_CST
6088 && TREE_CODE (shorter_type) == INTEGER_TYPE
6089 && int_fits_type_p (arg1_unw, shorter_type))))
6090 return fold (build (code, type, arg0_unw,
6091 fold_convert (shorter_type, arg1_unw)));
6093 if (TREE_CODE (arg1_unw) != INTEGER_CST)
6096 /* If we are comparing with the integer that does not fit into the range
6097 of the shorter type, the result is known. */
6098 outer_type = TREE_TYPE (arg1_unw);
6099 min = lower_bound_in_type (outer_type, shorter_type);
6100 max = upper_bound_in_type (outer_type, shorter_type);
6102 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6104 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6111 return omit_one_operand (type, integer_zero_node, arg0);
6116 return omit_one_operand (type, integer_one_node, arg0);
6122 return omit_one_operand (type, integer_one_node, arg0);
6124 return omit_one_operand (type, integer_zero_node, arg0);
6129 return omit_one_operand (type, integer_zero_node, arg0);
6131 return omit_one_operand (type, integer_one_node, arg0);
6140 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6141 ARG0 just the signedness is changed. */
6144 fold_sign_changed_comparison (enum tree_code code, tree type,
6145 tree arg0, tree arg1)
6147 tree arg0_inner, tmp;
6148 tree inner_type, outer_type;
6150 if (TREE_CODE (arg0) != NOP_EXPR)
6153 outer_type = TREE_TYPE (arg0);
6154 arg0_inner = TREE_OPERAND (arg0, 0);
6155 inner_type = TREE_TYPE (arg0_inner);
6157 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6160 if (TREE_CODE (arg1) != INTEGER_CST
6161 && !(TREE_CODE (arg1) == NOP_EXPR
6162 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6165 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6170 if (TREE_CODE (arg1) == INTEGER_CST)
6172 tmp = build_int_cst_wide (inner_type,
6173 TREE_INT_CST_LOW (arg1),
6174 TREE_INT_CST_HIGH (arg1));
6175 arg1 = force_fit_type (tmp, 0,
6176 TREE_OVERFLOW (arg1),
6177 TREE_CONSTANT_OVERFLOW (arg1));
6180 arg1 = fold_convert (inner_type, arg1);
6182 return fold (build (code, type, arg0_inner, arg1));
6185 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6186 step of the array. ADDR is the address. MULT is the multiplicative expression.
6187 If the function succeeds, the new address expression is returned. Otherwise
6188 NULL_TREE is returned. */
6191 try_move_mult_to_index (enum tree_code code, tree addr, tree mult)
6193 tree s, delta, step;
6194 tree arg0 = TREE_OPERAND (mult, 0), arg1 = TREE_OPERAND (mult, 1);
6195 tree ref = TREE_OPERAND (addr, 0), pref;
6202 if (TREE_CODE (arg0) == INTEGER_CST)
6207 else if (TREE_CODE (arg1) == INTEGER_CST)
6215 for (;; ref = TREE_OPERAND (ref, 0))
6217 if (TREE_CODE (ref) == ARRAY_REF)
6219 step = array_ref_element_size (ref);
6221 if (TREE_CODE (step) != INTEGER_CST)
6224 itype = TREE_TYPE (step);
6226 /* If the type sizes do not match, we might run into problems
6227 when one of them would overflow. */
6228 if (TYPE_PRECISION (itype) != TYPE_PRECISION (TREE_TYPE (s)))
6231 if (!operand_equal_p (step, fold_convert (itype, s), 0))
6234 delta = fold_convert (itype, delta);
6238 if (!handled_component_p (ref))
6242 /* We found the suitable array reference. So copy everything up to it,
6243 and replace the index. */
6245 pref = TREE_OPERAND (addr, 0);
6246 ret = copy_node (pref);
6251 pref = TREE_OPERAND (pref, 0);
6252 TREE_OPERAND (pos, 0) = copy_node (pref);
6253 pos = TREE_OPERAND (pos, 0);
6256 TREE_OPERAND (pos, 1) = fold (build2 (code, itype,
6257 TREE_OPERAND (pos, 1),
6260 return build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6264 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6265 means A >= Y && A != MAX, but in this case we know that
6266 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6269 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6271 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6273 if (TREE_CODE (bound) == LT_EXPR)
6274 a = TREE_OPERAND (bound, 0);
6275 else if (TREE_CODE (bound) == GT_EXPR)
6276 a = TREE_OPERAND (bound, 1);
6280 typea = TREE_TYPE (a);
6281 if (!INTEGRAL_TYPE_P (typea)
6282 && !POINTER_TYPE_P (typea))
6285 if (TREE_CODE (ineq) == LT_EXPR)
6287 a1 = TREE_OPERAND (ineq, 1);
6288 y = TREE_OPERAND (ineq, 0);
6290 else if (TREE_CODE (ineq) == GT_EXPR)
6292 a1 = TREE_OPERAND (ineq, 0);
6293 y = TREE_OPERAND (ineq, 1);
6298 if (TREE_TYPE (a1) != typea)
6301 diff = fold (build2 (MINUS_EXPR, typea, a1, a));
6302 if (!integer_onep (diff))
6305 return fold (build2 (GE_EXPR, type, a, y));
6308 /* Fold complex addition when both components are accessible by parts.
6309 Return non-null if successful. CODE should be PLUS_EXPR for addition,
6310 or MINUS_EXPR for subtraction. */
6313 fold_complex_add (tree type, tree ac, tree bc, enum tree_code code)
6315 tree ar, ai, br, bi, rr, ri, inner_type;
6317 if (TREE_CODE (ac) == COMPLEX_EXPR)
6318 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6319 else if (TREE_CODE (ac) == COMPLEX_CST)
6320 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6324 if (TREE_CODE (bc) == COMPLEX_EXPR)
6325 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6326 else if (TREE_CODE (bc) == COMPLEX_CST)
6327 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6331 inner_type = TREE_TYPE (type);
6333 rr = fold (build2 (code, inner_type, ar, br));
6334 ri = fold (build2 (code, inner_type, ai, bi));
6336 return fold (build2 (COMPLEX_EXPR, type, rr, ri));
6339 /* Perform some simplifications of complex multiplication when one or more
6340 of the components are constants or zeros. Return non-null if successful. */
6343 fold_complex_mult (tree type, tree ac, tree bc)
6345 tree ar, ai, br, bi, rr, ri, inner_type, zero;
6346 bool ar0, ai0, br0, bi0, bi1;
6348 if (TREE_CODE (ac) == COMPLEX_EXPR)
6349 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6350 else if (TREE_CODE (ac) == COMPLEX_CST)
6351 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6355 if (TREE_CODE (bc) == COMPLEX_EXPR)
6356 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6357 else if (TREE_CODE (bc) == COMPLEX_CST)
6358 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6362 inner_type = TREE_TYPE (type);
6365 if (SCALAR_FLOAT_TYPE_P (inner_type))
6367 ar0 = ai0 = br0 = bi0 = bi1 = false;
6369 /* We're only interested in +0.0 here, thus we don't use real_zerop. */
6371 if (TREE_CODE (ar) == REAL_CST
6372 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ar), dconst0))
6373 ar0 = true, zero = ar;
6375 if (TREE_CODE (ai) == REAL_CST
6376 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ai), dconst0))
6377 ai0 = true, zero = ai;
6379 if (TREE_CODE (br) == REAL_CST
6380 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (br), dconst0))
6381 br0 = true, zero = br;
6383 if (TREE_CODE (bi) == REAL_CST)
6385 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst0))
6386 bi0 = true, zero = bi;
6387 else if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst1))
6393 ar0 = integer_zerop (ar);
6396 ai0 = integer_zerop (ai);
6399 br0 = integer_zerop (br);
6402 bi0 = integer_zerop (bi);
6409 bi1 = integer_onep (bi);
6412 /* We won't optimize anything below unless something is zero. */
6416 if (ai0 && br0 && bi1)
6421 else if (ai0 && bi0)
6423 rr = fold (build2 (MULT_EXPR, inner_type, ar, br));
6426 else if (ai0 && br0)
6429 ri = fold (build2 (MULT_EXPR, inner_type, ar, bi));
6431 else if (ar0 && bi0)
6434 ri = fold (build2 (MULT_EXPR, inner_type, ai, br));
6436 else if (ar0 && br0)
6438 rr = fold (build2 (MULT_EXPR, inner_type, ai, br));
6439 rr = fold (build1 (NEGATE_EXPR, inner_type, rr));
6444 rr = fold (build2 (MULT_EXPR, inner_type, ar, br));
6445 ri = fold (build2 (MULT_EXPR, inner_type, ai, br));
6449 rr = fold (build2 (MULT_EXPR, inner_type, ar, br));
6450 ri = fold (build2 (MULT_EXPR, inner_type, ar, bi));
6454 rr = fold (build2 (MULT_EXPR, inner_type, ai, bi));
6455 rr = fold (build1 (NEGATE_EXPR, inner_type, rr));
6456 ri = fold (build2 (MULT_EXPR, inner_type, ar, bi));
6460 rr = fold (build2 (MULT_EXPR, inner_type, ai, bi));
6461 rr = fold (build1 (NEGATE_EXPR, inner_type, rr));
6462 ri = fold (build2 (MULT_EXPR, inner_type, ai, br));
6467 return fold (build2 (COMPLEX_EXPR, type, rr, ri));
6470 /* Perform constant folding and related simplification of EXPR.
6471 The related simplifications include x*1 => x, x*0 => 0, etc.,
6472 and application of the associative law.
6473 NOP_EXPR conversions may be removed freely (as long as we
6474 are careful not to change the type of the overall expression).
6475 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
6476 but we can constant-fold them if they have constant operands. */
6478 #ifdef ENABLE_FOLD_CHECKING
6479 # define fold(x) fold_1 (x)
6480 static tree fold_1 (tree);
6486 const tree t = expr;
6487 const tree type = TREE_TYPE (expr);
6488 tree t1 = NULL_TREE;
6490 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
6491 enum tree_code code = TREE_CODE (t);
6492 enum tree_code_class kind = TREE_CODE_CLASS (code);
6494 /* WINS will be nonzero when the switch is done
6495 if all operands are constant. */
6498 /* Return right away if a constant. */
6499 if (kind == tcc_constant)
6502 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
6506 /* Special case for conversion ops that can have fixed point args. */
6507 arg0 = TREE_OPERAND (t, 0);
6509 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
6511 STRIP_SIGN_NOPS (arg0);
6513 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
6514 subop = TREE_REALPART (arg0);
6518 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
6519 && TREE_CODE (subop) != REAL_CST)
6520 /* Note that TREE_CONSTANT isn't enough:
6521 static var addresses are constant but we can't
6522 do arithmetic on them. */
6525 else if (IS_EXPR_CODE_CLASS (kind))
6527 int len = TREE_CODE_LENGTH (code);
6529 for (i = 0; i < len; i++)
6531 tree op = TREE_OPERAND (t, i);
6535 continue; /* Valid for CALL_EXPR, at least. */
6537 /* Strip any conversions that don't change the mode. This is
6538 safe for every expression, except for a comparison expression
6539 because its signedness is derived from its operands. So, in
6540 the latter case, only strip conversions that don't change the
6543 Note that this is done as an internal manipulation within the
6544 constant folder, in order to find the simplest representation
6545 of the arguments so that their form can be studied. In any
6546 cases, the appropriate type conversions should be put back in
6547 the tree that will get out of the constant folder. */
6548 if (kind == tcc_comparison)
6549 STRIP_SIGN_NOPS (op);
6553 if (TREE_CODE (op) == COMPLEX_CST)
6554 subop = TREE_REALPART (op);
6558 if (TREE_CODE (subop) != INTEGER_CST
6559 && TREE_CODE (subop) != REAL_CST)
6560 /* Note that TREE_CONSTANT isn't enough:
6561 static var addresses are constant but we can't
6562 do arithmetic on them. */
6572 /* If this is a commutative operation, and ARG0 is a constant, move it
6573 to ARG1 to reduce the number of tests below. */
6574 if (commutative_tree_code (code)
6575 && tree_swap_operands_p (arg0, arg1, true))
6576 return fold (build2 (code, type, TREE_OPERAND (t, 1),
6577 TREE_OPERAND (t, 0)));
6579 /* Now WINS is set as described above,
6580 ARG0 is the first operand of EXPR,
6581 and ARG1 is the second operand (if it has more than one operand).
6583 First check for cases where an arithmetic operation is applied to a
6584 compound, conditional, or comparison operation. Push the arithmetic
6585 operation inside the compound or conditional to see if any folding
6586 can then be done. Convert comparison to conditional for this purpose.
6587 The also optimizes non-constant cases that used to be done in
6590 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
6591 one of the operands is a comparison and the other is a comparison, a
6592 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
6593 code below would make the expression more complex. Change it to a
6594 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
6595 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
6597 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
6598 || code == EQ_EXPR || code == NE_EXPR)
6599 && ((truth_value_p (TREE_CODE (arg0))
6600 && (truth_value_p (TREE_CODE (arg1))
6601 || (TREE_CODE (arg1) == BIT_AND_EXPR
6602 && integer_onep (TREE_OPERAND (arg1, 1)))))
6603 || (truth_value_p (TREE_CODE (arg1))
6604 && (truth_value_p (TREE_CODE (arg0))
6605 || (TREE_CODE (arg0) == BIT_AND_EXPR
6606 && integer_onep (TREE_OPERAND (arg0, 1)))))))
6608 tem = fold (build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
6609 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
6611 type, fold_convert (boolean_type_node, arg0),
6612 fold_convert (boolean_type_node, arg1)));
6614 if (code == EQ_EXPR)
6615 tem = invert_truthvalue (tem);
6620 if (TREE_CODE_CLASS (code) == tcc_unary)
6622 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6623 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6624 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
6625 else if (TREE_CODE (arg0) == COND_EXPR)
6627 tree arg01 = TREE_OPERAND (arg0, 1);
6628 tree arg02 = TREE_OPERAND (arg0, 2);
6629 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6630 arg01 = fold (build1 (code, type, arg01));
6631 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6632 arg02 = fold (build1 (code, type, arg02));
6633 tem = fold (build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6636 /* If this was a conversion, and all we did was to move into
6637 inside the COND_EXPR, bring it back out. But leave it if
6638 it is a conversion from integer to integer and the
6639 result precision is no wider than a word since such a
6640 conversion is cheap and may be optimized away by combine,
6641 while it couldn't if it were outside the COND_EXPR. Then return
6642 so we don't get into an infinite recursion loop taking the
6643 conversion out and then back in. */
6645 if ((code == NOP_EXPR || code == CONVERT_EXPR
6646 || code == NON_LVALUE_EXPR)
6647 && TREE_CODE (tem) == COND_EXPR
6648 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6649 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6650 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6651 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6652 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6653 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6654 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6656 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6657 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
6658 || flag_syntax_only))
6659 tem = build1 (code, type,
6661 TREE_TYPE (TREE_OPERAND
6662 (TREE_OPERAND (tem, 1), 0)),
6663 TREE_OPERAND (tem, 0),
6664 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6665 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6668 else if (COMPARISON_CLASS_P (arg0))
6670 if (TREE_CODE (type) == BOOLEAN_TYPE)
6672 arg0 = copy_node (arg0);
6673 TREE_TYPE (arg0) = type;
6676 else if (TREE_CODE (type) != INTEGER_TYPE)
6677 return fold (build3 (COND_EXPR, type, arg0,
6678 fold (build1 (code, type,
6680 fold (build1 (code, type,
6681 integer_zero_node))));
6684 else if (TREE_CODE_CLASS (code) == tcc_comparison
6685 && TREE_CODE (arg0) == COMPOUND_EXPR)
6686 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6687 fold (build2 (code, type, TREE_OPERAND (arg0, 1), arg1)));
6688 else if (TREE_CODE_CLASS (code) == tcc_comparison
6689 && TREE_CODE (arg1) == COMPOUND_EXPR)
6690 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6691 fold (build2 (code, type, arg0, TREE_OPERAND (arg1, 1))));
6692 else if (TREE_CODE_CLASS (code) == tcc_binary
6693 || TREE_CODE_CLASS (code) == tcc_comparison)
6695 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6696 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6697 fold (build2 (code, type, TREE_OPERAND (arg0, 1),
6699 if (TREE_CODE (arg1) == COMPOUND_EXPR
6700 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
6701 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6702 fold (build2 (code, type,
6703 arg0, TREE_OPERAND (arg1, 1))));
6705 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
6707 tem = fold_binary_op_with_conditional_arg (t, code, arg0, arg1,
6708 /*cond_first_p=*/1);
6709 if (tem != NULL_TREE)
6713 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
6715 tem = fold_binary_op_with_conditional_arg (t, code, arg1, arg0,
6716 /*cond_first_p=*/0);
6717 if (tem != NULL_TREE)
6725 return fold (DECL_INITIAL (t));
6730 case FIX_TRUNC_EXPR:
6732 case FIX_FLOOR_EXPR:
6733 case FIX_ROUND_EXPR:
6734 if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
6735 return TREE_OPERAND (t, 0);
6737 /* Handle cases of two conversions in a row. */
6738 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
6739 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
6741 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6742 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
6743 int inside_int = INTEGRAL_TYPE_P (inside_type);
6744 int inside_ptr = POINTER_TYPE_P (inside_type);
6745 int inside_float = FLOAT_TYPE_P (inside_type);
6746 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6747 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6748 int inter_int = INTEGRAL_TYPE_P (inter_type);
6749 int inter_ptr = POINTER_TYPE_P (inter_type);
6750 int inter_float = FLOAT_TYPE_P (inter_type);
6751 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6752 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6753 int final_int = INTEGRAL_TYPE_P (type);
6754 int final_ptr = POINTER_TYPE_P (type);
6755 int final_float = FLOAT_TYPE_P (type);
6756 unsigned int final_prec = TYPE_PRECISION (type);
6757 int final_unsignedp = TYPE_UNSIGNED (type);
6759 /* In addition to the cases of two conversions in a row
6760 handled below, if we are converting something to its own
6761 type via an object of identical or wider precision, neither
6762 conversion is needed. */
6763 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6764 && ((inter_int && final_int) || (inter_float && final_float))
6765 && inter_prec >= final_prec)
6766 return fold (build1 (code, type,
6767 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6769 /* Likewise, if the intermediate and final types are either both
6770 float or both integer, we don't need the middle conversion if
6771 it is wider than the final type and doesn't change the signedness
6772 (for integers). Avoid this if the final type is a pointer
6773 since then we sometimes need the inner conversion. Likewise if
6774 the outer has a precision not equal to the size of its mode. */
6775 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6776 || (inter_float && inside_float))
6777 && inter_prec >= inside_prec
6778 && (inter_float || inter_unsignedp == inside_unsignedp)
6779 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6780 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6782 return fold (build1 (code, type,
6783 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6785 /* If we have a sign-extension of a zero-extended value, we can
6786 replace that by a single zero-extension. */
6787 if (inside_int && inter_int && final_int
6788 && inside_prec < inter_prec && inter_prec < final_prec
6789 && inside_unsignedp && !inter_unsignedp)
6790 return fold (build1 (code, type,
6791 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6793 /* Two conversions in a row are not needed unless:
6794 - some conversion is floating-point (overstrict for now), or
6795 - the intermediate type is narrower than both initial and
6797 - the intermediate type and innermost type differ in signedness,
6798 and the outermost type is wider than the intermediate, or
6799 - the initial type is a pointer type and the precisions of the
6800 intermediate and final types differ, or
6801 - the final type is a pointer type and the precisions of the
6802 initial and intermediate types differ. */
6803 if (! inside_float && ! inter_float && ! final_float
6804 && (inter_prec > inside_prec || inter_prec > final_prec)
6805 && ! (inside_int && inter_int
6806 && inter_unsignedp != inside_unsignedp
6807 && inter_prec < final_prec)
6808 && ((inter_unsignedp && inter_prec > inside_prec)
6809 == (final_unsignedp && final_prec > inter_prec))
6810 && ! (inside_ptr && inter_prec != final_prec)
6811 && ! (final_ptr && inside_prec != inter_prec)
6812 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6813 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6815 return fold (build1 (code, type,
6816 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6819 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
6820 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
6821 /* Detect assigning a bitfield. */
6822 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
6823 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
6825 /* Don't leave an assignment inside a conversion
6826 unless assigning a bitfield. */
6827 tree prev = TREE_OPERAND (t, 0);
6828 tem = copy_node (t);
6829 TREE_OPERAND (tem, 0) = TREE_OPERAND (prev, 1);
6830 /* First do the assignment, then return converted constant. */
6831 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), prev, fold (tem));
6832 TREE_NO_WARNING (tem) = 1;
6833 TREE_USED (tem) = 1;
6837 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6838 constants (if x has signed type, the sign bit cannot be set
6839 in c). This folds extension into the BIT_AND_EXPR. */
6840 if (INTEGRAL_TYPE_P (type)
6841 && TREE_CODE (type) != BOOLEAN_TYPE
6842 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
6843 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
6845 tree and = TREE_OPERAND (t, 0);
6846 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6849 if (TYPE_UNSIGNED (TREE_TYPE (and))
6850 || (TYPE_PRECISION (type)
6851 <= TYPE_PRECISION (TREE_TYPE (and))))
6853 else if (TYPE_PRECISION (TREE_TYPE (and1))
6854 <= HOST_BITS_PER_WIDE_INT
6855 && host_integerp (and1, 1))
6857 unsigned HOST_WIDE_INT cst;
6859 cst = tree_low_cst (and1, 1);
6860 cst &= (HOST_WIDE_INT) -1
6861 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6862 change = (cst == 0);
6863 #ifdef LOAD_EXTEND_OP
6865 && !flag_syntax_only
6866 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6869 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6870 and0 = fold_convert (uns, and0);
6871 and1 = fold_convert (uns, and1);
6877 tem = build_int_cst_wide (type, TREE_INT_CST_LOW (and1),
6878 TREE_INT_CST_HIGH (and1));
6879 tem = force_fit_type (tem, 0, TREE_OVERFLOW (and1),
6880 TREE_CONSTANT_OVERFLOW (and1));
6881 return fold (build2 (BIT_AND_EXPR, type,
6882 fold_convert (type, and0), tem));
6886 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6887 T2 being pointers to types of the same size. */
6888 if (POINTER_TYPE_P (TREE_TYPE (t))
6889 && BINARY_CLASS_P (arg0)
6890 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6891 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6893 tree arg00 = TREE_OPERAND (arg0, 0);
6894 tree t0 = TREE_TYPE (t);
6895 tree t1 = TREE_TYPE (arg00);
6896 tree tt0 = TREE_TYPE (t0);
6897 tree tt1 = TREE_TYPE (t1);
6898 tree s0 = TYPE_SIZE (tt0);
6899 tree s1 = TYPE_SIZE (tt1);
6901 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6902 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6903 TREE_OPERAND (arg0, 1));
6906 tem = fold_convert_const (code, type, arg0);
6907 return tem ? tem : t;
6909 case VIEW_CONVERT_EXPR:
6910 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
6911 return build1 (VIEW_CONVERT_EXPR, type,
6912 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6916 if (TREE_CODE (arg0) == CONSTRUCTOR
6917 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
6919 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
6921 return TREE_VALUE (m);
6926 if (TREE_CONSTANT (t) != wins)
6928 tem = copy_node (t);
6929 TREE_CONSTANT (tem) = wins;
6930 TREE_INVARIANT (tem) = wins;
6936 if (negate_expr_p (arg0))
6937 return fold_convert (type, negate_expr (arg0));
6938 /* Convert - (~A) to A + 1. */
6939 if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == BIT_NOT_EXPR)
6940 return fold (build2 (PLUS_EXPR, type, TREE_OPERAND (arg0, 0),
6941 build_int_cst (type, 1)));
6945 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
6946 return fold_abs_const (arg0, type);
6947 else if (TREE_CODE (arg0) == NEGATE_EXPR)
6948 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
6949 /* Convert fabs((double)float) into (double)fabsf(float). */
6950 else if (TREE_CODE (arg0) == NOP_EXPR
6951 && TREE_CODE (type) == REAL_TYPE)
6953 tree targ0 = strip_float_extensions (arg0);
6955 return fold_convert (type, fold (build1 (ABS_EXPR,
6959 else if (tree_expr_nonnegative_p (arg0))
6962 /* Strip sign ops from argument. */
6963 if (TREE_CODE (type) == REAL_TYPE)
6965 tem = fold_strip_sign_ops (arg0);
6967 return fold (build1 (ABS_EXPR, type, fold_convert (type, tem)));
6972 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6973 return fold_convert (type, arg0);
6974 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6975 return build2 (COMPLEX_EXPR, type,
6976 TREE_OPERAND (arg0, 0),
6977 negate_expr (TREE_OPERAND (arg0, 1)));
6978 else if (TREE_CODE (arg0) == COMPLEX_CST)
6979 return build_complex (type, TREE_REALPART (arg0),
6980 negate_expr (TREE_IMAGPART (arg0)));
6981 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6982 return fold (build2 (TREE_CODE (arg0), type,
6983 fold (build1 (CONJ_EXPR, type,
6984 TREE_OPERAND (arg0, 0))),
6985 fold (build1 (CONJ_EXPR, type,
6986 TREE_OPERAND (arg0, 1)))));
6987 else if (TREE_CODE (arg0) == CONJ_EXPR)
6988 return TREE_OPERAND (arg0, 0);
6992 if (TREE_CODE (arg0) == INTEGER_CST)
6993 return fold_not_const (arg0, type);
6994 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
6995 return TREE_OPERAND (arg0, 0);
6996 /* Convert ~ (-A) to A - 1. */
6997 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
6998 return fold (build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
6999 build_int_cst (type, 1)));
7000 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
7001 else if (INTEGRAL_TYPE_P (type)
7002 && ((TREE_CODE (arg0) == MINUS_EXPR
7003 && integer_onep (TREE_OPERAND (arg0, 1)))
7004 || (TREE_CODE (arg0) == PLUS_EXPR
7005 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
7006 return fold (build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0)));
7010 /* A + (-B) -> A - B */
7011 if (TREE_CODE (arg1) == NEGATE_EXPR)
7012 return fold (build2 (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
7013 /* (-A) + B -> B - A */
7014 if (TREE_CODE (arg0) == NEGATE_EXPR
7015 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
7016 return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
7018 if (TREE_CODE (type) == COMPLEX_TYPE)
7020 tem = fold_complex_add (type, arg0, arg1, PLUS_EXPR);
7025 if (! FLOAT_TYPE_P (type))
7027 if (integer_zerop (arg1))
7028 return non_lvalue (fold_convert (type, arg0));
7030 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
7031 with a constant, and the two constants have no bits in common,
7032 we should treat this as a BIT_IOR_EXPR since this may produce more
7034 if (TREE_CODE (arg0) == BIT_AND_EXPR
7035 && TREE_CODE (arg1) == BIT_AND_EXPR
7036 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7037 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7038 && integer_zerop (const_binop (BIT_AND_EXPR,
7039 TREE_OPERAND (arg0, 1),
7040 TREE_OPERAND (arg1, 1), 0)))
7042 code = BIT_IOR_EXPR;
7046 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
7047 (plus (plus (mult) (mult)) (foo)) so that we can
7048 take advantage of the factoring cases below. */
7049 if (((TREE_CODE (arg0) == PLUS_EXPR
7050 || TREE_CODE (arg0) == MINUS_EXPR)
7051 && TREE_CODE (arg1) == MULT_EXPR)
7052 || ((TREE_CODE (arg1) == PLUS_EXPR
7053 || TREE_CODE (arg1) == MINUS_EXPR)
7054 && TREE_CODE (arg0) == MULT_EXPR))
7056 tree parg0, parg1, parg, marg;
7057 enum tree_code pcode;
7059 if (TREE_CODE (arg1) == MULT_EXPR)
7060 parg = arg0, marg = arg1;
7062 parg = arg1, marg = arg0;
7063 pcode = TREE_CODE (parg);
7064 parg0 = TREE_OPERAND (parg, 0);
7065 parg1 = TREE_OPERAND (parg, 1);
7069 if (TREE_CODE (parg0) == MULT_EXPR
7070 && TREE_CODE (parg1) != MULT_EXPR)
7071 return fold (build2 (pcode, type,
7072 fold (build2 (PLUS_EXPR, type,
7073 fold_convert (type, parg0),
7074 fold_convert (type, marg))),
7075 fold_convert (type, parg1)));
7076 if (TREE_CODE (parg0) != MULT_EXPR
7077 && TREE_CODE (parg1) == MULT_EXPR)
7078 return fold (build2 (PLUS_EXPR, type,
7079 fold_convert (type, parg0),
7080 fold (build2 (pcode, type,
7081 fold_convert (type, marg),
7086 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
7088 tree arg00, arg01, arg10, arg11;
7089 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7091 /* (A * C) + (B * C) -> (A+B) * C.
7092 We are most concerned about the case where C is a constant,
7093 but other combinations show up during loop reduction. Since
7094 it is not difficult, try all four possibilities. */
7096 arg00 = TREE_OPERAND (arg0, 0);
7097 arg01 = TREE_OPERAND (arg0, 1);
7098 arg10 = TREE_OPERAND (arg1, 0);
7099 arg11 = TREE_OPERAND (arg1, 1);
7102 if (operand_equal_p (arg01, arg11, 0))
7103 same = arg01, alt0 = arg00, alt1 = arg10;
7104 else if (operand_equal_p (arg00, arg10, 0))
7105 same = arg00, alt0 = arg01, alt1 = arg11;
7106 else if (operand_equal_p (arg00, arg11, 0))
7107 same = arg00, alt0 = arg01, alt1 = arg10;
7108 else if (operand_equal_p (arg01, arg10, 0))
7109 same = arg01, alt0 = arg00, alt1 = arg11;
7111 /* No identical multiplicands; see if we can find a common
7112 power-of-two factor in non-power-of-two multiplies. This
7113 can help in multi-dimensional array access. */
7114 else if (TREE_CODE (arg01) == INTEGER_CST
7115 && TREE_CODE (arg11) == INTEGER_CST
7116 && TREE_INT_CST_HIGH (arg01) == 0
7117 && TREE_INT_CST_HIGH (arg11) == 0)
7119 HOST_WIDE_INT int01, int11, tmp;
7120 int01 = TREE_INT_CST_LOW (arg01);
7121 int11 = TREE_INT_CST_LOW (arg11);
7123 /* Move min of absolute values to int11. */
7124 if ((int01 >= 0 ? int01 : -int01)
7125 < (int11 >= 0 ? int11 : -int11))
7127 tmp = int01, int01 = int11, int11 = tmp;
7128 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7129 alt0 = arg01, arg01 = arg11, arg11 = alt0;
7132 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
7134 alt0 = fold (build2 (MULT_EXPR, type, arg00,
7135 build_int_cst (NULL_TREE,
7143 return fold (build2 (MULT_EXPR, type,
7144 fold (build2 (PLUS_EXPR, type,
7145 fold_convert (type, alt0),
7146 fold_convert (type, alt1))),
7150 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
7151 of the array. Loop optimizer sometimes produce this type of
7153 if (TREE_CODE (arg0) == ADDR_EXPR
7154 && TREE_CODE (arg1) == MULT_EXPR)
7156 tem = try_move_mult_to_index (PLUS_EXPR, arg0, arg1);
7158 return fold_convert (type, fold (tem));
7160 else if (TREE_CODE (arg1) == ADDR_EXPR
7161 && TREE_CODE (arg0) == MULT_EXPR)
7163 tem = try_move_mult_to_index (PLUS_EXPR, arg1, arg0);
7165 return fold_convert (type, fold (tem));
7170 /* See if ARG1 is zero and X + ARG1 reduces to X. */
7171 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
7172 return non_lvalue (fold_convert (type, arg0));
7174 /* Likewise if the operands are reversed. */
7175 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7176 return non_lvalue (fold_convert (type, arg1));
7178 /* Convert X + -C into X - C. */
7179 if (TREE_CODE (arg1) == REAL_CST
7180 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
7182 tem = fold_negate_const (arg1, type);
7183 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
7184 return fold (build2 (MINUS_EXPR, type,
7185 fold_convert (type, arg0),
7186 fold_convert (type, tem)));
7189 /* Convert x+x into x*2.0. */
7190 if (operand_equal_p (arg0, arg1, 0)
7191 && SCALAR_FLOAT_TYPE_P (type))
7192 return fold (build2 (MULT_EXPR, type, arg0,
7193 build_real (type, dconst2)));
7195 /* Convert x*c+x into x*(c+1). */
7196 if (flag_unsafe_math_optimizations
7197 && TREE_CODE (arg0) == MULT_EXPR
7198 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7199 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
7200 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7204 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
7205 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7206 return fold (build2 (MULT_EXPR, type, arg1,
7207 build_real (type, c)));
7210 /* Convert x+x*c into x*(c+1). */
7211 if (flag_unsafe_math_optimizations
7212 && TREE_CODE (arg1) == MULT_EXPR
7213 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
7214 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
7215 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
7219 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
7220 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7221 return fold (build2 (MULT_EXPR, type, arg0,
7222 build_real (type, c)));
7225 /* Convert x*c1+x*c2 into x*(c1+c2). */
7226 if (flag_unsafe_math_optimizations
7227 && TREE_CODE (arg0) == MULT_EXPR
7228 && TREE_CODE (arg1) == MULT_EXPR
7229 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7230 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
7231 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
7232 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
7233 && operand_equal_p (TREE_OPERAND (arg0, 0),
7234 TREE_OPERAND (arg1, 0), 0))
7236 REAL_VALUE_TYPE c1, c2;
7238 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
7239 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
7240 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
7241 return fold (build2 (MULT_EXPR, type,
7242 TREE_OPERAND (arg0, 0),
7243 build_real (type, c1)));
7245 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
7246 if (flag_unsafe_math_optimizations
7247 && TREE_CODE (arg1) == PLUS_EXPR
7248 && TREE_CODE (arg0) != MULT_EXPR)
7250 tree tree10 = TREE_OPERAND (arg1, 0);
7251 tree tree11 = TREE_OPERAND (arg1, 1);
7252 if (TREE_CODE (tree11) == MULT_EXPR
7253 && TREE_CODE (tree10) == MULT_EXPR)
7256 tree0 = fold (build2 (PLUS_EXPR, type, arg0, tree10));
7257 return fold (build2 (PLUS_EXPR, type, tree0, tree11));
7260 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
7261 if (flag_unsafe_math_optimizations
7262 && TREE_CODE (arg0) == PLUS_EXPR
7263 && TREE_CODE (arg1) != MULT_EXPR)
7265 tree tree00 = TREE_OPERAND (arg0, 0);
7266 tree tree01 = TREE_OPERAND (arg0, 1);
7267 if (TREE_CODE (tree01) == MULT_EXPR
7268 && TREE_CODE (tree00) == MULT_EXPR)
7271 tree0 = fold (build2 (PLUS_EXPR, type, tree01, arg1));
7272 return fold (build2 (PLUS_EXPR, type, tree00, tree0));
7278 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
7279 is a rotate of A by C1 bits. */
7280 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
7281 is a rotate of A by B bits. */
7283 enum tree_code code0, code1;
7284 code0 = TREE_CODE (arg0);
7285 code1 = TREE_CODE (arg1);
7286 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
7287 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
7288 && operand_equal_p (TREE_OPERAND (arg0, 0),
7289 TREE_OPERAND (arg1, 0), 0)
7290 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7292 tree tree01, tree11;
7293 enum tree_code code01, code11;
7295 tree01 = TREE_OPERAND (arg0, 1);
7296 tree11 = TREE_OPERAND (arg1, 1);
7297 STRIP_NOPS (tree01);
7298 STRIP_NOPS (tree11);
7299 code01 = TREE_CODE (tree01);
7300 code11 = TREE_CODE (tree11);
7301 if (code01 == INTEGER_CST
7302 && code11 == INTEGER_CST
7303 && TREE_INT_CST_HIGH (tree01) == 0
7304 && TREE_INT_CST_HIGH (tree11) == 0
7305 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
7306 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
7307 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
7308 code0 == LSHIFT_EXPR ? tree01 : tree11);
7309 else if (code11 == MINUS_EXPR)
7311 tree tree110, tree111;
7312 tree110 = TREE_OPERAND (tree11, 0);
7313 tree111 = TREE_OPERAND (tree11, 1);
7314 STRIP_NOPS (tree110);
7315 STRIP_NOPS (tree111);
7316 if (TREE_CODE (tree110) == INTEGER_CST
7317 && 0 == compare_tree_int (tree110,
7319 (TREE_TYPE (TREE_OPERAND
7321 && operand_equal_p (tree01, tree111, 0))
7322 return build2 ((code0 == LSHIFT_EXPR
7325 type, TREE_OPERAND (arg0, 0), tree01);
7327 else if (code01 == MINUS_EXPR)
7329 tree tree010, tree011;
7330 tree010 = TREE_OPERAND (tree01, 0);
7331 tree011 = TREE_OPERAND (tree01, 1);
7332 STRIP_NOPS (tree010);
7333 STRIP_NOPS (tree011);
7334 if (TREE_CODE (tree010) == INTEGER_CST
7335 && 0 == compare_tree_int (tree010,
7337 (TREE_TYPE (TREE_OPERAND
7339 && operand_equal_p (tree11, tree011, 0))
7340 return build2 ((code0 != LSHIFT_EXPR
7343 type, TREE_OPERAND (arg0, 0), tree11);
7349 /* In most languages, can't associate operations on floats through
7350 parentheses. Rather than remember where the parentheses were, we
7351 don't associate floats at all, unless the user has specified
7352 -funsafe-math-optimizations. */
7355 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7357 tree var0, con0, lit0, minus_lit0;
7358 tree var1, con1, lit1, minus_lit1;
7360 /* Split both trees into variables, constants, and literals. Then
7361 associate each group together, the constants with literals,
7362 then the result with variables. This increases the chances of
7363 literals being recombined later and of generating relocatable
7364 expressions for the sum of a constant and literal. */
7365 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
7366 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
7367 code == MINUS_EXPR);
7369 /* Only do something if we found more than two objects. Otherwise,
7370 nothing has changed and we risk infinite recursion. */
7371 if (2 < ((var0 != 0) + (var1 != 0)
7372 + (con0 != 0) + (con1 != 0)
7373 + (lit0 != 0) + (lit1 != 0)
7374 + (minus_lit0 != 0) + (minus_lit1 != 0)))
7376 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
7377 if (code == MINUS_EXPR)
7380 var0 = associate_trees (var0, var1, code, type);
7381 con0 = associate_trees (con0, con1, code, type);
7382 lit0 = associate_trees (lit0, lit1, code, type);
7383 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
7385 /* Preserve the MINUS_EXPR if the negative part of the literal is
7386 greater than the positive part. Otherwise, the multiplicative
7387 folding code (i.e extract_muldiv) may be fooled in case
7388 unsigned constants are subtracted, like in the following
7389 example: ((X*2 + 4) - 8U)/2. */
7390 if (minus_lit0 && lit0)
7392 if (TREE_CODE (lit0) == INTEGER_CST
7393 && TREE_CODE (minus_lit0) == INTEGER_CST
7394 && tree_int_cst_lt (lit0, minus_lit0))
7396 minus_lit0 = associate_trees (minus_lit0, lit0,
7402 lit0 = associate_trees (lit0, minus_lit0,
7410 return fold_convert (type,
7411 associate_trees (var0, minus_lit0,
7415 con0 = associate_trees (con0, minus_lit0,
7417 return fold_convert (type,
7418 associate_trees (var0, con0,
7423 con0 = associate_trees (con0, lit0, code, type);
7424 return fold_convert (type, associate_trees (var0, con0,
7431 t1 = const_binop (code, arg0, arg1, 0);
7432 if (t1 != NULL_TREE)
7434 /* The return value should always have
7435 the same type as the original expression. */
7436 if (TREE_TYPE (t1) != type)
7437 t1 = fold_convert (type, t1);
7444 /* A - (-B) -> A + B */
7445 if (TREE_CODE (arg1) == NEGATE_EXPR)
7446 return fold (build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
7447 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
7448 if (TREE_CODE (arg0) == NEGATE_EXPR
7449 && (FLOAT_TYPE_P (type)
7450 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
7451 && negate_expr_p (arg1)
7452 && reorder_operands_p (arg0, arg1))
7453 return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
7454 TREE_OPERAND (arg0, 0)));
7456 if (TREE_CODE (type) == COMPLEX_TYPE)
7458 tem = fold_complex_add (type, arg0, arg1, MINUS_EXPR);
7463 if (! FLOAT_TYPE_P (type))
7465 if (! wins && integer_zerop (arg0))
7466 return negate_expr (fold_convert (type, arg1));
7467 if (integer_zerop (arg1))
7468 return non_lvalue (fold_convert (type, arg0));
7470 /* Fold A - (A & B) into ~B & A. */
7471 if (!TREE_SIDE_EFFECTS (arg0)
7472 && TREE_CODE (arg1) == BIT_AND_EXPR)
7474 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
7475 return fold (build2 (BIT_AND_EXPR, type,
7476 fold (build1 (BIT_NOT_EXPR, type,
7477 TREE_OPERAND (arg1, 0))),
7479 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7480 return fold (build2 (BIT_AND_EXPR, type,
7481 fold (build1 (BIT_NOT_EXPR, type,
7482 TREE_OPERAND (arg1, 1))),
7486 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
7487 any power of 2 minus 1. */
7488 if (TREE_CODE (arg0) == BIT_AND_EXPR
7489 && TREE_CODE (arg1) == BIT_AND_EXPR
7490 && operand_equal_p (TREE_OPERAND (arg0, 0),
7491 TREE_OPERAND (arg1, 0), 0))
7493 tree mask0 = TREE_OPERAND (arg0, 1);
7494 tree mask1 = TREE_OPERAND (arg1, 1);
7495 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
7497 if (operand_equal_p (tem, mask1, 0))
7499 tem = fold (build2 (BIT_XOR_EXPR, type,
7500 TREE_OPERAND (arg0, 0), mask1));
7501 return fold (build2 (MINUS_EXPR, type, tem, mask1));
7506 /* See if ARG1 is zero and X - ARG1 reduces to X. */
7507 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
7508 return non_lvalue (fold_convert (type, arg0));
7510 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
7511 ARG0 is zero and X + ARG0 reduces to X, since that would mean
7512 (-ARG1 + ARG0) reduces to -ARG1. */
7513 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7514 return negate_expr (fold_convert (type, arg1));
7516 /* Fold &x - &x. This can happen from &x.foo - &x.
7517 This is unsafe for certain floats even in non-IEEE formats.
7518 In IEEE, it is unsafe because it does wrong for NaNs.
7519 Also note that operand_equal_p is always false if an operand
7522 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
7523 && operand_equal_p (arg0, arg1, 0))
7524 return fold_convert (type, integer_zero_node);
7526 /* A - B -> A + (-B) if B is easily negatable. */
7527 if (!wins && negate_expr_p (arg1)
7528 && ((FLOAT_TYPE_P (type)
7529 /* Avoid this transformation if B is a positive REAL_CST. */
7530 && (TREE_CODE (arg1) != REAL_CST
7531 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
7532 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
7533 return fold (build2 (PLUS_EXPR, type, arg0, negate_expr (arg1)));
7535 /* Try folding difference of addresses. */
7539 if ((TREE_CODE (arg0) == ADDR_EXPR
7540 || TREE_CODE (arg1) == ADDR_EXPR)
7541 && ptr_difference_const (arg0, arg1, &diff))
7542 return build_int_cst_type (type, diff);
7545 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
7546 of the array. Loop optimizer sometimes produce this type of
7548 if (TREE_CODE (arg0) == ADDR_EXPR
7549 && TREE_CODE (arg1) == MULT_EXPR)
7551 tem = try_move_mult_to_index (MINUS_EXPR, arg0, arg1);
7553 return fold_convert (type, fold (tem));
7556 if (TREE_CODE (arg0) == MULT_EXPR
7557 && TREE_CODE (arg1) == MULT_EXPR
7558 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7560 /* (A * C) - (B * C) -> (A-B) * C. */
7561 if (operand_equal_p (TREE_OPERAND (arg0, 1),
7562 TREE_OPERAND (arg1, 1), 0))
7563 return fold (build2 (MULT_EXPR, type,
7564 fold (build2 (MINUS_EXPR, type,
7565 TREE_OPERAND (arg0, 0),
7566 TREE_OPERAND (arg1, 0))),
7567 TREE_OPERAND (arg0, 1)));
7568 /* (A * C1) - (A * C2) -> A * (C1-C2). */
7569 if (operand_equal_p (TREE_OPERAND (arg0, 0),
7570 TREE_OPERAND (arg1, 0), 0))
7571 return fold (build2 (MULT_EXPR, type,
7572 TREE_OPERAND (arg0, 0),
7573 fold (build2 (MINUS_EXPR, type,
7574 TREE_OPERAND (arg0, 1),
7575 TREE_OPERAND (arg1, 1)))));
7581 /* (-A) * (-B) -> A * B */
7582 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7583 return fold (build2 (MULT_EXPR, type,
7584 TREE_OPERAND (arg0, 0),
7585 negate_expr (arg1)));
7586 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7587 return fold (build2 (MULT_EXPR, type,
7589 TREE_OPERAND (arg1, 0)));
7591 if (TREE_CODE (type) == COMPLEX_TYPE)
7593 tem = fold_complex_mult (type, arg0, arg1);
7598 if (! FLOAT_TYPE_P (type))
7600 if (integer_zerop (arg1))
7601 return omit_one_operand (type, arg1, arg0);
7602 if (integer_onep (arg1))
7603 return non_lvalue (fold_convert (type, arg0));
7605 /* (a * (1 << b)) is (a << b) */
7606 if (TREE_CODE (arg1) == LSHIFT_EXPR
7607 && integer_onep (TREE_OPERAND (arg1, 0)))
7608 return fold (build2 (LSHIFT_EXPR, type, arg0,
7609 TREE_OPERAND (arg1, 1)));
7610 if (TREE_CODE (arg0) == LSHIFT_EXPR
7611 && integer_onep (TREE_OPERAND (arg0, 0)))
7612 return fold (build2 (LSHIFT_EXPR, type, arg1,
7613 TREE_OPERAND (arg0, 1)));
7615 if (TREE_CODE (arg1) == INTEGER_CST
7616 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
7617 fold_convert (type, arg1),
7619 return fold_convert (type, tem);
7624 /* Maybe fold x * 0 to 0. The expressions aren't the same
7625 when x is NaN, since x * 0 is also NaN. Nor are they the
7626 same in modes with signed zeros, since multiplying a
7627 negative value by 0 gives -0, not +0. */
7628 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
7629 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
7630 && real_zerop (arg1))
7631 return omit_one_operand (type, arg1, arg0);
7632 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7633 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7634 && real_onep (arg1))
7635 return non_lvalue (fold_convert (type, arg0));
7637 /* Transform x * -1.0 into -x. */
7638 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7639 && real_minus_onep (arg1))
7640 return fold_convert (type, negate_expr (arg0));
7642 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7643 if (flag_unsafe_math_optimizations
7644 && TREE_CODE (arg0) == RDIV_EXPR
7645 && TREE_CODE (arg1) == REAL_CST
7646 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
7648 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
7651 return fold (build2 (RDIV_EXPR, type, tem,
7652 TREE_OPERAND (arg0, 1)));
7655 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
7656 if (operand_equal_p (arg0, arg1, 0))
7658 tree tem = fold_strip_sign_ops (arg0);
7659 if (tem != NULL_TREE)
7661 tem = fold_convert (type, tem);
7662 return fold (build2 (MULT_EXPR, type, tem, tem));
7666 if (flag_unsafe_math_optimizations)
7668 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7669 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7671 /* Optimizations of root(...)*root(...). */
7672 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
7674 tree rootfn, arg, arglist;
7675 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7676 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7678 /* Optimize sqrt(x)*sqrt(x) as x. */
7679 if (BUILTIN_SQRT_P (fcode0)
7680 && operand_equal_p (arg00, arg10, 0)
7681 && ! HONOR_SNANS (TYPE_MODE (type)))
7684 /* Optimize root(x)*root(y) as root(x*y). */
7685 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7686 arg = fold (build2 (MULT_EXPR, type, arg00, arg10));
7687 arglist = build_tree_list (NULL_TREE, arg);
7688 return build_function_call_expr (rootfn, arglist);
7691 /* Optimize expN(x)*expN(y) as expN(x+y). */
7692 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
7694 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7695 tree arg = build2 (PLUS_EXPR, type,
7696 TREE_VALUE (TREE_OPERAND (arg0, 1)),
7697 TREE_VALUE (TREE_OPERAND (arg1, 1)));
7698 tree arglist = build_tree_list (NULL_TREE, fold (arg));
7699 return build_function_call_expr (expfn, arglist);
7702 /* Optimizations of pow(...)*pow(...). */
7703 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
7704 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
7705 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
7707 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7708 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7710 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7711 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7714 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7715 if (operand_equal_p (arg01, arg11, 0))
7717 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7718 tree arg = build2 (MULT_EXPR, type, arg00, arg10);
7719 tree arglist = tree_cons (NULL_TREE, fold (arg),
7720 build_tree_list (NULL_TREE,
7722 return build_function_call_expr (powfn, arglist);
7725 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7726 if (operand_equal_p (arg00, arg10, 0))
7728 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7729 tree arg = fold (build2 (PLUS_EXPR, type, arg01, arg11));
7730 tree arglist = tree_cons (NULL_TREE, arg00,
7731 build_tree_list (NULL_TREE,
7733 return build_function_call_expr (powfn, arglist);
7737 /* Optimize tan(x)*cos(x) as sin(x). */
7738 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
7739 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
7740 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
7741 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
7742 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
7743 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
7744 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7745 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7747 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
7749 if (sinfn != NULL_TREE)
7750 return build_function_call_expr (sinfn,
7751 TREE_OPERAND (arg0, 1));
7754 /* Optimize x*pow(x,c) as pow(x,c+1). */
7755 if (fcode1 == BUILT_IN_POW
7756 || fcode1 == BUILT_IN_POWF
7757 || fcode1 == BUILT_IN_POWL)
7759 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7760 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7762 if (TREE_CODE (arg11) == REAL_CST
7763 && ! TREE_CONSTANT_OVERFLOW (arg11)
7764 && operand_equal_p (arg0, arg10, 0))
7766 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7770 c = TREE_REAL_CST (arg11);
7771 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7772 arg = build_real (type, c);
7773 arglist = build_tree_list (NULL_TREE, arg);
7774 arglist = tree_cons (NULL_TREE, arg0, arglist);
7775 return build_function_call_expr (powfn, arglist);
7779 /* Optimize pow(x,c)*x as pow(x,c+1). */
7780 if (fcode0 == BUILT_IN_POW
7781 || fcode0 == BUILT_IN_POWF
7782 || fcode0 == BUILT_IN_POWL)
7784 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7785 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7787 if (TREE_CODE (arg01) == REAL_CST
7788 && ! TREE_CONSTANT_OVERFLOW (arg01)
7789 && operand_equal_p (arg1, arg00, 0))
7791 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7795 c = TREE_REAL_CST (arg01);
7796 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7797 arg = build_real (type, c);
7798 arglist = build_tree_list (NULL_TREE, arg);
7799 arglist = tree_cons (NULL_TREE, arg1, arglist);
7800 return build_function_call_expr (powfn, arglist);
7804 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
7806 && operand_equal_p (arg0, arg1, 0))
7808 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
7812 tree arg = build_real (type, dconst2);
7813 tree arglist = build_tree_list (NULL_TREE, arg);
7814 arglist = tree_cons (NULL_TREE, arg0, arglist);
7815 return build_function_call_expr (powfn, arglist);
7824 if (integer_all_onesp (arg1))
7825 return omit_one_operand (type, arg1, arg0);
7826 if (integer_zerop (arg1))
7827 return non_lvalue (fold_convert (type, arg0));
7828 if (operand_equal_p (arg0, arg1, 0))
7829 return non_lvalue (fold_convert (type, arg0));
7832 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7833 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7835 t1 = build_int_cst (type, -1);
7836 t1 = force_fit_type (t1, 0, false, false);
7837 return omit_one_operand (type, t1, arg1);
7841 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7842 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7844 t1 = build_int_cst (type, -1);
7845 t1 = force_fit_type (t1, 0, false, false);
7846 return omit_one_operand (type, t1, arg0);
7849 t1 = distribute_bit_expr (code, type, arg0, arg1);
7850 if (t1 != NULL_TREE)
7853 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
7855 This results in more efficient code for machines without a NAND
7856 instruction. Combine will canonicalize to the first form
7857 which will allow use of NAND instructions provided by the
7858 backend if they exist. */
7859 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7860 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7862 return fold (build1 (BIT_NOT_EXPR, type,
7863 build2 (BIT_AND_EXPR, type,
7864 TREE_OPERAND (arg0, 0),
7865 TREE_OPERAND (arg1, 0))));
7868 /* See if this can be simplified into a rotate first. If that
7869 is unsuccessful continue in the association code. */
7873 if (integer_zerop (arg1))
7874 return non_lvalue (fold_convert (type, arg0));
7875 if (integer_all_onesp (arg1))
7876 return fold (build1 (BIT_NOT_EXPR, type, arg0));
7877 if (operand_equal_p (arg0, arg1, 0))
7878 return omit_one_operand (type, integer_zero_node, arg0);
7881 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7882 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7884 t1 = build_int_cst (type, -1);
7885 t1 = force_fit_type (t1, 0, false, false);
7886 return omit_one_operand (type, t1, arg1);
7890 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7891 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7893 t1 = build_int_cst (type, -1);
7894 t1 = force_fit_type (t1, 0, false, false);
7895 return omit_one_operand (type, t1, arg0);
7898 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
7899 with a constant, and the two constants have no bits in common,
7900 we should treat this as a BIT_IOR_EXPR since this may produce more
7902 if (TREE_CODE (arg0) == BIT_AND_EXPR
7903 && TREE_CODE (arg1) == BIT_AND_EXPR
7904 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7905 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7906 && integer_zerop (const_binop (BIT_AND_EXPR,
7907 TREE_OPERAND (arg0, 1),
7908 TREE_OPERAND (arg1, 1), 0)))
7910 code = BIT_IOR_EXPR;
7914 /* See if this can be simplified into a rotate first. If that
7915 is unsuccessful continue in the association code. */
7919 if (integer_all_onesp (arg1))
7920 return non_lvalue (fold_convert (type, arg0));
7921 if (integer_zerop (arg1))
7922 return omit_one_operand (type, arg1, arg0);
7923 if (operand_equal_p (arg0, arg1, 0))
7924 return non_lvalue (fold_convert (type, arg0));
7926 /* ~X & X is always zero. */
7927 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7928 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7929 return omit_one_operand (type, integer_zero_node, arg1);
7931 /* X & ~X is always zero. */
7932 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7933 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7934 return omit_one_operand (type, integer_zero_node, arg0);
7936 t1 = distribute_bit_expr (code, type, arg0, arg1);
7937 if (t1 != NULL_TREE)
7939 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
7940 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
7941 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7944 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
7946 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
7947 && (~TREE_INT_CST_LOW (arg1)
7948 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
7949 return fold_convert (type, TREE_OPERAND (arg0, 0));
7952 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
7954 This results in more efficient code for machines without a NOR
7955 instruction. Combine will canonicalize to the first form
7956 which will allow use of NOR instructions provided by the
7957 backend if they exist. */
7958 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7959 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7961 return fold (build1 (BIT_NOT_EXPR, type,
7962 build2 (BIT_IOR_EXPR, type,
7963 TREE_OPERAND (arg0, 0),
7964 TREE_OPERAND (arg1, 0))));
7970 /* Don't touch a floating-point divide by zero unless the mode
7971 of the constant can represent infinity. */
7972 if (TREE_CODE (arg1) == REAL_CST
7973 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
7974 && real_zerop (arg1))
7977 /* (-A) / (-B) -> A / B */
7978 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7979 return fold (build2 (RDIV_EXPR, type,
7980 TREE_OPERAND (arg0, 0),
7981 negate_expr (arg1)));
7982 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7983 return fold (build2 (RDIV_EXPR, type,
7985 TREE_OPERAND (arg1, 0)));
7987 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
7988 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7989 && real_onep (arg1))
7990 return non_lvalue (fold_convert (type, arg0));
7992 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
7993 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7994 && real_minus_onep (arg1))
7995 return non_lvalue (fold_convert (type, negate_expr (arg0)));
7997 /* If ARG1 is a constant, we can convert this to a multiply by the
7998 reciprocal. This does not have the same rounding properties,
7999 so only do this if -funsafe-math-optimizations. We can actually
8000 always safely do it if ARG1 is a power of two, but it's hard to
8001 tell if it is or not in a portable manner. */
8002 if (TREE_CODE (arg1) == REAL_CST)
8004 if (flag_unsafe_math_optimizations
8005 && 0 != (tem = const_binop (code, build_real (type, dconst1),
8007 return fold (build2 (MULT_EXPR, type, arg0, tem));
8008 /* Find the reciprocal if optimizing and the result is exact. */
8012 r = TREE_REAL_CST (arg1);
8013 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
8015 tem = build_real (type, r);
8016 return fold (build2 (MULT_EXPR, type, arg0, tem));
8020 /* Convert A/B/C to A/(B*C). */
8021 if (flag_unsafe_math_optimizations
8022 && TREE_CODE (arg0) == RDIV_EXPR)
8023 return fold (build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
8024 fold (build2 (MULT_EXPR, type,
8025 TREE_OPERAND (arg0, 1), arg1))));
8027 /* Convert A/(B/C) to (A/B)*C. */
8028 if (flag_unsafe_math_optimizations
8029 && TREE_CODE (arg1) == RDIV_EXPR)
8030 return fold (build2 (MULT_EXPR, type,
8031 fold (build2 (RDIV_EXPR, type, arg0,
8032 TREE_OPERAND (arg1, 0))),
8033 TREE_OPERAND (arg1, 1)));
8035 /* Convert C1/(X*C2) into (C1/C2)/X. */
8036 if (flag_unsafe_math_optimizations
8037 && TREE_CODE (arg1) == MULT_EXPR
8038 && TREE_CODE (arg0) == REAL_CST
8039 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
8041 tree tem = const_binop (RDIV_EXPR, arg0,
8042 TREE_OPERAND (arg1, 1), 0);
8044 return fold (build2 (RDIV_EXPR, type, tem,
8045 TREE_OPERAND (arg1, 0)));
8048 if (flag_unsafe_math_optimizations)
8050 enum built_in_function fcode = builtin_mathfn_code (arg1);
8051 /* Optimize x/expN(y) into x*expN(-y). */
8052 if (BUILTIN_EXPONENT_P (fcode))
8054 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8055 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
8056 tree arglist = build_tree_list (NULL_TREE,
8057 fold_convert (type, arg));
8058 arg1 = build_function_call_expr (expfn, arglist);
8059 return fold (build2 (MULT_EXPR, type, arg0, arg1));
8062 /* Optimize x/pow(y,z) into x*pow(y,-z). */
8063 if (fcode == BUILT_IN_POW
8064 || fcode == BUILT_IN_POWF
8065 || fcode == BUILT_IN_POWL)
8067 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8068 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
8069 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
8070 tree neg11 = fold_convert (type, negate_expr (arg11));
8071 tree arglist = tree_cons(NULL_TREE, arg10,
8072 build_tree_list (NULL_TREE, neg11));
8073 arg1 = build_function_call_expr (powfn, arglist);
8074 return fold (build2 (MULT_EXPR, type, arg0, arg1));
8078 if (flag_unsafe_math_optimizations)
8080 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
8081 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
8083 /* Optimize sin(x)/cos(x) as tan(x). */
8084 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
8085 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
8086 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
8087 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8088 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8090 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
8092 if (tanfn != NULL_TREE)
8093 return build_function_call_expr (tanfn,
8094 TREE_OPERAND (arg0, 1));
8097 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
8098 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
8099 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
8100 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
8101 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8102 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8104 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
8106 if (tanfn != NULL_TREE)
8108 tree tmp = TREE_OPERAND (arg0, 1);
8109 tmp = build_function_call_expr (tanfn, tmp);
8110 return fold (build2 (RDIV_EXPR, type,
8111 build_real (type, dconst1), tmp));
8115 /* Optimize pow(x,c)/x as pow(x,c-1). */
8116 if (fcode0 == BUILT_IN_POW
8117 || fcode0 == BUILT_IN_POWF
8118 || fcode0 == BUILT_IN_POWL)
8120 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
8121 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
8122 if (TREE_CODE (arg01) == REAL_CST
8123 && ! TREE_CONSTANT_OVERFLOW (arg01)
8124 && operand_equal_p (arg1, arg00, 0))
8126 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8130 c = TREE_REAL_CST (arg01);
8131 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
8132 arg = build_real (type, c);
8133 arglist = build_tree_list (NULL_TREE, arg);
8134 arglist = tree_cons (NULL_TREE, arg1, arglist);
8135 return build_function_call_expr (powfn, arglist);
8141 case TRUNC_DIV_EXPR:
8142 case ROUND_DIV_EXPR:
8143 case FLOOR_DIV_EXPR:
8145 case EXACT_DIV_EXPR:
8146 if (integer_onep (arg1))
8147 return non_lvalue (fold_convert (type, arg0));
8148 if (integer_zerop (arg1))
8151 if (!TYPE_UNSIGNED (type)
8152 && TREE_CODE (arg1) == INTEGER_CST
8153 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
8154 && TREE_INT_CST_HIGH (arg1) == -1)
8155 return fold_convert (type, negate_expr (arg0));
8157 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
8158 operation, EXACT_DIV_EXPR.
8160 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
8161 At one time others generated faster code, it's not clear if they do
8162 after the last round to changes to the DIV code in expmed.c. */
8163 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
8164 && multiple_of_p (type, arg0, arg1))
8165 return fold (build2 (EXACT_DIV_EXPR, type, arg0, arg1));
8167 if (TREE_CODE (arg1) == INTEGER_CST
8168 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
8170 return fold_convert (type, tem);
8175 case FLOOR_MOD_EXPR:
8176 case ROUND_MOD_EXPR:
8177 case TRUNC_MOD_EXPR:
8178 /* X % 1 is always zero, but be sure to preserve any side
8180 if (integer_onep (arg1))
8181 return omit_one_operand (type, integer_zero_node, arg0);
8183 /* X % 0, return X % 0 unchanged so that we can get the
8184 proper warnings and errors. */
8185 if (integer_zerop (arg1))
8188 /* 0 % X is always zero, but be sure to preserve any side
8189 effects in X. Place this after checking for X == 0. */
8190 if (integer_zerop (arg0))
8191 return omit_one_operand (type, integer_zero_node, arg1);
8193 /* X % -1 is zero. */
8194 if (!TYPE_UNSIGNED (type)
8195 && TREE_CODE (arg1) == INTEGER_CST
8196 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
8197 && TREE_INT_CST_HIGH (arg1) == -1)
8198 return omit_one_operand (type, integer_zero_node, arg0);
8200 /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
8201 BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
8202 if (code == TRUNC_MOD_EXPR
8203 && TYPE_UNSIGNED (type)
8204 && integer_pow2p (arg1))
8206 unsigned HOST_WIDE_INT high, low;
8210 l = tree_log2 (arg1);
8211 if (l >= HOST_BITS_PER_WIDE_INT)
8213 high = ((unsigned HOST_WIDE_INT) 1
8214 << (l - HOST_BITS_PER_WIDE_INT)) - 1;
8220 low = ((unsigned HOST_WIDE_INT) 1 << l) - 1;
8223 mask = build_int_cst_wide (type, low, high);
8224 return fold (build2 (BIT_AND_EXPR, type,
8225 fold_convert (type, arg0), mask));
8228 /* X % -C is the same as X % C. */
8229 if (code == TRUNC_MOD_EXPR
8230 && !TYPE_UNSIGNED (type)
8231 && TREE_CODE (arg1) == INTEGER_CST
8232 && TREE_INT_CST_HIGH (arg1) < 0
8234 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
8235 && !sign_bit_p (arg1, arg1))
8236 return fold (build2 (code, type, fold_convert (type, arg0),
8237 fold_convert (type, negate_expr (arg1))));
8239 /* X % -Y is the same as X % Y. */
8240 if (code == TRUNC_MOD_EXPR
8241 && !TYPE_UNSIGNED (type)
8242 && TREE_CODE (arg1) == NEGATE_EXPR
8244 return fold (build2 (code, type, fold_convert (type, arg0),
8245 fold_convert (type, TREE_OPERAND (arg1, 0))));
8247 if (TREE_CODE (arg1) == INTEGER_CST
8248 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
8250 return fold_convert (type, tem);
8256 if (integer_all_onesp (arg0))
8257 return omit_one_operand (type, arg0, arg1);
8261 /* Optimize -1 >> x for arithmetic right shifts. */
8262 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
8263 return omit_one_operand (type, arg0, arg1);
8264 /* ... fall through ... */
8268 if (integer_zerop (arg1))
8269 return non_lvalue (fold_convert (type, arg0));
8270 if (integer_zerop (arg0))
8271 return omit_one_operand (type, arg0, arg1);
8273 /* Since negative shift count is not well-defined,
8274 don't try to compute it in the compiler. */
8275 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
8277 /* Rewrite an LROTATE_EXPR by a constant into an
8278 RROTATE_EXPR by a new constant. */
8279 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
8281 tree tem = build_int_cst (NULL_TREE,
8282 GET_MODE_BITSIZE (TYPE_MODE (type)));
8283 tem = fold_convert (TREE_TYPE (arg1), tem);
8284 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
8285 return fold (build2 (RROTATE_EXPR, type, arg0, tem));
8288 /* If we have a rotate of a bit operation with the rotate count and
8289 the second operand of the bit operation both constant,
8290 permute the two operations. */
8291 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8292 && (TREE_CODE (arg0) == BIT_AND_EXPR
8293 || TREE_CODE (arg0) == BIT_IOR_EXPR
8294 || TREE_CODE (arg0) == BIT_XOR_EXPR)
8295 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8296 return fold (build2 (TREE_CODE (arg0), type,
8297 fold (build2 (code, type,
8298 TREE_OPERAND (arg0, 0), arg1)),
8299 fold (build2 (code, type,
8300 TREE_OPERAND (arg0, 1), arg1))));
8302 /* Two consecutive rotates adding up to the width of the mode can
8304 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8305 && TREE_CODE (arg0) == RROTATE_EXPR
8306 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8307 && TREE_INT_CST_HIGH (arg1) == 0
8308 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
8309 && ((TREE_INT_CST_LOW (arg1)
8310 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
8311 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
8312 return TREE_OPERAND (arg0, 0);
8317 if (operand_equal_p (arg0, arg1, 0))
8318 return omit_one_operand (type, arg0, arg1);
8319 if (INTEGRAL_TYPE_P (type)
8320 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
8321 return omit_one_operand (type, arg1, arg0);
8325 if (operand_equal_p (arg0, arg1, 0))
8326 return omit_one_operand (type, arg0, arg1);
8327 if (INTEGRAL_TYPE_P (type)
8328 && TYPE_MAX_VALUE (type)
8329 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
8330 return omit_one_operand (type, arg1, arg0);
8333 case TRUTH_NOT_EXPR:
8334 /* The argument to invert_truthvalue must have Boolean type. */
8335 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8336 arg0 = fold_convert (boolean_type_node, arg0);
8338 /* Note that the operand of this must be an int
8339 and its values must be 0 or 1.
8340 ("true" is a fixed value perhaps depending on the language,
8341 but we don't handle values other than 1 correctly yet.) */
8342 tem = invert_truthvalue (arg0);
8343 /* Avoid infinite recursion. */
8344 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
8346 return fold_convert (type, tem);
8348 case TRUTH_ANDIF_EXPR:
8349 /* Note that the operands of this must be ints
8350 and their values must be 0 or 1.
8351 ("true" is a fixed value perhaps depending on the language.) */
8352 /* If first arg is constant zero, return it. */
8353 if (integer_zerop (arg0))
8354 return fold_convert (type, arg0);
8355 case TRUTH_AND_EXPR:
8356 /* If either arg is constant true, drop it. */
8357 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8358 return non_lvalue (fold_convert (type, arg1));
8359 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
8360 /* Preserve sequence points. */
8361 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8362 return non_lvalue (fold_convert (type, arg0));
8363 /* If second arg is constant zero, result is zero, but first arg
8364 must be evaluated. */
8365 if (integer_zerop (arg1))
8366 return omit_one_operand (type, arg1, arg0);
8367 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
8368 case will be handled here. */
8369 if (integer_zerop (arg0))
8370 return omit_one_operand (type, arg0, arg1);
8372 /* !X && X is always false. */
8373 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8374 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8375 return omit_one_operand (type, integer_zero_node, arg1);
8376 /* X && !X is always false. */
8377 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8378 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8379 return omit_one_operand (type, integer_zero_node, arg0);
8381 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
8382 means A >= Y && A != MAX, but in this case we know that
8385 if (!TREE_SIDE_EFFECTS (arg0)
8386 && !TREE_SIDE_EFFECTS (arg1))
8388 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
8390 return fold (build2 (code, type, tem, arg1));
8392 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
8394 return fold (build2 (code, type, arg0, tem));
8398 /* We only do these simplifications if we are optimizing. */
8402 /* Check for things like (A || B) && (A || C). We can convert this
8403 to A || (B && C). Note that either operator can be any of the four
8404 truth and/or operations and the transformation will still be
8405 valid. Also note that we only care about order for the
8406 ANDIF and ORIF operators. If B contains side effects, this
8407 might change the truth-value of A. */
8408 if (TREE_CODE (arg0) == TREE_CODE (arg1)
8409 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
8410 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
8411 || TREE_CODE (arg0) == TRUTH_AND_EXPR
8412 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
8413 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
8415 tree a00 = TREE_OPERAND (arg0, 0);
8416 tree a01 = TREE_OPERAND (arg0, 1);
8417 tree a10 = TREE_OPERAND (arg1, 0);
8418 tree a11 = TREE_OPERAND (arg1, 1);
8419 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
8420 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
8421 && (code == TRUTH_AND_EXPR
8422 || code == TRUTH_OR_EXPR));
8424 if (operand_equal_p (a00, a10, 0))
8425 return fold (build2 (TREE_CODE (arg0), type, a00,
8426 fold (build2 (code, type, a01, a11))));
8427 else if (commutative && operand_equal_p (a00, a11, 0))
8428 return fold (build2 (TREE_CODE (arg0), type, a00,
8429 fold (build2 (code, type, a01, a10))));
8430 else if (commutative && operand_equal_p (a01, a10, 0))
8431 return fold (build2 (TREE_CODE (arg0), type, a01,
8432 fold (build2 (code, type, a00, a11))));
8434 /* This case if tricky because we must either have commutative
8435 operators or else A10 must not have side-effects. */
8437 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
8438 && operand_equal_p (a01, a11, 0))
8439 return fold (build2 (TREE_CODE (arg0), type,
8440 fold (build2 (code, type, a00, a10)),
8444 /* See if we can build a range comparison. */
8445 if (0 != (tem = fold_range_test (t)))
8448 /* Check for the possibility of merging component references. If our
8449 lhs is another similar operation, try to merge its rhs with our
8450 rhs. Then try to merge our lhs and rhs. */
8451 if (TREE_CODE (arg0) == code
8452 && 0 != (tem = fold_truthop (code, type,
8453 TREE_OPERAND (arg0, 1), arg1)))
8454 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8456 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
8461 case TRUTH_ORIF_EXPR:
8462 /* Note that the operands of this must be ints
8463 and their values must be 0 or true.
8464 ("true" is a fixed value perhaps depending on the language.) */
8465 /* If first arg is constant true, return it. */
8466 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8467 return fold_convert (type, arg0);
8469 /* If either arg is constant zero, drop it. */
8470 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
8471 return non_lvalue (fold_convert (type, arg1));
8472 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
8473 /* Preserve sequence points. */
8474 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8475 return non_lvalue (fold_convert (type, arg0));
8476 /* If second arg is constant true, result is true, but we must
8477 evaluate first arg. */
8478 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
8479 return omit_one_operand (type, arg1, arg0);
8480 /* Likewise for first arg, but note this only occurs here for
8482 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8483 return omit_one_operand (type, arg0, arg1);
8485 /* !X || X is always true. */
8486 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8487 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8488 return omit_one_operand (type, integer_one_node, arg1);
8489 /* X || !X is always true. */
8490 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8491 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8492 return omit_one_operand (type, integer_one_node, arg0);
8496 case TRUTH_XOR_EXPR:
8497 /* If the second arg is constant zero, drop it. */
8498 if (integer_zerop (arg1))
8499 return non_lvalue (fold_convert (type, arg0));
8500 /* If the second arg is constant true, this is a logical inversion. */
8501 if (integer_onep (arg1))
8502 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
8503 /* Identical arguments cancel to zero. */
8504 if (operand_equal_p (arg0, arg1, 0))
8505 return omit_one_operand (type, integer_zero_node, arg0);
8507 /* !X ^ X is always true. */
8508 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8509 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8510 return omit_one_operand (type, integer_one_node, arg1);
8512 /* X ^ !X is always true. */
8513 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8514 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8515 return omit_one_operand (type, integer_one_node, arg0);
8525 /* If one arg is a real or integer constant, put it last. */
8526 if (tree_swap_operands_p (arg0, arg1, true))
8527 return fold (build2 (swap_tree_comparison (code), type, arg1, arg0));
8529 /* If this is an equality comparison of the address of a non-weak
8530 object against zero, then we know the result. */
8531 if ((code == EQ_EXPR || code == NE_EXPR)
8532 && TREE_CODE (arg0) == ADDR_EXPR
8533 && DECL_P (TREE_OPERAND (arg0, 0))
8534 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8535 && integer_zerop (arg1))
8536 return constant_boolean_node (code != EQ_EXPR, type);
8538 /* If this is an equality comparison of the address of two non-weak,
8539 unaliased symbols neither of which are extern (since we do not
8540 have access to attributes for externs), then we know the result. */
8541 if ((code == EQ_EXPR || code == NE_EXPR)
8542 && TREE_CODE (arg0) == ADDR_EXPR
8543 && DECL_P (TREE_OPERAND (arg0, 0))
8544 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8545 && ! lookup_attribute ("alias",
8546 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
8547 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
8548 && TREE_CODE (arg1) == ADDR_EXPR
8549 && DECL_P (TREE_OPERAND (arg1, 0))
8550 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
8551 && ! lookup_attribute ("alias",
8552 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
8553 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
8554 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
8555 ? code == EQ_EXPR : code != EQ_EXPR,
8558 /* If this is a comparison of two exprs that look like an
8559 ARRAY_REF of the same object, then we can fold this to a
8560 comparison of the two offsets. */
8561 if (COMPARISON_CLASS_P (t))
8563 tree base0, offset0, base1, offset1;
8565 if (extract_array_ref (arg0, &base0, &offset0)
8566 && extract_array_ref (arg1, &base1, &offset1)
8567 && operand_equal_p (base0, base1, 0))
8569 if (offset0 == NULL_TREE
8570 && offset1 == NULL_TREE)
8572 offset0 = integer_zero_node;
8573 offset1 = integer_zero_node;
8575 else if (offset0 == NULL_TREE)
8576 offset0 = build_int_cst (TREE_TYPE (offset1), 0);
8577 else if (offset1 == NULL_TREE)
8578 offset1 = build_int_cst (TREE_TYPE (offset0), 0);
8580 if (TREE_TYPE (offset0) == TREE_TYPE (offset1))
8581 return fold (build2 (code, type, offset0, offset1));
8585 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8587 tree targ0 = strip_float_extensions (arg0);
8588 tree targ1 = strip_float_extensions (arg1);
8589 tree newtype = TREE_TYPE (targ0);
8591 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8592 newtype = TREE_TYPE (targ1);
8594 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8595 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8596 return fold (build2 (code, type, fold_convert (newtype, targ0),
8597 fold_convert (newtype, targ1)));
8599 /* (-a) CMP (-b) -> b CMP a */
8600 if (TREE_CODE (arg0) == NEGATE_EXPR
8601 && TREE_CODE (arg1) == NEGATE_EXPR)
8602 return fold (build2 (code, type, TREE_OPERAND (arg1, 0),
8603 TREE_OPERAND (arg0, 0)));
8605 if (TREE_CODE (arg1) == REAL_CST)
8607 REAL_VALUE_TYPE cst;
8608 cst = TREE_REAL_CST (arg1);
8610 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8611 if (TREE_CODE (arg0) == NEGATE_EXPR)
8613 fold (build2 (swap_tree_comparison (code), type,
8614 TREE_OPERAND (arg0, 0),
8615 build_real (TREE_TYPE (arg1),
8616 REAL_VALUE_NEGATE (cst))));
8618 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8619 /* a CMP (-0) -> a CMP 0 */
8620 if (REAL_VALUE_MINUS_ZERO (cst))
8621 return fold (build2 (code, type, arg0,
8622 build_real (TREE_TYPE (arg1), dconst0)));
8624 /* x != NaN is always true, other ops are always false. */
8625 if (REAL_VALUE_ISNAN (cst)
8626 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8628 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8629 return omit_one_operand (type, tem, arg0);
8632 /* Fold comparisons against infinity. */
8633 if (REAL_VALUE_ISINF (cst))
8635 tem = fold_inf_compare (code, type, arg0, arg1);
8636 if (tem != NULL_TREE)
8641 /* If this is a comparison of a real constant with a PLUS_EXPR
8642 or a MINUS_EXPR of a real constant, we can convert it into a
8643 comparison with a revised real constant as long as no overflow
8644 occurs when unsafe_math_optimizations are enabled. */
8645 if (flag_unsafe_math_optimizations
8646 && TREE_CODE (arg1) == REAL_CST
8647 && (TREE_CODE (arg0) == PLUS_EXPR
8648 || TREE_CODE (arg0) == MINUS_EXPR)
8649 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8650 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8651 ? MINUS_EXPR : PLUS_EXPR,
8652 arg1, TREE_OPERAND (arg0, 1), 0))
8653 && ! TREE_CONSTANT_OVERFLOW (tem))
8654 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8656 /* Likewise, we can simplify a comparison of a real constant with
8657 a MINUS_EXPR whose first operand is also a real constant, i.e.
8658 (c1 - x) < c2 becomes x > c1-c2. */
8659 if (flag_unsafe_math_optimizations
8660 && TREE_CODE (arg1) == REAL_CST
8661 && TREE_CODE (arg0) == MINUS_EXPR
8662 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8663 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8665 && ! TREE_CONSTANT_OVERFLOW (tem))
8666 return fold (build2 (swap_tree_comparison (code), type,
8667 TREE_OPERAND (arg0, 1), tem));
8669 /* Fold comparisons against built-in math functions. */
8670 if (TREE_CODE (arg1) == REAL_CST
8671 && flag_unsafe_math_optimizations
8672 && ! flag_errno_math)
8674 enum built_in_function fcode = builtin_mathfn_code (arg0);
8676 if (fcode != END_BUILTINS)
8678 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8679 if (tem != NULL_TREE)
8685 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8686 if (TREE_CONSTANT (arg1)
8687 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8688 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8689 /* This optimization is invalid for ordered comparisons
8690 if CONST+INCR overflows or if foo+incr might overflow.
8691 This optimization is invalid for floating point due to rounding.
8692 For pointer types we assume overflow doesn't happen. */
8693 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8694 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8695 && (code == EQ_EXPR || code == NE_EXPR))))
8697 tree varop, newconst;
8699 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8701 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
8702 arg1, TREE_OPERAND (arg0, 1)));
8703 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8704 TREE_OPERAND (arg0, 0),
8705 TREE_OPERAND (arg0, 1));
8709 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
8710 arg1, TREE_OPERAND (arg0, 1)));
8711 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8712 TREE_OPERAND (arg0, 0),
8713 TREE_OPERAND (arg0, 1));
8717 /* If VAROP is a reference to a bitfield, we must mask
8718 the constant by the width of the field. */
8719 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8720 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8721 && host_integerp (DECL_SIZE (TREE_OPERAND
8722 (TREE_OPERAND (varop, 0), 1)), 1))
8724 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8725 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8726 tree folded_compare, shift;
8728 /* First check whether the comparison would come out
8729 always the same. If we don't do that we would
8730 change the meaning with the masking. */
8731 folded_compare = fold (build2 (code, type,
8732 TREE_OPERAND (varop, 0), arg1));
8733 if (integer_zerop (folded_compare)
8734 || integer_onep (folded_compare))
8735 return omit_one_operand (type, folded_compare, varop);
8737 shift = build_int_cst (NULL_TREE,
8738 TYPE_PRECISION (TREE_TYPE (varop)) - size);
8739 shift = fold_convert (TREE_TYPE (varop), shift);
8740 newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8742 newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8746 return fold (build2 (code, type, varop, newconst));
8749 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
8750 This transformation affects the cases which are handled in later
8751 optimizations involving comparisons with non-negative constants. */
8752 if (TREE_CODE (arg1) == INTEGER_CST
8753 && TREE_CODE (arg0) != INTEGER_CST
8754 && tree_int_cst_sgn (arg1) > 0)
8759 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8760 return fold (build2 (GT_EXPR, type, arg0, arg1));
8763 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8764 return fold (build2 (LE_EXPR, type, arg0, arg1));
8771 /* Comparisons with the highest or lowest possible integer of
8772 the specified size will have known values.
8774 This is quite similar to fold_relational_hi_lo, however,
8775 attempts to share the code have been nothing but trouble. */
8777 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
8779 if (TREE_CODE (arg1) == INTEGER_CST
8780 && ! TREE_CONSTANT_OVERFLOW (arg1)
8781 && width <= 2 * HOST_BITS_PER_WIDE_INT
8782 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
8783 || POINTER_TYPE_P (TREE_TYPE (arg1))))
8785 HOST_WIDE_INT signed_max_hi;
8786 unsigned HOST_WIDE_INT signed_max_lo;
8787 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
8789 if (width <= HOST_BITS_PER_WIDE_INT)
8791 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
8796 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
8798 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
8804 max_lo = signed_max_lo;
8805 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
8811 width -= HOST_BITS_PER_WIDE_INT;
8813 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
8818 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
8820 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
8825 max_hi = signed_max_hi;
8826 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
8830 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
8831 && TREE_INT_CST_LOW (arg1) == max_lo)
8835 return omit_one_operand (type, integer_zero_node, arg0);
8838 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8841 return omit_one_operand (type, integer_one_node, arg0);
8844 return fold (build2 (NE_EXPR, type, arg0, arg1));
8846 /* The GE_EXPR and LT_EXPR cases above are not normally
8847 reached because of previous transformations. */
8852 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
8854 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
8858 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8859 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8861 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8862 return fold (build2 (NE_EXPR, type, arg0, arg1));
8866 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
8868 && TREE_INT_CST_LOW (arg1) == min_lo)
8872 return omit_one_operand (type, integer_zero_node, arg0);
8875 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8878 return omit_one_operand (type, integer_one_node, arg0);
8881 return fold (build2 (NE_EXPR, type, arg0, arg1));
8886 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
8888 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
8892 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8893 return fold (build2 (NE_EXPR, type, arg0, arg1));
8895 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8896 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8901 else if (!in_gimple_form
8902 && TREE_INT_CST_HIGH (arg1) == signed_max_hi
8903 && TREE_INT_CST_LOW (arg1) == signed_max_lo
8904 && TYPE_UNSIGNED (TREE_TYPE (arg1))
8905 /* signed_type does not work on pointer types. */
8906 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
8908 /* The following case also applies to X < signed_max+1
8909 and X >= signed_max+1 because previous transformations. */
8910 if (code == LE_EXPR || code == GT_EXPR)
8913 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
8914 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
8916 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
8917 type, fold_convert (st0, arg0),
8918 fold_convert (st1, integer_zero_node)));
8924 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
8925 a MINUS_EXPR of a constant, we can convert it into a comparison with
8926 a revised constant as long as no overflow occurs. */
8927 if ((code == EQ_EXPR || code == NE_EXPR)
8928 && TREE_CODE (arg1) == INTEGER_CST
8929 && (TREE_CODE (arg0) == PLUS_EXPR
8930 || TREE_CODE (arg0) == MINUS_EXPR)
8931 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8932 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8933 ? MINUS_EXPR : PLUS_EXPR,
8934 arg1, TREE_OPERAND (arg0, 1), 0))
8935 && ! TREE_CONSTANT_OVERFLOW (tem))
8936 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8938 /* Similarly for a NEGATE_EXPR. */
8939 else if ((code == EQ_EXPR || code == NE_EXPR)
8940 && TREE_CODE (arg0) == NEGATE_EXPR
8941 && TREE_CODE (arg1) == INTEGER_CST
8942 && 0 != (tem = negate_expr (arg1))
8943 && TREE_CODE (tem) == INTEGER_CST
8944 && ! TREE_CONSTANT_OVERFLOW (tem))
8945 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8947 /* If we have X - Y == 0, we can convert that to X == Y and similarly
8948 for !=. Don't do this for ordered comparisons due to overflow. */
8949 else if ((code == NE_EXPR || code == EQ_EXPR)
8950 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
8951 return fold (build2 (code, type,
8952 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
8954 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8955 && TREE_CODE (arg0) == NOP_EXPR)
8957 /* If we are widening one operand of an integer comparison,
8958 see if the other operand is similarly being widened. Perhaps we
8959 can do the comparison in the narrower type. */
8960 tem = fold_widened_comparison (code, type, arg0, arg1);
8964 /* Or if we are changing signedness. */
8965 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
8970 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8971 constant, we can simplify it. */
8972 else if (TREE_CODE (arg1) == INTEGER_CST
8973 && (TREE_CODE (arg0) == MIN_EXPR
8974 || TREE_CODE (arg0) == MAX_EXPR)
8975 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8976 return optimize_minmax_comparison (t);
8978 /* If we are comparing an ABS_EXPR with a constant, we can
8979 convert all the cases into explicit comparisons, but they may
8980 well not be faster than doing the ABS and one comparison.
8981 But ABS (X) <= C is a range comparison, which becomes a subtraction
8982 and a comparison, and is probably faster. */
8983 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8984 && TREE_CODE (arg0) == ABS_EXPR
8985 && ! TREE_SIDE_EFFECTS (arg0)
8986 && (0 != (tem = negate_expr (arg1)))
8987 && TREE_CODE (tem) == INTEGER_CST
8988 && ! TREE_CONSTANT_OVERFLOW (tem))
8989 return fold (build2 (TRUTH_ANDIF_EXPR, type,
8990 build2 (GE_EXPR, type,
8991 TREE_OPERAND (arg0, 0), tem),
8992 build2 (LE_EXPR, type,
8993 TREE_OPERAND (arg0, 0), arg1)));
8995 /* Convert ABS_EXPR<x> >= 0 to true. */
8996 else if (code == GE_EXPR
8997 && tree_expr_nonnegative_p (arg0)
8998 && (integer_zerop (arg1)
8999 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9000 && real_zerop (arg1))))
9001 return omit_one_operand (type, integer_one_node, arg0);
9003 /* Convert ABS_EXPR<x> < 0 to false. */
9004 else if (code == LT_EXPR
9005 && tree_expr_nonnegative_p (arg0)
9006 && (integer_zerop (arg1) || real_zerop (arg1)))
9007 return omit_one_operand (type, integer_zero_node, arg0);
9009 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
9010 else if ((code == EQ_EXPR || code == NE_EXPR)
9011 && TREE_CODE (arg0) == ABS_EXPR
9012 && (integer_zerop (arg1) || real_zerop (arg1)))
9013 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), arg1));
9015 /* If this is an EQ or NE comparison with zero and ARG0 is
9016 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
9017 two operations, but the latter can be done in one less insn
9018 on machines that have only two-operand insns or on which a
9019 constant cannot be the first operand. */
9020 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
9021 && TREE_CODE (arg0) == BIT_AND_EXPR)
9023 tree arg00 = TREE_OPERAND (arg0, 0);
9024 tree arg01 = TREE_OPERAND (arg0, 1);
9025 if (TREE_CODE (arg00) == LSHIFT_EXPR
9026 && integer_onep (TREE_OPERAND (arg00, 0)))
9028 fold (build2 (code, type,
9029 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9030 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
9031 arg01, TREE_OPERAND (arg00, 1)),
9032 fold_convert (TREE_TYPE (arg0),
9035 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
9036 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
9038 fold (build2 (code, type,
9039 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9040 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
9041 arg00, TREE_OPERAND (arg01, 1)),
9042 fold_convert (TREE_TYPE (arg0),
9047 /* If this is an NE or EQ comparison of zero against the result of a
9048 signed MOD operation whose second operand is a power of 2, make
9049 the MOD operation unsigned since it is simpler and equivalent. */
9050 if ((code == NE_EXPR || code == EQ_EXPR)
9051 && integer_zerop (arg1)
9052 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
9053 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
9054 || TREE_CODE (arg0) == CEIL_MOD_EXPR
9055 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
9056 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
9057 && integer_pow2p (TREE_OPERAND (arg0, 1)))
9059 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
9060 tree newmod = fold (build2 (TREE_CODE (arg0), newtype,
9061 fold_convert (newtype,
9062 TREE_OPERAND (arg0, 0)),
9063 fold_convert (newtype,
9064 TREE_OPERAND (arg0, 1))));
9066 return fold (build2 (code, type, newmod,
9067 fold_convert (newtype, arg1)));
9070 /* If this is an NE comparison of zero with an AND of one, remove the
9071 comparison since the AND will give the correct value. */
9072 if (code == NE_EXPR && integer_zerop (arg1)
9073 && TREE_CODE (arg0) == BIT_AND_EXPR
9074 && integer_onep (TREE_OPERAND (arg0, 1)))
9075 return fold_convert (type, arg0);
9077 /* If we have (A & C) == C where C is a power of 2, convert this into
9078 (A & C) != 0. Similarly for NE_EXPR. */
9079 if ((code == EQ_EXPR || code == NE_EXPR)
9080 && TREE_CODE (arg0) == BIT_AND_EXPR
9081 && integer_pow2p (TREE_OPERAND (arg0, 1))
9082 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9083 return fold (build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
9084 arg0, fold_convert (TREE_TYPE (arg0),
9085 integer_zero_node)));
9087 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
9088 2, then fold the expression into shifts and logical operations. */
9089 tem = fold_single_bit_test (code, arg0, arg1, type);
9093 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
9094 Similarly for NE_EXPR. */
9095 if ((code == EQ_EXPR || code == NE_EXPR)
9096 && TREE_CODE (arg0) == BIT_AND_EXPR
9097 && TREE_CODE (arg1) == INTEGER_CST
9098 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9100 tree notc = fold (build1 (BIT_NOT_EXPR,
9101 TREE_TYPE (TREE_OPERAND (arg0, 1)),
9102 TREE_OPERAND (arg0, 1)));
9103 tree dandnotc = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9105 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
9106 if (integer_nonzerop (dandnotc))
9107 return omit_one_operand (type, rslt, arg0);
9110 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
9111 Similarly for NE_EXPR. */
9112 if ((code == EQ_EXPR || code == NE_EXPR)
9113 && TREE_CODE (arg0) == BIT_IOR_EXPR
9114 && TREE_CODE (arg1) == INTEGER_CST
9115 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9117 tree notd = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1));
9118 tree candnotd = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9119 TREE_OPERAND (arg0, 1), notd));
9120 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
9121 if (integer_nonzerop (candnotd))
9122 return omit_one_operand (type, rslt, arg0);
9125 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
9126 and similarly for >= into !=. */
9127 if ((code == LT_EXPR || code == GE_EXPR)
9128 && TYPE_UNSIGNED (TREE_TYPE (arg0))
9129 && TREE_CODE (arg1) == LSHIFT_EXPR
9130 && integer_onep (TREE_OPERAND (arg1, 0)))
9131 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
9132 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
9133 TREE_OPERAND (arg1, 1)),
9134 fold_convert (TREE_TYPE (arg0), integer_zero_node));
9136 else if ((code == LT_EXPR || code == GE_EXPR)
9137 && TYPE_UNSIGNED (TREE_TYPE (arg0))
9138 && (TREE_CODE (arg1) == NOP_EXPR
9139 || TREE_CODE (arg1) == CONVERT_EXPR)
9140 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
9141 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
9143 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
9144 fold_convert (TREE_TYPE (arg0),
9145 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
9146 TREE_OPERAND (TREE_OPERAND (arg1, 0),
9148 fold_convert (TREE_TYPE (arg0), integer_zero_node));
9150 /* Simplify comparison of something with itself. (For IEEE
9151 floating-point, we can only do some of these simplifications.) */
9152 if (operand_equal_p (arg0, arg1, 0))
9157 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9158 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9159 return constant_boolean_node (1, type);
9164 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9165 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9166 return constant_boolean_node (1, type);
9167 return fold (build2 (EQ_EXPR, type, arg0, arg1));
9170 /* For NE, we can only do this simplification if integer
9171 or we don't honor IEEE floating point NaNs. */
9172 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
9173 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9175 /* ... fall through ... */
9178 return constant_boolean_node (0, type);
9184 /* If we are comparing an expression that just has comparisons
9185 of two integer values, arithmetic expressions of those comparisons,
9186 and constants, we can simplify it. There are only three cases
9187 to check: the two values can either be equal, the first can be
9188 greater, or the second can be greater. Fold the expression for
9189 those three values. Since each value must be 0 or 1, we have
9190 eight possibilities, each of which corresponds to the constant 0
9191 or 1 or one of the six possible comparisons.
9193 This handles common cases like (a > b) == 0 but also handles
9194 expressions like ((x > y) - (y > x)) > 0, which supposedly
9195 occur in macroized code. */
9197 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
9199 tree cval1 = 0, cval2 = 0;
9202 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
9203 /* Don't handle degenerate cases here; they should already
9204 have been handled anyway. */
9205 && cval1 != 0 && cval2 != 0
9206 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
9207 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
9208 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
9209 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
9210 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
9211 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
9212 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9214 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9215 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9217 /* We can't just pass T to eval_subst in case cval1 or cval2
9218 was the same as ARG1. */
9221 = fold (build2 (code, type,
9222 eval_subst (arg0, cval1, maxval,
9226 = fold (build2 (code, type,
9227 eval_subst (arg0, cval1, maxval,
9231 = fold (build2 (code, type,
9232 eval_subst (arg0, cval1, minval,
9236 /* All three of these results should be 0 or 1. Confirm they
9237 are. Then use those values to select the proper code
9240 if ((integer_zerop (high_result)
9241 || integer_onep (high_result))
9242 && (integer_zerop (equal_result)
9243 || integer_onep (equal_result))
9244 && (integer_zerop (low_result)
9245 || integer_onep (low_result)))
9247 /* Make a 3-bit mask with the high-order bit being the
9248 value for `>', the next for '=', and the low for '<'. */
9249 switch ((integer_onep (high_result) * 4)
9250 + (integer_onep (equal_result) * 2)
9251 + integer_onep (low_result))
9255 return omit_one_operand (type, integer_zero_node, arg0);
9276 return omit_one_operand (type, integer_one_node, arg0);
9279 tem = build2 (code, type, cval1, cval2);
9281 return save_expr (tem);
9288 /* If this is a comparison of a field, we may be able to simplify it. */
9289 if (((TREE_CODE (arg0) == COMPONENT_REF
9290 && lang_hooks.can_use_bit_fields_p ())
9291 || TREE_CODE (arg0) == BIT_FIELD_REF)
9292 && (code == EQ_EXPR || code == NE_EXPR)
9293 /* Handle the constant case even without -O
9294 to make sure the warnings are given. */
9295 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
9297 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
9302 /* If this is a comparison of complex values and either or both sides
9303 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
9304 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
9305 This may prevent needless evaluations. */
9306 if ((code == EQ_EXPR || code == NE_EXPR)
9307 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
9308 && (TREE_CODE (arg0) == COMPLEX_EXPR
9309 || TREE_CODE (arg1) == COMPLEX_EXPR
9310 || TREE_CODE (arg0) == COMPLEX_CST
9311 || TREE_CODE (arg1) == COMPLEX_CST))
9313 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
9314 tree real0, imag0, real1, imag1;
9316 arg0 = save_expr (arg0);
9317 arg1 = save_expr (arg1);
9318 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
9319 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
9320 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
9321 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
9323 return fold (build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
9326 fold (build2 (code, type, real0, real1)),
9327 fold (build2 (code, type, imag0, imag1))));
9330 /* Optimize comparisons of strlen vs zero to a compare of the
9331 first character of the string vs zero. To wit,
9332 strlen(ptr) == 0 => *ptr == 0
9333 strlen(ptr) != 0 => *ptr != 0
9334 Other cases should reduce to one of these two (or a constant)
9335 due to the return value of strlen being unsigned. */
9336 if ((code == EQ_EXPR || code == NE_EXPR)
9337 && integer_zerop (arg1)
9338 && TREE_CODE (arg0) == CALL_EXPR)
9340 tree fndecl = get_callee_fndecl (arg0);
9344 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
9345 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
9346 && (arglist = TREE_OPERAND (arg0, 1))
9347 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
9348 && ! TREE_CHAIN (arglist))
9349 return fold (build2 (code, type,
9350 build1 (INDIRECT_REF, char_type_node,
9351 TREE_VALUE (arglist)),
9352 fold_convert (char_type_node,
9353 integer_zero_node)));
9356 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9357 into a single range test. */
9358 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9359 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9360 && TREE_CODE (arg1) == INTEGER_CST
9361 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9362 && !integer_zerop (TREE_OPERAND (arg0, 1))
9363 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9364 && !TREE_OVERFLOW (arg1))
9366 t1 = fold_div_compare (code, type, arg0, arg1);
9367 if (t1 != NULL_TREE)
9371 if ((code == EQ_EXPR || code == NE_EXPR)
9372 && !TREE_SIDE_EFFECTS (arg0)
9373 && integer_zerop (arg1)
9374 && tree_expr_nonzero_p (arg0))
9375 return constant_boolean_node (code==NE_EXPR, type);
9377 t1 = fold_relational_const (code, type, arg0, arg1);
9378 return t1 == NULL_TREE ? t : t1;
9380 case UNORDERED_EXPR:
9388 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9390 t1 = fold_relational_const (code, type, arg0, arg1);
9391 if (t1 != NULL_TREE)
9395 /* If the first operand is NaN, the result is constant. */
9396 if (TREE_CODE (arg0) == REAL_CST
9397 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
9398 && (code != LTGT_EXPR || ! flag_trapping_math))
9400 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9403 return omit_one_operand (type, t1, arg1);
9406 /* If the second operand is NaN, the result is constant. */
9407 if (TREE_CODE (arg1) == REAL_CST
9408 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
9409 && (code != LTGT_EXPR || ! flag_trapping_math))
9411 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9414 return omit_one_operand (type, t1, arg0);
9417 /* Simplify unordered comparison of something with itself. */
9418 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
9419 && operand_equal_p (arg0, arg1, 0))
9420 return constant_boolean_node (1, type);
9422 if (code == LTGT_EXPR
9423 && !flag_trapping_math
9424 && operand_equal_p (arg0, arg1, 0))
9425 return constant_boolean_node (0, type);
9427 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9429 tree targ0 = strip_float_extensions (arg0);
9430 tree targ1 = strip_float_extensions (arg1);
9431 tree newtype = TREE_TYPE (targ0);
9433 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
9434 newtype = TREE_TYPE (targ1);
9436 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
9437 return fold (build2 (code, type, fold_convert (newtype, targ0),
9438 fold_convert (newtype, targ1)));
9444 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
9445 so all simple results must be passed through pedantic_non_lvalue. */
9446 if (TREE_CODE (arg0) == INTEGER_CST)
9448 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
9449 /* Only optimize constant conditions when the selected branch
9450 has the same type as the COND_EXPR. This avoids optimizing
9451 away "c ? x : throw", where the throw has a void type. */
9452 if (! VOID_TYPE_P (TREE_TYPE (tem))
9453 || VOID_TYPE_P (type))
9454 return pedantic_non_lvalue (tem);
9457 if (operand_equal_p (arg1, TREE_OPERAND (t, 2), 0))
9458 return pedantic_omit_one_operand (type, arg1, arg0);
9460 /* If we have A op B ? A : C, we may be able to convert this to a
9461 simpler expression, depending on the operation and the values
9462 of B and C. Signed zeros prevent all of these transformations,
9463 for reasons given above each one.
9465 Also try swapping the arguments and inverting the conditional. */
9466 if (COMPARISON_CLASS_P (arg0)
9467 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
9468 arg1, TREE_OPERAND (arg0, 1))
9469 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
9471 tem = fold_cond_expr_with_comparison (type, arg0,
9472 TREE_OPERAND (t, 1),
9473 TREE_OPERAND (t, 2));
9478 if (COMPARISON_CLASS_P (arg0)
9479 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
9480 TREE_OPERAND (t, 2),
9481 TREE_OPERAND (arg0, 1))
9482 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 2)))))
9484 tem = invert_truthvalue (arg0);
9485 if (COMPARISON_CLASS_P (tem))
9487 tem = fold_cond_expr_with_comparison (type, tem,
9488 TREE_OPERAND (t, 2),
9489 TREE_OPERAND (t, 1));
9495 /* If the second operand is simpler than the third, swap them
9496 since that produces better jump optimization results. */
9497 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
9498 TREE_OPERAND (t, 2), false))
9500 /* See if this can be inverted. If it can't, possibly because
9501 it was a floating-point inequality comparison, don't do
9503 tem = invert_truthvalue (arg0);
9505 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9506 return fold (build3 (code, type, tem,
9507 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
9510 /* Convert A ? 1 : 0 to simply A. */
9511 if (integer_onep (TREE_OPERAND (t, 1))
9512 && integer_zerop (TREE_OPERAND (t, 2))
9513 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
9514 call to fold will try to move the conversion inside
9515 a COND, which will recurse. In that case, the COND_EXPR
9516 is probably the best choice, so leave it alone. */
9517 && type == TREE_TYPE (arg0))
9518 return pedantic_non_lvalue (arg0);
9520 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
9521 over COND_EXPR in cases such as floating point comparisons. */
9522 if (integer_zerop (TREE_OPERAND (t, 1))
9523 && integer_onep (TREE_OPERAND (t, 2))
9524 && truth_value_p (TREE_CODE (arg0)))
9525 return pedantic_non_lvalue (fold_convert (type,
9526 invert_truthvalue (arg0)));
9528 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
9529 if (TREE_CODE (arg0) == LT_EXPR
9530 && integer_zerop (TREE_OPERAND (arg0, 1))
9531 && integer_zerop (TREE_OPERAND (t, 2))
9532 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
9533 return fold_convert (type, fold (build2 (BIT_AND_EXPR,
9534 TREE_TYPE (tem), tem, arg1)));
9536 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
9537 already handled above. */
9538 if (TREE_CODE (arg0) == BIT_AND_EXPR
9539 && integer_onep (TREE_OPERAND (arg0, 1))
9540 && integer_zerop (TREE_OPERAND (t, 2))
9541 && integer_pow2p (arg1))
9543 tree tem = TREE_OPERAND (arg0, 0);
9545 if (TREE_CODE (tem) == RSHIFT_EXPR
9546 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
9547 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
9548 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
9549 return fold (build2 (BIT_AND_EXPR, type,
9550 TREE_OPERAND (tem, 0), arg1));
9553 /* A & N ? N : 0 is simply A & N if N is a power of two. This
9554 is probably obsolete because the first operand should be a
9555 truth value (that's why we have the two cases above), but let's
9556 leave it in until we can confirm this for all front-ends. */
9557 if (integer_zerop (TREE_OPERAND (t, 2))
9558 && TREE_CODE (arg0) == NE_EXPR
9559 && integer_zerop (TREE_OPERAND (arg0, 1))
9560 && integer_pow2p (arg1)
9561 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
9562 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
9563 arg1, OEP_ONLY_CONST))
9564 return pedantic_non_lvalue (fold_convert (type,
9565 TREE_OPERAND (arg0, 0)));
9567 /* Convert A ? B : 0 into A && B if A and B are truth values. */
9568 if (integer_zerop (TREE_OPERAND (t, 2))
9569 && truth_value_p (TREE_CODE (arg0))
9570 && truth_value_p (TREE_CODE (arg1)))
9571 return fold (build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1));
9573 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
9574 if (integer_onep (TREE_OPERAND (t, 2))
9575 && truth_value_p (TREE_CODE (arg0))
9576 && truth_value_p (TREE_CODE (arg1)))
9578 /* Only perform transformation if ARG0 is easily inverted. */
9579 tem = invert_truthvalue (arg0);
9580 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9581 return fold (build2 (TRUTH_ORIF_EXPR, type, tem, arg1));
9584 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
9585 if (integer_zerop (arg1)
9586 && truth_value_p (TREE_CODE (arg0))
9587 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
9589 /* Only perform transformation if ARG0 is easily inverted. */
9590 tem = invert_truthvalue (arg0);
9591 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9592 return fold (build2 (TRUTH_ANDIF_EXPR, type, tem,
9593 TREE_OPERAND (t, 2)));
9596 /* Convert A ? 1 : B into A || B if A and B are truth values. */
9597 if (integer_onep (arg1)
9598 && truth_value_p (TREE_CODE (arg0))
9599 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
9600 return fold (build2 (TRUTH_ORIF_EXPR, type, arg0,
9601 TREE_OPERAND (t, 2)));
9606 /* When pedantic, a compound expression can be neither an lvalue
9607 nor an integer constant expression. */
9608 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
9610 /* Don't let (0, 0) be null pointer constant. */
9611 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
9612 : fold_convert (type, arg1);
9613 return pedantic_non_lvalue (tem);
9617 return build_complex (type, arg0, arg1);
9621 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
9623 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
9624 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
9625 TREE_OPERAND (arg0, 1));
9626 else if (TREE_CODE (arg0) == COMPLEX_CST)
9627 return TREE_REALPART (arg0);
9628 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
9629 return fold (build2 (TREE_CODE (arg0), type,
9630 fold (build1 (REALPART_EXPR, type,
9631 TREE_OPERAND (arg0, 0))),
9632 fold (build1 (REALPART_EXPR, type,
9633 TREE_OPERAND (arg0, 1)))));
9637 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
9638 return fold_convert (type, integer_zero_node);
9639 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
9640 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
9641 TREE_OPERAND (arg0, 0));
9642 else if (TREE_CODE (arg0) == COMPLEX_CST)
9643 return TREE_IMAGPART (arg0);
9644 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
9645 return fold (build2 (TREE_CODE (arg0), type,
9646 fold (build1 (IMAGPART_EXPR, type,
9647 TREE_OPERAND (arg0, 0))),
9648 fold (build1 (IMAGPART_EXPR, type,
9649 TREE_OPERAND (arg0, 1)))));
9653 /* Check for a built-in function. */
9654 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
9655 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))
9657 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
9659 tree tmp = fold_builtin (t, false);
9667 } /* switch (code) */
9670 #ifdef ENABLE_FOLD_CHECKING
9673 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
9674 static void fold_check_failed (tree, tree);
9675 void print_fold_checksum (tree);
9677 /* When --enable-checking=fold, compute a digest of expr before
9678 and after actual fold call to see if fold did not accidentally
9679 change original expr. */
9686 unsigned char checksum_before[16], checksum_after[16];
9689 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9690 md5_init_ctx (&ctx);
9691 fold_checksum_tree (expr, &ctx, ht);
9692 md5_finish_ctx (&ctx, checksum_before);
9695 ret = fold_1 (expr);
9697 md5_init_ctx (&ctx);
9698 fold_checksum_tree (expr, &ctx, ht);
9699 md5_finish_ctx (&ctx, checksum_after);
9702 if (memcmp (checksum_before, checksum_after, 16))
9703 fold_check_failed (expr, ret);
9709 print_fold_checksum (tree expr)
9712 unsigned char checksum[16], cnt;
9715 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9716 md5_init_ctx (&ctx);
9717 fold_checksum_tree (expr, &ctx, ht);
9718 md5_finish_ctx (&ctx, checksum);
9720 for (cnt = 0; cnt < 16; ++cnt)
9721 fprintf (stderr, "%02x", checksum[cnt]);
9722 putc ('\n', stderr);
9726 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
9728 internal_error ("fold check: original tree changed by fold");
9732 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
9735 enum tree_code code;
9736 char buf[sizeof (struct tree_decl)];
9739 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
9740 <= sizeof (struct tree_decl))
9741 && sizeof (struct tree_type) <= sizeof (struct tree_decl));
9744 slot = htab_find_slot (ht, expr, INSERT);
9748 code = TREE_CODE (expr);
9749 if (TREE_CODE_CLASS (code) == tcc_declaration
9750 && DECL_ASSEMBLER_NAME_SET_P (expr))
9752 /* Allow DECL_ASSEMBLER_NAME to be modified. */
9753 memcpy (buf, expr, tree_size (expr));
9755 SET_DECL_ASSEMBLER_NAME (expr, NULL);
9757 else if (TREE_CODE_CLASS (code) == tcc_type
9758 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
9759 || TYPE_CACHED_VALUES_P (expr)))
9761 /* Allow these fields to be modified. */
9762 memcpy (buf, expr, tree_size (expr));
9764 TYPE_POINTER_TO (expr) = NULL;
9765 TYPE_REFERENCE_TO (expr) = NULL;
9766 TYPE_CACHED_VALUES_P (expr) = 0;
9767 TYPE_CACHED_VALUES (expr) = NULL;
9769 md5_process_bytes (expr, tree_size (expr), ctx);
9770 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
9771 if (TREE_CODE_CLASS (code) != tcc_type
9772 && TREE_CODE_CLASS (code) != tcc_declaration)
9773 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
9774 switch (TREE_CODE_CLASS (code))
9780 md5_process_bytes (TREE_STRING_POINTER (expr),
9781 TREE_STRING_LENGTH (expr), ctx);
9784 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
9785 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
9788 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
9794 case tcc_exceptional:
9798 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
9799 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
9802 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
9803 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
9809 case tcc_expression:
9811 case tcc_comparison:
9815 len = TREE_CODE_LENGTH (code);
9816 for (i = 0; i < len; ++i)
9817 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
9819 case tcc_declaration:
9820 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
9821 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
9822 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
9823 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
9824 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
9825 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
9826 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
9827 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
9828 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
9829 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
9830 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
9833 if (TREE_CODE (expr) == ENUMERAL_TYPE)
9834 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
9835 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
9836 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
9837 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
9838 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
9839 if (INTEGRAL_TYPE_P (expr)
9840 || SCALAR_FLOAT_TYPE_P (expr))
9842 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
9843 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
9845 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
9846 if (TREE_CODE (expr) == RECORD_TYPE
9847 || TREE_CODE (expr) == UNION_TYPE
9848 || TREE_CODE (expr) == QUAL_UNION_TYPE)
9849 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
9850 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
9859 /* Perform constant folding and related simplification of initializer
9860 expression EXPR. This behaves identically to "fold" but ignores
9861 potential run-time traps and exceptions that fold must preserve. */
9864 fold_initializer (tree expr)
9866 int saved_signaling_nans = flag_signaling_nans;
9867 int saved_trapping_math = flag_trapping_math;
9868 int saved_rounding_math = flag_rounding_math;
9869 int saved_trapv = flag_trapv;
9872 flag_signaling_nans = 0;
9873 flag_trapping_math = 0;
9874 flag_rounding_math = 0;
9877 result = fold (expr);
9879 flag_signaling_nans = saved_signaling_nans;
9880 flag_trapping_math = saved_trapping_math;
9881 flag_rounding_math = saved_rounding_math;
9882 flag_trapv = saved_trapv;
9887 /* Determine if first argument is a multiple of second argument. Return 0 if
9888 it is not, or we cannot easily determined it to be.
9890 An example of the sort of thing we care about (at this point; this routine
9891 could surely be made more general, and expanded to do what the *_DIV_EXPR's
9892 fold cases do now) is discovering that
9894 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9900 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
9902 This code also handles discovering that
9904 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9906 is a multiple of 8 so we don't have to worry about dealing with a
9909 Note that we *look* inside a SAVE_EXPR only to determine how it was
9910 calculated; it is not safe for fold to do much of anything else with the
9911 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
9912 at run time. For example, the latter example above *cannot* be implemented
9913 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
9914 evaluation time of the original SAVE_EXPR is not necessarily the same at
9915 the time the new expression is evaluated. The only optimization of this
9916 sort that would be valid is changing
9918 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
9922 SAVE_EXPR (I) * SAVE_EXPR (J)
9924 (where the same SAVE_EXPR (J) is used in the original and the
9925 transformed version). */
9928 multiple_of_p (tree type, tree top, tree bottom)
9930 if (operand_equal_p (top, bottom, 0))
9933 if (TREE_CODE (type) != INTEGER_TYPE)
9936 switch (TREE_CODE (top))
9939 /* Bitwise and provides a power of two multiple. If the mask is
9940 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
9941 if (!integer_pow2p (bottom))
9946 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9947 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9951 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9952 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9955 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
9959 op1 = TREE_OPERAND (top, 1);
9960 /* const_binop may not detect overflow correctly,
9961 so check for it explicitly here. */
9962 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
9963 > TREE_INT_CST_LOW (op1)
9964 && TREE_INT_CST_HIGH (op1) == 0
9965 && 0 != (t1 = fold_convert (type,
9966 const_binop (LSHIFT_EXPR,
9969 && ! TREE_OVERFLOW (t1))
9970 return multiple_of_p (type, t1, bottom);
9975 /* Can't handle conversions from non-integral or wider integral type. */
9976 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
9977 || (TYPE_PRECISION (type)
9978 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
9981 /* .. fall through ... */
9984 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
9987 if (TREE_CODE (bottom) != INTEGER_CST
9988 || (TYPE_UNSIGNED (type)
9989 && (tree_int_cst_sgn (top) < 0
9990 || tree_int_cst_sgn (bottom) < 0)))
9992 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
10000 /* Return true if `t' is known to be non-negative. */
10003 tree_expr_nonnegative_p (tree t)
10005 switch (TREE_CODE (t))
10011 return tree_int_cst_sgn (t) >= 0;
10014 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
10017 if (FLOAT_TYPE_P (TREE_TYPE (t)))
10018 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10019 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10021 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
10022 both unsigned and at least 2 bits shorter than the result. */
10023 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
10024 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
10025 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
10027 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
10028 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
10029 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
10030 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
10032 unsigned int prec = MAX (TYPE_PRECISION (inner1),
10033 TYPE_PRECISION (inner2)) + 1;
10034 return prec < TYPE_PRECISION (TREE_TYPE (t));
10040 if (FLOAT_TYPE_P (TREE_TYPE (t)))
10042 /* x * x for floating point x is always non-negative. */
10043 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
10045 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10046 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10049 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
10050 both unsigned and their total bits is shorter than the result. */
10051 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
10052 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
10053 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
10055 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
10056 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
10057 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
10058 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
10059 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
10060 < TYPE_PRECISION (TREE_TYPE (t));
10064 case TRUNC_DIV_EXPR:
10065 case CEIL_DIV_EXPR:
10066 case FLOOR_DIV_EXPR:
10067 case ROUND_DIV_EXPR:
10068 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10069 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10071 case TRUNC_MOD_EXPR:
10072 case CEIL_MOD_EXPR:
10073 case FLOOR_MOD_EXPR:
10074 case ROUND_MOD_EXPR:
10075 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10078 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10079 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10082 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
10083 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10086 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10087 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10091 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
10092 tree outer_type = TREE_TYPE (t);
10094 if (TREE_CODE (outer_type) == REAL_TYPE)
10096 if (TREE_CODE (inner_type) == REAL_TYPE)
10097 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10098 if (TREE_CODE (inner_type) == INTEGER_TYPE)
10100 if (TYPE_UNSIGNED (inner_type))
10102 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10105 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
10107 if (TREE_CODE (inner_type) == REAL_TYPE)
10108 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
10109 if (TREE_CODE (inner_type) == INTEGER_TYPE)
10110 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
10111 && TYPE_UNSIGNED (inner_type);
10117 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
10118 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
10119 case COMPOUND_EXPR:
10120 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10122 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10123 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10125 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10126 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10128 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10130 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
10132 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10133 case NON_LVALUE_EXPR:
10134 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10136 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10140 tree temp = TARGET_EXPR_SLOT (t);
10141 t = TARGET_EXPR_INITIAL (t);
10143 /* If the initializer is non-void, then it's a normal expression
10144 that will be assigned to the slot. */
10145 if (!VOID_TYPE_P (t))
10146 return tree_expr_nonnegative_p (t);
10148 /* Otherwise, the initializer sets the slot in some way. One common
10149 way is an assignment statement at the end of the initializer. */
10152 if (TREE_CODE (t) == BIND_EXPR)
10153 t = expr_last (BIND_EXPR_BODY (t));
10154 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
10155 || TREE_CODE (t) == TRY_CATCH_EXPR)
10156 t = expr_last (TREE_OPERAND (t, 0));
10157 else if (TREE_CODE (t) == STATEMENT_LIST)
10162 if (TREE_CODE (t) == MODIFY_EXPR
10163 && TREE_OPERAND (t, 0) == temp)
10164 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10171 tree fndecl = get_callee_fndecl (t);
10172 tree arglist = TREE_OPERAND (t, 1);
10173 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
10174 switch (DECL_FUNCTION_CODE (fndecl))
10176 #define CASE_BUILTIN_F(BUILT_IN_FN) \
10177 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
10178 #define CASE_BUILTIN_I(BUILT_IN_FN) \
10179 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
10181 CASE_BUILTIN_F (BUILT_IN_ACOS)
10182 CASE_BUILTIN_F (BUILT_IN_ACOSH)
10183 CASE_BUILTIN_F (BUILT_IN_CABS)
10184 CASE_BUILTIN_F (BUILT_IN_COSH)
10185 CASE_BUILTIN_F (BUILT_IN_ERFC)
10186 CASE_BUILTIN_F (BUILT_IN_EXP)
10187 CASE_BUILTIN_F (BUILT_IN_EXP10)
10188 CASE_BUILTIN_F (BUILT_IN_EXP2)
10189 CASE_BUILTIN_F (BUILT_IN_FABS)
10190 CASE_BUILTIN_F (BUILT_IN_FDIM)
10191 CASE_BUILTIN_F (BUILT_IN_FREXP)
10192 CASE_BUILTIN_F (BUILT_IN_HYPOT)
10193 CASE_BUILTIN_F (BUILT_IN_POW10)
10194 CASE_BUILTIN_I (BUILT_IN_FFS)
10195 CASE_BUILTIN_I (BUILT_IN_PARITY)
10196 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
10200 CASE_BUILTIN_F (BUILT_IN_SQRT)
10201 /* sqrt(-0.0) is -0.0. */
10202 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
10204 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
10206 CASE_BUILTIN_F (BUILT_IN_ASINH)
10207 CASE_BUILTIN_F (BUILT_IN_ATAN)
10208 CASE_BUILTIN_F (BUILT_IN_ATANH)
10209 CASE_BUILTIN_F (BUILT_IN_CBRT)
10210 CASE_BUILTIN_F (BUILT_IN_CEIL)
10211 CASE_BUILTIN_F (BUILT_IN_ERF)
10212 CASE_BUILTIN_F (BUILT_IN_EXPM1)
10213 CASE_BUILTIN_F (BUILT_IN_FLOOR)
10214 CASE_BUILTIN_F (BUILT_IN_FMOD)
10215 CASE_BUILTIN_F (BUILT_IN_LDEXP)
10216 CASE_BUILTIN_F (BUILT_IN_LLRINT)
10217 CASE_BUILTIN_F (BUILT_IN_LLROUND)
10218 CASE_BUILTIN_F (BUILT_IN_LRINT)
10219 CASE_BUILTIN_F (BUILT_IN_LROUND)
10220 CASE_BUILTIN_F (BUILT_IN_MODF)
10221 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
10222 CASE_BUILTIN_F (BUILT_IN_POW)
10223 CASE_BUILTIN_F (BUILT_IN_RINT)
10224 CASE_BUILTIN_F (BUILT_IN_ROUND)
10225 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
10226 CASE_BUILTIN_F (BUILT_IN_SINH)
10227 CASE_BUILTIN_F (BUILT_IN_TANH)
10228 CASE_BUILTIN_F (BUILT_IN_TRUNC)
10229 /* True if the 1st argument is nonnegative. */
10230 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
10232 CASE_BUILTIN_F (BUILT_IN_FMAX)
10233 /* True if the 1st OR 2nd arguments are nonnegative. */
10234 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
10235 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10237 CASE_BUILTIN_F (BUILT_IN_FMIN)
10238 /* True if the 1st AND 2nd arguments are nonnegative. */
10239 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
10240 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10242 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
10243 /* True if the 2nd argument is nonnegative. */
10244 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10248 #undef CASE_BUILTIN_F
10249 #undef CASE_BUILTIN_I
10253 /* ... fall through ... */
10256 if (truth_value_p (TREE_CODE (t)))
10257 /* Truth values evaluate to 0 or 1, which is nonnegative. */
10261 /* We don't know sign of `t', so be conservative and return false. */
10265 /* Return true when T is an address and is known to be nonzero.
10266 For floating point we further ensure that T is not denormal.
10267 Similar logic is present in nonzero_address in rtlanal.h. */
10270 tree_expr_nonzero_p (tree t)
10272 tree type = TREE_TYPE (t);
10274 /* Doing something useful for floating point would need more work. */
10275 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
10278 switch (TREE_CODE (t))
10281 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10282 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10285 /* We used to test for !integer_zerop here. This does not work correctly
10286 if TREE_CONSTANT_OVERFLOW (t). */
10287 return (TREE_INT_CST_LOW (t) != 0
10288 || TREE_INT_CST_HIGH (t) != 0);
10291 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10293 /* With the presence of negative values it is hard
10294 to say something. */
10295 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10296 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
10298 /* One of operands must be positive and the other non-negative. */
10299 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10300 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10305 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10307 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10308 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10314 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
10315 tree outer_type = TREE_TYPE (t);
10317 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
10318 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
10324 tree base = get_base_address (TREE_OPERAND (t, 0));
10329 /* Weak declarations may link to NULL. */
10331 return !DECL_WEAK (base);
10333 /* Constants are never weak. */
10334 if (CONSTANT_CLASS_P (base))
10341 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10342 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
10345 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10346 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10349 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
10351 /* When both operands are nonzero, then MAX must be too. */
10352 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
10355 /* MAX where operand 0 is positive is positive. */
10356 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10358 /* MAX where operand 1 is positive is positive. */
10359 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10360 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
10364 case COMPOUND_EXPR:
10367 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
10370 case NON_LVALUE_EXPR:
10371 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10374 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10375 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10383 /* See if we are applying CODE, a relational to the highest or lowest
10384 possible integer of TYPE. If so, then the result is a compile
10388 fold_relational_hi_lo (enum tree_code *code_p, const tree type, tree *op0_p,
10393 enum tree_code code = *code_p;
10394 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (op1)));
10396 if (TREE_CODE (op1) == INTEGER_CST
10397 && ! TREE_CONSTANT_OVERFLOW (op1)
10398 && width <= HOST_BITS_PER_WIDE_INT
10399 && (INTEGRAL_TYPE_P (TREE_TYPE (op1))
10400 || POINTER_TYPE_P (TREE_TYPE (op1))))
10402 unsigned HOST_WIDE_INT signed_max;
10403 unsigned HOST_WIDE_INT max, min;
10405 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
10407 if (TYPE_UNSIGNED (TREE_TYPE (op1)))
10409 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
10415 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
10418 if (TREE_INT_CST_HIGH (op1) == 0
10419 && TREE_INT_CST_LOW (op1) == max)
10423 return omit_one_operand (type, integer_zero_node, op0);
10429 return omit_one_operand (type, integer_one_node, op0);
10435 /* The GE_EXPR and LT_EXPR cases above are not normally
10436 reached because of previous transformations. */
10441 else if (TREE_INT_CST_HIGH (op1) == 0
10442 && TREE_INT_CST_LOW (op1) == max - 1)
10447 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
10451 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
10456 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
10457 && TREE_INT_CST_LOW (op1) == min)
10461 return omit_one_operand (type, integer_zero_node, op0);
10468 return omit_one_operand (type, integer_one_node, op0);
10477 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
10478 && TREE_INT_CST_LOW (op1) == min + 1)
10483 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10487 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10493 else if (TREE_INT_CST_HIGH (op1) == 0
10494 && TREE_INT_CST_LOW (op1) == signed_max
10495 && TYPE_UNSIGNED (TREE_TYPE (op1))
10496 /* signed_type does not work on pointer types. */
10497 && INTEGRAL_TYPE_P (TREE_TYPE (op1)))
10499 /* The following case also applies to X < signed_max+1
10500 and X >= signed_max+1 because previous transformations. */
10501 if (code == LE_EXPR || code == GT_EXPR)
10503 tree st0, st1, exp, retval;
10504 st0 = lang_hooks.types.signed_type (TREE_TYPE (op0));
10505 st1 = lang_hooks.types.signed_type (TREE_TYPE (op1));
10507 exp = build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
10509 fold_convert (st0, op0),
10510 fold_convert (st1, integer_zero_node));
10512 retval = fold_binary_to_constant (TREE_CODE (exp),
10514 TREE_OPERAND (exp, 0),
10515 TREE_OPERAND (exp, 1));
10517 /* If we are in gimple form, then returning EXP would create
10518 non-gimple expressions. Clearing it is safe and insures
10519 we do not allow a non-gimple expression to escape. */
10520 if (in_gimple_form)
10523 return (retval ? retval : exp);
10532 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
10533 attempt to fold the expression to a constant without modifying TYPE,
10536 If the expression could be simplified to a constant, then return
10537 the constant. If the expression would not be simplified to a
10538 constant, then return NULL_TREE.
10540 Note this is primarily designed to be called after gimplification
10541 of the tree structures and when at least one operand is a constant.
10542 As a result of those simplifying assumptions this routine is far
10543 simpler than the generic fold routine. */
10546 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
10553 /* If this is a commutative operation, and ARG0 is a constant, move it
10554 to ARG1 to reduce the number of tests below. */
10555 if (commutative_tree_code (code)
10556 && (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST))
10563 /* If either operand is a complex type, extract its real component. */
10564 if (TREE_CODE (op0) == COMPLEX_CST)
10565 subop0 = TREE_REALPART (op0);
10569 if (TREE_CODE (op1) == COMPLEX_CST)
10570 subop1 = TREE_REALPART (op1);
10574 /* Note if either argument is not a real or integer constant.
10575 With a few exceptions, simplification is limited to cases
10576 where both arguments are constants. */
10577 if ((TREE_CODE (subop0) != INTEGER_CST
10578 && TREE_CODE (subop0) != REAL_CST)
10579 || (TREE_CODE (subop1) != INTEGER_CST
10580 && TREE_CODE (subop1) != REAL_CST))
10586 /* (plus (address) (const_int)) is a constant. */
10587 if (TREE_CODE (op0) == PLUS_EXPR
10588 && TREE_CODE (op1) == INTEGER_CST
10589 && (TREE_CODE (TREE_OPERAND (op0, 0)) == ADDR_EXPR
10590 || (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
10591 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (op0, 0), 0))
10593 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
10595 return build2 (PLUS_EXPR, type, TREE_OPERAND (op0, 0),
10596 const_binop (PLUS_EXPR, op1,
10597 TREE_OPERAND (op0, 1), 0));
10605 /* Both arguments are constants. Simplify. */
10606 tem = const_binop (code, op0, op1, 0);
10607 if (tem != NULL_TREE)
10609 /* The return value should always have the same type as
10610 the original expression. */
10611 if (TREE_TYPE (tem) != type)
10612 tem = fold_convert (type, tem);
10619 /* Fold &x - &x. This can happen from &x.foo - &x.
10620 This is unsafe for certain floats even in non-IEEE formats.
10621 In IEEE, it is unsafe because it does wrong for NaNs.
10622 Also note that operand_equal_p is always false if an
10623 operand is volatile. */
10624 if (! FLOAT_TYPE_P (type) && operand_equal_p (op0, op1, 0))
10625 return fold_convert (type, integer_zero_node);
10631 /* Special case multiplication or bitwise AND where one argument
10633 if (! FLOAT_TYPE_P (type) && integer_zerop (op1))
10634 return omit_one_operand (type, op1, op0);
10636 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (op0)))
10637 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op0)))
10638 && real_zerop (op1))
10639 return omit_one_operand (type, op1, op0);
10644 /* Special case when we know the result will be all ones. */
10645 if (integer_all_onesp (op1))
10646 return omit_one_operand (type, op1, op0);
10650 case TRUNC_DIV_EXPR:
10651 case ROUND_DIV_EXPR:
10652 case FLOOR_DIV_EXPR:
10653 case CEIL_DIV_EXPR:
10654 case EXACT_DIV_EXPR:
10655 case TRUNC_MOD_EXPR:
10656 case ROUND_MOD_EXPR:
10657 case FLOOR_MOD_EXPR:
10658 case CEIL_MOD_EXPR:
10660 /* Division by zero is undefined. */
10661 if (integer_zerop (op1))
10664 if (TREE_CODE (op1) == REAL_CST
10665 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (op1)))
10666 && real_zerop (op1))
10672 if (INTEGRAL_TYPE_P (type)
10673 && operand_equal_p (op1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
10674 return omit_one_operand (type, op1, op0);
10679 if (INTEGRAL_TYPE_P (type)
10680 && TYPE_MAX_VALUE (type)
10681 && operand_equal_p (op1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
10682 return omit_one_operand (type, op1, op0);
10687 /* Optimize -1 >> x for arithmetic right shifts. */
10688 if (integer_all_onesp (op0) && ! TYPE_UNSIGNED (type))
10689 return omit_one_operand (type, op0, op1);
10690 /* ... fall through ... */
10693 if (integer_zerop (op0))
10694 return omit_one_operand (type, op0, op1);
10696 /* Since negative shift count is not well-defined, don't
10697 try to compute it in the compiler. */
10698 if (TREE_CODE (op1) == INTEGER_CST && tree_int_cst_sgn (op1) < 0)
10705 /* -1 rotated either direction by any amount is still -1. */
10706 if (integer_all_onesp (op0))
10707 return omit_one_operand (type, op0, op1);
10709 /* 0 rotated either direction by any amount is still zero. */
10710 if (integer_zerop (op0))
10711 return omit_one_operand (type, op0, op1);
10717 return build_complex (type, op0, op1);
10726 /* If one arg is a real or integer constant, put it last. */
10727 if ((TREE_CODE (op0) == INTEGER_CST
10728 && TREE_CODE (op1) != INTEGER_CST)
10729 || (TREE_CODE (op0) == REAL_CST
10730 && TREE_CODE (op0) != REAL_CST))
10737 code = swap_tree_comparison (code);
10740 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
10741 This transformation affects the cases which are handled in later
10742 optimizations involving comparisons with non-negative constants. */
10743 if (TREE_CODE (op1) == INTEGER_CST
10744 && TREE_CODE (op0) != INTEGER_CST
10745 && tree_int_cst_sgn (op1) > 0)
10751 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10756 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10764 tem = fold_relational_hi_lo (&code, type, &op0, &op1);
10768 /* Fall through. */
10771 case UNORDERED_EXPR:
10781 return fold_relational_const (code, type, op0, op1);
10784 /* This could probably be handled. */
10787 case TRUTH_AND_EXPR:
10788 /* If second arg is constant zero, result is zero, but first arg
10789 must be evaluated. */
10790 if (integer_zerop (op1))
10791 return omit_one_operand (type, op1, op0);
10792 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10793 case will be handled here. */
10794 if (integer_zerop (op0))
10795 return omit_one_operand (type, op0, op1);
10796 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10797 return constant_boolean_node (true, type);
10800 case TRUTH_OR_EXPR:
10801 /* If second arg is constant true, result is true, but we must
10802 evaluate first arg. */
10803 if (TREE_CODE (op1) == INTEGER_CST && ! integer_zerop (op1))
10804 return omit_one_operand (type, op1, op0);
10805 /* Likewise for first arg, but note this only occurs here for
10807 if (TREE_CODE (op0) == INTEGER_CST && ! integer_zerop (op0))
10808 return omit_one_operand (type, op0, op1);
10809 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10810 return constant_boolean_node (false, type);
10813 case TRUTH_XOR_EXPR:
10814 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10816 int x = ! integer_zerop (op0) ^ ! integer_zerop (op1);
10817 return constant_boolean_node (x, type);
10826 /* Given the components of a unary expression CODE, TYPE and OP0,
10827 attempt to fold the expression to a constant without modifying
10830 If the expression could be simplified to a constant, then return
10831 the constant. If the expression would not be simplified to a
10832 constant, then return NULL_TREE.
10834 Note this is primarily designed to be called after gimplification
10835 of the tree structures and when op0 is a constant. As a result
10836 of those simplifying assumptions this routine is far simpler than
10837 the generic fold routine. */
10840 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
10842 /* Make sure we have a suitable constant argument. */
10843 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
10847 if (TREE_CODE (op0) == COMPLEX_CST)
10848 subop = TREE_REALPART (op0);
10852 if (TREE_CODE (subop) != INTEGER_CST && TREE_CODE (subop) != REAL_CST)
10861 case FIX_TRUNC_EXPR:
10862 case FIX_FLOOR_EXPR:
10863 case FIX_CEIL_EXPR:
10864 return fold_convert_const (code, type, op0);
10867 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10868 return fold_negate_const (op0, type);
10873 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10874 return fold_abs_const (op0, type);
10879 if (TREE_CODE (op0) == INTEGER_CST)
10880 return fold_not_const (op0, type);
10884 case REALPART_EXPR:
10885 if (TREE_CODE (op0) == COMPLEX_CST)
10886 return TREE_REALPART (op0);
10890 case IMAGPART_EXPR:
10891 if (TREE_CODE (op0) == COMPLEX_CST)
10892 return TREE_IMAGPART (op0);
10897 if (TREE_CODE (op0) == COMPLEX_CST
10898 && TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
10899 return build_complex (type, TREE_REALPART (op0),
10900 negate_expr (TREE_IMAGPART (op0)));
10908 /* If EXP represents referencing an element in a constant string
10909 (either via pointer arithmetic or array indexing), return the
10910 tree representing the value accessed, otherwise return NULL. */
10913 fold_read_from_constant_string (tree exp)
10915 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
10917 tree exp1 = TREE_OPERAND (exp, 0);
10921 if (TREE_CODE (exp) == INDIRECT_REF)
10922 string = string_constant (exp1, &index);
10925 tree low_bound = array_ref_low_bound (exp);
10926 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
10928 /* Optimize the special-case of a zero lower bound.
10930 We convert the low_bound to sizetype to avoid some problems
10931 with constant folding. (E.g. suppose the lower bound is 1,
10932 and its mode is QI. Without the conversion,l (ARRAY
10933 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
10934 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
10935 if (! integer_zerop (low_bound))
10936 index = size_diffop (index, fold_convert (sizetype, low_bound));
10942 && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
10943 && TREE_CODE (string) == STRING_CST
10944 && TREE_CODE (index) == INTEGER_CST
10945 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
10946 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
10948 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
10949 return fold_convert (TREE_TYPE (exp),
10950 build_int_cst (NULL_TREE,
10951 (TREE_STRING_POINTER (string)
10952 [TREE_INT_CST_LOW (index)])));
10957 /* Return the tree for neg (ARG0) when ARG0 is known to be either
10958 an integer constant or real constant.
10960 TYPE is the type of the result. */
10963 fold_negate_const (tree arg0, tree type)
10965 tree t = NULL_TREE;
10967 switch (TREE_CODE (arg0))
10971 unsigned HOST_WIDE_INT low;
10972 HOST_WIDE_INT high;
10973 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10974 TREE_INT_CST_HIGH (arg0),
10976 t = build_int_cst_wide (type, low, high);
10977 t = force_fit_type (t, 1,
10978 (overflow | TREE_OVERFLOW (arg0))
10979 && !TYPE_UNSIGNED (type),
10980 TREE_CONSTANT_OVERFLOW (arg0));
10985 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10989 gcc_unreachable ();
10995 /* Return the tree for abs (ARG0) when ARG0 is known to be either
10996 an integer constant or real constant.
10998 TYPE is the type of the result. */
11001 fold_abs_const (tree arg0, tree type)
11003 tree t = NULL_TREE;
11005 switch (TREE_CODE (arg0))
11008 /* If the value is unsigned, then the absolute value is
11009 the same as the ordinary value. */
11010 if (TYPE_UNSIGNED (type))
11012 /* Similarly, if the value is non-negative. */
11013 else if (INT_CST_LT (integer_minus_one_node, arg0))
11015 /* If the value is negative, then the absolute value is
11019 unsigned HOST_WIDE_INT low;
11020 HOST_WIDE_INT high;
11021 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
11022 TREE_INT_CST_HIGH (arg0),
11024 t = build_int_cst_wide (type, low, high);
11025 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
11026 TREE_CONSTANT_OVERFLOW (arg0));
11031 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
11032 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
11038 gcc_unreachable ();
11044 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
11045 constant. TYPE is the type of the result. */
11048 fold_not_const (tree arg0, tree type)
11050 tree t = NULL_TREE;
11052 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
11054 t = build_int_cst_wide (type,
11055 ~ TREE_INT_CST_LOW (arg0),
11056 ~ TREE_INT_CST_HIGH (arg0));
11057 t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
11058 TREE_CONSTANT_OVERFLOW (arg0));
11063 /* Given CODE, a relational operator, the target type, TYPE and two
11064 constant operands OP0 and OP1, return the result of the
11065 relational operation. If the result is not a compile time
11066 constant, then return NULL_TREE. */
11069 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
11071 int result, invert;
11073 /* From here on, the only cases we handle are when the result is
11074 known to be a constant. */
11076 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
11078 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
11079 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
11081 /* Handle the cases where either operand is a NaN. */
11082 if (real_isnan (c0) || real_isnan (c1))
11092 case UNORDERED_EXPR:
11106 if (flag_trapping_math)
11112 gcc_unreachable ();
11115 return constant_boolean_node (result, type);
11118 return constant_boolean_node (real_compare (code, c0, c1), type);
11121 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
11123 To compute GT, swap the arguments and do LT.
11124 To compute GE, do LT and invert the result.
11125 To compute LE, swap the arguments, do LT and invert the result.
11126 To compute NE, do EQ and invert the result.
11128 Therefore, the code below must handle only EQ and LT. */
11130 if (code == LE_EXPR || code == GT_EXPR)
11135 code = swap_tree_comparison (code);
11138 /* Note that it is safe to invert for real values here because we
11139 have already handled the one case that it matters. */
11142 if (code == NE_EXPR || code == GE_EXPR)
11145 code = invert_tree_comparison (code, false);
11148 /* Compute a result for LT or EQ if args permit;
11149 Otherwise return T. */
11150 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
11152 if (code == EQ_EXPR)
11153 result = tree_int_cst_equal (op0, op1);
11154 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
11155 result = INT_CST_LT_UNSIGNED (op0, op1);
11157 result = INT_CST_LT (op0, op1);
11164 return constant_boolean_node (result, type);
11167 /* Build an expression for the a clean point containing EXPR with type TYPE.
11168 Don't build a cleanup point expression for EXPR which don't have side
11172 fold_build_cleanup_point_expr (tree type, tree expr)
11174 /* If the expression does not have side effects then we don't have to wrap
11175 it with a cleanup point expression. */
11176 if (!TREE_SIDE_EFFECTS (expr))
11179 /* If the expression is a return, check to see if the expression inside the
11180 return has no side effects or the right hand side of the modify expression
11181 inside the return. If either don't have side effects set we don't need to
11182 wrap the expression in a cleanup point expression. Note we don't check the
11183 left hand side of the modify because it should always be a return decl. */
11184 if (TREE_CODE (expr) == RETURN_EXPR)
11186 tree op = TREE_OPERAND (expr, 0);
11187 if (!op || !TREE_SIDE_EFFECTS (op))
11189 op = TREE_OPERAND (op, 1);
11190 if (!TREE_SIDE_EFFECTS (op))
11194 return build1 (CLEANUP_POINT_EXPR, type, expr);
11197 /* Build an expression for the address of T. Folds away INDIRECT_REF to
11198 avoid confusing the gimplify process. */
11201 build_fold_addr_expr_with_type (tree t, tree ptrtype)
11203 /* The size of the object is not relevant when talking about its address. */
11204 if (TREE_CODE (t) == WITH_SIZE_EXPR)
11205 t = TREE_OPERAND (t, 0);
11207 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
11208 if (TREE_CODE (t) == INDIRECT_REF
11209 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
11211 t = TREE_OPERAND (t, 0);
11212 if (TREE_TYPE (t) != ptrtype)
11213 t = build1 (NOP_EXPR, ptrtype, t);
11219 while (handled_component_p (base))
11220 base = TREE_OPERAND (base, 0);
11222 TREE_ADDRESSABLE (base) = 1;
11224 t = build1 (ADDR_EXPR, ptrtype, t);
11231 build_fold_addr_expr (tree t)
11233 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
11236 /* Given a pointer value T, return a simplified version of an indirection
11237 through T, or NULL_TREE if no simplification is possible. */
11240 fold_indirect_ref_1 (tree t)
11242 tree type = TREE_TYPE (TREE_TYPE (t));
11247 subtype = TREE_TYPE (sub);
11248 if (!POINTER_TYPE_P (subtype))
11251 if (TREE_CODE (sub) == ADDR_EXPR)
11253 tree op = TREE_OPERAND (sub, 0);
11254 tree optype = TREE_TYPE (op);
11256 if (lang_hooks.types_compatible_p (type, optype))
11258 /* *(foo *)&fooarray => fooarray[0] */
11259 else if (TREE_CODE (optype) == ARRAY_TYPE
11260 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
11262 tree type_domain = TYPE_DOMAIN (optype);
11263 tree min_val = size_zero_node;
11264 if (type_domain && TYPE_MIN_VALUE (type_domain))
11265 min_val = TYPE_MIN_VALUE (type_domain);
11266 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
11270 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
11271 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
11272 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
11275 tree min_val = size_zero_node;
11276 sub = build_fold_indirect_ref (sub);
11277 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
11278 if (type_domain && TYPE_MIN_VALUE (type_domain))
11279 min_val = TYPE_MIN_VALUE (type_domain);
11280 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
11286 /* Builds an expression for an indirection through T, simplifying some
11290 build_fold_indirect_ref (tree t)
11292 tree sub = fold_indirect_ref_1 (t);
11297 return build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (t)), t);
11300 /* Given an INDIRECT_REF T, return either T or a simplified version. */
11303 fold_indirect_ref (tree t)
11305 tree sub = fold_indirect_ref_1 (TREE_OPERAND (t, 0));
11313 /* Strip non-trapping, non-side-effecting tree nodes from an expression
11314 whose result is ignored. The type of the returned tree need not be
11315 the same as the original expression. */
11318 fold_ignored_result (tree t)
11320 if (!TREE_SIDE_EFFECTS (t))
11321 return integer_zero_node;
11324 switch (TREE_CODE_CLASS (TREE_CODE (t)))
11327 t = TREE_OPERAND (t, 0);
11331 case tcc_comparison:
11332 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
11333 t = TREE_OPERAND (t, 0);
11334 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
11335 t = TREE_OPERAND (t, 1);
11340 case tcc_expression:
11341 switch (TREE_CODE (t))
11343 case COMPOUND_EXPR:
11344 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
11346 t = TREE_OPERAND (t, 0);
11350 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
11351 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
11353 t = TREE_OPERAND (t, 0);
11366 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
11367 This can only be applied to objects of a sizetype. */
11370 round_up (tree value, int divisor)
11372 tree div = NULL_TREE;
11374 gcc_assert (divisor > 0);
11378 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11379 have to do anything. Only do this when we are not given a const,
11380 because in that case, this check is more expensive than just
11382 if (TREE_CODE (value) != INTEGER_CST)
11384 div = build_int_cst (TREE_TYPE (value), divisor);
11386 if (multiple_of_p (TREE_TYPE (value), value, div))
11390 /* If divisor is a power of two, simplify this to bit manipulation. */
11391 if (divisor == (divisor & -divisor))
11395 t = build_int_cst (TREE_TYPE (value), divisor - 1);
11396 value = size_binop (PLUS_EXPR, value, t);
11397 t = build_int_cst (TREE_TYPE (value), -divisor);
11398 value = size_binop (BIT_AND_EXPR, value, t);
11403 div = build_int_cst (TREE_TYPE (value), divisor);
11404 value = size_binop (CEIL_DIV_EXPR, value, div);
11405 value = size_binop (MULT_EXPR, value, div);
11411 /* Likewise, but round down. */
11414 round_down (tree value, int divisor)
11416 tree div = NULL_TREE;
11418 gcc_assert (divisor > 0);
11422 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11423 have to do anything. Only do this when we are not given a const,
11424 because in that case, this check is more expensive than just
11426 if (TREE_CODE (value) != INTEGER_CST)
11428 div = build_int_cst (TREE_TYPE (value), divisor);
11430 if (multiple_of_p (TREE_TYPE (value), value, div))
11434 /* If divisor is a power of two, simplify this to bit manipulation. */
11435 if (divisor == (divisor & -divisor))
11439 t = build_int_cst (TREE_TYPE (value), -divisor);
11440 value = size_binop (BIT_AND_EXPR, value, t);
11445 div = build_int_cst (TREE_TYPE (value), divisor);
11446 value = size_binop (FLOOR_DIV_EXPR, value, div);
11447 value = size_binop (MULT_EXPR, value, div);
11453 /* Returns the pointer to the base of the object addressed by EXP and
11454 extracts the information about the offset of the access, storing it
11455 to PBITPOS and POFFSET. */
11458 split_address_to_core_and_offset (tree exp,
11459 HOST_WIDE_INT *pbitpos, tree *poffset)
11462 enum machine_mode mode;
11463 int unsignedp, volatilep;
11464 HOST_WIDE_INT bitsize;
11466 if (TREE_CODE (exp) == ADDR_EXPR)
11468 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
11469 poffset, &mode, &unsignedp, &volatilep,
11472 if (TREE_CODE (core) == INDIRECT_REF)
11473 core = TREE_OPERAND (core, 0);
11479 *poffset = NULL_TREE;
11485 /* Returns true if addresses of E1 and E2 differ by a constant, false
11486 otherwise. If they do, E1 - E2 is stored in *DIFF. */
11489 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
11492 HOST_WIDE_INT bitpos1, bitpos2;
11493 tree toffset1, toffset2, tdiff, type;
11495 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
11496 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
11498 if (bitpos1 % BITS_PER_UNIT != 0
11499 || bitpos2 % BITS_PER_UNIT != 0
11500 || !operand_equal_p (core1, core2, 0))
11503 if (toffset1 && toffset2)
11505 type = TREE_TYPE (toffset1);
11506 if (type != TREE_TYPE (toffset2))
11507 toffset2 = fold_convert (type, toffset2);
11509 tdiff = fold (build2 (MINUS_EXPR, type, toffset1, toffset2));
11510 if (!host_integerp (tdiff, 0))
11513 *diff = tree_low_cst (tdiff, 0);
11515 else if (toffset1 || toffset2)
11517 /* If only one of the offsets is non-constant, the difference cannot
11524 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
11528 /* Simplify the floating point expression EXP when the sign of the
11529 result is not significant. Return NULL_TREE if no simplification
11533 fold_strip_sign_ops (tree exp)
11537 switch (TREE_CODE (exp))
11541 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
11542 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
11546 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
11548 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
11549 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
11550 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
11551 return fold (build2 (TREE_CODE (exp), TREE_TYPE (exp),
11552 arg0 ? arg0 : TREE_OPERAND (exp, 0),
11553 arg1 ? arg1 : TREE_OPERAND (exp, 1)));