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 (enum tree_code, tree, tree, 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 (enum tree_code, tree, tree, 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 (enum tree_code, tree,
127 static bool fold_real_zero_addition_p (tree, tree, int);
128 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
130 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
131 static tree fold_div_compare (enum tree_code, tree, tree, tree);
132 static bool reorder_operands_p (tree, tree);
133 static tree fold_negate_const (tree, tree);
134 static tree fold_not_const (tree, tree);
135 static tree fold_relational_const (enum tree_code, tree, tree, tree);
136 static bool tree_expr_nonzero_p (tree);
138 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
139 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
140 and SUM1. Then this yields nonzero if overflow occurred during the
143 Overflow occurs if A and B have the same sign, but A and SUM differ in
144 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
146 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
148 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
149 We do that by representing the two-word integer in 4 words, with only
150 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
151 number. The value of the word is LOWPART + HIGHPART * BASE. */
154 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
155 #define HIGHPART(x) \
156 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
157 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
159 /* Unpack a two-word integer into 4 words.
160 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
161 WORDS points to the array of HOST_WIDE_INTs. */
164 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
166 words[0] = LOWPART (low);
167 words[1] = HIGHPART (low);
168 words[2] = LOWPART (hi);
169 words[3] = HIGHPART (hi);
172 /* Pack an array of 4 words into a two-word integer.
173 WORDS points to the array of words.
174 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
177 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
180 *low = words[0] + words[1] * BASE;
181 *hi = words[2] + words[3] * BASE;
184 /* T is an INT_CST node. OVERFLOWABLE indicates if we are interested
185 in overflow of the value, when >0 we are only interested in signed
186 overflow, for <0 we are interested in any overflow. OVERFLOWED
187 indicates whether overflow has already occurred. CONST_OVERFLOWED
188 indicates whether constant overflow has already occurred. We force
189 T's value to be within range of T's type (by setting to 0 or 1 all
190 the bits outside the type's range). We set TREE_OVERFLOWED if,
191 OVERFLOWED is nonzero,
192 or OVERFLOWABLE is >0 and signed overflow occurs
193 or OVERFLOWABLE is <0 and any overflow occurs
194 We set TREE_CONSTANT_OVERFLOWED if,
195 CONST_OVERFLOWED is nonzero
196 or we set TREE_OVERFLOWED.
197 We return either the original T, or a copy. */
200 force_fit_type (tree t, int overflowable,
201 bool overflowed, bool overflowed_const)
203 unsigned HOST_WIDE_INT low;
206 int sign_extended_type;
208 gcc_assert (TREE_CODE (t) == INTEGER_CST);
210 low = TREE_INT_CST_LOW (t);
211 high = TREE_INT_CST_HIGH (t);
213 if (POINTER_TYPE_P (TREE_TYPE (t))
214 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
217 prec = TYPE_PRECISION (TREE_TYPE (t));
218 /* Size types *are* sign extended. */
219 sign_extended_type = (!TYPE_UNSIGNED (TREE_TYPE (t))
220 || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
221 && TYPE_IS_SIZETYPE (TREE_TYPE (t))));
223 /* First clear all bits that are beyond the type's precision. */
225 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
227 else if (prec > HOST_BITS_PER_WIDE_INT)
228 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
232 if (prec < HOST_BITS_PER_WIDE_INT)
233 low &= ~((HOST_WIDE_INT) (-1) << prec);
236 if (!sign_extended_type)
237 /* No sign extension */;
238 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
239 /* Correct width already. */;
240 else if (prec > HOST_BITS_PER_WIDE_INT)
242 /* Sign extend top half? */
243 if (high & ((unsigned HOST_WIDE_INT)1
244 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
245 high |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
247 else if (prec == HOST_BITS_PER_WIDE_INT)
249 if ((HOST_WIDE_INT)low < 0)
254 /* Sign extend bottom half? */
255 if (low & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
258 low |= (HOST_WIDE_INT)(-1) << prec;
262 /* If the value changed, return a new node. */
263 if (overflowed || overflowed_const
264 || low != TREE_INT_CST_LOW (t) || high != TREE_INT_CST_HIGH (t))
266 t = build_int_cst_wide (TREE_TYPE (t), low, high);
270 || (overflowable > 0 && sign_extended_type))
273 TREE_OVERFLOW (t) = 1;
274 TREE_CONSTANT_OVERFLOW (t) = 1;
276 else if (overflowed_const)
279 TREE_CONSTANT_OVERFLOW (t) = 1;
286 /* Add two doubleword integers with doubleword result.
287 Each argument is given as two `HOST_WIDE_INT' pieces.
288 One argument is L1 and H1; the other, L2 and H2.
289 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
292 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
293 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
294 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
296 unsigned HOST_WIDE_INT l;
300 h = h1 + h2 + (l < l1);
304 return OVERFLOW_SUM_SIGN (h1, h2, h);
307 /* Negate a doubleword integer with doubleword result.
308 Return nonzero if the operation overflows, assuming it's signed.
309 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
310 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
313 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
314 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
320 return (*hv & h1) < 0;
330 /* Multiply two doubleword integers with doubleword result.
331 Return nonzero if the operation overflows, assuming it's signed.
332 Each argument is given as two `HOST_WIDE_INT' pieces.
333 One argument is L1 and H1; the other, L2 and H2.
334 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
337 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
338 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
339 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
341 HOST_WIDE_INT arg1[4];
342 HOST_WIDE_INT arg2[4];
343 HOST_WIDE_INT prod[4 * 2];
344 unsigned HOST_WIDE_INT carry;
346 unsigned HOST_WIDE_INT toplow, neglow;
347 HOST_WIDE_INT tophigh, neghigh;
349 encode (arg1, l1, h1);
350 encode (arg2, l2, h2);
352 memset (prod, 0, sizeof prod);
354 for (i = 0; i < 4; i++)
357 for (j = 0; j < 4; j++)
360 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
361 carry += arg1[i] * arg2[j];
362 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
364 prod[k] = LOWPART (carry);
365 carry = HIGHPART (carry);
370 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
372 /* Check for overflow by calculating the top half of the answer in full;
373 it should agree with the low half's sign bit. */
374 decode (prod + 4, &toplow, &tophigh);
377 neg_double (l2, h2, &neglow, &neghigh);
378 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
382 neg_double (l1, h1, &neglow, &neghigh);
383 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
385 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
388 /* Shift the doubleword integer in L1, H1 left by COUNT places
389 keeping only PREC bits of result.
390 Shift right if COUNT is negative.
391 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
392 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
395 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
396 HOST_WIDE_INT count, unsigned int prec,
397 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
399 unsigned HOST_WIDE_INT signmask;
403 rshift_double (l1, h1, -count, prec, lv, hv, arith);
407 if (SHIFT_COUNT_TRUNCATED)
410 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
412 /* Shifting by the host word size is undefined according to the
413 ANSI standard, so we must handle this as a special case. */
417 else if (count >= HOST_BITS_PER_WIDE_INT)
419 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
424 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
425 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
429 /* Sign extend all bits that are beyond the precision. */
431 signmask = -((prec > HOST_BITS_PER_WIDE_INT
432 ? ((unsigned HOST_WIDE_INT) *hv
433 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
434 : (*lv >> (prec - 1))) & 1);
436 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
438 else if (prec >= HOST_BITS_PER_WIDE_INT)
440 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
441 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
446 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
447 *lv |= signmask << prec;
451 /* Shift the doubleword integer in L1, H1 right by COUNT places
452 keeping only PREC bits of result. COUNT must be positive.
453 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
454 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
457 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
458 HOST_WIDE_INT count, unsigned int prec,
459 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
462 unsigned HOST_WIDE_INT signmask;
465 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
468 if (SHIFT_COUNT_TRUNCATED)
471 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
473 /* Shifting by the host word size is undefined according to the
474 ANSI standard, so we must handle this as a special case. */
478 else if (count >= HOST_BITS_PER_WIDE_INT)
481 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
485 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
487 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
490 /* Zero / sign extend all bits that are beyond the precision. */
492 if (count >= (HOST_WIDE_INT)prec)
497 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
499 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
501 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
502 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
507 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
508 *lv |= signmask << (prec - count);
512 /* Rotate the doubleword integer in L1, H1 left by COUNT places
513 keeping only PREC bits of result.
514 Rotate right if COUNT is negative.
515 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
518 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
519 HOST_WIDE_INT count, unsigned int prec,
520 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
522 unsigned HOST_WIDE_INT s1l, s2l;
523 HOST_WIDE_INT s1h, s2h;
529 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
530 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
535 /* Rotate the doubleword integer in L1, H1 left by COUNT places
536 keeping only PREC bits of result. COUNT must be positive.
537 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
540 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
541 HOST_WIDE_INT count, unsigned int prec,
542 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
544 unsigned HOST_WIDE_INT s1l, s2l;
545 HOST_WIDE_INT s1h, s2h;
551 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
552 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
557 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
558 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
559 CODE is a tree code for a kind of division, one of
560 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
562 It controls how the quotient is rounded to an integer.
563 Return nonzero if the operation overflows.
564 UNS nonzero says do unsigned division. */
567 div_and_round_double (enum tree_code code, int uns,
568 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
569 HOST_WIDE_INT hnum_orig,
570 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
571 HOST_WIDE_INT hden_orig,
572 unsigned HOST_WIDE_INT *lquo,
573 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
577 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
578 HOST_WIDE_INT den[4], quo[4];
580 unsigned HOST_WIDE_INT work;
581 unsigned HOST_WIDE_INT carry = 0;
582 unsigned HOST_WIDE_INT lnum = lnum_orig;
583 HOST_WIDE_INT hnum = hnum_orig;
584 unsigned HOST_WIDE_INT lden = lden_orig;
585 HOST_WIDE_INT hden = hden_orig;
588 if (hden == 0 && lden == 0)
589 overflow = 1, lden = 1;
591 /* Calculate quotient sign and convert operands to unsigned. */
597 /* (minimum integer) / (-1) is the only overflow case. */
598 if (neg_double (lnum, hnum, &lnum, &hnum)
599 && ((HOST_WIDE_INT) lden & hden) == -1)
605 neg_double (lden, hden, &lden, &hden);
609 if (hnum == 0 && hden == 0)
610 { /* single precision */
612 /* This unsigned division rounds toward zero. */
618 { /* trivial case: dividend < divisor */
619 /* hden != 0 already checked. */
626 memset (quo, 0, sizeof quo);
628 memset (num, 0, sizeof num); /* to zero 9th element */
629 memset (den, 0, sizeof den);
631 encode (num, lnum, hnum);
632 encode (den, lden, hden);
634 /* Special code for when the divisor < BASE. */
635 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
637 /* hnum != 0 already checked. */
638 for (i = 4 - 1; i >= 0; i--)
640 work = num[i] + carry * BASE;
641 quo[i] = work / lden;
647 /* Full double precision division,
648 with thanks to Don Knuth's "Seminumerical Algorithms". */
649 int num_hi_sig, den_hi_sig;
650 unsigned HOST_WIDE_INT quo_est, scale;
652 /* Find the highest nonzero divisor digit. */
653 for (i = 4 - 1;; i--)
660 /* Insure that the first digit of the divisor is at least BASE/2.
661 This is required by the quotient digit estimation algorithm. */
663 scale = BASE / (den[den_hi_sig] + 1);
665 { /* scale divisor and dividend */
667 for (i = 0; i <= 4 - 1; i++)
669 work = (num[i] * scale) + carry;
670 num[i] = LOWPART (work);
671 carry = HIGHPART (work);
676 for (i = 0; i <= 4 - 1; i++)
678 work = (den[i] * scale) + carry;
679 den[i] = LOWPART (work);
680 carry = HIGHPART (work);
681 if (den[i] != 0) den_hi_sig = i;
688 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
690 /* Guess the next quotient digit, quo_est, by dividing the first
691 two remaining dividend digits by the high order quotient digit.
692 quo_est is never low and is at most 2 high. */
693 unsigned HOST_WIDE_INT tmp;
695 num_hi_sig = i + den_hi_sig + 1;
696 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
697 if (num[num_hi_sig] != den[den_hi_sig])
698 quo_est = work / den[den_hi_sig];
702 /* Refine quo_est so it's usually correct, and at most one high. */
703 tmp = work - quo_est * den[den_hi_sig];
705 && (den[den_hi_sig - 1] * quo_est
706 > (tmp * BASE + num[num_hi_sig - 2])))
709 /* Try QUO_EST as the quotient digit, by multiplying the
710 divisor by QUO_EST and subtracting from the remaining dividend.
711 Keep in mind that QUO_EST is the I - 1st digit. */
714 for (j = 0; j <= den_hi_sig; j++)
716 work = quo_est * den[j] + carry;
717 carry = HIGHPART (work);
718 work = num[i + j] - LOWPART (work);
719 num[i + j] = LOWPART (work);
720 carry += HIGHPART (work) != 0;
723 /* If quo_est was high by one, then num[i] went negative and
724 we need to correct things. */
725 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
728 carry = 0; /* add divisor back in */
729 for (j = 0; j <= den_hi_sig; j++)
731 work = num[i + j] + den[j] + carry;
732 carry = HIGHPART (work);
733 num[i + j] = LOWPART (work);
736 num [num_hi_sig] += carry;
739 /* Store the quotient digit. */
744 decode (quo, lquo, hquo);
747 /* If result is negative, make it so. */
749 neg_double (*lquo, *hquo, lquo, hquo);
751 /* Compute trial remainder: rem = num - (quo * den) */
752 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
753 neg_double (*lrem, *hrem, lrem, hrem);
754 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
759 case TRUNC_MOD_EXPR: /* round toward zero */
760 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
764 case FLOOR_MOD_EXPR: /* round toward negative infinity */
765 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
768 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
776 case CEIL_MOD_EXPR: /* round toward positive infinity */
777 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
779 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
787 case ROUND_MOD_EXPR: /* round to closest integer */
789 unsigned HOST_WIDE_INT labs_rem = *lrem;
790 HOST_WIDE_INT habs_rem = *hrem;
791 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
792 HOST_WIDE_INT habs_den = hden, htwice;
794 /* Get absolute values. */
796 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
798 neg_double (lden, hden, &labs_den, &habs_den);
800 /* If (2 * abs (lrem) >= abs (lden)) */
801 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
802 labs_rem, habs_rem, <wice, &htwice);
804 if (((unsigned HOST_WIDE_INT) habs_den
805 < (unsigned HOST_WIDE_INT) htwice)
806 || (((unsigned HOST_WIDE_INT) habs_den
807 == (unsigned HOST_WIDE_INT) htwice)
808 && (labs_den < ltwice)))
812 add_double (*lquo, *hquo,
813 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
816 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
828 /* Compute true remainder: rem = num - (quo * den) */
829 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
830 neg_double (*lrem, *hrem, lrem, hrem);
831 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
835 /* Return true if built-in mathematical function specified by CODE
836 preserves the sign of it argument, i.e. -f(x) == f(-x). */
839 negate_mathfn_p (enum built_in_function code)
863 /* Check whether we may negate an integer constant T without causing
867 may_negate_without_overflow_p (tree t)
869 unsigned HOST_WIDE_INT val;
873 gcc_assert (TREE_CODE (t) == INTEGER_CST);
875 type = TREE_TYPE (t);
876 if (TYPE_UNSIGNED (type))
879 prec = TYPE_PRECISION (type);
880 if (prec > HOST_BITS_PER_WIDE_INT)
882 if (TREE_INT_CST_LOW (t) != 0)
884 prec -= HOST_BITS_PER_WIDE_INT;
885 val = TREE_INT_CST_HIGH (t);
888 val = TREE_INT_CST_LOW (t);
889 if (prec < HOST_BITS_PER_WIDE_INT)
890 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
891 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
894 /* Determine whether an expression T can be cheaply negated using
895 the function negate_expr. */
898 negate_expr_p (tree t)
905 type = TREE_TYPE (t);
908 switch (TREE_CODE (t))
911 if (TYPE_UNSIGNED (type) || ! flag_trapv)
914 /* Check that -CST will not overflow type. */
915 return may_negate_without_overflow_p (t);
922 return negate_expr_p (TREE_REALPART (t))
923 && negate_expr_p (TREE_IMAGPART (t));
926 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
928 /* -(A + B) -> (-B) - A. */
929 if (negate_expr_p (TREE_OPERAND (t, 1))
930 && reorder_operands_p (TREE_OPERAND (t, 0),
931 TREE_OPERAND (t, 1)))
933 /* -(A + B) -> (-A) - B. */
934 return negate_expr_p (TREE_OPERAND (t, 0));
937 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
938 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
939 && reorder_operands_p (TREE_OPERAND (t, 0),
940 TREE_OPERAND (t, 1));
943 if (TYPE_UNSIGNED (TREE_TYPE (t)))
949 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
950 return negate_expr_p (TREE_OPERAND (t, 1))
951 || negate_expr_p (TREE_OPERAND (t, 0));
955 /* Negate -((double)float) as (double)(-float). */
956 if (TREE_CODE (type) == REAL_TYPE)
958 tree tem = strip_float_extensions (t);
960 return negate_expr_p (tem);
965 /* Negate -f(x) as f(-x). */
966 if (negate_mathfn_p (builtin_mathfn_code (t)))
967 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
971 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
972 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
974 tree op1 = TREE_OPERAND (t, 1);
975 if (TREE_INT_CST_HIGH (op1) == 0
976 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
977 == TREE_INT_CST_LOW (op1))
988 /* Given T, an expression, return the negation of T. Allow for T to be
989 null, in which case return null. */
1000 type = TREE_TYPE (t);
1001 STRIP_SIGN_NOPS (t);
1003 switch (TREE_CODE (t))
1006 tem = fold_negate_const (t, type);
1007 if (! TREE_OVERFLOW (tem)
1008 || TYPE_UNSIGNED (type)
1014 tem = fold_negate_const (t, type);
1015 /* Two's complement FP formats, such as c4x, may overflow. */
1016 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
1017 return fold_convert (type, tem);
1022 tree rpart = negate_expr (TREE_REALPART (t));
1023 tree ipart = negate_expr (TREE_IMAGPART (t));
1025 if ((TREE_CODE (rpart) == REAL_CST
1026 && TREE_CODE (ipart) == REAL_CST)
1027 || (TREE_CODE (rpart) == INTEGER_CST
1028 && TREE_CODE (ipart) == INTEGER_CST))
1029 return build_complex (type, rpart, ipart);
1034 return fold_convert (type, TREE_OPERAND (t, 0));
1037 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1039 /* -(A + B) -> (-B) - A. */
1040 if (negate_expr_p (TREE_OPERAND (t, 1))
1041 && reorder_operands_p (TREE_OPERAND (t, 0),
1042 TREE_OPERAND (t, 1)))
1044 tem = negate_expr (TREE_OPERAND (t, 1));
1045 tem = fold_build2 (MINUS_EXPR, TREE_TYPE (t),
1046 tem, TREE_OPERAND (t, 0));
1047 return fold_convert (type, tem);
1050 /* -(A + B) -> (-A) - B. */
1051 if (negate_expr_p (TREE_OPERAND (t, 0)))
1053 tem = negate_expr (TREE_OPERAND (t, 0));
1054 tem = fold_build2 (MINUS_EXPR, TREE_TYPE (t),
1055 tem, TREE_OPERAND (t, 1));
1056 return fold_convert (type, tem);
1062 /* - (A - B) -> B - A */
1063 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1064 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1065 return fold_convert (type,
1066 fold_build2 (MINUS_EXPR, TREE_TYPE (t),
1067 TREE_OPERAND (t, 1),
1068 TREE_OPERAND (t, 0)));
1072 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1078 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1080 tem = TREE_OPERAND (t, 1);
1081 if (negate_expr_p (tem))
1082 return fold_convert (type,
1083 fold_build2 (TREE_CODE (t), TREE_TYPE (t),
1084 TREE_OPERAND (t, 0),
1085 negate_expr (tem)));
1086 tem = TREE_OPERAND (t, 0);
1087 if (negate_expr_p (tem))
1088 return fold_convert (type,
1089 fold_build2 (TREE_CODE (t), TREE_TYPE (t),
1091 TREE_OPERAND (t, 1)));
1096 /* Convert -((double)float) into (double)(-float). */
1097 if (TREE_CODE (type) == REAL_TYPE)
1099 tem = strip_float_extensions (t);
1100 if (tem != t && negate_expr_p (tem))
1101 return fold_convert (type, negate_expr (tem));
1106 /* Negate -f(x) as f(-x). */
1107 if (negate_mathfn_p (builtin_mathfn_code (t))
1108 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1110 tree fndecl, arg, arglist;
1112 fndecl = get_callee_fndecl (t);
1113 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1114 arglist = build_tree_list (NULL_TREE, arg);
1115 return build_function_call_expr (fndecl, arglist);
1120 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1121 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1123 tree op1 = TREE_OPERAND (t, 1);
1124 if (TREE_INT_CST_HIGH (op1) == 0
1125 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1126 == TREE_INT_CST_LOW (op1))
1128 tree ntype = TYPE_UNSIGNED (type)
1129 ? lang_hooks.types.signed_type (type)
1130 : lang_hooks.types.unsigned_type (type);
1131 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1132 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1133 return fold_convert (type, temp);
1142 tem = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1143 return fold_convert (type, tem);
1146 /* Split a tree IN into a constant, literal and variable parts that could be
1147 combined with CODE to make IN. "constant" means an expression with
1148 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1149 commutative arithmetic operation. Store the constant part into *CONP,
1150 the literal in *LITP and return the variable part. If a part isn't
1151 present, set it to null. If the tree does not decompose in this way,
1152 return the entire tree as the variable part and the other parts as null.
1154 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1155 case, we negate an operand that was subtracted. Except if it is a
1156 literal for which we use *MINUS_LITP instead.
1158 If NEGATE_P is true, we are negating all of IN, again except a literal
1159 for which we use *MINUS_LITP instead.
1161 If IN is itself a literal or constant, return it as appropriate.
1163 Note that we do not guarantee that any of the three values will be the
1164 same type as IN, but they will have the same signedness and mode. */
1167 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1168 tree *minus_litp, int negate_p)
1176 /* Strip any conversions that don't change the machine mode or signedness. */
1177 STRIP_SIGN_NOPS (in);
1179 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1181 else if (TREE_CODE (in) == code
1182 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1183 /* We can associate addition and subtraction together (even
1184 though the C standard doesn't say so) for integers because
1185 the value is not affected. For reals, the value might be
1186 affected, so we can't. */
1187 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1188 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1190 tree op0 = TREE_OPERAND (in, 0);
1191 tree op1 = TREE_OPERAND (in, 1);
1192 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1193 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1195 /* First see if either of the operands is a literal, then a constant. */
1196 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1197 *litp = op0, op0 = 0;
1198 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1199 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1201 if (op0 != 0 && TREE_CONSTANT (op0))
1202 *conp = op0, op0 = 0;
1203 else if (op1 != 0 && TREE_CONSTANT (op1))
1204 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1206 /* If we haven't dealt with either operand, this is not a case we can
1207 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1208 if (op0 != 0 && op1 != 0)
1213 var = op1, neg_var_p = neg1_p;
1215 /* Now do any needed negations. */
1217 *minus_litp = *litp, *litp = 0;
1219 *conp = negate_expr (*conp);
1221 var = negate_expr (var);
1223 else if (TREE_CONSTANT (in))
1231 *minus_litp = *litp, *litp = 0;
1232 else if (*minus_litp)
1233 *litp = *minus_litp, *minus_litp = 0;
1234 *conp = negate_expr (*conp);
1235 var = negate_expr (var);
1241 /* Re-associate trees split by the above function. T1 and T2 are either
1242 expressions to associate or null. Return the new expression, if any. If
1243 we build an operation, do it in TYPE and with CODE. */
1246 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1253 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1254 try to fold this since we will have infinite recursion. But do
1255 deal with any NEGATE_EXPRs. */
1256 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1257 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1259 if (code == PLUS_EXPR)
1261 if (TREE_CODE (t1) == NEGATE_EXPR)
1262 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1263 fold_convert (type, TREE_OPERAND (t1, 0)));
1264 else if (TREE_CODE (t2) == NEGATE_EXPR)
1265 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1266 fold_convert (type, TREE_OPERAND (t2, 0)));
1267 else if (integer_zerop (t2))
1268 return fold_convert (type, t1);
1270 else if (code == MINUS_EXPR)
1272 if (integer_zerop (t2))
1273 return fold_convert (type, t1);
1276 return build2 (code, type, fold_convert (type, t1),
1277 fold_convert (type, t2));
1280 return fold_build2 (code, type, fold_convert (type, t1),
1281 fold_convert (type, t2));
1284 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1285 to produce a new constant.
1287 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1290 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1292 unsigned HOST_WIDE_INT int1l, int2l;
1293 HOST_WIDE_INT int1h, int2h;
1294 unsigned HOST_WIDE_INT low;
1296 unsigned HOST_WIDE_INT garbagel;
1297 HOST_WIDE_INT garbageh;
1299 tree type = TREE_TYPE (arg1);
1300 int uns = TYPE_UNSIGNED (type);
1302 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1305 int1l = TREE_INT_CST_LOW (arg1);
1306 int1h = TREE_INT_CST_HIGH (arg1);
1307 int2l = TREE_INT_CST_LOW (arg2);
1308 int2h = TREE_INT_CST_HIGH (arg2);
1313 low = int1l | int2l, hi = int1h | int2h;
1317 low = int1l ^ int2l, hi = int1h ^ int2h;
1321 low = int1l & int2l, hi = int1h & int2h;
1327 /* It's unclear from the C standard whether shifts can overflow.
1328 The following code ignores overflow; perhaps a C standard
1329 interpretation ruling is needed. */
1330 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1337 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1342 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1346 neg_double (int2l, int2h, &low, &hi);
1347 add_double (int1l, int1h, low, hi, &low, &hi);
1348 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1352 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1355 case TRUNC_DIV_EXPR:
1356 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1357 case EXACT_DIV_EXPR:
1358 /* This is a shortcut for a common special case. */
1359 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1360 && ! TREE_CONSTANT_OVERFLOW (arg1)
1361 && ! TREE_CONSTANT_OVERFLOW (arg2)
1362 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1364 if (code == CEIL_DIV_EXPR)
1367 low = int1l / int2l, hi = 0;
1371 /* ... fall through ... */
1373 case ROUND_DIV_EXPR:
1374 if (int2h == 0 && int2l == 1)
1376 low = int1l, hi = int1h;
1379 if (int1l == int2l && int1h == int2h
1380 && ! (int1l == 0 && int1h == 0))
1385 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1386 &low, &hi, &garbagel, &garbageh);
1389 case TRUNC_MOD_EXPR:
1390 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1391 /* This is a shortcut for a common special case. */
1392 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1393 && ! TREE_CONSTANT_OVERFLOW (arg1)
1394 && ! TREE_CONSTANT_OVERFLOW (arg2)
1395 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1397 if (code == CEIL_MOD_EXPR)
1399 low = int1l % int2l, hi = 0;
1403 /* ... fall through ... */
1405 case ROUND_MOD_EXPR:
1406 overflow = div_and_round_double (code, uns,
1407 int1l, int1h, int2l, int2h,
1408 &garbagel, &garbageh, &low, &hi);
1414 low = (((unsigned HOST_WIDE_INT) int1h
1415 < (unsigned HOST_WIDE_INT) int2h)
1416 || (((unsigned HOST_WIDE_INT) int1h
1417 == (unsigned HOST_WIDE_INT) int2h)
1420 low = (int1h < int2h
1421 || (int1h == int2h && int1l < int2l));
1423 if (low == (code == MIN_EXPR))
1424 low = int1l, hi = int1h;
1426 low = int2l, hi = int2h;
1433 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1437 /* Propagate overflow flags ourselves. */
1438 if (((!uns || is_sizetype) && overflow)
1439 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1442 TREE_OVERFLOW (t) = 1;
1443 TREE_CONSTANT_OVERFLOW (t) = 1;
1445 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1448 TREE_CONSTANT_OVERFLOW (t) = 1;
1452 t = force_fit_type (t, 1,
1453 ((!uns || is_sizetype) && overflow)
1454 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2),
1455 TREE_CONSTANT_OVERFLOW (arg1)
1456 | TREE_CONSTANT_OVERFLOW (arg2));
1461 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1462 constant. We assume ARG1 and ARG2 have the same data type, or at least
1463 are the same kind of constant and the same machine mode.
1465 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1468 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1473 if (TREE_CODE (arg1) == INTEGER_CST)
1474 return int_const_binop (code, arg1, arg2, notrunc);
1476 if (TREE_CODE (arg1) == REAL_CST)
1478 enum machine_mode mode;
1481 REAL_VALUE_TYPE value;
1482 REAL_VALUE_TYPE result;
1486 d1 = TREE_REAL_CST (arg1);
1487 d2 = TREE_REAL_CST (arg2);
1489 type = TREE_TYPE (arg1);
1490 mode = TYPE_MODE (type);
1492 /* Don't perform operation if we honor signaling NaNs and
1493 either operand is a NaN. */
1494 if (HONOR_SNANS (mode)
1495 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1498 /* Don't perform operation if it would raise a division
1499 by zero exception. */
1500 if (code == RDIV_EXPR
1501 && REAL_VALUES_EQUAL (d2, dconst0)
1502 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1505 /* If either operand is a NaN, just return it. Otherwise, set up
1506 for floating-point trap; we return an overflow. */
1507 if (REAL_VALUE_ISNAN (d1))
1509 else if (REAL_VALUE_ISNAN (d2))
1512 inexact = real_arithmetic (&value, code, &d1, &d2);
1513 real_convert (&result, mode, &value);
1515 /* Don't constant fold this floating point operation if the
1516 result may dependent upon the run-time rounding mode and
1517 flag_rounding_math is set, or if GCC's software emulation
1518 is unable to accurately represent the result. */
1520 if ((flag_rounding_math
1521 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1522 && !flag_unsafe_math_optimizations))
1523 && (inexact || !real_identical (&result, &value)))
1526 t = build_real (type, result);
1528 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1529 TREE_CONSTANT_OVERFLOW (t)
1531 | TREE_CONSTANT_OVERFLOW (arg1)
1532 | TREE_CONSTANT_OVERFLOW (arg2);
1535 if (TREE_CODE (arg1) == COMPLEX_CST)
1537 tree type = TREE_TYPE (arg1);
1538 tree r1 = TREE_REALPART (arg1);
1539 tree i1 = TREE_IMAGPART (arg1);
1540 tree r2 = TREE_REALPART (arg2);
1541 tree i2 = TREE_IMAGPART (arg2);
1547 t = build_complex (type,
1548 const_binop (PLUS_EXPR, r1, r2, notrunc),
1549 const_binop (PLUS_EXPR, i1, i2, notrunc));
1553 t = build_complex (type,
1554 const_binop (MINUS_EXPR, r1, r2, notrunc),
1555 const_binop (MINUS_EXPR, i1, i2, notrunc));
1559 t = build_complex (type,
1560 const_binop (MINUS_EXPR,
1561 const_binop (MULT_EXPR,
1563 const_binop (MULT_EXPR,
1566 const_binop (PLUS_EXPR,
1567 const_binop (MULT_EXPR,
1569 const_binop (MULT_EXPR,
1577 = const_binop (PLUS_EXPR,
1578 const_binop (MULT_EXPR, r2, r2, notrunc),
1579 const_binop (MULT_EXPR, i2, i2, notrunc),
1582 t = build_complex (type,
1584 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1585 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1586 const_binop (PLUS_EXPR,
1587 const_binop (MULT_EXPR, r1, r2,
1589 const_binop (MULT_EXPR, i1, i2,
1592 magsquared, notrunc),
1594 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1595 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1596 const_binop (MINUS_EXPR,
1597 const_binop (MULT_EXPR, i1, r2,
1599 const_binop (MULT_EXPR, r1, i2,
1602 magsquared, notrunc));
1614 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1615 indicates which particular sizetype to create. */
1618 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
1620 return build_int_cst (sizetype_tab[(int) kind], number);
1623 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1624 is a tree code. The type of the result is taken from the operands.
1625 Both must be the same type integer type and it must be a size type.
1626 If the operands are constant, so is the result. */
1629 size_binop (enum tree_code code, tree arg0, tree arg1)
1631 tree type = TREE_TYPE (arg0);
1633 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1634 && type == TREE_TYPE (arg1));
1636 /* Handle the special case of two integer constants faster. */
1637 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1639 /* And some specific cases even faster than that. */
1640 if (code == PLUS_EXPR && integer_zerop (arg0))
1642 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1643 && integer_zerop (arg1))
1645 else if (code == MULT_EXPR && integer_onep (arg0))
1648 /* Handle general case of two integer constants. */
1649 return int_const_binop (code, arg0, arg1, 0);
1652 if (arg0 == error_mark_node || arg1 == error_mark_node)
1653 return error_mark_node;
1655 return fold_build2 (code, type, arg0, arg1);
1658 /* Given two values, either both of sizetype or both of bitsizetype,
1659 compute the difference between the two values. Return the value
1660 in signed type corresponding to the type of the operands. */
1663 size_diffop (tree arg0, tree arg1)
1665 tree type = TREE_TYPE (arg0);
1668 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1669 && type == TREE_TYPE (arg1));
1671 /* If the type is already signed, just do the simple thing. */
1672 if (!TYPE_UNSIGNED (type))
1673 return size_binop (MINUS_EXPR, arg0, arg1);
1675 ctype = type == bitsizetype ? sbitsizetype : ssizetype;
1677 /* If either operand is not a constant, do the conversions to the signed
1678 type and subtract. The hardware will do the right thing with any
1679 overflow in the subtraction. */
1680 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1681 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1682 fold_convert (ctype, arg1));
1684 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1685 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1686 overflow) and negate (which can't either). Special-case a result
1687 of zero while we're here. */
1688 if (tree_int_cst_equal (arg0, arg1))
1689 return fold_convert (ctype, integer_zero_node);
1690 else if (tree_int_cst_lt (arg1, arg0))
1691 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1693 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1694 fold_convert (ctype, size_binop (MINUS_EXPR,
1698 /* A subroutine of fold_convert_const handling conversions of an
1699 INTEGER_CST to another integer type. */
1702 fold_convert_const_int_from_int (tree type, tree arg1)
1706 /* Given an integer constant, make new constant with new type,
1707 appropriately sign-extended or truncated. */
1708 t = build_int_cst_wide (type, TREE_INT_CST_LOW (arg1),
1709 TREE_INT_CST_HIGH (arg1));
1711 t = force_fit_type (t,
1712 /* Don't set the overflow when
1713 converting a pointer */
1714 !POINTER_TYPE_P (TREE_TYPE (arg1)),
1715 (TREE_INT_CST_HIGH (arg1) < 0
1716 && (TYPE_UNSIGNED (type)
1717 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
1718 | TREE_OVERFLOW (arg1),
1719 TREE_CONSTANT_OVERFLOW (arg1));
1724 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1725 to an integer type. */
1728 fold_convert_const_int_from_real (enum tree_code code, tree type, tree arg1)
1733 /* The following code implements the floating point to integer
1734 conversion rules required by the Java Language Specification,
1735 that IEEE NaNs are mapped to zero and values that overflow
1736 the target precision saturate, i.e. values greater than
1737 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1738 are mapped to INT_MIN. These semantics are allowed by the
1739 C and C++ standards that simply state that the behavior of
1740 FP-to-integer conversion is unspecified upon overflow. */
1742 HOST_WIDE_INT high, low;
1744 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1748 case FIX_TRUNC_EXPR:
1749 real_trunc (&r, VOIDmode, &x);
1753 real_ceil (&r, VOIDmode, &x);
1756 case FIX_FLOOR_EXPR:
1757 real_floor (&r, VOIDmode, &x);
1760 case FIX_ROUND_EXPR:
1761 real_round (&r, VOIDmode, &x);
1768 /* If R is NaN, return zero and show we have an overflow. */
1769 if (REAL_VALUE_ISNAN (r))
1776 /* See if R is less than the lower bound or greater than the
1781 tree lt = TYPE_MIN_VALUE (type);
1782 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1783 if (REAL_VALUES_LESS (r, l))
1786 high = TREE_INT_CST_HIGH (lt);
1787 low = TREE_INT_CST_LOW (lt);
1793 tree ut = TYPE_MAX_VALUE (type);
1796 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1797 if (REAL_VALUES_LESS (u, r))
1800 high = TREE_INT_CST_HIGH (ut);
1801 low = TREE_INT_CST_LOW (ut);
1807 REAL_VALUE_TO_INT (&low, &high, r);
1809 t = build_int_cst_wide (type, low, high);
1811 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg1),
1812 TREE_CONSTANT_OVERFLOW (arg1));
1816 /* A subroutine of fold_convert_const handling conversions a REAL_CST
1817 to another floating point type. */
1820 fold_convert_const_real_from_real (tree type, tree arg1)
1822 REAL_VALUE_TYPE value;
1825 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
1826 t = build_real (type, value);
1828 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
1829 TREE_CONSTANT_OVERFLOW (t)
1830 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1834 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1835 type TYPE. If no simplification can be done return NULL_TREE. */
1838 fold_convert_const (enum tree_code code, tree type, tree arg1)
1840 if (TREE_TYPE (arg1) == type)
1843 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1845 if (TREE_CODE (arg1) == INTEGER_CST)
1846 return fold_convert_const_int_from_int (type, arg1);
1847 else if (TREE_CODE (arg1) == REAL_CST)
1848 return fold_convert_const_int_from_real (code, type, arg1);
1850 else if (TREE_CODE (type) == REAL_TYPE)
1852 if (TREE_CODE (arg1) == INTEGER_CST)
1853 return build_real_from_int_cst (type, arg1);
1854 if (TREE_CODE (arg1) == REAL_CST)
1855 return fold_convert_const_real_from_real (type, arg1);
1860 /* Construct a vector of zero elements of vector type TYPE. */
1863 build_zero_vector (tree type)
1868 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
1869 units = TYPE_VECTOR_SUBPARTS (type);
1872 for (i = 0; i < units; i++)
1873 list = tree_cons (NULL_TREE, elem, list);
1874 return build_vector (type, list);
1877 /* Convert expression ARG to type TYPE. Used by the middle-end for
1878 simple conversions in preference to calling the front-end's convert. */
1881 fold_convert (tree type, tree arg)
1883 tree orig = TREE_TYPE (arg);
1889 if (TREE_CODE (arg) == ERROR_MARK
1890 || TREE_CODE (type) == ERROR_MARK
1891 || TREE_CODE (orig) == ERROR_MARK)
1892 return error_mark_node;
1894 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
1895 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
1896 TYPE_MAIN_VARIANT (orig)))
1897 return fold_build1 (NOP_EXPR, type, arg);
1899 switch (TREE_CODE (type))
1901 case INTEGER_TYPE: case CHAR_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1902 case POINTER_TYPE: case REFERENCE_TYPE:
1904 if (TREE_CODE (arg) == INTEGER_CST)
1906 tem = fold_convert_const (NOP_EXPR, type, arg);
1907 if (tem != NULL_TREE)
1910 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1911 || TREE_CODE (orig) == OFFSET_TYPE)
1912 return fold_build1 (NOP_EXPR, type, arg);
1913 if (TREE_CODE (orig) == COMPLEX_TYPE)
1915 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
1916 return fold_convert (type, tem);
1918 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
1919 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1920 return fold_build1 (NOP_EXPR, type, arg);
1923 if (TREE_CODE (arg) == INTEGER_CST)
1925 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1926 if (tem != NULL_TREE)
1929 else if (TREE_CODE (arg) == REAL_CST)
1931 tem = fold_convert_const (NOP_EXPR, type, arg);
1932 if (tem != NULL_TREE)
1936 switch (TREE_CODE (orig))
1938 case INTEGER_TYPE: case CHAR_TYPE:
1939 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1940 case POINTER_TYPE: case REFERENCE_TYPE:
1941 return fold_build1 (FLOAT_EXPR, type, arg);
1944 return fold_build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1948 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
1949 return fold_convert (type, tem);
1956 switch (TREE_CODE (orig))
1958 case INTEGER_TYPE: case CHAR_TYPE:
1959 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1960 case POINTER_TYPE: case REFERENCE_TYPE:
1962 return build2 (COMPLEX_EXPR, type,
1963 fold_convert (TREE_TYPE (type), arg),
1964 fold_convert (TREE_TYPE (type), integer_zero_node));
1969 if (TREE_CODE (arg) == COMPLEX_EXPR)
1971 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1972 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1973 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
1976 arg = save_expr (arg);
1977 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
1978 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
1979 rpart = fold_convert (TREE_TYPE (type), rpart);
1980 ipart = fold_convert (TREE_TYPE (type), ipart);
1981 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
1989 if (integer_zerop (arg))
1990 return build_zero_vector (type);
1991 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1992 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1993 || TREE_CODE (orig) == VECTOR_TYPE);
1994 return fold_build1 (NOP_EXPR, type, arg);
1997 return fold_build1 (CONVERT_EXPR, type, fold_ignored_result (arg));
2004 /* Return false if expr can be assumed not to be an value, true
2008 maybe_lvalue_p (tree x)
2010 /* We only need to wrap lvalue tree codes. */
2011 switch (TREE_CODE (x))
2022 case ALIGN_INDIRECT_REF:
2023 case MISALIGNED_INDIRECT_REF:
2025 case ARRAY_RANGE_REF:
2031 case PREINCREMENT_EXPR:
2032 case PREDECREMENT_EXPR:
2034 case TRY_CATCH_EXPR:
2035 case WITH_CLEANUP_EXPR:
2046 /* Assume the worst for front-end tree codes. */
2047 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2055 /* Return an expr equal to X but certainly not valid as an lvalue. */
2060 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2065 if (! maybe_lvalue_p (x))
2067 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2070 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2071 Zero means allow extended lvalues. */
2073 int pedantic_lvalues;
2075 /* When pedantic, return an expr equal to X but certainly not valid as a
2076 pedantic lvalue. Otherwise, return X. */
2079 pedantic_non_lvalue (tree x)
2081 if (pedantic_lvalues)
2082 return non_lvalue (x);
2087 /* Given a tree comparison code, return the code that is the logical inverse
2088 of the given code. It is not safe to do this for floating-point
2089 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2090 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2092 static enum tree_code
2093 invert_tree_comparison (enum tree_code code, bool honor_nans)
2095 if (honor_nans && flag_trapping_math)
2105 return honor_nans ? UNLE_EXPR : LE_EXPR;
2107 return honor_nans ? UNLT_EXPR : LT_EXPR;
2109 return honor_nans ? UNGE_EXPR : GE_EXPR;
2111 return honor_nans ? UNGT_EXPR : GT_EXPR;
2125 return UNORDERED_EXPR;
2126 case UNORDERED_EXPR:
2127 return ORDERED_EXPR;
2133 /* Similar, but return the comparison that results if the operands are
2134 swapped. This is safe for floating-point. */
2137 swap_tree_comparison (enum tree_code code)
2158 /* Convert a comparison tree code from an enum tree_code representation
2159 into a compcode bit-based encoding. This function is the inverse of
2160 compcode_to_comparison. */
2162 static enum comparison_code
2163 comparison_to_compcode (enum tree_code code)
2180 return COMPCODE_ORD;
2181 case UNORDERED_EXPR:
2182 return COMPCODE_UNORD;
2184 return COMPCODE_UNLT;
2186 return COMPCODE_UNEQ;
2188 return COMPCODE_UNLE;
2190 return COMPCODE_UNGT;
2192 return COMPCODE_LTGT;
2194 return COMPCODE_UNGE;
2200 /* Convert a compcode bit-based encoding of a comparison operator back
2201 to GCC's enum tree_code representation. This function is the
2202 inverse of comparison_to_compcode. */
2204 static enum tree_code
2205 compcode_to_comparison (enum comparison_code code)
2222 return ORDERED_EXPR;
2223 case COMPCODE_UNORD:
2224 return UNORDERED_EXPR;
2242 /* Return a tree for the comparison which is the combination of
2243 doing the AND or OR (depending on CODE) of the two operations LCODE
2244 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2245 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2246 if this makes the transformation invalid. */
2249 combine_comparisons (enum tree_code code, enum tree_code lcode,
2250 enum tree_code rcode, tree truth_type,
2251 tree ll_arg, tree lr_arg)
2253 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2254 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2255 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2256 enum comparison_code compcode;
2260 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2261 compcode = lcompcode & rcompcode;
2264 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2265 compcode = lcompcode | rcompcode;
2274 /* Eliminate unordered comparisons, as well as LTGT and ORD
2275 which are not used unless the mode has NaNs. */
2276 compcode &= ~COMPCODE_UNORD;
2277 if (compcode == COMPCODE_LTGT)
2278 compcode = COMPCODE_NE;
2279 else if (compcode == COMPCODE_ORD)
2280 compcode = COMPCODE_TRUE;
2282 else if (flag_trapping_math)
2284 /* Check that the original operation and the optimized ones will trap
2285 under the same condition. */
2286 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2287 && (lcompcode != COMPCODE_EQ)
2288 && (lcompcode != COMPCODE_ORD);
2289 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2290 && (rcompcode != COMPCODE_EQ)
2291 && (rcompcode != COMPCODE_ORD);
2292 bool trap = (compcode & COMPCODE_UNORD) == 0
2293 && (compcode != COMPCODE_EQ)
2294 && (compcode != COMPCODE_ORD);
2296 /* In a short-circuited boolean expression the LHS might be
2297 such that the RHS, if evaluated, will never trap. For
2298 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2299 if neither x nor y is NaN. (This is a mixed blessing: for
2300 example, the expression above will never trap, hence
2301 optimizing it to x < y would be invalid). */
2302 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2303 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2306 /* If the comparison was short-circuited, and only the RHS
2307 trapped, we may now generate a spurious trap. */
2309 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2312 /* If we changed the conditions that cause a trap, we lose. */
2313 if ((ltrap || rtrap) != trap)
2317 if (compcode == COMPCODE_TRUE)
2318 return constant_boolean_node (true, truth_type);
2319 else if (compcode == COMPCODE_FALSE)
2320 return constant_boolean_node (false, truth_type);
2322 return fold_build2 (compcode_to_comparison (compcode),
2323 truth_type, ll_arg, lr_arg);
2326 /* Return nonzero if CODE is a tree code that represents a truth value. */
2329 truth_value_p (enum tree_code code)
2331 return (TREE_CODE_CLASS (code) == tcc_comparison
2332 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2333 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2334 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2337 /* Return nonzero if two operands (typically of the same tree node)
2338 are necessarily equal. If either argument has side-effects this
2339 function returns zero. FLAGS modifies behavior as follows:
2341 If OEP_ONLY_CONST is set, only return nonzero for constants.
2342 This function tests whether the operands are indistinguishable;
2343 it does not test whether they are equal using C's == operation.
2344 The distinction is important for IEEE floating point, because
2345 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2346 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2348 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2349 even though it may hold multiple values during a function.
2350 This is because a GCC tree node guarantees that nothing else is
2351 executed between the evaluation of its "operands" (which may often
2352 be evaluated in arbitrary order). Hence if the operands themselves
2353 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2354 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2355 unset means assuming isochronic (or instantaneous) tree equivalence.
2356 Unless comparing arbitrary expression trees, such as from different
2357 statements, this flag can usually be left unset.
2359 If OEP_PURE_SAME is set, then pure functions with identical arguments
2360 are considered the same. It is used when the caller has other ways
2361 to ensure that global memory is unchanged in between. */
2364 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2366 /* If either is ERROR_MARK, they aren't equal. */
2367 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2370 /* If both types don't have the same signedness, then we can't consider
2371 them equal. We must check this before the STRIP_NOPS calls
2372 because they may change the signedness of the arguments. */
2373 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2379 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2380 /* This is needed for conversions and for COMPONENT_REF.
2381 Might as well play it safe and always test this. */
2382 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2383 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2384 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2387 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2388 We don't care about side effects in that case because the SAVE_EXPR
2389 takes care of that for us. In all other cases, two expressions are
2390 equal if they have no side effects. If we have two identical
2391 expressions with side effects that should be treated the same due
2392 to the only side effects being identical SAVE_EXPR's, that will
2393 be detected in the recursive calls below. */
2394 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2395 && (TREE_CODE (arg0) == SAVE_EXPR
2396 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2399 /* Next handle constant cases, those for which we can return 1 even
2400 if ONLY_CONST is set. */
2401 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2402 switch (TREE_CODE (arg0))
2405 return (! TREE_CONSTANT_OVERFLOW (arg0)
2406 && ! TREE_CONSTANT_OVERFLOW (arg1)
2407 && tree_int_cst_equal (arg0, arg1));
2410 return (! TREE_CONSTANT_OVERFLOW (arg0)
2411 && ! TREE_CONSTANT_OVERFLOW (arg1)
2412 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2413 TREE_REAL_CST (arg1)));
2419 if (TREE_CONSTANT_OVERFLOW (arg0)
2420 || TREE_CONSTANT_OVERFLOW (arg1))
2423 v1 = TREE_VECTOR_CST_ELTS (arg0);
2424 v2 = TREE_VECTOR_CST_ELTS (arg1);
2427 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2430 v1 = TREE_CHAIN (v1);
2431 v2 = TREE_CHAIN (v2);
2438 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2440 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2444 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2445 && ! memcmp (TREE_STRING_POINTER (arg0),
2446 TREE_STRING_POINTER (arg1),
2447 TREE_STRING_LENGTH (arg0)));
2450 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2456 if (flags & OEP_ONLY_CONST)
2459 /* Define macros to test an operand from arg0 and arg1 for equality and a
2460 variant that allows null and views null as being different from any
2461 non-null value. In the latter case, if either is null, the both
2462 must be; otherwise, do the normal comparison. */
2463 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
2464 TREE_OPERAND (arg1, N), flags)
2466 #define OP_SAME_WITH_NULL(N) \
2467 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
2468 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
2470 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2473 /* Two conversions are equal only if signedness and modes match. */
2474 switch (TREE_CODE (arg0))
2479 case FIX_TRUNC_EXPR:
2480 case FIX_FLOOR_EXPR:
2481 case FIX_ROUND_EXPR:
2482 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
2483 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2493 case tcc_comparison:
2495 if (OP_SAME (0) && OP_SAME (1))
2498 /* For commutative ops, allow the other order. */
2499 return (commutative_tree_code (TREE_CODE (arg0))
2500 && operand_equal_p (TREE_OPERAND (arg0, 0),
2501 TREE_OPERAND (arg1, 1), flags)
2502 && operand_equal_p (TREE_OPERAND (arg0, 1),
2503 TREE_OPERAND (arg1, 0), flags));
2506 /* If either of the pointer (or reference) expressions we are
2507 dereferencing contain a side effect, these cannot be equal. */
2508 if (TREE_SIDE_EFFECTS (arg0)
2509 || TREE_SIDE_EFFECTS (arg1))
2512 switch (TREE_CODE (arg0))
2515 case ALIGN_INDIRECT_REF:
2516 case MISALIGNED_INDIRECT_REF:
2522 case ARRAY_RANGE_REF:
2523 /* Operands 2 and 3 may be null. */
2526 && OP_SAME_WITH_NULL (2)
2527 && OP_SAME_WITH_NULL (3));
2530 /* Handle operand 2 the same as for ARRAY_REF. */
2531 return OP_SAME (0) && OP_SAME (1) && OP_SAME_WITH_NULL (2);
2534 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
2540 case tcc_expression:
2541 switch (TREE_CODE (arg0))
2544 case TRUTH_NOT_EXPR:
2547 case TRUTH_ANDIF_EXPR:
2548 case TRUTH_ORIF_EXPR:
2549 return OP_SAME (0) && OP_SAME (1);
2551 case TRUTH_AND_EXPR:
2553 case TRUTH_XOR_EXPR:
2554 if (OP_SAME (0) && OP_SAME (1))
2557 /* Otherwise take into account this is a commutative operation. */
2558 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2559 TREE_OPERAND (arg1, 1), flags)
2560 && operand_equal_p (TREE_OPERAND (arg0, 1),
2561 TREE_OPERAND (arg1, 0), flags));
2564 /* If the CALL_EXPRs call different functions, then they
2565 clearly can not be equal. */
2570 unsigned int cef = call_expr_flags (arg0);
2571 if (flags & OEP_PURE_SAME)
2572 cef &= ECF_CONST | ECF_PURE;
2579 /* Now see if all the arguments are the same. operand_equal_p
2580 does not handle TREE_LIST, so we walk the operands here
2581 feeding them to operand_equal_p. */
2582 arg0 = TREE_OPERAND (arg0, 1);
2583 arg1 = TREE_OPERAND (arg1, 1);
2584 while (arg0 && arg1)
2586 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2590 arg0 = TREE_CHAIN (arg0);
2591 arg1 = TREE_CHAIN (arg1);
2594 /* If we get here and both argument lists are exhausted
2595 then the CALL_EXPRs are equal. */
2596 return ! (arg0 || arg1);
2602 case tcc_declaration:
2603 /* Consider __builtin_sqrt equal to sqrt. */
2604 return (TREE_CODE (arg0) == FUNCTION_DECL
2605 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2606 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2607 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2614 #undef OP_SAME_WITH_NULL
2617 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2618 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2620 When in doubt, return 0. */
2623 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2625 int unsignedp1, unsignedpo;
2626 tree primarg0, primarg1, primother;
2627 unsigned int correct_width;
2629 if (operand_equal_p (arg0, arg1, 0))
2632 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2633 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2636 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2637 and see if the inner values are the same. This removes any
2638 signedness comparison, which doesn't matter here. */
2639 primarg0 = arg0, primarg1 = arg1;
2640 STRIP_NOPS (primarg0);
2641 STRIP_NOPS (primarg1);
2642 if (operand_equal_p (primarg0, primarg1, 0))
2645 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2646 actual comparison operand, ARG0.
2648 First throw away any conversions to wider types
2649 already present in the operands. */
2651 primarg1 = get_narrower (arg1, &unsignedp1);
2652 primother = get_narrower (other, &unsignedpo);
2654 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2655 if (unsignedp1 == unsignedpo
2656 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2657 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2659 tree type = TREE_TYPE (arg0);
2661 /* Make sure shorter operand is extended the right way
2662 to match the longer operand. */
2663 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2664 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2666 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2673 /* See if ARG is an expression that is either a comparison or is performing
2674 arithmetic on comparisons. The comparisons must only be comparing
2675 two different values, which will be stored in *CVAL1 and *CVAL2; if
2676 they are nonzero it means that some operands have already been found.
2677 No variables may be used anywhere else in the expression except in the
2678 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2679 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2681 If this is true, return 1. Otherwise, return zero. */
2684 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2686 enum tree_code code = TREE_CODE (arg);
2687 enum tree_code_class class = TREE_CODE_CLASS (code);
2689 /* We can handle some of the tcc_expression cases here. */
2690 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2692 else if (class == tcc_expression
2693 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2694 || code == COMPOUND_EXPR))
2697 else if (class == tcc_expression && code == SAVE_EXPR
2698 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2700 /* If we've already found a CVAL1 or CVAL2, this expression is
2701 two complex to handle. */
2702 if (*cval1 || *cval2)
2712 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2715 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2716 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2717 cval1, cval2, save_p));
2722 case tcc_expression:
2723 if (code == COND_EXPR)
2724 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2725 cval1, cval2, save_p)
2726 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2727 cval1, cval2, save_p)
2728 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2729 cval1, cval2, save_p));
2732 case tcc_comparison:
2733 /* First see if we can handle the first operand, then the second. For
2734 the second operand, we know *CVAL1 can't be zero. It must be that
2735 one side of the comparison is each of the values; test for the
2736 case where this isn't true by failing if the two operands
2739 if (operand_equal_p (TREE_OPERAND (arg, 0),
2740 TREE_OPERAND (arg, 1), 0))
2744 *cval1 = TREE_OPERAND (arg, 0);
2745 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2747 else if (*cval2 == 0)
2748 *cval2 = TREE_OPERAND (arg, 0);
2749 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2754 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2756 else if (*cval2 == 0)
2757 *cval2 = TREE_OPERAND (arg, 1);
2758 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2770 /* ARG is a tree that is known to contain just arithmetic operations and
2771 comparisons. Evaluate the operations in the tree substituting NEW0 for
2772 any occurrence of OLD0 as an operand of a comparison and likewise for
2776 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2778 tree type = TREE_TYPE (arg);
2779 enum tree_code code = TREE_CODE (arg);
2780 enum tree_code_class class = TREE_CODE_CLASS (code);
2782 /* We can handle some of the tcc_expression cases here. */
2783 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2785 else if (class == tcc_expression
2786 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2792 return fold_build1 (code, type,
2793 eval_subst (TREE_OPERAND (arg, 0),
2794 old0, new0, old1, new1));
2797 return fold_build2 (code, type,
2798 eval_subst (TREE_OPERAND (arg, 0),
2799 old0, new0, old1, new1),
2800 eval_subst (TREE_OPERAND (arg, 1),
2801 old0, new0, old1, new1));
2803 case tcc_expression:
2807 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2810 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2813 return fold_build3 (code, type,
2814 eval_subst (TREE_OPERAND (arg, 0),
2815 old0, new0, old1, new1),
2816 eval_subst (TREE_OPERAND (arg, 1),
2817 old0, new0, old1, new1),
2818 eval_subst (TREE_OPERAND (arg, 2),
2819 old0, new0, old1, new1));
2823 /* Fall through - ??? */
2825 case tcc_comparison:
2827 tree arg0 = TREE_OPERAND (arg, 0);
2828 tree arg1 = TREE_OPERAND (arg, 1);
2830 /* We need to check both for exact equality and tree equality. The
2831 former will be true if the operand has a side-effect. In that
2832 case, we know the operand occurred exactly once. */
2834 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2836 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2839 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2841 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2844 return fold_build2 (code, type, arg0, arg1);
2852 /* Return a tree for the case when the result of an expression is RESULT
2853 converted to TYPE and OMITTED was previously an operand of the expression
2854 but is now not needed (e.g., we folded OMITTED * 0).
2856 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2857 the conversion of RESULT to TYPE. */
2860 omit_one_operand (tree type, tree result, tree omitted)
2862 tree t = fold_convert (type, result);
2864 if (TREE_SIDE_EFFECTS (omitted))
2865 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2867 return non_lvalue (t);
2870 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2873 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2875 tree t = fold_convert (type, result);
2877 if (TREE_SIDE_EFFECTS (omitted))
2878 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2880 return pedantic_non_lvalue (t);
2883 /* Return a tree for the case when the result of an expression is RESULT
2884 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2885 of the expression but are now not needed.
2887 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2888 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
2889 evaluated before OMITTED2. Otherwise, if neither has side effects,
2890 just do the conversion of RESULT to TYPE. */
2893 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
2895 tree t = fold_convert (type, result);
2897 if (TREE_SIDE_EFFECTS (omitted2))
2898 t = build2 (COMPOUND_EXPR, type, omitted2, t);
2899 if (TREE_SIDE_EFFECTS (omitted1))
2900 t = build2 (COMPOUND_EXPR, type, omitted1, t);
2902 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
2906 /* Return a simplified tree node for the truth-negation of ARG. This
2907 never alters ARG itself. We assume that ARG is an operation that
2908 returns a truth value (0 or 1).
2910 FIXME: one would think we would fold the result, but it causes
2911 problems with the dominator optimizer. */
2913 invert_truthvalue (tree arg)
2915 tree type = TREE_TYPE (arg);
2916 enum tree_code code = TREE_CODE (arg);
2918 if (code == ERROR_MARK)
2921 /* If this is a comparison, we can simply invert it, except for
2922 floating-point non-equality comparisons, in which case we just
2923 enclose a TRUTH_NOT_EXPR around what we have. */
2925 if (TREE_CODE_CLASS (code) == tcc_comparison)
2927 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
2928 if (FLOAT_TYPE_P (op_type)
2929 && flag_trapping_math
2930 && code != ORDERED_EXPR && code != UNORDERED_EXPR
2931 && code != NE_EXPR && code != EQ_EXPR)
2932 return build1 (TRUTH_NOT_EXPR, type, arg);
2935 code = invert_tree_comparison (code,
2936 HONOR_NANS (TYPE_MODE (op_type)));
2937 if (code == ERROR_MARK)
2938 return build1 (TRUTH_NOT_EXPR, type, arg);
2940 return build2 (code, type,
2941 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2948 return constant_boolean_node (integer_zerop (arg), type);
2950 case TRUTH_AND_EXPR:
2951 return build2 (TRUTH_OR_EXPR, type,
2952 invert_truthvalue (TREE_OPERAND (arg, 0)),
2953 invert_truthvalue (TREE_OPERAND (arg, 1)));
2956 return build2 (TRUTH_AND_EXPR, type,
2957 invert_truthvalue (TREE_OPERAND (arg, 0)),
2958 invert_truthvalue (TREE_OPERAND (arg, 1)));
2960 case TRUTH_XOR_EXPR:
2961 /* Here we can invert either operand. We invert the first operand
2962 unless the second operand is a TRUTH_NOT_EXPR in which case our
2963 result is the XOR of the first operand with the inside of the
2964 negation of the second operand. */
2966 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2967 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2968 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2970 return build2 (TRUTH_XOR_EXPR, type,
2971 invert_truthvalue (TREE_OPERAND (arg, 0)),
2972 TREE_OPERAND (arg, 1));
2974 case TRUTH_ANDIF_EXPR:
2975 return build2 (TRUTH_ORIF_EXPR, type,
2976 invert_truthvalue (TREE_OPERAND (arg, 0)),
2977 invert_truthvalue (TREE_OPERAND (arg, 1)));
2979 case TRUTH_ORIF_EXPR:
2980 return build2 (TRUTH_ANDIF_EXPR, type,
2981 invert_truthvalue (TREE_OPERAND (arg, 0)),
2982 invert_truthvalue (TREE_OPERAND (arg, 1)));
2984 case TRUTH_NOT_EXPR:
2985 return TREE_OPERAND (arg, 0);
2988 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
2989 invert_truthvalue (TREE_OPERAND (arg, 1)),
2990 invert_truthvalue (TREE_OPERAND (arg, 2)));
2993 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2994 invert_truthvalue (TREE_OPERAND (arg, 1)));
2996 case NON_LVALUE_EXPR:
2997 return invert_truthvalue (TREE_OPERAND (arg, 0));
3000 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3005 return build1 (TREE_CODE (arg), type,
3006 invert_truthvalue (TREE_OPERAND (arg, 0)));
3009 if (!integer_onep (TREE_OPERAND (arg, 1)))
3011 return build2 (EQ_EXPR, type, arg,
3012 fold_convert (type, integer_zero_node));
3015 return build1 (TRUTH_NOT_EXPR, type, arg);
3017 case CLEANUP_POINT_EXPR:
3018 return build1 (CLEANUP_POINT_EXPR, type,
3019 invert_truthvalue (TREE_OPERAND (arg, 0)));
3024 gcc_assert (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE);
3025 return build1 (TRUTH_NOT_EXPR, type, arg);
3028 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3029 operands are another bit-wise operation with a common input. If so,
3030 distribute the bit operations to save an operation and possibly two if
3031 constants are involved. For example, convert
3032 (A | B) & (A | C) into A | (B & C)
3033 Further simplification will occur if B and C are constants.
3035 If this optimization cannot be done, 0 will be returned. */
3038 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3043 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3044 || TREE_CODE (arg0) == code
3045 || (TREE_CODE (arg0) != BIT_AND_EXPR
3046 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3049 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3051 common = TREE_OPERAND (arg0, 0);
3052 left = TREE_OPERAND (arg0, 1);
3053 right = TREE_OPERAND (arg1, 1);
3055 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3057 common = TREE_OPERAND (arg0, 0);
3058 left = TREE_OPERAND (arg0, 1);
3059 right = TREE_OPERAND (arg1, 0);
3061 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3063 common = TREE_OPERAND (arg0, 1);
3064 left = TREE_OPERAND (arg0, 0);
3065 right = TREE_OPERAND (arg1, 1);
3067 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3069 common = TREE_OPERAND (arg0, 1);
3070 left = TREE_OPERAND (arg0, 0);
3071 right = TREE_OPERAND (arg1, 0);
3076 return fold_build2 (TREE_CODE (arg0), type, common,
3077 fold_build2 (code, type, left, right));
3080 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3081 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3084 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3091 tree size = TYPE_SIZE (TREE_TYPE (inner));
3092 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3093 || POINTER_TYPE_P (TREE_TYPE (inner)))
3094 && host_integerp (size, 0)
3095 && tree_low_cst (size, 0) == bitsize)
3096 return fold_convert (type, inner);
3099 result = build3 (BIT_FIELD_REF, type, inner,
3100 size_int (bitsize), bitsize_int (bitpos));
3102 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3107 /* Optimize a bit-field compare.
3109 There are two cases: First is a compare against a constant and the
3110 second is a comparison of two items where the fields are at the same
3111 bit position relative to the start of a chunk (byte, halfword, word)
3112 large enough to contain it. In these cases we can avoid the shift
3113 implicit in bitfield extractions.
3115 For constants, we emit a compare of the shifted constant with the
3116 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3117 compared. For two fields at the same position, we do the ANDs with the
3118 similar mask and compare the result of the ANDs.
3120 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3121 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3122 are the left and right operands of the comparison, respectively.
3124 If the optimization described above can be done, we return the resulting
3125 tree. Otherwise we return zero. */
3128 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3131 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3132 tree type = TREE_TYPE (lhs);
3133 tree signed_type, unsigned_type;
3134 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3135 enum machine_mode lmode, rmode, nmode;
3136 int lunsignedp, runsignedp;
3137 int lvolatilep = 0, rvolatilep = 0;
3138 tree linner, rinner = NULL_TREE;
3142 /* Get all the information about the extractions being done. If the bit size
3143 if the same as the size of the underlying object, we aren't doing an
3144 extraction at all and so can do nothing. We also don't want to
3145 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3146 then will no longer be able to replace it. */
3147 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3148 &lunsignedp, &lvolatilep, false);
3149 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3150 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3155 /* If this is not a constant, we can only do something if bit positions,
3156 sizes, and signedness are the same. */
3157 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3158 &runsignedp, &rvolatilep, false);
3160 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3161 || lunsignedp != runsignedp || offset != 0
3162 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3166 /* See if we can find a mode to refer to this field. We should be able to,
3167 but fail if we can't. */
3168 nmode = get_best_mode (lbitsize, lbitpos,
3169 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3170 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3171 TYPE_ALIGN (TREE_TYPE (rinner))),
3172 word_mode, lvolatilep || rvolatilep);
3173 if (nmode == VOIDmode)
3176 /* Set signed and unsigned types of the precision of this mode for the
3178 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3179 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3181 /* Compute the bit position and size for the new reference and our offset
3182 within it. If the new reference is the same size as the original, we
3183 won't optimize anything, so return zero. */
3184 nbitsize = GET_MODE_BITSIZE (nmode);
3185 nbitpos = lbitpos & ~ (nbitsize - 1);
3187 if (nbitsize == lbitsize)
3190 if (BYTES_BIG_ENDIAN)
3191 lbitpos = nbitsize - lbitsize - lbitpos;
3193 /* Make the mask to be used against the extracted field. */
3194 mask = build_int_cst (unsigned_type, -1);
3195 mask = force_fit_type (mask, 0, false, false);
3196 mask = fold_convert (unsigned_type, mask);
3197 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3198 mask = const_binop (RSHIFT_EXPR, mask,
3199 size_int (nbitsize - lbitsize - lbitpos), 0);
3202 /* If not comparing with constant, just rework the comparison
3204 return build2 (code, compare_type,
3205 build2 (BIT_AND_EXPR, unsigned_type,
3206 make_bit_field_ref (linner, unsigned_type,
3207 nbitsize, nbitpos, 1),
3209 build2 (BIT_AND_EXPR, unsigned_type,
3210 make_bit_field_ref (rinner, unsigned_type,
3211 nbitsize, nbitpos, 1),
3214 /* Otherwise, we are handling the constant case. See if the constant is too
3215 big for the field. Warn and return a tree of for 0 (false) if so. We do
3216 this not only for its own sake, but to avoid having to test for this
3217 error case below. If we didn't, we might generate wrong code.
3219 For unsigned fields, the constant shifted right by the field length should
3220 be all zero. For signed fields, the high-order bits should agree with
3225 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3226 fold_convert (unsigned_type, rhs),
3227 size_int (lbitsize), 0)))
3229 warning ("comparison is always %d due to width of bit-field",
3231 return constant_boolean_node (code == NE_EXPR, compare_type);
3236 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3237 size_int (lbitsize - 1), 0);
3238 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3240 warning ("comparison is always %d due to width of bit-field",
3242 return constant_boolean_node (code == NE_EXPR, compare_type);
3246 /* Single-bit compares should always be against zero. */
3247 if (lbitsize == 1 && ! integer_zerop (rhs))
3249 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3250 rhs = fold_convert (type, integer_zero_node);
3253 /* Make a new bitfield reference, shift the constant over the
3254 appropriate number of bits and mask it with the computed mask
3255 (in case this was a signed field). If we changed it, make a new one. */
3256 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3259 TREE_SIDE_EFFECTS (lhs) = 1;
3260 TREE_THIS_VOLATILE (lhs) = 1;
3263 rhs = fold (const_binop (BIT_AND_EXPR,
3264 const_binop (LSHIFT_EXPR,
3265 fold_convert (unsigned_type, rhs),
3266 size_int (lbitpos), 0),
3269 return build2 (code, compare_type,
3270 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3274 /* Subroutine for fold_truthop: decode a field reference.
3276 If EXP is a comparison reference, we return the innermost reference.
3278 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3279 set to the starting bit number.
3281 If the innermost field can be completely contained in a mode-sized
3282 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3284 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3285 otherwise it is not changed.
3287 *PUNSIGNEDP is set to the signedness of the field.
3289 *PMASK is set to the mask used. This is either contained in a
3290 BIT_AND_EXPR or derived from the width of the field.
3292 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3294 Return 0 if this is not a component reference or is one that we can't
3295 do anything with. */
3298 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3299 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3300 int *punsignedp, int *pvolatilep,
3301 tree *pmask, tree *pand_mask)
3303 tree outer_type = 0;
3305 tree mask, inner, offset;
3307 unsigned int precision;
3309 /* All the optimizations using this function assume integer fields.
3310 There are problems with FP fields since the type_for_size call
3311 below can fail for, e.g., XFmode. */
3312 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3315 /* We are interested in the bare arrangement of bits, so strip everything
3316 that doesn't affect the machine mode. However, record the type of the
3317 outermost expression if it may matter below. */
3318 if (TREE_CODE (exp) == NOP_EXPR
3319 || TREE_CODE (exp) == CONVERT_EXPR
3320 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3321 outer_type = TREE_TYPE (exp);
3324 if (TREE_CODE (exp) == BIT_AND_EXPR)
3326 and_mask = TREE_OPERAND (exp, 1);
3327 exp = TREE_OPERAND (exp, 0);
3328 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3329 if (TREE_CODE (and_mask) != INTEGER_CST)
3333 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3334 punsignedp, pvolatilep, false);
3335 if ((inner == exp && and_mask == 0)
3336 || *pbitsize < 0 || offset != 0
3337 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3340 /* If the number of bits in the reference is the same as the bitsize of
3341 the outer type, then the outer type gives the signedness. Otherwise
3342 (in case of a small bitfield) the signedness is unchanged. */
3343 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3344 *punsignedp = TYPE_UNSIGNED (outer_type);
3346 /* Compute the mask to access the bitfield. */
3347 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3348 precision = TYPE_PRECISION (unsigned_type);
3350 mask = build_int_cst (unsigned_type, -1);
3351 mask = force_fit_type (mask, 0, false, false);
3353 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3354 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3356 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3358 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
3359 fold_convert (unsigned_type, and_mask), mask);
3362 *pand_mask = and_mask;
3366 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3370 all_ones_mask_p (tree mask, int size)
3372 tree type = TREE_TYPE (mask);
3373 unsigned int precision = TYPE_PRECISION (type);
3376 tmask = build_int_cst (lang_hooks.types.signed_type (type), -1);
3377 tmask = force_fit_type (tmask, 0, false, false);
3380 tree_int_cst_equal (mask,
3381 const_binop (RSHIFT_EXPR,
3382 const_binop (LSHIFT_EXPR, tmask,
3383 size_int (precision - size),
3385 size_int (precision - size), 0));
3388 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3389 represents the sign bit of EXP's type. If EXP represents a sign
3390 or zero extension, also test VAL against the unextended type.
3391 The return value is the (sub)expression whose sign bit is VAL,
3392 or NULL_TREE otherwise. */
3395 sign_bit_p (tree exp, tree val)
3397 unsigned HOST_WIDE_INT mask_lo, lo;
3398 HOST_WIDE_INT mask_hi, hi;
3402 /* Tree EXP must have an integral type. */
3403 t = TREE_TYPE (exp);
3404 if (! INTEGRAL_TYPE_P (t))
3407 /* Tree VAL must be an integer constant. */
3408 if (TREE_CODE (val) != INTEGER_CST
3409 || TREE_CONSTANT_OVERFLOW (val))
3412 width = TYPE_PRECISION (t);
3413 if (width > HOST_BITS_PER_WIDE_INT)
3415 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3418 mask_hi = ((unsigned HOST_WIDE_INT) -1
3419 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3425 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3428 mask_lo = ((unsigned HOST_WIDE_INT) -1
3429 >> (HOST_BITS_PER_WIDE_INT - width));
3432 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3433 treat VAL as if it were unsigned. */
3434 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3435 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3438 /* Handle extension from a narrower type. */
3439 if (TREE_CODE (exp) == NOP_EXPR
3440 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3441 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3446 /* Subroutine for fold_truthop: determine if an operand is simple enough
3447 to be evaluated unconditionally. */
3450 simple_operand_p (tree exp)
3452 /* Strip any conversions that don't change the machine mode. */
3455 return (CONSTANT_CLASS_P (exp)
3456 || TREE_CODE (exp) == SSA_NAME
3458 && ! TREE_ADDRESSABLE (exp)
3459 && ! TREE_THIS_VOLATILE (exp)
3460 && ! DECL_NONLOCAL (exp)
3461 /* Don't regard global variables as simple. They may be
3462 allocated in ways unknown to the compiler (shared memory,
3463 #pragma weak, etc). */
3464 && ! TREE_PUBLIC (exp)
3465 && ! DECL_EXTERNAL (exp)
3466 /* Loading a static variable is unduly expensive, but global
3467 registers aren't expensive. */
3468 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3471 /* The following functions are subroutines to fold_range_test and allow it to
3472 try to change a logical combination of comparisons into a range test.
3475 X == 2 || X == 3 || X == 4 || X == 5
3479 (unsigned) (X - 2) <= 3
3481 We describe each set of comparisons as being either inside or outside
3482 a range, using a variable named like IN_P, and then describe the
3483 range with a lower and upper bound. If one of the bounds is omitted,
3484 it represents either the highest or lowest value of the type.
3486 In the comments below, we represent a range by two numbers in brackets
3487 preceded by a "+" to designate being inside that range, or a "-" to
3488 designate being outside that range, so the condition can be inverted by
3489 flipping the prefix. An omitted bound is represented by a "-". For
3490 example, "- [-, 10]" means being outside the range starting at the lowest
3491 possible value and ending at 10, in other words, being greater than 10.
3492 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3495 We set up things so that the missing bounds are handled in a consistent
3496 manner so neither a missing bound nor "true" and "false" need to be
3497 handled using a special case. */
3499 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3500 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3501 and UPPER1_P are nonzero if the respective argument is an upper bound
3502 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3503 must be specified for a comparison. ARG1 will be converted to ARG0's
3504 type if both are specified. */
3507 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3508 tree arg1, int upper1_p)
3514 /* If neither arg represents infinity, do the normal operation.
3515 Else, if not a comparison, return infinity. Else handle the special
3516 comparison rules. Note that most of the cases below won't occur, but
3517 are handled for consistency. */
3519 if (arg0 != 0 && arg1 != 0)
3521 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3522 arg0, fold_convert (TREE_TYPE (arg0), arg1));
3524 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3527 if (TREE_CODE_CLASS (code) != tcc_comparison)
3530 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3531 for neither. In real maths, we cannot assume open ended ranges are
3532 the same. But, this is computer arithmetic, where numbers are finite.
3533 We can therefore make the transformation of any unbounded range with
3534 the value Z, Z being greater than any representable number. This permits
3535 us to treat unbounded ranges as equal. */
3536 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3537 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3541 result = sgn0 == sgn1;
3544 result = sgn0 != sgn1;
3547 result = sgn0 < sgn1;
3550 result = sgn0 <= sgn1;
3553 result = sgn0 > sgn1;
3556 result = sgn0 >= sgn1;
3562 return constant_boolean_node (result, type);
3565 /* Given EXP, a logical expression, set the range it is testing into
3566 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3567 actually being tested. *PLOW and *PHIGH will be made of the same type
3568 as the returned expression. If EXP is not a comparison, we will most
3569 likely not be returning a useful value and range. */
3572 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3574 enum tree_code code;
3575 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
3576 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
3578 tree low, high, n_low, n_high;
3580 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3581 and see if we can refine the range. Some of the cases below may not
3582 happen, but it doesn't seem worth worrying about this. We "continue"
3583 the outer loop when we've changed something; otherwise we "break"
3584 the switch, which will "break" the while. */
3587 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3591 code = TREE_CODE (exp);
3592 exp_type = TREE_TYPE (exp);
3594 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3596 if (TREE_CODE_LENGTH (code) > 0)
3597 arg0 = TREE_OPERAND (exp, 0);
3598 if (TREE_CODE_CLASS (code) == tcc_comparison
3599 || TREE_CODE_CLASS (code) == tcc_unary
3600 || TREE_CODE_CLASS (code) == tcc_binary)
3601 arg0_type = TREE_TYPE (arg0);
3602 if (TREE_CODE_CLASS (code) == tcc_binary
3603 || TREE_CODE_CLASS (code) == tcc_comparison
3604 || (TREE_CODE_CLASS (code) == tcc_expression
3605 && TREE_CODE_LENGTH (code) > 1))
3606 arg1 = TREE_OPERAND (exp, 1);
3611 case TRUTH_NOT_EXPR:
3612 in_p = ! in_p, exp = arg0;
3615 case EQ_EXPR: case NE_EXPR:
3616 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3617 /* We can only do something if the range is testing for zero
3618 and if the second operand is an integer constant. Note that
3619 saying something is "in" the range we make is done by
3620 complementing IN_P since it will set in the initial case of
3621 being not equal to zero; "out" is leaving it alone. */
3622 if (low == 0 || high == 0
3623 || ! integer_zerop (low) || ! integer_zerop (high)
3624 || TREE_CODE (arg1) != INTEGER_CST)
3629 case NE_EXPR: /* - [c, c] */
3632 case EQ_EXPR: /* + [c, c] */
3633 in_p = ! in_p, low = high = arg1;
3635 case GT_EXPR: /* - [-, c] */
3636 low = 0, high = arg1;
3638 case GE_EXPR: /* + [c, -] */
3639 in_p = ! in_p, low = arg1, high = 0;
3641 case LT_EXPR: /* - [c, -] */
3642 low = arg1, high = 0;
3644 case LE_EXPR: /* + [-, c] */
3645 in_p = ! in_p, low = 0, high = arg1;
3651 /* If this is an unsigned comparison, we also know that EXP is
3652 greater than or equal to zero. We base the range tests we make
3653 on that fact, so we record it here so we can parse existing
3654 range tests. We test arg0_type since often the return type
3655 of, e.g. EQ_EXPR, is boolean. */
3656 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
3658 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3660 fold_convert (arg0_type, integer_zero_node),
3664 in_p = n_in_p, low = n_low, high = n_high;
3666 /* If the high bound is missing, but we have a nonzero low
3667 bound, reverse the range so it goes from zero to the low bound
3669 if (high == 0 && low && ! integer_zerop (low))
3672 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3673 integer_one_node, 0);
3674 low = fold_convert (arg0_type, integer_zero_node);
3682 /* (-x) IN [a,b] -> x in [-b, -a] */
3683 n_low = range_binop (MINUS_EXPR, exp_type,
3684 fold_convert (exp_type, integer_zero_node),
3686 n_high = range_binop (MINUS_EXPR, exp_type,
3687 fold_convert (exp_type, integer_zero_node),
3689 low = n_low, high = n_high;
3695 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
3696 fold_convert (exp_type, integer_one_node));
3699 case PLUS_EXPR: case MINUS_EXPR:
3700 if (TREE_CODE (arg1) != INTEGER_CST)
3703 /* If EXP is signed, any overflow in the computation is undefined,
3704 so we don't worry about it so long as our computations on
3705 the bounds don't overflow. For unsigned, overflow is defined
3706 and this is exactly the right thing. */
3707 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3708 arg0_type, low, 0, arg1, 0);
3709 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3710 arg0_type, high, 1, arg1, 0);
3711 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3712 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3715 /* Check for an unsigned range which has wrapped around the maximum
3716 value thus making n_high < n_low, and normalize it. */
3717 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3719 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
3720 integer_one_node, 0);
3721 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
3722 integer_one_node, 0);
3724 /* If the range is of the form +/- [ x+1, x ], we won't
3725 be able to normalize it. But then, it represents the
3726 whole range or the empty set, so make it
3728 if (tree_int_cst_equal (n_low, low)
3729 && tree_int_cst_equal (n_high, high))
3735 low = n_low, high = n_high;
3740 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3741 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
3744 if (! INTEGRAL_TYPE_P (arg0_type)
3745 || (low != 0 && ! int_fits_type_p (low, arg0_type))
3746 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
3749 n_low = low, n_high = high;
3752 n_low = fold_convert (arg0_type, n_low);
3755 n_high = fold_convert (arg0_type, n_high);
3758 /* If we're converting arg0 from an unsigned type, to exp,
3759 a signed type, we will be doing the comparison as unsigned.
3760 The tests above have already verified that LOW and HIGH
3763 So we have to ensure that we will handle large unsigned
3764 values the same way that the current signed bounds treat
3767 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
3770 tree equiv_type = lang_hooks.types.type_for_mode
3771 (TYPE_MODE (arg0_type), 1);
3773 /* A range without an upper bound is, naturally, unbounded.
3774 Since convert would have cropped a very large value, use
3775 the max value for the destination type. */
3777 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3778 : TYPE_MAX_VALUE (arg0_type);
3780 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
3781 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
3782 fold_convert (arg0_type,
3784 fold_convert (arg0_type,
3787 /* If the low bound is specified, "and" the range with the
3788 range for which the original unsigned value will be
3792 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3793 1, n_low, n_high, 1,
3794 fold_convert (arg0_type,
3799 in_p = (n_in_p == in_p);
3803 /* Otherwise, "or" the range with the range of the input
3804 that will be interpreted as negative. */
3805 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3806 0, n_low, n_high, 1,
3807 fold_convert (arg0_type,
3812 in_p = (in_p != n_in_p);
3817 low = n_low, high = n_high;
3827 /* If EXP is a constant, we can evaluate whether this is true or false. */
3828 if (TREE_CODE (exp) == INTEGER_CST)
3830 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3832 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3838 *pin_p = in_p, *plow = low, *phigh = high;
3842 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3843 type, TYPE, return an expression to test if EXP is in (or out of, depending
3844 on IN_P) the range. Return 0 if the test couldn't be created. */
3847 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3849 tree etype = TREE_TYPE (exp);
3854 value = build_range_check (type, exp, 1, low, high);
3856 return invert_truthvalue (value);
3861 if (low == 0 && high == 0)
3862 return fold_convert (type, integer_one_node);
3865 return fold_build2 (LE_EXPR, type, exp, high);
3868 return fold_build2 (GE_EXPR, type, exp, low);
3870 if (operand_equal_p (low, high, 0))
3871 return fold_build2 (EQ_EXPR, type, exp, low);
3873 if (integer_zerop (low))
3875 if (! TYPE_UNSIGNED (etype))
3877 etype = lang_hooks.types.unsigned_type (etype);
3878 high = fold_convert (etype, high);
3879 exp = fold_convert (etype, exp);
3881 return build_range_check (type, exp, 1, 0, high);
3884 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3885 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3887 unsigned HOST_WIDE_INT lo;
3891 prec = TYPE_PRECISION (etype);
3892 if (prec <= HOST_BITS_PER_WIDE_INT)
3895 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3899 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3900 lo = (unsigned HOST_WIDE_INT) -1;
3903 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3905 if (TYPE_UNSIGNED (etype))
3907 etype = lang_hooks.types.signed_type (etype);
3908 exp = fold_convert (etype, exp);
3910 return fold_build2 (GT_EXPR, type, exp,
3911 fold_convert (etype, integer_zero_node));
3915 value = const_binop (MINUS_EXPR, high, low, 0);
3916 if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
3918 tree utype, minv, maxv;
3920 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
3921 for the type in question, as we rely on this here. */
3922 switch (TREE_CODE (etype))
3927 utype = lang_hooks.types.unsigned_type (etype);
3928 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
3929 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
3930 integer_one_node, 1);
3931 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
3932 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
3936 high = fold_convert (etype, high);
3937 low = fold_convert (etype, low);
3938 exp = fold_convert (etype, exp);
3939 value = const_binop (MINUS_EXPR, high, low, 0);
3947 if (value != 0 && ! TREE_OVERFLOW (value))
3948 return build_range_check (type,
3949 fold_build2 (MINUS_EXPR, etype, exp, low),
3950 1, fold_convert (etype, integer_zero_node),
3956 /* Given two ranges, see if we can merge them into one. Return 1 if we
3957 can, 0 if we can't. Set the output range into the specified parameters. */
3960 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3961 tree high0, int in1_p, tree low1, tree high1)
3969 int lowequal = ((low0 == 0 && low1 == 0)
3970 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3971 low0, 0, low1, 0)));
3972 int highequal = ((high0 == 0 && high1 == 0)
3973 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3974 high0, 1, high1, 1)));
3976 /* Make range 0 be the range that starts first, or ends last if they
3977 start at the same value. Swap them if it isn't. */
3978 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3981 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3982 high1, 1, high0, 1))))
3984 temp = in0_p, in0_p = in1_p, in1_p = temp;
3985 tem = low0, low0 = low1, low1 = tem;
3986 tem = high0, high0 = high1, high1 = tem;
3989 /* Now flag two cases, whether the ranges are disjoint or whether the
3990 second range is totally subsumed in the first. Note that the tests
3991 below are simplified by the ones above. */
3992 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3993 high0, 1, low1, 0));
3994 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3995 high1, 1, high0, 1));
3997 /* We now have four cases, depending on whether we are including or
3998 excluding the two ranges. */
4001 /* If they don't overlap, the result is false. If the second range
4002 is a subset it is the result. Otherwise, the range is from the start
4003 of the second to the end of the first. */
4005 in_p = 0, low = high = 0;
4007 in_p = 1, low = low1, high = high1;
4009 in_p = 1, low = low1, high = high0;
4012 else if (in0_p && ! in1_p)
4014 /* If they don't overlap, the result is the first range. If they are
4015 equal, the result is false. If the second range is a subset of the
4016 first, and the ranges begin at the same place, we go from just after
4017 the end of the first range to the end of the second. If the second
4018 range is not a subset of the first, or if it is a subset and both
4019 ranges end at the same place, the range starts at the start of the
4020 first range and ends just before the second range.
4021 Otherwise, we can't describe this as a single range. */
4023 in_p = 1, low = low0, high = high0;
4024 else if (lowequal && highequal)
4025 in_p = 0, low = high = 0;
4026 else if (subset && lowequal)
4028 in_p = 1, high = high0;
4029 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
4030 integer_one_node, 0);
4032 else if (! subset || highequal)
4034 in_p = 1, low = low0;
4035 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4036 integer_one_node, 0);
4042 else if (! in0_p && in1_p)
4044 /* If they don't overlap, the result is the second range. If the second
4045 is a subset of the first, the result is false. Otherwise,
4046 the range starts just after the first range and ends at the
4047 end of the second. */
4049 in_p = 1, low = low1, high = high1;
4050 else if (subset || highequal)
4051 in_p = 0, low = high = 0;
4054 in_p = 1, high = high1;
4055 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4056 integer_one_node, 0);
4062 /* The case where we are excluding both ranges. Here the complex case
4063 is if they don't overlap. In that case, the only time we have a
4064 range is if they are adjacent. If the second is a subset of the
4065 first, the result is the first. Otherwise, the range to exclude
4066 starts at the beginning of the first range and ends at the end of the
4070 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4071 range_binop (PLUS_EXPR, NULL_TREE,
4073 integer_one_node, 1),
4075 in_p = 0, low = low0, high = high1;
4078 /* Canonicalize - [min, x] into - [-, x]. */
4079 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4080 switch (TREE_CODE (TREE_TYPE (low0)))
4083 if (TYPE_PRECISION (TREE_TYPE (low0))
4084 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4089 if (tree_int_cst_equal (low0,
4090 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4094 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4095 && integer_zerop (low0))
4102 /* Canonicalize - [x, max] into - [x, -]. */
4103 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4104 switch (TREE_CODE (TREE_TYPE (high1)))
4107 if (TYPE_PRECISION (TREE_TYPE (high1))
4108 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4113 if (tree_int_cst_equal (high1,
4114 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4118 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4119 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4121 integer_one_node, 1)))
4128 /* The ranges might be also adjacent between the maximum and
4129 minimum values of the given type. For
4130 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4131 return + [x + 1, y - 1]. */
4132 if (low0 == 0 && high1 == 0)
4134 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4135 integer_one_node, 1);
4136 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4137 integer_one_node, 0);
4138 if (low == 0 || high == 0)
4148 in_p = 0, low = low0, high = high0;
4150 in_p = 0, low = low0, high = high1;
4153 *pin_p = in_p, *plow = low, *phigh = high;
4158 /* Subroutine of fold, looking inside expressions of the form
4159 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4160 of the COND_EXPR. This function is being used also to optimize
4161 A op B ? C : A, by reversing the comparison first.
4163 Return a folded expression whose code is not a COND_EXPR
4164 anymore, or NULL_TREE if no folding opportunity is found. */
4167 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4169 enum tree_code comp_code = TREE_CODE (arg0);
4170 tree arg00 = TREE_OPERAND (arg0, 0);
4171 tree arg01 = TREE_OPERAND (arg0, 1);
4172 tree arg1_type = TREE_TYPE (arg1);
4178 /* If we have A op 0 ? A : -A, consider applying the following
4181 A == 0? A : -A same as -A
4182 A != 0? A : -A same as A
4183 A >= 0? A : -A same as abs (A)
4184 A > 0? A : -A same as abs (A)
4185 A <= 0? A : -A same as -abs (A)
4186 A < 0? A : -A same as -abs (A)
4188 None of these transformations work for modes with signed
4189 zeros. If A is +/-0, the first two transformations will
4190 change the sign of the result (from +0 to -0, or vice
4191 versa). The last four will fix the sign of the result,
4192 even though the original expressions could be positive or
4193 negative, depending on the sign of A.
4195 Note that all these transformations are correct if A is
4196 NaN, since the two alternatives (A and -A) are also NaNs. */
4197 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4198 ? real_zerop (arg01)
4199 : integer_zerop (arg01))
4200 && ((TREE_CODE (arg2) == NEGATE_EXPR
4201 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4202 /* In the case that A is of the form X-Y, '-A' (arg2) may
4203 have already been folded to Y-X, check for that. */
4204 || (TREE_CODE (arg1) == MINUS_EXPR
4205 && TREE_CODE (arg2) == MINUS_EXPR
4206 && operand_equal_p (TREE_OPERAND (arg1, 0),
4207 TREE_OPERAND (arg2, 1), 0)
4208 && operand_equal_p (TREE_OPERAND (arg1, 1),
4209 TREE_OPERAND (arg2, 0), 0))))
4214 tem = fold_convert (arg1_type, arg1);
4215 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4218 return pedantic_non_lvalue (fold_convert (type, arg1));
4221 if (flag_trapping_math)
4226 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4227 arg1 = fold_convert (lang_hooks.types.signed_type
4228 (TREE_TYPE (arg1)), arg1);
4229 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4230 return pedantic_non_lvalue (fold_convert (type, tem));
4233 if (flag_trapping_math)
4237 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4238 arg1 = fold_convert (lang_hooks.types.signed_type
4239 (TREE_TYPE (arg1)), arg1);
4240 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4241 return negate_expr (fold_convert (type, tem));
4243 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4247 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4248 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4249 both transformations are correct when A is NaN: A != 0
4250 is then true, and A == 0 is false. */
4252 if (integer_zerop (arg01) && integer_zerop (arg2))
4254 if (comp_code == NE_EXPR)
4255 return pedantic_non_lvalue (fold_convert (type, arg1));
4256 else if (comp_code == EQ_EXPR)
4257 return fold_convert (type, integer_zero_node);
4260 /* Try some transformations of A op B ? A : B.
4262 A == B? A : B same as B
4263 A != B? A : B same as A
4264 A >= B? A : B same as max (A, B)
4265 A > B? A : B same as max (B, A)
4266 A <= B? A : B same as min (A, B)
4267 A < B? A : B same as min (B, A)
4269 As above, these transformations don't work in the presence
4270 of signed zeros. For example, if A and B are zeros of
4271 opposite sign, the first two transformations will change
4272 the sign of the result. In the last four, the original
4273 expressions give different results for (A=+0, B=-0) and
4274 (A=-0, B=+0), but the transformed expressions do not.
4276 The first two transformations are correct if either A or B
4277 is a NaN. In the first transformation, the condition will
4278 be false, and B will indeed be chosen. In the case of the
4279 second transformation, the condition A != B will be true,
4280 and A will be chosen.
4282 The conversions to max() and min() are not correct if B is
4283 a number and A is not. The conditions in the original
4284 expressions will be false, so all four give B. The min()
4285 and max() versions would give a NaN instead. */
4286 if (operand_equal_for_comparison_p (arg01, arg2, arg00)
4287 /* Avoid these transformations if the COND_EXPR may be used
4288 as an lvalue in the C++ front-end. PR c++/19199. */
4290 || strcmp (lang_hooks.name, "GNU C++") != 0
4291 || ! maybe_lvalue_p (arg1)
4292 || ! maybe_lvalue_p (arg2)))
4294 tree comp_op0 = arg00;
4295 tree comp_op1 = arg01;
4296 tree comp_type = TREE_TYPE (comp_op0);
4298 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4299 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4309 return pedantic_non_lvalue (fold_convert (type, arg2));
4311 return pedantic_non_lvalue (fold_convert (type, arg1));
4316 /* In C++ a ?: expression can be an lvalue, so put the
4317 operand which will be used if they are equal first
4318 so that we can convert this back to the
4319 corresponding COND_EXPR. */
4320 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4322 comp_op0 = fold_convert (comp_type, comp_op0);
4323 comp_op1 = fold_convert (comp_type, comp_op1);
4324 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4325 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
4326 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
4327 return pedantic_non_lvalue (fold_convert (type, tem));
4334 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4336 comp_op0 = fold_convert (comp_type, comp_op0);
4337 comp_op1 = fold_convert (comp_type, comp_op1);
4338 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
4339 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
4340 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
4341 return pedantic_non_lvalue (fold_convert (type, tem));
4345 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4346 return pedantic_non_lvalue (fold_convert (type, arg2));
4349 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4350 return pedantic_non_lvalue (fold_convert (type, arg1));
4353 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4358 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4359 we might still be able to simplify this. For example,
4360 if C1 is one less or one more than C2, this might have started
4361 out as a MIN or MAX and been transformed by this function.
4362 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4364 if (INTEGRAL_TYPE_P (type)
4365 && TREE_CODE (arg01) == INTEGER_CST
4366 && TREE_CODE (arg2) == INTEGER_CST)
4370 /* We can replace A with C1 in this case. */
4371 arg1 = fold_convert (type, arg01);
4372 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
4375 /* If C1 is C2 + 1, this is min(A, C2). */
4376 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4378 && operand_equal_p (arg01,
4379 const_binop (PLUS_EXPR, arg2,
4380 integer_one_node, 0),
4382 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
4387 /* If C1 is C2 - 1, this is min(A, C2). */
4388 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4390 && operand_equal_p (arg01,
4391 const_binop (MINUS_EXPR, arg2,
4392 integer_one_node, 0),
4394 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
4399 /* If C1 is C2 - 1, this is max(A, C2). */
4400 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4402 && operand_equal_p (arg01,
4403 const_binop (MINUS_EXPR, arg2,
4404 integer_one_node, 0),
4406 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
4411 /* If C1 is C2 + 1, this is max(A, C2). */
4412 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4414 && operand_equal_p (arg01,
4415 const_binop (PLUS_EXPR, arg2,
4416 integer_one_node, 0),
4418 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
4432 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
4433 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4436 /* EXP is some logical combination of boolean tests. See if we can
4437 merge it into some range test. Return the new tree if so. */
4440 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
4442 int or_op = (code == TRUTH_ORIF_EXPR
4443 || code == TRUTH_OR_EXPR);
4444 int in0_p, in1_p, in_p;
4445 tree low0, low1, low, high0, high1, high;
4446 tree lhs = make_range (op0, &in0_p, &low0, &high0);
4447 tree rhs = make_range (op1, &in1_p, &low1, &high1);
4450 /* If this is an OR operation, invert both sides; we will invert
4451 again at the end. */
4453 in0_p = ! in0_p, in1_p = ! in1_p;
4455 /* If both expressions are the same, if we can merge the ranges, and we
4456 can build the range test, return it or it inverted. If one of the
4457 ranges is always true or always false, consider it to be the same
4458 expression as the other. */
4459 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4460 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4462 && 0 != (tem = (build_range_check (type,
4464 : rhs != 0 ? rhs : integer_zero_node,
4466 return or_op ? invert_truthvalue (tem) : tem;
4468 /* On machines where the branch cost is expensive, if this is a
4469 short-circuited branch and the underlying object on both sides
4470 is the same, make a non-short-circuit operation. */
4471 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
4472 && lhs != 0 && rhs != 0
4473 && (code == TRUTH_ANDIF_EXPR
4474 || code == TRUTH_ORIF_EXPR)
4475 && operand_equal_p (lhs, rhs, 0))
4477 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4478 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4479 which cases we can't do this. */
4480 if (simple_operand_p (lhs))
4481 return build2 (code == TRUTH_ANDIF_EXPR
4482 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4485 else if (lang_hooks.decls.global_bindings_p () == 0
4486 && ! CONTAINS_PLACEHOLDER_P (lhs))
4488 tree common = save_expr (lhs);
4490 if (0 != (lhs = build_range_check (type, common,
4491 or_op ? ! in0_p : in0_p,
4493 && (0 != (rhs = build_range_check (type, common,
4494 or_op ? ! in1_p : in1_p,
4496 return build2 (code == TRUTH_ANDIF_EXPR
4497 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4505 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4506 bit value. Arrange things so the extra bits will be set to zero if and
4507 only if C is signed-extended to its full width. If MASK is nonzero,
4508 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4511 unextend (tree c, int p, int unsignedp, tree mask)
4513 tree type = TREE_TYPE (c);
4514 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4517 if (p == modesize || unsignedp)
4520 /* We work by getting just the sign bit into the low-order bit, then
4521 into the high-order bit, then sign-extend. We then XOR that value
4523 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4524 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
4526 /* We must use a signed type in order to get an arithmetic right shift.
4527 However, we must also avoid introducing accidental overflows, so that
4528 a subsequent call to integer_zerop will work. Hence we must
4529 do the type conversion here. At this point, the constant is either
4530 zero or one, and the conversion to a signed type can never overflow.
4531 We could get an overflow if this conversion is done anywhere else. */
4532 if (TYPE_UNSIGNED (type))
4533 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
4535 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4536 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
4538 temp = const_binop (BIT_AND_EXPR, temp,
4539 fold_convert (TREE_TYPE (c), mask), 0);
4540 /* If necessary, convert the type back to match the type of C. */
4541 if (TYPE_UNSIGNED (type))
4542 temp = fold_convert (type, temp);
4544 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
4547 /* Find ways of folding logical expressions of LHS and RHS:
4548 Try to merge two comparisons to the same innermost item.
4549 Look for range tests like "ch >= '0' && ch <= '9'".
4550 Look for combinations of simple terms on machines with expensive branches
4551 and evaluate the RHS unconditionally.
4553 For example, if we have p->a == 2 && p->b == 4 and we can make an
4554 object large enough to span both A and B, we can do this with a comparison
4555 against the object ANDed with the a mask.
4557 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4558 operations to do this with one comparison.
4560 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4561 function and the one above.
4563 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4564 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4566 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4569 We return the simplified tree or 0 if no optimization is possible. */
4572 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
4574 /* If this is the "or" of two comparisons, we can do something if
4575 the comparisons are NE_EXPR. If this is the "and", we can do something
4576 if the comparisons are EQ_EXPR. I.e.,
4577 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4579 WANTED_CODE is this operation code. For single bit fields, we can
4580 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4581 comparison for one-bit fields. */
4583 enum tree_code wanted_code;
4584 enum tree_code lcode, rcode;
4585 tree ll_arg, lr_arg, rl_arg, rr_arg;
4586 tree ll_inner, lr_inner, rl_inner, rr_inner;
4587 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
4588 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
4589 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
4590 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
4591 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
4592 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
4593 enum machine_mode lnmode, rnmode;
4594 tree ll_mask, lr_mask, rl_mask, rr_mask;
4595 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
4596 tree l_const, r_const;
4597 tree lntype, rntype, result;
4598 int first_bit, end_bit;
4601 /* Start by getting the comparison codes. Fail if anything is volatile.
4602 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4603 it were surrounded with a NE_EXPR. */
4605 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
4608 lcode = TREE_CODE (lhs);
4609 rcode = TREE_CODE (rhs);
4611 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
4613 lhs = build2 (NE_EXPR, truth_type, lhs,
4614 fold_convert (TREE_TYPE (lhs), integer_zero_node));
4618 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
4620 rhs = build2 (NE_EXPR, truth_type, rhs,
4621 fold_convert (TREE_TYPE (rhs), integer_zero_node));
4625 if (TREE_CODE_CLASS (lcode) != tcc_comparison
4626 || TREE_CODE_CLASS (rcode) != tcc_comparison)
4629 ll_arg = TREE_OPERAND (lhs, 0);
4630 lr_arg = TREE_OPERAND (lhs, 1);
4631 rl_arg = TREE_OPERAND (rhs, 0);
4632 rr_arg = TREE_OPERAND (rhs, 1);
4634 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4635 if (simple_operand_p (ll_arg)
4636 && simple_operand_p (lr_arg))
4639 if (operand_equal_p (ll_arg, rl_arg, 0)
4640 && operand_equal_p (lr_arg, rr_arg, 0))
4642 result = combine_comparisons (code, lcode, rcode,
4643 truth_type, ll_arg, lr_arg);
4647 else if (operand_equal_p (ll_arg, rr_arg, 0)
4648 && operand_equal_p (lr_arg, rl_arg, 0))
4650 result = combine_comparisons (code, lcode,
4651 swap_tree_comparison (rcode),
4652 truth_type, ll_arg, lr_arg);
4658 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4659 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4661 /* If the RHS can be evaluated unconditionally and its operands are
4662 simple, it wins to evaluate the RHS unconditionally on machines
4663 with expensive branches. In this case, this isn't a comparison
4664 that can be merged. Avoid doing this if the RHS is a floating-point
4665 comparison since those can trap. */
4667 if (BRANCH_COST >= 2
4668 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4669 && simple_operand_p (rl_arg)
4670 && simple_operand_p (rr_arg))
4672 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4673 if (code == TRUTH_OR_EXPR
4674 && lcode == NE_EXPR && integer_zerop (lr_arg)
4675 && rcode == NE_EXPR && integer_zerop (rr_arg)
4676 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4677 return build2 (NE_EXPR, truth_type,
4678 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4680 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4682 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4683 if (code == TRUTH_AND_EXPR
4684 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4685 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4686 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4687 return build2 (EQ_EXPR, truth_type,
4688 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4690 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4692 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
4693 return build2 (code, truth_type, lhs, rhs);
4696 /* See if the comparisons can be merged. Then get all the parameters for
4699 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4700 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4704 ll_inner = decode_field_reference (ll_arg,
4705 &ll_bitsize, &ll_bitpos, &ll_mode,
4706 &ll_unsignedp, &volatilep, &ll_mask,
4708 lr_inner = decode_field_reference (lr_arg,
4709 &lr_bitsize, &lr_bitpos, &lr_mode,
4710 &lr_unsignedp, &volatilep, &lr_mask,
4712 rl_inner = decode_field_reference (rl_arg,
4713 &rl_bitsize, &rl_bitpos, &rl_mode,
4714 &rl_unsignedp, &volatilep, &rl_mask,
4716 rr_inner = decode_field_reference (rr_arg,
4717 &rr_bitsize, &rr_bitpos, &rr_mode,
4718 &rr_unsignedp, &volatilep, &rr_mask,
4721 /* It must be true that the inner operation on the lhs of each
4722 comparison must be the same if we are to be able to do anything.
4723 Then see if we have constants. If not, the same must be true for
4725 if (volatilep || ll_inner == 0 || rl_inner == 0
4726 || ! operand_equal_p (ll_inner, rl_inner, 0))
4729 if (TREE_CODE (lr_arg) == INTEGER_CST
4730 && TREE_CODE (rr_arg) == INTEGER_CST)
4731 l_const = lr_arg, r_const = rr_arg;
4732 else if (lr_inner == 0 || rr_inner == 0
4733 || ! operand_equal_p (lr_inner, rr_inner, 0))
4736 l_const = r_const = 0;
4738 /* If either comparison code is not correct for our logical operation,
4739 fail. However, we can convert a one-bit comparison against zero into
4740 the opposite comparison against that bit being set in the field. */
4742 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4743 if (lcode != wanted_code)
4745 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4747 /* Make the left operand unsigned, since we are only interested
4748 in the value of one bit. Otherwise we are doing the wrong
4757 /* This is analogous to the code for l_const above. */
4758 if (rcode != wanted_code)
4760 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4769 /* After this point all optimizations will generate bit-field
4770 references, which we might not want. */
4771 if (! lang_hooks.can_use_bit_fields_p ())
4774 /* See if we can find a mode that contains both fields being compared on
4775 the left. If we can't, fail. Otherwise, update all constants and masks
4776 to be relative to a field of that size. */
4777 first_bit = MIN (ll_bitpos, rl_bitpos);
4778 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4779 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4780 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4782 if (lnmode == VOIDmode)
4785 lnbitsize = GET_MODE_BITSIZE (lnmode);
4786 lnbitpos = first_bit & ~ (lnbitsize - 1);
4787 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4788 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4790 if (BYTES_BIG_ENDIAN)
4792 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4793 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4796 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4797 size_int (xll_bitpos), 0);
4798 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4799 size_int (xrl_bitpos), 0);
4803 l_const = fold_convert (lntype, l_const);
4804 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4805 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4806 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4807 fold_build1 (BIT_NOT_EXPR,
4811 warning ("comparison is always %d", wanted_code == NE_EXPR);
4813 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4818 r_const = fold_convert (lntype, r_const);
4819 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4820 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4821 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4822 fold_build1 (BIT_NOT_EXPR,
4826 warning ("comparison is always %d", wanted_code == NE_EXPR);
4828 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4832 /* If the right sides are not constant, do the same for it. Also,
4833 disallow this optimization if a size or signedness mismatch occurs
4834 between the left and right sides. */
4837 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4838 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4839 /* Make sure the two fields on the right
4840 correspond to the left without being swapped. */
4841 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4844 first_bit = MIN (lr_bitpos, rr_bitpos);
4845 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4846 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4847 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4849 if (rnmode == VOIDmode)
4852 rnbitsize = GET_MODE_BITSIZE (rnmode);
4853 rnbitpos = first_bit & ~ (rnbitsize - 1);
4854 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4855 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4857 if (BYTES_BIG_ENDIAN)
4859 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4860 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4863 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4864 size_int (xlr_bitpos), 0);
4865 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4866 size_int (xrr_bitpos), 0);
4868 /* Make a mask that corresponds to both fields being compared.
4869 Do this for both items being compared. If the operands are the
4870 same size and the bits being compared are in the same position
4871 then we can do this by masking both and comparing the masked
4873 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4874 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4875 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4877 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4878 ll_unsignedp || rl_unsignedp);
4879 if (! all_ones_mask_p (ll_mask, lnbitsize))
4880 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
4882 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4883 lr_unsignedp || rr_unsignedp);
4884 if (! all_ones_mask_p (lr_mask, rnbitsize))
4885 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
4887 return build2 (wanted_code, truth_type, lhs, rhs);
4890 /* There is still another way we can do something: If both pairs of
4891 fields being compared are adjacent, we may be able to make a wider
4892 field containing them both.
4894 Note that we still must mask the lhs/rhs expressions. Furthermore,
4895 the mask must be shifted to account for the shift done by
4896 make_bit_field_ref. */
4897 if ((ll_bitsize + ll_bitpos == rl_bitpos
4898 && lr_bitsize + lr_bitpos == rr_bitpos)
4899 || (ll_bitpos == rl_bitpos + rl_bitsize
4900 && lr_bitpos == rr_bitpos + rr_bitsize))
4904 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4905 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4906 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4907 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4909 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4910 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4911 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4912 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4914 /* Convert to the smaller type before masking out unwanted bits. */
4916 if (lntype != rntype)
4918 if (lnbitsize > rnbitsize)
4920 lhs = fold_convert (rntype, lhs);
4921 ll_mask = fold_convert (rntype, ll_mask);
4924 else if (lnbitsize < rnbitsize)
4926 rhs = fold_convert (lntype, rhs);
4927 lr_mask = fold_convert (lntype, lr_mask);
4932 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4933 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
4935 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4936 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
4938 return build2 (wanted_code, truth_type, lhs, rhs);
4944 /* Handle the case of comparisons with constants. If there is something in
4945 common between the masks, those bits of the constants must be the same.
4946 If not, the condition is always false. Test for this to avoid generating
4947 incorrect code below. */
4948 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4949 if (! integer_zerop (result)
4950 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4951 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4953 if (wanted_code == NE_EXPR)
4955 warning ("%<or%> of unmatched not-equal tests is always 1");
4956 return constant_boolean_node (true, truth_type);
4960 warning ("%<and%> of mutually exclusive equal-tests is always 0");
4961 return constant_boolean_node (false, truth_type);
4965 /* Construct the expression we will return. First get the component
4966 reference we will make. Unless the mask is all ones the width of
4967 that field, perform the mask operation. Then compare with the
4969 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4970 ll_unsignedp || rl_unsignedp);
4972 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4973 if (! all_ones_mask_p (ll_mask, lnbitsize))
4974 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
4976 return build2 (wanted_code, truth_type, result,
4977 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4980 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4984 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
4987 enum tree_code op_code;
4988 tree comp_const = op1;
4990 int consts_equal, consts_lt;
4993 STRIP_SIGN_NOPS (arg0);
4995 op_code = TREE_CODE (arg0);
4996 minmax_const = TREE_OPERAND (arg0, 1);
4997 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4998 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4999 inner = TREE_OPERAND (arg0, 0);
5001 /* If something does not permit us to optimize, return the original tree. */
5002 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5003 || TREE_CODE (comp_const) != INTEGER_CST
5004 || TREE_CONSTANT_OVERFLOW (comp_const)
5005 || TREE_CODE (minmax_const) != INTEGER_CST
5006 || TREE_CONSTANT_OVERFLOW (minmax_const))
5009 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5010 and GT_EXPR, doing the rest with recursive calls using logical
5014 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5016 /* FIXME: We should be able to invert code without building a
5017 scratch tree node, but doing so would require us to
5018 duplicate a part of invert_truthvalue here. */
5019 tree tem = invert_truthvalue (build2 (code, type, op0, op1));
5020 tem = optimize_minmax_comparison (TREE_CODE (tem),
5022 TREE_OPERAND (tem, 0),
5023 TREE_OPERAND (tem, 1));
5024 return invert_truthvalue (tem);
5029 fold_build2 (TRUTH_ORIF_EXPR, type,
5030 optimize_minmax_comparison
5031 (EQ_EXPR, type, arg0, comp_const),
5032 optimize_minmax_comparison
5033 (GT_EXPR, type, arg0, comp_const));
5036 if (op_code == MAX_EXPR && consts_equal)
5037 /* MAX (X, 0) == 0 -> X <= 0 */
5038 return fold_build2 (LE_EXPR, type, inner, comp_const);
5040 else if (op_code == MAX_EXPR && consts_lt)
5041 /* MAX (X, 0) == 5 -> X == 5 */
5042 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5044 else if (op_code == MAX_EXPR)
5045 /* MAX (X, 0) == -1 -> false */
5046 return omit_one_operand (type, integer_zero_node, inner);
5048 else if (consts_equal)
5049 /* MIN (X, 0) == 0 -> X >= 0 */
5050 return fold_build2 (GE_EXPR, type, inner, comp_const);
5053 /* MIN (X, 0) == 5 -> false */
5054 return omit_one_operand (type, integer_zero_node, inner);
5057 /* MIN (X, 0) == -1 -> X == -1 */
5058 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5061 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5062 /* MAX (X, 0) > 0 -> X > 0
5063 MAX (X, 0) > 5 -> X > 5 */
5064 return fold_build2 (GT_EXPR, type, inner, comp_const);
5066 else if (op_code == MAX_EXPR)
5067 /* MAX (X, 0) > -1 -> true */
5068 return omit_one_operand (type, integer_one_node, inner);
5070 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5071 /* MIN (X, 0) > 0 -> false
5072 MIN (X, 0) > 5 -> false */
5073 return omit_one_operand (type, integer_zero_node, inner);
5076 /* MIN (X, 0) > -1 -> X > -1 */
5077 return fold_build2 (GT_EXPR, type, inner, comp_const);
5084 /* T is an integer expression that is being multiplied, divided, or taken a
5085 modulus (CODE says which and what kind of divide or modulus) by a
5086 constant C. See if we can eliminate that operation by folding it with
5087 other operations already in T. WIDE_TYPE, if non-null, is a type that
5088 should be used for the computation if wider than our type.
5090 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5091 (X * 2) + (Y * 4). We must, however, be assured that either the original
5092 expression would not overflow or that overflow is undefined for the type
5093 in the language in question.
5095 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5096 the machine has a multiply-accumulate insn or that this is part of an
5097 addressing calculation.
5099 If we return a non-null expression, it is an equivalent form of the
5100 original computation, but need not be in the original type. */
5103 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
5105 /* To avoid exponential search depth, refuse to allow recursion past
5106 three levels. Beyond that (1) it's highly unlikely that we'll find
5107 something interesting and (2) we've probably processed it before
5108 when we built the inner expression. */
5117 ret = extract_muldiv_1 (t, c, code, wide_type);
5124 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
5126 tree type = TREE_TYPE (t);
5127 enum tree_code tcode = TREE_CODE (t);
5128 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5129 > GET_MODE_SIZE (TYPE_MODE (type)))
5130 ? wide_type : type);
5132 int same_p = tcode == code;
5133 tree op0 = NULL_TREE, op1 = NULL_TREE;
5135 /* Don't deal with constants of zero here; they confuse the code below. */
5136 if (integer_zerop (c))
5139 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5140 op0 = TREE_OPERAND (t, 0);
5142 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5143 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5145 /* Note that we need not handle conditional operations here since fold
5146 already handles those cases. So just do arithmetic here. */
5150 /* For a constant, we can always simplify if we are a multiply
5151 or (for divide and modulus) if it is a multiple of our constant. */
5152 if (code == MULT_EXPR
5153 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5154 return const_binop (code, fold_convert (ctype, t),
5155 fold_convert (ctype, c), 0);
5158 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5159 /* If op0 is an expression ... */
5160 if ((COMPARISON_CLASS_P (op0)
5161 || UNARY_CLASS_P (op0)
5162 || BINARY_CLASS_P (op0)
5163 || EXPRESSION_CLASS_P (op0))
5164 /* ... and is unsigned, and its type is smaller than ctype,
5165 then we cannot pass through as widening. */
5166 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5167 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5168 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5169 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5170 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5171 /* ... or this is a truncation (t is narrower than op0),
5172 then we cannot pass through this narrowing. */
5173 || (GET_MODE_SIZE (TYPE_MODE (type))
5174 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5175 /* ... or signedness changes for division or modulus,
5176 then we cannot pass through this conversion. */
5177 || (code != MULT_EXPR
5178 && (TYPE_UNSIGNED (ctype)
5179 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5182 /* Pass the constant down and see if we can make a simplification. If
5183 we can, replace this expression with the inner simplification for
5184 possible later conversion to our or some other type. */
5185 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5186 && TREE_CODE (t2) == INTEGER_CST
5187 && ! TREE_CONSTANT_OVERFLOW (t2)
5188 && (0 != (t1 = extract_muldiv (op0, t2, code,
5190 ? ctype : NULL_TREE))))
5195 /* If widening the type changes it from signed to unsigned, then we
5196 must avoid building ABS_EXPR itself as unsigned. */
5197 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5199 tree cstype = (*lang_hooks.types.signed_type) (ctype);
5200 if ((t1 = extract_muldiv (op0, c, code, cstype)) != 0)
5202 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
5203 return fold_convert (ctype, t1);
5209 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5210 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
5213 case MIN_EXPR: case MAX_EXPR:
5214 /* If widening the type changes the signedness, then we can't perform
5215 this optimization as that changes the result. */
5216 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5219 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5220 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
5221 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
5223 if (tree_int_cst_sgn (c) < 0)
5224 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5226 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5227 fold_convert (ctype, t2));
5231 case LSHIFT_EXPR: case RSHIFT_EXPR:
5232 /* If the second operand is constant, this is a multiplication
5233 or floor division, by a power of two, so we can treat it that
5234 way unless the multiplier or divisor overflows. Signed
5235 left-shift overflow is implementation-defined rather than
5236 undefined in C90, so do not convert signed left shift into
5238 if (TREE_CODE (op1) == INTEGER_CST
5239 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5240 /* const_binop may not detect overflow correctly,
5241 so check for it explicitly here. */
5242 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5243 && TREE_INT_CST_HIGH (op1) == 0
5244 && 0 != (t1 = fold_convert (ctype,
5245 const_binop (LSHIFT_EXPR,
5248 && ! TREE_OVERFLOW (t1))
5249 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5250 ? MULT_EXPR : FLOOR_DIV_EXPR,
5251 ctype, fold_convert (ctype, op0), t1),
5252 c, code, wide_type);
5255 case PLUS_EXPR: case MINUS_EXPR:
5256 /* See if we can eliminate the operation on both sides. If we can, we
5257 can return a new PLUS or MINUS. If we can't, the only remaining
5258 cases where we can do anything are if the second operand is a
5260 t1 = extract_muldiv (op0, c, code, wide_type);
5261 t2 = extract_muldiv (op1, c, code, wide_type);
5262 if (t1 != 0 && t2 != 0
5263 && (code == MULT_EXPR
5264 /* If not multiplication, we can only do this if both operands
5265 are divisible by c. */
5266 || (multiple_of_p (ctype, op0, c)
5267 && multiple_of_p (ctype, op1, c))))
5268 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5269 fold_convert (ctype, t2));
5271 /* If this was a subtraction, negate OP1 and set it to be an addition.
5272 This simplifies the logic below. */
5273 if (tcode == MINUS_EXPR)
5274 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5276 if (TREE_CODE (op1) != INTEGER_CST)
5279 /* If either OP1 or C are negative, this optimization is not safe for
5280 some of the division and remainder types while for others we need
5281 to change the code. */
5282 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5284 if (code == CEIL_DIV_EXPR)
5285 code = FLOOR_DIV_EXPR;
5286 else if (code == FLOOR_DIV_EXPR)
5287 code = CEIL_DIV_EXPR;
5288 else if (code != MULT_EXPR
5289 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5293 /* If it's a multiply or a division/modulus operation of a multiple
5294 of our constant, do the operation and verify it doesn't overflow. */
5295 if (code == MULT_EXPR
5296 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5298 op1 = const_binop (code, fold_convert (ctype, op1),
5299 fold_convert (ctype, c), 0);
5300 /* We allow the constant to overflow with wrapping semantics. */
5302 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
5308 /* If we have an unsigned type is not a sizetype, we cannot widen
5309 the operation since it will change the result if the original
5310 computation overflowed. */
5311 if (TYPE_UNSIGNED (ctype)
5312 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5316 /* If we were able to eliminate our operation from the first side,
5317 apply our operation to the second side and reform the PLUS. */
5318 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5319 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
5321 /* The last case is if we are a multiply. In that case, we can
5322 apply the distributive law to commute the multiply and addition
5323 if the multiplication of the constants doesn't overflow. */
5324 if (code == MULT_EXPR)
5325 return fold_build2 (tcode, ctype,
5326 fold_build2 (code, ctype,
5327 fold_convert (ctype, op0),
5328 fold_convert (ctype, c)),
5334 /* We have a special case here if we are doing something like
5335 (C * 8) % 4 since we know that's zero. */
5336 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5337 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5338 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5339 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5340 return omit_one_operand (type, integer_zero_node, op0);
5342 /* ... fall through ... */
5344 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5345 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5346 /* If we can extract our operation from the LHS, do so and return a
5347 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5348 do something only if the second operand is a constant. */
5350 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5351 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5352 fold_convert (ctype, op1));
5353 else if (tcode == MULT_EXPR && code == MULT_EXPR
5354 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
5355 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5356 fold_convert (ctype, t1));
5357 else if (TREE_CODE (op1) != INTEGER_CST)
5360 /* If these are the same operation types, we can associate them
5361 assuming no overflow. */
5363 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5364 fold_convert (ctype, c), 0))
5365 && ! TREE_OVERFLOW (t1))
5366 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
5368 /* If these operations "cancel" each other, we have the main
5369 optimizations of this pass, which occur when either constant is a
5370 multiple of the other, in which case we replace this with either an
5371 operation or CODE or TCODE.
5373 If we have an unsigned type that is not a sizetype, we cannot do
5374 this since it will change the result if the original computation
5376 if ((! TYPE_UNSIGNED (ctype)
5377 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5379 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5380 || (tcode == MULT_EXPR
5381 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5382 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5384 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5385 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5386 fold_convert (ctype,
5387 const_binop (TRUNC_DIV_EXPR,
5389 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5390 return fold_build2 (code, ctype, fold_convert (ctype, op0),
5391 fold_convert (ctype,
5392 const_binop (TRUNC_DIV_EXPR,
5404 /* Return a node which has the indicated constant VALUE (either 0 or
5405 1), and is of the indicated TYPE. */
5408 constant_boolean_node (int value, tree type)
5410 if (type == integer_type_node)
5411 return value ? integer_one_node : integer_zero_node;
5412 else if (type == boolean_type_node)
5413 return value ? boolean_true_node : boolean_false_node;
5415 return build_int_cst (type, value);
5419 /* Return true if expr looks like an ARRAY_REF and set base and
5420 offset to the appropriate trees. If there is no offset,
5421 offset is set to NULL_TREE. */
5424 extract_array_ref (tree expr, tree *base, tree *offset)
5426 /* We have to be careful with stripping nops as with the
5427 base type the meaning of the offset can change. */
5428 tree inner_expr = expr;
5429 STRIP_NOPS (inner_expr);
5430 /* One canonical form is a PLUS_EXPR with the first
5431 argument being an ADDR_EXPR with a possible NOP_EXPR
5433 if (TREE_CODE (expr) == PLUS_EXPR)
5435 tree op0 = TREE_OPERAND (expr, 0);
5437 if (TREE_CODE (op0) == ADDR_EXPR)
5439 *base = TREE_OPERAND (expr, 0);
5440 *offset = TREE_OPERAND (expr, 1);
5444 /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
5445 which we transform into an ADDR_EXPR with appropriate
5446 offset. For other arguments to the ADDR_EXPR we assume
5447 zero offset and as such do not care about the ADDR_EXPR
5448 type and strip possible nops from it. */
5449 else if (TREE_CODE (inner_expr) == ADDR_EXPR)
5451 tree op0 = TREE_OPERAND (inner_expr, 0);
5452 if (TREE_CODE (op0) == ARRAY_REF)
5454 *base = build_fold_addr_expr (TREE_OPERAND (op0, 0));
5455 *offset = TREE_OPERAND (op0, 1);
5460 *offset = NULL_TREE;
5469 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5470 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5471 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5472 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5473 COND is the first argument to CODE; otherwise (as in the example
5474 given here), it is the second argument. TYPE is the type of the
5475 original expression. Return NULL_TREE if no simplification is
5479 fold_binary_op_with_conditional_arg (enum tree_code code,
5480 tree type, tree op0, tree op1,
5481 tree cond, tree arg, int cond_first_p)
5483 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
5484 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
5485 tree test, true_value, false_value;
5486 tree lhs = NULL_TREE;
5487 tree rhs = NULL_TREE;
5489 /* This transformation is only worthwhile if we don't have to wrap
5490 arg in a SAVE_EXPR, and the operation can be simplified on at least
5491 one of the branches once its pushed inside the COND_EXPR. */
5492 if (!TREE_CONSTANT (arg))
5495 if (TREE_CODE (cond) == COND_EXPR)
5497 test = TREE_OPERAND (cond, 0);
5498 true_value = TREE_OPERAND (cond, 1);
5499 false_value = TREE_OPERAND (cond, 2);
5500 /* If this operand throws an expression, then it does not make
5501 sense to try to perform a logical or arithmetic operation
5503 if (VOID_TYPE_P (TREE_TYPE (true_value)))
5505 if (VOID_TYPE_P (TREE_TYPE (false_value)))
5510 tree testtype = TREE_TYPE (cond);
5512 true_value = constant_boolean_node (true, testtype);
5513 false_value = constant_boolean_node (false, testtype);
5516 arg = fold_convert (arg_type, arg);
5519 true_value = fold_convert (cond_type, true_value);
5521 lhs = fold_build2 (code, type, true_value, arg);
5523 lhs = fold_build2 (code, type, arg, true_value);
5527 false_value = fold_convert (cond_type, false_value);
5529 rhs = fold_build2 (code, type, false_value, arg);
5531 rhs = fold_build2 (code, type, arg, false_value);
5534 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
5535 return fold_convert (type, test);
5539 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5541 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5542 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5543 ADDEND is the same as X.
5545 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5546 and finite. The problematic cases are when X is zero, and its mode
5547 has signed zeros. In the case of rounding towards -infinity,
5548 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5549 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5552 fold_real_zero_addition_p (tree type, tree addend, int negate)
5554 if (!real_zerop (addend))
5557 /* Don't allow the fold with -fsignaling-nans. */
5558 if (HONOR_SNANS (TYPE_MODE (type)))
5561 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5562 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5565 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5566 if (TREE_CODE (addend) == REAL_CST
5567 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5570 /* The mode has signed zeros, and we have to honor their sign.
5571 In this situation, there is only one case we can return true for.
5572 X - 0 is the same as X unless rounding towards -infinity is
5574 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5577 /* Subroutine of fold() that checks comparisons of built-in math
5578 functions against real constants.
5580 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5581 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5582 is the type of the result and ARG0 and ARG1 are the operands of the
5583 comparison. ARG1 must be a TREE_REAL_CST.
5585 The function returns the constant folded tree if a simplification
5586 can be made, and NULL_TREE otherwise. */
5589 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5590 tree type, tree arg0, tree arg1)
5594 if (BUILTIN_SQRT_P (fcode))
5596 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5597 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5599 c = TREE_REAL_CST (arg1);
5600 if (REAL_VALUE_NEGATIVE (c))
5602 /* sqrt(x) < y is always false, if y is negative. */
5603 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5604 return omit_one_operand (type, integer_zero_node, arg);
5606 /* sqrt(x) > y is always true, if y is negative and we
5607 don't care about NaNs, i.e. negative values of x. */
5608 if (code == NE_EXPR || !HONOR_NANS (mode))
5609 return omit_one_operand (type, integer_one_node, arg);
5611 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5612 return fold_build2 (GE_EXPR, type, arg,
5613 build_real (TREE_TYPE (arg), dconst0));
5615 else if (code == GT_EXPR || code == GE_EXPR)
5619 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5620 real_convert (&c2, mode, &c2);
5622 if (REAL_VALUE_ISINF (c2))
5624 /* sqrt(x) > y is x == +Inf, when y is very large. */
5625 if (HONOR_INFINITIES (mode))
5626 return fold_build2 (EQ_EXPR, type, arg,
5627 build_real (TREE_TYPE (arg), c2));
5629 /* sqrt(x) > y is always false, when y is very large
5630 and we don't care about infinities. */
5631 return omit_one_operand (type, integer_zero_node, arg);
5634 /* sqrt(x) > c is the same as x > c*c. */
5635 return fold_build2 (code, type, arg,
5636 build_real (TREE_TYPE (arg), c2));
5638 else if (code == LT_EXPR || code == LE_EXPR)
5642 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5643 real_convert (&c2, mode, &c2);
5645 if (REAL_VALUE_ISINF (c2))
5647 /* sqrt(x) < y is always true, when y is a very large
5648 value and we don't care about NaNs or Infinities. */
5649 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5650 return omit_one_operand (type, integer_one_node, arg);
5652 /* sqrt(x) < y is x != +Inf when y is very large and we
5653 don't care about NaNs. */
5654 if (! HONOR_NANS (mode))
5655 return fold_build2 (NE_EXPR, type, arg,
5656 build_real (TREE_TYPE (arg), c2));
5658 /* sqrt(x) < y is x >= 0 when y is very large and we
5659 don't care about Infinities. */
5660 if (! HONOR_INFINITIES (mode))
5661 return fold_build2 (GE_EXPR, type, arg,
5662 build_real (TREE_TYPE (arg), dconst0));
5664 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5665 if (lang_hooks.decls.global_bindings_p () != 0
5666 || CONTAINS_PLACEHOLDER_P (arg))
5669 arg = save_expr (arg);
5670 return fold_build2 (TRUTH_ANDIF_EXPR, type,
5671 fold_build2 (GE_EXPR, type, arg,
5672 build_real (TREE_TYPE (arg),
5674 fold_build2 (NE_EXPR, type, arg,
5675 build_real (TREE_TYPE (arg),
5679 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5680 if (! HONOR_NANS (mode))
5681 return fold_build2 (code, type, arg,
5682 build_real (TREE_TYPE (arg), c2));
5684 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5685 if (lang_hooks.decls.global_bindings_p () == 0
5686 && ! CONTAINS_PLACEHOLDER_P (arg))
5688 arg = save_expr (arg);
5689 return fold_build2 (TRUTH_ANDIF_EXPR, type,
5690 fold_build2 (GE_EXPR, type, arg,
5691 build_real (TREE_TYPE (arg),
5693 fold_build2 (code, type, arg,
5694 build_real (TREE_TYPE (arg),
5703 /* Subroutine of fold() that optimizes comparisons against Infinities,
5704 either +Inf or -Inf.
5706 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5707 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5708 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5710 The function returns the constant folded tree if a simplification
5711 can be made, and NULL_TREE otherwise. */
5714 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5716 enum machine_mode mode;
5717 REAL_VALUE_TYPE max;
5721 mode = TYPE_MODE (TREE_TYPE (arg0));
5723 /* For negative infinity swap the sense of the comparison. */
5724 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5726 code = swap_tree_comparison (code);
5731 /* x > +Inf is always false, if with ignore sNANs. */
5732 if (HONOR_SNANS (mode))
5734 return omit_one_operand (type, integer_zero_node, arg0);
5737 /* x <= +Inf is always true, if we don't case about NaNs. */
5738 if (! HONOR_NANS (mode))
5739 return omit_one_operand (type, integer_one_node, arg0);
5741 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5742 if (lang_hooks.decls.global_bindings_p () == 0
5743 && ! CONTAINS_PLACEHOLDER_P (arg0))
5745 arg0 = save_expr (arg0);
5746 return fold_build2 (EQ_EXPR, type, arg0, arg0);
5752 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5753 real_maxval (&max, neg, mode);
5754 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
5755 arg0, build_real (TREE_TYPE (arg0), max));
5758 /* x < +Inf is always equal to x <= DBL_MAX. */
5759 real_maxval (&max, neg, mode);
5760 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
5761 arg0, build_real (TREE_TYPE (arg0), max));
5764 /* x != +Inf is always equal to !(x > DBL_MAX). */
5765 real_maxval (&max, neg, mode);
5766 if (! HONOR_NANS (mode))
5767 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
5768 arg0, build_real (TREE_TYPE (arg0), max));
5770 /* The transformation below creates non-gimple code and thus is
5771 not appropriate if we are in gimple form. */
5775 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
5776 arg0, build_real (TREE_TYPE (arg0), max));
5777 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
5786 /* Subroutine of fold() that optimizes comparisons of a division by
5787 a nonzero integer constant against an integer constant, i.e.
5790 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5791 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5792 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5794 The function returns the constant folded tree if a simplification
5795 can be made, and NULL_TREE otherwise. */
5798 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5800 tree prod, tmp, hi, lo;
5801 tree arg00 = TREE_OPERAND (arg0, 0);
5802 tree arg01 = TREE_OPERAND (arg0, 1);
5803 unsigned HOST_WIDE_INT lpart;
5804 HOST_WIDE_INT hpart;
5807 /* We have to do this the hard way to detect unsigned overflow.
5808 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5809 overflow = mul_double (TREE_INT_CST_LOW (arg01),
5810 TREE_INT_CST_HIGH (arg01),
5811 TREE_INT_CST_LOW (arg1),
5812 TREE_INT_CST_HIGH (arg1), &lpart, &hpart);
5813 prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5814 prod = force_fit_type (prod, -1, overflow, false);
5816 if (TYPE_UNSIGNED (TREE_TYPE (arg0)))
5818 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5821 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5822 overflow = add_double (TREE_INT_CST_LOW (prod),
5823 TREE_INT_CST_HIGH (prod),
5824 TREE_INT_CST_LOW (tmp),
5825 TREE_INT_CST_HIGH (tmp),
5827 hi = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5828 hi = force_fit_type (hi, -1, overflow | TREE_OVERFLOW (prod),
5829 TREE_CONSTANT_OVERFLOW (prod));
5831 else if (tree_int_cst_sgn (arg01) >= 0)
5833 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5834 switch (tree_int_cst_sgn (arg1))
5837 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5842 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
5847 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5857 /* A negative divisor reverses the relational operators. */
5858 code = swap_tree_comparison (code);
5860 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
5861 switch (tree_int_cst_sgn (arg1))
5864 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5869 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
5874 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5886 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5887 return omit_one_operand (type, integer_zero_node, arg00);
5888 if (TREE_OVERFLOW (hi))
5889 return fold_build2 (GE_EXPR, type, arg00, lo);
5890 if (TREE_OVERFLOW (lo))
5891 return fold_build2 (LE_EXPR, type, arg00, hi);
5892 return build_range_check (type, arg00, 1, lo, hi);
5895 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5896 return omit_one_operand (type, integer_one_node, arg00);
5897 if (TREE_OVERFLOW (hi))
5898 return fold_build2 (LT_EXPR, type, arg00, lo);
5899 if (TREE_OVERFLOW (lo))
5900 return fold_build2 (GT_EXPR, type, arg00, hi);
5901 return build_range_check (type, arg00, 0, lo, hi);
5904 if (TREE_OVERFLOW (lo))
5905 return omit_one_operand (type, integer_zero_node, arg00);
5906 return fold_build2 (LT_EXPR, type, arg00, lo);
5909 if (TREE_OVERFLOW (hi))
5910 return omit_one_operand (type, integer_one_node, arg00);
5911 return fold_build2 (LE_EXPR, type, arg00, hi);
5914 if (TREE_OVERFLOW (hi))
5915 return omit_one_operand (type, integer_zero_node, arg00);
5916 return fold_build2 (GT_EXPR, type, arg00, hi);
5919 if (TREE_OVERFLOW (lo))
5920 return omit_one_operand (type, integer_one_node, arg00);
5921 return fold_build2 (GE_EXPR, type, arg00, lo);
5931 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5932 equality/inequality test, then return a simplified form of the test
5933 using a sign testing. Otherwise return NULL. TYPE is the desired
5937 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
5940 /* If this is testing a single bit, we can optimize the test. */
5941 if ((code == NE_EXPR || code == EQ_EXPR)
5942 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5943 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5945 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5946 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5947 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5949 if (arg00 != NULL_TREE
5950 /* This is only a win if casting to a signed type is cheap,
5951 i.e. when arg00's type is not a partial mode. */
5952 && TYPE_PRECISION (TREE_TYPE (arg00))
5953 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
5955 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5956 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
5957 result_type, fold_convert (stype, arg00),
5958 fold_convert (stype, integer_zero_node));
5965 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5966 equality/inequality test, then return a simplified form of
5967 the test using shifts and logical operations. Otherwise return
5968 NULL. TYPE is the desired result type. */
5971 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5974 /* If this is testing a single bit, we can optimize the test. */
5975 if ((code == NE_EXPR || code == EQ_EXPR)
5976 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5977 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5979 tree inner = TREE_OPERAND (arg0, 0);
5980 tree type = TREE_TYPE (arg0);
5981 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5982 enum machine_mode operand_mode = TYPE_MODE (type);
5984 tree signed_type, unsigned_type, intermediate_type;
5987 /* First, see if we can fold the single bit test into a sign-bit
5989 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
5994 /* Otherwise we have (A & C) != 0 where C is a single bit,
5995 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5996 Similarly for (A & C) == 0. */
5998 /* If INNER is a right shift of a constant and it plus BITNUM does
5999 not overflow, adjust BITNUM and INNER. */
6000 if (TREE_CODE (inner) == RSHIFT_EXPR
6001 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6002 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6003 && bitnum < TYPE_PRECISION (type)
6004 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6005 bitnum - TYPE_PRECISION (type)))
6007 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6008 inner = TREE_OPERAND (inner, 0);
6011 /* If we are going to be able to omit the AND below, we must do our
6012 operations as unsigned. If we must use the AND, we have a choice.
6013 Normally unsigned is faster, but for some machines signed is. */
6014 #ifdef LOAD_EXTEND_OP
6015 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6016 && !flag_syntax_only) ? 0 : 1;
6021 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6022 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6023 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6024 inner = fold_convert (intermediate_type, inner);
6027 inner = build2 (RSHIFT_EXPR, intermediate_type,
6028 inner, size_int (bitnum));
6030 if (code == EQ_EXPR)
6031 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type,
6032 inner, integer_one_node);
6034 /* Put the AND last so it can combine with more things. */
6035 inner = build2 (BIT_AND_EXPR, intermediate_type,
6036 inner, integer_one_node);
6038 /* Make sure to return the proper type. */
6039 inner = fold_convert (result_type, inner);
6046 /* Check whether we are allowed to reorder operands arg0 and arg1,
6047 such that the evaluation of arg1 occurs before arg0. */
6050 reorder_operands_p (tree arg0, tree arg1)
6052 if (! flag_evaluation_order)
6054 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6056 return ! TREE_SIDE_EFFECTS (arg0)
6057 && ! TREE_SIDE_EFFECTS (arg1);
6060 /* Test whether it is preferable two swap two operands, ARG0 and
6061 ARG1, for example because ARG0 is an integer constant and ARG1
6062 isn't. If REORDER is true, only recommend swapping if we can
6063 evaluate the operands in reverse order. */
6066 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
6068 STRIP_SIGN_NOPS (arg0);
6069 STRIP_SIGN_NOPS (arg1);
6071 if (TREE_CODE (arg1) == INTEGER_CST)
6073 if (TREE_CODE (arg0) == INTEGER_CST)
6076 if (TREE_CODE (arg1) == REAL_CST)
6078 if (TREE_CODE (arg0) == REAL_CST)
6081 if (TREE_CODE (arg1) == COMPLEX_CST)
6083 if (TREE_CODE (arg0) == COMPLEX_CST)
6086 if (TREE_CONSTANT (arg1))
6088 if (TREE_CONSTANT (arg0))
6094 if (reorder && flag_evaluation_order
6095 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6103 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6104 for commutative and comparison operators. Ensuring a canonical
6105 form allows the optimizers to find additional redundancies without
6106 having to explicitly check for both orderings. */
6107 if (TREE_CODE (arg0) == SSA_NAME
6108 && TREE_CODE (arg1) == SSA_NAME
6109 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6115 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6116 ARG0 is extended to a wider type. */
6119 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6121 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6123 tree shorter_type, outer_type;
6127 if (arg0_unw == arg0)
6129 shorter_type = TREE_TYPE (arg0_unw);
6131 #ifdef HAVE_canonicalize_funcptr_for_compare
6132 /* Disable this optimization if we're casting a function pointer
6133 type on targets that require function pointer canonicalization. */
6134 if (HAVE_canonicalize_funcptr_for_compare
6135 && TREE_CODE (shorter_type) == POINTER_TYPE
6136 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
6140 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6143 arg1_unw = get_unwidened (arg1, shorter_type);
6147 /* If possible, express the comparison in the shorter mode. */
6148 if ((code == EQ_EXPR || code == NE_EXPR
6149 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6150 && (TREE_TYPE (arg1_unw) == shorter_type
6151 || (TREE_CODE (arg1_unw) == INTEGER_CST
6152 && TREE_CODE (shorter_type) == INTEGER_TYPE
6153 && int_fits_type_p (arg1_unw, shorter_type))))
6154 return fold_build2 (code, type, arg0_unw,
6155 fold_convert (shorter_type, arg1_unw));
6157 if (TREE_CODE (arg1_unw) != INTEGER_CST)
6160 /* If we are comparing with the integer that does not fit into the range
6161 of the shorter type, the result is known. */
6162 outer_type = TREE_TYPE (arg1_unw);
6163 min = lower_bound_in_type (outer_type, shorter_type);
6164 max = upper_bound_in_type (outer_type, shorter_type);
6166 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6168 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6175 return omit_one_operand (type, integer_zero_node, arg0);
6180 return omit_one_operand (type, integer_one_node, arg0);
6186 return omit_one_operand (type, integer_one_node, arg0);
6188 return omit_one_operand (type, integer_zero_node, arg0);
6193 return omit_one_operand (type, integer_zero_node, arg0);
6195 return omit_one_operand (type, integer_one_node, arg0);
6204 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6205 ARG0 just the signedness is changed. */
6208 fold_sign_changed_comparison (enum tree_code code, tree type,
6209 tree arg0, tree arg1)
6211 tree arg0_inner, tmp;
6212 tree inner_type, outer_type;
6214 if (TREE_CODE (arg0) != NOP_EXPR
6215 && TREE_CODE (arg0) != CONVERT_EXPR)
6218 outer_type = TREE_TYPE (arg0);
6219 arg0_inner = TREE_OPERAND (arg0, 0);
6220 inner_type = TREE_TYPE (arg0_inner);
6222 #ifdef HAVE_canonicalize_funcptr_for_compare
6223 /* Disable this optimization if we're casting a function pointer
6224 type on targets that require function pointer canonicalization. */
6225 if (HAVE_canonicalize_funcptr_for_compare
6226 && TREE_CODE (inner_type) == POINTER_TYPE
6227 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
6231 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6234 if (TREE_CODE (arg1) != INTEGER_CST
6235 && !((TREE_CODE (arg1) == NOP_EXPR
6236 || TREE_CODE (arg1) == CONVERT_EXPR)
6237 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6240 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6245 if (TREE_CODE (arg1) == INTEGER_CST)
6247 tmp = build_int_cst_wide (inner_type,
6248 TREE_INT_CST_LOW (arg1),
6249 TREE_INT_CST_HIGH (arg1));
6250 arg1 = force_fit_type (tmp, 0,
6251 TREE_OVERFLOW (arg1),
6252 TREE_CONSTANT_OVERFLOW (arg1));
6255 arg1 = fold_convert (inner_type, arg1);
6257 return fold_build2 (code, type, arg0_inner, arg1);
6260 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6261 step of the array. ADDR is the address. MULT is the multiplicative expression.
6262 If the function succeeds, the new address expression is returned. Otherwise
6263 NULL_TREE is returned. */
6266 try_move_mult_to_index (enum tree_code code, tree addr, tree mult)
6268 tree s, delta, step;
6269 tree arg0 = TREE_OPERAND (mult, 0), arg1 = TREE_OPERAND (mult, 1);
6270 tree ref = TREE_OPERAND (addr, 0), pref;
6277 if (TREE_CODE (arg0) == INTEGER_CST)
6282 else if (TREE_CODE (arg1) == INTEGER_CST)
6290 for (;; ref = TREE_OPERAND (ref, 0))
6292 if (TREE_CODE (ref) == ARRAY_REF)
6294 step = array_ref_element_size (ref);
6296 if (TREE_CODE (step) != INTEGER_CST)
6299 itype = TREE_TYPE (step);
6301 /* If the type sizes do not match, we might run into problems
6302 when one of them would overflow. */
6303 if (TYPE_PRECISION (itype) != TYPE_PRECISION (TREE_TYPE (s)))
6306 if (!operand_equal_p (step, fold_convert (itype, s), 0))
6309 delta = fold_convert (itype, delta);
6313 if (!handled_component_p (ref))
6317 /* We found the suitable array reference. So copy everything up to it,
6318 and replace the index. */
6320 pref = TREE_OPERAND (addr, 0);
6321 ret = copy_node (pref);
6326 pref = TREE_OPERAND (pref, 0);
6327 TREE_OPERAND (pos, 0) = copy_node (pref);
6328 pos = TREE_OPERAND (pos, 0);
6331 TREE_OPERAND (pos, 1) = fold_build2 (code, itype,
6332 TREE_OPERAND (pos, 1),
6335 return build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6339 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6340 means A >= Y && A != MAX, but in this case we know that
6341 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6344 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6346 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6348 if (TREE_CODE (bound) == LT_EXPR)
6349 a = TREE_OPERAND (bound, 0);
6350 else if (TREE_CODE (bound) == GT_EXPR)
6351 a = TREE_OPERAND (bound, 1);
6355 typea = TREE_TYPE (a);
6356 if (!INTEGRAL_TYPE_P (typea)
6357 && !POINTER_TYPE_P (typea))
6360 if (TREE_CODE (ineq) == LT_EXPR)
6362 a1 = TREE_OPERAND (ineq, 1);
6363 y = TREE_OPERAND (ineq, 0);
6365 else if (TREE_CODE (ineq) == GT_EXPR)
6367 a1 = TREE_OPERAND (ineq, 0);
6368 y = TREE_OPERAND (ineq, 1);
6373 if (TREE_TYPE (a1) != typea)
6376 diff = fold_build2 (MINUS_EXPR, typea, a1, a);
6377 if (!integer_onep (diff))
6380 return fold_build2 (GE_EXPR, type, a, y);
6383 /* Fold complex addition when both components are accessible by parts.
6384 Return non-null if successful. CODE should be PLUS_EXPR for addition,
6385 or MINUS_EXPR for subtraction. */
6388 fold_complex_add (tree type, tree ac, tree bc, enum tree_code code)
6390 tree ar, ai, br, bi, rr, ri, inner_type;
6392 if (TREE_CODE (ac) == COMPLEX_EXPR)
6393 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6394 else if (TREE_CODE (ac) == COMPLEX_CST)
6395 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6399 if (TREE_CODE (bc) == COMPLEX_EXPR)
6400 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6401 else if (TREE_CODE (bc) == COMPLEX_CST)
6402 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6406 inner_type = TREE_TYPE (type);
6408 rr = fold_build2 (code, inner_type, ar, br);
6409 ri = fold_build2 (code, inner_type, ai, bi);
6411 return fold_build2 (COMPLEX_EXPR, type, rr, ri);
6414 /* Perform some simplifications of complex multiplication when one or more
6415 of the components are constants or zeros. Return non-null if successful. */
6418 fold_complex_mult_parts (tree type, tree ar, tree ai, tree br, tree bi)
6420 tree rr, ri, inner_type, zero;
6421 bool ar0, ai0, br0, bi0, bi1;
6423 inner_type = TREE_TYPE (type);
6426 if (SCALAR_FLOAT_TYPE_P (inner_type))
6428 ar0 = ai0 = br0 = bi0 = bi1 = false;
6430 /* We're only interested in +0.0 here, thus we don't use real_zerop. */
6432 if (TREE_CODE (ar) == REAL_CST
6433 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ar), dconst0))
6434 ar0 = true, zero = ar;
6436 if (TREE_CODE (ai) == REAL_CST
6437 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ai), dconst0))
6438 ai0 = true, zero = ai;
6440 if (TREE_CODE (br) == REAL_CST
6441 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (br), dconst0))
6442 br0 = true, zero = br;
6444 if (TREE_CODE (bi) == REAL_CST)
6446 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst0))
6447 bi0 = true, zero = bi;
6448 else if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst1))
6454 ar0 = integer_zerop (ar);
6457 ai0 = integer_zerop (ai);
6460 br0 = integer_zerop (br);
6463 bi0 = integer_zerop (bi);
6470 bi1 = integer_onep (bi);
6473 /* We won't optimize anything below unless something is zero. */
6477 if (ai0 && br0 && bi1)
6482 else if (ai0 && bi0)
6484 rr = fold_build2 (MULT_EXPR, inner_type, ar, br);
6487 else if (ai0 && br0)
6490 ri = fold_build2 (MULT_EXPR, inner_type, ar, bi);
6492 else if (ar0 && bi0)
6495 ri = fold_build2 (MULT_EXPR, inner_type, ai, br);
6497 else if (ar0 && br0)
6499 rr = fold_build2 (MULT_EXPR, inner_type, ai, bi);
6500 rr = fold_build1 (NEGATE_EXPR, inner_type, rr);
6505 rr = fold_build2 (MULT_EXPR, inner_type, ar, br);
6506 ri = fold_build2 (MULT_EXPR, inner_type, ai, br);
6510 rr = fold_build2 (MULT_EXPR, inner_type, ar, br);
6511 ri = fold_build2 (MULT_EXPR, inner_type, ar, bi);
6515 rr = fold_build2 (MULT_EXPR, inner_type, ai, bi);
6516 rr = fold_build1 (NEGATE_EXPR, inner_type, rr);
6517 ri = fold_build2 (MULT_EXPR, inner_type, ar, bi);
6521 rr = fold_build2 (MULT_EXPR, inner_type, ai, bi);
6522 rr = fold_build1 (NEGATE_EXPR, inner_type, rr);
6523 ri = fold_build2 (MULT_EXPR, inner_type, ai, br);
6528 return fold_build2 (COMPLEX_EXPR, type, rr, ri);
6532 fold_complex_mult (tree type, tree ac, tree bc)
6534 tree ar, ai, br, bi;
6536 if (TREE_CODE (ac) == COMPLEX_EXPR)
6537 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6538 else if (TREE_CODE (ac) == COMPLEX_CST)
6539 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6543 if (TREE_CODE (bc) == COMPLEX_EXPR)
6544 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6545 else if (TREE_CODE (bc) == COMPLEX_CST)
6546 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6550 return fold_complex_mult_parts (type, ar, ai, br, bi);
6553 /* Perform some simplifications of complex division when one or more of
6554 the components are constants or zeros. Return non-null if successful. */
6557 fold_complex_div_parts (tree type, tree ar, tree ai, tree br, tree bi,
6558 enum tree_code code)
6560 tree rr, ri, inner_type, zero;
6561 bool ar0, ai0, br0, bi0, bi1;
6563 inner_type = TREE_TYPE (type);
6566 if (SCALAR_FLOAT_TYPE_P (inner_type))
6568 ar0 = ai0 = br0 = bi0 = bi1 = false;
6570 /* We're only interested in +0.0 here, thus we don't use real_zerop. */
6572 if (TREE_CODE (ar) == REAL_CST
6573 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ar), dconst0))
6574 ar0 = true, zero = ar;
6576 if (TREE_CODE (ai) == REAL_CST
6577 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ai), dconst0))
6578 ai0 = true, zero = ai;
6580 if (TREE_CODE (br) == REAL_CST
6581 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (br), dconst0))
6582 br0 = true, zero = br;
6584 if (TREE_CODE (bi) == REAL_CST)
6586 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst0))
6587 bi0 = true, zero = bi;
6588 else if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst1))
6594 ar0 = integer_zerop (ar);
6597 ai0 = integer_zerop (ai);
6600 br0 = integer_zerop (br);
6603 bi0 = integer_zerop (bi);
6610 bi1 = integer_onep (bi);
6613 /* We won't optimize anything below unless something is zero. */
6619 rr = fold_build2 (code, inner_type, ar, br);
6622 else if (ai0 && br0)
6625 ri = fold_build2 (code, inner_type, ar, bi);
6626 ri = fold_build1 (NEGATE_EXPR, inner_type, ri);
6628 else if (ar0 && bi0)
6631 ri = fold_build2 (code, inner_type, ai, br);
6633 else if (ar0 && br0)
6635 rr = fold_build2 (code, inner_type, ai, bi);
6640 rr = fold_build2 (code, inner_type, ar, br);
6641 ri = fold_build2 (code, inner_type, ai, br);
6645 rr = fold_build2 (code, inner_type, ai, bi);
6646 ri = fold_build2 (code, inner_type, ar, bi);
6647 ri = fold_build1 (NEGATE_EXPR, inner_type, ri);
6652 return fold_build2 (COMPLEX_EXPR, type, rr, ri);
6656 fold_complex_div (tree type, tree ac, tree bc, enum tree_code code)
6658 tree ar, ai, br, bi;
6660 if (TREE_CODE (ac) == COMPLEX_EXPR)
6661 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6662 else if (TREE_CODE (ac) == COMPLEX_CST)
6663 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6667 if (TREE_CODE (bc) == COMPLEX_EXPR)
6668 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6669 else if (TREE_CODE (bc) == COMPLEX_CST)
6670 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6674 return fold_complex_div_parts (type, ar, ai, br, bi, code);
6677 /* Fold a unary expression of code CODE and type TYPE with operand
6678 OP0. Return the folded expression if folding is successful.
6679 Otherwise, return NULL_TREE. */
6682 fold_unary (enum tree_code code, tree type, tree op0)
6686 enum tree_code_class kind = TREE_CODE_CLASS (code);
6688 gcc_assert (IS_EXPR_CODE_CLASS (kind)
6689 && TREE_CODE_LENGTH (code) == 1);
6694 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
6696 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
6697 STRIP_SIGN_NOPS (arg0);
6701 /* Strip any conversions that don't change the mode. This
6702 is safe for every expression, except for a comparison
6703 expression because its signedness is derived from its
6706 Note that this is done as an internal manipulation within
6707 the constant folder, in order to find the simplest
6708 representation of the arguments so that their form can be
6709 studied. In any cases, the appropriate type conversions
6710 should be put back in the tree that will get out of the
6716 if (TREE_CODE_CLASS (code) == tcc_unary)
6718 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6719 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6720 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
6721 else if (TREE_CODE (arg0) == COND_EXPR)
6723 tree arg01 = TREE_OPERAND (arg0, 1);
6724 tree arg02 = TREE_OPERAND (arg0, 2);
6725 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6726 arg01 = fold_build1 (code, type, arg01);
6727 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6728 arg02 = fold_build1 (code, type, arg02);
6729 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6732 /* If this was a conversion, and all we did was to move into
6733 inside the COND_EXPR, bring it back out. But leave it if
6734 it is a conversion from integer to integer and the
6735 result precision is no wider than a word since such a
6736 conversion is cheap and may be optimized away by combine,
6737 while it couldn't if it were outside the COND_EXPR. Then return
6738 so we don't get into an infinite recursion loop taking the
6739 conversion out and then back in. */
6741 if ((code == NOP_EXPR || code == CONVERT_EXPR
6742 || code == NON_LVALUE_EXPR)
6743 && TREE_CODE (tem) == COND_EXPR
6744 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6745 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6746 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6747 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6748 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6749 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6750 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6752 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6753 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
6754 || flag_syntax_only))
6755 tem = build1 (code, type,
6757 TREE_TYPE (TREE_OPERAND
6758 (TREE_OPERAND (tem, 1), 0)),
6759 TREE_OPERAND (tem, 0),
6760 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6761 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6764 else if (COMPARISON_CLASS_P (arg0))
6766 if (TREE_CODE (type) == BOOLEAN_TYPE)
6768 arg0 = copy_node (arg0);
6769 TREE_TYPE (arg0) = type;
6772 else if (TREE_CODE (type) != INTEGER_TYPE)
6773 return fold_build3 (COND_EXPR, type, arg0,
6774 fold_build1 (code, type,
6776 fold_build1 (code, type,
6777 integer_zero_node));
6786 case FIX_TRUNC_EXPR:
6788 case FIX_FLOOR_EXPR:
6789 case FIX_ROUND_EXPR:
6790 if (TREE_TYPE (op0) == type)
6793 /* Handle cases of two conversions in a row. */
6794 if (TREE_CODE (op0) == NOP_EXPR
6795 || TREE_CODE (op0) == CONVERT_EXPR)
6797 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
6798 tree inter_type = TREE_TYPE (op0);
6799 int inside_int = INTEGRAL_TYPE_P (inside_type);
6800 int inside_ptr = POINTER_TYPE_P (inside_type);
6801 int inside_float = FLOAT_TYPE_P (inside_type);
6802 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
6803 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6804 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6805 int inter_int = INTEGRAL_TYPE_P (inter_type);
6806 int inter_ptr = POINTER_TYPE_P (inter_type);
6807 int inter_float = FLOAT_TYPE_P (inter_type);
6808 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
6809 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6810 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6811 int final_int = INTEGRAL_TYPE_P (type);
6812 int final_ptr = POINTER_TYPE_P (type);
6813 int final_float = FLOAT_TYPE_P (type);
6814 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
6815 unsigned int final_prec = TYPE_PRECISION (type);
6816 int final_unsignedp = TYPE_UNSIGNED (type);
6818 /* In addition to the cases of two conversions in a row
6819 handled below, if we are converting something to its own
6820 type via an object of identical or wider precision, neither
6821 conversion is needed. */
6822 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6823 && ((inter_int && final_int) || (inter_float && final_float))
6824 && inter_prec >= final_prec)
6825 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
6827 /* Likewise, if the intermediate and final types are either both
6828 float or both integer, we don't need the middle conversion if
6829 it is wider than the final type and doesn't change the signedness
6830 (for integers). Avoid this if the final type is a pointer
6831 since then we sometimes need the inner conversion. Likewise if
6832 the outer has a precision not equal to the size of its mode. */
6833 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6834 || (inter_float && inside_float)
6835 || (inter_vec && inside_vec))
6836 && inter_prec >= inside_prec
6837 && (inter_float || inter_vec
6838 || inter_unsignedp == inside_unsignedp)
6839 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6840 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6842 && (! final_vec || inter_prec == inside_prec))
6843 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
6845 /* If we have a sign-extension of a zero-extended value, we can
6846 replace that by a single zero-extension. */
6847 if (inside_int && inter_int && final_int
6848 && inside_prec < inter_prec && inter_prec < final_prec
6849 && inside_unsignedp && !inter_unsignedp)
6850 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
6852 /* Two conversions in a row are not needed unless:
6853 - some conversion is floating-point (overstrict for now), or
6854 - some conversion is a vector (overstrict for now), or
6855 - the intermediate type is narrower than both initial and
6857 - the intermediate type and innermost type differ in signedness,
6858 and the outermost type is wider than the intermediate, or
6859 - the initial type is a pointer type and the precisions of the
6860 intermediate and final types differ, or
6861 - the final type is a pointer type and the precisions of the
6862 initial and intermediate types differ. */
6863 if (! inside_float && ! inter_float && ! final_float
6864 && ! inside_vec && ! inter_vec && ! final_vec
6865 && (inter_prec > inside_prec || inter_prec > final_prec)
6866 && ! (inside_int && inter_int
6867 && inter_unsignedp != inside_unsignedp
6868 && inter_prec < final_prec)
6869 && ((inter_unsignedp && inter_prec > inside_prec)
6870 == (final_unsignedp && final_prec > inter_prec))
6871 && ! (inside_ptr && inter_prec != final_prec)
6872 && ! (final_ptr && inside_prec != inter_prec)
6873 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6874 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6876 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
6879 if (TREE_CODE (op0) == MODIFY_EXPR
6880 && TREE_CONSTANT (TREE_OPERAND (op0, 1))
6881 /* Detect assigning a bitfield. */
6882 && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
6883 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
6885 /* Don't leave an assignment inside a conversion
6886 unless assigning a bitfield. */
6887 tem = fold_build1 (code, type, TREE_OPERAND (op0, 1));
6888 /* First do the assignment, then return converted constant. */
6889 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
6890 TREE_NO_WARNING (tem) = 1;
6891 TREE_USED (tem) = 1;
6895 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6896 constants (if x has signed type, the sign bit cannot be set
6897 in c). This folds extension into the BIT_AND_EXPR. */
6898 if (INTEGRAL_TYPE_P (type)
6899 && TREE_CODE (type) != BOOLEAN_TYPE
6900 && TREE_CODE (op0) == BIT_AND_EXPR
6901 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
6904 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6907 if (TYPE_UNSIGNED (TREE_TYPE (and))
6908 || (TYPE_PRECISION (type)
6909 <= TYPE_PRECISION (TREE_TYPE (and))))
6911 else if (TYPE_PRECISION (TREE_TYPE (and1))
6912 <= HOST_BITS_PER_WIDE_INT
6913 && host_integerp (and1, 1))
6915 unsigned HOST_WIDE_INT cst;
6917 cst = tree_low_cst (and1, 1);
6918 cst &= (HOST_WIDE_INT) -1
6919 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6920 change = (cst == 0);
6921 #ifdef LOAD_EXTEND_OP
6923 && !flag_syntax_only
6924 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6927 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6928 and0 = fold_convert (uns, and0);
6929 and1 = fold_convert (uns, and1);
6935 tem = build_int_cst_wide (type, TREE_INT_CST_LOW (and1),
6936 TREE_INT_CST_HIGH (and1));
6937 tem = force_fit_type (tem, 0, TREE_OVERFLOW (and1),
6938 TREE_CONSTANT_OVERFLOW (and1));
6939 return fold_build2 (BIT_AND_EXPR, type,
6940 fold_convert (type, and0), tem);
6944 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6945 T2 being pointers to types of the same size. */
6946 if (POINTER_TYPE_P (type)
6947 && BINARY_CLASS_P (arg0)
6948 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6949 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6951 tree arg00 = TREE_OPERAND (arg0, 0);
6953 tree t1 = TREE_TYPE (arg00);
6954 tree tt0 = TREE_TYPE (t0);
6955 tree tt1 = TREE_TYPE (t1);
6956 tree s0 = TYPE_SIZE (tt0);
6957 tree s1 = TYPE_SIZE (tt1);
6959 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6960 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6961 TREE_OPERAND (arg0, 1));
6964 tem = fold_convert_const (code, type, arg0);
6965 return tem ? tem : NULL_TREE;
6967 case VIEW_CONVERT_EXPR:
6968 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
6969 return build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
6973 if (negate_expr_p (arg0))
6974 return fold_convert (type, negate_expr (arg0));
6975 /* Convert - (~A) to A + 1. */
6976 if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == BIT_NOT_EXPR)
6977 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (arg0, 0),
6978 build_int_cst (type, 1));
6982 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
6983 return fold_abs_const (arg0, type);
6984 else if (TREE_CODE (arg0) == NEGATE_EXPR)
6985 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
6986 /* Convert fabs((double)float) into (double)fabsf(float). */
6987 else if (TREE_CODE (arg0) == NOP_EXPR
6988 && TREE_CODE (type) == REAL_TYPE)
6990 tree targ0 = strip_float_extensions (arg0);
6992 return fold_convert (type, fold_build1 (ABS_EXPR,
6996 else if (tree_expr_nonnegative_p (arg0))
6999 /* Strip sign ops from argument. */
7000 if (TREE_CODE (type) == REAL_TYPE)
7002 tem = fold_strip_sign_ops (arg0);
7004 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
7009 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7010 return fold_convert (type, arg0);
7011 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7012 return build2 (COMPLEX_EXPR, type,
7013 TREE_OPERAND (arg0, 0),
7014 negate_expr (TREE_OPERAND (arg0, 1)));
7015 else if (TREE_CODE (arg0) == COMPLEX_CST)
7016 return build_complex (type, TREE_REALPART (arg0),
7017 negate_expr (TREE_IMAGPART (arg0)));
7018 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7019 return fold_build2 (TREE_CODE (arg0), type,
7020 fold_build1 (CONJ_EXPR, type,
7021 TREE_OPERAND (arg0, 0)),
7022 fold_build1 (CONJ_EXPR, type,
7023 TREE_OPERAND (arg0, 1)));
7024 else if (TREE_CODE (arg0) == CONJ_EXPR)
7025 return TREE_OPERAND (arg0, 0);
7029 if (TREE_CODE (arg0) == INTEGER_CST)
7030 return fold_not_const (arg0, type);
7031 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
7032 return TREE_OPERAND (arg0, 0);
7033 /* Convert ~ (-A) to A - 1. */
7034 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
7035 return fold_build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
7036 build_int_cst (type, 1));
7037 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
7038 else if (INTEGRAL_TYPE_P (type)
7039 && ((TREE_CODE (arg0) == MINUS_EXPR
7040 && integer_onep (TREE_OPERAND (arg0, 1)))
7041 || (TREE_CODE (arg0) == PLUS_EXPR
7042 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
7043 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
7044 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
7045 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7046 && (tem = fold_unary (BIT_NOT_EXPR, type,
7048 TREE_OPERAND (arg0, 0)))))
7049 return fold_build2 (BIT_XOR_EXPR, type, tem,
7050 fold_convert (type, TREE_OPERAND (arg0, 1)));
7051 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7052 && (tem = fold_unary (BIT_NOT_EXPR, type,
7054 TREE_OPERAND (arg0, 1)))))
7055 return fold_build2 (BIT_XOR_EXPR, type,
7056 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
7060 case TRUTH_NOT_EXPR:
7061 /* The argument to invert_truthvalue must have Boolean type. */
7062 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7063 arg0 = fold_convert (boolean_type_node, arg0);
7065 /* Note that the operand of this must be an int
7066 and its values must be 0 or 1.
7067 ("true" is a fixed value perhaps depending on the language,
7068 but we don't handle values other than 1 correctly yet.) */
7069 tem = invert_truthvalue (arg0);
7070 /* Avoid infinite recursion. */
7071 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7073 return fold_convert (type, tem);
7076 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7078 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7079 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7080 TREE_OPERAND (arg0, 1));
7081 else if (TREE_CODE (arg0) == COMPLEX_CST)
7082 return TREE_REALPART (arg0);
7083 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7084 return fold_build2 (TREE_CODE (arg0), type,
7085 fold_build1 (REALPART_EXPR, type,
7086 TREE_OPERAND (arg0, 0)),
7087 fold_build1 (REALPART_EXPR, type,
7088 TREE_OPERAND (arg0, 1)));
7092 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7093 return fold_convert (type, integer_zero_node);
7094 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7095 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7096 TREE_OPERAND (arg0, 0));
7097 else if (TREE_CODE (arg0) == COMPLEX_CST)
7098 return TREE_IMAGPART (arg0);
7099 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7100 return fold_build2 (TREE_CODE (arg0), type,
7101 fold_build1 (IMAGPART_EXPR, type,
7102 TREE_OPERAND (arg0, 0)),
7103 fold_build1 (IMAGPART_EXPR, type,
7104 TREE_OPERAND (arg0, 1)));
7109 } /* switch (code) */
7112 /* Fold a binary expression of code CODE and type TYPE with operands
7113 OP0 and OP1. Return the folded expression if folding is
7114 successful. Otherwise, return NULL_TREE. */
7117 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
7119 tree t1 = NULL_TREE;
7121 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
7122 enum tree_code_class kind = TREE_CODE_CLASS (code);
7124 /* WINS will be nonzero when the switch is done
7125 if all operands are constant. */
7128 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7129 && TREE_CODE_LENGTH (code) == 2);
7138 /* Strip any conversions that don't change the mode. This is
7139 safe for every expression, except for a comparison expression
7140 because its signedness is derived from its operands. So, in
7141 the latter case, only strip conversions that don't change the
7144 Note that this is done as an internal manipulation within the
7145 constant folder, in order to find the simplest representation
7146 of the arguments so that their form can be studied. In any
7147 cases, the appropriate type conversions should be put back in
7148 the tree that will get out of the constant folder. */
7149 if (kind == tcc_comparison)
7150 STRIP_SIGN_NOPS (arg0);
7154 if (TREE_CODE (arg0) == COMPLEX_CST)
7155 subop = TREE_REALPART (arg0);
7159 if (TREE_CODE (subop) != INTEGER_CST
7160 && TREE_CODE (subop) != REAL_CST)
7161 /* Note that TREE_CONSTANT isn't enough:
7162 static var addresses are constant but we can't
7163 do arithmetic on them. */
7171 /* Strip any conversions that don't change the mode. This is
7172 safe for every expression, except for a comparison expression
7173 because its signedness is derived from its operands. So, in
7174 the latter case, only strip conversions that don't change the
7177 Note that this is done as an internal manipulation within the
7178 constant folder, in order to find the simplest representation
7179 of the arguments so that their form can be studied. In any
7180 cases, the appropriate type conversions should be put back in
7181 the tree that will get out of the constant folder. */
7182 if (kind == tcc_comparison)
7183 STRIP_SIGN_NOPS (arg1);
7187 if (TREE_CODE (arg1) == COMPLEX_CST)
7188 subop = TREE_REALPART (arg1);
7192 if (TREE_CODE (subop) != INTEGER_CST
7193 && TREE_CODE (subop) != REAL_CST)
7194 /* Note that TREE_CONSTANT isn't enough:
7195 static var addresses are constant but we can't
7196 do arithmetic on them. */
7200 /* If this is a commutative operation, and ARG0 is a constant, move it
7201 to ARG1 to reduce the number of tests below. */
7202 if (commutative_tree_code (code)
7203 && tree_swap_operands_p (arg0, arg1, true))
7204 return fold_build2 (code, type, op1, op0);
7206 /* Now WINS is set as described above,
7207 ARG0 is the first operand of EXPR,
7208 and ARG1 is the second operand (if it has more than one operand).
7210 First check for cases where an arithmetic operation is applied to a
7211 compound, conditional, or comparison operation. Push the arithmetic
7212 operation inside the compound or conditional to see if any folding
7213 can then be done. Convert comparison to conditional for this purpose.
7214 The also optimizes non-constant cases that used to be done in
7217 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
7218 one of the operands is a comparison and the other is a comparison, a
7219 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
7220 code below would make the expression more complex. Change it to a
7221 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
7222 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
7224 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
7225 || code == EQ_EXPR || code == NE_EXPR)
7226 && ((truth_value_p (TREE_CODE (arg0))
7227 && (truth_value_p (TREE_CODE (arg1))
7228 || (TREE_CODE (arg1) == BIT_AND_EXPR
7229 && integer_onep (TREE_OPERAND (arg1, 1)))))
7230 || (truth_value_p (TREE_CODE (arg1))
7231 && (truth_value_p (TREE_CODE (arg0))
7232 || (TREE_CODE (arg0) == BIT_AND_EXPR
7233 && integer_onep (TREE_OPERAND (arg0, 1)))))))
7235 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
7236 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
7239 fold_convert (boolean_type_node, arg0),
7240 fold_convert (boolean_type_node, arg1));
7242 if (code == EQ_EXPR)
7243 tem = invert_truthvalue (tem);
7245 return fold_convert (type, tem);
7248 if (TREE_CODE_CLASS (code) == tcc_comparison
7249 && TREE_CODE (arg0) == COMPOUND_EXPR)
7250 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7251 fold_build2 (code, type, TREE_OPERAND (arg0, 1), arg1));
7252 else if (TREE_CODE_CLASS (code) == tcc_comparison
7253 && TREE_CODE (arg1) == COMPOUND_EXPR)
7254 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
7255 fold_build2 (code, type, arg0, TREE_OPERAND (arg1, 1)));
7256 else if (TREE_CODE_CLASS (code) == tcc_binary
7257 || TREE_CODE_CLASS (code) == tcc_comparison)
7259 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7260 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7261 fold_build2 (code, type, TREE_OPERAND (arg0, 1),
7263 if (TREE_CODE (arg1) == COMPOUND_EXPR
7264 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
7265 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
7266 fold_build2 (code, type,
7267 arg0, TREE_OPERAND (arg1, 1)));
7269 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
7271 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
7273 /*cond_first_p=*/1);
7274 if (tem != NULL_TREE)
7278 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
7280 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
7282 /*cond_first_p=*/0);
7283 if (tem != NULL_TREE)
7291 /* A + (-B) -> A - B */
7292 if (TREE_CODE (arg1) == NEGATE_EXPR)
7293 return fold_build2 (MINUS_EXPR, type,
7294 fold_convert (type, arg0),
7295 fold_convert (type, TREE_OPERAND (arg1, 0)));
7296 /* (-A) + B -> B - A */
7297 if (TREE_CODE (arg0) == NEGATE_EXPR
7298 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
7299 return fold_build2 (MINUS_EXPR, type,
7300 fold_convert (type, arg1),
7301 fold_convert (type, TREE_OPERAND (arg0, 0)));
7302 /* Convert ~A + 1 to -A. */
7303 if (INTEGRAL_TYPE_P (type)
7304 && TREE_CODE (arg0) == BIT_NOT_EXPR
7305 && integer_onep (arg1))
7306 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
7308 if (TREE_CODE (type) == COMPLEX_TYPE)
7310 tem = fold_complex_add (type, arg0, arg1, PLUS_EXPR);
7315 if (! FLOAT_TYPE_P (type))
7317 if (integer_zerop (arg1))
7318 return non_lvalue (fold_convert (type, arg0));
7320 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
7321 with a constant, and the two constants have no bits in common,
7322 we should treat this as a BIT_IOR_EXPR since this may produce more
7324 if (TREE_CODE (arg0) == BIT_AND_EXPR
7325 && TREE_CODE (arg1) == BIT_AND_EXPR
7326 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7327 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7328 && integer_zerop (const_binop (BIT_AND_EXPR,
7329 TREE_OPERAND (arg0, 1),
7330 TREE_OPERAND (arg1, 1), 0)))
7332 code = BIT_IOR_EXPR;
7336 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
7337 (plus (plus (mult) (mult)) (foo)) so that we can
7338 take advantage of the factoring cases below. */
7339 if (((TREE_CODE (arg0) == PLUS_EXPR
7340 || TREE_CODE (arg0) == MINUS_EXPR)
7341 && TREE_CODE (arg1) == MULT_EXPR)
7342 || ((TREE_CODE (arg1) == PLUS_EXPR
7343 || TREE_CODE (arg1) == MINUS_EXPR)
7344 && TREE_CODE (arg0) == MULT_EXPR))
7346 tree parg0, parg1, parg, marg;
7347 enum tree_code pcode;
7349 if (TREE_CODE (arg1) == MULT_EXPR)
7350 parg = arg0, marg = arg1;
7352 parg = arg1, marg = arg0;
7353 pcode = TREE_CODE (parg);
7354 parg0 = TREE_OPERAND (parg, 0);
7355 parg1 = TREE_OPERAND (parg, 1);
7359 if (TREE_CODE (parg0) == MULT_EXPR
7360 && TREE_CODE (parg1) != MULT_EXPR)
7361 return fold_build2 (pcode, type,
7362 fold_build2 (PLUS_EXPR, type,
7363 fold_convert (type, parg0),
7364 fold_convert (type, marg)),
7365 fold_convert (type, parg1));
7366 if (TREE_CODE (parg0) != MULT_EXPR
7367 && TREE_CODE (parg1) == MULT_EXPR)
7368 return fold_build2 (PLUS_EXPR, type,
7369 fold_convert (type, parg0),
7370 fold_build2 (pcode, type,
7371 fold_convert (type, marg),
7376 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
7378 tree arg00, arg01, arg10, arg11;
7379 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7381 /* (A * C) + (B * C) -> (A+B) * C.
7382 We are most concerned about the case where C is a constant,
7383 but other combinations show up during loop reduction. Since
7384 it is not difficult, try all four possibilities. */
7386 arg00 = TREE_OPERAND (arg0, 0);
7387 arg01 = TREE_OPERAND (arg0, 1);
7388 arg10 = TREE_OPERAND (arg1, 0);
7389 arg11 = TREE_OPERAND (arg1, 1);
7392 if (operand_equal_p (arg01, arg11, 0))
7393 same = arg01, alt0 = arg00, alt1 = arg10;
7394 else if (operand_equal_p (arg00, arg10, 0))
7395 same = arg00, alt0 = arg01, alt1 = arg11;
7396 else if (operand_equal_p (arg00, arg11, 0))
7397 same = arg00, alt0 = arg01, alt1 = arg10;
7398 else if (operand_equal_p (arg01, arg10, 0))
7399 same = arg01, alt0 = arg00, alt1 = arg11;
7401 /* No identical multiplicands; see if we can find a common
7402 power-of-two factor in non-power-of-two multiplies. This
7403 can help in multi-dimensional array access. */
7404 else if (TREE_CODE (arg01) == INTEGER_CST
7405 && TREE_CODE (arg11) == INTEGER_CST
7406 && TREE_INT_CST_HIGH (arg01) == 0
7407 && TREE_INT_CST_HIGH (arg11) == 0)
7409 HOST_WIDE_INT int01, int11, tmp;
7410 int01 = TREE_INT_CST_LOW (arg01);
7411 int11 = TREE_INT_CST_LOW (arg11);
7413 /* Move min of absolute values to int11. */
7414 if ((int01 >= 0 ? int01 : -int01)
7415 < (int11 >= 0 ? int11 : -int11))
7417 tmp = int01, int01 = int11, int11 = tmp;
7418 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7419 alt0 = arg01, arg01 = arg11, arg11 = alt0;
7422 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
7424 alt0 = fold_build2 (MULT_EXPR, type, arg00,
7425 build_int_cst (NULL_TREE,
7433 return fold_build2 (MULT_EXPR, type,
7434 fold_build2 (PLUS_EXPR, type,
7435 fold_convert (type, alt0),
7436 fold_convert (type, alt1)),
7437 fold_convert (type, same));
7440 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
7441 of the array. Loop optimizer sometimes produce this type of
7443 if (TREE_CODE (arg0) == ADDR_EXPR
7444 && TREE_CODE (arg1) == MULT_EXPR)
7446 tem = try_move_mult_to_index (PLUS_EXPR, arg0, arg1);
7448 return fold_convert (type, fold (tem));
7450 else if (TREE_CODE (arg1) == ADDR_EXPR
7451 && TREE_CODE (arg0) == MULT_EXPR)
7453 tem = try_move_mult_to_index (PLUS_EXPR, arg1, arg0);
7455 return fold_convert (type, fold (tem));
7460 /* See if ARG1 is zero and X + ARG1 reduces to X. */
7461 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
7462 return non_lvalue (fold_convert (type, arg0));
7464 /* Likewise if the operands are reversed. */
7465 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7466 return non_lvalue (fold_convert (type, arg1));
7468 /* Convert X + -C into X - C. */
7469 if (TREE_CODE (arg1) == REAL_CST
7470 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
7472 tem = fold_negate_const (arg1, type);
7473 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
7474 return fold_build2 (MINUS_EXPR, type,
7475 fold_convert (type, arg0),
7476 fold_convert (type, tem));
7479 /* Convert x+x into x*2.0. */
7480 if (operand_equal_p (arg0, arg1, 0)
7481 && SCALAR_FLOAT_TYPE_P (type))
7482 return fold_build2 (MULT_EXPR, type, arg0,
7483 build_real (type, dconst2));
7485 /* Convert x*c+x into x*(c+1). */
7486 if (flag_unsafe_math_optimizations
7487 && TREE_CODE (arg0) == MULT_EXPR
7488 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7489 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
7490 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7494 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
7495 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7496 return fold_build2 (MULT_EXPR, type, arg1,
7497 build_real (type, c));
7500 /* Convert x+x*c into x*(c+1). */
7501 if (flag_unsafe_math_optimizations
7502 && TREE_CODE (arg1) == MULT_EXPR
7503 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
7504 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
7505 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
7509 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
7510 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7511 return fold_build2 (MULT_EXPR, type, arg0,
7512 build_real (type, c));
7515 /* Convert x*c1+x*c2 into x*(c1+c2). */
7516 if (flag_unsafe_math_optimizations
7517 && TREE_CODE (arg0) == MULT_EXPR
7518 && TREE_CODE (arg1) == MULT_EXPR
7519 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7520 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
7521 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
7522 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
7523 && operand_equal_p (TREE_OPERAND (arg0, 0),
7524 TREE_OPERAND (arg1, 0), 0))
7526 REAL_VALUE_TYPE c1, c2;
7528 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
7529 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
7530 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
7531 return fold_build2 (MULT_EXPR, type,
7532 TREE_OPERAND (arg0, 0),
7533 build_real (type, c1));
7535 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
7536 if (flag_unsafe_math_optimizations
7537 && TREE_CODE (arg1) == PLUS_EXPR
7538 && TREE_CODE (arg0) != MULT_EXPR)
7540 tree tree10 = TREE_OPERAND (arg1, 0);
7541 tree tree11 = TREE_OPERAND (arg1, 1);
7542 if (TREE_CODE (tree11) == MULT_EXPR
7543 && TREE_CODE (tree10) == MULT_EXPR)
7546 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
7547 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
7550 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
7551 if (flag_unsafe_math_optimizations
7552 && TREE_CODE (arg0) == PLUS_EXPR
7553 && TREE_CODE (arg1) != MULT_EXPR)
7555 tree tree00 = TREE_OPERAND (arg0, 0);
7556 tree tree01 = TREE_OPERAND (arg0, 1);
7557 if (TREE_CODE (tree01) == MULT_EXPR
7558 && TREE_CODE (tree00) == MULT_EXPR)
7561 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
7562 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
7568 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
7569 is a rotate of A by C1 bits. */
7570 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
7571 is a rotate of A by B bits. */
7573 enum tree_code code0, code1;
7574 code0 = TREE_CODE (arg0);
7575 code1 = TREE_CODE (arg1);
7576 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
7577 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
7578 && operand_equal_p (TREE_OPERAND (arg0, 0),
7579 TREE_OPERAND (arg1, 0), 0)
7580 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7582 tree tree01, tree11;
7583 enum tree_code code01, code11;
7585 tree01 = TREE_OPERAND (arg0, 1);
7586 tree11 = TREE_OPERAND (arg1, 1);
7587 STRIP_NOPS (tree01);
7588 STRIP_NOPS (tree11);
7589 code01 = TREE_CODE (tree01);
7590 code11 = TREE_CODE (tree11);
7591 if (code01 == INTEGER_CST
7592 && code11 == INTEGER_CST
7593 && TREE_INT_CST_HIGH (tree01) == 0
7594 && TREE_INT_CST_HIGH (tree11) == 0
7595 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
7596 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
7597 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
7598 code0 == LSHIFT_EXPR ? tree01 : tree11);
7599 else if (code11 == MINUS_EXPR)
7601 tree tree110, tree111;
7602 tree110 = TREE_OPERAND (tree11, 0);
7603 tree111 = TREE_OPERAND (tree11, 1);
7604 STRIP_NOPS (tree110);
7605 STRIP_NOPS (tree111);
7606 if (TREE_CODE (tree110) == INTEGER_CST
7607 && 0 == compare_tree_int (tree110,
7609 (TREE_TYPE (TREE_OPERAND
7611 && operand_equal_p (tree01, tree111, 0))
7612 return build2 ((code0 == LSHIFT_EXPR
7615 type, TREE_OPERAND (arg0, 0), tree01);
7617 else if (code01 == MINUS_EXPR)
7619 tree tree010, tree011;
7620 tree010 = TREE_OPERAND (tree01, 0);
7621 tree011 = TREE_OPERAND (tree01, 1);
7622 STRIP_NOPS (tree010);
7623 STRIP_NOPS (tree011);
7624 if (TREE_CODE (tree010) == INTEGER_CST
7625 && 0 == compare_tree_int (tree010,
7627 (TREE_TYPE (TREE_OPERAND
7629 && operand_equal_p (tree11, tree011, 0))
7630 return build2 ((code0 != LSHIFT_EXPR
7633 type, TREE_OPERAND (arg0, 0), tree11);
7639 /* In most languages, can't associate operations on floats through
7640 parentheses. Rather than remember where the parentheses were, we
7641 don't associate floats at all, unless the user has specified
7642 -funsafe-math-optimizations. */
7645 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7647 tree var0, con0, lit0, minus_lit0;
7648 tree var1, con1, lit1, minus_lit1;
7650 /* Split both trees into variables, constants, and literals. Then
7651 associate each group together, the constants with literals,
7652 then the result with variables. This increases the chances of
7653 literals being recombined later and of generating relocatable
7654 expressions for the sum of a constant and literal. */
7655 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
7656 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
7657 code == MINUS_EXPR);
7659 /* Only do something if we found more than two objects. Otherwise,
7660 nothing has changed and we risk infinite recursion. */
7661 if (2 < ((var0 != 0) + (var1 != 0)
7662 + (con0 != 0) + (con1 != 0)
7663 + (lit0 != 0) + (lit1 != 0)
7664 + (minus_lit0 != 0) + (minus_lit1 != 0)))
7666 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
7667 if (code == MINUS_EXPR)
7670 var0 = associate_trees (var0, var1, code, type);
7671 con0 = associate_trees (con0, con1, code, type);
7672 lit0 = associate_trees (lit0, lit1, code, type);
7673 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
7675 /* Preserve the MINUS_EXPR if the negative part of the literal is
7676 greater than the positive part. Otherwise, the multiplicative
7677 folding code (i.e extract_muldiv) may be fooled in case
7678 unsigned constants are subtracted, like in the following
7679 example: ((X*2 + 4) - 8U)/2. */
7680 if (minus_lit0 && lit0)
7682 if (TREE_CODE (lit0) == INTEGER_CST
7683 && TREE_CODE (minus_lit0) == INTEGER_CST
7684 && tree_int_cst_lt (lit0, minus_lit0))
7686 minus_lit0 = associate_trees (minus_lit0, lit0,
7692 lit0 = associate_trees (lit0, minus_lit0,
7700 return fold_convert (type,
7701 associate_trees (var0, minus_lit0,
7705 con0 = associate_trees (con0, minus_lit0,
7707 return fold_convert (type,
7708 associate_trees (var0, con0,
7713 con0 = associate_trees (con0, lit0, code, type);
7714 return fold_convert (type, associate_trees (var0, con0,
7721 t1 = const_binop (code, arg0, arg1, 0);
7722 if (t1 != NULL_TREE)
7724 /* The return value should always have
7725 the same type as the original expression. */
7726 if (TREE_TYPE (t1) != type)
7727 t1 = fold_convert (type, t1);
7734 /* A - (-B) -> A + B */
7735 if (TREE_CODE (arg1) == NEGATE_EXPR)
7736 return fold_build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0));
7737 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
7738 if (TREE_CODE (arg0) == NEGATE_EXPR
7739 && (FLOAT_TYPE_P (type)
7740 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
7741 && negate_expr_p (arg1)
7742 && reorder_operands_p (arg0, arg1))
7743 return fold_build2 (MINUS_EXPR, type, negate_expr (arg1),
7744 TREE_OPERAND (arg0, 0));
7745 /* Convert -A - 1 to ~A. */
7746 if (INTEGRAL_TYPE_P (type)
7747 && TREE_CODE (arg0) == NEGATE_EXPR
7748 && integer_onep (arg1))
7749 return fold_build1 (BIT_NOT_EXPR, type, TREE_OPERAND (arg0, 0));
7751 /* Convert -1 - A to ~A. */
7752 if (INTEGRAL_TYPE_P (type)
7753 && integer_all_onesp (arg0))
7754 return fold_build1 (BIT_NOT_EXPR, type, arg1);
7756 if (TREE_CODE (type) == COMPLEX_TYPE)
7758 tem = fold_complex_add (type, arg0, arg1, MINUS_EXPR);
7763 if (! FLOAT_TYPE_P (type))
7765 if (! wins && integer_zerop (arg0))
7766 return negate_expr (fold_convert (type, arg1));
7767 if (integer_zerop (arg1))
7768 return non_lvalue (fold_convert (type, arg0));
7770 /* Fold A - (A & B) into ~B & A. */
7771 if (!TREE_SIDE_EFFECTS (arg0)
7772 && TREE_CODE (arg1) == BIT_AND_EXPR)
7774 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
7775 return fold_build2 (BIT_AND_EXPR, type,
7776 fold_build1 (BIT_NOT_EXPR, type,
7777 TREE_OPERAND (arg1, 0)),
7779 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7780 return fold_build2 (BIT_AND_EXPR, type,
7781 fold_build1 (BIT_NOT_EXPR, type,
7782 TREE_OPERAND (arg1, 1)),
7786 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
7787 any power of 2 minus 1. */
7788 if (TREE_CODE (arg0) == BIT_AND_EXPR
7789 && TREE_CODE (arg1) == BIT_AND_EXPR
7790 && operand_equal_p (TREE_OPERAND (arg0, 0),
7791 TREE_OPERAND (arg1, 0), 0))
7793 tree mask0 = TREE_OPERAND (arg0, 1);
7794 tree mask1 = TREE_OPERAND (arg1, 1);
7795 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
7797 if (operand_equal_p (tem, mask1, 0))
7799 tem = fold_build2 (BIT_XOR_EXPR, type,
7800 TREE_OPERAND (arg0, 0), mask1);
7801 return fold_build2 (MINUS_EXPR, type, tem, mask1);
7806 /* See if ARG1 is zero and X - ARG1 reduces to X. */
7807 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
7808 return non_lvalue (fold_convert (type, arg0));
7810 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
7811 ARG0 is zero and X + ARG0 reduces to X, since that would mean
7812 (-ARG1 + ARG0) reduces to -ARG1. */
7813 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7814 return negate_expr (fold_convert (type, arg1));
7816 /* Fold &x - &x. This can happen from &x.foo - &x.
7817 This is unsafe for certain floats even in non-IEEE formats.
7818 In IEEE, it is unsafe because it does wrong for NaNs.
7819 Also note that operand_equal_p is always false if an operand
7822 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
7823 && operand_equal_p (arg0, arg1, 0))
7824 return fold_convert (type, integer_zero_node);
7826 /* A - B -> A + (-B) if B is easily negatable. */
7827 if (!wins && negate_expr_p (arg1)
7828 && ((FLOAT_TYPE_P (type)
7829 /* Avoid this transformation if B is a positive REAL_CST. */
7830 && (TREE_CODE (arg1) != REAL_CST
7831 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
7832 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
7833 return fold_build2 (PLUS_EXPR, type, arg0, negate_expr (arg1));
7835 /* Try folding difference of addresses. */
7839 if ((TREE_CODE (arg0) == ADDR_EXPR
7840 || TREE_CODE (arg1) == ADDR_EXPR)
7841 && ptr_difference_const (arg0, arg1, &diff))
7842 return build_int_cst_type (type, diff);
7845 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
7846 of the array. Loop optimizer sometimes produce this type of
7848 if (TREE_CODE (arg0) == ADDR_EXPR
7849 && TREE_CODE (arg1) == MULT_EXPR)
7851 tem = try_move_mult_to_index (MINUS_EXPR, arg0, arg1);
7853 return fold_convert (type, fold (tem));
7856 if (TREE_CODE (arg0) == MULT_EXPR
7857 && TREE_CODE (arg1) == MULT_EXPR
7858 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7860 /* (A * C) - (B * C) -> (A-B) * C. */
7861 if (operand_equal_p (TREE_OPERAND (arg0, 1),
7862 TREE_OPERAND (arg1, 1), 0))
7863 return fold_build2 (MULT_EXPR, type,
7864 fold_build2 (MINUS_EXPR, type,
7865 TREE_OPERAND (arg0, 0),
7866 TREE_OPERAND (arg1, 0)),
7867 TREE_OPERAND (arg0, 1));
7868 /* (A * C1) - (A * C2) -> A * (C1-C2). */
7869 if (operand_equal_p (TREE_OPERAND (arg0, 0),
7870 TREE_OPERAND (arg1, 0), 0))
7871 return fold_build2 (MULT_EXPR, type,
7872 TREE_OPERAND (arg0, 0),
7873 fold_build2 (MINUS_EXPR, type,
7874 TREE_OPERAND (arg0, 1),
7875 TREE_OPERAND (arg1, 1)));
7881 /* (-A) * (-B) -> A * B */
7882 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7883 return fold_build2 (MULT_EXPR, type,
7884 TREE_OPERAND (arg0, 0),
7885 negate_expr (arg1));
7886 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7887 return fold_build2 (MULT_EXPR, type,
7889 TREE_OPERAND (arg1, 0));
7891 if (TREE_CODE (type) == COMPLEX_TYPE)
7893 tem = fold_complex_mult (type, arg0, arg1);
7898 if (! FLOAT_TYPE_P (type))
7900 if (integer_zerop (arg1))
7901 return omit_one_operand (type, arg1, arg0);
7902 if (integer_onep (arg1))
7903 return non_lvalue (fold_convert (type, arg0));
7904 /* Transform x * -1 into -x. */
7905 if (integer_all_onesp (arg1))
7906 return fold_convert (type, negate_expr (arg0));
7908 /* (a * (1 << b)) is (a << b) */
7909 if (TREE_CODE (arg1) == LSHIFT_EXPR
7910 && integer_onep (TREE_OPERAND (arg1, 0)))
7911 return fold_build2 (LSHIFT_EXPR, type, arg0,
7912 TREE_OPERAND (arg1, 1));
7913 if (TREE_CODE (arg0) == LSHIFT_EXPR
7914 && integer_onep (TREE_OPERAND (arg0, 0)))
7915 return fold_build2 (LSHIFT_EXPR, type, arg1,
7916 TREE_OPERAND (arg0, 1));
7918 if (TREE_CODE (arg1) == INTEGER_CST
7919 && 0 != (tem = extract_muldiv (op0,
7920 fold_convert (type, arg1),
7922 return fold_convert (type, tem);
7927 /* Maybe fold x * 0 to 0. The expressions aren't the same
7928 when x is NaN, since x * 0 is also NaN. Nor are they the
7929 same in modes with signed zeros, since multiplying a
7930 negative value by 0 gives -0, not +0. */
7931 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
7932 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
7933 && real_zerop (arg1))
7934 return omit_one_operand (type, arg1, arg0);
7935 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7936 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7937 && real_onep (arg1))
7938 return non_lvalue (fold_convert (type, arg0));
7940 /* Transform x * -1.0 into -x. */
7941 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7942 && real_minus_onep (arg1))
7943 return fold_convert (type, negate_expr (arg0));
7945 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7946 if (flag_unsafe_math_optimizations
7947 && TREE_CODE (arg0) == RDIV_EXPR
7948 && TREE_CODE (arg1) == REAL_CST
7949 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
7951 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
7954 return fold_build2 (RDIV_EXPR, type, tem,
7955 TREE_OPERAND (arg0, 1));
7958 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
7959 if (operand_equal_p (arg0, arg1, 0))
7961 tree tem = fold_strip_sign_ops (arg0);
7962 if (tem != NULL_TREE)
7964 tem = fold_convert (type, tem);
7965 return fold_build2 (MULT_EXPR, type, tem, tem);
7969 if (flag_unsafe_math_optimizations)
7971 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7972 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7974 /* Optimizations of root(...)*root(...). */
7975 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
7977 tree rootfn, arg, arglist;
7978 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7979 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7981 /* Optimize sqrt(x)*sqrt(x) as x. */
7982 if (BUILTIN_SQRT_P (fcode0)
7983 && operand_equal_p (arg00, arg10, 0)
7984 && ! HONOR_SNANS (TYPE_MODE (type)))
7987 /* Optimize root(x)*root(y) as root(x*y). */
7988 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7989 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
7990 arglist = build_tree_list (NULL_TREE, arg);
7991 return build_function_call_expr (rootfn, arglist);
7994 /* Optimize expN(x)*expN(y) as expN(x+y). */
7995 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
7997 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7998 tree arg = fold_build2 (PLUS_EXPR, type,
7999 TREE_VALUE (TREE_OPERAND (arg0, 1)),
8000 TREE_VALUE (TREE_OPERAND (arg1, 1)));
8001 tree arglist = build_tree_list (NULL_TREE, arg);
8002 return build_function_call_expr (expfn, arglist);
8005 /* Optimizations of pow(...)*pow(...). */
8006 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
8007 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
8008 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
8010 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
8011 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
8013 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
8014 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
8017 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
8018 if (operand_equal_p (arg01, arg11, 0))
8020 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8021 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
8022 tree arglist = tree_cons (NULL_TREE, arg,
8023 build_tree_list (NULL_TREE,
8025 return build_function_call_expr (powfn, arglist);
8028 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
8029 if (operand_equal_p (arg00, arg10, 0))
8031 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8032 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
8033 tree arglist = tree_cons (NULL_TREE, arg00,
8034 build_tree_list (NULL_TREE,
8036 return build_function_call_expr (powfn, arglist);
8040 /* Optimize tan(x)*cos(x) as sin(x). */
8041 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
8042 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
8043 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
8044 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
8045 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
8046 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
8047 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8048 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8050 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
8052 if (sinfn != NULL_TREE)
8053 return build_function_call_expr (sinfn,
8054 TREE_OPERAND (arg0, 1));
8057 /* Optimize x*pow(x,c) as pow(x,c+1). */
8058 if (fcode1 == BUILT_IN_POW
8059 || fcode1 == BUILT_IN_POWF
8060 || fcode1 == BUILT_IN_POWL)
8062 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
8063 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
8065 if (TREE_CODE (arg11) == REAL_CST
8066 && ! TREE_CONSTANT_OVERFLOW (arg11)
8067 && operand_equal_p (arg0, arg10, 0))
8069 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8073 c = TREE_REAL_CST (arg11);
8074 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
8075 arg = build_real (type, c);
8076 arglist = build_tree_list (NULL_TREE, arg);
8077 arglist = tree_cons (NULL_TREE, arg0, arglist);
8078 return build_function_call_expr (powfn, arglist);
8082 /* Optimize pow(x,c)*x as pow(x,c+1). */
8083 if (fcode0 == BUILT_IN_POW
8084 || fcode0 == BUILT_IN_POWF
8085 || fcode0 == BUILT_IN_POWL)
8087 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
8088 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
8090 if (TREE_CODE (arg01) == REAL_CST
8091 && ! TREE_CONSTANT_OVERFLOW (arg01)
8092 && operand_equal_p (arg1, arg00, 0))
8094 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8098 c = TREE_REAL_CST (arg01);
8099 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
8100 arg = build_real (type, c);
8101 arglist = build_tree_list (NULL_TREE, arg);
8102 arglist = tree_cons (NULL_TREE, arg1, arglist);
8103 return build_function_call_expr (powfn, arglist);
8107 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
8109 && operand_equal_p (arg0, arg1, 0))
8111 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
8115 tree arg = build_real (type, dconst2);
8116 tree arglist = build_tree_list (NULL_TREE, arg);
8117 arglist = tree_cons (NULL_TREE, arg0, arglist);
8118 return build_function_call_expr (powfn, arglist);
8127 if (integer_all_onesp (arg1))
8128 return omit_one_operand (type, arg1, arg0);
8129 if (integer_zerop (arg1))
8130 return non_lvalue (fold_convert (type, arg0));
8131 if (operand_equal_p (arg0, arg1, 0))
8132 return non_lvalue (fold_convert (type, arg0));
8135 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8136 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8138 t1 = build_int_cst (type, -1);
8139 t1 = force_fit_type (t1, 0, false, false);
8140 return omit_one_operand (type, t1, arg1);
8144 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8145 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8147 t1 = build_int_cst (type, -1);
8148 t1 = force_fit_type (t1, 0, false, false);
8149 return omit_one_operand (type, t1, arg0);
8152 t1 = distribute_bit_expr (code, type, arg0, arg1);
8153 if (t1 != NULL_TREE)
8156 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
8158 This results in more efficient code for machines without a NAND
8159 instruction. Combine will canonicalize to the first form
8160 which will allow use of NAND instructions provided by the
8161 backend if they exist. */
8162 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8163 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8165 return fold_build1 (BIT_NOT_EXPR, type,
8166 build2 (BIT_AND_EXPR, type,
8167 TREE_OPERAND (arg0, 0),
8168 TREE_OPERAND (arg1, 0)));
8171 /* See if this can be simplified into a rotate first. If that
8172 is unsuccessful continue in the association code. */
8176 if (integer_zerop (arg1))
8177 return non_lvalue (fold_convert (type, arg0));
8178 if (integer_all_onesp (arg1))
8179 return fold_build1 (BIT_NOT_EXPR, type, arg0);
8180 if (operand_equal_p (arg0, arg1, 0))
8181 return omit_one_operand (type, integer_zero_node, arg0);
8184 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8185 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8187 t1 = build_int_cst (type, -1);
8188 t1 = force_fit_type (t1, 0, false, false);
8189 return omit_one_operand (type, t1, arg1);
8193 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8194 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8196 t1 = build_int_cst (type, -1);
8197 t1 = force_fit_type (t1, 0, false, false);
8198 return omit_one_operand (type, t1, arg0);
8201 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
8202 with a constant, and the two constants have no bits in common,
8203 we should treat this as a BIT_IOR_EXPR since this may produce more
8205 if (TREE_CODE (arg0) == BIT_AND_EXPR
8206 && TREE_CODE (arg1) == BIT_AND_EXPR
8207 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8208 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8209 && integer_zerop (const_binop (BIT_AND_EXPR,
8210 TREE_OPERAND (arg0, 1),
8211 TREE_OPERAND (arg1, 1), 0)))
8213 code = BIT_IOR_EXPR;
8217 /* Convert ~X ^ ~Y to X ^ Y. */
8218 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8219 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8220 return fold_build2 (code, type,
8221 fold_convert (type, TREE_OPERAND (arg0, 0)),
8222 fold_convert (type, TREE_OPERAND (arg1, 0)));
8224 /* See if this can be simplified into a rotate first. If that
8225 is unsuccessful continue in the association code. */
8229 if (integer_all_onesp (arg1))
8230 return non_lvalue (fold_convert (type, arg0));
8231 if (integer_zerop (arg1))
8232 return omit_one_operand (type, arg1, arg0);
8233 if (operand_equal_p (arg0, arg1, 0))
8234 return non_lvalue (fold_convert (type, arg0));
8236 /* ~X & X is always zero. */
8237 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8238 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8239 return omit_one_operand (type, integer_zero_node, arg1);
8241 /* X & ~X is always zero. */
8242 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8243 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8244 return omit_one_operand (type, integer_zero_node, arg0);
8246 t1 = distribute_bit_expr (code, type, arg0, arg1);
8247 if (t1 != NULL_TREE)
8249 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
8250 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
8251 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
8254 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
8256 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
8257 && (~TREE_INT_CST_LOW (arg1)
8258 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
8259 return fold_convert (type, TREE_OPERAND (arg0, 0));
8262 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
8264 This results in more efficient code for machines without a NOR
8265 instruction. Combine will canonicalize to the first form
8266 which will allow use of NOR instructions provided by the
8267 backend if they exist. */
8268 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8269 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8271 return fold_build1 (BIT_NOT_EXPR, type,
8272 build2 (BIT_IOR_EXPR, type,
8273 TREE_OPERAND (arg0, 0),
8274 TREE_OPERAND (arg1, 0)));
8280 /* Don't touch a floating-point divide by zero unless the mode
8281 of the constant can represent infinity. */
8282 if (TREE_CODE (arg1) == REAL_CST
8283 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
8284 && real_zerop (arg1))
8287 /* (-A) / (-B) -> A / B */
8288 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
8289 return fold_build2 (RDIV_EXPR, type,
8290 TREE_OPERAND (arg0, 0),
8291 negate_expr (arg1));
8292 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
8293 return fold_build2 (RDIV_EXPR, type,
8295 TREE_OPERAND (arg1, 0));
8297 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
8298 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
8299 && real_onep (arg1))
8300 return non_lvalue (fold_convert (type, arg0));
8302 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
8303 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
8304 && real_minus_onep (arg1))
8305 return non_lvalue (fold_convert (type, negate_expr (arg0)));
8307 /* If ARG1 is a constant, we can convert this to a multiply by the
8308 reciprocal. This does not have the same rounding properties,
8309 so only do this if -funsafe-math-optimizations. We can actually
8310 always safely do it if ARG1 is a power of two, but it's hard to
8311 tell if it is or not in a portable manner. */
8312 if (TREE_CODE (arg1) == REAL_CST)
8314 if (flag_unsafe_math_optimizations
8315 && 0 != (tem = const_binop (code, build_real (type, dconst1),
8317 return fold_build2 (MULT_EXPR, type, arg0, tem);
8318 /* Find the reciprocal if optimizing and the result is exact. */
8322 r = TREE_REAL_CST (arg1);
8323 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
8325 tem = build_real (type, r);
8326 return fold_build2 (MULT_EXPR, type, arg0, tem);
8330 /* Convert A/B/C to A/(B*C). */
8331 if (flag_unsafe_math_optimizations
8332 && TREE_CODE (arg0) == RDIV_EXPR)
8333 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
8334 fold_build2 (MULT_EXPR, type,
8335 TREE_OPERAND (arg0, 1), arg1));
8337 /* Convert A/(B/C) to (A/B)*C. */
8338 if (flag_unsafe_math_optimizations
8339 && TREE_CODE (arg1) == RDIV_EXPR)
8340 return fold_build2 (MULT_EXPR, type,
8341 fold_build2 (RDIV_EXPR, type, arg0,
8342 TREE_OPERAND (arg1, 0)),
8343 TREE_OPERAND (arg1, 1));
8345 /* Convert C1/(X*C2) into (C1/C2)/X. */
8346 if (flag_unsafe_math_optimizations
8347 && TREE_CODE (arg1) == MULT_EXPR
8348 && TREE_CODE (arg0) == REAL_CST
8349 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
8351 tree tem = const_binop (RDIV_EXPR, arg0,
8352 TREE_OPERAND (arg1, 1), 0);
8354 return fold_build2 (RDIV_EXPR, type, tem,
8355 TREE_OPERAND (arg1, 0));
8358 if (TREE_CODE (type) == COMPLEX_TYPE)
8360 tem = fold_complex_div (type, arg0, arg1, code);
8365 if (flag_unsafe_math_optimizations)
8367 enum built_in_function fcode = builtin_mathfn_code (arg1);
8368 /* Optimize x/expN(y) into x*expN(-y). */
8369 if (BUILTIN_EXPONENT_P (fcode))
8371 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8372 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
8373 tree arglist = build_tree_list (NULL_TREE,
8374 fold_convert (type, arg));
8375 arg1 = build_function_call_expr (expfn, arglist);
8376 return fold_build2 (MULT_EXPR, type, arg0, arg1);
8379 /* Optimize x/pow(y,z) into x*pow(y,-z). */
8380 if (fcode == BUILT_IN_POW
8381 || fcode == BUILT_IN_POWF
8382 || fcode == BUILT_IN_POWL)
8384 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8385 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
8386 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
8387 tree neg11 = fold_convert (type, negate_expr (arg11));
8388 tree arglist = tree_cons(NULL_TREE, arg10,
8389 build_tree_list (NULL_TREE, neg11));
8390 arg1 = build_function_call_expr (powfn, arglist);
8391 return fold_build2 (MULT_EXPR, type, arg0, arg1);
8395 if (flag_unsafe_math_optimizations)
8397 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
8398 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
8400 /* Optimize sin(x)/cos(x) as tan(x). */
8401 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
8402 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
8403 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
8404 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8405 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8407 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
8409 if (tanfn != NULL_TREE)
8410 return build_function_call_expr (tanfn,
8411 TREE_OPERAND (arg0, 1));
8414 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
8415 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
8416 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
8417 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
8418 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8419 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8421 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
8423 if (tanfn != NULL_TREE)
8425 tree tmp = TREE_OPERAND (arg0, 1);
8426 tmp = build_function_call_expr (tanfn, tmp);
8427 return fold_build2 (RDIV_EXPR, type,
8428 build_real (type, dconst1), tmp);
8432 /* Optimize pow(x,c)/x as pow(x,c-1). */
8433 if (fcode0 == BUILT_IN_POW
8434 || fcode0 == BUILT_IN_POWF
8435 || fcode0 == BUILT_IN_POWL)
8437 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
8438 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
8439 if (TREE_CODE (arg01) == REAL_CST
8440 && ! TREE_CONSTANT_OVERFLOW (arg01)
8441 && operand_equal_p (arg1, arg00, 0))
8443 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8447 c = TREE_REAL_CST (arg01);
8448 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
8449 arg = build_real (type, c);
8450 arglist = build_tree_list (NULL_TREE, arg);
8451 arglist = tree_cons (NULL_TREE, arg1, arglist);
8452 return build_function_call_expr (powfn, arglist);
8458 case TRUNC_DIV_EXPR:
8459 case ROUND_DIV_EXPR:
8460 case FLOOR_DIV_EXPR:
8462 case EXACT_DIV_EXPR:
8463 if (integer_onep (arg1))
8464 return non_lvalue (fold_convert (type, arg0));
8465 if (integer_zerop (arg1))
8468 if (!TYPE_UNSIGNED (type)
8469 && TREE_CODE (arg1) == INTEGER_CST
8470 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
8471 && TREE_INT_CST_HIGH (arg1) == -1)
8472 return fold_convert (type, negate_expr (arg0));
8474 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
8475 operation, EXACT_DIV_EXPR.
8477 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
8478 At one time others generated faster code, it's not clear if they do
8479 after the last round to changes to the DIV code in expmed.c. */
8480 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
8481 && multiple_of_p (type, arg0, arg1))
8482 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
8484 if (TREE_CODE (arg1) == INTEGER_CST
8485 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE)))
8486 return fold_convert (type, tem);
8488 if (TREE_CODE (type) == COMPLEX_TYPE)
8490 tem = fold_complex_div (type, arg0, arg1, code);
8497 case FLOOR_MOD_EXPR:
8498 case ROUND_MOD_EXPR:
8499 case TRUNC_MOD_EXPR:
8500 /* X % 1 is always zero, but be sure to preserve any side
8502 if (integer_onep (arg1))
8503 return omit_one_operand (type, integer_zero_node, arg0);
8505 /* X % 0, return X % 0 unchanged so that we can get the
8506 proper warnings and errors. */
8507 if (integer_zerop (arg1))
8510 /* 0 % X is always zero, but be sure to preserve any side
8511 effects in X. Place this after checking for X == 0. */
8512 if (integer_zerop (arg0))
8513 return omit_one_operand (type, integer_zero_node, arg1);
8515 /* X % -1 is zero. */
8516 if (!TYPE_UNSIGNED (type)
8517 && TREE_CODE (arg1) == INTEGER_CST
8518 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
8519 && TREE_INT_CST_HIGH (arg1) == -1)
8520 return omit_one_operand (type, integer_zero_node, arg0);
8522 /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
8523 BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
8524 if (code == TRUNC_MOD_EXPR
8525 && TYPE_UNSIGNED (type)
8526 && integer_pow2p (arg1))
8528 unsigned HOST_WIDE_INT high, low;
8532 l = tree_log2 (arg1);
8533 if (l >= HOST_BITS_PER_WIDE_INT)
8535 high = ((unsigned HOST_WIDE_INT) 1
8536 << (l - HOST_BITS_PER_WIDE_INT)) - 1;
8542 low = ((unsigned HOST_WIDE_INT) 1 << l) - 1;
8545 mask = build_int_cst_wide (type, low, high);
8546 return fold_build2 (BIT_AND_EXPR, type,
8547 fold_convert (type, arg0), mask);
8550 /* X % -C is the same as X % C. */
8551 if (code == TRUNC_MOD_EXPR
8552 && !TYPE_UNSIGNED (type)
8553 && TREE_CODE (arg1) == INTEGER_CST
8554 && !TREE_CONSTANT_OVERFLOW (arg1)
8555 && TREE_INT_CST_HIGH (arg1) < 0
8557 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
8558 && !sign_bit_p (arg1, arg1))
8559 return fold_build2 (code, type, fold_convert (type, arg0),
8560 fold_convert (type, negate_expr (arg1)));
8562 /* X % -Y is the same as X % Y. */
8563 if (code == TRUNC_MOD_EXPR
8564 && !TYPE_UNSIGNED (type)
8565 && TREE_CODE (arg1) == NEGATE_EXPR
8567 return fold_build2 (code, type, fold_convert (type, arg0),
8568 fold_convert (type, TREE_OPERAND (arg1, 0)));
8570 if (TREE_CODE (arg1) == INTEGER_CST
8571 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE)))
8572 return fold_convert (type, tem);
8578 if (integer_all_onesp (arg0))
8579 return omit_one_operand (type, arg0, arg1);
8583 /* Optimize -1 >> x for arithmetic right shifts. */
8584 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
8585 return omit_one_operand (type, arg0, arg1);
8586 /* ... fall through ... */
8590 if (integer_zerop (arg1))
8591 return non_lvalue (fold_convert (type, arg0));
8592 if (integer_zerop (arg0))
8593 return omit_one_operand (type, arg0, arg1);
8595 /* Since negative shift count is not well-defined,
8596 don't try to compute it in the compiler. */
8597 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
8599 /* Rewrite an LROTATE_EXPR by a constant into an
8600 RROTATE_EXPR by a new constant. */
8601 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
8603 tree tem = build_int_cst (NULL_TREE,
8604 GET_MODE_BITSIZE (TYPE_MODE (type)));
8605 tem = fold_convert (TREE_TYPE (arg1), tem);
8606 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
8607 return fold_build2 (RROTATE_EXPR, type, arg0, tem);
8610 /* If we have a rotate of a bit operation with the rotate count and
8611 the second operand of the bit operation both constant,
8612 permute the two operations. */
8613 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8614 && (TREE_CODE (arg0) == BIT_AND_EXPR
8615 || TREE_CODE (arg0) == BIT_IOR_EXPR
8616 || TREE_CODE (arg0) == BIT_XOR_EXPR)
8617 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8618 return fold_build2 (TREE_CODE (arg0), type,
8619 fold_build2 (code, type,
8620 TREE_OPERAND (arg0, 0), arg1),
8621 fold_build2 (code, type,
8622 TREE_OPERAND (arg0, 1), arg1));
8624 /* Two consecutive rotates adding up to the width of the mode can
8626 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8627 && TREE_CODE (arg0) == RROTATE_EXPR
8628 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8629 && TREE_INT_CST_HIGH (arg1) == 0
8630 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
8631 && ((TREE_INT_CST_LOW (arg1)
8632 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
8633 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
8634 return TREE_OPERAND (arg0, 0);
8639 if (operand_equal_p (arg0, arg1, 0))
8640 return omit_one_operand (type, arg0, arg1);
8641 if (INTEGRAL_TYPE_P (type)
8642 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
8643 return omit_one_operand (type, arg1, arg0);
8647 if (operand_equal_p (arg0, arg1, 0))
8648 return omit_one_operand (type, arg0, arg1);
8649 if (INTEGRAL_TYPE_P (type)
8650 && TYPE_MAX_VALUE (type)
8651 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
8652 return omit_one_operand (type, arg1, arg0);
8655 case TRUTH_ANDIF_EXPR:
8656 /* Note that the operands of this must be ints
8657 and their values must be 0 or 1.
8658 ("true" is a fixed value perhaps depending on the language.) */
8659 /* If first arg is constant zero, return it. */
8660 if (integer_zerop (arg0))
8661 return fold_convert (type, arg0);
8662 case TRUTH_AND_EXPR:
8663 /* If either arg is constant true, drop it. */
8664 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8665 return non_lvalue (fold_convert (type, arg1));
8666 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
8667 /* Preserve sequence points. */
8668 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8669 return non_lvalue (fold_convert (type, arg0));
8670 /* If second arg is constant zero, result is zero, but first arg
8671 must be evaluated. */
8672 if (integer_zerop (arg1))
8673 return omit_one_operand (type, arg1, arg0);
8674 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
8675 case will be handled here. */
8676 if (integer_zerop (arg0))
8677 return omit_one_operand (type, arg0, arg1);
8679 /* !X && X is always false. */
8680 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8681 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8682 return omit_one_operand (type, integer_zero_node, arg1);
8683 /* X && !X is always false. */
8684 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8685 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8686 return omit_one_operand (type, integer_zero_node, arg0);
8688 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
8689 means A >= Y && A != MAX, but in this case we know that
8692 if (!TREE_SIDE_EFFECTS (arg0)
8693 && !TREE_SIDE_EFFECTS (arg1))
8695 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
8697 return fold_build2 (code, type, tem, arg1);
8699 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
8701 return fold_build2 (code, type, arg0, tem);
8705 /* We only do these simplifications if we are optimizing. */
8709 /* Check for things like (A || B) && (A || C). We can convert this
8710 to A || (B && C). Note that either operator can be any of the four
8711 truth and/or operations and the transformation will still be
8712 valid. Also note that we only care about order for the
8713 ANDIF and ORIF operators. If B contains side effects, this
8714 might change the truth-value of A. */
8715 if (TREE_CODE (arg0) == TREE_CODE (arg1)
8716 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
8717 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
8718 || TREE_CODE (arg0) == TRUTH_AND_EXPR
8719 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
8720 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
8722 tree a00 = TREE_OPERAND (arg0, 0);
8723 tree a01 = TREE_OPERAND (arg0, 1);
8724 tree a10 = TREE_OPERAND (arg1, 0);
8725 tree a11 = TREE_OPERAND (arg1, 1);
8726 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
8727 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
8728 && (code == TRUTH_AND_EXPR
8729 || code == TRUTH_OR_EXPR));
8731 if (operand_equal_p (a00, a10, 0))
8732 return fold_build2 (TREE_CODE (arg0), type, a00,
8733 fold_build2 (code, type, a01, a11));
8734 else if (commutative && operand_equal_p (a00, a11, 0))
8735 return fold_build2 (TREE_CODE (arg0), type, a00,
8736 fold_build2 (code, type, a01, a10));
8737 else if (commutative && operand_equal_p (a01, a10, 0))
8738 return fold_build2 (TREE_CODE (arg0), type, a01,
8739 fold_build2 (code, type, a00, a11));
8741 /* This case if tricky because we must either have commutative
8742 operators or else A10 must not have side-effects. */
8744 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
8745 && operand_equal_p (a01, a11, 0))
8746 return fold_build2 (TREE_CODE (arg0), type,
8747 fold_build2 (code, type, a00, a10),
8751 /* See if we can build a range comparison. */
8752 if (0 != (tem = fold_range_test (code, type, op0, op1)))
8755 /* Check for the possibility of merging component references. If our
8756 lhs is another similar operation, try to merge its rhs with our
8757 rhs. Then try to merge our lhs and rhs. */
8758 if (TREE_CODE (arg0) == code
8759 && 0 != (tem = fold_truthop (code, type,
8760 TREE_OPERAND (arg0, 1), arg1)))
8761 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
8763 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
8768 case TRUTH_ORIF_EXPR:
8769 /* Note that the operands of this must be ints
8770 and their values must be 0 or true.
8771 ("true" is a fixed value perhaps depending on the language.) */
8772 /* If first arg is constant true, return it. */
8773 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8774 return fold_convert (type, arg0);
8776 /* If either arg is constant zero, drop it. */
8777 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
8778 return non_lvalue (fold_convert (type, arg1));
8779 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
8780 /* Preserve sequence points. */
8781 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8782 return non_lvalue (fold_convert (type, arg0));
8783 /* If second arg is constant true, result is true, but we must
8784 evaluate first arg. */
8785 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
8786 return omit_one_operand (type, arg1, arg0);
8787 /* Likewise for first arg, but note this only occurs here for
8789 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8790 return omit_one_operand (type, arg0, arg1);
8792 /* !X || X is always true. */
8793 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8794 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8795 return omit_one_operand (type, integer_one_node, arg1);
8796 /* X || !X is always true. */
8797 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8798 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8799 return omit_one_operand (type, integer_one_node, arg0);
8803 case TRUTH_XOR_EXPR:
8804 /* If the second arg is constant zero, drop it. */
8805 if (integer_zerop (arg1))
8806 return non_lvalue (fold_convert (type, arg0));
8807 /* If the second arg is constant true, this is a logical inversion. */
8808 if (integer_onep (arg1))
8810 /* Only call invert_truthvalue if operand is a truth value. */
8811 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8812 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
8814 tem = invert_truthvalue (arg0);
8815 return non_lvalue (fold_convert (type, tem));
8817 /* Identical arguments cancel to zero. */
8818 if (operand_equal_p (arg0, arg1, 0))
8819 return omit_one_operand (type, integer_zero_node, arg0);
8821 /* !X ^ X is always true. */
8822 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8823 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8824 return omit_one_operand (type, integer_one_node, arg1);
8826 /* X ^ !X is always true. */
8827 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8828 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8829 return omit_one_operand (type, integer_one_node, arg0);
8839 /* If one arg is a real or integer constant, put it last. */
8840 if (tree_swap_operands_p (arg0, arg1, true))
8841 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8843 /* If this is an equality comparison of the address of a non-weak
8844 object against zero, then we know the result. */
8845 if ((code == EQ_EXPR || code == NE_EXPR)
8846 && TREE_CODE (arg0) == ADDR_EXPR
8847 && DECL_P (TREE_OPERAND (arg0, 0))
8848 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8849 && integer_zerop (arg1))
8850 return constant_boolean_node (code != EQ_EXPR, type);
8852 /* If this is an equality comparison of the address of two non-weak,
8853 unaliased symbols neither of which are extern (since we do not
8854 have access to attributes for externs), then we know the result. */
8855 if ((code == EQ_EXPR || code == NE_EXPR)
8856 && TREE_CODE (arg0) == ADDR_EXPR
8857 && DECL_P (TREE_OPERAND (arg0, 0))
8858 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8859 && ! lookup_attribute ("alias",
8860 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
8861 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
8862 && TREE_CODE (arg1) == ADDR_EXPR
8863 && DECL_P (TREE_OPERAND (arg1, 0))
8864 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
8865 && ! lookup_attribute ("alias",
8866 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
8867 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
8868 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
8869 ? code == EQ_EXPR : code != EQ_EXPR,
8872 /* If this is a comparison of two exprs that look like an
8873 ARRAY_REF of the same object, then we can fold this to a
8874 comparison of the two offsets. */
8875 if (TREE_CODE_CLASS (code) == tcc_comparison)
8877 tree base0, offset0, base1, offset1;
8879 if (extract_array_ref (arg0, &base0, &offset0)
8880 && extract_array_ref (arg1, &base1, &offset1)
8881 && operand_equal_p (base0, base1, 0))
8883 if (offset0 == NULL_TREE
8884 && offset1 == NULL_TREE)
8886 offset0 = integer_zero_node;
8887 offset1 = integer_zero_node;
8889 else if (offset0 == NULL_TREE)
8890 offset0 = build_int_cst (TREE_TYPE (offset1), 0);
8891 else if (offset1 == NULL_TREE)
8892 offset1 = build_int_cst (TREE_TYPE (offset0), 0);
8894 if (TREE_TYPE (offset0) == TREE_TYPE (offset1))
8895 return fold_build2 (code, type, offset0, offset1);
8899 /* Transform comparisons of the form X +- C CMP X. */
8900 if ((code != EQ_EXPR && code != NE_EXPR)
8901 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8902 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
8903 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8904 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
8905 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8906 && !TYPE_UNSIGNED (TREE_TYPE (arg1))
8907 && !(flag_wrapv || flag_trapv))))
8909 tree arg01 = TREE_OPERAND (arg0, 1);
8910 enum tree_code code0 = TREE_CODE (arg0);
8913 if (TREE_CODE (arg01) == REAL_CST)
8914 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
8916 is_positive = tree_int_cst_sgn (arg01);
8918 /* (X - c) > X becomes false. */
8920 && ((code0 == MINUS_EXPR && is_positive >= 0)
8921 || (code0 == PLUS_EXPR && is_positive <= 0)))
8922 return constant_boolean_node (0, type);
8924 /* Likewise (X + c) < X becomes false. */
8926 && ((code0 == PLUS_EXPR && is_positive >= 0)
8927 || (code0 == MINUS_EXPR && is_positive <= 0)))
8928 return constant_boolean_node (0, type);
8930 /* Convert (X - c) <= X to true. */
8931 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
8933 && ((code0 == MINUS_EXPR && is_positive >= 0)
8934 || (code0 == PLUS_EXPR && is_positive <= 0)))
8935 return constant_boolean_node (1, type);
8937 /* Convert (X + c) >= X to true. */
8938 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
8940 && ((code0 == PLUS_EXPR && is_positive >= 0)
8941 || (code0 == MINUS_EXPR && is_positive <= 0)))
8942 return constant_boolean_node (1, type);
8944 if (TREE_CODE (arg01) == INTEGER_CST)
8946 /* Convert X + c > X and X - c < X to true for integers. */
8948 && ((code0 == PLUS_EXPR && is_positive > 0)
8949 || (code0 == MINUS_EXPR && is_positive < 0)))
8950 return constant_boolean_node (1, type);
8953 && ((code0 == MINUS_EXPR && is_positive > 0)
8954 || (code0 == PLUS_EXPR && is_positive < 0)))
8955 return constant_boolean_node (1, type);
8957 /* Convert X + c <= X and X - c >= X to false for integers. */
8959 && ((code0 == PLUS_EXPR && is_positive > 0)
8960 || (code0 == MINUS_EXPR && is_positive < 0)))
8961 return constant_boolean_node (0, type);
8964 && ((code0 == MINUS_EXPR && is_positive > 0)
8965 || (code0 == PLUS_EXPR && is_positive < 0)))
8966 return constant_boolean_node (0, type);
8970 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8972 tree targ0 = strip_float_extensions (arg0);
8973 tree targ1 = strip_float_extensions (arg1);
8974 tree newtype = TREE_TYPE (targ0);
8976 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8977 newtype = TREE_TYPE (targ1);
8979 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8980 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8981 return fold_build2 (code, type, fold_convert (newtype, targ0),
8982 fold_convert (newtype, targ1));
8984 /* (-a) CMP (-b) -> b CMP a */
8985 if (TREE_CODE (arg0) == NEGATE_EXPR
8986 && TREE_CODE (arg1) == NEGATE_EXPR)
8987 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8988 TREE_OPERAND (arg0, 0));
8990 if (TREE_CODE (arg1) == REAL_CST)
8992 REAL_VALUE_TYPE cst;
8993 cst = TREE_REAL_CST (arg1);
8995 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8996 if (TREE_CODE (arg0) == NEGATE_EXPR)
8998 fold_build2 (swap_tree_comparison (code), type,
8999 TREE_OPERAND (arg0, 0),
9000 build_real (TREE_TYPE (arg1),
9001 REAL_VALUE_NEGATE (cst)));
9003 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
9004 /* a CMP (-0) -> a CMP 0 */
9005 if (REAL_VALUE_MINUS_ZERO (cst))
9006 return fold_build2 (code, type, arg0,
9007 build_real (TREE_TYPE (arg1), dconst0));
9009 /* x != NaN is always true, other ops are always false. */
9010 if (REAL_VALUE_ISNAN (cst)
9011 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
9013 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
9014 return omit_one_operand (type, tem, arg0);
9017 /* Fold comparisons against infinity. */
9018 if (REAL_VALUE_ISINF (cst))
9020 tem = fold_inf_compare (code, type, arg0, arg1);
9021 if (tem != NULL_TREE)
9026 /* If this is a comparison of a real constant with a PLUS_EXPR
9027 or a MINUS_EXPR of a real constant, we can convert it into a
9028 comparison with a revised real constant as long as no overflow
9029 occurs when unsafe_math_optimizations are enabled. */
9030 if (flag_unsafe_math_optimizations
9031 && TREE_CODE (arg1) == REAL_CST
9032 && (TREE_CODE (arg0) == PLUS_EXPR
9033 || TREE_CODE (arg0) == MINUS_EXPR)
9034 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
9035 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9036 ? MINUS_EXPR : PLUS_EXPR,
9037 arg1, TREE_OPERAND (arg0, 1), 0))
9038 && ! TREE_CONSTANT_OVERFLOW (tem))
9039 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9041 /* Likewise, we can simplify a comparison of a real constant with
9042 a MINUS_EXPR whose first operand is also a real constant, i.e.
9043 (c1 - x) < c2 becomes x > c1-c2. */
9044 if (flag_unsafe_math_optimizations
9045 && TREE_CODE (arg1) == REAL_CST
9046 && TREE_CODE (arg0) == MINUS_EXPR
9047 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
9048 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
9050 && ! TREE_CONSTANT_OVERFLOW (tem))
9051 return fold_build2 (swap_tree_comparison (code), type,
9052 TREE_OPERAND (arg0, 1), tem);
9054 /* Fold comparisons against built-in math functions. */
9055 if (TREE_CODE (arg1) == REAL_CST
9056 && flag_unsafe_math_optimizations
9057 && ! flag_errno_math)
9059 enum built_in_function fcode = builtin_mathfn_code (arg0);
9061 if (fcode != END_BUILTINS)
9063 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
9064 if (tem != NULL_TREE)
9070 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
9071 if (TREE_CONSTANT (arg1)
9072 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
9073 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
9074 /* This optimization is invalid for ordered comparisons
9075 if CONST+INCR overflows or if foo+incr might overflow.
9076 This optimization is invalid for floating point due to rounding.
9077 For pointer types we assume overflow doesn't happen. */
9078 && (POINTER_TYPE_P (TREE_TYPE (arg0))
9079 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
9080 && (code == EQ_EXPR || code == NE_EXPR))))
9082 tree varop, newconst;
9084 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
9086 newconst = fold_build2 (PLUS_EXPR, TREE_TYPE (arg0),
9087 arg1, TREE_OPERAND (arg0, 1));
9088 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
9089 TREE_OPERAND (arg0, 0),
9090 TREE_OPERAND (arg0, 1));
9094 newconst = fold_build2 (MINUS_EXPR, TREE_TYPE (arg0),
9095 arg1, TREE_OPERAND (arg0, 1));
9096 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
9097 TREE_OPERAND (arg0, 0),
9098 TREE_OPERAND (arg0, 1));
9102 /* If VAROP is a reference to a bitfield, we must mask
9103 the constant by the width of the field. */
9104 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
9105 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
9106 && host_integerp (DECL_SIZE (TREE_OPERAND
9107 (TREE_OPERAND (varop, 0), 1)), 1))
9109 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
9110 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
9111 tree folded_compare, shift;
9113 /* First check whether the comparison would come out
9114 always the same. If we don't do that we would
9115 change the meaning with the masking. */
9116 folded_compare = fold_build2 (code, type,
9117 TREE_OPERAND (varop, 0), arg1);
9118 if (integer_zerop (folded_compare)
9119 || integer_onep (folded_compare))
9120 return omit_one_operand (type, folded_compare, varop);
9122 shift = build_int_cst (NULL_TREE,
9123 TYPE_PRECISION (TREE_TYPE (varop)) - size);
9124 shift = fold_convert (TREE_TYPE (varop), shift);
9125 newconst = fold_build2 (LSHIFT_EXPR, TREE_TYPE (varop),
9127 newconst = fold_build2 (RSHIFT_EXPR, TREE_TYPE (varop),
9131 return fold_build2 (code, type, varop, newconst);
9134 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
9135 This transformation affects the cases which are handled in later
9136 optimizations involving comparisons with non-negative constants. */
9137 if (TREE_CODE (arg1) == INTEGER_CST
9138 && TREE_CODE (arg0) != INTEGER_CST
9139 && tree_int_cst_sgn (arg1) > 0)
9144 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9145 return fold_build2 (GT_EXPR, type, arg0, arg1);
9148 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9149 return fold_build2 (LE_EXPR, type, arg0, arg1);
9156 /* Comparisons with the highest or lowest possible integer of
9157 the specified size will have known values. */
9159 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
9161 if (TREE_CODE (arg1) == INTEGER_CST
9162 && ! TREE_CONSTANT_OVERFLOW (arg1)
9163 && width <= 2 * HOST_BITS_PER_WIDE_INT
9164 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9165 || POINTER_TYPE_P (TREE_TYPE (arg1))))
9167 HOST_WIDE_INT signed_max_hi;
9168 unsigned HOST_WIDE_INT signed_max_lo;
9169 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
9171 if (width <= HOST_BITS_PER_WIDE_INT)
9173 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
9178 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
9180 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9186 max_lo = signed_max_lo;
9187 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9193 width -= HOST_BITS_PER_WIDE_INT;
9195 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
9200 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
9202 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9207 max_hi = signed_max_hi;
9208 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9212 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
9213 && TREE_INT_CST_LOW (arg1) == max_lo)
9217 return omit_one_operand (type, integer_zero_node, arg0);
9220 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9223 return omit_one_operand (type, integer_one_node, arg0);
9226 return fold_build2 (NE_EXPR, type, arg0, arg1);
9228 /* The GE_EXPR and LT_EXPR cases above are not normally
9229 reached because of previous transformations. */
9234 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9236 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
9240 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
9241 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9243 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
9244 return fold_build2 (NE_EXPR, type, arg0, arg1);
9248 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9250 && TREE_INT_CST_LOW (arg1) == min_lo)
9254 return omit_one_operand (type, integer_zero_node, arg0);
9257 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9260 return omit_one_operand (type, integer_one_node, arg0);
9263 return fold_build2 (NE_EXPR, type, arg0, arg1);
9268 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9270 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
9274 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9275 return fold_build2 (NE_EXPR, type, arg0, arg1);
9277 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9278 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9283 else if (!in_gimple_form
9284 && TREE_INT_CST_HIGH (arg1) == signed_max_hi
9285 && TREE_INT_CST_LOW (arg1) == signed_max_lo
9286 && TYPE_UNSIGNED (TREE_TYPE (arg1))
9287 /* signed_type does not work on pointer types. */
9288 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9290 /* The following case also applies to X < signed_max+1
9291 and X >= signed_max+1 because previous transformations. */
9292 if (code == LE_EXPR || code == GT_EXPR)
9295 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
9296 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
9298 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
9299 type, fold_convert (st0, arg0),
9300 fold_convert (st1, integer_zero_node)));
9306 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
9307 a MINUS_EXPR of a constant, we can convert it into a comparison with
9308 a revised constant as long as no overflow occurs. */
9309 if ((code == EQ_EXPR || code == NE_EXPR)
9310 && TREE_CODE (arg1) == INTEGER_CST
9311 && (TREE_CODE (arg0) == PLUS_EXPR
9312 || TREE_CODE (arg0) == MINUS_EXPR)
9313 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9314 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9315 ? MINUS_EXPR : PLUS_EXPR,
9316 arg1, TREE_OPERAND (arg0, 1), 0))
9317 && ! TREE_CONSTANT_OVERFLOW (tem))
9318 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9320 /* Similarly for a NEGATE_EXPR. */
9321 else if ((code == EQ_EXPR || code == NE_EXPR)
9322 && TREE_CODE (arg0) == NEGATE_EXPR
9323 && TREE_CODE (arg1) == INTEGER_CST
9324 && 0 != (tem = negate_expr (arg1))
9325 && TREE_CODE (tem) == INTEGER_CST
9326 && ! TREE_CONSTANT_OVERFLOW (tem))
9327 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9329 /* If we have X - Y == 0, we can convert that to X == Y and similarly
9330 for !=. Don't do this for ordered comparisons due to overflow. */
9331 else if ((code == NE_EXPR || code == EQ_EXPR)
9332 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
9333 return fold_build2 (code, type,
9334 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
9336 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
9337 && (TREE_CODE (arg0) == NOP_EXPR
9338 || TREE_CODE (arg0) == CONVERT_EXPR))
9340 /* If we are widening one operand of an integer comparison,
9341 see if the other operand is similarly being widened. Perhaps we
9342 can do the comparison in the narrower type. */
9343 tem = fold_widened_comparison (code, type, arg0, arg1);
9347 /* Or if we are changing signedness. */
9348 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
9353 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9354 constant, we can simplify it. */
9355 else if (TREE_CODE (arg1) == INTEGER_CST
9356 && (TREE_CODE (arg0) == MIN_EXPR
9357 || TREE_CODE (arg0) == MAX_EXPR)
9358 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9360 tem = optimize_minmax_comparison (code, type, op0, op1);
9367 /* If we are comparing an ABS_EXPR with a constant, we can
9368 convert all the cases into explicit comparisons, but they may
9369 well not be faster than doing the ABS and one comparison.
9370 But ABS (X) <= C is a range comparison, which becomes a subtraction
9371 and a comparison, and is probably faster. */
9372 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
9373 && TREE_CODE (arg0) == ABS_EXPR
9374 && ! TREE_SIDE_EFFECTS (arg0)
9375 && (0 != (tem = negate_expr (arg1)))
9376 && TREE_CODE (tem) == INTEGER_CST
9377 && ! TREE_CONSTANT_OVERFLOW (tem))
9378 return fold_build2 (TRUTH_ANDIF_EXPR, type,
9379 build2 (GE_EXPR, type,
9380 TREE_OPERAND (arg0, 0), tem),
9381 build2 (LE_EXPR, type,
9382 TREE_OPERAND (arg0, 0), arg1));
9384 /* Convert ABS_EXPR<x> >= 0 to true. */
9385 else if (code == GE_EXPR
9386 && tree_expr_nonnegative_p (arg0)
9387 && (integer_zerop (arg1)
9388 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9389 && real_zerop (arg1))))
9390 return omit_one_operand (type, integer_one_node, arg0);
9392 /* Convert ABS_EXPR<x> < 0 to false. */
9393 else if (code == LT_EXPR
9394 && tree_expr_nonnegative_p (arg0)
9395 && (integer_zerop (arg1) || real_zerop (arg1)))
9396 return omit_one_operand (type, integer_zero_node, arg0);
9398 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
9399 else if ((code == EQ_EXPR || code == NE_EXPR)
9400 && TREE_CODE (arg0) == ABS_EXPR
9401 && (integer_zerop (arg1) || real_zerop (arg1)))
9402 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
9404 /* If this is an EQ or NE comparison with zero and ARG0 is
9405 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
9406 two operations, but the latter can be done in one less insn
9407 on machines that have only two-operand insns or on which a
9408 constant cannot be the first operand. */
9409 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
9410 && TREE_CODE (arg0) == BIT_AND_EXPR)
9412 tree arg00 = TREE_OPERAND (arg0, 0);
9413 tree arg01 = TREE_OPERAND (arg0, 1);
9414 if (TREE_CODE (arg00) == LSHIFT_EXPR
9415 && integer_onep (TREE_OPERAND (arg00, 0)))
9417 fold_build2 (code, type,
9418 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9419 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
9420 arg01, TREE_OPERAND (arg00, 1)),
9421 fold_convert (TREE_TYPE (arg0),
9424 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
9425 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
9427 fold_build2 (code, type,
9428 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9429 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
9430 arg00, TREE_OPERAND (arg01, 1)),
9431 fold_convert (TREE_TYPE (arg0),
9436 /* If this is an NE or EQ comparison of zero against the result of a
9437 signed MOD operation whose second operand is a power of 2, make
9438 the MOD operation unsigned since it is simpler and equivalent. */
9439 if ((code == NE_EXPR || code == EQ_EXPR)
9440 && integer_zerop (arg1)
9441 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
9442 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
9443 || TREE_CODE (arg0) == CEIL_MOD_EXPR
9444 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
9445 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
9446 && integer_pow2p (TREE_OPERAND (arg0, 1)))
9448 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
9449 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
9450 fold_convert (newtype,
9451 TREE_OPERAND (arg0, 0)),
9452 fold_convert (newtype,
9453 TREE_OPERAND (arg0, 1)));
9455 return fold_build2 (code, type, newmod,
9456 fold_convert (newtype, arg1));
9459 /* If this is an NE comparison of zero with an AND of one, remove the
9460 comparison since the AND will give the correct value. */
9461 if (code == NE_EXPR && integer_zerop (arg1)
9462 && TREE_CODE (arg0) == BIT_AND_EXPR
9463 && integer_onep (TREE_OPERAND (arg0, 1)))
9464 return fold_convert (type, arg0);
9466 /* If we have (A & C) == C where C is a power of 2, convert this into
9467 (A & C) != 0. Similarly for NE_EXPR. */
9468 if ((code == EQ_EXPR || code == NE_EXPR)
9469 && TREE_CODE (arg0) == BIT_AND_EXPR
9470 && integer_pow2p (TREE_OPERAND (arg0, 1))
9471 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9472 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
9473 arg0, fold_convert (TREE_TYPE (arg0),
9474 integer_zero_node));
9476 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
9477 bit, then fold the expression into A < 0 or A >= 0. */
9478 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
9482 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
9483 Similarly for NE_EXPR. */
9484 if ((code == EQ_EXPR || code == NE_EXPR)
9485 && TREE_CODE (arg0) == BIT_AND_EXPR
9486 && TREE_CODE (arg1) == INTEGER_CST
9487 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9489 tree notc = fold_build1 (BIT_NOT_EXPR,
9490 TREE_TYPE (TREE_OPERAND (arg0, 1)),
9491 TREE_OPERAND (arg0, 1));
9492 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9494 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
9495 if (integer_nonzerop (dandnotc))
9496 return omit_one_operand (type, rslt, arg0);
9499 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
9500 Similarly for NE_EXPR. */
9501 if ((code == EQ_EXPR || code == NE_EXPR)
9502 && TREE_CODE (arg0) == BIT_IOR_EXPR
9503 && TREE_CODE (arg1) == INTEGER_CST
9504 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9506 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
9507 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9508 TREE_OPERAND (arg0, 1), notd);
9509 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
9510 if (integer_nonzerop (candnotd))
9511 return omit_one_operand (type, rslt, arg0);
9514 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
9515 and similarly for >= into !=. */
9516 if ((code == LT_EXPR || code == GE_EXPR)
9517 && TYPE_UNSIGNED (TREE_TYPE (arg0))
9518 && TREE_CODE (arg1) == LSHIFT_EXPR
9519 && integer_onep (TREE_OPERAND (arg1, 0)))
9520 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
9521 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
9522 TREE_OPERAND (arg1, 1)),
9523 fold_convert (TREE_TYPE (arg0), integer_zero_node));
9525 else if ((code == LT_EXPR || code == GE_EXPR)
9526 && TYPE_UNSIGNED (TREE_TYPE (arg0))
9527 && (TREE_CODE (arg1) == NOP_EXPR
9528 || TREE_CODE (arg1) == CONVERT_EXPR)
9529 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
9530 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
9532 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
9533 fold_convert (TREE_TYPE (arg0),
9534 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
9535 TREE_OPERAND (TREE_OPERAND (arg1, 0),
9537 fold_convert (TREE_TYPE (arg0), integer_zero_node));
9539 /* Simplify comparison of something with itself. (For IEEE
9540 floating-point, we can only do some of these simplifications.) */
9541 if (operand_equal_p (arg0, arg1, 0))
9546 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9547 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9548 return constant_boolean_node (1, type);
9553 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9554 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9555 return constant_boolean_node (1, type);
9556 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9559 /* For NE, we can only do this simplification if integer
9560 or we don't honor IEEE floating point NaNs. */
9561 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
9562 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9564 /* ... fall through ... */
9567 return constant_boolean_node (0, type);
9573 /* If we are comparing an expression that just has comparisons
9574 of two integer values, arithmetic expressions of those comparisons,
9575 and constants, we can simplify it. There are only three cases
9576 to check: the two values can either be equal, the first can be
9577 greater, or the second can be greater. Fold the expression for
9578 those three values. Since each value must be 0 or 1, we have
9579 eight possibilities, each of which corresponds to the constant 0
9580 or 1 or one of the six possible comparisons.
9582 This handles common cases like (a > b) == 0 but also handles
9583 expressions like ((x > y) - (y > x)) > 0, which supposedly
9584 occur in macroized code. */
9586 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
9588 tree cval1 = 0, cval2 = 0;
9591 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
9592 /* Don't handle degenerate cases here; they should already
9593 have been handled anyway. */
9594 && cval1 != 0 && cval2 != 0
9595 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
9596 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
9597 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
9598 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
9599 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
9600 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
9601 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9603 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9604 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9606 /* We can't just pass T to eval_subst in case cval1 or cval2
9607 was the same as ARG1. */
9610 = fold_build2 (code, type,
9611 eval_subst (arg0, cval1, maxval,
9615 = fold_build2 (code, type,
9616 eval_subst (arg0, cval1, maxval,
9620 = fold_build2 (code, type,
9621 eval_subst (arg0, cval1, minval,
9625 /* All three of these results should be 0 or 1. Confirm they
9626 are. Then use those values to select the proper code
9629 if ((integer_zerop (high_result)
9630 || integer_onep (high_result))
9631 && (integer_zerop (equal_result)
9632 || integer_onep (equal_result))
9633 && (integer_zerop (low_result)
9634 || integer_onep (low_result)))
9636 /* Make a 3-bit mask with the high-order bit being the
9637 value for `>', the next for '=', and the low for '<'. */
9638 switch ((integer_onep (high_result) * 4)
9639 + (integer_onep (equal_result) * 2)
9640 + integer_onep (low_result))
9644 return omit_one_operand (type, integer_zero_node, arg0);
9665 return omit_one_operand (type, integer_one_node, arg0);
9669 return save_expr (build2 (code, type, cval1, cval2));
9671 return fold_build2 (code, type, cval1, cval2);
9676 /* If this is a comparison of a field, we may be able to simplify it. */
9677 if (((TREE_CODE (arg0) == COMPONENT_REF
9678 && lang_hooks.can_use_bit_fields_p ())
9679 || TREE_CODE (arg0) == BIT_FIELD_REF)
9680 && (code == EQ_EXPR || code == NE_EXPR)
9681 /* Handle the constant case even without -O
9682 to make sure the warnings are given. */
9683 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
9685 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
9690 /* If this is a comparison of complex values and either or both sides
9691 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
9692 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
9693 This may prevent needless evaluations. */
9694 if ((code == EQ_EXPR || code == NE_EXPR)
9695 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
9696 && (TREE_CODE (arg0) == COMPLEX_EXPR
9697 || TREE_CODE (arg1) == COMPLEX_EXPR
9698 || TREE_CODE (arg0) == COMPLEX_CST
9699 || TREE_CODE (arg1) == COMPLEX_CST))
9701 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
9702 tree real0, imag0, real1, imag1;
9704 arg0 = save_expr (arg0);
9705 arg1 = save_expr (arg1);
9706 real0 = fold_build1 (REALPART_EXPR, subtype, arg0);
9707 imag0 = fold_build1 (IMAGPART_EXPR, subtype, arg0);
9708 real1 = fold_build1 (REALPART_EXPR, subtype, arg1);
9709 imag1 = fold_build1 (IMAGPART_EXPR, subtype, arg1);
9711 return fold_build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
9714 fold_build2 (code, type, real0, real1),
9715 fold_build2 (code, type, imag0, imag1));
9718 /* Optimize comparisons of strlen vs zero to a compare of the
9719 first character of the string vs zero. To wit,
9720 strlen(ptr) == 0 => *ptr == 0
9721 strlen(ptr) != 0 => *ptr != 0
9722 Other cases should reduce to one of these two (or a constant)
9723 due to the return value of strlen being unsigned. */
9724 if ((code == EQ_EXPR || code == NE_EXPR)
9725 && integer_zerop (arg1)
9726 && TREE_CODE (arg0) == CALL_EXPR)
9728 tree fndecl = get_callee_fndecl (arg0);
9732 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
9733 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
9734 && (arglist = TREE_OPERAND (arg0, 1))
9735 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
9736 && ! TREE_CHAIN (arglist))
9737 return fold_build2 (code, type,
9738 build1 (INDIRECT_REF, char_type_node,
9739 TREE_VALUE (arglist)),
9740 fold_convert (char_type_node,
9741 integer_zero_node));
9744 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9745 into a single range test. */
9746 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9747 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9748 && TREE_CODE (arg1) == INTEGER_CST
9749 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9750 && !integer_zerop (TREE_OPERAND (arg0, 1))
9751 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9752 && !TREE_OVERFLOW (arg1))
9754 t1 = fold_div_compare (code, type, arg0, arg1);
9755 if (t1 != NULL_TREE)
9759 if ((code == EQ_EXPR || code == NE_EXPR)
9760 && !TREE_SIDE_EFFECTS (arg0)
9761 && integer_zerop (arg1)
9762 && tree_expr_nonzero_p (arg0))
9763 return constant_boolean_node (code==NE_EXPR, type);
9765 t1 = fold_relational_const (code, type, arg0, arg1);
9766 return t1 == NULL_TREE ? NULL_TREE : t1;
9768 case UNORDERED_EXPR:
9776 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9778 t1 = fold_relational_const (code, type, arg0, arg1);
9779 if (t1 != NULL_TREE)
9783 /* If the first operand is NaN, the result is constant. */
9784 if (TREE_CODE (arg0) == REAL_CST
9785 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
9786 && (code != LTGT_EXPR || ! flag_trapping_math))
9788 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9791 return omit_one_operand (type, t1, arg1);
9794 /* If the second operand is NaN, the result is constant. */
9795 if (TREE_CODE (arg1) == REAL_CST
9796 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
9797 && (code != LTGT_EXPR || ! flag_trapping_math))
9799 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9802 return omit_one_operand (type, t1, arg0);
9805 /* Simplify unordered comparison of something with itself. */
9806 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
9807 && operand_equal_p (arg0, arg1, 0))
9808 return constant_boolean_node (1, type);
9810 if (code == LTGT_EXPR
9811 && !flag_trapping_math
9812 && operand_equal_p (arg0, arg1, 0))
9813 return constant_boolean_node (0, type);
9815 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9817 tree targ0 = strip_float_extensions (arg0);
9818 tree targ1 = strip_float_extensions (arg1);
9819 tree newtype = TREE_TYPE (targ0);
9821 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
9822 newtype = TREE_TYPE (targ1);
9824 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
9825 return fold_build2 (code, type, fold_convert (newtype, targ0),
9826 fold_convert (newtype, targ1));
9832 /* When pedantic, a compound expression can be neither an lvalue
9833 nor an integer constant expression. */
9834 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
9836 /* Don't let (0, 0) be null pointer constant. */
9837 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
9838 : fold_convert (type, arg1);
9839 return pedantic_non_lvalue (tem);
9843 return build_complex (type, arg0, arg1);
9848 } /* switch (code) */
9851 /* Fold a ternary expression of code CODE and type TYPE with operands
9852 OP0, OP1, and OP2. Return the folded expression if folding is
9853 successful. Otherwise, return NULL_TREE. */
9856 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
9859 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
9860 enum tree_code_class kind = TREE_CODE_CLASS (code);
9862 gcc_assert (IS_EXPR_CODE_CLASS (kind)
9863 && TREE_CODE_LENGTH (code) == 3);
9865 /* Strip any conversions that don't change the mode. This is safe
9866 for every expression, except for a comparison expression because
9867 its signedness is derived from its operands. So, in the latter
9868 case, only strip conversions that don't change the signedness.
9870 Note that this is done as an internal manipulation within the
9871 constant folder, in order to find the simplest representation of
9872 the arguments so that their form can be studied. In any cases,
9873 the appropriate type conversions should be put back in the tree
9874 that will get out of the constant folder. */
9890 if (TREE_CODE (arg0) == CONSTRUCTOR
9891 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
9893 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
9895 return TREE_VALUE (m);
9900 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
9901 so all simple results must be passed through pedantic_non_lvalue. */
9902 if (TREE_CODE (arg0) == INTEGER_CST)
9904 tem = integer_zerop (arg0) ? op2 : op1;
9905 /* Only optimize constant conditions when the selected branch
9906 has the same type as the COND_EXPR. This avoids optimizing
9907 away "c ? x : throw", where the throw has a void type. */
9908 if (! VOID_TYPE_P (TREE_TYPE (tem))
9909 || VOID_TYPE_P (type))
9910 return pedantic_non_lvalue (tem);
9913 if (operand_equal_p (arg1, op2, 0))
9914 return pedantic_omit_one_operand (type, arg1, arg0);
9916 /* If we have A op B ? A : C, we may be able to convert this to a
9917 simpler expression, depending on the operation and the values
9918 of B and C. Signed zeros prevent all of these transformations,
9919 for reasons given above each one.
9921 Also try swapping the arguments and inverting the conditional. */
9922 if (COMPARISON_CLASS_P (arg0)
9923 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
9924 arg1, TREE_OPERAND (arg0, 1))
9925 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
9927 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
9932 if (COMPARISON_CLASS_P (arg0)
9933 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
9935 TREE_OPERAND (arg0, 1))
9936 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
9938 tem = invert_truthvalue (arg0);
9939 if (COMPARISON_CLASS_P (tem))
9941 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
9947 /* If the second operand is simpler than the third, swap them
9948 since that produces better jump optimization results. */
9949 if (tree_swap_operands_p (op1, op2, false))
9951 /* See if this can be inverted. If it can't, possibly because
9952 it was a floating-point inequality comparison, don't do
9954 tem = invert_truthvalue (arg0);
9956 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9957 return fold_build3 (code, type, tem, op2, op1);
9960 /* Convert A ? 1 : 0 to simply A. */
9961 if (integer_onep (op1)
9962 && integer_zerop (op2)
9963 /* If we try to convert OP0 to our type, the
9964 call to fold will try to move the conversion inside
9965 a COND, which will recurse. In that case, the COND_EXPR
9966 is probably the best choice, so leave it alone. */
9967 && type == TREE_TYPE (arg0))
9968 return pedantic_non_lvalue (arg0);
9970 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
9971 over COND_EXPR in cases such as floating point comparisons. */
9972 if (integer_zerop (op1)
9973 && integer_onep (op2)
9974 && truth_value_p (TREE_CODE (arg0)))
9975 return pedantic_non_lvalue (fold_convert (type,
9976 invert_truthvalue (arg0)));
9978 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
9979 if (TREE_CODE (arg0) == LT_EXPR
9980 && integer_zerop (TREE_OPERAND (arg0, 1))
9981 && integer_zerop (op2)
9982 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
9983 return fold_convert (type, fold_build2 (BIT_AND_EXPR,
9984 TREE_TYPE (tem), tem, arg1));
9986 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
9987 already handled above. */
9988 if (TREE_CODE (arg0) == BIT_AND_EXPR
9989 && integer_onep (TREE_OPERAND (arg0, 1))
9990 && integer_zerop (op2)
9991 && integer_pow2p (arg1))
9993 tree tem = TREE_OPERAND (arg0, 0);
9995 if (TREE_CODE (tem) == RSHIFT_EXPR
9996 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
9997 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
9998 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
9999 return fold_build2 (BIT_AND_EXPR, type,
10000 TREE_OPERAND (tem, 0), arg1);
10003 /* A & N ? N : 0 is simply A & N if N is a power of two. This
10004 is probably obsolete because the first operand should be a
10005 truth value (that's why we have the two cases above), but let's
10006 leave it in until we can confirm this for all front-ends. */
10007 if (integer_zerop (op2)
10008 && TREE_CODE (arg0) == NE_EXPR
10009 && integer_zerop (TREE_OPERAND (arg0, 1))
10010 && integer_pow2p (arg1)
10011 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
10012 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
10013 arg1, OEP_ONLY_CONST))
10014 return pedantic_non_lvalue (fold_convert (type,
10015 TREE_OPERAND (arg0, 0)));
10017 /* Convert A ? B : 0 into A && B if A and B are truth values. */
10018 if (integer_zerop (op2)
10019 && truth_value_p (TREE_CODE (arg0))
10020 && truth_value_p (TREE_CODE (arg1)))
10021 return fold_build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1);
10023 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
10024 if (integer_onep (op2)
10025 && truth_value_p (TREE_CODE (arg0))
10026 && truth_value_p (TREE_CODE (arg1)))
10028 /* Only perform transformation if ARG0 is easily inverted. */
10029 tem = invert_truthvalue (arg0);
10030 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
10031 return fold_build2 (TRUTH_ORIF_EXPR, type, tem, arg1);
10034 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
10035 if (integer_zerop (arg1)
10036 && truth_value_p (TREE_CODE (arg0))
10037 && truth_value_p (TREE_CODE (op2)))
10039 /* Only perform transformation if ARG0 is easily inverted. */
10040 tem = invert_truthvalue (arg0);
10041 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
10042 return fold_build2 (TRUTH_ANDIF_EXPR, type, tem, op2);
10045 /* Convert A ? 1 : B into A || B if A and B are truth values. */
10046 if (integer_onep (arg1)
10047 && truth_value_p (TREE_CODE (arg0))
10048 && truth_value_p (TREE_CODE (op2)))
10049 return fold_build2 (TRUTH_ORIF_EXPR, type, arg0, op2);
10054 /* Check for a built-in function. */
10055 if (TREE_CODE (op0) == ADDR_EXPR
10056 && TREE_CODE (TREE_OPERAND (op0, 0)) == FUNCTION_DECL
10057 && DECL_BUILT_IN (TREE_OPERAND (op0, 0)))
10059 tree fndecl = TREE_OPERAND (op0, 0);
10060 tree arglist = op1;
10061 tree tmp = fold_builtin (fndecl, arglist, false);
10069 } /* switch (code) */
10072 /* Perform constant folding and related simplification of EXPR.
10073 The related simplifications include x*1 => x, x*0 => 0, etc.,
10074 and application of the associative law.
10075 NOP_EXPR conversions may be removed freely (as long as we
10076 are careful not to change the type of the overall expression).
10077 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
10078 but we can constant-fold them if they have constant operands. */
10080 #ifdef ENABLE_FOLD_CHECKING
10081 # define fold(x) fold_1 (x)
10082 static tree fold_1 (tree);
10088 const tree t = expr;
10089 enum tree_code code = TREE_CODE (t);
10090 enum tree_code_class kind = TREE_CODE_CLASS (code);
10093 /* Return right away if a constant. */
10094 if (kind == tcc_constant)
10097 if (IS_EXPR_CODE_CLASS (kind))
10099 tree type = TREE_TYPE (t);
10100 tree op0, op1, op2;
10102 switch (TREE_CODE_LENGTH (code))
10105 op0 = TREE_OPERAND (t, 0);
10106 tem = fold_unary (code, type, op0);
10107 return tem ? tem : expr;
10109 op0 = TREE_OPERAND (t, 0);
10110 op1 = TREE_OPERAND (t, 1);
10111 tem = fold_binary (code, type, op0, op1);
10112 return tem ? tem : expr;
10114 op0 = TREE_OPERAND (t, 0);
10115 op1 = TREE_OPERAND (t, 1);
10116 op2 = TREE_OPERAND (t, 2);
10117 tem = fold_ternary (code, type, op0, op1, op2);
10118 return tem ? tem : expr;
10127 return fold (DECL_INITIAL (t));
10131 /* Given ASSERT_EXPR <Y, COND>, return Y if COND can be folded
10132 to boolean_true_node. If COND folds to boolean_false_node,
10133 return ASSERT_EXPR <Y, 0>. Otherwise, return the original
10135 tree c = fold (ASSERT_EXPR_COND (t));
10136 if (c == boolean_true_node)
10137 return ASSERT_EXPR_VAR (t);
10138 else if (c == boolean_false_node)
10139 return build (ASSERT_EXPR, TREE_TYPE (t), ASSERT_EXPR_VAR (t), c);
10146 } /* switch (code) */
10149 #ifdef ENABLE_FOLD_CHECKING
10152 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
10153 static void fold_check_failed (tree, tree);
10154 void print_fold_checksum (tree);
10156 /* When --enable-checking=fold, compute a digest of expr before
10157 and after actual fold call to see if fold did not accidentally
10158 change original expr. */
10164 struct md5_ctx ctx;
10165 unsigned char checksum_before[16], checksum_after[16];
10168 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
10169 md5_init_ctx (&ctx);
10170 fold_checksum_tree (expr, &ctx, ht);
10171 md5_finish_ctx (&ctx, checksum_before);
10174 ret = fold_1 (expr);
10176 md5_init_ctx (&ctx);
10177 fold_checksum_tree (expr, &ctx, ht);
10178 md5_finish_ctx (&ctx, checksum_after);
10181 if (memcmp (checksum_before, checksum_after, 16))
10182 fold_check_failed (expr, ret);
10188 print_fold_checksum (tree expr)
10190 struct md5_ctx ctx;
10191 unsigned char checksum[16], cnt;
10194 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
10195 md5_init_ctx (&ctx);
10196 fold_checksum_tree (expr, &ctx, ht);
10197 md5_finish_ctx (&ctx, checksum);
10199 for (cnt = 0; cnt < 16; ++cnt)
10200 fprintf (stderr, "%02x", checksum[cnt]);
10201 putc ('\n', stderr);
10205 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
10207 internal_error ("fold check: original tree changed by fold");
10211 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
10214 enum tree_code code;
10215 char buf[sizeof (struct tree_decl)];
10218 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
10219 <= sizeof (struct tree_decl))
10220 && sizeof (struct tree_type) <= sizeof (struct tree_decl));
10223 slot = htab_find_slot (ht, expr, INSERT);
10227 code = TREE_CODE (expr);
10228 if (TREE_CODE_CLASS (code) == tcc_declaration
10229 && DECL_ASSEMBLER_NAME_SET_P (expr))
10231 /* Allow DECL_ASSEMBLER_NAME to be modified. */
10232 memcpy (buf, expr, tree_size (expr));
10234 SET_DECL_ASSEMBLER_NAME (expr, NULL);
10236 else if (TREE_CODE_CLASS (code) == tcc_type
10237 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
10238 || TYPE_CACHED_VALUES_P (expr)))
10240 /* Allow these fields to be modified. */
10241 memcpy (buf, expr, tree_size (expr));
10243 TYPE_POINTER_TO (expr) = NULL;
10244 TYPE_REFERENCE_TO (expr) = NULL;
10245 if (TYPE_CACHED_VALUES_P (expr))
10247 TYPE_CACHED_VALUES_P (expr) = 0;
10248 TYPE_CACHED_VALUES (expr) = NULL;
10251 md5_process_bytes (expr, tree_size (expr), ctx);
10252 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
10253 if (TREE_CODE_CLASS (code) != tcc_type
10254 && TREE_CODE_CLASS (code) != tcc_declaration)
10255 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
10256 switch (TREE_CODE_CLASS (code))
10262 md5_process_bytes (TREE_STRING_POINTER (expr),
10263 TREE_STRING_LENGTH (expr), ctx);
10266 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
10267 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
10270 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
10276 case tcc_exceptional:
10280 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
10281 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
10284 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
10285 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
10291 case tcc_expression:
10292 case tcc_reference:
10293 case tcc_comparison:
10296 case tcc_statement:
10297 len = TREE_CODE_LENGTH (code);
10298 for (i = 0; i < len; ++i)
10299 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
10301 case tcc_declaration:
10302 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
10303 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
10304 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
10305 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
10306 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
10307 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
10308 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
10309 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
10310 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
10311 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
10312 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
10315 if (TREE_CODE (expr) == ENUMERAL_TYPE)
10316 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
10317 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
10318 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
10319 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
10320 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
10321 if (INTEGRAL_TYPE_P (expr)
10322 || SCALAR_FLOAT_TYPE_P (expr))
10324 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
10325 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
10327 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
10328 if (TREE_CODE (expr) == RECORD_TYPE
10329 || TREE_CODE (expr) == UNION_TYPE
10330 || TREE_CODE (expr) == QUAL_UNION_TYPE)
10331 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
10332 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
10341 /* Fold a unary tree expression with code CODE of type TYPE with an
10342 operand OP0. Return a folded expression if successful. Otherwise,
10343 return a tree expression with code CODE of type TYPE with an
10347 fold_build1 (enum tree_code code, tree type, tree op0)
10349 tree tem = fold_unary (code, type, op0);
10353 return build1 (code, type, op0);
10356 /* Fold a binary tree expression with code CODE of type TYPE with
10357 operands OP0 and OP1. Return a folded expression if successful.
10358 Otherwise, return a tree expression with code CODE of type TYPE
10359 with operands OP0 and OP1. */
10362 fold_build2 (enum tree_code code, tree type, tree op0, tree op1)
10364 tree tem = fold_binary (code, type, op0, op1);
10368 return build2 (code, type, op0, op1);
10371 /* Fold a ternary tree expression with code CODE of type TYPE with
10372 operands OP0, OP1, and OP2. Return a folded expression if
10373 successful. Otherwise, return a tree expression with code CODE of
10374 type TYPE with operands OP0, OP1, and OP2. */
10377 fold_build3 (enum tree_code code, tree type, tree op0, tree op1, tree op2)
10379 tree tem = fold_ternary (code, type, op0, op1, op2);
10383 return build3 (code, type, op0, op1, op2);
10386 /* Perform constant folding and related simplification of initializer
10387 expression EXPR. This behaves identically to "fold" but ignores
10388 potential run-time traps and exceptions that fold must preserve. */
10391 fold_initializer (tree expr)
10393 int saved_signaling_nans = flag_signaling_nans;
10394 int saved_trapping_math = flag_trapping_math;
10395 int saved_rounding_math = flag_rounding_math;
10396 int saved_trapv = flag_trapv;
10399 flag_signaling_nans = 0;
10400 flag_trapping_math = 0;
10401 flag_rounding_math = 0;
10404 result = fold (expr);
10406 flag_signaling_nans = saved_signaling_nans;
10407 flag_trapping_math = saved_trapping_math;
10408 flag_rounding_math = saved_rounding_math;
10409 flag_trapv = saved_trapv;
10414 /* Determine if first argument is a multiple of second argument. Return 0 if
10415 it is not, or we cannot easily determined it to be.
10417 An example of the sort of thing we care about (at this point; this routine
10418 could surely be made more general, and expanded to do what the *_DIV_EXPR's
10419 fold cases do now) is discovering that
10421 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
10427 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
10429 This code also handles discovering that
10431 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
10433 is a multiple of 8 so we don't have to worry about dealing with a
10434 possible remainder.
10436 Note that we *look* inside a SAVE_EXPR only to determine how it was
10437 calculated; it is not safe for fold to do much of anything else with the
10438 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
10439 at run time. For example, the latter example above *cannot* be implemented
10440 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
10441 evaluation time of the original SAVE_EXPR is not necessarily the same at
10442 the time the new expression is evaluated. The only optimization of this
10443 sort that would be valid is changing
10445 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
10449 SAVE_EXPR (I) * SAVE_EXPR (J)
10451 (where the same SAVE_EXPR (J) is used in the original and the
10452 transformed version). */
10455 multiple_of_p (tree type, tree top, tree bottom)
10457 if (operand_equal_p (top, bottom, 0))
10460 if (TREE_CODE (type) != INTEGER_TYPE)
10463 switch (TREE_CODE (top))
10466 /* Bitwise and provides a power of two multiple. If the mask is
10467 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
10468 if (!integer_pow2p (bottom))
10473 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
10474 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
10478 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
10479 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
10482 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
10486 op1 = TREE_OPERAND (top, 1);
10487 /* const_binop may not detect overflow correctly,
10488 so check for it explicitly here. */
10489 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
10490 > TREE_INT_CST_LOW (op1)
10491 && TREE_INT_CST_HIGH (op1) == 0
10492 && 0 != (t1 = fold_convert (type,
10493 const_binop (LSHIFT_EXPR,
10496 && ! TREE_OVERFLOW (t1))
10497 return multiple_of_p (type, t1, bottom);
10502 /* Can't handle conversions from non-integral or wider integral type. */
10503 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
10504 || (TYPE_PRECISION (type)
10505 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
10508 /* .. fall through ... */
10511 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
10514 if (TREE_CODE (bottom) != INTEGER_CST
10515 || (TYPE_UNSIGNED (type)
10516 && (tree_int_cst_sgn (top) < 0
10517 || tree_int_cst_sgn (bottom) < 0)))
10519 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
10527 /* Return true if `t' is known to be non-negative. */
10530 tree_expr_nonnegative_p (tree t)
10532 switch (TREE_CODE (t))
10538 return tree_int_cst_sgn (t) >= 0;
10541 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
10544 if (FLOAT_TYPE_P (TREE_TYPE (t)))
10545 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10546 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10548 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
10549 both unsigned and at least 2 bits shorter than the result. */
10550 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
10551 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
10552 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
10554 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
10555 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
10556 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
10557 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
10559 unsigned int prec = MAX (TYPE_PRECISION (inner1),
10560 TYPE_PRECISION (inner2)) + 1;
10561 return prec < TYPE_PRECISION (TREE_TYPE (t));
10567 if (FLOAT_TYPE_P (TREE_TYPE (t)))
10569 /* x * x for floating point x is always non-negative. */
10570 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
10572 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10573 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10576 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
10577 both unsigned and their total bits is shorter than the result. */
10578 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
10579 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
10580 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
10582 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
10583 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
10584 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
10585 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
10586 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
10587 < TYPE_PRECISION (TREE_TYPE (t));
10591 case TRUNC_DIV_EXPR:
10592 case CEIL_DIV_EXPR:
10593 case FLOOR_DIV_EXPR:
10594 case ROUND_DIV_EXPR:
10595 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10596 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10598 case TRUNC_MOD_EXPR:
10599 case CEIL_MOD_EXPR:
10600 case FLOOR_MOD_EXPR:
10601 case ROUND_MOD_EXPR:
10602 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10605 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10606 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10609 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
10610 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10613 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10614 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10618 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
10619 tree outer_type = TREE_TYPE (t);
10621 if (TREE_CODE (outer_type) == REAL_TYPE)
10623 if (TREE_CODE (inner_type) == REAL_TYPE)
10624 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10625 if (TREE_CODE (inner_type) == INTEGER_TYPE)
10627 if (TYPE_UNSIGNED (inner_type))
10629 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10632 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
10634 if (TREE_CODE (inner_type) == REAL_TYPE)
10635 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
10636 if (TREE_CODE (inner_type) == INTEGER_TYPE)
10637 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
10638 && TYPE_UNSIGNED (inner_type);
10644 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
10645 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
10646 case COMPOUND_EXPR:
10647 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10649 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10650 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10652 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10653 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10655 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10657 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
10659 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10660 case NON_LVALUE_EXPR:
10661 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10663 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10667 tree temp = TARGET_EXPR_SLOT (t);
10668 t = TARGET_EXPR_INITIAL (t);
10670 /* If the initializer is non-void, then it's a normal expression
10671 that will be assigned to the slot. */
10672 if (!VOID_TYPE_P (t))
10673 return tree_expr_nonnegative_p (t);
10675 /* Otherwise, the initializer sets the slot in some way. One common
10676 way is an assignment statement at the end of the initializer. */
10679 if (TREE_CODE (t) == BIND_EXPR)
10680 t = expr_last (BIND_EXPR_BODY (t));
10681 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
10682 || TREE_CODE (t) == TRY_CATCH_EXPR)
10683 t = expr_last (TREE_OPERAND (t, 0));
10684 else if (TREE_CODE (t) == STATEMENT_LIST)
10689 if (TREE_CODE (t) == MODIFY_EXPR
10690 && TREE_OPERAND (t, 0) == temp)
10691 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10698 tree fndecl = get_callee_fndecl (t);
10699 tree arglist = TREE_OPERAND (t, 1);
10700 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
10701 switch (DECL_FUNCTION_CODE (fndecl))
10703 #define CASE_BUILTIN_F(BUILT_IN_FN) \
10704 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
10705 #define CASE_BUILTIN_I(BUILT_IN_FN) \
10706 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
10708 CASE_BUILTIN_F (BUILT_IN_ACOS)
10709 CASE_BUILTIN_F (BUILT_IN_ACOSH)
10710 CASE_BUILTIN_F (BUILT_IN_CABS)
10711 CASE_BUILTIN_F (BUILT_IN_COSH)
10712 CASE_BUILTIN_F (BUILT_IN_ERFC)
10713 CASE_BUILTIN_F (BUILT_IN_EXP)
10714 CASE_BUILTIN_F (BUILT_IN_EXP10)
10715 CASE_BUILTIN_F (BUILT_IN_EXP2)
10716 CASE_BUILTIN_F (BUILT_IN_FABS)
10717 CASE_BUILTIN_F (BUILT_IN_FDIM)
10718 CASE_BUILTIN_F (BUILT_IN_FREXP)
10719 CASE_BUILTIN_F (BUILT_IN_HYPOT)
10720 CASE_BUILTIN_F (BUILT_IN_POW10)
10721 CASE_BUILTIN_I (BUILT_IN_FFS)
10722 CASE_BUILTIN_I (BUILT_IN_PARITY)
10723 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
10727 CASE_BUILTIN_F (BUILT_IN_SQRT)
10728 /* sqrt(-0.0) is -0.0. */
10729 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
10731 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
10733 CASE_BUILTIN_F (BUILT_IN_ASINH)
10734 CASE_BUILTIN_F (BUILT_IN_ATAN)
10735 CASE_BUILTIN_F (BUILT_IN_ATANH)
10736 CASE_BUILTIN_F (BUILT_IN_CBRT)
10737 CASE_BUILTIN_F (BUILT_IN_CEIL)
10738 CASE_BUILTIN_F (BUILT_IN_ERF)
10739 CASE_BUILTIN_F (BUILT_IN_EXPM1)
10740 CASE_BUILTIN_F (BUILT_IN_FLOOR)
10741 CASE_BUILTIN_F (BUILT_IN_FMOD)
10742 CASE_BUILTIN_F (BUILT_IN_LCEIL)
10743 CASE_BUILTIN_F (BUILT_IN_LDEXP)
10744 CASE_BUILTIN_F (BUILT_IN_LFLOOR)
10745 CASE_BUILTIN_F (BUILT_IN_LLCEIL)
10746 CASE_BUILTIN_F (BUILT_IN_LLFLOOR)
10747 CASE_BUILTIN_F (BUILT_IN_LLRINT)
10748 CASE_BUILTIN_F (BUILT_IN_LLROUND)
10749 CASE_BUILTIN_F (BUILT_IN_LRINT)
10750 CASE_BUILTIN_F (BUILT_IN_LROUND)
10751 CASE_BUILTIN_F (BUILT_IN_MODF)
10752 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
10753 CASE_BUILTIN_F (BUILT_IN_POW)
10754 CASE_BUILTIN_F (BUILT_IN_RINT)
10755 CASE_BUILTIN_F (BUILT_IN_ROUND)
10756 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
10757 CASE_BUILTIN_F (BUILT_IN_SINH)
10758 CASE_BUILTIN_F (BUILT_IN_TANH)
10759 CASE_BUILTIN_F (BUILT_IN_TRUNC)
10760 /* True if the 1st argument is nonnegative. */
10761 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
10763 CASE_BUILTIN_F (BUILT_IN_FMAX)
10764 /* True if the 1st OR 2nd arguments are nonnegative. */
10765 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
10766 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10768 CASE_BUILTIN_F (BUILT_IN_FMIN)
10769 /* True if the 1st AND 2nd arguments are nonnegative. */
10770 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
10771 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10773 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
10774 /* True if the 2nd argument is nonnegative. */
10775 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10779 #undef CASE_BUILTIN_F
10780 #undef CASE_BUILTIN_I
10784 /* ... fall through ... */
10787 if (truth_value_p (TREE_CODE (t)))
10788 /* Truth values evaluate to 0 or 1, which is nonnegative. */
10792 /* We don't know sign of `t', so be conservative and return false. */
10796 /* Return true when T is an address and is known to be nonzero.
10797 For floating point we further ensure that T is not denormal.
10798 Similar logic is present in nonzero_address in rtlanal.h. */
10801 tree_expr_nonzero_p (tree t)
10803 tree type = TREE_TYPE (t);
10805 /* Doing something useful for floating point would need more work. */
10806 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
10809 switch (TREE_CODE (t))
10812 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10813 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10816 /* We used to test for !integer_zerop here. This does not work correctly
10817 if TREE_CONSTANT_OVERFLOW (t). */
10818 return (TREE_INT_CST_LOW (t) != 0
10819 || TREE_INT_CST_HIGH (t) != 0);
10822 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10824 /* With the presence of negative values it is hard
10825 to say something. */
10826 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10827 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
10829 /* One of operands must be positive and the other non-negative. */
10830 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10831 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10836 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10838 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10839 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10845 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
10846 tree outer_type = TREE_TYPE (t);
10848 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
10849 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
10855 tree base = get_base_address (TREE_OPERAND (t, 0));
10860 /* Weak declarations may link to NULL. */
10862 return !DECL_WEAK (base);
10864 /* Constants are never weak. */
10865 if (CONSTANT_CLASS_P (base))
10872 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10873 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
10876 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10877 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10880 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
10882 /* When both operands are nonzero, then MAX must be too. */
10883 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
10886 /* MAX where operand 0 is positive is positive. */
10887 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10889 /* MAX where operand 1 is positive is positive. */
10890 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10891 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
10895 case COMPOUND_EXPR:
10898 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
10901 case NON_LVALUE_EXPR:
10902 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10905 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10906 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10914 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
10915 attempt to fold the expression to a constant without modifying TYPE,
10918 If the expression could be simplified to a constant, then return
10919 the constant. If the expression would not be simplified to a
10920 constant, then return NULL_TREE. */
10923 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
10925 tree tem = fold_binary (code, type, op0, op1);
10926 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
10929 /* Given the components of a unary expression CODE, TYPE and OP0,
10930 attempt to fold the expression to a constant without modifying
10933 If the expression could be simplified to a constant, then return
10934 the constant. If the expression would not be simplified to a
10935 constant, then return NULL_TREE. */
10938 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
10940 tree tem = fold_unary (code, type, op0);
10941 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
10944 /* If EXP represents referencing an element in a constant string
10945 (either via pointer arithmetic or array indexing), return the
10946 tree representing the value accessed, otherwise return NULL. */
10949 fold_read_from_constant_string (tree exp)
10951 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
10953 tree exp1 = TREE_OPERAND (exp, 0);
10957 if (TREE_CODE (exp) == INDIRECT_REF)
10958 string = string_constant (exp1, &index);
10961 tree low_bound = array_ref_low_bound (exp);
10962 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
10964 /* Optimize the special-case of a zero lower bound.
10966 We convert the low_bound to sizetype to avoid some problems
10967 with constant folding. (E.g. suppose the lower bound is 1,
10968 and its mode is QI. Without the conversion,l (ARRAY
10969 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
10970 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
10971 if (! integer_zerop (low_bound))
10972 index = size_diffop (index, fold_convert (sizetype, low_bound));
10978 && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
10979 && TREE_CODE (string) == STRING_CST
10980 && TREE_CODE (index) == INTEGER_CST
10981 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
10982 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
10984 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
10985 return fold_convert (TREE_TYPE (exp),
10986 build_int_cst (NULL_TREE,
10987 (TREE_STRING_POINTER (string)
10988 [TREE_INT_CST_LOW (index)])));
10993 /* Return the tree for neg (ARG0) when ARG0 is known to be either
10994 an integer constant or real constant.
10996 TYPE is the type of the result. */
10999 fold_negate_const (tree arg0, tree type)
11001 tree t = NULL_TREE;
11003 switch (TREE_CODE (arg0))
11007 unsigned HOST_WIDE_INT low;
11008 HOST_WIDE_INT high;
11009 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
11010 TREE_INT_CST_HIGH (arg0),
11012 t = build_int_cst_wide (type, low, high);
11013 t = force_fit_type (t, 1,
11014 (overflow | TREE_OVERFLOW (arg0))
11015 && !TYPE_UNSIGNED (type),
11016 TREE_CONSTANT_OVERFLOW (arg0));
11021 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
11025 gcc_unreachable ();
11031 /* Return the tree for abs (ARG0) when ARG0 is known to be either
11032 an integer constant or real constant.
11034 TYPE is the type of the result. */
11037 fold_abs_const (tree arg0, tree type)
11039 tree t = NULL_TREE;
11041 switch (TREE_CODE (arg0))
11044 /* If the value is unsigned, then the absolute value is
11045 the same as the ordinary value. */
11046 if (TYPE_UNSIGNED (type))
11048 /* Similarly, if the value is non-negative. */
11049 else if (INT_CST_LT (integer_minus_one_node, arg0))
11051 /* If the value is negative, then the absolute value is
11055 unsigned HOST_WIDE_INT low;
11056 HOST_WIDE_INT high;
11057 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
11058 TREE_INT_CST_HIGH (arg0),
11060 t = build_int_cst_wide (type, low, high);
11061 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
11062 TREE_CONSTANT_OVERFLOW (arg0));
11067 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
11068 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
11074 gcc_unreachable ();
11080 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
11081 constant. TYPE is the type of the result. */
11084 fold_not_const (tree arg0, tree type)
11086 tree t = NULL_TREE;
11088 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
11090 t = build_int_cst_wide (type,
11091 ~ TREE_INT_CST_LOW (arg0),
11092 ~ TREE_INT_CST_HIGH (arg0));
11093 t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
11094 TREE_CONSTANT_OVERFLOW (arg0));
11099 /* Given CODE, a relational operator, the target type, TYPE and two
11100 constant operands OP0 and OP1, return the result of the
11101 relational operation. If the result is not a compile time
11102 constant, then return NULL_TREE. */
11105 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
11107 int result, invert;
11109 /* From here on, the only cases we handle are when the result is
11110 known to be a constant. */
11112 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
11114 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
11115 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
11117 /* Handle the cases where either operand is a NaN. */
11118 if (real_isnan (c0) || real_isnan (c1))
11128 case UNORDERED_EXPR:
11142 if (flag_trapping_math)
11148 gcc_unreachable ();
11151 return constant_boolean_node (result, type);
11154 return constant_boolean_node (real_compare (code, c0, c1), type);
11157 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
11159 To compute GT, swap the arguments and do LT.
11160 To compute GE, do LT and invert the result.
11161 To compute LE, swap the arguments, do LT and invert the result.
11162 To compute NE, do EQ and invert the result.
11164 Therefore, the code below must handle only EQ and LT. */
11166 if (code == LE_EXPR || code == GT_EXPR)
11171 code = swap_tree_comparison (code);
11174 /* Note that it is safe to invert for real values here because we
11175 have already handled the one case that it matters. */
11178 if (code == NE_EXPR || code == GE_EXPR)
11181 code = invert_tree_comparison (code, false);
11184 /* Compute a result for LT or EQ if args permit;
11185 Otherwise return T. */
11186 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
11188 if (code == EQ_EXPR)
11189 result = tree_int_cst_equal (op0, op1);
11190 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
11191 result = INT_CST_LT_UNSIGNED (op0, op1);
11193 result = INT_CST_LT (op0, op1);
11200 return constant_boolean_node (result, type);
11203 /* Build an expression for the a clean point containing EXPR with type TYPE.
11204 Don't build a cleanup point expression for EXPR which don't have side
11208 fold_build_cleanup_point_expr (tree type, tree expr)
11210 /* If the expression does not have side effects then we don't have to wrap
11211 it with a cleanup point expression. */
11212 if (!TREE_SIDE_EFFECTS (expr))
11215 /* If the expression is a return, check to see if the expression inside the
11216 return has no side effects or the right hand side of the modify expression
11217 inside the return. If either don't have side effects set we don't need to
11218 wrap the expression in a cleanup point expression. Note we don't check the
11219 left hand side of the modify because it should always be a return decl. */
11220 if (TREE_CODE (expr) == RETURN_EXPR)
11222 tree op = TREE_OPERAND (expr, 0);
11223 if (!op || !TREE_SIDE_EFFECTS (op))
11225 op = TREE_OPERAND (op, 1);
11226 if (!TREE_SIDE_EFFECTS (op))
11230 return build1 (CLEANUP_POINT_EXPR, type, expr);
11233 /* Build an expression for the address of T. Folds away INDIRECT_REF to
11234 avoid confusing the gimplify process. */
11237 build_fold_addr_expr_with_type (tree t, tree ptrtype)
11239 /* The size of the object is not relevant when talking about its address. */
11240 if (TREE_CODE (t) == WITH_SIZE_EXPR)
11241 t = TREE_OPERAND (t, 0);
11243 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
11244 if (TREE_CODE (t) == INDIRECT_REF
11245 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
11247 t = TREE_OPERAND (t, 0);
11248 if (TREE_TYPE (t) != ptrtype)
11249 t = build1 (NOP_EXPR, ptrtype, t);
11255 while (handled_component_p (base))
11256 base = TREE_OPERAND (base, 0);
11258 TREE_ADDRESSABLE (base) = 1;
11260 t = build1 (ADDR_EXPR, ptrtype, t);
11267 build_fold_addr_expr (tree t)
11269 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
11272 /* Given a pointer value T, return a simplified version of an indirection
11273 through T, or NULL_TREE if no simplification is possible. */
11276 fold_indirect_ref_1 (tree t)
11278 tree type = TREE_TYPE (TREE_TYPE (t));
11283 subtype = TREE_TYPE (sub);
11284 if (!POINTER_TYPE_P (subtype))
11287 if (TREE_CODE (sub) == ADDR_EXPR)
11289 tree op = TREE_OPERAND (sub, 0);
11290 tree optype = TREE_TYPE (op);
11292 if (lang_hooks.types_compatible_p (type, optype))
11294 /* *(foo *)&fooarray => fooarray[0] */
11295 else if (TREE_CODE (optype) == ARRAY_TYPE
11296 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
11298 tree type_domain = TYPE_DOMAIN (optype);
11299 tree min_val = size_zero_node;
11300 if (type_domain && TYPE_MIN_VALUE (type_domain))
11301 min_val = TYPE_MIN_VALUE (type_domain);
11302 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
11306 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
11307 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
11308 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
11311 tree min_val = size_zero_node;
11312 sub = build_fold_indirect_ref (sub);
11313 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
11314 if (type_domain && TYPE_MIN_VALUE (type_domain))
11315 min_val = TYPE_MIN_VALUE (type_domain);
11316 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
11322 /* Builds an expression for an indirection through T, simplifying some
11326 build_fold_indirect_ref (tree t)
11328 tree sub = fold_indirect_ref_1 (t);
11333 return build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (t)), t);
11336 /* Given an INDIRECT_REF T, return either T or a simplified version. */
11339 fold_indirect_ref (tree t)
11341 tree sub = fold_indirect_ref_1 (TREE_OPERAND (t, 0));
11349 /* Strip non-trapping, non-side-effecting tree nodes from an expression
11350 whose result is ignored. The type of the returned tree need not be
11351 the same as the original expression. */
11354 fold_ignored_result (tree t)
11356 if (!TREE_SIDE_EFFECTS (t))
11357 return integer_zero_node;
11360 switch (TREE_CODE_CLASS (TREE_CODE (t)))
11363 t = TREE_OPERAND (t, 0);
11367 case tcc_comparison:
11368 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
11369 t = TREE_OPERAND (t, 0);
11370 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
11371 t = TREE_OPERAND (t, 1);
11376 case tcc_expression:
11377 switch (TREE_CODE (t))
11379 case COMPOUND_EXPR:
11380 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
11382 t = TREE_OPERAND (t, 0);
11386 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
11387 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
11389 t = TREE_OPERAND (t, 0);
11402 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
11403 This can only be applied to objects of a sizetype. */
11406 round_up (tree value, int divisor)
11408 tree div = NULL_TREE;
11410 gcc_assert (divisor > 0);
11414 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11415 have to do anything. Only do this when we are not given a const,
11416 because in that case, this check is more expensive than just
11418 if (TREE_CODE (value) != INTEGER_CST)
11420 div = build_int_cst (TREE_TYPE (value), divisor);
11422 if (multiple_of_p (TREE_TYPE (value), value, div))
11426 /* If divisor is a power of two, simplify this to bit manipulation. */
11427 if (divisor == (divisor & -divisor))
11431 t = build_int_cst (TREE_TYPE (value), divisor - 1);
11432 value = size_binop (PLUS_EXPR, value, t);
11433 t = build_int_cst (TREE_TYPE (value), -divisor);
11434 value = size_binop (BIT_AND_EXPR, value, t);
11439 div = build_int_cst (TREE_TYPE (value), divisor);
11440 value = size_binop (CEIL_DIV_EXPR, value, div);
11441 value = size_binop (MULT_EXPR, value, div);
11447 /* Likewise, but round down. */
11450 round_down (tree value, int divisor)
11452 tree div = NULL_TREE;
11454 gcc_assert (divisor > 0);
11458 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11459 have to do anything. Only do this when we are not given a const,
11460 because in that case, this check is more expensive than just
11462 if (TREE_CODE (value) != INTEGER_CST)
11464 div = build_int_cst (TREE_TYPE (value), divisor);
11466 if (multiple_of_p (TREE_TYPE (value), value, div))
11470 /* If divisor is a power of two, simplify this to bit manipulation. */
11471 if (divisor == (divisor & -divisor))
11475 t = build_int_cst (TREE_TYPE (value), -divisor);
11476 value = size_binop (BIT_AND_EXPR, value, t);
11481 div = build_int_cst (TREE_TYPE (value), divisor);
11482 value = size_binop (FLOOR_DIV_EXPR, value, div);
11483 value = size_binop (MULT_EXPR, value, div);
11489 /* Returns the pointer to the base of the object addressed by EXP and
11490 extracts the information about the offset of the access, storing it
11491 to PBITPOS and POFFSET. */
11494 split_address_to_core_and_offset (tree exp,
11495 HOST_WIDE_INT *pbitpos, tree *poffset)
11498 enum machine_mode mode;
11499 int unsignedp, volatilep;
11500 HOST_WIDE_INT bitsize;
11502 if (TREE_CODE (exp) == ADDR_EXPR)
11504 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
11505 poffset, &mode, &unsignedp, &volatilep,
11508 if (TREE_CODE (core) == INDIRECT_REF)
11509 core = TREE_OPERAND (core, 0);
11515 *poffset = NULL_TREE;
11521 /* Returns true if addresses of E1 and E2 differ by a constant, false
11522 otherwise. If they do, E1 - E2 is stored in *DIFF. */
11525 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
11528 HOST_WIDE_INT bitpos1, bitpos2;
11529 tree toffset1, toffset2, tdiff, type;
11531 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
11532 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
11534 if (bitpos1 % BITS_PER_UNIT != 0
11535 || bitpos2 % BITS_PER_UNIT != 0
11536 || !operand_equal_p (core1, core2, 0))
11539 if (toffset1 && toffset2)
11541 type = TREE_TYPE (toffset1);
11542 if (type != TREE_TYPE (toffset2))
11543 toffset2 = fold_convert (type, toffset2);
11545 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
11546 if (!host_integerp (tdiff, 0))
11549 *diff = tree_low_cst (tdiff, 0);
11551 else if (toffset1 || toffset2)
11553 /* If only one of the offsets is non-constant, the difference cannot
11560 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
11564 /* Simplify the floating point expression EXP when the sign of the
11565 result is not significant. Return NULL_TREE if no simplification
11569 fold_strip_sign_ops (tree exp)
11573 switch (TREE_CODE (exp))
11577 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
11578 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
11582 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
11584 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
11585 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
11586 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
11587 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
11588 arg0 ? arg0 : TREE_OPERAND (exp, 0),
11589 arg1 ? arg1 : TREE_OPERAND (exp, 1));