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 (0, "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 (0, "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 (0, "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 (0, "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 (0, "%<or%> of unmatched not-equal tests is always 1");
4956 return constant_boolean_node (true, truth_type);
4960 warning (0, "%<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 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
6154 && int_fits_type_p (arg1_unw, shorter_type))))
6155 return fold_build2 (code, type, arg0_unw,
6156 fold_convert (shorter_type, arg1_unw));
6158 if (TREE_CODE (arg1_unw) != INTEGER_CST)
6161 /* If we are comparing with the integer that does not fit into the range
6162 of the shorter type, the result is known. */
6163 outer_type = TREE_TYPE (arg1_unw);
6164 min = lower_bound_in_type (outer_type, shorter_type);
6165 max = upper_bound_in_type (outer_type, shorter_type);
6167 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6169 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6176 return omit_one_operand (type, integer_zero_node, arg0);
6181 return omit_one_operand (type, integer_one_node, arg0);
6187 return omit_one_operand (type, integer_one_node, arg0);
6189 return omit_one_operand (type, integer_zero_node, arg0);
6194 return omit_one_operand (type, integer_zero_node, arg0);
6196 return omit_one_operand (type, integer_one_node, arg0);
6205 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6206 ARG0 just the signedness is changed. */
6209 fold_sign_changed_comparison (enum tree_code code, tree type,
6210 tree arg0, tree arg1)
6212 tree arg0_inner, tmp;
6213 tree inner_type, outer_type;
6215 if (TREE_CODE (arg0) != NOP_EXPR
6216 && TREE_CODE (arg0) != CONVERT_EXPR)
6219 outer_type = TREE_TYPE (arg0);
6220 arg0_inner = TREE_OPERAND (arg0, 0);
6221 inner_type = TREE_TYPE (arg0_inner);
6223 #ifdef HAVE_canonicalize_funcptr_for_compare
6224 /* Disable this optimization if we're casting a function pointer
6225 type on targets that require function pointer canonicalization. */
6226 if (HAVE_canonicalize_funcptr_for_compare
6227 && TREE_CODE (inner_type) == POINTER_TYPE
6228 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
6232 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6235 if (TREE_CODE (arg1) != INTEGER_CST
6236 && !((TREE_CODE (arg1) == NOP_EXPR
6237 || TREE_CODE (arg1) == CONVERT_EXPR)
6238 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6241 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6246 if (TREE_CODE (arg1) == INTEGER_CST)
6248 tmp = build_int_cst_wide (inner_type,
6249 TREE_INT_CST_LOW (arg1),
6250 TREE_INT_CST_HIGH (arg1));
6251 arg1 = force_fit_type (tmp, 0,
6252 TREE_OVERFLOW (arg1),
6253 TREE_CONSTANT_OVERFLOW (arg1));
6256 arg1 = fold_convert (inner_type, arg1);
6258 return fold_build2 (code, type, arg0_inner, arg1);
6261 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
6262 step of the array. Reconstructs s and delta in the case of s * delta
6263 being an integer constant (and thus already folded).
6264 ADDR is the address. MULT is the multiplicative expression.
6265 If the function succeeds, the new address expression is returned. Otherwise
6266 NULL_TREE is returned. */
6269 try_move_mult_to_index (enum tree_code code, tree addr, tree op1)
6271 tree s, delta, step;
6272 tree ref = TREE_OPERAND (addr, 0), pref;
6276 /* Canonicalize op1 into a possibly non-constant delta
6277 and an INTEGER_CST s. */
6278 if (TREE_CODE (op1) == MULT_EXPR)
6280 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
6285 if (TREE_CODE (arg0) == INTEGER_CST)
6290 else if (TREE_CODE (arg1) == INTEGER_CST)
6298 else if (TREE_CODE (op1) == INTEGER_CST)
6305 /* Simulate we are delta * 1. */
6307 s = integer_one_node;
6310 for (;; ref = TREE_OPERAND (ref, 0))
6312 if (TREE_CODE (ref) == ARRAY_REF)
6314 step = array_ref_element_size (ref);
6315 if (TREE_CODE (step) != INTEGER_CST)
6320 if (! tree_int_cst_equal (step, s))
6325 /* Try if delta is a multiple of step. */
6326 tree mod = int_const_binop (TRUNC_MOD_EXPR, delta, step, 0);
6327 if (!integer_zerop (mod))
6330 delta = int_const_binop (EXACT_DIV_EXPR, delta, step, 0);
6333 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
6340 if (!handled_component_p (ref))
6344 /* We found the suitable array reference. So copy everything up to it,
6345 and replace the index. */
6347 pref = TREE_OPERAND (addr, 0);
6348 ret = copy_node (pref);
6353 pref = TREE_OPERAND (pref, 0);
6354 TREE_OPERAND (pos, 0) = copy_node (pref);
6355 pos = TREE_OPERAND (pos, 0);
6358 TREE_OPERAND (pos, 1) = fold_build2 (code, itype,
6359 fold_convert (itype,
6360 TREE_OPERAND (pos, 1)),
6361 fold_convert (itype, delta));
6363 return build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6367 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6368 means A >= Y && A != MAX, but in this case we know that
6369 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6372 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6374 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6376 if (TREE_CODE (bound) == LT_EXPR)
6377 a = TREE_OPERAND (bound, 0);
6378 else if (TREE_CODE (bound) == GT_EXPR)
6379 a = TREE_OPERAND (bound, 1);
6383 typea = TREE_TYPE (a);
6384 if (!INTEGRAL_TYPE_P (typea)
6385 && !POINTER_TYPE_P (typea))
6388 if (TREE_CODE (ineq) == LT_EXPR)
6390 a1 = TREE_OPERAND (ineq, 1);
6391 y = TREE_OPERAND (ineq, 0);
6393 else if (TREE_CODE (ineq) == GT_EXPR)
6395 a1 = TREE_OPERAND (ineq, 0);
6396 y = TREE_OPERAND (ineq, 1);
6401 if (TREE_TYPE (a1) != typea)
6404 diff = fold_build2 (MINUS_EXPR, typea, a1, a);
6405 if (!integer_onep (diff))
6408 return fold_build2 (GE_EXPR, type, a, y);
6411 /* Fold complex addition when both components are accessible by parts.
6412 Return non-null if successful. CODE should be PLUS_EXPR for addition,
6413 or MINUS_EXPR for subtraction. */
6416 fold_complex_add (tree type, tree ac, tree bc, enum tree_code code)
6418 tree ar, ai, br, bi, rr, ri, inner_type;
6420 if (TREE_CODE (ac) == COMPLEX_EXPR)
6421 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6422 else if (TREE_CODE (ac) == COMPLEX_CST)
6423 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6427 if (TREE_CODE (bc) == COMPLEX_EXPR)
6428 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6429 else if (TREE_CODE (bc) == COMPLEX_CST)
6430 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6434 inner_type = TREE_TYPE (type);
6436 rr = fold_build2 (code, inner_type, ar, br);
6437 ri = fold_build2 (code, inner_type, ai, bi);
6439 return fold_build2 (COMPLEX_EXPR, type, rr, ri);
6442 /* Perform some simplifications of complex multiplication when one or more
6443 of the components are constants or zeros. Return non-null if successful. */
6446 fold_complex_mult_parts (tree type, tree ar, tree ai, tree br, tree bi)
6448 tree rr, ri, inner_type, zero;
6449 bool ar0, ai0, br0, bi0, bi1;
6451 inner_type = TREE_TYPE (type);
6454 if (SCALAR_FLOAT_TYPE_P (inner_type))
6456 ar0 = ai0 = br0 = bi0 = bi1 = false;
6458 /* We're only interested in +0.0 here, thus we don't use real_zerop. */
6460 if (TREE_CODE (ar) == REAL_CST
6461 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ar), dconst0))
6462 ar0 = true, zero = ar;
6464 if (TREE_CODE (ai) == REAL_CST
6465 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ai), dconst0))
6466 ai0 = true, zero = ai;
6468 if (TREE_CODE (br) == REAL_CST
6469 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (br), dconst0))
6470 br0 = true, zero = br;
6472 if (TREE_CODE (bi) == REAL_CST)
6474 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst0))
6475 bi0 = true, zero = bi;
6476 else if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst1))
6482 ar0 = integer_zerop (ar);
6485 ai0 = integer_zerop (ai);
6488 br0 = integer_zerop (br);
6491 bi0 = integer_zerop (bi);
6498 bi1 = integer_onep (bi);
6501 /* We won't optimize anything below unless something is zero. */
6505 if (ai0 && br0 && bi1)
6510 else if (ai0 && bi0)
6512 rr = fold_build2 (MULT_EXPR, inner_type, ar, br);
6515 else if (ai0 && br0)
6518 ri = fold_build2 (MULT_EXPR, inner_type, ar, bi);
6520 else if (ar0 && bi0)
6523 ri = fold_build2 (MULT_EXPR, inner_type, ai, br);
6525 else if (ar0 && br0)
6527 rr = fold_build2 (MULT_EXPR, inner_type, ai, bi);
6528 rr = fold_build1 (NEGATE_EXPR, inner_type, rr);
6533 rr = fold_build2 (MULT_EXPR, inner_type, ar, br);
6534 ri = fold_build2 (MULT_EXPR, inner_type, ai, br);
6538 rr = fold_build2 (MULT_EXPR, inner_type, ar, br);
6539 ri = fold_build2 (MULT_EXPR, inner_type, ar, bi);
6543 rr = fold_build2 (MULT_EXPR, inner_type, ai, bi);
6544 rr = fold_build1 (NEGATE_EXPR, inner_type, rr);
6545 ri = fold_build2 (MULT_EXPR, inner_type, ar, bi);
6549 rr = fold_build2 (MULT_EXPR, inner_type, ai, bi);
6550 rr = fold_build1 (NEGATE_EXPR, inner_type, rr);
6551 ri = fold_build2 (MULT_EXPR, inner_type, ai, br);
6556 return fold_build2 (COMPLEX_EXPR, type, rr, ri);
6560 fold_complex_mult (tree type, tree ac, tree bc)
6562 tree ar, ai, br, bi;
6564 if (TREE_CODE (ac) == COMPLEX_EXPR)
6565 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6566 else if (TREE_CODE (ac) == COMPLEX_CST)
6567 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6571 if (TREE_CODE (bc) == COMPLEX_EXPR)
6572 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6573 else if (TREE_CODE (bc) == COMPLEX_CST)
6574 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6578 return fold_complex_mult_parts (type, ar, ai, br, bi);
6581 /* Perform some simplifications of complex division when one or more of
6582 the components are constants or zeros. Return non-null if successful. */
6585 fold_complex_div_parts (tree type, tree ar, tree ai, tree br, tree bi,
6586 enum tree_code code)
6588 tree rr, ri, inner_type, zero;
6589 bool ar0, ai0, br0, bi0, bi1;
6591 inner_type = TREE_TYPE (type);
6594 if (SCALAR_FLOAT_TYPE_P (inner_type))
6596 ar0 = ai0 = br0 = bi0 = bi1 = false;
6598 /* We're only interested in +0.0 here, thus we don't use real_zerop. */
6600 if (TREE_CODE (ar) == REAL_CST
6601 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ar), dconst0))
6602 ar0 = true, zero = ar;
6604 if (TREE_CODE (ai) == REAL_CST
6605 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (ai), dconst0))
6606 ai0 = true, zero = ai;
6608 if (TREE_CODE (br) == REAL_CST
6609 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (br), dconst0))
6610 br0 = true, zero = br;
6612 if (TREE_CODE (bi) == REAL_CST)
6614 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst0))
6615 bi0 = true, zero = bi;
6616 else if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (bi), dconst1))
6622 ar0 = integer_zerop (ar);
6625 ai0 = integer_zerop (ai);
6628 br0 = integer_zerop (br);
6631 bi0 = integer_zerop (bi);
6638 bi1 = integer_onep (bi);
6641 /* We won't optimize anything below unless something is zero. */
6647 rr = fold_build2 (code, inner_type, ar, br);
6650 else if (ai0 && br0)
6653 ri = fold_build2 (code, inner_type, ar, bi);
6654 ri = fold_build1 (NEGATE_EXPR, inner_type, ri);
6656 else if (ar0 && bi0)
6659 ri = fold_build2 (code, inner_type, ai, br);
6661 else if (ar0 && br0)
6663 rr = fold_build2 (code, inner_type, ai, bi);
6668 rr = fold_build2 (code, inner_type, ar, br);
6669 ri = fold_build2 (code, inner_type, ai, br);
6673 rr = fold_build2 (code, inner_type, ai, bi);
6674 ri = fold_build2 (code, inner_type, ar, bi);
6675 ri = fold_build1 (NEGATE_EXPR, inner_type, ri);
6680 return fold_build2 (COMPLEX_EXPR, type, rr, ri);
6684 fold_complex_div (tree type, tree ac, tree bc, enum tree_code code)
6686 tree ar, ai, br, bi;
6688 if (TREE_CODE (ac) == COMPLEX_EXPR)
6689 ar = TREE_OPERAND (ac, 0), ai = TREE_OPERAND (ac, 1);
6690 else if (TREE_CODE (ac) == COMPLEX_CST)
6691 ar = TREE_REALPART (ac), ai = TREE_IMAGPART (ac);
6695 if (TREE_CODE (bc) == COMPLEX_EXPR)
6696 br = TREE_OPERAND (bc, 0), bi = TREE_OPERAND (bc, 1);
6697 else if (TREE_CODE (bc) == COMPLEX_CST)
6698 br = TREE_REALPART (bc), bi = TREE_IMAGPART (bc);
6702 return fold_complex_div_parts (type, ar, ai, br, bi, code);
6705 /* Fold a unary expression of code CODE and type TYPE with operand
6706 OP0. Return the folded expression if folding is successful.
6707 Otherwise, return NULL_TREE. */
6710 fold_unary (enum tree_code code, tree type, tree op0)
6714 enum tree_code_class kind = TREE_CODE_CLASS (code);
6716 gcc_assert (IS_EXPR_CODE_CLASS (kind)
6717 && TREE_CODE_LENGTH (code) == 1);
6722 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
6724 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
6725 STRIP_SIGN_NOPS (arg0);
6729 /* Strip any conversions that don't change the mode. This
6730 is safe for every expression, except for a comparison
6731 expression because its signedness is derived from its
6734 Note that this is done as an internal manipulation within
6735 the constant folder, in order to find the simplest
6736 representation of the arguments so that their form can be
6737 studied. In any cases, the appropriate type conversions
6738 should be put back in the tree that will get out of the
6744 if (TREE_CODE_CLASS (code) == tcc_unary)
6746 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6747 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6748 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
6749 else if (TREE_CODE (arg0) == COND_EXPR)
6751 tree arg01 = TREE_OPERAND (arg0, 1);
6752 tree arg02 = TREE_OPERAND (arg0, 2);
6753 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6754 arg01 = fold_build1 (code, type, arg01);
6755 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6756 arg02 = fold_build1 (code, type, arg02);
6757 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6760 /* If this was a conversion, and all we did was to move into
6761 inside the COND_EXPR, bring it back out. But leave it if
6762 it is a conversion from integer to integer and the
6763 result precision is no wider than a word since such a
6764 conversion is cheap and may be optimized away by combine,
6765 while it couldn't if it were outside the COND_EXPR. Then return
6766 so we don't get into an infinite recursion loop taking the
6767 conversion out and then back in. */
6769 if ((code == NOP_EXPR || code == CONVERT_EXPR
6770 || code == NON_LVALUE_EXPR)
6771 && TREE_CODE (tem) == COND_EXPR
6772 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6773 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6774 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6775 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6776 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6777 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6778 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6780 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6781 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
6782 || flag_syntax_only))
6783 tem = build1 (code, type,
6785 TREE_TYPE (TREE_OPERAND
6786 (TREE_OPERAND (tem, 1), 0)),
6787 TREE_OPERAND (tem, 0),
6788 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6789 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6792 else if (COMPARISON_CLASS_P (arg0))
6794 if (TREE_CODE (type) == BOOLEAN_TYPE)
6796 arg0 = copy_node (arg0);
6797 TREE_TYPE (arg0) = type;
6800 else if (TREE_CODE (type) != INTEGER_TYPE)
6801 return fold_build3 (COND_EXPR, type, arg0,
6802 fold_build1 (code, type,
6804 fold_build1 (code, type,
6805 integer_zero_node));
6814 case FIX_TRUNC_EXPR:
6816 case FIX_FLOOR_EXPR:
6817 case FIX_ROUND_EXPR:
6818 if (TREE_TYPE (op0) == type)
6821 /* Handle cases of two conversions in a row. */
6822 if (TREE_CODE (op0) == NOP_EXPR
6823 || TREE_CODE (op0) == CONVERT_EXPR)
6825 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
6826 tree inter_type = TREE_TYPE (op0);
6827 int inside_int = INTEGRAL_TYPE_P (inside_type);
6828 int inside_ptr = POINTER_TYPE_P (inside_type);
6829 int inside_float = FLOAT_TYPE_P (inside_type);
6830 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
6831 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6832 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6833 int inter_int = INTEGRAL_TYPE_P (inter_type);
6834 int inter_ptr = POINTER_TYPE_P (inter_type);
6835 int inter_float = FLOAT_TYPE_P (inter_type);
6836 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
6837 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6838 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6839 int final_int = INTEGRAL_TYPE_P (type);
6840 int final_ptr = POINTER_TYPE_P (type);
6841 int final_float = FLOAT_TYPE_P (type);
6842 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
6843 unsigned int final_prec = TYPE_PRECISION (type);
6844 int final_unsignedp = TYPE_UNSIGNED (type);
6846 /* In addition to the cases of two conversions in a row
6847 handled below, if we are converting something to its own
6848 type via an object of identical or wider precision, neither
6849 conversion is needed. */
6850 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6851 && ((inter_int && final_int) || (inter_float && final_float))
6852 && inter_prec >= final_prec)
6853 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
6855 /* Likewise, if the intermediate and final types are either both
6856 float or both integer, we don't need the middle conversion if
6857 it is wider than the final type and doesn't change the signedness
6858 (for integers). Avoid this if the final type is a pointer
6859 since then we sometimes need the inner conversion. Likewise if
6860 the outer has a precision not equal to the size of its mode. */
6861 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6862 || (inter_float && inside_float)
6863 || (inter_vec && inside_vec))
6864 && inter_prec >= inside_prec
6865 && (inter_float || inter_vec
6866 || inter_unsignedp == inside_unsignedp)
6867 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6868 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6870 && (! final_vec || inter_prec == inside_prec))
6871 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
6873 /* If we have a sign-extension of a zero-extended value, we can
6874 replace that by a single zero-extension. */
6875 if (inside_int && inter_int && final_int
6876 && inside_prec < inter_prec && inter_prec < final_prec
6877 && inside_unsignedp && !inter_unsignedp)
6878 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
6880 /* Two conversions in a row are not needed unless:
6881 - some conversion is floating-point (overstrict for now), or
6882 - some conversion is a vector (overstrict for now), or
6883 - the intermediate type is narrower than both initial and
6885 - the intermediate type and innermost type differ in signedness,
6886 and the outermost type is wider than the intermediate, or
6887 - the initial type is a pointer type and the precisions of the
6888 intermediate and final types differ, or
6889 - the final type is a pointer type and the precisions of the
6890 initial and intermediate types differ. */
6891 if (! inside_float && ! inter_float && ! final_float
6892 && ! inside_vec && ! inter_vec && ! final_vec
6893 && (inter_prec > inside_prec || inter_prec > final_prec)
6894 && ! (inside_int && inter_int
6895 && inter_unsignedp != inside_unsignedp
6896 && inter_prec < final_prec)
6897 && ((inter_unsignedp && inter_prec > inside_prec)
6898 == (final_unsignedp && final_prec > inter_prec))
6899 && ! (inside_ptr && inter_prec != final_prec)
6900 && ! (final_ptr && inside_prec != inter_prec)
6901 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6902 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6904 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
6907 if (TREE_CODE (op0) == MODIFY_EXPR
6908 && TREE_CONSTANT (TREE_OPERAND (op0, 1))
6909 /* Detect assigning a bitfield. */
6910 && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
6911 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
6913 /* Don't leave an assignment inside a conversion
6914 unless assigning a bitfield. */
6915 tem = fold_build1 (code, type, TREE_OPERAND (op0, 1));
6916 /* First do the assignment, then return converted constant. */
6917 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
6918 TREE_NO_WARNING (tem) = 1;
6919 TREE_USED (tem) = 1;
6923 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6924 constants (if x has signed type, the sign bit cannot be set
6925 in c). This folds extension into the BIT_AND_EXPR. */
6926 if (INTEGRAL_TYPE_P (type)
6927 && TREE_CODE (type) != BOOLEAN_TYPE
6928 && TREE_CODE (op0) == BIT_AND_EXPR
6929 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
6932 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6935 if (TYPE_UNSIGNED (TREE_TYPE (and))
6936 || (TYPE_PRECISION (type)
6937 <= TYPE_PRECISION (TREE_TYPE (and))))
6939 else if (TYPE_PRECISION (TREE_TYPE (and1))
6940 <= HOST_BITS_PER_WIDE_INT
6941 && host_integerp (and1, 1))
6943 unsigned HOST_WIDE_INT cst;
6945 cst = tree_low_cst (and1, 1);
6946 cst &= (HOST_WIDE_INT) -1
6947 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6948 change = (cst == 0);
6949 #ifdef LOAD_EXTEND_OP
6951 && !flag_syntax_only
6952 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6955 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6956 and0 = fold_convert (uns, and0);
6957 and1 = fold_convert (uns, and1);
6963 tem = build_int_cst_wide (type, TREE_INT_CST_LOW (and1),
6964 TREE_INT_CST_HIGH (and1));
6965 tem = force_fit_type (tem, 0, TREE_OVERFLOW (and1),
6966 TREE_CONSTANT_OVERFLOW (and1));
6967 return fold_build2 (BIT_AND_EXPR, type,
6968 fold_convert (type, and0), tem);
6972 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6973 T2 being pointers to types of the same size. */
6974 if (POINTER_TYPE_P (type)
6975 && BINARY_CLASS_P (arg0)
6976 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6977 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6979 tree arg00 = TREE_OPERAND (arg0, 0);
6981 tree t1 = TREE_TYPE (arg00);
6982 tree tt0 = TREE_TYPE (t0);
6983 tree tt1 = TREE_TYPE (t1);
6984 tree s0 = TYPE_SIZE (tt0);
6985 tree s1 = TYPE_SIZE (tt1);
6987 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6988 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6989 TREE_OPERAND (arg0, 1));
6992 tem = fold_convert_const (code, type, arg0);
6993 return tem ? tem : NULL_TREE;
6995 case VIEW_CONVERT_EXPR:
6996 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
6997 return build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7001 if (negate_expr_p (arg0))
7002 return fold_convert (type, negate_expr (arg0));
7003 /* Convert - (~A) to A + 1. */
7004 if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == BIT_NOT_EXPR)
7005 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (arg0, 0),
7006 build_int_cst (type, 1));
7010 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
7011 return fold_abs_const (arg0, type);
7012 else if (TREE_CODE (arg0) == NEGATE_EXPR)
7013 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
7014 /* Convert fabs((double)float) into (double)fabsf(float). */
7015 else if (TREE_CODE (arg0) == NOP_EXPR
7016 && TREE_CODE (type) == REAL_TYPE)
7018 tree targ0 = strip_float_extensions (arg0);
7020 return fold_convert (type, fold_build1 (ABS_EXPR,
7024 else if (tree_expr_nonnegative_p (arg0))
7027 /* Strip sign ops from argument. */
7028 if (TREE_CODE (type) == REAL_TYPE)
7030 tem = fold_strip_sign_ops (arg0);
7032 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
7037 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7038 return fold_convert (type, arg0);
7039 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7040 return build2 (COMPLEX_EXPR, type,
7041 TREE_OPERAND (arg0, 0),
7042 negate_expr (TREE_OPERAND (arg0, 1)));
7043 else if (TREE_CODE (arg0) == COMPLEX_CST)
7044 return build_complex (type, TREE_REALPART (arg0),
7045 negate_expr (TREE_IMAGPART (arg0)));
7046 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7047 return fold_build2 (TREE_CODE (arg0), type,
7048 fold_build1 (CONJ_EXPR, type,
7049 TREE_OPERAND (arg0, 0)),
7050 fold_build1 (CONJ_EXPR, type,
7051 TREE_OPERAND (arg0, 1)));
7052 else if (TREE_CODE (arg0) == CONJ_EXPR)
7053 return TREE_OPERAND (arg0, 0);
7057 if (TREE_CODE (arg0) == INTEGER_CST)
7058 return fold_not_const (arg0, type);
7059 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
7060 return TREE_OPERAND (arg0, 0);
7061 /* Convert ~ (-A) to A - 1. */
7062 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
7063 return fold_build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
7064 build_int_cst (type, 1));
7065 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
7066 else if (INTEGRAL_TYPE_P (type)
7067 && ((TREE_CODE (arg0) == MINUS_EXPR
7068 && integer_onep (TREE_OPERAND (arg0, 1)))
7069 || (TREE_CODE (arg0) == PLUS_EXPR
7070 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
7071 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
7072 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
7073 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7074 && (tem = fold_unary (BIT_NOT_EXPR, type,
7076 TREE_OPERAND (arg0, 0)))))
7077 return fold_build2 (BIT_XOR_EXPR, type, tem,
7078 fold_convert (type, TREE_OPERAND (arg0, 1)));
7079 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7080 && (tem = fold_unary (BIT_NOT_EXPR, type,
7082 TREE_OPERAND (arg0, 1)))))
7083 return fold_build2 (BIT_XOR_EXPR, type,
7084 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
7088 case TRUTH_NOT_EXPR:
7089 /* The argument to invert_truthvalue must have Boolean type. */
7090 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7091 arg0 = fold_convert (boolean_type_node, arg0);
7093 /* Note that the operand of this must be an int
7094 and its values must be 0 or 1.
7095 ("true" is a fixed value perhaps depending on the language,
7096 but we don't handle values other than 1 correctly yet.) */
7097 tem = invert_truthvalue (arg0);
7098 /* Avoid infinite recursion. */
7099 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7101 return fold_convert (type, tem);
7104 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7106 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7107 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7108 TREE_OPERAND (arg0, 1));
7109 else if (TREE_CODE (arg0) == COMPLEX_CST)
7110 return TREE_REALPART (arg0);
7111 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7112 return fold_build2 (TREE_CODE (arg0), type,
7113 fold_build1 (REALPART_EXPR, type,
7114 TREE_OPERAND (arg0, 0)),
7115 fold_build1 (REALPART_EXPR, type,
7116 TREE_OPERAND (arg0, 1)));
7120 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7121 return fold_convert (type, integer_zero_node);
7122 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7123 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7124 TREE_OPERAND (arg0, 0));
7125 else if (TREE_CODE (arg0) == COMPLEX_CST)
7126 return TREE_IMAGPART (arg0);
7127 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7128 return fold_build2 (TREE_CODE (arg0), type,
7129 fold_build1 (IMAGPART_EXPR, type,
7130 TREE_OPERAND (arg0, 0)),
7131 fold_build1 (IMAGPART_EXPR, type,
7132 TREE_OPERAND (arg0, 1)));
7137 } /* switch (code) */
7140 /* Fold a binary expression of code CODE and type TYPE with operands
7141 OP0 and OP1. Return the folded expression if folding is
7142 successful. Otherwise, return NULL_TREE. */
7145 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
7147 tree t1 = NULL_TREE;
7149 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
7150 enum tree_code_class kind = TREE_CODE_CLASS (code);
7152 /* WINS will be nonzero when the switch is done
7153 if all operands are constant. */
7156 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7157 && TREE_CODE_LENGTH (code) == 2);
7166 /* Strip any conversions that don't change the mode. This is
7167 safe for every expression, except for a comparison expression
7168 because its signedness is derived from its operands. So, in
7169 the latter case, only strip conversions that don't change the
7172 Note that this is done as an internal manipulation within the
7173 constant folder, in order to find the simplest representation
7174 of the arguments so that their form can be studied. In any
7175 cases, the appropriate type conversions should be put back in
7176 the tree that will get out of the constant folder. */
7177 if (kind == tcc_comparison)
7178 STRIP_SIGN_NOPS (arg0);
7182 if (TREE_CODE (arg0) == COMPLEX_CST)
7183 subop = TREE_REALPART (arg0);
7187 if (TREE_CODE (subop) != INTEGER_CST
7188 && TREE_CODE (subop) != REAL_CST)
7189 /* Note that TREE_CONSTANT isn't enough:
7190 static var addresses are constant but we can't
7191 do arithmetic on them. */
7199 /* Strip any conversions that don't change the mode. This is
7200 safe for every expression, except for a comparison expression
7201 because its signedness is derived from its operands. So, in
7202 the latter case, only strip conversions that don't change the
7205 Note that this is done as an internal manipulation within the
7206 constant folder, in order to find the simplest representation
7207 of the arguments so that their form can be studied. In any
7208 cases, the appropriate type conversions should be put back in
7209 the tree that will get out of the constant folder. */
7210 if (kind == tcc_comparison)
7211 STRIP_SIGN_NOPS (arg1);
7215 if (TREE_CODE (arg1) == COMPLEX_CST)
7216 subop = TREE_REALPART (arg1);
7220 if (TREE_CODE (subop) != INTEGER_CST
7221 && TREE_CODE (subop) != REAL_CST)
7222 /* Note that TREE_CONSTANT isn't enough:
7223 static var addresses are constant but we can't
7224 do arithmetic on them. */
7228 /* If this is a commutative operation, and ARG0 is a constant, move it
7229 to ARG1 to reduce the number of tests below. */
7230 if (commutative_tree_code (code)
7231 && tree_swap_operands_p (arg0, arg1, true))
7232 return fold_build2 (code, type, op1, op0);
7234 /* Now WINS is set as described above,
7235 ARG0 is the first operand of EXPR,
7236 and ARG1 is the second operand (if it has more than one operand).
7238 First check for cases where an arithmetic operation is applied to a
7239 compound, conditional, or comparison operation. Push the arithmetic
7240 operation inside the compound or conditional to see if any folding
7241 can then be done. Convert comparison to conditional for this purpose.
7242 The also optimizes non-constant cases that used to be done in
7245 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
7246 one of the operands is a comparison and the other is a comparison, a
7247 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
7248 code below would make the expression more complex. Change it to a
7249 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
7250 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
7252 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
7253 || code == EQ_EXPR || code == NE_EXPR)
7254 && ((truth_value_p (TREE_CODE (arg0))
7255 && (truth_value_p (TREE_CODE (arg1))
7256 || (TREE_CODE (arg1) == BIT_AND_EXPR
7257 && integer_onep (TREE_OPERAND (arg1, 1)))))
7258 || (truth_value_p (TREE_CODE (arg1))
7259 && (truth_value_p (TREE_CODE (arg0))
7260 || (TREE_CODE (arg0) == BIT_AND_EXPR
7261 && integer_onep (TREE_OPERAND (arg0, 1)))))))
7263 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
7264 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
7267 fold_convert (boolean_type_node, arg0),
7268 fold_convert (boolean_type_node, arg1));
7270 if (code == EQ_EXPR)
7271 tem = invert_truthvalue (tem);
7273 return fold_convert (type, tem);
7276 if (TREE_CODE_CLASS (code) == tcc_comparison
7277 && TREE_CODE (arg0) == COMPOUND_EXPR)
7278 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7279 fold_build2 (code, type, TREE_OPERAND (arg0, 1), arg1));
7280 else if (TREE_CODE_CLASS (code) == tcc_comparison
7281 && TREE_CODE (arg1) == COMPOUND_EXPR)
7282 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
7283 fold_build2 (code, type, arg0, TREE_OPERAND (arg1, 1)));
7284 else if (TREE_CODE_CLASS (code) == tcc_binary
7285 || TREE_CODE_CLASS (code) == tcc_comparison)
7287 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7288 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7289 fold_build2 (code, type, TREE_OPERAND (arg0, 1),
7291 if (TREE_CODE (arg1) == COMPOUND_EXPR
7292 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
7293 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
7294 fold_build2 (code, type,
7295 arg0, TREE_OPERAND (arg1, 1)));
7297 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
7299 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
7301 /*cond_first_p=*/1);
7302 if (tem != NULL_TREE)
7306 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
7308 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
7310 /*cond_first_p=*/0);
7311 if (tem != NULL_TREE)
7319 /* A + (-B) -> A - B */
7320 if (TREE_CODE (arg1) == NEGATE_EXPR)
7321 return fold_build2 (MINUS_EXPR, type,
7322 fold_convert (type, arg0),
7323 fold_convert (type, TREE_OPERAND (arg1, 0)));
7324 /* (-A) + B -> B - A */
7325 if (TREE_CODE (arg0) == NEGATE_EXPR
7326 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
7327 return fold_build2 (MINUS_EXPR, type,
7328 fold_convert (type, arg1),
7329 fold_convert (type, TREE_OPERAND (arg0, 0)));
7330 /* Convert ~A + 1 to -A. */
7331 if (INTEGRAL_TYPE_P (type)
7332 && TREE_CODE (arg0) == BIT_NOT_EXPR
7333 && integer_onep (arg1))
7334 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
7336 if (TREE_CODE (type) == COMPLEX_TYPE)
7338 tem = fold_complex_add (type, arg0, arg1, PLUS_EXPR);
7343 if (! FLOAT_TYPE_P (type))
7345 if (integer_zerop (arg1))
7346 return non_lvalue (fold_convert (type, arg0));
7348 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
7349 with a constant, and the two constants have no bits in common,
7350 we should treat this as a BIT_IOR_EXPR since this may produce more
7352 if (TREE_CODE (arg0) == BIT_AND_EXPR
7353 && TREE_CODE (arg1) == BIT_AND_EXPR
7354 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7355 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7356 && integer_zerop (const_binop (BIT_AND_EXPR,
7357 TREE_OPERAND (arg0, 1),
7358 TREE_OPERAND (arg1, 1), 0)))
7360 code = BIT_IOR_EXPR;
7364 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
7365 (plus (plus (mult) (mult)) (foo)) so that we can
7366 take advantage of the factoring cases below. */
7367 if (((TREE_CODE (arg0) == PLUS_EXPR
7368 || TREE_CODE (arg0) == MINUS_EXPR)
7369 && TREE_CODE (arg1) == MULT_EXPR)
7370 || ((TREE_CODE (arg1) == PLUS_EXPR
7371 || TREE_CODE (arg1) == MINUS_EXPR)
7372 && TREE_CODE (arg0) == MULT_EXPR))
7374 tree parg0, parg1, parg, marg;
7375 enum tree_code pcode;
7377 if (TREE_CODE (arg1) == MULT_EXPR)
7378 parg = arg0, marg = arg1;
7380 parg = arg1, marg = arg0;
7381 pcode = TREE_CODE (parg);
7382 parg0 = TREE_OPERAND (parg, 0);
7383 parg1 = TREE_OPERAND (parg, 1);
7387 if (TREE_CODE (parg0) == MULT_EXPR
7388 && TREE_CODE (parg1) != MULT_EXPR)
7389 return fold_build2 (pcode, type,
7390 fold_build2 (PLUS_EXPR, type,
7391 fold_convert (type, parg0),
7392 fold_convert (type, marg)),
7393 fold_convert (type, parg1));
7394 if (TREE_CODE (parg0) != MULT_EXPR
7395 && TREE_CODE (parg1) == MULT_EXPR)
7396 return fold_build2 (PLUS_EXPR, type,
7397 fold_convert (type, parg0),
7398 fold_build2 (pcode, type,
7399 fold_convert (type, marg),
7404 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
7406 tree arg00, arg01, arg10, arg11;
7407 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7409 /* (A * C) + (B * C) -> (A+B) * C.
7410 We are most concerned about the case where C is a constant,
7411 but other combinations show up during loop reduction. Since
7412 it is not difficult, try all four possibilities. */
7414 arg00 = TREE_OPERAND (arg0, 0);
7415 arg01 = TREE_OPERAND (arg0, 1);
7416 arg10 = TREE_OPERAND (arg1, 0);
7417 arg11 = TREE_OPERAND (arg1, 1);
7420 if (operand_equal_p (arg01, arg11, 0))
7421 same = arg01, alt0 = arg00, alt1 = arg10;
7422 else if (operand_equal_p (arg00, arg10, 0))
7423 same = arg00, alt0 = arg01, alt1 = arg11;
7424 else if (operand_equal_p (arg00, arg11, 0))
7425 same = arg00, alt0 = arg01, alt1 = arg10;
7426 else if (operand_equal_p (arg01, arg10, 0))
7427 same = arg01, alt0 = arg00, alt1 = arg11;
7429 /* No identical multiplicands; see if we can find a common
7430 power-of-two factor in non-power-of-two multiplies. This
7431 can help in multi-dimensional array access. */
7432 else if (TREE_CODE (arg01) == INTEGER_CST
7433 && TREE_CODE (arg11) == INTEGER_CST
7434 && TREE_INT_CST_HIGH (arg01) == 0
7435 && TREE_INT_CST_HIGH (arg11) == 0)
7437 HOST_WIDE_INT int01, int11, tmp;
7438 int01 = TREE_INT_CST_LOW (arg01);
7439 int11 = TREE_INT_CST_LOW (arg11);
7441 /* Move min of absolute values to int11. */
7442 if ((int01 >= 0 ? int01 : -int01)
7443 < (int11 >= 0 ? int11 : -int11))
7445 tmp = int01, int01 = int11, int11 = tmp;
7446 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7447 alt0 = arg01, arg01 = arg11, arg11 = alt0;
7450 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
7452 alt0 = fold_build2 (MULT_EXPR, type, arg00,
7453 build_int_cst (NULL_TREE,
7461 return fold_build2 (MULT_EXPR, type,
7462 fold_build2 (PLUS_EXPR, type,
7463 fold_convert (type, alt0),
7464 fold_convert (type, alt1)),
7465 fold_convert (type, same));
7468 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
7469 of the array. Loop optimizer sometimes produce this type of
7471 if (TREE_CODE (arg0) == ADDR_EXPR)
7473 tem = try_move_mult_to_index (PLUS_EXPR, arg0, arg1);
7475 return fold_convert (type, fold (tem));
7477 else if (TREE_CODE (arg1) == ADDR_EXPR)
7479 tem = try_move_mult_to_index (PLUS_EXPR, arg1, arg0);
7481 return fold_convert (type, fold (tem));
7486 /* See if ARG1 is zero and X + ARG1 reduces to X. */
7487 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
7488 return non_lvalue (fold_convert (type, arg0));
7490 /* Likewise if the operands are reversed. */
7491 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7492 return non_lvalue (fold_convert (type, arg1));
7494 /* Convert X + -C into X - C. */
7495 if (TREE_CODE (arg1) == REAL_CST
7496 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
7498 tem = fold_negate_const (arg1, type);
7499 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
7500 return fold_build2 (MINUS_EXPR, type,
7501 fold_convert (type, arg0),
7502 fold_convert (type, tem));
7505 /* Convert x+x into x*2.0. */
7506 if (operand_equal_p (arg0, arg1, 0)
7507 && SCALAR_FLOAT_TYPE_P (type))
7508 return fold_build2 (MULT_EXPR, type, arg0,
7509 build_real (type, dconst2));
7511 /* Convert x*c+x into x*(c+1). */
7512 if (flag_unsafe_math_optimizations
7513 && TREE_CODE (arg0) == MULT_EXPR
7514 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7515 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
7516 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7520 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
7521 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7522 return fold_build2 (MULT_EXPR, type, arg1,
7523 build_real (type, c));
7526 /* Convert x+x*c into x*(c+1). */
7527 if (flag_unsafe_math_optimizations
7528 && TREE_CODE (arg1) == MULT_EXPR
7529 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
7530 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
7531 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
7535 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
7536 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7537 return fold_build2 (MULT_EXPR, type, arg0,
7538 build_real (type, c));
7541 /* Convert x*c1+x*c2 into x*(c1+c2). */
7542 if (flag_unsafe_math_optimizations
7543 && TREE_CODE (arg0) == MULT_EXPR
7544 && TREE_CODE (arg1) == MULT_EXPR
7545 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7546 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
7547 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
7548 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
7549 && operand_equal_p (TREE_OPERAND (arg0, 0),
7550 TREE_OPERAND (arg1, 0), 0))
7552 REAL_VALUE_TYPE c1, c2;
7554 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
7555 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
7556 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
7557 return fold_build2 (MULT_EXPR, type,
7558 TREE_OPERAND (arg0, 0),
7559 build_real (type, c1));
7561 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
7562 if (flag_unsafe_math_optimizations
7563 && TREE_CODE (arg1) == PLUS_EXPR
7564 && TREE_CODE (arg0) != MULT_EXPR)
7566 tree tree10 = TREE_OPERAND (arg1, 0);
7567 tree tree11 = TREE_OPERAND (arg1, 1);
7568 if (TREE_CODE (tree11) == MULT_EXPR
7569 && TREE_CODE (tree10) == MULT_EXPR)
7572 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
7573 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
7576 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
7577 if (flag_unsafe_math_optimizations
7578 && TREE_CODE (arg0) == PLUS_EXPR
7579 && TREE_CODE (arg1) != MULT_EXPR)
7581 tree tree00 = TREE_OPERAND (arg0, 0);
7582 tree tree01 = TREE_OPERAND (arg0, 1);
7583 if (TREE_CODE (tree01) == MULT_EXPR
7584 && TREE_CODE (tree00) == MULT_EXPR)
7587 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
7588 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
7594 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
7595 is a rotate of A by C1 bits. */
7596 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
7597 is a rotate of A by B bits. */
7599 enum tree_code code0, code1;
7600 code0 = TREE_CODE (arg0);
7601 code1 = TREE_CODE (arg1);
7602 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
7603 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
7604 && operand_equal_p (TREE_OPERAND (arg0, 0),
7605 TREE_OPERAND (arg1, 0), 0)
7606 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7608 tree tree01, tree11;
7609 enum tree_code code01, code11;
7611 tree01 = TREE_OPERAND (arg0, 1);
7612 tree11 = TREE_OPERAND (arg1, 1);
7613 STRIP_NOPS (tree01);
7614 STRIP_NOPS (tree11);
7615 code01 = TREE_CODE (tree01);
7616 code11 = TREE_CODE (tree11);
7617 if (code01 == INTEGER_CST
7618 && code11 == INTEGER_CST
7619 && TREE_INT_CST_HIGH (tree01) == 0
7620 && TREE_INT_CST_HIGH (tree11) == 0
7621 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
7622 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
7623 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
7624 code0 == LSHIFT_EXPR ? tree01 : tree11);
7625 else if (code11 == MINUS_EXPR)
7627 tree tree110, tree111;
7628 tree110 = TREE_OPERAND (tree11, 0);
7629 tree111 = TREE_OPERAND (tree11, 1);
7630 STRIP_NOPS (tree110);
7631 STRIP_NOPS (tree111);
7632 if (TREE_CODE (tree110) == INTEGER_CST
7633 && 0 == compare_tree_int (tree110,
7635 (TREE_TYPE (TREE_OPERAND
7637 && operand_equal_p (tree01, tree111, 0))
7638 return build2 ((code0 == LSHIFT_EXPR
7641 type, TREE_OPERAND (arg0, 0), tree01);
7643 else if (code01 == MINUS_EXPR)
7645 tree tree010, tree011;
7646 tree010 = TREE_OPERAND (tree01, 0);
7647 tree011 = TREE_OPERAND (tree01, 1);
7648 STRIP_NOPS (tree010);
7649 STRIP_NOPS (tree011);
7650 if (TREE_CODE (tree010) == INTEGER_CST
7651 && 0 == compare_tree_int (tree010,
7653 (TREE_TYPE (TREE_OPERAND
7655 && operand_equal_p (tree11, tree011, 0))
7656 return build2 ((code0 != LSHIFT_EXPR
7659 type, TREE_OPERAND (arg0, 0), tree11);
7665 /* In most languages, can't associate operations on floats through
7666 parentheses. Rather than remember where the parentheses were, we
7667 don't associate floats at all, unless the user has specified
7668 -funsafe-math-optimizations. */
7671 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7673 tree var0, con0, lit0, minus_lit0;
7674 tree var1, con1, lit1, minus_lit1;
7676 /* Split both trees into variables, constants, and literals. Then
7677 associate each group together, the constants with literals,
7678 then the result with variables. This increases the chances of
7679 literals being recombined later and of generating relocatable
7680 expressions for the sum of a constant and literal. */
7681 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
7682 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
7683 code == MINUS_EXPR);
7685 /* Only do something if we found more than two objects. Otherwise,
7686 nothing has changed and we risk infinite recursion. */
7687 if (2 < ((var0 != 0) + (var1 != 0)
7688 + (con0 != 0) + (con1 != 0)
7689 + (lit0 != 0) + (lit1 != 0)
7690 + (minus_lit0 != 0) + (minus_lit1 != 0)))
7692 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
7693 if (code == MINUS_EXPR)
7696 var0 = associate_trees (var0, var1, code, type);
7697 con0 = associate_trees (con0, con1, code, type);
7698 lit0 = associate_trees (lit0, lit1, code, type);
7699 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
7701 /* Preserve the MINUS_EXPR if the negative part of the literal is
7702 greater than the positive part. Otherwise, the multiplicative
7703 folding code (i.e extract_muldiv) may be fooled in case
7704 unsigned constants are subtracted, like in the following
7705 example: ((X*2 + 4) - 8U)/2. */
7706 if (minus_lit0 && lit0)
7708 if (TREE_CODE (lit0) == INTEGER_CST
7709 && TREE_CODE (minus_lit0) == INTEGER_CST
7710 && tree_int_cst_lt (lit0, minus_lit0))
7712 minus_lit0 = associate_trees (minus_lit0, lit0,
7718 lit0 = associate_trees (lit0, minus_lit0,
7726 return fold_convert (type,
7727 associate_trees (var0, minus_lit0,
7731 con0 = associate_trees (con0, minus_lit0,
7733 return fold_convert (type,
7734 associate_trees (var0, con0,
7739 con0 = associate_trees (con0, lit0, code, type);
7740 return fold_convert (type, associate_trees (var0, con0,
7747 t1 = const_binop (code, arg0, arg1, 0);
7748 if (t1 != NULL_TREE)
7750 /* The return value should always have
7751 the same type as the original expression. */
7752 if (TREE_TYPE (t1) != type)
7753 t1 = fold_convert (type, t1);
7760 /* A - (-B) -> A + B */
7761 if (TREE_CODE (arg1) == NEGATE_EXPR)
7762 return fold_build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0));
7763 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
7764 if (TREE_CODE (arg0) == NEGATE_EXPR
7765 && (FLOAT_TYPE_P (type)
7766 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
7767 && negate_expr_p (arg1)
7768 && reorder_operands_p (arg0, arg1))
7769 return fold_build2 (MINUS_EXPR, type, negate_expr (arg1),
7770 TREE_OPERAND (arg0, 0));
7771 /* Convert -A - 1 to ~A. */
7772 if (INTEGRAL_TYPE_P (type)
7773 && TREE_CODE (arg0) == NEGATE_EXPR
7774 && integer_onep (arg1))
7775 return fold_build1 (BIT_NOT_EXPR, type, TREE_OPERAND (arg0, 0));
7777 /* Convert -1 - A to ~A. */
7778 if (INTEGRAL_TYPE_P (type)
7779 && integer_all_onesp (arg0))
7780 return fold_build1 (BIT_NOT_EXPR, type, arg1);
7782 if (TREE_CODE (type) == COMPLEX_TYPE)
7784 tem = fold_complex_add (type, arg0, arg1, MINUS_EXPR);
7789 if (! FLOAT_TYPE_P (type))
7791 if (! wins && integer_zerop (arg0))
7792 return negate_expr (fold_convert (type, arg1));
7793 if (integer_zerop (arg1))
7794 return non_lvalue (fold_convert (type, arg0));
7796 /* Fold A - (A & B) into ~B & A. */
7797 if (!TREE_SIDE_EFFECTS (arg0)
7798 && TREE_CODE (arg1) == BIT_AND_EXPR)
7800 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
7801 return fold_build2 (BIT_AND_EXPR, type,
7802 fold_build1 (BIT_NOT_EXPR, type,
7803 TREE_OPERAND (arg1, 0)),
7805 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7806 return fold_build2 (BIT_AND_EXPR, type,
7807 fold_build1 (BIT_NOT_EXPR, type,
7808 TREE_OPERAND (arg1, 1)),
7812 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
7813 any power of 2 minus 1. */
7814 if (TREE_CODE (arg0) == BIT_AND_EXPR
7815 && TREE_CODE (arg1) == BIT_AND_EXPR
7816 && operand_equal_p (TREE_OPERAND (arg0, 0),
7817 TREE_OPERAND (arg1, 0), 0))
7819 tree mask0 = TREE_OPERAND (arg0, 1);
7820 tree mask1 = TREE_OPERAND (arg1, 1);
7821 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
7823 if (operand_equal_p (tem, mask1, 0))
7825 tem = fold_build2 (BIT_XOR_EXPR, type,
7826 TREE_OPERAND (arg0, 0), mask1);
7827 return fold_build2 (MINUS_EXPR, type, tem, mask1);
7832 /* See if ARG1 is zero and X - ARG1 reduces to X. */
7833 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
7834 return non_lvalue (fold_convert (type, arg0));
7836 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
7837 ARG0 is zero and X + ARG0 reduces to X, since that would mean
7838 (-ARG1 + ARG0) reduces to -ARG1. */
7839 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7840 return negate_expr (fold_convert (type, arg1));
7842 /* Fold &x - &x. This can happen from &x.foo - &x.
7843 This is unsafe for certain floats even in non-IEEE formats.
7844 In IEEE, it is unsafe because it does wrong for NaNs.
7845 Also note that operand_equal_p is always false if an operand
7848 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
7849 && operand_equal_p (arg0, arg1, 0))
7850 return fold_convert (type, integer_zero_node);
7852 /* A - B -> A + (-B) if B is easily negatable. */
7853 if (!wins && negate_expr_p (arg1)
7854 && ((FLOAT_TYPE_P (type)
7855 /* Avoid this transformation if B is a positive REAL_CST. */
7856 && (TREE_CODE (arg1) != REAL_CST
7857 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
7858 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
7859 return fold_build2 (PLUS_EXPR, type, arg0, negate_expr (arg1));
7861 /* Try folding difference of addresses. */
7865 if ((TREE_CODE (arg0) == ADDR_EXPR
7866 || TREE_CODE (arg1) == ADDR_EXPR)
7867 && ptr_difference_const (arg0, arg1, &diff))
7868 return build_int_cst_type (type, diff);
7871 /* Fold &a[i] - &a[j] to i-j. */
7872 if (TREE_CODE (arg0) == ADDR_EXPR
7873 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
7874 && TREE_CODE (arg1) == ADDR_EXPR
7875 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
7877 tree aref0 = TREE_OPERAND (arg0, 0);
7878 tree aref1 = TREE_OPERAND (arg1, 0);
7879 if (operand_equal_p (TREE_OPERAND (aref0, 0),
7880 TREE_OPERAND (aref1, 0), 0))
7882 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
7883 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
7884 tree esz = array_ref_element_size (aref0);
7885 tree diff = build2 (MINUS_EXPR, type, op0, op1);
7886 return fold_build2 (MULT_EXPR, type, diff,
7887 fold_convert (type, esz));
7892 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
7893 of the array. Loop optimizer sometimes produce this type of
7895 if (TREE_CODE (arg0) == ADDR_EXPR)
7897 tem = try_move_mult_to_index (MINUS_EXPR, arg0, arg1);
7899 return fold_convert (type, fold (tem));
7902 if (TREE_CODE (arg0) == MULT_EXPR
7903 && TREE_CODE (arg1) == MULT_EXPR
7904 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7906 /* (A * C) - (B * C) -> (A-B) * C. */
7907 if (operand_equal_p (TREE_OPERAND (arg0, 1),
7908 TREE_OPERAND (arg1, 1), 0))
7909 return fold_build2 (MULT_EXPR, type,
7910 fold_build2 (MINUS_EXPR, type,
7911 TREE_OPERAND (arg0, 0),
7912 TREE_OPERAND (arg1, 0)),
7913 TREE_OPERAND (arg0, 1));
7914 /* (A * C1) - (A * C2) -> A * (C1-C2). */
7915 if (operand_equal_p (TREE_OPERAND (arg0, 0),
7916 TREE_OPERAND (arg1, 0), 0))
7917 return fold_build2 (MULT_EXPR, type,
7918 TREE_OPERAND (arg0, 0),
7919 fold_build2 (MINUS_EXPR, type,
7920 TREE_OPERAND (arg0, 1),
7921 TREE_OPERAND (arg1, 1)));
7927 /* (-A) * (-B) -> A * B */
7928 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7929 return fold_build2 (MULT_EXPR, type,
7930 TREE_OPERAND (arg0, 0),
7931 negate_expr (arg1));
7932 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7933 return fold_build2 (MULT_EXPR, type,
7935 TREE_OPERAND (arg1, 0));
7937 if (TREE_CODE (type) == COMPLEX_TYPE)
7939 tem = fold_complex_mult (type, arg0, arg1);
7944 if (! FLOAT_TYPE_P (type))
7946 if (integer_zerop (arg1))
7947 return omit_one_operand (type, arg1, arg0);
7948 if (integer_onep (arg1))
7949 return non_lvalue (fold_convert (type, arg0));
7950 /* Transform x * -1 into -x. */
7951 if (integer_all_onesp (arg1))
7952 return fold_convert (type, negate_expr (arg0));
7954 /* (a * (1 << b)) is (a << b) */
7955 if (TREE_CODE (arg1) == LSHIFT_EXPR
7956 && integer_onep (TREE_OPERAND (arg1, 0)))
7957 return fold_build2 (LSHIFT_EXPR, type, arg0,
7958 TREE_OPERAND (arg1, 1));
7959 if (TREE_CODE (arg0) == LSHIFT_EXPR
7960 && integer_onep (TREE_OPERAND (arg0, 0)))
7961 return fold_build2 (LSHIFT_EXPR, type, arg1,
7962 TREE_OPERAND (arg0, 1));
7964 if (TREE_CODE (arg1) == INTEGER_CST
7965 && 0 != (tem = extract_muldiv (op0,
7966 fold_convert (type, arg1),
7968 return fold_convert (type, tem);
7973 /* Maybe fold x * 0 to 0. The expressions aren't the same
7974 when x is NaN, since x * 0 is also NaN. Nor are they the
7975 same in modes with signed zeros, since multiplying a
7976 negative value by 0 gives -0, not +0. */
7977 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
7978 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
7979 && real_zerop (arg1))
7980 return omit_one_operand (type, arg1, arg0);
7981 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7982 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7983 && real_onep (arg1))
7984 return non_lvalue (fold_convert (type, arg0));
7986 /* Transform x * -1.0 into -x. */
7987 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7988 && real_minus_onep (arg1))
7989 return fold_convert (type, negate_expr (arg0));
7991 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7992 if (flag_unsafe_math_optimizations
7993 && TREE_CODE (arg0) == RDIV_EXPR
7994 && TREE_CODE (arg1) == REAL_CST
7995 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
7997 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
8000 return fold_build2 (RDIV_EXPR, type, tem,
8001 TREE_OPERAND (arg0, 1));
8004 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
8005 if (operand_equal_p (arg0, arg1, 0))
8007 tree tem = fold_strip_sign_ops (arg0);
8008 if (tem != NULL_TREE)
8010 tem = fold_convert (type, tem);
8011 return fold_build2 (MULT_EXPR, type, tem, tem);
8015 if (flag_unsafe_math_optimizations)
8017 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
8018 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
8020 /* Optimizations of root(...)*root(...). */
8021 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
8023 tree rootfn, arg, arglist;
8024 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
8025 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
8027 /* Optimize sqrt(x)*sqrt(x) as x. */
8028 if (BUILTIN_SQRT_P (fcode0)
8029 && operand_equal_p (arg00, arg10, 0)
8030 && ! HONOR_SNANS (TYPE_MODE (type)))
8033 /* Optimize root(x)*root(y) as root(x*y). */
8034 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8035 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
8036 arglist = build_tree_list (NULL_TREE, arg);
8037 return build_function_call_expr (rootfn, arglist);
8040 /* Optimize expN(x)*expN(y) as expN(x+y). */
8041 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
8043 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8044 tree arg = fold_build2 (PLUS_EXPR, type,
8045 TREE_VALUE (TREE_OPERAND (arg0, 1)),
8046 TREE_VALUE (TREE_OPERAND (arg1, 1)));
8047 tree arglist = build_tree_list (NULL_TREE, arg);
8048 return build_function_call_expr (expfn, arglist);
8051 /* Optimizations of pow(...)*pow(...). */
8052 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
8053 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
8054 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
8056 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
8057 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
8059 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
8060 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
8063 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
8064 if (operand_equal_p (arg01, arg11, 0))
8066 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8067 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
8068 tree arglist = tree_cons (NULL_TREE, arg,
8069 build_tree_list (NULL_TREE,
8071 return build_function_call_expr (powfn, arglist);
8074 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
8075 if (operand_equal_p (arg00, arg10, 0))
8077 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8078 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
8079 tree arglist = tree_cons (NULL_TREE, arg00,
8080 build_tree_list (NULL_TREE,
8082 return build_function_call_expr (powfn, arglist);
8086 /* Optimize tan(x)*cos(x) as sin(x). */
8087 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
8088 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
8089 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
8090 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
8091 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
8092 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
8093 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8094 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8096 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
8098 if (sinfn != NULL_TREE)
8099 return build_function_call_expr (sinfn,
8100 TREE_OPERAND (arg0, 1));
8103 /* Optimize x*pow(x,c) as pow(x,c+1). */
8104 if (fcode1 == BUILT_IN_POW
8105 || fcode1 == BUILT_IN_POWF
8106 || fcode1 == BUILT_IN_POWL)
8108 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
8109 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
8111 if (TREE_CODE (arg11) == REAL_CST
8112 && ! TREE_CONSTANT_OVERFLOW (arg11)
8113 && operand_equal_p (arg0, arg10, 0))
8115 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8119 c = TREE_REAL_CST (arg11);
8120 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
8121 arg = build_real (type, c);
8122 arglist = build_tree_list (NULL_TREE, arg);
8123 arglist = tree_cons (NULL_TREE, arg0, arglist);
8124 return build_function_call_expr (powfn, arglist);
8128 /* Optimize pow(x,c)*x as pow(x,c+1). */
8129 if (fcode0 == BUILT_IN_POW
8130 || fcode0 == BUILT_IN_POWF
8131 || fcode0 == BUILT_IN_POWL)
8133 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
8134 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
8136 if (TREE_CODE (arg01) == REAL_CST
8137 && ! TREE_CONSTANT_OVERFLOW (arg01)
8138 && operand_equal_p (arg1, arg00, 0))
8140 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8144 c = TREE_REAL_CST (arg01);
8145 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
8146 arg = build_real (type, c);
8147 arglist = build_tree_list (NULL_TREE, arg);
8148 arglist = tree_cons (NULL_TREE, arg1, arglist);
8149 return build_function_call_expr (powfn, arglist);
8153 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
8155 && operand_equal_p (arg0, arg1, 0))
8157 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
8161 tree arg = build_real (type, dconst2);
8162 tree arglist = build_tree_list (NULL_TREE, arg);
8163 arglist = tree_cons (NULL_TREE, arg0, arglist);
8164 return build_function_call_expr (powfn, arglist);
8173 if (integer_all_onesp (arg1))
8174 return omit_one_operand (type, arg1, arg0);
8175 if (integer_zerop (arg1))
8176 return non_lvalue (fold_convert (type, arg0));
8177 if (operand_equal_p (arg0, arg1, 0))
8178 return non_lvalue (fold_convert (type, arg0));
8181 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8182 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8184 t1 = build_int_cst (type, -1);
8185 t1 = force_fit_type (t1, 0, false, false);
8186 return omit_one_operand (type, t1, arg1);
8190 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8191 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8193 t1 = build_int_cst (type, -1);
8194 t1 = force_fit_type (t1, 0, false, false);
8195 return omit_one_operand (type, t1, arg0);
8198 t1 = distribute_bit_expr (code, type, arg0, arg1);
8199 if (t1 != NULL_TREE)
8202 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
8204 This results in more efficient code for machines without a NAND
8205 instruction. Combine will canonicalize to the first form
8206 which will allow use of NAND instructions provided by the
8207 backend if they exist. */
8208 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8209 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8211 return fold_build1 (BIT_NOT_EXPR, type,
8212 build2 (BIT_AND_EXPR, type,
8213 TREE_OPERAND (arg0, 0),
8214 TREE_OPERAND (arg1, 0)));
8217 /* See if this can be simplified into a rotate first. If that
8218 is unsuccessful continue in the association code. */
8222 if (integer_zerop (arg1))
8223 return non_lvalue (fold_convert (type, arg0));
8224 if (integer_all_onesp (arg1))
8225 return fold_build1 (BIT_NOT_EXPR, type, arg0);
8226 if (operand_equal_p (arg0, arg1, 0))
8227 return omit_one_operand (type, integer_zero_node, arg0);
8230 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8231 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8233 t1 = build_int_cst (type, -1);
8234 t1 = force_fit_type (t1, 0, false, false);
8235 return omit_one_operand (type, t1, arg1);
8239 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8240 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8242 t1 = build_int_cst (type, -1);
8243 t1 = force_fit_type (t1, 0, false, false);
8244 return omit_one_operand (type, t1, arg0);
8247 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
8248 with a constant, and the two constants have no bits in common,
8249 we should treat this as a BIT_IOR_EXPR since this may produce more
8251 if (TREE_CODE (arg0) == BIT_AND_EXPR
8252 && TREE_CODE (arg1) == BIT_AND_EXPR
8253 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8254 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8255 && integer_zerop (const_binop (BIT_AND_EXPR,
8256 TREE_OPERAND (arg0, 1),
8257 TREE_OPERAND (arg1, 1), 0)))
8259 code = BIT_IOR_EXPR;
8263 /* Convert ~X ^ ~Y to X ^ Y. */
8264 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8265 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8266 return fold_build2 (code, type,
8267 fold_convert (type, TREE_OPERAND (arg0, 0)),
8268 fold_convert (type, TREE_OPERAND (arg1, 0)));
8270 /* See if this can be simplified into a rotate first. If that
8271 is unsuccessful continue in the association code. */
8275 if (integer_all_onesp (arg1))
8276 return non_lvalue (fold_convert (type, arg0));
8277 if (integer_zerop (arg1))
8278 return omit_one_operand (type, arg1, arg0);
8279 if (operand_equal_p (arg0, arg1, 0))
8280 return non_lvalue (fold_convert (type, arg0));
8282 /* ~X & X is always zero. */
8283 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8284 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8285 return omit_one_operand (type, integer_zero_node, arg1);
8287 /* X & ~X is always zero. */
8288 if (TREE_CODE (arg1) == BIT_NOT_EXPR
8289 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8290 return omit_one_operand (type, integer_zero_node, arg0);
8292 t1 = distribute_bit_expr (code, type, arg0, arg1);
8293 if (t1 != NULL_TREE)
8295 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
8296 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
8297 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
8300 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
8302 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
8303 && (~TREE_INT_CST_LOW (arg1)
8304 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
8305 return fold_convert (type, TREE_OPERAND (arg0, 0));
8308 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
8310 This results in more efficient code for machines without a NOR
8311 instruction. Combine will canonicalize to the first form
8312 which will allow use of NOR instructions provided by the
8313 backend if they exist. */
8314 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8315 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8317 return fold_build1 (BIT_NOT_EXPR, type,
8318 build2 (BIT_IOR_EXPR, type,
8319 TREE_OPERAND (arg0, 0),
8320 TREE_OPERAND (arg1, 0)));
8326 /* Don't touch a floating-point divide by zero unless the mode
8327 of the constant can represent infinity. */
8328 if (TREE_CODE (arg1) == REAL_CST
8329 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
8330 && real_zerop (arg1))
8333 /* (-A) / (-B) -> A / B */
8334 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
8335 return fold_build2 (RDIV_EXPR, type,
8336 TREE_OPERAND (arg0, 0),
8337 negate_expr (arg1));
8338 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
8339 return fold_build2 (RDIV_EXPR, type,
8341 TREE_OPERAND (arg1, 0));
8343 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
8344 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
8345 && real_onep (arg1))
8346 return non_lvalue (fold_convert (type, arg0));
8348 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
8349 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
8350 && real_minus_onep (arg1))
8351 return non_lvalue (fold_convert (type, negate_expr (arg0)));
8353 /* If ARG1 is a constant, we can convert this to a multiply by the
8354 reciprocal. This does not have the same rounding properties,
8355 so only do this if -funsafe-math-optimizations. We can actually
8356 always safely do it if ARG1 is a power of two, but it's hard to
8357 tell if it is or not in a portable manner. */
8358 if (TREE_CODE (arg1) == REAL_CST)
8360 if (flag_unsafe_math_optimizations
8361 && 0 != (tem = const_binop (code, build_real (type, dconst1),
8363 return fold_build2 (MULT_EXPR, type, arg0, tem);
8364 /* Find the reciprocal if optimizing and the result is exact. */
8368 r = TREE_REAL_CST (arg1);
8369 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
8371 tem = build_real (type, r);
8372 return fold_build2 (MULT_EXPR, type, arg0, tem);
8376 /* Convert A/B/C to A/(B*C). */
8377 if (flag_unsafe_math_optimizations
8378 && TREE_CODE (arg0) == RDIV_EXPR)
8379 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
8380 fold_build2 (MULT_EXPR, type,
8381 TREE_OPERAND (arg0, 1), arg1));
8383 /* Convert A/(B/C) to (A/B)*C. */
8384 if (flag_unsafe_math_optimizations
8385 && TREE_CODE (arg1) == RDIV_EXPR)
8386 return fold_build2 (MULT_EXPR, type,
8387 fold_build2 (RDIV_EXPR, type, arg0,
8388 TREE_OPERAND (arg1, 0)),
8389 TREE_OPERAND (arg1, 1));
8391 /* Convert C1/(X*C2) into (C1/C2)/X. */
8392 if (flag_unsafe_math_optimizations
8393 && TREE_CODE (arg1) == MULT_EXPR
8394 && TREE_CODE (arg0) == REAL_CST
8395 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
8397 tree tem = const_binop (RDIV_EXPR, arg0,
8398 TREE_OPERAND (arg1, 1), 0);
8400 return fold_build2 (RDIV_EXPR, type, tem,
8401 TREE_OPERAND (arg1, 0));
8404 if (TREE_CODE (type) == COMPLEX_TYPE)
8406 tem = fold_complex_div (type, arg0, arg1, code);
8411 if (flag_unsafe_math_optimizations)
8413 enum built_in_function fcode = builtin_mathfn_code (arg1);
8414 /* Optimize x/expN(y) into x*expN(-y). */
8415 if (BUILTIN_EXPONENT_P (fcode))
8417 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8418 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
8419 tree arglist = build_tree_list (NULL_TREE,
8420 fold_convert (type, arg));
8421 arg1 = build_function_call_expr (expfn, arglist);
8422 return fold_build2 (MULT_EXPR, type, arg0, arg1);
8425 /* Optimize x/pow(y,z) into x*pow(y,-z). */
8426 if (fcode == BUILT_IN_POW
8427 || fcode == BUILT_IN_POWF
8428 || fcode == BUILT_IN_POWL)
8430 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
8431 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
8432 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
8433 tree neg11 = fold_convert (type, negate_expr (arg11));
8434 tree arglist = tree_cons(NULL_TREE, arg10,
8435 build_tree_list (NULL_TREE, neg11));
8436 arg1 = build_function_call_expr (powfn, arglist);
8437 return fold_build2 (MULT_EXPR, type, arg0, arg1);
8441 if (flag_unsafe_math_optimizations)
8443 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
8444 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
8446 /* Optimize sin(x)/cos(x) as tan(x). */
8447 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
8448 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
8449 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
8450 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8451 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8453 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
8455 if (tanfn != NULL_TREE)
8456 return build_function_call_expr (tanfn,
8457 TREE_OPERAND (arg0, 1));
8460 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
8461 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
8462 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
8463 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
8464 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
8465 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
8467 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
8469 if (tanfn != NULL_TREE)
8471 tree tmp = TREE_OPERAND (arg0, 1);
8472 tmp = build_function_call_expr (tanfn, tmp);
8473 return fold_build2 (RDIV_EXPR, type,
8474 build_real (type, dconst1), tmp);
8478 /* Optimize pow(x,c)/x as pow(x,c-1). */
8479 if (fcode0 == BUILT_IN_POW
8480 || fcode0 == BUILT_IN_POWF
8481 || fcode0 == BUILT_IN_POWL)
8483 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
8484 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
8485 if (TREE_CODE (arg01) == REAL_CST
8486 && ! TREE_CONSTANT_OVERFLOW (arg01)
8487 && operand_equal_p (arg1, arg00, 0))
8489 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
8493 c = TREE_REAL_CST (arg01);
8494 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
8495 arg = build_real (type, c);
8496 arglist = build_tree_list (NULL_TREE, arg);
8497 arglist = tree_cons (NULL_TREE, arg1, arglist);
8498 return build_function_call_expr (powfn, arglist);
8504 case TRUNC_DIV_EXPR:
8505 case ROUND_DIV_EXPR:
8506 case FLOOR_DIV_EXPR:
8508 case EXACT_DIV_EXPR:
8509 if (integer_onep (arg1))
8510 return non_lvalue (fold_convert (type, arg0));
8511 if (integer_zerop (arg1))
8514 if (!TYPE_UNSIGNED (type)
8515 && TREE_CODE (arg1) == INTEGER_CST
8516 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
8517 && TREE_INT_CST_HIGH (arg1) == -1)
8518 return fold_convert (type, negate_expr (arg0));
8520 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
8521 operation, EXACT_DIV_EXPR.
8523 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
8524 At one time others generated faster code, it's not clear if they do
8525 after the last round to changes to the DIV code in expmed.c. */
8526 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
8527 && multiple_of_p (type, arg0, arg1))
8528 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
8530 if (TREE_CODE (arg1) == INTEGER_CST
8531 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE)))
8532 return fold_convert (type, tem);
8534 if (TREE_CODE (type) == COMPLEX_TYPE)
8536 tem = fold_complex_div (type, arg0, arg1, code);
8543 case FLOOR_MOD_EXPR:
8544 case ROUND_MOD_EXPR:
8545 case TRUNC_MOD_EXPR:
8546 /* X % 1 is always zero, but be sure to preserve any side
8548 if (integer_onep (arg1))
8549 return omit_one_operand (type, integer_zero_node, arg0);
8551 /* X % 0, return X % 0 unchanged so that we can get the
8552 proper warnings and errors. */
8553 if (integer_zerop (arg1))
8556 /* 0 % X is always zero, but be sure to preserve any side
8557 effects in X. Place this after checking for X == 0. */
8558 if (integer_zerop (arg0))
8559 return omit_one_operand (type, integer_zero_node, arg1);
8561 /* X % -1 is zero. */
8562 if (!TYPE_UNSIGNED (type)
8563 && TREE_CODE (arg1) == INTEGER_CST
8564 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
8565 && TREE_INT_CST_HIGH (arg1) == -1)
8566 return omit_one_operand (type, integer_zero_node, arg0);
8568 /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
8569 BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
8570 if (code == TRUNC_MOD_EXPR
8571 && TYPE_UNSIGNED (type)
8572 && integer_pow2p (arg1))
8574 unsigned HOST_WIDE_INT high, low;
8578 l = tree_log2 (arg1);
8579 if (l >= HOST_BITS_PER_WIDE_INT)
8581 high = ((unsigned HOST_WIDE_INT) 1
8582 << (l - HOST_BITS_PER_WIDE_INT)) - 1;
8588 low = ((unsigned HOST_WIDE_INT) 1 << l) - 1;
8591 mask = build_int_cst_wide (type, low, high);
8592 return fold_build2 (BIT_AND_EXPR, type,
8593 fold_convert (type, arg0), mask);
8596 /* X % -C is the same as X % C. */
8597 if (code == TRUNC_MOD_EXPR
8598 && !TYPE_UNSIGNED (type)
8599 && TREE_CODE (arg1) == INTEGER_CST
8600 && !TREE_CONSTANT_OVERFLOW (arg1)
8601 && TREE_INT_CST_HIGH (arg1) < 0
8603 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
8604 && !sign_bit_p (arg1, arg1))
8605 return fold_build2 (code, type, fold_convert (type, arg0),
8606 fold_convert (type, negate_expr (arg1)));
8608 /* X % -Y is the same as X % Y. */
8609 if (code == TRUNC_MOD_EXPR
8610 && !TYPE_UNSIGNED (type)
8611 && TREE_CODE (arg1) == NEGATE_EXPR
8613 return fold_build2 (code, type, fold_convert (type, arg0),
8614 fold_convert (type, TREE_OPERAND (arg1, 0)));
8616 if (TREE_CODE (arg1) == INTEGER_CST
8617 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE)))
8618 return fold_convert (type, tem);
8624 if (integer_all_onesp (arg0))
8625 return omit_one_operand (type, arg0, arg1);
8629 /* Optimize -1 >> x for arithmetic right shifts. */
8630 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
8631 return omit_one_operand (type, arg0, arg1);
8632 /* ... fall through ... */
8636 if (integer_zerop (arg1))
8637 return non_lvalue (fold_convert (type, arg0));
8638 if (integer_zerop (arg0))
8639 return omit_one_operand (type, arg0, arg1);
8641 /* Since negative shift count is not well-defined,
8642 don't try to compute it in the compiler. */
8643 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
8645 /* Rewrite an LROTATE_EXPR by a constant into an
8646 RROTATE_EXPR by a new constant. */
8647 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
8649 tree tem = build_int_cst (NULL_TREE,
8650 GET_MODE_BITSIZE (TYPE_MODE (type)));
8651 tem = fold_convert (TREE_TYPE (arg1), tem);
8652 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
8653 return fold_build2 (RROTATE_EXPR, type, arg0, tem);
8656 /* If we have a rotate of a bit operation with the rotate count and
8657 the second operand of the bit operation both constant,
8658 permute the two operations. */
8659 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8660 && (TREE_CODE (arg0) == BIT_AND_EXPR
8661 || TREE_CODE (arg0) == BIT_IOR_EXPR
8662 || TREE_CODE (arg0) == BIT_XOR_EXPR)
8663 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8664 return fold_build2 (TREE_CODE (arg0), type,
8665 fold_build2 (code, type,
8666 TREE_OPERAND (arg0, 0), arg1),
8667 fold_build2 (code, type,
8668 TREE_OPERAND (arg0, 1), arg1));
8670 /* Two consecutive rotates adding up to the width of the mode can
8672 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8673 && TREE_CODE (arg0) == RROTATE_EXPR
8674 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8675 && TREE_INT_CST_HIGH (arg1) == 0
8676 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
8677 && ((TREE_INT_CST_LOW (arg1)
8678 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
8679 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
8680 return TREE_OPERAND (arg0, 0);
8685 if (operand_equal_p (arg0, arg1, 0))
8686 return omit_one_operand (type, arg0, arg1);
8687 if (INTEGRAL_TYPE_P (type)
8688 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
8689 return omit_one_operand (type, arg1, arg0);
8693 if (operand_equal_p (arg0, arg1, 0))
8694 return omit_one_operand (type, arg0, arg1);
8695 if (INTEGRAL_TYPE_P (type)
8696 && TYPE_MAX_VALUE (type)
8697 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
8698 return omit_one_operand (type, arg1, arg0);
8701 case TRUTH_ANDIF_EXPR:
8702 /* Note that the operands of this must be ints
8703 and their values must be 0 or 1.
8704 ("true" is a fixed value perhaps depending on the language.) */
8705 /* If first arg is constant zero, return it. */
8706 if (integer_zerop (arg0))
8707 return fold_convert (type, arg0);
8708 case TRUTH_AND_EXPR:
8709 /* If either arg is constant true, drop it. */
8710 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8711 return non_lvalue (fold_convert (type, arg1));
8712 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
8713 /* Preserve sequence points. */
8714 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8715 return non_lvalue (fold_convert (type, arg0));
8716 /* If second arg is constant zero, result is zero, but first arg
8717 must be evaluated. */
8718 if (integer_zerop (arg1))
8719 return omit_one_operand (type, arg1, arg0);
8720 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
8721 case will be handled here. */
8722 if (integer_zerop (arg0))
8723 return omit_one_operand (type, arg0, arg1);
8725 /* !X && X is always false. */
8726 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8727 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8728 return omit_one_operand (type, integer_zero_node, arg1);
8729 /* X && !X is always false. */
8730 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8731 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8732 return omit_one_operand (type, integer_zero_node, arg0);
8734 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
8735 means A >= Y && A != MAX, but in this case we know that
8738 if (!TREE_SIDE_EFFECTS (arg0)
8739 && !TREE_SIDE_EFFECTS (arg1))
8741 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
8743 return fold_build2 (code, type, tem, arg1);
8745 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
8747 return fold_build2 (code, type, arg0, tem);
8751 /* We only do these simplifications if we are optimizing. */
8755 /* Check for things like (A || B) && (A || C). We can convert this
8756 to A || (B && C). Note that either operator can be any of the four
8757 truth and/or operations and the transformation will still be
8758 valid. Also note that we only care about order for the
8759 ANDIF and ORIF operators. If B contains side effects, this
8760 might change the truth-value of A. */
8761 if (TREE_CODE (arg0) == TREE_CODE (arg1)
8762 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
8763 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
8764 || TREE_CODE (arg0) == TRUTH_AND_EXPR
8765 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
8766 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
8768 tree a00 = TREE_OPERAND (arg0, 0);
8769 tree a01 = TREE_OPERAND (arg0, 1);
8770 tree a10 = TREE_OPERAND (arg1, 0);
8771 tree a11 = TREE_OPERAND (arg1, 1);
8772 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
8773 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
8774 && (code == TRUTH_AND_EXPR
8775 || code == TRUTH_OR_EXPR));
8777 if (operand_equal_p (a00, a10, 0))
8778 return fold_build2 (TREE_CODE (arg0), type, a00,
8779 fold_build2 (code, type, a01, a11));
8780 else if (commutative && operand_equal_p (a00, a11, 0))
8781 return fold_build2 (TREE_CODE (arg0), type, a00,
8782 fold_build2 (code, type, a01, a10));
8783 else if (commutative && operand_equal_p (a01, a10, 0))
8784 return fold_build2 (TREE_CODE (arg0), type, a01,
8785 fold_build2 (code, type, a00, a11));
8787 /* This case if tricky because we must either have commutative
8788 operators or else A10 must not have side-effects. */
8790 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
8791 && operand_equal_p (a01, a11, 0))
8792 return fold_build2 (TREE_CODE (arg0), type,
8793 fold_build2 (code, type, a00, a10),
8797 /* See if we can build a range comparison. */
8798 if (0 != (tem = fold_range_test (code, type, op0, op1)))
8801 /* Check for the possibility of merging component references. If our
8802 lhs is another similar operation, try to merge its rhs with our
8803 rhs. Then try to merge our lhs and rhs. */
8804 if (TREE_CODE (arg0) == code
8805 && 0 != (tem = fold_truthop (code, type,
8806 TREE_OPERAND (arg0, 1), arg1)))
8807 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
8809 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
8814 case TRUTH_ORIF_EXPR:
8815 /* Note that the operands of this must be ints
8816 and their values must be 0 or true.
8817 ("true" is a fixed value perhaps depending on the language.) */
8818 /* If first arg is constant true, return it. */
8819 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8820 return fold_convert (type, arg0);
8822 /* If either arg is constant zero, drop it. */
8823 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
8824 return non_lvalue (fold_convert (type, arg1));
8825 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
8826 /* Preserve sequence points. */
8827 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
8828 return non_lvalue (fold_convert (type, arg0));
8829 /* If second arg is constant true, result is true, but we must
8830 evaluate first arg. */
8831 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
8832 return omit_one_operand (type, arg1, arg0);
8833 /* Likewise for first arg, but note this only occurs here for
8835 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
8836 return omit_one_operand (type, arg0, arg1);
8838 /* !X || X is always true. */
8839 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8840 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8841 return omit_one_operand (type, integer_one_node, arg1);
8842 /* X || !X is always true. */
8843 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8844 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8845 return omit_one_operand (type, integer_one_node, arg0);
8849 case TRUTH_XOR_EXPR:
8850 /* If the second arg is constant zero, drop it. */
8851 if (integer_zerop (arg1))
8852 return non_lvalue (fold_convert (type, arg0));
8853 /* If the second arg is constant true, this is a logical inversion. */
8854 if (integer_onep (arg1))
8856 /* Only call invert_truthvalue if operand is a truth value. */
8857 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8858 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
8860 tem = invert_truthvalue (arg0);
8861 return non_lvalue (fold_convert (type, tem));
8863 /* Identical arguments cancel to zero. */
8864 if (operand_equal_p (arg0, arg1, 0))
8865 return omit_one_operand (type, integer_zero_node, arg0);
8867 /* !X ^ X is always true. */
8868 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8869 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8870 return omit_one_operand (type, integer_one_node, arg1);
8872 /* X ^ !X is always true. */
8873 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8874 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8875 return omit_one_operand (type, integer_one_node, arg0);
8885 /* If one arg is a real or integer constant, put it last. */
8886 if (tree_swap_operands_p (arg0, arg1, true))
8887 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8889 /* bool_var != 0 becomes bool_var. */
8890 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
8892 return non_lvalue (fold_convert (type, arg0));
8894 /* bool_var == 1 becomes bool_var. */
8895 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
8897 return non_lvalue (fold_convert (type, arg0));
8899 /* If this is an equality comparison of the address of a non-weak
8900 object against zero, then we know the result. */
8901 if ((code == EQ_EXPR || code == NE_EXPR)
8902 && TREE_CODE (arg0) == ADDR_EXPR
8903 && DECL_P (TREE_OPERAND (arg0, 0))
8904 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8905 && integer_zerop (arg1))
8906 return constant_boolean_node (code != EQ_EXPR, type);
8908 /* If this is an equality comparison of the address of two non-weak,
8909 unaliased symbols neither of which are extern (since we do not
8910 have access to attributes for externs), then we know the result. */
8911 if ((code == EQ_EXPR || code == NE_EXPR)
8912 && TREE_CODE (arg0) == ADDR_EXPR
8913 && DECL_P (TREE_OPERAND (arg0, 0))
8914 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8915 && ! lookup_attribute ("alias",
8916 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
8917 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
8918 && TREE_CODE (arg1) == ADDR_EXPR
8919 && DECL_P (TREE_OPERAND (arg1, 0))
8920 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
8921 && ! lookup_attribute ("alias",
8922 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
8923 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
8924 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
8925 ? code == EQ_EXPR : code != EQ_EXPR,
8928 /* If this is a comparison of two exprs that look like an
8929 ARRAY_REF of the same object, then we can fold this to a
8930 comparison of the two offsets. */
8931 if (TREE_CODE_CLASS (code) == tcc_comparison)
8933 tree base0, offset0, base1, offset1;
8935 if (extract_array_ref (arg0, &base0, &offset0)
8936 && extract_array_ref (arg1, &base1, &offset1)
8937 && operand_equal_p (base0, base1, 0))
8939 if (offset0 == NULL_TREE
8940 && offset1 == NULL_TREE)
8942 offset0 = integer_zero_node;
8943 offset1 = integer_zero_node;
8945 else if (offset0 == NULL_TREE)
8946 offset0 = build_int_cst (TREE_TYPE (offset1), 0);
8947 else if (offset1 == NULL_TREE)
8948 offset1 = build_int_cst (TREE_TYPE (offset0), 0);
8950 if (TREE_TYPE (offset0) == TREE_TYPE (offset1))
8951 return fold_build2 (code, type, offset0, offset1);
8955 /* Transform comparisons of the form X +- C CMP X. */
8956 if ((code != EQ_EXPR && code != NE_EXPR)
8957 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8958 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
8959 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8960 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
8961 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8962 && !TYPE_UNSIGNED (TREE_TYPE (arg1))
8963 && !(flag_wrapv || flag_trapv))))
8965 tree arg01 = TREE_OPERAND (arg0, 1);
8966 enum tree_code code0 = TREE_CODE (arg0);
8969 if (TREE_CODE (arg01) == REAL_CST)
8970 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
8972 is_positive = tree_int_cst_sgn (arg01);
8974 /* (X - c) > X becomes false. */
8976 && ((code0 == MINUS_EXPR && is_positive >= 0)
8977 || (code0 == PLUS_EXPR && is_positive <= 0)))
8978 return constant_boolean_node (0, type);
8980 /* Likewise (X + c) < X becomes false. */
8982 && ((code0 == PLUS_EXPR && is_positive >= 0)
8983 || (code0 == MINUS_EXPR && is_positive <= 0)))
8984 return constant_boolean_node (0, type);
8986 /* Convert (X - c) <= X to true. */
8987 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
8989 && ((code0 == MINUS_EXPR && is_positive >= 0)
8990 || (code0 == PLUS_EXPR && is_positive <= 0)))
8991 return constant_boolean_node (1, type);
8993 /* Convert (X + c) >= X to true. */
8994 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
8996 && ((code0 == PLUS_EXPR && is_positive >= 0)
8997 || (code0 == MINUS_EXPR && is_positive <= 0)))
8998 return constant_boolean_node (1, type);
9000 if (TREE_CODE (arg01) == INTEGER_CST)
9002 /* Convert X + c > X and X - c < X to true for integers. */
9004 && ((code0 == PLUS_EXPR && is_positive > 0)
9005 || (code0 == MINUS_EXPR && is_positive < 0)))
9006 return constant_boolean_node (1, type);
9009 && ((code0 == MINUS_EXPR && is_positive > 0)
9010 || (code0 == PLUS_EXPR && is_positive < 0)))
9011 return constant_boolean_node (1, type);
9013 /* Convert X + c <= X and X - c >= X to false for integers. */
9015 && ((code0 == PLUS_EXPR && is_positive > 0)
9016 || (code0 == MINUS_EXPR && is_positive < 0)))
9017 return constant_boolean_node (0, type);
9020 && ((code0 == MINUS_EXPR && is_positive > 0)
9021 || (code0 == PLUS_EXPR && is_positive < 0)))
9022 return constant_boolean_node (0, type);
9026 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
9028 tree targ0 = strip_float_extensions (arg0);
9029 tree targ1 = strip_float_extensions (arg1);
9030 tree newtype = TREE_TYPE (targ0);
9032 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
9033 newtype = TREE_TYPE (targ1);
9035 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9036 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
9037 return fold_build2 (code, type, fold_convert (newtype, targ0),
9038 fold_convert (newtype, targ1));
9040 /* (-a) CMP (-b) -> b CMP a */
9041 if (TREE_CODE (arg0) == NEGATE_EXPR
9042 && TREE_CODE (arg1) == NEGATE_EXPR)
9043 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
9044 TREE_OPERAND (arg0, 0));
9046 if (TREE_CODE (arg1) == REAL_CST)
9048 REAL_VALUE_TYPE cst;
9049 cst = TREE_REAL_CST (arg1);
9051 /* (-a) CMP CST -> a swap(CMP) (-CST) */
9052 if (TREE_CODE (arg0) == NEGATE_EXPR)
9054 fold_build2 (swap_tree_comparison (code), type,
9055 TREE_OPERAND (arg0, 0),
9056 build_real (TREE_TYPE (arg1),
9057 REAL_VALUE_NEGATE (cst)));
9059 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
9060 /* a CMP (-0) -> a CMP 0 */
9061 if (REAL_VALUE_MINUS_ZERO (cst))
9062 return fold_build2 (code, type, arg0,
9063 build_real (TREE_TYPE (arg1), dconst0));
9065 /* x != NaN is always true, other ops are always false. */
9066 if (REAL_VALUE_ISNAN (cst)
9067 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
9069 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
9070 return omit_one_operand (type, tem, arg0);
9073 /* Fold comparisons against infinity. */
9074 if (REAL_VALUE_ISINF (cst))
9076 tem = fold_inf_compare (code, type, arg0, arg1);
9077 if (tem != NULL_TREE)
9082 /* If this is a comparison of a real constant with a PLUS_EXPR
9083 or a MINUS_EXPR of a real constant, we can convert it into a
9084 comparison with a revised real constant as long as no overflow
9085 occurs when unsafe_math_optimizations are enabled. */
9086 if (flag_unsafe_math_optimizations
9087 && TREE_CODE (arg1) == REAL_CST
9088 && (TREE_CODE (arg0) == PLUS_EXPR
9089 || TREE_CODE (arg0) == MINUS_EXPR)
9090 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
9091 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9092 ? MINUS_EXPR : PLUS_EXPR,
9093 arg1, TREE_OPERAND (arg0, 1), 0))
9094 && ! TREE_CONSTANT_OVERFLOW (tem))
9095 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9097 /* Likewise, we can simplify a comparison of a real constant with
9098 a MINUS_EXPR whose first operand is also a real constant, i.e.
9099 (c1 - x) < c2 becomes x > c1-c2. */
9100 if (flag_unsafe_math_optimizations
9101 && TREE_CODE (arg1) == REAL_CST
9102 && TREE_CODE (arg0) == MINUS_EXPR
9103 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
9104 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
9106 && ! TREE_CONSTANT_OVERFLOW (tem))
9107 return fold_build2 (swap_tree_comparison (code), type,
9108 TREE_OPERAND (arg0, 1), tem);
9110 /* Fold comparisons against built-in math functions. */
9111 if (TREE_CODE (arg1) == REAL_CST
9112 && flag_unsafe_math_optimizations
9113 && ! flag_errno_math)
9115 enum built_in_function fcode = builtin_mathfn_code (arg0);
9117 if (fcode != END_BUILTINS)
9119 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
9120 if (tem != NULL_TREE)
9126 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
9127 if (TREE_CONSTANT (arg1)
9128 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
9129 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
9130 /* This optimization is invalid for ordered comparisons
9131 if CONST+INCR overflows or if foo+incr might overflow.
9132 This optimization is invalid for floating point due to rounding.
9133 For pointer types we assume overflow doesn't happen. */
9134 && (POINTER_TYPE_P (TREE_TYPE (arg0))
9135 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
9136 && (code == EQ_EXPR || code == NE_EXPR))))
9138 tree varop, newconst;
9140 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
9142 newconst = fold_build2 (PLUS_EXPR, TREE_TYPE (arg0),
9143 arg1, TREE_OPERAND (arg0, 1));
9144 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
9145 TREE_OPERAND (arg0, 0),
9146 TREE_OPERAND (arg0, 1));
9150 newconst = fold_build2 (MINUS_EXPR, TREE_TYPE (arg0),
9151 arg1, TREE_OPERAND (arg0, 1));
9152 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
9153 TREE_OPERAND (arg0, 0),
9154 TREE_OPERAND (arg0, 1));
9158 /* If VAROP is a reference to a bitfield, we must mask
9159 the constant by the width of the field. */
9160 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
9161 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
9162 && host_integerp (DECL_SIZE (TREE_OPERAND
9163 (TREE_OPERAND (varop, 0), 1)), 1))
9165 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
9166 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
9167 tree folded_compare, shift;
9169 /* First check whether the comparison would come out
9170 always the same. If we don't do that we would
9171 change the meaning with the masking. */
9172 folded_compare = fold_build2 (code, type,
9173 TREE_OPERAND (varop, 0), arg1);
9174 if (integer_zerop (folded_compare)
9175 || integer_onep (folded_compare))
9176 return omit_one_operand (type, folded_compare, varop);
9178 shift = build_int_cst (NULL_TREE,
9179 TYPE_PRECISION (TREE_TYPE (varop)) - size);
9180 shift = fold_convert (TREE_TYPE (varop), shift);
9181 newconst = fold_build2 (LSHIFT_EXPR, TREE_TYPE (varop),
9183 newconst = fold_build2 (RSHIFT_EXPR, TREE_TYPE (varop),
9187 return fold_build2 (code, type, varop, newconst);
9190 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
9191 This transformation affects the cases which are handled in later
9192 optimizations involving comparisons with non-negative constants. */
9193 if (TREE_CODE (arg1) == INTEGER_CST
9194 && TREE_CODE (arg0) != INTEGER_CST
9195 && tree_int_cst_sgn (arg1) > 0)
9200 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9201 return fold_build2 (GT_EXPR, type, arg0, arg1);
9204 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9205 return fold_build2 (LE_EXPR, type, arg0, arg1);
9212 /* Comparisons with the highest or lowest possible integer of
9213 the specified size will have known values. */
9215 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
9217 if (TREE_CODE (arg1) == INTEGER_CST
9218 && ! TREE_CONSTANT_OVERFLOW (arg1)
9219 && width <= 2 * HOST_BITS_PER_WIDE_INT
9220 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9221 || POINTER_TYPE_P (TREE_TYPE (arg1))))
9223 HOST_WIDE_INT signed_max_hi;
9224 unsigned HOST_WIDE_INT signed_max_lo;
9225 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
9227 if (width <= HOST_BITS_PER_WIDE_INT)
9229 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
9234 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
9236 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9242 max_lo = signed_max_lo;
9243 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9249 width -= HOST_BITS_PER_WIDE_INT;
9251 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
9256 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
9258 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9263 max_hi = signed_max_hi;
9264 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9268 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
9269 && TREE_INT_CST_LOW (arg1) == max_lo)
9273 return omit_one_operand (type, integer_zero_node, arg0);
9276 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9279 return omit_one_operand (type, integer_one_node, arg0);
9282 return fold_build2 (NE_EXPR, type, arg0, arg1);
9284 /* The GE_EXPR and LT_EXPR cases above are not normally
9285 reached because of previous transformations. */
9290 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9292 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
9296 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
9297 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9299 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
9300 return fold_build2 (NE_EXPR, type, arg0, arg1);
9304 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9306 && TREE_INT_CST_LOW (arg1) == min_lo)
9310 return omit_one_operand (type, integer_zero_node, arg0);
9313 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9316 return omit_one_operand (type, integer_one_node, arg0);
9319 return fold_build2 (NE_EXPR, type, arg0, arg1);
9324 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
9326 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
9330 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9331 return fold_build2 (NE_EXPR, type, arg0, arg1);
9333 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
9334 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9339 else if (!in_gimple_form
9340 && TREE_INT_CST_HIGH (arg1) == signed_max_hi
9341 && TREE_INT_CST_LOW (arg1) == signed_max_lo
9342 && TYPE_UNSIGNED (TREE_TYPE (arg1))
9343 /* signed_type does not work on pointer types. */
9344 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9346 /* The following case also applies to X < signed_max+1
9347 and X >= signed_max+1 because previous transformations. */
9348 if (code == LE_EXPR || code == GT_EXPR)
9351 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
9352 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
9354 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
9355 type, fold_convert (st0, arg0),
9356 fold_convert (st1, integer_zero_node)));
9362 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
9363 a MINUS_EXPR of a constant, we can convert it into a comparison with
9364 a revised constant as long as no overflow occurs. */
9365 if ((code == EQ_EXPR || code == NE_EXPR)
9366 && TREE_CODE (arg1) == INTEGER_CST
9367 && (TREE_CODE (arg0) == PLUS_EXPR
9368 || TREE_CODE (arg0) == MINUS_EXPR)
9369 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9370 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
9371 ? MINUS_EXPR : PLUS_EXPR,
9372 arg1, TREE_OPERAND (arg0, 1), 0))
9373 && ! TREE_CONSTANT_OVERFLOW (tem))
9374 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9376 /* Similarly for a NEGATE_EXPR. */
9377 else if ((code == EQ_EXPR || code == NE_EXPR)
9378 && TREE_CODE (arg0) == NEGATE_EXPR
9379 && TREE_CODE (arg1) == INTEGER_CST
9380 && 0 != (tem = negate_expr (arg1))
9381 && TREE_CODE (tem) == INTEGER_CST
9382 && ! TREE_CONSTANT_OVERFLOW (tem))
9383 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
9385 /* If we have X - Y == 0, we can convert that to X == Y and similarly
9386 for !=. Don't do this for ordered comparisons due to overflow. */
9387 else if ((code == NE_EXPR || code == EQ_EXPR)
9388 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
9389 return fold_build2 (code, type,
9390 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
9392 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
9393 && (TREE_CODE (arg0) == NOP_EXPR
9394 || TREE_CODE (arg0) == CONVERT_EXPR))
9396 /* If we are widening one operand of an integer comparison,
9397 see if the other operand is similarly being widened. Perhaps we
9398 can do the comparison in the narrower type. */
9399 tem = fold_widened_comparison (code, type, arg0, arg1);
9403 /* Or if we are changing signedness. */
9404 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
9409 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
9410 constant, we can simplify it. */
9411 else if (TREE_CODE (arg1) == INTEGER_CST
9412 && (TREE_CODE (arg0) == MIN_EXPR
9413 || TREE_CODE (arg0) == MAX_EXPR)
9414 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9416 tem = optimize_minmax_comparison (code, type, op0, op1);
9423 /* If we are comparing an ABS_EXPR with a constant, we can
9424 convert all the cases into explicit comparisons, but they may
9425 well not be faster than doing the ABS and one comparison.
9426 But ABS (X) <= C is a range comparison, which becomes a subtraction
9427 and a comparison, and is probably faster. */
9428 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
9429 && TREE_CODE (arg0) == ABS_EXPR
9430 && ! TREE_SIDE_EFFECTS (arg0)
9431 && (0 != (tem = negate_expr (arg1)))
9432 && TREE_CODE (tem) == INTEGER_CST
9433 && ! TREE_CONSTANT_OVERFLOW (tem))
9434 return fold_build2 (TRUTH_ANDIF_EXPR, type,
9435 build2 (GE_EXPR, type,
9436 TREE_OPERAND (arg0, 0), tem),
9437 build2 (LE_EXPR, type,
9438 TREE_OPERAND (arg0, 0), arg1));
9440 /* Convert ABS_EXPR<x> >= 0 to true. */
9441 else if (code == GE_EXPR
9442 && tree_expr_nonnegative_p (arg0)
9443 && (integer_zerop (arg1)
9444 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
9445 && real_zerop (arg1))))
9446 return omit_one_operand (type, integer_one_node, arg0);
9448 /* Convert ABS_EXPR<x> < 0 to false. */
9449 else if (code == LT_EXPR
9450 && tree_expr_nonnegative_p (arg0)
9451 && (integer_zerop (arg1) || real_zerop (arg1)))
9452 return omit_one_operand (type, integer_zero_node, arg0);
9454 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
9455 else if ((code == EQ_EXPR || code == NE_EXPR)
9456 && TREE_CODE (arg0) == ABS_EXPR
9457 && (integer_zerop (arg1) || real_zerop (arg1)))
9458 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
9460 /* If this is an EQ or NE comparison with zero and ARG0 is
9461 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
9462 two operations, but the latter can be done in one less insn
9463 on machines that have only two-operand insns or on which a
9464 constant cannot be the first operand. */
9465 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
9466 && TREE_CODE (arg0) == BIT_AND_EXPR)
9468 tree arg00 = TREE_OPERAND (arg0, 0);
9469 tree arg01 = TREE_OPERAND (arg0, 1);
9470 if (TREE_CODE (arg00) == LSHIFT_EXPR
9471 && integer_onep (TREE_OPERAND (arg00, 0)))
9473 fold_build2 (code, type,
9474 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9475 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
9476 arg01, TREE_OPERAND (arg00, 1)),
9477 fold_convert (TREE_TYPE (arg0),
9480 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
9481 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
9483 fold_build2 (code, type,
9484 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9485 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
9486 arg00, TREE_OPERAND (arg01, 1)),
9487 fold_convert (TREE_TYPE (arg0),
9492 /* If this is an NE or EQ comparison of zero against the result of a
9493 signed MOD operation whose second operand is a power of 2, make
9494 the MOD operation unsigned since it is simpler and equivalent. */
9495 if ((code == NE_EXPR || code == EQ_EXPR)
9496 && integer_zerop (arg1)
9497 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
9498 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
9499 || TREE_CODE (arg0) == CEIL_MOD_EXPR
9500 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
9501 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
9502 && integer_pow2p (TREE_OPERAND (arg0, 1)))
9504 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
9505 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
9506 fold_convert (newtype,
9507 TREE_OPERAND (arg0, 0)),
9508 fold_convert (newtype,
9509 TREE_OPERAND (arg0, 1)));
9511 return fold_build2 (code, type, newmod,
9512 fold_convert (newtype, arg1));
9515 /* If this is an NE comparison of zero with an AND of one, remove the
9516 comparison since the AND will give the correct value. */
9517 if (code == NE_EXPR && integer_zerop (arg1)
9518 && TREE_CODE (arg0) == BIT_AND_EXPR
9519 && integer_onep (TREE_OPERAND (arg0, 1)))
9520 return fold_convert (type, arg0);
9522 /* If we have (A & C) == C where C is a power of 2, convert this into
9523 (A & C) != 0. Similarly for NE_EXPR. */
9524 if ((code == EQ_EXPR || code == NE_EXPR)
9525 && TREE_CODE (arg0) == BIT_AND_EXPR
9526 && integer_pow2p (TREE_OPERAND (arg0, 1))
9527 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
9528 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
9529 arg0, fold_convert (TREE_TYPE (arg0),
9530 integer_zero_node));
9532 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
9533 bit, then fold the expression into A < 0 or A >= 0. */
9534 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
9538 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
9539 Similarly for NE_EXPR. */
9540 if ((code == EQ_EXPR || code == NE_EXPR)
9541 && TREE_CODE (arg0) == BIT_AND_EXPR
9542 && TREE_CODE (arg1) == INTEGER_CST
9543 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9545 tree notc = fold_build1 (BIT_NOT_EXPR,
9546 TREE_TYPE (TREE_OPERAND (arg0, 1)),
9547 TREE_OPERAND (arg0, 1));
9548 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9550 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
9551 if (integer_nonzerop (dandnotc))
9552 return omit_one_operand (type, rslt, arg0);
9555 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
9556 Similarly for NE_EXPR. */
9557 if ((code == EQ_EXPR || code == NE_EXPR)
9558 && TREE_CODE (arg0) == BIT_IOR_EXPR
9559 && TREE_CODE (arg1) == INTEGER_CST
9560 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
9562 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
9563 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
9564 TREE_OPERAND (arg0, 1), notd);
9565 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
9566 if (integer_nonzerop (candnotd))
9567 return omit_one_operand (type, rslt, arg0);
9570 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
9571 and similarly for >= into !=. */
9572 if ((code == LT_EXPR || code == GE_EXPR)
9573 && TYPE_UNSIGNED (TREE_TYPE (arg0))
9574 && TREE_CODE (arg1) == LSHIFT_EXPR
9575 && integer_onep (TREE_OPERAND (arg1, 0)))
9576 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
9577 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
9578 TREE_OPERAND (arg1, 1)),
9579 fold_convert (TREE_TYPE (arg0), integer_zero_node));
9581 else if ((code == LT_EXPR || code == GE_EXPR)
9582 && TYPE_UNSIGNED (TREE_TYPE (arg0))
9583 && (TREE_CODE (arg1) == NOP_EXPR
9584 || TREE_CODE (arg1) == CONVERT_EXPR)
9585 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
9586 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
9588 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
9589 fold_convert (TREE_TYPE (arg0),
9590 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
9591 TREE_OPERAND (TREE_OPERAND (arg1, 0),
9593 fold_convert (TREE_TYPE (arg0), integer_zero_node));
9595 /* Simplify comparison of something with itself. (For IEEE
9596 floating-point, we can only do some of these simplifications.) */
9597 if (operand_equal_p (arg0, arg1, 0))
9602 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9603 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9604 return constant_boolean_node (1, type);
9609 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
9610 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9611 return constant_boolean_node (1, type);
9612 return fold_build2 (EQ_EXPR, type, arg0, arg1);
9615 /* For NE, we can only do this simplification if integer
9616 or we don't honor IEEE floating point NaNs. */
9617 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
9618 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
9620 /* ... fall through ... */
9623 return constant_boolean_node (0, type);
9629 /* If we are comparing an expression that just has comparisons
9630 of two integer values, arithmetic expressions of those comparisons,
9631 and constants, we can simplify it. There are only three cases
9632 to check: the two values can either be equal, the first can be
9633 greater, or the second can be greater. Fold the expression for
9634 those three values. Since each value must be 0 or 1, we have
9635 eight possibilities, each of which corresponds to the constant 0
9636 or 1 or one of the six possible comparisons.
9638 This handles common cases like (a > b) == 0 but also handles
9639 expressions like ((x > y) - (y > x)) > 0, which supposedly
9640 occur in macroized code. */
9642 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
9644 tree cval1 = 0, cval2 = 0;
9647 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
9648 /* Don't handle degenerate cases here; they should already
9649 have been handled anyway. */
9650 && cval1 != 0 && cval2 != 0
9651 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
9652 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
9653 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
9654 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
9655 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
9656 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
9657 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9659 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9660 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9662 /* We can't just pass T to eval_subst in case cval1 or cval2
9663 was the same as ARG1. */
9666 = fold_build2 (code, type,
9667 eval_subst (arg0, cval1, maxval,
9671 = fold_build2 (code, type,
9672 eval_subst (arg0, cval1, maxval,
9676 = fold_build2 (code, type,
9677 eval_subst (arg0, cval1, minval,
9681 /* All three of these results should be 0 or 1. Confirm they
9682 are. Then use those values to select the proper code
9685 if ((integer_zerop (high_result)
9686 || integer_onep (high_result))
9687 && (integer_zerop (equal_result)
9688 || integer_onep (equal_result))
9689 && (integer_zerop (low_result)
9690 || integer_onep (low_result)))
9692 /* Make a 3-bit mask with the high-order bit being the
9693 value for `>', the next for '=', and the low for '<'. */
9694 switch ((integer_onep (high_result) * 4)
9695 + (integer_onep (equal_result) * 2)
9696 + integer_onep (low_result))
9700 return omit_one_operand (type, integer_zero_node, arg0);
9721 return omit_one_operand (type, integer_one_node, arg0);
9725 return save_expr (build2 (code, type, cval1, cval2));
9727 return fold_build2 (code, type, cval1, cval2);
9732 /* If this is a comparison of a field, we may be able to simplify it. */
9733 if (((TREE_CODE (arg0) == COMPONENT_REF
9734 && lang_hooks.can_use_bit_fields_p ())
9735 || TREE_CODE (arg0) == BIT_FIELD_REF)
9736 && (code == EQ_EXPR || code == NE_EXPR)
9737 /* Handle the constant case even without -O
9738 to make sure the warnings are given. */
9739 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
9741 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
9746 /* Fold a comparison of the address of COMPONENT_REFs with the same
9747 type and component to a comparison of the address of the base
9748 object. In short, &x->a OP &y->a to x OP y and
9749 &x->a OP &y.a to x OP &y */
9750 if (TREE_CODE (arg0) == ADDR_EXPR
9751 && TREE_CODE (TREE_OPERAND (arg0, 0)) == COMPONENT_REF
9752 && TREE_CODE (arg1) == ADDR_EXPR
9753 && TREE_CODE (TREE_OPERAND (arg1, 0)) == COMPONENT_REF)
9755 tree cref0 = TREE_OPERAND (arg0, 0);
9756 tree cref1 = TREE_OPERAND (arg1, 0);
9757 if (TREE_OPERAND (cref0, 1) == TREE_OPERAND (cref1, 1))
9759 tree op0 = TREE_OPERAND (cref0, 0);
9760 tree op1 = TREE_OPERAND (cref1, 0);
9761 return fold_build2 (code, type,
9762 build_fold_addr_expr (op0),
9763 build_fold_addr_expr (op1));
9767 /* If this is a comparison of complex values and either or both sides
9768 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
9769 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
9770 This may prevent needless evaluations. */
9771 if ((code == EQ_EXPR || code == NE_EXPR)
9772 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
9773 && (TREE_CODE (arg0) == COMPLEX_EXPR
9774 || TREE_CODE (arg1) == COMPLEX_EXPR
9775 || TREE_CODE (arg0) == COMPLEX_CST
9776 || TREE_CODE (arg1) == COMPLEX_CST))
9778 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
9779 tree real0, imag0, real1, imag1;
9781 arg0 = save_expr (arg0);
9782 arg1 = save_expr (arg1);
9783 real0 = fold_build1 (REALPART_EXPR, subtype, arg0);
9784 imag0 = fold_build1 (IMAGPART_EXPR, subtype, arg0);
9785 real1 = fold_build1 (REALPART_EXPR, subtype, arg1);
9786 imag1 = fold_build1 (IMAGPART_EXPR, subtype, arg1);
9788 return fold_build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
9791 fold_build2 (code, type, real0, real1),
9792 fold_build2 (code, type, imag0, imag1));
9795 /* Optimize comparisons of strlen vs zero to a compare of the
9796 first character of the string vs zero. To wit,
9797 strlen(ptr) == 0 => *ptr == 0
9798 strlen(ptr) != 0 => *ptr != 0
9799 Other cases should reduce to one of these two (or a constant)
9800 due to the return value of strlen being unsigned. */
9801 if ((code == EQ_EXPR || code == NE_EXPR)
9802 && integer_zerop (arg1)
9803 && TREE_CODE (arg0) == CALL_EXPR)
9805 tree fndecl = get_callee_fndecl (arg0);
9809 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
9810 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
9811 && (arglist = TREE_OPERAND (arg0, 1))
9812 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
9813 && ! TREE_CHAIN (arglist))
9814 return fold_build2 (code, type,
9815 build1 (INDIRECT_REF, char_type_node,
9816 TREE_VALUE (arglist)),
9817 fold_convert (char_type_node,
9818 integer_zero_node));
9821 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9822 into a single range test. */
9823 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9824 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9825 && TREE_CODE (arg1) == INTEGER_CST
9826 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9827 && !integer_zerop (TREE_OPERAND (arg0, 1))
9828 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9829 && !TREE_OVERFLOW (arg1))
9831 t1 = fold_div_compare (code, type, arg0, arg1);
9832 if (t1 != NULL_TREE)
9836 if ((code == EQ_EXPR || code == NE_EXPR)
9837 && !TREE_SIDE_EFFECTS (arg0)
9838 && integer_zerop (arg1)
9839 && tree_expr_nonzero_p (arg0))
9840 return constant_boolean_node (code==NE_EXPR, type);
9842 t1 = fold_relational_const (code, type, arg0, arg1);
9843 return t1 == NULL_TREE ? NULL_TREE : t1;
9845 case UNORDERED_EXPR:
9853 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9855 t1 = fold_relational_const (code, type, arg0, arg1);
9856 if (t1 != NULL_TREE)
9860 /* If the first operand is NaN, the result is constant. */
9861 if (TREE_CODE (arg0) == REAL_CST
9862 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
9863 && (code != LTGT_EXPR || ! flag_trapping_math))
9865 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9868 return omit_one_operand (type, t1, arg1);
9871 /* If the second operand is NaN, the result is constant. */
9872 if (TREE_CODE (arg1) == REAL_CST
9873 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
9874 && (code != LTGT_EXPR || ! flag_trapping_math))
9876 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
9879 return omit_one_operand (type, t1, arg0);
9882 /* Simplify unordered comparison of something with itself. */
9883 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
9884 && operand_equal_p (arg0, arg1, 0))
9885 return constant_boolean_node (1, type);
9887 if (code == LTGT_EXPR
9888 && !flag_trapping_math
9889 && operand_equal_p (arg0, arg1, 0))
9890 return constant_boolean_node (0, type);
9892 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
9894 tree targ0 = strip_float_extensions (arg0);
9895 tree targ1 = strip_float_extensions (arg1);
9896 tree newtype = TREE_TYPE (targ0);
9898 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
9899 newtype = TREE_TYPE (targ1);
9901 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
9902 return fold_build2 (code, type, fold_convert (newtype, targ0),
9903 fold_convert (newtype, targ1));
9909 /* When pedantic, a compound expression can be neither an lvalue
9910 nor an integer constant expression. */
9911 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
9913 /* Don't let (0, 0) be null pointer constant. */
9914 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
9915 : fold_convert (type, arg1);
9916 return pedantic_non_lvalue (tem);
9920 return build_complex (type, arg0, arg1);
9924 /* An ASSERT_EXPR should never be passed to fold_binary. */
9929 } /* switch (code) */
9932 /* Callback for walk_tree, looking for LABEL_EXPR.
9933 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
9934 Do not check the sub-tree of GOTO_EXPR. */
9937 contains_label_1 (tree *tp,
9939 void *data ATTRIBUTE_UNUSED)
9941 switch (TREE_CODE (*tp))
9953 /* Checks wheter the sub-tree ST contains a label LABEL_EXPR which is
9954 accessible from outside the sub-tree. Returns NULL_TREE if no
9955 addressable label is found. */
9958 contains_label_p (tree st)
9960 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
9963 /* Fold a ternary expression of code CODE and type TYPE with operands
9964 OP0, OP1, and OP2. Return the folded expression if folding is
9965 successful. Otherwise, return NULL_TREE. */
9968 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
9971 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
9972 enum tree_code_class kind = TREE_CODE_CLASS (code);
9974 gcc_assert (IS_EXPR_CODE_CLASS (kind)
9975 && TREE_CODE_LENGTH (code) == 3);
9977 /* Strip any conversions that don't change the mode. This is safe
9978 for every expression, except for a comparison expression because
9979 its signedness is derived from its operands. So, in the latter
9980 case, only strip conversions that don't change the signedness.
9982 Note that this is done as an internal manipulation within the
9983 constant folder, in order to find the simplest representation of
9984 the arguments so that their form can be studied. In any cases,
9985 the appropriate type conversions should be put back in the tree
9986 that will get out of the constant folder. */
10001 case COMPONENT_REF:
10002 if (TREE_CODE (arg0) == CONSTRUCTOR
10003 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
10005 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
10007 return TREE_VALUE (m);
10012 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
10013 so all simple results must be passed through pedantic_non_lvalue. */
10014 if (TREE_CODE (arg0) == INTEGER_CST)
10016 tree unused_op = integer_zerop (arg0) ? op1 : op2;
10017 tem = integer_zerop (arg0) ? op2 : op1;
10018 /* Only optimize constant conditions when the selected branch
10019 has the same type as the COND_EXPR. This avoids optimizing
10020 away "c ? x : throw", where the throw has a void type.
10021 Avoid throwing away that operand which contains label. */
10022 if ((!TREE_SIDE_EFFECTS (unused_op)
10023 || !contains_label_p (unused_op))
10024 && (! VOID_TYPE_P (TREE_TYPE (tem))
10025 || VOID_TYPE_P (type)))
10026 return pedantic_non_lvalue (tem);
10029 if (operand_equal_p (arg1, op2, 0))
10030 return pedantic_omit_one_operand (type, arg1, arg0);
10032 /* If we have A op B ? A : C, we may be able to convert this to a
10033 simpler expression, depending on the operation and the values
10034 of B and C. Signed zeros prevent all of these transformations,
10035 for reasons given above each one.
10037 Also try swapping the arguments and inverting the conditional. */
10038 if (COMPARISON_CLASS_P (arg0)
10039 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
10040 arg1, TREE_OPERAND (arg0, 1))
10041 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
10043 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
10048 if (COMPARISON_CLASS_P (arg0)
10049 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
10051 TREE_OPERAND (arg0, 1))
10052 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
10054 tem = invert_truthvalue (arg0);
10055 if (COMPARISON_CLASS_P (tem))
10057 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
10063 /* If the second operand is simpler than the third, swap them
10064 since that produces better jump optimization results. */
10065 if (tree_swap_operands_p (op1, op2, false))
10067 /* See if this can be inverted. If it can't, possibly because
10068 it was a floating-point inequality comparison, don't do
10070 tem = invert_truthvalue (arg0);
10072 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
10073 return fold_build3 (code, type, tem, op2, op1);
10076 /* Convert A ? 1 : 0 to simply A. */
10077 if (integer_onep (op1)
10078 && integer_zerop (op2)
10079 /* If we try to convert OP0 to our type, the
10080 call to fold will try to move the conversion inside
10081 a COND, which will recurse. In that case, the COND_EXPR
10082 is probably the best choice, so leave it alone. */
10083 && type == TREE_TYPE (arg0))
10084 return pedantic_non_lvalue (arg0);
10086 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
10087 over COND_EXPR in cases such as floating point comparisons. */
10088 if (integer_zerop (op1)
10089 && integer_onep (op2)
10090 && truth_value_p (TREE_CODE (arg0)))
10091 return pedantic_non_lvalue (fold_convert (type,
10092 invert_truthvalue (arg0)));
10094 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
10095 if (TREE_CODE (arg0) == LT_EXPR
10096 && integer_zerop (TREE_OPERAND (arg0, 1))
10097 && integer_zerop (op2)
10098 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
10099 return fold_convert (type, fold_build2 (BIT_AND_EXPR,
10100 TREE_TYPE (tem), tem, arg1));
10102 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
10103 already handled above. */
10104 if (TREE_CODE (arg0) == BIT_AND_EXPR
10105 && integer_onep (TREE_OPERAND (arg0, 1))
10106 && integer_zerop (op2)
10107 && integer_pow2p (arg1))
10109 tree tem = TREE_OPERAND (arg0, 0);
10111 if (TREE_CODE (tem) == RSHIFT_EXPR
10112 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
10113 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
10114 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
10115 return fold_build2 (BIT_AND_EXPR, type,
10116 TREE_OPERAND (tem, 0), arg1);
10119 /* A & N ? N : 0 is simply A & N if N is a power of two. This
10120 is probably obsolete because the first operand should be a
10121 truth value (that's why we have the two cases above), but let's
10122 leave it in until we can confirm this for all front-ends. */
10123 if (integer_zerop (op2)
10124 && TREE_CODE (arg0) == NE_EXPR
10125 && integer_zerop (TREE_OPERAND (arg0, 1))
10126 && integer_pow2p (arg1)
10127 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
10128 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
10129 arg1, OEP_ONLY_CONST))
10130 return pedantic_non_lvalue (fold_convert (type,
10131 TREE_OPERAND (arg0, 0)));
10133 /* Convert A ? B : 0 into A && B if A and B are truth values. */
10134 if (integer_zerop (op2)
10135 && truth_value_p (TREE_CODE (arg0))
10136 && truth_value_p (TREE_CODE (arg1)))
10137 return fold_build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1);
10139 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
10140 if (integer_onep (op2)
10141 && truth_value_p (TREE_CODE (arg0))
10142 && truth_value_p (TREE_CODE (arg1)))
10144 /* Only perform transformation if ARG0 is easily inverted. */
10145 tem = invert_truthvalue (arg0);
10146 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
10147 return fold_build2 (TRUTH_ORIF_EXPR, type, tem, arg1);
10150 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
10151 if (integer_zerop (arg1)
10152 && truth_value_p (TREE_CODE (arg0))
10153 && truth_value_p (TREE_CODE (op2)))
10155 /* Only perform transformation if ARG0 is easily inverted. */
10156 tem = invert_truthvalue (arg0);
10157 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
10158 return fold_build2 (TRUTH_ANDIF_EXPR, type, tem, op2);
10161 /* Convert A ? 1 : B into A || B if A and B are truth values. */
10162 if (integer_onep (arg1)
10163 && truth_value_p (TREE_CODE (arg0))
10164 && truth_value_p (TREE_CODE (op2)))
10165 return fold_build2 (TRUTH_ORIF_EXPR, type, arg0, op2);
10170 /* Check for a built-in function. */
10171 if (TREE_CODE (op0) == ADDR_EXPR
10172 && TREE_CODE (TREE_OPERAND (op0, 0)) == FUNCTION_DECL
10173 && DECL_BUILT_IN (TREE_OPERAND (op0, 0)))
10175 tree fndecl = TREE_OPERAND (op0, 0);
10176 tree arglist = op1;
10177 tree tmp = fold_builtin (fndecl, arglist, false);
10185 } /* switch (code) */
10188 /* Perform constant folding and related simplification of EXPR.
10189 The related simplifications include x*1 => x, x*0 => 0, etc.,
10190 and application of the associative law.
10191 NOP_EXPR conversions may be removed freely (as long as we
10192 are careful not to change the type of the overall expression).
10193 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
10194 but we can constant-fold them if they have constant operands. */
10196 #ifdef ENABLE_FOLD_CHECKING
10197 # define fold(x) fold_1 (x)
10198 static tree fold_1 (tree);
10204 const tree t = expr;
10205 enum tree_code code = TREE_CODE (t);
10206 enum tree_code_class kind = TREE_CODE_CLASS (code);
10209 /* Return right away if a constant. */
10210 if (kind == tcc_constant)
10213 if (IS_EXPR_CODE_CLASS (kind))
10215 tree type = TREE_TYPE (t);
10216 tree op0, op1, op2;
10218 switch (TREE_CODE_LENGTH (code))
10221 op0 = TREE_OPERAND (t, 0);
10222 tem = fold_unary (code, type, op0);
10223 return tem ? tem : expr;
10225 op0 = TREE_OPERAND (t, 0);
10226 op1 = TREE_OPERAND (t, 1);
10227 tem = fold_binary (code, type, op0, op1);
10228 return tem ? tem : expr;
10230 op0 = TREE_OPERAND (t, 0);
10231 op1 = TREE_OPERAND (t, 1);
10232 op2 = TREE_OPERAND (t, 2);
10233 tem = fold_ternary (code, type, op0, op1, op2);
10234 return tem ? tem : expr;
10243 return fold (DECL_INITIAL (t));
10247 } /* switch (code) */
10250 #ifdef ENABLE_FOLD_CHECKING
10253 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
10254 static void fold_check_failed (tree, tree);
10255 void print_fold_checksum (tree);
10257 /* When --enable-checking=fold, compute a digest of expr before
10258 and after actual fold call to see if fold did not accidentally
10259 change original expr. */
10265 struct md5_ctx ctx;
10266 unsigned char checksum_before[16], checksum_after[16];
10269 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
10270 md5_init_ctx (&ctx);
10271 fold_checksum_tree (expr, &ctx, ht);
10272 md5_finish_ctx (&ctx, checksum_before);
10275 ret = fold_1 (expr);
10277 md5_init_ctx (&ctx);
10278 fold_checksum_tree (expr, &ctx, ht);
10279 md5_finish_ctx (&ctx, checksum_after);
10282 if (memcmp (checksum_before, checksum_after, 16))
10283 fold_check_failed (expr, ret);
10289 print_fold_checksum (tree expr)
10291 struct md5_ctx ctx;
10292 unsigned char checksum[16], cnt;
10295 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
10296 md5_init_ctx (&ctx);
10297 fold_checksum_tree (expr, &ctx, ht);
10298 md5_finish_ctx (&ctx, checksum);
10300 for (cnt = 0; cnt < 16; ++cnt)
10301 fprintf (stderr, "%02x", checksum[cnt]);
10302 putc ('\n', stderr);
10306 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
10308 internal_error ("fold check: original tree changed by fold");
10312 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
10315 enum tree_code code;
10316 char buf[sizeof (struct tree_decl)];
10319 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
10320 <= sizeof (struct tree_decl))
10321 && sizeof (struct tree_type) <= sizeof (struct tree_decl));
10324 slot = htab_find_slot (ht, expr, INSERT);
10328 code = TREE_CODE (expr);
10329 if (TREE_CODE_CLASS (code) == tcc_declaration
10330 && DECL_ASSEMBLER_NAME_SET_P (expr))
10332 /* Allow DECL_ASSEMBLER_NAME to be modified. */
10333 memcpy (buf, expr, tree_size (expr));
10335 SET_DECL_ASSEMBLER_NAME (expr, NULL);
10337 else if (TREE_CODE_CLASS (code) == tcc_type
10338 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
10339 || TYPE_CACHED_VALUES_P (expr)))
10341 /* Allow these fields to be modified. */
10342 memcpy (buf, expr, tree_size (expr));
10344 TYPE_POINTER_TO (expr) = NULL;
10345 TYPE_REFERENCE_TO (expr) = NULL;
10346 if (TYPE_CACHED_VALUES_P (expr))
10348 TYPE_CACHED_VALUES_P (expr) = 0;
10349 TYPE_CACHED_VALUES (expr) = NULL;
10352 md5_process_bytes (expr, tree_size (expr), ctx);
10353 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
10354 if (TREE_CODE_CLASS (code) != tcc_type
10355 && TREE_CODE_CLASS (code) != tcc_declaration)
10356 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
10357 switch (TREE_CODE_CLASS (code))
10363 md5_process_bytes (TREE_STRING_POINTER (expr),
10364 TREE_STRING_LENGTH (expr), ctx);
10367 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
10368 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
10371 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
10377 case tcc_exceptional:
10381 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
10382 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
10385 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
10386 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
10392 case tcc_expression:
10393 case tcc_reference:
10394 case tcc_comparison:
10397 case tcc_statement:
10398 len = TREE_CODE_LENGTH (code);
10399 for (i = 0; i < len; ++i)
10400 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
10402 case tcc_declaration:
10403 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
10404 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
10405 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
10406 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
10407 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
10408 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
10409 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
10410 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
10411 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
10412 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
10413 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
10416 if (TREE_CODE (expr) == ENUMERAL_TYPE)
10417 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
10418 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
10419 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
10420 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
10421 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
10422 if (INTEGRAL_TYPE_P (expr)
10423 || SCALAR_FLOAT_TYPE_P (expr))
10425 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
10426 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
10428 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
10429 if (TREE_CODE (expr) == RECORD_TYPE
10430 || TREE_CODE (expr) == UNION_TYPE
10431 || TREE_CODE (expr) == QUAL_UNION_TYPE)
10432 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
10433 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
10442 /* Fold a unary tree expression with code CODE of type TYPE with an
10443 operand OP0. Return a folded expression if successful. Otherwise,
10444 return a tree expression with code CODE of type TYPE with an
10448 fold_build1 (enum tree_code code, tree type, tree op0)
10450 tree tem = fold_unary (code, type, op0);
10454 return build1 (code, type, op0);
10457 /* Fold a binary tree expression with code CODE of type TYPE with
10458 operands OP0 and OP1. Return a folded expression if successful.
10459 Otherwise, return a tree expression with code CODE of type TYPE
10460 with operands OP0 and OP1. */
10463 fold_build2 (enum tree_code code, tree type, tree op0, tree op1)
10465 tree tem = fold_binary (code, type, op0, op1);
10469 return build2 (code, type, op0, op1);
10472 /* Fold a ternary tree expression with code CODE of type TYPE with
10473 operands OP0, OP1, and OP2. Return a folded expression if
10474 successful. Otherwise, return a tree expression with code CODE of
10475 type TYPE with operands OP0, OP1, and OP2. */
10478 fold_build3 (enum tree_code code, tree type, tree op0, tree op1, tree op2)
10480 tree tem = fold_ternary (code, type, op0, op1, op2);
10484 return build3 (code, type, op0, op1, op2);
10487 /* Perform constant folding and related simplification of initializer
10488 expression EXPR. This behaves identically to "fold" but ignores
10489 potential run-time traps and exceptions that fold must preserve. */
10492 fold_initializer (tree expr)
10494 int saved_signaling_nans = flag_signaling_nans;
10495 int saved_trapping_math = flag_trapping_math;
10496 int saved_rounding_math = flag_rounding_math;
10497 int saved_trapv = flag_trapv;
10500 flag_signaling_nans = 0;
10501 flag_trapping_math = 0;
10502 flag_rounding_math = 0;
10505 result = fold (expr);
10507 flag_signaling_nans = saved_signaling_nans;
10508 flag_trapping_math = saved_trapping_math;
10509 flag_rounding_math = saved_rounding_math;
10510 flag_trapv = saved_trapv;
10515 /* Determine if first argument is a multiple of second argument. Return 0 if
10516 it is not, or we cannot easily determined it to be.
10518 An example of the sort of thing we care about (at this point; this routine
10519 could surely be made more general, and expanded to do what the *_DIV_EXPR's
10520 fold cases do now) is discovering that
10522 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
10528 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
10530 This code also handles discovering that
10532 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
10534 is a multiple of 8 so we don't have to worry about dealing with a
10535 possible remainder.
10537 Note that we *look* inside a SAVE_EXPR only to determine how it was
10538 calculated; it is not safe for fold to do much of anything else with the
10539 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
10540 at run time. For example, the latter example above *cannot* be implemented
10541 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
10542 evaluation time of the original SAVE_EXPR is not necessarily the same at
10543 the time the new expression is evaluated. The only optimization of this
10544 sort that would be valid is changing
10546 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
10550 SAVE_EXPR (I) * SAVE_EXPR (J)
10552 (where the same SAVE_EXPR (J) is used in the original and the
10553 transformed version). */
10556 multiple_of_p (tree type, tree top, tree bottom)
10558 if (operand_equal_p (top, bottom, 0))
10561 if (TREE_CODE (type) != INTEGER_TYPE)
10564 switch (TREE_CODE (top))
10567 /* Bitwise and provides a power of two multiple. If the mask is
10568 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
10569 if (!integer_pow2p (bottom))
10574 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
10575 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
10579 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
10580 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
10583 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
10587 op1 = TREE_OPERAND (top, 1);
10588 /* const_binop may not detect overflow correctly,
10589 so check for it explicitly here. */
10590 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
10591 > TREE_INT_CST_LOW (op1)
10592 && TREE_INT_CST_HIGH (op1) == 0
10593 && 0 != (t1 = fold_convert (type,
10594 const_binop (LSHIFT_EXPR,
10597 && ! TREE_OVERFLOW (t1))
10598 return multiple_of_p (type, t1, bottom);
10603 /* Can't handle conversions from non-integral or wider integral type. */
10604 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
10605 || (TYPE_PRECISION (type)
10606 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
10609 /* .. fall through ... */
10612 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
10615 if (TREE_CODE (bottom) != INTEGER_CST
10616 || (TYPE_UNSIGNED (type)
10617 && (tree_int_cst_sgn (top) < 0
10618 || tree_int_cst_sgn (bottom) < 0)))
10620 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
10628 /* Return true if `t' is known to be non-negative. */
10631 tree_expr_nonnegative_p (tree t)
10633 switch (TREE_CODE (t))
10639 return tree_int_cst_sgn (t) >= 0;
10642 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
10645 if (FLOAT_TYPE_P (TREE_TYPE (t)))
10646 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10647 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10649 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
10650 both unsigned and at least 2 bits shorter than the result. */
10651 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
10652 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
10653 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
10655 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
10656 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
10657 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
10658 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
10660 unsigned int prec = MAX (TYPE_PRECISION (inner1),
10661 TYPE_PRECISION (inner2)) + 1;
10662 return prec < TYPE_PRECISION (TREE_TYPE (t));
10668 if (FLOAT_TYPE_P (TREE_TYPE (t)))
10670 /* x * x for floating point x is always non-negative. */
10671 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
10673 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10674 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10677 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
10678 both unsigned and their total bits is shorter than the result. */
10679 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
10680 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
10681 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
10683 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
10684 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
10685 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
10686 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
10687 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
10688 < TYPE_PRECISION (TREE_TYPE (t));
10692 case TRUNC_DIV_EXPR:
10693 case CEIL_DIV_EXPR:
10694 case FLOOR_DIV_EXPR:
10695 case ROUND_DIV_EXPR:
10696 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10697 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10699 case TRUNC_MOD_EXPR:
10700 case CEIL_MOD_EXPR:
10701 case FLOOR_MOD_EXPR:
10702 case ROUND_MOD_EXPR:
10703 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10706 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10707 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10710 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
10711 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10714 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10715 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10719 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
10720 tree outer_type = TREE_TYPE (t);
10722 if (TREE_CODE (outer_type) == REAL_TYPE)
10724 if (TREE_CODE (inner_type) == REAL_TYPE)
10725 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10726 if (TREE_CODE (inner_type) == INTEGER_TYPE)
10728 if (TYPE_UNSIGNED (inner_type))
10730 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10733 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
10735 if (TREE_CODE (inner_type) == REAL_TYPE)
10736 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
10737 if (TREE_CODE (inner_type) == INTEGER_TYPE)
10738 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
10739 && TYPE_UNSIGNED (inner_type);
10745 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
10746 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
10747 case COMPOUND_EXPR:
10748 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10750 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10751 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10753 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10754 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10756 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10758 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
10760 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10761 case NON_LVALUE_EXPR:
10762 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10764 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10768 tree temp = TARGET_EXPR_SLOT (t);
10769 t = TARGET_EXPR_INITIAL (t);
10771 /* If the initializer is non-void, then it's a normal expression
10772 that will be assigned to the slot. */
10773 if (!VOID_TYPE_P (t))
10774 return tree_expr_nonnegative_p (t);
10776 /* Otherwise, the initializer sets the slot in some way. One common
10777 way is an assignment statement at the end of the initializer. */
10780 if (TREE_CODE (t) == BIND_EXPR)
10781 t = expr_last (BIND_EXPR_BODY (t));
10782 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
10783 || TREE_CODE (t) == TRY_CATCH_EXPR)
10784 t = expr_last (TREE_OPERAND (t, 0));
10785 else if (TREE_CODE (t) == STATEMENT_LIST)
10790 if (TREE_CODE (t) == MODIFY_EXPR
10791 && TREE_OPERAND (t, 0) == temp)
10792 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
10799 tree fndecl = get_callee_fndecl (t);
10800 tree arglist = TREE_OPERAND (t, 1);
10801 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
10802 switch (DECL_FUNCTION_CODE (fndecl))
10804 #define CASE_BUILTIN_F(BUILT_IN_FN) \
10805 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
10806 #define CASE_BUILTIN_I(BUILT_IN_FN) \
10807 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
10809 CASE_BUILTIN_F (BUILT_IN_ACOS)
10810 CASE_BUILTIN_F (BUILT_IN_ACOSH)
10811 CASE_BUILTIN_F (BUILT_IN_CABS)
10812 CASE_BUILTIN_F (BUILT_IN_COSH)
10813 CASE_BUILTIN_F (BUILT_IN_ERFC)
10814 CASE_BUILTIN_F (BUILT_IN_EXP)
10815 CASE_BUILTIN_F (BUILT_IN_EXP10)
10816 CASE_BUILTIN_F (BUILT_IN_EXP2)
10817 CASE_BUILTIN_F (BUILT_IN_FABS)
10818 CASE_BUILTIN_F (BUILT_IN_FDIM)
10819 CASE_BUILTIN_F (BUILT_IN_FREXP)
10820 CASE_BUILTIN_F (BUILT_IN_HYPOT)
10821 CASE_BUILTIN_F (BUILT_IN_POW10)
10822 CASE_BUILTIN_I (BUILT_IN_FFS)
10823 CASE_BUILTIN_I (BUILT_IN_PARITY)
10824 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
10828 CASE_BUILTIN_F (BUILT_IN_SQRT)
10829 /* sqrt(-0.0) is -0.0. */
10830 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
10832 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
10834 CASE_BUILTIN_F (BUILT_IN_ASINH)
10835 CASE_BUILTIN_F (BUILT_IN_ATAN)
10836 CASE_BUILTIN_F (BUILT_IN_ATANH)
10837 CASE_BUILTIN_F (BUILT_IN_CBRT)
10838 CASE_BUILTIN_F (BUILT_IN_CEIL)
10839 CASE_BUILTIN_F (BUILT_IN_ERF)
10840 CASE_BUILTIN_F (BUILT_IN_EXPM1)
10841 CASE_BUILTIN_F (BUILT_IN_FLOOR)
10842 CASE_BUILTIN_F (BUILT_IN_FMOD)
10843 CASE_BUILTIN_F (BUILT_IN_LCEIL)
10844 CASE_BUILTIN_F (BUILT_IN_LDEXP)
10845 CASE_BUILTIN_F (BUILT_IN_LFLOOR)
10846 CASE_BUILTIN_F (BUILT_IN_LLCEIL)
10847 CASE_BUILTIN_F (BUILT_IN_LLFLOOR)
10848 CASE_BUILTIN_F (BUILT_IN_LLRINT)
10849 CASE_BUILTIN_F (BUILT_IN_LLROUND)
10850 CASE_BUILTIN_F (BUILT_IN_LRINT)
10851 CASE_BUILTIN_F (BUILT_IN_LROUND)
10852 CASE_BUILTIN_F (BUILT_IN_MODF)
10853 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
10854 CASE_BUILTIN_F (BUILT_IN_POW)
10855 CASE_BUILTIN_F (BUILT_IN_RINT)
10856 CASE_BUILTIN_F (BUILT_IN_ROUND)
10857 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
10858 CASE_BUILTIN_F (BUILT_IN_SINH)
10859 CASE_BUILTIN_F (BUILT_IN_TANH)
10860 CASE_BUILTIN_F (BUILT_IN_TRUNC)
10861 /* True if the 1st argument is nonnegative. */
10862 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
10864 CASE_BUILTIN_F (BUILT_IN_FMAX)
10865 /* True if the 1st OR 2nd arguments are nonnegative. */
10866 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
10867 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10869 CASE_BUILTIN_F (BUILT_IN_FMIN)
10870 /* True if the 1st AND 2nd arguments are nonnegative. */
10871 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
10872 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10874 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
10875 /* True if the 2nd argument is nonnegative. */
10876 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
10880 #undef CASE_BUILTIN_F
10881 #undef CASE_BUILTIN_I
10885 /* ... fall through ... */
10888 if (truth_value_p (TREE_CODE (t)))
10889 /* Truth values evaluate to 0 or 1, which is nonnegative. */
10893 /* We don't know sign of `t', so be conservative and return false. */
10897 /* Return true when T is an address and is known to be nonzero.
10898 For floating point we further ensure that T is not denormal.
10899 Similar logic is present in nonzero_address in rtlanal.h. */
10902 tree_expr_nonzero_p (tree t)
10904 tree type = TREE_TYPE (t);
10906 /* Doing something useful for floating point would need more work. */
10907 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
10910 switch (TREE_CODE (t))
10913 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10914 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
10917 /* We used to test for !integer_zerop here. This does not work correctly
10918 if TREE_CONSTANT_OVERFLOW (t). */
10919 return (TREE_INT_CST_LOW (t) != 0
10920 || TREE_INT_CST_HIGH (t) != 0);
10923 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10925 /* With the presence of negative values it is hard
10926 to say something. */
10927 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
10928 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
10930 /* One of operands must be positive and the other non-negative. */
10931 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10932 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10937 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
10939 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10940 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10946 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
10947 tree outer_type = TREE_TYPE (t);
10949 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
10950 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
10956 tree base = get_base_address (TREE_OPERAND (t, 0));
10961 /* Weak declarations may link to NULL. */
10963 return !DECL_WEAK (base);
10965 /* Constants are never weak. */
10966 if (CONSTANT_CLASS_P (base))
10973 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10974 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
10977 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
10978 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
10981 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
10983 /* When both operands are nonzero, then MAX must be too. */
10984 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
10987 /* MAX where operand 0 is positive is positive. */
10988 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
10990 /* MAX where operand 1 is positive is positive. */
10991 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
10992 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
10996 case COMPOUND_EXPR:
10999 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
11002 case NON_LVALUE_EXPR:
11003 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
11006 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
11007 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
11015 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
11016 attempt to fold the expression to a constant without modifying TYPE,
11019 If the expression could be simplified to a constant, then return
11020 the constant. If the expression would not be simplified to a
11021 constant, then return NULL_TREE. */
11024 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
11026 tree tem = fold_binary (code, type, op0, op1);
11027 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
11030 /* Given the components of a unary expression CODE, TYPE and OP0,
11031 attempt to fold the expression to a constant without modifying
11034 If the expression could be simplified to a constant, then return
11035 the constant. If the expression would not be simplified to a
11036 constant, then return NULL_TREE. */
11039 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
11041 tree tem = fold_unary (code, type, op0);
11042 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
11045 /* If EXP represents referencing an element in a constant string
11046 (either via pointer arithmetic or array indexing), return the
11047 tree representing the value accessed, otherwise return NULL. */
11050 fold_read_from_constant_string (tree exp)
11052 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
11054 tree exp1 = TREE_OPERAND (exp, 0);
11058 if (TREE_CODE (exp) == INDIRECT_REF)
11059 string = string_constant (exp1, &index);
11062 tree low_bound = array_ref_low_bound (exp);
11063 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
11065 /* Optimize the special-case of a zero lower bound.
11067 We convert the low_bound to sizetype to avoid some problems
11068 with constant folding. (E.g. suppose the lower bound is 1,
11069 and its mode is QI. Without the conversion,l (ARRAY
11070 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
11071 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
11072 if (! integer_zerop (low_bound))
11073 index = size_diffop (index, fold_convert (sizetype, low_bound));
11079 && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
11080 && TREE_CODE (string) == STRING_CST
11081 && TREE_CODE (index) == INTEGER_CST
11082 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
11083 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
11085 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
11086 return fold_convert (TREE_TYPE (exp),
11087 build_int_cst (NULL_TREE,
11088 (TREE_STRING_POINTER (string)
11089 [TREE_INT_CST_LOW (index)])));
11094 /* Return the tree for neg (ARG0) when ARG0 is known to be either
11095 an integer constant or real constant.
11097 TYPE is the type of the result. */
11100 fold_negate_const (tree arg0, tree type)
11102 tree t = NULL_TREE;
11104 switch (TREE_CODE (arg0))
11108 unsigned HOST_WIDE_INT low;
11109 HOST_WIDE_INT high;
11110 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
11111 TREE_INT_CST_HIGH (arg0),
11113 t = build_int_cst_wide (type, low, high);
11114 t = force_fit_type (t, 1,
11115 (overflow | TREE_OVERFLOW (arg0))
11116 && !TYPE_UNSIGNED (type),
11117 TREE_CONSTANT_OVERFLOW (arg0));
11122 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
11126 gcc_unreachable ();
11132 /* Return the tree for abs (ARG0) when ARG0 is known to be either
11133 an integer constant or real constant.
11135 TYPE is the type of the result. */
11138 fold_abs_const (tree arg0, tree type)
11140 tree t = NULL_TREE;
11142 switch (TREE_CODE (arg0))
11145 /* If the value is unsigned, then the absolute value is
11146 the same as the ordinary value. */
11147 if (TYPE_UNSIGNED (type))
11149 /* Similarly, if the value is non-negative. */
11150 else if (INT_CST_LT (integer_minus_one_node, arg0))
11152 /* If the value is negative, then the absolute value is
11156 unsigned HOST_WIDE_INT low;
11157 HOST_WIDE_INT high;
11158 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
11159 TREE_INT_CST_HIGH (arg0),
11161 t = build_int_cst_wide (type, low, high);
11162 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
11163 TREE_CONSTANT_OVERFLOW (arg0));
11168 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
11169 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
11175 gcc_unreachable ();
11181 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
11182 constant. TYPE is the type of the result. */
11185 fold_not_const (tree arg0, tree type)
11187 tree t = NULL_TREE;
11189 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
11191 t = build_int_cst_wide (type,
11192 ~ TREE_INT_CST_LOW (arg0),
11193 ~ TREE_INT_CST_HIGH (arg0));
11194 t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
11195 TREE_CONSTANT_OVERFLOW (arg0));
11200 /* Given CODE, a relational operator, the target type, TYPE and two
11201 constant operands OP0 and OP1, return the result of the
11202 relational operation. If the result is not a compile time
11203 constant, then return NULL_TREE. */
11206 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
11208 int result, invert;
11210 /* From here on, the only cases we handle are when the result is
11211 known to be a constant. */
11213 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
11215 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
11216 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
11218 /* Handle the cases where either operand is a NaN. */
11219 if (real_isnan (c0) || real_isnan (c1))
11229 case UNORDERED_EXPR:
11243 if (flag_trapping_math)
11249 gcc_unreachable ();
11252 return constant_boolean_node (result, type);
11255 return constant_boolean_node (real_compare (code, c0, c1), type);
11258 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
11260 To compute GT, swap the arguments and do LT.
11261 To compute GE, do LT and invert the result.
11262 To compute LE, swap the arguments, do LT and invert the result.
11263 To compute NE, do EQ and invert the result.
11265 Therefore, the code below must handle only EQ and LT. */
11267 if (code == LE_EXPR || code == GT_EXPR)
11272 code = swap_tree_comparison (code);
11275 /* Note that it is safe to invert for real values here because we
11276 have already handled the one case that it matters. */
11279 if (code == NE_EXPR || code == GE_EXPR)
11282 code = invert_tree_comparison (code, false);
11285 /* Compute a result for LT or EQ if args permit;
11286 Otherwise return T. */
11287 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
11289 if (code == EQ_EXPR)
11290 result = tree_int_cst_equal (op0, op1);
11291 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
11292 result = INT_CST_LT_UNSIGNED (op0, op1);
11294 result = INT_CST_LT (op0, op1);
11301 return constant_boolean_node (result, type);
11304 /* Build an expression for the a clean point containing EXPR with type TYPE.
11305 Don't build a cleanup point expression for EXPR which don't have side
11309 fold_build_cleanup_point_expr (tree type, tree expr)
11311 /* If the expression does not have side effects then we don't have to wrap
11312 it with a cleanup point expression. */
11313 if (!TREE_SIDE_EFFECTS (expr))
11316 /* If the expression is a return, check to see if the expression inside the
11317 return has no side effects or the right hand side of the modify expression
11318 inside the return. If either don't have side effects set we don't need to
11319 wrap the expression in a cleanup point expression. Note we don't check the
11320 left hand side of the modify because it should always be a return decl. */
11321 if (TREE_CODE (expr) == RETURN_EXPR)
11323 tree op = TREE_OPERAND (expr, 0);
11324 if (!op || !TREE_SIDE_EFFECTS (op))
11326 op = TREE_OPERAND (op, 1);
11327 if (!TREE_SIDE_EFFECTS (op))
11331 return build1 (CLEANUP_POINT_EXPR, type, expr);
11334 /* Build an expression for the address of T. Folds away INDIRECT_REF to
11335 avoid confusing the gimplify process. */
11338 build_fold_addr_expr_with_type (tree t, tree ptrtype)
11340 /* The size of the object is not relevant when talking about its address. */
11341 if (TREE_CODE (t) == WITH_SIZE_EXPR)
11342 t = TREE_OPERAND (t, 0);
11344 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
11345 if (TREE_CODE (t) == INDIRECT_REF
11346 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
11348 t = TREE_OPERAND (t, 0);
11349 if (TREE_TYPE (t) != ptrtype)
11350 t = build1 (NOP_EXPR, ptrtype, t);
11356 while (handled_component_p (base))
11357 base = TREE_OPERAND (base, 0);
11359 TREE_ADDRESSABLE (base) = 1;
11361 t = build1 (ADDR_EXPR, ptrtype, t);
11368 build_fold_addr_expr (tree t)
11370 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
11373 /* Given a pointer value T, return a simplified version of an indirection
11374 through T, or NULL_TREE if no simplification is possible. */
11377 fold_indirect_ref_1 (tree t)
11379 tree type = TREE_TYPE (TREE_TYPE (t));
11383 STRIP_TYPE_NOPS (sub);
11384 subtype = TREE_TYPE (sub);
11385 if (!POINTER_TYPE_P (subtype))
11388 if (TREE_CODE (sub) == ADDR_EXPR)
11390 tree op = TREE_OPERAND (sub, 0);
11391 tree optype = TREE_TYPE (op);
11393 if (lang_hooks.types_compatible_p (type, optype))
11395 /* *(foo *)&fooarray => fooarray[0] */
11396 else if (TREE_CODE (optype) == ARRAY_TYPE
11397 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
11399 tree type_domain = TYPE_DOMAIN (optype);
11400 tree min_val = size_zero_node;
11401 if (type_domain && TYPE_MIN_VALUE (type_domain))
11402 min_val = TYPE_MIN_VALUE (type_domain);
11403 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
11407 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
11408 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
11409 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
11412 tree min_val = size_zero_node;
11413 sub = build_fold_indirect_ref (sub);
11414 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
11415 if (type_domain && TYPE_MIN_VALUE (type_domain))
11416 min_val = TYPE_MIN_VALUE (type_domain);
11417 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
11423 /* Builds an expression for an indirection through T, simplifying some
11427 build_fold_indirect_ref (tree t)
11429 tree sub = fold_indirect_ref_1 (t);
11434 return build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (t)), t);
11437 /* Given an INDIRECT_REF T, return either T or a simplified version. */
11440 fold_indirect_ref (tree t)
11442 tree sub = fold_indirect_ref_1 (TREE_OPERAND (t, 0));
11450 /* Strip non-trapping, non-side-effecting tree nodes from an expression
11451 whose result is ignored. The type of the returned tree need not be
11452 the same as the original expression. */
11455 fold_ignored_result (tree t)
11457 if (!TREE_SIDE_EFFECTS (t))
11458 return integer_zero_node;
11461 switch (TREE_CODE_CLASS (TREE_CODE (t)))
11464 t = TREE_OPERAND (t, 0);
11468 case tcc_comparison:
11469 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
11470 t = TREE_OPERAND (t, 0);
11471 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
11472 t = TREE_OPERAND (t, 1);
11477 case tcc_expression:
11478 switch (TREE_CODE (t))
11480 case COMPOUND_EXPR:
11481 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
11483 t = TREE_OPERAND (t, 0);
11487 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
11488 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
11490 t = TREE_OPERAND (t, 0);
11503 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
11504 This can only be applied to objects of a sizetype. */
11507 round_up (tree value, int divisor)
11509 tree div = NULL_TREE;
11511 gcc_assert (divisor > 0);
11515 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11516 have to do anything. Only do this when we are not given a const,
11517 because in that case, this check is more expensive than just
11519 if (TREE_CODE (value) != INTEGER_CST)
11521 div = build_int_cst (TREE_TYPE (value), divisor);
11523 if (multiple_of_p (TREE_TYPE (value), value, div))
11527 /* If divisor is a power of two, simplify this to bit manipulation. */
11528 if (divisor == (divisor & -divisor))
11532 t = build_int_cst (TREE_TYPE (value), divisor - 1);
11533 value = size_binop (PLUS_EXPR, value, t);
11534 t = build_int_cst (TREE_TYPE (value), -divisor);
11535 value = size_binop (BIT_AND_EXPR, value, t);
11540 div = build_int_cst (TREE_TYPE (value), divisor);
11541 value = size_binop (CEIL_DIV_EXPR, value, div);
11542 value = size_binop (MULT_EXPR, value, div);
11548 /* Likewise, but round down. */
11551 round_down (tree value, int divisor)
11553 tree div = NULL_TREE;
11555 gcc_assert (divisor > 0);
11559 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
11560 have to do anything. Only do this when we are not given a const,
11561 because in that case, this check is more expensive than just
11563 if (TREE_CODE (value) != INTEGER_CST)
11565 div = build_int_cst (TREE_TYPE (value), divisor);
11567 if (multiple_of_p (TREE_TYPE (value), value, div))
11571 /* If divisor is a power of two, simplify this to bit manipulation. */
11572 if (divisor == (divisor & -divisor))
11576 t = build_int_cst (TREE_TYPE (value), -divisor);
11577 value = size_binop (BIT_AND_EXPR, value, t);
11582 div = build_int_cst (TREE_TYPE (value), divisor);
11583 value = size_binop (FLOOR_DIV_EXPR, value, div);
11584 value = size_binop (MULT_EXPR, value, div);
11590 /* Returns the pointer to the base of the object addressed by EXP and
11591 extracts the information about the offset of the access, storing it
11592 to PBITPOS and POFFSET. */
11595 split_address_to_core_and_offset (tree exp,
11596 HOST_WIDE_INT *pbitpos, tree *poffset)
11599 enum machine_mode mode;
11600 int unsignedp, volatilep;
11601 HOST_WIDE_INT bitsize;
11603 if (TREE_CODE (exp) == ADDR_EXPR)
11605 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
11606 poffset, &mode, &unsignedp, &volatilep,
11609 if (TREE_CODE (core) == INDIRECT_REF)
11610 core = TREE_OPERAND (core, 0);
11616 *poffset = NULL_TREE;
11622 /* Returns true if addresses of E1 and E2 differ by a constant, false
11623 otherwise. If they do, E1 - E2 is stored in *DIFF. */
11626 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
11629 HOST_WIDE_INT bitpos1, bitpos2;
11630 tree toffset1, toffset2, tdiff, type;
11632 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
11633 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
11635 if (bitpos1 % BITS_PER_UNIT != 0
11636 || bitpos2 % BITS_PER_UNIT != 0
11637 || !operand_equal_p (core1, core2, 0))
11640 if (toffset1 && toffset2)
11642 type = TREE_TYPE (toffset1);
11643 if (type != TREE_TYPE (toffset2))
11644 toffset2 = fold_convert (type, toffset2);
11646 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
11647 if (!host_integerp (tdiff, 0))
11650 *diff = tree_low_cst (tdiff, 0);
11652 else if (toffset1 || toffset2)
11654 /* If only one of the offsets is non-constant, the difference cannot
11661 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
11665 /* Simplify the floating point expression EXP when the sign of the
11666 result is not significant. Return NULL_TREE if no simplification
11670 fold_strip_sign_ops (tree exp)
11674 switch (TREE_CODE (exp))
11678 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
11679 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
11683 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
11685 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
11686 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
11687 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
11688 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
11689 arg0 ? arg0 : TREE_OPERAND (exp, 0),
11690 arg1 ? arg1 : TREE_OPERAND (exp, 1));