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 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 tree build_zero_vector (tree);
93 static tree fold_convert_const (enum tree_code, tree, tree);
94 static enum tree_code invert_tree_comparison (enum tree_code, bool);
95 static enum comparison_code comparison_to_compcode (enum tree_code);
96 static enum tree_code compcode_to_comparison (enum comparison_code);
97 static tree combine_comparisons (enum tree_code, enum tree_code,
98 enum tree_code, tree, tree, tree);
99 static int truth_value_p (enum tree_code);
100 static int operand_equal_for_comparison_p (tree, tree, tree);
101 static int twoval_comparison_p (tree, tree *, tree *, int *);
102 static tree eval_subst (tree, tree, tree, tree, tree);
103 static tree pedantic_omit_one_operand (tree, tree, tree);
104 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
105 static tree make_bit_field_ref (tree, tree, int, int, int);
106 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
107 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
108 enum machine_mode *, int *, int *,
110 static int all_ones_mask_p (tree, int);
111 static tree sign_bit_p (tree, tree);
112 static int simple_operand_p (tree);
113 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
114 static tree make_range (tree, int *, tree *, tree *);
115 static tree build_range_check (tree, tree, int, tree, tree);
116 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
118 static tree fold_range_test (tree);
119 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
120 static tree unextend (tree, int, int, tree);
121 static tree fold_truthop (enum tree_code, tree, tree, tree);
122 static tree optimize_minmax_comparison (tree);
123 static tree extract_muldiv (tree, tree, enum tree_code, tree);
124 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
125 static int multiple_of_p (tree, tree, tree);
126 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
128 static bool fold_real_zero_addition_p (tree, tree, int);
129 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
131 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
132 static tree fold_div_compare (enum tree_code, tree, tree, tree);
133 static bool reorder_operands_p (tree, tree);
134 static tree fold_negate_const (tree, tree);
135 static tree fold_not_const (tree, tree);
136 static tree fold_relational_const (enum tree_code, tree, tree, tree);
137 static tree fold_relational_hi_lo (enum tree_code *, const tree,
139 static bool tree_expr_nonzero_p (tree);
141 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
142 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
143 and SUM1. Then this yields nonzero if overflow occurred during the
146 Overflow occurs if A and B have the same sign, but A and SUM differ in
147 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
149 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
151 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
152 We do that by representing the two-word integer in 4 words, with only
153 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
154 number. The value of the word is LOWPART + HIGHPART * BASE. */
157 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
158 #define HIGHPART(x) \
159 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
160 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
162 /* Unpack a two-word integer into 4 words.
163 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
164 WORDS points to the array of HOST_WIDE_INTs. */
167 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
169 words[0] = LOWPART (low);
170 words[1] = HIGHPART (low);
171 words[2] = LOWPART (hi);
172 words[3] = HIGHPART (hi);
175 /* Pack an array of 4 words into a two-word integer.
176 WORDS points to the array of words.
177 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
180 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
183 *low = words[0] + words[1] * BASE;
184 *hi = words[2] + words[3] * BASE;
187 /* T is an INT_CST node. OVERFLOWABLE indicates if we are interested
188 in overflow of the value, when >0 we are only interested in signed
189 overflow, for <0 we are interested in any overflow. OVERFLOWED
190 indicates whether overflow has already occurred. CONST_OVERFLOWED
191 indicates whether constant overflow has already occurred. We force
192 T's value to be within range of T's type (by setting to 0 or 1 all
193 the bits outside the type's range). We set TREE_OVERFLOWED if,
194 OVERFLOWED is nonzero,
195 or OVERFLOWABLE is >0 and signed overflow occurs
196 or OVERFLOWABLE is <0 and any overflow occurs
197 We set TREE_CONSTANT_OVERFLOWED if,
198 CONST_OVERFLOWED is nonzero
199 or we set TREE_OVERFLOWED.
200 We return either the original T, or a copy. */
203 force_fit_type (tree t, int overflowable,
204 bool overflowed, bool overflowed_const)
206 unsigned HOST_WIDE_INT low;
209 int sign_extended_type;
211 gcc_assert (TREE_CODE (t) == INTEGER_CST);
213 low = TREE_INT_CST_LOW (t);
214 high = TREE_INT_CST_HIGH (t);
216 if (POINTER_TYPE_P (TREE_TYPE (t))
217 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
220 prec = TYPE_PRECISION (TREE_TYPE (t));
221 /* Size types *are* sign extended. */
222 sign_extended_type = (!TYPE_UNSIGNED (TREE_TYPE (t))
223 || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
224 && TYPE_IS_SIZETYPE (TREE_TYPE (t))));
226 /* First clear all bits that are beyond the type's precision. */
228 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
230 else if (prec > HOST_BITS_PER_WIDE_INT)
231 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
235 if (prec < HOST_BITS_PER_WIDE_INT)
236 low &= ~((HOST_WIDE_INT) (-1) << prec);
239 if (!sign_extended_type)
240 /* No sign extension */;
241 else if (prec == 2 * HOST_BITS_PER_WIDE_INT)
242 /* Correct width already. */;
243 else if (prec > HOST_BITS_PER_WIDE_INT)
245 /* Sign extend top half? */
246 if (high & ((unsigned HOST_WIDE_INT)1
247 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
248 high |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
250 else if (prec == HOST_BITS_PER_WIDE_INT)
252 if ((HOST_WIDE_INT)low < 0)
257 /* Sign extend bottom half? */
258 if (low & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
261 low |= (HOST_WIDE_INT)(-1) << prec;
265 /* If the value changed, return a new node. */
266 if (overflowed || overflowed_const
267 || low != TREE_INT_CST_LOW (t) || high != TREE_INT_CST_HIGH (t))
269 t = build_int_cst_wide (TREE_TYPE (t), low, high);
273 || (overflowable > 0 && sign_extended_type))
276 TREE_OVERFLOW (t) = 1;
277 TREE_CONSTANT_OVERFLOW (t) = 1;
279 else if (overflowed_const)
282 TREE_CONSTANT_OVERFLOW (t) = 1;
289 /* Add two doubleword integers with doubleword result.
290 Each argument is given as two `HOST_WIDE_INT' pieces.
291 One argument is L1 and H1; the other, L2 and H2.
292 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
295 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
296 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
297 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
299 unsigned HOST_WIDE_INT l;
303 h = h1 + h2 + (l < l1);
307 return OVERFLOW_SUM_SIGN (h1, h2, h);
310 /* Negate a doubleword integer with doubleword result.
311 Return nonzero if the operation overflows, assuming it's signed.
312 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
313 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
316 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
317 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
323 return (*hv & h1) < 0;
333 /* Multiply two doubleword integers with doubleword result.
334 Return nonzero if the operation overflows, assuming it's signed.
335 Each argument is given as two `HOST_WIDE_INT' pieces.
336 One argument is L1 and H1; the other, L2 and H2.
337 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
340 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
341 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
342 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
344 HOST_WIDE_INT arg1[4];
345 HOST_WIDE_INT arg2[4];
346 HOST_WIDE_INT prod[4 * 2];
347 unsigned HOST_WIDE_INT carry;
349 unsigned HOST_WIDE_INT toplow, neglow;
350 HOST_WIDE_INT tophigh, neghigh;
352 encode (arg1, l1, h1);
353 encode (arg2, l2, h2);
355 memset (prod, 0, sizeof prod);
357 for (i = 0; i < 4; i++)
360 for (j = 0; j < 4; j++)
363 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
364 carry += arg1[i] * arg2[j];
365 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
367 prod[k] = LOWPART (carry);
368 carry = HIGHPART (carry);
373 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
375 /* Check for overflow by calculating the top half of the answer in full;
376 it should agree with the low half's sign bit. */
377 decode (prod + 4, &toplow, &tophigh);
380 neg_double (l2, h2, &neglow, &neghigh);
381 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
385 neg_double (l1, h1, &neglow, &neghigh);
386 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
388 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
391 /* Shift the doubleword integer in L1, H1 left by COUNT places
392 keeping only PREC bits of result.
393 Shift right if COUNT is negative.
394 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
395 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
398 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
399 HOST_WIDE_INT count, unsigned int prec,
400 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
402 unsigned HOST_WIDE_INT signmask;
406 rshift_double (l1, h1, -count, prec, lv, hv, arith);
410 if (SHIFT_COUNT_TRUNCATED)
413 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
415 /* Shifting by the host word size is undefined according to the
416 ANSI standard, so we must handle this as a special case. */
420 else if (count >= HOST_BITS_PER_WIDE_INT)
422 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
427 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
428 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
432 /* Sign extend all bits that are beyond the precision. */
434 signmask = -((prec > HOST_BITS_PER_WIDE_INT
435 ? ((unsigned HOST_WIDE_INT) *hv
436 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
437 : (*lv >> (prec - 1))) & 1);
439 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
441 else if (prec >= HOST_BITS_PER_WIDE_INT)
443 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
444 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
449 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
450 *lv |= signmask << prec;
454 /* Shift the doubleword integer in L1, H1 right by COUNT places
455 keeping only PREC bits of result. COUNT must be positive.
456 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
457 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
460 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
461 HOST_WIDE_INT count, unsigned int prec,
462 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
465 unsigned HOST_WIDE_INT signmask;
468 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
471 if (SHIFT_COUNT_TRUNCATED)
474 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
476 /* Shifting by the host word size is undefined according to the
477 ANSI standard, so we must handle this as a special case. */
481 else if (count >= HOST_BITS_PER_WIDE_INT)
484 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
488 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
490 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
493 /* Zero / sign extend all bits that are beyond the precision. */
495 if (count >= (HOST_WIDE_INT)prec)
500 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
502 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
504 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
505 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
510 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
511 *lv |= signmask << (prec - count);
515 /* Rotate the doubleword integer in L1, H1 left by COUNT places
516 keeping only PREC bits of result.
517 Rotate right if COUNT is negative.
518 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
521 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
522 HOST_WIDE_INT count, unsigned int prec,
523 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
525 unsigned HOST_WIDE_INT s1l, s2l;
526 HOST_WIDE_INT s1h, s2h;
532 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
533 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
538 /* Rotate the doubleword integer in L1, H1 left by COUNT places
539 keeping only PREC bits of result. COUNT must be positive.
540 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
543 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
544 HOST_WIDE_INT count, unsigned int prec,
545 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
547 unsigned HOST_WIDE_INT s1l, s2l;
548 HOST_WIDE_INT s1h, s2h;
554 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
555 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
560 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
561 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
562 CODE is a tree code for a kind of division, one of
563 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
565 It controls how the quotient is rounded to an integer.
566 Return nonzero if the operation overflows.
567 UNS nonzero says do unsigned division. */
570 div_and_round_double (enum tree_code code, int uns,
571 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
572 HOST_WIDE_INT hnum_orig,
573 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
574 HOST_WIDE_INT hden_orig,
575 unsigned HOST_WIDE_INT *lquo,
576 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
580 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
581 HOST_WIDE_INT den[4], quo[4];
583 unsigned HOST_WIDE_INT work;
584 unsigned HOST_WIDE_INT carry = 0;
585 unsigned HOST_WIDE_INT lnum = lnum_orig;
586 HOST_WIDE_INT hnum = hnum_orig;
587 unsigned HOST_WIDE_INT lden = lden_orig;
588 HOST_WIDE_INT hden = hden_orig;
591 if (hden == 0 && lden == 0)
592 overflow = 1, lden = 1;
594 /* Calculate quotient sign and convert operands to unsigned. */
600 /* (minimum integer) / (-1) is the only overflow case. */
601 if (neg_double (lnum, hnum, &lnum, &hnum)
602 && ((HOST_WIDE_INT) lden & hden) == -1)
608 neg_double (lden, hden, &lden, &hden);
612 if (hnum == 0 && hden == 0)
613 { /* single precision */
615 /* This unsigned division rounds toward zero. */
621 { /* trivial case: dividend < divisor */
622 /* hden != 0 already checked. */
629 memset (quo, 0, sizeof quo);
631 memset (num, 0, sizeof num); /* to zero 9th element */
632 memset (den, 0, sizeof den);
634 encode (num, lnum, hnum);
635 encode (den, lden, hden);
637 /* Special code for when the divisor < BASE. */
638 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
640 /* hnum != 0 already checked. */
641 for (i = 4 - 1; i >= 0; i--)
643 work = num[i] + carry * BASE;
644 quo[i] = work / lden;
650 /* Full double precision division,
651 with thanks to Don Knuth's "Seminumerical Algorithms". */
652 int num_hi_sig, den_hi_sig;
653 unsigned HOST_WIDE_INT quo_est, scale;
655 /* Find the highest nonzero divisor digit. */
656 for (i = 4 - 1;; i--)
663 /* Insure that the first digit of the divisor is at least BASE/2.
664 This is required by the quotient digit estimation algorithm. */
666 scale = BASE / (den[den_hi_sig] + 1);
668 { /* scale divisor and dividend */
670 for (i = 0; i <= 4 - 1; i++)
672 work = (num[i] * scale) + carry;
673 num[i] = LOWPART (work);
674 carry = HIGHPART (work);
679 for (i = 0; i <= 4 - 1; i++)
681 work = (den[i] * scale) + carry;
682 den[i] = LOWPART (work);
683 carry = HIGHPART (work);
684 if (den[i] != 0) den_hi_sig = i;
691 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
693 /* Guess the next quotient digit, quo_est, by dividing the first
694 two remaining dividend digits by the high order quotient digit.
695 quo_est is never low and is at most 2 high. */
696 unsigned HOST_WIDE_INT tmp;
698 num_hi_sig = i + den_hi_sig + 1;
699 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
700 if (num[num_hi_sig] != den[den_hi_sig])
701 quo_est = work / den[den_hi_sig];
705 /* Refine quo_est so it's usually correct, and at most one high. */
706 tmp = work - quo_est * den[den_hi_sig];
708 && (den[den_hi_sig - 1] * quo_est
709 > (tmp * BASE + num[num_hi_sig - 2])))
712 /* Try QUO_EST as the quotient digit, by multiplying the
713 divisor by QUO_EST and subtracting from the remaining dividend.
714 Keep in mind that QUO_EST is the I - 1st digit. */
717 for (j = 0; j <= den_hi_sig; j++)
719 work = quo_est * den[j] + carry;
720 carry = HIGHPART (work);
721 work = num[i + j] - LOWPART (work);
722 num[i + j] = LOWPART (work);
723 carry += HIGHPART (work) != 0;
726 /* If quo_est was high by one, then num[i] went negative and
727 we need to correct things. */
728 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
731 carry = 0; /* add divisor back in */
732 for (j = 0; j <= den_hi_sig; j++)
734 work = num[i + j] + den[j] + carry;
735 carry = HIGHPART (work);
736 num[i + j] = LOWPART (work);
739 num [num_hi_sig] += carry;
742 /* Store the quotient digit. */
747 decode (quo, lquo, hquo);
750 /* If result is negative, make it so. */
752 neg_double (*lquo, *hquo, lquo, hquo);
754 /* Compute trial remainder: rem = num - (quo * den) */
755 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
756 neg_double (*lrem, *hrem, lrem, hrem);
757 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
762 case TRUNC_MOD_EXPR: /* round toward zero */
763 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
767 case FLOOR_MOD_EXPR: /* round toward negative infinity */
768 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
771 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
779 case CEIL_MOD_EXPR: /* round toward positive infinity */
780 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
782 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
790 case ROUND_MOD_EXPR: /* round to closest integer */
792 unsigned HOST_WIDE_INT labs_rem = *lrem;
793 HOST_WIDE_INT habs_rem = *hrem;
794 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
795 HOST_WIDE_INT habs_den = hden, htwice;
797 /* Get absolute values. */
799 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
801 neg_double (lden, hden, &labs_den, &habs_den);
803 /* If (2 * abs (lrem) >= abs (lden)) */
804 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
805 labs_rem, habs_rem, <wice, &htwice);
807 if (((unsigned HOST_WIDE_INT) habs_den
808 < (unsigned HOST_WIDE_INT) htwice)
809 || (((unsigned HOST_WIDE_INT) habs_den
810 == (unsigned HOST_WIDE_INT) htwice)
811 && (labs_den < ltwice)))
815 add_double (*lquo, *hquo,
816 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
819 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
831 /* Compute true remainder: rem = num - (quo * den) */
832 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
833 neg_double (*lrem, *hrem, lrem, hrem);
834 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
838 /* Return true if built-in mathematical function specified by CODE
839 preserves the sign of it argument, i.e. -f(x) == f(-x). */
842 negate_mathfn_p (enum built_in_function code)
866 /* Check whether we may negate an integer constant T without causing
870 may_negate_without_overflow_p (tree t)
872 unsigned HOST_WIDE_INT val;
876 gcc_assert (TREE_CODE (t) == INTEGER_CST);
878 type = TREE_TYPE (t);
879 if (TYPE_UNSIGNED (type))
882 prec = TYPE_PRECISION (type);
883 if (prec > HOST_BITS_PER_WIDE_INT)
885 if (TREE_INT_CST_LOW (t) != 0)
887 prec -= HOST_BITS_PER_WIDE_INT;
888 val = TREE_INT_CST_HIGH (t);
891 val = TREE_INT_CST_LOW (t);
892 if (prec < HOST_BITS_PER_WIDE_INT)
893 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
894 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
897 /* Determine whether an expression T can be cheaply negated using
898 the function negate_expr. */
901 negate_expr_p (tree t)
908 type = TREE_TYPE (t);
911 switch (TREE_CODE (t))
914 if (TYPE_UNSIGNED (type) || ! flag_trapv)
917 /* Check that -CST will not overflow type. */
918 return may_negate_without_overflow_p (t);
925 return negate_expr_p (TREE_REALPART (t))
926 && negate_expr_p (TREE_IMAGPART (t));
929 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
931 /* -(A + B) -> (-B) - A. */
932 if (negate_expr_p (TREE_OPERAND (t, 1))
933 && reorder_operands_p (TREE_OPERAND (t, 0),
934 TREE_OPERAND (t, 1)))
936 /* -(A + B) -> (-A) - B. */
937 return negate_expr_p (TREE_OPERAND (t, 0));
940 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
941 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
942 && reorder_operands_p (TREE_OPERAND (t, 0),
943 TREE_OPERAND (t, 1));
946 if (TYPE_UNSIGNED (TREE_TYPE (t)))
952 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
953 return negate_expr_p (TREE_OPERAND (t, 1))
954 || negate_expr_p (TREE_OPERAND (t, 0));
958 /* Negate -((double)float) as (double)(-float). */
959 if (TREE_CODE (type) == REAL_TYPE)
961 tree tem = strip_float_extensions (t);
963 return negate_expr_p (tem);
968 /* Negate -f(x) as f(-x). */
969 if (negate_mathfn_p (builtin_mathfn_code (t)))
970 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
974 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
975 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
977 tree op1 = TREE_OPERAND (t, 1);
978 if (TREE_INT_CST_HIGH (op1) == 0
979 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
980 == TREE_INT_CST_LOW (op1))
991 /* Given T, an expression, return the negation of T. Allow for T to be
992 null, in which case return null. */
1003 type = TREE_TYPE (t);
1004 STRIP_SIGN_NOPS (t);
1006 switch (TREE_CODE (t))
1009 tem = fold_negate_const (t, type);
1010 if (! TREE_OVERFLOW (tem)
1011 || TYPE_UNSIGNED (type)
1017 tem = fold_negate_const (t, type);
1018 /* Two's complement FP formats, such as c4x, may overflow. */
1019 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
1020 return fold_convert (type, tem);
1025 tree rpart = negate_expr (TREE_REALPART (t));
1026 tree ipart = negate_expr (TREE_IMAGPART (t));
1028 if ((TREE_CODE (rpart) == REAL_CST
1029 && TREE_CODE (ipart) == REAL_CST)
1030 || (TREE_CODE (rpart) == INTEGER_CST
1031 && TREE_CODE (ipart) == INTEGER_CST))
1032 return build_complex (type, rpart, ipart);
1037 return fold_convert (type, TREE_OPERAND (t, 0));
1040 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1042 /* -(A + B) -> (-B) - A. */
1043 if (negate_expr_p (TREE_OPERAND (t, 1))
1044 && reorder_operands_p (TREE_OPERAND (t, 0),
1045 TREE_OPERAND (t, 1)))
1047 tem = negate_expr (TREE_OPERAND (t, 1));
1048 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1049 tem, TREE_OPERAND (t, 0)));
1050 return fold_convert (type, tem);
1053 /* -(A + B) -> (-A) - B. */
1054 if (negate_expr_p (TREE_OPERAND (t, 0)))
1056 tem = negate_expr (TREE_OPERAND (t, 0));
1057 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1058 tem, TREE_OPERAND (t, 1)));
1059 return fold_convert (type, tem);
1065 /* - (A - B) -> B - A */
1066 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1067 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1068 return fold_convert (type,
1069 fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1070 TREE_OPERAND (t, 1),
1071 TREE_OPERAND (t, 0))));
1075 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1081 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1083 tem = TREE_OPERAND (t, 1);
1084 if (negate_expr_p (tem))
1085 return fold_convert (type,
1086 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1087 TREE_OPERAND (t, 0),
1088 negate_expr (tem))));
1089 tem = TREE_OPERAND (t, 0);
1090 if (negate_expr_p (tem))
1091 return fold_convert (type,
1092 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1094 TREE_OPERAND (t, 1))));
1099 /* Convert -((double)float) into (double)(-float). */
1100 if (TREE_CODE (type) == REAL_TYPE)
1102 tem = strip_float_extensions (t);
1103 if (tem != t && negate_expr_p (tem))
1104 return fold_convert (type, negate_expr (tem));
1109 /* Negate -f(x) as f(-x). */
1110 if (negate_mathfn_p (builtin_mathfn_code (t))
1111 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1113 tree fndecl, arg, arglist;
1115 fndecl = get_callee_fndecl (t);
1116 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1117 arglist = build_tree_list (NULL_TREE, arg);
1118 return build_function_call_expr (fndecl, arglist);
1123 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1124 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1126 tree op1 = TREE_OPERAND (t, 1);
1127 if (TREE_INT_CST_HIGH (op1) == 0
1128 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1129 == TREE_INT_CST_LOW (op1))
1131 tree ntype = TYPE_UNSIGNED (type)
1132 ? lang_hooks.types.signed_type (type)
1133 : lang_hooks.types.unsigned_type (type);
1134 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1135 temp = fold (build2 (RSHIFT_EXPR, ntype, temp, op1));
1136 return fold_convert (type, temp);
1145 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1146 return fold_convert (type, tem);
1149 /* Split a tree IN into a constant, literal and variable parts that could be
1150 combined with CODE to make IN. "constant" means an expression with
1151 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1152 commutative arithmetic operation. Store the constant part into *CONP,
1153 the literal in *LITP and return the variable part. If a part isn't
1154 present, set it to null. If the tree does not decompose in this way,
1155 return the entire tree as the variable part and the other parts as null.
1157 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1158 case, we negate an operand that was subtracted. Except if it is a
1159 literal for which we use *MINUS_LITP instead.
1161 If NEGATE_P is true, we are negating all of IN, again except a literal
1162 for which we use *MINUS_LITP instead.
1164 If IN is itself a literal or constant, return it as appropriate.
1166 Note that we do not guarantee that any of the three values will be the
1167 same type as IN, but they will have the same signedness and mode. */
1170 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1171 tree *minus_litp, int negate_p)
1179 /* Strip any conversions that don't change the machine mode or signedness. */
1180 STRIP_SIGN_NOPS (in);
1182 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1184 else if (TREE_CODE (in) == code
1185 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1186 /* We can associate addition and subtraction together (even
1187 though the C standard doesn't say so) for integers because
1188 the value is not affected. For reals, the value might be
1189 affected, so we can't. */
1190 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1191 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1193 tree op0 = TREE_OPERAND (in, 0);
1194 tree op1 = TREE_OPERAND (in, 1);
1195 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1196 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1198 /* First see if either of the operands is a literal, then a constant. */
1199 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1200 *litp = op0, op0 = 0;
1201 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1202 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1204 if (op0 != 0 && TREE_CONSTANT (op0))
1205 *conp = op0, op0 = 0;
1206 else if (op1 != 0 && TREE_CONSTANT (op1))
1207 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1209 /* If we haven't dealt with either operand, this is not a case we can
1210 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1211 if (op0 != 0 && op1 != 0)
1216 var = op1, neg_var_p = neg1_p;
1218 /* Now do any needed negations. */
1220 *minus_litp = *litp, *litp = 0;
1222 *conp = negate_expr (*conp);
1224 var = negate_expr (var);
1226 else if (TREE_CONSTANT (in))
1234 *minus_litp = *litp, *litp = 0;
1235 else if (*minus_litp)
1236 *litp = *minus_litp, *minus_litp = 0;
1237 *conp = negate_expr (*conp);
1238 var = negate_expr (var);
1244 /* Re-associate trees split by the above function. T1 and T2 are either
1245 expressions to associate or null. Return the new expression, if any. If
1246 we build an operation, do it in TYPE and with CODE. */
1249 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1256 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1257 try to fold this since we will have infinite recursion. But do
1258 deal with any NEGATE_EXPRs. */
1259 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1260 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1262 if (code == PLUS_EXPR)
1264 if (TREE_CODE (t1) == NEGATE_EXPR)
1265 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1266 fold_convert (type, TREE_OPERAND (t1, 0)));
1267 else if (TREE_CODE (t2) == NEGATE_EXPR)
1268 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1269 fold_convert (type, TREE_OPERAND (t2, 0)));
1271 return build2 (code, type, fold_convert (type, t1),
1272 fold_convert (type, t2));
1275 return fold (build2 (code, type, fold_convert (type, t1),
1276 fold_convert (type, t2)));
1279 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1280 to produce a new constant.
1282 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1285 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1287 unsigned HOST_WIDE_INT int1l, int2l;
1288 HOST_WIDE_INT int1h, int2h;
1289 unsigned HOST_WIDE_INT low;
1291 unsigned HOST_WIDE_INT garbagel;
1292 HOST_WIDE_INT garbageh;
1294 tree type = TREE_TYPE (arg1);
1295 int uns = TYPE_UNSIGNED (type);
1297 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1299 int no_overflow = 0;
1301 int1l = TREE_INT_CST_LOW (arg1);
1302 int1h = TREE_INT_CST_HIGH (arg1);
1303 int2l = TREE_INT_CST_LOW (arg2);
1304 int2h = TREE_INT_CST_HIGH (arg2);
1309 low = int1l | int2l, hi = int1h | int2h;
1313 low = int1l ^ int2l, hi = int1h ^ int2h;
1317 low = int1l & int2l, hi = int1h & int2h;
1323 /* It's unclear from the C standard whether shifts can overflow.
1324 The following code ignores overflow; perhaps a C standard
1325 interpretation ruling is needed. */
1326 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1334 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1339 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1343 neg_double (int2l, int2h, &low, &hi);
1344 add_double (int1l, int1h, low, hi, &low, &hi);
1345 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1349 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1352 case TRUNC_DIV_EXPR:
1353 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1354 case EXACT_DIV_EXPR:
1355 /* This is a shortcut for a common special case. */
1356 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1357 && ! TREE_CONSTANT_OVERFLOW (arg1)
1358 && ! TREE_CONSTANT_OVERFLOW (arg2)
1359 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1361 if (code == CEIL_DIV_EXPR)
1364 low = int1l / int2l, hi = 0;
1368 /* ... fall through ... */
1370 case ROUND_DIV_EXPR:
1371 if (int2h == 0 && int2l == 1)
1373 low = int1l, hi = int1h;
1376 if (int1l == int2l && int1h == int2h
1377 && ! (int1l == 0 && int1h == 0))
1382 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1383 &low, &hi, &garbagel, &garbageh);
1386 case TRUNC_MOD_EXPR:
1387 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1388 /* This is a shortcut for a common special case. */
1389 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1390 && ! TREE_CONSTANT_OVERFLOW (arg1)
1391 && ! TREE_CONSTANT_OVERFLOW (arg2)
1392 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1394 if (code == CEIL_MOD_EXPR)
1396 low = int1l % int2l, hi = 0;
1400 /* ... fall through ... */
1402 case ROUND_MOD_EXPR:
1403 overflow = div_and_round_double (code, uns,
1404 int1l, int1h, int2l, int2h,
1405 &garbagel, &garbageh, &low, &hi);
1411 low = (((unsigned HOST_WIDE_INT) int1h
1412 < (unsigned HOST_WIDE_INT) int2h)
1413 || (((unsigned HOST_WIDE_INT) int1h
1414 == (unsigned HOST_WIDE_INT) int2h)
1417 low = (int1h < int2h
1418 || (int1h == int2h && int1l < int2l));
1420 if (low == (code == MIN_EXPR))
1421 low = int1l, hi = int1h;
1423 low = int2l, hi = int2h;
1430 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1434 /* Propagate overflow flags ourselves. */
1435 if (((!uns || is_sizetype) && overflow)
1436 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1439 TREE_OVERFLOW (t) = 1;
1440 TREE_CONSTANT_OVERFLOW (t) = 1;
1442 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1445 TREE_CONSTANT_OVERFLOW (t) = 1;
1449 t = force_fit_type (t, 1,
1450 ((!uns || is_sizetype) && overflow)
1451 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2),
1452 TREE_CONSTANT_OVERFLOW (arg1)
1453 | TREE_CONSTANT_OVERFLOW (arg2));
1458 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1459 constant. We assume ARG1 and ARG2 have the same data type, or at least
1460 are the same kind of constant and the same machine mode.
1462 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1465 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1470 if (TREE_CODE (arg1) == INTEGER_CST)
1471 return int_const_binop (code, arg1, arg2, notrunc);
1473 if (TREE_CODE (arg1) == REAL_CST)
1475 enum machine_mode mode;
1478 REAL_VALUE_TYPE value;
1481 d1 = TREE_REAL_CST (arg1);
1482 d2 = TREE_REAL_CST (arg2);
1484 type = TREE_TYPE (arg1);
1485 mode = TYPE_MODE (type);
1487 /* Don't perform operation if we honor signaling NaNs and
1488 either operand is a NaN. */
1489 if (HONOR_SNANS (mode)
1490 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1493 /* Don't perform operation if it would raise a division
1494 by zero exception. */
1495 if (code == RDIV_EXPR
1496 && REAL_VALUES_EQUAL (d2, dconst0)
1497 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1500 /* If either operand is a NaN, just return it. Otherwise, set up
1501 for floating-point trap; we return an overflow. */
1502 if (REAL_VALUE_ISNAN (d1))
1504 else if (REAL_VALUE_ISNAN (d2))
1507 REAL_ARITHMETIC (value, code, d1, d2);
1509 t = build_real (type, real_value_truncate (mode, value));
1511 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1512 TREE_CONSTANT_OVERFLOW (t)
1514 | TREE_CONSTANT_OVERFLOW (arg1)
1515 | TREE_CONSTANT_OVERFLOW (arg2);
1518 if (TREE_CODE (arg1) == COMPLEX_CST)
1520 tree type = TREE_TYPE (arg1);
1521 tree r1 = TREE_REALPART (arg1);
1522 tree i1 = TREE_IMAGPART (arg1);
1523 tree r2 = TREE_REALPART (arg2);
1524 tree i2 = TREE_IMAGPART (arg2);
1530 t = build_complex (type,
1531 const_binop (PLUS_EXPR, r1, r2, notrunc),
1532 const_binop (PLUS_EXPR, i1, i2, notrunc));
1536 t = build_complex (type,
1537 const_binop (MINUS_EXPR, r1, r2, notrunc),
1538 const_binop (MINUS_EXPR, i1, i2, notrunc));
1542 t = build_complex (type,
1543 const_binop (MINUS_EXPR,
1544 const_binop (MULT_EXPR,
1546 const_binop (MULT_EXPR,
1549 const_binop (PLUS_EXPR,
1550 const_binop (MULT_EXPR,
1552 const_binop (MULT_EXPR,
1560 = const_binop (PLUS_EXPR,
1561 const_binop (MULT_EXPR, r2, r2, notrunc),
1562 const_binop (MULT_EXPR, i2, i2, notrunc),
1565 t = build_complex (type,
1567 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1568 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1569 const_binop (PLUS_EXPR,
1570 const_binop (MULT_EXPR, r1, r2,
1572 const_binop (MULT_EXPR, i1, i2,
1575 magsquared, notrunc),
1577 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1578 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1579 const_binop (MINUS_EXPR,
1580 const_binop (MULT_EXPR, i1, r2,
1582 const_binop (MULT_EXPR, r1, i2,
1585 magsquared, notrunc));
1597 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1598 indicates which particular sizetype to create. */
1601 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
1603 return build_int_cst (sizetype_tab[(int) kind], number);
1606 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1607 is a tree code. The type of the result is taken from the operands.
1608 Both must be the same type integer type and it must be a size type.
1609 If the operands are constant, so is the result. */
1612 size_binop (enum tree_code code, tree arg0, tree arg1)
1614 tree type = TREE_TYPE (arg0);
1616 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1617 && type == TREE_TYPE (arg1));
1619 /* Handle the special case of two integer constants faster. */
1620 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1622 /* And some specific cases even faster than that. */
1623 if (code == PLUS_EXPR && integer_zerop (arg0))
1625 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1626 && integer_zerop (arg1))
1628 else if (code == MULT_EXPR && integer_onep (arg0))
1631 /* Handle general case of two integer constants. */
1632 return int_const_binop (code, arg0, arg1, 0);
1635 if (arg0 == error_mark_node || arg1 == error_mark_node)
1636 return error_mark_node;
1638 return fold (build2 (code, type, arg0, arg1));
1641 /* Given two values, either both of sizetype or both of bitsizetype,
1642 compute the difference between the two values. Return the value
1643 in signed type corresponding to the type of the operands. */
1646 size_diffop (tree arg0, tree arg1)
1648 tree type = TREE_TYPE (arg0);
1651 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1652 && type == TREE_TYPE (arg1));
1654 /* If the type is already signed, just do the simple thing. */
1655 if (!TYPE_UNSIGNED (type))
1656 return size_binop (MINUS_EXPR, arg0, arg1);
1658 ctype = type == bitsizetype ? sbitsizetype : ssizetype;
1660 /* If either operand is not a constant, do the conversions to the signed
1661 type and subtract. The hardware will do the right thing with any
1662 overflow in the subtraction. */
1663 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1664 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1665 fold_convert (ctype, arg1));
1667 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1668 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1669 overflow) and negate (which can't either). Special-case a result
1670 of zero while we're here. */
1671 if (tree_int_cst_equal (arg0, arg1))
1672 return fold_convert (ctype, integer_zero_node);
1673 else if (tree_int_cst_lt (arg1, arg0))
1674 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1676 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1677 fold_convert (ctype, size_binop (MINUS_EXPR,
1681 /* Construct a vector of zero elements of vector type TYPE. */
1684 build_zero_vector (tree type)
1689 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
1690 units = TYPE_VECTOR_SUBPARTS (type);
1693 for (i = 0; i < units; i++)
1694 list = tree_cons (NULL_TREE, elem, list);
1695 return build_vector (type, list);
1699 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1700 type TYPE. If no simplification can be done return NULL_TREE. */
1703 fold_convert_const (enum tree_code code, tree type, tree arg1)
1708 if (TREE_TYPE (arg1) == type)
1711 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1713 if (TREE_CODE (arg1) == INTEGER_CST)
1715 /* If we would build a constant wider than GCC supports,
1716 leave the conversion unfolded. */
1717 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1720 /* Given an integer constant, make new constant with new type,
1721 appropriately sign-extended or truncated. */
1722 t = build_int_cst_wide (type, TREE_INT_CST_LOW (arg1),
1723 TREE_INT_CST_HIGH (arg1));
1725 t = force_fit_type (t,
1726 /* Don't set the overflow when
1727 converting a pointer */
1728 !POINTER_TYPE_P (TREE_TYPE (arg1)),
1729 (TREE_INT_CST_HIGH (arg1) < 0
1730 && (TYPE_UNSIGNED (type)
1731 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
1732 | TREE_OVERFLOW (arg1),
1733 TREE_CONSTANT_OVERFLOW (arg1));
1736 else if (TREE_CODE (arg1) == REAL_CST)
1738 /* The following code implements the floating point to integer
1739 conversion rules required by the Java Language Specification,
1740 that IEEE NaNs are mapped to zero and values that overflow
1741 the target precision saturate, i.e. values greater than
1742 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1743 are mapped to INT_MIN. These semantics are allowed by the
1744 C and C++ standards that simply state that the behavior of
1745 FP-to-integer conversion is unspecified upon overflow. */
1747 HOST_WIDE_INT high, low;
1749 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1753 case FIX_TRUNC_EXPR:
1754 real_trunc (&r, VOIDmode, &x);
1758 real_ceil (&r, VOIDmode, &x);
1761 case FIX_FLOOR_EXPR:
1762 real_floor (&r, VOIDmode, &x);
1765 case FIX_ROUND_EXPR:
1766 real_round (&r, VOIDmode, &x);
1773 /* If R is NaN, return zero and show we have an overflow. */
1774 if (REAL_VALUE_ISNAN (r))
1781 /* See if R is less than the lower bound or greater than the
1786 tree lt = TYPE_MIN_VALUE (type);
1787 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1788 if (REAL_VALUES_LESS (r, l))
1791 high = TREE_INT_CST_HIGH (lt);
1792 low = TREE_INT_CST_LOW (lt);
1798 tree ut = TYPE_MAX_VALUE (type);
1801 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1802 if (REAL_VALUES_LESS (u, r))
1805 high = TREE_INT_CST_HIGH (ut);
1806 low = TREE_INT_CST_LOW (ut);
1812 REAL_VALUE_TO_INT (&low, &high, r);
1814 t = build_int_cst_wide (type, low, high);
1816 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg1),
1817 TREE_CONSTANT_OVERFLOW (arg1));
1821 else if (TREE_CODE (type) == REAL_TYPE)
1823 if (TREE_CODE (arg1) == INTEGER_CST)
1824 return build_real_from_int_cst (type, arg1);
1825 if (TREE_CODE (arg1) == REAL_CST)
1827 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1829 /* We make a copy of ARG1 so that we don't modify an
1830 existing constant tree. */
1831 t = copy_node (arg1);
1832 TREE_TYPE (t) = type;
1836 t = build_real (type,
1837 real_value_truncate (TYPE_MODE (type),
1838 TREE_REAL_CST (arg1)));
1840 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
1841 TREE_CONSTANT_OVERFLOW (t)
1842 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1849 /* Convert expression ARG to type TYPE. Used by the middle-end for
1850 simple conversions in preference to calling the front-end's convert. */
1853 fold_convert (tree type, tree arg)
1855 tree orig = TREE_TYPE (arg);
1861 if (TREE_CODE (arg) == ERROR_MARK
1862 || TREE_CODE (type) == ERROR_MARK
1863 || TREE_CODE (orig) == ERROR_MARK)
1864 return error_mark_node;
1866 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
1867 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
1868 TYPE_MAIN_VARIANT (orig)))
1869 return fold (build1 (NOP_EXPR, type, arg));
1871 switch (TREE_CODE (type))
1873 case INTEGER_TYPE: case CHAR_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1874 case POINTER_TYPE: case REFERENCE_TYPE:
1876 if (TREE_CODE (arg) == INTEGER_CST)
1878 tem = fold_convert_const (NOP_EXPR, type, arg);
1879 if (tem != NULL_TREE)
1882 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1883 || TREE_CODE (orig) == OFFSET_TYPE)
1884 return fold (build1 (NOP_EXPR, type, arg));
1885 if (TREE_CODE (orig) == COMPLEX_TYPE)
1887 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1888 return fold_convert (type, tem);
1890 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
1891 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1892 return fold (build1 (NOP_EXPR, type, arg));
1895 if (TREE_CODE (arg) == INTEGER_CST)
1897 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1898 if (tem != NULL_TREE)
1901 else if (TREE_CODE (arg) == REAL_CST)
1903 tem = fold_convert_const (NOP_EXPR, type, arg);
1904 if (tem != NULL_TREE)
1908 switch (TREE_CODE (orig))
1910 case INTEGER_TYPE: case CHAR_TYPE:
1911 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1912 case POINTER_TYPE: case REFERENCE_TYPE:
1913 return fold (build1 (FLOAT_EXPR, type, arg));
1916 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1920 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1921 return fold_convert (type, tem);
1928 switch (TREE_CODE (orig))
1930 case INTEGER_TYPE: case CHAR_TYPE:
1931 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1932 case POINTER_TYPE: case REFERENCE_TYPE:
1934 return build2 (COMPLEX_EXPR, type,
1935 fold_convert (TREE_TYPE (type), arg),
1936 fold_convert (TREE_TYPE (type), integer_zero_node));
1941 if (TREE_CODE (arg) == COMPLEX_EXPR)
1943 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1944 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1945 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1948 arg = save_expr (arg);
1949 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1950 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1951 rpart = fold_convert (TREE_TYPE (type), rpart);
1952 ipart = fold_convert (TREE_TYPE (type), ipart);
1953 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1961 if (integer_zerop (arg))
1962 return build_zero_vector (type);
1963 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1964 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1965 || TREE_CODE (orig) == VECTOR_TYPE);
1966 return fold (build1 (NOP_EXPR, type, arg));
1969 return fold (build1 (CONVERT_EXPR, type, fold_ignored_result (arg)));
1976 /* Return an expr equal to X but certainly not valid as an lvalue. */
1981 /* We only need to wrap lvalue tree codes. */
1982 switch (TREE_CODE (x))
1993 case ALIGN_INDIRECT_REF:
1994 case MISALIGNED_INDIRECT_REF:
1996 case ARRAY_RANGE_REF:
2002 case PREINCREMENT_EXPR:
2003 case PREDECREMENT_EXPR:
2005 case TRY_CATCH_EXPR:
2006 case WITH_CLEANUP_EXPR:
2017 /* Assume the worst for front-end tree codes. */
2018 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2022 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2025 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2026 Zero means allow extended lvalues. */
2028 int pedantic_lvalues;
2030 /* When pedantic, return an expr equal to X but certainly not valid as a
2031 pedantic lvalue. Otherwise, return X. */
2034 pedantic_non_lvalue (tree x)
2036 if (pedantic_lvalues)
2037 return non_lvalue (x);
2042 /* Given a tree comparison code, return the code that is the logical inverse
2043 of the given code. It is not safe to do this for floating-point
2044 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2045 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2047 static enum tree_code
2048 invert_tree_comparison (enum tree_code code, bool honor_nans)
2050 if (honor_nans && flag_trapping_math)
2060 return honor_nans ? UNLE_EXPR : LE_EXPR;
2062 return honor_nans ? UNLT_EXPR : LT_EXPR;
2064 return honor_nans ? UNGE_EXPR : GE_EXPR;
2066 return honor_nans ? UNGT_EXPR : GT_EXPR;
2080 return UNORDERED_EXPR;
2081 case UNORDERED_EXPR:
2082 return ORDERED_EXPR;
2088 /* Similar, but return the comparison that results if the operands are
2089 swapped. This is safe for floating-point. */
2092 swap_tree_comparison (enum tree_code code)
2113 /* Convert a comparison tree code from an enum tree_code representation
2114 into a compcode bit-based encoding. This function is the inverse of
2115 compcode_to_comparison. */
2117 static enum comparison_code
2118 comparison_to_compcode (enum tree_code code)
2135 return COMPCODE_ORD;
2136 case UNORDERED_EXPR:
2137 return COMPCODE_UNORD;
2139 return COMPCODE_UNLT;
2141 return COMPCODE_UNEQ;
2143 return COMPCODE_UNLE;
2145 return COMPCODE_UNGT;
2147 return COMPCODE_LTGT;
2149 return COMPCODE_UNGE;
2155 /* Convert a compcode bit-based encoding of a comparison operator back
2156 to GCC's enum tree_code representation. This function is the
2157 inverse of comparison_to_compcode. */
2159 static enum tree_code
2160 compcode_to_comparison (enum comparison_code code)
2177 return ORDERED_EXPR;
2178 case COMPCODE_UNORD:
2179 return UNORDERED_EXPR;
2197 /* Return a tree for the comparison which is the combination of
2198 doing the AND or OR (depending on CODE) of the two operations LCODE
2199 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2200 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2201 if this makes the transformation invalid. */
2204 combine_comparisons (enum tree_code code, enum tree_code lcode,
2205 enum tree_code rcode, tree truth_type,
2206 tree ll_arg, tree lr_arg)
2208 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2209 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2210 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2211 enum comparison_code compcode;
2215 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2216 compcode = lcompcode & rcompcode;
2219 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2220 compcode = lcompcode | rcompcode;
2229 /* Eliminate unordered comparisons, as well as LTGT and ORD
2230 which are not used unless the mode has NaNs. */
2231 compcode &= ~COMPCODE_UNORD;
2232 if (compcode == COMPCODE_LTGT)
2233 compcode = COMPCODE_NE;
2234 else if (compcode == COMPCODE_ORD)
2235 compcode = COMPCODE_TRUE;
2237 else if (flag_trapping_math)
2239 /* Check that the original operation and the optimized ones will trap
2240 under the same condition. */
2241 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2242 && (lcompcode != COMPCODE_EQ)
2243 && (lcompcode != COMPCODE_ORD);
2244 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2245 && (rcompcode != COMPCODE_EQ)
2246 && (rcompcode != COMPCODE_ORD);
2247 bool trap = (compcode & COMPCODE_UNORD) == 0
2248 && (compcode != COMPCODE_EQ)
2249 && (compcode != COMPCODE_ORD);
2251 /* In a short-circuited boolean expression the LHS might be
2252 such that the RHS, if evaluated, will never trap. For
2253 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2254 if neither x nor y is NaN. (This is a mixed blessing: for
2255 example, the expression above will never trap, hence
2256 optimizing it to x < y would be invalid). */
2257 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2258 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2261 /* If the comparison was short-circuited, and only the RHS
2262 trapped, we may now generate a spurious trap. */
2264 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2267 /* If we changed the conditions that cause a trap, we lose. */
2268 if ((ltrap || rtrap) != trap)
2272 if (compcode == COMPCODE_TRUE)
2273 return constant_boolean_node (true, truth_type);
2274 else if (compcode == COMPCODE_FALSE)
2275 return constant_boolean_node (false, truth_type);
2277 return fold (build2 (compcode_to_comparison (compcode),
2278 truth_type, ll_arg, lr_arg));
2281 /* Return nonzero if CODE is a tree code that represents a truth value. */
2284 truth_value_p (enum tree_code code)
2286 return (TREE_CODE_CLASS (code) == tcc_comparison
2287 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2288 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2289 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2292 /* Return nonzero if two operands (typically of the same tree node)
2293 are necessarily equal. If either argument has side-effects this
2294 function returns zero. FLAGS modifies behavior as follows:
2296 If OEP_ONLY_CONST is set, only return nonzero for constants.
2297 This function tests whether the operands are indistinguishable;
2298 it does not test whether they are equal using C's == operation.
2299 The distinction is important for IEEE floating point, because
2300 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2301 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2303 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2304 even though it may hold multiple values during a function.
2305 This is because a GCC tree node guarantees that nothing else is
2306 executed between the evaluation of its "operands" (which may often
2307 be evaluated in arbitrary order). Hence if the operands themselves
2308 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2309 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2310 unset means assuming isochronic (or instantaneous) tree equivalence.
2311 Unless comparing arbitrary expression trees, such as from different
2312 statements, this flag can usually be left unset.
2314 If OEP_PURE_SAME is set, then pure functions with identical arguments
2315 are considered the same. It is used when the caller has other ways
2316 to ensure that global memory is unchanged in between. */
2319 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2321 /* If one is specified and the other isn't, they aren't equal and if
2322 neither is specified, they are.
2324 ??? This is temporary and is meant only to handle the cases of the
2325 optional operands for COMPONENT_REF and ARRAY_REF. */
2326 if ((arg0 && !arg1) || (!arg0 && arg1))
2328 else if (!arg0 && !arg1)
2330 /* If either is ERROR_MARK, they aren't equal. */
2331 else if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2334 /* If both types don't have the same signedness, then we can't consider
2335 them equal. We must check this before the STRIP_NOPS calls
2336 because they may change the signedness of the arguments. */
2337 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2343 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2344 /* This is needed for conversions and for COMPONENT_REF.
2345 Might as well play it safe and always test this. */
2346 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2347 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2348 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2351 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2352 We don't care about side effects in that case because the SAVE_EXPR
2353 takes care of that for us. In all other cases, two expressions are
2354 equal if they have no side effects. If we have two identical
2355 expressions with side effects that should be treated the same due
2356 to the only side effects being identical SAVE_EXPR's, that will
2357 be detected in the recursive calls below. */
2358 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2359 && (TREE_CODE (arg0) == SAVE_EXPR
2360 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2363 /* Next handle constant cases, those for which we can return 1 even
2364 if ONLY_CONST is set. */
2365 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2366 switch (TREE_CODE (arg0))
2369 return (! TREE_CONSTANT_OVERFLOW (arg0)
2370 && ! TREE_CONSTANT_OVERFLOW (arg1)
2371 && tree_int_cst_equal (arg0, arg1));
2374 return (! TREE_CONSTANT_OVERFLOW (arg0)
2375 && ! TREE_CONSTANT_OVERFLOW (arg1)
2376 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2377 TREE_REAL_CST (arg1)));
2383 if (TREE_CONSTANT_OVERFLOW (arg0)
2384 || TREE_CONSTANT_OVERFLOW (arg1))
2387 v1 = TREE_VECTOR_CST_ELTS (arg0);
2388 v2 = TREE_VECTOR_CST_ELTS (arg1);
2391 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2394 v1 = TREE_CHAIN (v1);
2395 v2 = TREE_CHAIN (v2);
2402 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2404 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2408 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2409 && ! memcmp (TREE_STRING_POINTER (arg0),
2410 TREE_STRING_POINTER (arg1),
2411 TREE_STRING_LENGTH (arg0)));
2414 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2420 if (flags & OEP_ONLY_CONST)
2423 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2426 /* Two conversions are equal only if signedness and modes match. */
2427 switch (TREE_CODE (arg0))
2432 case FIX_TRUNC_EXPR:
2433 case FIX_FLOOR_EXPR:
2434 case FIX_ROUND_EXPR:
2435 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
2436 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2443 return operand_equal_p (TREE_OPERAND (arg0, 0),
2444 TREE_OPERAND (arg1, 0), flags);
2446 case tcc_comparison:
2448 if (operand_equal_p (TREE_OPERAND (arg0, 0),
2449 TREE_OPERAND (arg1, 0), flags)
2450 && operand_equal_p (TREE_OPERAND (arg0, 1),
2451 TREE_OPERAND (arg1, 1), flags))
2454 /* For commutative ops, allow the other order. */
2455 return (commutative_tree_code (TREE_CODE (arg0))
2456 && operand_equal_p (TREE_OPERAND (arg0, 0),
2457 TREE_OPERAND (arg1, 1), flags)
2458 && operand_equal_p (TREE_OPERAND (arg0, 1),
2459 TREE_OPERAND (arg1, 0), flags));
2462 /* If either of the pointer (or reference) expressions we are
2463 dereferencing contain a side effect, these cannot be equal. */
2464 if (TREE_SIDE_EFFECTS (arg0)
2465 || TREE_SIDE_EFFECTS (arg1))
2468 switch (TREE_CODE (arg0))
2471 case ALIGN_INDIRECT_REF:
2472 case MISALIGNED_INDIRECT_REF:
2475 return operand_equal_p (TREE_OPERAND (arg0, 0),
2476 TREE_OPERAND (arg1, 0), flags);
2479 case ARRAY_RANGE_REF:
2480 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2481 TREE_OPERAND (arg1, 0), flags)
2482 && operand_equal_p (TREE_OPERAND (arg0, 1),
2483 TREE_OPERAND (arg1, 1), flags)
2484 && operand_equal_p (TREE_OPERAND (arg0, 2),
2485 TREE_OPERAND (arg1, 2), flags)
2486 && operand_equal_p (TREE_OPERAND (arg0, 3),
2487 TREE_OPERAND (arg1, 3), flags));
2491 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2492 TREE_OPERAND (arg1, 0), flags)
2493 && operand_equal_p (TREE_OPERAND (arg0, 1),
2494 TREE_OPERAND (arg1, 1), flags)
2495 && operand_equal_p (TREE_OPERAND (arg0, 2),
2496 TREE_OPERAND (arg1, 2), flags));
2500 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2501 TREE_OPERAND (arg1, 0), flags)
2502 && operand_equal_p (TREE_OPERAND (arg0, 1),
2503 TREE_OPERAND (arg1, 1), flags)
2504 && operand_equal_p (TREE_OPERAND (arg0, 2),
2505 TREE_OPERAND (arg1, 2), flags));
2510 case tcc_expression:
2511 switch (TREE_CODE (arg0))
2514 case TRUTH_NOT_EXPR:
2515 return operand_equal_p (TREE_OPERAND (arg0, 0),
2516 TREE_OPERAND (arg1, 0), flags);
2518 case TRUTH_ANDIF_EXPR:
2519 case TRUTH_ORIF_EXPR:
2520 return operand_equal_p (TREE_OPERAND (arg0, 0),
2521 TREE_OPERAND (arg1, 0), flags)
2522 && operand_equal_p (TREE_OPERAND (arg0, 1),
2523 TREE_OPERAND (arg1, 1), flags);
2525 case TRUTH_AND_EXPR:
2527 case TRUTH_XOR_EXPR:
2528 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2529 TREE_OPERAND (arg1, 0), flags)
2530 && operand_equal_p (TREE_OPERAND (arg0, 1),
2531 TREE_OPERAND (arg1, 1), flags))
2532 || (operand_equal_p (TREE_OPERAND (arg0, 0),
2533 TREE_OPERAND (arg1, 1), flags)
2534 && operand_equal_p (TREE_OPERAND (arg0, 1),
2535 TREE_OPERAND (arg1, 0), flags));
2538 /* If the CALL_EXPRs call different functions, then they
2539 clearly can not be equal. */
2540 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2541 TREE_OPERAND (arg1, 0), flags))
2545 unsigned int cef = call_expr_flags (arg0);
2546 if (flags & OEP_PURE_SAME)
2547 cef &= ECF_CONST | ECF_PURE;
2554 /* Now see if all the arguments are the same. operand_equal_p
2555 does not handle TREE_LIST, so we walk the operands here
2556 feeding them to operand_equal_p. */
2557 arg0 = TREE_OPERAND (arg0, 1);
2558 arg1 = TREE_OPERAND (arg1, 1);
2559 while (arg0 && arg1)
2561 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2565 arg0 = TREE_CHAIN (arg0);
2566 arg1 = TREE_CHAIN (arg1);
2569 /* If we get here and both argument lists are exhausted
2570 then the CALL_EXPRs are equal. */
2571 return ! (arg0 || arg1);
2577 case tcc_declaration:
2578 /* Consider __builtin_sqrt equal to sqrt. */
2579 return (TREE_CODE (arg0) == FUNCTION_DECL
2580 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2581 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2582 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2589 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2590 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2592 When in doubt, return 0. */
2595 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2597 int unsignedp1, unsignedpo;
2598 tree primarg0, primarg1, primother;
2599 unsigned int correct_width;
2601 if (operand_equal_p (arg0, arg1, 0))
2604 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2605 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2608 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2609 and see if the inner values are the same. This removes any
2610 signedness comparison, which doesn't matter here. */
2611 primarg0 = arg0, primarg1 = arg1;
2612 STRIP_NOPS (primarg0);
2613 STRIP_NOPS (primarg1);
2614 if (operand_equal_p (primarg0, primarg1, 0))
2617 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2618 actual comparison operand, ARG0.
2620 First throw away any conversions to wider types
2621 already present in the operands. */
2623 primarg1 = get_narrower (arg1, &unsignedp1);
2624 primother = get_narrower (other, &unsignedpo);
2626 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2627 if (unsignedp1 == unsignedpo
2628 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2629 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2631 tree type = TREE_TYPE (arg0);
2633 /* Make sure shorter operand is extended the right way
2634 to match the longer operand. */
2635 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2636 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2638 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2645 /* See if ARG is an expression that is either a comparison or is performing
2646 arithmetic on comparisons. The comparisons must only be comparing
2647 two different values, which will be stored in *CVAL1 and *CVAL2; if
2648 they are nonzero it means that some operands have already been found.
2649 No variables may be used anywhere else in the expression except in the
2650 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2651 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2653 If this is true, return 1. Otherwise, return zero. */
2656 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2658 enum tree_code code = TREE_CODE (arg);
2659 enum tree_code_class class = TREE_CODE_CLASS (code);
2661 /* We can handle some of the tcc_expression cases here. */
2662 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2664 else if (class == tcc_expression
2665 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2666 || code == COMPOUND_EXPR))
2669 else if (class == tcc_expression && code == SAVE_EXPR
2670 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2672 /* If we've already found a CVAL1 or CVAL2, this expression is
2673 two complex to handle. */
2674 if (*cval1 || *cval2)
2684 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2687 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2688 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2689 cval1, cval2, save_p));
2694 case tcc_expression:
2695 if (code == COND_EXPR)
2696 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2697 cval1, cval2, save_p)
2698 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2699 cval1, cval2, save_p)
2700 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2701 cval1, cval2, save_p));
2704 case tcc_comparison:
2705 /* First see if we can handle the first operand, then the second. For
2706 the second operand, we know *CVAL1 can't be zero. It must be that
2707 one side of the comparison is each of the values; test for the
2708 case where this isn't true by failing if the two operands
2711 if (operand_equal_p (TREE_OPERAND (arg, 0),
2712 TREE_OPERAND (arg, 1), 0))
2716 *cval1 = TREE_OPERAND (arg, 0);
2717 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2719 else if (*cval2 == 0)
2720 *cval2 = TREE_OPERAND (arg, 0);
2721 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2726 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2728 else if (*cval2 == 0)
2729 *cval2 = TREE_OPERAND (arg, 1);
2730 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2742 /* ARG is a tree that is known to contain just arithmetic operations and
2743 comparisons. Evaluate the operations in the tree substituting NEW0 for
2744 any occurrence of OLD0 as an operand of a comparison and likewise for
2748 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2750 tree type = TREE_TYPE (arg);
2751 enum tree_code code = TREE_CODE (arg);
2752 enum tree_code_class class = TREE_CODE_CLASS (code);
2754 /* We can handle some of the tcc_expression cases here. */
2755 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2757 else if (class == tcc_expression
2758 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2764 return fold (build1 (code, type,
2765 eval_subst (TREE_OPERAND (arg, 0),
2766 old0, new0, old1, new1)));
2769 return fold (build2 (code, type,
2770 eval_subst (TREE_OPERAND (arg, 0),
2771 old0, new0, old1, new1),
2772 eval_subst (TREE_OPERAND (arg, 1),
2773 old0, new0, old1, new1)));
2775 case tcc_expression:
2779 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2782 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2785 return fold (build3 (code, type,
2786 eval_subst (TREE_OPERAND (arg, 0),
2787 old0, new0, old1, new1),
2788 eval_subst (TREE_OPERAND (arg, 1),
2789 old0, new0, old1, new1),
2790 eval_subst (TREE_OPERAND (arg, 2),
2791 old0, new0, old1, new1)));
2795 /* Fall through - ??? */
2797 case tcc_comparison:
2799 tree arg0 = TREE_OPERAND (arg, 0);
2800 tree arg1 = TREE_OPERAND (arg, 1);
2802 /* We need to check both for exact equality and tree equality. The
2803 former will be true if the operand has a side-effect. In that
2804 case, we know the operand occurred exactly once. */
2806 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2808 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2811 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2813 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2816 return fold (build2 (code, type, arg0, arg1));
2824 /* Return a tree for the case when the result of an expression is RESULT
2825 converted to TYPE and OMITTED was previously an operand of the expression
2826 but is now not needed (e.g., we folded OMITTED * 0).
2828 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2829 the conversion of RESULT to TYPE. */
2832 omit_one_operand (tree type, tree result, tree omitted)
2834 tree t = fold_convert (type, result);
2836 if (TREE_SIDE_EFFECTS (omitted))
2837 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2839 return non_lvalue (t);
2842 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2845 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2847 tree t = fold_convert (type, result);
2849 if (TREE_SIDE_EFFECTS (omitted))
2850 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2852 return pedantic_non_lvalue (t);
2855 /* Return a tree for the case when the result of an expression is RESULT
2856 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2857 of the expression but are now not needed.
2859 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2860 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
2861 evaluated before OMITTED2. Otherwise, if neither has side effects,
2862 just do the conversion of RESULT to TYPE. */
2865 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
2867 tree t = fold_convert (type, result);
2869 if (TREE_SIDE_EFFECTS (omitted2))
2870 t = build2 (COMPOUND_EXPR, type, omitted2, t);
2871 if (TREE_SIDE_EFFECTS (omitted1))
2872 t = build2 (COMPOUND_EXPR, type, omitted1, t);
2874 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
2878 /* Return a simplified tree node for the truth-negation of ARG. This
2879 never alters ARG itself. We assume that ARG is an operation that
2880 returns a truth value (0 or 1).
2882 FIXME: one would think we would fold the result, but it causes
2883 problems with the dominator optimizer. */
2885 invert_truthvalue (tree arg)
2887 tree type = TREE_TYPE (arg);
2888 enum tree_code code = TREE_CODE (arg);
2890 if (code == ERROR_MARK)
2893 /* If this is a comparison, we can simply invert it, except for
2894 floating-point non-equality comparisons, in which case we just
2895 enclose a TRUTH_NOT_EXPR around what we have. */
2897 if (TREE_CODE_CLASS (code) == tcc_comparison)
2899 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
2900 if (FLOAT_TYPE_P (op_type)
2901 && flag_trapping_math
2902 && code != ORDERED_EXPR && code != UNORDERED_EXPR
2903 && code != NE_EXPR && code != EQ_EXPR)
2904 return build1 (TRUTH_NOT_EXPR, type, arg);
2907 code = invert_tree_comparison (code,
2908 HONOR_NANS (TYPE_MODE (op_type)));
2909 if (code == ERROR_MARK)
2910 return build1 (TRUTH_NOT_EXPR, type, arg);
2912 return build2 (code, type,
2913 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2920 return fold_convert (type,
2921 build_int_cst (NULL_TREE, integer_zerop (arg)));
2923 case TRUTH_AND_EXPR:
2924 return build2 (TRUTH_OR_EXPR, type,
2925 invert_truthvalue (TREE_OPERAND (arg, 0)),
2926 invert_truthvalue (TREE_OPERAND (arg, 1)));
2929 return build2 (TRUTH_AND_EXPR, type,
2930 invert_truthvalue (TREE_OPERAND (arg, 0)),
2931 invert_truthvalue (TREE_OPERAND (arg, 1)));
2933 case TRUTH_XOR_EXPR:
2934 /* Here we can invert either operand. We invert the first operand
2935 unless the second operand is a TRUTH_NOT_EXPR in which case our
2936 result is the XOR of the first operand with the inside of the
2937 negation of the second operand. */
2939 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2940 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2941 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2943 return build2 (TRUTH_XOR_EXPR, type,
2944 invert_truthvalue (TREE_OPERAND (arg, 0)),
2945 TREE_OPERAND (arg, 1));
2947 case TRUTH_ANDIF_EXPR:
2948 return build2 (TRUTH_ORIF_EXPR, type,
2949 invert_truthvalue (TREE_OPERAND (arg, 0)),
2950 invert_truthvalue (TREE_OPERAND (arg, 1)));
2952 case TRUTH_ORIF_EXPR:
2953 return build2 (TRUTH_ANDIF_EXPR, type,
2954 invert_truthvalue (TREE_OPERAND (arg, 0)),
2955 invert_truthvalue (TREE_OPERAND (arg, 1)));
2957 case TRUTH_NOT_EXPR:
2958 return TREE_OPERAND (arg, 0);
2961 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
2962 invert_truthvalue (TREE_OPERAND (arg, 1)),
2963 invert_truthvalue (TREE_OPERAND (arg, 2)));
2966 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2967 invert_truthvalue (TREE_OPERAND (arg, 1)));
2969 case NON_LVALUE_EXPR:
2970 return invert_truthvalue (TREE_OPERAND (arg, 0));
2973 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2978 return build1 (TREE_CODE (arg), type,
2979 invert_truthvalue (TREE_OPERAND (arg, 0)));
2982 if (!integer_onep (TREE_OPERAND (arg, 1)))
2984 return build2 (EQ_EXPR, type, arg,
2985 fold_convert (type, integer_zero_node));
2988 return build1 (TRUTH_NOT_EXPR, type, arg);
2990 case CLEANUP_POINT_EXPR:
2991 return build1 (CLEANUP_POINT_EXPR, type,
2992 invert_truthvalue (TREE_OPERAND (arg, 0)));
2997 gcc_assert (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE);
2998 return build1 (TRUTH_NOT_EXPR, type, arg);
3001 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3002 operands are another bit-wise operation with a common input. If so,
3003 distribute the bit operations to save an operation and possibly two if
3004 constants are involved. For example, convert
3005 (A | B) & (A | C) into A | (B & C)
3006 Further simplification will occur if B and C are constants.
3008 If this optimization cannot be done, 0 will be returned. */
3011 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3016 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3017 || TREE_CODE (arg0) == code
3018 || (TREE_CODE (arg0) != BIT_AND_EXPR
3019 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3022 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3024 common = TREE_OPERAND (arg0, 0);
3025 left = TREE_OPERAND (arg0, 1);
3026 right = TREE_OPERAND (arg1, 1);
3028 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3030 common = TREE_OPERAND (arg0, 0);
3031 left = TREE_OPERAND (arg0, 1);
3032 right = TREE_OPERAND (arg1, 0);
3034 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3036 common = TREE_OPERAND (arg0, 1);
3037 left = TREE_OPERAND (arg0, 0);
3038 right = TREE_OPERAND (arg1, 1);
3040 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3042 common = TREE_OPERAND (arg0, 1);
3043 left = TREE_OPERAND (arg0, 0);
3044 right = TREE_OPERAND (arg1, 0);
3049 return fold (build2 (TREE_CODE (arg0), type, common,
3050 fold (build2 (code, type, left, right))));
3053 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3054 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3057 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3060 tree result = build3 (BIT_FIELD_REF, type, inner,
3061 size_int (bitsize), bitsize_int (bitpos));
3063 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3068 /* Optimize a bit-field compare.
3070 There are two cases: First is a compare against a constant and the
3071 second is a comparison of two items where the fields are at the same
3072 bit position relative to the start of a chunk (byte, halfword, word)
3073 large enough to contain it. In these cases we can avoid the shift
3074 implicit in bitfield extractions.
3076 For constants, we emit a compare of the shifted constant with the
3077 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3078 compared. For two fields at the same position, we do the ANDs with the
3079 similar mask and compare the result of the ANDs.
3081 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3082 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3083 are the left and right operands of the comparison, respectively.
3085 If the optimization described above can be done, we return the resulting
3086 tree. Otherwise we return zero. */
3089 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3092 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3093 tree type = TREE_TYPE (lhs);
3094 tree signed_type, unsigned_type;
3095 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3096 enum machine_mode lmode, rmode, nmode;
3097 int lunsignedp, runsignedp;
3098 int lvolatilep = 0, rvolatilep = 0;
3099 tree linner, rinner = NULL_TREE;
3103 /* Get all the information about the extractions being done. If the bit size
3104 if the same as the size of the underlying object, we aren't doing an
3105 extraction at all and so can do nothing. We also don't want to
3106 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3107 then will no longer be able to replace it. */
3108 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3109 &lunsignedp, &lvolatilep);
3110 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3111 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3116 /* If this is not a constant, we can only do something if bit positions,
3117 sizes, and signedness are the same. */
3118 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3119 &runsignedp, &rvolatilep);
3121 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3122 || lunsignedp != runsignedp || offset != 0
3123 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3127 /* See if we can find a mode to refer to this field. We should be able to,
3128 but fail if we can't. */
3129 nmode = get_best_mode (lbitsize, lbitpos,
3130 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3131 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3132 TYPE_ALIGN (TREE_TYPE (rinner))),
3133 word_mode, lvolatilep || rvolatilep);
3134 if (nmode == VOIDmode)
3137 /* Set signed and unsigned types of the precision of this mode for the
3139 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3140 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3142 /* Compute the bit position and size for the new reference and our offset
3143 within it. If the new reference is the same size as the original, we
3144 won't optimize anything, so return zero. */
3145 nbitsize = GET_MODE_BITSIZE (nmode);
3146 nbitpos = lbitpos & ~ (nbitsize - 1);
3148 if (nbitsize == lbitsize)
3151 if (BYTES_BIG_ENDIAN)
3152 lbitpos = nbitsize - lbitsize - lbitpos;
3154 /* Make the mask to be used against the extracted field. */
3155 mask = build_int_cst (unsigned_type, -1);
3156 mask = force_fit_type (mask, 0, false, false);
3157 mask = fold_convert (unsigned_type, mask);
3158 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3159 mask = const_binop (RSHIFT_EXPR, mask,
3160 size_int (nbitsize - lbitsize - lbitpos), 0);
3163 /* If not comparing with constant, just rework the comparison
3165 return build2 (code, compare_type,
3166 build2 (BIT_AND_EXPR, unsigned_type,
3167 make_bit_field_ref (linner, unsigned_type,
3168 nbitsize, nbitpos, 1),
3170 build2 (BIT_AND_EXPR, unsigned_type,
3171 make_bit_field_ref (rinner, unsigned_type,
3172 nbitsize, nbitpos, 1),
3175 /* Otherwise, we are handling the constant case. See if the constant is too
3176 big for the field. Warn and return a tree of for 0 (false) if so. We do
3177 this not only for its own sake, but to avoid having to test for this
3178 error case below. If we didn't, we might generate wrong code.
3180 For unsigned fields, the constant shifted right by the field length should
3181 be all zero. For signed fields, the high-order bits should agree with
3186 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3187 fold_convert (unsigned_type, rhs),
3188 size_int (lbitsize), 0)))
3190 warning ("comparison is always %d due to width of bit-field",
3192 return constant_boolean_node (code == NE_EXPR, compare_type);
3197 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3198 size_int (lbitsize - 1), 0);
3199 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3201 warning ("comparison is always %d due to width of bit-field",
3203 return constant_boolean_node (code == NE_EXPR, compare_type);
3207 /* Single-bit compares should always be against zero. */
3208 if (lbitsize == 1 && ! integer_zerop (rhs))
3210 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3211 rhs = fold_convert (type, integer_zero_node);
3214 /* Make a new bitfield reference, shift the constant over the
3215 appropriate number of bits and mask it with the computed mask
3216 (in case this was a signed field). If we changed it, make a new one. */
3217 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3220 TREE_SIDE_EFFECTS (lhs) = 1;
3221 TREE_THIS_VOLATILE (lhs) = 1;
3224 rhs = fold (const_binop (BIT_AND_EXPR,
3225 const_binop (LSHIFT_EXPR,
3226 fold_convert (unsigned_type, rhs),
3227 size_int (lbitpos), 0),
3230 return build2 (code, compare_type,
3231 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3235 /* Subroutine for fold_truthop: decode a field reference.
3237 If EXP is a comparison reference, we return the innermost reference.
3239 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3240 set to the starting bit number.
3242 If the innermost field can be completely contained in a mode-sized
3243 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3245 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3246 otherwise it is not changed.
3248 *PUNSIGNEDP is set to the signedness of the field.
3250 *PMASK is set to the mask used. This is either contained in a
3251 BIT_AND_EXPR or derived from the width of the field.
3253 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3255 Return 0 if this is not a component reference or is one that we can't
3256 do anything with. */
3259 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3260 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3261 int *punsignedp, int *pvolatilep,
3262 tree *pmask, tree *pand_mask)
3264 tree outer_type = 0;
3266 tree mask, inner, offset;
3268 unsigned int precision;
3270 /* All the optimizations using this function assume integer fields.
3271 There are problems with FP fields since the type_for_size call
3272 below can fail for, e.g., XFmode. */
3273 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3276 /* We are interested in the bare arrangement of bits, so strip everything
3277 that doesn't affect the machine mode. However, record the type of the
3278 outermost expression if it may matter below. */
3279 if (TREE_CODE (exp) == NOP_EXPR
3280 || TREE_CODE (exp) == CONVERT_EXPR
3281 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3282 outer_type = TREE_TYPE (exp);
3285 if (TREE_CODE (exp) == BIT_AND_EXPR)
3287 and_mask = TREE_OPERAND (exp, 1);
3288 exp = TREE_OPERAND (exp, 0);
3289 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3290 if (TREE_CODE (and_mask) != INTEGER_CST)
3294 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3295 punsignedp, pvolatilep);
3296 if ((inner == exp && and_mask == 0)
3297 || *pbitsize < 0 || offset != 0
3298 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3301 /* If the number of bits in the reference is the same as the bitsize of
3302 the outer type, then the outer type gives the signedness. Otherwise
3303 (in case of a small bitfield) the signedness is unchanged. */
3304 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3305 *punsignedp = TYPE_UNSIGNED (outer_type);
3307 /* Compute the mask to access the bitfield. */
3308 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3309 precision = TYPE_PRECISION (unsigned_type);
3311 mask = build_int_cst (unsigned_type, -1);
3312 mask = force_fit_type (mask, 0, false, false);
3314 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3315 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3317 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3319 mask = fold (build2 (BIT_AND_EXPR, unsigned_type,
3320 fold_convert (unsigned_type, and_mask), mask));
3323 *pand_mask = and_mask;
3327 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3331 all_ones_mask_p (tree mask, int size)
3333 tree type = TREE_TYPE (mask);
3334 unsigned int precision = TYPE_PRECISION (type);
3337 tmask = build_int_cst (lang_hooks.types.signed_type (type), -1);
3338 tmask = force_fit_type (tmask, 0, false, false);
3341 tree_int_cst_equal (mask,
3342 const_binop (RSHIFT_EXPR,
3343 const_binop (LSHIFT_EXPR, tmask,
3344 size_int (precision - size),
3346 size_int (precision - size), 0));
3349 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3350 represents the sign bit of EXP's type. If EXP represents a sign
3351 or zero extension, also test VAL against the unextended type.
3352 The return value is the (sub)expression whose sign bit is VAL,
3353 or NULL_TREE otherwise. */
3356 sign_bit_p (tree exp, tree val)
3358 unsigned HOST_WIDE_INT mask_lo, lo;
3359 HOST_WIDE_INT mask_hi, hi;
3363 /* Tree EXP must have an integral type. */
3364 t = TREE_TYPE (exp);
3365 if (! INTEGRAL_TYPE_P (t))
3368 /* Tree VAL must be an integer constant. */
3369 if (TREE_CODE (val) != INTEGER_CST
3370 || TREE_CONSTANT_OVERFLOW (val))
3373 width = TYPE_PRECISION (t);
3374 if (width > HOST_BITS_PER_WIDE_INT)
3376 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3379 mask_hi = ((unsigned HOST_WIDE_INT) -1
3380 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3386 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3389 mask_lo = ((unsigned HOST_WIDE_INT) -1
3390 >> (HOST_BITS_PER_WIDE_INT - width));
3393 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3394 treat VAL as if it were unsigned. */
3395 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3396 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3399 /* Handle extension from a narrower type. */
3400 if (TREE_CODE (exp) == NOP_EXPR
3401 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3402 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3407 /* Subroutine for fold_truthop: determine if an operand is simple enough
3408 to be evaluated unconditionally. */
3411 simple_operand_p (tree exp)
3413 /* Strip any conversions that don't change the machine mode. */
3414 while ((TREE_CODE (exp) == NOP_EXPR
3415 || TREE_CODE (exp) == CONVERT_EXPR)
3416 && (TYPE_MODE (TREE_TYPE (exp))
3417 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3418 exp = TREE_OPERAND (exp, 0);
3420 return (CONSTANT_CLASS_P (exp)
3422 && ! TREE_ADDRESSABLE (exp)
3423 && ! TREE_THIS_VOLATILE (exp)
3424 && ! DECL_NONLOCAL (exp)
3425 /* Don't regard global variables as simple. They may be
3426 allocated in ways unknown to the compiler (shared memory,
3427 #pragma weak, etc). */
3428 && ! TREE_PUBLIC (exp)
3429 && ! DECL_EXTERNAL (exp)
3430 /* Loading a static variable is unduly expensive, but global
3431 registers aren't expensive. */
3432 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3435 /* The following functions are subroutines to fold_range_test and allow it to
3436 try to change a logical combination of comparisons into a range test.
3439 X == 2 || X == 3 || X == 4 || X == 5
3443 (unsigned) (X - 2) <= 3
3445 We describe each set of comparisons as being either inside or outside
3446 a range, using a variable named like IN_P, and then describe the
3447 range with a lower and upper bound. If one of the bounds is omitted,
3448 it represents either the highest or lowest value of the type.
3450 In the comments below, we represent a range by two numbers in brackets
3451 preceded by a "+" to designate being inside that range, or a "-" to
3452 designate being outside that range, so the condition can be inverted by
3453 flipping the prefix. An omitted bound is represented by a "-". For
3454 example, "- [-, 10]" means being outside the range starting at the lowest
3455 possible value and ending at 10, in other words, being greater than 10.
3456 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3459 We set up things so that the missing bounds are handled in a consistent
3460 manner so neither a missing bound nor "true" and "false" need to be
3461 handled using a special case. */
3463 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3464 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3465 and UPPER1_P are nonzero if the respective argument is an upper bound
3466 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3467 must be specified for a comparison. ARG1 will be converted to ARG0's
3468 type if both are specified. */
3471 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3472 tree arg1, int upper1_p)
3478 /* If neither arg represents infinity, do the normal operation.
3479 Else, if not a comparison, return infinity. Else handle the special
3480 comparison rules. Note that most of the cases below won't occur, but
3481 are handled for consistency. */
3483 if (arg0 != 0 && arg1 != 0)
3485 tem = fold (build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3486 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3488 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3491 if (TREE_CODE_CLASS (code) != tcc_comparison)
3494 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3495 for neither. In real maths, we cannot assume open ended ranges are
3496 the same. But, this is computer arithmetic, where numbers are finite.
3497 We can therefore make the transformation of any unbounded range with
3498 the value Z, Z being greater than any representable number. This permits
3499 us to treat unbounded ranges as equal. */
3500 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3501 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3505 result = sgn0 == sgn1;
3508 result = sgn0 != sgn1;
3511 result = sgn0 < sgn1;
3514 result = sgn0 <= sgn1;
3517 result = sgn0 > sgn1;
3520 result = sgn0 >= sgn1;
3526 return constant_boolean_node (result, type);
3529 /* Given EXP, a logical expression, set the range it is testing into
3530 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3531 actually being tested. *PLOW and *PHIGH will be made of the same type
3532 as the returned expression. If EXP is not a comparison, we will most
3533 likely not be returning a useful value and range. */
3536 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3538 enum tree_code code;
3539 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
3540 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
3542 tree low, high, n_low, n_high;
3544 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3545 and see if we can refine the range. Some of the cases below may not
3546 happen, but it doesn't seem worth worrying about this. We "continue"
3547 the outer loop when we've changed something; otherwise we "break"
3548 the switch, which will "break" the while. */
3551 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3555 code = TREE_CODE (exp);
3556 exp_type = TREE_TYPE (exp);
3558 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3560 if (first_rtl_op (code) > 0)
3561 arg0 = TREE_OPERAND (exp, 0);
3562 if (TREE_CODE_CLASS (code) == tcc_comparison
3563 || TREE_CODE_CLASS (code) == tcc_unary
3564 || TREE_CODE_CLASS (code) == tcc_binary)
3565 arg0_type = TREE_TYPE (arg0);
3566 if (TREE_CODE_CLASS (code) == tcc_binary
3567 || TREE_CODE_CLASS (code) == tcc_comparison
3568 || (TREE_CODE_CLASS (code) == tcc_expression
3569 && TREE_CODE_LENGTH (code) > 1))
3570 arg1 = TREE_OPERAND (exp, 1);
3575 case TRUTH_NOT_EXPR:
3576 in_p = ! in_p, exp = arg0;
3579 case EQ_EXPR: case NE_EXPR:
3580 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3581 /* We can only do something if the range is testing for zero
3582 and if the second operand is an integer constant. Note that
3583 saying something is "in" the range we make is done by
3584 complementing IN_P since it will set in the initial case of
3585 being not equal to zero; "out" is leaving it alone. */
3586 if (low == 0 || high == 0
3587 || ! integer_zerop (low) || ! integer_zerop (high)
3588 || TREE_CODE (arg1) != INTEGER_CST)
3593 case NE_EXPR: /* - [c, c] */
3596 case EQ_EXPR: /* + [c, c] */
3597 in_p = ! in_p, low = high = arg1;
3599 case GT_EXPR: /* - [-, c] */
3600 low = 0, high = arg1;
3602 case GE_EXPR: /* + [c, -] */
3603 in_p = ! in_p, low = arg1, high = 0;
3605 case LT_EXPR: /* - [c, -] */
3606 low = arg1, high = 0;
3608 case LE_EXPR: /* + [-, c] */
3609 in_p = ! in_p, low = 0, high = arg1;
3615 /* If this is an unsigned comparison, we also know that EXP is
3616 greater than or equal to zero. We base the range tests we make
3617 on that fact, so we record it here so we can parse existing
3618 range tests. We test arg0_type since often the return type
3619 of, e.g. EQ_EXPR, is boolean. */
3620 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
3622 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3624 fold_convert (arg0_type, integer_zero_node),
3628 in_p = n_in_p, low = n_low, high = n_high;
3630 /* If the high bound is missing, but we have a nonzero low
3631 bound, reverse the range so it goes from zero to the low bound
3633 if (high == 0 && low && ! integer_zerop (low))
3636 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3637 integer_one_node, 0);
3638 low = fold_convert (arg0_type, integer_zero_node);
3646 /* (-x) IN [a,b] -> x in [-b, -a] */
3647 n_low = range_binop (MINUS_EXPR, exp_type,
3648 fold_convert (exp_type, integer_zero_node),
3650 n_high = range_binop (MINUS_EXPR, exp_type,
3651 fold_convert (exp_type, integer_zero_node),
3653 low = n_low, high = n_high;
3659 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
3660 fold_convert (exp_type, integer_one_node));
3663 case PLUS_EXPR: case MINUS_EXPR:
3664 if (TREE_CODE (arg1) != INTEGER_CST)
3667 /* If EXP is signed, any overflow in the computation is undefined,
3668 so we don't worry about it so long as our computations on
3669 the bounds don't overflow. For unsigned, overflow is defined
3670 and this is exactly the right thing. */
3671 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3672 arg0_type, low, 0, arg1, 0);
3673 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3674 arg0_type, high, 1, arg1, 0);
3675 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3676 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3679 /* Check for an unsigned range which has wrapped around the maximum
3680 value thus making n_high < n_low, and normalize it. */
3681 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3683 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
3684 integer_one_node, 0);
3685 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
3686 integer_one_node, 0);
3688 /* If the range is of the form +/- [ x+1, x ], we won't
3689 be able to normalize it. But then, it represents the
3690 whole range or the empty set, so make it
3692 if (tree_int_cst_equal (n_low, low)
3693 && tree_int_cst_equal (n_high, high))
3699 low = n_low, high = n_high;
3704 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3705 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
3708 if (! INTEGRAL_TYPE_P (arg0_type)
3709 || (low != 0 && ! int_fits_type_p (low, arg0_type))
3710 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
3713 n_low = low, n_high = high;
3716 n_low = fold_convert (arg0_type, n_low);
3719 n_high = fold_convert (arg0_type, n_high);
3722 /* If we're converting arg0 from an unsigned type, to exp,
3723 a signed type, we will be doing the comparison as unsigned.
3724 The tests above have already verified that LOW and HIGH
3727 So we have to ensure that we will handle large unsigned
3728 values the same way that the current signed bounds treat
3731 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
3734 tree equiv_type = lang_hooks.types.type_for_mode
3735 (TYPE_MODE (arg0_type), 1);
3737 /* A range without an upper bound is, naturally, unbounded.
3738 Since convert would have cropped a very large value, use
3739 the max value for the destination type. */
3741 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3742 : TYPE_MAX_VALUE (arg0_type);
3744 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
3745 high_positive = fold (build2 (RSHIFT_EXPR, arg0_type,
3746 fold_convert (arg0_type,
3748 fold_convert (arg0_type,
3749 integer_one_node)));
3751 /* If the low bound is specified, "and" the range with the
3752 range for which the original unsigned value will be
3756 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3757 1, n_low, n_high, 1,
3758 fold_convert (arg0_type,
3763 in_p = (n_in_p == in_p);
3767 /* Otherwise, "or" the range with the range of the input
3768 that will be interpreted as negative. */
3769 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3770 0, n_low, n_high, 1,
3771 fold_convert (arg0_type,
3776 in_p = (in_p != n_in_p);
3781 low = n_low, high = n_high;
3791 /* If EXP is a constant, we can evaluate whether this is true or false. */
3792 if (TREE_CODE (exp) == INTEGER_CST)
3794 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3796 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3802 *pin_p = in_p, *plow = low, *phigh = high;
3806 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3807 type, TYPE, return an expression to test if EXP is in (or out of, depending
3808 on IN_P) the range. Return 0 if the test couldn't be created. */
3811 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3813 tree etype = TREE_TYPE (exp);
3818 value = build_range_check (type, exp, 1, low, high);
3820 return invert_truthvalue (value);
3825 if (low == 0 && high == 0)
3826 return fold_convert (type, integer_one_node);
3829 return fold (build2 (LE_EXPR, type, exp, high));
3832 return fold (build2 (GE_EXPR, type, exp, low));
3834 if (operand_equal_p (low, high, 0))
3835 return fold (build2 (EQ_EXPR, type, exp, low));
3837 if (integer_zerop (low))
3839 if (! TYPE_UNSIGNED (etype))
3841 etype = lang_hooks.types.unsigned_type (etype);
3842 high = fold_convert (etype, high);
3843 exp = fold_convert (etype, exp);
3845 return build_range_check (type, exp, 1, 0, high);
3848 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3849 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3851 unsigned HOST_WIDE_INT lo;
3855 prec = TYPE_PRECISION (etype);
3856 if (prec <= HOST_BITS_PER_WIDE_INT)
3859 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3863 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3864 lo = (unsigned HOST_WIDE_INT) -1;
3867 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3869 if (TYPE_UNSIGNED (etype))
3871 etype = lang_hooks.types.signed_type (etype);
3872 exp = fold_convert (etype, exp);
3874 return fold (build2 (GT_EXPR, type, exp,
3875 fold_convert (etype, integer_zero_node)));
3879 value = const_binop (MINUS_EXPR, high, low, 0);
3880 if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
3882 tree utype, minv, maxv;
3884 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
3885 for the type in question, as we rely on this here. */
3886 switch (TREE_CODE (etype))
3891 utype = lang_hooks.types.unsigned_type (etype);
3892 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
3893 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
3894 integer_one_node, 1);
3895 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
3896 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
3900 high = fold_convert (etype, high);
3901 low = fold_convert (etype, low);
3902 exp = fold_convert (etype, exp);
3903 value = const_binop (MINUS_EXPR, high, low, 0);
3911 if (value != 0 && ! TREE_OVERFLOW (value))
3912 return build_range_check (type,
3913 fold (build2 (MINUS_EXPR, etype, exp, low)),
3914 1, fold_convert (etype, integer_zero_node),
3920 /* Given two ranges, see if we can merge them into one. Return 1 if we
3921 can, 0 if we can't. Set the output range into the specified parameters. */
3924 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3925 tree high0, int in1_p, tree low1, tree high1)
3933 int lowequal = ((low0 == 0 && low1 == 0)
3934 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3935 low0, 0, low1, 0)));
3936 int highequal = ((high0 == 0 && high1 == 0)
3937 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3938 high0, 1, high1, 1)));
3940 /* Make range 0 be the range that starts first, or ends last if they
3941 start at the same value. Swap them if it isn't. */
3942 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3945 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3946 high1, 1, high0, 1))))
3948 temp = in0_p, in0_p = in1_p, in1_p = temp;
3949 tem = low0, low0 = low1, low1 = tem;
3950 tem = high0, high0 = high1, high1 = tem;
3953 /* Now flag two cases, whether the ranges are disjoint or whether the
3954 second range is totally subsumed in the first. Note that the tests
3955 below are simplified by the ones above. */
3956 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3957 high0, 1, low1, 0));
3958 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3959 high1, 1, high0, 1));
3961 /* We now have four cases, depending on whether we are including or
3962 excluding the two ranges. */
3965 /* If they don't overlap, the result is false. If the second range
3966 is a subset it is the result. Otherwise, the range is from the start
3967 of the second to the end of the first. */
3969 in_p = 0, low = high = 0;
3971 in_p = 1, low = low1, high = high1;
3973 in_p = 1, low = low1, high = high0;
3976 else if (in0_p && ! in1_p)
3978 /* If they don't overlap, the result is the first range. If they are
3979 equal, the result is false. If the second range is a subset of the
3980 first, and the ranges begin at the same place, we go from just after
3981 the end of the first range to the end of the second. If the second
3982 range is not a subset of the first, or if it is a subset and both
3983 ranges end at the same place, the range starts at the start of the
3984 first range and ends just before the second range.
3985 Otherwise, we can't describe this as a single range. */
3987 in_p = 1, low = low0, high = high0;
3988 else if (lowequal && highequal)
3989 in_p = 0, low = high = 0;
3990 else if (subset && lowequal)
3992 in_p = 1, high = high0;
3993 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3994 integer_one_node, 0);
3996 else if (! subset || highequal)
3998 in_p = 1, low = low0;
3999 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4000 integer_one_node, 0);
4006 else if (! in0_p && in1_p)
4008 /* If they don't overlap, the result is the second range. If the second
4009 is a subset of the first, the result is false. Otherwise,
4010 the range starts just after the first range and ends at the
4011 end of the second. */
4013 in_p = 1, low = low1, high = high1;
4014 else if (subset || highequal)
4015 in_p = 0, low = high = 0;
4018 in_p = 1, high = high1;
4019 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4020 integer_one_node, 0);
4026 /* The case where we are excluding both ranges. Here the complex case
4027 is if they don't overlap. In that case, the only time we have a
4028 range is if they are adjacent. If the second is a subset of the
4029 first, the result is the first. Otherwise, the range to exclude
4030 starts at the beginning of the first range and ends at the end of the
4034 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4035 range_binop (PLUS_EXPR, NULL_TREE,
4037 integer_one_node, 1),
4039 in_p = 0, low = low0, high = high1;
4042 /* Canonicalize - [min, x] into - [-, x]. */
4043 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4044 switch (TREE_CODE (TREE_TYPE (low0)))
4047 if (TYPE_PRECISION (TREE_TYPE (low0))
4048 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4053 if (tree_int_cst_equal (low0,
4054 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4058 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4059 && integer_zerop (low0))
4066 /* Canonicalize - [x, max] into - [x, -]. */
4067 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4068 switch (TREE_CODE (TREE_TYPE (high1)))
4071 if (TYPE_PRECISION (TREE_TYPE (high1))
4072 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4077 if (tree_int_cst_equal (high1,
4078 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4082 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4083 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4085 integer_one_node, 1)))
4092 /* The ranges might be also adjacent between the maximum and
4093 minimum values of the given type. For
4094 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4095 return + [x + 1, y - 1]. */
4096 if (low0 == 0 && high1 == 0)
4098 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4099 integer_one_node, 1);
4100 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4101 integer_one_node, 0);
4102 if (low == 0 || high == 0)
4112 in_p = 0, low = low0, high = high0;
4114 in_p = 0, low = low0, high = high1;
4117 *pin_p = in_p, *plow = low, *phigh = high;
4122 /* Subroutine of fold, looking inside expressions of the form
4123 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4124 of the COND_EXPR. This function is being used also to optimize
4125 A op B ? C : A, by reversing the comparison first.
4127 Return a folded expression whose code is not a COND_EXPR
4128 anymore, or NULL_TREE if no folding opportunity is found. */
4131 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4133 enum tree_code comp_code = TREE_CODE (arg0);
4134 tree arg00 = TREE_OPERAND (arg0, 0);
4135 tree arg01 = TREE_OPERAND (arg0, 1);
4136 tree arg1_type = TREE_TYPE (arg1);
4142 /* If we have A op 0 ? A : -A, consider applying the following
4145 A == 0? A : -A same as -A
4146 A != 0? A : -A same as A
4147 A >= 0? A : -A same as abs (A)
4148 A > 0? A : -A same as abs (A)
4149 A <= 0? A : -A same as -abs (A)
4150 A < 0? A : -A same as -abs (A)
4152 None of these transformations work for modes with signed
4153 zeros. If A is +/-0, the first two transformations will
4154 change the sign of the result (from +0 to -0, or vice
4155 versa). The last four will fix the sign of the result,
4156 even though the original expressions could be positive or
4157 negative, depending on the sign of A.
4159 Note that all these transformations are correct if A is
4160 NaN, since the two alternatives (A and -A) are also NaNs. */
4161 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4162 ? real_zerop (arg01)
4163 : integer_zerop (arg01))
4164 && TREE_CODE (arg2) == NEGATE_EXPR
4165 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4170 tem = fold_convert (arg1_type, arg1);
4171 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4174 return pedantic_non_lvalue (fold_convert (type, arg1));
4177 if (flag_trapping_math)
4182 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4183 arg1 = fold_convert (lang_hooks.types.signed_type
4184 (TREE_TYPE (arg1)), arg1);
4185 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4186 return pedantic_non_lvalue (fold_convert (type, tem));
4189 if (flag_trapping_math)
4193 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4194 arg1 = fold_convert (lang_hooks.types.signed_type
4195 (TREE_TYPE (arg1)), arg1);
4196 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4197 return negate_expr (fold_convert (type, tem));
4199 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4203 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4204 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4205 both transformations are correct when A is NaN: A != 0
4206 is then true, and A == 0 is false. */
4208 if (integer_zerop (arg01) && integer_zerop (arg2))
4210 if (comp_code == NE_EXPR)
4211 return pedantic_non_lvalue (fold_convert (type, arg1));
4212 else if (comp_code == EQ_EXPR)
4213 return fold_convert (type, integer_zero_node);
4216 /* Try some transformations of A op B ? A : B.
4218 A == B? A : B same as B
4219 A != B? A : B same as A
4220 A >= B? A : B same as max (A, B)
4221 A > B? A : B same as max (B, A)
4222 A <= B? A : B same as min (A, B)
4223 A < B? A : B same as min (B, A)
4225 As above, these transformations don't work in the presence
4226 of signed zeros. For example, if A and B are zeros of
4227 opposite sign, the first two transformations will change
4228 the sign of the result. In the last four, the original
4229 expressions give different results for (A=+0, B=-0) and
4230 (A=-0, B=+0), but the transformed expressions do not.
4232 The first two transformations are correct if either A or B
4233 is a NaN. In the first transformation, the condition will
4234 be false, and B will indeed be chosen. In the case of the
4235 second transformation, the condition A != B will be true,
4236 and A will be chosen.
4238 The conversions to max() and min() are not correct if B is
4239 a number and A is not. The conditions in the original
4240 expressions will be false, so all four give B. The min()
4241 and max() versions would give a NaN instead. */
4242 if (operand_equal_for_comparison_p (arg01, arg2, arg00))
4244 tree comp_op0 = arg00;
4245 tree comp_op1 = arg01;
4246 tree comp_type = TREE_TYPE (comp_op0);
4248 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4249 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4259 return pedantic_non_lvalue (fold_convert (type, arg2));
4261 return pedantic_non_lvalue (fold_convert (type, arg1));
4266 /* In C++ a ?: expression can be an lvalue, so put the
4267 operand which will be used if they are equal first
4268 so that we can convert this back to the
4269 corresponding COND_EXPR. */
4270 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4272 comp_op0 = fold_convert (comp_type, comp_op0);
4273 comp_op1 = fold_convert (comp_type, comp_op1);
4274 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4275 ? fold (build2 (MIN_EXPR, comp_type, comp_op0, comp_op1))
4276 : fold (build2 (MIN_EXPR, comp_type, comp_op1, comp_op0));
4277 return pedantic_non_lvalue (fold_convert (type, tem));
4284 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4286 comp_op0 = fold_convert (comp_type, comp_op0);
4287 comp_op1 = fold_convert (comp_type, comp_op1);
4288 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
4289 ? fold (build2 (MAX_EXPR, comp_type, comp_op0, comp_op1))
4290 : fold (build2 (MAX_EXPR, comp_type, comp_op1, comp_op0));
4291 return pedantic_non_lvalue (fold_convert (type, tem));
4295 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4296 return pedantic_non_lvalue (fold_convert (type, arg2));
4299 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4300 return pedantic_non_lvalue (fold_convert (type, arg1));
4303 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4308 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4309 we might still be able to simplify this. For example,
4310 if C1 is one less or one more than C2, this might have started
4311 out as a MIN or MAX and been transformed by this function.
4312 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4314 if (INTEGRAL_TYPE_P (type)
4315 && TREE_CODE (arg01) == INTEGER_CST
4316 && TREE_CODE (arg2) == INTEGER_CST)
4320 /* We can replace A with C1 in this case. */
4321 arg1 = fold_convert (type, arg01);
4322 return fold (build3 (COND_EXPR, type, arg0, arg1, arg2));
4325 /* If C1 is C2 + 1, this is min(A, C2). */
4326 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4328 && operand_equal_p (arg01,
4329 const_binop (PLUS_EXPR, arg2,
4330 integer_one_node, 0),
4332 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4333 type, arg1, arg2)));
4337 /* If C1 is C2 - 1, this is min(A, C2). */
4338 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4340 && operand_equal_p (arg01,
4341 const_binop (MINUS_EXPR, arg2,
4342 integer_one_node, 0),
4344 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4345 type, arg1, arg2)));
4349 /* If C1 is C2 - 1, this is max(A, C2). */
4350 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4352 && operand_equal_p (arg01,
4353 const_binop (MINUS_EXPR, arg2,
4354 integer_one_node, 0),
4356 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4357 type, arg1, arg2)));
4361 /* If C1 is C2 + 1, this is max(A, C2). */
4362 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4364 && operand_equal_p (arg01,
4365 const_binop (PLUS_EXPR, arg2,
4366 integer_one_node, 0),
4368 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4369 type, arg1, arg2)));
4382 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
4383 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4386 /* EXP is some logical combination of boolean tests. See if we can
4387 merge it into some range test. Return the new tree if so. */
4390 fold_range_test (tree exp)
4392 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
4393 || TREE_CODE (exp) == TRUTH_OR_EXPR);
4394 int in0_p, in1_p, in_p;
4395 tree low0, low1, low, high0, high1, high;
4396 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
4397 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
4400 /* If this is an OR operation, invert both sides; we will invert
4401 again at the end. */
4403 in0_p = ! in0_p, in1_p = ! in1_p;
4405 /* If both expressions are the same, if we can merge the ranges, and we
4406 can build the range test, return it or it inverted. If one of the
4407 ranges is always true or always false, consider it to be the same
4408 expression as the other. */
4409 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4410 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4412 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
4414 : rhs != 0 ? rhs : integer_zero_node,
4416 return or_op ? invert_truthvalue (tem) : tem;
4418 /* On machines where the branch cost is expensive, if this is a
4419 short-circuited branch and the underlying object on both sides
4420 is the same, make a non-short-circuit operation. */
4421 else if (RANGE_TEST_NON_SHORT_CIRCUIT
4422 && lhs != 0 && rhs != 0
4423 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4424 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
4425 && operand_equal_p (lhs, rhs, 0))
4427 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4428 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4429 which cases we can't do this. */
4430 if (simple_operand_p (lhs))
4431 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4432 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4433 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
4434 TREE_OPERAND (exp, 1));
4436 else if (lang_hooks.decls.global_bindings_p () == 0
4437 && ! CONTAINS_PLACEHOLDER_P (lhs))
4439 tree common = save_expr (lhs);
4441 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
4442 or_op ? ! in0_p : in0_p,
4444 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
4445 or_op ? ! in1_p : in1_p,
4447 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4448 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4449 TREE_TYPE (exp), lhs, rhs);
4456 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4457 bit value. Arrange things so the extra bits will be set to zero if and
4458 only if C is signed-extended to its full width. If MASK is nonzero,
4459 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4462 unextend (tree c, int p, int unsignedp, tree mask)
4464 tree type = TREE_TYPE (c);
4465 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4468 if (p == modesize || unsignedp)
4471 /* We work by getting just the sign bit into the low-order bit, then
4472 into the high-order bit, then sign-extend. We then XOR that value
4474 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4475 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
4477 /* We must use a signed type in order to get an arithmetic right shift.
4478 However, we must also avoid introducing accidental overflows, so that
4479 a subsequent call to integer_zerop will work. Hence we must
4480 do the type conversion here. At this point, the constant is either
4481 zero or one, and the conversion to a signed type can never overflow.
4482 We could get an overflow if this conversion is done anywhere else. */
4483 if (TYPE_UNSIGNED (type))
4484 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
4486 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4487 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
4489 temp = const_binop (BIT_AND_EXPR, temp,
4490 fold_convert (TREE_TYPE (c), mask), 0);
4491 /* If necessary, convert the type back to match the type of C. */
4492 if (TYPE_UNSIGNED (type))
4493 temp = fold_convert (type, temp);
4495 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
4498 /* Find ways of folding logical expressions of LHS and RHS:
4499 Try to merge two comparisons to the same innermost item.
4500 Look for range tests like "ch >= '0' && ch <= '9'".
4501 Look for combinations of simple terms on machines with expensive branches
4502 and evaluate the RHS unconditionally.
4504 For example, if we have p->a == 2 && p->b == 4 and we can make an
4505 object large enough to span both A and B, we can do this with a comparison
4506 against the object ANDed with the a mask.
4508 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4509 operations to do this with one comparison.
4511 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4512 function and the one above.
4514 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4515 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4517 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4520 We return the simplified tree or 0 if no optimization is possible. */
4523 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
4525 /* If this is the "or" of two comparisons, we can do something if
4526 the comparisons are NE_EXPR. If this is the "and", we can do something
4527 if the comparisons are EQ_EXPR. I.e.,
4528 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4530 WANTED_CODE is this operation code. For single bit fields, we can
4531 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4532 comparison for one-bit fields. */
4534 enum tree_code wanted_code;
4535 enum tree_code lcode, rcode;
4536 tree ll_arg, lr_arg, rl_arg, rr_arg;
4537 tree ll_inner, lr_inner, rl_inner, rr_inner;
4538 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
4539 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
4540 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
4541 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
4542 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
4543 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
4544 enum machine_mode lnmode, rnmode;
4545 tree ll_mask, lr_mask, rl_mask, rr_mask;
4546 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
4547 tree l_const, r_const;
4548 tree lntype, rntype, result;
4549 int first_bit, end_bit;
4552 /* Start by getting the comparison codes. Fail if anything is volatile.
4553 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4554 it were surrounded with a NE_EXPR. */
4556 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
4559 lcode = TREE_CODE (lhs);
4560 rcode = TREE_CODE (rhs);
4562 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
4564 lhs = build2 (NE_EXPR, truth_type, lhs,
4565 fold_convert (TREE_TYPE (lhs), integer_zero_node));
4569 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
4571 rhs = build2 (NE_EXPR, truth_type, rhs,
4572 fold_convert (TREE_TYPE (rhs), integer_zero_node));
4576 if (TREE_CODE_CLASS (lcode) != tcc_comparison
4577 || TREE_CODE_CLASS (rcode) != tcc_comparison)
4580 ll_arg = TREE_OPERAND (lhs, 0);
4581 lr_arg = TREE_OPERAND (lhs, 1);
4582 rl_arg = TREE_OPERAND (rhs, 0);
4583 rr_arg = TREE_OPERAND (rhs, 1);
4585 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4586 if (simple_operand_p (ll_arg)
4587 && simple_operand_p (lr_arg))
4590 if (operand_equal_p (ll_arg, rl_arg, 0)
4591 && operand_equal_p (lr_arg, rr_arg, 0))
4593 result = combine_comparisons (code, lcode, rcode,
4594 truth_type, ll_arg, lr_arg);
4598 else if (operand_equal_p (ll_arg, rr_arg, 0)
4599 && operand_equal_p (lr_arg, rl_arg, 0))
4601 result = combine_comparisons (code, lcode,
4602 swap_tree_comparison (rcode),
4603 truth_type, ll_arg, lr_arg);
4609 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4610 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4612 /* If the RHS can be evaluated unconditionally and its operands are
4613 simple, it wins to evaluate the RHS unconditionally on machines
4614 with expensive branches. In this case, this isn't a comparison
4615 that can be merged. Avoid doing this if the RHS is a floating-point
4616 comparison since those can trap. */
4618 if (BRANCH_COST >= 2
4619 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4620 && simple_operand_p (rl_arg)
4621 && simple_operand_p (rr_arg))
4623 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4624 if (code == TRUTH_OR_EXPR
4625 && lcode == NE_EXPR && integer_zerop (lr_arg)
4626 && rcode == NE_EXPR && integer_zerop (rr_arg)
4627 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4628 return build2 (NE_EXPR, truth_type,
4629 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4631 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4633 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4634 if (code == TRUTH_AND_EXPR
4635 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4636 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4637 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4638 return build2 (EQ_EXPR, truth_type,
4639 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4641 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4643 return build2 (code, truth_type, lhs, rhs);
4646 /* See if the comparisons can be merged. Then get all the parameters for
4649 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4650 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4654 ll_inner = decode_field_reference (ll_arg,
4655 &ll_bitsize, &ll_bitpos, &ll_mode,
4656 &ll_unsignedp, &volatilep, &ll_mask,
4658 lr_inner = decode_field_reference (lr_arg,
4659 &lr_bitsize, &lr_bitpos, &lr_mode,
4660 &lr_unsignedp, &volatilep, &lr_mask,
4662 rl_inner = decode_field_reference (rl_arg,
4663 &rl_bitsize, &rl_bitpos, &rl_mode,
4664 &rl_unsignedp, &volatilep, &rl_mask,
4666 rr_inner = decode_field_reference (rr_arg,
4667 &rr_bitsize, &rr_bitpos, &rr_mode,
4668 &rr_unsignedp, &volatilep, &rr_mask,
4671 /* It must be true that the inner operation on the lhs of each
4672 comparison must be the same if we are to be able to do anything.
4673 Then see if we have constants. If not, the same must be true for
4675 if (volatilep || ll_inner == 0 || rl_inner == 0
4676 || ! operand_equal_p (ll_inner, rl_inner, 0))
4679 if (TREE_CODE (lr_arg) == INTEGER_CST
4680 && TREE_CODE (rr_arg) == INTEGER_CST)
4681 l_const = lr_arg, r_const = rr_arg;
4682 else if (lr_inner == 0 || rr_inner == 0
4683 || ! operand_equal_p (lr_inner, rr_inner, 0))
4686 l_const = r_const = 0;
4688 /* If either comparison code is not correct for our logical operation,
4689 fail. However, we can convert a one-bit comparison against zero into
4690 the opposite comparison against that bit being set in the field. */
4692 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4693 if (lcode != wanted_code)
4695 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4697 /* Make the left operand unsigned, since we are only interested
4698 in the value of one bit. Otherwise we are doing the wrong
4707 /* This is analogous to the code for l_const above. */
4708 if (rcode != wanted_code)
4710 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4719 /* After this point all optimizations will generate bit-field
4720 references, which we might not want. */
4721 if (! lang_hooks.can_use_bit_fields_p ())
4724 /* See if we can find a mode that contains both fields being compared on
4725 the left. If we can't, fail. Otherwise, update all constants and masks
4726 to be relative to a field of that size. */
4727 first_bit = MIN (ll_bitpos, rl_bitpos);
4728 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4729 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4730 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4732 if (lnmode == VOIDmode)
4735 lnbitsize = GET_MODE_BITSIZE (lnmode);
4736 lnbitpos = first_bit & ~ (lnbitsize - 1);
4737 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4738 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4740 if (BYTES_BIG_ENDIAN)
4742 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4743 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4746 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4747 size_int (xll_bitpos), 0);
4748 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4749 size_int (xrl_bitpos), 0);
4753 l_const = fold_convert (lntype, l_const);
4754 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4755 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4756 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4757 fold (build1 (BIT_NOT_EXPR,
4761 warning ("comparison is always %d", wanted_code == NE_EXPR);
4763 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4768 r_const = fold_convert (lntype, r_const);
4769 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4770 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4771 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4772 fold (build1 (BIT_NOT_EXPR,
4776 warning ("comparison is always %d", wanted_code == NE_EXPR);
4778 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4782 /* If the right sides are not constant, do the same for it. Also,
4783 disallow this optimization if a size or signedness mismatch occurs
4784 between the left and right sides. */
4787 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4788 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4789 /* Make sure the two fields on the right
4790 correspond to the left without being swapped. */
4791 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4794 first_bit = MIN (lr_bitpos, rr_bitpos);
4795 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4796 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4797 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4799 if (rnmode == VOIDmode)
4802 rnbitsize = GET_MODE_BITSIZE (rnmode);
4803 rnbitpos = first_bit & ~ (rnbitsize - 1);
4804 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4805 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4807 if (BYTES_BIG_ENDIAN)
4809 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4810 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4813 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4814 size_int (xlr_bitpos), 0);
4815 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4816 size_int (xrr_bitpos), 0);
4818 /* Make a mask that corresponds to both fields being compared.
4819 Do this for both items being compared. If the operands are the
4820 same size and the bits being compared are in the same position
4821 then we can do this by masking both and comparing the masked
4823 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4824 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4825 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4827 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4828 ll_unsignedp || rl_unsignedp);
4829 if (! all_ones_mask_p (ll_mask, lnbitsize))
4830 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
4832 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4833 lr_unsignedp || rr_unsignedp);
4834 if (! all_ones_mask_p (lr_mask, rnbitsize))
4835 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
4837 return build2 (wanted_code, truth_type, lhs, rhs);
4840 /* There is still another way we can do something: If both pairs of
4841 fields being compared are adjacent, we may be able to make a wider
4842 field containing them both.
4844 Note that we still must mask the lhs/rhs expressions. Furthermore,
4845 the mask must be shifted to account for the shift done by
4846 make_bit_field_ref. */
4847 if ((ll_bitsize + ll_bitpos == rl_bitpos
4848 && lr_bitsize + lr_bitpos == rr_bitpos)
4849 || (ll_bitpos == rl_bitpos + rl_bitsize
4850 && lr_bitpos == rr_bitpos + rr_bitsize))
4854 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4855 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4856 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4857 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4859 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4860 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4861 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4862 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4864 /* Convert to the smaller type before masking out unwanted bits. */
4866 if (lntype != rntype)
4868 if (lnbitsize > rnbitsize)
4870 lhs = fold_convert (rntype, lhs);
4871 ll_mask = fold_convert (rntype, ll_mask);
4874 else if (lnbitsize < rnbitsize)
4876 rhs = fold_convert (lntype, rhs);
4877 lr_mask = fold_convert (lntype, lr_mask);
4882 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4883 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
4885 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4886 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
4888 return build2 (wanted_code, truth_type, lhs, rhs);
4894 /* Handle the case of comparisons with constants. If there is something in
4895 common between the masks, those bits of the constants must be the same.
4896 If not, the condition is always false. Test for this to avoid generating
4897 incorrect code below. */
4898 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4899 if (! integer_zerop (result)
4900 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4901 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4903 if (wanted_code == NE_EXPR)
4905 warning ("%<or%> of unmatched not-equal tests is always 1");
4906 return constant_boolean_node (true, truth_type);
4910 warning ("%<and%> of mutually exclusive equal-tests is always 0");
4911 return constant_boolean_node (false, truth_type);
4915 /* Construct the expression we will return. First get the component
4916 reference we will make. Unless the mask is all ones the width of
4917 that field, perform the mask operation. Then compare with the
4919 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4920 ll_unsignedp || rl_unsignedp);
4922 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4923 if (! all_ones_mask_p (ll_mask, lnbitsize))
4924 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
4926 return build2 (wanted_code, truth_type, result,
4927 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4930 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4934 optimize_minmax_comparison (tree t)
4936 tree type = TREE_TYPE (t);
4937 tree arg0 = TREE_OPERAND (t, 0);
4938 enum tree_code op_code;
4939 tree comp_const = TREE_OPERAND (t, 1);
4941 int consts_equal, consts_lt;
4944 STRIP_SIGN_NOPS (arg0);
4946 op_code = TREE_CODE (arg0);
4947 minmax_const = TREE_OPERAND (arg0, 1);
4948 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4949 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4950 inner = TREE_OPERAND (arg0, 0);
4952 /* If something does not permit us to optimize, return the original tree. */
4953 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4954 || TREE_CODE (comp_const) != INTEGER_CST
4955 || TREE_CONSTANT_OVERFLOW (comp_const)
4956 || TREE_CODE (minmax_const) != INTEGER_CST
4957 || TREE_CONSTANT_OVERFLOW (minmax_const))
4960 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4961 and GT_EXPR, doing the rest with recursive calls using logical
4963 switch (TREE_CODE (t))
4965 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4967 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4971 fold (build2 (TRUTH_ORIF_EXPR, type,
4972 optimize_minmax_comparison
4973 (build2 (EQ_EXPR, type, arg0, comp_const)),
4974 optimize_minmax_comparison
4975 (build2 (GT_EXPR, type, arg0, comp_const))));
4978 if (op_code == MAX_EXPR && consts_equal)
4979 /* MAX (X, 0) == 0 -> X <= 0 */
4980 return fold (build2 (LE_EXPR, type, inner, comp_const));
4982 else if (op_code == MAX_EXPR && consts_lt)
4983 /* MAX (X, 0) == 5 -> X == 5 */
4984 return fold (build2 (EQ_EXPR, type, inner, comp_const));
4986 else if (op_code == MAX_EXPR)
4987 /* MAX (X, 0) == -1 -> false */
4988 return omit_one_operand (type, integer_zero_node, inner);
4990 else if (consts_equal)
4991 /* MIN (X, 0) == 0 -> X >= 0 */
4992 return fold (build2 (GE_EXPR, type, inner, comp_const));
4995 /* MIN (X, 0) == 5 -> false */
4996 return omit_one_operand (type, integer_zero_node, inner);
4999 /* MIN (X, 0) == -1 -> X == -1 */
5000 return fold (build2 (EQ_EXPR, type, inner, comp_const));
5003 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5004 /* MAX (X, 0) > 0 -> X > 0
5005 MAX (X, 0) > 5 -> X > 5 */
5006 return fold (build2 (GT_EXPR, type, inner, comp_const));
5008 else if (op_code == MAX_EXPR)
5009 /* MAX (X, 0) > -1 -> true */
5010 return omit_one_operand (type, integer_one_node, inner);
5012 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5013 /* MIN (X, 0) > 0 -> false
5014 MIN (X, 0) > 5 -> false */
5015 return omit_one_operand (type, integer_zero_node, inner);
5018 /* MIN (X, 0) > -1 -> X > -1 */
5019 return fold (build2 (GT_EXPR, type, inner, comp_const));
5026 /* T is an integer expression that is being multiplied, divided, or taken a
5027 modulus (CODE says which and what kind of divide or modulus) by a
5028 constant C. See if we can eliminate that operation by folding it with
5029 other operations already in T. WIDE_TYPE, if non-null, is a type that
5030 should be used for the computation if wider than our type.
5032 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5033 (X * 2) + (Y * 4). We must, however, be assured that either the original
5034 expression would not overflow or that overflow is undefined for the type
5035 in the language in question.
5037 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5038 the machine has a multiply-accumulate insn or that this is part of an
5039 addressing calculation.
5041 If we return a non-null expression, it is an equivalent form of the
5042 original computation, but need not be in the original type. */
5045 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
5047 /* To avoid exponential search depth, refuse to allow recursion past
5048 three levels. Beyond that (1) it's highly unlikely that we'll find
5049 something interesting and (2) we've probably processed it before
5050 when we built the inner expression. */
5059 ret = extract_muldiv_1 (t, c, code, wide_type);
5066 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
5068 tree type = TREE_TYPE (t);
5069 enum tree_code tcode = TREE_CODE (t);
5070 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5071 > GET_MODE_SIZE (TYPE_MODE (type)))
5072 ? wide_type : type);
5074 int same_p = tcode == code;
5075 tree op0 = NULL_TREE, op1 = NULL_TREE;
5077 /* Don't deal with constants of zero here; they confuse the code below. */
5078 if (integer_zerop (c))
5081 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5082 op0 = TREE_OPERAND (t, 0);
5084 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5085 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5087 /* Note that we need not handle conditional operations here since fold
5088 already handles those cases. So just do arithmetic here. */
5092 /* For a constant, we can always simplify if we are a multiply
5093 or (for divide and modulus) if it is a multiple of our constant. */
5094 if (code == MULT_EXPR
5095 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5096 return const_binop (code, fold_convert (ctype, t),
5097 fold_convert (ctype, c), 0);
5100 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5101 /* If op0 is an expression ... */
5102 if ((COMPARISON_CLASS_P (op0)
5103 || UNARY_CLASS_P (op0)
5104 || BINARY_CLASS_P (op0)
5105 || EXPRESSION_CLASS_P (op0))
5106 /* ... and is unsigned, and its type is smaller than ctype,
5107 then we cannot pass through as widening. */
5108 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5109 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5110 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5111 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5112 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5113 /* ... or this is a truncation (t is narrower than op0),
5114 then we cannot pass through this narrowing. */
5115 || (GET_MODE_SIZE (TYPE_MODE (type))
5116 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5117 /* ... or signedness changes for division or modulus,
5118 then we cannot pass through this conversion. */
5119 || (code != MULT_EXPR
5120 && (TYPE_UNSIGNED (ctype)
5121 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5124 /* Pass the constant down and see if we can make a simplification. If
5125 we can, replace this expression with the inner simplification for
5126 possible later conversion to our or some other type. */
5127 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5128 && TREE_CODE (t2) == INTEGER_CST
5129 && ! TREE_CONSTANT_OVERFLOW (t2)
5130 && (0 != (t1 = extract_muldiv (op0, t2, code,
5132 ? ctype : NULL_TREE))))
5136 case NEGATE_EXPR: case ABS_EXPR:
5137 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5138 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
5141 case MIN_EXPR: case MAX_EXPR:
5142 /* If widening the type changes the signedness, then we can't perform
5143 this optimization as that changes the result. */
5144 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5147 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5148 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
5149 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
5151 if (tree_int_cst_sgn (c) < 0)
5152 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5154 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5155 fold_convert (ctype, t2)));
5159 case LSHIFT_EXPR: case RSHIFT_EXPR:
5160 /* If the second operand is constant, this is a multiplication
5161 or floor division, by a power of two, so we can treat it that
5162 way unless the multiplier or divisor overflows. Signed
5163 left-shift overflow is implementation-defined rather than
5164 undefined in C90, so do not convert signed left shift into
5166 if (TREE_CODE (op1) == INTEGER_CST
5167 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5168 /* const_binop may not detect overflow correctly,
5169 so check for it explicitly here. */
5170 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5171 && TREE_INT_CST_HIGH (op1) == 0
5172 && 0 != (t1 = fold_convert (ctype,
5173 const_binop (LSHIFT_EXPR,
5176 && ! TREE_OVERFLOW (t1))
5177 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5178 ? MULT_EXPR : FLOOR_DIV_EXPR,
5179 ctype, fold_convert (ctype, op0), t1),
5180 c, code, wide_type);
5183 case PLUS_EXPR: case MINUS_EXPR:
5184 /* See if we can eliminate the operation on both sides. If we can, we
5185 can return a new PLUS or MINUS. If we can't, the only remaining
5186 cases where we can do anything are if the second operand is a
5188 t1 = extract_muldiv (op0, c, code, wide_type);
5189 t2 = extract_muldiv (op1, c, code, wide_type);
5190 if (t1 != 0 && t2 != 0
5191 && (code == MULT_EXPR
5192 /* If not multiplication, we can only do this if both operands
5193 are divisible by c. */
5194 || (multiple_of_p (ctype, op0, c)
5195 && multiple_of_p (ctype, op1, c))))
5196 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5197 fold_convert (ctype, t2)));
5199 /* If this was a subtraction, negate OP1 and set it to be an addition.
5200 This simplifies the logic below. */
5201 if (tcode == MINUS_EXPR)
5202 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5204 if (TREE_CODE (op1) != INTEGER_CST)
5207 /* If either OP1 or C are negative, this optimization is not safe for
5208 some of the division and remainder types while for others we need
5209 to change the code. */
5210 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5212 if (code == CEIL_DIV_EXPR)
5213 code = FLOOR_DIV_EXPR;
5214 else if (code == FLOOR_DIV_EXPR)
5215 code = CEIL_DIV_EXPR;
5216 else if (code != MULT_EXPR
5217 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5221 /* If it's a multiply or a division/modulus operation of a multiple
5222 of our constant, do the operation and verify it doesn't overflow. */
5223 if (code == MULT_EXPR
5224 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5226 op1 = const_binop (code, fold_convert (ctype, op1),
5227 fold_convert (ctype, c), 0);
5228 /* We allow the constant to overflow with wrapping semantics. */
5230 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
5236 /* If we have an unsigned type is not a sizetype, we cannot widen
5237 the operation since it will change the result if the original
5238 computation overflowed. */
5239 if (TYPE_UNSIGNED (ctype)
5240 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5244 /* If we were able to eliminate our operation from the first side,
5245 apply our operation to the second side and reform the PLUS. */
5246 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5247 return fold (build2 (tcode, ctype, fold_convert (ctype, t1), op1));
5249 /* The last case is if we are a multiply. In that case, we can
5250 apply the distributive law to commute the multiply and addition
5251 if the multiplication of the constants doesn't overflow. */
5252 if (code == MULT_EXPR)
5253 return fold (build2 (tcode, ctype,
5254 fold (build2 (code, ctype,
5255 fold_convert (ctype, op0),
5256 fold_convert (ctype, c))),
5262 /* We have a special case here if we are doing something like
5263 (C * 8) % 4 since we know that's zero. */
5264 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5265 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5266 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5267 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5268 return omit_one_operand (type, integer_zero_node, op0);
5270 /* ... fall through ... */
5272 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5273 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5274 /* If we can extract our operation from the LHS, do so and return a
5275 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5276 do something only if the second operand is a constant. */
5278 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5279 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5280 fold_convert (ctype, op1)));
5281 else if (tcode == MULT_EXPR && code == MULT_EXPR
5282 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
5283 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5284 fold_convert (ctype, t1)));
5285 else if (TREE_CODE (op1) != INTEGER_CST)
5288 /* If these are the same operation types, we can associate them
5289 assuming no overflow. */
5291 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5292 fold_convert (ctype, c), 0))
5293 && ! TREE_OVERFLOW (t1))
5294 return fold (build2 (tcode, ctype, fold_convert (ctype, op0), t1));
5296 /* If these operations "cancel" each other, we have the main
5297 optimizations of this pass, which occur when either constant is a
5298 multiple of the other, in which case we replace this with either an
5299 operation or CODE or TCODE.
5301 If we have an unsigned type that is not a sizetype, we cannot do
5302 this since it will change the result if the original computation
5304 if ((! TYPE_UNSIGNED (ctype)
5305 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5307 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5308 || (tcode == MULT_EXPR
5309 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5310 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5312 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5313 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5314 fold_convert (ctype,
5315 const_binop (TRUNC_DIV_EXPR,
5317 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5318 return fold (build2 (code, ctype, fold_convert (ctype, op0),
5319 fold_convert (ctype,
5320 const_binop (TRUNC_DIV_EXPR,
5332 /* Return a node which has the indicated constant VALUE (either 0 or
5333 1), and is of the indicated TYPE. */
5336 constant_boolean_node (int value, tree type)
5338 if (type == integer_type_node)
5339 return value ? integer_one_node : integer_zero_node;
5340 else if (type == boolean_type_node)
5341 return value ? boolean_true_node : boolean_false_node;
5342 else if (TREE_CODE (type) == BOOLEAN_TYPE)
5343 return lang_hooks.truthvalue_conversion (value ? integer_one_node
5344 : integer_zero_node);
5346 return build_int_cst (type, value);
5349 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5350 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5351 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5352 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5353 COND is the first argument to CODE; otherwise (as in the example
5354 given here), it is the second argument. TYPE is the type of the
5355 original expression. Return NULL_TREE if no simplification is
5359 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
5360 tree cond, tree arg, int cond_first_p)
5362 tree test, true_value, false_value;
5363 tree lhs = NULL_TREE;
5364 tree rhs = NULL_TREE;
5366 /* This transformation is only worthwhile if we don't have to wrap
5367 arg in a SAVE_EXPR, and the operation can be simplified on atleast
5368 one of the branches once its pushed inside the COND_EXPR. */
5369 if (!TREE_CONSTANT (arg))
5372 if (TREE_CODE (cond) == COND_EXPR)
5374 test = TREE_OPERAND (cond, 0);
5375 true_value = TREE_OPERAND (cond, 1);
5376 false_value = TREE_OPERAND (cond, 2);
5377 /* If this operand throws an expression, then it does not make
5378 sense to try to perform a logical or arithmetic operation
5380 if (VOID_TYPE_P (TREE_TYPE (true_value)))
5382 if (VOID_TYPE_P (TREE_TYPE (false_value)))
5387 tree testtype = TREE_TYPE (cond);
5389 true_value = constant_boolean_node (true, testtype);
5390 false_value = constant_boolean_node (false, testtype);
5394 lhs = fold (cond_first_p ? build2 (code, type, true_value, arg)
5395 : build2 (code, type, arg, true_value));
5397 rhs = fold (cond_first_p ? build2 (code, type, false_value, arg)
5398 : build2 (code, type, arg, false_value));
5400 test = fold (build3 (COND_EXPR, type, test, lhs, rhs));
5401 return fold_convert (type, test);
5405 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5407 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5408 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5409 ADDEND is the same as X.
5411 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5412 and finite. The problematic cases are when X is zero, and its mode
5413 has signed zeros. In the case of rounding towards -infinity,
5414 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5415 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5418 fold_real_zero_addition_p (tree type, tree addend, int negate)
5420 if (!real_zerop (addend))
5423 /* Don't allow the fold with -fsignaling-nans. */
5424 if (HONOR_SNANS (TYPE_MODE (type)))
5427 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5428 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5431 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5432 if (TREE_CODE (addend) == REAL_CST
5433 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5436 /* The mode has signed zeros, and we have to honor their sign.
5437 In this situation, there is only one case we can return true for.
5438 X - 0 is the same as X unless rounding towards -infinity is
5440 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5443 /* Subroutine of fold() that checks comparisons of built-in math
5444 functions against real constants.
5446 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5447 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5448 is the type of the result and ARG0 and ARG1 are the operands of the
5449 comparison. ARG1 must be a TREE_REAL_CST.
5451 The function returns the constant folded tree if a simplification
5452 can be made, and NULL_TREE otherwise. */
5455 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5456 tree type, tree arg0, tree arg1)
5460 if (BUILTIN_SQRT_P (fcode))
5462 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5463 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5465 c = TREE_REAL_CST (arg1);
5466 if (REAL_VALUE_NEGATIVE (c))
5468 /* sqrt(x) < y is always false, if y is negative. */
5469 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5470 return omit_one_operand (type, integer_zero_node, arg);
5472 /* sqrt(x) > y is always true, if y is negative and we
5473 don't care about NaNs, i.e. negative values of x. */
5474 if (code == NE_EXPR || !HONOR_NANS (mode))
5475 return omit_one_operand (type, integer_one_node, arg);
5477 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5478 return fold (build2 (GE_EXPR, type, arg,
5479 build_real (TREE_TYPE (arg), dconst0)));
5481 else if (code == GT_EXPR || code == GE_EXPR)
5485 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5486 real_convert (&c2, mode, &c2);
5488 if (REAL_VALUE_ISINF (c2))
5490 /* sqrt(x) > y is x == +Inf, when y is very large. */
5491 if (HONOR_INFINITIES (mode))
5492 return fold (build2 (EQ_EXPR, type, arg,
5493 build_real (TREE_TYPE (arg), c2)));
5495 /* sqrt(x) > y is always false, when y is very large
5496 and we don't care about infinities. */
5497 return omit_one_operand (type, integer_zero_node, arg);
5500 /* sqrt(x) > c is the same as x > c*c. */
5501 return fold (build2 (code, type, arg,
5502 build_real (TREE_TYPE (arg), c2)));
5504 else if (code == LT_EXPR || code == LE_EXPR)
5508 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5509 real_convert (&c2, mode, &c2);
5511 if (REAL_VALUE_ISINF (c2))
5513 /* sqrt(x) < y is always true, when y is a very large
5514 value and we don't care about NaNs or Infinities. */
5515 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5516 return omit_one_operand (type, integer_one_node, arg);
5518 /* sqrt(x) < y is x != +Inf when y is very large and we
5519 don't care about NaNs. */
5520 if (! HONOR_NANS (mode))
5521 return fold (build2 (NE_EXPR, type, arg,
5522 build_real (TREE_TYPE (arg), c2)));
5524 /* sqrt(x) < y is x >= 0 when y is very large and we
5525 don't care about Infinities. */
5526 if (! HONOR_INFINITIES (mode))
5527 return fold (build2 (GE_EXPR, type, arg,
5528 build_real (TREE_TYPE (arg), dconst0)));
5530 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5531 if (lang_hooks.decls.global_bindings_p () != 0
5532 || CONTAINS_PLACEHOLDER_P (arg))
5535 arg = save_expr (arg);
5536 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5537 fold (build2 (GE_EXPR, type, arg,
5538 build_real (TREE_TYPE (arg),
5540 fold (build2 (NE_EXPR, type, arg,
5541 build_real (TREE_TYPE (arg),
5545 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5546 if (! HONOR_NANS (mode))
5547 return fold (build2 (code, type, arg,
5548 build_real (TREE_TYPE (arg), c2)));
5550 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5551 if (lang_hooks.decls.global_bindings_p () == 0
5552 && ! CONTAINS_PLACEHOLDER_P (arg))
5554 arg = save_expr (arg);
5555 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5556 fold (build2 (GE_EXPR, type, arg,
5557 build_real (TREE_TYPE (arg),
5559 fold (build2 (code, type, arg,
5560 build_real (TREE_TYPE (arg),
5569 /* Subroutine of fold() that optimizes comparisons against Infinities,
5570 either +Inf or -Inf.
5572 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5573 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5574 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5576 The function returns the constant folded tree if a simplification
5577 can be made, and NULL_TREE otherwise. */
5580 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5582 enum machine_mode mode;
5583 REAL_VALUE_TYPE max;
5587 mode = TYPE_MODE (TREE_TYPE (arg0));
5589 /* For negative infinity swap the sense of the comparison. */
5590 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5592 code = swap_tree_comparison (code);
5597 /* x > +Inf is always false, if with ignore sNANs. */
5598 if (HONOR_SNANS (mode))
5600 return omit_one_operand (type, integer_zero_node, arg0);
5603 /* x <= +Inf is always true, if we don't case about NaNs. */
5604 if (! HONOR_NANS (mode))
5605 return omit_one_operand (type, integer_one_node, arg0);
5607 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5608 if (lang_hooks.decls.global_bindings_p () == 0
5609 && ! CONTAINS_PLACEHOLDER_P (arg0))
5611 arg0 = save_expr (arg0);
5612 return fold (build2 (EQ_EXPR, type, arg0, arg0));
5618 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5619 real_maxval (&max, neg, mode);
5620 return fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5621 arg0, build_real (TREE_TYPE (arg0), max)));
5624 /* x < +Inf is always equal to x <= DBL_MAX. */
5625 real_maxval (&max, neg, mode);
5626 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5627 arg0, build_real (TREE_TYPE (arg0), max)));
5630 /* x != +Inf is always equal to !(x > DBL_MAX). */
5631 real_maxval (&max, neg, mode);
5632 if (! HONOR_NANS (mode))
5633 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5634 arg0, build_real (TREE_TYPE (arg0), max)));
5636 /* The transformation below creates non-gimple code and thus is
5637 not appropriate if we are in gimple form. */
5641 temp = fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5642 arg0, build_real (TREE_TYPE (arg0), max)));
5643 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5652 /* Subroutine of fold() that optimizes comparisons of a division by
5653 a nonzero integer constant against an integer constant, i.e.
5656 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5657 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5658 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5660 The function returns the constant folded tree if a simplification
5661 can be made, and NULL_TREE otherwise. */
5664 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5666 tree prod, tmp, hi, lo;
5667 tree arg00 = TREE_OPERAND (arg0, 0);
5668 tree arg01 = TREE_OPERAND (arg0, 1);
5669 unsigned HOST_WIDE_INT lpart;
5670 HOST_WIDE_INT hpart;
5673 /* We have to do this the hard way to detect unsigned overflow.
5674 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5675 overflow = mul_double (TREE_INT_CST_LOW (arg01),
5676 TREE_INT_CST_HIGH (arg01),
5677 TREE_INT_CST_LOW (arg1),
5678 TREE_INT_CST_HIGH (arg1), &lpart, &hpart);
5679 prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5680 prod = force_fit_type (prod, -1, overflow, false);
5682 if (TYPE_UNSIGNED (TREE_TYPE (arg0)))
5684 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5687 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5688 overflow = add_double (TREE_INT_CST_LOW (prod),
5689 TREE_INT_CST_HIGH (prod),
5690 TREE_INT_CST_LOW (tmp),
5691 TREE_INT_CST_HIGH (tmp),
5693 hi = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5694 hi = force_fit_type (hi, -1, overflow | TREE_OVERFLOW (prod),
5695 TREE_CONSTANT_OVERFLOW (prod));
5697 else if (tree_int_cst_sgn (arg01) >= 0)
5699 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5700 switch (tree_int_cst_sgn (arg1))
5703 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5708 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
5713 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5723 /* A negative divisor reverses the relational operators. */
5724 code = swap_tree_comparison (code);
5726 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
5727 switch (tree_int_cst_sgn (arg1))
5730 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5735 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
5740 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5752 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5753 return omit_one_operand (type, integer_zero_node, arg00);
5754 if (TREE_OVERFLOW (hi))
5755 return fold (build2 (GE_EXPR, type, arg00, lo));
5756 if (TREE_OVERFLOW (lo))
5757 return fold (build2 (LE_EXPR, type, arg00, hi));
5758 return build_range_check (type, arg00, 1, lo, hi);
5761 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5762 return omit_one_operand (type, integer_one_node, arg00);
5763 if (TREE_OVERFLOW (hi))
5764 return fold (build2 (LT_EXPR, type, arg00, lo));
5765 if (TREE_OVERFLOW (lo))
5766 return fold (build2 (GT_EXPR, type, arg00, hi));
5767 return build_range_check (type, arg00, 0, lo, hi);
5770 if (TREE_OVERFLOW (lo))
5771 return omit_one_operand (type, integer_zero_node, arg00);
5772 return fold (build2 (LT_EXPR, type, arg00, lo));
5775 if (TREE_OVERFLOW (hi))
5776 return omit_one_operand (type, integer_one_node, arg00);
5777 return fold (build2 (LE_EXPR, type, arg00, hi));
5780 if (TREE_OVERFLOW (hi))
5781 return omit_one_operand (type, integer_zero_node, arg00);
5782 return fold (build2 (GT_EXPR, type, arg00, hi));
5785 if (TREE_OVERFLOW (lo))
5786 return omit_one_operand (type, integer_one_node, arg00);
5787 return fold (build2 (GE_EXPR, type, arg00, lo));
5797 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5798 equality/inequality test, then return a simplified form of
5799 the test using shifts and logical operations. Otherwise return
5800 NULL. TYPE is the desired result type. */
5803 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5806 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5808 if (code == TRUTH_NOT_EXPR)
5810 code = TREE_CODE (arg0);
5811 if (code != NE_EXPR && code != EQ_EXPR)
5814 /* Extract the arguments of the EQ/NE. */
5815 arg1 = TREE_OPERAND (arg0, 1);
5816 arg0 = TREE_OPERAND (arg0, 0);
5818 /* This requires us to invert the code. */
5819 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
5822 /* If this is testing a single bit, we can optimize the test. */
5823 if ((code == NE_EXPR || code == EQ_EXPR)
5824 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5825 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5827 tree inner = TREE_OPERAND (arg0, 0);
5828 tree type = TREE_TYPE (arg0);
5829 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5830 enum machine_mode operand_mode = TYPE_MODE (type);
5832 tree signed_type, unsigned_type, intermediate_type;
5835 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5836 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5837 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5838 if (arg00 != NULL_TREE
5839 /* This is only a win if casting to a signed type is cheap,
5840 i.e. when arg00's type is not a partial mode. */
5841 && TYPE_PRECISION (TREE_TYPE (arg00))
5842 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
5844 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5845 return fold (build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
5846 result_type, fold_convert (stype, arg00),
5847 fold_convert (stype, integer_zero_node)));
5850 /* Otherwise we have (A & C) != 0 where C is a single bit,
5851 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5852 Similarly for (A & C) == 0. */
5854 /* If INNER is a right shift of a constant and it plus BITNUM does
5855 not overflow, adjust BITNUM and INNER. */
5856 if (TREE_CODE (inner) == RSHIFT_EXPR
5857 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5858 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5859 && bitnum < TYPE_PRECISION (type)
5860 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5861 bitnum - TYPE_PRECISION (type)))
5863 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5864 inner = TREE_OPERAND (inner, 0);
5867 /* If we are going to be able to omit the AND below, we must do our
5868 operations as unsigned. If we must use the AND, we have a choice.
5869 Normally unsigned is faster, but for some machines signed is. */
5870 #ifdef LOAD_EXTEND_OP
5871 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
5876 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5877 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5878 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5879 inner = fold_convert (intermediate_type, inner);
5882 inner = build2 (RSHIFT_EXPR, intermediate_type,
5883 inner, size_int (bitnum));
5885 if (code == EQ_EXPR)
5886 inner = fold (build2 (BIT_XOR_EXPR, intermediate_type,
5887 inner, integer_one_node));
5889 /* Put the AND last so it can combine with more things. */
5890 inner = build2 (BIT_AND_EXPR, intermediate_type,
5891 inner, integer_one_node);
5893 /* Make sure to return the proper type. */
5894 inner = fold_convert (result_type, inner);
5901 /* Check whether we are allowed to reorder operands arg0 and arg1,
5902 such that the evaluation of arg1 occurs before arg0. */
5905 reorder_operands_p (tree arg0, tree arg1)
5907 if (! flag_evaluation_order)
5909 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5911 return ! TREE_SIDE_EFFECTS (arg0)
5912 && ! TREE_SIDE_EFFECTS (arg1);
5915 /* Test whether it is preferable two swap two operands, ARG0 and
5916 ARG1, for example because ARG0 is an integer constant and ARG1
5917 isn't. If REORDER is true, only recommend swapping if we can
5918 evaluate the operands in reverse order. */
5921 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
5923 STRIP_SIGN_NOPS (arg0);
5924 STRIP_SIGN_NOPS (arg1);
5926 if (TREE_CODE (arg1) == INTEGER_CST)
5928 if (TREE_CODE (arg0) == INTEGER_CST)
5931 if (TREE_CODE (arg1) == REAL_CST)
5933 if (TREE_CODE (arg0) == REAL_CST)
5936 if (TREE_CODE (arg1) == COMPLEX_CST)
5938 if (TREE_CODE (arg0) == COMPLEX_CST)
5941 if (TREE_CONSTANT (arg1))
5943 if (TREE_CONSTANT (arg0))
5949 if (reorder && flag_evaluation_order
5950 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5958 /* It is preferable to swap two SSA_NAME to ensure a canonical form
5959 for commutative and comparison operators. Ensuring a canonical
5960 form allows the optimizers to find additional redundancies without
5961 having to explicitly check for both orderings. */
5962 if (TREE_CODE (arg0) == SSA_NAME
5963 && TREE_CODE (arg1) == SSA_NAME
5964 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
5970 /* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
5971 step of the array. TYPE is the type of the expression. ADDR is the address.
5972 MULT is the multiplicative expression. If the function succeeds, the new
5973 address expression is returned. Otherwise NULL_TREE is returned. */
5976 try_move_mult_to_index (tree type, enum tree_code code, tree addr, tree mult)
5978 tree s, delta, step;
5979 tree arg0 = TREE_OPERAND (mult, 0), arg1 = TREE_OPERAND (mult, 1);
5980 tree ref = TREE_OPERAND (addr, 0), pref;
5987 if (TREE_CODE (arg0) == INTEGER_CST)
5992 else if (TREE_CODE (arg1) == INTEGER_CST)
6000 for (;; ref = TREE_OPERAND (ref, 0))
6002 if (TREE_CODE (ref) == ARRAY_REF)
6004 step = array_ref_element_size (ref);
6006 if (TREE_CODE (step) != INTEGER_CST)
6009 itype = TREE_TYPE (step);
6011 /* If the type sizes do not match, we might run into problems
6012 when one of them would overflow. */
6013 if (TYPE_PRECISION (itype) != TYPE_PRECISION (type))
6016 if (!operand_equal_p (step, fold_convert (itype, s), 0))
6019 delta = fold_convert (itype, delta);
6023 if (!handled_component_p (ref))
6027 /* We found the suitable array reference. So copy everything up to it,
6028 and replace the index. */
6030 pref = TREE_OPERAND (addr, 0);
6031 ret = copy_node (pref);
6036 pref = TREE_OPERAND (pref, 0);
6037 TREE_OPERAND (pos, 0) = copy_node (pref);
6038 pos = TREE_OPERAND (pos, 0);
6041 TREE_OPERAND (pos, 1) = fold (build2 (code, itype,
6042 TREE_OPERAND (pos, 1),
6045 return build1 (ADDR_EXPR, type, ret);
6048 /* Perform constant folding and related simplification of EXPR.
6049 The related simplifications include x*1 => x, x*0 => 0, etc.,
6050 and application of the associative law.
6051 NOP_EXPR conversions may be removed freely (as long as we
6052 are careful not to change the type of the overall expression).
6053 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
6054 but we can constant-fold them if they have constant operands. */
6056 #ifdef ENABLE_FOLD_CHECKING
6057 # define fold(x) fold_1 (x)
6058 static tree fold_1 (tree);
6064 const tree t = expr;
6065 const tree type = TREE_TYPE (expr);
6066 tree t1 = NULL_TREE;
6068 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
6069 enum tree_code code = TREE_CODE (t);
6070 enum tree_code_class kind = TREE_CODE_CLASS (code);
6072 /* WINS will be nonzero when the switch is done
6073 if all operands are constant. */
6076 /* Return right away if a constant. */
6077 if (kind == tcc_constant)
6080 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
6084 /* Special case for conversion ops that can have fixed point args. */
6085 arg0 = TREE_OPERAND (t, 0);
6087 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
6089 STRIP_SIGN_NOPS (arg0);
6091 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
6092 subop = TREE_REALPART (arg0);
6096 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
6097 && TREE_CODE (subop) != REAL_CST)
6098 /* Note that TREE_CONSTANT isn't enough:
6099 static var addresses are constant but we can't
6100 do arithmetic on them. */
6103 else if (IS_EXPR_CODE_CLASS (kind))
6105 int len = first_rtl_op (code);
6107 for (i = 0; i < len; i++)
6109 tree op = TREE_OPERAND (t, i);
6113 continue; /* Valid for CALL_EXPR, at least. */
6115 /* Strip any conversions that don't change the mode. This is
6116 safe for every expression, except for a comparison expression
6117 because its signedness is derived from its operands. So, in
6118 the latter case, only strip conversions that don't change the
6121 Note that this is done as an internal manipulation within the
6122 constant folder, in order to find the simplest representation
6123 of the arguments so that their form can be studied. In any
6124 cases, the appropriate type conversions should be put back in
6125 the tree that will get out of the constant folder. */
6126 if (kind == tcc_comparison)
6127 STRIP_SIGN_NOPS (op);
6131 if (TREE_CODE (op) == COMPLEX_CST)
6132 subop = TREE_REALPART (op);
6136 if (TREE_CODE (subop) != INTEGER_CST
6137 && TREE_CODE (subop) != REAL_CST)
6138 /* Note that TREE_CONSTANT isn't enough:
6139 static var addresses are constant but we can't
6140 do arithmetic on them. */
6150 /* If this is a commutative operation, and ARG0 is a constant, move it
6151 to ARG1 to reduce the number of tests below. */
6152 if (commutative_tree_code (code)
6153 && tree_swap_operands_p (arg0, arg1, true))
6154 return fold (build2 (code, type, TREE_OPERAND (t, 1),
6155 TREE_OPERAND (t, 0)));
6157 /* Now WINS is set as described above,
6158 ARG0 is the first operand of EXPR,
6159 and ARG1 is the second operand (if it has more than one operand).
6161 First check for cases where an arithmetic operation is applied to a
6162 compound, conditional, or comparison operation. Push the arithmetic
6163 operation inside the compound or conditional to see if any folding
6164 can then be done. Convert comparison to conditional for this purpose.
6165 The also optimizes non-constant cases that used to be done in
6168 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
6169 one of the operands is a comparison and the other is a comparison, a
6170 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
6171 code below would make the expression more complex. Change it to a
6172 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
6173 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
6175 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
6176 || code == EQ_EXPR || code == NE_EXPR)
6177 && ((truth_value_p (TREE_CODE (arg0))
6178 && (truth_value_p (TREE_CODE (arg1))
6179 || (TREE_CODE (arg1) == BIT_AND_EXPR
6180 && integer_onep (TREE_OPERAND (arg1, 1)))))
6181 || (truth_value_p (TREE_CODE (arg1))
6182 && (truth_value_p (TREE_CODE (arg0))
6183 || (TREE_CODE (arg0) == BIT_AND_EXPR
6184 && integer_onep (TREE_OPERAND (arg0, 1)))))))
6186 tem = fold (build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
6187 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
6189 type, fold_convert (boolean_type_node, arg0),
6190 fold_convert (boolean_type_node, arg1)));
6192 if (code == EQ_EXPR)
6193 tem = invert_truthvalue (tem);
6198 if (TREE_CODE_CLASS (code) == tcc_unary)
6200 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6201 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6202 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
6203 else if (TREE_CODE (arg0) == COND_EXPR)
6205 tree arg01 = TREE_OPERAND (arg0, 1);
6206 tree arg02 = TREE_OPERAND (arg0, 2);
6207 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6208 arg01 = fold (build1 (code, type, arg01));
6209 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6210 arg02 = fold (build1 (code, type, arg02));
6211 tem = fold (build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6214 /* If this was a conversion, and all we did was to move into
6215 inside the COND_EXPR, bring it back out. But leave it if
6216 it is a conversion from integer to integer and the
6217 result precision is no wider than a word since such a
6218 conversion is cheap and may be optimized away by combine,
6219 while it couldn't if it were outside the COND_EXPR. Then return
6220 so we don't get into an infinite recursion loop taking the
6221 conversion out and then back in. */
6223 if ((code == NOP_EXPR || code == CONVERT_EXPR
6224 || code == NON_LVALUE_EXPR)
6225 && TREE_CODE (tem) == COND_EXPR
6226 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6227 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6228 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6229 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6230 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6231 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6232 && ! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6234 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6235 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD))
6236 tem = build1 (code, type,
6238 TREE_TYPE (TREE_OPERAND
6239 (TREE_OPERAND (tem, 1), 0)),
6240 TREE_OPERAND (tem, 0),
6241 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6242 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6245 else if (COMPARISON_CLASS_P (arg0))
6247 if (TREE_CODE (type) == BOOLEAN_TYPE)
6249 arg0 = copy_node (arg0);
6250 TREE_TYPE (arg0) = type;
6253 else if (TREE_CODE (type) != INTEGER_TYPE)
6254 return fold (build3 (COND_EXPR, type, arg0,
6255 fold (build1 (code, type,
6257 fold (build1 (code, type,
6258 integer_zero_node))));
6261 else if (TREE_CODE_CLASS (code) == tcc_comparison
6262 && TREE_CODE (arg0) == COMPOUND_EXPR)
6263 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6264 fold (build2 (code, type, TREE_OPERAND (arg0, 1), arg1)));
6265 else if (TREE_CODE_CLASS (code) == tcc_comparison
6266 && TREE_CODE (arg1) == COMPOUND_EXPR)
6267 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6268 fold (build2 (code, type, arg0, TREE_OPERAND (arg1, 1))));
6269 else if (TREE_CODE_CLASS (code) == tcc_binary
6270 || TREE_CODE_CLASS (code) == tcc_comparison)
6272 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6273 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6274 fold (build2 (code, type, TREE_OPERAND (arg0, 1),
6276 if (TREE_CODE (arg1) == COMPOUND_EXPR
6277 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
6278 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6279 fold (build2 (code, type,
6280 arg0, TREE_OPERAND (arg1, 1))));
6282 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
6284 tem = fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
6285 /*cond_first_p=*/1);
6286 if (tem != NULL_TREE)
6290 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
6292 tem = fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
6293 /*cond_first_p=*/0);
6294 if (tem != NULL_TREE)
6302 return fold (DECL_INITIAL (t));
6307 case FIX_TRUNC_EXPR:
6309 case FIX_FLOOR_EXPR:
6310 case FIX_ROUND_EXPR:
6311 if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
6312 return TREE_OPERAND (t, 0);
6314 /* Handle cases of two conversions in a row. */
6315 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
6316 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
6318 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6319 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
6320 int inside_int = INTEGRAL_TYPE_P (inside_type);
6321 int inside_ptr = POINTER_TYPE_P (inside_type);
6322 int inside_float = FLOAT_TYPE_P (inside_type);
6323 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6324 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6325 int inter_int = INTEGRAL_TYPE_P (inter_type);
6326 int inter_ptr = POINTER_TYPE_P (inter_type);
6327 int inter_float = FLOAT_TYPE_P (inter_type);
6328 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6329 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6330 int final_int = INTEGRAL_TYPE_P (type);
6331 int final_ptr = POINTER_TYPE_P (type);
6332 int final_float = FLOAT_TYPE_P (type);
6333 unsigned int final_prec = TYPE_PRECISION (type);
6334 int final_unsignedp = TYPE_UNSIGNED (type);
6336 /* In addition to the cases of two conversions in a row
6337 handled below, if we are converting something to its own
6338 type via an object of identical or wider precision, neither
6339 conversion is needed. */
6340 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6341 && ((inter_int && final_int) || (inter_float && final_float))
6342 && inter_prec >= final_prec)
6343 return fold (build1 (code, type,
6344 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6346 /* Likewise, if the intermediate and final types are either both
6347 float or both integer, we don't need the middle conversion if
6348 it is wider than the final type and doesn't change the signedness
6349 (for integers). Avoid this if the final type is a pointer
6350 since then we sometimes need the inner conversion. Likewise if
6351 the outer has a precision not equal to the size of its mode. */
6352 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6353 || (inter_float && inside_float))
6354 && inter_prec >= inside_prec
6355 && (inter_float || inter_unsignedp == inside_unsignedp)
6356 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6357 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6359 return fold (build1 (code, type,
6360 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6362 /* If we have a sign-extension of a zero-extended value, we can
6363 replace that by a single zero-extension. */
6364 if (inside_int && inter_int && final_int
6365 && inside_prec < inter_prec && inter_prec < final_prec
6366 && inside_unsignedp && !inter_unsignedp)
6367 return fold (build1 (code, type,
6368 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6370 /* Two conversions in a row are not needed unless:
6371 - some conversion is floating-point (overstrict for now), or
6372 - the intermediate type is narrower than both initial and
6374 - the intermediate type and innermost type differ in signedness,
6375 and the outermost type is wider than the intermediate, or
6376 - the initial type is a pointer type and the precisions of the
6377 intermediate and final types differ, or
6378 - the final type is a pointer type and the precisions of the
6379 initial and intermediate types differ. */
6380 if (! inside_float && ! inter_float && ! final_float
6381 && (inter_prec > inside_prec || inter_prec > final_prec)
6382 && ! (inside_int && inter_int
6383 && inter_unsignedp != inside_unsignedp
6384 && inter_prec < final_prec)
6385 && ((inter_unsignedp && inter_prec > inside_prec)
6386 == (final_unsignedp && final_prec > inter_prec))
6387 && ! (inside_ptr && inter_prec != final_prec)
6388 && ! (final_ptr && inside_prec != inter_prec)
6389 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6390 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6392 return fold (build1 (code, type,
6393 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6396 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
6397 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
6398 /* Detect assigning a bitfield. */
6399 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
6400 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
6402 /* Don't leave an assignment inside a conversion
6403 unless assigning a bitfield. */
6404 tree prev = TREE_OPERAND (t, 0);
6405 tem = copy_node (t);
6406 TREE_OPERAND (tem, 0) = TREE_OPERAND (prev, 1);
6407 /* First do the assignment, then return converted constant. */
6408 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), prev, fold (tem));
6409 TREE_NO_WARNING (tem) = 1;
6410 TREE_USED (tem) = 1;
6414 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6415 constants (if x has signed type, the sign bit cannot be set
6416 in c). This folds extension into the BIT_AND_EXPR. */
6417 if (INTEGRAL_TYPE_P (type)
6418 && TREE_CODE (type) != BOOLEAN_TYPE
6419 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
6420 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
6422 tree and = TREE_OPERAND (t, 0);
6423 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6426 if (TYPE_UNSIGNED (TREE_TYPE (and))
6427 || (TYPE_PRECISION (type)
6428 <= TYPE_PRECISION (TREE_TYPE (and))))
6430 else if (TYPE_PRECISION (TREE_TYPE (and1))
6431 <= HOST_BITS_PER_WIDE_INT
6432 && host_integerp (and1, 1))
6434 unsigned HOST_WIDE_INT cst;
6436 cst = tree_low_cst (and1, 1);
6437 cst &= (HOST_WIDE_INT) -1
6438 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6439 change = (cst == 0);
6440 #ifdef LOAD_EXTEND_OP
6442 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6445 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6446 and0 = fold_convert (uns, and0);
6447 and1 = fold_convert (uns, and1);
6452 return fold (build2 (BIT_AND_EXPR, type,
6453 fold_convert (type, and0),
6454 fold_convert (type, and1)));
6457 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6458 T2 being pointers to types of the same size. */
6459 if (POINTER_TYPE_P (TREE_TYPE (t))
6460 && BINARY_CLASS_P (arg0)
6461 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6462 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6464 tree arg00 = TREE_OPERAND (arg0, 0);
6465 tree t0 = TREE_TYPE (t);
6466 tree t1 = TREE_TYPE (arg00);
6467 tree tt0 = TREE_TYPE (t0);
6468 tree tt1 = TREE_TYPE (t1);
6469 tree s0 = TYPE_SIZE (tt0);
6470 tree s1 = TYPE_SIZE (tt1);
6472 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6473 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6474 TREE_OPERAND (arg0, 1));
6477 tem = fold_convert_const (code, type, arg0);
6478 return tem ? tem : t;
6480 case VIEW_CONVERT_EXPR:
6481 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
6482 return build1 (VIEW_CONVERT_EXPR, type,
6483 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6487 if (TREE_CODE (arg0) == CONSTRUCTOR
6488 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
6490 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
6492 return TREE_VALUE (m);
6497 if (TREE_CONSTANT (t) != wins)
6499 tem = copy_node (t);
6500 TREE_CONSTANT (tem) = wins;
6501 TREE_INVARIANT (tem) = wins;
6507 if (negate_expr_p (arg0))
6508 return fold_convert (type, negate_expr (arg0));
6512 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
6513 return fold_abs_const (arg0, type);
6514 else if (TREE_CODE (arg0) == NEGATE_EXPR)
6515 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
6516 /* Convert fabs((double)float) into (double)fabsf(float). */
6517 else if (TREE_CODE (arg0) == NOP_EXPR
6518 && TREE_CODE (type) == REAL_TYPE)
6520 tree targ0 = strip_float_extensions (arg0);
6522 return fold_convert (type, fold (build1 (ABS_EXPR,
6526 else if (tree_expr_nonnegative_p (arg0))
6531 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6532 return fold_convert (type, arg0);
6533 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6534 return build2 (COMPLEX_EXPR, type,
6535 TREE_OPERAND (arg0, 0),
6536 negate_expr (TREE_OPERAND (arg0, 1)));
6537 else if (TREE_CODE (arg0) == COMPLEX_CST)
6538 return build_complex (type, TREE_REALPART (arg0),
6539 negate_expr (TREE_IMAGPART (arg0)));
6540 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6541 return fold (build2 (TREE_CODE (arg0), type,
6542 fold (build1 (CONJ_EXPR, type,
6543 TREE_OPERAND (arg0, 0))),
6544 fold (build1 (CONJ_EXPR, type,
6545 TREE_OPERAND (arg0, 1)))));
6546 else if (TREE_CODE (arg0) == CONJ_EXPR)
6547 return TREE_OPERAND (arg0, 0);
6551 if (TREE_CODE (arg0) == INTEGER_CST)
6552 return fold_not_const (arg0, type);
6553 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
6554 return TREE_OPERAND (arg0, 0);
6558 /* A + (-B) -> A - B */
6559 if (TREE_CODE (arg1) == NEGATE_EXPR)
6560 return fold (build2 (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6561 /* (-A) + B -> B - A */
6562 if (TREE_CODE (arg0) == NEGATE_EXPR
6563 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
6564 return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
6565 if (! FLOAT_TYPE_P (type))
6567 if (integer_zerop (arg1))
6568 return non_lvalue (fold_convert (type, arg0));
6570 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
6571 with a constant, and the two constants have no bits in common,
6572 we should treat this as a BIT_IOR_EXPR since this may produce more
6574 if (TREE_CODE (arg0) == BIT_AND_EXPR
6575 && TREE_CODE (arg1) == BIT_AND_EXPR
6576 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6577 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6578 && integer_zerop (const_binop (BIT_AND_EXPR,
6579 TREE_OPERAND (arg0, 1),
6580 TREE_OPERAND (arg1, 1), 0)))
6582 code = BIT_IOR_EXPR;
6586 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
6587 (plus (plus (mult) (mult)) (foo)) so that we can
6588 take advantage of the factoring cases below. */
6589 if (((TREE_CODE (arg0) == PLUS_EXPR
6590 || TREE_CODE (arg0) == MINUS_EXPR)
6591 && TREE_CODE (arg1) == MULT_EXPR)
6592 || ((TREE_CODE (arg1) == PLUS_EXPR
6593 || TREE_CODE (arg1) == MINUS_EXPR)
6594 && TREE_CODE (arg0) == MULT_EXPR))
6596 tree parg0, parg1, parg, marg;
6597 enum tree_code pcode;
6599 if (TREE_CODE (arg1) == MULT_EXPR)
6600 parg = arg0, marg = arg1;
6602 parg = arg1, marg = arg0;
6603 pcode = TREE_CODE (parg);
6604 parg0 = TREE_OPERAND (parg, 0);
6605 parg1 = TREE_OPERAND (parg, 1);
6609 if (TREE_CODE (parg0) == MULT_EXPR
6610 && TREE_CODE (parg1) != MULT_EXPR)
6611 return fold (build2 (pcode, type,
6612 fold (build2 (PLUS_EXPR, type,
6613 fold_convert (type, parg0),
6614 fold_convert (type, marg))),
6615 fold_convert (type, parg1)));
6616 if (TREE_CODE (parg0) != MULT_EXPR
6617 && TREE_CODE (parg1) == MULT_EXPR)
6618 return fold (build2 (PLUS_EXPR, type,
6619 fold_convert (type, parg0),
6620 fold (build2 (pcode, type,
6621 fold_convert (type, marg),
6626 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
6628 tree arg00, arg01, arg10, arg11;
6629 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
6631 /* (A * C) + (B * C) -> (A+B) * C.
6632 We are most concerned about the case where C is a constant,
6633 but other combinations show up during loop reduction. Since
6634 it is not difficult, try all four possibilities. */
6636 arg00 = TREE_OPERAND (arg0, 0);
6637 arg01 = TREE_OPERAND (arg0, 1);
6638 arg10 = TREE_OPERAND (arg1, 0);
6639 arg11 = TREE_OPERAND (arg1, 1);
6642 if (operand_equal_p (arg01, arg11, 0))
6643 same = arg01, alt0 = arg00, alt1 = arg10;
6644 else if (operand_equal_p (arg00, arg10, 0))
6645 same = arg00, alt0 = arg01, alt1 = arg11;
6646 else if (operand_equal_p (arg00, arg11, 0))
6647 same = arg00, alt0 = arg01, alt1 = arg10;
6648 else if (operand_equal_p (arg01, arg10, 0))
6649 same = arg01, alt0 = arg00, alt1 = arg11;
6651 /* No identical multiplicands; see if we can find a common
6652 power-of-two factor in non-power-of-two multiplies. This
6653 can help in multi-dimensional array access. */
6654 else if (TREE_CODE (arg01) == INTEGER_CST
6655 && TREE_CODE (arg11) == INTEGER_CST
6656 && TREE_INT_CST_HIGH (arg01) == 0
6657 && TREE_INT_CST_HIGH (arg11) == 0)
6659 HOST_WIDE_INT int01, int11, tmp;
6660 int01 = TREE_INT_CST_LOW (arg01);
6661 int11 = TREE_INT_CST_LOW (arg11);
6663 /* Move min of absolute values to int11. */
6664 if ((int01 >= 0 ? int01 : -int01)
6665 < (int11 >= 0 ? int11 : -int11))
6667 tmp = int01, int01 = int11, int11 = tmp;
6668 alt0 = arg00, arg00 = arg10, arg10 = alt0;
6669 alt0 = arg01, arg01 = arg11, arg11 = alt0;
6672 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
6674 alt0 = fold (build2 (MULT_EXPR, type, arg00,
6675 build_int_cst (NULL_TREE,
6683 return fold (build2 (MULT_EXPR, type,
6684 fold (build2 (PLUS_EXPR, type,
6685 fold_convert (type, alt0),
6686 fold_convert (type, alt1))),
6690 /* Try replacing &a[i1] + c * i2 with &a[i1 + i2], if c is step
6691 of the array. Loop optimizer sometimes produce this type of
6693 if (TREE_CODE (arg0) == ADDR_EXPR
6694 && TREE_CODE (arg1) == MULT_EXPR)
6696 tem = try_move_mult_to_index (type, PLUS_EXPR, arg0, arg1);
6700 else if (TREE_CODE (arg1) == ADDR_EXPR
6701 && TREE_CODE (arg0) == MULT_EXPR)
6703 tem = try_move_mult_to_index (type, PLUS_EXPR, arg1, arg0);
6710 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6711 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
6712 return non_lvalue (fold_convert (type, arg0));
6714 /* Likewise if the operands are reversed. */
6715 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6716 return non_lvalue (fold_convert (type, arg1));
6718 /* Convert X + -C into X - C. */
6719 if (TREE_CODE (arg1) == REAL_CST
6720 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
6722 tem = fold_negate_const (arg1, type);
6723 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
6724 return fold (build2 (MINUS_EXPR, type,
6725 fold_convert (type, arg0),
6726 fold_convert (type, tem)));
6729 /* Convert x+x into x*2.0. */
6730 if (operand_equal_p (arg0, arg1, 0)
6731 && SCALAR_FLOAT_TYPE_P (type))
6732 return fold (build2 (MULT_EXPR, type, arg0,
6733 build_real (type, dconst2)));
6735 /* Convert x*c+x into x*(c+1). */
6736 if (flag_unsafe_math_optimizations
6737 && TREE_CODE (arg0) == MULT_EXPR
6738 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6739 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6740 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
6744 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6745 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6746 return fold (build2 (MULT_EXPR, type, arg1,
6747 build_real (type, c)));
6750 /* Convert x+x*c into x*(c+1). */
6751 if (flag_unsafe_math_optimizations
6752 && TREE_CODE (arg1) == MULT_EXPR
6753 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6754 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6755 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
6759 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6760 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6761 return fold (build2 (MULT_EXPR, type, arg0,
6762 build_real (type, c)));
6765 /* Convert x*c1+x*c2 into x*(c1+c2). */
6766 if (flag_unsafe_math_optimizations
6767 && TREE_CODE (arg0) == MULT_EXPR
6768 && TREE_CODE (arg1) == MULT_EXPR
6769 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6770 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6771 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6772 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6773 && operand_equal_p (TREE_OPERAND (arg0, 0),
6774 TREE_OPERAND (arg1, 0), 0))
6776 REAL_VALUE_TYPE c1, c2;
6778 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6779 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6780 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
6781 return fold (build2 (MULT_EXPR, type,
6782 TREE_OPERAND (arg0, 0),
6783 build_real (type, c1)));
6785 /* Convert a + (b*c + d*e) into (a + b*c) + d*e. */
6786 if (flag_unsafe_math_optimizations
6787 && TREE_CODE (arg1) == PLUS_EXPR
6788 && TREE_CODE (arg0) != MULT_EXPR)
6790 tree tree10 = TREE_OPERAND (arg1, 0);
6791 tree tree11 = TREE_OPERAND (arg1, 1);
6792 if (TREE_CODE (tree11) == MULT_EXPR
6793 && TREE_CODE (tree10) == MULT_EXPR)
6796 tree0 = fold (build2 (PLUS_EXPR, type, arg0, tree10));
6797 return fold (build2 (PLUS_EXPR, type, tree0, tree11));
6800 /* Convert (b*c + d*e) + a into b*c + (d*e +a). */
6801 if (flag_unsafe_math_optimizations
6802 && TREE_CODE (arg0) == PLUS_EXPR
6803 && TREE_CODE (arg1) != MULT_EXPR)
6805 tree tree00 = TREE_OPERAND (arg0, 0);
6806 tree tree01 = TREE_OPERAND (arg0, 1);
6807 if (TREE_CODE (tree01) == MULT_EXPR
6808 && TREE_CODE (tree00) == MULT_EXPR)
6811 tree0 = fold (build2 (PLUS_EXPR, type, tree01, arg1));
6812 return fold (build2 (PLUS_EXPR, type, tree00, tree0));
6818 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6819 is a rotate of A by C1 bits. */
6820 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6821 is a rotate of A by B bits. */
6823 enum tree_code code0, code1;
6824 code0 = TREE_CODE (arg0);
6825 code1 = TREE_CODE (arg1);
6826 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
6827 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
6828 && operand_equal_p (TREE_OPERAND (arg0, 0),
6829 TREE_OPERAND (arg1, 0), 0)
6830 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6832 tree tree01, tree11;
6833 enum tree_code code01, code11;
6835 tree01 = TREE_OPERAND (arg0, 1);
6836 tree11 = TREE_OPERAND (arg1, 1);
6837 STRIP_NOPS (tree01);
6838 STRIP_NOPS (tree11);
6839 code01 = TREE_CODE (tree01);
6840 code11 = TREE_CODE (tree11);
6841 if (code01 == INTEGER_CST
6842 && code11 == INTEGER_CST
6843 && TREE_INT_CST_HIGH (tree01) == 0
6844 && TREE_INT_CST_HIGH (tree11) == 0
6845 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
6846 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
6847 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
6848 code0 == LSHIFT_EXPR ? tree01 : tree11);
6849 else if (code11 == MINUS_EXPR)
6851 tree tree110, tree111;
6852 tree110 = TREE_OPERAND (tree11, 0);
6853 tree111 = TREE_OPERAND (tree11, 1);
6854 STRIP_NOPS (tree110);
6855 STRIP_NOPS (tree111);
6856 if (TREE_CODE (tree110) == INTEGER_CST
6857 && 0 == compare_tree_int (tree110,
6859 (TREE_TYPE (TREE_OPERAND
6861 && operand_equal_p (tree01, tree111, 0))
6862 return build2 ((code0 == LSHIFT_EXPR
6865 type, TREE_OPERAND (arg0, 0), tree01);
6867 else if (code01 == MINUS_EXPR)
6869 tree tree010, tree011;
6870 tree010 = TREE_OPERAND (tree01, 0);
6871 tree011 = TREE_OPERAND (tree01, 1);
6872 STRIP_NOPS (tree010);
6873 STRIP_NOPS (tree011);
6874 if (TREE_CODE (tree010) == INTEGER_CST
6875 && 0 == compare_tree_int (tree010,
6877 (TREE_TYPE (TREE_OPERAND
6879 && operand_equal_p (tree11, tree011, 0))
6880 return build2 ((code0 != LSHIFT_EXPR
6883 type, TREE_OPERAND (arg0, 0), tree11);
6889 /* In most languages, can't associate operations on floats through
6890 parentheses. Rather than remember where the parentheses were, we
6891 don't associate floats at all, unless the user has specified
6892 -funsafe-math-optimizations. */
6895 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
6897 tree var0, con0, lit0, minus_lit0;
6898 tree var1, con1, lit1, minus_lit1;
6900 /* Split both trees into variables, constants, and literals. Then
6901 associate each group together, the constants with literals,
6902 then the result with variables. This increases the chances of
6903 literals being recombined later and of generating relocatable
6904 expressions for the sum of a constant and literal. */
6905 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
6906 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
6907 code == MINUS_EXPR);
6909 /* Only do something if we found more than two objects. Otherwise,
6910 nothing has changed and we risk infinite recursion. */
6911 if (2 < ((var0 != 0) + (var1 != 0)
6912 + (con0 != 0) + (con1 != 0)
6913 + (lit0 != 0) + (lit1 != 0)
6914 + (minus_lit0 != 0) + (minus_lit1 != 0)))
6916 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
6917 if (code == MINUS_EXPR)
6920 var0 = associate_trees (var0, var1, code, type);
6921 con0 = associate_trees (con0, con1, code, type);
6922 lit0 = associate_trees (lit0, lit1, code, type);
6923 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
6925 /* Preserve the MINUS_EXPR if the negative part of the literal is
6926 greater than the positive part. Otherwise, the multiplicative
6927 folding code (i.e extract_muldiv) may be fooled in case
6928 unsigned constants are subtracted, like in the following
6929 example: ((X*2 + 4) - 8U)/2. */
6930 if (minus_lit0 && lit0)
6932 if (TREE_CODE (lit0) == INTEGER_CST
6933 && TREE_CODE (minus_lit0) == INTEGER_CST
6934 && tree_int_cst_lt (lit0, minus_lit0))
6936 minus_lit0 = associate_trees (minus_lit0, lit0,
6942 lit0 = associate_trees (lit0, minus_lit0,
6950 return fold_convert (type,
6951 associate_trees (var0, minus_lit0,
6955 con0 = associate_trees (con0, minus_lit0,
6957 return fold_convert (type,
6958 associate_trees (var0, con0,
6963 con0 = associate_trees (con0, lit0, code, type);
6964 return fold_convert (type, associate_trees (var0, con0,
6971 t1 = const_binop (code, arg0, arg1, 0);
6972 if (t1 != NULL_TREE)
6974 /* The return value should always have
6975 the same type as the original expression. */
6976 if (TREE_TYPE (t1) != type)
6977 t1 = fold_convert (type, t1);
6984 /* A - (-B) -> A + B */
6985 if (TREE_CODE (arg1) == NEGATE_EXPR)
6986 return fold (build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6987 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
6988 if (TREE_CODE (arg0) == NEGATE_EXPR
6989 && (FLOAT_TYPE_P (type)
6990 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
6991 && negate_expr_p (arg1)
6992 && reorder_operands_p (arg0, arg1))
6993 return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
6994 TREE_OPERAND (arg0, 0)));
6996 if (! FLOAT_TYPE_P (type))
6998 if (! wins && integer_zerop (arg0))
6999 return negate_expr (fold_convert (type, arg1));
7000 if (integer_zerop (arg1))
7001 return non_lvalue (fold_convert (type, arg0));
7003 /* Fold A - (A & B) into ~B & A. */
7004 if (!TREE_SIDE_EFFECTS (arg0)
7005 && TREE_CODE (arg1) == BIT_AND_EXPR)
7007 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
7008 return fold (build2 (BIT_AND_EXPR, type,
7009 fold (build1 (BIT_NOT_EXPR, type,
7010 TREE_OPERAND (arg1, 0))),
7012 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7013 return fold (build2 (BIT_AND_EXPR, type,
7014 fold (build1 (BIT_NOT_EXPR, type,
7015 TREE_OPERAND (arg1, 1))),
7019 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
7020 any power of 2 minus 1. */
7021 if (TREE_CODE (arg0) == BIT_AND_EXPR
7022 && TREE_CODE (arg1) == BIT_AND_EXPR
7023 && operand_equal_p (TREE_OPERAND (arg0, 0),
7024 TREE_OPERAND (arg1, 0), 0))
7026 tree mask0 = TREE_OPERAND (arg0, 1);
7027 tree mask1 = TREE_OPERAND (arg1, 1);
7028 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
7030 if (operand_equal_p (tem, mask1, 0))
7032 tem = fold (build2 (BIT_XOR_EXPR, type,
7033 TREE_OPERAND (arg0, 0), mask1));
7034 return fold (build2 (MINUS_EXPR, type, tem, mask1));
7039 /* See if ARG1 is zero and X - ARG1 reduces to X. */
7040 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
7041 return non_lvalue (fold_convert (type, arg0));
7043 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
7044 ARG0 is zero and X + ARG0 reduces to X, since that would mean
7045 (-ARG1 + ARG0) reduces to -ARG1. */
7046 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
7047 return negate_expr (fold_convert (type, arg1));
7049 /* Fold &x - &x. This can happen from &x.foo - &x.
7050 This is unsafe for certain floats even in non-IEEE formats.
7051 In IEEE, it is unsafe because it does wrong for NaNs.
7052 Also note that operand_equal_p is always false if an operand
7055 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
7056 && operand_equal_p (arg0, arg1, 0))
7057 return fold_convert (type, integer_zero_node);
7059 /* A - B -> A + (-B) if B is easily negatable. */
7060 if (!wins && negate_expr_p (arg1)
7061 && ((FLOAT_TYPE_P (type)
7062 /* Avoid this transformation if B is a positive REAL_CST. */
7063 && (TREE_CODE (arg1) != REAL_CST
7064 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
7065 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
7066 return fold (build2 (PLUS_EXPR, type, arg0, negate_expr (arg1)));
7068 /* Try folding difference of addresses. */
7072 if (TREE_CODE (arg0) == ADDR_EXPR
7073 && TREE_CODE (arg1) == ADDR_EXPR
7074 && ptr_difference_const (TREE_OPERAND (arg0, 0),
7075 TREE_OPERAND (arg1, 0),
7077 return build_int_cst_type (type, diff);
7080 /* Try replacing &a[i1] - c * i2 with &a[i1 - i2], if c is step
7081 of the array. Loop optimizer sometimes produce this type of
7083 if (TREE_CODE (arg0) == ADDR_EXPR
7084 && TREE_CODE (arg1) == MULT_EXPR)
7086 tem = try_move_mult_to_index (type, MINUS_EXPR, arg0, arg1);
7091 if (TREE_CODE (arg0) == MULT_EXPR
7092 && TREE_CODE (arg1) == MULT_EXPR
7093 && (!FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
7095 /* (A * C) - (B * C) -> (A-B) * C. */
7096 if (operand_equal_p (TREE_OPERAND (arg0, 1),
7097 TREE_OPERAND (arg1, 1), 0))
7098 return fold (build2 (MULT_EXPR, type,
7099 fold (build2 (MINUS_EXPR, type,
7100 TREE_OPERAND (arg0, 0),
7101 TREE_OPERAND (arg1, 0))),
7102 TREE_OPERAND (arg0, 1)));
7103 /* (A * C1) - (A * C2) -> A * (C1-C2). */
7104 if (operand_equal_p (TREE_OPERAND (arg0, 0),
7105 TREE_OPERAND (arg1, 0), 0))
7106 return fold (build2 (MULT_EXPR, type,
7107 TREE_OPERAND (arg0, 0),
7108 fold (build2 (MINUS_EXPR, type,
7109 TREE_OPERAND (arg0, 1),
7110 TREE_OPERAND (arg1, 1)))));
7116 /* (-A) * (-B) -> A * B */
7117 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7118 return fold (build2 (MULT_EXPR, type,
7119 TREE_OPERAND (arg0, 0),
7120 negate_expr (arg1)));
7121 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7122 return fold (build2 (MULT_EXPR, type,
7124 TREE_OPERAND (arg1, 0)));
7126 if (! FLOAT_TYPE_P (type))
7128 if (integer_zerop (arg1))
7129 return omit_one_operand (type, arg1, arg0);
7130 if (integer_onep (arg1))
7131 return non_lvalue (fold_convert (type, arg0));
7133 /* (a * (1 << b)) is (a << b) */
7134 if (TREE_CODE (arg1) == LSHIFT_EXPR
7135 && integer_onep (TREE_OPERAND (arg1, 0)))
7136 return fold (build2 (LSHIFT_EXPR, type, arg0,
7137 TREE_OPERAND (arg1, 1)));
7138 if (TREE_CODE (arg0) == LSHIFT_EXPR
7139 && integer_onep (TREE_OPERAND (arg0, 0)))
7140 return fold (build2 (LSHIFT_EXPR, type, arg1,
7141 TREE_OPERAND (arg0, 1)));
7143 if (TREE_CODE (arg1) == INTEGER_CST
7144 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
7145 fold_convert (type, arg1),
7147 return fold_convert (type, tem);
7152 /* Maybe fold x * 0 to 0. The expressions aren't the same
7153 when x is NaN, since x * 0 is also NaN. Nor are they the
7154 same in modes with signed zeros, since multiplying a
7155 negative value by 0 gives -0, not +0. */
7156 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
7157 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
7158 && real_zerop (arg1))
7159 return omit_one_operand (type, arg1, arg0);
7160 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7161 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7162 && real_onep (arg1))
7163 return non_lvalue (fold_convert (type, arg0));
7165 /* Transform x * -1.0 into -x. */
7166 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7167 && real_minus_onep (arg1))
7168 return fold_convert (type, negate_expr (arg0));
7170 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7171 if (flag_unsafe_math_optimizations
7172 && TREE_CODE (arg0) == RDIV_EXPR
7173 && TREE_CODE (arg1) == REAL_CST
7174 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
7176 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
7179 return fold (build2 (RDIV_EXPR, type, tem,
7180 TREE_OPERAND (arg0, 1)));
7183 if (flag_unsafe_math_optimizations)
7185 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7186 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7188 /* Optimizations of root(...)*root(...). */
7189 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
7191 tree rootfn, arg, arglist;
7192 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7193 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7195 /* Optimize sqrt(x)*sqrt(x) as x. */
7196 if (BUILTIN_SQRT_P (fcode0)
7197 && operand_equal_p (arg00, arg10, 0)
7198 && ! HONOR_SNANS (TYPE_MODE (type)))
7201 /* Optimize root(x)*root(y) as root(x*y). */
7202 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7203 arg = fold (build2 (MULT_EXPR, type, arg00, arg10));
7204 arglist = build_tree_list (NULL_TREE, arg);
7205 return build_function_call_expr (rootfn, arglist);
7208 /* Optimize expN(x)*expN(y) as expN(x+y). */
7209 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
7211 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7212 tree arg = build2 (PLUS_EXPR, type,
7213 TREE_VALUE (TREE_OPERAND (arg0, 1)),
7214 TREE_VALUE (TREE_OPERAND (arg1, 1)));
7215 tree arglist = build_tree_list (NULL_TREE, fold (arg));
7216 return build_function_call_expr (expfn, arglist);
7219 /* Optimizations of pow(...)*pow(...). */
7220 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
7221 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
7222 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
7224 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7225 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7227 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7228 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7231 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7232 if (operand_equal_p (arg01, arg11, 0))
7234 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7235 tree arg = build2 (MULT_EXPR, type, arg00, arg10);
7236 tree arglist = tree_cons (NULL_TREE, fold (arg),
7237 build_tree_list (NULL_TREE,
7239 return build_function_call_expr (powfn, arglist);
7242 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7243 if (operand_equal_p (arg00, arg10, 0))
7245 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7246 tree arg = fold (build2 (PLUS_EXPR, type, arg01, arg11));
7247 tree arglist = tree_cons (NULL_TREE, arg00,
7248 build_tree_list (NULL_TREE,
7250 return build_function_call_expr (powfn, arglist);
7254 /* Optimize tan(x)*cos(x) as sin(x). */
7255 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
7256 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
7257 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
7258 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
7259 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
7260 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
7261 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7262 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7264 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
7266 if (sinfn != NULL_TREE)
7267 return build_function_call_expr (sinfn,
7268 TREE_OPERAND (arg0, 1));
7271 /* Optimize x*pow(x,c) as pow(x,c+1). */
7272 if (fcode1 == BUILT_IN_POW
7273 || fcode1 == BUILT_IN_POWF
7274 || fcode1 == BUILT_IN_POWL)
7276 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7277 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7279 if (TREE_CODE (arg11) == REAL_CST
7280 && ! TREE_CONSTANT_OVERFLOW (arg11)
7281 && operand_equal_p (arg0, arg10, 0))
7283 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7287 c = TREE_REAL_CST (arg11);
7288 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7289 arg = build_real (type, c);
7290 arglist = build_tree_list (NULL_TREE, arg);
7291 arglist = tree_cons (NULL_TREE, arg0, arglist);
7292 return build_function_call_expr (powfn, arglist);
7296 /* Optimize pow(x,c)*x as pow(x,c+1). */
7297 if (fcode0 == BUILT_IN_POW
7298 || fcode0 == BUILT_IN_POWF
7299 || fcode0 == BUILT_IN_POWL)
7301 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7302 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7304 if (TREE_CODE (arg01) == REAL_CST
7305 && ! TREE_CONSTANT_OVERFLOW (arg01)
7306 && operand_equal_p (arg1, arg00, 0))
7308 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7312 c = TREE_REAL_CST (arg01);
7313 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7314 arg = build_real (type, c);
7315 arglist = build_tree_list (NULL_TREE, arg);
7316 arglist = tree_cons (NULL_TREE, arg1, arglist);
7317 return build_function_call_expr (powfn, arglist);
7321 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
7323 && operand_equal_p (arg0, arg1, 0))
7325 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
7329 tree arg = build_real (type, dconst2);
7330 tree arglist = build_tree_list (NULL_TREE, arg);
7331 arglist = tree_cons (NULL_TREE, arg0, arglist);
7332 return build_function_call_expr (powfn, arglist);
7341 if (integer_all_onesp (arg1))
7342 return omit_one_operand (type, arg1, arg0);
7343 if (integer_zerop (arg1))
7344 return non_lvalue (fold_convert (type, arg0));
7345 if (operand_equal_p (arg0, arg1, 0))
7346 return non_lvalue (fold_convert (type, arg0));
7349 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7350 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7352 t1 = build_int_cst (type, -1);
7353 t1 = force_fit_type (t1, 0, false, false);
7354 return omit_one_operand (type, t1, arg1);
7358 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7359 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7361 t1 = build_int_cst (type, -1);
7362 t1 = force_fit_type (t1, 0, false, false);
7363 return omit_one_operand (type, t1, arg0);
7366 t1 = distribute_bit_expr (code, type, arg0, arg1);
7367 if (t1 != NULL_TREE)
7370 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
7372 This results in more efficient code for machines without a NAND
7373 instruction. Combine will canonicalize to the first form
7374 which will allow use of NAND instructions provided by the
7375 backend if they exist. */
7376 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7377 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7379 return fold (build1 (BIT_NOT_EXPR, type,
7380 build2 (BIT_AND_EXPR, type,
7381 TREE_OPERAND (arg0, 0),
7382 TREE_OPERAND (arg1, 0))));
7385 /* See if this can be simplified into a rotate first. If that
7386 is unsuccessful continue in the association code. */
7390 if (integer_zerop (arg1))
7391 return non_lvalue (fold_convert (type, arg0));
7392 if (integer_all_onesp (arg1))
7393 return fold (build1 (BIT_NOT_EXPR, type, arg0));
7394 if (operand_equal_p (arg0, arg1, 0))
7395 return omit_one_operand (type, integer_zero_node, arg0);
7398 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7399 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7401 t1 = build_int_cst (type, -1);
7402 t1 = force_fit_type (t1, 0, false, false);
7403 return omit_one_operand (type, t1, arg1);
7407 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7408 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7410 t1 = build_int_cst (type, -1);
7411 t1 = force_fit_type (t1, 0, false, false);
7412 return omit_one_operand (type, t1, arg0);
7415 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
7416 with a constant, and the two constants have no bits in common,
7417 we should treat this as a BIT_IOR_EXPR since this may produce more
7419 if (TREE_CODE (arg0) == BIT_AND_EXPR
7420 && TREE_CODE (arg1) == BIT_AND_EXPR
7421 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7422 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7423 && integer_zerop (const_binop (BIT_AND_EXPR,
7424 TREE_OPERAND (arg0, 1),
7425 TREE_OPERAND (arg1, 1), 0)))
7427 code = BIT_IOR_EXPR;
7431 /* See if this can be simplified into a rotate first. If that
7432 is unsuccessful continue in the association code. */
7436 if (integer_all_onesp (arg1))
7437 return non_lvalue (fold_convert (type, arg0));
7438 if (integer_zerop (arg1))
7439 return omit_one_operand (type, arg1, arg0);
7440 if (operand_equal_p (arg0, arg1, 0))
7441 return non_lvalue (fold_convert (type, arg0));
7443 /* ~X & X is always zero. */
7444 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7445 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7446 return omit_one_operand (type, integer_zero_node, arg1);
7448 /* X & ~X is always zero. */
7449 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7450 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7451 return omit_one_operand (type, integer_zero_node, arg0);
7453 t1 = distribute_bit_expr (code, type, arg0, arg1);
7454 if (t1 != NULL_TREE)
7456 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
7457 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
7458 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7461 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
7463 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
7464 && (~TREE_INT_CST_LOW (arg1)
7465 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
7466 return fold_convert (type, TREE_OPERAND (arg0, 0));
7469 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
7471 This results in more efficient code for machines without a NOR
7472 instruction. Combine will canonicalize to the first form
7473 which will allow use of NOR instructions provided by the
7474 backend if they exist. */
7475 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7476 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7478 return fold (build1 (BIT_NOT_EXPR, type,
7479 build2 (BIT_IOR_EXPR, type,
7480 TREE_OPERAND (arg0, 0),
7481 TREE_OPERAND (arg1, 0))));
7487 /* Don't touch a floating-point divide by zero unless the mode
7488 of the constant can represent infinity. */
7489 if (TREE_CODE (arg1) == REAL_CST
7490 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
7491 && real_zerop (arg1))
7494 /* (-A) / (-B) -> A / B */
7495 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7496 return fold (build2 (RDIV_EXPR, type,
7497 TREE_OPERAND (arg0, 0),
7498 negate_expr (arg1)));
7499 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7500 return fold (build2 (RDIV_EXPR, type,
7502 TREE_OPERAND (arg1, 0)));
7504 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
7505 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7506 && real_onep (arg1))
7507 return non_lvalue (fold_convert (type, arg0));
7509 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
7510 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7511 && real_minus_onep (arg1))
7512 return non_lvalue (fold_convert (type, negate_expr (arg0)));
7514 /* If ARG1 is a constant, we can convert this to a multiply by the
7515 reciprocal. This does not have the same rounding properties,
7516 so only do this if -funsafe-math-optimizations. We can actually
7517 always safely do it if ARG1 is a power of two, but it's hard to
7518 tell if it is or not in a portable manner. */
7519 if (TREE_CODE (arg1) == REAL_CST)
7521 if (flag_unsafe_math_optimizations
7522 && 0 != (tem = const_binop (code, build_real (type, dconst1),
7524 return fold (build2 (MULT_EXPR, type, arg0, tem));
7525 /* Find the reciprocal if optimizing and the result is exact. */
7529 r = TREE_REAL_CST (arg1);
7530 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
7532 tem = build_real (type, r);
7533 return fold (build2 (MULT_EXPR, type, arg0, tem));
7537 /* Convert A/B/C to A/(B*C). */
7538 if (flag_unsafe_math_optimizations
7539 && TREE_CODE (arg0) == RDIV_EXPR)
7540 return fold (build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
7541 fold (build2 (MULT_EXPR, type,
7542 TREE_OPERAND (arg0, 1), arg1))));
7544 /* Convert A/(B/C) to (A/B)*C. */
7545 if (flag_unsafe_math_optimizations
7546 && TREE_CODE (arg1) == RDIV_EXPR)
7547 return fold (build2 (MULT_EXPR, type,
7548 fold (build2 (RDIV_EXPR, type, arg0,
7549 TREE_OPERAND (arg1, 0))),
7550 TREE_OPERAND (arg1, 1)));
7552 /* Convert C1/(X*C2) into (C1/C2)/X. */
7553 if (flag_unsafe_math_optimizations
7554 && TREE_CODE (arg1) == MULT_EXPR
7555 && TREE_CODE (arg0) == REAL_CST
7556 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
7558 tree tem = const_binop (RDIV_EXPR, arg0,
7559 TREE_OPERAND (arg1, 1), 0);
7561 return fold (build2 (RDIV_EXPR, type, tem,
7562 TREE_OPERAND (arg1, 0)));
7565 if (flag_unsafe_math_optimizations)
7567 enum built_in_function fcode = builtin_mathfn_code (arg1);
7568 /* Optimize x/expN(y) into x*expN(-y). */
7569 if (BUILTIN_EXPONENT_P (fcode))
7571 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7572 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
7573 tree arglist = build_tree_list (NULL_TREE,
7574 fold_convert (type, arg));
7575 arg1 = build_function_call_expr (expfn, arglist);
7576 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7579 /* Optimize x/pow(y,z) into x*pow(y,-z). */
7580 if (fcode == BUILT_IN_POW
7581 || fcode == BUILT_IN_POWF
7582 || fcode == BUILT_IN_POWL)
7584 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7585 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7586 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
7587 tree neg11 = fold_convert (type, negate_expr (arg11));
7588 tree arglist = tree_cons(NULL_TREE, arg10,
7589 build_tree_list (NULL_TREE, neg11));
7590 arg1 = build_function_call_expr (powfn, arglist);
7591 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7595 if (flag_unsafe_math_optimizations)
7597 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7598 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7600 /* Optimize sin(x)/cos(x) as tan(x). */
7601 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
7602 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
7603 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
7604 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7605 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7607 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7609 if (tanfn != NULL_TREE)
7610 return build_function_call_expr (tanfn,
7611 TREE_OPERAND (arg0, 1));
7614 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
7615 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
7616 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
7617 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
7618 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7619 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7621 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7623 if (tanfn != NULL_TREE)
7625 tree tmp = TREE_OPERAND (arg0, 1);
7626 tmp = build_function_call_expr (tanfn, tmp);
7627 return fold (build2 (RDIV_EXPR, type,
7628 build_real (type, dconst1), tmp));
7632 /* Optimize pow(x,c)/x as pow(x,c-1). */
7633 if (fcode0 == BUILT_IN_POW
7634 || fcode0 == BUILT_IN_POWF
7635 || fcode0 == BUILT_IN_POWL)
7637 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7638 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
7639 if (TREE_CODE (arg01) == REAL_CST
7640 && ! TREE_CONSTANT_OVERFLOW (arg01)
7641 && operand_equal_p (arg1, arg00, 0))
7643 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7647 c = TREE_REAL_CST (arg01);
7648 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
7649 arg = build_real (type, c);
7650 arglist = build_tree_list (NULL_TREE, arg);
7651 arglist = tree_cons (NULL_TREE, arg1, arglist);
7652 return build_function_call_expr (powfn, arglist);
7658 case TRUNC_DIV_EXPR:
7659 case ROUND_DIV_EXPR:
7660 case FLOOR_DIV_EXPR:
7662 case EXACT_DIV_EXPR:
7663 if (integer_onep (arg1))
7664 return non_lvalue (fold_convert (type, arg0));
7665 if (integer_zerop (arg1))
7668 if (!TYPE_UNSIGNED (type)
7669 && TREE_CODE (arg1) == INTEGER_CST
7670 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7671 && TREE_INT_CST_HIGH (arg1) == -1)
7672 return fold_convert (type, negate_expr (arg0));
7674 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
7675 operation, EXACT_DIV_EXPR.
7677 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
7678 At one time others generated faster code, it's not clear if they do
7679 after the last round to changes to the DIV code in expmed.c. */
7680 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
7681 && multiple_of_p (type, arg0, arg1))
7682 return fold (build2 (EXACT_DIV_EXPR, type, arg0, arg1));
7684 if (TREE_CODE (arg1) == INTEGER_CST
7685 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7687 return fold_convert (type, tem);
7692 case FLOOR_MOD_EXPR:
7693 case ROUND_MOD_EXPR:
7694 case TRUNC_MOD_EXPR:
7695 if (integer_onep (arg1))
7696 return omit_one_operand (type, integer_zero_node, arg0);
7697 if (integer_zerop (arg1))
7700 /* X % -1 is zero. */
7701 if (!TYPE_UNSIGNED (type)
7702 && TREE_CODE (arg1) == INTEGER_CST
7703 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7704 && TREE_INT_CST_HIGH (arg1) == -1)
7705 return omit_one_operand (type, integer_zero_node, arg0);
7707 /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
7708 BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
7709 if (code == TRUNC_MOD_EXPR
7710 && TYPE_UNSIGNED (type)
7711 && integer_pow2p (arg1))
7713 unsigned HOST_WIDE_INT high, low;
7717 l = tree_log2 (arg1);
7718 if (l >= HOST_BITS_PER_WIDE_INT)
7720 high = ((unsigned HOST_WIDE_INT) 1
7721 << (l - HOST_BITS_PER_WIDE_INT)) - 1;
7727 low = ((unsigned HOST_WIDE_INT) 1 << l) - 1;
7730 mask = build_int_cst_wide (type, low, high);
7731 return fold (build2 (BIT_AND_EXPR, type,
7732 fold_convert (type, arg0), mask));
7735 /* X % -C is the same as X % C. */
7736 if (code == TRUNC_MOD_EXPR
7737 && !TYPE_UNSIGNED (type)
7738 && TREE_CODE (arg1) == INTEGER_CST
7739 && TREE_INT_CST_HIGH (arg1) < 0
7741 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
7742 && !sign_bit_p (arg1, arg1))
7743 return fold (build2 (code, type, fold_convert (type, arg0),
7744 fold_convert (type, negate_expr (arg1))));
7746 /* X % -Y is the same as X % Y. */
7747 if (code == TRUNC_MOD_EXPR
7748 && !TYPE_UNSIGNED (type)
7749 && TREE_CODE (arg1) == NEGATE_EXPR
7751 return fold (build2 (code, type, fold_convert (type, arg0),
7752 fold_convert (type, TREE_OPERAND (arg1, 0))));
7754 if (TREE_CODE (arg1) == INTEGER_CST
7755 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7757 return fold_convert (type, tem);
7763 if (integer_all_onesp (arg0))
7764 return omit_one_operand (type, arg0, arg1);
7768 /* Optimize -1 >> x for arithmetic right shifts. */
7769 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
7770 return omit_one_operand (type, arg0, arg1);
7771 /* ... fall through ... */
7775 if (integer_zerop (arg1))
7776 return non_lvalue (fold_convert (type, arg0));
7777 if (integer_zerop (arg0))
7778 return omit_one_operand (type, arg0, arg1);
7780 /* Since negative shift count is not well-defined,
7781 don't try to compute it in the compiler. */
7782 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
7784 /* Rewrite an LROTATE_EXPR by a constant into an
7785 RROTATE_EXPR by a new constant. */
7786 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
7788 tree tem = build_int_cst (NULL_TREE,
7789 GET_MODE_BITSIZE (TYPE_MODE (type)));
7790 tem = fold_convert (TREE_TYPE (arg1), tem);
7791 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
7792 return fold (build2 (RROTATE_EXPR, type, arg0, tem));
7795 /* If we have a rotate of a bit operation with the rotate count and
7796 the second operand of the bit operation both constant,
7797 permute the two operations. */
7798 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7799 && (TREE_CODE (arg0) == BIT_AND_EXPR
7800 || TREE_CODE (arg0) == BIT_IOR_EXPR
7801 || TREE_CODE (arg0) == BIT_XOR_EXPR)
7802 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7803 return fold (build2 (TREE_CODE (arg0), type,
7804 fold (build2 (code, type,
7805 TREE_OPERAND (arg0, 0), arg1)),
7806 fold (build2 (code, type,
7807 TREE_OPERAND (arg0, 1), arg1))));
7809 /* Two consecutive rotates adding up to the width of the mode can
7811 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7812 && TREE_CODE (arg0) == RROTATE_EXPR
7813 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7814 && TREE_INT_CST_HIGH (arg1) == 0
7815 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
7816 && ((TREE_INT_CST_LOW (arg1)
7817 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
7818 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
7819 return TREE_OPERAND (arg0, 0);
7824 if (operand_equal_p (arg0, arg1, 0))
7825 return omit_one_operand (type, arg0, arg1);
7826 if (INTEGRAL_TYPE_P (type)
7827 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
7828 return omit_one_operand (type, arg1, arg0);
7832 if (operand_equal_p (arg0, arg1, 0))
7833 return omit_one_operand (type, arg0, arg1);
7834 if (INTEGRAL_TYPE_P (type)
7835 && TYPE_MAX_VALUE (type)
7836 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
7837 return omit_one_operand (type, arg1, arg0);
7840 case TRUTH_NOT_EXPR:
7841 /* The argument to invert_truthvalue must have Boolean type. */
7842 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7843 arg0 = fold_convert (boolean_type_node, arg0);
7845 /* Note that the operand of this must be an int
7846 and its values must be 0 or 1.
7847 ("true" is a fixed value perhaps depending on the language,
7848 but we don't handle values other than 1 correctly yet.) */
7849 tem = invert_truthvalue (arg0);
7850 /* Avoid infinite recursion. */
7851 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7853 tem = fold_single_bit_test (code, arg0, arg1, type);
7858 return fold_convert (type, tem);
7860 case TRUTH_ANDIF_EXPR:
7861 /* Note that the operands of this must be ints
7862 and their values must be 0 or 1.
7863 ("true" is a fixed value perhaps depending on the language.) */
7864 /* If first arg is constant zero, return it. */
7865 if (integer_zerop (arg0))
7866 return fold_convert (type, arg0);
7867 case TRUTH_AND_EXPR:
7868 /* If either arg is constant true, drop it. */
7869 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7870 return non_lvalue (fold_convert (type, arg1));
7871 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
7872 /* Preserve sequence points. */
7873 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7874 return non_lvalue (fold_convert (type, arg0));
7875 /* If second arg is constant zero, result is zero, but first arg
7876 must be evaluated. */
7877 if (integer_zerop (arg1))
7878 return omit_one_operand (type, arg1, arg0);
7879 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
7880 case will be handled here. */
7881 if (integer_zerop (arg0))
7882 return omit_one_operand (type, arg0, arg1);
7884 /* !X && X is always false. */
7885 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
7886 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7887 return omit_one_operand (type, integer_zero_node, arg1);
7888 /* X && !X is always false. */
7889 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
7890 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7891 return omit_one_operand (type, integer_zero_node, arg0);
7894 /* We only do these simplifications if we are optimizing. */
7898 /* Check for things like (A || B) && (A || C). We can convert this
7899 to A || (B && C). Note that either operator can be any of the four
7900 truth and/or operations and the transformation will still be
7901 valid. Also note that we only care about order for the
7902 ANDIF and ORIF operators. If B contains side effects, this
7903 might change the truth-value of A. */
7904 if (TREE_CODE (arg0) == TREE_CODE (arg1)
7905 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
7906 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
7907 || TREE_CODE (arg0) == TRUTH_AND_EXPR
7908 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
7909 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
7911 tree a00 = TREE_OPERAND (arg0, 0);
7912 tree a01 = TREE_OPERAND (arg0, 1);
7913 tree a10 = TREE_OPERAND (arg1, 0);
7914 tree a11 = TREE_OPERAND (arg1, 1);
7915 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
7916 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
7917 && (code == TRUTH_AND_EXPR
7918 || code == TRUTH_OR_EXPR));
7920 if (operand_equal_p (a00, a10, 0))
7921 return fold (build2 (TREE_CODE (arg0), type, a00,
7922 fold (build2 (code, type, a01, a11))));
7923 else if (commutative && operand_equal_p (a00, a11, 0))
7924 return fold (build2 (TREE_CODE (arg0), type, a00,
7925 fold (build2 (code, type, a01, a10))));
7926 else if (commutative && operand_equal_p (a01, a10, 0))
7927 return fold (build2 (TREE_CODE (arg0), type, a01,
7928 fold (build2 (code, type, a00, a11))));
7930 /* This case if tricky because we must either have commutative
7931 operators or else A10 must not have side-effects. */
7933 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
7934 && operand_equal_p (a01, a11, 0))
7935 return fold (build2 (TREE_CODE (arg0), type,
7936 fold (build2 (code, type, a00, a10)),
7940 /* See if we can build a range comparison. */
7941 if (0 != (tem = fold_range_test (t)))
7944 /* Check for the possibility of merging component references. If our
7945 lhs is another similar operation, try to merge its rhs with our
7946 rhs. Then try to merge our lhs and rhs. */
7947 if (TREE_CODE (arg0) == code
7948 && 0 != (tem = fold_truthop (code, type,
7949 TREE_OPERAND (arg0, 1), arg1)))
7950 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
7952 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
7957 case TRUTH_ORIF_EXPR:
7958 /* Note that the operands of this must be ints
7959 and their values must be 0 or true.
7960 ("true" is a fixed value perhaps depending on the language.) */
7961 /* If first arg is constant true, return it. */
7962 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7963 return fold_convert (type, arg0);
7965 /* If either arg is constant zero, drop it. */
7966 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
7967 return non_lvalue (fold_convert (type, arg1));
7968 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
7969 /* Preserve sequence points. */
7970 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7971 return non_lvalue (fold_convert (type, arg0));
7972 /* If second arg is constant true, result is true, but we must
7973 evaluate first arg. */
7974 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
7975 return omit_one_operand (type, arg1, arg0);
7976 /* Likewise for first arg, but note this only occurs here for
7978 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7979 return omit_one_operand (type, arg0, arg1);
7981 /* !X || X is always true. */
7982 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
7983 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7984 return omit_one_operand (type, integer_one_node, arg1);
7985 /* X || !X is always true. */
7986 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
7987 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7988 return omit_one_operand (type, integer_one_node, arg0);
7992 case TRUTH_XOR_EXPR:
7993 /* If the second arg is constant zero, drop it. */
7994 if (integer_zerop (arg1))
7995 return non_lvalue (fold_convert (type, arg0));
7996 /* If the second arg is constant true, this is a logical inversion. */
7997 if (integer_onep (arg1))
7998 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
7999 /* Identical arguments cancel to zero. */
8000 if (operand_equal_p (arg0, arg1, 0))
8001 return omit_one_operand (type, integer_zero_node, arg0);
8003 /* !X ^ X is always true. */
8004 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
8005 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
8006 return omit_one_operand (type, integer_one_node, arg1);
8008 /* X ^ !X is always true. */
8009 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
8010 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
8011 return omit_one_operand (type, integer_one_node, arg0);
8021 /* If one arg is a real or integer constant, put it last. */
8022 if (tree_swap_operands_p (arg0, arg1, true))
8023 return fold (build2 (swap_tree_comparison (code), type, arg1, arg0));
8025 /* If this is an equality comparison of the address of a non-weak
8026 object against zero, then we know the result. */
8027 if ((code == EQ_EXPR || code == NE_EXPR)
8028 && TREE_CODE (arg0) == ADDR_EXPR
8029 && DECL_P (TREE_OPERAND (arg0, 0))
8030 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8031 && integer_zerop (arg1))
8032 return constant_boolean_node (code != EQ_EXPR, type);
8034 /* If this is an equality comparison of the address of two non-weak,
8035 unaliased symbols neither of which are extern (since we do not
8036 have access to attributes for externs), then we know the result. */
8037 if ((code == EQ_EXPR || code == NE_EXPR)
8038 && TREE_CODE (arg0) == ADDR_EXPR
8039 && DECL_P (TREE_OPERAND (arg0, 0))
8040 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
8041 && ! lookup_attribute ("alias",
8042 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
8043 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
8044 && TREE_CODE (arg1) == ADDR_EXPR
8045 && DECL_P (TREE_OPERAND (arg1, 0))
8046 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
8047 && ! lookup_attribute ("alias",
8048 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
8049 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
8050 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
8051 ? code == EQ_EXPR : code != EQ_EXPR,
8054 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8056 tree targ0 = strip_float_extensions (arg0);
8057 tree targ1 = strip_float_extensions (arg1);
8058 tree newtype = TREE_TYPE (targ0);
8060 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8061 newtype = TREE_TYPE (targ1);
8063 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8064 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8065 return fold (build2 (code, type, fold_convert (newtype, targ0),
8066 fold_convert (newtype, targ1)));
8068 /* (-a) CMP (-b) -> b CMP a */
8069 if (TREE_CODE (arg0) == NEGATE_EXPR
8070 && TREE_CODE (arg1) == NEGATE_EXPR)
8071 return fold (build2 (code, type, TREE_OPERAND (arg1, 0),
8072 TREE_OPERAND (arg0, 0)));
8074 if (TREE_CODE (arg1) == REAL_CST)
8076 REAL_VALUE_TYPE cst;
8077 cst = TREE_REAL_CST (arg1);
8079 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8080 if (TREE_CODE (arg0) == NEGATE_EXPR)
8082 fold (build2 (swap_tree_comparison (code), type,
8083 TREE_OPERAND (arg0, 0),
8084 build_real (TREE_TYPE (arg1),
8085 REAL_VALUE_NEGATE (cst))));
8087 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8088 /* a CMP (-0) -> a CMP 0 */
8089 if (REAL_VALUE_MINUS_ZERO (cst))
8090 return fold (build2 (code, type, arg0,
8091 build_real (TREE_TYPE (arg1), dconst0)));
8093 /* x != NaN is always true, other ops are always false. */
8094 if (REAL_VALUE_ISNAN (cst)
8095 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8097 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8098 return omit_one_operand (type, tem, arg0);
8101 /* Fold comparisons against infinity. */
8102 if (REAL_VALUE_ISINF (cst))
8104 tem = fold_inf_compare (code, type, arg0, arg1);
8105 if (tem != NULL_TREE)
8110 /* If this is a comparison of a real constant with a PLUS_EXPR
8111 or a MINUS_EXPR of a real constant, we can convert it into a
8112 comparison with a revised real constant as long as no overflow
8113 occurs when unsafe_math_optimizations are enabled. */
8114 if (flag_unsafe_math_optimizations
8115 && TREE_CODE (arg1) == REAL_CST
8116 && (TREE_CODE (arg0) == PLUS_EXPR
8117 || TREE_CODE (arg0) == MINUS_EXPR)
8118 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8119 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8120 ? MINUS_EXPR : PLUS_EXPR,
8121 arg1, TREE_OPERAND (arg0, 1), 0))
8122 && ! TREE_CONSTANT_OVERFLOW (tem))
8123 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8125 /* Likewise, we can simplify a comparison of a real constant with
8126 a MINUS_EXPR whose first operand is also a real constant, i.e.
8127 (c1 - x) < c2 becomes x > c1-c2. */
8128 if (flag_unsafe_math_optimizations
8129 && TREE_CODE (arg1) == REAL_CST
8130 && TREE_CODE (arg0) == MINUS_EXPR
8131 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8132 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8134 && ! TREE_CONSTANT_OVERFLOW (tem))
8135 return fold (build2 (swap_tree_comparison (code), type,
8136 TREE_OPERAND (arg0, 1), tem));
8138 /* Fold comparisons against built-in math functions. */
8139 if (TREE_CODE (arg1) == REAL_CST
8140 && flag_unsafe_math_optimizations
8141 && ! flag_errno_math)
8143 enum built_in_function fcode = builtin_mathfn_code (arg0);
8145 if (fcode != END_BUILTINS)
8147 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8148 if (tem != NULL_TREE)
8154 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8155 if (TREE_CONSTANT (arg1)
8156 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8157 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8158 /* This optimization is invalid for ordered comparisons
8159 if CONST+INCR overflows or if foo+incr might overflow.
8160 This optimization is invalid for floating point due to rounding.
8161 For pointer types we assume overflow doesn't happen. */
8162 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8163 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8164 && (code == EQ_EXPR || code == NE_EXPR))))
8166 tree varop, newconst;
8168 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8170 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
8171 arg1, TREE_OPERAND (arg0, 1)));
8172 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8173 TREE_OPERAND (arg0, 0),
8174 TREE_OPERAND (arg0, 1));
8178 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
8179 arg1, TREE_OPERAND (arg0, 1)));
8180 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8181 TREE_OPERAND (arg0, 0),
8182 TREE_OPERAND (arg0, 1));
8186 /* If VAROP is a reference to a bitfield, we must mask
8187 the constant by the width of the field. */
8188 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8189 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8190 && host_integerp (DECL_SIZE (TREE_OPERAND
8191 (TREE_OPERAND (varop, 0), 1)), 1))
8193 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8194 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8195 tree folded_compare, shift;
8197 /* First check whether the comparison would come out
8198 always the same. If we don't do that we would
8199 change the meaning with the masking. */
8200 folded_compare = fold (build2 (code, type,
8201 TREE_OPERAND (varop, 0), arg1));
8202 if (integer_zerop (folded_compare)
8203 || integer_onep (folded_compare))
8204 return omit_one_operand (type, folded_compare, varop);
8206 shift = build_int_cst (NULL_TREE,
8207 TYPE_PRECISION (TREE_TYPE (varop)) - size);
8208 shift = fold_convert (TREE_TYPE (varop), shift);
8209 newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8211 newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8215 return fold (build2 (code, type, varop, newconst));
8218 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
8219 This transformation affects the cases which are handled in later
8220 optimizations involving comparisons with non-negative constants. */
8221 if (TREE_CODE (arg1) == INTEGER_CST
8222 && TREE_CODE (arg0) != INTEGER_CST
8223 && tree_int_cst_sgn (arg1) > 0)
8228 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8229 return fold (build2 (GT_EXPR, type, arg0, arg1));
8232 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8233 return fold (build2 (LE_EXPR, type, arg0, arg1));
8240 /* Comparisons with the highest or lowest possible integer of
8241 the specified size will have known values.
8243 This is quite similar to fold_relational_hi_lo; however, my
8244 attempts to share the code have been nothing but trouble.
8245 I give up for now. */
8247 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
8249 if (TREE_CODE (arg1) == INTEGER_CST
8250 && ! TREE_CONSTANT_OVERFLOW (arg1)
8251 && width <= HOST_BITS_PER_WIDE_INT
8252 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
8253 || POINTER_TYPE_P (TREE_TYPE (arg1))))
8255 unsigned HOST_WIDE_INT signed_max;
8256 unsigned HOST_WIDE_INT max, min;
8258 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
8260 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
8262 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
8268 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
8271 if (TREE_INT_CST_HIGH (arg1) == 0
8272 && TREE_INT_CST_LOW (arg1) == max)
8276 return omit_one_operand (type, integer_zero_node, arg0);
8279 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8282 return omit_one_operand (type, integer_one_node, arg0);
8285 return fold (build2 (NE_EXPR, type, arg0, arg1));
8287 /* The GE_EXPR and LT_EXPR cases above are not normally
8288 reached because of previous transformations. */
8293 else if (TREE_INT_CST_HIGH (arg1) == 0
8294 && TREE_INT_CST_LOW (arg1) == max - 1)
8298 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8299 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8301 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8302 return fold (build2 (NE_EXPR, type, arg0, arg1));
8306 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8307 && TREE_INT_CST_LOW (arg1) == min)
8311 return omit_one_operand (type, integer_zero_node, arg0);
8314 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8317 return omit_one_operand (type, integer_one_node, arg0);
8320 return fold (build2 (NE_EXPR, type, arg0, arg1));
8325 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8326 && TREE_INT_CST_LOW (arg1) == min + 1)
8330 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8331 return fold (build2 (NE_EXPR, type, arg0, arg1));
8333 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8334 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8339 else if (!in_gimple_form
8340 && TREE_INT_CST_HIGH (arg1) == 0
8341 && TREE_INT_CST_LOW (arg1) == signed_max
8342 && TYPE_UNSIGNED (TREE_TYPE (arg1))
8343 /* signed_type does not work on pointer types. */
8344 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
8346 /* The following case also applies to X < signed_max+1
8347 and X >= signed_max+1 because previous transformations. */
8348 if (code == LE_EXPR || code == GT_EXPR)
8351 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
8352 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
8354 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
8355 type, fold_convert (st0, arg0),
8356 fold_convert (st1, integer_zero_node)));
8362 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
8363 a MINUS_EXPR of a constant, we can convert it into a comparison with
8364 a revised constant as long as no overflow occurs. */
8365 if ((code == EQ_EXPR || code == NE_EXPR)
8366 && TREE_CODE (arg1) == INTEGER_CST
8367 && (TREE_CODE (arg0) == PLUS_EXPR
8368 || TREE_CODE (arg0) == MINUS_EXPR)
8369 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8370 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8371 ? MINUS_EXPR : PLUS_EXPR,
8372 arg1, TREE_OPERAND (arg0, 1), 0))
8373 && ! TREE_CONSTANT_OVERFLOW (tem))
8374 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8376 /* Similarly for a NEGATE_EXPR. */
8377 else if ((code == EQ_EXPR || code == NE_EXPR)
8378 && TREE_CODE (arg0) == NEGATE_EXPR
8379 && TREE_CODE (arg1) == INTEGER_CST
8380 && 0 != (tem = negate_expr (arg1))
8381 && TREE_CODE (tem) == INTEGER_CST
8382 && ! TREE_CONSTANT_OVERFLOW (tem))
8383 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8385 /* If we have X - Y == 0, we can convert that to X == Y and similarly
8386 for !=. Don't do this for ordered comparisons due to overflow. */
8387 else if ((code == NE_EXPR || code == EQ_EXPR)
8388 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
8389 return fold (build2 (code, type,
8390 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
8392 /* If we are widening one operand of an integer comparison,
8393 see if the other operand is similarly being widened. Perhaps we
8394 can do the comparison in the narrower type. */
8395 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8396 && TREE_CODE (arg0) == NOP_EXPR
8397 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
8398 && (code == EQ_EXPR || code == NE_EXPR
8399 || TYPE_UNSIGNED (TREE_TYPE (arg0))
8400 == TYPE_UNSIGNED (TREE_TYPE (tem)))
8401 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
8402 && (TREE_TYPE (t1) == TREE_TYPE (tem)
8403 || (TREE_CODE (t1) == INTEGER_CST
8404 && TREE_CODE (TREE_TYPE (tem)) == INTEGER_TYPE
8405 && int_fits_type_p (t1, TREE_TYPE (tem)))))
8406 return fold (build2 (code, type, tem,
8407 fold_convert (TREE_TYPE (tem), t1)));
8409 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8410 constant, we can simplify it. */
8411 else if (TREE_CODE (arg1) == INTEGER_CST
8412 && (TREE_CODE (arg0) == MIN_EXPR
8413 || TREE_CODE (arg0) == MAX_EXPR)
8414 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8415 return optimize_minmax_comparison (t);
8417 /* If we are comparing an ABS_EXPR with a constant, we can
8418 convert all the cases into explicit comparisons, but they may
8419 well not be faster than doing the ABS and one comparison.
8420 But ABS (X) <= C is a range comparison, which becomes a subtraction
8421 and a comparison, and is probably faster. */
8422 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8423 && TREE_CODE (arg0) == ABS_EXPR
8424 && ! TREE_SIDE_EFFECTS (arg0)
8425 && (0 != (tem = negate_expr (arg1)))
8426 && TREE_CODE (tem) == INTEGER_CST
8427 && ! TREE_CONSTANT_OVERFLOW (tem))
8428 return fold (build2 (TRUTH_ANDIF_EXPR, type,
8429 build2 (GE_EXPR, type,
8430 TREE_OPERAND (arg0, 0), tem),
8431 build2 (LE_EXPR, type,
8432 TREE_OPERAND (arg0, 0), arg1)));
8434 /* If this is an EQ or NE comparison with zero and ARG0 is
8435 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
8436 two operations, but the latter can be done in one less insn
8437 on machines that have only two-operand insns or on which a
8438 constant cannot be the first operand. */
8439 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
8440 && TREE_CODE (arg0) == BIT_AND_EXPR)
8442 tree arg00 = TREE_OPERAND (arg0, 0);
8443 tree arg01 = TREE_OPERAND (arg0, 1);
8444 if (TREE_CODE (arg00) == LSHIFT_EXPR
8445 && integer_onep (TREE_OPERAND (arg00, 0)))
8447 fold (build2 (code, type,
8448 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8449 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
8450 arg01, TREE_OPERAND (arg00, 1)),
8451 fold_convert (TREE_TYPE (arg0),
8454 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
8455 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
8457 fold (build2 (code, type,
8458 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8459 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
8460 arg00, TREE_OPERAND (arg01, 1)),
8461 fold_convert (TREE_TYPE (arg0),
8466 /* If this is an NE or EQ comparison of zero against the result of a
8467 signed MOD operation whose second operand is a power of 2, make
8468 the MOD operation unsigned since it is simpler and equivalent. */
8469 if ((code == NE_EXPR || code == EQ_EXPR)
8470 && integer_zerop (arg1)
8471 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
8472 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
8473 || TREE_CODE (arg0) == CEIL_MOD_EXPR
8474 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
8475 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
8476 && integer_pow2p (TREE_OPERAND (arg0, 1)))
8478 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
8479 tree newmod = fold (build2 (TREE_CODE (arg0), newtype,
8480 fold_convert (newtype,
8481 TREE_OPERAND (arg0, 0)),
8482 fold_convert (newtype,
8483 TREE_OPERAND (arg0, 1))));
8485 return fold (build2 (code, type, newmod,
8486 fold_convert (newtype, arg1)));
8489 /* If this is an NE comparison of zero with an AND of one, remove the
8490 comparison since the AND will give the correct value. */
8491 if (code == NE_EXPR && integer_zerop (arg1)
8492 && TREE_CODE (arg0) == BIT_AND_EXPR
8493 && integer_onep (TREE_OPERAND (arg0, 1)))
8494 return fold_convert (type, arg0);
8496 /* If we have (A & C) == C where C is a power of 2, convert this into
8497 (A & C) != 0. Similarly for NE_EXPR. */
8498 if ((code == EQ_EXPR || code == NE_EXPR)
8499 && TREE_CODE (arg0) == BIT_AND_EXPR
8500 && integer_pow2p (TREE_OPERAND (arg0, 1))
8501 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
8502 return fold (build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
8503 arg0, fold_convert (TREE_TYPE (arg0),
8504 integer_zero_node)));
8506 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
8507 2, then fold the expression into shifts and logical operations. */
8508 tem = fold_single_bit_test (code, arg0, arg1, type);
8512 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
8513 Similarly for NE_EXPR. */
8514 if ((code == EQ_EXPR || code == NE_EXPR)
8515 && TREE_CODE (arg0) == BIT_AND_EXPR
8516 && TREE_CODE (arg1) == INTEGER_CST
8517 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8519 tree notc = fold (build1 (BIT_NOT_EXPR,
8520 TREE_TYPE (TREE_OPERAND (arg0, 1)),
8521 TREE_OPERAND (arg0, 1)));
8522 tree dandnotc = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8524 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8525 if (integer_nonzerop (dandnotc))
8526 return omit_one_operand (type, rslt, arg0);
8529 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
8530 Similarly for NE_EXPR. */
8531 if ((code == EQ_EXPR || code == NE_EXPR)
8532 && TREE_CODE (arg0) == BIT_IOR_EXPR
8533 && TREE_CODE (arg1) == INTEGER_CST
8534 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8536 tree notd = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1));
8537 tree candnotd = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8538 TREE_OPERAND (arg0, 1), notd));
8539 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8540 if (integer_nonzerop (candnotd))
8541 return omit_one_operand (type, rslt, arg0);
8544 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
8545 and similarly for >= into !=. */
8546 if ((code == LT_EXPR || code == GE_EXPR)
8547 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8548 && TREE_CODE (arg1) == LSHIFT_EXPR
8549 && integer_onep (TREE_OPERAND (arg1, 0)))
8550 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8551 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8552 TREE_OPERAND (arg1, 1)),
8553 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8555 else if ((code == LT_EXPR || code == GE_EXPR)
8556 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8557 && (TREE_CODE (arg1) == NOP_EXPR
8558 || TREE_CODE (arg1) == CONVERT_EXPR)
8559 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
8560 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
8562 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8563 fold_convert (TREE_TYPE (arg0),
8564 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8565 TREE_OPERAND (TREE_OPERAND (arg1, 0),
8567 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8569 /* Simplify comparison of something with itself. (For IEEE
8570 floating-point, we can only do some of these simplifications.) */
8571 if (operand_equal_p (arg0, arg1, 0))
8576 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8577 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8578 return constant_boolean_node (1, type);
8583 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8584 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8585 return constant_boolean_node (1, type);
8586 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8589 /* For NE, we can only do this simplification if integer
8590 or we don't honor IEEE floating point NaNs. */
8591 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8592 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8594 /* ... fall through ... */
8597 return constant_boolean_node (0, type);
8603 /* If we are comparing an expression that just has comparisons
8604 of two integer values, arithmetic expressions of those comparisons,
8605 and constants, we can simplify it. There are only three cases
8606 to check: the two values can either be equal, the first can be
8607 greater, or the second can be greater. Fold the expression for
8608 those three values. Since each value must be 0 or 1, we have
8609 eight possibilities, each of which corresponds to the constant 0
8610 or 1 or one of the six possible comparisons.
8612 This handles common cases like (a > b) == 0 but also handles
8613 expressions like ((x > y) - (y > x)) > 0, which supposedly
8614 occur in macroized code. */
8616 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8618 tree cval1 = 0, cval2 = 0;
8621 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8622 /* Don't handle degenerate cases here; they should already
8623 have been handled anyway. */
8624 && cval1 != 0 && cval2 != 0
8625 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8626 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8627 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8628 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8629 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8630 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8631 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8633 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8634 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8636 /* We can't just pass T to eval_subst in case cval1 or cval2
8637 was the same as ARG1. */
8640 = fold (build2 (code, type,
8641 eval_subst (arg0, cval1, maxval,
8645 = fold (build2 (code, type,
8646 eval_subst (arg0, cval1, maxval,
8650 = fold (build2 (code, type,
8651 eval_subst (arg0, cval1, minval,
8655 /* All three of these results should be 0 or 1. Confirm they
8656 are. Then use those values to select the proper code
8659 if ((integer_zerop (high_result)
8660 || integer_onep (high_result))
8661 && (integer_zerop (equal_result)
8662 || integer_onep (equal_result))
8663 && (integer_zerop (low_result)
8664 || integer_onep (low_result)))
8666 /* Make a 3-bit mask with the high-order bit being the
8667 value for `>', the next for '=', and the low for '<'. */
8668 switch ((integer_onep (high_result) * 4)
8669 + (integer_onep (equal_result) * 2)
8670 + integer_onep (low_result))
8674 return omit_one_operand (type, integer_zero_node, arg0);
8695 return omit_one_operand (type, integer_one_node, arg0);
8698 tem = build2 (code, type, cval1, cval2);
8700 return save_expr (tem);
8707 /* If this is a comparison of a field, we may be able to simplify it. */
8708 if (((TREE_CODE (arg0) == COMPONENT_REF
8709 && lang_hooks.can_use_bit_fields_p ())
8710 || TREE_CODE (arg0) == BIT_FIELD_REF)
8711 && (code == EQ_EXPR || code == NE_EXPR)
8712 /* Handle the constant case even without -O
8713 to make sure the warnings are given. */
8714 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
8716 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
8721 /* If this is a comparison of complex values and either or both sides
8722 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
8723 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
8724 This may prevent needless evaluations. */
8725 if ((code == EQ_EXPR || code == NE_EXPR)
8726 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
8727 && (TREE_CODE (arg0) == COMPLEX_EXPR
8728 || TREE_CODE (arg1) == COMPLEX_EXPR
8729 || TREE_CODE (arg0) == COMPLEX_CST
8730 || TREE_CODE (arg1) == COMPLEX_CST))
8732 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
8733 tree real0, imag0, real1, imag1;
8735 arg0 = save_expr (arg0);
8736 arg1 = save_expr (arg1);
8737 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
8738 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
8739 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
8740 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
8742 return fold (build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
8745 fold (build2 (code, type, real0, real1)),
8746 fold (build2 (code, type, imag0, imag1))));
8749 /* Optimize comparisons of strlen vs zero to a compare of the
8750 first character of the string vs zero. To wit,
8751 strlen(ptr) == 0 => *ptr == 0
8752 strlen(ptr) != 0 => *ptr != 0
8753 Other cases should reduce to one of these two (or a constant)
8754 due to the return value of strlen being unsigned. */
8755 if ((code == EQ_EXPR || code == NE_EXPR)
8756 && integer_zerop (arg1)
8757 && TREE_CODE (arg0) == CALL_EXPR)
8759 tree fndecl = get_callee_fndecl (arg0);
8763 && DECL_BUILT_IN (fndecl)
8764 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
8765 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
8766 && (arglist = TREE_OPERAND (arg0, 1))
8767 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
8768 && ! TREE_CHAIN (arglist))
8769 return fold (build2 (code, type,
8770 build1 (INDIRECT_REF, char_type_node,
8771 TREE_VALUE (arglist)),
8772 fold_convert (char_type_node,
8773 integer_zero_node)));
8776 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8777 into a single range test. */
8778 if (TREE_CODE (arg0) == TRUNC_DIV_EXPR
8779 && TREE_CODE (arg1) == INTEGER_CST
8780 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8781 && !integer_zerop (TREE_OPERAND (arg0, 1))
8782 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8783 && !TREE_OVERFLOW (arg1))
8785 t1 = fold_div_compare (code, type, arg0, arg1);
8786 if (t1 != NULL_TREE)
8790 if ((code == EQ_EXPR || code == NE_EXPR)
8791 && !TREE_SIDE_EFFECTS (arg0)
8792 && integer_zerop (arg1)
8793 && tree_expr_nonzero_p (arg0))
8794 return constant_boolean_node (code==NE_EXPR, type);
8796 t1 = fold_relational_const (code, type, arg0, arg1);
8797 return t1 == NULL_TREE ? t : t1;
8799 case UNORDERED_EXPR:
8807 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
8809 t1 = fold_relational_const (code, type, arg0, arg1);
8810 if (t1 != NULL_TREE)
8814 /* If the first operand is NaN, the result is constant. */
8815 if (TREE_CODE (arg0) == REAL_CST
8816 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
8817 && (code != LTGT_EXPR || ! flag_trapping_math))
8819 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8822 return omit_one_operand (type, t1, arg1);
8825 /* If the second operand is NaN, the result is constant. */
8826 if (TREE_CODE (arg1) == REAL_CST
8827 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
8828 && (code != LTGT_EXPR || ! flag_trapping_math))
8830 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8833 return omit_one_operand (type, t1, arg0);
8836 /* Simplify unordered comparison of something with itself. */
8837 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
8838 && operand_equal_p (arg0, arg1, 0))
8839 return constant_boolean_node (1, type);
8841 if (code == LTGT_EXPR
8842 && !flag_trapping_math
8843 && operand_equal_p (arg0, arg1, 0))
8844 return constant_boolean_node (0, type);
8846 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8848 tree targ0 = strip_float_extensions (arg0);
8849 tree targ1 = strip_float_extensions (arg1);
8850 tree newtype = TREE_TYPE (targ0);
8852 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8853 newtype = TREE_TYPE (targ1);
8855 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8856 return fold (build2 (code, type, fold_convert (newtype, targ0),
8857 fold_convert (newtype, targ1)));
8863 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
8864 so all simple results must be passed through pedantic_non_lvalue. */
8865 if (TREE_CODE (arg0) == INTEGER_CST)
8867 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
8868 /* Only optimize constant conditions when the selected branch
8869 has the same type as the COND_EXPR. This avoids optimizing
8870 away "c ? x : throw", where the throw has a void type. */
8871 if (! VOID_TYPE_P (TREE_TYPE (tem))
8872 || VOID_TYPE_P (type))
8873 return pedantic_non_lvalue (tem);
8876 if (operand_equal_p (arg1, TREE_OPERAND (t, 2), 0))
8877 return pedantic_omit_one_operand (type, arg1, arg0);
8879 /* If we have A op B ? A : C, we may be able to convert this to a
8880 simpler expression, depending on the operation and the values
8881 of B and C. Signed zeros prevent all of these transformations,
8882 for reasons given above each one.
8884 Also try swapping the arguments and inverting the conditional. */
8885 if (COMPARISON_CLASS_P (arg0)
8886 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8887 arg1, TREE_OPERAND (arg0, 1))
8888 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
8890 tem = fold_cond_expr_with_comparison (type, arg0,
8891 TREE_OPERAND (t, 1),
8892 TREE_OPERAND (t, 2));
8897 if (COMPARISON_CLASS_P (arg0)
8898 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8899 TREE_OPERAND (t, 2),
8900 TREE_OPERAND (arg0, 1))
8901 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 2)))))
8903 tem = invert_truthvalue (arg0);
8904 if (COMPARISON_CLASS_P (tem))
8906 tem = fold_cond_expr_with_comparison (type, tem,
8907 TREE_OPERAND (t, 2),
8908 TREE_OPERAND (t, 1));
8914 /* If the second operand is simpler than the third, swap them
8915 since that produces better jump optimization results. */
8916 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
8917 TREE_OPERAND (t, 2), false))
8919 /* See if this can be inverted. If it can't, possibly because
8920 it was a floating-point inequality comparison, don't do
8922 tem = invert_truthvalue (arg0);
8924 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8925 return fold (build3 (code, type, tem,
8926 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
8929 /* Convert A ? 1 : 0 to simply A. */
8930 if (integer_onep (TREE_OPERAND (t, 1))
8931 && integer_zerop (TREE_OPERAND (t, 2))
8932 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8933 call to fold will try to move the conversion inside
8934 a COND, which will recurse. In that case, the COND_EXPR
8935 is probably the best choice, so leave it alone. */
8936 && type == TREE_TYPE (arg0))
8937 return pedantic_non_lvalue (arg0);
8939 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8940 over COND_EXPR in cases such as floating point comparisons. */
8941 if (integer_zerop (TREE_OPERAND (t, 1))
8942 && integer_onep (TREE_OPERAND (t, 2))
8943 && truth_value_p (TREE_CODE (arg0)))
8944 return pedantic_non_lvalue (fold_convert (type,
8945 invert_truthvalue (arg0)));
8947 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
8948 if (TREE_CODE (arg0) == LT_EXPR
8949 && integer_zerop (TREE_OPERAND (arg0, 1))
8950 && integer_zerop (TREE_OPERAND (t, 2))
8951 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
8952 return fold_convert (type, fold (build2 (BIT_AND_EXPR,
8953 TREE_TYPE (tem), tem, arg1)));
8955 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
8956 already handled above. */
8957 if (TREE_CODE (arg0) == BIT_AND_EXPR
8958 && integer_onep (TREE_OPERAND (arg0, 1))
8959 && integer_zerop (TREE_OPERAND (t, 2))
8960 && integer_pow2p (arg1))
8962 tree tem = TREE_OPERAND (arg0, 0);
8964 if (TREE_CODE (tem) == RSHIFT_EXPR
8965 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
8966 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
8967 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
8968 return fold (build2 (BIT_AND_EXPR, type,
8969 TREE_OPERAND (tem, 0), arg1));
8972 /* A & N ? N : 0 is simply A & N if N is a power of two. This
8973 is probably obsolete because the first operand should be a
8974 truth value (that's why we have the two cases above), but let's
8975 leave it in until we can confirm this for all front-ends. */
8976 if (integer_zerop (TREE_OPERAND (t, 2))
8977 && TREE_CODE (arg0) == NE_EXPR
8978 && integer_zerop (TREE_OPERAND (arg0, 1))
8979 && integer_pow2p (arg1)
8980 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
8981 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
8982 arg1, OEP_ONLY_CONST))
8983 return pedantic_non_lvalue (fold_convert (type,
8984 TREE_OPERAND (arg0, 0)));
8986 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8987 if (integer_zerop (TREE_OPERAND (t, 2))
8988 && truth_value_p (TREE_CODE (arg0))
8989 && truth_value_p (TREE_CODE (arg1)))
8990 return fold (build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1));
8992 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8993 if (integer_onep (TREE_OPERAND (t, 2))
8994 && truth_value_p (TREE_CODE (arg0))
8995 && truth_value_p (TREE_CODE (arg1)))
8997 /* Only perform transformation if ARG0 is easily inverted. */
8998 tem = invert_truthvalue (arg0);
8999 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9000 return fold (build2 (TRUTH_ORIF_EXPR, type, tem, arg1));
9003 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
9004 if (integer_zerop (arg1)
9005 && truth_value_p (TREE_CODE (arg0))
9006 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
9008 /* Only perform transformation if ARG0 is easily inverted. */
9009 tem = invert_truthvalue (arg0);
9010 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
9011 return fold (build2 (TRUTH_ANDIF_EXPR, type, tem,
9012 TREE_OPERAND (t, 2)));
9015 /* Convert A ? 1 : B into A || B if A and B are truth values. */
9016 if (integer_onep (arg1)
9017 && truth_value_p (TREE_CODE (arg0))
9018 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
9019 return fold (build2 (TRUTH_ORIF_EXPR, type, arg0,
9020 TREE_OPERAND (t, 2)));
9025 /* When pedantic, a compound expression can be neither an lvalue
9026 nor an integer constant expression. */
9027 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
9029 /* Don't let (0, 0) be null pointer constant. */
9030 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
9031 : fold_convert (type, arg1);
9032 return pedantic_non_lvalue (tem);
9036 return build_complex (type, arg0, arg1);
9040 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
9042 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
9043 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
9044 TREE_OPERAND (arg0, 1));
9045 else if (TREE_CODE (arg0) == COMPLEX_CST)
9046 return TREE_REALPART (arg0);
9047 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
9048 return fold (build2 (TREE_CODE (arg0), type,
9049 fold (build1 (REALPART_EXPR, type,
9050 TREE_OPERAND (arg0, 0))),
9051 fold (build1 (REALPART_EXPR, type,
9052 TREE_OPERAND (arg0, 1)))));
9056 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
9057 return fold_convert (type, integer_zero_node);
9058 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
9059 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
9060 TREE_OPERAND (arg0, 0));
9061 else if (TREE_CODE (arg0) == COMPLEX_CST)
9062 return TREE_IMAGPART (arg0);
9063 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
9064 return fold (build2 (TREE_CODE (arg0), type,
9065 fold (build1 (IMAGPART_EXPR, type,
9066 TREE_OPERAND (arg0, 0))),
9067 fold (build1 (IMAGPART_EXPR, type,
9068 TREE_OPERAND (arg0, 1)))));
9072 /* Check for a built-in function. */
9073 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
9074 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))
9076 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
9078 tree tmp = fold_builtin (t, false);
9086 } /* switch (code) */
9089 #ifdef ENABLE_FOLD_CHECKING
9092 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
9093 static void fold_check_failed (tree, tree);
9094 void print_fold_checksum (tree);
9096 /* When --enable-checking=fold, compute a digest of expr before
9097 and after actual fold call to see if fold did not accidentally
9098 change original expr. */
9105 unsigned char checksum_before[16], checksum_after[16];
9108 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9109 md5_init_ctx (&ctx);
9110 fold_checksum_tree (expr, &ctx, ht);
9111 md5_finish_ctx (&ctx, checksum_before);
9114 ret = fold_1 (expr);
9116 md5_init_ctx (&ctx);
9117 fold_checksum_tree (expr, &ctx, ht);
9118 md5_finish_ctx (&ctx, checksum_after);
9121 if (memcmp (checksum_before, checksum_after, 16))
9122 fold_check_failed (expr, ret);
9128 print_fold_checksum (tree expr)
9131 unsigned char checksum[16], cnt;
9134 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9135 md5_init_ctx (&ctx);
9136 fold_checksum_tree (expr, &ctx, ht);
9137 md5_finish_ctx (&ctx, checksum);
9139 for (cnt = 0; cnt < 16; ++cnt)
9140 fprintf (stderr, "%02x", checksum[cnt]);
9141 putc ('\n', stderr);
9145 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
9147 internal_error ("fold check: original tree changed by fold");
9151 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
9154 enum tree_code code;
9155 char buf[sizeof (struct tree_decl)];
9158 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
9159 <= sizeof (struct tree_decl))
9160 && sizeof (struct tree_type) <= sizeof (struct tree_decl));
9163 slot = htab_find_slot (ht, expr, INSERT);
9167 code = TREE_CODE (expr);
9168 if (TREE_CODE_CLASS (code) == tcc_declaration
9169 && DECL_ASSEMBLER_NAME_SET_P (expr))
9171 /* Allow DECL_ASSEMBLER_NAME to be modified. */
9172 memcpy (buf, expr, tree_size (expr));
9174 SET_DECL_ASSEMBLER_NAME (expr, NULL);
9176 else if (TREE_CODE_CLASS (code) == tcc_type
9177 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
9178 || TYPE_CACHED_VALUES_P (expr)))
9180 /* Allow these fields to be modified. */
9181 memcpy (buf, expr, tree_size (expr));
9183 TYPE_POINTER_TO (expr) = NULL;
9184 TYPE_REFERENCE_TO (expr) = NULL;
9185 TYPE_CACHED_VALUES_P (expr) = 0;
9186 TYPE_CACHED_VALUES (expr) = NULL;
9188 md5_process_bytes (expr, tree_size (expr), ctx);
9189 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
9190 if (TREE_CODE_CLASS (code) != tcc_type
9191 && TREE_CODE_CLASS (code) != tcc_declaration)
9192 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
9193 switch (TREE_CODE_CLASS (code))
9199 md5_process_bytes (TREE_STRING_POINTER (expr),
9200 TREE_STRING_LENGTH (expr), ctx);
9203 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
9204 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
9207 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
9213 case tcc_exceptional:
9217 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
9218 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
9221 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
9222 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
9228 case tcc_expression:
9230 case tcc_comparison:
9234 len = first_rtl_op (code);
9235 for (i = 0; i < len; ++i)
9236 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
9238 case tcc_declaration:
9239 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
9240 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
9241 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
9242 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
9243 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
9244 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
9245 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
9246 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
9247 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
9248 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
9249 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
9252 if (TREE_CODE (expr) == ENUMERAL_TYPE)
9253 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
9254 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
9255 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
9256 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
9257 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
9258 if (INTEGRAL_TYPE_P (expr)
9259 || SCALAR_FLOAT_TYPE_P (expr))
9261 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
9262 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
9264 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
9265 if (TREE_CODE (expr) == RECORD_TYPE
9266 || TREE_CODE (expr) == UNION_TYPE
9267 || TREE_CODE (expr) == QUAL_UNION_TYPE)
9268 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
9269 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
9278 /* Perform constant folding and related simplification of initializer
9279 expression EXPR. This behaves identically to "fold" but ignores
9280 potential run-time traps and exceptions that fold must preserve. */
9283 fold_initializer (tree expr)
9285 int saved_signaling_nans = flag_signaling_nans;
9286 int saved_trapping_math = flag_trapping_math;
9287 int saved_trapv = flag_trapv;
9290 flag_signaling_nans = 0;
9291 flag_trapping_math = 0;
9294 result = fold (expr);
9296 flag_signaling_nans = saved_signaling_nans;
9297 flag_trapping_math = saved_trapping_math;
9298 flag_trapv = saved_trapv;
9303 /* Determine if first argument is a multiple of second argument. Return 0 if
9304 it is not, or we cannot easily determined it to be.
9306 An example of the sort of thing we care about (at this point; this routine
9307 could surely be made more general, and expanded to do what the *_DIV_EXPR's
9308 fold cases do now) is discovering that
9310 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9316 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
9318 This code also handles discovering that
9320 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9322 is a multiple of 8 so we don't have to worry about dealing with a
9325 Note that we *look* inside a SAVE_EXPR only to determine how it was
9326 calculated; it is not safe for fold to do much of anything else with the
9327 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
9328 at run time. For example, the latter example above *cannot* be implemented
9329 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
9330 evaluation time of the original SAVE_EXPR is not necessarily the same at
9331 the time the new expression is evaluated. The only optimization of this
9332 sort that would be valid is changing
9334 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
9338 SAVE_EXPR (I) * SAVE_EXPR (J)
9340 (where the same SAVE_EXPR (J) is used in the original and the
9341 transformed version). */
9344 multiple_of_p (tree type, tree top, tree bottom)
9346 if (operand_equal_p (top, bottom, 0))
9349 if (TREE_CODE (type) != INTEGER_TYPE)
9352 switch (TREE_CODE (top))
9355 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9356 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9360 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9361 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9364 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
9368 op1 = TREE_OPERAND (top, 1);
9369 /* const_binop may not detect overflow correctly,
9370 so check for it explicitly here. */
9371 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
9372 > TREE_INT_CST_LOW (op1)
9373 && TREE_INT_CST_HIGH (op1) == 0
9374 && 0 != (t1 = fold_convert (type,
9375 const_binop (LSHIFT_EXPR,
9378 && ! TREE_OVERFLOW (t1))
9379 return multiple_of_p (type, t1, bottom);
9384 /* Can't handle conversions from non-integral or wider integral type. */
9385 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
9386 || (TYPE_PRECISION (type)
9387 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
9390 /* .. fall through ... */
9393 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
9396 if (TREE_CODE (bottom) != INTEGER_CST
9397 || (TYPE_UNSIGNED (type)
9398 && (tree_int_cst_sgn (top) < 0
9399 || tree_int_cst_sgn (bottom) < 0)))
9401 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
9409 /* Return true if `t' is known to be non-negative. */
9412 tree_expr_nonnegative_p (tree t)
9414 switch (TREE_CODE (t))
9420 return tree_int_cst_sgn (t) >= 0;
9423 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
9426 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9427 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9428 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9430 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
9431 both unsigned and at least 2 bits shorter than the result. */
9432 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9433 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9434 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9436 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9437 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9438 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9439 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9441 unsigned int prec = MAX (TYPE_PRECISION (inner1),
9442 TYPE_PRECISION (inner2)) + 1;
9443 return prec < TYPE_PRECISION (TREE_TYPE (t));
9449 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9451 /* x * x for floating point x is always non-negative. */
9452 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
9454 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9455 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9458 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
9459 both unsigned and their total bits is shorter than the result. */
9460 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9461 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9462 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9464 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9465 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9466 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9467 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9468 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
9469 < TYPE_PRECISION (TREE_TYPE (t));
9473 case TRUNC_DIV_EXPR:
9475 case FLOOR_DIV_EXPR:
9476 case ROUND_DIV_EXPR:
9477 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9478 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9480 case TRUNC_MOD_EXPR:
9482 case FLOOR_MOD_EXPR:
9483 case ROUND_MOD_EXPR:
9484 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9487 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9488 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9491 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9492 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9495 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9496 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9500 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9501 tree outer_type = TREE_TYPE (t);
9503 if (TREE_CODE (outer_type) == REAL_TYPE)
9505 if (TREE_CODE (inner_type) == REAL_TYPE)
9506 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9507 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9509 if (TYPE_UNSIGNED (inner_type))
9511 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9514 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
9516 if (TREE_CODE (inner_type) == REAL_TYPE)
9517 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
9518 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9519 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
9520 && TYPE_UNSIGNED (inner_type);
9526 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9527 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
9529 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9531 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9532 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9534 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9535 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9537 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9539 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
9541 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9542 case NON_LVALUE_EXPR:
9543 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9545 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9549 tree temp = TARGET_EXPR_SLOT (t);
9550 t = TARGET_EXPR_INITIAL (t);
9552 /* If the initializer is non-void, then it's a normal expression
9553 that will be assigned to the slot. */
9554 if (!VOID_TYPE_P (t))
9555 return tree_expr_nonnegative_p (t);
9557 /* Otherwise, the initializer sets the slot in some way. One common
9558 way is an assignment statement at the end of the initializer. */
9561 if (TREE_CODE (t) == BIND_EXPR)
9562 t = expr_last (BIND_EXPR_BODY (t));
9563 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
9564 || TREE_CODE (t) == TRY_CATCH_EXPR)
9565 t = expr_last (TREE_OPERAND (t, 0));
9566 else if (TREE_CODE (t) == STATEMENT_LIST)
9571 if (TREE_CODE (t) == MODIFY_EXPR
9572 && TREE_OPERAND (t, 0) == temp)
9573 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9580 tree fndecl = get_callee_fndecl (t);
9581 tree arglist = TREE_OPERAND (t, 1);
9583 && DECL_BUILT_IN (fndecl)
9584 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
9585 switch (DECL_FUNCTION_CODE (fndecl))
9587 #define CASE_BUILTIN_F(BUILT_IN_FN) \
9588 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
9589 #define CASE_BUILTIN_I(BUILT_IN_FN) \
9590 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
9592 CASE_BUILTIN_F (BUILT_IN_ACOS)
9593 CASE_BUILTIN_F (BUILT_IN_ACOSH)
9594 CASE_BUILTIN_F (BUILT_IN_CABS)
9595 CASE_BUILTIN_F (BUILT_IN_COSH)
9596 CASE_BUILTIN_F (BUILT_IN_ERFC)
9597 CASE_BUILTIN_F (BUILT_IN_EXP)
9598 CASE_BUILTIN_F (BUILT_IN_EXP10)
9599 CASE_BUILTIN_F (BUILT_IN_EXP2)
9600 CASE_BUILTIN_F (BUILT_IN_FABS)
9601 CASE_BUILTIN_F (BUILT_IN_FDIM)
9602 CASE_BUILTIN_F (BUILT_IN_FREXP)
9603 CASE_BUILTIN_F (BUILT_IN_HYPOT)
9604 CASE_BUILTIN_F (BUILT_IN_POW10)
9605 CASE_BUILTIN_I (BUILT_IN_FFS)
9606 CASE_BUILTIN_I (BUILT_IN_PARITY)
9607 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
9611 CASE_BUILTIN_F (BUILT_IN_SQRT)
9612 /* sqrt(-0.0) is -0.0. */
9613 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
9615 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9617 CASE_BUILTIN_F (BUILT_IN_ASINH)
9618 CASE_BUILTIN_F (BUILT_IN_ATAN)
9619 CASE_BUILTIN_F (BUILT_IN_ATANH)
9620 CASE_BUILTIN_F (BUILT_IN_CBRT)
9621 CASE_BUILTIN_F (BUILT_IN_CEIL)
9622 CASE_BUILTIN_F (BUILT_IN_ERF)
9623 CASE_BUILTIN_F (BUILT_IN_EXPM1)
9624 CASE_BUILTIN_F (BUILT_IN_FLOOR)
9625 CASE_BUILTIN_F (BUILT_IN_FMOD)
9626 CASE_BUILTIN_F (BUILT_IN_LDEXP)
9627 CASE_BUILTIN_F (BUILT_IN_LLRINT)
9628 CASE_BUILTIN_F (BUILT_IN_LLROUND)
9629 CASE_BUILTIN_F (BUILT_IN_LRINT)
9630 CASE_BUILTIN_F (BUILT_IN_LROUND)
9631 CASE_BUILTIN_F (BUILT_IN_MODF)
9632 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
9633 CASE_BUILTIN_F (BUILT_IN_POW)
9634 CASE_BUILTIN_F (BUILT_IN_RINT)
9635 CASE_BUILTIN_F (BUILT_IN_ROUND)
9636 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
9637 CASE_BUILTIN_F (BUILT_IN_SINH)
9638 CASE_BUILTIN_F (BUILT_IN_TANH)
9639 CASE_BUILTIN_F (BUILT_IN_TRUNC)
9640 /* True if the 1st argument is nonnegative. */
9641 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9643 CASE_BUILTIN_F (BUILT_IN_FMAX)
9644 /* True if the 1st OR 2nd arguments are nonnegative. */
9645 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9646 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9648 CASE_BUILTIN_F (BUILT_IN_FMIN)
9649 /* True if the 1st AND 2nd arguments are nonnegative. */
9650 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9651 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9653 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
9654 /* True if the 2nd argument is nonnegative. */
9655 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9659 #undef CASE_BUILTIN_F
9660 #undef CASE_BUILTIN_I
9664 /* ... fall through ... */
9667 if (truth_value_p (TREE_CODE (t)))
9668 /* Truth values evaluate to 0 or 1, which is nonnegative. */
9672 /* We don't know sign of `t', so be conservative and return false. */
9676 /* Return true when T is an address and is known to be nonzero.
9677 For floating point we further ensure that T is not denormal.
9678 Similar logic is present in nonzero_address in rtlanal.h. */
9681 tree_expr_nonzero_p (tree t)
9683 tree type = TREE_TYPE (t);
9685 /* Doing something useful for floating point would need more work. */
9686 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
9689 switch (TREE_CODE (t))
9692 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9693 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9696 /* We used to test for !integer_zerop here. This does not work correctly
9697 if TREE_CONSTANT_OVERFLOW (t). */
9698 return (TREE_INT_CST_LOW (t) != 0
9699 || TREE_INT_CST_HIGH (t) != 0);
9702 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9704 /* With the presence of negative values it is hard
9705 to say something. */
9706 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9707 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9709 /* One of operands must be positive and the other non-negative. */
9710 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9711 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9716 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9718 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9719 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9725 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9726 tree outer_type = TREE_TYPE (t);
9728 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
9729 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
9735 tree base = get_base_address (TREE_OPERAND (t, 0));
9740 /* Weak declarations may link to NULL. */
9742 return !DECL_WEAK (base);
9744 /* Constants are never weak. */
9745 if (CONSTANT_CLASS_P (base))
9752 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9753 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
9756 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9757 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9760 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
9762 /* When both operands are nonzero, then MAX must be too. */
9763 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
9766 /* MAX where operand 0 is positive is positive. */
9767 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9769 /* MAX where operand 1 is positive is positive. */
9770 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9771 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9778 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
9781 case NON_LVALUE_EXPR:
9782 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9785 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9786 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9794 /* See if we are applying CODE, a relational to the highest or lowest
9795 possible integer of TYPE. If so, then the result is a compile
9799 fold_relational_hi_lo (enum tree_code *code_p, const tree type, tree *op0_p,
9804 enum tree_code code = *code_p;
9805 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (op1)));
9807 if (TREE_CODE (op1) == INTEGER_CST
9808 && ! TREE_CONSTANT_OVERFLOW (op1)
9809 && width <= HOST_BITS_PER_WIDE_INT
9810 && (INTEGRAL_TYPE_P (TREE_TYPE (op1))
9811 || POINTER_TYPE_P (TREE_TYPE (op1))))
9813 unsigned HOST_WIDE_INT signed_max;
9814 unsigned HOST_WIDE_INT max, min;
9816 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
9818 if (TYPE_UNSIGNED (TREE_TYPE (op1)))
9820 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9826 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9829 if (TREE_INT_CST_HIGH (op1) == 0
9830 && TREE_INT_CST_LOW (op1) == max)
9834 return omit_one_operand (type, integer_zero_node, op0);
9840 return omit_one_operand (type, integer_one_node, op0);
9846 /* The GE_EXPR and LT_EXPR cases above are not normally
9847 reached because of previous transformations. */
9852 else if (TREE_INT_CST_HIGH (op1) == 0
9853 && TREE_INT_CST_LOW (op1) == max - 1)
9858 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9862 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9867 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9868 && TREE_INT_CST_LOW (op1) == min)
9872 return omit_one_operand (type, integer_zero_node, op0);
9879 return omit_one_operand (type, integer_one_node, op0);
9888 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9889 && TREE_INT_CST_LOW (op1) == min + 1)
9894 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9898 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9904 else if (TREE_INT_CST_HIGH (op1) == 0
9905 && TREE_INT_CST_LOW (op1) == signed_max
9906 && TYPE_UNSIGNED (TREE_TYPE (op1))
9907 /* signed_type does not work on pointer types. */
9908 && INTEGRAL_TYPE_P (TREE_TYPE (op1)))
9910 /* The following case also applies to X < signed_max+1
9911 and X >= signed_max+1 because previous transformations. */
9912 if (code == LE_EXPR || code == GT_EXPR)
9914 tree st0, st1, exp, retval;
9915 st0 = lang_hooks.types.signed_type (TREE_TYPE (op0));
9916 st1 = lang_hooks.types.signed_type (TREE_TYPE (op1));
9918 exp = build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
9920 fold_convert (st0, op0),
9921 fold_convert (st1, integer_zero_node));
9924 = nondestructive_fold_binary_to_constant (TREE_CODE (exp),
9926 TREE_OPERAND (exp, 0),
9927 TREE_OPERAND (exp, 1));
9929 /* If we are in gimple form, then returning EXP would create
9930 non-gimple expressions. Clearing it is safe and insures
9931 we do not allow a non-gimple expression to escape. */
9935 return (retval ? retval : exp);
9944 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
9945 attempt to fold the expression to a constant without modifying TYPE,
9948 If the expression could be simplified to a constant, then return
9949 the constant. If the expression would not be simplified to a
9950 constant, then return NULL_TREE.
9952 Note this is primarily designed to be called after gimplification
9953 of the tree structures and when at least one operand is a constant.
9954 As a result of those simplifying assumptions this routine is far
9955 simpler than the generic fold routine. */
9958 nondestructive_fold_binary_to_constant (enum tree_code code, tree type,
9966 /* If this is a commutative operation, and ARG0 is a constant, move it
9967 to ARG1 to reduce the number of tests below. */
9968 if (commutative_tree_code (code)
9969 && (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST))
9976 /* If either operand is a complex type, extract its real component. */
9977 if (TREE_CODE (op0) == COMPLEX_CST)
9978 subop0 = TREE_REALPART (op0);
9982 if (TREE_CODE (op1) == COMPLEX_CST)
9983 subop1 = TREE_REALPART (op1);
9987 /* Note if either argument is not a real or integer constant.
9988 With a few exceptions, simplification is limited to cases
9989 where both arguments are constants. */
9990 if ((TREE_CODE (subop0) != INTEGER_CST
9991 && TREE_CODE (subop0) != REAL_CST)
9992 || (TREE_CODE (subop1) != INTEGER_CST
9993 && TREE_CODE (subop1) != REAL_CST))
9999 /* (plus (address) (const_int)) is a constant. */
10000 if (TREE_CODE (op0) == PLUS_EXPR
10001 && TREE_CODE (op1) == INTEGER_CST
10002 && (TREE_CODE (TREE_OPERAND (op0, 0)) == ADDR_EXPR
10003 || (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
10004 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (op0, 0), 0))
10006 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
10008 return build2 (PLUS_EXPR, type, TREE_OPERAND (op0, 0),
10009 const_binop (PLUS_EXPR, op1,
10010 TREE_OPERAND (op0, 1), 0));
10018 /* Both arguments are constants. Simplify. */
10019 tem = const_binop (code, op0, op1, 0);
10020 if (tem != NULL_TREE)
10022 /* The return value should always have the same type as
10023 the original expression. */
10024 if (TREE_TYPE (tem) != type)
10025 tem = fold_convert (type, tem);
10032 /* Fold &x - &x. This can happen from &x.foo - &x.
10033 This is unsafe for certain floats even in non-IEEE formats.
10034 In IEEE, it is unsafe because it does wrong for NaNs.
10035 Also note that operand_equal_p is always false if an
10036 operand is volatile. */
10037 if (! FLOAT_TYPE_P (type) && operand_equal_p (op0, op1, 0))
10038 return fold_convert (type, integer_zero_node);
10044 /* Special case multiplication or bitwise AND where one argument
10046 if (! FLOAT_TYPE_P (type) && integer_zerop (op1))
10047 return omit_one_operand (type, op1, op0);
10049 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (op0)))
10050 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op0)))
10051 && real_zerop (op1))
10052 return omit_one_operand (type, op1, op0);
10057 /* Special case when we know the result will be all ones. */
10058 if (integer_all_onesp (op1))
10059 return omit_one_operand (type, op1, op0);
10063 case TRUNC_DIV_EXPR:
10064 case ROUND_DIV_EXPR:
10065 case FLOOR_DIV_EXPR:
10066 case CEIL_DIV_EXPR:
10067 case EXACT_DIV_EXPR:
10068 case TRUNC_MOD_EXPR:
10069 case ROUND_MOD_EXPR:
10070 case FLOOR_MOD_EXPR:
10071 case CEIL_MOD_EXPR:
10073 /* Division by zero is undefined. */
10074 if (integer_zerop (op1))
10077 if (TREE_CODE (op1) == REAL_CST
10078 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (op1)))
10079 && real_zerop (op1))
10085 if (INTEGRAL_TYPE_P (type)
10086 && operand_equal_p (op1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
10087 return omit_one_operand (type, op1, op0);
10092 if (INTEGRAL_TYPE_P (type)
10093 && TYPE_MAX_VALUE (type)
10094 && operand_equal_p (op1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
10095 return omit_one_operand (type, op1, op0);
10100 /* Optimize -1 >> x for arithmetic right shifts. */
10101 if (integer_all_onesp (op0) && ! TYPE_UNSIGNED (type))
10102 return omit_one_operand (type, op0, op1);
10103 /* ... fall through ... */
10106 if (integer_zerop (op0))
10107 return omit_one_operand (type, op0, op1);
10109 /* Since negative shift count is not well-defined, don't
10110 try to compute it in the compiler. */
10111 if (TREE_CODE (op1) == INTEGER_CST && tree_int_cst_sgn (op1) < 0)
10118 /* -1 rotated either direction by any amount is still -1. */
10119 if (integer_all_onesp (op0))
10120 return omit_one_operand (type, op0, op1);
10122 /* 0 rotated either direction by any amount is still zero. */
10123 if (integer_zerop (op0))
10124 return omit_one_operand (type, op0, op1);
10130 return build_complex (type, op0, op1);
10139 /* If one arg is a real or integer constant, put it last. */
10140 if ((TREE_CODE (op0) == INTEGER_CST
10141 && TREE_CODE (op1) != INTEGER_CST)
10142 || (TREE_CODE (op0) == REAL_CST
10143 && TREE_CODE (op0) != REAL_CST))
10150 code = swap_tree_comparison (code);
10153 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
10154 This transformation affects the cases which are handled in later
10155 optimizations involving comparisons with non-negative constants. */
10156 if (TREE_CODE (op1) == INTEGER_CST
10157 && TREE_CODE (op0) != INTEGER_CST
10158 && tree_int_cst_sgn (op1) > 0)
10164 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10169 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10177 tem = fold_relational_hi_lo (&code, type, &op0, &op1);
10181 /* Fall through. */
10184 case UNORDERED_EXPR:
10194 return fold_relational_const (code, type, op0, op1);
10197 /* This could probably be handled. */
10200 case TRUTH_AND_EXPR:
10201 /* If second arg is constant zero, result is zero, but first arg
10202 must be evaluated. */
10203 if (integer_zerop (op1))
10204 return omit_one_operand (type, op1, op0);
10205 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10206 case will be handled here. */
10207 if (integer_zerop (op0))
10208 return omit_one_operand (type, op0, op1);
10209 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10210 return constant_boolean_node (true, type);
10213 case TRUTH_OR_EXPR:
10214 /* If second arg is constant true, result is true, but we must
10215 evaluate first arg. */
10216 if (TREE_CODE (op1) == INTEGER_CST && ! integer_zerop (op1))
10217 return omit_one_operand (type, op1, op0);
10218 /* Likewise for first arg, but note this only occurs here for
10220 if (TREE_CODE (op0) == INTEGER_CST && ! integer_zerop (op0))
10221 return omit_one_operand (type, op0, op1);
10222 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10223 return constant_boolean_node (false, type);
10226 case TRUTH_XOR_EXPR:
10227 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10229 int x = ! integer_zerop (op0) ^ ! integer_zerop (op1);
10230 return constant_boolean_node (x, type);
10239 /* Given the components of a unary expression CODE, TYPE and OP0,
10240 attempt to fold the expression to a constant without modifying
10243 If the expression could be simplified to a constant, then return
10244 the constant. If the expression would not be simplified to a
10245 constant, then return NULL_TREE.
10247 Note this is primarily designed to be called after gimplification
10248 of the tree structures and when op0 is a constant. As a result
10249 of those simplifying assumptions this routine is far simpler than
10250 the generic fold routine. */
10253 nondestructive_fold_unary_to_constant (enum tree_code code, tree type,
10256 /* Make sure we have a suitable constant argument. */
10257 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
10261 if (TREE_CODE (op0) == COMPLEX_CST)
10262 subop = TREE_REALPART (op0);
10266 if (TREE_CODE (subop) != INTEGER_CST && TREE_CODE (subop) != REAL_CST)
10275 case FIX_TRUNC_EXPR:
10276 case FIX_FLOOR_EXPR:
10277 case FIX_CEIL_EXPR:
10278 return fold_convert_const (code, type, op0);
10281 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10282 return fold_negate_const (op0, type);
10287 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10288 return fold_abs_const (op0, type);
10293 if (TREE_CODE (op0) == INTEGER_CST)
10294 return fold_not_const (op0, type);
10298 case REALPART_EXPR:
10299 if (TREE_CODE (op0) == COMPLEX_CST)
10300 return TREE_REALPART (op0);
10304 case IMAGPART_EXPR:
10305 if (TREE_CODE (op0) == COMPLEX_CST)
10306 return TREE_IMAGPART (op0);
10311 if (TREE_CODE (op0) == COMPLEX_CST
10312 && TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
10313 return build_complex (type, TREE_REALPART (op0),
10314 negate_expr (TREE_IMAGPART (op0)));
10322 /* If EXP represents referencing an element in a constant string
10323 (either via pointer arithmetic or array indexing), return the
10324 tree representing the value accessed, otherwise return NULL. */
10327 fold_read_from_constant_string (tree exp)
10329 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
10331 tree exp1 = TREE_OPERAND (exp, 0);
10335 if (TREE_CODE (exp) == INDIRECT_REF)
10336 string = string_constant (exp1, &index);
10339 tree low_bound = array_ref_low_bound (exp);
10340 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
10342 /* Optimize the special-case of a zero lower bound.
10344 We convert the low_bound to sizetype to avoid some problems
10345 with constant folding. (E.g. suppose the lower bound is 1,
10346 and its mode is QI. Without the conversion,l (ARRAY
10347 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
10348 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
10349 if (! integer_zerop (low_bound))
10350 index = size_diffop (index, fold_convert (sizetype, low_bound));
10356 && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
10357 && TREE_CODE (string) == STRING_CST
10358 && TREE_CODE (index) == INTEGER_CST
10359 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
10360 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
10362 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
10363 return fold_convert (TREE_TYPE (exp),
10364 build_int_cst (NULL_TREE,
10365 (TREE_STRING_POINTER (string)
10366 [TREE_INT_CST_LOW (index)])));
10371 /* Return the tree for neg (ARG0) when ARG0 is known to be either
10372 an integer constant or real constant.
10374 TYPE is the type of the result. */
10377 fold_negate_const (tree arg0, tree type)
10379 tree t = NULL_TREE;
10381 switch (TREE_CODE (arg0))
10385 unsigned HOST_WIDE_INT low;
10386 HOST_WIDE_INT high;
10387 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10388 TREE_INT_CST_HIGH (arg0),
10390 t = build_int_cst_wide (type, low, high);
10391 t = force_fit_type (t, 1,
10392 (overflow | TREE_OVERFLOW (arg0))
10393 && !TYPE_UNSIGNED (type),
10394 TREE_CONSTANT_OVERFLOW (arg0));
10399 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10403 gcc_unreachable ();
10409 /* Return the tree for abs (ARG0) when ARG0 is known to be either
10410 an integer constant or real constant.
10412 TYPE is the type of the result. */
10415 fold_abs_const (tree arg0, tree type)
10417 tree t = NULL_TREE;
10419 switch (TREE_CODE (arg0))
10422 /* If the value is unsigned, then the absolute value is
10423 the same as the ordinary value. */
10424 if (TYPE_UNSIGNED (type))
10426 /* Similarly, if the value is non-negative. */
10427 else if (INT_CST_LT (integer_minus_one_node, arg0))
10429 /* If the value is negative, then the absolute value is
10433 unsigned HOST_WIDE_INT low;
10434 HOST_WIDE_INT high;
10435 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10436 TREE_INT_CST_HIGH (arg0),
10438 t = build_int_cst_wide (type, low, high);
10439 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
10440 TREE_CONSTANT_OVERFLOW (arg0));
10445 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
10446 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10452 gcc_unreachable ();
10458 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
10459 constant. TYPE is the type of the result. */
10462 fold_not_const (tree arg0, tree type)
10464 tree t = NULL_TREE;
10466 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
10468 t = build_int_cst_wide (type,
10469 ~ TREE_INT_CST_LOW (arg0),
10470 ~ TREE_INT_CST_HIGH (arg0));
10471 t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
10472 TREE_CONSTANT_OVERFLOW (arg0));
10477 /* Given CODE, a relational operator, the target type, TYPE and two
10478 constant operands OP0 and OP1, return the result of the
10479 relational operation. If the result is not a compile time
10480 constant, then return NULL_TREE. */
10483 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
10485 int result, invert;
10487 /* From here on, the only cases we handle are when the result is
10488 known to be a constant. */
10490 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
10492 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
10493 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
10495 /* Handle the cases where either operand is a NaN. */
10496 if (real_isnan (c0) || real_isnan (c1))
10506 case UNORDERED_EXPR:
10520 if (flag_trapping_math)
10526 gcc_unreachable ();
10529 return constant_boolean_node (result, type);
10532 return constant_boolean_node (real_compare (code, c0, c1), type);
10535 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
10537 To compute GT, swap the arguments and do LT.
10538 To compute GE, do LT and invert the result.
10539 To compute LE, swap the arguments, do LT and invert the result.
10540 To compute NE, do EQ and invert the result.
10542 Therefore, the code below must handle only EQ and LT. */
10544 if (code == LE_EXPR || code == GT_EXPR)
10549 code = swap_tree_comparison (code);
10552 /* Note that it is safe to invert for real values here because we
10553 have already handled the one case that it matters. */
10556 if (code == NE_EXPR || code == GE_EXPR)
10559 code = invert_tree_comparison (code, false);
10562 /* Compute a result for LT or EQ if args permit;
10563 Otherwise return T. */
10564 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10566 if (code == EQ_EXPR)
10567 result = tree_int_cst_equal (op0, op1);
10568 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
10569 result = INT_CST_LT_UNSIGNED (op0, op1);
10571 result = INT_CST_LT (op0, op1);
10578 return constant_boolean_node (result, type);
10581 /* Build an expression for the a clean point containing EXPR with type TYPE.
10582 Don't build a cleanup point expression for EXPR which don't have side
10586 fold_build_cleanup_point_expr (tree type, tree expr)
10588 /* If the expression does not have side effects then we don't have to wrap
10589 it with a cleanup point expression. */
10590 if (!TREE_SIDE_EFFECTS (expr))
10593 return build1 (CLEANUP_POINT_EXPR, type, expr);
10596 /* Build an expression for the address of T. Folds away INDIRECT_REF to
10597 avoid confusing the gimplify process. */
10600 build_fold_addr_expr_with_type (tree t, tree ptrtype)
10602 /* The size of the object is not relevant when talking about its address. */
10603 if (TREE_CODE (t) == WITH_SIZE_EXPR)
10604 t = TREE_OPERAND (t, 0);
10606 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
10607 if (TREE_CODE (t) == INDIRECT_REF
10608 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
10610 t = TREE_OPERAND (t, 0);
10611 if (TREE_TYPE (t) != ptrtype)
10612 t = build1 (NOP_EXPR, ptrtype, t);
10618 while (handled_component_p (base)
10619 || TREE_CODE (base) == REALPART_EXPR
10620 || TREE_CODE (base) == IMAGPART_EXPR)
10621 base = TREE_OPERAND (base, 0);
10623 TREE_ADDRESSABLE (base) = 1;
10625 t = build1 (ADDR_EXPR, ptrtype, t);
10632 build_fold_addr_expr (tree t)
10634 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
10637 /* Builds an expression for an indirection through T, simplifying some
10641 build_fold_indirect_ref (tree t)
10643 tree type = TREE_TYPE (TREE_TYPE (t));
10648 if (TREE_CODE (sub) == ADDR_EXPR)
10650 tree op = TREE_OPERAND (sub, 0);
10651 tree optype = TREE_TYPE (op);
10653 if (lang_hooks.types_compatible_p (type, optype))
10655 /* *(foo *)&fooarray => fooarray[0] */
10656 else if (TREE_CODE (optype) == ARRAY_TYPE
10657 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
10658 return build4 (ARRAY_REF, type, op, size_zero_node, NULL_TREE, NULL_TREE);
10661 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
10662 subtype = TREE_TYPE (sub);
10663 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
10664 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
10666 sub = build_fold_indirect_ref (sub);
10667 return build4 (ARRAY_REF, type, sub, size_zero_node, NULL_TREE, NULL_TREE);
10670 return build1 (INDIRECT_REF, type, t);
10673 /* Strip non-trapping, non-side-effecting tree nodes from an expression
10674 whose result is ignored. The type of the returned tree need not be
10675 the same as the original expression. */
10678 fold_ignored_result (tree t)
10680 if (!TREE_SIDE_EFFECTS (t))
10681 return integer_zero_node;
10684 switch (TREE_CODE_CLASS (TREE_CODE (t)))
10687 t = TREE_OPERAND (t, 0);
10691 case tcc_comparison:
10692 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
10693 t = TREE_OPERAND (t, 0);
10694 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
10695 t = TREE_OPERAND (t, 1);
10700 case tcc_expression:
10701 switch (TREE_CODE (t))
10703 case COMPOUND_EXPR:
10704 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
10706 t = TREE_OPERAND (t, 0);
10710 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
10711 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
10713 t = TREE_OPERAND (t, 0);
10726 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
10727 This can only be applied to objects of a sizetype. */
10730 round_up (tree value, int divisor)
10732 tree div = NULL_TREE;
10734 gcc_assert (divisor > 0);
10738 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
10739 have to do anything. Only do this when we are not given a const,
10740 because in that case, this check is more expensive than just
10742 if (TREE_CODE (value) != INTEGER_CST)
10744 div = build_int_cst (TREE_TYPE (value), divisor);
10746 if (multiple_of_p (TREE_TYPE (value), value, div))
10750 /* If divisor is a power of two, simplify this to bit manipulation. */
10751 if (divisor == (divisor & -divisor))
10755 t = build_int_cst (TREE_TYPE (value), divisor - 1);
10756 value = size_binop (PLUS_EXPR, value, t);
10757 t = build_int_cst (TREE_TYPE (value), -divisor);
10758 value = size_binop (BIT_AND_EXPR, value, t);
10763 div = build_int_cst (TREE_TYPE (value), divisor);
10764 value = size_binop (CEIL_DIV_EXPR, value, div);
10765 value = size_binop (MULT_EXPR, value, div);
10771 /* Likewise, but round down. */
10774 round_down (tree value, int divisor)
10776 tree div = NULL_TREE;
10778 gcc_assert (divisor > 0);
10782 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
10783 have to do anything. Only do this when we are not given a const,
10784 because in that case, this check is more expensive than just
10786 if (TREE_CODE (value) != INTEGER_CST)
10788 div = build_int_cst (TREE_TYPE (value), divisor);
10790 if (multiple_of_p (TREE_TYPE (value), value, div))
10794 /* If divisor is a power of two, simplify this to bit manipulation. */
10795 if (divisor == (divisor & -divisor))
10799 t = build_int_cst (TREE_TYPE (value), -divisor);
10800 value = size_binop (BIT_AND_EXPR, value, t);
10805 div = build_int_cst (TREE_TYPE (value), divisor);
10806 value = size_binop (FLOOR_DIV_EXPR, value, div);
10807 value = size_binop (MULT_EXPR, value, div);
10813 /* Returns true if addresses of E1 and E2 differ by a constant, false
10814 otherwise. If they do, &E1 - &E2 is stored in *DIFF. */
10817 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
10820 HOST_WIDE_INT bitsize1, bitsize2;
10821 HOST_WIDE_INT bitpos1, bitpos2;
10822 tree toffset1, toffset2, tdiff, type;
10823 enum machine_mode mode1, mode2;
10824 int unsignedp1, unsignedp2, volatilep1, volatilep2;
10826 core1 = get_inner_reference (e1, &bitsize1, &bitpos1, &toffset1, &mode1,
10827 &unsignedp1, &volatilep1);
10828 core2 = get_inner_reference (e2, &bitsize2, &bitpos2, &toffset2, &mode2,
10829 &unsignedp2, &volatilep2);
10831 if (bitpos1 % BITS_PER_UNIT != 0
10832 || bitpos2 % BITS_PER_UNIT != 0
10833 || !operand_equal_p (core1, core2, 0))
10836 if (toffset1 && toffset2)
10838 type = TREE_TYPE (toffset1);
10839 if (type != TREE_TYPE (toffset2))
10840 toffset2 = fold_convert (type, toffset2);
10842 tdiff = fold (build2 (MINUS_EXPR, type, toffset1, toffset2));
10843 if (!host_integerp (tdiff, 0))
10846 *diff = tree_low_cst (tdiff, 0);
10848 else if (toffset1 || toffset2)
10850 /* If only one of the offsets is non-constant, the difference cannot
10857 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;