1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
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
31 and force_fit_type_double.
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_double takes a constant, an overflowable flag and a
43 prior overflow indicator. It forces the value to fit the type and
46 Note: Since the folders get called on non-gimple code as well as
47 gimple code, we need to handle GIMPLE tuples as well as their
48 corresponding tree equivalents. */
52 #include "coretypes.h"
57 #include "fixed-value.h"
66 #include "langhooks.h"
69 /* Nonzero if we are folding constants inside an initializer; zero
71 int folding_initializer = 0;
73 /* The following constants represent a bit based encoding of GCC's
74 comparison operators. This encoding simplifies transformations
75 on relational comparison operators, such as AND and OR. */
76 enum comparison_code {
95 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
96 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
97 static bool negate_mathfn_p (enum built_in_function);
98 static bool negate_expr_p (tree);
99 static tree negate_expr (tree);
100 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
101 static tree associate_trees (tree, tree, enum tree_code, tree);
102 static tree const_binop (enum tree_code, tree, tree, int);
103 static enum comparison_code comparison_to_compcode (enum tree_code);
104 static enum tree_code compcode_to_comparison (enum comparison_code);
105 static tree combine_comparisons (enum tree_code, enum tree_code,
106 enum tree_code, tree, tree, tree);
107 static int truth_value_p (enum tree_code);
108 static int operand_equal_for_comparison_p (tree, tree, tree);
109 static int twoval_comparison_p (tree, tree *, tree *, int *);
110 static tree eval_subst (tree, tree, tree, tree, tree);
111 static tree pedantic_omit_one_operand (tree, tree, tree);
112 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
113 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
114 enum machine_mode *, int *, int *,
116 static tree sign_bit_p (tree, const_tree);
117 static int simple_operand_p (const_tree);
118 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
119 static tree range_predecessor (tree);
120 static tree range_successor (tree);
121 static tree make_range (tree, int *, tree *, tree *, bool *);
122 static tree build_range_check (tree, tree, int, tree, tree);
123 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
125 static tree fold_range_test (enum tree_code, tree, tree, tree);
126 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
127 static tree unextend (tree, int, int, tree);
128 static tree fold_truthop (enum tree_code, tree, tree, tree);
129 static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
130 static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
131 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
132 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
135 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
137 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
138 static tree fold_div_compare (enum tree_code, tree, tree, tree);
139 static bool reorder_operands_p (const_tree, const_tree);
140 static tree fold_negate_const (tree, tree);
141 static tree fold_not_const (tree, tree);
142 static tree fold_relational_const (enum tree_code, tree, tree, tree);
145 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
146 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
147 and SUM1. Then this yields nonzero if overflow occurred during the
150 Overflow occurs if A and B have the same sign, but A and SUM differ in
151 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
153 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
155 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
156 We do that by representing the two-word integer in 4 words, with only
157 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
158 number. The value of the word is LOWPART + HIGHPART * BASE. */
161 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
162 #define HIGHPART(x) \
163 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
164 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
166 /* Unpack a two-word integer into 4 words.
167 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
168 WORDS points to the array of HOST_WIDE_INTs. */
171 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
173 words[0] = LOWPART (low);
174 words[1] = HIGHPART (low);
175 words[2] = LOWPART (hi);
176 words[3] = HIGHPART (hi);
179 /* Pack an array of 4 words into a two-word integer.
180 WORDS points to the array of words.
181 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
184 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
187 *low = words[0] + words[1] * BASE;
188 *hi = words[2] + words[3] * BASE;
191 /* Force the double-word integer L1, H1 to be within the range of the
192 integer type TYPE. Stores the properly truncated and sign-extended
193 double-word integer in *LV, *HV. Returns true if the operation
194 overflows, that is, argument and result are different. */
197 fit_double_type (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
198 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, const_tree type)
200 unsigned HOST_WIDE_INT low0 = l1;
201 HOST_WIDE_INT high0 = h1;
203 int sign_extended_type;
205 if (POINTER_TYPE_P (type)
206 || TREE_CODE (type) == OFFSET_TYPE)
209 prec = TYPE_PRECISION (type);
211 /* Size types *are* sign extended. */
212 sign_extended_type = (!TYPE_UNSIGNED (type)
213 || (TREE_CODE (type) == INTEGER_TYPE
214 && TYPE_IS_SIZETYPE (type)));
216 /* First clear all bits that are beyond the type's precision. */
217 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
219 else if (prec > HOST_BITS_PER_WIDE_INT)
220 h1 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
224 if (prec < HOST_BITS_PER_WIDE_INT)
225 l1 &= ~((HOST_WIDE_INT) (-1) << prec);
228 /* Then do sign extension if necessary. */
229 if (!sign_extended_type)
230 /* No sign extension */;
231 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
232 /* Correct width already. */;
233 else if (prec > HOST_BITS_PER_WIDE_INT)
235 /* Sign extend top half? */
236 if (h1 & ((unsigned HOST_WIDE_INT)1
237 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
238 h1 |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
240 else if (prec == HOST_BITS_PER_WIDE_INT)
242 if ((HOST_WIDE_INT)l1 < 0)
247 /* Sign extend bottom half? */
248 if (l1 & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
251 l1 |= (HOST_WIDE_INT)(-1) << prec;
258 /* If the value didn't fit, signal overflow. */
259 return l1 != low0 || h1 != high0;
262 /* We force the double-int HIGH:LOW to the range of the type TYPE by
263 sign or zero extending it.
264 OVERFLOWABLE indicates if we are interested
265 in overflow of the value, when >0 we are only interested in signed
266 overflow, for <0 we are interested in any overflow. OVERFLOWED
267 indicates whether overflow has already occurred. CONST_OVERFLOWED
268 indicates whether constant overflow has already occurred. We force
269 T's value to be within range of T's type (by setting to 0 or 1 all
270 the bits outside the type's range). We set TREE_OVERFLOWED if,
271 OVERFLOWED is nonzero,
272 or OVERFLOWABLE is >0 and signed overflow occurs
273 or OVERFLOWABLE is <0 and any overflow occurs
274 We return a new tree node for the extended double-int. The node
275 is shared if no overflow flags are set. */
278 force_fit_type_double (tree type, unsigned HOST_WIDE_INT low,
279 HOST_WIDE_INT high, int overflowable,
282 int sign_extended_type;
285 /* Size types *are* sign extended. */
286 sign_extended_type = (!TYPE_UNSIGNED (type)
287 || (TREE_CODE (type) == INTEGER_TYPE
288 && TYPE_IS_SIZETYPE (type)));
290 overflow = fit_double_type (low, high, &low, &high, type);
292 /* If we need to set overflow flags, return a new unshared node. */
293 if (overflowed || overflow)
297 || (overflowable > 0 && sign_extended_type))
299 tree t = make_node (INTEGER_CST);
300 TREE_INT_CST_LOW (t) = low;
301 TREE_INT_CST_HIGH (t) = high;
302 TREE_TYPE (t) = type;
303 TREE_OVERFLOW (t) = 1;
308 /* Else build a shared node. */
309 return build_int_cst_wide (type, low, high);
312 /* Add two doubleword integers with doubleword result.
313 Return nonzero if the operation overflows according to UNSIGNED_P.
314 Each argument is given as two `HOST_WIDE_INT' pieces.
315 One argument is L1 and H1; the other, L2 and H2.
316 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
319 add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
320 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
321 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
324 unsigned HOST_WIDE_INT l;
328 h = h1 + h2 + (l < l1);
334 return (unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1;
336 return OVERFLOW_SUM_SIGN (h1, h2, h);
339 /* Negate a doubleword integer with doubleword result.
340 Return nonzero if the operation overflows, assuming it's signed.
341 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
342 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
345 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
346 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
352 return (*hv & h1) < 0;
362 /* Multiply two doubleword integers with doubleword result.
363 Return nonzero if the operation overflows according to UNSIGNED_P.
364 Each argument is given as two `HOST_WIDE_INT' pieces.
365 One argument is L1 and H1; the other, L2 and H2.
366 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
369 mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
370 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
371 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
374 HOST_WIDE_INT arg1[4];
375 HOST_WIDE_INT arg2[4];
376 HOST_WIDE_INT prod[4 * 2];
377 unsigned HOST_WIDE_INT carry;
379 unsigned HOST_WIDE_INT toplow, neglow;
380 HOST_WIDE_INT tophigh, neghigh;
382 encode (arg1, l1, h1);
383 encode (arg2, l2, h2);
385 memset (prod, 0, sizeof prod);
387 for (i = 0; i < 4; i++)
390 for (j = 0; j < 4; j++)
393 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
394 carry += arg1[i] * arg2[j];
395 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
397 prod[k] = LOWPART (carry);
398 carry = HIGHPART (carry);
403 decode (prod, lv, hv);
404 decode (prod + 4, &toplow, &tophigh);
406 /* Unsigned overflow is immediate. */
408 return (toplow | tophigh) != 0;
410 /* Check for signed overflow by calculating the signed representation of the
411 top half of the result; it should agree with the low half's sign bit. */
414 neg_double (l2, h2, &neglow, &neghigh);
415 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
419 neg_double (l1, h1, &neglow, &neghigh);
420 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
422 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
425 /* Shift the doubleword integer in L1, H1 left by COUNT places
426 keeping only PREC bits of result.
427 Shift right if COUNT is negative.
428 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
429 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
432 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
433 HOST_WIDE_INT count, unsigned int prec,
434 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
436 unsigned HOST_WIDE_INT signmask;
440 rshift_double (l1, h1, -count, prec, lv, hv, arith);
444 if (SHIFT_COUNT_TRUNCATED)
447 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
449 /* Shifting by the host word size is undefined according to the
450 ANSI standard, so we must handle this as a special case. */
454 else if (count >= HOST_BITS_PER_WIDE_INT)
456 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
461 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
462 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
466 /* Sign extend all bits that are beyond the precision. */
468 signmask = -((prec > HOST_BITS_PER_WIDE_INT
469 ? ((unsigned HOST_WIDE_INT) *hv
470 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
471 : (*lv >> (prec - 1))) & 1);
473 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
475 else if (prec >= HOST_BITS_PER_WIDE_INT)
477 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
478 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
483 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
484 *lv |= signmask << prec;
488 /* Shift the doubleword integer in L1, H1 right by COUNT places
489 keeping only PREC bits of result. COUNT must be positive.
490 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
491 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
494 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
495 HOST_WIDE_INT count, unsigned int prec,
496 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
499 unsigned HOST_WIDE_INT signmask;
502 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
505 if (SHIFT_COUNT_TRUNCATED)
508 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
510 /* Shifting by the host word size is undefined according to the
511 ANSI standard, so we must handle this as a special case. */
515 else if (count >= HOST_BITS_PER_WIDE_INT)
518 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
522 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
524 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
527 /* Zero / sign extend all bits that are beyond the precision. */
529 if (count >= (HOST_WIDE_INT)prec)
534 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
536 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
538 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
539 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
544 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
545 *lv |= signmask << (prec - count);
549 /* Rotate the doubleword integer in L1, H1 left by COUNT places
550 keeping only PREC bits of result.
551 Rotate right if COUNT is negative.
552 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
555 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
556 HOST_WIDE_INT count, unsigned int prec,
557 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
559 unsigned HOST_WIDE_INT s1l, s2l;
560 HOST_WIDE_INT s1h, s2h;
566 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
567 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
572 /* Rotate the doubleword integer in L1, H1 left by COUNT places
573 keeping only PREC bits of result. COUNT must be positive.
574 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
577 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
578 HOST_WIDE_INT count, unsigned int prec,
579 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
581 unsigned HOST_WIDE_INT s1l, s2l;
582 HOST_WIDE_INT s1h, s2h;
588 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
589 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
594 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
595 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
596 CODE is a tree code for a kind of division, one of
597 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
599 It controls how the quotient is rounded to an integer.
600 Return nonzero if the operation overflows.
601 UNS nonzero says do unsigned division. */
604 div_and_round_double (enum tree_code code, int uns,
605 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
606 HOST_WIDE_INT hnum_orig,
607 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
608 HOST_WIDE_INT hden_orig,
609 unsigned HOST_WIDE_INT *lquo,
610 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
614 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
615 HOST_WIDE_INT den[4], quo[4];
617 unsigned HOST_WIDE_INT work;
618 unsigned HOST_WIDE_INT carry = 0;
619 unsigned HOST_WIDE_INT lnum = lnum_orig;
620 HOST_WIDE_INT hnum = hnum_orig;
621 unsigned HOST_WIDE_INT lden = lden_orig;
622 HOST_WIDE_INT hden = hden_orig;
625 if (hden == 0 && lden == 0)
626 overflow = 1, lden = 1;
628 /* Calculate quotient sign and convert operands to unsigned. */
634 /* (minimum integer) / (-1) is the only overflow case. */
635 if (neg_double (lnum, hnum, &lnum, &hnum)
636 && ((HOST_WIDE_INT) lden & hden) == -1)
642 neg_double (lden, hden, &lden, &hden);
646 if (hnum == 0 && hden == 0)
647 { /* single precision */
649 /* This unsigned division rounds toward zero. */
655 { /* trivial case: dividend < divisor */
656 /* hden != 0 already checked. */
663 memset (quo, 0, sizeof quo);
665 memset (num, 0, sizeof num); /* to zero 9th element */
666 memset (den, 0, sizeof den);
668 encode (num, lnum, hnum);
669 encode (den, lden, hden);
671 /* Special code for when the divisor < BASE. */
672 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
674 /* hnum != 0 already checked. */
675 for (i = 4 - 1; i >= 0; i--)
677 work = num[i] + carry * BASE;
678 quo[i] = work / lden;
684 /* Full double precision division,
685 with thanks to Don Knuth's "Seminumerical Algorithms". */
686 int num_hi_sig, den_hi_sig;
687 unsigned HOST_WIDE_INT quo_est, scale;
689 /* Find the highest nonzero divisor digit. */
690 for (i = 4 - 1;; i--)
697 /* Insure that the first digit of the divisor is at least BASE/2.
698 This is required by the quotient digit estimation algorithm. */
700 scale = BASE / (den[den_hi_sig] + 1);
702 { /* scale divisor and dividend */
704 for (i = 0; i <= 4 - 1; i++)
706 work = (num[i] * scale) + carry;
707 num[i] = LOWPART (work);
708 carry = HIGHPART (work);
713 for (i = 0; i <= 4 - 1; i++)
715 work = (den[i] * scale) + carry;
716 den[i] = LOWPART (work);
717 carry = HIGHPART (work);
718 if (den[i] != 0) den_hi_sig = i;
725 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
727 /* Guess the next quotient digit, quo_est, by dividing the first
728 two remaining dividend digits by the high order quotient digit.
729 quo_est is never low and is at most 2 high. */
730 unsigned HOST_WIDE_INT tmp;
732 num_hi_sig = i + den_hi_sig + 1;
733 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
734 if (num[num_hi_sig] != den[den_hi_sig])
735 quo_est = work / den[den_hi_sig];
739 /* Refine quo_est so it's usually correct, and at most one high. */
740 tmp = work - quo_est * den[den_hi_sig];
742 && (den[den_hi_sig - 1] * quo_est
743 > (tmp * BASE + num[num_hi_sig - 2])))
746 /* Try QUO_EST as the quotient digit, by multiplying the
747 divisor by QUO_EST and subtracting from the remaining dividend.
748 Keep in mind that QUO_EST is the I - 1st digit. */
751 for (j = 0; j <= den_hi_sig; j++)
753 work = quo_est * den[j] + carry;
754 carry = HIGHPART (work);
755 work = num[i + j] - LOWPART (work);
756 num[i + j] = LOWPART (work);
757 carry += HIGHPART (work) != 0;
760 /* If quo_est was high by one, then num[i] went negative and
761 we need to correct things. */
762 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
765 carry = 0; /* add divisor back in */
766 for (j = 0; j <= den_hi_sig; j++)
768 work = num[i + j] + den[j] + carry;
769 carry = HIGHPART (work);
770 num[i + j] = LOWPART (work);
773 num [num_hi_sig] += carry;
776 /* Store the quotient digit. */
781 decode (quo, lquo, hquo);
784 /* If result is negative, make it so. */
786 neg_double (*lquo, *hquo, lquo, hquo);
788 /* Compute trial remainder: rem = num - (quo * den) */
789 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
790 neg_double (*lrem, *hrem, lrem, hrem);
791 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
796 case TRUNC_MOD_EXPR: /* round toward zero */
797 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
801 case FLOOR_MOD_EXPR: /* round toward negative infinity */
802 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
805 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
813 case CEIL_MOD_EXPR: /* round toward positive infinity */
814 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
816 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
824 case ROUND_MOD_EXPR: /* round to closest integer */
826 unsigned HOST_WIDE_INT labs_rem = *lrem;
827 HOST_WIDE_INT habs_rem = *hrem;
828 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
829 HOST_WIDE_INT habs_den = hden, htwice;
831 /* Get absolute values. */
833 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
835 neg_double (lden, hden, &labs_den, &habs_den);
837 /* If (2 * abs (lrem) >= abs (lden)) */
838 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
839 labs_rem, habs_rem, <wice, &htwice);
841 if (((unsigned HOST_WIDE_INT) habs_den
842 < (unsigned HOST_WIDE_INT) htwice)
843 || (((unsigned HOST_WIDE_INT) habs_den
844 == (unsigned HOST_WIDE_INT) htwice)
845 && (labs_den < ltwice)))
849 add_double (*lquo, *hquo,
850 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
853 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
865 /* Compute true remainder: rem = num - (quo * den) */
866 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
867 neg_double (*lrem, *hrem, lrem, hrem);
868 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
872 /* If ARG2 divides ARG1 with zero remainder, carries out the division
873 of type CODE and returns the quotient.
874 Otherwise returns NULL_TREE. */
877 div_if_zero_remainder (enum tree_code code, const_tree arg1, const_tree arg2)
879 unsigned HOST_WIDE_INT int1l, int2l;
880 HOST_WIDE_INT int1h, int2h;
881 unsigned HOST_WIDE_INT quol, reml;
882 HOST_WIDE_INT quoh, remh;
883 tree type = TREE_TYPE (arg1);
884 int uns = TYPE_UNSIGNED (type);
886 int1l = TREE_INT_CST_LOW (arg1);
887 int1h = TREE_INT_CST_HIGH (arg1);
888 /* &obj[0] + -128 really should be compiled as &obj[-8] rather than
889 &obj[some_exotic_number]. */
890 if (POINTER_TYPE_P (type))
893 type = signed_type_for (type);
894 fit_double_type (int1l, int1h, &int1l, &int1h,
898 fit_double_type (int1l, int1h, &int1l, &int1h, type);
899 int2l = TREE_INT_CST_LOW (arg2);
900 int2h = TREE_INT_CST_HIGH (arg2);
902 div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
903 &quol, &quoh, &reml, &remh);
904 if (remh != 0 || reml != 0)
907 return build_int_cst_wide (type, quol, quoh);
910 /* This is nonzero if we should defer warnings about undefined
911 overflow. This facility exists because these warnings are a
912 special case. The code to estimate loop iterations does not want
913 to issue any warnings, since it works with expressions which do not
914 occur in user code. Various bits of cleanup code call fold(), but
915 only use the result if it has certain characteristics (e.g., is a
916 constant); that code only wants to issue a warning if the result is
919 static int fold_deferring_overflow_warnings;
921 /* If a warning about undefined overflow is deferred, this is the
922 warning. Note that this may cause us to turn two warnings into
923 one, but that is fine since it is sufficient to only give one
924 warning per expression. */
926 static const char* fold_deferred_overflow_warning;
928 /* If a warning about undefined overflow is deferred, this is the
929 level at which the warning should be emitted. */
931 static enum warn_strict_overflow_code fold_deferred_overflow_code;
933 /* Start deferring overflow warnings. We could use a stack here to
934 permit nested calls, but at present it is not necessary. */
937 fold_defer_overflow_warnings (void)
939 ++fold_deferring_overflow_warnings;
942 /* Stop deferring overflow warnings. If there is a pending warning,
943 and ISSUE is true, then issue the warning if appropriate. STMT is
944 the statement with which the warning should be associated (used for
945 location information); STMT may be NULL. CODE is the level of the
946 warning--a warn_strict_overflow_code value. This function will use
947 the smaller of CODE and the deferred code when deciding whether to
948 issue the warning. CODE may be zero to mean to always use the
952 fold_undefer_overflow_warnings (bool issue, const_tree stmt, int code)
957 gcc_assert (fold_deferring_overflow_warnings > 0);
958 --fold_deferring_overflow_warnings;
959 if (fold_deferring_overflow_warnings > 0)
961 if (fold_deferred_overflow_warning != NULL
963 && code < (int) fold_deferred_overflow_code)
964 fold_deferred_overflow_code = code;
968 warnmsg = fold_deferred_overflow_warning;
969 fold_deferred_overflow_warning = NULL;
971 if (!issue || warnmsg == NULL)
974 if (stmt != NULL_TREE && TREE_NO_WARNING (stmt))
977 /* Use the smallest code level when deciding to issue the
979 if (code == 0 || code > (int) fold_deferred_overflow_code)
980 code = fold_deferred_overflow_code;
982 if (!issue_strict_overflow_warning (code))
985 if (stmt == NULL_TREE || !expr_has_location (stmt))
986 locus = input_location;
988 locus = expr_location (stmt);
989 warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
992 /* Stop deferring overflow warnings, ignoring any deferred
996 fold_undefer_and_ignore_overflow_warnings (void)
998 fold_undefer_overflow_warnings (false, NULL_TREE, 0);
1001 /* Whether we are deferring overflow warnings. */
1004 fold_deferring_overflow_warnings_p (void)
1006 return fold_deferring_overflow_warnings > 0;
1009 /* This is called when we fold something based on the fact that signed
1010 overflow is undefined. */
1013 fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
1015 if (fold_deferring_overflow_warnings > 0)
1017 if (fold_deferred_overflow_warning == NULL
1018 || wc < fold_deferred_overflow_code)
1020 fold_deferred_overflow_warning = gmsgid;
1021 fold_deferred_overflow_code = wc;
1024 else if (issue_strict_overflow_warning (wc))
1025 warning (OPT_Wstrict_overflow, gmsgid);
1028 /* Return true if the built-in mathematical function specified by CODE
1029 is odd, i.e. -f(x) == f(-x). */
1032 negate_mathfn_p (enum built_in_function code)
1036 CASE_FLT_FN (BUILT_IN_ASIN):
1037 CASE_FLT_FN (BUILT_IN_ASINH):
1038 CASE_FLT_FN (BUILT_IN_ATAN):
1039 CASE_FLT_FN (BUILT_IN_ATANH):
1040 CASE_FLT_FN (BUILT_IN_CASIN):
1041 CASE_FLT_FN (BUILT_IN_CASINH):
1042 CASE_FLT_FN (BUILT_IN_CATAN):
1043 CASE_FLT_FN (BUILT_IN_CATANH):
1044 CASE_FLT_FN (BUILT_IN_CBRT):
1045 CASE_FLT_FN (BUILT_IN_CPROJ):
1046 CASE_FLT_FN (BUILT_IN_CSIN):
1047 CASE_FLT_FN (BUILT_IN_CSINH):
1048 CASE_FLT_FN (BUILT_IN_CTAN):
1049 CASE_FLT_FN (BUILT_IN_CTANH):
1050 CASE_FLT_FN (BUILT_IN_ERF):
1051 CASE_FLT_FN (BUILT_IN_LLROUND):
1052 CASE_FLT_FN (BUILT_IN_LROUND):
1053 CASE_FLT_FN (BUILT_IN_ROUND):
1054 CASE_FLT_FN (BUILT_IN_SIN):
1055 CASE_FLT_FN (BUILT_IN_SINH):
1056 CASE_FLT_FN (BUILT_IN_TAN):
1057 CASE_FLT_FN (BUILT_IN_TANH):
1058 CASE_FLT_FN (BUILT_IN_TRUNC):
1061 CASE_FLT_FN (BUILT_IN_LLRINT):
1062 CASE_FLT_FN (BUILT_IN_LRINT):
1063 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1064 CASE_FLT_FN (BUILT_IN_RINT):
1065 return !flag_rounding_math;
1073 /* Check whether we may negate an integer constant T without causing
1077 may_negate_without_overflow_p (const_tree t)
1079 unsigned HOST_WIDE_INT val;
1083 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1085 type = TREE_TYPE (t);
1086 if (TYPE_UNSIGNED (type))
1089 prec = TYPE_PRECISION (type);
1090 if (prec > HOST_BITS_PER_WIDE_INT)
1092 if (TREE_INT_CST_LOW (t) != 0)
1094 prec -= HOST_BITS_PER_WIDE_INT;
1095 val = TREE_INT_CST_HIGH (t);
1098 val = TREE_INT_CST_LOW (t);
1099 if (prec < HOST_BITS_PER_WIDE_INT)
1100 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1101 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1104 /* Determine whether an expression T can be cheaply negated using
1105 the function negate_expr without introducing undefined overflow. */
1108 negate_expr_p (tree t)
1115 type = TREE_TYPE (t);
1117 STRIP_SIGN_NOPS (t);
1118 switch (TREE_CODE (t))
1121 if (TYPE_OVERFLOW_WRAPS (type))
1124 /* Check that -CST will not overflow type. */
1125 return may_negate_without_overflow_p (t);
1127 return (INTEGRAL_TYPE_P (type)
1128 && TYPE_OVERFLOW_WRAPS (type));
1136 return negate_expr_p (TREE_REALPART (t))
1137 && negate_expr_p (TREE_IMAGPART (t));
1140 return negate_expr_p (TREE_OPERAND (t, 0))
1141 && negate_expr_p (TREE_OPERAND (t, 1));
1144 return negate_expr_p (TREE_OPERAND (t, 0));
1147 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1148 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1150 /* -(A + B) -> (-B) - A. */
1151 if (negate_expr_p (TREE_OPERAND (t, 1))
1152 && reorder_operands_p (TREE_OPERAND (t, 0),
1153 TREE_OPERAND (t, 1)))
1155 /* -(A + B) -> (-A) - B. */
1156 return negate_expr_p (TREE_OPERAND (t, 0));
1159 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1160 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1161 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1162 && reorder_operands_p (TREE_OPERAND (t, 0),
1163 TREE_OPERAND (t, 1));
1166 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1172 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1173 return negate_expr_p (TREE_OPERAND (t, 1))
1174 || negate_expr_p (TREE_OPERAND (t, 0));
1177 case TRUNC_DIV_EXPR:
1178 case ROUND_DIV_EXPR:
1179 case FLOOR_DIV_EXPR:
1181 case EXACT_DIV_EXPR:
1182 /* In general we can't negate A / B, because if A is INT_MIN and
1183 B is 1, we may turn this into INT_MIN / -1 which is undefined
1184 and actually traps on some architectures. But if overflow is
1185 undefined, we can negate, because - (INT_MIN / 1) is an
1187 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1188 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1190 return negate_expr_p (TREE_OPERAND (t, 1))
1191 || negate_expr_p (TREE_OPERAND (t, 0));
1194 /* Negate -((double)float) as (double)(-float). */
1195 if (TREE_CODE (type) == REAL_TYPE)
1197 tree tem = strip_float_extensions (t);
1199 return negate_expr_p (tem);
1204 /* Negate -f(x) as f(-x). */
1205 if (negate_mathfn_p (builtin_mathfn_code (t)))
1206 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1210 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1211 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1213 tree op1 = TREE_OPERAND (t, 1);
1214 if (TREE_INT_CST_HIGH (op1) == 0
1215 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1216 == TREE_INT_CST_LOW (op1))
1227 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1228 simplification is possible.
1229 If negate_expr_p would return true for T, NULL_TREE will never be
1233 fold_negate_expr (tree t)
1235 tree type = TREE_TYPE (t);
1238 switch (TREE_CODE (t))
1240 /* Convert - (~A) to A + 1. */
1242 if (INTEGRAL_TYPE_P (type))
1243 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1244 build_int_cst (type, 1));
1248 tem = fold_negate_const (t, type);
1249 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1250 || !TYPE_OVERFLOW_TRAPS (type))
1255 tem = fold_negate_const (t, type);
1256 /* Two's complement FP formats, such as c4x, may overflow. */
1257 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1262 tem = fold_negate_const (t, type);
1267 tree rpart = negate_expr (TREE_REALPART (t));
1268 tree ipart = negate_expr (TREE_IMAGPART (t));
1270 if ((TREE_CODE (rpart) == REAL_CST
1271 && TREE_CODE (ipart) == REAL_CST)
1272 || (TREE_CODE (rpart) == INTEGER_CST
1273 && TREE_CODE (ipart) == INTEGER_CST))
1274 return build_complex (type, rpart, ipart);
1279 if (negate_expr_p (t))
1280 return fold_build2 (COMPLEX_EXPR, type,
1281 fold_negate_expr (TREE_OPERAND (t, 0)),
1282 fold_negate_expr (TREE_OPERAND (t, 1)));
1286 if (negate_expr_p (t))
1287 return fold_build1 (CONJ_EXPR, type,
1288 fold_negate_expr (TREE_OPERAND (t, 0)));
1292 return TREE_OPERAND (t, 0);
1295 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1296 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1298 /* -(A + B) -> (-B) - A. */
1299 if (negate_expr_p (TREE_OPERAND (t, 1))
1300 && reorder_operands_p (TREE_OPERAND (t, 0),
1301 TREE_OPERAND (t, 1)))
1303 tem = negate_expr (TREE_OPERAND (t, 1));
1304 return fold_build2 (MINUS_EXPR, type,
1305 tem, TREE_OPERAND (t, 0));
1308 /* -(A + B) -> (-A) - B. */
1309 if (negate_expr_p (TREE_OPERAND (t, 0)))
1311 tem = negate_expr (TREE_OPERAND (t, 0));
1312 return fold_build2 (MINUS_EXPR, type,
1313 tem, TREE_OPERAND (t, 1));
1319 /* - (A - B) -> B - A */
1320 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1321 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1322 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1323 return fold_build2 (MINUS_EXPR, type,
1324 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1328 if (TYPE_UNSIGNED (type))
1334 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1336 tem = TREE_OPERAND (t, 1);
1337 if (negate_expr_p (tem))
1338 return fold_build2 (TREE_CODE (t), type,
1339 TREE_OPERAND (t, 0), negate_expr (tem));
1340 tem = TREE_OPERAND (t, 0);
1341 if (negate_expr_p (tem))
1342 return fold_build2 (TREE_CODE (t), type,
1343 negate_expr (tem), TREE_OPERAND (t, 1));
1347 case TRUNC_DIV_EXPR:
1348 case ROUND_DIV_EXPR:
1349 case FLOOR_DIV_EXPR:
1351 case EXACT_DIV_EXPR:
1352 /* In general we can't negate A / B, because if A is INT_MIN and
1353 B is 1, we may turn this into INT_MIN / -1 which is undefined
1354 and actually traps on some architectures. But if overflow is
1355 undefined, we can negate, because - (INT_MIN / 1) is an
1357 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1359 const char * const warnmsg = G_("assuming signed overflow does not "
1360 "occur when negating a division");
1361 tem = TREE_OPERAND (t, 1);
1362 if (negate_expr_p (tem))
1364 if (INTEGRAL_TYPE_P (type)
1365 && (TREE_CODE (tem) != INTEGER_CST
1366 || integer_onep (tem)))
1367 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1368 return fold_build2 (TREE_CODE (t), type,
1369 TREE_OPERAND (t, 0), negate_expr (tem));
1371 tem = TREE_OPERAND (t, 0);
1372 if (negate_expr_p (tem))
1374 if (INTEGRAL_TYPE_P (type)
1375 && (TREE_CODE (tem) != INTEGER_CST
1376 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1377 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1378 return fold_build2 (TREE_CODE (t), type,
1379 negate_expr (tem), TREE_OPERAND (t, 1));
1385 /* Convert -((double)float) into (double)(-float). */
1386 if (TREE_CODE (type) == REAL_TYPE)
1388 tem = strip_float_extensions (t);
1389 if (tem != t && negate_expr_p (tem))
1390 return fold_convert (type, negate_expr (tem));
1395 /* Negate -f(x) as f(-x). */
1396 if (negate_mathfn_p (builtin_mathfn_code (t))
1397 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1401 fndecl = get_callee_fndecl (t);
1402 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1403 return build_call_expr (fndecl, 1, arg);
1408 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1409 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1411 tree op1 = TREE_OPERAND (t, 1);
1412 if (TREE_INT_CST_HIGH (op1) == 0
1413 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1414 == TREE_INT_CST_LOW (op1))
1416 tree ntype = TYPE_UNSIGNED (type)
1417 ? signed_type_for (type)
1418 : unsigned_type_for (type);
1419 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1420 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1421 return fold_convert (type, temp);
1433 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1434 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1435 return NULL_TREE. */
1438 negate_expr (tree t)
1445 type = TREE_TYPE (t);
1446 STRIP_SIGN_NOPS (t);
1448 tem = fold_negate_expr (t);
1450 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1451 return fold_convert (type, tem);
1454 /* Split a tree IN into a constant, literal and variable parts that could be
1455 combined with CODE to make IN. "constant" means an expression with
1456 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1457 commutative arithmetic operation. Store the constant part into *CONP,
1458 the literal in *LITP and return the variable part. If a part isn't
1459 present, set it to null. If the tree does not decompose in this way,
1460 return the entire tree as the variable part and the other parts as null.
1462 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1463 case, we negate an operand that was subtracted. Except if it is a
1464 literal for which we use *MINUS_LITP instead.
1466 If NEGATE_P is true, we are negating all of IN, again except a literal
1467 for which we use *MINUS_LITP instead.
1469 If IN is itself a literal or constant, return it as appropriate.
1471 Note that we do not guarantee that any of the three values will be the
1472 same type as IN, but they will have the same signedness and mode. */
1475 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1476 tree *minus_litp, int negate_p)
1484 /* Strip any conversions that don't change the machine mode or signedness. */
1485 STRIP_SIGN_NOPS (in);
1487 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
1488 || TREE_CODE (in) == FIXED_CST)
1490 else if (TREE_CODE (in) == code
1491 || ((! FLOAT_TYPE_P (TREE_TYPE (in)) || flag_associative_math)
1492 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
1493 /* We can associate addition and subtraction together (even
1494 though the C standard doesn't say so) for integers because
1495 the value is not affected. For reals, the value might be
1496 affected, so we can't. */
1497 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1498 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1500 tree op0 = TREE_OPERAND (in, 0);
1501 tree op1 = TREE_OPERAND (in, 1);
1502 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1503 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1505 /* First see if either of the operands is a literal, then a constant. */
1506 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
1507 || TREE_CODE (op0) == FIXED_CST)
1508 *litp = op0, op0 = 0;
1509 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
1510 || TREE_CODE (op1) == FIXED_CST)
1511 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1513 if (op0 != 0 && TREE_CONSTANT (op0))
1514 *conp = op0, op0 = 0;
1515 else if (op1 != 0 && TREE_CONSTANT (op1))
1516 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1518 /* If we haven't dealt with either operand, this is not a case we can
1519 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1520 if (op0 != 0 && op1 != 0)
1525 var = op1, neg_var_p = neg1_p;
1527 /* Now do any needed negations. */
1529 *minus_litp = *litp, *litp = 0;
1531 *conp = negate_expr (*conp);
1533 var = negate_expr (var);
1535 else if (TREE_CONSTANT (in))
1543 *minus_litp = *litp, *litp = 0;
1544 else if (*minus_litp)
1545 *litp = *minus_litp, *minus_litp = 0;
1546 *conp = negate_expr (*conp);
1547 var = negate_expr (var);
1553 /* Re-associate trees split by the above function. T1 and T2 are either
1554 expressions to associate or null. Return the new expression, if any. If
1555 we build an operation, do it in TYPE and with CODE. */
1558 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1565 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1566 try to fold this since we will have infinite recursion. But do
1567 deal with any NEGATE_EXPRs. */
1568 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1569 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1571 if (code == PLUS_EXPR)
1573 if (TREE_CODE (t1) == NEGATE_EXPR)
1574 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1575 fold_convert (type, TREE_OPERAND (t1, 0)));
1576 else if (TREE_CODE (t2) == NEGATE_EXPR)
1577 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1578 fold_convert (type, TREE_OPERAND (t2, 0)));
1579 else if (integer_zerop (t2))
1580 return fold_convert (type, t1);
1582 else if (code == MINUS_EXPR)
1584 if (integer_zerop (t2))
1585 return fold_convert (type, t1);
1588 return build2 (code, type, fold_convert (type, t1),
1589 fold_convert (type, t2));
1592 return fold_build2 (code, type, fold_convert (type, t1),
1593 fold_convert (type, t2));
1596 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1597 for use in int_const_binop, size_binop and size_diffop. */
1600 int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
1602 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1604 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1619 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1620 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1621 && TYPE_MODE (type1) == TYPE_MODE (type2);
1625 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1626 to produce a new constant. Return NULL_TREE if we don't know how
1627 to evaluate CODE at compile-time.
1629 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1632 int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2, int notrunc)
1634 unsigned HOST_WIDE_INT int1l, int2l;
1635 HOST_WIDE_INT int1h, int2h;
1636 unsigned HOST_WIDE_INT low;
1638 unsigned HOST_WIDE_INT garbagel;
1639 HOST_WIDE_INT garbageh;
1641 tree type = TREE_TYPE (arg1);
1642 int uns = TYPE_UNSIGNED (type);
1644 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1647 int1l = TREE_INT_CST_LOW (arg1);
1648 int1h = TREE_INT_CST_HIGH (arg1);
1649 int2l = TREE_INT_CST_LOW (arg2);
1650 int2h = TREE_INT_CST_HIGH (arg2);
1655 low = int1l | int2l, hi = int1h | int2h;
1659 low = int1l ^ int2l, hi = int1h ^ int2h;
1663 low = int1l & int2l, hi = int1h & int2h;
1669 /* It's unclear from the C standard whether shifts can overflow.
1670 The following code ignores overflow; perhaps a C standard
1671 interpretation ruling is needed. */
1672 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1679 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1684 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1688 neg_double (int2l, int2h, &low, &hi);
1689 add_double (int1l, int1h, low, hi, &low, &hi);
1690 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1694 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1697 case TRUNC_DIV_EXPR:
1698 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1699 case EXACT_DIV_EXPR:
1700 /* This is a shortcut for a common special case. */
1701 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1702 && !TREE_OVERFLOW (arg1)
1703 && !TREE_OVERFLOW (arg2)
1704 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1706 if (code == CEIL_DIV_EXPR)
1709 low = int1l / int2l, hi = 0;
1713 /* ... fall through ... */
1715 case ROUND_DIV_EXPR:
1716 if (int2h == 0 && int2l == 0)
1718 if (int2h == 0 && int2l == 1)
1720 low = int1l, hi = int1h;
1723 if (int1l == int2l && int1h == int2h
1724 && ! (int1l == 0 && int1h == 0))
1729 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1730 &low, &hi, &garbagel, &garbageh);
1733 case TRUNC_MOD_EXPR:
1734 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1735 /* This is a shortcut for a common special case. */
1736 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1737 && !TREE_OVERFLOW (arg1)
1738 && !TREE_OVERFLOW (arg2)
1739 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1741 if (code == CEIL_MOD_EXPR)
1743 low = int1l % int2l, hi = 0;
1747 /* ... fall through ... */
1749 case ROUND_MOD_EXPR:
1750 if (int2h == 0 && int2l == 0)
1752 overflow = div_and_round_double (code, uns,
1753 int1l, int1h, int2l, int2h,
1754 &garbagel, &garbageh, &low, &hi);
1760 low = (((unsigned HOST_WIDE_INT) int1h
1761 < (unsigned HOST_WIDE_INT) int2h)
1762 || (((unsigned HOST_WIDE_INT) int1h
1763 == (unsigned HOST_WIDE_INT) int2h)
1766 low = (int1h < int2h
1767 || (int1h == int2h && int1l < int2l));
1769 if (low == (code == MIN_EXPR))
1770 low = int1l, hi = int1h;
1772 low = int2l, hi = int2h;
1781 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1783 /* Propagate overflow flags ourselves. */
1784 if (((!uns || is_sizetype) && overflow)
1785 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1788 TREE_OVERFLOW (t) = 1;
1792 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1793 ((!uns || is_sizetype) && overflow)
1794 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1799 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1800 constant. We assume ARG1 and ARG2 have the same data type, or at least
1801 are the same kind of constant and the same machine mode. Return zero if
1802 combining the constants is not allowed in the current operating mode.
1804 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1807 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1809 /* Sanity check for the recursive cases. */
1816 if (TREE_CODE (arg1) == INTEGER_CST)
1817 return int_const_binop (code, arg1, arg2, notrunc);
1819 if (TREE_CODE (arg1) == REAL_CST)
1821 enum machine_mode mode;
1824 REAL_VALUE_TYPE value;
1825 REAL_VALUE_TYPE result;
1829 /* The following codes are handled by real_arithmetic. */
1844 d1 = TREE_REAL_CST (arg1);
1845 d2 = TREE_REAL_CST (arg2);
1847 type = TREE_TYPE (arg1);
1848 mode = TYPE_MODE (type);
1850 /* Don't perform operation if we honor signaling NaNs and
1851 either operand is a NaN. */
1852 if (HONOR_SNANS (mode)
1853 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1856 /* Don't perform operation if it would raise a division
1857 by zero exception. */
1858 if (code == RDIV_EXPR
1859 && REAL_VALUES_EQUAL (d2, dconst0)
1860 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1863 /* If either operand is a NaN, just return it. Otherwise, set up
1864 for floating-point trap; we return an overflow. */
1865 if (REAL_VALUE_ISNAN (d1))
1867 else if (REAL_VALUE_ISNAN (d2))
1870 inexact = real_arithmetic (&value, code, &d1, &d2);
1871 real_convert (&result, mode, &value);
1873 /* Don't constant fold this floating point operation if
1874 the result has overflowed and flag_trapping_math. */
1875 if (flag_trapping_math
1876 && MODE_HAS_INFINITIES (mode)
1877 && REAL_VALUE_ISINF (result)
1878 && !REAL_VALUE_ISINF (d1)
1879 && !REAL_VALUE_ISINF (d2))
1882 /* Don't constant fold this floating point operation if the
1883 result may dependent upon the run-time rounding mode and
1884 flag_rounding_math is set, or if GCC's software emulation
1885 is unable to accurately represent the result. */
1886 if ((flag_rounding_math
1887 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1888 && !flag_unsafe_math_optimizations))
1889 && (inexact || !real_identical (&result, &value)))
1892 t = build_real (type, result);
1894 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1898 if (TREE_CODE (arg1) == FIXED_CST)
1900 FIXED_VALUE_TYPE f1;
1901 FIXED_VALUE_TYPE f2;
1902 FIXED_VALUE_TYPE result;
1907 /* The following codes are handled by fixed_arithmetic. */
1913 case TRUNC_DIV_EXPR:
1914 f2 = TREE_FIXED_CST (arg2);
1919 f2.data.high = TREE_INT_CST_HIGH (arg2);
1920 f2.data.low = TREE_INT_CST_LOW (arg2);
1928 f1 = TREE_FIXED_CST (arg1);
1929 type = TREE_TYPE (arg1);
1930 sat_p = TYPE_SATURATING (type);
1931 overflow_p = fixed_arithmetic (&result, code, &f1, &f2, sat_p);
1932 t = build_fixed (type, result);
1933 /* Propagate overflow flags. */
1934 if (overflow_p | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1936 TREE_OVERFLOW (t) = 1;
1937 TREE_CONSTANT_OVERFLOW (t) = 1;
1939 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1940 TREE_CONSTANT_OVERFLOW (t) = 1;
1944 if (TREE_CODE (arg1) == COMPLEX_CST)
1946 tree type = TREE_TYPE (arg1);
1947 tree r1 = TREE_REALPART (arg1);
1948 tree i1 = TREE_IMAGPART (arg1);
1949 tree r2 = TREE_REALPART (arg2);
1950 tree i2 = TREE_IMAGPART (arg2);
1957 real = const_binop (code, r1, r2, notrunc);
1958 imag = const_binop (code, i1, i2, notrunc);
1962 real = const_binop (MINUS_EXPR,
1963 const_binop (MULT_EXPR, r1, r2, notrunc),
1964 const_binop (MULT_EXPR, i1, i2, notrunc),
1966 imag = const_binop (PLUS_EXPR,
1967 const_binop (MULT_EXPR, r1, i2, notrunc),
1968 const_binop (MULT_EXPR, i1, r2, notrunc),
1975 = const_binop (PLUS_EXPR,
1976 const_binop (MULT_EXPR, r2, r2, notrunc),
1977 const_binop (MULT_EXPR, i2, i2, notrunc),
1980 = const_binop (PLUS_EXPR,
1981 const_binop (MULT_EXPR, r1, r2, notrunc),
1982 const_binop (MULT_EXPR, i1, i2, notrunc),
1985 = const_binop (MINUS_EXPR,
1986 const_binop (MULT_EXPR, i1, r2, notrunc),
1987 const_binop (MULT_EXPR, r1, i2, notrunc),
1990 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1991 code = TRUNC_DIV_EXPR;
1993 real = const_binop (code, t1, magsquared, notrunc);
1994 imag = const_binop (code, t2, magsquared, notrunc);
2003 return build_complex (type, real, imag);
2009 /* Create a size type INT_CST node with NUMBER sign extended. KIND
2010 indicates which particular sizetype to create. */
2013 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
2015 return build_int_cst (sizetype_tab[(int) kind], number);
2018 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2019 is a tree code. The type of the result is taken from the operands.
2020 Both must be equivalent integer types, ala int_binop_types_match_p.
2021 If the operands are constant, so is the result. */
2024 size_binop (enum tree_code code, tree arg0, tree arg1)
2026 tree type = TREE_TYPE (arg0);
2028 if (arg0 == error_mark_node || arg1 == error_mark_node)
2029 return error_mark_node;
2031 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
2034 /* Handle the special case of two integer constants faster. */
2035 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
2037 /* And some specific cases even faster than that. */
2038 if (code == PLUS_EXPR)
2040 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
2042 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2045 else if (code == MINUS_EXPR)
2047 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2050 else if (code == MULT_EXPR)
2052 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
2056 /* Handle general case of two integer constants. */
2057 return int_const_binop (code, arg0, arg1, 0);
2060 return fold_build2 (code, type, arg0, arg1);
2063 /* Given two values, either both of sizetype or both of bitsizetype,
2064 compute the difference between the two values. Return the value
2065 in signed type corresponding to the type of the operands. */
2068 size_diffop (tree arg0, tree arg1)
2070 tree type = TREE_TYPE (arg0);
2073 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
2076 /* If the type is already signed, just do the simple thing. */
2077 if (!TYPE_UNSIGNED (type))
2078 return size_binop (MINUS_EXPR, arg0, arg1);
2080 if (type == sizetype)
2082 else if (type == bitsizetype)
2083 ctype = sbitsizetype;
2085 ctype = signed_type_for (type);
2087 /* If either operand is not a constant, do the conversions to the signed
2088 type and subtract. The hardware will do the right thing with any
2089 overflow in the subtraction. */
2090 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2091 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
2092 fold_convert (ctype, arg1));
2094 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2095 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2096 overflow) and negate (which can't either). Special-case a result
2097 of zero while we're here. */
2098 if (tree_int_cst_equal (arg0, arg1))
2099 return build_int_cst (ctype, 0);
2100 else if (tree_int_cst_lt (arg1, arg0))
2101 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2103 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
2104 fold_convert (ctype, size_binop (MINUS_EXPR,
2108 /* A subroutine of fold_convert_const handling conversions of an
2109 INTEGER_CST to another integer type. */
2112 fold_convert_const_int_from_int (tree type, const_tree arg1)
2116 /* Given an integer constant, make new constant with new type,
2117 appropriately sign-extended or truncated. */
2118 t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
2119 TREE_INT_CST_HIGH (arg1),
2120 /* Don't set the overflow when
2121 converting from a pointer, */
2122 !POINTER_TYPE_P (TREE_TYPE (arg1))
2123 /* or to a sizetype with same signedness
2124 and the precision is unchanged.
2125 ??? sizetype is always sign-extended,
2126 but its signedness depends on the
2127 frontend. Thus we see spurious overflows
2128 here if we do not check this. */
2129 && !((TYPE_PRECISION (TREE_TYPE (arg1))
2130 == TYPE_PRECISION (type))
2131 && (TYPE_UNSIGNED (TREE_TYPE (arg1))
2132 == TYPE_UNSIGNED (type))
2133 && ((TREE_CODE (TREE_TYPE (arg1)) == INTEGER_TYPE
2134 && TYPE_IS_SIZETYPE (TREE_TYPE (arg1)))
2135 || (TREE_CODE (type) == INTEGER_TYPE
2136 && TYPE_IS_SIZETYPE (type)))),
2137 (TREE_INT_CST_HIGH (arg1) < 0
2138 && (TYPE_UNSIGNED (type)
2139 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2140 | TREE_OVERFLOW (arg1));
2145 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2146 to an integer type. */
2149 fold_convert_const_int_from_real (enum tree_code code, tree type, const_tree arg1)
2154 /* The following code implements the floating point to integer
2155 conversion rules required by the Java Language Specification,
2156 that IEEE NaNs are mapped to zero and values that overflow
2157 the target precision saturate, i.e. values greater than
2158 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2159 are mapped to INT_MIN. These semantics are allowed by the
2160 C and C++ standards that simply state that the behavior of
2161 FP-to-integer conversion is unspecified upon overflow. */
2163 HOST_WIDE_INT high, low;
2165 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2169 case FIX_TRUNC_EXPR:
2170 real_trunc (&r, VOIDmode, &x);
2177 /* If R is NaN, return zero and show we have an overflow. */
2178 if (REAL_VALUE_ISNAN (r))
2185 /* See if R is less than the lower bound or greater than the
2190 tree lt = TYPE_MIN_VALUE (type);
2191 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2192 if (REAL_VALUES_LESS (r, l))
2195 high = TREE_INT_CST_HIGH (lt);
2196 low = TREE_INT_CST_LOW (lt);
2202 tree ut = TYPE_MAX_VALUE (type);
2205 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2206 if (REAL_VALUES_LESS (u, r))
2209 high = TREE_INT_CST_HIGH (ut);
2210 low = TREE_INT_CST_LOW (ut);
2216 REAL_VALUE_TO_INT (&low, &high, r);
2218 t = force_fit_type_double (type, low, high, -1,
2219 overflow | TREE_OVERFLOW (arg1));
2223 /* A subroutine of fold_convert_const handling conversions of a
2224 FIXED_CST to an integer type. */
2227 fold_convert_const_int_from_fixed (tree type, const_tree arg1)
2230 double_int temp, temp_trunc;
2233 /* Right shift FIXED_CST to temp by fbit. */
2234 temp = TREE_FIXED_CST (arg1).data;
2235 mode = TREE_FIXED_CST (arg1).mode;
2236 if (GET_MODE_FBIT (mode) < 2 * HOST_BITS_PER_WIDE_INT)
2238 lshift_double (temp.low, temp.high,
2239 - GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2240 &temp.low, &temp.high, SIGNED_FIXED_POINT_MODE_P (mode));
2242 /* Left shift temp to temp_trunc by fbit. */
2243 lshift_double (temp.low, temp.high,
2244 GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2245 &temp_trunc.low, &temp_trunc.high,
2246 SIGNED_FIXED_POINT_MODE_P (mode));
2253 temp_trunc.high = 0;
2256 /* If FIXED_CST is negative, we need to round the value toward 0.
2257 By checking if the fractional bits are not zero to add 1 to temp. */
2258 if (SIGNED_FIXED_POINT_MODE_P (mode) && temp_trunc.high < 0
2259 && !double_int_equal_p (TREE_FIXED_CST (arg1).data, temp_trunc))
2264 temp = double_int_add (temp, one);
2267 /* Given a fixed-point constant, make new constant with new type,
2268 appropriately sign-extended or truncated. */
2269 t = force_fit_type_double (type, temp.low, temp.high, -1,
2271 && (TYPE_UNSIGNED (type)
2272 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2273 | TREE_OVERFLOW (arg1));
2278 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2279 to another floating point type. */
2282 fold_convert_const_real_from_real (tree type, const_tree arg1)
2284 REAL_VALUE_TYPE value;
2287 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2288 t = build_real (type, value);
2290 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2294 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2295 to a floating point type. */
2298 fold_convert_const_real_from_fixed (tree type, const_tree arg1)
2300 REAL_VALUE_TYPE value;
2303 real_convert_from_fixed (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1));
2304 t = build_real (type, value);
2306 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2307 TREE_CONSTANT_OVERFLOW (t)
2308 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2312 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2313 to another fixed-point type. */
2316 fold_convert_const_fixed_from_fixed (tree type, const_tree arg1)
2318 FIXED_VALUE_TYPE value;
2322 overflow_p = fixed_convert (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1),
2323 TYPE_SATURATING (type));
2324 t = build_fixed (type, value);
2326 /* Propagate overflow flags. */
2327 if (overflow_p | TREE_OVERFLOW (arg1))
2329 TREE_OVERFLOW (t) = 1;
2330 TREE_CONSTANT_OVERFLOW (t) = 1;
2332 else if (TREE_CONSTANT_OVERFLOW (arg1))
2333 TREE_CONSTANT_OVERFLOW (t) = 1;
2337 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2338 to a fixed-point type. */
2341 fold_convert_const_fixed_from_int (tree type, const_tree arg1)
2343 FIXED_VALUE_TYPE value;
2347 overflow_p = fixed_convert_from_int (&value, TYPE_MODE (type),
2348 TREE_INT_CST (arg1),
2349 TYPE_UNSIGNED (TREE_TYPE (arg1)),
2350 TYPE_SATURATING (type));
2351 t = build_fixed (type, value);
2353 /* Propagate overflow flags. */
2354 if (overflow_p | TREE_OVERFLOW (arg1))
2356 TREE_OVERFLOW (t) = 1;
2357 TREE_CONSTANT_OVERFLOW (t) = 1;
2359 else if (TREE_CONSTANT_OVERFLOW (arg1))
2360 TREE_CONSTANT_OVERFLOW (t) = 1;
2364 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2365 to a fixed-point type. */
2368 fold_convert_const_fixed_from_real (tree type, const_tree arg1)
2370 FIXED_VALUE_TYPE value;
2374 overflow_p = fixed_convert_from_real (&value, TYPE_MODE (type),
2375 &TREE_REAL_CST (arg1),
2376 TYPE_SATURATING (type));
2377 t = build_fixed (type, value);
2379 /* Propagate overflow flags. */
2380 if (overflow_p | TREE_OVERFLOW (arg1))
2382 TREE_OVERFLOW (t) = 1;
2383 TREE_CONSTANT_OVERFLOW (t) = 1;
2385 else if (TREE_CONSTANT_OVERFLOW (arg1))
2386 TREE_CONSTANT_OVERFLOW (t) = 1;
2390 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2391 type TYPE. If no simplification can be done return NULL_TREE. */
2394 fold_convert_const (enum tree_code code, tree type, tree arg1)
2396 if (TREE_TYPE (arg1) == type)
2399 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2401 if (TREE_CODE (arg1) == INTEGER_CST)
2402 return fold_convert_const_int_from_int (type, arg1);
2403 else if (TREE_CODE (arg1) == REAL_CST)
2404 return fold_convert_const_int_from_real (code, type, arg1);
2405 else if (TREE_CODE (arg1) == FIXED_CST)
2406 return fold_convert_const_int_from_fixed (type, arg1);
2408 else if (TREE_CODE (type) == REAL_TYPE)
2410 if (TREE_CODE (arg1) == INTEGER_CST)
2411 return build_real_from_int_cst (type, arg1);
2412 else if (TREE_CODE (arg1) == REAL_CST)
2413 return fold_convert_const_real_from_real (type, arg1);
2414 else if (TREE_CODE (arg1) == FIXED_CST)
2415 return fold_convert_const_real_from_fixed (type, arg1);
2417 else if (TREE_CODE (type) == FIXED_POINT_TYPE)
2419 if (TREE_CODE (arg1) == FIXED_CST)
2420 return fold_convert_const_fixed_from_fixed (type, arg1);
2421 else if (TREE_CODE (arg1) == INTEGER_CST)
2422 return fold_convert_const_fixed_from_int (type, arg1);
2423 else if (TREE_CODE (arg1) == REAL_CST)
2424 return fold_convert_const_fixed_from_real (type, arg1);
2429 /* Construct a vector of zero elements of vector type TYPE. */
2432 build_zero_vector (tree type)
2437 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2438 units = TYPE_VECTOR_SUBPARTS (type);
2441 for (i = 0; i < units; i++)
2442 list = tree_cons (NULL_TREE, elem, list);
2443 return build_vector (type, list);
2446 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2449 fold_convertible_p (const_tree type, const_tree arg)
2451 tree orig = TREE_TYPE (arg);
2456 if (TREE_CODE (arg) == ERROR_MARK
2457 || TREE_CODE (type) == ERROR_MARK
2458 || TREE_CODE (orig) == ERROR_MARK)
2461 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2464 switch (TREE_CODE (type))
2466 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2467 case POINTER_TYPE: case REFERENCE_TYPE:
2469 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2470 || TREE_CODE (orig) == OFFSET_TYPE)
2472 return (TREE_CODE (orig) == VECTOR_TYPE
2473 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2476 case FIXED_POINT_TYPE:
2480 return TREE_CODE (type) == TREE_CODE (orig);
2487 /* Convert expression ARG to type TYPE. Used by the middle-end for
2488 simple conversions in preference to calling the front-end's convert. */
2491 fold_convert (tree type, tree arg)
2493 tree orig = TREE_TYPE (arg);
2499 if (TREE_CODE (arg) == ERROR_MARK
2500 || TREE_CODE (type) == ERROR_MARK
2501 || TREE_CODE (orig) == ERROR_MARK)
2502 return error_mark_node;
2504 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2505 return fold_build1 (NOP_EXPR, type, arg);
2507 switch (TREE_CODE (type))
2509 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2510 case POINTER_TYPE: case REFERENCE_TYPE:
2512 if (TREE_CODE (arg) == INTEGER_CST)
2514 tem = fold_convert_const (NOP_EXPR, type, arg);
2515 if (tem != NULL_TREE)
2518 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2519 || TREE_CODE (orig) == OFFSET_TYPE)
2520 return fold_build1 (NOP_EXPR, type, arg);
2521 if (TREE_CODE (orig) == COMPLEX_TYPE)
2523 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2524 return fold_convert (type, tem);
2526 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2527 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2528 return fold_build1 (NOP_EXPR, type, arg);
2531 if (TREE_CODE (arg) == INTEGER_CST)
2533 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2534 if (tem != NULL_TREE)
2537 else if (TREE_CODE (arg) == REAL_CST)
2539 tem = fold_convert_const (NOP_EXPR, type, arg);
2540 if (tem != NULL_TREE)
2543 else if (TREE_CODE (arg) == FIXED_CST)
2545 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2546 if (tem != NULL_TREE)
2550 switch (TREE_CODE (orig))
2553 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2554 case POINTER_TYPE: case REFERENCE_TYPE:
2555 return fold_build1 (FLOAT_EXPR, type, arg);
2558 return fold_build1 (NOP_EXPR, type, arg);
2560 case FIXED_POINT_TYPE:
2561 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2564 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2565 return fold_convert (type, tem);
2571 case FIXED_POINT_TYPE:
2572 if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
2573 || TREE_CODE (arg) == REAL_CST)
2575 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2576 if (tem != NULL_TREE)
2580 switch (TREE_CODE (orig))
2582 case FIXED_POINT_TYPE:
2587 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2590 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2591 return fold_convert (type, tem);
2598 switch (TREE_CODE (orig))
2601 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2602 case POINTER_TYPE: case REFERENCE_TYPE:
2604 case FIXED_POINT_TYPE:
2605 return build2 (COMPLEX_EXPR, type,
2606 fold_convert (TREE_TYPE (type), arg),
2607 fold_convert (TREE_TYPE (type), integer_zero_node));
2612 if (TREE_CODE (arg) == COMPLEX_EXPR)
2614 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2615 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2616 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2619 arg = save_expr (arg);
2620 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2621 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2622 rpart = fold_convert (TREE_TYPE (type), rpart);
2623 ipart = fold_convert (TREE_TYPE (type), ipart);
2624 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2632 if (integer_zerop (arg))
2633 return build_zero_vector (type);
2634 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2635 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2636 || TREE_CODE (orig) == VECTOR_TYPE);
2637 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2640 tem = fold_ignored_result (arg);
2641 if (TREE_CODE (tem) == GIMPLE_MODIFY_STMT)
2643 return fold_build1 (NOP_EXPR, type, tem);
2650 /* Return false if expr can be assumed not to be an lvalue, true
2654 maybe_lvalue_p (const_tree x)
2656 /* We only need to wrap lvalue tree codes. */
2657 switch (TREE_CODE (x))
2668 case ALIGN_INDIRECT_REF:
2669 case MISALIGNED_INDIRECT_REF:
2671 case ARRAY_RANGE_REF:
2677 case PREINCREMENT_EXPR:
2678 case PREDECREMENT_EXPR:
2680 case TRY_CATCH_EXPR:
2681 case WITH_CLEANUP_EXPR:
2684 case GIMPLE_MODIFY_STMT:
2693 /* Assume the worst for front-end tree codes. */
2694 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2702 /* Return an expr equal to X but certainly not valid as an lvalue. */
2707 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2712 if (! maybe_lvalue_p (x))
2714 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2717 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2718 Zero means allow extended lvalues. */
2720 int pedantic_lvalues;
2722 /* When pedantic, return an expr equal to X but certainly not valid as a
2723 pedantic lvalue. Otherwise, return X. */
2726 pedantic_non_lvalue (tree x)
2728 if (pedantic_lvalues)
2729 return non_lvalue (x);
2734 /* Given a tree comparison code, return the code that is the logical inverse
2735 of the given code. It is not safe to do this for floating-point
2736 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2737 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2740 invert_tree_comparison (enum tree_code code, bool honor_nans)
2742 if (honor_nans && flag_trapping_math)
2752 return honor_nans ? UNLE_EXPR : LE_EXPR;
2754 return honor_nans ? UNLT_EXPR : LT_EXPR;
2756 return honor_nans ? UNGE_EXPR : GE_EXPR;
2758 return honor_nans ? UNGT_EXPR : GT_EXPR;
2772 return UNORDERED_EXPR;
2773 case UNORDERED_EXPR:
2774 return ORDERED_EXPR;
2780 /* Similar, but return the comparison that results if the operands are
2781 swapped. This is safe for floating-point. */
2784 swap_tree_comparison (enum tree_code code)
2791 case UNORDERED_EXPR:
2817 /* Convert a comparison tree code from an enum tree_code representation
2818 into a compcode bit-based encoding. This function is the inverse of
2819 compcode_to_comparison. */
2821 static enum comparison_code
2822 comparison_to_compcode (enum tree_code code)
2839 return COMPCODE_ORD;
2840 case UNORDERED_EXPR:
2841 return COMPCODE_UNORD;
2843 return COMPCODE_UNLT;
2845 return COMPCODE_UNEQ;
2847 return COMPCODE_UNLE;
2849 return COMPCODE_UNGT;
2851 return COMPCODE_LTGT;
2853 return COMPCODE_UNGE;
2859 /* Convert a compcode bit-based encoding of a comparison operator back
2860 to GCC's enum tree_code representation. This function is the
2861 inverse of comparison_to_compcode. */
2863 static enum tree_code
2864 compcode_to_comparison (enum comparison_code code)
2881 return ORDERED_EXPR;
2882 case COMPCODE_UNORD:
2883 return UNORDERED_EXPR;
2901 /* Return a tree for the comparison which is the combination of
2902 doing the AND or OR (depending on CODE) of the two operations LCODE
2903 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2904 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2905 if this makes the transformation invalid. */
2908 combine_comparisons (enum tree_code code, enum tree_code lcode,
2909 enum tree_code rcode, tree truth_type,
2910 tree ll_arg, tree lr_arg)
2912 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2913 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2914 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2915 enum comparison_code compcode;
2919 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2920 compcode = lcompcode & rcompcode;
2923 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2924 compcode = lcompcode | rcompcode;
2933 /* Eliminate unordered comparisons, as well as LTGT and ORD
2934 which are not used unless the mode has NaNs. */
2935 compcode &= ~COMPCODE_UNORD;
2936 if (compcode == COMPCODE_LTGT)
2937 compcode = COMPCODE_NE;
2938 else if (compcode == COMPCODE_ORD)
2939 compcode = COMPCODE_TRUE;
2941 else if (flag_trapping_math)
2943 /* Check that the original operation and the optimized ones will trap
2944 under the same condition. */
2945 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2946 && (lcompcode != COMPCODE_EQ)
2947 && (lcompcode != COMPCODE_ORD);
2948 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2949 && (rcompcode != COMPCODE_EQ)
2950 && (rcompcode != COMPCODE_ORD);
2951 bool trap = (compcode & COMPCODE_UNORD) == 0
2952 && (compcode != COMPCODE_EQ)
2953 && (compcode != COMPCODE_ORD);
2955 /* In a short-circuited boolean expression the LHS might be
2956 such that the RHS, if evaluated, will never trap. For
2957 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2958 if neither x nor y is NaN. (This is a mixed blessing: for
2959 example, the expression above will never trap, hence
2960 optimizing it to x < y would be invalid). */
2961 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2962 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2965 /* If the comparison was short-circuited, and only the RHS
2966 trapped, we may now generate a spurious trap. */
2968 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2971 /* If we changed the conditions that cause a trap, we lose. */
2972 if ((ltrap || rtrap) != trap)
2976 if (compcode == COMPCODE_TRUE)
2977 return constant_boolean_node (true, truth_type);
2978 else if (compcode == COMPCODE_FALSE)
2979 return constant_boolean_node (false, truth_type);
2981 return fold_build2 (compcode_to_comparison (compcode),
2982 truth_type, ll_arg, lr_arg);
2985 /* Return nonzero if CODE is a tree code that represents a truth value. */
2988 truth_value_p (enum tree_code code)
2990 return (TREE_CODE_CLASS (code) == tcc_comparison
2991 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2992 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2993 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2996 /* Return nonzero if two operands (typically of the same tree node)
2997 are necessarily equal. If either argument has side-effects this
2998 function returns zero. FLAGS modifies behavior as follows:
3000 If OEP_ONLY_CONST is set, only return nonzero for constants.
3001 This function tests whether the operands are indistinguishable;
3002 it does not test whether they are equal using C's == operation.
3003 The distinction is important for IEEE floating point, because
3004 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
3005 (2) two NaNs may be indistinguishable, but NaN!=NaN.
3007 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
3008 even though it may hold multiple values during a function.
3009 This is because a GCC tree node guarantees that nothing else is
3010 executed between the evaluation of its "operands" (which may often
3011 be evaluated in arbitrary order). Hence if the operands themselves
3012 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
3013 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
3014 unset means assuming isochronic (or instantaneous) tree equivalence.
3015 Unless comparing arbitrary expression trees, such as from different
3016 statements, this flag can usually be left unset.
3018 If OEP_PURE_SAME is set, then pure functions with identical arguments
3019 are considered the same. It is used when the caller has other ways
3020 to ensure that global memory is unchanged in between. */
3023 operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
3025 /* If either is ERROR_MARK, they aren't equal. */
3026 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
3029 /* Check equality of integer constants before bailing out due to
3030 precision differences. */
3031 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
3032 return tree_int_cst_equal (arg0, arg1);
3034 /* If both types don't have the same signedness, then we can't consider
3035 them equal. We must check this before the STRIP_NOPS calls
3036 because they may change the signedness of the arguments. As pointers
3037 strictly don't have a signedness, require either two pointers or
3038 two non-pointers as well. */
3039 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1))
3040 || POINTER_TYPE_P (TREE_TYPE (arg0)) != POINTER_TYPE_P (TREE_TYPE (arg1)))
3043 /* If both types don't have the same precision, then it is not safe
3045 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
3051 /* In case both args are comparisons but with different comparison
3052 code, try to swap the comparison operands of one arg to produce
3053 a match and compare that variant. */
3054 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3055 && COMPARISON_CLASS_P (arg0)
3056 && COMPARISON_CLASS_P (arg1))
3058 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
3060 if (TREE_CODE (arg0) == swap_code)
3061 return operand_equal_p (TREE_OPERAND (arg0, 0),
3062 TREE_OPERAND (arg1, 1), flags)
3063 && operand_equal_p (TREE_OPERAND (arg0, 1),
3064 TREE_OPERAND (arg1, 0), flags);
3067 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3068 /* This is needed for conversions and for COMPONENT_REF.
3069 Might as well play it safe and always test this. */
3070 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
3071 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
3072 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
3075 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3076 We don't care about side effects in that case because the SAVE_EXPR
3077 takes care of that for us. In all other cases, two expressions are
3078 equal if they have no side effects. If we have two identical
3079 expressions with side effects that should be treated the same due
3080 to the only side effects being identical SAVE_EXPR's, that will
3081 be detected in the recursive calls below. */
3082 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
3083 && (TREE_CODE (arg0) == SAVE_EXPR
3084 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
3087 /* Next handle constant cases, those for which we can return 1 even
3088 if ONLY_CONST is set. */
3089 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
3090 switch (TREE_CODE (arg0))
3093 return tree_int_cst_equal (arg0, arg1);
3096 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
3097 TREE_FIXED_CST (arg1));
3100 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
3101 TREE_REAL_CST (arg1)))
3105 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
3107 /* If we do not distinguish between signed and unsigned zero,
3108 consider them equal. */
3109 if (real_zerop (arg0) && real_zerop (arg1))
3118 v1 = TREE_VECTOR_CST_ELTS (arg0);
3119 v2 = TREE_VECTOR_CST_ELTS (arg1);
3122 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
3125 v1 = TREE_CHAIN (v1);
3126 v2 = TREE_CHAIN (v2);
3133 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
3135 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
3139 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
3140 && ! memcmp (TREE_STRING_POINTER (arg0),
3141 TREE_STRING_POINTER (arg1),
3142 TREE_STRING_LENGTH (arg0)));
3145 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
3151 if (flags & OEP_ONLY_CONST)
3154 /* Define macros to test an operand from arg0 and arg1 for equality and a
3155 variant that allows null and views null as being different from any
3156 non-null value. In the latter case, if either is null, the both
3157 must be; otherwise, do the normal comparison. */
3158 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3159 TREE_OPERAND (arg1, N), flags)
3161 #define OP_SAME_WITH_NULL(N) \
3162 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3163 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3165 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
3168 /* Two conversions are equal only if signedness and modes match. */
3169 switch (TREE_CODE (arg0))
3172 case FIX_TRUNC_EXPR:
3173 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
3174 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3184 case tcc_comparison:
3186 if (OP_SAME (0) && OP_SAME (1))
3189 /* For commutative ops, allow the other order. */
3190 return (commutative_tree_code (TREE_CODE (arg0))
3191 && operand_equal_p (TREE_OPERAND (arg0, 0),
3192 TREE_OPERAND (arg1, 1), flags)
3193 && operand_equal_p (TREE_OPERAND (arg0, 1),
3194 TREE_OPERAND (arg1, 0), flags));
3197 /* If either of the pointer (or reference) expressions we are
3198 dereferencing contain a side effect, these cannot be equal. */
3199 if (TREE_SIDE_EFFECTS (arg0)
3200 || TREE_SIDE_EFFECTS (arg1))
3203 switch (TREE_CODE (arg0))
3206 case ALIGN_INDIRECT_REF:
3207 case MISALIGNED_INDIRECT_REF:
3213 case ARRAY_RANGE_REF:
3214 /* Operands 2 and 3 may be null.
3215 Compare the array index by value if it is constant first as we
3216 may have different types but same value here. */
3218 && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
3219 TREE_OPERAND (arg1, 1))
3221 && OP_SAME_WITH_NULL (2)
3222 && OP_SAME_WITH_NULL (3));
3225 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3226 may be NULL when we're called to compare MEM_EXPRs. */
3227 return OP_SAME_WITH_NULL (0)
3229 && OP_SAME_WITH_NULL (2);
3232 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3238 case tcc_expression:
3239 switch (TREE_CODE (arg0))
3242 case TRUTH_NOT_EXPR:
3245 case TRUTH_ANDIF_EXPR:
3246 case TRUTH_ORIF_EXPR:
3247 return OP_SAME (0) && OP_SAME (1);
3249 case TRUTH_AND_EXPR:
3251 case TRUTH_XOR_EXPR:
3252 if (OP_SAME (0) && OP_SAME (1))
3255 /* Otherwise take into account this is a commutative operation. */
3256 return (operand_equal_p (TREE_OPERAND (arg0, 0),
3257 TREE_OPERAND (arg1, 1), flags)
3258 && operand_equal_p (TREE_OPERAND (arg0, 1),
3259 TREE_OPERAND (arg1, 0), flags));
3262 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3269 switch (TREE_CODE (arg0))
3272 /* If the CALL_EXPRs call different functions, then they
3273 clearly can not be equal. */
3274 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
3279 unsigned int cef = call_expr_flags (arg0);
3280 if (flags & OEP_PURE_SAME)
3281 cef &= ECF_CONST | ECF_PURE;
3288 /* Now see if all the arguments are the same. */
3290 const_call_expr_arg_iterator iter0, iter1;
3292 for (a0 = first_const_call_expr_arg (arg0, &iter0),
3293 a1 = first_const_call_expr_arg (arg1, &iter1);
3295 a0 = next_const_call_expr_arg (&iter0),
3296 a1 = next_const_call_expr_arg (&iter1))
3297 if (! operand_equal_p (a0, a1, flags))
3300 /* If we get here and both argument lists are exhausted
3301 then the CALL_EXPRs are equal. */
3302 return ! (a0 || a1);
3308 case tcc_declaration:
3309 /* Consider __builtin_sqrt equal to sqrt. */
3310 return (TREE_CODE (arg0) == FUNCTION_DECL
3311 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
3312 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
3313 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
3320 #undef OP_SAME_WITH_NULL
3323 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3324 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3326 When in doubt, return 0. */
3329 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
3331 int unsignedp1, unsignedpo;
3332 tree primarg0, primarg1, primother;
3333 unsigned int correct_width;
3335 if (operand_equal_p (arg0, arg1, 0))
3338 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3339 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3342 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3343 and see if the inner values are the same. This removes any
3344 signedness comparison, which doesn't matter here. */
3345 primarg0 = arg0, primarg1 = arg1;
3346 STRIP_NOPS (primarg0);
3347 STRIP_NOPS (primarg1);
3348 if (operand_equal_p (primarg0, primarg1, 0))
3351 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3352 actual comparison operand, ARG0.
3354 First throw away any conversions to wider types
3355 already present in the operands. */
3357 primarg1 = get_narrower (arg1, &unsignedp1);
3358 primother = get_narrower (other, &unsignedpo);
3360 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3361 if (unsignedp1 == unsignedpo
3362 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3363 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3365 tree type = TREE_TYPE (arg0);
3367 /* Make sure shorter operand is extended the right way
3368 to match the longer operand. */
3369 primarg1 = fold_convert (signed_or_unsigned_type_for
3370 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3372 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3379 /* See if ARG is an expression that is either a comparison or is performing
3380 arithmetic on comparisons. The comparisons must only be comparing
3381 two different values, which will be stored in *CVAL1 and *CVAL2; if
3382 they are nonzero it means that some operands have already been found.
3383 No variables may be used anywhere else in the expression except in the
3384 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3385 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3387 If this is true, return 1. Otherwise, return zero. */
3390 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3392 enum tree_code code = TREE_CODE (arg);
3393 enum tree_code_class class = TREE_CODE_CLASS (code);
3395 /* We can handle some of the tcc_expression cases here. */
3396 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3398 else if (class == tcc_expression
3399 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3400 || code == COMPOUND_EXPR))
3403 else if (class == tcc_expression && code == SAVE_EXPR
3404 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3406 /* If we've already found a CVAL1 or CVAL2, this expression is
3407 two complex to handle. */
3408 if (*cval1 || *cval2)
3418 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3421 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3422 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3423 cval1, cval2, save_p));
3428 case tcc_expression:
3429 if (code == COND_EXPR)
3430 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3431 cval1, cval2, save_p)
3432 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3433 cval1, cval2, save_p)
3434 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3435 cval1, cval2, save_p));
3438 case tcc_comparison:
3439 /* First see if we can handle the first operand, then the second. For
3440 the second operand, we know *CVAL1 can't be zero. It must be that
3441 one side of the comparison is each of the values; test for the
3442 case where this isn't true by failing if the two operands
3445 if (operand_equal_p (TREE_OPERAND (arg, 0),
3446 TREE_OPERAND (arg, 1), 0))
3450 *cval1 = TREE_OPERAND (arg, 0);
3451 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3453 else if (*cval2 == 0)
3454 *cval2 = TREE_OPERAND (arg, 0);
3455 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3460 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3462 else if (*cval2 == 0)
3463 *cval2 = TREE_OPERAND (arg, 1);
3464 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3476 /* ARG is a tree that is known to contain just arithmetic operations and
3477 comparisons. Evaluate the operations in the tree substituting NEW0 for
3478 any occurrence of OLD0 as an operand of a comparison and likewise for
3482 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3484 tree type = TREE_TYPE (arg);
3485 enum tree_code code = TREE_CODE (arg);
3486 enum tree_code_class class = TREE_CODE_CLASS (code);
3488 /* We can handle some of the tcc_expression cases here. */
3489 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3491 else if (class == tcc_expression
3492 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3498 return fold_build1 (code, type,
3499 eval_subst (TREE_OPERAND (arg, 0),
3500 old0, new0, old1, new1));
3503 return fold_build2 (code, type,
3504 eval_subst (TREE_OPERAND (arg, 0),
3505 old0, new0, old1, new1),
3506 eval_subst (TREE_OPERAND (arg, 1),
3507 old0, new0, old1, new1));
3509 case tcc_expression:
3513 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3516 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3519 return fold_build3 (code, type,
3520 eval_subst (TREE_OPERAND (arg, 0),
3521 old0, new0, old1, new1),
3522 eval_subst (TREE_OPERAND (arg, 1),
3523 old0, new0, old1, new1),
3524 eval_subst (TREE_OPERAND (arg, 2),
3525 old0, new0, old1, new1));
3529 /* Fall through - ??? */
3531 case tcc_comparison:
3533 tree arg0 = TREE_OPERAND (arg, 0);
3534 tree arg1 = TREE_OPERAND (arg, 1);
3536 /* We need to check both for exact equality and tree equality. The
3537 former will be true if the operand has a side-effect. In that
3538 case, we know the operand occurred exactly once. */
3540 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3542 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3545 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3547 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3550 return fold_build2 (code, type, arg0, arg1);
3558 /* Return a tree for the case when the result of an expression is RESULT
3559 converted to TYPE and OMITTED was previously an operand of the expression
3560 but is now not needed (e.g., we folded OMITTED * 0).
3562 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3563 the conversion of RESULT to TYPE. */
3566 omit_one_operand (tree type, tree result, tree omitted)
3568 tree t = fold_convert (type, result);
3570 /* If the resulting operand is an empty statement, just return the omitted
3571 statement casted to void. */
3572 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3573 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3575 if (TREE_SIDE_EFFECTS (omitted))
3576 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3578 return non_lvalue (t);
3581 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3584 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3586 tree t = fold_convert (type, result);
3588 /* If the resulting operand is an empty statement, just return the omitted
3589 statement casted to void. */
3590 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3591 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3593 if (TREE_SIDE_EFFECTS (omitted))
3594 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3596 return pedantic_non_lvalue (t);
3599 /* Return a tree for the case when the result of an expression is RESULT
3600 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3601 of the expression but are now not needed.
3603 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3604 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3605 evaluated before OMITTED2. Otherwise, if neither has side effects,
3606 just do the conversion of RESULT to TYPE. */
3609 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3611 tree t = fold_convert (type, result);
3613 if (TREE_SIDE_EFFECTS (omitted2))
3614 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3615 if (TREE_SIDE_EFFECTS (omitted1))
3616 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3618 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3622 /* Return a simplified tree node for the truth-negation of ARG. This
3623 never alters ARG itself. We assume that ARG is an operation that
3624 returns a truth value (0 or 1).
3626 FIXME: one would think we would fold the result, but it causes
3627 problems with the dominator optimizer. */
3630 fold_truth_not_expr (tree arg)
3632 tree type = TREE_TYPE (arg);
3633 enum tree_code code = TREE_CODE (arg);
3635 /* If this is a comparison, we can simply invert it, except for
3636 floating-point non-equality comparisons, in which case we just
3637 enclose a TRUTH_NOT_EXPR around what we have. */
3639 if (TREE_CODE_CLASS (code) == tcc_comparison)
3641 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3642 if (FLOAT_TYPE_P (op_type)
3643 && flag_trapping_math
3644 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3645 && code != NE_EXPR && code != EQ_EXPR)
3649 code = invert_tree_comparison (code,
3650 HONOR_NANS (TYPE_MODE (op_type)));
3651 if (code == ERROR_MARK)
3654 return build2 (code, type,
3655 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3662 return constant_boolean_node (integer_zerop (arg), type);
3664 case TRUTH_AND_EXPR:
3665 return build2 (TRUTH_OR_EXPR, type,
3666 invert_truthvalue (TREE_OPERAND (arg, 0)),
3667 invert_truthvalue (TREE_OPERAND (arg, 1)));
3670 return build2 (TRUTH_AND_EXPR, type,
3671 invert_truthvalue (TREE_OPERAND (arg, 0)),
3672 invert_truthvalue (TREE_OPERAND (arg, 1)));
3674 case TRUTH_XOR_EXPR:
3675 /* Here we can invert either operand. We invert the first operand
3676 unless the second operand is a TRUTH_NOT_EXPR in which case our
3677 result is the XOR of the first operand with the inside of the
3678 negation of the second operand. */
3680 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3681 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3682 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3684 return build2 (TRUTH_XOR_EXPR, type,
3685 invert_truthvalue (TREE_OPERAND (arg, 0)),
3686 TREE_OPERAND (arg, 1));
3688 case TRUTH_ANDIF_EXPR:
3689 return build2 (TRUTH_ORIF_EXPR, type,
3690 invert_truthvalue (TREE_OPERAND (arg, 0)),
3691 invert_truthvalue (TREE_OPERAND (arg, 1)));
3693 case TRUTH_ORIF_EXPR:
3694 return build2 (TRUTH_ANDIF_EXPR, type,
3695 invert_truthvalue (TREE_OPERAND (arg, 0)),
3696 invert_truthvalue (TREE_OPERAND (arg, 1)));
3698 case TRUTH_NOT_EXPR:
3699 return TREE_OPERAND (arg, 0);
3703 tree arg1 = TREE_OPERAND (arg, 1);
3704 tree arg2 = TREE_OPERAND (arg, 2);
3705 /* A COND_EXPR may have a throw as one operand, which
3706 then has void type. Just leave void operands
3708 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3709 VOID_TYPE_P (TREE_TYPE (arg1))
3710 ? arg1 : invert_truthvalue (arg1),
3711 VOID_TYPE_P (TREE_TYPE (arg2))
3712 ? arg2 : invert_truthvalue (arg2));
3716 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3717 invert_truthvalue (TREE_OPERAND (arg, 1)));
3719 case NON_LVALUE_EXPR:
3720 return invert_truthvalue (TREE_OPERAND (arg, 0));
3723 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3724 return build1 (TRUTH_NOT_EXPR, type, arg);
3728 return build1 (TREE_CODE (arg), type,
3729 invert_truthvalue (TREE_OPERAND (arg, 0)));
3732 if (!integer_onep (TREE_OPERAND (arg, 1)))
3734 return build2 (EQ_EXPR, type, arg,
3735 build_int_cst (type, 0));
3738 return build1 (TRUTH_NOT_EXPR, type, arg);
3740 case CLEANUP_POINT_EXPR:
3741 return build1 (CLEANUP_POINT_EXPR, type,
3742 invert_truthvalue (TREE_OPERAND (arg, 0)));
3751 /* Return a simplified tree node for the truth-negation of ARG. This
3752 never alters ARG itself. We assume that ARG is an operation that
3753 returns a truth value (0 or 1).
3755 FIXME: one would think we would fold the result, but it causes
3756 problems with the dominator optimizer. */
3759 invert_truthvalue (tree arg)
3763 if (TREE_CODE (arg) == ERROR_MARK)
3766 tem = fold_truth_not_expr (arg);
3768 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3773 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3774 operands are another bit-wise operation with a common input. If so,
3775 distribute the bit operations to save an operation and possibly two if
3776 constants are involved. For example, convert
3777 (A | B) & (A | C) into A | (B & C)
3778 Further simplification will occur if B and C are constants.
3780 If this optimization cannot be done, 0 will be returned. */
3783 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3788 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3789 || TREE_CODE (arg0) == code
3790 || (TREE_CODE (arg0) != BIT_AND_EXPR
3791 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3794 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3796 common = TREE_OPERAND (arg0, 0);
3797 left = TREE_OPERAND (arg0, 1);
3798 right = TREE_OPERAND (arg1, 1);
3800 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3802 common = TREE_OPERAND (arg0, 0);
3803 left = TREE_OPERAND (arg0, 1);
3804 right = TREE_OPERAND (arg1, 0);
3806 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3808 common = TREE_OPERAND (arg0, 1);
3809 left = TREE_OPERAND (arg0, 0);
3810 right = TREE_OPERAND (arg1, 1);
3812 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3814 common = TREE_OPERAND (arg0, 1);
3815 left = TREE_OPERAND (arg0, 0);
3816 right = TREE_OPERAND (arg1, 0);
3821 return fold_build2 (TREE_CODE (arg0), type, common,
3822 fold_build2 (code, type, left, right));
3825 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3826 with code CODE. This optimization is unsafe. */
3828 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3830 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3831 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3833 /* (A / C) +- (B / C) -> (A +- B) / C. */
3835 && operand_equal_p (TREE_OPERAND (arg0, 1),
3836 TREE_OPERAND (arg1, 1), 0))
3837 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3838 fold_build2 (code, type,
3839 TREE_OPERAND (arg0, 0),
3840 TREE_OPERAND (arg1, 0)),
3841 TREE_OPERAND (arg0, 1));
3843 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3844 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3845 TREE_OPERAND (arg1, 0), 0)
3846 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3847 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3849 REAL_VALUE_TYPE r0, r1;
3850 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3851 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3853 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3855 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3856 real_arithmetic (&r0, code, &r0, &r1);
3857 return fold_build2 (MULT_EXPR, type,
3858 TREE_OPERAND (arg0, 0),
3859 build_real (type, r0));
3865 /* Subroutine for fold_truthop: decode a field reference.
3867 If EXP is a comparison reference, we return the innermost reference.
3869 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3870 set to the starting bit number.
3872 If the innermost field can be completely contained in a mode-sized
3873 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3875 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3876 otherwise it is not changed.
3878 *PUNSIGNEDP is set to the signedness of the field.
3880 *PMASK is set to the mask used. This is either contained in a
3881 BIT_AND_EXPR or derived from the width of the field.
3883 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3885 Return 0 if this is not a component reference or is one that we can't
3886 do anything with. */
3889 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3890 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3891 int *punsignedp, int *pvolatilep,
3892 tree *pmask, tree *pand_mask)
3894 tree outer_type = 0;
3896 tree mask, inner, offset;
3898 unsigned int precision;
3900 /* All the optimizations using this function assume integer fields.
3901 There are problems with FP fields since the type_for_size call
3902 below can fail for, e.g., XFmode. */
3903 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3906 /* We are interested in the bare arrangement of bits, so strip everything
3907 that doesn't affect the machine mode. However, record the type of the
3908 outermost expression if it may matter below. */
3909 if (CONVERT_EXPR_P (exp)
3910 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3911 outer_type = TREE_TYPE (exp);
3914 if (TREE_CODE (exp) == BIT_AND_EXPR)
3916 and_mask = TREE_OPERAND (exp, 1);
3917 exp = TREE_OPERAND (exp, 0);
3918 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3919 if (TREE_CODE (and_mask) != INTEGER_CST)
3923 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3924 punsignedp, pvolatilep, false);
3925 if ((inner == exp && and_mask == 0)
3926 || *pbitsize < 0 || offset != 0
3927 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3930 /* If the number of bits in the reference is the same as the bitsize of
3931 the outer type, then the outer type gives the signedness. Otherwise
3932 (in case of a small bitfield) the signedness is unchanged. */
3933 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3934 *punsignedp = TYPE_UNSIGNED (outer_type);
3936 /* Compute the mask to access the bitfield. */
3937 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3938 precision = TYPE_PRECISION (unsigned_type);
3940 mask = build_int_cst_type (unsigned_type, -1);
3942 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3943 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3945 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3947 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
3948 fold_convert (unsigned_type, and_mask), mask);
3951 *pand_mask = and_mask;
3955 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3956 represents the sign bit of EXP's type. If EXP represents a sign
3957 or zero extension, also test VAL against the unextended type.
3958 The return value is the (sub)expression whose sign bit is VAL,
3959 or NULL_TREE otherwise. */
3962 sign_bit_p (tree exp, const_tree val)
3964 unsigned HOST_WIDE_INT mask_lo, lo;
3965 HOST_WIDE_INT mask_hi, hi;
3969 /* Tree EXP must have an integral type. */
3970 t = TREE_TYPE (exp);
3971 if (! INTEGRAL_TYPE_P (t))
3974 /* Tree VAL must be an integer constant. */
3975 if (TREE_CODE (val) != INTEGER_CST
3976 || TREE_OVERFLOW (val))
3979 width = TYPE_PRECISION (t);
3980 if (width > HOST_BITS_PER_WIDE_INT)
3982 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3985 mask_hi = ((unsigned HOST_WIDE_INT) -1
3986 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3992 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3995 mask_lo = ((unsigned HOST_WIDE_INT) -1
3996 >> (HOST_BITS_PER_WIDE_INT - width));
3999 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
4000 treat VAL as if it were unsigned. */
4001 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
4002 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
4005 /* Handle extension from a narrower type. */
4006 if (TREE_CODE (exp) == NOP_EXPR
4007 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
4008 return sign_bit_p (TREE_OPERAND (exp, 0), val);
4013 /* Subroutine for fold_truthop: determine if an operand is simple enough
4014 to be evaluated unconditionally. */
4017 simple_operand_p (const_tree exp)
4019 /* Strip any conversions that don't change the machine mode. */
4022 return (CONSTANT_CLASS_P (exp)
4023 || TREE_CODE (exp) == SSA_NAME
4025 && ! TREE_ADDRESSABLE (exp)
4026 && ! TREE_THIS_VOLATILE (exp)
4027 && ! DECL_NONLOCAL (exp)
4028 /* Don't regard global variables as simple. They may be
4029 allocated in ways unknown to the compiler (shared memory,
4030 #pragma weak, etc). */
4031 && ! TREE_PUBLIC (exp)
4032 && ! DECL_EXTERNAL (exp)
4033 /* Loading a static variable is unduly expensive, but global
4034 registers aren't expensive. */
4035 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
4038 /* The following functions are subroutines to fold_range_test and allow it to
4039 try to change a logical combination of comparisons into a range test.
4042 X == 2 || X == 3 || X == 4 || X == 5
4046 (unsigned) (X - 2) <= 3
4048 We describe each set of comparisons as being either inside or outside
4049 a range, using a variable named like IN_P, and then describe the
4050 range with a lower and upper bound. If one of the bounds is omitted,
4051 it represents either the highest or lowest value of the type.
4053 In the comments below, we represent a range by two numbers in brackets
4054 preceded by a "+" to designate being inside that range, or a "-" to
4055 designate being outside that range, so the condition can be inverted by
4056 flipping the prefix. An omitted bound is represented by a "-". For
4057 example, "- [-, 10]" means being outside the range starting at the lowest
4058 possible value and ending at 10, in other words, being greater than 10.
4059 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4062 We set up things so that the missing bounds are handled in a consistent
4063 manner so neither a missing bound nor "true" and "false" need to be
4064 handled using a special case. */
4066 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4067 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4068 and UPPER1_P are nonzero if the respective argument is an upper bound
4069 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4070 must be specified for a comparison. ARG1 will be converted to ARG0's
4071 type if both are specified. */
4074 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
4075 tree arg1, int upper1_p)
4081 /* If neither arg represents infinity, do the normal operation.
4082 Else, if not a comparison, return infinity. Else handle the special
4083 comparison rules. Note that most of the cases below won't occur, but
4084 are handled for consistency. */
4086 if (arg0 != 0 && arg1 != 0)
4088 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
4089 arg0, fold_convert (TREE_TYPE (arg0), arg1));
4091 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
4094 if (TREE_CODE_CLASS (code) != tcc_comparison)
4097 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4098 for neither. In real maths, we cannot assume open ended ranges are
4099 the same. But, this is computer arithmetic, where numbers are finite.
4100 We can therefore make the transformation of any unbounded range with
4101 the value Z, Z being greater than any representable number. This permits
4102 us to treat unbounded ranges as equal. */
4103 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
4104 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
4108 result = sgn0 == sgn1;
4111 result = sgn0 != sgn1;
4114 result = sgn0 < sgn1;
4117 result = sgn0 <= sgn1;
4120 result = sgn0 > sgn1;
4123 result = sgn0 >= sgn1;
4129 return constant_boolean_node (result, type);
4132 /* Given EXP, a logical expression, set the range it is testing into
4133 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4134 actually being tested. *PLOW and *PHIGH will be made of the same
4135 type as the returned expression. If EXP is not a comparison, we
4136 will most likely not be returning a useful value and range. Set
4137 *STRICT_OVERFLOW_P to true if the return value is only valid
4138 because signed overflow is undefined; otherwise, do not change
4139 *STRICT_OVERFLOW_P. */
4142 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4143 bool *strict_overflow_p)
4145 enum tree_code code;
4146 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4147 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4149 tree low, high, n_low, n_high;
4151 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4152 and see if we can refine the range. Some of the cases below may not
4153 happen, but it doesn't seem worth worrying about this. We "continue"
4154 the outer loop when we've changed something; otherwise we "break"
4155 the switch, which will "break" the while. */
4158 low = high = build_int_cst (TREE_TYPE (exp), 0);
4162 code = TREE_CODE (exp);
4163 exp_type = TREE_TYPE (exp);
4165 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4167 if (TREE_OPERAND_LENGTH (exp) > 0)
4168 arg0 = TREE_OPERAND (exp, 0);
4169 if (TREE_CODE_CLASS (code) == tcc_comparison
4170 || TREE_CODE_CLASS (code) == tcc_unary
4171 || TREE_CODE_CLASS (code) == tcc_binary)
4172 arg0_type = TREE_TYPE (arg0);
4173 if (TREE_CODE_CLASS (code) == tcc_binary
4174 || TREE_CODE_CLASS (code) == tcc_comparison
4175 || (TREE_CODE_CLASS (code) == tcc_expression
4176 && TREE_OPERAND_LENGTH (exp) > 1))
4177 arg1 = TREE_OPERAND (exp, 1);
4182 case TRUTH_NOT_EXPR:
4183 in_p = ! in_p, exp = arg0;
4186 case EQ_EXPR: case NE_EXPR:
4187 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4188 /* We can only do something if the range is testing for zero
4189 and if the second operand is an integer constant. Note that
4190 saying something is "in" the range we make is done by
4191 complementing IN_P since it will set in the initial case of
4192 being not equal to zero; "out" is leaving it alone. */
4193 if (low == 0 || high == 0
4194 || ! integer_zerop (low) || ! integer_zerop (high)
4195 || TREE_CODE (arg1) != INTEGER_CST)
4200 case NE_EXPR: /* - [c, c] */
4203 case EQ_EXPR: /* + [c, c] */
4204 in_p = ! in_p, low = high = arg1;
4206 case GT_EXPR: /* - [-, c] */
4207 low = 0, high = arg1;
4209 case GE_EXPR: /* + [c, -] */
4210 in_p = ! in_p, low = arg1, high = 0;
4212 case LT_EXPR: /* - [c, -] */
4213 low = arg1, high = 0;
4215 case LE_EXPR: /* + [-, c] */
4216 in_p = ! in_p, low = 0, high = arg1;
4222 /* If this is an unsigned comparison, we also know that EXP is
4223 greater than or equal to zero. We base the range tests we make
4224 on that fact, so we record it here so we can parse existing
4225 range tests. We test arg0_type since often the return type
4226 of, e.g. EQ_EXPR, is boolean. */
4227 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4229 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4231 build_int_cst (arg0_type, 0),
4235 in_p = n_in_p, low = n_low, high = n_high;
4237 /* If the high bound is missing, but we have a nonzero low
4238 bound, reverse the range so it goes from zero to the low bound
4240 if (high == 0 && low && ! integer_zerop (low))
4243 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4244 integer_one_node, 0);
4245 low = build_int_cst (arg0_type, 0);
4253 /* (-x) IN [a,b] -> x in [-b, -a] */
4254 n_low = range_binop (MINUS_EXPR, exp_type,
4255 build_int_cst (exp_type, 0),
4257 n_high = range_binop (MINUS_EXPR, exp_type,
4258 build_int_cst (exp_type, 0),
4260 low = n_low, high = n_high;
4266 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4267 build_int_cst (exp_type, 1));
4270 case PLUS_EXPR: case MINUS_EXPR:
4271 if (TREE_CODE (arg1) != INTEGER_CST)
4274 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4275 move a constant to the other side. */
4276 if (!TYPE_UNSIGNED (arg0_type)
4277 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4280 /* If EXP is signed, any overflow in the computation is undefined,
4281 so we don't worry about it so long as our computations on
4282 the bounds don't overflow. For unsigned, overflow is defined
4283 and this is exactly the right thing. */
4284 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4285 arg0_type, low, 0, arg1, 0);
4286 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4287 arg0_type, high, 1, arg1, 0);
4288 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4289 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4292 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4293 *strict_overflow_p = true;
4295 /* Check for an unsigned range which has wrapped around the maximum
4296 value thus making n_high < n_low, and normalize it. */
4297 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4299 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4300 integer_one_node, 0);
4301 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4302 integer_one_node, 0);
4304 /* If the range is of the form +/- [ x+1, x ], we won't
4305 be able to normalize it. But then, it represents the
4306 whole range or the empty set, so make it
4308 if (tree_int_cst_equal (n_low, low)
4309 && tree_int_cst_equal (n_high, high))
4315 low = n_low, high = n_high;
4320 CASE_CONVERT: case NON_LVALUE_EXPR:
4321 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4324 if (! INTEGRAL_TYPE_P (arg0_type)
4325 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4326 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4329 n_low = low, n_high = high;
4332 n_low = fold_convert (arg0_type, n_low);
4335 n_high = fold_convert (arg0_type, n_high);
4338 /* If we're converting arg0 from an unsigned type, to exp,
4339 a signed type, we will be doing the comparison as unsigned.
4340 The tests above have already verified that LOW and HIGH
4343 So we have to ensure that we will handle large unsigned
4344 values the same way that the current signed bounds treat
4347 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4351 /* For fixed-point modes, we need to pass the saturating flag
4352 as the 2nd parameter. */
4353 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
4354 equiv_type = lang_hooks.types.type_for_mode
4355 (TYPE_MODE (arg0_type),
4356 TYPE_SATURATING (arg0_type));
4358 equiv_type = lang_hooks.types.type_for_mode
4359 (TYPE_MODE (arg0_type), 1);
4361 /* A range without an upper bound is, naturally, unbounded.
4362 Since convert would have cropped a very large value, use
4363 the max value for the destination type. */
4365 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4366 : TYPE_MAX_VALUE (arg0_type);
4368 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4369 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4370 fold_convert (arg0_type,
4372 build_int_cst (arg0_type, 1));
4374 /* If the low bound is specified, "and" the range with the
4375 range for which the original unsigned value will be
4379 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4380 1, n_low, n_high, 1,
4381 fold_convert (arg0_type,
4386 in_p = (n_in_p == in_p);
4390 /* Otherwise, "or" the range with the range of the input
4391 that will be interpreted as negative. */
4392 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4393 0, n_low, n_high, 1,
4394 fold_convert (arg0_type,
4399 in_p = (in_p != n_in_p);
4404 low = n_low, high = n_high;
4414 /* If EXP is a constant, we can evaluate whether this is true or false. */
4415 if (TREE_CODE (exp) == INTEGER_CST)
4417 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4419 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4425 *pin_p = in_p, *plow = low, *phigh = high;
4429 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4430 type, TYPE, return an expression to test if EXP is in (or out of, depending
4431 on IN_P) the range. Return 0 if the test couldn't be created. */
4434 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4436 tree etype = TREE_TYPE (exp);
4439 #ifdef HAVE_canonicalize_funcptr_for_compare
4440 /* Disable this optimization for function pointer expressions
4441 on targets that require function pointer canonicalization. */
4442 if (HAVE_canonicalize_funcptr_for_compare
4443 && TREE_CODE (etype) == POINTER_TYPE
4444 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4450 value = build_range_check (type, exp, 1, low, high);
4452 return invert_truthvalue (value);
4457 if (low == 0 && high == 0)
4458 return build_int_cst (type, 1);
4461 return fold_build2 (LE_EXPR, type, exp,
4462 fold_convert (etype, high));
4465 return fold_build2 (GE_EXPR, type, exp,
4466 fold_convert (etype, low));
4468 if (operand_equal_p (low, high, 0))
4469 return fold_build2 (EQ_EXPR, type, exp,
4470 fold_convert (etype, low));
4472 if (integer_zerop (low))
4474 if (! TYPE_UNSIGNED (etype))
4476 etype = unsigned_type_for (etype);
4477 high = fold_convert (etype, high);
4478 exp = fold_convert (etype, exp);
4480 return build_range_check (type, exp, 1, 0, high);
4483 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4484 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4486 unsigned HOST_WIDE_INT lo;
4490 prec = TYPE_PRECISION (etype);
4491 if (prec <= HOST_BITS_PER_WIDE_INT)
4494 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4498 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4499 lo = (unsigned HOST_WIDE_INT) -1;
4502 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4504 if (TYPE_UNSIGNED (etype))
4506 etype = signed_type_for (etype);
4507 exp = fold_convert (etype, exp);
4509 return fold_build2 (GT_EXPR, type, exp,
4510 build_int_cst (etype, 0));
4514 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4515 This requires wrap-around arithmetics for the type of the expression. */
4516 switch (TREE_CODE (etype))
4519 /* There is no requirement that LOW be within the range of ETYPE
4520 if the latter is a subtype. It must, however, be within the base
4521 type of ETYPE. So be sure we do the subtraction in that type. */
4522 if (TREE_TYPE (etype))
4523 etype = TREE_TYPE (etype);
4528 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4529 TYPE_UNSIGNED (etype));
4536 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4537 if (TREE_CODE (etype) == INTEGER_TYPE
4538 && !TYPE_OVERFLOW_WRAPS (etype))
4540 tree utype, minv, maxv;
4542 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4543 for the type in question, as we rely on this here. */
4544 utype = unsigned_type_for (etype);
4545 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4546 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4547 integer_one_node, 1);
4548 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4550 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4557 high = fold_convert (etype, high);
4558 low = fold_convert (etype, low);
4559 exp = fold_convert (etype, exp);
4561 value = const_binop (MINUS_EXPR, high, low, 0);
4564 if (POINTER_TYPE_P (etype))
4566 if (value != 0 && !TREE_OVERFLOW (value))
4568 low = fold_convert (sizetype, low);
4569 low = fold_build1 (NEGATE_EXPR, sizetype, low);
4570 return build_range_check (type,
4571 fold_build2 (POINTER_PLUS_EXPR, etype, exp, low),
4572 1, build_int_cst (etype, 0), value);
4577 if (value != 0 && !TREE_OVERFLOW (value))
4578 return build_range_check (type,
4579 fold_build2 (MINUS_EXPR, etype, exp, low),
4580 1, build_int_cst (etype, 0), value);
4585 /* Return the predecessor of VAL in its type, handling the infinite case. */
4588 range_predecessor (tree val)
4590 tree type = TREE_TYPE (val);
4592 if (INTEGRAL_TYPE_P (type)
4593 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4596 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4599 /* Return the successor of VAL in its type, handling the infinite case. */
4602 range_successor (tree val)
4604 tree type = TREE_TYPE (val);
4606 if (INTEGRAL_TYPE_P (type)
4607 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4610 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4613 /* Given two ranges, see if we can merge them into one. Return 1 if we
4614 can, 0 if we can't. Set the output range into the specified parameters. */
4617 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4618 tree high0, int in1_p, tree low1, tree high1)
4626 int lowequal = ((low0 == 0 && low1 == 0)
4627 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4628 low0, 0, low1, 0)));
4629 int highequal = ((high0 == 0 && high1 == 0)
4630 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4631 high0, 1, high1, 1)));
4633 /* Make range 0 be the range that starts first, or ends last if they
4634 start at the same value. Swap them if it isn't. */
4635 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4638 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4639 high1, 1, high0, 1))))
4641 temp = in0_p, in0_p = in1_p, in1_p = temp;
4642 tem = low0, low0 = low1, low1 = tem;
4643 tem = high0, high0 = high1, high1 = tem;
4646 /* Now flag two cases, whether the ranges are disjoint or whether the
4647 second range is totally subsumed in the first. Note that the tests
4648 below are simplified by the ones above. */
4649 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4650 high0, 1, low1, 0));
4651 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4652 high1, 1, high0, 1));
4654 /* We now have four cases, depending on whether we are including or
4655 excluding the two ranges. */
4658 /* If they don't overlap, the result is false. If the second range
4659 is a subset it is the result. Otherwise, the range is from the start
4660 of the second to the end of the first. */
4662 in_p = 0, low = high = 0;
4664 in_p = 1, low = low1, high = high1;
4666 in_p = 1, low = low1, high = high0;
4669 else if (in0_p && ! in1_p)
4671 /* If they don't overlap, the result is the first range. If they are
4672 equal, the result is false. If the second range is a subset of the
4673 first, and the ranges begin at the same place, we go from just after
4674 the end of the second range to the end of the first. If the second
4675 range is not a subset of the first, or if it is a subset and both
4676 ranges end at the same place, the range starts at the start of the
4677 first range and ends just before the second range.
4678 Otherwise, we can't describe this as a single range. */
4680 in_p = 1, low = low0, high = high0;
4681 else if (lowequal && highequal)
4682 in_p = 0, low = high = 0;
4683 else if (subset && lowequal)
4685 low = range_successor (high1);
4690 /* We are in the weird situation where high0 > high1 but
4691 high1 has no successor. Punt. */
4695 else if (! subset || highequal)
4698 high = range_predecessor (low1);
4702 /* low0 < low1 but low1 has no predecessor. Punt. */
4710 else if (! in0_p && in1_p)
4712 /* If they don't overlap, the result is the second range. If the second
4713 is a subset of the first, the result is false. Otherwise,
4714 the range starts just after the first range and ends at the
4715 end of the second. */
4717 in_p = 1, low = low1, high = high1;
4718 else if (subset || highequal)
4719 in_p = 0, low = high = 0;
4722 low = range_successor (high0);
4727 /* high1 > high0 but high0 has no successor. Punt. */
4735 /* The case where we are excluding both ranges. Here the complex case
4736 is if they don't overlap. In that case, the only time we have a
4737 range is if they are adjacent. If the second is a subset of the
4738 first, the result is the first. Otherwise, the range to exclude
4739 starts at the beginning of the first range and ends at the end of the
4743 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4744 range_successor (high0),
4746 in_p = 0, low = low0, high = high1;
4749 /* Canonicalize - [min, x] into - [-, x]. */
4750 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4751 switch (TREE_CODE (TREE_TYPE (low0)))
4754 if (TYPE_PRECISION (TREE_TYPE (low0))
4755 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4759 if (tree_int_cst_equal (low0,
4760 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4764 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4765 && integer_zerop (low0))
4772 /* Canonicalize - [x, max] into - [x, -]. */
4773 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4774 switch (TREE_CODE (TREE_TYPE (high1)))
4777 if (TYPE_PRECISION (TREE_TYPE (high1))
4778 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4782 if (tree_int_cst_equal (high1,
4783 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4787 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4788 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4790 integer_one_node, 1)))
4797 /* The ranges might be also adjacent between the maximum and
4798 minimum values of the given type. For
4799 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4800 return + [x + 1, y - 1]. */
4801 if (low0 == 0 && high1 == 0)
4803 low = range_successor (high0);
4804 high = range_predecessor (low1);
4805 if (low == 0 || high == 0)
4815 in_p = 0, low = low0, high = high0;
4817 in_p = 0, low = low0, high = high1;
4820 *pin_p = in_p, *plow = low, *phigh = high;
4825 /* Subroutine of fold, looking inside expressions of the form
4826 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4827 of the COND_EXPR. This function is being used also to optimize
4828 A op B ? C : A, by reversing the comparison first.
4830 Return a folded expression whose code is not a COND_EXPR
4831 anymore, or NULL_TREE if no folding opportunity is found. */
4834 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4836 enum tree_code comp_code = TREE_CODE (arg0);
4837 tree arg00 = TREE_OPERAND (arg0, 0);
4838 tree arg01 = TREE_OPERAND (arg0, 1);
4839 tree arg1_type = TREE_TYPE (arg1);
4845 /* If we have A op 0 ? A : -A, consider applying the following
4848 A == 0? A : -A same as -A
4849 A != 0? A : -A same as A
4850 A >= 0? A : -A same as abs (A)
4851 A > 0? A : -A same as abs (A)
4852 A <= 0? A : -A same as -abs (A)
4853 A < 0? A : -A same as -abs (A)
4855 None of these transformations work for modes with signed
4856 zeros. If A is +/-0, the first two transformations will
4857 change the sign of the result (from +0 to -0, or vice
4858 versa). The last four will fix the sign of the result,
4859 even though the original expressions could be positive or
4860 negative, depending on the sign of A.
4862 Note that all these transformations are correct if A is
4863 NaN, since the two alternatives (A and -A) are also NaNs. */
4864 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4865 && (FLOAT_TYPE_P (TREE_TYPE (arg01))
4866 ? real_zerop (arg01)
4867 : integer_zerop (arg01))
4868 && ((TREE_CODE (arg2) == NEGATE_EXPR
4869 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4870 /* In the case that A is of the form X-Y, '-A' (arg2) may
4871 have already been folded to Y-X, check for that. */
4872 || (TREE_CODE (arg1) == MINUS_EXPR
4873 && TREE_CODE (arg2) == MINUS_EXPR
4874 && operand_equal_p (TREE_OPERAND (arg1, 0),
4875 TREE_OPERAND (arg2, 1), 0)
4876 && operand_equal_p (TREE_OPERAND (arg1, 1),
4877 TREE_OPERAND (arg2, 0), 0))))
4882 tem = fold_convert (arg1_type, arg1);
4883 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4886 return pedantic_non_lvalue (fold_convert (type, arg1));
4889 if (flag_trapping_math)
4894 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4895 arg1 = fold_convert (signed_type_for
4896 (TREE_TYPE (arg1)), arg1);
4897 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4898 return pedantic_non_lvalue (fold_convert (type, tem));
4901 if (flag_trapping_math)
4905 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4906 arg1 = fold_convert (signed_type_for
4907 (TREE_TYPE (arg1)), arg1);
4908 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4909 return negate_expr (fold_convert (type, tem));
4911 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4915 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4916 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4917 both transformations are correct when A is NaN: A != 0
4918 is then true, and A == 0 is false. */
4920 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4921 && integer_zerop (arg01) && integer_zerop (arg2))
4923 if (comp_code == NE_EXPR)
4924 return pedantic_non_lvalue (fold_convert (type, arg1));
4925 else if (comp_code == EQ_EXPR)
4926 return build_int_cst (type, 0);
4929 /* Try some transformations of A op B ? A : B.
4931 A == B? A : B same as B
4932 A != B? A : B same as A
4933 A >= B? A : B same as max (A, B)
4934 A > B? A : B same as max (B, A)
4935 A <= B? A : B same as min (A, B)
4936 A < B? A : B same as min (B, A)
4938 As above, these transformations don't work in the presence
4939 of signed zeros. For example, if A and B are zeros of
4940 opposite sign, the first two transformations will change
4941 the sign of the result. In the last four, the original
4942 expressions give different results for (A=+0, B=-0) and
4943 (A=-0, B=+0), but the transformed expressions do not.
4945 The first two transformations are correct if either A or B
4946 is a NaN. In the first transformation, the condition will
4947 be false, and B will indeed be chosen. In the case of the
4948 second transformation, the condition A != B will be true,
4949 and A will be chosen.
4951 The conversions to max() and min() are not correct if B is
4952 a number and A is not. The conditions in the original
4953 expressions will be false, so all four give B. The min()
4954 and max() versions would give a NaN instead. */
4955 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4956 && operand_equal_for_comparison_p (arg01, arg2, arg00)
4957 /* Avoid these transformations if the COND_EXPR may be used
4958 as an lvalue in the C++ front-end. PR c++/19199. */
4960 || (strcmp (lang_hooks.name, "GNU C++") != 0
4961 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
4962 || ! maybe_lvalue_p (arg1)
4963 || ! maybe_lvalue_p (arg2)))
4965 tree comp_op0 = arg00;
4966 tree comp_op1 = arg01;
4967 tree comp_type = TREE_TYPE (comp_op0);
4969 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4970 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4980 return pedantic_non_lvalue (fold_convert (type, arg2));
4982 return pedantic_non_lvalue (fold_convert (type, arg1));
4987 /* In C++ a ?: expression can be an lvalue, so put the
4988 operand which will be used if they are equal first
4989 so that we can convert this back to the
4990 corresponding COND_EXPR. */
4991 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4993 comp_op0 = fold_convert (comp_type, comp_op0);
4994 comp_op1 = fold_convert (comp_type, comp_op1);
4995 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4996 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
4997 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
4998 return pedantic_non_lvalue (fold_convert (type, tem));
5005 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5007 comp_op0 = fold_convert (comp_type, comp_op0);
5008 comp_op1 = fold_convert (comp_type, comp_op1);
5009 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
5010 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
5011 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
5012 return pedantic_non_lvalue (fold_convert (type, tem));
5016 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5017 return pedantic_non_lvalue (fold_convert (type, arg2));
5020 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5021 return pedantic_non_lvalue (fold_convert (type, arg1));
5024 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5029 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
5030 we might still be able to simplify this. For example,
5031 if C1 is one less or one more than C2, this might have started
5032 out as a MIN or MAX and been transformed by this function.
5033 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
5035 if (INTEGRAL_TYPE_P (type)
5036 && TREE_CODE (arg01) == INTEGER_CST
5037 && TREE_CODE (arg2) == INTEGER_CST)
5041 /* We can replace A with C1 in this case. */
5042 arg1 = fold_convert (type, arg01);
5043 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
5046 /* If C1 is C2 + 1, this is min(A, C2). */
5047 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5049 && operand_equal_p (arg01,
5050 const_binop (PLUS_EXPR, arg2,
5051 build_int_cst (type, 1), 0),
5053 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5055 fold_convert (type, arg1),
5060 /* If C1 is C2 - 1, this is min(A, C2). */
5061 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5063 && operand_equal_p (arg01,
5064 const_binop (MINUS_EXPR, arg2,
5065 build_int_cst (type, 1), 0),
5067 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5069 fold_convert (type, arg1),
5074 /* If C1 is C2 - 1, this is max(A, C2). */
5075 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5077 && operand_equal_p (arg01,
5078 const_binop (MINUS_EXPR, arg2,
5079 build_int_cst (type, 1), 0),
5081 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5083 fold_convert (type, arg1),
5088 /* If C1 is C2 + 1, this is max(A, C2). */
5089 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5091 && operand_equal_p (arg01,
5092 const_binop (PLUS_EXPR, arg2,
5093 build_int_cst (type, 1), 0),
5095 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5097 fold_convert (type, arg1),
5111 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5112 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
5115 /* EXP is some logical combination of boolean tests. See if we can
5116 merge it into some range test. Return the new tree if so. */
5119 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
5121 int or_op = (code == TRUTH_ORIF_EXPR
5122 || code == TRUTH_OR_EXPR);
5123 int in0_p, in1_p, in_p;
5124 tree low0, low1, low, high0, high1, high;
5125 bool strict_overflow_p = false;
5126 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
5127 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
5129 const char * const warnmsg = G_("assuming signed overflow does not occur "
5130 "when simplifying range test");
5132 /* If this is an OR operation, invert both sides; we will invert
5133 again at the end. */
5135 in0_p = ! in0_p, in1_p = ! in1_p;
5137 /* If both expressions are the same, if we can merge the ranges, and we
5138 can build the range test, return it or it inverted. If one of the
5139 ranges is always true or always false, consider it to be the same
5140 expression as the other. */
5141 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
5142 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
5144 && 0 != (tem = (build_range_check (type,
5146 : rhs != 0 ? rhs : integer_zero_node,
5149 if (strict_overflow_p)
5150 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
5151 return or_op ? invert_truthvalue (tem) : tem;
5154 /* On machines where the branch cost is expensive, if this is a
5155 short-circuited branch and the underlying object on both sides
5156 is the same, make a non-short-circuit operation. */
5157 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5158 && lhs != 0 && rhs != 0
5159 && (code == TRUTH_ANDIF_EXPR
5160 || code == TRUTH_ORIF_EXPR)
5161 && operand_equal_p (lhs, rhs, 0))
5163 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5164 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5165 which cases we can't do this. */
5166 if (simple_operand_p (lhs))
5167 return build2 (code == TRUTH_ANDIF_EXPR
5168 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5171 else if (lang_hooks.decls.global_bindings_p () == 0
5172 && ! CONTAINS_PLACEHOLDER_P (lhs))
5174 tree common = save_expr (lhs);
5176 if (0 != (lhs = build_range_check (type, common,
5177 or_op ? ! in0_p : in0_p,
5179 && (0 != (rhs = build_range_check (type, common,
5180 or_op ? ! in1_p : in1_p,
5183 if (strict_overflow_p)
5184 fold_overflow_warning (warnmsg,
5185 WARN_STRICT_OVERFLOW_COMPARISON);
5186 return build2 (code == TRUTH_ANDIF_EXPR
5187 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5196 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5197 bit value. Arrange things so the extra bits will be set to zero if and
5198 only if C is signed-extended to its full width. If MASK is nonzero,
5199 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5202 unextend (tree c, int p, int unsignedp, tree mask)
5204 tree type = TREE_TYPE (c);
5205 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5208 if (p == modesize || unsignedp)
5211 /* We work by getting just the sign bit into the low-order bit, then
5212 into the high-order bit, then sign-extend. We then XOR that value
5214 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5215 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5217 /* We must use a signed type in order to get an arithmetic right shift.
5218 However, we must also avoid introducing accidental overflows, so that
5219 a subsequent call to integer_zerop will work. Hence we must
5220 do the type conversion here. At this point, the constant is either
5221 zero or one, and the conversion to a signed type can never overflow.
5222 We could get an overflow if this conversion is done anywhere else. */
5223 if (TYPE_UNSIGNED (type))
5224 temp = fold_convert (signed_type_for (type), temp);
5226 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5227 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5229 temp = const_binop (BIT_AND_EXPR, temp,
5230 fold_convert (TREE_TYPE (c), mask), 0);
5231 /* If necessary, convert the type back to match the type of C. */
5232 if (TYPE_UNSIGNED (type))
5233 temp = fold_convert (type, temp);
5235 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5238 /* Find ways of folding logical expressions of LHS and RHS:
5239 Try to merge two comparisons to the same innermost item.
5240 Look for range tests like "ch >= '0' && ch <= '9'".
5241 Look for combinations of simple terms on machines with expensive branches
5242 and evaluate the RHS unconditionally.
5244 For example, if we have p->a == 2 && p->b == 4 and we can make an
5245 object large enough to span both A and B, we can do this with a comparison
5246 against the object ANDed with the a mask.
5248 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5249 operations to do this with one comparison.
5251 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5252 function and the one above.
5254 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5255 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5257 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5260 We return the simplified tree or 0 if no optimization is possible. */
5263 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5265 /* If this is the "or" of two comparisons, we can do something if
5266 the comparisons are NE_EXPR. If this is the "and", we can do something
5267 if the comparisons are EQ_EXPR. I.e.,
5268 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5270 WANTED_CODE is this operation code. For single bit fields, we can
5271 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5272 comparison for one-bit fields. */
5274 enum tree_code wanted_code;
5275 enum tree_code lcode, rcode;
5276 tree ll_arg, lr_arg, rl_arg, rr_arg;
5277 tree ll_inner, lr_inner, rl_inner, rr_inner;
5278 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5279 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5280 HOST_WIDE_INT xll_bitpos, xrl_bitpos;
5281 HOST_WIDE_INT lnbitsize, lnbitpos;
5282 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5283 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5284 enum machine_mode lnmode;
5285 tree ll_mask, lr_mask, rl_mask, rr_mask;
5286 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5287 tree l_const, r_const;
5288 tree lntype, result;
5289 int first_bit, end_bit;
5291 tree orig_lhs = lhs, orig_rhs = rhs;
5292 enum tree_code orig_code = code;
5294 /* Start by getting the comparison codes. Fail if anything is volatile.
5295 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5296 it were surrounded with a NE_EXPR. */
5298 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5301 lcode = TREE_CODE (lhs);
5302 rcode = TREE_CODE (rhs);
5304 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5306 lhs = build2 (NE_EXPR, truth_type, lhs,
5307 build_int_cst (TREE_TYPE (lhs), 0));
5311 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5313 rhs = build2 (NE_EXPR, truth_type, rhs,
5314 build_int_cst (TREE_TYPE (rhs), 0));
5318 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5319 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5322 ll_arg = TREE_OPERAND (lhs, 0);
5323 lr_arg = TREE_OPERAND (lhs, 1);
5324 rl_arg = TREE_OPERAND (rhs, 0);
5325 rr_arg = TREE_OPERAND (rhs, 1);
5327 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5328 if (simple_operand_p (ll_arg)
5329 && simple_operand_p (lr_arg))
5332 if (operand_equal_p (ll_arg, rl_arg, 0)
5333 && operand_equal_p (lr_arg, rr_arg, 0))
5335 result = combine_comparisons (code, lcode, rcode,
5336 truth_type, ll_arg, lr_arg);
5340 else if (operand_equal_p (ll_arg, rr_arg, 0)
5341 && operand_equal_p (lr_arg, rl_arg, 0))
5343 result = combine_comparisons (code, lcode,
5344 swap_tree_comparison (rcode),
5345 truth_type, ll_arg, lr_arg);
5351 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5352 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5354 /* If the RHS can be evaluated unconditionally and its operands are
5355 simple, it wins to evaluate the RHS unconditionally on machines
5356 with expensive branches. In this case, this isn't a comparison
5357 that can be merged. Avoid doing this if the RHS is a floating-point
5358 comparison since those can trap. */
5360 if (BRANCH_COST >= 2
5361 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5362 && simple_operand_p (rl_arg)
5363 && simple_operand_p (rr_arg))
5365 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5366 if (code == TRUTH_OR_EXPR
5367 && lcode == NE_EXPR && integer_zerop (lr_arg)
5368 && rcode == NE_EXPR && integer_zerop (rr_arg)
5369 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5370 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5371 return build2 (NE_EXPR, truth_type,
5372 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5374 build_int_cst (TREE_TYPE (ll_arg), 0));
5376 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5377 if (code == TRUTH_AND_EXPR
5378 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5379 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5380 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5381 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5382 return build2 (EQ_EXPR, truth_type,
5383 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5385 build_int_cst (TREE_TYPE (ll_arg), 0));
5387 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5389 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5390 return build2 (code, truth_type, lhs, rhs);
5395 /* See if the comparisons can be merged. Then get all the parameters for
5398 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5399 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5403 ll_inner = decode_field_reference (ll_arg,
5404 &ll_bitsize, &ll_bitpos, &ll_mode,
5405 &ll_unsignedp, &volatilep, &ll_mask,
5407 lr_inner = decode_field_reference (lr_arg,
5408 &lr_bitsize, &lr_bitpos, &lr_mode,
5409 &lr_unsignedp, &volatilep, &lr_mask,
5411 rl_inner = decode_field_reference (rl_arg,
5412 &rl_bitsize, &rl_bitpos, &rl_mode,
5413 &rl_unsignedp, &volatilep, &rl_mask,
5415 rr_inner = decode_field_reference (rr_arg,
5416 &rr_bitsize, &rr_bitpos, &rr_mode,
5417 &rr_unsignedp, &volatilep, &rr_mask,
5420 /* It must be true that the inner operation on the lhs of each
5421 comparison must be the same if we are to be able to do anything.
5422 Then see if we have constants. If not, the same must be true for
5424 if (volatilep || ll_inner == 0 || rl_inner == 0
5425 || ! operand_equal_p (ll_inner, rl_inner, 0))
5428 if (TREE_CODE (lr_arg) == INTEGER_CST
5429 && TREE_CODE (rr_arg) == INTEGER_CST)
5430 l_const = lr_arg, r_const = rr_arg;
5431 else if (lr_inner == 0 || rr_inner == 0
5432 || ! operand_equal_p (lr_inner, rr_inner, 0))
5435 l_const = r_const = 0;
5437 /* If either comparison code is not correct for our logical operation,
5438 fail. However, we can convert a one-bit comparison against zero into
5439 the opposite comparison against that bit being set in the field. */
5441 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5442 if (lcode != wanted_code)
5444 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5446 /* Make the left operand unsigned, since we are only interested
5447 in the value of one bit. Otherwise we are doing the wrong
5456 /* This is analogous to the code for l_const above. */
5457 if (rcode != wanted_code)
5459 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5468 /* See if we can find a mode that contains both fields being compared on
5469 the left. If we can't, fail. Otherwise, update all constants and masks
5470 to be relative to a field of that size. */
5471 first_bit = MIN (ll_bitpos, rl_bitpos);
5472 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5473 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5474 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5476 if (lnmode == VOIDmode)
5479 lnbitsize = GET_MODE_BITSIZE (lnmode);
5480 lnbitpos = first_bit & ~ (lnbitsize - 1);
5481 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5482 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5484 if (BYTES_BIG_ENDIAN)
5486 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5487 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5490 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5491 size_int (xll_bitpos), 0);
5492 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5493 size_int (xrl_bitpos), 0);
5497 l_const = fold_convert (lntype, l_const);
5498 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5499 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5500 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5501 fold_build1 (BIT_NOT_EXPR,
5505 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5507 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5512 r_const = fold_convert (lntype, r_const);
5513 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5514 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5515 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5516 fold_build1 (BIT_NOT_EXPR,
5520 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5522 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5526 /* Handle the case of comparisons with constants. If there is something in
5527 common between the masks, those bits of the constants must be the same.
5528 If not, the condition is always false. Test for this to avoid generating
5529 incorrect code below. */
5530 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5531 if (! integer_zerop (result)
5532 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5533 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5535 if (wanted_code == NE_EXPR)
5537 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5538 return constant_boolean_node (true, truth_type);
5542 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5543 return constant_boolean_node (false, truth_type);
5550 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5554 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5557 enum tree_code op_code;
5560 int consts_equal, consts_lt;
5563 STRIP_SIGN_NOPS (arg0);
5565 op_code = TREE_CODE (arg0);
5566 minmax_const = TREE_OPERAND (arg0, 1);
5567 comp_const = fold_convert (TREE_TYPE (arg0), op1);
5568 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5569 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5570 inner = TREE_OPERAND (arg0, 0);
5572 /* If something does not permit us to optimize, return the original tree. */
5573 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5574 || TREE_CODE (comp_const) != INTEGER_CST
5575 || TREE_OVERFLOW (comp_const)
5576 || TREE_CODE (minmax_const) != INTEGER_CST
5577 || TREE_OVERFLOW (minmax_const))
5580 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5581 and GT_EXPR, doing the rest with recursive calls using logical
5585 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5587 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5590 return invert_truthvalue (tem);
5596 fold_build2 (TRUTH_ORIF_EXPR, type,
5597 optimize_minmax_comparison
5598 (EQ_EXPR, type, arg0, comp_const),
5599 optimize_minmax_comparison
5600 (GT_EXPR, type, arg0, comp_const));
5603 if (op_code == MAX_EXPR && consts_equal)
5604 /* MAX (X, 0) == 0 -> X <= 0 */
5605 return fold_build2 (LE_EXPR, type, inner, comp_const);
5607 else if (op_code == MAX_EXPR && consts_lt)
5608 /* MAX (X, 0) == 5 -> X == 5 */
5609 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5611 else if (op_code == MAX_EXPR)
5612 /* MAX (X, 0) == -1 -> false */
5613 return omit_one_operand (type, integer_zero_node, inner);
5615 else if (consts_equal)
5616 /* MIN (X, 0) == 0 -> X >= 0 */
5617 return fold_build2 (GE_EXPR, type, inner, comp_const);
5620 /* MIN (X, 0) == 5 -> false */
5621 return omit_one_operand (type, integer_zero_node, inner);
5624 /* MIN (X, 0) == -1 -> X == -1 */
5625 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5628 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5629 /* MAX (X, 0) > 0 -> X > 0
5630 MAX (X, 0) > 5 -> X > 5 */
5631 return fold_build2 (GT_EXPR, type, inner, comp_const);
5633 else if (op_code == MAX_EXPR)
5634 /* MAX (X, 0) > -1 -> true */
5635 return omit_one_operand (type, integer_one_node, inner);
5637 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5638 /* MIN (X, 0) > 0 -> false
5639 MIN (X, 0) > 5 -> false */
5640 return omit_one_operand (type, integer_zero_node, inner);
5643 /* MIN (X, 0) > -1 -> X > -1 */
5644 return fold_build2 (GT_EXPR, type, inner, comp_const);
5651 /* T is an integer expression that is being multiplied, divided, or taken a
5652 modulus (CODE says which and what kind of divide or modulus) by a
5653 constant C. See if we can eliminate that operation by folding it with
5654 other operations already in T. WIDE_TYPE, if non-null, is a type that
5655 should be used for the computation if wider than our type.
5657 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5658 (X * 2) + (Y * 4). We must, however, be assured that either the original
5659 expression would not overflow or that overflow is undefined for the type
5660 in the language in question.
5662 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5663 the machine has a multiply-accumulate insn or that this is part of an
5664 addressing calculation.
5666 If we return a non-null expression, it is an equivalent form of the
5667 original computation, but need not be in the original type.
5669 We set *STRICT_OVERFLOW_P to true if the return values depends on
5670 signed overflow being undefined. Otherwise we do not change
5671 *STRICT_OVERFLOW_P. */
5674 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
5675 bool *strict_overflow_p)
5677 /* To avoid exponential search depth, refuse to allow recursion past
5678 three levels. Beyond that (1) it's highly unlikely that we'll find
5679 something interesting and (2) we've probably processed it before
5680 when we built the inner expression. */
5689 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
5696 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
5697 bool *strict_overflow_p)
5699 tree type = TREE_TYPE (t);
5700 enum tree_code tcode = TREE_CODE (t);
5701 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5702 > GET_MODE_SIZE (TYPE_MODE (type)))
5703 ? wide_type : type);
5705 int same_p = tcode == code;
5706 tree op0 = NULL_TREE, op1 = NULL_TREE;
5707 bool sub_strict_overflow_p;
5709 /* Don't deal with constants of zero here; they confuse the code below. */
5710 if (integer_zerop (c))
5713 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5714 op0 = TREE_OPERAND (t, 0);
5716 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5717 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5719 /* Note that we need not handle conditional operations here since fold
5720 already handles those cases. So just do arithmetic here. */
5724 /* For a constant, we can always simplify if we are a multiply
5725 or (for divide and modulus) if it is a multiple of our constant. */
5726 if (code == MULT_EXPR
5727 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5728 return const_binop (code, fold_convert (ctype, t),
5729 fold_convert (ctype, c), 0);
5732 CASE_CONVERT: case NON_LVALUE_EXPR:
5733 /* If op0 is an expression ... */
5734 if ((COMPARISON_CLASS_P (op0)
5735 || UNARY_CLASS_P (op0)
5736 || BINARY_CLASS_P (op0)
5737 || VL_EXP_CLASS_P (op0)
5738 || EXPRESSION_CLASS_P (op0))
5739 /* ... and is unsigned, and its type is smaller than ctype,
5740 then we cannot pass through as widening. */
5741 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5742 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5743 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5744 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5745 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5746 /* ... or this is a truncation (t is narrower than op0),
5747 then we cannot pass through this narrowing. */
5748 || (GET_MODE_SIZE (TYPE_MODE (type))
5749 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5750 /* ... or signedness changes for division or modulus,
5751 then we cannot pass through this conversion. */
5752 || (code != MULT_EXPR
5753 && (TYPE_UNSIGNED (ctype)
5754 != TYPE_UNSIGNED (TREE_TYPE (op0))))
5755 /* ... or has undefined overflow while the converted to
5756 type has not, we cannot do the operation in the inner type
5757 as that would introduce undefined overflow. */
5758 || (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))
5759 && !TYPE_OVERFLOW_UNDEFINED (type))))
5762 /* Pass the constant down and see if we can make a simplification. If
5763 we can, replace this expression with the inner simplification for
5764 possible later conversion to our or some other type. */
5765 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5766 && TREE_CODE (t2) == INTEGER_CST
5767 && !TREE_OVERFLOW (t2)
5768 && (0 != (t1 = extract_muldiv (op0, t2, code,
5770 ? ctype : NULL_TREE,
5771 strict_overflow_p))))
5776 /* If widening the type changes it from signed to unsigned, then we
5777 must avoid building ABS_EXPR itself as unsigned. */
5778 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5780 tree cstype = (*signed_type_for) (ctype);
5781 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
5784 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
5785 return fold_convert (ctype, t1);
5789 /* If the constant is negative, we cannot simplify this. */
5790 if (tree_int_cst_sgn (c) == -1)
5794 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
5796 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
5799 case MIN_EXPR: case MAX_EXPR:
5800 /* If widening the type changes the signedness, then we can't perform
5801 this optimization as that changes the result. */
5802 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5805 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5806 sub_strict_overflow_p = false;
5807 if ((t1 = extract_muldiv (op0, c, code, wide_type,
5808 &sub_strict_overflow_p)) != 0
5809 && (t2 = extract_muldiv (op1, c, code, wide_type,
5810 &sub_strict_overflow_p)) != 0)
5812 if (tree_int_cst_sgn (c) < 0)
5813 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5814 if (sub_strict_overflow_p)
5815 *strict_overflow_p = true;
5816 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5817 fold_convert (ctype, t2));
5821 case LSHIFT_EXPR: case RSHIFT_EXPR:
5822 /* If the second operand is constant, this is a multiplication
5823 or floor division, by a power of two, so we can treat it that
5824 way unless the multiplier or divisor overflows. Signed
5825 left-shift overflow is implementation-defined rather than
5826 undefined in C90, so do not convert signed left shift into
5828 if (TREE_CODE (op1) == INTEGER_CST
5829 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5830 /* const_binop may not detect overflow correctly,
5831 so check for it explicitly here. */
5832 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5833 && TREE_INT_CST_HIGH (op1) == 0
5834 && 0 != (t1 = fold_convert (ctype,
5835 const_binop (LSHIFT_EXPR,
5838 && !TREE_OVERFLOW (t1))
5839 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5840 ? MULT_EXPR : FLOOR_DIV_EXPR,
5841 ctype, fold_convert (ctype, op0), t1),
5842 c, code, wide_type, strict_overflow_p);
5845 case PLUS_EXPR: case MINUS_EXPR:
5846 /* See if we can eliminate the operation on both sides. If we can, we
5847 can return a new PLUS or MINUS. If we can't, the only remaining
5848 cases where we can do anything are if the second operand is a
5850 sub_strict_overflow_p = false;
5851 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
5852 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
5853 if (t1 != 0 && t2 != 0
5854 && (code == MULT_EXPR
5855 /* If not multiplication, we can only do this if both operands
5856 are divisible by c. */
5857 || (multiple_of_p (ctype, op0, c)
5858 && multiple_of_p (ctype, op1, c))))
5860 if (sub_strict_overflow_p)
5861 *strict_overflow_p = true;
5862 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5863 fold_convert (ctype, t2));
5866 /* If this was a subtraction, negate OP1 and set it to be an addition.
5867 This simplifies the logic below. */
5868 if (tcode == MINUS_EXPR)
5869 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5871 if (TREE_CODE (op1) != INTEGER_CST)
5874 /* If either OP1 or C are negative, this optimization is not safe for
5875 some of the division and remainder types while for others we need
5876 to change the code. */
5877 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5879 if (code == CEIL_DIV_EXPR)
5880 code = FLOOR_DIV_EXPR;
5881 else if (code == FLOOR_DIV_EXPR)
5882 code = CEIL_DIV_EXPR;
5883 else if (code != MULT_EXPR
5884 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5888 /* If it's a multiply or a division/modulus operation of a multiple
5889 of our constant, do the operation and verify it doesn't overflow. */
5890 if (code == MULT_EXPR
5891 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5893 op1 = const_binop (code, fold_convert (ctype, op1),
5894 fold_convert (ctype, c), 0);
5895 /* We allow the constant to overflow with wrapping semantics. */
5897 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
5903 /* If we have an unsigned type is not a sizetype, we cannot widen
5904 the operation since it will change the result if the original
5905 computation overflowed. */
5906 if (TYPE_UNSIGNED (ctype)
5907 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5911 /* If we were able to eliminate our operation from the first side,
5912 apply our operation to the second side and reform the PLUS. */
5913 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5914 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
5916 /* The last case is if we are a multiply. In that case, we can
5917 apply the distributive law to commute the multiply and addition
5918 if the multiplication of the constants doesn't overflow. */
5919 if (code == MULT_EXPR)
5920 return fold_build2 (tcode, ctype,
5921 fold_build2 (code, ctype,
5922 fold_convert (ctype, op0),
5923 fold_convert (ctype, c)),
5929 /* We have a special case here if we are doing something like
5930 (C * 8) % 4 since we know that's zero. */
5931 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5932 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5933 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5934 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5935 return omit_one_operand (type, integer_zero_node, op0);
5937 /* ... fall through ... */
5939 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5940 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5941 /* If we can extract our operation from the LHS, do so and return a
5942 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5943 do something only if the second operand is a constant. */
5945 && (t1 = extract_muldiv (op0, c, code, wide_type,
5946 strict_overflow_p)) != 0)
5947 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5948 fold_convert (ctype, op1));
5949 else if (tcode == MULT_EXPR && code == MULT_EXPR
5950 && (t1 = extract_muldiv (op1, c, code, wide_type,
5951 strict_overflow_p)) != 0)
5952 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5953 fold_convert (ctype, t1));
5954 else if (TREE_CODE (op1) != INTEGER_CST)
5957 /* If these are the same operation types, we can associate them
5958 assuming no overflow. */
5960 && 0 != (t1 = int_const_binop (MULT_EXPR, fold_convert (ctype, op1),
5961 fold_convert (ctype, c), 1))
5962 && 0 != (t1 = force_fit_type_double (ctype, TREE_INT_CST_LOW (t1),
5963 TREE_INT_CST_HIGH (t1),
5964 (TYPE_UNSIGNED (ctype)
5965 && tcode != MULT_EXPR) ? -1 : 1,
5966 TREE_OVERFLOW (t1)))
5967 && !TREE_OVERFLOW (t1))
5968 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
5970 /* If these operations "cancel" each other, we have the main
5971 optimizations of this pass, which occur when either constant is a
5972 multiple of the other, in which case we replace this with either an
5973 operation or CODE or TCODE.
5975 If we have an unsigned type that is not a sizetype, we cannot do
5976 this since it will change the result if the original computation
5978 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
5979 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5980 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5981 || (tcode == MULT_EXPR
5982 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5983 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
5984 && code != MULT_EXPR)))
5986 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5988 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5989 *strict_overflow_p = true;
5990 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5991 fold_convert (ctype,
5992 const_binop (TRUNC_DIV_EXPR,
5995 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5997 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5998 *strict_overflow_p = true;
5999 return fold_build2 (code, ctype, fold_convert (ctype, op0),
6000 fold_convert (ctype,
6001 const_binop (TRUNC_DIV_EXPR,
6014 /* Return a node which has the indicated constant VALUE (either 0 or
6015 1), and is of the indicated TYPE. */
6018 constant_boolean_node (int value, tree type)
6020 if (type == integer_type_node)
6021 return value ? integer_one_node : integer_zero_node;
6022 else if (type == boolean_type_node)
6023 return value ? boolean_true_node : boolean_false_node;
6025 return build_int_cst (type, value);
6029 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6030 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6031 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6032 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6033 COND is the first argument to CODE; otherwise (as in the example
6034 given here), it is the second argument. TYPE is the type of the
6035 original expression. Return NULL_TREE if no simplification is
6039 fold_binary_op_with_conditional_arg (enum tree_code code,
6040 tree type, tree op0, tree op1,
6041 tree cond, tree arg, int cond_first_p)
6043 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6044 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6045 tree test, true_value, false_value;
6046 tree lhs = NULL_TREE;
6047 tree rhs = NULL_TREE;
6049 /* This transformation is only worthwhile if we don't have to wrap
6050 arg in a SAVE_EXPR, and the operation can be simplified on at least
6051 one of the branches once its pushed inside the COND_EXPR. */
6052 if (!TREE_CONSTANT (arg))
6055 if (TREE_CODE (cond) == COND_EXPR)
6057 test = TREE_OPERAND (cond, 0);
6058 true_value = TREE_OPERAND (cond, 1);
6059 false_value = TREE_OPERAND (cond, 2);
6060 /* If this operand throws an expression, then it does not make
6061 sense to try to perform a logical or arithmetic operation
6063 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6065 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6070 tree testtype = TREE_TYPE (cond);
6072 true_value = constant_boolean_node (true, testtype);
6073 false_value = constant_boolean_node (false, testtype);
6076 arg = fold_convert (arg_type, arg);
6079 true_value = fold_convert (cond_type, true_value);
6081 lhs = fold_build2 (code, type, true_value, arg);
6083 lhs = fold_build2 (code, type, arg, true_value);
6087 false_value = fold_convert (cond_type, false_value);
6089 rhs = fold_build2 (code, type, false_value, arg);
6091 rhs = fold_build2 (code, type, arg, false_value);
6094 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6095 return fold_convert (type, test);
6099 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6101 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6102 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6103 ADDEND is the same as X.
6105 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6106 and finite. The problematic cases are when X is zero, and its mode
6107 has signed zeros. In the case of rounding towards -infinity,
6108 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6109 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6112 fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
6114 if (!real_zerop (addend))
6117 /* Don't allow the fold with -fsignaling-nans. */
6118 if (HONOR_SNANS (TYPE_MODE (type)))
6121 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6122 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6125 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6126 if (TREE_CODE (addend) == REAL_CST
6127 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6130 /* The mode has signed zeros, and we have to honor their sign.
6131 In this situation, there is only one case we can return true for.
6132 X - 0 is the same as X unless rounding towards -infinity is
6134 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6137 /* Subroutine of fold() that checks comparisons of built-in math
6138 functions against real constants.
6140 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6141 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6142 is the type of the result and ARG0 and ARG1 are the operands of the
6143 comparison. ARG1 must be a TREE_REAL_CST.
6145 The function returns the constant folded tree if a simplification
6146 can be made, and NULL_TREE otherwise. */
6149 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6150 tree type, tree arg0, tree arg1)
6154 if (BUILTIN_SQRT_P (fcode))
6156 tree arg = CALL_EXPR_ARG (arg0, 0);
6157 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6159 c = TREE_REAL_CST (arg1);
6160 if (REAL_VALUE_NEGATIVE (c))
6162 /* sqrt(x) < y is always false, if y is negative. */
6163 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6164 return omit_one_operand (type, integer_zero_node, arg);
6166 /* sqrt(x) > y is always true, if y is negative and we
6167 don't care about NaNs, i.e. negative values of x. */
6168 if (code == NE_EXPR || !HONOR_NANS (mode))
6169 return omit_one_operand (type, integer_one_node, arg);
6171 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6172 return fold_build2 (GE_EXPR, type, arg,
6173 build_real (TREE_TYPE (arg), dconst0));
6175 else if (code == GT_EXPR || code == GE_EXPR)
6179 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6180 real_convert (&c2, mode, &c2);
6182 if (REAL_VALUE_ISINF (c2))
6184 /* sqrt(x) > y is x == +Inf, when y is very large. */
6185 if (HONOR_INFINITIES (mode))
6186 return fold_build2 (EQ_EXPR, type, arg,
6187 build_real (TREE_TYPE (arg), c2));
6189 /* sqrt(x) > y is always false, when y is very large
6190 and we don't care about infinities. */
6191 return omit_one_operand (type, integer_zero_node, arg);
6194 /* sqrt(x) > c is the same as x > c*c. */
6195 return fold_build2 (code, type, arg,
6196 build_real (TREE_TYPE (arg), c2));
6198 else if (code == LT_EXPR || code == LE_EXPR)
6202 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6203 real_convert (&c2, mode, &c2);
6205 if (REAL_VALUE_ISINF (c2))
6207 /* sqrt(x) < y is always true, when y is a very large
6208 value and we don't care about NaNs or Infinities. */
6209 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6210 return omit_one_operand (type, integer_one_node, arg);
6212 /* sqrt(x) < y is x != +Inf when y is very large and we
6213 don't care about NaNs. */
6214 if (! HONOR_NANS (mode))
6215 return fold_build2 (NE_EXPR, type, arg,
6216 build_real (TREE_TYPE (arg), c2));
6218 /* sqrt(x) < y is x >= 0 when y is very large and we
6219 don't care about Infinities. */
6220 if (! HONOR_INFINITIES (mode))
6221 return fold_build2 (GE_EXPR, type, arg,
6222 build_real (TREE_TYPE (arg), dconst0));
6224 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6225 if (lang_hooks.decls.global_bindings_p () != 0
6226 || CONTAINS_PLACEHOLDER_P (arg))
6229 arg = save_expr (arg);
6230 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6231 fold_build2 (GE_EXPR, type, arg,
6232 build_real (TREE_TYPE (arg),
6234 fold_build2 (NE_EXPR, type, arg,
6235 build_real (TREE_TYPE (arg),
6239 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6240 if (! HONOR_NANS (mode))
6241 return fold_build2 (code, type, arg,
6242 build_real (TREE_TYPE (arg), c2));
6244 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6245 if (lang_hooks.decls.global_bindings_p () == 0
6246 && ! CONTAINS_PLACEHOLDER_P (arg))
6248 arg = save_expr (arg);
6249 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6250 fold_build2 (GE_EXPR, type, arg,
6251 build_real (TREE_TYPE (arg),
6253 fold_build2 (code, type, arg,
6254 build_real (TREE_TYPE (arg),
6263 /* Subroutine of fold() that optimizes comparisons against Infinities,
6264 either +Inf or -Inf.
6266 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6267 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6268 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6270 The function returns the constant folded tree if a simplification
6271 can be made, and NULL_TREE otherwise. */
6274 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6276 enum machine_mode mode;
6277 REAL_VALUE_TYPE max;
6281 mode = TYPE_MODE (TREE_TYPE (arg0));
6283 /* For negative infinity swap the sense of the comparison. */
6284 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6286 code = swap_tree_comparison (code);
6291 /* x > +Inf is always false, if with ignore sNANs. */
6292 if (HONOR_SNANS (mode))
6294 return omit_one_operand (type, integer_zero_node, arg0);
6297 /* x <= +Inf is always true, if we don't case about NaNs. */
6298 if (! HONOR_NANS (mode))
6299 return omit_one_operand (type, integer_one_node, arg0);
6301 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6302 if (lang_hooks.decls.global_bindings_p () == 0
6303 && ! CONTAINS_PLACEHOLDER_P (arg0))
6305 arg0 = save_expr (arg0);
6306 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6312 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6313 real_maxval (&max, neg, mode);
6314 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6315 arg0, build_real (TREE_TYPE (arg0), max));
6318 /* x < +Inf is always equal to x <= DBL_MAX. */
6319 real_maxval (&max, neg, mode);
6320 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6321 arg0, build_real (TREE_TYPE (arg0), max));
6324 /* x != +Inf is always equal to !(x > DBL_MAX). */
6325 real_maxval (&max, neg, mode);
6326 if (! HONOR_NANS (mode))
6327 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6328 arg0, build_real (TREE_TYPE (arg0), max));
6330 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6331 arg0, build_real (TREE_TYPE (arg0), max));
6332 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6341 /* Subroutine of fold() that optimizes comparisons of a division by
6342 a nonzero integer constant against an integer constant, i.e.
6345 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6346 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6347 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6349 The function returns the constant folded tree if a simplification
6350 can be made, and NULL_TREE otherwise. */
6353 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6355 tree prod, tmp, hi, lo;
6356 tree arg00 = TREE_OPERAND (arg0, 0);
6357 tree arg01 = TREE_OPERAND (arg0, 1);
6358 unsigned HOST_WIDE_INT lpart;
6359 HOST_WIDE_INT hpart;
6360 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6364 /* We have to do this the hard way to detect unsigned overflow.
6365 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6366 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6367 TREE_INT_CST_HIGH (arg01),
6368 TREE_INT_CST_LOW (arg1),
6369 TREE_INT_CST_HIGH (arg1),
6370 &lpart, &hpart, unsigned_p);
6371 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6373 neg_overflow = false;
6377 tmp = int_const_binop (MINUS_EXPR, arg01,
6378 build_int_cst (TREE_TYPE (arg01), 1), 0);
6381 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6382 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6383 TREE_INT_CST_HIGH (prod),
6384 TREE_INT_CST_LOW (tmp),
6385 TREE_INT_CST_HIGH (tmp),
6386 &lpart, &hpart, unsigned_p);
6387 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6388 -1, overflow | TREE_OVERFLOW (prod));
6390 else if (tree_int_cst_sgn (arg01) >= 0)
6392 tmp = int_const_binop (MINUS_EXPR, arg01,
6393 build_int_cst (TREE_TYPE (arg01), 1), 0);
6394 switch (tree_int_cst_sgn (arg1))
6397 neg_overflow = true;
6398 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6403 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6408 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6418 /* A negative divisor reverses the relational operators. */
6419 code = swap_tree_comparison (code);
6421 tmp = int_const_binop (PLUS_EXPR, arg01,
6422 build_int_cst (TREE_TYPE (arg01), 1), 0);
6423 switch (tree_int_cst_sgn (arg1))
6426 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6431 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6436 neg_overflow = true;
6437 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6449 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6450 return omit_one_operand (type, integer_zero_node, arg00);
6451 if (TREE_OVERFLOW (hi))
6452 return fold_build2 (GE_EXPR, type, arg00, lo);
6453 if (TREE_OVERFLOW (lo))
6454 return fold_build2 (LE_EXPR, type, arg00, hi);
6455 return build_range_check (type, arg00, 1, lo, hi);
6458 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6459 return omit_one_operand (type, integer_one_node, arg00);
6460 if (TREE_OVERFLOW (hi))
6461 return fold_build2 (LT_EXPR, type, arg00, lo);
6462 if (TREE_OVERFLOW (lo))
6463 return fold_build2 (GT_EXPR, type, arg00, hi);
6464 return build_range_check (type, arg00, 0, lo, hi);
6467 if (TREE_OVERFLOW (lo))
6469 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6470 return omit_one_operand (type, tmp, arg00);
6472 return fold_build2 (LT_EXPR, type, arg00, lo);
6475 if (TREE_OVERFLOW (hi))
6477 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6478 return omit_one_operand (type, tmp, arg00);
6480 return fold_build2 (LE_EXPR, type, arg00, hi);
6483 if (TREE_OVERFLOW (hi))
6485 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6486 return omit_one_operand (type, tmp, arg00);
6488 return fold_build2 (GT_EXPR, type, arg00, hi);
6491 if (TREE_OVERFLOW (lo))
6493 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6494 return omit_one_operand (type, tmp, arg00);
6496 return fold_build2 (GE_EXPR, type, arg00, lo);
6506 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6507 equality/inequality test, then return a simplified form of the test
6508 using a sign testing. Otherwise return NULL. TYPE is the desired
6512 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6515 /* If this is testing a single bit, we can optimize the test. */
6516 if ((code == NE_EXPR || code == EQ_EXPR)
6517 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6518 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6520 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6521 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6522 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6524 if (arg00 != NULL_TREE
6525 /* This is only a win if casting to a signed type is cheap,
6526 i.e. when arg00's type is not a partial mode. */
6527 && TYPE_PRECISION (TREE_TYPE (arg00))
6528 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6530 tree stype = signed_type_for (TREE_TYPE (arg00));
6531 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6532 result_type, fold_convert (stype, arg00),
6533 build_int_cst (stype, 0));
6540 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6541 equality/inequality test, then return a simplified form of
6542 the test using shifts and logical operations. Otherwise return
6543 NULL. TYPE is the desired result type. */
6546 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6549 /* If this is testing a single bit, we can optimize the test. */
6550 if ((code == NE_EXPR || code == EQ_EXPR)
6551 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6552 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6554 tree inner = TREE_OPERAND (arg0, 0);
6555 tree type = TREE_TYPE (arg0);
6556 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6557 enum machine_mode operand_mode = TYPE_MODE (type);
6559 tree signed_type, unsigned_type, intermediate_type;
6562 /* First, see if we can fold the single bit test into a sign-bit
6564 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6569 /* Otherwise we have (A & C) != 0 where C is a single bit,
6570 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6571 Similarly for (A & C) == 0. */
6573 /* If INNER is a right shift of a constant and it plus BITNUM does
6574 not overflow, adjust BITNUM and INNER. */
6575 if (TREE_CODE (inner) == RSHIFT_EXPR
6576 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6577 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6578 && bitnum < TYPE_PRECISION (type)
6579 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6580 bitnum - TYPE_PRECISION (type)))
6582 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6583 inner = TREE_OPERAND (inner, 0);
6586 /* If we are going to be able to omit the AND below, we must do our
6587 operations as unsigned. If we must use the AND, we have a choice.
6588 Normally unsigned is faster, but for some machines signed is. */
6589 #ifdef LOAD_EXTEND_OP
6590 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6591 && !flag_syntax_only) ? 0 : 1;
6596 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6597 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6598 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6599 inner = fold_convert (intermediate_type, inner);
6602 inner = build2 (RSHIFT_EXPR, intermediate_type,
6603 inner, size_int (bitnum));
6605 one = build_int_cst (intermediate_type, 1);
6607 if (code == EQ_EXPR)
6608 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6610 /* Put the AND last so it can combine with more things. */
6611 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6613 /* Make sure to return the proper type. */
6614 inner = fold_convert (result_type, inner);
6621 /* Check whether we are allowed to reorder operands arg0 and arg1,
6622 such that the evaluation of arg1 occurs before arg0. */
6625 reorder_operands_p (const_tree arg0, const_tree arg1)
6627 if (! flag_evaluation_order)
6629 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6631 return ! TREE_SIDE_EFFECTS (arg0)
6632 && ! TREE_SIDE_EFFECTS (arg1);
6635 /* Test whether it is preferable two swap two operands, ARG0 and
6636 ARG1, for example because ARG0 is an integer constant and ARG1
6637 isn't. If REORDER is true, only recommend swapping if we can
6638 evaluate the operands in reverse order. */
6641 tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
6643 STRIP_SIGN_NOPS (arg0);
6644 STRIP_SIGN_NOPS (arg1);
6646 if (TREE_CODE (arg1) == INTEGER_CST)
6648 if (TREE_CODE (arg0) == INTEGER_CST)
6651 if (TREE_CODE (arg1) == REAL_CST)
6653 if (TREE_CODE (arg0) == REAL_CST)
6656 if (TREE_CODE (arg1) == FIXED_CST)
6658 if (TREE_CODE (arg0) == FIXED_CST)
6661 if (TREE_CODE (arg1) == COMPLEX_CST)
6663 if (TREE_CODE (arg0) == COMPLEX_CST)
6666 if (TREE_CONSTANT (arg1))
6668 if (TREE_CONSTANT (arg0))
6674 if (reorder && flag_evaluation_order
6675 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6678 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6679 for commutative and comparison operators. Ensuring a canonical
6680 form allows the optimizers to find additional redundancies without
6681 having to explicitly check for both orderings. */
6682 if (TREE_CODE (arg0) == SSA_NAME
6683 && TREE_CODE (arg1) == SSA_NAME
6684 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6687 /* Put SSA_NAMEs last. */
6688 if (TREE_CODE (arg1) == SSA_NAME)
6690 if (TREE_CODE (arg0) == SSA_NAME)
6693 /* Put variables last. */
6702 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6703 ARG0 is extended to a wider type. */
6706 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6708 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6710 tree shorter_type, outer_type;
6714 if (arg0_unw == arg0)
6716 shorter_type = TREE_TYPE (arg0_unw);
6718 #ifdef HAVE_canonicalize_funcptr_for_compare
6719 /* Disable this optimization if we're casting a function pointer
6720 type on targets that require function pointer canonicalization. */
6721 if (HAVE_canonicalize_funcptr_for_compare
6722 && TREE_CODE (shorter_type) == POINTER_TYPE
6723 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
6727 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6730 arg1_unw = get_unwidened (arg1, NULL_TREE);
6732 /* If possible, express the comparison in the shorter mode. */
6733 if ((code == EQ_EXPR || code == NE_EXPR
6734 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6735 && (TREE_TYPE (arg1_unw) == shorter_type
6736 || (TYPE_PRECISION (shorter_type)
6737 > TYPE_PRECISION (TREE_TYPE (arg1_unw)))
6738 || ((TYPE_PRECISION (shorter_type)
6739 == TYPE_PRECISION (TREE_TYPE (arg1_unw)))
6740 && (TYPE_UNSIGNED (shorter_type)
6741 == TYPE_UNSIGNED (TREE_TYPE (arg1_unw))))
6742 || (TREE_CODE (arg1_unw) == INTEGER_CST
6743 && (TREE_CODE (shorter_type) == INTEGER_TYPE
6744 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
6745 && int_fits_type_p (arg1_unw, shorter_type))))
6746 return fold_build2 (code, type, arg0_unw,
6747 fold_convert (shorter_type, arg1_unw));
6749 if (TREE_CODE (arg1_unw) != INTEGER_CST
6750 || TREE_CODE (shorter_type) != INTEGER_TYPE
6751 || !int_fits_type_p (arg1_unw, shorter_type))
6754 /* If we are comparing with the integer that does not fit into the range
6755 of the shorter type, the result is known. */
6756 outer_type = TREE_TYPE (arg1_unw);
6757 min = lower_bound_in_type (outer_type, shorter_type);
6758 max = upper_bound_in_type (outer_type, shorter_type);
6760 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6762 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6769 return omit_one_operand (type, integer_zero_node, arg0);
6774 return omit_one_operand (type, integer_one_node, arg0);
6780 return omit_one_operand (type, integer_one_node, arg0);
6782 return omit_one_operand (type, integer_zero_node, arg0);
6787 return omit_one_operand (type, integer_zero_node, arg0);
6789 return omit_one_operand (type, integer_one_node, arg0);
6798 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6799 ARG0 just the signedness is changed. */
6802 fold_sign_changed_comparison (enum tree_code code, tree type,
6803 tree arg0, tree arg1)
6806 tree inner_type, outer_type;
6808 if (!CONVERT_EXPR_P (arg0))
6811 outer_type = TREE_TYPE (arg0);
6812 arg0_inner = TREE_OPERAND (arg0, 0);
6813 inner_type = TREE_TYPE (arg0_inner);
6815 #ifdef HAVE_canonicalize_funcptr_for_compare
6816 /* Disable this optimization if we're casting a function pointer
6817 type on targets that require function pointer canonicalization. */
6818 if (HAVE_canonicalize_funcptr_for_compare
6819 && TREE_CODE (inner_type) == POINTER_TYPE
6820 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
6824 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6827 /* If the conversion is from an integral subtype to its basetype
6829 if (TREE_TYPE (inner_type) == outer_type)
6832 if (TREE_CODE (arg1) != INTEGER_CST
6833 && !(CONVERT_EXPR_P (arg1)
6834 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6837 if ((TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6838 || POINTER_TYPE_P (inner_type) != POINTER_TYPE_P (outer_type))
6843 if (TREE_CODE (arg1) == INTEGER_CST)
6844 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
6845 TREE_INT_CST_HIGH (arg1), 0,
6846 TREE_OVERFLOW (arg1));
6848 arg1 = fold_convert (inner_type, arg1);
6850 return fold_build2 (code, type, arg0_inner, arg1);
6853 /* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
6854 step of the array. Reconstructs s and delta in the case of s * delta
6855 being an integer constant (and thus already folded).
6856 ADDR is the address. MULT is the multiplicative expression.
6857 If the function succeeds, the new address expression is returned. Otherwise
6858 NULL_TREE is returned. */
6861 try_move_mult_to_index (tree addr, tree op1)
6863 tree s, delta, step;
6864 tree ref = TREE_OPERAND (addr, 0), pref;
6869 /* Strip the nops that might be added when converting op1 to sizetype. */
6872 /* Canonicalize op1 into a possibly non-constant delta
6873 and an INTEGER_CST s. */
6874 if (TREE_CODE (op1) == MULT_EXPR)
6876 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
6881 if (TREE_CODE (arg0) == INTEGER_CST)
6886 else if (TREE_CODE (arg1) == INTEGER_CST)
6894 else if (TREE_CODE (op1) == INTEGER_CST)
6901 /* Simulate we are delta * 1. */
6903 s = integer_one_node;
6906 for (;; ref = TREE_OPERAND (ref, 0))
6908 if (TREE_CODE (ref) == ARRAY_REF)
6910 /* Remember if this was a multi-dimensional array. */
6911 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
6914 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
6918 step = array_ref_element_size (ref);
6919 if (TREE_CODE (step) != INTEGER_CST)
6924 if (! tree_int_cst_equal (step, s))
6929 /* Try if delta is a multiple of step. */
6930 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, op1, step);
6936 /* Only fold here if we can verify we do not overflow one
6937 dimension of a multi-dimensional array. */
6942 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
6943 || !INTEGRAL_TYPE_P (itype)
6944 || !TYPE_MAX_VALUE (itype)
6945 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
6948 tmp = fold_binary (PLUS_EXPR, itype,
6949 fold_convert (itype,
6950 TREE_OPERAND (ref, 1)),
6951 fold_convert (itype, delta));
6953 || TREE_CODE (tmp) != INTEGER_CST
6954 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
6963 if (!handled_component_p (ref))
6967 /* We found the suitable array reference. So copy everything up to it,
6968 and replace the index. */
6970 pref = TREE_OPERAND (addr, 0);
6971 ret = copy_node (pref);
6976 pref = TREE_OPERAND (pref, 0);
6977 TREE_OPERAND (pos, 0) = copy_node (pref);
6978 pos = TREE_OPERAND (pos, 0);
6981 TREE_OPERAND (pos, 1) = fold_build2 (PLUS_EXPR, itype,
6982 fold_convert (itype,
6983 TREE_OPERAND (pos, 1)),
6984 fold_convert (itype, delta));
6986 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6990 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6991 means A >= Y && A != MAX, but in this case we know that
6992 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6995 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6997 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6999 if (TREE_CODE (bound) == LT_EXPR)
7000 a = TREE_OPERAND (bound, 0);
7001 else if (TREE_CODE (bound) == GT_EXPR)
7002 a = TREE_OPERAND (bound, 1);
7006 typea = TREE_TYPE (a);
7007 if (!INTEGRAL_TYPE_P (typea)
7008 && !POINTER_TYPE_P (typea))
7011 if (TREE_CODE (ineq) == LT_EXPR)
7013 a1 = TREE_OPERAND (ineq, 1);
7014 y = TREE_OPERAND (ineq, 0);
7016 else if (TREE_CODE (ineq) == GT_EXPR)
7018 a1 = TREE_OPERAND (ineq, 0);
7019 y = TREE_OPERAND (ineq, 1);
7024 if (TREE_TYPE (a1) != typea)
7027 if (POINTER_TYPE_P (typea))
7029 /* Convert the pointer types into integer before taking the difference. */
7030 tree ta = fold_convert (ssizetype, a);
7031 tree ta1 = fold_convert (ssizetype, a1);
7032 diff = fold_binary (MINUS_EXPR, ssizetype, ta1, ta);
7035 diff = fold_binary (MINUS_EXPR, typea, a1, a);
7037 if (!diff || !integer_onep (diff))
7040 return fold_build2 (GE_EXPR, type, a, y);
7043 /* Fold a sum or difference of at least one multiplication.
7044 Returns the folded tree or NULL if no simplification could be made. */
7047 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7049 tree arg00, arg01, arg10, arg11;
7050 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7052 /* (A * C) +- (B * C) -> (A+-B) * C.
7053 (A * C) +- A -> A * (C+-1).
7054 We are most concerned about the case where C is a constant,
7055 but other combinations show up during loop reduction. Since
7056 it is not difficult, try all four possibilities. */
7058 if (TREE_CODE (arg0) == MULT_EXPR)
7060 arg00 = TREE_OPERAND (arg0, 0);
7061 arg01 = TREE_OPERAND (arg0, 1);
7063 else if (TREE_CODE (arg0) == INTEGER_CST)
7065 arg00 = build_one_cst (type);
7070 /* We cannot generate constant 1 for fract. */
7071 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7074 arg01 = build_one_cst (type);
7076 if (TREE_CODE (arg1) == MULT_EXPR)
7078 arg10 = TREE_OPERAND (arg1, 0);
7079 arg11 = TREE_OPERAND (arg1, 1);
7081 else if (TREE_CODE (arg1) == INTEGER_CST)
7083 arg10 = build_one_cst (type);
7088 /* We cannot generate constant 1 for fract. */
7089 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7092 arg11 = build_one_cst (type);
7096 if (operand_equal_p (arg01, arg11, 0))
7097 same = arg01, alt0 = arg00, alt1 = arg10;
7098 else if (operand_equal_p (arg00, arg10, 0))
7099 same = arg00, alt0 = arg01, alt1 = arg11;
7100 else if (operand_equal_p (arg00, arg11, 0))
7101 same = arg00, alt0 = arg01, alt1 = arg10;
7102 else if (operand_equal_p (arg01, arg10, 0))
7103 same = arg01, alt0 = arg00, alt1 = arg11;
7105 /* No identical multiplicands; see if we can find a common
7106 power-of-two factor in non-power-of-two multiplies. This
7107 can help in multi-dimensional array access. */
7108 else if (host_integerp (arg01, 0)
7109 && host_integerp (arg11, 0))
7111 HOST_WIDE_INT int01, int11, tmp;
7114 int01 = TREE_INT_CST_LOW (arg01);
7115 int11 = TREE_INT_CST_LOW (arg11);
7117 /* Move min of absolute values to int11. */
7118 if ((int01 >= 0 ? int01 : -int01)
7119 < (int11 >= 0 ? int11 : -int11))
7121 tmp = int01, int01 = int11, int11 = tmp;
7122 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7129 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
7131 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7132 build_int_cst (TREE_TYPE (arg00),
7137 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7142 return fold_build2 (MULT_EXPR, type,
7143 fold_build2 (code, type,
7144 fold_convert (type, alt0),
7145 fold_convert (type, alt1)),
7146 fold_convert (type, same));
7151 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7152 specified by EXPR into the buffer PTR of length LEN bytes.
7153 Return the number of bytes placed in the buffer, or zero
7157 native_encode_int (const_tree expr, unsigned char *ptr, int len)
7159 tree type = TREE_TYPE (expr);
7160 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7161 int byte, offset, word, words;
7162 unsigned char value;
7164 if (total_bytes > len)
7166 words = total_bytes / UNITS_PER_WORD;
7168 for (byte = 0; byte < total_bytes; byte++)
7170 int bitpos = byte * BITS_PER_UNIT;
7171 if (bitpos < HOST_BITS_PER_WIDE_INT)
7172 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7174 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7175 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7177 if (total_bytes > UNITS_PER_WORD)
7179 word = byte / UNITS_PER_WORD;
7180 if (WORDS_BIG_ENDIAN)
7181 word = (words - 1) - word;
7182 offset = word * UNITS_PER_WORD;
7183 if (BYTES_BIG_ENDIAN)
7184 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7186 offset += byte % UNITS_PER_WORD;
7189 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7190 ptr[offset] = value;
7196 /* Subroutine of native_encode_expr. Encode the REAL_CST
7197 specified by EXPR into the buffer PTR of length LEN bytes.
7198 Return the number of bytes placed in the buffer, or zero
7202 native_encode_real (const_tree expr, unsigned char *ptr, int len)
7204 tree type = TREE_TYPE (expr);
7205 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7206 int byte, offset, word, words, bitpos;
7207 unsigned char value;
7209 /* There are always 32 bits in each long, no matter the size of
7210 the hosts long. We handle floating point representations with
7214 if (total_bytes > len)
7216 words = 32 / UNITS_PER_WORD;
7218 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7220 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7221 bitpos += BITS_PER_UNIT)
7223 byte = (bitpos / BITS_PER_UNIT) & 3;
7224 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7226 if (UNITS_PER_WORD < 4)
7228 word = byte / UNITS_PER_WORD;
7229 if (WORDS_BIG_ENDIAN)
7230 word = (words - 1) - word;
7231 offset = word * UNITS_PER_WORD;
7232 if (BYTES_BIG_ENDIAN)
7233 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7235 offset += byte % UNITS_PER_WORD;
7238 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7239 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7244 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7245 specified by EXPR into the buffer PTR of length LEN bytes.
7246 Return the number of bytes placed in the buffer, or zero
7250 native_encode_complex (const_tree expr, unsigned char *ptr, int len)
7255 part = TREE_REALPART (expr);
7256 rsize = native_encode_expr (part, ptr, len);
7259 part = TREE_IMAGPART (expr);
7260 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7263 return rsize + isize;
7267 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7268 specified by EXPR into the buffer PTR of length LEN bytes.
7269 Return the number of bytes placed in the buffer, or zero
7273 native_encode_vector (const_tree expr, unsigned char *ptr, int len)
7275 int i, size, offset, count;
7276 tree itype, elem, elements;
7279 elements = TREE_VECTOR_CST_ELTS (expr);
7280 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7281 itype = TREE_TYPE (TREE_TYPE (expr));
7282 size = GET_MODE_SIZE (TYPE_MODE (itype));
7283 for (i = 0; i < count; i++)
7287 elem = TREE_VALUE (elements);
7288 elements = TREE_CHAIN (elements);
7295 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7300 if (offset + size > len)
7302 memset (ptr+offset, 0, size);
7310 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7311 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7312 buffer PTR of length LEN bytes. Return the number of bytes
7313 placed in the buffer, or zero upon failure. */
7316 native_encode_expr (const_tree expr, unsigned char *ptr, int len)
7318 switch (TREE_CODE (expr))
7321 return native_encode_int (expr, ptr, len);
7324 return native_encode_real (expr, ptr, len);
7327 return native_encode_complex (expr, ptr, len);
7330 return native_encode_vector (expr, ptr, len);
7338 /* Subroutine of native_interpret_expr. Interpret the contents of
7339 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7340 If the buffer cannot be interpreted, return NULL_TREE. */
7343 native_interpret_int (tree type, const unsigned char *ptr, int len)
7345 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7346 int byte, offset, word, words;
7347 unsigned char value;
7348 unsigned int HOST_WIDE_INT lo = 0;
7349 HOST_WIDE_INT hi = 0;
7351 if (total_bytes > len)
7353 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7355 words = total_bytes / UNITS_PER_WORD;
7357 for (byte = 0; byte < total_bytes; byte++)
7359 int bitpos = byte * BITS_PER_UNIT;
7360 if (total_bytes > UNITS_PER_WORD)
7362 word = byte / UNITS_PER_WORD;
7363 if (WORDS_BIG_ENDIAN)
7364 word = (words - 1) - word;
7365 offset = word * UNITS_PER_WORD;
7366 if (BYTES_BIG_ENDIAN)
7367 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7369 offset += byte % UNITS_PER_WORD;
7372 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7373 value = ptr[offset];
7375 if (bitpos < HOST_BITS_PER_WIDE_INT)
7376 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7378 hi |= (unsigned HOST_WIDE_INT) value
7379 << (bitpos - HOST_BITS_PER_WIDE_INT);
7382 return build_int_cst_wide_type (type, lo, hi);
7386 /* Subroutine of native_interpret_expr. Interpret the contents of
7387 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7388 If the buffer cannot be interpreted, return NULL_TREE. */
7391 native_interpret_real (tree type, const unsigned char *ptr, int len)
7393 enum machine_mode mode = TYPE_MODE (type);
7394 int total_bytes = GET_MODE_SIZE (mode);
7395 int byte, offset, word, words, bitpos;
7396 unsigned char value;
7397 /* There are always 32 bits in each long, no matter the size of
7398 the hosts long. We handle floating point representations with
7403 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7404 if (total_bytes > len || total_bytes > 24)
7406 words = 32 / UNITS_PER_WORD;
7408 memset (tmp, 0, sizeof (tmp));
7409 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7410 bitpos += BITS_PER_UNIT)
7412 byte = (bitpos / BITS_PER_UNIT) & 3;
7413 if (UNITS_PER_WORD < 4)
7415 word = byte / UNITS_PER_WORD;
7416 if (WORDS_BIG_ENDIAN)
7417 word = (words - 1) - word;
7418 offset = word * UNITS_PER_WORD;
7419 if (BYTES_BIG_ENDIAN)
7420 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7422 offset += byte % UNITS_PER_WORD;
7425 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7426 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7428 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7431 real_from_target (&r, tmp, mode);
7432 return build_real (type, r);
7436 /* Subroutine of native_interpret_expr. Interpret the contents of
7437 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7438 If the buffer cannot be interpreted, return NULL_TREE. */
7441 native_interpret_complex (tree type, const unsigned char *ptr, int len)
7443 tree etype, rpart, ipart;
7446 etype = TREE_TYPE (type);
7447 size = GET_MODE_SIZE (TYPE_MODE (etype));
7450 rpart = native_interpret_expr (etype, ptr, size);
7453 ipart = native_interpret_expr (etype, ptr+size, size);
7456 return build_complex (type, rpart, ipart);
7460 /* Subroutine of native_interpret_expr. Interpret the contents of
7461 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7462 If the buffer cannot be interpreted, return NULL_TREE. */
7465 native_interpret_vector (tree type, const unsigned char *ptr, int len)
7467 tree etype, elem, elements;
7470 etype = TREE_TYPE (type);
7471 size = GET_MODE_SIZE (TYPE_MODE (etype));
7472 count = TYPE_VECTOR_SUBPARTS (type);
7473 if (size * count > len)
7476 elements = NULL_TREE;
7477 for (i = count - 1; i >= 0; i--)
7479 elem = native_interpret_expr (etype, ptr+(i*size), size);
7482 elements = tree_cons (NULL_TREE, elem, elements);
7484 return build_vector (type, elements);
7488 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7489 the buffer PTR of length LEN as a constant of type TYPE. For
7490 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7491 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7492 return NULL_TREE. */
7495 native_interpret_expr (tree type, const unsigned char *ptr, int len)
7497 switch (TREE_CODE (type))
7502 return native_interpret_int (type, ptr, len);
7505 return native_interpret_real (type, ptr, len);
7508 return native_interpret_complex (type, ptr, len);
7511 return native_interpret_vector (type, ptr, len);
7519 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7520 TYPE at compile-time. If we're unable to perform the conversion
7521 return NULL_TREE. */
7524 fold_view_convert_expr (tree type, tree expr)
7526 /* We support up to 512-bit values (for V8DFmode). */
7527 unsigned char buffer[64];
7530 /* Check that the host and target are sane. */
7531 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7534 len = native_encode_expr (expr, buffer, sizeof (buffer));
7538 return native_interpret_expr (type, buffer, len);
7541 /* Build an expression for the address of T. Folds away INDIRECT_REF
7542 to avoid confusing the gimplify process. When IN_FOLD is true
7543 avoid modifications of T. */
7546 build_fold_addr_expr_with_type_1 (tree t, tree ptrtype, bool in_fold)
7548 /* The size of the object is not relevant when talking about its address. */
7549 if (TREE_CODE (t) == WITH_SIZE_EXPR)
7550 t = TREE_OPERAND (t, 0);
7552 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
7553 if (TREE_CODE (t) == INDIRECT_REF
7554 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
7556 t = TREE_OPERAND (t, 0);
7558 if (TREE_TYPE (t) != ptrtype)
7559 t = build1 (NOP_EXPR, ptrtype, t);
7565 while (handled_component_p (base))
7566 base = TREE_OPERAND (base, 0);
7569 TREE_ADDRESSABLE (base) = 1;
7571 t = build1 (ADDR_EXPR, ptrtype, t);
7574 t = build1 (ADDR_EXPR, ptrtype, t);
7579 /* Build an expression for the address of T with type PTRTYPE. This
7580 function modifies the input parameter 'T' by sometimes setting the
7581 TREE_ADDRESSABLE flag. */
7584 build_fold_addr_expr_with_type (tree t, tree ptrtype)
7586 return build_fold_addr_expr_with_type_1 (t, ptrtype, false);
7589 /* Build an expression for the address of T. This function modifies
7590 the input parameter 'T' by sometimes setting the TREE_ADDRESSABLE
7591 flag. When called from fold functions, use fold_addr_expr instead. */
7594 build_fold_addr_expr (tree t)
7596 return build_fold_addr_expr_with_type_1 (t,
7597 build_pointer_type (TREE_TYPE (t)),
7601 /* Same as build_fold_addr_expr, builds an expression for the address
7602 of T, but avoids touching the input node 't'. Fold functions
7603 should use this version. */
7606 fold_addr_expr (tree t)
7608 tree ptrtype = build_pointer_type (TREE_TYPE (t));
7610 return build_fold_addr_expr_with_type_1 (t, ptrtype, true);
7613 /* Fold a unary expression of code CODE and type TYPE with operand
7614 OP0. Return the folded expression if folding is successful.
7615 Otherwise, return NULL_TREE. */
7618 fold_unary (enum tree_code code, tree type, tree op0)
7622 enum tree_code_class kind = TREE_CODE_CLASS (code);
7624 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7625 && TREE_CODE_LENGTH (code) == 1);
7630 if (code == NOP_EXPR || code == CONVERT_EXPR
7631 || code == FLOAT_EXPR || code == ABS_EXPR)
7633 /* Don't use STRIP_NOPS, because signedness of argument type
7635 STRIP_SIGN_NOPS (arg0);
7639 /* Strip any conversions that don't change the mode. This
7640 is safe for every expression, except for a comparison
7641 expression because its signedness is derived from its
7644 Note that this is done as an internal manipulation within
7645 the constant folder, in order to find the simplest
7646 representation of the arguments so that their form can be
7647 studied. In any cases, the appropriate type conversions
7648 should be put back in the tree that will get out of the
7654 if (TREE_CODE_CLASS (code) == tcc_unary)
7656 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7657 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7658 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
7659 else if (TREE_CODE (arg0) == COND_EXPR)
7661 tree arg01 = TREE_OPERAND (arg0, 1);
7662 tree arg02 = TREE_OPERAND (arg0, 2);
7663 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7664 arg01 = fold_build1 (code, type, arg01);
7665 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7666 arg02 = fold_build1 (code, type, arg02);
7667 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
7670 /* If this was a conversion, and all we did was to move into
7671 inside the COND_EXPR, bring it back out. But leave it if
7672 it is a conversion from integer to integer and the
7673 result precision is no wider than a word since such a
7674 conversion is cheap and may be optimized away by combine,
7675 while it couldn't if it were outside the COND_EXPR. Then return
7676 so we don't get into an infinite recursion loop taking the
7677 conversion out and then back in. */
7679 if ((code == NOP_EXPR || code == CONVERT_EXPR
7680 || code == NON_LVALUE_EXPR)
7681 && TREE_CODE (tem) == COND_EXPR
7682 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7683 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7684 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7685 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7686 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7687 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7688 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7690 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7691 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7692 || flag_syntax_only))
7693 tem = build1 (code, type,
7695 TREE_TYPE (TREE_OPERAND
7696 (TREE_OPERAND (tem, 1), 0)),
7697 TREE_OPERAND (tem, 0),
7698 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7699 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
7702 else if (COMPARISON_CLASS_P (arg0))
7704 if (TREE_CODE (type) == BOOLEAN_TYPE)
7706 arg0 = copy_node (arg0);
7707 TREE_TYPE (arg0) = type;
7710 else if (TREE_CODE (type) != INTEGER_TYPE)
7711 return fold_build3 (COND_EXPR, type, arg0,
7712 fold_build1 (code, type,
7714 fold_build1 (code, type,
7715 integer_zero_node));
7722 /* Re-association barriers around constants and other re-association
7723 barriers can be removed. */
7724 if (CONSTANT_CLASS_P (op0)
7725 || TREE_CODE (op0) == PAREN_EXPR)
7726 return fold_convert (type, op0);
7731 case FIX_TRUNC_EXPR:
7732 if (TREE_TYPE (op0) == type)
7735 /* If we have (type) (a CMP b) and type is an integral type, return
7736 new expression involving the new type. */
7737 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
7738 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
7739 TREE_OPERAND (op0, 1));
7741 /* Handle cases of two conversions in a row. */
7742 if (CONVERT_EXPR_P (op0))
7744 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
7745 tree inter_type = TREE_TYPE (op0);
7746 int inside_int = INTEGRAL_TYPE_P (inside_type);
7747 int inside_ptr = POINTER_TYPE_P (inside_type);
7748 int inside_float = FLOAT_TYPE_P (inside_type);
7749 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
7750 unsigned int inside_prec = TYPE_PRECISION (inside_type);
7751 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
7752 int inter_int = INTEGRAL_TYPE_P (inter_type);
7753 int inter_ptr = POINTER_TYPE_P (inter_type);
7754 int inter_float = FLOAT_TYPE_P (inter_type);
7755 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
7756 unsigned int inter_prec = TYPE_PRECISION (inter_type);
7757 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
7758 int final_int = INTEGRAL_TYPE_P (type);
7759 int final_ptr = POINTER_TYPE_P (type);
7760 int final_float = FLOAT_TYPE_P (type);
7761 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
7762 unsigned int final_prec = TYPE_PRECISION (type);
7763 int final_unsignedp = TYPE_UNSIGNED (type);
7765 /* In addition to the cases of two conversions in a row
7766 handled below, if we are converting something to its own
7767 type via an object of identical or wider precision, neither
7768 conversion is needed. */
7769 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
7770 && (((inter_int || inter_ptr) && final_int)
7771 || (inter_float && final_float))
7772 && inter_prec >= final_prec)
7773 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7775 /* Likewise, if the intermediate and final types are either both
7776 float or both integer, we don't need the middle conversion if
7777 it is wider than the final type and doesn't change the signedness
7778 (for integers). Avoid this if the final type is a pointer
7779 since then we sometimes need the inner conversion. Likewise if
7780 the outer has a precision not equal to the size of its mode. */
7781 if (((inter_int && inside_int)
7782 || (inter_float && inside_float)
7783 || (inter_vec && inside_vec))
7784 && inter_prec >= inside_prec
7785 && (inter_float || inter_vec
7786 || inter_unsignedp == inside_unsignedp)
7787 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7788 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7790 && (! final_vec || inter_prec == inside_prec))
7791 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7793 /* If we have a sign-extension of a zero-extended value, we can
7794 replace that by a single zero-extension. */
7795 if (inside_int && inter_int && final_int
7796 && inside_prec < inter_prec && inter_prec < final_prec
7797 && inside_unsignedp && !inter_unsignedp)
7798 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7800 /* Two conversions in a row are not needed unless:
7801 - some conversion is floating-point (overstrict for now), or
7802 - some conversion is a vector (overstrict for now), or
7803 - the intermediate type is narrower than both initial and
7805 - the intermediate type and innermost type differ in signedness,
7806 and the outermost type is wider than the intermediate, or
7807 - the initial type is a pointer type and the precisions of the
7808 intermediate and final types differ, or
7809 - the final type is a pointer type and the precisions of the
7810 initial and intermediate types differ. */
7811 if (! inside_float && ! inter_float && ! final_float
7812 && ! inside_vec && ! inter_vec && ! final_vec
7813 && (inter_prec >= inside_prec || inter_prec >= final_prec)
7814 && ! (inside_int && inter_int
7815 && inter_unsignedp != inside_unsignedp
7816 && inter_prec < final_prec)
7817 && ((inter_unsignedp && inter_prec > inside_prec)
7818 == (final_unsignedp && final_prec > inter_prec))
7819 && ! (inside_ptr && inter_prec != final_prec)
7820 && ! (final_ptr && inside_prec != inter_prec)
7821 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7822 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
7823 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7826 /* Handle (T *)&A.B.C for A being of type T and B and C
7827 living at offset zero. This occurs frequently in
7828 C++ upcasting and then accessing the base. */
7829 if (TREE_CODE (op0) == ADDR_EXPR
7830 && POINTER_TYPE_P (type)
7831 && handled_component_p (TREE_OPERAND (op0, 0)))
7833 HOST_WIDE_INT bitsize, bitpos;
7835 enum machine_mode mode;
7836 int unsignedp, volatilep;
7837 tree base = TREE_OPERAND (op0, 0);
7838 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
7839 &mode, &unsignedp, &volatilep, false);
7840 /* If the reference was to a (constant) zero offset, we can use
7841 the address of the base if it has the same base type
7842 as the result type. */
7843 if (! offset && bitpos == 0
7844 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
7845 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
7846 return fold_convert (type, fold_addr_expr (base));
7849 if ((TREE_CODE (op0) == MODIFY_EXPR
7850 || TREE_CODE (op0) == GIMPLE_MODIFY_STMT)
7851 && TREE_CONSTANT (GENERIC_TREE_OPERAND (op0, 1))
7852 /* Detect assigning a bitfield. */
7853 && !(TREE_CODE (GENERIC_TREE_OPERAND (op0, 0)) == COMPONENT_REF
7855 (TREE_OPERAND (GENERIC_TREE_OPERAND (op0, 0), 1))))
7857 /* Don't leave an assignment inside a conversion
7858 unless assigning a bitfield. */
7859 tem = fold_build1 (code, type, GENERIC_TREE_OPERAND (op0, 1));
7860 /* First do the assignment, then return converted constant. */
7861 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
7862 TREE_NO_WARNING (tem) = 1;
7863 TREE_USED (tem) = 1;
7867 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7868 constants (if x has signed type, the sign bit cannot be set
7869 in c). This folds extension into the BIT_AND_EXPR. */
7870 if (TREE_CODE (type) == INTEGER_TYPE
7871 && TREE_CODE (op0) == BIT_AND_EXPR
7872 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
7875 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
7878 if (TYPE_UNSIGNED (TREE_TYPE (and))
7879 || (TYPE_PRECISION (type)
7880 <= TYPE_PRECISION (TREE_TYPE (and))))
7882 else if (TYPE_PRECISION (TREE_TYPE (and1))
7883 <= HOST_BITS_PER_WIDE_INT
7884 && host_integerp (and1, 1))
7886 unsigned HOST_WIDE_INT cst;
7888 cst = tree_low_cst (and1, 1);
7889 cst &= (HOST_WIDE_INT) -1
7890 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
7891 change = (cst == 0);
7892 #ifdef LOAD_EXTEND_OP
7894 && !flag_syntax_only
7895 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
7898 tree uns = unsigned_type_for (TREE_TYPE (and0));
7899 and0 = fold_convert (uns, and0);
7900 and1 = fold_convert (uns, and1);
7906 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
7907 TREE_INT_CST_HIGH (and1), 0,
7908 TREE_OVERFLOW (and1));
7909 return fold_build2 (BIT_AND_EXPR, type,
7910 fold_convert (type, and0), tem);
7914 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
7915 when one of the new casts will fold away. Conservatively we assume
7916 that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
7917 if (POINTER_TYPE_P (type)
7918 && TREE_CODE (arg0) == POINTER_PLUS_EXPR
7919 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7920 || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
7921 || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
7923 tree arg00 = TREE_OPERAND (arg0, 0);
7924 tree arg01 = TREE_OPERAND (arg0, 1);
7926 return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
7927 fold_convert (sizetype, arg01));
7930 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
7931 of the same precision, and X is an integer type not narrower than
7932 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
7933 if (INTEGRAL_TYPE_P (type)
7934 && TREE_CODE (op0) == BIT_NOT_EXPR
7935 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7936 && CONVERT_EXPR_P (TREE_OPERAND (op0, 0))
7937 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
7939 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
7940 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7941 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
7942 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
7945 /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the
7946 type of X and Y (integer types only). */
7947 if (INTEGRAL_TYPE_P (type)
7948 && TREE_CODE (op0) == MULT_EXPR
7949 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7950 && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (op0)))
7952 /* Be careful not to introduce new overflows. */
7954 if (TYPE_OVERFLOW_WRAPS (type))
7957 mult_type = unsigned_type_for (type);
7959 tem = fold_build2 (MULT_EXPR, mult_type,
7960 fold_convert (mult_type, TREE_OPERAND (op0, 0)),
7961 fold_convert (mult_type, TREE_OPERAND (op0, 1)));
7962 return fold_convert (type, tem);
7965 tem = fold_convert_const (code, type, op0);
7966 return tem ? tem : NULL_TREE;
7968 case FIXED_CONVERT_EXPR:
7969 tem = fold_convert_const (code, type, arg0);
7970 return tem ? tem : NULL_TREE;
7972 case VIEW_CONVERT_EXPR:
7973 if (TREE_TYPE (op0) == type)
7975 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
7976 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7978 /* For integral conversions with the same precision or pointer
7979 conversions use a NOP_EXPR instead. */
7980 if ((INTEGRAL_TYPE_P (type)
7981 || POINTER_TYPE_P (type))
7982 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
7983 || POINTER_TYPE_P (TREE_TYPE (op0)))
7984 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0))
7985 /* Do not muck with VIEW_CONVERT_EXPRs that convert from
7986 a sub-type to its base type as generated by the Ada FE. */
7987 && !(INTEGRAL_TYPE_P (TREE_TYPE (op0))
7988 && TREE_TYPE (TREE_TYPE (op0))))
7989 return fold_convert (type, op0);
7991 /* Strip inner integral conversions that do not change the precision. */
7992 if (CONVERT_EXPR_P (op0)
7993 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
7994 || POINTER_TYPE_P (TREE_TYPE (op0)))
7995 && (INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
7996 || POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0))))
7997 && (TYPE_PRECISION (TREE_TYPE (op0))
7998 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
7999 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
8001 return fold_view_convert_expr (type, op0);
8004 tem = fold_negate_expr (arg0);
8006 return fold_convert (type, tem);
8010 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
8011 return fold_abs_const (arg0, type);
8012 else if (TREE_CODE (arg0) == NEGATE_EXPR)
8013 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
8014 /* Convert fabs((double)float) into (double)fabsf(float). */
8015 else if (TREE_CODE (arg0) == NOP_EXPR
8016 && TREE_CODE (type) == REAL_TYPE)
8018 tree targ0 = strip_float_extensions (arg0);
8020 return fold_convert (type, fold_build1 (ABS_EXPR,
8024 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
8025 else if (TREE_CODE (arg0) == ABS_EXPR)
8027 else if (tree_expr_nonnegative_p (arg0))
8030 /* Strip sign ops from argument. */
8031 if (TREE_CODE (type) == REAL_TYPE)
8033 tem = fold_strip_sign_ops (arg0);
8035 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
8040 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8041 return fold_convert (type, arg0);
8042 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8044 tree itype = TREE_TYPE (type);
8045 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
8046 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
8047 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
8049 if (TREE_CODE (arg0) == COMPLEX_CST)
8051 tree itype = TREE_TYPE (type);
8052 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
8053 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
8054 return build_complex (type, rpart, negate_expr (ipart));
8056 if (TREE_CODE (arg0) == CONJ_EXPR)
8057 return fold_convert (type, TREE_OPERAND (arg0, 0));
8061 if (TREE_CODE (arg0) == INTEGER_CST)
8062 return fold_not_const (arg0, type);
8063 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
8064 return fold_convert (type, TREE_OPERAND (arg0, 0));
8065 /* Convert ~ (-A) to A - 1. */
8066 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
8067 return fold_build2 (MINUS_EXPR, type,
8068 fold_convert (type, TREE_OPERAND (arg0, 0)),
8069 build_int_cst (type, 1));
8070 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
8071 else if (INTEGRAL_TYPE_P (type)
8072 && ((TREE_CODE (arg0) == MINUS_EXPR
8073 && integer_onep (TREE_OPERAND (arg0, 1)))
8074 || (TREE_CODE (arg0) == PLUS_EXPR
8075 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
8076 return fold_build1 (NEGATE_EXPR, type,
8077 fold_convert (type, TREE_OPERAND (arg0, 0)));
8078 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8079 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8080 && (tem = fold_unary (BIT_NOT_EXPR, type,
8082 TREE_OPERAND (arg0, 0)))))
8083 return fold_build2 (BIT_XOR_EXPR, type, tem,
8084 fold_convert (type, TREE_OPERAND (arg0, 1)));
8085 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8086 && (tem = fold_unary (BIT_NOT_EXPR, type,
8088 TREE_OPERAND (arg0, 1)))))
8089 return fold_build2 (BIT_XOR_EXPR, type,
8090 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
8091 /* Perform BIT_NOT_EXPR on each element individually. */
8092 else if (TREE_CODE (arg0) == VECTOR_CST)
8094 tree elements = TREE_VECTOR_CST_ELTS (arg0), elem, list = NULL_TREE;
8095 int count = TYPE_VECTOR_SUBPARTS (type), i;
8097 for (i = 0; i < count; i++)
8101 elem = TREE_VALUE (elements);
8102 elem = fold_unary (BIT_NOT_EXPR, TREE_TYPE (type), elem);
8103 if (elem == NULL_TREE)
8105 elements = TREE_CHAIN (elements);
8108 elem = build_int_cst (TREE_TYPE (type), -1);
8109 list = tree_cons (NULL_TREE, elem, list);
8112 return build_vector (type, nreverse (list));
8117 case TRUTH_NOT_EXPR:
8118 /* The argument to invert_truthvalue must have Boolean type. */
8119 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8120 arg0 = fold_convert (boolean_type_node, arg0);
8122 /* Note that the operand of this must be an int
8123 and its values must be 0 or 1.
8124 ("true" is a fixed value perhaps depending on the language,
8125 but we don't handle values other than 1 correctly yet.) */
8126 tem = fold_truth_not_expr (arg0);
8129 return fold_convert (type, tem);
8132 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8133 return fold_convert (type, arg0);
8134 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8135 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8136 TREE_OPERAND (arg0, 1));
8137 if (TREE_CODE (arg0) == COMPLEX_CST)
8138 return fold_convert (type, TREE_REALPART (arg0));
8139 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8141 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8142 tem = fold_build2 (TREE_CODE (arg0), itype,
8143 fold_build1 (REALPART_EXPR, itype,
8144 TREE_OPERAND (arg0, 0)),
8145 fold_build1 (REALPART_EXPR, itype,
8146 TREE_OPERAND (arg0, 1)));
8147 return fold_convert (type, tem);
8149 if (TREE_CODE (arg0) == CONJ_EXPR)
8151 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8152 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8153 return fold_convert (type, tem);
8155 if (TREE_CODE (arg0) == CALL_EXPR)
8157 tree fn = get_callee_fndecl (arg0);
8158 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8159 switch (DECL_FUNCTION_CODE (fn))
8161 CASE_FLT_FN (BUILT_IN_CEXPI):
8162 fn = mathfn_built_in (type, BUILT_IN_COS);
8164 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8174 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8175 return fold_convert (type, integer_zero_node);
8176 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8177 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8178 TREE_OPERAND (arg0, 0));
8179 if (TREE_CODE (arg0) == COMPLEX_CST)
8180 return fold_convert (type, TREE_IMAGPART (arg0));
8181 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8183 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8184 tem = fold_build2 (TREE_CODE (arg0), itype,
8185 fold_build1 (IMAGPART_EXPR, itype,
8186 TREE_OPERAND (arg0, 0)),
8187 fold_build1 (IMAGPART_EXPR, itype,
8188 TREE_OPERAND (arg0, 1)));
8189 return fold_convert (type, tem);
8191 if (TREE_CODE (arg0) == CONJ_EXPR)
8193 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8194 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8195 return fold_convert (type, negate_expr (tem));
8197 if (TREE_CODE (arg0) == CALL_EXPR)
8199 tree fn = get_callee_fndecl (arg0);
8200 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8201 switch (DECL_FUNCTION_CODE (fn))
8203 CASE_FLT_FN (BUILT_IN_CEXPI):
8204 fn = mathfn_built_in (type, BUILT_IN_SIN);
8206 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8217 } /* switch (code) */
8220 /* Fold a binary expression of code CODE and type TYPE with operands
8221 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8222 Return the folded expression if folding is successful. Otherwise,
8223 return NULL_TREE. */
8226 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8228 enum tree_code compl_code;
8230 if (code == MIN_EXPR)
8231 compl_code = MAX_EXPR;
8232 else if (code == MAX_EXPR)
8233 compl_code = MIN_EXPR;
8237 /* MIN (MAX (a, b), b) == b. */
8238 if (TREE_CODE (op0) == compl_code
8239 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8240 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8242 /* MIN (MAX (b, a), b) == b. */
8243 if (TREE_CODE (op0) == compl_code
8244 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8245 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8246 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8248 /* MIN (a, MAX (a, b)) == a. */
8249 if (TREE_CODE (op1) == compl_code
8250 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8251 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8252 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8254 /* MIN (a, MAX (b, a)) == a. */
8255 if (TREE_CODE (op1) == compl_code
8256 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8257 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8258 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8263 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8264 by changing CODE to reduce the magnitude of constants involved in
8265 ARG0 of the comparison.
8266 Returns a canonicalized comparison tree if a simplification was
8267 possible, otherwise returns NULL_TREE.
8268 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8269 valid if signed overflow is undefined. */
8272 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8273 tree arg0, tree arg1,
8274 bool *strict_overflow_p)
8276 enum tree_code code0 = TREE_CODE (arg0);
8277 tree t, cst0 = NULL_TREE;
8281 /* Match A +- CST code arg1 and CST code arg1. */
8282 if (!(((code0 == MINUS_EXPR
8283 || code0 == PLUS_EXPR)
8284 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8285 || code0 == INTEGER_CST))
8288 /* Identify the constant in arg0 and its sign. */
8289 if (code0 == INTEGER_CST)
8292 cst0 = TREE_OPERAND (arg0, 1);
8293 sgn0 = tree_int_cst_sgn (cst0);
8295 /* Overflowed constants and zero will cause problems. */
8296 if (integer_zerop (cst0)
8297 || TREE_OVERFLOW (cst0))
8300 /* See if we can reduce the magnitude of the constant in
8301 arg0 by changing the comparison code. */
8302 if (code0 == INTEGER_CST)
8304 /* CST <= arg1 -> CST-1 < arg1. */
8305 if (code == LE_EXPR && sgn0 == 1)
8307 /* -CST < arg1 -> -CST-1 <= arg1. */
8308 else if (code == LT_EXPR && sgn0 == -1)
8310 /* CST > arg1 -> CST-1 >= arg1. */
8311 else if (code == GT_EXPR && sgn0 == 1)
8313 /* -CST >= arg1 -> -CST-1 > arg1. */
8314 else if (code == GE_EXPR && sgn0 == -1)
8318 /* arg1 code' CST' might be more canonical. */
8323 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8325 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8327 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8328 else if (code == GT_EXPR
8329 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8331 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8332 else if (code == LE_EXPR
8333 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8335 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8336 else if (code == GE_EXPR
8337 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8341 *strict_overflow_p = true;
8344 /* Now build the constant reduced in magnitude. */
8345 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8346 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8347 if (code0 != INTEGER_CST)
8348 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8350 /* If swapping might yield to a more canonical form, do so. */
8352 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8354 return fold_build2 (code, type, t, arg1);
8357 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8358 overflow further. Try to decrease the magnitude of constants involved
8359 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8360 and put sole constants at the second argument position.
8361 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8364 maybe_canonicalize_comparison (enum tree_code code, tree type,
8365 tree arg0, tree arg1)
8368 bool strict_overflow_p;
8369 const char * const warnmsg = G_("assuming signed overflow does not occur "
8370 "when reducing constant in comparison");
8372 /* In principle pointers also have undefined overflow behavior,
8373 but that causes problems elsewhere. */
8374 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8375 || POINTER_TYPE_P (TREE_TYPE (arg0)))
8378 /* Try canonicalization by simplifying arg0. */
8379 strict_overflow_p = false;
8380 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8381 &strict_overflow_p);
8384 if (strict_overflow_p)
8385 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8389 /* Try canonicalization by simplifying arg1 using the swapped
8391 code = swap_tree_comparison (code);
8392 strict_overflow_p = false;
8393 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8394 &strict_overflow_p);
8395 if (t && strict_overflow_p)
8396 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8400 /* Return whether BASE + OFFSET + BITPOS may wrap around the address
8401 space. This is used to avoid issuing overflow warnings for
8402 expressions like &p->x which can not wrap. */
8405 pointer_may_wrap_p (tree base, tree offset, HOST_WIDE_INT bitpos)
8407 unsigned HOST_WIDE_INT offset_low, total_low;
8408 HOST_WIDE_INT size, offset_high, total_high;
8410 if (!POINTER_TYPE_P (TREE_TYPE (base)))
8416 if (offset == NULL_TREE)
8421 else if (TREE_CODE (offset) != INTEGER_CST || TREE_OVERFLOW (offset))
8425 offset_low = TREE_INT_CST_LOW (offset);
8426 offset_high = TREE_INT_CST_HIGH (offset);
8429 if (add_double_with_sign (offset_low, offset_high,
8430 bitpos / BITS_PER_UNIT, 0,
8431 &total_low, &total_high,
8435 if (total_high != 0)
8438 size = int_size_in_bytes (TREE_TYPE (TREE_TYPE (base)));
8442 /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
8444 if (TREE_CODE (base) == ADDR_EXPR)
8446 HOST_WIDE_INT base_size;
8448 base_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (base, 0)));
8449 if (base_size > 0 && size < base_size)
8453 return total_low > (unsigned HOST_WIDE_INT) size;
8456 /* Subroutine of fold_binary. This routine performs all of the
8457 transformations that are common to the equality/inequality
8458 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8459 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8460 fold_binary should call fold_binary. Fold a comparison with
8461 tree code CODE and type TYPE with operands OP0 and OP1. Return
8462 the folded comparison or NULL_TREE. */
8465 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8467 tree arg0, arg1, tem;
8472 STRIP_SIGN_NOPS (arg0);
8473 STRIP_SIGN_NOPS (arg1);
8475 tem = fold_relational_const (code, type, arg0, arg1);
8476 if (tem != NULL_TREE)
8479 /* If one arg is a real or integer constant, put it last. */
8480 if (tree_swap_operands_p (arg0, arg1, true))
8481 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8483 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8484 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8485 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8486 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8487 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8488 && (TREE_CODE (arg1) == INTEGER_CST
8489 && !TREE_OVERFLOW (arg1)))
8491 tree const1 = TREE_OPERAND (arg0, 1);
8493 tree variable = TREE_OPERAND (arg0, 0);
8496 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8498 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8499 TREE_TYPE (arg1), const2, const1);
8501 /* If the constant operation overflowed this can be
8502 simplified as a comparison against INT_MAX/INT_MIN. */
8503 if (TREE_CODE (lhs) == INTEGER_CST
8504 && TREE_OVERFLOW (lhs))
8506 int const1_sgn = tree_int_cst_sgn (const1);
8507 enum tree_code code2 = code;
8509 /* Get the sign of the constant on the lhs if the
8510 operation were VARIABLE + CONST1. */
8511 if (TREE_CODE (arg0) == MINUS_EXPR)
8512 const1_sgn = -const1_sgn;
8514 /* The sign of the constant determines if we overflowed
8515 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8516 Canonicalize to the INT_MIN overflow by swapping the comparison
8518 if (const1_sgn == -1)
8519 code2 = swap_tree_comparison (code);
8521 /* We now can look at the canonicalized case
8522 VARIABLE + 1 CODE2 INT_MIN
8523 and decide on the result. */
8524 if (code2 == LT_EXPR
8526 || code2 == EQ_EXPR)
8527 return omit_one_operand (type, boolean_false_node, variable);
8528 else if (code2 == NE_EXPR
8530 || code2 == GT_EXPR)
8531 return omit_one_operand (type, boolean_true_node, variable);
8534 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8535 && (TREE_CODE (lhs) != INTEGER_CST
8536 || !TREE_OVERFLOW (lhs)))
8538 fold_overflow_warning (("assuming signed overflow does not occur "
8539 "when changing X +- C1 cmp C2 to "
8541 WARN_STRICT_OVERFLOW_COMPARISON);
8542 return fold_build2 (code, type, variable, lhs);
8546 /* For comparisons of pointers we can decompose it to a compile time
8547 comparison of the base objects and the offsets into the object.
8548 This requires at least one operand being an ADDR_EXPR or a
8549 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8550 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8551 && (TREE_CODE (arg0) == ADDR_EXPR
8552 || TREE_CODE (arg1) == ADDR_EXPR
8553 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
8554 || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
8556 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8557 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8558 enum machine_mode mode;
8559 int volatilep, unsignedp;
8560 bool indirect_base0 = false, indirect_base1 = false;
8562 /* Get base and offset for the access. Strip ADDR_EXPR for
8563 get_inner_reference, but put it back by stripping INDIRECT_REF
8564 off the base object if possible. indirect_baseN will be true
8565 if baseN is not an address but refers to the object itself. */
8567 if (TREE_CODE (arg0) == ADDR_EXPR)
8569 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8570 &bitsize, &bitpos0, &offset0, &mode,
8571 &unsignedp, &volatilep, false);
8572 if (TREE_CODE (base0) == INDIRECT_REF)
8573 base0 = TREE_OPERAND (base0, 0);
8575 indirect_base0 = true;
8577 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
8579 base0 = TREE_OPERAND (arg0, 0);
8580 offset0 = TREE_OPERAND (arg0, 1);
8584 if (TREE_CODE (arg1) == ADDR_EXPR)
8586 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8587 &bitsize, &bitpos1, &offset1, &mode,
8588 &unsignedp, &volatilep, false);
8589 if (TREE_CODE (base1) == INDIRECT_REF)
8590 base1 = TREE_OPERAND (base1, 0);
8592 indirect_base1 = true;
8594 else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
8596 base1 = TREE_OPERAND (arg1, 0);
8597 offset1 = TREE_OPERAND (arg1, 1);
8600 /* If we have equivalent bases we might be able to simplify. */
8601 if (indirect_base0 == indirect_base1
8602 && operand_equal_p (base0, base1, 0))
8604 /* We can fold this expression to a constant if the non-constant
8605 offset parts are equal. */
8606 if ((offset0 == offset1
8607 || (offset0 && offset1
8608 && operand_equal_p (offset0, offset1, 0)))
8611 || POINTER_TYPE_OVERFLOW_UNDEFINED))
8616 && bitpos0 != bitpos1
8617 && (pointer_may_wrap_p (base0, offset0, bitpos0)
8618 || pointer_may_wrap_p (base1, offset1, bitpos1)))
8619 fold_overflow_warning (("assuming pointer wraparound does not "
8620 "occur when comparing P +- C1 with "
8622 WARN_STRICT_OVERFLOW_CONDITIONAL);
8627 return build_int_cst (boolean_type_node, bitpos0 == bitpos1);
8629 return build_int_cst (boolean_type_node, bitpos0 != bitpos1);
8631 return build_int_cst (boolean_type_node, bitpos0 < bitpos1);
8633 return build_int_cst (boolean_type_node, bitpos0 <= bitpos1);
8635 return build_int_cst (boolean_type_node, bitpos0 >= bitpos1);
8637 return build_int_cst (boolean_type_node, bitpos0 > bitpos1);
8641 /* We can simplify the comparison to a comparison of the variable
8642 offset parts if the constant offset parts are equal.
8643 Be careful to use signed size type here because otherwise we
8644 mess with array offsets in the wrong way. This is possible
8645 because pointer arithmetic is restricted to retain within an
8646 object and overflow on pointer differences is undefined as of
8647 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8648 else if (bitpos0 == bitpos1
8649 && ((code == EQ_EXPR || code == NE_EXPR)
8650 || POINTER_TYPE_OVERFLOW_UNDEFINED))
8652 tree signed_size_type_node;
8653 signed_size_type_node = signed_type_for (size_type_node);
8655 /* By converting to signed size type we cover middle-end pointer
8656 arithmetic which operates on unsigned pointer types of size
8657 type size and ARRAY_REF offsets which are properly sign or
8658 zero extended from their type in case it is narrower than
8660 if (offset0 == NULL_TREE)
8661 offset0 = build_int_cst (signed_size_type_node, 0);
8663 offset0 = fold_convert (signed_size_type_node, offset0);
8664 if (offset1 == NULL_TREE)
8665 offset1 = build_int_cst (signed_size_type_node, 0);
8667 offset1 = fold_convert (signed_size_type_node, offset1);
8671 && (pointer_may_wrap_p (base0, offset0, bitpos0)
8672 || pointer_may_wrap_p (base1, offset1, bitpos1)))
8673 fold_overflow_warning (("assuming pointer wraparound does not "
8674 "occur when comparing P +- C1 with "
8676 WARN_STRICT_OVERFLOW_COMPARISON);
8678 return fold_build2 (code, type, offset0, offset1);
8681 /* For non-equal bases we can simplify if they are addresses
8682 of local binding decls or constants. */
8683 else if (indirect_base0 && indirect_base1
8684 /* We know that !operand_equal_p (base0, base1, 0)
8685 because the if condition was false. But make
8686 sure two decls are not the same. */
8688 && TREE_CODE (arg0) == ADDR_EXPR
8689 && TREE_CODE (arg1) == ADDR_EXPR
8690 && (((TREE_CODE (base0) == VAR_DECL
8691 || TREE_CODE (base0) == PARM_DECL)
8692 && (targetm.binds_local_p (base0)
8693 || CONSTANT_CLASS_P (base1)))
8694 || CONSTANT_CLASS_P (base0))
8695 && (((TREE_CODE (base1) == VAR_DECL
8696 || TREE_CODE (base1) == PARM_DECL)
8697 && (targetm.binds_local_p (base1)
8698 || CONSTANT_CLASS_P (base0)))
8699 || CONSTANT_CLASS_P (base1)))
8701 if (code == EQ_EXPR)
8702 return omit_two_operands (type, boolean_false_node, arg0, arg1);
8703 else if (code == NE_EXPR)
8704 return omit_two_operands (type, boolean_true_node, arg0, arg1);
8706 /* For equal offsets we can simplify to a comparison of the
8708 else if (bitpos0 == bitpos1
8710 ? base0 != TREE_OPERAND (arg0, 0) : base0 != arg0)
8712 ? base1 != TREE_OPERAND (arg1, 0) : base1 != arg1)
8713 && ((offset0 == offset1)
8714 || (offset0 && offset1
8715 && operand_equal_p (offset0, offset1, 0))))
8718 base0 = fold_addr_expr (base0);
8720 base1 = fold_addr_expr (base1);
8721 return fold_build2 (code, type, base0, base1);
8725 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8726 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8727 the resulting offset is smaller in absolute value than the
8729 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8730 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8731 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8732 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8733 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
8734 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8735 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
8737 tree const1 = TREE_OPERAND (arg0, 1);
8738 tree const2 = TREE_OPERAND (arg1, 1);
8739 tree variable1 = TREE_OPERAND (arg0, 0);
8740 tree variable2 = TREE_OPERAND (arg1, 0);
8742 const char * const warnmsg = G_("assuming signed overflow does not "
8743 "occur when combining constants around "
8746 /* Put the constant on the side where it doesn't overflow and is
8747 of lower absolute value than before. */
8748 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8749 ? MINUS_EXPR : PLUS_EXPR,
8751 if (!TREE_OVERFLOW (cst)
8752 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
8754 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8755 return fold_build2 (code, type,
8757 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
8761 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8762 ? MINUS_EXPR : PLUS_EXPR,
8764 if (!TREE_OVERFLOW (cst)
8765 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
8767 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8768 return fold_build2 (code, type,
8769 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
8775 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
8776 signed arithmetic case. That form is created by the compiler
8777 often enough for folding it to be of value. One example is in
8778 computing loop trip counts after Operator Strength Reduction. */
8779 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8780 && TREE_CODE (arg0) == MULT_EXPR
8781 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8782 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8783 && integer_zerop (arg1))
8785 tree const1 = TREE_OPERAND (arg0, 1);
8786 tree const2 = arg1; /* zero */
8787 tree variable1 = TREE_OPERAND (arg0, 0);
8788 enum tree_code cmp_code = code;
8790 gcc_assert (!integer_zerop (const1));
8792 fold_overflow_warning (("assuming signed overflow does not occur when "
8793 "eliminating multiplication in comparison "
8795 WARN_STRICT_OVERFLOW_COMPARISON);
8797 /* If const1 is negative we swap the sense of the comparison. */
8798 if (tree_int_cst_sgn (const1) < 0)
8799 cmp_code = swap_tree_comparison (cmp_code);
8801 return fold_build2 (cmp_code, type, variable1, const2);
8804 tem = maybe_canonicalize_comparison (code, type, op0, op1);
8808 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8810 tree targ0 = strip_float_extensions (arg0);
8811 tree targ1 = strip_float_extensions (arg1);
8812 tree newtype = TREE_TYPE (targ0);
8814 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8815 newtype = TREE_TYPE (targ1);
8817 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8818 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8819 return fold_build2 (code, type, fold_convert (newtype, targ0),
8820 fold_convert (newtype, targ1));
8822 /* (-a) CMP (-b) -> b CMP a */
8823 if (TREE_CODE (arg0) == NEGATE_EXPR
8824 && TREE_CODE (arg1) == NEGATE_EXPR)
8825 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8826 TREE_OPERAND (arg0, 0));
8828 if (TREE_CODE (arg1) == REAL_CST)
8830 REAL_VALUE_TYPE cst;
8831 cst = TREE_REAL_CST (arg1);
8833 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8834 if (TREE_CODE (arg0) == NEGATE_EXPR)
8835 return fold_build2 (swap_tree_comparison (code), type,
8836 TREE_OPERAND (arg0, 0),
8837 build_real (TREE_TYPE (arg1),
8838 REAL_VALUE_NEGATE (cst)));
8840 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8841 /* a CMP (-0) -> a CMP 0 */
8842 if (REAL_VALUE_MINUS_ZERO (cst))
8843 return fold_build2 (code, type, arg0,
8844 build_real (TREE_TYPE (arg1), dconst0));
8846 /* x != NaN is always true, other ops are always false. */
8847 if (REAL_VALUE_ISNAN (cst)
8848 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8850 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8851 return omit_one_operand (type, tem, arg0);
8854 /* Fold comparisons against infinity. */
8855 if (REAL_VALUE_ISINF (cst))
8857 tem = fold_inf_compare (code, type, arg0, arg1);
8858 if (tem != NULL_TREE)
8863 /* If this is a comparison of a real constant with a PLUS_EXPR
8864 or a MINUS_EXPR of a real constant, we can convert it into a
8865 comparison with a revised real constant as long as no overflow
8866 occurs when unsafe_math_optimizations are enabled. */
8867 if (flag_unsafe_math_optimizations
8868 && TREE_CODE (arg1) == REAL_CST
8869 && (TREE_CODE (arg0) == PLUS_EXPR
8870 || TREE_CODE (arg0) == MINUS_EXPR)
8871 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8872 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8873 ? MINUS_EXPR : PLUS_EXPR,
8874 arg1, TREE_OPERAND (arg0, 1), 0))
8875 && !TREE_OVERFLOW (tem))
8876 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
8878 /* Likewise, we can simplify a comparison of a real constant with
8879 a MINUS_EXPR whose first operand is also a real constant, i.e.
8880 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
8881 floating-point types only if -fassociative-math is set. */
8882 if (flag_associative_math
8883 && TREE_CODE (arg1) == REAL_CST
8884 && TREE_CODE (arg0) == MINUS_EXPR
8885 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8886 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8888 && !TREE_OVERFLOW (tem))
8889 return fold_build2 (swap_tree_comparison (code), type,
8890 TREE_OPERAND (arg0, 1), tem);
8892 /* Fold comparisons against built-in math functions. */
8893 if (TREE_CODE (arg1) == REAL_CST
8894 && flag_unsafe_math_optimizations
8895 && ! flag_errno_math)
8897 enum built_in_function fcode = builtin_mathfn_code (arg0);
8899 if (fcode != END_BUILTINS)
8901 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8902 if (tem != NULL_TREE)
8908 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8909 && CONVERT_EXPR_P (arg0))
8911 /* If we are widening one operand of an integer comparison,
8912 see if the other operand is similarly being widened. Perhaps we
8913 can do the comparison in the narrower type. */
8914 tem = fold_widened_comparison (code, type, arg0, arg1);
8918 /* Or if we are changing signedness. */
8919 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
8924 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8925 constant, we can simplify it. */
8926 if (TREE_CODE (arg1) == INTEGER_CST
8927 && (TREE_CODE (arg0) == MIN_EXPR
8928 || TREE_CODE (arg0) == MAX_EXPR)
8929 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8931 tem = optimize_minmax_comparison (code, type, op0, op1);
8936 /* Simplify comparison of something with itself. (For IEEE
8937 floating-point, we can only do some of these simplifications.) */
8938 if (operand_equal_p (arg0, arg1, 0))
8943 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8944 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8945 return constant_boolean_node (1, type);
8950 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8951 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8952 return constant_boolean_node (1, type);
8953 return fold_build2 (EQ_EXPR, type, arg0, arg1);
8956 /* For NE, we can only do this simplification if integer
8957 or we don't honor IEEE floating point NaNs. */
8958 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8959 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8961 /* ... fall through ... */
8964 return constant_boolean_node (0, type);
8970 /* If we are comparing an expression that just has comparisons
8971 of two integer values, arithmetic expressions of those comparisons,
8972 and constants, we can simplify it. There are only three cases
8973 to check: the two values can either be equal, the first can be
8974 greater, or the second can be greater. Fold the expression for
8975 those three values. Since each value must be 0 or 1, we have
8976 eight possibilities, each of which corresponds to the constant 0
8977 or 1 or one of the six possible comparisons.
8979 This handles common cases like (a > b) == 0 but also handles
8980 expressions like ((x > y) - (y > x)) > 0, which supposedly
8981 occur in macroized code. */
8983 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8985 tree cval1 = 0, cval2 = 0;
8988 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8989 /* Don't handle degenerate cases here; they should already
8990 have been handled anyway. */
8991 && cval1 != 0 && cval2 != 0
8992 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8993 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8994 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8995 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8996 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8997 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8998 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9000 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9001 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9003 /* We can't just pass T to eval_subst in case cval1 or cval2
9004 was the same as ARG1. */
9007 = fold_build2 (code, type,
9008 eval_subst (arg0, cval1, maxval,
9012 = fold_build2 (code, type,
9013 eval_subst (arg0, cval1, maxval,
9017 = fold_build2 (code, type,
9018 eval_subst (arg0, cval1, minval,
9022 /* All three of these results should be 0 or 1. Confirm they are.
9023 Then use those values to select the proper code to use. */
9025 if (TREE_CODE (high_result) == INTEGER_CST
9026 && TREE_CODE (equal_result) == INTEGER_CST
9027 && TREE_CODE (low_result) == INTEGER_CST)
9029 /* Make a 3-bit mask with the high-order bit being the
9030 value for `>', the next for '=', and the low for '<'. */
9031 switch ((integer_onep (high_result) * 4)
9032 + (integer_onep (equal_result) * 2)
9033 + integer_onep (low_result))
9037 return omit_one_operand (type, integer_zero_node, arg0);
9058 return omit_one_operand (type, integer_one_node, arg0);
9062 return save_expr (build2 (code, type, cval1, cval2));
9063 return fold_build2 (code, type, cval1, cval2);
9068 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9069 into a single range test. */
9070 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9071 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9072 && TREE_CODE (arg1) == INTEGER_CST
9073 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9074 && !integer_zerop (TREE_OPERAND (arg0, 1))
9075 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9076 && !TREE_OVERFLOW (arg1))
9078 tem = fold_div_compare (code, type, arg0, arg1);
9079 if (tem != NULL_TREE)
9083 /* Fold ~X op ~Y as Y op X. */
9084 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9085 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9087 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9088 return fold_build2 (code, type,
9089 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
9090 TREE_OPERAND (arg0, 0));
9093 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
9094 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9095 && TREE_CODE (arg1) == INTEGER_CST)
9097 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9098 return fold_build2 (swap_tree_comparison (code), type,
9099 TREE_OPERAND (arg0, 0),
9100 fold_build1 (BIT_NOT_EXPR, cmp_type,
9101 fold_convert (cmp_type, arg1)));
9108 /* Subroutine of fold_binary. Optimize complex multiplications of the
9109 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9110 argument EXPR represents the expression "z" of type TYPE. */
9113 fold_mult_zconjz (tree type, tree expr)
9115 tree itype = TREE_TYPE (type);
9116 tree rpart, ipart, tem;
9118 if (TREE_CODE (expr) == COMPLEX_EXPR)
9120 rpart = TREE_OPERAND (expr, 0);
9121 ipart = TREE_OPERAND (expr, 1);
9123 else if (TREE_CODE (expr) == COMPLEX_CST)
9125 rpart = TREE_REALPART (expr);
9126 ipart = TREE_IMAGPART (expr);
9130 expr = save_expr (expr);
9131 rpart = fold_build1 (REALPART_EXPR, itype, expr);
9132 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
9135 rpart = save_expr (rpart);
9136 ipart = save_expr (ipart);
9137 tem = fold_build2 (PLUS_EXPR, itype,
9138 fold_build2 (MULT_EXPR, itype, rpart, rpart),
9139 fold_build2 (MULT_EXPR, itype, ipart, ipart));
9140 return fold_build2 (COMPLEX_EXPR, type, tem,
9141 fold_convert (itype, integer_zero_node));
9145 /* Subroutine of fold_binary. If P is the value of EXPR, computes
9146 power-of-two M and (arbitrary) N such that M divides (P-N). This condition
9147 guarantees that P and N have the same least significant log2(M) bits.
9148 N is not otherwise constrained. In particular, N is not normalized to
9149 0 <= N < M as is common. In general, the precise value of P is unknown.
9150 M is chosen as large as possible such that constant N can be determined.
9152 Returns M and sets *RESIDUE to N. */
9154 static unsigned HOST_WIDE_INT
9155 get_pointer_modulus_and_residue (tree expr, unsigned HOST_WIDE_INT *residue)
9157 enum tree_code code;
9161 code = TREE_CODE (expr);
9162 if (code == ADDR_EXPR)
9164 expr = TREE_OPERAND (expr, 0);
9165 if (handled_component_p (expr))
9167 HOST_WIDE_INT bitsize, bitpos;
9169 enum machine_mode mode;
9170 int unsignedp, volatilep;
9172 expr = get_inner_reference (expr, &bitsize, &bitpos, &offset,
9173 &mode, &unsignedp, &volatilep, false);
9174 *residue = bitpos / BITS_PER_UNIT;
9177 if (TREE_CODE (offset) == INTEGER_CST)
9178 *residue += TREE_INT_CST_LOW (offset);
9180 /* We don't handle more complicated offset expressions. */
9185 if (DECL_P (expr) && TREE_CODE (expr) != FUNCTION_DECL)
9186 return DECL_ALIGN_UNIT (expr);
9188 else if (code == POINTER_PLUS_EXPR)
9191 unsigned HOST_WIDE_INT modulus;
9192 enum tree_code inner_code;
9194 op0 = TREE_OPERAND (expr, 0);
9196 modulus = get_pointer_modulus_and_residue (op0, residue);
9198 op1 = TREE_OPERAND (expr, 1);
9200 inner_code = TREE_CODE (op1);
9201 if (inner_code == INTEGER_CST)
9203 *residue += TREE_INT_CST_LOW (op1);
9206 else if (inner_code == MULT_EXPR)
9208 op1 = TREE_OPERAND (op1, 1);
9209 if (TREE_CODE (op1) == INTEGER_CST)
9211 unsigned HOST_WIDE_INT align;
9213 /* Compute the greatest power-of-2 divisor of op1. */
9214 align = TREE_INT_CST_LOW (op1);
9217 /* If align is non-zero and less than *modulus, replace
9218 *modulus with align., If align is 0, then either op1 is 0
9219 or the greatest power-of-2 divisor of op1 doesn't fit in an
9220 unsigned HOST_WIDE_INT. In either case, no additional
9221 constraint is imposed. */
9223 modulus = MIN (modulus, align);
9230 /* If we get here, we were unable to determine anything useful about the
9236 /* Fold a binary expression of code CODE and type TYPE with operands
9237 OP0 and OP1. Return the folded expression if folding is
9238 successful. Otherwise, return NULL_TREE. */
9241 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
9243 enum tree_code_class kind = TREE_CODE_CLASS (code);
9244 tree arg0, arg1, tem;
9245 tree t1 = NULL_TREE;
9246 bool strict_overflow_p;
9248 gcc_assert ((IS_EXPR_CODE_CLASS (kind)
9249 || IS_GIMPLE_STMT_CODE_CLASS (kind))
9250 && TREE_CODE_LENGTH (code) == 2
9252 && op1 != NULL_TREE);
9257 /* Strip any conversions that don't change the mode. This is
9258 safe for every expression, except for a comparison expression
9259 because its signedness is derived from its operands. So, in
9260 the latter case, only strip conversions that don't change the
9261 signedness. MIN_EXPR/MAX_EXPR also need signedness of arguments
9264 Note that this is done as an internal manipulation within the
9265 constant folder, in order to find the simplest representation
9266 of the arguments so that their form can be studied. In any
9267 cases, the appropriate type conversions should be put back in
9268 the tree that will get out of the constant folder. */
9270 if (kind == tcc_comparison || code == MIN_EXPR || code == MAX_EXPR)
9272 STRIP_SIGN_NOPS (arg0);
9273 STRIP_SIGN_NOPS (arg1);
9281 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9282 constant but we can't do arithmetic on them. */
9283 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9284 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9285 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == FIXED_CST)
9286 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == INTEGER_CST)
9287 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9288 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9290 if (kind == tcc_binary)
9292 /* Make sure type and arg0 have the same saturating flag. */
9293 gcc_assert (TYPE_SATURATING (type)
9294 == TYPE_SATURATING (TREE_TYPE (arg0)));
9295 tem = const_binop (code, arg0, arg1, 0);
9297 else if (kind == tcc_comparison)
9298 tem = fold_relational_const (code, type, arg0, arg1);
9302 if (tem != NULL_TREE)
9304 if (TREE_TYPE (tem) != type)
9305 tem = fold_convert (type, tem);
9310 /* If this is a commutative operation, and ARG0 is a constant, move it
9311 to ARG1 to reduce the number of tests below. */
9312 if (commutative_tree_code (code)
9313 && tree_swap_operands_p (arg0, arg1, true))
9314 return fold_build2 (code, type, op1, op0);
9316 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9318 First check for cases where an arithmetic operation is applied to a
9319 compound, conditional, or comparison operation. Push the arithmetic
9320 operation inside the compound or conditional to see if any folding
9321 can then be done. Convert comparison to conditional for this purpose.
9322 The also optimizes non-constant cases that used to be done in
9325 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9326 one of the operands is a comparison and the other is a comparison, a
9327 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9328 code below would make the expression more complex. Change it to a
9329 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9330 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9332 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9333 || code == EQ_EXPR || code == NE_EXPR)
9334 && ((truth_value_p (TREE_CODE (arg0))
9335 && (truth_value_p (TREE_CODE (arg1))
9336 || (TREE_CODE (arg1) == BIT_AND_EXPR
9337 && integer_onep (TREE_OPERAND (arg1, 1)))))
9338 || (truth_value_p (TREE_CODE (arg1))
9339 && (truth_value_p (TREE_CODE (arg0))
9340 || (TREE_CODE (arg0) == BIT_AND_EXPR
9341 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9343 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9344 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9347 fold_convert (boolean_type_node, arg0),
9348 fold_convert (boolean_type_node, arg1));
9350 if (code == EQ_EXPR)
9351 tem = invert_truthvalue (tem);
9353 return fold_convert (type, tem);
9356 if (TREE_CODE_CLASS (code) == tcc_binary
9357 || TREE_CODE_CLASS (code) == tcc_comparison)
9359 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9360 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9361 fold_build2 (code, type,
9362 fold_convert (TREE_TYPE (op0),
9363 TREE_OPERAND (arg0, 1)),
9365 if (TREE_CODE (arg1) == COMPOUND_EXPR
9366 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9367 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9368 fold_build2 (code, type, op0,
9369 fold_convert (TREE_TYPE (op1),
9370 TREE_OPERAND (arg1, 1))));
9372 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9374 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9376 /*cond_first_p=*/1);
9377 if (tem != NULL_TREE)
9381 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9383 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9385 /*cond_first_p=*/0);
9386 if (tem != NULL_TREE)
9393 case POINTER_PLUS_EXPR:
9394 /* 0 +p index -> (type)index */
9395 if (integer_zerop (arg0))
9396 return non_lvalue (fold_convert (type, arg1));
9398 /* PTR +p 0 -> PTR */
9399 if (integer_zerop (arg1))
9400 return non_lvalue (fold_convert (type, arg0));
9402 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9403 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9404 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9405 return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
9406 fold_convert (sizetype, arg1),
9407 fold_convert (sizetype, arg0)));
9409 /* index +p PTR -> PTR +p index */
9410 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9411 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9412 return fold_build2 (POINTER_PLUS_EXPR, type,
9413 fold_convert (type, arg1),
9414 fold_convert (sizetype, arg0));
9416 /* (PTR +p B) +p A -> PTR +p (B + A) */
9417 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9420 tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
9421 tree arg00 = TREE_OPERAND (arg0, 0);
9422 inner = fold_build2 (PLUS_EXPR, sizetype,
9423 arg01, fold_convert (sizetype, arg1));
9424 return fold_convert (type,
9425 fold_build2 (POINTER_PLUS_EXPR,
9426 TREE_TYPE (arg00), arg00, inner));
9429 /* PTR_CST +p CST -> CST1 */
9430 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9431 return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
9433 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9434 of the array. Loop optimizer sometimes produce this type of
9436 if (TREE_CODE (arg0) == ADDR_EXPR)
9438 tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
9440 return fold_convert (type, tem);
9446 /* PTR + INT -> (INT)(PTR p+ INT) */
9447 if (POINTER_TYPE_P (TREE_TYPE (arg0))
9448 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9449 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9452 fold_convert (sizetype, arg1)));
9453 /* INT + PTR -> (INT)(PTR p+ INT) */
9454 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9455 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9456 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9459 fold_convert (sizetype, arg0)));
9460 /* A + (-B) -> A - B */
9461 if (TREE_CODE (arg1) == NEGATE_EXPR)
9462 return fold_build2 (MINUS_EXPR, type,
9463 fold_convert (type, arg0),
9464 fold_convert (type, TREE_OPERAND (arg1, 0)));
9465 /* (-A) + B -> B - A */
9466 if (TREE_CODE (arg0) == NEGATE_EXPR
9467 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9468 return fold_build2 (MINUS_EXPR, type,
9469 fold_convert (type, arg1),
9470 fold_convert (type, TREE_OPERAND (arg0, 0)));
9472 if (INTEGRAL_TYPE_P (type))
9474 /* Convert ~A + 1 to -A. */
9475 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9476 && integer_onep (arg1))
9477 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
9480 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9481 && !TYPE_OVERFLOW_TRAPS (type))
9483 tree tem = TREE_OPERAND (arg0, 0);
9486 if (operand_equal_p (tem, arg1, 0))
9488 t1 = build_int_cst_type (type, -1);
9489 return omit_one_operand (type, t1, arg1);
9494 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9495 && !TYPE_OVERFLOW_TRAPS (type))
9497 tree tem = TREE_OPERAND (arg1, 0);
9500 if (operand_equal_p (arg0, tem, 0))
9502 t1 = build_int_cst_type (type, -1);
9503 return omit_one_operand (type, t1, arg0);
9507 /* X + (X / CST) * -CST is X % CST. */
9508 if (TREE_CODE (arg1) == MULT_EXPR
9509 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9510 && operand_equal_p (arg0,
9511 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
9513 tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
9514 tree cst1 = TREE_OPERAND (arg1, 1);
9515 tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
9516 if (sum && integer_zerop (sum))
9517 return fold_convert (type,
9518 fold_build2 (TRUNC_MOD_EXPR,
9519 TREE_TYPE (arg0), arg0, cst0));
9523 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9524 same or one. Make sure type is not saturating.
9525 fold_plusminus_mult_expr will re-associate. */
9526 if ((TREE_CODE (arg0) == MULT_EXPR
9527 || TREE_CODE (arg1) == MULT_EXPR)
9528 && !TYPE_SATURATING (type)
9529 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9531 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9536 if (! FLOAT_TYPE_P (type))
9538 if (integer_zerop (arg1))
9539 return non_lvalue (fold_convert (type, arg0));
9541 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9542 with a constant, and the two constants have no bits in common,
9543 we should treat this as a BIT_IOR_EXPR since this may produce more
9545 if (TREE_CODE (arg0) == BIT_AND_EXPR
9546 && TREE_CODE (arg1) == BIT_AND_EXPR
9547 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9548 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9549 && integer_zerop (const_binop (BIT_AND_EXPR,
9550 TREE_OPERAND (arg0, 1),
9551 TREE_OPERAND (arg1, 1), 0)))
9553 code = BIT_IOR_EXPR;
9557 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9558 (plus (plus (mult) (mult)) (foo)) so that we can
9559 take advantage of the factoring cases below. */
9560 if (((TREE_CODE (arg0) == PLUS_EXPR
9561 || TREE_CODE (arg0) == MINUS_EXPR)
9562 && TREE_CODE (arg1) == MULT_EXPR)
9563 || ((TREE_CODE (arg1) == PLUS_EXPR
9564 || TREE_CODE (arg1) == MINUS_EXPR)
9565 && TREE_CODE (arg0) == MULT_EXPR))
9567 tree parg0, parg1, parg, marg;
9568 enum tree_code pcode;
9570 if (TREE_CODE (arg1) == MULT_EXPR)
9571 parg = arg0, marg = arg1;
9573 parg = arg1, marg = arg0;
9574 pcode = TREE_CODE (parg);
9575 parg0 = TREE_OPERAND (parg, 0);
9576 parg1 = TREE_OPERAND (parg, 1);
9580 if (TREE_CODE (parg0) == MULT_EXPR
9581 && TREE_CODE (parg1) != MULT_EXPR)
9582 return fold_build2 (pcode, type,
9583 fold_build2 (PLUS_EXPR, type,
9584 fold_convert (type, parg0),
9585 fold_convert (type, marg)),
9586 fold_convert (type, parg1));
9587 if (TREE_CODE (parg0) != MULT_EXPR
9588 && TREE_CODE (parg1) == MULT_EXPR)
9589 return fold_build2 (PLUS_EXPR, type,
9590 fold_convert (type, parg0),
9591 fold_build2 (pcode, type,
9592 fold_convert (type, marg),
9599 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9600 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
9601 return non_lvalue (fold_convert (type, arg0));
9603 /* Likewise if the operands are reversed. */
9604 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9605 return non_lvalue (fold_convert (type, arg1));
9607 /* Convert X + -C into X - C. */
9608 if (TREE_CODE (arg1) == REAL_CST
9609 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
9611 tem = fold_negate_const (arg1, type);
9612 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
9613 return fold_build2 (MINUS_EXPR, type,
9614 fold_convert (type, arg0),
9615 fold_convert (type, tem));
9618 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9619 to __complex__ ( x, y ). This is not the same for SNaNs or
9620 if signed zeros are involved. */
9621 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9622 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9623 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9625 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9626 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9627 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9628 bool arg0rz = false, arg0iz = false;
9629 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9630 || (arg0i && (arg0iz = real_zerop (arg0i))))
9632 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9633 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9634 if (arg0rz && arg1i && real_zerop (arg1i))
9636 tree rp = arg1r ? arg1r
9637 : build1 (REALPART_EXPR, rtype, arg1);
9638 tree ip = arg0i ? arg0i
9639 : build1 (IMAGPART_EXPR, rtype, arg0);
9640 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9642 else if (arg0iz && arg1r && real_zerop (arg1r))
9644 tree rp = arg0r ? arg0r
9645 : build1 (REALPART_EXPR, rtype, arg0);
9646 tree ip = arg1i ? arg1i
9647 : build1 (IMAGPART_EXPR, rtype, arg1);
9648 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9653 if (flag_unsafe_math_optimizations
9654 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9655 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9656 && (tem = distribute_real_division (code, type, arg0, arg1)))
9659 /* Convert x+x into x*2.0. */
9660 if (operand_equal_p (arg0, arg1, 0)
9661 && SCALAR_FLOAT_TYPE_P (type))
9662 return fold_build2 (MULT_EXPR, type, arg0,
9663 build_real (type, dconst2));
9665 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
9666 We associate floats only if the user has specified
9667 -fassociative-math. */
9668 if (flag_associative_math
9669 && TREE_CODE (arg1) == PLUS_EXPR
9670 && TREE_CODE (arg0) != MULT_EXPR)
9672 tree tree10 = TREE_OPERAND (arg1, 0);
9673 tree tree11 = TREE_OPERAND (arg1, 1);
9674 if (TREE_CODE (tree11) == MULT_EXPR
9675 && TREE_CODE (tree10) == MULT_EXPR)
9678 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
9679 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
9682 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
9683 We associate floats only if the user has specified
9684 -fassociative-math. */
9685 if (flag_associative_math
9686 && TREE_CODE (arg0) == PLUS_EXPR
9687 && TREE_CODE (arg1) != MULT_EXPR)
9689 tree tree00 = TREE_OPERAND (arg0, 0);
9690 tree tree01 = TREE_OPERAND (arg0, 1);
9691 if (TREE_CODE (tree01) == MULT_EXPR
9692 && TREE_CODE (tree00) == MULT_EXPR)
9695 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
9696 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
9702 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9703 is a rotate of A by C1 bits. */
9704 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9705 is a rotate of A by B bits. */
9707 enum tree_code code0, code1;
9709 code0 = TREE_CODE (arg0);
9710 code1 = TREE_CODE (arg1);
9711 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
9712 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
9713 && operand_equal_p (TREE_OPERAND (arg0, 0),
9714 TREE_OPERAND (arg1, 0), 0)
9715 && (rtype = TREE_TYPE (TREE_OPERAND (arg0, 0)),
9716 TYPE_UNSIGNED (rtype))
9717 /* Only create rotates in complete modes. Other cases are not
9718 expanded properly. */
9719 && TYPE_PRECISION (rtype) == GET_MODE_PRECISION (TYPE_MODE (rtype)))
9721 tree tree01, tree11;
9722 enum tree_code code01, code11;
9724 tree01 = TREE_OPERAND (arg0, 1);
9725 tree11 = TREE_OPERAND (arg1, 1);
9726 STRIP_NOPS (tree01);
9727 STRIP_NOPS (tree11);
9728 code01 = TREE_CODE (tree01);
9729 code11 = TREE_CODE (tree11);
9730 if (code01 == INTEGER_CST
9731 && code11 == INTEGER_CST
9732 && TREE_INT_CST_HIGH (tree01) == 0
9733 && TREE_INT_CST_HIGH (tree11) == 0
9734 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
9735 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
9736 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
9737 code0 == LSHIFT_EXPR ? tree01 : tree11);
9738 else if (code11 == MINUS_EXPR)
9740 tree tree110, tree111;
9741 tree110 = TREE_OPERAND (tree11, 0);
9742 tree111 = TREE_OPERAND (tree11, 1);
9743 STRIP_NOPS (tree110);
9744 STRIP_NOPS (tree111);
9745 if (TREE_CODE (tree110) == INTEGER_CST
9746 && 0 == compare_tree_int (tree110,
9748 (TREE_TYPE (TREE_OPERAND
9750 && operand_equal_p (tree01, tree111, 0))
9751 return build2 ((code0 == LSHIFT_EXPR
9754 type, TREE_OPERAND (arg0, 0), tree01);
9756 else if (code01 == MINUS_EXPR)
9758 tree tree010, tree011;
9759 tree010 = TREE_OPERAND (tree01, 0);
9760 tree011 = TREE_OPERAND (tree01, 1);
9761 STRIP_NOPS (tree010);
9762 STRIP_NOPS (tree011);
9763 if (TREE_CODE (tree010) == INTEGER_CST
9764 && 0 == compare_tree_int (tree010,
9766 (TREE_TYPE (TREE_OPERAND
9768 && operand_equal_p (tree11, tree011, 0))
9769 return build2 ((code0 != LSHIFT_EXPR
9772 type, TREE_OPERAND (arg0, 0), tree11);
9778 /* In most languages, can't associate operations on floats through
9779 parentheses. Rather than remember where the parentheses were, we
9780 don't associate floats at all, unless the user has specified
9782 And, we need to make sure type is not saturating. */
9784 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
9785 && !TYPE_SATURATING (type))
9787 tree var0, con0, lit0, minus_lit0;
9788 tree var1, con1, lit1, minus_lit1;
9791 /* Split both trees into variables, constants, and literals. Then
9792 associate each group together, the constants with literals,
9793 then the result with variables. This increases the chances of
9794 literals being recombined later and of generating relocatable
9795 expressions for the sum of a constant and literal. */
9796 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
9797 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
9798 code == MINUS_EXPR);
9800 /* With undefined overflow we can only associate constants
9801 with one variable. */
9802 if (((POINTER_TYPE_P (type) && POINTER_TYPE_OVERFLOW_UNDEFINED)
9803 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
9809 if (TREE_CODE (tmp0) == NEGATE_EXPR)
9810 tmp0 = TREE_OPERAND (tmp0, 0);
9811 if (TREE_CODE (tmp1) == NEGATE_EXPR)
9812 tmp1 = TREE_OPERAND (tmp1, 0);
9813 /* The only case we can still associate with two variables
9814 is if they are the same, modulo negation. */
9815 if (!operand_equal_p (tmp0, tmp1, 0))
9819 /* Only do something if we found more than two objects. Otherwise,
9820 nothing has changed and we risk infinite recursion. */
9822 && (2 < ((var0 != 0) + (var1 != 0)
9823 + (con0 != 0) + (con1 != 0)
9824 + (lit0 != 0) + (lit1 != 0)
9825 + (minus_lit0 != 0) + (minus_lit1 != 0))))
9827 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9828 if (code == MINUS_EXPR)
9831 var0 = associate_trees (var0, var1, code, type);
9832 con0 = associate_trees (con0, con1, code, type);
9833 lit0 = associate_trees (lit0, lit1, code, type);
9834 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
9836 /* Preserve the MINUS_EXPR if the negative part of the literal is
9837 greater than the positive part. Otherwise, the multiplicative
9838 folding code (i.e extract_muldiv) may be fooled in case
9839 unsigned constants are subtracted, like in the following
9840 example: ((X*2 + 4) - 8U)/2. */
9841 if (minus_lit0 && lit0)
9843 if (TREE_CODE (lit0) == INTEGER_CST
9844 && TREE_CODE (minus_lit0) == INTEGER_CST
9845 && tree_int_cst_lt (lit0, minus_lit0))
9847 minus_lit0 = associate_trees (minus_lit0, lit0,
9853 lit0 = associate_trees (lit0, minus_lit0,
9861 return fold_convert (type,
9862 associate_trees (var0, minus_lit0,
9866 con0 = associate_trees (con0, minus_lit0,
9868 return fold_convert (type,
9869 associate_trees (var0, con0,
9874 con0 = associate_trees (con0, lit0, code, type);
9875 return fold_convert (type, associate_trees (var0, con0,
9883 /* Pointer simplifications for subtraction, simple reassociations. */
9884 if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
9886 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
9887 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
9888 && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
9890 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
9891 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
9892 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
9893 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
9894 return fold_build2 (PLUS_EXPR, type,
9895 fold_build2 (MINUS_EXPR, type, arg00, arg10),
9896 fold_build2 (MINUS_EXPR, type, arg01, arg11));
9898 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
9899 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9901 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
9902 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
9903 tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
9905 return fold_build2 (PLUS_EXPR, type, tmp, arg01);
9908 /* A - (-B) -> A + B */
9909 if (TREE_CODE (arg1) == NEGATE_EXPR)
9910 return fold_build2 (PLUS_EXPR, type, op0,
9911 fold_convert (type, TREE_OPERAND (arg1, 0)));
9912 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
9913 if (TREE_CODE (arg0) == NEGATE_EXPR
9914 && (FLOAT_TYPE_P (type)
9915 || INTEGRAL_TYPE_P (type))
9916 && negate_expr_p (arg1)
9917 && reorder_operands_p (arg0, arg1))
9918 return fold_build2 (MINUS_EXPR, type,
9919 fold_convert (type, negate_expr (arg1)),
9920 fold_convert (type, TREE_OPERAND (arg0, 0)));
9921 /* Convert -A - 1 to ~A. */
9922 if (INTEGRAL_TYPE_P (type)
9923 && TREE_CODE (arg0) == NEGATE_EXPR
9924 && integer_onep (arg1)
9925 && !TYPE_OVERFLOW_TRAPS (type))
9926 return fold_build1 (BIT_NOT_EXPR, type,
9927 fold_convert (type, TREE_OPERAND (arg0, 0)));
9929 /* Convert -1 - A to ~A. */
9930 if (INTEGRAL_TYPE_P (type)
9931 && integer_all_onesp (arg0))
9932 return fold_build1 (BIT_NOT_EXPR, type, op1);
9935 /* X - (X / CST) * CST is X % CST. */
9936 if (INTEGRAL_TYPE_P (type)
9937 && TREE_CODE (arg1) == MULT_EXPR
9938 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9939 && operand_equal_p (arg0,
9940 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
9941 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
9942 TREE_OPERAND (arg1, 1), 0))
9943 return fold_convert (type,
9944 fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
9945 arg0, TREE_OPERAND (arg1, 1)));
9947 if (! FLOAT_TYPE_P (type))
9949 if (integer_zerop (arg0))
9950 return negate_expr (fold_convert (type, arg1));
9951 if (integer_zerop (arg1))
9952 return non_lvalue (fold_convert (type, arg0));
9954 /* Fold A - (A & B) into ~B & A. */
9955 if (!TREE_SIDE_EFFECTS (arg0)
9956 && TREE_CODE (arg1) == BIT_AND_EXPR)
9958 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
9960 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
9961 return fold_build2 (BIT_AND_EXPR, type,
9962 fold_build1 (BIT_NOT_EXPR, type, arg10),
9963 fold_convert (type, arg0));
9965 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9967 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
9968 return fold_build2 (BIT_AND_EXPR, type,
9969 fold_build1 (BIT_NOT_EXPR, type, arg11),
9970 fold_convert (type, arg0));
9974 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
9975 any power of 2 minus 1. */
9976 if (TREE_CODE (arg0) == BIT_AND_EXPR
9977 && TREE_CODE (arg1) == BIT_AND_EXPR
9978 && operand_equal_p (TREE_OPERAND (arg0, 0),
9979 TREE_OPERAND (arg1, 0), 0))
9981 tree mask0 = TREE_OPERAND (arg0, 1);
9982 tree mask1 = TREE_OPERAND (arg1, 1);
9983 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
9985 if (operand_equal_p (tem, mask1, 0))
9987 tem = fold_build2 (BIT_XOR_EXPR, type,
9988 TREE_OPERAND (arg0, 0), mask1);
9989 return fold_build2 (MINUS_EXPR, type, tem, mask1);
9994 /* See if ARG1 is zero and X - ARG1 reduces to X. */
9995 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
9996 return non_lvalue (fold_convert (type, arg0));
9998 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
9999 ARG0 is zero and X + ARG0 reduces to X, since that would mean
10000 (-ARG1 + ARG0) reduces to -ARG1. */
10001 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
10002 return negate_expr (fold_convert (type, arg1));
10004 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
10005 __complex__ ( x, -y ). This is not the same for SNaNs or if
10006 signed zeros are involved. */
10007 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10008 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10009 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10011 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10012 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10013 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10014 bool arg0rz = false, arg0iz = false;
10015 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10016 || (arg0i && (arg0iz = real_zerop (arg0i))))
10018 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10019 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10020 if (arg0rz && arg1i && real_zerop (arg1i))
10022 tree rp = fold_build1 (NEGATE_EXPR, rtype,
10024 : build1 (REALPART_EXPR, rtype, arg1));
10025 tree ip = arg0i ? arg0i
10026 : build1 (IMAGPART_EXPR, rtype, arg0);
10027 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10029 else if (arg0iz && arg1r && real_zerop (arg1r))
10031 tree rp = arg0r ? arg0r
10032 : build1 (REALPART_EXPR, rtype, arg0);
10033 tree ip = fold_build1 (NEGATE_EXPR, rtype,
10035 : build1 (IMAGPART_EXPR, rtype, arg1));
10036 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10041 /* Fold &x - &x. This can happen from &x.foo - &x.
10042 This is unsafe for certain floats even in non-IEEE formats.
10043 In IEEE, it is unsafe because it does wrong for NaNs.
10044 Also note that operand_equal_p is always false if an operand
10047 if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
10048 && operand_equal_p (arg0, arg1, 0))
10049 return fold_convert (type, integer_zero_node);
10051 /* A - B -> A + (-B) if B is easily negatable. */
10052 if (negate_expr_p (arg1)
10053 && ((FLOAT_TYPE_P (type)
10054 /* Avoid this transformation if B is a positive REAL_CST. */
10055 && (TREE_CODE (arg1) != REAL_CST
10056 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
10057 || INTEGRAL_TYPE_P (type)))
10058 return fold_build2 (PLUS_EXPR, type,
10059 fold_convert (type, arg0),
10060 fold_convert (type, negate_expr (arg1)));
10062 /* Try folding difference of addresses. */
10064 HOST_WIDE_INT diff;
10066 if ((TREE_CODE (arg0) == ADDR_EXPR
10067 || TREE_CODE (arg1) == ADDR_EXPR)
10068 && ptr_difference_const (arg0, arg1, &diff))
10069 return build_int_cst_type (type, diff);
10072 /* Fold &a[i] - &a[j] to i-j. */
10073 if (TREE_CODE (arg0) == ADDR_EXPR
10074 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
10075 && TREE_CODE (arg1) == ADDR_EXPR
10076 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
10078 tree aref0 = TREE_OPERAND (arg0, 0);
10079 tree aref1 = TREE_OPERAND (arg1, 0);
10080 if (operand_equal_p (TREE_OPERAND (aref0, 0),
10081 TREE_OPERAND (aref1, 0), 0))
10083 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
10084 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
10085 tree esz = array_ref_element_size (aref0);
10086 tree diff = build2 (MINUS_EXPR, type, op0, op1);
10087 return fold_build2 (MULT_EXPR, type, diff,
10088 fold_convert (type, esz));
10093 if (flag_unsafe_math_optimizations
10094 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10095 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10096 && (tem = distribute_real_division (code, type, arg0, arg1)))
10099 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
10100 same or one. Make sure type is not saturating.
10101 fold_plusminus_mult_expr will re-associate. */
10102 if ((TREE_CODE (arg0) == MULT_EXPR
10103 || TREE_CODE (arg1) == MULT_EXPR)
10104 && !TYPE_SATURATING (type)
10105 && (!FLOAT_TYPE_P (type) || flag_associative_math))
10107 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
10115 /* (-A) * (-B) -> A * B */
10116 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10117 return fold_build2 (MULT_EXPR, type,
10118 fold_convert (type, TREE_OPERAND (arg0, 0)),
10119 fold_convert (type, negate_expr (arg1)));
10120 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10121 return fold_build2 (MULT_EXPR, type,
10122 fold_convert (type, negate_expr (arg0)),
10123 fold_convert (type, TREE_OPERAND (arg1, 0)));
10125 if (! FLOAT_TYPE_P (type))
10127 if (integer_zerop (arg1))
10128 return omit_one_operand (type, arg1, arg0);
10129 if (integer_onep (arg1))
10130 return non_lvalue (fold_convert (type, arg0));
10131 /* Transform x * -1 into -x. Make sure to do the negation
10132 on the original operand with conversions not stripped
10133 because we can only strip non-sign-changing conversions. */
10134 if (integer_all_onesp (arg1))
10135 return fold_convert (type, negate_expr (op0));
10136 /* Transform x * -C into -x * C if x is easily negatable. */
10137 if (TREE_CODE (arg1) == INTEGER_CST
10138 && tree_int_cst_sgn (arg1) == -1
10139 && negate_expr_p (arg0)
10140 && (tem = negate_expr (arg1)) != arg1
10141 && !TREE_OVERFLOW (tem))
10142 return fold_build2 (MULT_EXPR, type,
10143 fold_convert (type, negate_expr (arg0)), tem);
10145 /* (a * (1 << b)) is (a << b) */
10146 if (TREE_CODE (arg1) == LSHIFT_EXPR
10147 && integer_onep (TREE_OPERAND (arg1, 0)))
10148 return fold_build2 (LSHIFT_EXPR, type, op0,
10149 TREE_OPERAND (arg1, 1));
10150 if (TREE_CODE (arg0) == LSHIFT_EXPR
10151 && integer_onep (TREE_OPERAND (arg0, 0)))
10152 return fold_build2 (LSHIFT_EXPR, type, op1,
10153 TREE_OPERAND (arg0, 1));
10155 /* (A + A) * C -> A * 2 * C */
10156 if (TREE_CODE (arg0) == PLUS_EXPR
10157 && TREE_CODE (arg1) == INTEGER_CST
10158 && operand_equal_p (TREE_OPERAND (arg0, 0),
10159 TREE_OPERAND (arg0, 1), 0))
10160 return fold_build2 (MULT_EXPR, type,
10161 omit_one_operand (type, TREE_OPERAND (arg0, 0),
10162 TREE_OPERAND (arg0, 1)),
10163 fold_build2 (MULT_EXPR, type,
10164 build_int_cst (type, 2) , arg1));
10166 strict_overflow_p = false;
10167 if (TREE_CODE (arg1) == INTEGER_CST
10168 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10169 &strict_overflow_p)))
10171 if (strict_overflow_p)
10172 fold_overflow_warning (("assuming signed overflow does not "
10173 "occur when simplifying "
10175 WARN_STRICT_OVERFLOW_MISC);
10176 return fold_convert (type, tem);
10179 /* Optimize z * conj(z) for integer complex numbers. */
10180 if (TREE_CODE (arg0) == CONJ_EXPR
10181 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10182 return fold_mult_zconjz (type, arg1);
10183 if (TREE_CODE (arg1) == CONJ_EXPR
10184 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10185 return fold_mult_zconjz (type, arg0);
10189 /* Maybe fold x * 0 to 0. The expressions aren't the same
10190 when x is NaN, since x * 0 is also NaN. Nor are they the
10191 same in modes with signed zeros, since multiplying a
10192 negative value by 0 gives -0, not +0. */
10193 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10194 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10195 && real_zerop (arg1))
10196 return omit_one_operand (type, arg1, arg0);
10197 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
10198 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10199 && real_onep (arg1))
10200 return non_lvalue (fold_convert (type, arg0));
10202 /* Transform x * -1.0 into -x. */
10203 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10204 && real_minus_onep (arg1))
10205 return fold_convert (type, negate_expr (arg0));
10207 /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
10208 the result for floating point types due to rounding so it is applied
10209 only if -fassociative-math was specify. */
10210 if (flag_associative_math
10211 && TREE_CODE (arg0) == RDIV_EXPR
10212 && TREE_CODE (arg1) == REAL_CST
10213 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
10215 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
10218 return fold_build2 (RDIV_EXPR, type, tem,
10219 TREE_OPERAND (arg0, 1));
10222 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10223 if (operand_equal_p (arg0, arg1, 0))
10225 tree tem = fold_strip_sign_ops (arg0);
10226 if (tem != NULL_TREE)
10228 tem = fold_convert (type, tem);
10229 return fold_build2 (MULT_EXPR, type, tem, tem);
10233 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10234 This is not the same for NaNs or if signed zeros are
10236 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10237 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10238 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10239 && TREE_CODE (arg1) == COMPLEX_CST
10240 && real_zerop (TREE_REALPART (arg1)))
10242 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10243 if (real_onep (TREE_IMAGPART (arg1)))
10244 return fold_build2 (COMPLEX_EXPR, type,
10245 negate_expr (fold_build1 (IMAGPART_EXPR,
10247 fold_build1 (REALPART_EXPR, rtype, arg0));
10248 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10249 return fold_build2 (COMPLEX_EXPR, type,
10250 fold_build1 (IMAGPART_EXPR, rtype, arg0),
10251 negate_expr (fold_build1 (REALPART_EXPR,
10255 /* Optimize z * conj(z) for floating point complex numbers.
10256 Guarded by flag_unsafe_math_optimizations as non-finite
10257 imaginary components don't produce scalar results. */
10258 if (flag_unsafe_math_optimizations
10259 && TREE_CODE (arg0) == CONJ_EXPR
10260 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10261 return fold_mult_zconjz (type, arg1);
10262 if (flag_unsafe_math_optimizations
10263 && TREE_CODE (arg1) == CONJ_EXPR
10264 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10265 return fold_mult_zconjz (type, arg0);
10267 if (flag_unsafe_math_optimizations)
10269 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10270 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10272 /* Optimizations of root(...)*root(...). */
10273 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
10276 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10277 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10279 /* Optimize sqrt(x)*sqrt(x) as x. */
10280 if (BUILTIN_SQRT_P (fcode0)
10281 && operand_equal_p (arg00, arg10, 0)
10282 && ! HONOR_SNANS (TYPE_MODE (type)))
10285 /* Optimize root(x)*root(y) as root(x*y). */
10286 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10287 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10288 return build_call_expr (rootfn, 1, arg);
10291 /* Optimize expN(x)*expN(y) as expN(x+y). */
10292 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
10294 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10295 tree arg = fold_build2 (PLUS_EXPR, type,
10296 CALL_EXPR_ARG (arg0, 0),
10297 CALL_EXPR_ARG (arg1, 0));
10298 return build_call_expr (expfn, 1, arg);
10301 /* Optimizations of pow(...)*pow(...). */
10302 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
10303 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
10304 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
10306 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10307 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10308 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10309 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10311 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10312 if (operand_equal_p (arg01, arg11, 0))
10314 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10315 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10316 return build_call_expr (powfn, 2, arg, arg01);
10319 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10320 if (operand_equal_p (arg00, arg10, 0))
10322 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10323 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
10324 return build_call_expr (powfn, 2, arg00, arg);
10328 /* Optimize tan(x)*cos(x) as sin(x). */
10329 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
10330 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
10331 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
10332 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
10333 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
10334 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
10335 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10336 CALL_EXPR_ARG (arg1, 0), 0))
10338 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
10340 if (sinfn != NULL_TREE)
10341 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
10344 /* Optimize x*pow(x,c) as pow(x,c+1). */
10345 if (fcode1 == BUILT_IN_POW
10346 || fcode1 == BUILT_IN_POWF
10347 || fcode1 == BUILT_IN_POWL)
10349 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10350 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10351 if (TREE_CODE (arg11) == REAL_CST
10352 && !TREE_OVERFLOW (arg11)
10353 && operand_equal_p (arg0, arg10, 0))
10355 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10359 c = TREE_REAL_CST (arg11);
10360 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10361 arg = build_real (type, c);
10362 return build_call_expr (powfn, 2, arg0, arg);
10366 /* Optimize pow(x,c)*x as pow(x,c+1). */
10367 if (fcode0 == BUILT_IN_POW
10368 || fcode0 == BUILT_IN_POWF
10369 || fcode0 == BUILT_IN_POWL)
10371 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10372 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10373 if (TREE_CODE (arg01) == REAL_CST
10374 && !TREE_OVERFLOW (arg01)
10375 && operand_equal_p (arg1, arg00, 0))
10377 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10381 c = TREE_REAL_CST (arg01);
10382 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10383 arg = build_real (type, c);
10384 return build_call_expr (powfn, 2, arg1, arg);
10388 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10389 if (! optimize_size
10390 && operand_equal_p (arg0, arg1, 0))
10392 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
10396 tree arg = build_real (type, dconst2);
10397 return build_call_expr (powfn, 2, arg0, arg);
10406 if (integer_all_onesp (arg1))
10407 return omit_one_operand (type, arg1, arg0);
10408 if (integer_zerop (arg1))
10409 return non_lvalue (fold_convert (type, arg0));
10410 if (operand_equal_p (arg0, arg1, 0))
10411 return non_lvalue (fold_convert (type, arg0));
10413 /* ~X | X is -1. */
10414 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10415 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10417 t1 = fold_convert (type, integer_zero_node);
10418 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10419 return omit_one_operand (type, t1, arg1);
10422 /* X | ~X is -1. */
10423 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10424 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10426 t1 = fold_convert (type, integer_zero_node);
10427 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10428 return omit_one_operand (type, t1, arg0);
10431 /* Canonicalize (X & C1) | C2. */
10432 if (TREE_CODE (arg0) == BIT_AND_EXPR
10433 && TREE_CODE (arg1) == INTEGER_CST
10434 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10436 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, hi3, lo3, mlo, mhi;
10437 int width = TYPE_PRECISION (type), w;
10438 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10439 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10440 hi2 = TREE_INT_CST_HIGH (arg1);
10441 lo2 = TREE_INT_CST_LOW (arg1);
10443 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10444 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10445 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10447 if (width > HOST_BITS_PER_WIDE_INT)
10449 mhi = (unsigned HOST_WIDE_INT) -1
10450 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10456 mlo = (unsigned HOST_WIDE_INT) -1
10457 >> (HOST_BITS_PER_WIDE_INT - width);
10460 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10461 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10462 return fold_build2 (BIT_IOR_EXPR, type,
10463 TREE_OPERAND (arg0, 0), arg1);
10465 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
10466 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
10467 mode which allows further optimizations. */
10474 for (w = BITS_PER_UNIT;
10475 w <= width && w <= HOST_BITS_PER_WIDE_INT;
10478 unsigned HOST_WIDE_INT mask
10479 = (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
10480 if (((lo1 | lo2) & mask) == mask
10481 && (lo1 & ~mask) == 0 && hi1 == 0)
10488 if (hi3 != hi1 || lo3 != lo1)
10489 return fold_build2 (BIT_IOR_EXPR, type,
10490 fold_build2 (BIT_AND_EXPR, type,
10491 TREE_OPERAND (arg0, 0),
10492 build_int_cst_wide (type,
10497 /* (X & Y) | Y is (X, Y). */
10498 if (TREE_CODE (arg0) == BIT_AND_EXPR
10499 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10500 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10501 /* (X & Y) | X is (Y, X). */
10502 if (TREE_CODE (arg0) == BIT_AND_EXPR
10503 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10504 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10505 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10506 /* X | (X & Y) is (Y, X). */
10507 if (TREE_CODE (arg1) == BIT_AND_EXPR
10508 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10509 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10510 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10511 /* X | (Y & X) is (Y, X). */
10512 if (TREE_CODE (arg1) == BIT_AND_EXPR
10513 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10514 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10515 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10517 t1 = distribute_bit_expr (code, type, arg0, arg1);
10518 if (t1 != NULL_TREE)
10521 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10523 This results in more efficient code for machines without a NAND
10524 instruction. Combine will canonicalize to the first form
10525 which will allow use of NAND instructions provided by the
10526 backend if they exist. */
10527 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10528 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10530 return fold_build1 (BIT_NOT_EXPR, type,
10531 build2 (BIT_AND_EXPR, type,
10532 fold_convert (type,
10533 TREE_OPERAND (arg0, 0)),
10534 fold_convert (type,
10535 TREE_OPERAND (arg1, 0))));
10538 /* See if this can be simplified into a rotate first. If that
10539 is unsuccessful continue in the association code. */
10543 if (integer_zerop (arg1))
10544 return non_lvalue (fold_convert (type, arg0));
10545 if (integer_all_onesp (arg1))
10546 return fold_build1 (BIT_NOT_EXPR, type, op0);
10547 if (operand_equal_p (arg0, arg1, 0))
10548 return omit_one_operand (type, integer_zero_node, arg0);
10550 /* ~X ^ X is -1. */
10551 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10552 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10554 t1 = fold_convert (type, integer_zero_node);
10555 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10556 return omit_one_operand (type, t1, arg1);
10559 /* X ^ ~X is -1. */
10560 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10561 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10563 t1 = fold_convert (type, integer_zero_node);
10564 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10565 return omit_one_operand (type, t1, arg0);
10568 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10569 with a constant, and the two constants have no bits in common,
10570 we should treat this as a BIT_IOR_EXPR since this may produce more
10571 simplifications. */
10572 if (TREE_CODE (arg0) == BIT_AND_EXPR
10573 && TREE_CODE (arg1) == BIT_AND_EXPR
10574 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10575 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10576 && integer_zerop (const_binop (BIT_AND_EXPR,
10577 TREE_OPERAND (arg0, 1),
10578 TREE_OPERAND (arg1, 1), 0)))
10580 code = BIT_IOR_EXPR;
10584 /* (X | Y) ^ X -> Y & ~ X*/
10585 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10586 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10588 tree t2 = TREE_OPERAND (arg0, 1);
10589 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10591 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10592 fold_convert (type, t1));
10596 /* (Y | X) ^ X -> Y & ~ X*/
10597 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10598 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10600 tree t2 = TREE_OPERAND (arg0, 0);
10601 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10603 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10604 fold_convert (type, t1));
10608 /* X ^ (X | Y) -> Y & ~ X*/
10609 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10610 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
10612 tree t2 = TREE_OPERAND (arg1, 1);
10613 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10615 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10616 fold_convert (type, t1));
10620 /* X ^ (Y | X) -> Y & ~ X*/
10621 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10622 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
10624 tree t2 = TREE_OPERAND (arg1, 0);
10625 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10627 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10628 fold_convert (type, t1));
10632 /* Convert ~X ^ ~Y to X ^ Y. */
10633 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10634 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10635 return fold_build2 (code, type,
10636 fold_convert (type, TREE_OPERAND (arg0, 0)),
10637 fold_convert (type, TREE_OPERAND (arg1, 0)));
10639 /* Convert ~X ^ C to X ^ ~C. */
10640 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10641 && TREE_CODE (arg1) == INTEGER_CST)
10642 return fold_build2 (code, type,
10643 fold_convert (type, TREE_OPERAND (arg0, 0)),
10644 fold_build1 (BIT_NOT_EXPR, type, arg1));
10646 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10647 if (TREE_CODE (arg0) == BIT_AND_EXPR
10648 && integer_onep (TREE_OPERAND (arg0, 1))
10649 && integer_onep (arg1))
10650 return fold_build2 (EQ_EXPR, type, arg0,
10651 build_int_cst (TREE_TYPE (arg0), 0));
10653 /* Fold (X & Y) ^ Y as ~X & Y. */
10654 if (TREE_CODE (arg0) == BIT_AND_EXPR
10655 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10657 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10658 return fold_build2 (BIT_AND_EXPR, type,
10659 fold_build1 (BIT_NOT_EXPR, type, tem),
10660 fold_convert (type, arg1));
10662 /* Fold (X & Y) ^ X as ~Y & X. */
10663 if (TREE_CODE (arg0) == BIT_AND_EXPR
10664 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10665 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10667 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10668 return fold_build2 (BIT_AND_EXPR, type,
10669 fold_build1 (BIT_NOT_EXPR, type, tem),
10670 fold_convert (type, arg1));
10672 /* Fold X ^ (X & Y) as X & ~Y. */
10673 if (TREE_CODE (arg1) == BIT_AND_EXPR
10674 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10676 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10677 return fold_build2 (BIT_AND_EXPR, type,
10678 fold_convert (type, arg0),
10679 fold_build1 (BIT_NOT_EXPR, type, tem));
10681 /* Fold X ^ (Y & X) as ~Y & X. */
10682 if (TREE_CODE (arg1) == BIT_AND_EXPR
10683 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10684 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10686 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10687 return fold_build2 (BIT_AND_EXPR, type,
10688 fold_build1 (BIT_NOT_EXPR, type, tem),
10689 fold_convert (type, arg0));
10692 /* See if this can be simplified into a rotate first. If that
10693 is unsuccessful continue in the association code. */
10697 if (integer_all_onesp (arg1))
10698 return non_lvalue (fold_convert (type, arg0));
10699 if (integer_zerop (arg1))
10700 return omit_one_operand (type, arg1, arg0);
10701 if (operand_equal_p (arg0, arg1, 0))
10702 return non_lvalue (fold_convert (type, arg0));
10704 /* ~X & X is always zero. */
10705 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10706 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10707 return omit_one_operand (type, integer_zero_node, arg1);
10709 /* X & ~X is always zero. */
10710 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10711 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10712 return omit_one_operand (type, integer_zero_node, arg0);
10714 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
10715 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10716 && TREE_CODE (arg1) == INTEGER_CST
10717 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10719 tree tmp1 = fold_convert (TREE_TYPE (arg0), arg1);
10720 tree tmp2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10721 TREE_OPERAND (arg0, 0), tmp1);
10722 tree tmp3 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10723 TREE_OPERAND (arg0, 1), tmp1);
10724 return fold_convert (type,
10725 fold_build2 (BIT_IOR_EXPR, TREE_TYPE (arg0),
10729 /* (X | Y) & Y is (X, Y). */
10730 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10731 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10732 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10733 /* (X | Y) & X is (Y, X). */
10734 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10735 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10736 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10737 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10738 /* X & (X | Y) is (Y, X). */
10739 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10740 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10741 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10742 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10743 /* X & (Y | X) is (Y, X). */
10744 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10745 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10746 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10747 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10749 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10750 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10751 && integer_onep (TREE_OPERAND (arg0, 1))
10752 && integer_onep (arg1))
10754 tem = TREE_OPERAND (arg0, 0);
10755 return fold_build2 (EQ_EXPR, type,
10756 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10757 build_int_cst (TREE_TYPE (tem), 1)),
10758 build_int_cst (TREE_TYPE (tem), 0));
10760 /* Fold ~X & 1 as (X & 1) == 0. */
10761 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10762 && integer_onep (arg1))
10764 tem = TREE_OPERAND (arg0, 0);
10765 return fold_build2 (EQ_EXPR, type,
10766 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10767 build_int_cst (TREE_TYPE (tem), 1)),
10768 build_int_cst (TREE_TYPE (tem), 0));
10771 /* Fold (X ^ Y) & Y as ~X & Y. */
10772 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10773 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10775 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10776 return fold_build2 (BIT_AND_EXPR, type,
10777 fold_build1 (BIT_NOT_EXPR, type, tem),
10778 fold_convert (type, arg1));
10780 /* Fold (X ^ Y) & X as ~Y & X. */
10781 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10782 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10783 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10785 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10786 return fold_build2 (BIT_AND_EXPR, type,
10787 fold_build1 (BIT_NOT_EXPR, type, tem),
10788 fold_convert (type, arg1));
10790 /* Fold X & (X ^ Y) as X & ~Y. */
10791 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10792 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10794 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10795 return fold_build2 (BIT_AND_EXPR, type,
10796 fold_convert (type, arg0),
10797 fold_build1 (BIT_NOT_EXPR, type, tem));
10799 /* Fold X & (Y ^ X) as ~Y & X. */
10800 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10801 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10802 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10804 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10805 return fold_build2 (BIT_AND_EXPR, type,
10806 fold_build1 (BIT_NOT_EXPR, type, tem),
10807 fold_convert (type, arg0));
10810 t1 = distribute_bit_expr (code, type, arg0, arg1);
10811 if (t1 != NULL_TREE)
10813 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10814 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
10815 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
10818 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
10820 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
10821 && (~TREE_INT_CST_LOW (arg1)
10822 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
10823 return fold_convert (type, TREE_OPERAND (arg0, 0));
10826 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
10828 This results in more efficient code for machines without a NOR
10829 instruction. Combine will canonicalize to the first form
10830 which will allow use of NOR instructions provided by the
10831 backend if they exist. */
10832 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10833 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10835 return fold_build1 (BIT_NOT_EXPR, type,
10836 build2 (BIT_IOR_EXPR, type,
10837 fold_convert (type,
10838 TREE_OPERAND (arg0, 0)),
10839 fold_convert (type,
10840 TREE_OPERAND (arg1, 0))));
10843 /* If arg0 is derived from the address of an object or function, we may
10844 be able to fold this expression using the object or function's
10846 if (POINTER_TYPE_P (TREE_TYPE (arg0)) && host_integerp (arg1, 1))
10848 unsigned HOST_WIDE_INT modulus, residue;
10849 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (arg1);
10851 modulus = get_pointer_modulus_and_residue (arg0, &residue);
10853 /* This works because modulus is a power of 2. If this weren't the
10854 case, we'd have to replace it by its greatest power-of-2
10855 divisor: modulus & -modulus. */
10857 return build_int_cst (type, residue & low);
10860 /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
10861 (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
10862 if the new mask might be further optimized. */
10863 if ((TREE_CODE (arg0) == LSHIFT_EXPR
10864 || TREE_CODE (arg0) == RSHIFT_EXPR)
10865 && host_integerp (TREE_OPERAND (arg0, 1), 1)
10866 && host_integerp (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)))
10867 && tree_low_cst (TREE_OPERAND (arg0, 1), 1)
10868 < TYPE_PRECISION (TREE_TYPE (arg0))
10869 && TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
10870 && tree_low_cst (TREE_OPERAND (arg0, 1), 1) > 0)
10872 unsigned int shiftc = tree_low_cst (TREE_OPERAND (arg0, 1), 1);
10873 unsigned HOST_WIDE_INT mask
10874 = tree_low_cst (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)));
10875 unsigned HOST_WIDE_INT newmask, zerobits = 0;
10876 tree shift_type = TREE_TYPE (arg0);
10878 if (TREE_CODE (arg0) == LSHIFT_EXPR)
10879 zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
10880 else if (TREE_CODE (arg0) == RSHIFT_EXPR
10881 && TYPE_PRECISION (TREE_TYPE (arg0))
10882 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg0))))
10884 unsigned int prec = TYPE_PRECISION (TREE_TYPE (arg0));
10885 tree arg00 = TREE_OPERAND (arg0, 0);
10886 /* See if more bits can be proven as zero because of
10888 if (TREE_CODE (arg00) == NOP_EXPR
10889 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
10891 tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
10892 if (TYPE_PRECISION (inner_type)
10893 == GET_MODE_BITSIZE (TYPE_MODE (inner_type))
10894 && TYPE_PRECISION (inner_type) < prec)
10896 prec = TYPE_PRECISION (inner_type);
10897 /* See if we can shorten the right shift. */
10899 shift_type = inner_type;
10902 zerobits = ~(unsigned HOST_WIDE_INT) 0;
10903 zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
10904 zerobits <<= prec - shiftc;
10905 /* For arithmetic shift if sign bit could be set, zerobits
10906 can contain actually sign bits, so no transformation is
10907 possible, unless MASK masks them all away. In that
10908 case the shift needs to be converted into logical shift. */
10909 if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
10910 && prec == TYPE_PRECISION (TREE_TYPE (arg0)))
10912 if ((mask & zerobits) == 0)
10913 shift_type = unsigned_type_for (TREE_TYPE (arg0));
10919 /* ((X << 16) & 0xff00) is (X, 0). */
10920 if ((mask & zerobits) == mask)
10921 return omit_one_operand (type, build_int_cst (type, 0), arg0);
10923 newmask = mask | zerobits;
10924 if (newmask != mask && (newmask & (newmask + 1)) == 0)
10928 /* Only do the transformation if NEWMASK is some integer
10930 for (prec = BITS_PER_UNIT;
10931 prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
10932 if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
10934 if (prec < HOST_BITS_PER_WIDE_INT
10935 || newmask == ~(unsigned HOST_WIDE_INT) 0)
10937 if (shift_type != TREE_TYPE (arg0))
10939 tem = fold_build2 (TREE_CODE (arg0), shift_type,
10940 fold_convert (shift_type,
10941 TREE_OPERAND (arg0, 0)),
10942 TREE_OPERAND (arg0, 1));
10943 tem = fold_convert (type, tem);
10947 return fold_build2 (BIT_AND_EXPR, type, tem,
10948 build_int_cst_type (TREE_TYPE (op1),
10957 /* Don't touch a floating-point divide by zero unless the mode
10958 of the constant can represent infinity. */
10959 if (TREE_CODE (arg1) == REAL_CST
10960 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
10961 && real_zerop (arg1))
10964 /* Optimize A / A to 1.0 if we don't care about
10965 NaNs or Infinities. Skip the transformation
10966 for non-real operands. */
10967 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
10968 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10969 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
10970 && operand_equal_p (arg0, arg1, 0))
10972 tree r = build_real (TREE_TYPE (arg0), dconst1);
10974 return omit_two_operands (type, r, arg0, arg1);
10977 /* The complex version of the above A / A optimization. */
10978 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10979 && operand_equal_p (arg0, arg1, 0))
10981 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
10982 if (! HONOR_NANS (TYPE_MODE (elem_type))
10983 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
10985 tree r = build_real (elem_type, dconst1);
10986 /* omit_two_operands will call fold_convert for us. */
10987 return omit_two_operands (type, r, arg0, arg1);
10991 /* (-A) / (-B) -> A / B */
10992 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10993 return fold_build2 (RDIV_EXPR, type,
10994 TREE_OPERAND (arg0, 0),
10995 negate_expr (arg1));
10996 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10997 return fold_build2 (RDIV_EXPR, type,
10998 negate_expr (arg0),
10999 TREE_OPERAND (arg1, 0));
11001 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
11002 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11003 && real_onep (arg1))
11004 return non_lvalue (fold_convert (type, arg0));
11006 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
11007 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11008 && real_minus_onep (arg1))
11009 return non_lvalue (fold_convert (type, negate_expr (arg0)));
11011 /* If ARG1 is a constant, we can convert this to a multiply by the
11012 reciprocal. This does not have the same rounding properties,
11013 so only do this if -freciprocal-math. We can actually
11014 always safely do it if ARG1 is a power of two, but it's hard to
11015 tell if it is or not in a portable manner. */
11016 if (TREE_CODE (arg1) == REAL_CST)
11018 if (flag_reciprocal_math
11019 && 0 != (tem = const_binop (code, build_real (type, dconst1),
11021 return fold_build2 (MULT_EXPR, type, arg0, tem);
11022 /* Find the reciprocal if optimizing and the result is exact. */
11026 r = TREE_REAL_CST (arg1);
11027 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
11029 tem = build_real (type, r);
11030 return fold_build2 (MULT_EXPR, type,
11031 fold_convert (type, arg0), tem);
11035 /* Convert A/B/C to A/(B*C). */
11036 if (flag_reciprocal_math
11037 && TREE_CODE (arg0) == RDIV_EXPR)
11038 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
11039 fold_build2 (MULT_EXPR, type,
11040 TREE_OPERAND (arg0, 1), arg1));
11042 /* Convert A/(B/C) to (A/B)*C. */
11043 if (flag_reciprocal_math
11044 && TREE_CODE (arg1) == RDIV_EXPR)
11045 return fold_build2 (MULT_EXPR, type,
11046 fold_build2 (RDIV_EXPR, type, arg0,
11047 TREE_OPERAND (arg1, 0)),
11048 TREE_OPERAND (arg1, 1));
11050 /* Convert C1/(X*C2) into (C1/C2)/X. */
11051 if (flag_reciprocal_math
11052 && TREE_CODE (arg1) == MULT_EXPR
11053 && TREE_CODE (arg0) == REAL_CST
11054 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
11056 tree tem = const_binop (RDIV_EXPR, arg0,
11057 TREE_OPERAND (arg1, 1), 0);
11059 return fold_build2 (RDIV_EXPR, type, tem,
11060 TREE_OPERAND (arg1, 0));
11063 if (flag_unsafe_math_optimizations)
11065 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
11066 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
11068 /* Optimize sin(x)/cos(x) as tan(x). */
11069 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
11070 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
11071 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
11072 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11073 CALL_EXPR_ARG (arg1, 0), 0))
11075 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11077 if (tanfn != NULL_TREE)
11078 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11081 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
11082 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
11083 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
11084 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
11085 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11086 CALL_EXPR_ARG (arg1, 0), 0))
11088 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11090 if (tanfn != NULL_TREE)
11092 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11093 return fold_build2 (RDIV_EXPR, type,
11094 build_real (type, dconst1), tmp);
11098 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
11099 NaNs or Infinities. */
11100 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
11101 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
11102 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
11104 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11105 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11107 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11108 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11109 && operand_equal_p (arg00, arg01, 0))
11111 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11113 if (cosfn != NULL_TREE)
11114 return build_call_expr (cosfn, 1, arg00);
11118 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11119 NaNs or Infinities. */
11120 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
11121 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
11122 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
11124 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11125 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11127 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11128 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11129 && operand_equal_p (arg00, arg01, 0))
11131 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11133 if (cosfn != NULL_TREE)
11135 tree tmp = build_call_expr (cosfn, 1, arg00);
11136 return fold_build2 (RDIV_EXPR, type,
11137 build_real (type, dconst1),
11143 /* Optimize pow(x,c)/x as pow(x,c-1). */
11144 if (fcode0 == BUILT_IN_POW
11145 || fcode0 == BUILT_IN_POWF
11146 || fcode0 == BUILT_IN_POWL)
11148 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11149 tree arg01 = CALL_EXPR_ARG (arg0, 1);
11150 if (TREE_CODE (arg01) == REAL_CST
11151 && !TREE_OVERFLOW (arg01)
11152 && operand_equal_p (arg1, arg00, 0))
11154 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
11158 c = TREE_REAL_CST (arg01);
11159 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
11160 arg = build_real (type, c);
11161 return build_call_expr (powfn, 2, arg1, arg);
11165 /* Optimize a/root(b/c) into a*root(c/b). */
11166 if (BUILTIN_ROOT_P (fcode1))
11168 tree rootarg = CALL_EXPR_ARG (arg1, 0);
11170 if (TREE_CODE (rootarg) == RDIV_EXPR)
11172 tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11173 tree b = TREE_OPERAND (rootarg, 0);
11174 tree c = TREE_OPERAND (rootarg, 1);
11176 tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
11178 tmp = build_call_expr (rootfn, 1, tmp);
11179 return fold_build2 (MULT_EXPR, type, arg0, tmp);
11183 /* Optimize x/expN(y) into x*expN(-y). */
11184 if (BUILTIN_EXPONENT_P (fcode1))
11186 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11187 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
11188 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
11189 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11192 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11193 if (fcode1 == BUILT_IN_POW
11194 || fcode1 == BUILT_IN_POWF
11195 || fcode1 == BUILT_IN_POWL)
11197 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11198 tree arg10 = CALL_EXPR_ARG (arg1, 0);
11199 tree arg11 = CALL_EXPR_ARG (arg1, 1);
11200 tree neg11 = fold_convert (type, negate_expr (arg11));
11201 arg1 = build_call_expr (powfn, 2, arg10, neg11);
11202 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11207 case TRUNC_DIV_EXPR:
11208 case FLOOR_DIV_EXPR:
11209 /* Simplify A / (B << N) where A and B are positive and B is
11210 a power of 2, to A >> (N + log2(B)). */
11211 strict_overflow_p = false;
11212 if (TREE_CODE (arg1) == LSHIFT_EXPR
11213 && (TYPE_UNSIGNED (type)
11214 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11216 tree sval = TREE_OPERAND (arg1, 0);
11217 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
11219 tree sh_cnt = TREE_OPERAND (arg1, 1);
11220 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
11222 if (strict_overflow_p)
11223 fold_overflow_warning (("assuming signed overflow does not "
11224 "occur when simplifying A / (B << N)"),
11225 WARN_STRICT_OVERFLOW_MISC);
11227 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
11228 sh_cnt, build_int_cst (NULL_TREE, pow2));
11229 return fold_build2 (RSHIFT_EXPR, type,
11230 fold_convert (type, arg0), sh_cnt);
11234 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
11235 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
11236 if (INTEGRAL_TYPE_P (type)
11237 && TYPE_UNSIGNED (type)
11238 && code == FLOOR_DIV_EXPR)
11239 return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
11243 case ROUND_DIV_EXPR:
11244 case CEIL_DIV_EXPR:
11245 case EXACT_DIV_EXPR:
11246 if (integer_onep (arg1))
11247 return non_lvalue (fold_convert (type, arg0));
11248 if (integer_zerop (arg1))
11250 /* X / -1 is -X. */
11251 if (!TYPE_UNSIGNED (type)
11252 && TREE_CODE (arg1) == INTEGER_CST
11253 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11254 && TREE_INT_CST_HIGH (arg1) == -1)
11255 return fold_convert (type, negate_expr (arg0));
11257 /* Convert -A / -B to A / B when the type is signed and overflow is
11259 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11260 && TREE_CODE (arg0) == NEGATE_EXPR
11261 && negate_expr_p (arg1))
11263 if (INTEGRAL_TYPE_P (type))
11264 fold_overflow_warning (("assuming signed overflow does not occur "
11265 "when distributing negation across "
11267 WARN_STRICT_OVERFLOW_MISC);
11268 return fold_build2 (code, type,
11269 fold_convert (type, TREE_OPERAND (arg0, 0)),
11270 negate_expr (arg1));
11272 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11273 && TREE_CODE (arg1) == NEGATE_EXPR
11274 && negate_expr_p (arg0))
11276 if (INTEGRAL_TYPE_P (type))
11277 fold_overflow_warning (("assuming signed overflow does not occur "
11278 "when distributing negation across "
11280 WARN_STRICT_OVERFLOW_MISC);
11281 return fold_build2 (code, type, negate_expr (arg0),
11282 TREE_OPERAND (arg1, 0));
11285 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11286 operation, EXACT_DIV_EXPR.
11288 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11289 At one time others generated faster code, it's not clear if they do
11290 after the last round to changes to the DIV code in expmed.c. */
11291 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
11292 && multiple_of_p (type, arg0, arg1))
11293 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
11295 strict_overflow_p = false;
11296 if (TREE_CODE (arg1) == INTEGER_CST
11297 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11298 &strict_overflow_p)))
11300 if (strict_overflow_p)
11301 fold_overflow_warning (("assuming signed overflow does not occur "
11302 "when simplifying division"),
11303 WARN_STRICT_OVERFLOW_MISC);
11304 return fold_convert (type, tem);
11309 case CEIL_MOD_EXPR:
11310 case FLOOR_MOD_EXPR:
11311 case ROUND_MOD_EXPR:
11312 case TRUNC_MOD_EXPR:
11313 /* X % 1 is always zero, but be sure to preserve any side
11315 if (integer_onep (arg1))
11316 return omit_one_operand (type, integer_zero_node, arg0);
11318 /* X % 0, return X % 0 unchanged so that we can get the
11319 proper warnings and errors. */
11320 if (integer_zerop (arg1))
11323 /* 0 % X is always zero, but be sure to preserve any side
11324 effects in X. Place this after checking for X == 0. */
11325 if (integer_zerop (arg0))
11326 return omit_one_operand (type, integer_zero_node, arg1);
11328 /* X % -1 is zero. */
11329 if (!TYPE_UNSIGNED (type)
11330 && TREE_CODE (arg1) == INTEGER_CST
11331 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11332 && TREE_INT_CST_HIGH (arg1) == -1)
11333 return omit_one_operand (type, integer_zero_node, arg0);
11335 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11336 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11337 strict_overflow_p = false;
11338 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
11339 && (TYPE_UNSIGNED (type)
11340 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11343 /* Also optimize A % (C << N) where C is a power of 2,
11344 to A & ((C << N) - 1). */
11345 if (TREE_CODE (arg1) == LSHIFT_EXPR)
11346 c = TREE_OPERAND (arg1, 0);
11348 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
11350 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
11351 build_int_cst (TREE_TYPE (arg1), 1));
11352 if (strict_overflow_p)
11353 fold_overflow_warning (("assuming signed overflow does not "
11354 "occur when simplifying "
11355 "X % (power of two)"),
11356 WARN_STRICT_OVERFLOW_MISC);
11357 return fold_build2 (BIT_AND_EXPR, type,
11358 fold_convert (type, arg0),
11359 fold_convert (type, mask));
11363 /* X % -C is the same as X % C. */
11364 if (code == TRUNC_MOD_EXPR
11365 && !TYPE_UNSIGNED (type)
11366 && TREE_CODE (arg1) == INTEGER_CST
11367 && !TREE_OVERFLOW (arg1)
11368 && TREE_INT_CST_HIGH (arg1) < 0
11369 && !TYPE_OVERFLOW_TRAPS (type)
11370 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11371 && !sign_bit_p (arg1, arg1))
11372 return fold_build2 (code, type, fold_convert (type, arg0),
11373 fold_convert (type, negate_expr (arg1)));
11375 /* X % -Y is the same as X % Y. */
11376 if (code == TRUNC_MOD_EXPR
11377 && !TYPE_UNSIGNED (type)
11378 && TREE_CODE (arg1) == NEGATE_EXPR
11379 && !TYPE_OVERFLOW_TRAPS (type))
11380 return fold_build2 (code, type, fold_convert (type, arg0),
11381 fold_convert (type, TREE_OPERAND (arg1, 0)));
11383 if (TREE_CODE (arg1) == INTEGER_CST
11384 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11385 &strict_overflow_p)))
11387 if (strict_overflow_p)
11388 fold_overflow_warning (("assuming signed overflow does not occur "
11389 "when simplifying modulos"),
11390 WARN_STRICT_OVERFLOW_MISC);
11391 return fold_convert (type, tem);
11398 if (integer_all_onesp (arg0))
11399 return omit_one_operand (type, arg0, arg1);
11403 /* Optimize -1 >> x for arithmetic right shifts. */
11404 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
11405 return omit_one_operand (type, arg0, arg1);
11406 /* ... fall through ... */
11410 if (integer_zerop (arg1))
11411 return non_lvalue (fold_convert (type, arg0));
11412 if (integer_zerop (arg0))
11413 return omit_one_operand (type, arg0, arg1);
11415 /* Since negative shift count is not well-defined,
11416 don't try to compute it in the compiler. */
11417 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
11420 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11421 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
11422 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11423 && host_integerp (TREE_OPERAND (arg0, 1), false)
11424 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11426 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
11427 + TREE_INT_CST_LOW (arg1));
11429 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11430 being well defined. */
11431 if (low >= TYPE_PRECISION (type))
11433 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
11434 low = low % TYPE_PRECISION (type);
11435 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
11436 return build_int_cst (type, 0);
11438 low = TYPE_PRECISION (type) - 1;
11441 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11442 build_int_cst (type, low));
11445 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11446 into x & ((unsigned)-1 >> c) for unsigned types. */
11447 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
11448 || (TYPE_UNSIGNED (type)
11449 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
11450 && host_integerp (arg1, false)
11451 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11452 && host_integerp (TREE_OPERAND (arg0, 1), false)
11453 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11455 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
11456 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
11462 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
11464 lshift = build_int_cst (type, -1);
11465 lshift = int_const_binop (code, lshift, arg1, 0);
11467 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
11471 /* Rewrite an LROTATE_EXPR by a constant into an
11472 RROTATE_EXPR by a new constant. */
11473 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
11475 tree tem = build_int_cst (TREE_TYPE (arg1),
11476 TYPE_PRECISION (type));
11477 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
11478 return fold_build2 (RROTATE_EXPR, type, op0, tem);
11481 /* If we have a rotate of a bit operation with the rotate count and
11482 the second operand of the bit operation both constant,
11483 permute the two operations. */
11484 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11485 && (TREE_CODE (arg0) == BIT_AND_EXPR
11486 || TREE_CODE (arg0) == BIT_IOR_EXPR
11487 || TREE_CODE (arg0) == BIT_XOR_EXPR)
11488 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11489 return fold_build2 (TREE_CODE (arg0), type,
11490 fold_build2 (code, type,
11491 TREE_OPERAND (arg0, 0), arg1),
11492 fold_build2 (code, type,
11493 TREE_OPERAND (arg0, 1), arg1));
11495 /* Two consecutive rotates adding up to the precision of the
11496 type can be ignored. */
11497 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11498 && TREE_CODE (arg0) == RROTATE_EXPR
11499 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11500 && TREE_INT_CST_HIGH (arg1) == 0
11501 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
11502 && ((TREE_INT_CST_LOW (arg1)
11503 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
11504 == (unsigned int) TYPE_PRECISION (type)))
11505 return TREE_OPERAND (arg0, 0);
11507 /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
11508 (X & C2) >> C1 into (X >> C1) & (C2 >> C1)
11509 if the latter can be further optimized. */
11510 if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
11511 && TREE_CODE (arg0) == BIT_AND_EXPR
11512 && TREE_CODE (arg1) == INTEGER_CST
11513 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11515 tree mask = fold_build2 (code, type,
11516 fold_convert (type, TREE_OPERAND (arg0, 1)),
11518 tree shift = fold_build2 (code, type,
11519 fold_convert (type, TREE_OPERAND (arg0, 0)),
11521 tem = fold_binary (BIT_AND_EXPR, type, shift, mask);
11529 if (operand_equal_p (arg0, arg1, 0))
11530 return omit_one_operand (type, arg0, arg1);
11531 if (INTEGRAL_TYPE_P (type)
11532 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
11533 return omit_one_operand (type, arg1, arg0);
11534 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
11540 if (operand_equal_p (arg0, arg1, 0))
11541 return omit_one_operand (type, arg0, arg1);
11542 if (INTEGRAL_TYPE_P (type)
11543 && TYPE_MAX_VALUE (type)
11544 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
11545 return omit_one_operand (type, arg1, arg0);
11546 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
11551 case TRUTH_ANDIF_EXPR:
11552 /* Note that the operands of this must be ints
11553 and their values must be 0 or 1.
11554 ("true" is a fixed value perhaps depending on the language.) */
11555 /* If first arg is constant zero, return it. */
11556 if (integer_zerop (arg0))
11557 return fold_convert (type, arg0);
11558 case TRUTH_AND_EXPR:
11559 /* If either arg is constant true, drop it. */
11560 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11561 return non_lvalue (fold_convert (type, arg1));
11562 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
11563 /* Preserve sequence points. */
11564 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11565 return non_lvalue (fold_convert (type, arg0));
11566 /* If second arg is constant zero, result is zero, but first arg
11567 must be evaluated. */
11568 if (integer_zerop (arg1))
11569 return omit_one_operand (type, arg1, arg0);
11570 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11571 case will be handled here. */
11572 if (integer_zerop (arg0))
11573 return omit_one_operand (type, arg0, arg1);
11575 /* !X && X is always false. */
11576 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11577 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11578 return omit_one_operand (type, integer_zero_node, arg1);
11579 /* X && !X is always false. */
11580 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11581 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11582 return omit_one_operand (type, integer_zero_node, arg0);
11584 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
11585 means A >= Y && A != MAX, but in this case we know that
11588 if (!TREE_SIDE_EFFECTS (arg0)
11589 && !TREE_SIDE_EFFECTS (arg1))
11591 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
11592 if (tem && !operand_equal_p (tem, arg0, 0))
11593 return fold_build2 (code, type, tem, arg1);
11595 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
11596 if (tem && !operand_equal_p (tem, arg1, 0))
11597 return fold_build2 (code, type, arg0, tem);
11601 /* We only do these simplifications if we are optimizing. */
11605 /* Check for things like (A || B) && (A || C). We can convert this
11606 to A || (B && C). Note that either operator can be any of the four
11607 truth and/or operations and the transformation will still be
11608 valid. Also note that we only care about order for the
11609 ANDIF and ORIF operators. If B contains side effects, this
11610 might change the truth-value of A. */
11611 if (TREE_CODE (arg0) == TREE_CODE (arg1)
11612 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
11613 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
11614 || TREE_CODE (arg0) == TRUTH_AND_EXPR
11615 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
11616 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
11618 tree a00 = TREE_OPERAND (arg0, 0);
11619 tree a01 = TREE_OPERAND (arg0, 1);
11620 tree a10 = TREE_OPERAND (arg1, 0);
11621 tree a11 = TREE_OPERAND (arg1, 1);
11622 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
11623 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
11624 && (code == TRUTH_AND_EXPR
11625 || code == TRUTH_OR_EXPR));
11627 if (operand_equal_p (a00, a10, 0))
11628 return fold_build2 (TREE_CODE (arg0), type, a00,
11629 fold_build2 (code, type, a01, a11));
11630 else if (commutative && operand_equal_p (a00, a11, 0))
11631 return fold_build2 (TREE_CODE (arg0), type, a00,
11632 fold_build2 (code, type, a01, a10));
11633 else if (commutative && operand_equal_p (a01, a10, 0))
11634 return fold_build2 (TREE_CODE (arg0), type, a01,
11635 fold_build2 (code, type, a00, a11));
11637 /* This case if tricky because we must either have commutative
11638 operators or else A10 must not have side-effects. */
11640 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
11641 && operand_equal_p (a01, a11, 0))
11642 return fold_build2 (TREE_CODE (arg0), type,
11643 fold_build2 (code, type, a00, a10),
11647 /* See if we can build a range comparison. */
11648 if (0 != (tem = fold_range_test (code, type, op0, op1)))
11651 /* Check for the possibility of merging component references. If our
11652 lhs is another similar operation, try to merge its rhs with our
11653 rhs. Then try to merge our lhs and rhs. */
11654 if (TREE_CODE (arg0) == code
11655 && 0 != (tem = fold_truthop (code, type,
11656 TREE_OPERAND (arg0, 1), arg1)))
11657 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11659 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
11664 case TRUTH_ORIF_EXPR:
11665 /* Note that the operands of this must be ints
11666 and their values must be 0 or true.
11667 ("true" is a fixed value perhaps depending on the language.) */
11668 /* If first arg is constant true, return it. */
11669 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11670 return fold_convert (type, arg0);
11671 case TRUTH_OR_EXPR:
11672 /* If either arg is constant zero, drop it. */
11673 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
11674 return non_lvalue (fold_convert (type, arg1));
11675 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
11676 /* Preserve sequence points. */
11677 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11678 return non_lvalue (fold_convert (type, arg0));
11679 /* If second arg is constant true, result is true, but we must
11680 evaluate first arg. */
11681 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
11682 return omit_one_operand (type, arg1, arg0);
11683 /* Likewise for first arg, but note this only occurs here for
11685 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11686 return omit_one_operand (type, arg0, arg1);
11688 /* !X || X is always true. */
11689 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11690 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11691 return omit_one_operand (type, integer_one_node, arg1);
11692 /* X || !X is always true. */
11693 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11694 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11695 return omit_one_operand (type, integer_one_node, arg0);
11699 case TRUTH_XOR_EXPR:
11700 /* If the second arg is constant zero, drop it. */
11701 if (integer_zerop (arg1))
11702 return non_lvalue (fold_convert (type, arg0));
11703 /* If the second arg is constant true, this is a logical inversion. */
11704 if (integer_onep (arg1))
11706 /* Only call invert_truthvalue if operand is a truth value. */
11707 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
11708 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
11710 tem = invert_truthvalue (arg0);
11711 return non_lvalue (fold_convert (type, tem));
11713 /* Identical arguments cancel to zero. */
11714 if (operand_equal_p (arg0, arg1, 0))
11715 return omit_one_operand (type, integer_zero_node, arg0);
11717 /* !X ^ X is always true. */
11718 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11719 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11720 return omit_one_operand (type, integer_one_node, arg1);
11722 /* X ^ !X is always true. */
11723 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11724 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11725 return omit_one_operand (type, integer_one_node, arg0);
11731 tem = fold_comparison (code, type, op0, op1);
11732 if (tem != NULL_TREE)
11735 /* bool_var != 0 becomes bool_var. */
11736 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11737 && code == NE_EXPR)
11738 return non_lvalue (fold_convert (type, arg0));
11740 /* bool_var == 1 becomes bool_var. */
11741 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11742 && code == EQ_EXPR)
11743 return non_lvalue (fold_convert (type, arg0));
11745 /* bool_var != 1 becomes !bool_var. */
11746 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11747 && code == NE_EXPR)
11748 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11750 /* bool_var == 0 becomes !bool_var. */
11751 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11752 && code == EQ_EXPR)
11753 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11755 /* If this is an equality comparison of the address of two non-weak,
11756 unaliased symbols neither of which are extern (since we do not
11757 have access to attributes for externs), then we know the result. */
11758 if (TREE_CODE (arg0) == ADDR_EXPR
11759 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
11760 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
11761 && ! lookup_attribute ("alias",
11762 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
11763 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
11764 && TREE_CODE (arg1) == ADDR_EXPR
11765 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
11766 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
11767 && ! lookup_attribute ("alias",
11768 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
11769 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
11771 /* We know that we're looking at the address of two
11772 non-weak, unaliased, static _DECL nodes.
11774 It is both wasteful and incorrect to call operand_equal_p
11775 to compare the two ADDR_EXPR nodes. It is wasteful in that
11776 all we need to do is test pointer equality for the arguments
11777 to the two ADDR_EXPR nodes. It is incorrect to use
11778 operand_equal_p as that function is NOT equivalent to a
11779 C equality test. It can in fact return false for two
11780 objects which would test as equal using the C equality
11782 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
11783 return constant_boolean_node (equal
11784 ? code == EQ_EXPR : code != EQ_EXPR,
11788 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
11789 a MINUS_EXPR of a constant, we can convert it into a comparison with
11790 a revised constant as long as no overflow occurs. */
11791 if (TREE_CODE (arg1) == INTEGER_CST
11792 && (TREE_CODE (arg0) == PLUS_EXPR
11793 || TREE_CODE (arg0) == MINUS_EXPR)
11794 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11795 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
11796 ? MINUS_EXPR : PLUS_EXPR,
11797 fold_convert (TREE_TYPE (arg0), arg1),
11798 TREE_OPERAND (arg0, 1), 0))
11799 && !TREE_OVERFLOW (tem))
11800 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11802 /* Similarly for a NEGATE_EXPR. */
11803 if (TREE_CODE (arg0) == NEGATE_EXPR
11804 && TREE_CODE (arg1) == INTEGER_CST
11805 && 0 != (tem = negate_expr (arg1))
11806 && TREE_CODE (tem) == INTEGER_CST
11807 && !TREE_OVERFLOW (tem))
11808 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11810 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
11811 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11812 && TREE_CODE (arg1) == INTEGER_CST
11813 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11814 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11815 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
11816 fold_convert (TREE_TYPE (arg0), arg1),
11817 TREE_OPERAND (arg0, 1)));
11819 /* Transform comparisons of the form X +- C CMP X. */
11820 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11821 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11822 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11823 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
11824 || POINTER_TYPE_P (TREE_TYPE (arg0))))
11826 tree cst = TREE_OPERAND (arg0, 1);
11828 if (code == EQ_EXPR
11829 && !integer_zerop (cst))
11830 return omit_two_operands (type, boolean_false_node,
11831 TREE_OPERAND (arg0, 0), arg1);
11833 return omit_two_operands (type, boolean_true_node,
11834 TREE_OPERAND (arg0, 0), arg1);
11837 /* If we have X - Y == 0, we can convert that to X == Y and similarly
11838 for !=. Don't do this for ordered comparisons due to overflow. */
11839 if (TREE_CODE (arg0) == MINUS_EXPR
11840 && integer_zerop (arg1))
11841 return fold_build2 (code, type,
11842 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
11844 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
11845 if (TREE_CODE (arg0) == ABS_EXPR
11846 && (integer_zerop (arg1) || real_zerop (arg1)))
11847 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
11849 /* If this is an EQ or NE comparison with zero and ARG0 is
11850 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
11851 two operations, but the latter can be done in one less insn
11852 on machines that have only two-operand insns or on which a
11853 constant cannot be the first operand. */
11854 if (TREE_CODE (arg0) == BIT_AND_EXPR
11855 && integer_zerop (arg1))
11857 tree arg00 = TREE_OPERAND (arg0, 0);
11858 tree arg01 = TREE_OPERAND (arg0, 1);
11859 if (TREE_CODE (arg00) == LSHIFT_EXPR
11860 && integer_onep (TREE_OPERAND (arg00, 0)))
11862 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
11863 arg01, TREE_OPERAND (arg00, 1));
11864 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11865 build_int_cst (TREE_TYPE (arg0), 1));
11866 return fold_build2 (code, type,
11867 fold_convert (TREE_TYPE (arg1), tem), arg1);
11869 else if (TREE_CODE (arg01) == LSHIFT_EXPR
11870 && integer_onep (TREE_OPERAND (arg01, 0)))
11872 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
11873 arg00, TREE_OPERAND (arg01, 1));
11874 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11875 build_int_cst (TREE_TYPE (arg0), 1));
11876 return fold_build2 (code, type,
11877 fold_convert (TREE_TYPE (arg1), tem), arg1);
11881 /* If this is an NE or EQ comparison of zero against the result of a
11882 signed MOD operation whose second operand is a power of 2, make
11883 the MOD operation unsigned since it is simpler and equivalent. */
11884 if (integer_zerop (arg1)
11885 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
11886 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
11887 || TREE_CODE (arg0) == CEIL_MOD_EXPR
11888 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
11889 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
11890 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11892 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
11893 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
11894 fold_convert (newtype,
11895 TREE_OPERAND (arg0, 0)),
11896 fold_convert (newtype,
11897 TREE_OPERAND (arg0, 1)));
11899 return fold_build2 (code, type, newmod,
11900 fold_convert (newtype, arg1));
11903 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
11904 C1 is a valid shift constant, and C2 is a power of two, i.e.
11906 if (TREE_CODE (arg0) == BIT_AND_EXPR
11907 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
11908 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
11910 && integer_pow2p (TREE_OPERAND (arg0, 1))
11911 && integer_zerop (arg1))
11913 tree itype = TREE_TYPE (arg0);
11914 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
11915 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
11917 /* Check for a valid shift count. */
11918 if (TREE_INT_CST_HIGH (arg001) == 0
11919 && TREE_INT_CST_LOW (arg001) < prec)
11921 tree arg01 = TREE_OPERAND (arg0, 1);
11922 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11923 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
11924 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
11925 can be rewritten as (X & (C2 << C1)) != 0. */
11926 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
11928 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
11929 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
11930 return fold_build2 (code, type, tem, arg1);
11932 /* Otherwise, for signed (arithmetic) shifts,
11933 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
11934 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
11935 else if (!TYPE_UNSIGNED (itype))
11936 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
11937 arg000, build_int_cst (itype, 0));
11938 /* Otherwise, of unsigned (logical) shifts,
11939 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
11940 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
11942 return omit_one_operand (type,
11943 code == EQ_EXPR ? integer_one_node
11944 : integer_zero_node,
11949 /* If this is an NE comparison of zero with an AND of one, remove the
11950 comparison since the AND will give the correct value. */
11951 if (code == NE_EXPR
11952 && integer_zerop (arg1)
11953 && TREE_CODE (arg0) == BIT_AND_EXPR
11954 && integer_onep (TREE_OPERAND (arg0, 1)))
11955 return fold_convert (type, arg0);
11957 /* If we have (A & C) == C where C is a power of 2, convert this into
11958 (A & C) != 0. Similarly for NE_EXPR. */
11959 if (TREE_CODE (arg0) == BIT_AND_EXPR
11960 && integer_pow2p (TREE_OPERAND (arg0, 1))
11961 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11962 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11963 arg0, fold_convert (TREE_TYPE (arg0),
11964 integer_zero_node));
11966 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
11967 bit, then fold the expression into A < 0 or A >= 0. */
11968 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
11972 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
11973 Similarly for NE_EXPR. */
11974 if (TREE_CODE (arg0) == BIT_AND_EXPR
11975 && TREE_CODE (arg1) == INTEGER_CST
11976 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11978 tree notc = fold_build1 (BIT_NOT_EXPR,
11979 TREE_TYPE (TREE_OPERAND (arg0, 1)),
11980 TREE_OPERAND (arg0, 1));
11981 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11983 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11984 if (integer_nonzerop (dandnotc))
11985 return omit_one_operand (type, rslt, arg0);
11988 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
11989 Similarly for NE_EXPR. */
11990 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11991 && TREE_CODE (arg1) == INTEGER_CST
11992 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11994 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
11995 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11996 TREE_OPERAND (arg0, 1), notd);
11997 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11998 if (integer_nonzerop (candnotd))
11999 return omit_one_operand (type, rslt, arg0);
12002 /* Optimize comparisons of strlen vs zero to a compare of the
12003 first character of the string vs zero. To wit,
12004 strlen(ptr) == 0 => *ptr == 0
12005 strlen(ptr) != 0 => *ptr != 0
12006 Other cases should reduce to one of these two (or a constant)
12007 due to the return value of strlen being unsigned. */
12008 if (TREE_CODE (arg0) == CALL_EXPR
12009 && integer_zerop (arg1))
12011 tree fndecl = get_callee_fndecl (arg0);
12014 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
12015 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
12016 && call_expr_nargs (arg0) == 1
12017 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
12019 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
12020 return fold_build2 (code, type, iref,
12021 build_int_cst (TREE_TYPE (iref), 0));
12025 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
12026 of X. Similarly fold (X >> C) == 0 into X >= 0. */
12027 if (TREE_CODE (arg0) == RSHIFT_EXPR
12028 && integer_zerop (arg1)
12029 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12031 tree arg00 = TREE_OPERAND (arg0, 0);
12032 tree arg01 = TREE_OPERAND (arg0, 1);
12033 tree itype = TREE_TYPE (arg00);
12034 if (TREE_INT_CST_HIGH (arg01) == 0
12035 && TREE_INT_CST_LOW (arg01)
12036 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
12038 if (TYPE_UNSIGNED (itype))
12040 itype = signed_type_for (itype);
12041 arg00 = fold_convert (itype, arg00);
12043 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
12044 type, arg00, build_int_cst (itype, 0));
12048 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
12049 if (integer_zerop (arg1)
12050 && TREE_CODE (arg0) == BIT_XOR_EXPR)
12051 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12052 TREE_OPERAND (arg0, 1));
12054 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
12055 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12056 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12057 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12058 build_int_cst (TREE_TYPE (arg1), 0));
12059 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
12060 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12061 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12062 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
12063 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
12064 build_int_cst (TREE_TYPE (arg1), 0));
12066 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
12067 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12068 && TREE_CODE (arg1) == INTEGER_CST
12069 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12070 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12071 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
12072 TREE_OPERAND (arg0, 1), arg1));
12074 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
12075 (X & C) == 0 when C is a single bit. */
12076 if (TREE_CODE (arg0) == BIT_AND_EXPR
12077 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
12078 && integer_zerop (arg1)
12079 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12081 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12082 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
12083 TREE_OPERAND (arg0, 1));
12084 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
12088 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12089 constant C is a power of two, i.e. a single bit. */
12090 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12091 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12092 && integer_zerop (arg1)
12093 && integer_pow2p (TREE_OPERAND (arg0, 1))
12094 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12095 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12097 tree arg00 = TREE_OPERAND (arg0, 0);
12098 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12099 arg00, build_int_cst (TREE_TYPE (arg00), 0));
12102 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12103 when is C is a power of two, i.e. a single bit. */
12104 if (TREE_CODE (arg0) == BIT_AND_EXPR
12105 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
12106 && integer_zerop (arg1)
12107 && integer_pow2p (TREE_OPERAND (arg0, 1))
12108 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12109 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12111 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12112 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
12113 arg000, TREE_OPERAND (arg0, 1));
12114 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12115 tem, build_int_cst (TREE_TYPE (tem), 0));
12118 if (integer_zerop (arg1)
12119 && tree_expr_nonzero_p (arg0))
12121 tree res = constant_boolean_node (code==NE_EXPR, type);
12122 return omit_one_operand (type, res, arg0);
12125 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12126 if (TREE_CODE (arg0) == NEGATE_EXPR
12127 && TREE_CODE (arg1) == NEGATE_EXPR)
12128 return fold_build2 (code, type,
12129 TREE_OPERAND (arg0, 0),
12130 TREE_OPERAND (arg1, 0));
12132 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12133 if (TREE_CODE (arg0) == BIT_AND_EXPR
12134 && TREE_CODE (arg1) == BIT_AND_EXPR)
12136 tree arg00 = TREE_OPERAND (arg0, 0);
12137 tree arg01 = TREE_OPERAND (arg0, 1);
12138 tree arg10 = TREE_OPERAND (arg1, 0);
12139 tree arg11 = TREE_OPERAND (arg1, 1);
12140 tree itype = TREE_TYPE (arg0);
12142 if (operand_equal_p (arg01, arg11, 0))
12143 return fold_build2 (code, type,
12144 fold_build2 (BIT_AND_EXPR, itype,
12145 fold_build2 (BIT_XOR_EXPR, itype,
12148 build_int_cst (itype, 0));
12150 if (operand_equal_p (arg01, arg10, 0))
12151 return fold_build2 (code, type,
12152 fold_build2 (BIT_AND_EXPR, itype,
12153 fold_build2 (BIT_XOR_EXPR, itype,
12156 build_int_cst (itype, 0));
12158 if (operand_equal_p (arg00, arg11, 0))
12159 return fold_build2 (code, type,
12160 fold_build2 (BIT_AND_EXPR, itype,
12161 fold_build2 (BIT_XOR_EXPR, itype,
12164 build_int_cst (itype, 0));
12166 if (operand_equal_p (arg00, arg10, 0))
12167 return fold_build2 (code, type,
12168 fold_build2 (BIT_AND_EXPR, itype,
12169 fold_build2 (BIT_XOR_EXPR, itype,
12172 build_int_cst (itype, 0));
12175 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12176 && TREE_CODE (arg1) == BIT_XOR_EXPR)
12178 tree arg00 = TREE_OPERAND (arg0, 0);
12179 tree arg01 = TREE_OPERAND (arg0, 1);
12180 tree arg10 = TREE_OPERAND (arg1, 0);
12181 tree arg11 = TREE_OPERAND (arg1, 1);
12182 tree itype = TREE_TYPE (arg0);
12184 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12185 operand_equal_p guarantees no side-effects so we don't need
12186 to use omit_one_operand on Z. */
12187 if (operand_equal_p (arg01, arg11, 0))
12188 return fold_build2 (code, type, arg00, arg10);
12189 if (operand_equal_p (arg01, arg10, 0))
12190 return fold_build2 (code, type, arg00, arg11);
12191 if (operand_equal_p (arg00, arg11, 0))
12192 return fold_build2 (code, type, arg01, arg10);
12193 if (operand_equal_p (arg00, arg10, 0))
12194 return fold_build2 (code, type, arg01, arg11);
12196 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12197 if (TREE_CODE (arg01) == INTEGER_CST
12198 && TREE_CODE (arg11) == INTEGER_CST)
12199 return fold_build2 (code, type,
12200 fold_build2 (BIT_XOR_EXPR, itype, arg00,
12201 fold_build2 (BIT_XOR_EXPR, itype,
12206 /* Attempt to simplify equality/inequality comparisons of complex
12207 values. Only lower the comparison if the result is known or
12208 can be simplified to a single scalar comparison. */
12209 if ((TREE_CODE (arg0) == COMPLEX_EXPR
12210 || TREE_CODE (arg0) == COMPLEX_CST)
12211 && (TREE_CODE (arg1) == COMPLEX_EXPR
12212 || TREE_CODE (arg1) == COMPLEX_CST))
12214 tree real0, imag0, real1, imag1;
12217 if (TREE_CODE (arg0) == COMPLEX_EXPR)
12219 real0 = TREE_OPERAND (arg0, 0);
12220 imag0 = TREE_OPERAND (arg0, 1);
12224 real0 = TREE_REALPART (arg0);
12225 imag0 = TREE_IMAGPART (arg0);
12228 if (TREE_CODE (arg1) == COMPLEX_EXPR)
12230 real1 = TREE_OPERAND (arg1, 0);
12231 imag1 = TREE_OPERAND (arg1, 1);
12235 real1 = TREE_REALPART (arg1);
12236 imag1 = TREE_IMAGPART (arg1);
12239 rcond = fold_binary (code, type, real0, real1);
12240 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
12242 if (integer_zerop (rcond))
12244 if (code == EQ_EXPR)
12245 return omit_two_operands (type, boolean_false_node,
12247 return fold_build2 (NE_EXPR, type, imag0, imag1);
12251 if (code == NE_EXPR)
12252 return omit_two_operands (type, boolean_true_node,
12254 return fold_build2 (EQ_EXPR, type, imag0, imag1);
12258 icond = fold_binary (code, type, imag0, imag1);
12259 if (icond && TREE_CODE (icond) == INTEGER_CST)
12261 if (integer_zerop (icond))
12263 if (code == EQ_EXPR)
12264 return omit_two_operands (type, boolean_false_node,
12266 return fold_build2 (NE_EXPR, type, real0, real1);
12270 if (code == NE_EXPR)
12271 return omit_two_operands (type, boolean_true_node,
12273 return fold_build2 (EQ_EXPR, type, real0, real1);
12284 tem = fold_comparison (code, type, op0, op1);
12285 if (tem != NULL_TREE)
12288 /* Transform comparisons of the form X +- C CMP X. */
12289 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12290 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12291 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
12292 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
12293 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12294 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
12296 tree arg01 = TREE_OPERAND (arg0, 1);
12297 enum tree_code code0 = TREE_CODE (arg0);
12300 if (TREE_CODE (arg01) == REAL_CST)
12301 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
12303 is_positive = tree_int_cst_sgn (arg01);
12305 /* (X - c) > X becomes false. */
12306 if (code == GT_EXPR
12307 && ((code0 == MINUS_EXPR && is_positive >= 0)
12308 || (code0 == PLUS_EXPR && is_positive <= 0)))
12310 if (TREE_CODE (arg01) == INTEGER_CST
12311 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12312 fold_overflow_warning (("assuming signed overflow does not "
12313 "occur when assuming that (X - c) > X "
12314 "is always false"),
12315 WARN_STRICT_OVERFLOW_ALL);
12316 return constant_boolean_node (0, type);
12319 /* Likewise (X + c) < X becomes false. */
12320 if (code == LT_EXPR
12321 && ((code0 == PLUS_EXPR && is_positive >= 0)
12322 || (code0 == MINUS_EXPR && is_positive <= 0)))
12324 if (TREE_CODE (arg01) == INTEGER_CST
12325 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12326 fold_overflow_warning (("assuming signed overflow does not "
12327 "occur when assuming that "
12328 "(X + c) < X is always false"),
12329 WARN_STRICT_OVERFLOW_ALL);
12330 return constant_boolean_node (0, type);
12333 /* Convert (X - c) <= X to true. */
12334 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12336 && ((code0 == MINUS_EXPR && is_positive >= 0)
12337 || (code0 == PLUS_EXPR && is_positive <= 0)))
12339 if (TREE_CODE (arg01) == INTEGER_CST
12340 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12341 fold_overflow_warning (("assuming signed overflow does not "
12342 "occur when assuming that "
12343 "(X - c) <= X is always true"),
12344 WARN_STRICT_OVERFLOW_ALL);
12345 return constant_boolean_node (1, type);
12348 /* Convert (X + c) >= X to true. */
12349 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12351 && ((code0 == PLUS_EXPR && is_positive >= 0)
12352 || (code0 == MINUS_EXPR && is_positive <= 0)))
12354 if (TREE_CODE (arg01) == INTEGER_CST
12355 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12356 fold_overflow_warning (("assuming signed overflow does not "
12357 "occur when assuming that "
12358 "(X + c) >= X is always true"),
12359 WARN_STRICT_OVERFLOW_ALL);
12360 return constant_boolean_node (1, type);
12363 if (TREE_CODE (arg01) == INTEGER_CST)
12365 /* Convert X + c > X and X - c < X to true for integers. */
12366 if (code == GT_EXPR
12367 && ((code0 == PLUS_EXPR && is_positive > 0)
12368 || (code0 == MINUS_EXPR && is_positive < 0)))
12370 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12371 fold_overflow_warning (("assuming signed overflow does "
12372 "not occur when assuming that "
12373 "(X + c) > X is always true"),
12374 WARN_STRICT_OVERFLOW_ALL);
12375 return constant_boolean_node (1, type);
12378 if (code == LT_EXPR
12379 && ((code0 == MINUS_EXPR && is_positive > 0)
12380 || (code0 == PLUS_EXPR && is_positive < 0)))
12382 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12383 fold_overflow_warning (("assuming signed overflow does "
12384 "not occur when assuming that "
12385 "(X - c) < X is always true"),
12386 WARN_STRICT_OVERFLOW_ALL);
12387 return constant_boolean_node (1, type);
12390 /* Convert X + c <= X and X - c >= X to false for integers. */
12391 if (code == LE_EXPR
12392 && ((code0 == PLUS_EXPR && is_positive > 0)
12393 || (code0 == MINUS_EXPR && is_positive < 0)))
12395 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12396 fold_overflow_warning (("assuming signed overflow does "
12397 "not occur when assuming that "
12398 "(X + c) <= X is always false"),
12399 WARN_STRICT_OVERFLOW_ALL);
12400 return constant_boolean_node (0, type);
12403 if (code == GE_EXPR
12404 && ((code0 == MINUS_EXPR && is_positive > 0)
12405 || (code0 == PLUS_EXPR && is_positive < 0)))
12407 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12408 fold_overflow_warning (("assuming signed overflow does "
12409 "not occur when assuming that "
12410 "(X - c) >= X is always false"),
12411 WARN_STRICT_OVERFLOW_ALL);
12412 return constant_boolean_node (0, type);
12417 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
12418 This transformation affects the cases which are handled in later
12419 optimizations involving comparisons with non-negative constants. */
12420 if (TREE_CODE (arg1) == INTEGER_CST
12421 && TREE_CODE (arg0) != INTEGER_CST
12422 && tree_int_cst_sgn (arg1) > 0)
12424 if (code == GE_EXPR)
12426 arg1 = const_binop (MINUS_EXPR, arg1,
12427 build_int_cst (TREE_TYPE (arg1), 1), 0);
12428 return fold_build2 (GT_EXPR, type, arg0,
12429 fold_convert (TREE_TYPE (arg0), arg1));
12431 if (code == LT_EXPR)
12433 arg1 = const_binop (MINUS_EXPR, arg1,
12434 build_int_cst (TREE_TYPE (arg1), 1), 0);
12435 return fold_build2 (LE_EXPR, type, arg0,
12436 fold_convert (TREE_TYPE (arg0), arg1));
12440 /* Comparisons with the highest or lowest possible integer of
12441 the specified precision will have known values. */
12443 tree arg1_type = TREE_TYPE (arg1);
12444 unsigned int width = TYPE_PRECISION (arg1_type);
12446 if (TREE_CODE (arg1) == INTEGER_CST
12447 && !TREE_OVERFLOW (arg1)
12448 && width <= 2 * HOST_BITS_PER_WIDE_INT
12449 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
12451 HOST_WIDE_INT signed_max_hi;
12452 unsigned HOST_WIDE_INT signed_max_lo;
12453 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
12455 if (width <= HOST_BITS_PER_WIDE_INT)
12457 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12462 if (TYPE_UNSIGNED (arg1_type))
12464 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12470 max_lo = signed_max_lo;
12471 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12477 width -= HOST_BITS_PER_WIDE_INT;
12478 signed_max_lo = -1;
12479 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12484 if (TYPE_UNSIGNED (arg1_type))
12486 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12491 max_hi = signed_max_hi;
12492 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12496 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
12497 && TREE_INT_CST_LOW (arg1) == max_lo)
12501 return omit_one_operand (type, integer_zero_node, arg0);
12504 return fold_build2 (EQ_EXPR, type, op0, op1);
12507 return omit_one_operand (type, integer_one_node, arg0);
12510 return fold_build2 (NE_EXPR, type, op0, op1);
12512 /* The GE_EXPR and LT_EXPR cases above are not normally
12513 reached because of previous transformations. */
12518 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12520 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
12524 arg1 = const_binop (PLUS_EXPR, arg1,
12525 build_int_cst (TREE_TYPE (arg1), 1), 0);
12526 return fold_build2 (EQ_EXPR, type,
12527 fold_convert (TREE_TYPE (arg1), arg0),
12530 arg1 = const_binop (PLUS_EXPR, arg1,
12531 build_int_cst (TREE_TYPE (arg1), 1), 0);
12532 return fold_build2 (NE_EXPR, type,
12533 fold_convert (TREE_TYPE (arg1), arg0),
12538 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12540 && TREE_INT_CST_LOW (arg1) == min_lo)
12544 return omit_one_operand (type, integer_zero_node, arg0);
12547 return fold_build2 (EQ_EXPR, type, op0, op1);
12550 return omit_one_operand (type, integer_one_node, arg0);
12553 return fold_build2 (NE_EXPR, type, op0, op1);
12558 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12560 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
12564 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12565 return fold_build2 (NE_EXPR, type,
12566 fold_convert (TREE_TYPE (arg1), arg0),
12569 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12570 return fold_build2 (EQ_EXPR, type,
12571 fold_convert (TREE_TYPE (arg1), arg0),
12577 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
12578 && TREE_INT_CST_LOW (arg1) == signed_max_lo
12579 && TYPE_UNSIGNED (arg1_type)
12580 /* We will flip the signedness of the comparison operator
12581 associated with the mode of arg1, so the sign bit is
12582 specified by this mode. Check that arg1 is the signed
12583 max associated with this sign bit. */
12584 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
12585 /* signed_type does not work on pointer types. */
12586 && INTEGRAL_TYPE_P (arg1_type))
12588 /* The following case also applies to X < signed_max+1
12589 and X >= signed_max+1 because previous transformations. */
12590 if (code == LE_EXPR || code == GT_EXPR)
12593 st = signed_type_for (TREE_TYPE (arg1));
12594 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
12595 type, fold_convert (st, arg0),
12596 build_int_cst (st, 0));
12602 /* If we are comparing an ABS_EXPR with a constant, we can
12603 convert all the cases into explicit comparisons, but they may
12604 well not be faster than doing the ABS and one comparison.
12605 But ABS (X) <= C is a range comparison, which becomes a subtraction
12606 and a comparison, and is probably faster. */
12607 if (code == LE_EXPR
12608 && TREE_CODE (arg1) == INTEGER_CST
12609 && TREE_CODE (arg0) == ABS_EXPR
12610 && ! TREE_SIDE_EFFECTS (arg0)
12611 && (0 != (tem = negate_expr (arg1)))
12612 && TREE_CODE (tem) == INTEGER_CST
12613 && !TREE_OVERFLOW (tem))
12614 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12615 build2 (GE_EXPR, type,
12616 TREE_OPERAND (arg0, 0), tem),
12617 build2 (LE_EXPR, type,
12618 TREE_OPERAND (arg0, 0), arg1));
12620 /* Convert ABS_EXPR<x> >= 0 to true. */
12621 strict_overflow_p = false;
12622 if (code == GE_EXPR
12623 && (integer_zerop (arg1)
12624 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
12625 && real_zerop (arg1)))
12626 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12628 if (strict_overflow_p)
12629 fold_overflow_warning (("assuming signed overflow does not occur "
12630 "when simplifying comparison of "
12631 "absolute value and zero"),
12632 WARN_STRICT_OVERFLOW_CONDITIONAL);
12633 return omit_one_operand (type, integer_one_node, arg0);
12636 /* Convert ABS_EXPR<x> < 0 to false. */
12637 strict_overflow_p = false;
12638 if (code == LT_EXPR
12639 && (integer_zerop (arg1) || real_zerop (arg1))
12640 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12642 if (strict_overflow_p)
12643 fold_overflow_warning (("assuming signed overflow does not occur "
12644 "when simplifying comparison of "
12645 "absolute value and zero"),
12646 WARN_STRICT_OVERFLOW_CONDITIONAL);
12647 return omit_one_operand (type, integer_zero_node, arg0);
12650 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
12651 and similarly for >= into !=. */
12652 if ((code == LT_EXPR || code == GE_EXPR)
12653 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12654 && TREE_CODE (arg1) == LSHIFT_EXPR
12655 && integer_onep (TREE_OPERAND (arg1, 0)))
12656 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12657 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12658 TREE_OPERAND (arg1, 1)),
12659 build_int_cst (TREE_TYPE (arg0), 0));
12661 if ((code == LT_EXPR || code == GE_EXPR)
12662 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12663 && CONVERT_EXPR_P (arg1)
12664 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
12665 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
12667 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12668 fold_convert (TREE_TYPE (arg0),
12669 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12670 TREE_OPERAND (TREE_OPERAND (arg1, 0),
12672 build_int_cst (TREE_TYPE (arg0), 0));
12676 case UNORDERED_EXPR:
12684 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
12686 t1 = fold_relational_const (code, type, arg0, arg1);
12687 if (t1 != NULL_TREE)
12691 /* If the first operand is NaN, the result is constant. */
12692 if (TREE_CODE (arg0) == REAL_CST
12693 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
12694 && (code != LTGT_EXPR || ! flag_trapping_math))
12696 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12697 ? integer_zero_node
12698 : integer_one_node;
12699 return omit_one_operand (type, t1, arg1);
12702 /* If the second operand is NaN, the result is constant. */
12703 if (TREE_CODE (arg1) == REAL_CST
12704 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
12705 && (code != LTGT_EXPR || ! flag_trapping_math))
12707 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12708 ? integer_zero_node
12709 : integer_one_node;
12710 return omit_one_operand (type, t1, arg0);
12713 /* Simplify unordered comparison of something with itself. */
12714 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
12715 && operand_equal_p (arg0, arg1, 0))
12716 return constant_boolean_node (1, type);
12718 if (code == LTGT_EXPR
12719 && !flag_trapping_math
12720 && operand_equal_p (arg0, arg1, 0))
12721 return constant_boolean_node (0, type);
12723 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12725 tree targ0 = strip_float_extensions (arg0);
12726 tree targ1 = strip_float_extensions (arg1);
12727 tree newtype = TREE_TYPE (targ0);
12729 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
12730 newtype = TREE_TYPE (targ1);
12732 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
12733 return fold_build2 (code, type, fold_convert (newtype, targ0),
12734 fold_convert (newtype, targ1));
12739 case COMPOUND_EXPR:
12740 /* When pedantic, a compound expression can be neither an lvalue
12741 nor an integer constant expression. */
12742 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
12744 /* Don't let (0, 0) be null pointer constant. */
12745 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
12746 : fold_convert (type, arg1);
12747 return pedantic_non_lvalue (tem);
12750 if ((TREE_CODE (arg0) == REAL_CST
12751 && TREE_CODE (arg1) == REAL_CST)
12752 || (TREE_CODE (arg0) == INTEGER_CST
12753 && TREE_CODE (arg1) == INTEGER_CST))
12754 return build_complex (type, arg0, arg1);
12758 /* An ASSERT_EXPR should never be passed to fold_binary. */
12759 gcc_unreachable ();
12763 } /* switch (code) */
12766 /* Callback for walk_tree, looking for LABEL_EXPR.
12767 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
12768 Do not check the sub-tree of GOTO_EXPR. */
12771 contains_label_1 (tree *tp,
12772 int *walk_subtrees,
12773 void *data ATTRIBUTE_UNUSED)
12775 switch (TREE_CODE (*tp))
12780 *walk_subtrees = 0;
12787 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
12788 accessible from outside the sub-tree. Returns NULL_TREE if no
12789 addressable label is found. */
12792 contains_label_p (tree st)
12794 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
12797 /* Fold a ternary expression of code CODE and type TYPE with operands
12798 OP0, OP1, and OP2. Return the folded expression if folding is
12799 successful. Otherwise, return NULL_TREE. */
12802 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
12805 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
12806 enum tree_code_class kind = TREE_CODE_CLASS (code);
12808 gcc_assert (IS_EXPR_CODE_CLASS (kind)
12809 && TREE_CODE_LENGTH (code) == 3);
12811 /* Strip any conversions that don't change the mode. This is safe
12812 for every expression, except for a comparison expression because
12813 its signedness is derived from its operands. So, in the latter
12814 case, only strip conversions that don't change the signedness.
12816 Note that this is done as an internal manipulation within the
12817 constant folder, in order to find the simplest representation of
12818 the arguments so that their form can be studied. In any cases,
12819 the appropriate type conversions should be put back in the tree
12820 that will get out of the constant folder. */
12835 case COMPONENT_REF:
12836 if (TREE_CODE (arg0) == CONSTRUCTOR
12837 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
12839 unsigned HOST_WIDE_INT idx;
12841 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
12848 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
12849 so all simple results must be passed through pedantic_non_lvalue. */
12850 if (TREE_CODE (arg0) == INTEGER_CST)
12852 tree unused_op = integer_zerop (arg0) ? op1 : op2;
12853 tem = integer_zerop (arg0) ? op2 : op1;
12854 /* Only optimize constant conditions when the selected branch
12855 has the same type as the COND_EXPR. This avoids optimizing
12856 away "c ? x : throw", where the throw has a void type.
12857 Avoid throwing away that operand which contains label. */
12858 if ((!TREE_SIDE_EFFECTS (unused_op)
12859 || !contains_label_p (unused_op))
12860 && (! VOID_TYPE_P (TREE_TYPE (tem))
12861 || VOID_TYPE_P (type)))
12862 return pedantic_non_lvalue (tem);
12865 if (operand_equal_p (arg1, op2, 0))
12866 return pedantic_omit_one_operand (type, arg1, arg0);
12868 /* If we have A op B ? A : C, we may be able to convert this to a
12869 simpler expression, depending on the operation and the values
12870 of B and C. Signed zeros prevent all of these transformations,
12871 for reasons given above each one.
12873 Also try swapping the arguments and inverting the conditional. */
12874 if (COMPARISON_CLASS_P (arg0)
12875 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12876 arg1, TREE_OPERAND (arg0, 1))
12877 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
12879 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
12884 if (COMPARISON_CLASS_P (arg0)
12885 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12887 TREE_OPERAND (arg0, 1))
12888 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
12890 tem = fold_truth_not_expr (arg0);
12891 if (tem && COMPARISON_CLASS_P (tem))
12893 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
12899 /* If the second operand is simpler than the third, swap them
12900 since that produces better jump optimization results. */
12901 if (truth_value_p (TREE_CODE (arg0))
12902 && tree_swap_operands_p (op1, op2, false))
12904 /* See if this can be inverted. If it can't, possibly because
12905 it was a floating-point inequality comparison, don't do
12907 tem = fold_truth_not_expr (arg0);
12909 return fold_build3 (code, type, tem, op2, op1);
12912 /* Convert A ? 1 : 0 to simply A. */
12913 if (integer_onep (op1)
12914 && integer_zerop (op2)
12915 /* If we try to convert OP0 to our type, the
12916 call to fold will try to move the conversion inside
12917 a COND, which will recurse. In that case, the COND_EXPR
12918 is probably the best choice, so leave it alone. */
12919 && type == TREE_TYPE (arg0))
12920 return pedantic_non_lvalue (arg0);
12922 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
12923 over COND_EXPR in cases such as floating point comparisons. */
12924 if (integer_zerop (op1)
12925 && integer_onep (op2)
12926 && truth_value_p (TREE_CODE (arg0)))
12927 return pedantic_non_lvalue (fold_convert (type,
12928 invert_truthvalue (arg0)));
12930 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
12931 if (TREE_CODE (arg0) == LT_EXPR
12932 && integer_zerop (TREE_OPERAND (arg0, 1))
12933 && integer_zerop (op2)
12934 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
12936 /* sign_bit_p only checks ARG1 bits within A's precision.
12937 If <sign bit of A> has wider type than A, bits outside
12938 of A's precision in <sign bit of A> need to be checked.
12939 If they are all 0, this optimization needs to be done
12940 in unsigned A's type, if they are all 1 in signed A's type,
12941 otherwise this can't be done. */
12942 if (TYPE_PRECISION (TREE_TYPE (tem))
12943 < TYPE_PRECISION (TREE_TYPE (arg1))
12944 && TYPE_PRECISION (TREE_TYPE (tem))
12945 < TYPE_PRECISION (type))
12947 unsigned HOST_WIDE_INT mask_lo;
12948 HOST_WIDE_INT mask_hi;
12949 int inner_width, outer_width;
12952 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
12953 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
12954 if (outer_width > TYPE_PRECISION (type))
12955 outer_width = TYPE_PRECISION (type);
12957 if (outer_width > HOST_BITS_PER_WIDE_INT)
12959 mask_hi = ((unsigned HOST_WIDE_INT) -1
12960 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
12966 mask_lo = ((unsigned HOST_WIDE_INT) -1
12967 >> (HOST_BITS_PER_WIDE_INT - outer_width));
12969 if (inner_width > HOST_BITS_PER_WIDE_INT)
12971 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
12972 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12976 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
12977 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12979 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
12980 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
12982 tem_type = signed_type_for (TREE_TYPE (tem));
12983 tem = fold_convert (tem_type, tem);
12985 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
12986 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
12988 tem_type = unsigned_type_for (TREE_TYPE (tem));
12989 tem = fold_convert (tem_type, tem);
12996 return fold_convert (type,
12997 fold_build2 (BIT_AND_EXPR,
12998 TREE_TYPE (tem), tem,
12999 fold_convert (TREE_TYPE (tem),
13003 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
13004 already handled above. */
13005 if (TREE_CODE (arg0) == BIT_AND_EXPR
13006 && integer_onep (TREE_OPERAND (arg0, 1))
13007 && integer_zerop (op2)
13008 && integer_pow2p (arg1))
13010 tree tem = TREE_OPERAND (arg0, 0);
13012 if (TREE_CODE (tem) == RSHIFT_EXPR
13013 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
13014 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
13015 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
13016 return fold_build2 (BIT_AND_EXPR, type,
13017 TREE_OPERAND (tem, 0), arg1);
13020 /* A & N ? N : 0 is simply A & N if N is a power of two. This
13021 is probably obsolete because the first operand should be a
13022 truth value (that's why we have the two cases above), but let's
13023 leave it in until we can confirm this for all front-ends. */
13024 if (integer_zerop (op2)
13025 && TREE_CODE (arg0) == NE_EXPR
13026 && integer_zerop (TREE_OPERAND (arg0, 1))
13027 && integer_pow2p (arg1)
13028 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
13029 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
13030 arg1, OEP_ONLY_CONST))
13031 return pedantic_non_lvalue (fold_convert (type,
13032 TREE_OPERAND (arg0, 0)));
13034 /* Convert A ? B : 0 into A && B if A and B are truth values. */
13035 if (integer_zerop (op2)
13036 && truth_value_p (TREE_CODE (arg0))
13037 && truth_value_p (TREE_CODE (arg1)))
13038 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13039 fold_convert (type, arg0),
13042 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
13043 if (integer_onep (op2)
13044 && truth_value_p (TREE_CODE (arg0))
13045 && truth_value_p (TREE_CODE (arg1)))
13047 /* Only perform transformation if ARG0 is easily inverted. */
13048 tem = fold_truth_not_expr (arg0);
13050 return fold_build2 (TRUTH_ORIF_EXPR, type,
13051 fold_convert (type, tem),
13055 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
13056 if (integer_zerop (arg1)
13057 && truth_value_p (TREE_CODE (arg0))
13058 && truth_value_p (TREE_CODE (op2)))
13060 /* Only perform transformation if ARG0 is easily inverted. */
13061 tem = fold_truth_not_expr (arg0);
13063 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13064 fold_convert (type, tem),
13068 /* Convert A ? 1 : B into A || B if A and B are truth values. */
13069 if (integer_onep (arg1)
13070 && truth_value_p (TREE_CODE (arg0))
13071 && truth_value_p (TREE_CODE (op2)))
13072 return fold_build2 (TRUTH_ORIF_EXPR, type,
13073 fold_convert (type, arg0),
13079 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
13080 of fold_ternary on them. */
13081 gcc_unreachable ();
13083 case BIT_FIELD_REF:
13084 if ((TREE_CODE (arg0) == VECTOR_CST
13085 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
13086 && type == TREE_TYPE (TREE_TYPE (arg0)))
13088 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
13089 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
13092 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
13093 && (idx % width) == 0
13094 && (idx = idx / width)
13095 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
13097 tree elements = NULL_TREE;
13099 if (TREE_CODE (arg0) == VECTOR_CST)
13100 elements = TREE_VECTOR_CST_ELTS (arg0);
13103 unsigned HOST_WIDE_INT idx;
13106 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
13107 elements = tree_cons (NULL_TREE, value, elements);
13109 while (idx-- > 0 && elements)
13110 elements = TREE_CHAIN (elements);
13112 return TREE_VALUE (elements);
13114 return fold_convert (type, integer_zero_node);
13121 } /* switch (code) */
13124 /* Perform constant folding and related simplification of EXPR.
13125 The related simplifications include x*1 => x, x*0 => 0, etc.,
13126 and application of the associative law.
13127 NOP_EXPR conversions may be removed freely (as long as we
13128 are careful not to change the type of the overall expression).
13129 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13130 but we can constant-fold them if they have constant operands. */
13132 #ifdef ENABLE_FOLD_CHECKING
13133 # define fold(x) fold_1 (x)
13134 static tree fold_1 (tree);
13140 const tree t = expr;
13141 enum tree_code code = TREE_CODE (t);
13142 enum tree_code_class kind = TREE_CODE_CLASS (code);
13145 /* Return right away if a constant. */
13146 if (kind == tcc_constant)
13149 /* CALL_EXPR-like objects with variable numbers of operands are
13150 treated specially. */
13151 if (kind == tcc_vl_exp)
13153 if (code == CALL_EXPR)
13155 tem = fold_call_expr (expr, false);
13156 return tem ? tem : expr;
13161 if (IS_EXPR_CODE_CLASS (kind)
13162 || IS_GIMPLE_STMT_CODE_CLASS (kind))
13164 tree type = TREE_TYPE (t);
13165 tree op0, op1, op2;
13167 switch (TREE_CODE_LENGTH (code))
13170 op0 = TREE_OPERAND (t, 0);
13171 tem = fold_unary (code, type, op0);
13172 return tem ? tem : expr;
13174 op0 = TREE_OPERAND (t, 0);
13175 op1 = TREE_OPERAND (t, 1);
13176 tem = fold_binary (code, type, op0, op1);
13177 return tem ? tem : expr;
13179 op0 = TREE_OPERAND (t, 0);
13180 op1 = TREE_OPERAND (t, 1);
13181 op2 = TREE_OPERAND (t, 2);
13182 tem = fold_ternary (code, type, op0, op1, op2);
13183 return tem ? tem : expr;
13193 tree op0 = TREE_OPERAND (t, 0);
13194 tree op1 = TREE_OPERAND (t, 1);
13196 if (TREE_CODE (op1) == INTEGER_CST
13197 && TREE_CODE (op0) == CONSTRUCTOR
13198 && ! type_contains_placeholder_p (TREE_TYPE (op0)))
13200 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (op0);
13201 unsigned HOST_WIDE_INT end = VEC_length (constructor_elt, elts);
13202 unsigned HOST_WIDE_INT begin = 0;
13204 /* Find a matching index by means of a binary search. */
13205 while (begin != end)
13207 unsigned HOST_WIDE_INT middle = (begin + end) / 2;
13208 tree index = VEC_index (constructor_elt, elts, middle)->index;
13210 if (TREE_CODE (index) == INTEGER_CST
13211 && tree_int_cst_lt (index, op1))
13212 begin = middle + 1;
13213 else if (TREE_CODE (index) == INTEGER_CST
13214 && tree_int_cst_lt (op1, index))
13216 else if (TREE_CODE (index) == RANGE_EXPR
13217 && tree_int_cst_lt (TREE_OPERAND (index, 1), op1))
13218 begin = middle + 1;
13219 else if (TREE_CODE (index) == RANGE_EXPR
13220 && tree_int_cst_lt (op1, TREE_OPERAND (index, 0)))
13223 return VEC_index (constructor_elt, elts, middle)->value;
13231 return fold (DECL_INITIAL (t));
13235 } /* switch (code) */
13238 #ifdef ENABLE_FOLD_CHECKING
13241 static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
13242 static void fold_check_failed (const_tree, const_tree);
13243 void print_fold_checksum (const_tree);
13245 /* When --enable-checking=fold, compute a digest of expr before
13246 and after actual fold call to see if fold did not accidentally
13247 change original expr. */
13253 struct md5_ctx ctx;
13254 unsigned char checksum_before[16], checksum_after[16];
13257 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13258 md5_init_ctx (&ctx);
13259 fold_checksum_tree (expr, &ctx, ht);
13260 md5_finish_ctx (&ctx, checksum_before);
13263 ret = fold_1 (expr);
13265 md5_init_ctx (&ctx);
13266 fold_checksum_tree (expr, &ctx, ht);
13267 md5_finish_ctx (&ctx, checksum_after);
13270 if (memcmp (checksum_before, checksum_after, 16))
13271 fold_check_failed (expr, ret);
13277 print_fold_checksum (const_tree expr)
13279 struct md5_ctx ctx;
13280 unsigned char checksum[16], cnt;
13283 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13284 md5_init_ctx (&ctx);
13285 fold_checksum_tree (expr, &ctx, ht);
13286 md5_finish_ctx (&ctx, checksum);
13288 for (cnt = 0; cnt < 16; ++cnt)
13289 fprintf (stderr, "%02x", checksum[cnt]);
13290 putc ('\n', stderr);
13294 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
13296 internal_error ("fold check: original tree changed by fold");
13300 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
13303 enum tree_code code;
13304 struct tree_function_decl buf;
13309 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
13310 <= sizeof (struct tree_function_decl))
13311 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
13314 slot = (const void **) htab_find_slot (ht, expr, INSERT);
13318 code = TREE_CODE (expr);
13319 if (TREE_CODE_CLASS (code) == tcc_declaration
13320 && DECL_ASSEMBLER_NAME_SET_P (expr))
13322 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13323 memcpy ((char *) &buf, expr, tree_size (expr));
13324 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
13325 expr = (tree) &buf;
13327 else if (TREE_CODE_CLASS (code) == tcc_type
13328 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
13329 || TYPE_CACHED_VALUES_P (expr)
13330 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
13332 /* Allow these fields to be modified. */
13334 memcpy ((char *) &buf, expr, tree_size (expr));
13335 expr = tmp = (tree) &buf;
13336 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
13337 TYPE_POINTER_TO (tmp) = NULL;
13338 TYPE_REFERENCE_TO (tmp) = NULL;
13339 if (TYPE_CACHED_VALUES_P (tmp))
13341 TYPE_CACHED_VALUES_P (tmp) = 0;
13342 TYPE_CACHED_VALUES (tmp) = NULL;
13345 md5_process_bytes (expr, tree_size (expr), ctx);
13346 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
13347 if (TREE_CODE_CLASS (code) != tcc_type
13348 && TREE_CODE_CLASS (code) != tcc_declaration
13349 && code != TREE_LIST
13350 && code != SSA_NAME)
13351 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
13352 switch (TREE_CODE_CLASS (code))
13358 md5_process_bytes (TREE_STRING_POINTER (expr),
13359 TREE_STRING_LENGTH (expr), ctx);
13362 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
13363 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
13366 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
13372 case tcc_exceptional:
13376 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
13377 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
13378 expr = TREE_CHAIN (expr);
13379 goto recursive_label;
13382 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
13383 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
13389 case tcc_expression:
13390 case tcc_reference:
13391 case tcc_comparison:
13394 case tcc_statement:
13396 len = TREE_OPERAND_LENGTH (expr);
13397 for (i = 0; i < len; ++i)
13398 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
13400 case tcc_declaration:
13401 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
13402 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
13403 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
13405 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
13406 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
13407 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
13408 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
13409 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
13411 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
13412 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
13414 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
13416 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
13417 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
13418 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
13422 if (TREE_CODE (expr) == ENUMERAL_TYPE)
13423 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
13424 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
13425 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
13426 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
13427 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
13428 if (INTEGRAL_TYPE_P (expr)
13429 || SCALAR_FLOAT_TYPE_P (expr))
13431 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
13432 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
13434 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
13435 if (TREE_CODE (expr) == RECORD_TYPE
13436 || TREE_CODE (expr) == UNION_TYPE
13437 || TREE_CODE (expr) == QUAL_UNION_TYPE)
13438 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
13439 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
13446 /* Helper function for outputting the checksum of a tree T. When
13447 debugging with gdb, you can "define mynext" to be "next" followed
13448 by "call debug_fold_checksum (op0)", then just trace down till the
13452 debug_fold_checksum (const_tree t)
13455 unsigned char checksum[16];
13456 struct md5_ctx ctx;
13457 htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13459 md5_init_ctx (&ctx);
13460 fold_checksum_tree (t, &ctx, ht);
13461 md5_finish_ctx (&ctx, checksum);
13464 for (i = 0; i < 16; i++)
13465 fprintf (stderr, "%d ", checksum[i]);
13467 fprintf (stderr, "\n");
13472 /* Fold a unary tree expression with code CODE of type TYPE with an
13473 operand OP0. Return a folded expression if successful. Otherwise,
13474 return a tree expression with code CODE of type TYPE with an
13478 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
13481 #ifdef ENABLE_FOLD_CHECKING
13482 unsigned char checksum_before[16], checksum_after[16];
13483 struct md5_ctx ctx;
13486 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13487 md5_init_ctx (&ctx);
13488 fold_checksum_tree (op0, &ctx, ht);
13489 md5_finish_ctx (&ctx, checksum_before);
13493 tem = fold_unary (code, type, op0);
13495 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
13497 #ifdef ENABLE_FOLD_CHECKING
13498 md5_init_ctx (&ctx);
13499 fold_checksum_tree (op0, &ctx, ht);
13500 md5_finish_ctx (&ctx, checksum_after);
13503 if (memcmp (checksum_before, checksum_after, 16))
13504 fold_check_failed (op0, tem);
13509 /* Fold a binary tree expression with code CODE of type TYPE with
13510 operands OP0 and OP1. Return a folded expression if successful.
13511 Otherwise, return a tree expression with code CODE of type TYPE
13512 with operands OP0 and OP1. */
13515 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
13519 #ifdef ENABLE_FOLD_CHECKING
13520 unsigned char checksum_before_op0[16],
13521 checksum_before_op1[16],
13522 checksum_after_op0[16],
13523 checksum_after_op1[16];
13524 struct md5_ctx ctx;
13527 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13528 md5_init_ctx (&ctx);
13529 fold_checksum_tree (op0, &ctx, ht);
13530 md5_finish_ctx (&ctx, checksum_before_op0);
13533 md5_init_ctx (&ctx);
13534 fold_checksum_tree (op1, &ctx, ht);
13535 md5_finish_ctx (&ctx, checksum_before_op1);
13539 tem = fold_binary (code, type, op0, op1);
13541 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
13543 #ifdef ENABLE_FOLD_CHECKING
13544 md5_init_ctx (&ctx);
13545 fold_checksum_tree (op0, &ctx, ht);
13546 md5_finish_ctx (&ctx, checksum_after_op0);
13549 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13550 fold_check_failed (op0, tem);
13552 md5_init_ctx (&ctx);
13553 fold_checksum_tree (op1, &ctx, ht);
13554 md5_finish_ctx (&ctx, checksum_after_op1);
13557 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13558 fold_check_failed (op1, tem);
13563 /* Fold a ternary tree expression with code CODE of type TYPE with
13564 operands OP0, OP1, and OP2. Return a folded expression if
13565 successful. Otherwise, return a tree expression with code CODE of
13566 type TYPE with operands OP0, OP1, and OP2. */
13569 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
13573 #ifdef ENABLE_FOLD_CHECKING
13574 unsigned char checksum_before_op0[16],
13575 checksum_before_op1[16],
13576 checksum_before_op2[16],
13577 checksum_after_op0[16],
13578 checksum_after_op1[16],
13579 checksum_after_op2[16];
13580 struct md5_ctx ctx;
13583 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13584 md5_init_ctx (&ctx);
13585 fold_checksum_tree (op0, &ctx, ht);
13586 md5_finish_ctx (&ctx, checksum_before_op0);
13589 md5_init_ctx (&ctx);
13590 fold_checksum_tree (op1, &ctx, ht);
13591 md5_finish_ctx (&ctx, checksum_before_op1);
13594 md5_init_ctx (&ctx);
13595 fold_checksum_tree (op2, &ctx, ht);
13596 md5_finish_ctx (&ctx, checksum_before_op2);
13600 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
13601 tem = fold_ternary (code, type, op0, op1, op2);
13603 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
13605 #ifdef ENABLE_FOLD_CHECKING
13606 md5_init_ctx (&ctx);
13607 fold_checksum_tree (op0, &ctx, ht);
13608 md5_finish_ctx (&ctx, checksum_after_op0);
13611 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13612 fold_check_failed (op0, tem);
13614 md5_init_ctx (&ctx);
13615 fold_checksum_tree (op1, &ctx, ht);
13616 md5_finish_ctx (&ctx, checksum_after_op1);
13619 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13620 fold_check_failed (op1, tem);
13622 md5_init_ctx (&ctx);
13623 fold_checksum_tree (op2, &ctx, ht);
13624 md5_finish_ctx (&ctx, checksum_after_op2);
13627 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
13628 fold_check_failed (op2, tem);
13633 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
13634 arguments in ARGARRAY, and a null static chain.
13635 Return a folded expression if successful. Otherwise, return a CALL_EXPR
13636 of type TYPE from the given operands as constructed by build_call_array. */
13639 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
13642 #ifdef ENABLE_FOLD_CHECKING
13643 unsigned char checksum_before_fn[16],
13644 checksum_before_arglist[16],
13645 checksum_after_fn[16],
13646 checksum_after_arglist[16];
13647 struct md5_ctx ctx;
13651 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13652 md5_init_ctx (&ctx);
13653 fold_checksum_tree (fn, &ctx, ht);
13654 md5_finish_ctx (&ctx, checksum_before_fn);
13657 md5_init_ctx (&ctx);
13658 for (i = 0; i < nargs; i++)
13659 fold_checksum_tree (argarray[i], &ctx, ht);
13660 md5_finish_ctx (&ctx, checksum_before_arglist);
13664 tem = fold_builtin_call_array (type, fn, nargs, argarray);
13666 #ifdef ENABLE_FOLD_CHECKING
13667 md5_init_ctx (&ctx);
13668 fold_checksum_tree (fn, &ctx, ht);
13669 md5_finish_ctx (&ctx, checksum_after_fn);
13672 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
13673 fold_check_failed (fn, tem);
13675 md5_init_ctx (&ctx);
13676 for (i = 0; i < nargs; i++)
13677 fold_checksum_tree (argarray[i], &ctx, ht);
13678 md5_finish_ctx (&ctx, checksum_after_arglist);
13681 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
13682 fold_check_failed (NULL_TREE, tem);
13687 /* Perform constant folding and related simplification of initializer
13688 expression EXPR. These behave identically to "fold_buildN" but ignore
13689 potential run-time traps and exceptions that fold must preserve. */
13691 #define START_FOLD_INIT \
13692 int saved_signaling_nans = flag_signaling_nans;\
13693 int saved_trapping_math = flag_trapping_math;\
13694 int saved_rounding_math = flag_rounding_math;\
13695 int saved_trapv = flag_trapv;\
13696 int saved_folding_initializer = folding_initializer;\
13697 flag_signaling_nans = 0;\
13698 flag_trapping_math = 0;\
13699 flag_rounding_math = 0;\
13701 folding_initializer = 1;
13703 #define END_FOLD_INIT \
13704 flag_signaling_nans = saved_signaling_nans;\
13705 flag_trapping_math = saved_trapping_math;\
13706 flag_rounding_math = saved_rounding_math;\
13707 flag_trapv = saved_trapv;\
13708 folding_initializer = saved_folding_initializer;
13711 fold_build1_initializer (enum tree_code code, tree type, tree op)
13716 result = fold_build1 (code, type, op);
13723 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
13728 result = fold_build2 (code, type, op0, op1);
13735 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
13741 result = fold_build3 (code, type, op0, op1, op2);
13748 fold_build_call_array_initializer (tree type, tree fn,
13749 int nargs, tree *argarray)
13754 result = fold_build_call_array (type, fn, nargs, argarray);
13760 #undef START_FOLD_INIT
13761 #undef END_FOLD_INIT
13763 /* Determine if first argument is a multiple of second argument. Return 0 if
13764 it is not, or we cannot easily determined it to be.
13766 An example of the sort of thing we care about (at this point; this routine
13767 could surely be made more general, and expanded to do what the *_DIV_EXPR's
13768 fold cases do now) is discovering that
13770 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13776 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
13778 This code also handles discovering that
13780 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13782 is a multiple of 8 so we don't have to worry about dealing with a
13783 possible remainder.
13785 Note that we *look* inside a SAVE_EXPR only to determine how it was
13786 calculated; it is not safe for fold to do much of anything else with the
13787 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
13788 at run time. For example, the latter example above *cannot* be implemented
13789 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
13790 evaluation time of the original SAVE_EXPR is not necessarily the same at
13791 the time the new expression is evaluated. The only optimization of this
13792 sort that would be valid is changing
13794 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
13798 SAVE_EXPR (I) * SAVE_EXPR (J)
13800 (where the same SAVE_EXPR (J) is used in the original and the
13801 transformed version). */
13804 multiple_of_p (tree type, const_tree top, const_tree bottom)
13806 if (operand_equal_p (top, bottom, 0))
13809 if (TREE_CODE (type) != INTEGER_TYPE)
13812 switch (TREE_CODE (top))
13815 /* Bitwise and provides a power of two multiple. If the mask is
13816 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
13817 if (!integer_pow2p (bottom))
13822 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13823 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13827 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13828 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13831 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
13835 op1 = TREE_OPERAND (top, 1);
13836 /* const_binop may not detect overflow correctly,
13837 so check for it explicitly here. */
13838 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
13839 > TREE_INT_CST_LOW (op1)
13840 && TREE_INT_CST_HIGH (op1) == 0
13841 && 0 != (t1 = fold_convert (type,
13842 const_binop (LSHIFT_EXPR,
13845 && !TREE_OVERFLOW (t1))
13846 return multiple_of_p (type, t1, bottom);
13851 /* Can't handle conversions from non-integral or wider integral type. */
13852 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
13853 || (TYPE_PRECISION (type)
13854 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
13857 /* .. fall through ... */
13860 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
13863 if (TREE_CODE (bottom) != INTEGER_CST
13864 || integer_zerop (bottom)
13865 || (TYPE_UNSIGNED (type)
13866 && (tree_int_cst_sgn (top) < 0
13867 || tree_int_cst_sgn (bottom) < 0)))
13869 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
13877 /* Return true if CODE or TYPE is known to be non-negative. */
13880 tree_simple_nonnegative_warnv_p (enum tree_code code, tree type)
13882 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
13883 && truth_value_p (code))
13884 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
13885 have a signed:1 type (where the value is -1 and 0). */
13890 /* Return true if (CODE OP0) is known to be non-negative. If the return
13891 value is based on the assumption that signed overflow is undefined,
13892 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13893 *STRICT_OVERFLOW_P. */
13896 tree_unary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
13897 bool *strict_overflow_p)
13899 if (TYPE_UNSIGNED (type))
13905 /* We can't return 1 if flag_wrapv is set because
13906 ABS_EXPR<INT_MIN> = INT_MIN. */
13907 if (!INTEGRAL_TYPE_P (type))
13909 if (TYPE_OVERFLOW_UNDEFINED (type))
13911 *strict_overflow_p = true;
13916 case NON_LVALUE_EXPR:
13918 case FIX_TRUNC_EXPR:
13919 return tree_expr_nonnegative_warnv_p (op0,
13920 strict_overflow_p);
13924 tree inner_type = TREE_TYPE (op0);
13925 tree outer_type = type;
13927 if (TREE_CODE (outer_type) == REAL_TYPE)
13929 if (TREE_CODE (inner_type) == REAL_TYPE)
13930 return tree_expr_nonnegative_warnv_p (op0,
13931 strict_overflow_p);
13932 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13934 if (TYPE_UNSIGNED (inner_type))
13936 return tree_expr_nonnegative_warnv_p (op0,
13937 strict_overflow_p);
13940 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
13942 if (TREE_CODE (inner_type) == REAL_TYPE)
13943 return tree_expr_nonnegative_warnv_p (op0,
13944 strict_overflow_p);
13945 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13946 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
13947 && TYPE_UNSIGNED (inner_type);
13953 return tree_simple_nonnegative_warnv_p (code, type);
13956 /* We don't know sign of `t', so be conservative and return false. */
13960 /* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
13961 value is based on the assumption that signed overflow is undefined,
13962 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13963 *STRICT_OVERFLOW_P. */
13966 tree_binary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
13967 tree op1, bool *strict_overflow_p)
13969 if (TYPE_UNSIGNED (type))
13974 case POINTER_PLUS_EXPR:
13976 if (FLOAT_TYPE_P (type))
13977 return (tree_expr_nonnegative_warnv_p (op0,
13979 && tree_expr_nonnegative_warnv_p (op1,
13980 strict_overflow_p));
13982 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
13983 both unsigned and at least 2 bits shorter than the result. */
13984 if (TREE_CODE (type) == INTEGER_TYPE
13985 && TREE_CODE (op0) == NOP_EXPR
13986 && TREE_CODE (op1) == NOP_EXPR)
13988 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
13989 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
13990 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13991 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13993 unsigned int prec = MAX (TYPE_PRECISION (inner1),
13994 TYPE_PRECISION (inner2)) + 1;
13995 return prec < TYPE_PRECISION (type);
14001 if (FLOAT_TYPE_P (type))
14003 /* x * x for floating point x is always non-negative. */
14004 if (operand_equal_p (op0, op1, 0))
14006 return (tree_expr_nonnegative_warnv_p (op0,
14008 && tree_expr_nonnegative_warnv_p (op1,
14009 strict_overflow_p));
14012 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
14013 both unsigned and their total bits is shorter than the result. */
14014 if (TREE_CODE (type) == INTEGER_TYPE
14015 && TREE_CODE (op0) == NOP_EXPR
14016 && TREE_CODE (op1) == NOP_EXPR)
14018 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
14019 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
14020 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
14021 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
14022 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
14023 < TYPE_PRECISION (type);
14029 return (tree_expr_nonnegative_warnv_p (op0,
14031 || tree_expr_nonnegative_warnv_p (op1,
14032 strict_overflow_p));
14038 case TRUNC_DIV_EXPR:
14039 case CEIL_DIV_EXPR:
14040 case FLOOR_DIV_EXPR:
14041 case ROUND_DIV_EXPR:
14042 return (tree_expr_nonnegative_warnv_p (op0,
14044 && tree_expr_nonnegative_warnv_p (op1,
14045 strict_overflow_p));
14047 case TRUNC_MOD_EXPR:
14048 case CEIL_MOD_EXPR:
14049 case FLOOR_MOD_EXPR:
14050 case ROUND_MOD_EXPR:
14051 return tree_expr_nonnegative_warnv_p (op0,
14052 strict_overflow_p);
14054 return tree_simple_nonnegative_warnv_p (code, type);
14057 /* We don't know sign of `t', so be conservative and return false. */
14061 /* Return true if T is known to be non-negative. If the return
14062 value is based on the assumption that signed overflow is undefined,
14063 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14064 *STRICT_OVERFLOW_P. */
14067 tree_single_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14069 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14072 switch (TREE_CODE (t))
14075 /* Query VRP to see if it has recorded any information about
14076 the range of this object. */
14077 return ssa_name_nonnegative_p (t);
14080 return tree_int_cst_sgn (t) >= 0;
14083 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
14086 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
14089 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14091 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
14092 strict_overflow_p));
14094 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14097 /* We don't know sign of `t', so be conservative and return false. */
14101 /* Return true if T is known to be non-negative. If the return
14102 value is based on the assumption that signed overflow is undefined,
14103 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14104 *STRICT_OVERFLOW_P. */
14107 tree_call_nonnegative_warnv_p (enum tree_code code, tree type, tree fndecl,
14108 tree arg0, tree arg1, bool *strict_overflow_p)
14110 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
14111 switch (DECL_FUNCTION_CODE (fndecl))
14113 CASE_FLT_FN (BUILT_IN_ACOS):
14114 CASE_FLT_FN (BUILT_IN_ACOSH):
14115 CASE_FLT_FN (BUILT_IN_CABS):
14116 CASE_FLT_FN (BUILT_IN_COSH):
14117 CASE_FLT_FN (BUILT_IN_ERFC):
14118 CASE_FLT_FN (BUILT_IN_EXP):
14119 CASE_FLT_FN (BUILT_IN_EXP10):
14120 CASE_FLT_FN (BUILT_IN_EXP2):
14121 CASE_FLT_FN (BUILT_IN_FABS):
14122 CASE_FLT_FN (BUILT_IN_FDIM):
14123 CASE_FLT_FN (BUILT_IN_HYPOT):
14124 CASE_FLT_FN (BUILT_IN_POW10):
14125 CASE_INT_FN (BUILT_IN_FFS):
14126 CASE_INT_FN (BUILT_IN_PARITY):
14127 CASE_INT_FN (BUILT_IN_POPCOUNT):
14128 case BUILT_IN_BSWAP32:
14129 case BUILT_IN_BSWAP64:
14133 CASE_FLT_FN (BUILT_IN_SQRT):
14134 /* sqrt(-0.0) is -0.0. */
14135 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
14137 return tree_expr_nonnegative_warnv_p (arg0,
14138 strict_overflow_p);
14140 CASE_FLT_FN (BUILT_IN_ASINH):
14141 CASE_FLT_FN (BUILT_IN_ATAN):
14142 CASE_FLT_FN (BUILT_IN_ATANH):
14143 CASE_FLT_FN (BUILT_IN_CBRT):
14144 CASE_FLT_FN (BUILT_IN_CEIL):
14145 CASE_FLT_FN (BUILT_IN_ERF):
14146 CASE_FLT_FN (BUILT_IN_EXPM1):
14147 CASE_FLT_FN (BUILT_IN_FLOOR):
14148 CASE_FLT_FN (BUILT_IN_FMOD):
14149 CASE_FLT_FN (BUILT_IN_FREXP):
14150 CASE_FLT_FN (BUILT_IN_LCEIL):
14151 CASE_FLT_FN (BUILT_IN_LDEXP):
14152 CASE_FLT_FN (BUILT_IN_LFLOOR):
14153 CASE_FLT_FN (BUILT_IN_LLCEIL):
14154 CASE_FLT_FN (BUILT_IN_LLFLOOR):
14155 CASE_FLT_FN (BUILT_IN_LLRINT):
14156 CASE_FLT_FN (BUILT_IN_LLROUND):
14157 CASE_FLT_FN (BUILT_IN_LRINT):
14158 CASE_FLT_FN (BUILT_IN_LROUND):
14159 CASE_FLT_FN (BUILT_IN_MODF):
14160 CASE_FLT_FN (BUILT_IN_NEARBYINT):
14161 CASE_FLT_FN (BUILT_IN_RINT):
14162 CASE_FLT_FN (BUILT_IN_ROUND):
14163 CASE_FLT_FN (BUILT_IN_SCALB):
14164 CASE_FLT_FN (BUILT_IN_SCALBLN):
14165 CASE_FLT_FN (BUILT_IN_SCALBN):
14166 CASE_FLT_FN (BUILT_IN_SIGNBIT):
14167 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
14168 CASE_FLT_FN (BUILT_IN_SINH):
14169 CASE_FLT_FN (BUILT_IN_TANH):
14170 CASE_FLT_FN (BUILT_IN_TRUNC):
14171 /* True if the 1st argument is nonnegative. */
14172 return tree_expr_nonnegative_warnv_p (arg0,
14173 strict_overflow_p);
14175 CASE_FLT_FN (BUILT_IN_FMAX):
14176 /* True if the 1st OR 2nd arguments are nonnegative. */
14177 return (tree_expr_nonnegative_warnv_p (arg0,
14179 || (tree_expr_nonnegative_warnv_p (arg1,
14180 strict_overflow_p)));
14182 CASE_FLT_FN (BUILT_IN_FMIN):
14183 /* True if the 1st AND 2nd arguments are nonnegative. */
14184 return (tree_expr_nonnegative_warnv_p (arg0,
14186 && (tree_expr_nonnegative_warnv_p (arg1,
14187 strict_overflow_p)));
14189 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14190 /* True if the 2nd argument is nonnegative. */
14191 return tree_expr_nonnegative_warnv_p (arg1,
14192 strict_overflow_p);
14194 CASE_FLT_FN (BUILT_IN_POWI):
14195 /* True if the 1st argument is nonnegative or the second
14196 argument is an even integer. */
14197 if (TREE_CODE (arg1) == INTEGER_CST
14198 && (TREE_INT_CST_LOW (arg1) & 1) == 0)
14200 return tree_expr_nonnegative_warnv_p (arg0,
14201 strict_overflow_p);
14203 CASE_FLT_FN (BUILT_IN_POW):
14204 /* True if the 1st argument is nonnegative or the second
14205 argument is an even integer valued real. */
14206 if (TREE_CODE (arg1) == REAL_CST)
14211 c = TREE_REAL_CST (arg1);
14212 n = real_to_integer (&c);
14215 REAL_VALUE_TYPE cint;
14216 real_from_integer (&cint, VOIDmode, n,
14217 n < 0 ? -1 : 0, 0);
14218 if (real_identical (&c, &cint))
14222 return tree_expr_nonnegative_warnv_p (arg0,
14223 strict_overflow_p);
14228 return tree_simple_nonnegative_warnv_p (code,
14232 /* Return true if T is known to be non-negative. If the return
14233 value is based on the assumption that signed overflow is undefined,
14234 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14235 *STRICT_OVERFLOW_P. */
14238 tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14240 enum tree_code code = TREE_CODE (t);
14241 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14248 tree temp = TARGET_EXPR_SLOT (t);
14249 t = TARGET_EXPR_INITIAL (t);
14251 /* If the initializer is non-void, then it's a normal expression
14252 that will be assigned to the slot. */
14253 if (!VOID_TYPE_P (t))
14254 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
14256 /* Otherwise, the initializer sets the slot in some way. One common
14257 way is an assignment statement at the end of the initializer. */
14260 if (TREE_CODE (t) == BIND_EXPR)
14261 t = expr_last (BIND_EXPR_BODY (t));
14262 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
14263 || TREE_CODE (t) == TRY_CATCH_EXPR)
14264 t = expr_last (TREE_OPERAND (t, 0));
14265 else if (TREE_CODE (t) == STATEMENT_LIST)
14270 if ((TREE_CODE (t) == MODIFY_EXPR
14271 || TREE_CODE (t) == GIMPLE_MODIFY_STMT)
14272 && GENERIC_TREE_OPERAND (t, 0) == temp)
14273 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14274 strict_overflow_p);
14281 tree arg0 = call_expr_nargs (t) > 0 ? CALL_EXPR_ARG (t, 0) : NULL_TREE;
14282 tree arg1 = call_expr_nargs (t) > 1 ? CALL_EXPR_ARG (t, 1) : NULL_TREE;
14284 return tree_call_nonnegative_warnv_p (TREE_CODE (t),
14286 get_callee_fndecl (t),
14289 strict_overflow_p);
14291 case COMPOUND_EXPR:
14293 case GIMPLE_MODIFY_STMT:
14294 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14295 strict_overflow_p);
14297 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
14298 strict_overflow_p);
14300 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14301 strict_overflow_p);
14304 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14308 /* We don't know sign of `t', so be conservative and return false. */
14312 /* Return true if T is known to be non-negative. If the return
14313 value is based on the assumption that signed overflow is undefined,
14314 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14315 *STRICT_OVERFLOW_P. */
14318 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14320 enum tree_code code;
14321 if (t == error_mark_node)
14324 code = TREE_CODE (t);
14325 switch (TREE_CODE_CLASS (code))
14328 case tcc_comparison:
14329 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14331 TREE_OPERAND (t, 0),
14332 TREE_OPERAND (t, 1),
14333 strict_overflow_p);
14336 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14338 TREE_OPERAND (t, 0),
14339 strict_overflow_p);
14342 case tcc_declaration:
14343 case tcc_reference:
14344 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14352 case TRUTH_AND_EXPR:
14353 case TRUTH_OR_EXPR:
14354 case TRUTH_XOR_EXPR:
14355 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14357 TREE_OPERAND (t, 0),
14358 TREE_OPERAND (t, 1),
14359 strict_overflow_p);
14360 case TRUTH_NOT_EXPR:
14361 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14363 TREE_OPERAND (t, 0),
14364 strict_overflow_p);
14371 case WITH_SIZE_EXPR:
14375 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14378 return tree_invalid_nonnegative_warnv_p (t, strict_overflow_p);
14382 /* Return true if `t' is known to be non-negative. Handle warnings
14383 about undefined signed overflow. */
14386 tree_expr_nonnegative_p (tree t)
14388 bool ret, strict_overflow_p;
14390 strict_overflow_p = false;
14391 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
14392 if (strict_overflow_p)
14393 fold_overflow_warning (("assuming signed overflow does not occur when "
14394 "determining that expression is always "
14396 WARN_STRICT_OVERFLOW_MISC);
14401 /* Return true when (CODE OP0) is an address and is known to be nonzero.
14402 For floating point we further ensure that T is not denormal.
14403 Similar logic is present in nonzero_address in rtlanal.h.
14405 If the return value is based on the assumption that signed overflow
14406 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14407 change *STRICT_OVERFLOW_P. */
14410 tree_unary_nonzero_warnv_p (enum tree_code code, tree type, tree op0,
14411 bool *strict_overflow_p)
14416 return tree_expr_nonzero_warnv_p (op0,
14417 strict_overflow_p);
14421 tree inner_type = TREE_TYPE (op0);
14422 tree outer_type = type;
14424 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
14425 && tree_expr_nonzero_warnv_p (op0,
14426 strict_overflow_p));
14430 case NON_LVALUE_EXPR:
14431 return tree_expr_nonzero_warnv_p (op0,
14432 strict_overflow_p);
14441 /* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
14442 For floating point we further ensure that T is not denormal.
14443 Similar logic is present in nonzero_address in rtlanal.h.
14445 If the return value is based on the assumption that signed overflow
14446 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14447 change *STRICT_OVERFLOW_P. */
14450 tree_binary_nonzero_warnv_p (enum tree_code code,
14453 tree op1, bool *strict_overflow_p)
14455 bool sub_strict_overflow_p;
14458 case POINTER_PLUS_EXPR:
14460 if (TYPE_OVERFLOW_UNDEFINED (type))
14462 /* With the presence of negative values it is hard
14463 to say something. */
14464 sub_strict_overflow_p = false;
14465 if (!tree_expr_nonnegative_warnv_p (op0,
14466 &sub_strict_overflow_p)
14467 || !tree_expr_nonnegative_warnv_p (op1,
14468 &sub_strict_overflow_p))
14470 /* One of operands must be positive and the other non-negative. */
14471 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14472 overflows, on a twos-complement machine the sum of two
14473 nonnegative numbers can never be zero. */
14474 return (tree_expr_nonzero_warnv_p (op0,
14476 || tree_expr_nonzero_warnv_p (op1,
14477 strict_overflow_p));
14482 if (TYPE_OVERFLOW_UNDEFINED (type))
14484 if (tree_expr_nonzero_warnv_p (op0,
14486 && tree_expr_nonzero_warnv_p (op1,
14487 strict_overflow_p))
14489 *strict_overflow_p = true;
14496 sub_strict_overflow_p = false;
14497 if (tree_expr_nonzero_warnv_p (op0,
14498 &sub_strict_overflow_p)
14499 && tree_expr_nonzero_warnv_p (op1,
14500 &sub_strict_overflow_p))
14502 if (sub_strict_overflow_p)
14503 *strict_overflow_p = true;
14508 sub_strict_overflow_p = false;
14509 if (tree_expr_nonzero_warnv_p (op0,
14510 &sub_strict_overflow_p))
14512 if (sub_strict_overflow_p)
14513 *strict_overflow_p = true;
14515 /* When both operands are nonzero, then MAX must be too. */
14516 if (tree_expr_nonzero_warnv_p (op1,
14517 strict_overflow_p))
14520 /* MAX where operand 0 is positive is positive. */
14521 return tree_expr_nonnegative_warnv_p (op0,
14522 strict_overflow_p);
14524 /* MAX where operand 1 is positive is positive. */
14525 else if (tree_expr_nonzero_warnv_p (op1,
14526 &sub_strict_overflow_p)
14527 && tree_expr_nonnegative_warnv_p (op1,
14528 &sub_strict_overflow_p))
14530 if (sub_strict_overflow_p)
14531 *strict_overflow_p = true;
14537 return (tree_expr_nonzero_warnv_p (op1,
14539 || tree_expr_nonzero_warnv_p (op0,
14540 strict_overflow_p));
14549 /* Return true when T is an address and is known to be nonzero.
14550 For floating point we further ensure that T is not denormal.
14551 Similar logic is present in nonzero_address in rtlanal.h.
14553 If the return value is based on the assumption that signed overflow
14554 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14555 change *STRICT_OVERFLOW_P. */
14558 tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14560 bool sub_strict_overflow_p;
14561 switch (TREE_CODE (t))
14564 /* Query VRP to see if it has recorded any information about
14565 the range of this object. */
14566 return ssa_name_nonzero_p (t);
14569 return !integer_zerop (t);
14573 tree base = get_base_address (TREE_OPERAND (t, 0));
14578 /* Weak declarations may link to NULL. */
14579 if (VAR_OR_FUNCTION_DECL_P (base))
14580 return !DECL_WEAK (base);
14582 /* Constants are never weak. */
14583 if (CONSTANT_CLASS_P (base))
14590 sub_strict_overflow_p = false;
14591 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14592 &sub_strict_overflow_p)
14593 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
14594 &sub_strict_overflow_p))
14596 if (sub_strict_overflow_p)
14597 *strict_overflow_p = true;
14608 /* Return true when T is an address and is known to be nonzero.
14609 For floating point we further ensure that T is not denormal.
14610 Similar logic is present in nonzero_address in rtlanal.h.
14612 If the return value is based on the assumption that signed overflow
14613 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14614 change *STRICT_OVERFLOW_P. */
14617 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14619 tree type = TREE_TYPE (t);
14620 enum tree_code code;
14622 /* Doing something useful for floating point would need more work. */
14623 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
14626 code = TREE_CODE (t);
14627 switch (TREE_CODE_CLASS (code))
14630 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
14631 strict_overflow_p);
14633 case tcc_comparison:
14634 return tree_binary_nonzero_warnv_p (code, type,
14635 TREE_OPERAND (t, 0),
14636 TREE_OPERAND (t, 1),
14637 strict_overflow_p);
14639 case tcc_declaration:
14640 case tcc_reference:
14641 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
14649 case TRUTH_NOT_EXPR:
14650 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
14651 strict_overflow_p);
14653 case TRUTH_AND_EXPR:
14654 case TRUTH_OR_EXPR:
14655 case TRUTH_XOR_EXPR:
14656 return tree_binary_nonzero_warnv_p (code, type,
14657 TREE_OPERAND (t, 0),
14658 TREE_OPERAND (t, 1),
14659 strict_overflow_p);
14666 case WITH_SIZE_EXPR:
14670 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
14672 case COMPOUND_EXPR:
14674 case GIMPLE_MODIFY_STMT:
14676 return tree_expr_nonzero_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14677 strict_overflow_p);
14680 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14681 strict_overflow_p);
14684 return alloca_call_p (t);
14692 /* Return true when T is an address and is known to be nonzero.
14693 Handle warnings about undefined signed overflow. */
14696 tree_expr_nonzero_p (tree t)
14698 bool ret, strict_overflow_p;
14700 strict_overflow_p = false;
14701 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
14702 if (strict_overflow_p)
14703 fold_overflow_warning (("assuming signed overflow does not occur when "
14704 "determining that expression is always "
14706 WARN_STRICT_OVERFLOW_MISC);
14710 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
14711 attempt to fold the expression to a constant without modifying TYPE,
14714 If the expression could be simplified to a constant, then return
14715 the constant. If the expression would not be simplified to a
14716 constant, then return NULL_TREE. */
14719 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
14721 tree tem = fold_binary (code, type, op0, op1);
14722 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14725 /* Given the components of a unary expression CODE, TYPE and OP0,
14726 attempt to fold the expression to a constant without modifying
14729 If the expression could be simplified to a constant, then return
14730 the constant. If the expression would not be simplified to a
14731 constant, then return NULL_TREE. */
14734 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
14736 tree tem = fold_unary (code, type, op0);
14737 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14740 /* If EXP represents referencing an element in a constant string
14741 (either via pointer arithmetic or array indexing), return the
14742 tree representing the value accessed, otherwise return NULL. */
14745 fold_read_from_constant_string (tree exp)
14747 if ((TREE_CODE (exp) == INDIRECT_REF
14748 || TREE_CODE (exp) == ARRAY_REF)
14749 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
14751 tree exp1 = TREE_OPERAND (exp, 0);
14755 if (TREE_CODE (exp) == INDIRECT_REF)
14756 string = string_constant (exp1, &index);
14759 tree low_bound = array_ref_low_bound (exp);
14760 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
14762 /* Optimize the special-case of a zero lower bound.
14764 We convert the low_bound to sizetype to avoid some problems
14765 with constant folding. (E.g. suppose the lower bound is 1,
14766 and its mode is QI. Without the conversion,l (ARRAY
14767 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
14768 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
14769 if (! integer_zerop (low_bound))
14770 index = size_diffop (index, fold_convert (sizetype, low_bound));
14776 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
14777 && TREE_CODE (string) == STRING_CST
14778 && TREE_CODE (index) == INTEGER_CST
14779 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
14780 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
14782 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
14783 return build_int_cst_type (TREE_TYPE (exp),
14784 (TREE_STRING_POINTER (string)
14785 [TREE_INT_CST_LOW (index)]));
14790 /* Return the tree for neg (ARG0) when ARG0 is known to be either
14791 an integer constant, real, or fixed-point constant.
14793 TYPE is the type of the result. */
14796 fold_negate_const (tree arg0, tree type)
14798 tree t = NULL_TREE;
14800 switch (TREE_CODE (arg0))
14804 unsigned HOST_WIDE_INT low;
14805 HOST_WIDE_INT high;
14806 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14807 TREE_INT_CST_HIGH (arg0),
14809 t = force_fit_type_double (type, low, high, 1,
14810 (overflow | TREE_OVERFLOW (arg0))
14811 && !TYPE_UNSIGNED (type));
14816 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14821 FIXED_VALUE_TYPE f;
14822 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
14823 &(TREE_FIXED_CST (arg0)), NULL,
14824 TYPE_SATURATING (type));
14825 t = build_fixed (type, f);
14826 /* Propagate overflow flags. */
14827 if (overflow_p | TREE_OVERFLOW (arg0))
14829 TREE_OVERFLOW (t) = 1;
14830 TREE_CONSTANT_OVERFLOW (t) = 1;
14832 else if (TREE_CONSTANT_OVERFLOW (arg0))
14833 TREE_CONSTANT_OVERFLOW (t) = 1;
14838 gcc_unreachable ();
14844 /* Return the tree for abs (ARG0) when ARG0 is known to be either
14845 an integer constant or real constant.
14847 TYPE is the type of the result. */
14850 fold_abs_const (tree arg0, tree type)
14852 tree t = NULL_TREE;
14854 switch (TREE_CODE (arg0))
14857 /* If the value is unsigned, then the absolute value is
14858 the same as the ordinary value. */
14859 if (TYPE_UNSIGNED (type))
14861 /* Similarly, if the value is non-negative. */
14862 else if (INT_CST_LT (integer_minus_one_node, arg0))
14864 /* If the value is negative, then the absolute value is
14868 unsigned HOST_WIDE_INT low;
14869 HOST_WIDE_INT high;
14870 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14871 TREE_INT_CST_HIGH (arg0),
14873 t = force_fit_type_double (type, low, high, -1,
14874 overflow | TREE_OVERFLOW (arg0));
14879 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
14880 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14886 gcc_unreachable ();
14892 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
14893 constant. TYPE is the type of the result. */
14896 fold_not_const (tree arg0, tree type)
14898 tree t = NULL_TREE;
14900 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
14902 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
14903 ~TREE_INT_CST_HIGH (arg0), 0,
14904 TREE_OVERFLOW (arg0));
14909 /* Given CODE, a relational operator, the target type, TYPE and two
14910 constant operands OP0 and OP1, return the result of the
14911 relational operation. If the result is not a compile time
14912 constant, then return NULL_TREE. */
14915 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
14917 int result, invert;
14919 /* From here on, the only cases we handle are when the result is
14920 known to be a constant. */
14922 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
14924 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
14925 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
14927 /* Handle the cases where either operand is a NaN. */
14928 if (real_isnan (c0) || real_isnan (c1))
14938 case UNORDERED_EXPR:
14952 if (flag_trapping_math)
14958 gcc_unreachable ();
14961 return constant_boolean_node (result, type);
14964 return constant_boolean_node (real_compare (code, c0, c1), type);
14967 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
14969 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
14970 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
14971 return constant_boolean_node (fixed_compare (code, c0, c1), type);
14974 /* Handle equality/inequality of complex constants. */
14975 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
14977 tree rcond = fold_relational_const (code, type,
14978 TREE_REALPART (op0),
14979 TREE_REALPART (op1));
14980 tree icond = fold_relational_const (code, type,
14981 TREE_IMAGPART (op0),
14982 TREE_IMAGPART (op1));
14983 if (code == EQ_EXPR)
14984 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
14985 else if (code == NE_EXPR)
14986 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
14991 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14993 To compute GT, swap the arguments and do LT.
14994 To compute GE, do LT and invert the result.
14995 To compute LE, swap the arguments, do LT and invert the result.
14996 To compute NE, do EQ and invert the result.
14998 Therefore, the code below must handle only EQ and LT. */
15000 if (code == LE_EXPR || code == GT_EXPR)
15005 code = swap_tree_comparison (code);
15008 /* Note that it is safe to invert for real values here because we
15009 have already handled the one case that it matters. */
15012 if (code == NE_EXPR || code == GE_EXPR)
15015 code = invert_tree_comparison (code, false);
15018 /* Compute a result for LT or EQ if args permit;
15019 Otherwise return T. */
15020 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
15022 if (code == EQ_EXPR)
15023 result = tree_int_cst_equal (op0, op1);
15024 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
15025 result = INT_CST_LT_UNSIGNED (op0, op1);
15027 result = INT_CST_LT (op0, op1);
15034 return constant_boolean_node (result, type);
15037 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
15038 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
15042 fold_build_cleanup_point_expr (tree type, tree expr)
15044 /* If the expression does not have side effects then we don't have to wrap
15045 it with a cleanup point expression. */
15046 if (!TREE_SIDE_EFFECTS (expr))
15049 /* If the expression is a return, check to see if the expression inside the
15050 return has no side effects or the right hand side of the modify expression
15051 inside the return. If either don't have side effects set we don't need to
15052 wrap the expression in a cleanup point expression. Note we don't check the
15053 left hand side of the modify because it should always be a return decl. */
15054 if (TREE_CODE (expr) == RETURN_EXPR)
15056 tree op = TREE_OPERAND (expr, 0);
15057 if (!op || !TREE_SIDE_EFFECTS (op))
15059 op = TREE_OPERAND (op, 1);
15060 if (!TREE_SIDE_EFFECTS (op))
15064 return build1 (CLEANUP_POINT_EXPR, type, expr);
15067 /* Given a pointer value OP0 and a type TYPE, return a simplified version
15068 of an indirection through OP0, or NULL_TREE if no simplification is
15072 fold_indirect_ref_1 (tree type, tree op0)
15078 subtype = TREE_TYPE (sub);
15079 if (!POINTER_TYPE_P (subtype))
15082 if (TREE_CODE (sub) == ADDR_EXPR)
15084 tree op = TREE_OPERAND (sub, 0);
15085 tree optype = TREE_TYPE (op);
15086 /* *&CONST_DECL -> to the value of the const decl. */
15087 if (TREE_CODE (op) == CONST_DECL)
15088 return DECL_INITIAL (op);
15089 /* *&p => p; make sure to handle *&"str"[cst] here. */
15090 if (type == optype)
15092 tree fop = fold_read_from_constant_string (op);
15098 /* *(foo *)&fooarray => fooarray[0] */
15099 else if (TREE_CODE (optype) == ARRAY_TYPE
15100 && type == TREE_TYPE (optype))
15102 tree type_domain = TYPE_DOMAIN (optype);
15103 tree min_val = size_zero_node;
15104 if (type_domain && TYPE_MIN_VALUE (type_domain))
15105 min_val = TYPE_MIN_VALUE (type_domain);
15106 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
15108 /* *(foo *)&complexfoo => __real__ complexfoo */
15109 else if (TREE_CODE (optype) == COMPLEX_TYPE
15110 && type == TREE_TYPE (optype))
15111 return fold_build1 (REALPART_EXPR, type, op);
15112 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
15113 else if (TREE_CODE (optype) == VECTOR_TYPE
15114 && type == TREE_TYPE (optype))
15116 tree part_width = TYPE_SIZE (type);
15117 tree index = bitsize_int (0);
15118 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
15122 /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
15123 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15124 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15126 tree op00 = TREE_OPERAND (sub, 0);
15127 tree op01 = TREE_OPERAND (sub, 1);
15131 op00type = TREE_TYPE (op00);
15132 if (TREE_CODE (op00) == ADDR_EXPR
15133 && TREE_CODE (TREE_TYPE (op00type)) == VECTOR_TYPE
15134 && type == TREE_TYPE (TREE_TYPE (op00type)))
15136 HOST_WIDE_INT offset = tree_low_cst (op01, 0);
15137 tree part_width = TYPE_SIZE (type);
15138 unsigned HOST_WIDE_INT part_widthi = tree_low_cst (part_width, 0)/BITS_PER_UNIT;
15139 unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
15140 tree index = bitsize_int (indexi);
15142 if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (op00type)))
15143 return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (op00, 0),
15144 part_width, index);
15150 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
15151 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15152 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15154 tree op00 = TREE_OPERAND (sub, 0);
15155 tree op01 = TREE_OPERAND (sub, 1);
15159 op00type = TREE_TYPE (op00);
15160 if (TREE_CODE (op00) == ADDR_EXPR
15161 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
15162 && type == TREE_TYPE (TREE_TYPE (op00type)))
15164 tree size = TYPE_SIZE_UNIT (type);
15165 if (tree_int_cst_equal (size, op01))
15166 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
15170 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
15171 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
15172 && type == TREE_TYPE (TREE_TYPE (subtype)))
15175 tree min_val = size_zero_node;
15176 sub = build_fold_indirect_ref (sub);
15177 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
15178 if (type_domain && TYPE_MIN_VALUE (type_domain))
15179 min_val = TYPE_MIN_VALUE (type_domain);
15180 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
15186 /* Builds an expression for an indirection through T, simplifying some
15190 build_fold_indirect_ref (tree t)
15192 tree type = TREE_TYPE (TREE_TYPE (t));
15193 tree sub = fold_indirect_ref_1 (type, t);
15198 return build1 (INDIRECT_REF, type, t);
15201 /* Given an INDIRECT_REF T, return either T or a simplified version. */
15204 fold_indirect_ref (tree t)
15206 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
15214 /* Strip non-trapping, non-side-effecting tree nodes from an expression
15215 whose result is ignored. The type of the returned tree need not be
15216 the same as the original expression. */
15219 fold_ignored_result (tree t)
15221 if (!TREE_SIDE_EFFECTS (t))
15222 return integer_zero_node;
15225 switch (TREE_CODE_CLASS (TREE_CODE (t)))
15228 t = TREE_OPERAND (t, 0);
15232 case tcc_comparison:
15233 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15234 t = TREE_OPERAND (t, 0);
15235 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
15236 t = TREE_OPERAND (t, 1);
15241 case tcc_expression:
15242 switch (TREE_CODE (t))
15244 case COMPOUND_EXPR:
15245 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15247 t = TREE_OPERAND (t, 0);
15251 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
15252 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
15254 t = TREE_OPERAND (t, 0);
15267 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
15268 This can only be applied to objects of a sizetype. */
15271 round_up (tree value, int divisor)
15273 tree div = NULL_TREE;
15275 gcc_assert (divisor > 0);
15279 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15280 have to do anything. Only do this when we are not given a const,
15281 because in that case, this check is more expensive than just
15283 if (TREE_CODE (value) != INTEGER_CST)
15285 div = build_int_cst (TREE_TYPE (value), divisor);
15287 if (multiple_of_p (TREE_TYPE (value), value, div))
15291 /* If divisor is a power of two, simplify this to bit manipulation. */
15292 if (divisor == (divisor & -divisor))
15294 if (TREE_CODE (value) == INTEGER_CST)
15296 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
15297 unsigned HOST_WIDE_INT high;
15300 if ((low & (divisor - 1)) == 0)
15303 overflow_p = TREE_OVERFLOW (value);
15304 high = TREE_INT_CST_HIGH (value);
15305 low &= ~(divisor - 1);
15314 return force_fit_type_double (TREE_TYPE (value), low, high,
15321 t = build_int_cst (TREE_TYPE (value), divisor - 1);
15322 value = size_binop (PLUS_EXPR, value, t);
15323 t = build_int_cst (TREE_TYPE (value), -divisor);
15324 value = size_binop (BIT_AND_EXPR, value, t);
15330 div = build_int_cst (TREE_TYPE (value), divisor);
15331 value = size_binop (CEIL_DIV_EXPR, value, div);
15332 value = size_binop (MULT_EXPR, value, div);
15338 /* Likewise, but round down. */
15341 round_down (tree value, int divisor)
15343 tree div = NULL_TREE;
15345 gcc_assert (divisor > 0);
15349 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15350 have to do anything. Only do this when we are not given a const,
15351 because in that case, this check is more expensive than just
15353 if (TREE_CODE (value) != INTEGER_CST)
15355 div = build_int_cst (TREE_TYPE (value), divisor);
15357 if (multiple_of_p (TREE_TYPE (value), value, div))
15361 /* If divisor is a power of two, simplify this to bit manipulation. */
15362 if (divisor == (divisor & -divisor))
15366 t = build_int_cst (TREE_TYPE (value), -divisor);
15367 value = size_binop (BIT_AND_EXPR, value, t);
15372 div = build_int_cst (TREE_TYPE (value), divisor);
15373 value = size_binop (FLOOR_DIV_EXPR, value, div);
15374 value = size_binop (MULT_EXPR, value, div);
15380 /* Returns the pointer to the base of the object addressed by EXP and
15381 extracts the information about the offset of the access, storing it
15382 to PBITPOS and POFFSET. */
15385 split_address_to_core_and_offset (tree exp,
15386 HOST_WIDE_INT *pbitpos, tree *poffset)
15389 enum machine_mode mode;
15390 int unsignedp, volatilep;
15391 HOST_WIDE_INT bitsize;
15393 if (TREE_CODE (exp) == ADDR_EXPR)
15395 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
15396 poffset, &mode, &unsignedp, &volatilep,
15398 core = fold_addr_expr (core);
15404 *poffset = NULL_TREE;
15410 /* Returns true if addresses of E1 and E2 differ by a constant, false
15411 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15414 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
15417 HOST_WIDE_INT bitpos1, bitpos2;
15418 tree toffset1, toffset2, tdiff, type;
15420 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
15421 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
15423 if (bitpos1 % BITS_PER_UNIT != 0
15424 || bitpos2 % BITS_PER_UNIT != 0
15425 || !operand_equal_p (core1, core2, 0))
15428 if (toffset1 && toffset2)
15430 type = TREE_TYPE (toffset1);
15431 if (type != TREE_TYPE (toffset2))
15432 toffset2 = fold_convert (type, toffset2);
15434 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
15435 if (!cst_and_fits_in_hwi (tdiff))
15438 *diff = int_cst_value (tdiff);
15440 else if (toffset1 || toffset2)
15442 /* If only one of the offsets is non-constant, the difference cannot
15449 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
15453 /* Simplify the floating point expression EXP when the sign of the
15454 result is not significant. Return NULL_TREE if no simplification
15458 fold_strip_sign_ops (tree exp)
15462 switch (TREE_CODE (exp))
15466 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15467 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
15471 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
15473 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15474 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15475 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
15476 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
15477 arg0 ? arg0 : TREE_OPERAND (exp, 0),
15478 arg1 ? arg1 : TREE_OPERAND (exp, 1));
15481 case COMPOUND_EXPR:
15482 arg0 = TREE_OPERAND (exp, 0);
15483 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15485 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
15489 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15490 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
15492 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
15493 arg0 ? arg0 : TREE_OPERAND (exp, 1),
15494 arg1 ? arg1 : TREE_OPERAND (exp, 2));
15499 const enum built_in_function fcode = builtin_mathfn_code (exp);
15502 CASE_FLT_FN (BUILT_IN_COPYSIGN):
15503 /* Strip copysign function call, return the 1st argument. */
15504 arg0 = CALL_EXPR_ARG (exp, 0);
15505 arg1 = CALL_EXPR_ARG (exp, 1);
15506 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
15509 /* Strip sign ops from the argument of "odd" math functions. */
15510 if (negate_mathfn_p (fcode))
15512 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
15514 return build_call_expr (get_callee_fndecl (exp), 1, arg0);