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
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 gcc_assert (!flag_wrapv && !flag_trapv);
1016 if (fold_deferring_overflow_warnings > 0)
1018 if (fold_deferred_overflow_warning == NULL
1019 || wc < fold_deferred_overflow_code)
1021 fold_deferred_overflow_warning = gmsgid;
1022 fold_deferred_overflow_code = wc;
1025 else if (issue_strict_overflow_warning (wc))
1026 warning (OPT_Wstrict_overflow, gmsgid);
1029 /* Return true if the built-in mathematical function specified by CODE
1030 is odd, i.e. -f(x) == f(-x). */
1033 negate_mathfn_p (enum built_in_function code)
1037 CASE_FLT_FN (BUILT_IN_ASIN):
1038 CASE_FLT_FN (BUILT_IN_ASINH):
1039 CASE_FLT_FN (BUILT_IN_ATAN):
1040 CASE_FLT_FN (BUILT_IN_ATANH):
1041 CASE_FLT_FN (BUILT_IN_CASIN):
1042 CASE_FLT_FN (BUILT_IN_CASINH):
1043 CASE_FLT_FN (BUILT_IN_CATAN):
1044 CASE_FLT_FN (BUILT_IN_CATANH):
1045 CASE_FLT_FN (BUILT_IN_CBRT):
1046 CASE_FLT_FN (BUILT_IN_CPROJ):
1047 CASE_FLT_FN (BUILT_IN_CSIN):
1048 CASE_FLT_FN (BUILT_IN_CSINH):
1049 CASE_FLT_FN (BUILT_IN_CTAN):
1050 CASE_FLT_FN (BUILT_IN_CTANH):
1051 CASE_FLT_FN (BUILT_IN_ERF):
1052 CASE_FLT_FN (BUILT_IN_LLROUND):
1053 CASE_FLT_FN (BUILT_IN_LROUND):
1054 CASE_FLT_FN (BUILT_IN_ROUND):
1055 CASE_FLT_FN (BUILT_IN_SIN):
1056 CASE_FLT_FN (BUILT_IN_SINH):
1057 CASE_FLT_FN (BUILT_IN_TAN):
1058 CASE_FLT_FN (BUILT_IN_TANH):
1059 CASE_FLT_FN (BUILT_IN_TRUNC):
1062 CASE_FLT_FN (BUILT_IN_LLRINT):
1063 CASE_FLT_FN (BUILT_IN_LRINT):
1064 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1065 CASE_FLT_FN (BUILT_IN_RINT):
1066 return !flag_rounding_math;
1074 /* Check whether we may negate an integer constant T without causing
1078 may_negate_without_overflow_p (const_tree t)
1080 unsigned HOST_WIDE_INT val;
1084 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1086 type = TREE_TYPE (t);
1087 if (TYPE_UNSIGNED (type))
1090 prec = TYPE_PRECISION (type);
1091 if (prec > HOST_BITS_PER_WIDE_INT)
1093 if (TREE_INT_CST_LOW (t) != 0)
1095 prec -= HOST_BITS_PER_WIDE_INT;
1096 val = TREE_INT_CST_HIGH (t);
1099 val = TREE_INT_CST_LOW (t);
1100 if (prec < HOST_BITS_PER_WIDE_INT)
1101 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1102 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1105 /* Determine whether an expression T can be cheaply negated using
1106 the function negate_expr without introducing undefined overflow. */
1109 negate_expr_p (tree t)
1116 type = TREE_TYPE (t);
1118 STRIP_SIGN_NOPS (t);
1119 switch (TREE_CODE (t))
1122 if (TYPE_OVERFLOW_WRAPS (type))
1125 /* Check that -CST will not overflow type. */
1126 return may_negate_without_overflow_p (t);
1128 return (INTEGRAL_TYPE_P (type)
1129 && TYPE_OVERFLOW_WRAPS (type));
1137 return negate_expr_p (TREE_REALPART (t))
1138 && negate_expr_p (TREE_IMAGPART (t));
1141 return negate_expr_p (TREE_OPERAND (t, 0))
1142 && negate_expr_p (TREE_OPERAND (t, 1));
1145 return negate_expr_p (TREE_OPERAND (t, 0));
1148 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1149 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1151 /* -(A + B) -> (-B) - A. */
1152 if (negate_expr_p (TREE_OPERAND (t, 1))
1153 && reorder_operands_p (TREE_OPERAND (t, 0),
1154 TREE_OPERAND (t, 1)))
1156 /* -(A + B) -> (-A) - B. */
1157 return negate_expr_p (TREE_OPERAND (t, 0));
1160 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1161 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1162 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1163 && reorder_operands_p (TREE_OPERAND (t, 0),
1164 TREE_OPERAND (t, 1));
1167 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1173 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1174 return negate_expr_p (TREE_OPERAND (t, 1))
1175 || negate_expr_p (TREE_OPERAND (t, 0));
1178 case TRUNC_DIV_EXPR:
1179 case ROUND_DIV_EXPR:
1180 case FLOOR_DIV_EXPR:
1182 case EXACT_DIV_EXPR:
1183 /* In general we can't negate A / B, because if A is INT_MIN and
1184 B is 1, we may turn this into INT_MIN / -1 which is undefined
1185 and actually traps on some architectures. But if overflow is
1186 undefined, we can negate, because - (INT_MIN / 1) is an
1188 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1189 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1191 return negate_expr_p (TREE_OPERAND (t, 1))
1192 || negate_expr_p (TREE_OPERAND (t, 0));
1195 /* Negate -((double)float) as (double)(-float). */
1196 if (TREE_CODE (type) == REAL_TYPE)
1198 tree tem = strip_float_extensions (t);
1200 return negate_expr_p (tem);
1205 /* Negate -f(x) as f(-x). */
1206 if (negate_mathfn_p (builtin_mathfn_code (t)))
1207 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1211 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1212 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1214 tree op1 = TREE_OPERAND (t, 1);
1215 if (TREE_INT_CST_HIGH (op1) == 0
1216 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1217 == TREE_INT_CST_LOW (op1))
1228 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1229 simplification is possible.
1230 If negate_expr_p would return true for T, NULL_TREE will never be
1234 fold_negate_expr (tree t)
1236 tree type = TREE_TYPE (t);
1239 switch (TREE_CODE (t))
1241 /* Convert - (~A) to A + 1. */
1243 if (INTEGRAL_TYPE_P (type))
1244 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1245 build_int_cst (type, 1));
1249 tem = fold_negate_const (t, type);
1250 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1251 || !TYPE_OVERFLOW_TRAPS (type))
1256 tem = fold_negate_const (t, type);
1257 /* Two's complement FP formats, such as c4x, may overflow. */
1258 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1263 tem = fold_negate_const (t, type);
1268 tree rpart = negate_expr (TREE_REALPART (t));
1269 tree ipart = negate_expr (TREE_IMAGPART (t));
1271 if ((TREE_CODE (rpart) == REAL_CST
1272 && TREE_CODE (ipart) == REAL_CST)
1273 || (TREE_CODE (rpart) == INTEGER_CST
1274 && TREE_CODE (ipart) == INTEGER_CST))
1275 return build_complex (type, rpart, ipart);
1280 if (negate_expr_p (t))
1281 return fold_build2 (COMPLEX_EXPR, type,
1282 fold_negate_expr (TREE_OPERAND (t, 0)),
1283 fold_negate_expr (TREE_OPERAND (t, 1)));
1287 if (negate_expr_p (t))
1288 return fold_build1 (CONJ_EXPR, type,
1289 fold_negate_expr (TREE_OPERAND (t, 0)));
1293 return TREE_OPERAND (t, 0);
1296 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1297 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1299 /* -(A + B) -> (-B) - A. */
1300 if (negate_expr_p (TREE_OPERAND (t, 1))
1301 && reorder_operands_p (TREE_OPERAND (t, 0),
1302 TREE_OPERAND (t, 1)))
1304 tem = negate_expr (TREE_OPERAND (t, 1));
1305 return fold_build2 (MINUS_EXPR, type,
1306 tem, TREE_OPERAND (t, 0));
1309 /* -(A + B) -> (-A) - B. */
1310 if (negate_expr_p (TREE_OPERAND (t, 0)))
1312 tem = negate_expr (TREE_OPERAND (t, 0));
1313 return fold_build2 (MINUS_EXPR, type,
1314 tem, TREE_OPERAND (t, 1));
1320 /* - (A - B) -> B - A */
1321 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1322 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1323 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1324 return fold_build2 (MINUS_EXPR, type,
1325 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1329 if (TYPE_UNSIGNED (type))
1335 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1337 tem = TREE_OPERAND (t, 1);
1338 if (negate_expr_p (tem))
1339 return fold_build2 (TREE_CODE (t), type,
1340 TREE_OPERAND (t, 0), negate_expr (tem));
1341 tem = TREE_OPERAND (t, 0);
1342 if (negate_expr_p (tem))
1343 return fold_build2 (TREE_CODE (t), type,
1344 negate_expr (tem), TREE_OPERAND (t, 1));
1348 case TRUNC_DIV_EXPR:
1349 case ROUND_DIV_EXPR:
1350 case FLOOR_DIV_EXPR:
1352 case EXACT_DIV_EXPR:
1353 /* In general we can't negate A / B, because if A is INT_MIN and
1354 B is 1, we may turn this into INT_MIN / -1 which is undefined
1355 and actually traps on some architectures. But if overflow is
1356 undefined, we can negate, because - (INT_MIN / 1) is an
1358 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1360 const char * const warnmsg = G_("assuming signed overflow does not "
1361 "occur when negating a division");
1362 tem = TREE_OPERAND (t, 1);
1363 if (negate_expr_p (tem))
1365 if (INTEGRAL_TYPE_P (type)
1366 && (TREE_CODE (tem) != INTEGER_CST
1367 || integer_onep (tem)))
1368 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1369 return fold_build2 (TREE_CODE (t), type,
1370 TREE_OPERAND (t, 0), negate_expr (tem));
1372 tem = TREE_OPERAND (t, 0);
1373 if (negate_expr_p (tem))
1375 if (INTEGRAL_TYPE_P (type)
1376 && (TREE_CODE (tem) != INTEGER_CST
1377 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1378 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1379 return fold_build2 (TREE_CODE (t), type,
1380 negate_expr (tem), TREE_OPERAND (t, 1));
1386 /* Convert -((double)float) into (double)(-float). */
1387 if (TREE_CODE (type) == REAL_TYPE)
1389 tem = strip_float_extensions (t);
1390 if (tem != t && negate_expr_p (tem))
1391 return fold_convert (type, negate_expr (tem));
1396 /* Negate -f(x) as f(-x). */
1397 if (negate_mathfn_p (builtin_mathfn_code (t))
1398 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1402 fndecl = get_callee_fndecl (t);
1403 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1404 return build_call_expr (fndecl, 1, arg);
1409 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1410 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1412 tree op1 = TREE_OPERAND (t, 1);
1413 if (TREE_INT_CST_HIGH (op1) == 0
1414 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1415 == TREE_INT_CST_LOW (op1))
1417 tree ntype = TYPE_UNSIGNED (type)
1418 ? signed_type_for (type)
1419 : unsigned_type_for (type);
1420 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1421 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1422 return fold_convert (type, temp);
1434 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1435 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1436 return NULL_TREE. */
1439 negate_expr (tree t)
1446 type = TREE_TYPE (t);
1447 STRIP_SIGN_NOPS (t);
1449 tem = fold_negate_expr (t);
1451 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1452 return fold_convert (type, tem);
1455 /* Split a tree IN into a constant, literal and variable parts that could be
1456 combined with CODE to make IN. "constant" means an expression with
1457 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1458 commutative arithmetic operation. Store the constant part into *CONP,
1459 the literal in *LITP and return the variable part. If a part isn't
1460 present, set it to null. If the tree does not decompose in this way,
1461 return the entire tree as the variable part and the other parts as null.
1463 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1464 case, we negate an operand that was subtracted. Except if it is a
1465 literal for which we use *MINUS_LITP instead.
1467 If NEGATE_P is true, we are negating all of IN, again except a literal
1468 for which we use *MINUS_LITP instead.
1470 If IN is itself a literal or constant, return it as appropriate.
1472 Note that we do not guarantee that any of the three values will be the
1473 same type as IN, but they will have the same signedness and mode. */
1476 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1477 tree *minus_litp, int negate_p)
1485 /* Strip any conversions that don't change the machine mode or signedness. */
1486 STRIP_SIGN_NOPS (in);
1488 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
1489 || TREE_CODE (in) == FIXED_CST)
1491 else if (TREE_CODE (in) == code
1492 || ((! FLOAT_TYPE_P (TREE_TYPE (in)) || flag_associative_math)
1493 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
1494 /* We can associate addition and subtraction together (even
1495 though the C standard doesn't say so) for integers because
1496 the value is not affected. For reals, the value might be
1497 affected, so we can't. */
1498 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1499 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1501 tree op0 = TREE_OPERAND (in, 0);
1502 tree op1 = TREE_OPERAND (in, 1);
1503 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1504 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1506 /* First see if either of the operands is a literal, then a constant. */
1507 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
1508 || TREE_CODE (op0) == FIXED_CST)
1509 *litp = op0, op0 = 0;
1510 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
1511 || TREE_CODE (op1) == FIXED_CST)
1512 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1514 if (op0 != 0 && TREE_CONSTANT (op0))
1515 *conp = op0, op0 = 0;
1516 else if (op1 != 0 && TREE_CONSTANT (op1))
1517 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1519 /* If we haven't dealt with either operand, this is not a case we can
1520 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1521 if (op0 != 0 && op1 != 0)
1526 var = op1, neg_var_p = neg1_p;
1528 /* Now do any needed negations. */
1530 *minus_litp = *litp, *litp = 0;
1532 *conp = negate_expr (*conp);
1534 var = negate_expr (var);
1536 else if (TREE_CONSTANT (in))
1544 *minus_litp = *litp, *litp = 0;
1545 else if (*minus_litp)
1546 *litp = *minus_litp, *minus_litp = 0;
1547 *conp = negate_expr (*conp);
1548 var = negate_expr (var);
1554 /* Re-associate trees split by the above function. T1 and T2 are either
1555 expressions to associate or null. Return the new expression, if any. If
1556 we build an operation, do it in TYPE and with CODE. */
1559 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1566 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1567 try to fold this since we will have infinite recursion. But do
1568 deal with any NEGATE_EXPRs. */
1569 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1570 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1572 if (code == PLUS_EXPR)
1574 if (TREE_CODE (t1) == NEGATE_EXPR)
1575 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1576 fold_convert (type, TREE_OPERAND (t1, 0)));
1577 else if (TREE_CODE (t2) == NEGATE_EXPR)
1578 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1579 fold_convert (type, TREE_OPERAND (t2, 0)));
1580 else if (integer_zerop (t2))
1581 return fold_convert (type, t1);
1583 else if (code == MINUS_EXPR)
1585 if (integer_zerop (t2))
1586 return fold_convert (type, t1);
1589 return build2 (code, type, fold_convert (type, t1),
1590 fold_convert (type, t2));
1593 return fold_build2 (code, type, fold_convert (type, t1),
1594 fold_convert (type, t2));
1597 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1598 for use in int_const_binop, size_binop and size_diffop. */
1601 int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
1603 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1605 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1620 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1621 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1622 && TYPE_MODE (type1) == TYPE_MODE (type2);
1626 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1627 to produce a new constant. Return NULL_TREE if we don't know how
1628 to evaluate CODE at compile-time.
1630 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1633 int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2, int notrunc)
1635 unsigned HOST_WIDE_INT int1l, int2l;
1636 HOST_WIDE_INT int1h, int2h;
1637 unsigned HOST_WIDE_INT low;
1639 unsigned HOST_WIDE_INT garbagel;
1640 HOST_WIDE_INT garbageh;
1642 tree type = TREE_TYPE (arg1);
1643 int uns = TYPE_UNSIGNED (type);
1645 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1648 int1l = TREE_INT_CST_LOW (arg1);
1649 int1h = TREE_INT_CST_HIGH (arg1);
1650 int2l = TREE_INT_CST_LOW (arg2);
1651 int2h = TREE_INT_CST_HIGH (arg2);
1656 low = int1l | int2l, hi = int1h | int2h;
1660 low = int1l ^ int2l, hi = int1h ^ int2h;
1664 low = int1l & int2l, hi = int1h & int2h;
1670 /* It's unclear from the C standard whether shifts can overflow.
1671 The following code ignores overflow; perhaps a C standard
1672 interpretation ruling is needed. */
1673 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1680 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1685 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1689 neg_double (int2l, int2h, &low, &hi);
1690 add_double (int1l, int1h, low, hi, &low, &hi);
1691 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1695 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1698 case TRUNC_DIV_EXPR:
1699 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1700 case EXACT_DIV_EXPR:
1701 /* This is a shortcut for a common special case. */
1702 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1703 && !TREE_OVERFLOW (arg1)
1704 && !TREE_OVERFLOW (arg2)
1705 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1707 if (code == CEIL_DIV_EXPR)
1710 low = int1l / int2l, hi = 0;
1714 /* ... fall through ... */
1716 case ROUND_DIV_EXPR:
1717 if (int2h == 0 && int2l == 0)
1719 if (int2h == 0 && int2l == 1)
1721 low = int1l, hi = int1h;
1724 if (int1l == int2l && int1h == int2h
1725 && ! (int1l == 0 && int1h == 0))
1730 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1731 &low, &hi, &garbagel, &garbageh);
1734 case TRUNC_MOD_EXPR:
1735 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1736 /* This is a shortcut for a common special case. */
1737 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1738 && !TREE_OVERFLOW (arg1)
1739 && !TREE_OVERFLOW (arg2)
1740 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1742 if (code == CEIL_MOD_EXPR)
1744 low = int1l % int2l, hi = 0;
1748 /* ... fall through ... */
1750 case ROUND_MOD_EXPR:
1751 if (int2h == 0 && int2l == 0)
1753 overflow = div_and_round_double (code, uns,
1754 int1l, int1h, int2l, int2h,
1755 &garbagel, &garbageh, &low, &hi);
1761 low = (((unsigned HOST_WIDE_INT) int1h
1762 < (unsigned HOST_WIDE_INT) int2h)
1763 || (((unsigned HOST_WIDE_INT) int1h
1764 == (unsigned HOST_WIDE_INT) int2h)
1767 low = (int1h < int2h
1768 || (int1h == int2h && int1l < int2l));
1770 if (low == (code == MIN_EXPR))
1771 low = int1l, hi = int1h;
1773 low = int2l, hi = int2h;
1782 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1784 /* Propagate overflow flags ourselves. */
1785 if (((!uns || is_sizetype) && overflow)
1786 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1789 TREE_OVERFLOW (t) = 1;
1793 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1794 ((!uns || is_sizetype) && overflow)
1795 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1800 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1801 constant. We assume ARG1 and ARG2 have the same data type, or at least
1802 are the same kind of constant and the same machine mode. Return zero if
1803 combining the constants is not allowed in the current operating mode.
1805 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1808 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1810 /* Sanity check for the recursive cases. */
1817 if (TREE_CODE (arg1) == INTEGER_CST)
1818 return int_const_binop (code, arg1, arg2, notrunc);
1820 if (TREE_CODE (arg1) == REAL_CST)
1822 enum machine_mode mode;
1825 REAL_VALUE_TYPE value;
1826 REAL_VALUE_TYPE result;
1830 /* The following codes are handled by real_arithmetic. */
1845 d1 = TREE_REAL_CST (arg1);
1846 d2 = TREE_REAL_CST (arg2);
1848 type = TREE_TYPE (arg1);
1849 mode = TYPE_MODE (type);
1851 /* Don't perform operation if we honor signaling NaNs and
1852 either operand is a NaN. */
1853 if (HONOR_SNANS (mode)
1854 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1857 /* Don't perform operation if it would raise a division
1858 by zero exception. */
1859 if (code == RDIV_EXPR
1860 && REAL_VALUES_EQUAL (d2, dconst0)
1861 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1864 /* If either operand is a NaN, just return it. Otherwise, set up
1865 for floating-point trap; we return an overflow. */
1866 if (REAL_VALUE_ISNAN (d1))
1868 else if (REAL_VALUE_ISNAN (d2))
1871 inexact = real_arithmetic (&value, code, &d1, &d2);
1872 real_convert (&result, mode, &value);
1874 /* Don't constant fold this floating point operation if
1875 the result has overflowed and flag_trapping_math. */
1876 if (flag_trapping_math
1877 && MODE_HAS_INFINITIES (mode)
1878 && REAL_VALUE_ISINF (result)
1879 && !REAL_VALUE_ISINF (d1)
1880 && !REAL_VALUE_ISINF (d2))
1883 /* Don't constant fold this floating point operation if the
1884 result may dependent upon the run-time rounding mode and
1885 flag_rounding_math is set, or if GCC's software emulation
1886 is unable to accurately represent the result. */
1887 if ((flag_rounding_math
1888 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1889 && !flag_unsafe_math_optimizations))
1890 && (inexact || !real_identical (&result, &value)))
1893 t = build_real (type, result);
1895 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1899 if (TREE_CODE (arg1) == FIXED_CST)
1901 FIXED_VALUE_TYPE f1;
1902 FIXED_VALUE_TYPE f2;
1903 FIXED_VALUE_TYPE result;
1908 /* The following codes are handled by fixed_arithmetic. */
1914 case TRUNC_DIV_EXPR:
1915 f2 = TREE_FIXED_CST (arg2);
1920 f2.data.high = TREE_INT_CST_HIGH (arg2);
1921 f2.data.low = TREE_INT_CST_LOW (arg2);
1929 f1 = TREE_FIXED_CST (arg1);
1930 type = TREE_TYPE (arg1);
1931 sat_p = TYPE_SATURATING (type);
1932 overflow_p = fixed_arithmetic (&result, code, &f1, &f2, sat_p);
1933 t = build_fixed (type, result);
1934 /* Propagate overflow flags. */
1935 if (overflow_p | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1937 TREE_OVERFLOW (t) = 1;
1938 TREE_CONSTANT_OVERFLOW (t) = 1;
1940 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1941 TREE_CONSTANT_OVERFLOW (t) = 1;
1945 if (TREE_CODE (arg1) == COMPLEX_CST)
1947 tree type = TREE_TYPE (arg1);
1948 tree r1 = TREE_REALPART (arg1);
1949 tree i1 = TREE_IMAGPART (arg1);
1950 tree r2 = TREE_REALPART (arg2);
1951 tree i2 = TREE_IMAGPART (arg2);
1958 real = const_binop (code, r1, r2, notrunc);
1959 imag = const_binop (code, i1, i2, notrunc);
1963 real = const_binop (MINUS_EXPR,
1964 const_binop (MULT_EXPR, r1, r2, notrunc),
1965 const_binop (MULT_EXPR, i1, i2, notrunc),
1967 imag = const_binop (PLUS_EXPR,
1968 const_binop (MULT_EXPR, r1, i2, notrunc),
1969 const_binop (MULT_EXPR, i1, r2, notrunc),
1976 = const_binop (PLUS_EXPR,
1977 const_binop (MULT_EXPR, r2, r2, notrunc),
1978 const_binop (MULT_EXPR, i2, i2, notrunc),
1981 = const_binop (PLUS_EXPR,
1982 const_binop (MULT_EXPR, r1, r2, notrunc),
1983 const_binop (MULT_EXPR, i1, i2, notrunc),
1986 = const_binop (MINUS_EXPR,
1987 const_binop (MULT_EXPR, i1, r2, notrunc),
1988 const_binop (MULT_EXPR, r1, i2, notrunc),
1991 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1992 code = TRUNC_DIV_EXPR;
1994 real = const_binop (code, t1, magsquared, notrunc);
1995 imag = const_binop (code, t2, magsquared, notrunc);
2004 return build_complex (type, real, imag);
2010 /* Create a size type INT_CST node with NUMBER sign extended. KIND
2011 indicates which particular sizetype to create. */
2014 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
2016 return build_int_cst (sizetype_tab[(int) kind], number);
2019 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2020 is a tree code. The type of the result is taken from the operands.
2021 Both must be equivalent integer types, ala int_binop_types_match_p.
2022 If the operands are constant, so is the result. */
2025 size_binop (enum tree_code code, tree arg0, tree arg1)
2027 tree type = TREE_TYPE (arg0);
2029 if (arg0 == error_mark_node || arg1 == error_mark_node)
2030 return error_mark_node;
2032 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
2035 /* Handle the special case of two integer constants faster. */
2036 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
2038 /* And some specific cases even faster than that. */
2039 if (code == PLUS_EXPR)
2041 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
2043 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2046 else if (code == MINUS_EXPR)
2048 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2051 else if (code == MULT_EXPR)
2053 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
2057 /* Handle general case of two integer constants. */
2058 return int_const_binop (code, arg0, arg1, 0);
2061 return fold_build2 (code, type, arg0, arg1);
2064 /* Given two values, either both of sizetype or both of bitsizetype,
2065 compute the difference between the two values. Return the value
2066 in signed type corresponding to the type of the operands. */
2069 size_diffop (tree arg0, tree arg1)
2071 tree type = TREE_TYPE (arg0);
2074 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
2077 /* If the type is already signed, just do the simple thing. */
2078 if (!TYPE_UNSIGNED (type))
2079 return size_binop (MINUS_EXPR, arg0, arg1);
2081 if (type == sizetype)
2083 else if (type == bitsizetype)
2084 ctype = sbitsizetype;
2086 ctype = signed_type_for (type);
2088 /* If either operand is not a constant, do the conversions to the signed
2089 type and subtract. The hardware will do the right thing with any
2090 overflow in the subtraction. */
2091 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2092 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
2093 fold_convert (ctype, arg1));
2095 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2096 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2097 overflow) and negate (which can't either). Special-case a result
2098 of zero while we're here. */
2099 if (tree_int_cst_equal (arg0, arg1))
2100 return build_int_cst (ctype, 0);
2101 else if (tree_int_cst_lt (arg1, arg0))
2102 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2104 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
2105 fold_convert (ctype, size_binop (MINUS_EXPR,
2109 /* A subroutine of fold_convert_const handling conversions of an
2110 INTEGER_CST to another integer type. */
2113 fold_convert_const_int_from_int (tree type, const_tree arg1)
2117 /* Given an integer constant, make new constant with new type,
2118 appropriately sign-extended or truncated. */
2119 t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
2120 TREE_INT_CST_HIGH (arg1),
2121 /* Don't set the overflow when
2122 converting from a pointer, */
2123 !POINTER_TYPE_P (TREE_TYPE (arg1))
2124 /* or to a sizetype with same signedness
2125 and the precision is unchanged.
2126 ??? sizetype is always sign-extended,
2127 but its signedness depends on the
2128 frontend. Thus we see spurious overflows
2129 here if we do not check this. */
2130 && !((TYPE_PRECISION (TREE_TYPE (arg1))
2131 == TYPE_PRECISION (type))
2132 && (TYPE_UNSIGNED (TREE_TYPE (arg1))
2133 == TYPE_UNSIGNED (type))
2134 && ((TREE_CODE (TREE_TYPE (arg1)) == INTEGER_TYPE
2135 && TYPE_IS_SIZETYPE (TREE_TYPE (arg1)))
2136 || (TREE_CODE (type) == INTEGER_TYPE
2137 && TYPE_IS_SIZETYPE (type)))),
2138 (TREE_INT_CST_HIGH (arg1) < 0
2139 && (TYPE_UNSIGNED (type)
2140 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2141 | TREE_OVERFLOW (arg1));
2146 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2147 to an integer type. */
2150 fold_convert_const_int_from_real (enum tree_code code, tree type, const_tree arg1)
2155 /* The following code implements the floating point to integer
2156 conversion rules required by the Java Language Specification,
2157 that IEEE NaNs are mapped to zero and values that overflow
2158 the target precision saturate, i.e. values greater than
2159 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2160 are mapped to INT_MIN. These semantics are allowed by the
2161 C and C++ standards that simply state that the behavior of
2162 FP-to-integer conversion is unspecified upon overflow. */
2164 HOST_WIDE_INT high, low;
2166 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2170 case FIX_TRUNC_EXPR:
2171 real_trunc (&r, VOIDmode, &x);
2178 /* If R is NaN, return zero and show we have an overflow. */
2179 if (REAL_VALUE_ISNAN (r))
2186 /* See if R is less than the lower bound or greater than the
2191 tree lt = TYPE_MIN_VALUE (type);
2192 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2193 if (REAL_VALUES_LESS (r, l))
2196 high = TREE_INT_CST_HIGH (lt);
2197 low = TREE_INT_CST_LOW (lt);
2203 tree ut = TYPE_MAX_VALUE (type);
2206 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2207 if (REAL_VALUES_LESS (u, r))
2210 high = TREE_INT_CST_HIGH (ut);
2211 low = TREE_INT_CST_LOW (ut);
2217 REAL_VALUE_TO_INT (&low, &high, r);
2219 t = force_fit_type_double (type, low, high, -1,
2220 overflow | TREE_OVERFLOW (arg1));
2224 /* A subroutine of fold_convert_const handling conversions of a
2225 FIXED_CST to an integer type. */
2228 fold_convert_const_int_from_fixed (tree type, const_tree arg1)
2231 double_int temp, temp_trunc;
2234 /* Right shift FIXED_CST to temp by fbit. */
2235 temp = TREE_FIXED_CST (arg1).data;
2236 mode = TREE_FIXED_CST (arg1).mode;
2237 if (GET_MODE_FBIT (mode) < 2 * HOST_BITS_PER_WIDE_INT)
2239 lshift_double (temp.low, temp.high,
2240 - GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2241 &temp.low, &temp.high, SIGNED_FIXED_POINT_MODE_P (mode));
2243 /* Left shift temp to temp_trunc by fbit. */
2244 lshift_double (temp.low, temp.high,
2245 GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2246 &temp_trunc.low, &temp_trunc.high,
2247 SIGNED_FIXED_POINT_MODE_P (mode));
2254 temp_trunc.high = 0;
2257 /* If FIXED_CST is negative, we need to round the value toward 0.
2258 By checking if the fractional bits are not zero to add 1 to temp. */
2259 if (SIGNED_FIXED_POINT_MODE_P (mode) && temp_trunc.high < 0
2260 && !double_int_equal_p (TREE_FIXED_CST (arg1).data, temp_trunc))
2265 temp = double_int_add (temp, one);
2268 /* Given a fixed-point constant, make new constant with new type,
2269 appropriately sign-extended or truncated. */
2270 t = force_fit_type_double (type, temp.low, temp.high, -1,
2272 && (TYPE_UNSIGNED (type)
2273 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2274 | TREE_OVERFLOW (arg1));
2279 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2280 to another floating point type. */
2283 fold_convert_const_real_from_real (tree type, const_tree arg1)
2285 REAL_VALUE_TYPE value;
2288 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2289 t = build_real (type, value);
2291 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2295 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2296 to a floating point type. */
2299 fold_convert_const_real_from_fixed (tree type, const_tree arg1)
2301 REAL_VALUE_TYPE value;
2304 real_convert_from_fixed (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1));
2305 t = build_real (type, value);
2307 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2308 TREE_CONSTANT_OVERFLOW (t)
2309 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2313 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2314 to another fixed-point type. */
2317 fold_convert_const_fixed_from_fixed (tree type, const_tree arg1)
2319 FIXED_VALUE_TYPE value;
2323 overflow_p = fixed_convert (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1),
2324 TYPE_SATURATING (type));
2325 t = build_fixed (type, value);
2327 /* Propagate overflow flags. */
2328 if (overflow_p | TREE_OVERFLOW (arg1))
2330 TREE_OVERFLOW (t) = 1;
2331 TREE_CONSTANT_OVERFLOW (t) = 1;
2333 else if (TREE_CONSTANT_OVERFLOW (arg1))
2334 TREE_CONSTANT_OVERFLOW (t) = 1;
2338 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2339 to a fixed-point type. */
2342 fold_convert_const_fixed_from_int (tree type, const_tree arg1)
2344 FIXED_VALUE_TYPE value;
2348 overflow_p = fixed_convert_from_int (&value, TYPE_MODE (type),
2349 TREE_INT_CST (arg1),
2350 TYPE_UNSIGNED (TREE_TYPE (arg1)),
2351 TYPE_SATURATING (type));
2352 t = build_fixed (type, value);
2354 /* Propagate overflow flags. */
2355 if (overflow_p | TREE_OVERFLOW (arg1))
2357 TREE_OVERFLOW (t) = 1;
2358 TREE_CONSTANT_OVERFLOW (t) = 1;
2360 else if (TREE_CONSTANT_OVERFLOW (arg1))
2361 TREE_CONSTANT_OVERFLOW (t) = 1;
2365 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2366 to a fixed-point type. */
2369 fold_convert_const_fixed_from_real (tree type, const_tree arg1)
2371 FIXED_VALUE_TYPE value;
2375 overflow_p = fixed_convert_from_real (&value, TYPE_MODE (type),
2376 &TREE_REAL_CST (arg1),
2377 TYPE_SATURATING (type));
2378 t = build_fixed (type, value);
2380 /* Propagate overflow flags. */
2381 if (overflow_p | TREE_OVERFLOW (arg1))
2383 TREE_OVERFLOW (t) = 1;
2384 TREE_CONSTANT_OVERFLOW (t) = 1;
2386 else if (TREE_CONSTANT_OVERFLOW (arg1))
2387 TREE_CONSTANT_OVERFLOW (t) = 1;
2391 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2392 type TYPE. If no simplification can be done return NULL_TREE. */
2395 fold_convert_const (enum tree_code code, tree type, tree arg1)
2397 if (TREE_TYPE (arg1) == type)
2400 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2402 if (TREE_CODE (arg1) == INTEGER_CST)
2403 return fold_convert_const_int_from_int (type, arg1);
2404 else if (TREE_CODE (arg1) == REAL_CST)
2405 return fold_convert_const_int_from_real (code, type, arg1);
2406 else if (TREE_CODE (arg1) == FIXED_CST)
2407 return fold_convert_const_int_from_fixed (type, arg1);
2409 else if (TREE_CODE (type) == REAL_TYPE)
2411 if (TREE_CODE (arg1) == INTEGER_CST)
2412 return build_real_from_int_cst (type, arg1);
2413 else if (TREE_CODE (arg1) == REAL_CST)
2414 return fold_convert_const_real_from_real (type, arg1);
2415 else if (TREE_CODE (arg1) == FIXED_CST)
2416 return fold_convert_const_real_from_fixed (type, arg1);
2418 else if (TREE_CODE (type) == FIXED_POINT_TYPE)
2420 if (TREE_CODE (arg1) == FIXED_CST)
2421 return fold_convert_const_fixed_from_fixed (type, arg1);
2422 else if (TREE_CODE (arg1) == INTEGER_CST)
2423 return fold_convert_const_fixed_from_int (type, arg1);
2424 else if (TREE_CODE (arg1) == REAL_CST)
2425 return fold_convert_const_fixed_from_real (type, arg1);
2430 /* Construct a vector of zero elements of vector type TYPE. */
2433 build_zero_vector (tree type)
2438 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2439 units = TYPE_VECTOR_SUBPARTS (type);
2442 for (i = 0; i < units; i++)
2443 list = tree_cons (NULL_TREE, elem, list);
2444 return build_vector (type, list);
2447 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2450 fold_convertible_p (const_tree type, const_tree arg)
2452 tree orig = TREE_TYPE (arg);
2457 if (TREE_CODE (arg) == ERROR_MARK
2458 || TREE_CODE (type) == ERROR_MARK
2459 || TREE_CODE (orig) == ERROR_MARK)
2462 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2465 switch (TREE_CODE (type))
2467 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2468 case POINTER_TYPE: case REFERENCE_TYPE:
2470 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2471 || TREE_CODE (orig) == OFFSET_TYPE)
2473 return (TREE_CODE (orig) == VECTOR_TYPE
2474 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2477 case FIXED_POINT_TYPE:
2481 return TREE_CODE (type) == TREE_CODE (orig);
2488 /* Convert expression ARG to type TYPE. Used by the middle-end for
2489 simple conversions in preference to calling the front-end's convert. */
2492 fold_convert (tree type, tree arg)
2494 tree orig = TREE_TYPE (arg);
2500 if (TREE_CODE (arg) == ERROR_MARK
2501 || TREE_CODE (type) == ERROR_MARK
2502 || TREE_CODE (orig) == ERROR_MARK)
2503 return error_mark_node;
2505 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2506 return fold_build1 (NOP_EXPR, type, arg);
2508 switch (TREE_CODE (type))
2510 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2511 case POINTER_TYPE: case REFERENCE_TYPE:
2513 if (TREE_CODE (arg) == INTEGER_CST)
2515 tem = fold_convert_const (NOP_EXPR, type, arg);
2516 if (tem != NULL_TREE)
2519 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2520 || TREE_CODE (orig) == OFFSET_TYPE)
2521 return fold_build1 (NOP_EXPR, type, arg);
2522 if (TREE_CODE (orig) == COMPLEX_TYPE)
2524 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2525 return fold_convert (type, tem);
2527 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2528 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2529 return fold_build1 (NOP_EXPR, type, arg);
2532 if (TREE_CODE (arg) == INTEGER_CST)
2534 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2535 if (tem != NULL_TREE)
2538 else if (TREE_CODE (arg) == REAL_CST)
2540 tem = fold_convert_const (NOP_EXPR, type, arg);
2541 if (tem != NULL_TREE)
2544 else if (TREE_CODE (arg) == FIXED_CST)
2546 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2547 if (tem != NULL_TREE)
2551 switch (TREE_CODE (orig))
2554 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2555 case POINTER_TYPE: case REFERENCE_TYPE:
2556 return fold_build1 (FLOAT_EXPR, type, arg);
2559 return fold_build1 (NOP_EXPR, type, arg);
2561 case FIXED_POINT_TYPE:
2562 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2565 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2566 return fold_convert (type, tem);
2572 case FIXED_POINT_TYPE:
2573 if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
2574 || TREE_CODE (arg) == REAL_CST)
2576 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2577 if (tem != NULL_TREE)
2581 switch (TREE_CODE (orig))
2583 case FIXED_POINT_TYPE:
2588 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2591 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2592 return fold_convert (type, tem);
2599 switch (TREE_CODE (orig))
2602 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2603 case POINTER_TYPE: case REFERENCE_TYPE:
2605 case FIXED_POINT_TYPE:
2606 return build2 (COMPLEX_EXPR, type,
2607 fold_convert (TREE_TYPE (type), arg),
2608 fold_convert (TREE_TYPE (type), integer_zero_node));
2613 if (TREE_CODE (arg) == COMPLEX_EXPR)
2615 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2616 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2617 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2620 arg = save_expr (arg);
2621 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2622 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2623 rpart = fold_convert (TREE_TYPE (type), rpart);
2624 ipart = fold_convert (TREE_TYPE (type), ipart);
2625 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2633 if (integer_zerop (arg))
2634 return build_zero_vector (type);
2635 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2636 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2637 || TREE_CODE (orig) == VECTOR_TYPE);
2638 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2641 tem = fold_ignored_result (arg);
2642 if (TREE_CODE (tem) == GIMPLE_MODIFY_STMT)
2644 return fold_build1 (NOP_EXPR, type, tem);
2651 /* Return false if expr can be assumed not to be an lvalue, true
2655 maybe_lvalue_p (const_tree x)
2657 /* We only need to wrap lvalue tree codes. */
2658 switch (TREE_CODE (x))
2669 case ALIGN_INDIRECT_REF:
2670 case MISALIGNED_INDIRECT_REF:
2672 case ARRAY_RANGE_REF:
2678 case PREINCREMENT_EXPR:
2679 case PREDECREMENT_EXPR:
2681 case TRY_CATCH_EXPR:
2682 case WITH_CLEANUP_EXPR:
2685 case GIMPLE_MODIFY_STMT:
2694 /* Assume the worst for front-end tree codes. */
2695 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2703 /* Return an expr equal to X but certainly not valid as an lvalue. */
2708 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2713 if (! maybe_lvalue_p (x))
2715 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2718 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2719 Zero means allow extended lvalues. */
2721 int pedantic_lvalues;
2723 /* When pedantic, return an expr equal to X but certainly not valid as a
2724 pedantic lvalue. Otherwise, return X. */
2727 pedantic_non_lvalue (tree x)
2729 if (pedantic_lvalues)
2730 return non_lvalue (x);
2735 /* Given a tree comparison code, return the code that is the logical inverse
2736 of the given code. It is not safe to do this for floating-point
2737 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2738 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2741 invert_tree_comparison (enum tree_code code, bool honor_nans)
2743 if (honor_nans && flag_trapping_math)
2753 return honor_nans ? UNLE_EXPR : LE_EXPR;
2755 return honor_nans ? UNLT_EXPR : LT_EXPR;
2757 return honor_nans ? UNGE_EXPR : GE_EXPR;
2759 return honor_nans ? UNGT_EXPR : GT_EXPR;
2773 return UNORDERED_EXPR;
2774 case UNORDERED_EXPR:
2775 return ORDERED_EXPR;
2781 /* Similar, but return the comparison that results if the operands are
2782 swapped. This is safe for floating-point. */
2785 swap_tree_comparison (enum tree_code code)
2792 case UNORDERED_EXPR:
2818 /* Convert a comparison tree code from an enum tree_code representation
2819 into a compcode bit-based encoding. This function is the inverse of
2820 compcode_to_comparison. */
2822 static enum comparison_code
2823 comparison_to_compcode (enum tree_code code)
2840 return COMPCODE_ORD;
2841 case UNORDERED_EXPR:
2842 return COMPCODE_UNORD;
2844 return COMPCODE_UNLT;
2846 return COMPCODE_UNEQ;
2848 return COMPCODE_UNLE;
2850 return COMPCODE_UNGT;
2852 return COMPCODE_LTGT;
2854 return COMPCODE_UNGE;
2860 /* Convert a compcode bit-based encoding of a comparison operator back
2861 to GCC's enum tree_code representation. This function is the
2862 inverse of comparison_to_compcode. */
2864 static enum tree_code
2865 compcode_to_comparison (enum comparison_code code)
2882 return ORDERED_EXPR;
2883 case COMPCODE_UNORD:
2884 return UNORDERED_EXPR;
2902 /* Return a tree for the comparison which is the combination of
2903 doing the AND or OR (depending on CODE) of the two operations LCODE
2904 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2905 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2906 if this makes the transformation invalid. */
2909 combine_comparisons (enum tree_code code, enum tree_code lcode,
2910 enum tree_code rcode, tree truth_type,
2911 tree ll_arg, tree lr_arg)
2913 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2914 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2915 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2916 enum comparison_code compcode;
2920 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2921 compcode = lcompcode & rcompcode;
2924 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2925 compcode = lcompcode | rcompcode;
2934 /* Eliminate unordered comparisons, as well as LTGT and ORD
2935 which are not used unless the mode has NaNs. */
2936 compcode &= ~COMPCODE_UNORD;
2937 if (compcode == COMPCODE_LTGT)
2938 compcode = COMPCODE_NE;
2939 else if (compcode == COMPCODE_ORD)
2940 compcode = COMPCODE_TRUE;
2942 else if (flag_trapping_math)
2944 /* Check that the original operation and the optimized ones will trap
2945 under the same condition. */
2946 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2947 && (lcompcode != COMPCODE_EQ)
2948 && (lcompcode != COMPCODE_ORD);
2949 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2950 && (rcompcode != COMPCODE_EQ)
2951 && (rcompcode != COMPCODE_ORD);
2952 bool trap = (compcode & COMPCODE_UNORD) == 0
2953 && (compcode != COMPCODE_EQ)
2954 && (compcode != COMPCODE_ORD);
2956 /* In a short-circuited boolean expression the LHS might be
2957 such that the RHS, if evaluated, will never trap. For
2958 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2959 if neither x nor y is NaN. (This is a mixed blessing: for
2960 example, the expression above will never trap, hence
2961 optimizing it to x < y would be invalid). */
2962 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2963 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2966 /* If the comparison was short-circuited, and only the RHS
2967 trapped, we may now generate a spurious trap. */
2969 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2972 /* If we changed the conditions that cause a trap, we lose. */
2973 if ((ltrap || rtrap) != trap)
2977 if (compcode == COMPCODE_TRUE)
2978 return constant_boolean_node (true, truth_type);
2979 else if (compcode == COMPCODE_FALSE)
2980 return constant_boolean_node (false, truth_type);
2982 return fold_build2 (compcode_to_comparison (compcode),
2983 truth_type, ll_arg, lr_arg);
2986 /* Return nonzero if CODE is a tree code that represents a truth value. */
2989 truth_value_p (enum tree_code code)
2991 return (TREE_CODE_CLASS (code) == tcc_comparison
2992 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2993 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2994 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2997 /* Return nonzero if two operands (typically of the same tree node)
2998 are necessarily equal. If either argument has side-effects this
2999 function returns zero. FLAGS modifies behavior as follows:
3001 If OEP_ONLY_CONST is set, only return nonzero for constants.
3002 This function tests whether the operands are indistinguishable;
3003 it does not test whether they are equal using C's == operation.
3004 The distinction is important for IEEE floating point, because
3005 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
3006 (2) two NaNs may be indistinguishable, but NaN!=NaN.
3008 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
3009 even though it may hold multiple values during a function.
3010 This is because a GCC tree node guarantees that nothing else is
3011 executed between the evaluation of its "operands" (which may often
3012 be evaluated in arbitrary order). Hence if the operands themselves
3013 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
3014 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
3015 unset means assuming isochronic (or instantaneous) tree equivalence.
3016 Unless comparing arbitrary expression trees, such as from different
3017 statements, this flag can usually be left unset.
3019 If OEP_PURE_SAME is set, then pure functions with identical arguments
3020 are considered the same. It is used when the caller has other ways
3021 to ensure that global memory is unchanged in between. */
3024 operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
3026 /* If either is ERROR_MARK, they aren't equal. */
3027 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
3030 /* If both types don't have the same signedness, then we can't consider
3031 them equal. We must check this before the STRIP_NOPS calls
3032 because they may change the signedness of the arguments. */
3033 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3036 /* If both types don't have the same precision, then it is not safe
3038 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
3044 /* In case both args are comparisons but with different comparison
3045 code, try to swap the comparison operands of one arg to produce
3046 a match and compare that variant. */
3047 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3048 && COMPARISON_CLASS_P (arg0)
3049 && COMPARISON_CLASS_P (arg1))
3051 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
3053 if (TREE_CODE (arg0) == swap_code)
3054 return operand_equal_p (TREE_OPERAND (arg0, 0),
3055 TREE_OPERAND (arg1, 1), flags)
3056 && operand_equal_p (TREE_OPERAND (arg0, 1),
3057 TREE_OPERAND (arg1, 0), flags);
3060 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3061 /* This is needed for conversions and for COMPONENT_REF.
3062 Might as well play it safe and always test this. */
3063 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
3064 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
3065 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
3068 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3069 We don't care about side effects in that case because the SAVE_EXPR
3070 takes care of that for us. In all other cases, two expressions are
3071 equal if they have no side effects. If we have two identical
3072 expressions with side effects that should be treated the same due
3073 to the only side effects being identical SAVE_EXPR's, that will
3074 be detected in the recursive calls below. */
3075 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
3076 && (TREE_CODE (arg0) == SAVE_EXPR
3077 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
3080 /* Next handle constant cases, those for which we can return 1 even
3081 if ONLY_CONST is set. */
3082 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
3083 switch (TREE_CODE (arg0))
3086 return tree_int_cst_equal (arg0, arg1);
3089 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
3090 TREE_FIXED_CST (arg1));
3093 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
3094 TREE_REAL_CST (arg1)))
3098 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
3100 /* If we do not distinguish between signed and unsigned zero,
3101 consider them equal. */
3102 if (real_zerop (arg0) && real_zerop (arg1))
3111 v1 = TREE_VECTOR_CST_ELTS (arg0);
3112 v2 = TREE_VECTOR_CST_ELTS (arg1);
3115 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
3118 v1 = TREE_CHAIN (v1);
3119 v2 = TREE_CHAIN (v2);
3126 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
3128 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
3132 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
3133 && ! memcmp (TREE_STRING_POINTER (arg0),
3134 TREE_STRING_POINTER (arg1),
3135 TREE_STRING_LENGTH (arg0)));
3138 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
3144 if (flags & OEP_ONLY_CONST)
3147 /* Define macros to test an operand from arg0 and arg1 for equality and a
3148 variant that allows null and views null as being different from any
3149 non-null value. In the latter case, if either is null, the both
3150 must be; otherwise, do the normal comparison. */
3151 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3152 TREE_OPERAND (arg1, N), flags)
3154 #define OP_SAME_WITH_NULL(N) \
3155 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3156 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3158 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
3161 /* Two conversions are equal only if signedness and modes match. */
3162 switch (TREE_CODE (arg0))
3166 case FIX_TRUNC_EXPR:
3167 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
3168 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3178 case tcc_comparison:
3180 if (OP_SAME (0) && OP_SAME (1))
3183 /* For commutative ops, allow the other order. */
3184 return (commutative_tree_code (TREE_CODE (arg0))
3185 && operand_equal_p (TREE_OPERAND (arg0, 0),
3186 TREE_OPERAND (arg1, 1), flags)
3187 && operand_equal_p (TREE_OPERAND (arg0, 1),
3188 TREE_OPERAND (arg1, 0), flags));
3191 /* If either of the pointer (or reference) expressions we are
3192 dereferencing contain a side effect, these cannot be equal. */
3193 if (TREE_SIDE_EFFECTS (arg0)
3194 || TREE_SIDE_EFFECTS (arg1))
3197 switch (TREE_CODE (arg0))
3200 case ALIGN_INDIRECT_REF:
3201 case MISALIGNED_INDIRECT_REF:
3207 case ARRAY_RANGE_REF:
3208 /* Operands 2 and 3 may be null.
3209 Compare the array index by value if it is constant first as we
3210 may have different types but same value here. */
3212 && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
3213 TREE_OPERAND (arg1, 1))
3215 && OP_SAME_WITH_NULL (2)
3216 && OP_SAME_WITH_NULL (3));
3219 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3220 may be NULL when we're called to compare MEM_EXPRs. */
3221 return OP_SAME_WITH_NULL (0)
3223 && OP_SAME_WITH_NULL (2);
3226 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3232 case tcc_expression:
3233 switch (TREE_CODE (arg0))
3236 case TRUTH_NOT_EXPR:
3239 case TRUTH_ANDIF_EXPR:
3240 case TRUTH_ORIF_EXPR:
3241 return OP_SAME (0) && OP_SAME (1);
3243 case TRUTH_AND_EXPR:
3245 case TRUTH_XOR_EXPR:
3246 if (OP_SAME (0) && OP_SAME (1))
3249 /* Otherwise take into account this is a commutative operation. */
3250 return (operand_equal_p (TREE_OPERAND (arg0, 0),
3251 TREE_OPERAND (arg1, 1), flags)
3252 && operand_equal_p (TREE_OPERAND (arg0, 1),
3253 TREE_OPERAND (arg1, 0), flags));
3260 switch (TREE_CODE (arg0))
3263 /* If the CALL_EXPRs call different functions, then they
3264 clearly can not be equal. */
3265 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
3270 unsigned int cef = call_expr_flags (arg0);
3271 if (flags & OEP_PURE_SAME)
3272 cef &= ECF_CONST | ECF_PURE;
3279 /* Now see if all the arguments are the same. */
3281 const_call_expr_arg_iterator iter0, iter1;
3283 for (a0 = first_const_call_expr_arg (arg0, &iter0),
3284 a1 = first_const_call_expr_arg (arg1, &iter1);
3286 a0 = next_const_call_expr_arg (&iter0),
3287 a1 = next_const_call_expr_arg (&iter1))
3288 if (! operand_equal_p (a0, a1, flags))
3291 /* If we get here and both argument lists are exhausted
3292 then the CALL_EXPRs are equal. */
3293 return ! (a0 || a1);
3299 case tcc_declaration:
3300 /* Consider __builtin_sqrt equal to sqrt. */
3301 return (TREE_CODE (arg0) == FUNCTION_DECL
3302 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
3303 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
3304 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
3311 #undef OP_SAME_WITH_NULL
3314 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3315 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3317 When in doubt, return 0. */
3320 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
3322 int unsignedp1, unsignedpo;
3323 tree primarg0, primarg1, primother;
3324 unsigned int correct_width;
3326 if (operand_equal_p (arg0, arg1, 0))
3329 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3330 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3333 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3334 and see if the inner values are the same. This removes any
3335 signedness comparison, which doesn't matter here. */
3336 primarg0 = arg0, primarg1 = arg1;
3337 STRIP_NOPS (primarg0);
3338 STRIP_NOPS (primarg1);
3339 if (operand_equal_p (primarg0, primarg1, 0))
3342 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3343 actual comparison operand, ARG0.
3345 First throw away any conversions to wider types
3346 already present in the operands. */
3348 primarg1 = get_narrower (arg1, &unsignedp1);
3349 primother = get_narrower (other, &unsignedpo);
3351 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3352 if (unsignedp1 == unsignedpo
3353 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3354 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3356 tree type = TREE_TYPE (arg0);
3358 /* Make sure shorter operand is extended the right way
3359 to match the longer operand. */
3360 primarg1 = fold_convert (signed_or_unsigned_type_for
3361 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3363 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3370 /* See if ARG is an expression that is either a comparison or is performing
3371 arithmetic on comparisons. The comparisons must only be comparing
3372 two different values, which will be stored in *CVAL1 and *CVAL2; if
3373 they are nonzero it means that some operands have already been found.
3374 No variables may be used anywhere else in the expression except in the
3375 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3376 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3378 If this is true, return 1. Otherwise, return zero. */
3381 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3383 enum tree_code code = TREE_CODE (arg);
3384 enum tree_code_class class = TREE_CODE_CLASS (code);
3386 /* We can handle some of the tcc_expression cases here. */
3387 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3389 else if (class == tcc_expression
3390 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3391 || code == COMPOUND_EXPR))
3394 else if (class == tcc_expression && code == SAVE_EXPR
3395 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3397 /* If we've already found a CVAL1 or CVAL2, this expression is
3398 two complex to handle. */
3399 if (*cval1 || *cval2)
3409 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3412 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3413 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3414 cval1, cval2, save_p));
3419 case tcc_expression:
3420 if (code == COND_EXPR)
3421 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3422 cval1, cval2, save_p)
3423 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3424 cval1, cval2, save_p)
3425 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3426 cval1, cval2, save_p));
3429 case tcc_comparison:
3430 /* First see if we can handle the first operand, then the second. For
3431 the second operand, we know *CVAL1 can't be zero. It must be that
3432 one side of the comparison is each of the values; test for the
3433 case where this isn't true by failing if the two operands
3436 if (operand_equal_p (TREE_OPERAND (arg, 0),
3437 TREE_OPERAND (arg, 1), 0))
3441 *cval1 = TREE_OPERAND (arg, 0);
3442 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3444 else if (*cval2 == 0)
3445 *cval2 = TREE_OPERAND (arg, 0);
3446 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3451 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3453 else if (*cval2 == 0)
3454 *cval2 = TREE_OPERAND (arg, 1);
3455 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3467 /* ARG is a tree that is known to contain just arithmetic operations and
3468 comparisons. Evaluate the operations in the tree substituting NEW0 for
3469 any occurrence of OLD0 as an operand of a comparison and likewise for
3473 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3475 tree type = TREE_TYPE (arg);
3476 enum tree_code code = TREE_CODE (arg);
3477 enum tree_code_class class = TREE_CODE_CLASS (code);
3479 /* We can handle some of the tcc_expression cases here. */
3480 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3482 else if (class == tcc_expression
3483 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3489 return fold_build1 (code, type,
3490 eval_subst (TREE_OPERAND (arg, 0),
3491 old0, new0, old1, new1));
3494 return fold_build2 (code, type,
3495 eval_subst (TREE_OPERAND (arg, 0),
3496 old0, new0, old1, new1),
3497 eval_subst (TREE_OPERAND (arg, 1),
3498 old0, new0, old1, new1));
3500 case tcc_expression:
3504 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3507 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3510 return fold_build3 (code, type,
3511 eval_subst (TREE_OPERAND (arg, 0),
3512 old0, new0, old1, new1),
3513 eval_subst (TREE_OPERAND (arg, 1),
3514 old0, new0, old1, new1),
3515 eval_subst (TREE_OPERAND (arg, 2),
3516 old0, new0, old1, new1));
3520 /* Fall through - ??? */
3522 case tcc_comparison:
3524 tree arg0 = TREE_OPERAND (arg, 0);
3525 tree arg1 = TREE_OPERAND (arg, 1);
3527 /* We need to check both for exact equality and tree equality. The
3528 former will be true if the operand has a side-effect. In that
3529 case, we know the operand occurred exactly once. */
3531 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3533 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3536 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3538 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3541 return fold_build2 (code, type, arg0, arg1);
3549 /* Return a tree for the case when the result of an expression is RESULT
3550 converted to TYPE and OMITTED was previously an operand of the expression
3551 but is now not needed (e.g., we folded OMITTED * 0).
3553 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3554 the conversion of RESULT to TYPE. */
3557 omit_one_operand (tree type, tree result, tree omitted)
3559 tree t = fold_convert (type, result);
3561 /* If the resulting operand is an empty statement, just return the omitted
3562 statement casted to void. */
3563 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3564 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3566 if (TREE_SIDE_EFFECTS (omitted))
3567 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3569 return non_lvalue (t);
3572 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3575 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3577 tree t = fold_convert (type, result);
3579 /* If the resulting operand is an empty statement, just return the omitted
3580 statement casted to void. */
3581 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3582 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3584 if (TREE_SIDE_EFFECTS (omitted))
3585 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3587 return pedantic_non_lvalue (t);
3590 /* Return a tree for the case when the result of an expression is RESULT
3591 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3592 of the expression but are now not needed.
3594 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3595 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3596 evaluated before OMITTED2. Otherwise, if neither has side effects,
3597 just do the conversion of RESULT to TYPE. */
3600 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3602 tree t = fold_convert (type, result);
3604 if (TREE_SIDE_EFFECTS (omitted2))
3605 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3606 if (TREE_SIDE_EFFECTS (omitted1))
3607 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3609 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3613 /* Return a simplified tree node for the truth-negation of ARG. This
3614 never alters ARG itself. We assume that ARG is an operation that
3615 returns a truth value (0 or 1).
3617 FIXME: one would think we would fold the result, but it causes
3618 problems with the dominator optimizer. */
3621 fold_truth_not_expr (tree arg)
3623 tree type = TREE_TYPE (arg);
3624 enum tree_code code = TREE_CODE (arg);
3626 /* If this is a comparison, we can simply invert it, except for
3627 floating-point non-equality comparisons, in which case we just
3628 enclose a TRUTH_NOT_EXPR around what we have. */
3630 if (TREE_CODE_CLASS (code) == tcc_comparison)
3632 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3633 if (FLOAT_TYPE_P (op_type)
3634 && flag_trapping_math
3635 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3636 && code != NE_EXPR && code != EQ_EXPR)
3640 code = invert_tree_comparison (code,
3641 HONOR_NANS (TYPE_MODE (op_type)));
3642 if (code == ERROR_MARK)
3645 return build2 (code, type,
3646 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3653 return constant_boolean_node (integer_zerop (arg), type);
3655 case TRUTH_AND_EXPR:
3656 return build2 (TRUTH_OR_EXPR, type,
3657 invert_truthvalue (TREE_OPERAND (arg, 0)),
3658 invert_truthvalue (TREE_OPERAND (arg, 1)));
3661 return build2 (TRUTH_AND_EXPR, type,
3662 invert_truthvalue (TREE_OPERAND (arg, 0)),
3663 invert_truthvalue (TREE_OPERAND (arg, 1)));
3665 case TRUTH_XOR_EXPR:
3666 /* Here we can invert either operand. We invert the first operand
3667 unless the second operand is a TRUTH_NOT_EXPR in which case our
3668 result is the XOR of the first operand with the inside of the
3669 negation of the second operand. */
3671 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3672 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3673 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3675 return build2 (TRUTH_XOR_EXPR, type,
3676 invert_truthvalue (TREE_OPERAND (arg, 0)),
3677 TREE_OPERAND (arg, 1));
3679 case TRUTH_ANDIF_EXPR:
3680 return build2 (TRUTH_ORIF_EXPR, type,
3681 invert_truthvalue (TREE_OPERAND (arg, 0)),
3682 invert_truthvalue (TREE_OPERAND (arg, 1)));
3684 case TRUTH_ORIF_EXPR:
3685 return build2 (TRUTH_ANDIF_EXPR, type,
3686 invert_truthvalue (TREE_OPERAND (arg, 0)),
3687 invert_truthvalue (TREE_OPERAND (arg, 1)));
3689 case TRUTH_NOT_EXPR:
3690 return TREE_OPERAND (arg, 0);
3694 tree arg1 = TREE_OPERAND (arg, 1);
3695 tree arg2 = TREE_OPERAND (arg, 2);
3696 /* A COND_EXPR may have a throw as one operand, which
3697 then has void type. Just leave void operands
3699 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3700 VOID_TYPE_P (TREE_TYPE (arg1))
3701 ? arg1 : invert_truthvalue (arg1),
3702 VOID_TYPE_P (TREE_TYPE (arg2))
3703 ? arg2 : invert_truthvalue (arg2));
3707 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3708 invert_truthvalue (TREE_OPERAND (arg, 1)));
3710 case NON_LVALUE_EXPR:
3711 return invert_truthvalue (TREE_OPERAND (arg, 0));
3714 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3715 return build1 (TRUTH_NOT_EXPR, type, arg);
3719 return build1 (TREE_CODE (arg), type,
3720 invert_truthvalue (TREE_OPERAND (arg, 0)));
3723 if (!integer_onep (TREE_OPERAND (arg, 1)))
3725 return build2 (EQ_EXPR, type, arg,
3726 build_int_cst (type, 0));
3729 return build1 (TRUTH_NOT_EXPR, type, arg);
3731 case CLEANUP_POINT_EXPR:
3732 return build1 (CLEANUP_POINT_EXPR, type,
3733 invert_truthvalue (TREE_OPERAND (arg, 0)));
3742 /* Return a simplified tree node for the truth-negation of ARG. This
3743 never alters ARG itself. We assume that ARG is an operation that
3744 returns a truth value (0 or 1).
3746 FIXME: one would think we would fold the result, but it causes
3747 problems with the dominator optimizer. */
3750 invert_truthvalue (tree arg)
3754 if (TREE_CODE (arg) == ERROR_MARK)
3757 tem = fold_truth_not_expr (arg);
3759 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3764 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3765 operands are another bit-wise operation with a common input. If so,
3766 distribute the bit operations to save an operation and possibly two if
3767 constants are involved. For example, convert
3768 (A | B) & (A | C) into A | (B & C)
3769 Further simplification will occur if B and C are constants.
3771 If this optimization cannot be done, 0 will be returned. */
3774 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3779 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3780 || TREE_CODE (arg0) == code
3781 || (TREE_CODE (arg0) != BIT_AND_EXPR
3782 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3785 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3787 common = TREE_OPERAND (arg0, 0);
3788 left = TREE_OPERAND (arg0, 1);
3789 right = TREE_OPERAND (arg1, 1);
3791 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3793 common = TREE_OPERAND (arg0, 0);
3794 left = TREE_OPERAND (arg0, 1);
3795 right = TREE_OPERAND (arg1, 0);
3797 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3799 common = TREE_OPERAND (arg0, 1);
3800 left = TREE_OPERAND (arg0, 0);
3801 right = TREE_OPERAND (arg1, 1);
3803 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3805 common = TREE_OPERAND (arg0, 1);
3806 left = TREE_OPERAND (arg0, 0);
3807 right = TREE_OPERAND (arg1, 0);
3812 return fold_build2 (TREE_CODE (arg0), type, common,
3813 fold_build2 (code, type, left, right));
3816 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3817 with code CODE. This optimization is unsafe. */
3819 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3821 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3822 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3824 /* (A / C) +- (B / C) -> (A +- B) / C. */
3826 && operand_equal_p (TREE_OPERAND (arg0, 1),
3827 TREE_OPERAND (arg1, 1), 0))
3828 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3829 fold_build2 (code, type,
3830 TREE_OPERAND (arg0, 0),
3831 TREE_OPERAND (arg1, 0)),
3832 TREE_OPERAND (arg0, 1));
3834 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3835 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3836 TREE_OPERAND (arg1, 0), 0)
3837 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3838 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3840 REAL_VALUE_TYPE r0, r1;
3841 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3842 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3844 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3846 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3847 real_arithmetic (&r0, code, &r0, &r1);
3848 return fold_build2 (MULT_EXPR, type,
3849 TREE_OPERAND (arg0, 0),
3850 build_real (type, r0));
3856 /* Subroutine for fold_truthop: decode a field reference.
3858 If EXP is a comparison reference, we return the innermost reference.
3860 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3861 set to the starting bit number.
3863 If the innermost field can be completely contained in a mode-sized
3864 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3866 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3867 otherwise it is not changed.
3869 *PUNSIGNEDP is set to the signedness of the field.
3871 *PMASK is set to the mask used. This is either contained in a
3872 BIT_AND_EXPR or derived from the width of the field.
3874 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3876 Return 0 if this is not a component reference or is one that we can't
3877 do anything with. */
3880 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3881 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3882 int *punsignedp, int *pvolatilep,
3883 tree *pmask, tree *pand_mask)
3885 tree outer_type = 0;
3887 tree mask, inner, offset;
3889 unsigned int precision;
3891 /* All the optimizations using this function assume integer fields.
3892 There are problems with FP fields since the type_for_size call
3893 below can fail for, e.g., XFmode. */
3894 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3897 /* We are interested in the bare arrangement of bits, so strip everything
3898 that doesn't affect the machine mode. However, record the type of the
3899 outermost expression if it may matter below. */
3900 if (TREE_CODE (exp) == NOP_EXPR
3901 || TREE_CODE (exp) == CONVERT_EXPR
3902 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3903 outer_type = TREE_TYPE (exp);
3906 if (TREE_CODE (exp) == BIT_AND_EXPR)
3908 and_mask = TREE_OPERAND (exp, 1);
3909 exp = TREE_OPERAND (exp, 0);
3910 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3911 if (TREE_CODE (and_mask) != INTEGER_CST)
3915 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3916 punsignedp, pvolatilep, false);
3917 if ((inner == exp && and_mask == 0)
3918 || *pbitsize < 0 || offset != 0
3919 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3922 /* If the number of bits in the reference is the same as the bitsize of
3923 the outer type, then the outer type gives the signedness. Otherwise
3924 (in case of a small bitfield) the signedness is unchanged. */
3925 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3926 *punsignedp = TYPE_UNSIGNED (outer_type);
3928 /* Compute the mask to access the bitfield. */
3929 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3930 precision = TYPE_PRECISION (unsigned_type);
3932 mask = build_int_cst_type (unsigned_type, -1);
3934 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3935 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3937 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3939 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
3940 fold_convert (unsigned_type, and_mask), mask);
3943 *pand_mask = and_mask;
3947 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3948 represents the sign bit of EXP's type. If EXP represents a sign
3949 or zero extension, also test VAL against the unextended type.
3950 The return value is the (sub)expression whose sign bit is VAL,
3951 or NULL_TREE otherwise. */
3954 sign_bit_p (tree exp, const_tree val)
3956 unsigned HOST_WIDE_INT mask_lo, lo;
3957 HOST_WIDE_INT mask_hi, hi;
3961 /* Tree EXP must have an integral type. */
3962 t = TREE_TYPE (exp);
3963 if (! INTEGRAL_TYPE_P (t))
3966 /* Tree VAL must be an integer constant. */
3967 if (TREE_CODE (val) != INTEGER_CST
3968 || TREE_OVERFLOW (val))
3971 width = TYPE_PRECISION (t);
3972 if (width > HOST_BITS_PER_WIDE_INT)
3974 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3977 mask_hi = ((unsigned HOST_WIDE_INT) -1
3978 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3984 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3987 mask_lo = ((unsigned HOST_WIDE_INT) -1
3988 >> (HOST_BITS_PER_WIDE_INT - width));
3991 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3992 treat VAL as if it were unsigned. */
3993 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3994 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3997 /* Handle extension from a narrower type. */
3998 if (TREE_CODE (exp) == NOP_EXPR
3999 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
4000 return sign_bit_p (TREE_OPERAND (exp, 0), val);
4005 /* Subroutine for fold_truthop: determine if an operand is simple enough
4006 to be evaluated unconditionally. */
4009 simple_operand_p (const_tree exp)
4011 /* Strip any conversions that don't change the machine mode. */
4014 return (CONSTANT_CLASS_P (exp)
4015 || TREE_CODE (exp) == SSA_NAME
4017 && ! TREE_ADDRESSABLE (exp)
4018 && ! TREE_THIS_VOLATILE (exp)
4019 && ! DECL_NONLOCAL (exp)
4020 /* Don't regard global variables as simple. They may be
4021 allocated in ways unknown to the compiler (shared memory,
4022 #pragma weak, etc). */
4023 && ! TREE_PUBLIC (exp)
4024 && ! DECL_EXTERNAL (exp)
4025 /* Loading a static variable is unduly expensive, but global
4026 registers aren't expensive. */
4027 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
4030 /* The following functions are subroutines to fold_range_test and allow it to
4031 try to change a logical combination of comparisons into a range test.
4034 X == 2 || X == 3 || X == 4 || X == 5
4038 (unsigned) (X - 2) <= 3
4040 We describe each set of comparisons as being either inside or outside
4041 a range, using a variable named like IN_P, and then describe the
4042 range with a lower and upper bound. If one of the bounds is omitted,
4043 it represents either the highest or lowest value of the type.
4045 In the comments below, we represent a range by two numbers in brackets
4046 preceded by a "+" to designate being inside that range, or a "-" to
4047 designate being outside that range, so the condition can be inverted by
4048 flipping the prefix. An omitted bound is represented by a "-". For
4049 example, "- [-, 10]" means being outside the range starting at the lowest
4050 possible value and ending at 10, in other words, being greater than 10.
4051 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4054 We set up things so that the missing bounds are handled in a consistent
4055 manner so neither a missing bound nor "true" and "false" need to be
4056 handled using a special case. */
4058 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4059 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4060 and UPPER1_P are nonzero if the respective argument is an upper bound
4061 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4062 must be specified for a comparison. ARG1 will be converted to ARG0's
4063 type if both are specified. */
4066 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
4067 tree arg1, int upper1_p)
4073 /* If neither arg represents infinity, do the normal operation.
4074 Else, if not a comparison, return infinity. Else handle the special
4075 comparison rules. Note that most of the cases below won't occur, but
4076 are handled for consistency. */
4078 if (arg0 != 0 && arg1 != 0)
4080 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
4081 arg0, fold_convert (TREE_TYPE (arg0), arg1));
4083 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
4086 if (TREE_CODE_CLASS (code) != tcc_comparison)
4089 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4090 for neither. In real maths, we cannot assume open ended ranges are
4091 the same. But, this is computer arithmetic, where numbers are finite.
4092 We can therefore make the transformation of any unbounded range with
4093 the value Z, Z being greater than any representable number. This permits
4094 us to treat unbounded ranges as equal. */
4095 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
4096 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
4100 result = sgn0 == sgn1;
4103 result = sgn0 != sgn1;
4106 result = sgn0 < sgn1;
4109 result = sgn0 <= sgn1;
4112 result = sgn0 > sgn1;
4115 result = sgn0 >= sgn1;
4121 return constant_boolean_node (result, type);
4124 /* Given EXP, a logical expression, set the range it is testing into
4125 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4126 actually being tested. *PLOW and *PHIGH will be made of the same
4127 type as the returned expression. If EXP is not a comparison, we
4128 will most likely not be returning a useful value and range. Set
4129 *STRICT_OVERFLOW_P to true if the return value is only valid
4130 because signed overflow is undefined; otherwise, do not change
4131 *STRICT_OVERFLOW_P. */
4134 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4135 bool *strict_overflow_p)
4137 enum tree_code code;
4138 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4139 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4141 tree low, high, n_low, n_high;
4143 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4144 and see if we can refine the range. Some of the cases below may not
4145 happen, but it doesn't seem worth worrying about this. We "continue"
4146 the outer loop when we've changed something; otherwise we "break"
4147 the switch, which will "break" the while. */
4150 low = high = build_int_cst (TREE_TYPE (exp), 0);
4154 code = TREE_CODE (exp);
4155 exp_type = TREE_TYPE (exp);
4157 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4159 if (TREE_OPERAND_LENGTH (exp) > 0)
4160 arg0 = TREE_OPERAND (exp, 0);
4161 if (TREE_CODE_CLASS (code) == tcc_comparison
4162 || TREE_CODE_CLASS (code) == tcc_unary
4163 || TREE_CODE_CLASS (code) == tcc_binary)
4164 arg0_type = TREE_TYPE (arg0);
4165 if (TREE_CODE_CLASS (code) == tcc_binary
4166 || TREE_CODE_CLASS (code) == tcc_comparison
4167 || (TREE_CODE_CLASS (code) == tcc_expression
4168 && TREE_OPERAND_LENGTH (exp) > 1))
4169 arg1 = TREE_OPERAND (exp, 1);
4174 case TRUTH_NOT_EXPR:
4175 in_p = ! in_p, exp = arg0;
4178 case EQ_EXPR: case NE_EXPR:
4179 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4180 /* We can only do something if the range is testing for zero
4181 and if the second operand is an integer constant. Note that
4182 saying something is "in" the range we make is done by
4183 complementing IN_P since it will set in the initial case of
4184 being not equal to zero; "out" is leaving it alone. */
4185 if (low == 0 || high == 0
4186 || ! integer_zerop (low) || ! integer_zerop (high)
4187 || TREE_CODE (arg1) != INTEGER_CST)
4192 case NE_EXPR: /* - [c, c] */
4195 case EQ_EXPR: /* + [c, c] */
4196 in_p = ! in_p, low = high = arg1;
4198 case GT_EXPR: /* - [-, c] */
4199 low = 0, high = arg1;
4201 case GE_EXPR: /* + [c, -] */
4202 in_p = ! in_p, low = arg1, high = 0;
4204 case LT_EXPR: /* - [c, -] */
4205 low = arg1, high = 0;
4207 case LE_EXPR: /* + [-, c] */
4208 in_p = ! in_p, low = 0, high = arg1;
4214 /* If this is an unsigned comparison, we also know that EXP is
4215 greater than or equal to zero. We base the range tests we make
4216 on that fact, so we record it here so we can parse existing
4217 range tests. We test arg0_type since often the return type
4218 of, e.g. EQ_EXPR, is boolean. */
4219 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4221 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4223 build_int_cst (arg0_type, 0),
4227 in_p = n_in_p, low = n_low, high = n_high;
4229 /* If the high bound is missing, but we have a nonzero low
4230 bound, reverse the range so it goes from zero to the low bound
4232 if (high == 0 && low && ! integer_zerop (low))
4235 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4236 integer_one_node, 0);
4237 low = build_int_cst (arg0_type, 0);
4245 /* (-x) IN [a,b] -> x in [-b, -a] */
4246 n_low = range_binop (MINUS_EXPR, exp_type,
4247 build_int_cst (exp_type, 0),
4249 n_high = range_binop (MINUS_EXPR, exp_type,
4250 build_int_cst (exp_type, 0),
4252 low = n_low, high = n_high;
4258 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4259 build_int_cst (exp_type, 1));
4262 case PLUS_EXPR: case MINUS_EXPR:
4263 if (TREE_CODE (arg1) != INTEGER_CST)
4266 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4267 move a constant to the other side. */
4268 if (!TYPE_UNSIGNED (arg0_type)
4269 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4272 /* If EXP is signed, any overflow in the computation is undefined,
4273 so we don't worry about it so long as our computations on
4274 the bounds don't overflow. For unsigned, overflow is defined
4275 and this is exactly the right thing. */
4276 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4277 arg0_type, low, 0, arg1, 0);
4278 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4279 arg0_type, high, 1, arg1, 0);
4280 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4281 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4284 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4285 *strict_overflow_p = true;
4287 /* Check for an unsigned range which has wrapped around the maximum
4288 value thus making n_high < n_low, and normalize it. */
4289 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4291 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4292 integer_one_node, 0);
4293 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4294 integer_one_node, 0);
4296 /* If the range is of the form +/- [ x+1, x ], we won't
4297 be able to normalize it. But then, it represents the
4298 whole range or the empty set, so make it
4300 if (tree_int_cst_equal (n_low, low)
4301 && tree_int_cst_equal (n_high, high))
4307 low = n_low, high = n_high;
4312 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
4313 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4316 if (! INTEGRAL_TYPE_P (arg0_type)
4317 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4318 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4321 n_low = low, n_high = high;
4324 n_low = fold_convert (arg0_type, n_low);
4327 n_high = fold_convert (arg0_type, n_high);
4330 /* If we're converting arg0 from an unsigned type, to exp,
4331 a signed type, we will be doing the comparison as unsigned.
4332 The tests above have already verified that LOW and HIGH
4335 So we have to ensure that we will handle large unsigned
4336 values the same way that the current signed bounds treat
4339 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4343 /* For fixed-point modes, we need to pass the saturating flag
4344 as the 2nd parameter. */
4345 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
4346 equiv_type = lang_hooks.types.type_for_mode
4347 (TYPE_MODE (arg0_type),
4348 TYPE_SATURATING (arg0_type));
4350 equiv_type = lang_hooks.types.type_for_mode
4351 (TYPE_MODE (arg0_type), 1);
4353 /* A range without an upper bound is, naturally, unbounded.
4354 Since convert would have cropped a very large value, use
4355 the max value for the destination type. */
4357 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4358 : TYPE_MAX_VALUE (arg0_type);
4360 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4361 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4362 fold_convert (arg0_type,
4364 build_int_cst (arg0_type, 1));
4366 /* If the low bound is specified, "and" the range with the
4367 range for which the original unsigned value will be
4371 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4372 1, n_low, n_high, 1,
4373 fold_convert (arg0_type,
4378 in_p = (n_in_p == in_p);
4382 /* Otherwise, "or" the range with the range of the input
4383 that will be interpreted as negative. */
4384 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4385 0, n_low, n_high, 1,
4386 fold_convert (arg0_type,
4391 in_p = (in_p != n_in_p);
4396 low = n_low, high = n_high;
4406 /* If EXP is a constant, we can evaluate whether this is true or false. */
4407 if (TREE_CODE (exp) == INTEGER_CST)
4409 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4411 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4417 *pin_p = in_p, *plow = low, *phigh = high;
4421 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4422 type, TYPE, return an expression to test if EXP is in (or out of, depending
4423 on IN_P) the range. Return 0 if the test couldn't be created. */
4426 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4428 tree etype = TREE_TYPE (exp);
4431 #ifdef HAVE_canonicalize_funcptr_for_compare
4432 /* Disable this optimization for function pointer expressions
4433 on targets that require function pointer canonicalization. */
4434 if (HAVE_canonicalize_funcptr_for_compare
4435 && TREE_CODE (etype) == POINTER_TYPE
4436 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4442 value = build_range_check (type, exp, 1, low, high);
4444 return invert_truthvalue (value);
4449 if (low == 0 && high == 0)
4450 return build_int_cst (type, 1);
4453 return fold_build2 (LE_EXPR, type, exp,
4454 fold_convert (etype, high));
4457 return fold_build2 (GE_EXPR, type, exp,
4458 fold_convert (etype, low));
4460 if (operand_equal_p (low, high, 0))
4461 return fold_build2 (EQ_EXPR, type, exp,
4462 fold_convert (etype, low));
4464 if (integer_zerop (low))
4466 if (! TYPE_UNSIGNED (etype))
4468 etype = unsigned_type_for (etype);
4469 high = fold_convert (etype, high);
4470 exp = fold_convert (etype, exp);
4472 return build_range_check (type, exp, 1, 0, high);
4475 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4476 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4478 unsigned HOST_WIDE_INT lo;
4482 prec = TYPE_PRECISION (etype);
4483 if (prec <= HOST_BITS_PER_WIDE_INT)
4486 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4490 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4491 lo = (unsigned HOST_WIDE_INT) -1;
4494 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4496 if (TYPE_UNSIGNED (etype))
4498 etype = signed_type_for (etype);
4499 exp = fold_convert (etype, exp);
4501 return fold_build2 (GT_EXPR, type, exp,
4502 build_int_cst (etype, 0));
4506 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4507 This requires wrap-around arithmetics for the type of the expression. */
4508 switch (TREE_CODE (etype))
4511 /* There is no requirement that LOW be within the range of ETYPE
4512 if the latter is a subtype. It must, however, be within the base
4513 type of ETYPE. So be sure we do the subtraction in that type. */
4514 if (TREE_TYPE (etype))
4515 etype = TREE_TYPE (etype);
4520 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4521 TYPE_UNSIGNED (etype));
4528 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4529 if (TREE_CODE (etype) == INTEGER_TYPE
4530 && !TYPE_OVERFLOW_WRAPS (etype))
4532 tree utype, minv, maxv;
4534 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4535 for the type in question, as we rely on this here. */
4536 utype = unsigned_type_for (etype);
4537 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4538 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4539 integer_one_node, 1);
4540 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4542 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4549 high = fold_convert (etype, high);
4550 low = fold_convert (etype, low);
4551 exp = fold_convert (etype, exp);
4553 value = const_binop (MINUS_EXPR, high, low, 0);
4556 if (POINTER_TYPE_P (etype))
4558 if (value != 0 && !TREE_OVERFLOW (value))
4560 low = fold_convert (sizetype, low);
4561 low = fold_build1 (NEGATE_EXPR, sizetype, low);
4562 return build_range_check (type,
4563 fold_build2 (POINTER_PLUS_EXPR, etype, exp, low),
4564 1, build_int_cst (etype, 0), value);
4569 if (value != 0 && !TREE_OVERFLOW (value))
4570 return build_range_check (type,
4571 fold_build2 (MINUS_EXPR, etype, exp, low),
4572 1, build_int_cst (etype, 0), value);
4577 /* Return the predecessor of VAL in its type, handling the infinite case. */
4580 range_predecessor (tree val)
4582 tree type = TREE_TYPE (val);
4584 if (INTEGRAL_TYPE_P (type)
4585 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4588 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4591 /* Return the successor of VAL in its type, handling the infinite case. */
4594 range_successor (tree val)
4596 tree type = TREE_TYPE (val);
4598 if (INTEGRAL_TYPE_P (type)
4599 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4602 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4605 /* Given two ranges, see if we can merge them into one. Return 1 if we
4606 can, 0 if we can't. Set the output range into the specified parameters. */
4609 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4610 tree high0, int in1_p, tree low1, tree high1)
4618 int lowequal = ((low0 == 0 && low1 == 0)
4619 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4620 low0, 0, low1, 0)));
4621 int highequal = ((high0 == 0 && high1 == 0)
4622 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4623 high0, 1, high1, 1)));
4625 /* Make range 0 be the range that starts first, or ends last if they
4626 start at the same value. Swap them if it isn't. */
4627 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4630 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4631 high1, 1, high0, 1))))
4633 temp = in0_p, in0_p = in1_p, in1_p = temp;
4634 tem = low0, low0 = low1, low1 = tem;
4635 tem = high0, high0 = high1, high1 = tem;
4638 /* Now flag two cases, whether the ranges are disjoint or whether the
4639 second range is totally subsumed in the first. Note that the tests
4640 below are simplified by the ones above. */
4641 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4642 high0, 1, low1, 0));
4643 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4644 high1, 1, high0, 1));
4646 /* We now have four cases, depending on whether we are including or
4647 excluding the two ranges. */
4650 /* If they don't overlap, the result is false. If the second range
4651 is a subset it is the result. Otherwise, the range is from the start
4652 of the second to the end of the first. */
4654 in_p = 0, low = high = 0;
4656 in_p = 1, low = low1, high = high1;
4658 in_p = 1, low = low1, high = high0;
4661 else if (in0_p && ! in1_p)
4663 /* If they don't overlap, the result is the first range. If they are
4664 equal, the result is false. If the second range is a subset of the
4665 first, and the ranges begin at the same place, we go from just after
4666 the end of the second range to the end of the first. If the second
4667 range is not a subset of the first, or if it is a subset and both
4668 ranges end at the same place, the range starts at the start of the
4669 first range and ends just before the second range.
4670 Otherwise, we can't describe this as a single range. */
4672 in_p = 1, low = low0, high = high0;
4673 else if (lowequal && highequal)
4674 in_p = 0, low = high = 0;
4675 else if (subset && lowequal)
4677 low = range_successor (high1);
4682 /* We are in the weird situation where high0 > high1 but
4683 high1 has no successor. Punt. */
4687 else if (! subset || highequal)
4690 high = range_predecessor (low1);
4694 /* low0 < low1 but low1 has no predecessor. Punt. */
4702 else if (! in0_p && in1_p)
4704 /* If they don't overlap, the result is the second range. If the second
4705 is a subset of the first, the result is false. Otherwise,
4706 the range starts just after the first range and ends at the
4707 end of the second. */
4709 in_p = 1, low = low1, high = high1;
4710 else if (subset || highequal)
4711 in_p = 0, low = high = 0;
4714 low = range_successor (high0);
4719 /* high1 > high0 but high0 has no successor. Punt. */
4727 /* The case where we are excluding both ranges. Here the complex case
4728 is if they don't overlap. In that case, the only time we have a
4729 range is if they are adjacent. If the second is a subset of the
4730 first, the result is the first. Otherwise, the range to exclude
4731 starts at the beginning of the first range and ends at the end of the
4735 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4736 range_successor (high0),
4738 in_p = 0, low = low0, high = high1;
4741 /* Canonicalize - [min, x] into - [-, x]. */
4742 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4743 switch (TREE_CODE (TREE_TYPE (low0)))
4746 if (TYPE_PRECISION (TREE_TYPE (low0))
4747 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4751 if (tree_int_cst_equal (low0,
4752 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4756 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4757 && integer_zerop (low0))
4764 /* Canonicalize - [x, max] into - [x, -]. */
4765 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4766 switch (TREE_CODE (TREE_TYPE (high1)))
4769 if (TYPE_PRECISION (TREE_TYPE (high1))
4770 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4774 if (tree_int_cst_equal (high1,
4775 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4779 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4780 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4782 integer_one_node, 1)))
4789 /* The ranges might be also adjacent between the maximum and
4790 minimum values of the given type. For
4791 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4792 return + [x + 1, y - 1]. */
4793 if (low0 == 0 && high1 == 0)
4795 low = range_successor (high0);
4796 high = range_predecessor (low1);
4797 if (low == 0 || high == 0)
4807 in_p = 0, low = low0, high = high0;
4809 in_p = 0, low = low0, high = high1;
4812 *pin_p = in_p, *plow = low, *phigh = high;
4817 /* Subroutine of fold, looking inside expressions of the form
4818 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4819 of the COND_EXPR. This function is being used also to optimize
4820 A op B ? C : A, by reversing the comparison first.
4822 Return a folded expression whose code is not a COND_EXPR
4823 anymore, or NULL_TREE if no folding opportunity is found. */
4826 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4828 enum tree_code comp_code = TREE_CODE (arg0);
4829 tree arg00 = TREE_OPERAND (arg0, 0);
4830 tree arg01 = TREE_OPERAND (arg0, 1);
4831 tree arg1_type = TREE_TYPE (arg1);
4837 /* If we have A op 0 ? A : -A, consider applying the following
4840 A == 0? A : -A same as -A
4841 A != 0? A : -A same as A
4842 A >= 0? A : -A same as abs (A)
4843 A > 0? A : -A same as abs (A)
4844 A <= 0? A : -A same as -abs (A)
4845 A < 0? A : -A same as -abs (A)
4847 None of these transformations work for modes with signed
4848 zeros. If A is +/-0, the first two transformations will
4849 change the sign of the result (from +0 to -0, or vice
4850 versa). The last four will fix the sign of the result,
4851 even though the original expressions could be positive or
4852 negative, depending on the sign of A.
4854 Note that all these transformations are correct if A is
4855 NaN, since the two alternatives (A and -A) are also NaNs. */
4856 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4857 && (FLOAT_TYPE_P (TREE_TYPE (arg01))
4858 ? real_zerop (arg01)
4859 : integer_zerop (arg01))
4860 && ((TREE_CODE (arg2) == NEGATE_EXPR
4861 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4862 /* In the case that A is of the form X-Y, '-A' (arg2) may
4863 have already been folded to Y-X, check for that. */
4864 || (TREE_CODE (arg1) == MINUS_EXPR
4865 && TREE_CODE (arg2) == MINUS_EXPR
4866 && operand_equal_p (TREE_OPERAND (arg1, 0),
4867 TREE_OPERAND (arg2, 1), 0)
4868 && operand_equal_p (TREE_OPERAND (arg1, 1),
4869 TREE_OPERAND (arg2, 0), 0))))
4874 tem = fold_convert (arg1_type, arg1);
4875 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4878 return pedantic_non_lvalue (fold_convert (type, arg1));
4881 if (flag_trapping_math)
4886 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4887 arg1 = fold_convert (signed_type_for
4888 (TREE_TYPE (arg1)), arg1);
4889 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4890 return pedantic_non_lvalue (fold_convert (type, tem));
4893 if (flag_trapping_math)
4897 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4898 arg1 = fold_convert (signed_type_for
4899 (TREE_TYPE (arg1)), arg1);
4900 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4901 return negate_expr (fold_convert (type, tem));
4903 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4907 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4908 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4909 both transformations are correct when A is NaN: A != 0
4910 is then true, and A == 0 is false. */
4912 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4913 && integer_zerop (arg01) && integer_zerop (arg2))
4915 if (comp_code == NE_EXPR)
4916 return pedantic_non_lvalue (fold_convert (type, arg1));
4917 else if (comp_code == EQ_EXPR)
4918 return build_int_cst (type, 0);
4921 /* Try some transformations of A op B ? A : B.
4923 A == B? A : B same as B
4924 A != B? A : B same as A
4925 A >= B? A : B same as max (A, B)
4926 A > B? A : B same as max (B, A)
4927 A <= B? A : B same as min (A, B)
4928 A < B? A : B same as min (B, A)
4930 As above, these transformations don't work in the presence
4931 of signed zeros. For example, if A and B are zeros of
4932 opposite sign, the first two transformations will change
4933 the sign of the result. In the last four, the original
4934 expressions give different results for (A=+0, B=-0) and
4935 (A=-0, B=+0), but the transformed expressions do not.
4937 The first two transformations are correct if either A or B
4938 is a NaN. In the first transformation, the condition will
4939 be false, and B will indeed be chosen. In the case of the
4940 second transformation, the condition A != B will be true,
4941 and A will be chosen.
4943 The conversions to max() and min() are not correct if B is
4944 a number and A is not. The conditions in the original
4945 expressions will be false, so all four give B. The min()
4946 and max() versions would give a NaN instead. */
4947 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4948 && operand_equal_for_comparison_p (arg01, arg2, arg00)
4949 /* Avoid these transformations if the COND_EXPR may be used
4950 as an lvalue in the C++ front-end. PR c++/19199. */
4952 || (strcmp (lang_hooks.name, "GNU C++") != 0
4953 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
4954 || ! maybe_lvalue_p (arg1)
4955 || ! maybe_lvalue_p (arg2)))
4957 tree comp_op0 = arg00;
4958 tree comp_op1 = arg01;
4959 tree comp_type = TREE_TYPE (comp_op0);
4961 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4962 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4972 return pedantic_non_lvalue (fold_convert (type, arg2));
4974 return pedantic_non_lvalue (fold_convert (type, arg1));
4979 /* In C++ a ?: expression can be an lvalue, so put the
4980 operand which will be used if they are equal first
4981 so that we can convert this back to the
4982 corresponding COND_EXPR. */
4983 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4985 comp_op0 = fold_convert (comp_type, comp_op0);
4986 comp_op1 = fold_convert (comp_type, comp_op1);
4987 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4988 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
4989 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
4990 return pedantic_non_lvalue (fold_convert (type, tem));
4997 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4999 comp_op0 = fold_convert (comp_type, comp_op0);
5000 comp_op1 = fold_convert (comp_type, comp_op1);
5001 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
5002 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
5003 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
5004 return pedantic_non_lvalue (fold_convert (type, tem));
5008 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5009 return pedantic_non_lvalue (fold_convert (type, arg2));
5012 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5013 return pedantic_non_lvalue (fold_convert (type, arg1));
5016 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5021 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
5022 we might still be able to simplify this. For example,
5023 if C1 is one less or one more than C2, this might have started
5024 out as a MIN or MAX and been transformed by this function.
5025 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
5027 if (INTEGRAL_TYPE_P (type)
5028 && TREE_CODE (arg01) == INTEGER_CST
5029 && TREE_CODE (arg2) == INTEGER_CST)
5033 /* We can replace A with C1 in this case. */
5034 arg1 = fold_convert (type, arg01);
5035 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
5038 /* If C1 is C2 + 1, this is min(A, C2). */
5039 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5041 && operand_equal_p (arg01,
5042 const_binop (PLUS_EXPR, arg2,
5043 build_int_cst (type, 1), 0),
5045 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5047 fold_convert (type, arg1),
5052 /* If C1 is C2 - 1, this is min(A, C2). */
5053 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5055 && operand_equal_p (arg01,
5056 const_binop (MINUS_EXPR, arg2,
5057 build_int_cst (type, 1), 0),
5059 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5061 fold_convert (type, arg1),
5066 /* If C1 is C2 - 1, this is max(A, C2). */
5067 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5069 && operand_equal_p (arg01,
5070 const_binop (MINUS_EXPR, arg2,
5071 build_int_cst (type, 1), 0),
5073 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5075 fold_convert (type, arg1),
5080 /* If C1 is C2 + 1, this is max(A, C2). */
5081 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5083 && operand_equal_p (arg01,
5084 const_binop (PLUS_EXPR, arg2,
5085 build_int_cst (type, 1), 0),
5087 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5089 fold_convert (type, arg1),
5103 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5104 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
5107 /* EXP is some logical combination of boolean tests. See if we can
5108 merge it into some range test. Return the new tree if so. */
5111 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
5113 int or_op = (code == TRUTH_ORIF_EXPR
5114 || code == TRUTH_OR_EXPR);
5115 int in0_p, in1_p, in_p;
5116 tree low0, low1, low, high0, high1, high;
5117 bool strict_overflow_p = false;
5118 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
5119 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
5121 const char * const warnmsg = G_("assuming signed overflow does not occur "
5122 "when simplifying range test");
5124 /* If this is an OR operation, invert both sides; we will invert
5125 again at the end. */
5127 in0_p = ! in0_p, in1_p = ! in1_p;
5129 /* If both expressions are the same, if we can merge the ranges, and we
5130 can build the range test, return it or it inverted. If one of the
5131 ranges is always true or always false, consider it to be the same
5132 expression as the other. */
5133 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
5134 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
5136 && 0 != (tem = (build_range_check (type,
5138 : rhs != 0 ? rhs : integer_zero_node,
5141 if (strict_overflow_p)
5142 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
5143 return or_op ? invert_truthvalue (tem) : tem;
5146 /* On machines where the branch cost is expensive, if this is a
5147 short-circuited branch and the underlying object on both sides
5148 is the same, make a non-short-circuit operation. */
5149 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5150 && lhs != 0 && rhs != 0
5151 && (code == TRUTH_ANDIF_EXPR
5152 || code == TRUTH_ORIF_EXPR)
5153 && operand_equal_p (lhs, rhs, 0))
5155 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5156 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5157 which cases we can't do this. */
5158 if (simple_operand_p (lhs))
5159 return build2 (code == TRUTH_ANDIF_EXPR
5160 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5163 else if (lang_hooks.decls.global_bindings_p () == 0
5164 && ! CONTAINS_PLACEHOLDER_P (lhs))
5166 tree common = save_expr (lhs);
5168 if (0 != (lhs = build_range_check (type, common,
5169 or_op ? ! in0_p : in0_p,
5171 && (0 != (rhs = build_range_check (type, common,
5172 or_op ? ! in1_p : in1_p,
5175 if (strict_overflow_p)
5176 fold_overflow_warning (warnmsg,
5177 WARN_STRICT_OVERFLOW_COMPARISON);
5178 return build2 (code == TRUTH_ANDIF_EXPR
5179 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5188 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5189 bit value. Arrange things so the extra bits will be set to zero if and
5190 only if C is signed-extended to its full width. If MASK is nonzero,
5191 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5194 unextend (tree c, int p, int unsignedp, tree mask)
5196 tree type = TREE_TYPE (c);
5197 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5200 if (p == modesize || unsignedp)
5203 /* We work by getting just the sign bit into the low-order bit, then
5204 into the high-order bit, then sign-extend. We then XOR that value
5206 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5207 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5209 /* We must use a signed type in order to get an arithmetic right shift.
5210 However, we must also avoid introducing accidental overflows, so that
5211 a subsequent call to integer_zerop will work. Hence we must
5212 do the type conversion here. At this point, the constant is either
5213 zero or one, and the conversion to a signed type can never overflow.
5214 We could get an overflow if this conversion is done anywhere else. */
5215 if (TYPE_UNSIGNED (type))
5216 temp = fold_convert (signed_type_for (type), temp);
5218 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5219 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5221 temp = const_binop (BIT_AND_EXPR, temp,
5222 fold_convert (TREE_TYPE (c), mask), 0);
5223 /* If necessary, convert the type back to match the type of C. */
5224 if (TYPE_UNSIGNED (type))
5225 temp = fold_convert (type, temp);
5227 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5230 /* Find ways of folding logical expressions of LHS and RHS:
5231 Try to merge two comparisons to the same innermost item.
5232 Look for range tests like "ch >= '0' && ch <= '9'".
5233 Look for combinations of simple terms on machines with expensive branches
5234 and evaluate the RHS unconditionally.
5236 For example, if we have p->a == 2 && p->b == 4 and we can make an
5237 object large enough to span both A and B, we can do this with a comparison
5238 against the object ANDed with the a mask.
5240 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5241 operations to do this with one comparison.
5243 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5244 function and the one above.
5246 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5247 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5249 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5252 We return the simplified tree or 0 if no optimization is possible. */
5255 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5257 /* If this is the "or" of two comparisons, we can do something if
5258 the comparisons are NE_EXPR. If this is the "and", we can do something
5259 if the comparisons are EQ_EXPR. I.e.,
5260 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5262 WANTED_CODE is this operation code. For single bit fields, we can
5263 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5264 comparison for one-bit fields. */
5266 enum tree_code wanted_code;
5267 enum tree_code lcode, rcode;
5268 tree ll_arg, lr_arg, rl_arg, rr_arg;
5269 tree ll_inner, lr_inner, rl_inner, rr_inner;
5270 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5271 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5272 HOST_WIDE_INT xll_bitpos, xrl_bitpos;
5273 HOST_WIDE_INT lnbitsize, lnbitpos;
5274 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5275 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5276 enum machine_mode lnmode;
5277 tree ll_mask, lr_mask, rl_mask, rr_mask;
5278 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5279 tree l_const, r_const;
5280 tree lntype, result;
5281 int first_bit, end_bit;
5283 tree orig_lhs = lhs, orig_rhs = rhs;
5284 enum tree_code orig_code = code;
5286 /* Start by getting the comparison codes. Fail if anything is volatile.
5287 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5288 it were surrounded with a NE_EXPR. */
5290 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5293 lcode = TREE_CODE (lhs);
5294 rcode = TREE_CODE (rhs);
5296 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5298 lhs = build2 (NE_EXPR, truth_type, lhs,
5299 build_int_cst (TREE_TYPE (lhs), 0));
5303 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5305 rhs = build2 (NE_EXPR, truth_type, rhs,
5306 build_int_cst (TREE_TYPE (rhs), 0));
5310 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5311 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5314 ll_arg = TREE_OPERAND (lhs, 0);
5315 lr_arg = TREE_OPERAND (lhs, 1);
5316 rl_arg = TREE_OPERAND (rhs, 0);
5317 rr_arg = TREE_OPERAND (rhs, 1);
5319 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5320 if (simple_operand_p (ll_arg)
5321 && simple_operand_p (lr_arg))
5324 if (operand_equal_p (ll_arg, rl_arg, 0)
5325 && operand_equal_p (lr_arg, rr_arg, 0))
5327 result = combine_comparisons (code, lcode, rcode,
5328 truth_type, ll_arg, lr_arg);
5332 else if (operand_equal_p (ll_arg, rr_arg, 0)
5333 && operand_equal_p (lr_arg, rl_arg, 0))
5335 result = combine_comparisons (code, lcode,
5336 swap_tree_comparison (rcode),
5337 truth_type, ll_arg, lr_arg);
5343 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5344 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5346 /* If the RHS can be evaluated unconditionally and its operands are
5347 simple, it wins to evaluate the RHS unconditionally on machines
5348 with expensive branches. In this case, this isn't a comparison
5349 that can be merged. Avoid doing this if the RHS is a floating-point
5350 comparison since those can trap. */
5352 if (BRANCH_COST >= 2
5353 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5354 && simple_operand_p (rl_arg)
5355 && simple_operand_p (rr_arg))
5357 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5358 if (code == TRUTH_OR_EXPR
5359 && lcode == NE_EXPR && integer_zerop (lr_arg)
5360 && rcode == NE_EXPR && integer_zerop (rr_arg)
5361 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5362 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5363 return build2 (NE_EXPR, truth_type,
5364 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5366 build_int_cst (TREE_TYPE (ll_arg), 0));
5368 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5369 if (code == TRUTH_AND_EXPR
5370 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5371 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5372 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5373 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5374 return build2 (EQ_EXPR, truth_type,
5375 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5377 build_int_cst (TREE_TYPE (ll_arg), 0));
5379 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5381 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5382 return build2 (code, truth_type, lhs, rhs);
5387 /* See if the comparisons can be merged. Then get all the parameters for
5390 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5391 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5395 ll_inner = decode_field_reference (ll_arg,
5396 &ll_bitsize, &ll_bitpos, &ll_mode,
5397 &ll_unsignedp, &volatilep, &ll_mask,
5399 lr_inner = decode_field_reference (lr_arg,
5400 &lr_bitsize, &lr_bitpos, &lr_mode,
5401 &lr_unsignedp, &volatilep, &lr_mask,
5403 rl_inner = decode_field_reference (rl_arg,
5404 &rl_bitsize, &rl_bitpos, &rl_mode,
5405 &rl_unsignedp, &volatilep, &rl_mask,
5407 rr_inner = decode_field_reference (rr_arg,
5408 &rr_bitsize, &rr_bitpos, &rr_mode,
5409 &rr_unsignedp, &volatilep, &rr_mask,
5412 /* It must be true that the inner operation on the lhs of each
5413 comparison must be the same if we are to be able to do anything.
5414 Then see if we have constants. If not, the same must be true for
5416 if (volatilep || ll_inner == 0 || rl_inner == 0
5417 || ! operand_equal_p (ll_inner, rl_inner, 0))
5420 if (TREE_CODE (lr_arg) == INTEGER_CST
5421 && TREE_CODE (rr_arg) == INTEGER_CST)
5422 l_const = lr_arg, r_const = rr_arg;
5423 else if (lr_inner == 0 || rr_inner == 0
5424 || ! operand_equal_p (lr_inner, rr_inner, 0))
5427 l_const = r_const = 0;
5429 /* If either comparison code is not correct for our logical operation,
5430 fail. However, we can convert a one-bit comparison against zero into
5431 the opposite comparison against that bit being set in the field. */
5433 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5434 if (lcode != wanted_code)
5436 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5438 /* Make the left operand unsigned, since we are only interested
5439 in the value of one bit. Otherwise we are doing the wrong
5448 /* This is analogous to the code for l_const above. */
5449 if (rcode != wanted_code)
5451 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5460 /* See if we can find a mode that contains both fields being compared on
5461 the left. If we can't, fail. Otherwise, update all constants and masks
5462 to be relative to a field of that size. */
5463 first_bit = MIN (ll_bitpos, rl_bitpos);
5464 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5465 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5466 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5468 if (lnmode == VOIDmode)
5471 lnbitsize = GET_MODE_BITSIZE (lnmode);
5472 lnbitpos = first_bit & ~ (lnbitsize - 1);
5473 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5474 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5476 if (BYTES_BIG_ENDIAN)
5478 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5479 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5482 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5483 size_int (xll_bitpos), 0);
5484 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5485 size_int (xrl_bitpos), 0);
5489 l_const = fold_convert (lntype, l_const);
5490 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5491 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5492 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5493 fold_build1 (BIT_NOT_EXPR,
5497 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5499 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5504 r_const = fold_convert (lntype, r_const);
5505 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5506 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5507 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5508 fold_build1 (BIT_NOT_EXPR,
5512 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5514 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5518 /* Handle the case of comparisons with constants. If there is something in
5519 common between the masks, those bits of the constants must be the same.
5520 If not, the condition is always false. Test for this to avoid generating
5521 incorrect code below. */
5522 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5523 if (! integer_zerop (result)
5524 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5525 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5527 if (wanted_code == NE_EXPR)
5529 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5530 return constant_boolean_node (true, truth_type);
5534 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5535 return constant_boolean_node (false, truth_type);
5542 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5546 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5549 enum tree_code op_code;
5550 tree comp_const = op1;
5552 int consts_equal, consts_lt;
5555 STRIP_SIGN_NOPS (arg0);
5557 op_code = TREE_CODE (arg0);
5558 minmax_const = TREE_OPERAND (arg0, 1);
5559 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5560 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5561 inner = TREE_OPERAND (arg0, 0);
5563 /* If something does not permit us to optimize, return the original tree. */
5564 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5565 || TREE_CODE (comp_const) != INTEGER_CST
5566 || TREE_OVERFLOW (comp_const)
5567 || TREE_CODE (minmax_const) != INTEGER_CST
5568 || TREE_OVERFLOW (minmax_const))
5571 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5572 and GT_EXPR, doing the rest with recursive calls using logical
5576 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5578 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5581 return invert_truthvalue (tem);
5587 fold_build2 (TRUTH_ORIF_EXPR, type,
5588 optimize_minmax_comparison
5589 (EQ_EXPR, type, arg0, comp_const),
5590 optimize_minmax_comparison
5591 (GT_EXPR, type, arg0, comp_const));
5594 if (op_code == MAX_EXPR && consts_equal)
5595 /* MAX (X, 0) == 0 -> X <= 0 */
5596 return fold_build2 (LE_EXPR, type, inner, comp_const);
5598 else if (op_code == MAX_EXPR && consts_lt)
5599 /* MAX (X, 0) == 5 -> X == 5 */
5600 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5602 else if (op_code == MAX_EXPR)
5603 /* MAX (X, 0) == -1 -> false */
5604 return omit_one_operand (type, integer_zero_node, inner);
5606 else if (consts_equal)
5607 /* MIN (X, 0) == 0 -> X >= 0 */
5608 return fold_build2 (GE_EXPR, type, inner, comp_const);
5611 /* MIN (X, 0) == 5 -> false */
5612 return omit_one_operand (type, integer_zero_node, inner);
5615 /* MIN (X, 0) == -1 -> X == -1 */
5616 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5619 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5620 /* MAX (X, 0) > 0 -> X > 0
5621 MAX (X, 0) > 5 -> X > 5 */
5622 return fold_build2 (GT_EXPR, type, inner, comp_const);
5624 else if (op_code == MAX_EXPR)
5625 /* MAX (X, 0) > -1 -> true */
5626 return omit_one_operand (type, integer_one_node, inner);
5628 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5629 /* MIN (X, 0) > 0 -> false
5630 MIN (X, 0) > 5 -> false */
5631 return omit_one_operand (type, integer_zero_node, inner);
5634 /* MIN (X, 0) > -1 -> X > -1 */
5635 return fold_build2 (GT_EXPR, type, inner, comp_const);
5642 /* T is an integer expression that is being multiplied, divided, or taken a
5643 modulus (CODE says which and what kind of divide or modulus) by a
5644 constant C. See if we can eliminate that operation by folding it with
5645 other operations already in T. WIDE_TYPE, if non-null, is a type that
5646 should be used for the computation if wider than our type.
5648 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5649 (X * 2) + (Y * 4). We must, however, be assured that either the original
5650 expression would not overflow or that overflow is undefined for the type
5651 in the language in question.
5653 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5654 the machine has a multiply-accumulate insn or that this is part of an
5655 addressing calculation.
5657 If we return a non-null expression, it is an equivalent form of the
5658 original computation, but need not be in the original type.
5660 We set *STRICT_OVERFLOW_P to true if the return values depends on
5661 signed overflow being undefined. Otherwise we do not change
5662 *STRICT_OVERFLOW_P. */
5665 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
5666 bool *strict_overflow_p)
5668 /* To avoid exponential search depth, refuse to allow recursion past
5669 three levels. Beyond that (1) it's highly unlikely that we'll find
5670 something interesting and (2) we've probably processed it before
5671 when we built the inner expression. */
5680 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
5687 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
5688 bool *strict_overflow_p)
5690 tree type = TREE_TYPE (t);
5691 enum tree_code tcode = TREE_CODE (t);
5692 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5693 > GET_MODE_SIZE (TYPE_MODE (type)))
5694 ? wide_type : type);
5696 int same_p = tcode == code;
5697 tree op0 = NULL_TREE, op1 = NULL_TREE;
5698 bool sub_strict_overflow_p;
5700 /* Don't deal with constants of zero here; they confuse the code below. */
5701 if (integer_zerop (c))
5704 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5705 op0 = TREE_OPERAND (t, 0);
5707 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5708 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5710 /* Note that we need not handle conditional operations here since fold
5711 already handles those cases. So just do arithmetic here. */
5715 /* For a constant, we can always simplify if we are a multiply
5716 or (for divide and modulus) if it is a multiple of our constant. */
5717 if (code == MULT_EXPR
5718 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5719 return const_binop (code, fold_convert (ctype, t),
5720 fold_convert (ctype, c), 0);
5723 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5724 /* If op0 is an expression ... */
5725 if ((COMPARISON_CLASS_P (op0)
5726 || UNARY_CLASS_P (op0)
5727 || BINARY_CLASS_P (op0)
5728 || VL_EXP_CLASS_P (op0)
5729 || EXPRESSION_CLASS_P (op0))
5730 /* ... and is unsigned, and its type is smaller than ctype,
5731 then we cannot pass through as widening. */
5732 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5733 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5734 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5735 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5736 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5737 /* ... or this is a truncation (t is narrower than op0),
5738 then we cannot pass through this narrowing. */
5739 || (GET_MODE_SIZE (TYPE_MODE (type))
5740 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5741 /* ... or signedness changes for division or modulus,
5742 then we cannot pass through this conversion. */
5743 || (code != MULT_EXPR
5744 && (TYPE_UNSIGNED (ctype)
5745 != TYPE_UNSIGNED (TREE_TYPE (op0))))
5746 /* ... or has undefined overflow while the converted to
5747 type has not, we cannot do the operation in the inner type
5748 as that would introduce undefined overflow. */
5749 || (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))
5750 && !TYPE_OVERFLOW_UNDEFINED (type))))
5753 /* Pass the constant down and see if we can make a simplification. If
5754 we can, replace this expression with the inner simplification for
5755 possible later conversion to our or some other type. */
5756 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5757 && TREE_CODE (t2) == INTEGER_CST
5758 && !TREE_OVERFLOW (t2)
5759 && (0 != (t1 = extract_muldiv (op0, t2, code,
5761 ? ctype : NULL_TREE,
5762 strict_overflow_p))))
5767 /* If widening the type changes it from signed to unsigned, then we
5768 must avoid building ABS_EXPR itself as unsigned. */
5769 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5771 tree cstype = (*signed_type_for) (ctype);
5772 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
5775 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
5776 return fold_convert (ctype, t1);
5780 /* If the constant is negative, we cannot simplify this. */
5781 if (tree_int_cst_sgn (c) == -1)
5785 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
5787 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
5790 case MIN_EXPR: case MAX_EXPR:
5791 /* If widening the type changes the signedness, then we can't perform
5792 this optimization as that changes the result. */
5793 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5796 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5797 sub_strict_overflow_p = false;
5798 if ((t1 = extract_muldiv (op0, c, code, wide_type,
5799 &sub_strict_overflow_p)) != 0
5800 && (t2 = extract_muldiv (op1, c, code, wide_type,
5801 &sub_strict_overflow_p)) != 0)
5803 if (tree_int_cst_sgn (c) < 0)
5804 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5805 if (sub_strict_overflow_p)
5806 *strict_overflow_p = true;
5807 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5808 fold_convert (ctype, t2));
5812 case LSHIFT_EXPR: case RSHIFT_EXPR:
5813 /* If the second operand is constant, this is a multiplication
5814 or floor division, by a power of two, so we can treat it that
5815 way unless the multiplier or divisor overflows. Signed
5816 left-shift overflow is implementation-defined rather than
5817 undefined in C90, so do not convert signed left shift into
5819 if (TREE_CODE (op1) == INTEGER_CST
5820 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5821 /* const_binop may not detect overflow correctly,
5822 so check for it explicitly here. */
5823 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5824 && TREE_INT_CST_HIGH (op1) == 0
5825 && 0 != (t1 = fold_convert (ctype,
5826 const_binop (LSHIFT_EXPR,
5829 && !TREE_OVERFLOW (t1))
5830 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5831 ? MULT_EXPR : FLOOR_DIV_EXPR,
5832 ctype, fold_convert (ctype, op0), t1),
5833 c, code, wide_type, strict_overflow_p);
5836 case PLUS_EXPR: case MINUS_EXPR:
5837 /* See if we can eliminate the operation on both sides. If we can, we
5838 can return a new PLUS or MINUS. If we can't, the only remaining
5839 cases where we can do anything are if the second operand is a
5841 sub_strict_overflow_p = false;
5842 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
5843 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
5844 if (t1 != 0 && t2 != 0
5845 && (code == MULT_EXPR
5846 /* If not multiplication, we can only do this if both operands
5847 are divisible by c. */
5848 || (multiple_of_p (ctype, op0, c)
5849 && multiple_of_p (ctype, op1, c))))
5851 if (sub_strict_overflow_p)
5852 *strict_overflow_p = true;
5853 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5854 fold_convert (ctype, t2));
5857 /* If this was a subtraction, negate OP1 and set it to be an addition.
5858 This simplifies the logic below. */
5859 if (tcode == MINUS_EXPR)
5860 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5862 if (TREE_CODE (op1) != INTEGER_CST)
5865 /* If either OP1 or C are negative, this optimization is not safe for
5866 some of the division and remainder types while for others we need
5867 to change the code. */
5868 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5870 if (code == CEIL_DIV_EXPR)
5871 code = FLOOR_DIV_EXPR;
5872 else if (code == FLOOR_DIV_EXPR)
5873 code = CEIL_DIV_EXPR;
5874 else if (code != MULT_EXPR
5875 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5879 /* If it's a multiply or a division/modulus operation of a multiple
5880 of our constant, do the operation and verify it doesn't overflow. */
5881 if (code == MULT_EXPR
5882 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5884 op1 = const_binop (code, fold_convert (ctype, op1),
5885 fold_convert (ctype, c), 0);
5886 /* We allow the constant to overflow with wrapping semantics. */
5888 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
5894 /* If we have an unsigned type is not a sizetype, we cannot widen
5895 the operation since it will change the result if the original
5896 computation overflowed. */
5897 if (TYPE_UNSIGNED (ctype)
5898 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5902 /* If we were able to eliminate our operation from the first side,
5903 apply our operation to the second side and reform the PLUS. */
5904 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5905 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
5907 /* The last case is if we are a multiply. In that case, we can
5908 apply the distributive law to commute the multiply and addition
5909 if the multiplication of the constants doesn't overflow. */
5910 if (code == MULT_EXPR)
5911 return fold_build2 (tcode, ctype,
5912 fold_build2 (code, ctype,
5913 fold_convert (ctype, op0),
5914 fold_convert (ctype, c)),
5920 /* We have a special case here if we are doing something like
5921 (C * 8) % 4 since we know that's zero. */
5922 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5923 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5924 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5925 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5926 return omit_one_operand (type, integer_zero_node, op0);
5928 /* ... fall through ... */
5930 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5931 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5932 /* If we can extract our operation from the LHS, do so and return a
5933 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5934 do something only if the second operand is a constant. */
5936 && (t1 = extract_muldiv (op0, c, code, wide_type,
5937 strict_overflow_p)) != 0)
5938 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5939 fold_convert (ctype, op1));
5940 else if (tcode == MULT_EXPR && code == MULT_EXPR
5941 && (t1 = extract_muldiv (op1, c, code, wide_type,
5942 strict_overflow_p)) != 0)
5943 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5944 fold_convert (ctype, t1));
5945 else if (TREE_CODE (op1) != INTEGER_CST)
5948 /* If these are the same operation types, we can associate them
5949 assuming no overflow. */
5951 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5952 fold_convert (ctype, c), 0))
5953 && !TREE_OVERFLOW (t1))
5954 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
5956 /* If these operations "cancel" each other, we have the main
5957 optimizations of this pass, which occur when either constant is a
5958 multiple of the other, in which case we replace this with either an
5959 operation or CODE or TCODE.
5961 If we have an unsigned type that is not a sizetype, we cannot do
5962 this since it will change the result if the original computation
5964 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
5965 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5966 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5967 || (tcode == MULT_EXPR
5968 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5969 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
5970 && code != MULT_EXPR)))
5972 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5974 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5975 *strict_overflow_p = true;
5976 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5977 fold_convert (ctype,
5978 const_binop (TRUNC_DIV_EXPR,
5981 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5983 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5984 *strict_overflow_p = true;
5985 return fold_build2 (code, ctype, fold_convert (ctype, op0),
5986 fold_convert (ctype,
5987 const_binop (TRUNC_DIV_EXPR,
6000 /* Return a node which has the indicated constant VALUE (either 0 or
6001 1), and is of the indicated TYPE. */
6004 constant_boolean_node (int value, tree type)
6006 if (type == integer_type_node)
6007 return value ? integer_one_node : integer_zero_node;
6008 else if (type == boolean_type_node)
6009 return value ? boolean_true_node : boolean_false_node;
6011 return build_int_cst (type, value);
6015 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6016 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6017 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6018 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6019 COND is the first argument to CODE; otherwise (as in the example
6020 given here), it is the second argument. TYPE is the type of the
6021 original expression. Return NULL_TREE if no simplification is
6025 fold_binary_op_with_conditional_arg (enum tree_code code,
6026 tree type, tree op0, tree op1,
6027 tree cond, tree arg, int cond_first_p)
6029 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6030 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6031 tree test, true_value, false_value;
6032 tree lhs = NULL_TREE;
6033 tree rhs = NULL_TREE;
6035 /* This transformation is only worthwhile if we don't have to wrap
6036 arg in a SAVE_EXPR, and the operation can be simplified on at least
6037 one of the branches once its pushed inside the COND_EXPR. */
6038 if (!TREE_CONSTANT (arg))
6041 if (TREE_CODE (cond) == COND_EXPR)
6043 test = TREE_OPERAND (cond, 0);
6044 true_value = TREE_OPERAND (cond, 1);
6045 false_value = TREE_OPERAND (cond, 2);
6046 /* If this operand throws an expression, then it does not make
6047 sense to try to perform a logical or arithmetic operation
6049 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6051 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6056 tree testtype = TREE_TYPE (cond);
6058 true_value = constant_boolean_node (true, testtype);
6059 false_value = constant_boolean_node (false, testtype);
6062 arg = fold_convert (arg_type, arg);
6065 true_value = fold_convert (cond_type, true_value);
6067 lhs = fold_build2 (code, type, true_value, arg);
6069 lhs = fold_build2 (code, type, arg, true_value);
6073 false_value = fold_convert (cond_type, false_value);
6075 rhs = fold_build2 (code, type, false_value, arg);
6077 rhs = fold_build2 (code, type, arg, false_value);
6080 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6081 return fold_convert (type, test);
6085 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6087 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6088 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6089 ADDEND is the same as X.
6091 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6092 and finite. The problematic cases are when X is zero, and its mode
6093 has signed zeros. In the case of rounding towards -infinity,
6094 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6095 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6098 fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
6100 if (!real_zerop (addend))
6103 /* Don't allow the fold with -fsignaling-nans. */
6104 if (HONOR_SNANS (TYPE_MODE (type)))
6107 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6108 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6111 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6112 if (TREE_CODE (addend) == REAL_CST
6113 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6116 /* The mode has signed zeros, and we have to honor their sign.
6117 In this situation, there is only one case we can return true for.
6118 X - 0 is the same as X unless rounding towards -infinity is
6120 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6123 /* Subroutine of fold() that checks comparisons of built-in math
6124 functions against real constants.
6126 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6127 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6128 is the type of the result and ARG0 and ARG1 are the operands of the
6129 comparison. ARG1 must be a TREE_REAL_CST.
6131 The function returns the constant folded tree if a simplification
6132 can be made, and NULL_TREE otherwise. */
6135 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6136 tree type, tree arg0, tree arg1)
6140 if (BUILTIN_SQRT_P (fcode))
6142 tree arg = CALL_EXPR_ARG (arg0, 0);
6143 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6145 c = TREE_REAL_CST (arg1);
6146 if (REAL_VALUE_NEGATIVE (c))
6148 /* sqrt(x) < y is always false, if y is negative. */
6149 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6150 return omit_one_operand (type, integer_zero_node, arg);
6152 /* sqrt(x) > y is always true, if y is negative and we
6153 don't care about NaNs, i.e. negative values of x. */
6154 if (code == NE_EXPR || !HONOR_NANS (mode))
6155 return omit_one_operand (type, integer_one_node, arg);
6157 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6158 return fold_build2 (GE_EXPR, type, arg,
6159 build_real (TREE_TYPE (arg), dconst0));
6161 else if (code == GT_EXPR || code == GE_EXPR)
6165 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6166 real_convert (&c2, mode, &c2);
6168 if (REAL_VALUE_ISINF (c2))
6170 /* sqrt(x) > y is x == +Inf, when y is very large. */
6171 if (HONOR_INFINITIES (mode))
6172 return fold_build2 (EQ_EXPR, type, arg,
6173 build_real (TREE_TYPE (arg), c2));
6175 /* sqrt(x) > y is always false, when y is very large
6176 and we don't care about infinities. */
6177 return omit_one_operand (type, integer_zero_node, arg);
6180 /* sqrt(x) > c is the same as x > c*c. */
6181 return fold_build2 (code, type, arg,
6182 build_real (TREE_TYPE (arg), c2));
6184 else if (code == LT_EXPR || code == LE_EXPR)
6188 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6189 real_convert (&c2, mode, &c2);
6191 if (REAL_VALUE_ISINF (c2))
6193 /* sqrt(x) < y is always true, when y is a very large
6194 value and we don't care about NaNs or Infinities. */
6195 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6196 return omit_one_operand (type, integer_one_node, arg);
6198 /* sqrt(x) < y is x != +Inf when y is very large and we
6199 don't care about NaNs. */
6200 if (! HONOR_NANS (mode))
6201 return fold_build2 (NE_EXPR, type, arg,
6202 build_real (TREE_TYPE (arg), c2));
6204 /* sqrt(x) < y is x >= 0 when y is very large and we
6205 don't care about Infinities. */
6206 if (! HONOR_INFINITIES (mode))
6207 return fold_build2 (GE_EXPR, type, arg,
6208 build_real (TREE_TYPE (arg), dconst0));
6210 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6211 if (lang_hooks.decls.global_bindings_p () != 0
6212 || CONTAINS_PLACEHOLDER_P (arg))
6215 arg = save_expr (arg);
6216 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6217 fold_build2 (GE_EXPR, type, arg,
6218 build_real (TREE_TYPE (arg),
6220 fold_build2 (NE_EXPR, type, arg,
6221 build_real (TREE_TYPE (arg),
6225 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6226 if (! HONOR_NANS (mode))
6227 return fold_build2 (code, type, arg,
6228 build_real (TREE_TYPE (arg), c2));
6230 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6231 if (lang_hooks.decls.global_bindings_p () == 0
6232 && ! CONTAINS_PLACEHOLDER_P (arg))
6234 arg = save_expr (arg);
6235 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6236 fold_build2 (GE_EXPR, type, arg,
6237 build_real (TREE_TYPE (arg),
6239 fold_build2 (code, type, arg,
6240 build_real (TREE_TYPE (arg),
6249 /* Subroutine of fold() that optimizes comparisons against Infinities,
6250 either +Inf or -Inf.
6252 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6253 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6254 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6256 The function returns the constant folded tree if a simplification
6257 can be made, and NULL_TREE otherwise. */
6260 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6262 enum machine_mode mode;
6263 REAL_VALUE_TYPE max;
6267 mode = TYPE_MODE (TREE_TYPE (arg0));
6269 /* For negative infinity swap the sense of the comparison. */
6270 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6272 code = swap_tree_comparison (code);
6277 /* x > +Inf is always false, if with ignore sNANs. */
6278 if (HONOR_SNANS (mode))
6280 return omit_one_operand (type, integer_zero_node, arg0);
6283 /* x <= +Inf is always true, if we don't case about NaNs. */
6284 if (! HONOR_NANS (mode))
6285 return omit_one_operand (type, integer_one_node, arg0);
6287 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6288 if (lang_hooks.decls.global_bindings_p () == 0
6289 && ! CONTAINS_PLACEHOLDER_P (arg0))
6291 arg0 = save_expr (arg0);
6292 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6298 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6299 real_maxval (&max, neg, mode);
6300 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6301 arg0, build_real (TREE_TYPE (arg0), max));
6304 /* x < +Inf is always equal to x <= DBL_MAX. */
6305 real_maxval (&max, neg, mode);
6306 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6307 arg0, build_real (TREE_TYPE (arg0), max));
6310 /* x != +Inf is always equal to !(x > DBL_MAX). */
6311 real_maxval (&max, neg, mode);
6312 if (! HONOR_NANS (mode))
6313 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6314 arg0, build_real (TREE_TYPE (arg0), max));
6316 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6317 arg0, build_real (TREE_TYPE (arg0), max));
6318 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6327 /* Subroutine of fold() that optimizes comparisons of a division by
6328 a nonzero integer constant against an integer constant, i.e.
6331 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6332 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6333 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6335 The function returns the constant folded tree if a simplification
6336 can be made, and NULL_TREE otherwise. */
6339 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6341 tree prod, tmp, hi, lo;
6342 tree arg00 = TREE_OPERAND (arg0, 0);
6343 tree arg01 = TREE_OPERAND (arg0, 1);
6344 unsigned HOST_WIDE_INT lpart;
6345 HOST_WIDE_INT hpart;
6346 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6350 /* We have to do this the hard way to detect unsigned overflow.
6351 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6352 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6353 TREE_INT_CST_HIGH (arg01),
6354 TREE_INT_CST_LOW (arg1),
6355 TREE_INT_CST_HIGH (arg1),
6356 &lpart, &hpart, unsigned_p);
6357 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6359 neg_overflow = false;
6363 tmp = int_const_binop (MINUS_EXPR, arg01,
6364 build_int_cst (TREE_TYPE (arg01), 1), 0);
6367 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6368 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6369 TREE_INT_CST_HIGH (prod),
6370 TREE_INT_CST_LOW (tmp),
6371 TREE_INT_CST_HIGH (tmp),
6372 &lpart, &hpart, unsigned_p);
6373 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6374 -1, overflow | TREE_OVERFLOW (prod));
6376 else if (tree_int_cst_sgn (arg01) >= 0)
6378 tmp = int_const_binop (MINUS_EXPR, arg01,
6379 build_int_cst (TREE_TYPE (arg01), 1), 0);
6380 switch (tree_int_cst_sgn (arg1))
6383 neg_overflow = true;
6384 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6389 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6394 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6404 /* A negative divisor reverses the relational operators. */
6405 code = swap_tree_comparison (code);
6407 tmp = int_const_binop (PLUS_EXPR, arg01,
6408 build_int_cst (TREE_TYPE (arg01), 1), 0);
6409 switch (tree_int_cst_sgn (arg1))
6412 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6417 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6422 neg_overflow = true;
6423 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6435 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6436 return omit_one_operand (type, integer_zero_node, arg00);
6437 if (TREE_OVERFLOW (hi))
6438 return fold_build2 (GE_EXPR, type, arg00, lo);
6439 if (TREE_OVERFLOW (lo))
6440 return fold_build2 (LE_EXPR, type, arg00, hi);
6441 return build_range_check (type, arg00, 1, lo, hi);
6444 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6445 return omit_one_operand (type, integer_one_node, arg00);
6446 if (TREE_OVERFLOW (hi))
6447 return fold_build2 (LT_EXPR, type, arg00, lo);
6448 if (TREE_OVERFLOW (lo))
6449 return fold_build2 (GT_EXPR, type, arg00, hi);
6450 return build_range_check (type, arg00, 0, lo, hi);
6453 if (TREE_OVERFLOW (lo))
6455 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6456 return omit_one_operand (type, tmp, arg00);
6458 return fold_build2 (LT_EXPR, type, arg00, lo);
6461 if (TREE_OVERFLOW (hi))
6463 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6464 return omit_one_operand (type, tmp, arg00);
6466 return fold_build2 (LE_EXPR, type, arg00, hi);
6469 if (TREE_OVERFLOW (hi))
6471 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6472 return omit_one_operand (type, tmp, arg00);
6474 return fold_build2 (GT_EXPR, type, arg00, hi);
6477 if (TREE_OVERFLOW (lo))
6479 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6480 return omit_one_operand (type, tmp, arg00);
6482 return fold_build2 (GE_EXPR, type, arg00, lo);
6492 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6493 equality/inequality test, then return a simplified form of the test
6494 using a sign testing. Otherwise return NULL. TYPE is the desired
6498 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6501 /* If this is testing a single bit, we can optimize the test. */
6502 if ((code == NE_EXPR || code == EQ_EXPR)
6503 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6504 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6506 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6507 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6508 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6510 if (arg00 != NULL_TREE
6511 /* This is only a win if casting to a signed type is cheap,
6512 i.e. when arg00's type is not a partial mode. */
6513 && TYPE_PRECISION (TREE_TYPE (arg00))
6514 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6516 tree stype = signed_type_for (TREE_TYPE (arg00));
6517 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6518 result_type, fold_convert (stype, arg00),
6519 build_int_cst (stype, 0));
6526 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6527 equality/inequality test, then return a simplified form of
6528 the test using shifts and logical operations. Otherwise return
6529 NULL. TYPE is the desired result type. */
6532 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6535 /* If this is testing a single bit, we can optimize the test. */
6536 if ((code == NE_EXPR || code == EQ_EXPR)
6537 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6538 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6540 tree inner = TREE_OPERAND (arg0, 0);
6541 tree type = TREE_TYPE (arg0);
6542 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6543 enum machine_mode operand_mode = TYPE_MODE (type);
6545 tree signed_type, unsigned_type, intermediate_type;
6548 /* First, see if we can fold the single bit test into a sign-bit
6550 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6555 /* Otherwise we have (A & C) != 0 where C is a single bit,
6556 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6557 Similarly for (A & C) == 0. */
6559 /* If INNER is a right shift of a constant and it plus BITNUM does
6560 not overflow, adjust BITNUM and INNER. */
6561 if (TREE_CODE (inner) == RSHIFT_EXPR
6562 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6563 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6564 && bitnum < TYPE_PRECISION (type)
6565 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6566 bitnum - TYPE_PRECISION (type)))
6568 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6569 inner = TREE_OPERAND (inner, 0);
6572 /* If we are going to be able to omit the AND below, we must do our
6573 operations as unsigned. If we must use the AND, we have a choice.
6574 Normally unsigned is faster, but for some machines signed is. */
6575 #ifdef LOAD_EXTEND_OP
6576 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6577 && !flag_syntax_only) ? 0 : 1;
6582 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6583 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6584 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6585 inner = fold_convert (intermediate_type, inner);
6588 inner = build2 (RSHIFT_EXPR, intermediate_type,
6589 inner, size_int (bitnum));
6591 one = build_int_cst (intermediate_type, 1);
6593 if (code == EQ_EXPR)
6594 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6596 /* Put the AND last so it can combine with more things. */
6597 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6599 /* Make sure to return the proper type. */
6600 inner = fold_convert (result_type, inner);
6607 /* Check whether we are allowed to reorder operands arg0 and arg1,
6608 such that the evaluation of arg1 occurs before arg0. */
6611 reorder_operands_p (const_tree arg0, const_tree arg1)
6613 if (! flag_evaluation_order)
6615 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6617 return ! TREE_SIDE_EFFECTS (arg0)
6618 && ! TREE_SIDE_EFFECTS (arg1);
6621 /* Test whether it is preferable two swap two operands, ARG0 and
6622 ARG1, for example because ARG0 is an integer constant and ARG1
6623 isn't. If REORDER is true, only recommend swapping if we can
6624 evaluate the operands in reverse order. */
6627 tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
6629 STRIP_SIGN_NOPS (arg0);
6630 STRIP_SIGN_NOPS (arg1);
6632 if (TREE_CODE (arg1) == INTEGER_CST)
6634 if (TREE_CODE (arg0) == INTEGER_CST)
6637 if (TREE_CODE (arg1) == REAL_CST)
6639 if (TREE_CODE (arg0) == REAL_CST)
6642 if (TREE_CODE (arg1) == FIXED_CST)
6644 if (TREE_CODE (arg0) == FIXED_CST)
6647 if (TREE_CODE (arg1) == COMPLEX_CST)
6649 if (TREE_CODE (arg0) == COMPLEX_CST)
6652 if (TREE_CONSTANT (arg1))
6654 if (TREE_CONSTANT (arg0))
6660 if (reorder && flag_evaluation_order
6661 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6664 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6665 for commutative and comparison operators. Ensuring a canonical
6666 form allows the optimizers to find additional redundancies without
6667 having to explicitly check for both orderings. */
6668 if (TREE_CODE (arg0) == SSA_NAME
6669 && TREE_CODE (arg1) == SSA_NAME
6670 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6673 /* Put SSA_NAMEs last. */
6674 if (TREE_CODE (arg1) == SSA_NAME)
6676 if (TREE_CODE (arg0) == SSA_NAME)
6679 /* Put variables last. */
6688 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6689 ARG0 is extended to a wider type. */
6692 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6694 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6696 tree shorter_type, outer_type;
6700 if (arg0_unw == arg0)
6702 shorter_type = TREE_TYPE (arg0_unw);
6704 #ifdef HAVE_canonicalize_funcptr_for_compare
6705 /* Disable this optimization if we're casting a function pointer
6706 type on targets that require function pointer canonicalization. */
6707 if (HAVE_canonicalize_funcptr_for_compare
6708 && TREE_CODE (shorter_type) == POINTER_TYPE
6709 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
6713 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6716 arg1_unw = get_unwidened (arg1, NULL_TREE);
6718 /* If possible, express the comparison in the shorter mode. */
6719 if ((code == EQ_EXPR || code == NE_EXPR
6720 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6721 && (TREE_TYPE (arg1_unw) == shorter_type
6722 || (TYPE_PRECISION (shorter_type)
6723 >= TYPE_PRECISION (TREE_TYPE (arg1_unw)))
6724 || (TREE_CODE (arg1_unw) == INTEGER_CST
6725 && (TREE_CODE (shorter_type) == INTEGER_TYPE
6726 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
6727 && int_fits_type_p (arg1_unw, shorter_type))))
6728 return fold_build2 (code, type, arg0_unw,
6729 fold_convert (shorter_type, arg1_unw));
6731 if (TREE_CODE (arg1_unw) != INTEGER_CST
6732 || TREE_CODE (shorter_type) != INTEGER_TYPE
6733 || !int_fits_type_p (arg1_unw, shorter_type))
6736 /* If we are comparing with the integer that does not fit into the range
6737 of the shorter type, the result is known. */
6738 outer_type = TREE_TYPE (arg1_unw);
6739 min = lower_bound_in_type (outer_type, shorter_type);
6740 max = upper_bound_in_type (outer_type, shorter_type);
6742 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6744 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6751 return omit_one_operand (type, integer_zero_node, arg0);
6756 return omit_one_operand (type, integer_one_node, arg0);
6762 return omit_one_operand (type, integer_one_node, arg0);
6764 return omit_one_operand (type, integer_zero_node, arg0);
6769 return omit_one_operand (type, integer_zero_node, arg0);
6771 return omit_one_operand (type, integer_one_node, arg0);
6780 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6781 ARG0 just the signedness is changed. */
6784 fold_sign_changed_comparison (enum tree_code code, tree type,
6785 tree arg0, tree arg1)
6788 tree inner_type, outer_type;
6790 if (TREE_CODE (arg0) != NOP_EXPR
6791 && TREE_CODE (arg0) != CONVERT_EXPR)
6794 outer_type = TREE_TYPE (arg0);
6795 arg0_inner = TREE_OPERAND (arg0, 0);
6796 inner_type = TREE_TYPE (arg0_inner);
6798 #ifdef HAVE_canonicalize_funcptr_for_compare
6799 /* Disable this optimization if we're casting a function pointer
6800 type on targets that require function pointer canonicalization. */
6801 if (HAVE_canonicalize_funcptr_for_compare
6802 && TREE_CODE (inner_type) == POINTER_TYPE
6803 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
6807 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6810 if (TREE_CODE (arg1) != INTEGER_CST
6811 && !((TREE_CODE (arg1) == NOP_EXPR
6812 || TREE_CODE (arg1) == CONVERT_EXPR)
6813 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6816 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6821 if (TREE_CODE (arg1) == INTEGER_CST)
6822 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
6823 TREE_INT_CST_HIGH (arg1), 0,
6824 TREE_OVERFLOW (arg1));
6826 arg1 = fold_convert (inner_type, arg1);
6828 return fold_build2 (code, type, arg0_inner, arg1);
6831 /* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
6832 step of the array. Reconstructs s and delta in the case of s * delta
6833 being an integer constant (and thus already folded).
6834 ADDR is the address. MULT is the multiplicative expression.
6835 If the function succeeds, the new address expression is returned. Otherwise
6836 NULL_TREE is returned. */
6839 try_move_mult_to_index (tree addr, tree op1)
6841 tree s, delta, step;
6842 tree ref = TREE_OPERAND (addr, 0), pref;
6847 /* Strip the nops that might be added when converting op1 to sizetype. */
6850 /* Canonicalize op1 into a possibly non-constant delta
6851 and an INTEGER_CST s. */
6852 if (TREE_CODE (op1) == MULT_EXPR)
6854 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
6859 if (TREE_CODE (arg0) == INTEGER_CST)
6864 else if (TREE_CODE (arg1) == INTEGER_CST)
6872 else if (TREE_CODE (op1) == INTEGER_CST)
6879 /* Simulate we are delta * 1. */
6881 s = integer_one_node;
6884 for (;; ref = TREE_OPERAND (ref, 0))
6886 if (TREE_CODE (ref) == ARRAY_REF)
6888 /* Remember if this was a multi-dimensional array. */
6889 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
6892 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
6896 step = array_ref_element_size (ref);
6897 if (TREE_CODE (step) != INTEGER_CST)
6902 if (! tree_int_cst_equal (step, s))
6907 /* Try if delta is a multiple of step. */
6908 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
6914 /* Only fold here if we can verify we do not overflow one
6915 dimension of a multi-dimensional array. */
6920 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
6921 || !INTEGRAL_TYPE_P (itype)
6922 || !TYPE_MAX_VALUE (itype)
6923 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
6926 tmp = fold_binary (PLUS_EXPR, itype,
6927 fold_convert (itype,
6928 TREE_OPERAND (ref, 1)),
6929 fold_convert (itype, delta));
6931 || TREE_CODE (tmp) != INTEGER_CST
6932 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
6941 if (!handled_component_p (ref))
6945 /* We found the suitable array reference. So copy everything up to it,
6946 and replace the index. */
6948 pref = TREE_OPERAND (addr, 0);
6949 ret = copy_node (pref);
6954 pref = TREE_OPERAND (pref, 0);
6955 TREE_OPERAND (pos, 0) = copy_node (pref);
6956 pos = TREE_OPERAND (pos, 0);
6959 TREE_OPERAND (pos, 1) = fold_build2 (PLUS_EXPR, itype,
6960 fold_convert (itype,
6961 TREE_OPERAND (pos, 1)),
6962 fold_convert (itype, delta));
6964 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6968 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6969 means A >= Y && A != MAX, but in this case we know that
6970 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6973 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6975 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6977 if (TREE_CODE (bound) == LT_EXPR)
6978 a = TREE_OPERAND (bound, 0);
6979 else if (TREE_CODE (bound) == GT_EXPR)
6980 a = TREE_OPERAND (bound, 1);
6984 typea = TREE_TYPE (a);
6985 if (!INTEGRAL_TYPE_P (typea)
6986 && !POINTER_TYPE_P (typea))
6989 if (TREE_CODE (ineq) == LT_EXPR)
6991 a1 = TREE_OPERAND (ineq, 1);
6992 y = TREE_OPERAND (ineq, 0);
6994 else if (TREE_CODE (ineq) == GT_EXPR)
6996 a1 = TREE_OPERAND (ineq, 0);
6997 y = TREE_OPERAND (ineq, 1);
7002 if (TREE_TYPE (a1) != typea)
7005 if (POINTER_TYPE_P (typea))
7007 /* Convert the pointer types into integer before taking the difference. */
7008 tree ta = fold_convert (ssizetype, a);
7009 tree ta1 = fold_convert (ssizetype, a1);
7010 diff = fold_binary (MINUS_EXPR, ssizetype, ta1, ta);
7013 diff = fold_binary (MINUS_EXPR, typea, a1, a);
7015 if (!diff || !integer_onep (diff))
7018 return fold_build2 (GE_EXPR, type, a, y);
7021 /* Fold a sum or difference of at least one multiplication.
7022 Returns the folded tree or NULL if no simplification could be made. */
7025 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7027 tree arg00, arg01, arg10, arg11;
7028 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7030 /* (A * C) +- (B * C) -> (A+-B) * C.
7031 (A * C) +- A -> A * (C+-1).
7032 We are most concerned about the case where C is a constant,
7033 but other combinations show up during loop reduction. Since
7034 it is not difficult, try all four possibilities. */
7036 if (TREE_CODE (arg0) == MULT_EXPR)
7038 arg00 = TREE_OPERAND (arg0, 0);
7039 arg01 = TREE_OPERAND (arg0, 1);
7041 else if (TREE_CODE (arg0) == INTEGER_CST)
7043 arg00 = build_one_cst (type);
7048 /* We cannot generate constant 1 for fract. */
7049 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7052 arg01 = build_one_cst (type);
7054 if (TREE_CODE (arg1) == MULT_EXPR)
7056 arg10 = TREE_OPERAND (arg1, 0);
7057 arg11 = TREE_OPERAND (arg1, 1);
7059 else if (TREE_CODE (arg1) == INTEGER_CST)
7061 arg10 = build_one_cst (type);
7066 /* We cannot generate constant 1 for fract. */
7067 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7070 arg11 = build_one_cst (type);
7074 if (operand_equal_p (arg01, arg11, 0))
7075 same = arg01, alt0 = arg00, alt1 = arg10;
7076 else if (operand_equal_p (arg00, arg10, 0))
7077 same = arg00, alt0 = arg01, alt1 = arg11;
7078 else if (operand_equal_p (arg00, arg11, 0))
7079 same = arg00, alt0 = arg01, alt1 = arg10;
7080 else if (operand_equal_p (arg01, arg10, 0))
7081 same = arg01, alt0 = arg00, alt1 = arg11;
7083 /* No identical multiplicands; see if we can find a common
7084 power-of-two factor in non-power-of-two multiplies. This
7085 can help in multi-dimensional array access. */
7086 else if (host_integerp (arg01, 0)
7087 && host_integerp (arg11, 0))
7089 HOST_WIDE_INT int01, int11, tmp;
7092 int01 = TREE_INT_CST_LOW (arg01);
7093 int11 = TREE_INT_CST_LOW (arg11);
7095 /* Move min of absolute values to int11. */
7096 if ((int01 >= 0 ? int01 : -int01)
7097 < (int11 >= 0 ? int11 : -int11))
7099 tmp = int01, int01 = int11, int11 = tmp;
7100 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7107 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
7109 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7110 build_int_cst (TREE_TYPE (arg00),
7115 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7120 return fold_build2 (MULT_EXPR, type,
7121 fold_build2 (code, type,
7122 fold_convert (type, alt0),
7123 fold_convert (type, alt1)),
7124 fold_convert (type, same));
7129 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7130 specified by EXPR into the buffer PTR of length LEN bytes.
7131 Return the number of bytes placed in the buffer, or zero
7135 native_encode_int (const_tree expr, unsigned char *ptr, int len)
7137 tree type = TREE_TYPE (expr);
7138 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7139 int byte, offset, word, words;
7140 unsigned char value;
7142 if (total_bytes > len)
7144 words = total_bytes / UNITS_PER_WORD;
7146 for (byte = 0; byte < total_bytes; byte++)
7148 int bitpos = byte * BITS_PER_UNIT;
7149 if (bitpos < HOST_BITS_PER_WIDE_INT)
7150 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7152 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7153 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7155 if (total_bytes > UNITS_PER_WORD)
7157 word = byte / UNITS_PER_WORD;
7158 if (WORDS_BIG_ENDIAN)
7159 word = (words - 1) - word;
7160 offset = word * UNITS_PER_WORD;
7161 if (BYTES_BIG_ENDIAN)
7162 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7164 offset += byte % UNITS_PER_WORD;
7167 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7168 ptr[offset] = value;
7174 /* Subroutine of native_encode_expr. Encode the REAL_CST
7175 specified by EXPR into the buffer PTR of length LEN bytes.
7176 Return the number of bytes placed in the buffer, or zero
7180 native_encode_real (const_tree expr, unsigned char *ptr, int len)
7182 tree type = TREE_TYPE (expr);
7183 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7184 int byte, offset, word, words, bitpos;
7185 unsigned char value;
7187 /* There are always 32 bits in each long, no matter the size of
7188 the hosts long. We handle floating point representations with
7192 if (total_bytes > len)
7194 words = 32 / UNITS_PER_WORD;
7196 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7198 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7199 bitpos += BITS_PER_UNIT)
7201 byte = (bitpos / BITS_PER_UNIT) & 3;
7202 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7204 if (UNITS_PER_WORD < 4)
7206 word = byte / UNITS_PER_WORD;
7207 if (WORDS_BIG_ENDIAN)
7208 word = (words - 1) - word;
7209 offset = word * UNITS_PER_WORD;
7210 if (BYTES_BIG_ENDIAN)
7211 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7213 offset += byte % UNITS_PER_WORD;
7216 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7217 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7222 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7223 specified by EXPR into the buffer PTR of length LEN bytes.
7224 Return the number of bytes placed in the buffer, or zero
7228 native_encode_complex (const_tree expr, unsigned char *ptr, int len)
7233 part = TREE_REALPART (expr);
7234 rsize = native_encode_expr (part, ptr, len);
7237 part = TREE_IMAGPART (expr);
7238 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7241 return rsize + isize;
7245 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7246 specified by EXPR into the buffer PTR of length LEN bytes.
7247 Return the number of bytes placed in the buffer, or zero
7251 native_encode_vector (const_tree expr, unsigned char *ptr, int len)
7253 int i, size, offset, count;
7254 tree itype, elem, elements;
7257 elements = TREE_VECTOR_CST_ELTS (expr);
7258 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7259 itype = TREE_TYPE (TREE_TYPE (expr));
7260 size = GET_MODE_SIZE (TYPE_MODE (itype));
7261 for (i = 0; i < count; i++)
7265 elem = TREE_VALUE (elements);
7266 elements = TREE_CHAIN (elements);
7273 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7278 if (offset + size > len)
7280 memset (ptr+offset, 0, size);
7288 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7289 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7290 buffer PTR of length LEN bytes. Return the number of bytes
7291 placed in the buffer, or zero upon failure. */
7294 native_encode_expr (const_tree expr, unsigned char *ptr, int len)
7296 switch (TREE_CODE (expr))
7299 return native_encode_int (expr, ptr, len);
7302 return native_encode_real (expr, ptr, len);
7305 return native_encode_complex (expr, ptr, len);
7308 return native_encode_vector (expr, ptr, len);
7316 /* Subroutine of native_interpret_expr. Interpret the contents of
7317 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7318 If the buffer cannot be interpreted, return NULL_TREE. */
7321 native_interpret_int (tree type, const unsigned char *ptr, int len)
7323 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7324 int byte, offset, word, words;
7325 unsigned char value;
7326 unsigned int HOST_WIDE_INT lo = 0;
7327 HOST_WIDE_INT hi = 0;
7329 if (total_bytes > len)
7331 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7333 words = total_bytes / UNITS_PER_WORD;
7335 for (byte = 0; byte < total_bytes; byte++)
7337 int bitpos = byte * BITS_PER_UNIT;
7338 if (total_bytes > UNITS_PER_WORD)
7340 word = byte / UNITS_PER_WORD;
7341 if (WORDS_BIG_ENDIAN)
7342 word = (words - 1) - word;
7343 offset = word * UNITS_PER_WORD;
7344 if (BYTES_BIG_ENDIAN)
7345 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7347 offset += byte % UNITS_PER_WORD;
7350 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7351 value = ptr[offset];
7353 if (bitpos < HOST_BITS_PER_WIDE_INT)
7354 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7356 hi |= (unsigned HOST_WIDE_INT) value
7357 << (bitpos - HOST_BITS_PER_WIDE_INT);
7360 return build_int_cst_wide_type (type, lo, hi);
7364 /* Subroutine of native_interpret_expr. Interpret the contents of
7365 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7366 If the buffer cannot be interpreted, return NULL_TREE. */
7369 native_interpret_real (tree type, const unsigned char *ptr, int len)
7371 enum machine_mode mode = TYPE_MODE (type);
7372 int total_bytes = GET_MODE_SIZE (mode);
7373 int byte, offset, word, words, bitpos;
7374 unsigned char value;
7375 /* There are always 32 bits in each long, no matter the size of
7376 the hosts long. We handle floating point representations with
7381 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7382 if (total_bytes > len || total_bytes > 24)
7384 words = 32 / UNITS_PER_WORD;
7386 memset (tmp, 0, sizeof (tmp));
7387 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7388 bitpos += BITS_PER_UNIT)
7390 byte = (bitpos / BITS_PER_UNIT) & 3;
7391 if (UNITS_PER_WORD < 4)
7393 word = byte / UNITS_PER_WORD;
7394 if (WORDS_BIG_ENDIAN)
7395 word = (words - 1) - word;
7396 offset = word * UNITS_PER_WORD;
7397 if (BYTES_BIG_ENDIAN)
7398 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7400 offset += byte % UNITS_PER_WORD;
7403 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7404 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7406 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7409 real_from_target (&r, tmp, mode);
7410 return build_real (type, r);
7414 /* Subroutine of native_interpret_expr. Interpret the contents of
7415 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7416 If the buffer cannot be interpreted, return NULL_TREE. */
7419 native_interpret_complex (tree type, const unsigned char *ptr, int len)
7421 tree etype, rpart, ipart;
7424 etype = TREE_TYPE (type);
7425 size = GET_MODE_SIZE (TYPE_MODE (etype));
7428 rpart = native_interpret_expr (etype, ptr, size);
7431 ipart = native_interpret_expr (etype, ptr+size, size);
7434 return build_complex (type, rpart, ipart);
7438 /* Subroutine of native_interpret_expr. Interpret the contents of
7439 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7440 If the buffer cannot be interpreted, return NULL_TREE. */
7443 native_interpret_vector (tree type, const unsigned char *ptr, int len)
7445 tree etype, elem, elements;
7448 etype = TREE_TYPE (type);
7449 size = GET_MODE_SIZE (TYPE_MODE (etype));
7450 count = TYPE_VECTOR_SUBPARTS (type);
7451 if (size * count > len)
7454 elements = NULL_TREE;
7455 for (i = count - 1; i >= 0; i--)
7457 elem = native_interpret_expr (etype, ptr+(i*size), size);
7460 elements = tree_cons (NULL_TREE, elem, elements);
7462 return build_vector (type, elements);
7466 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7467 the buffer PTR of length LEN as a constant of type TYPE. For
7468 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7469 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7470 return NULL_TREE. */
7473 native_interpret_expr (tree type, const unsigned char *ptr, int len)
7475 switch (TREE_CODE (type))
7480 return native_interpret_int (type, ptr, len);
7483 return native_interpret_real (type, ptr, len);
7486 return native_interpret_complex (type, ptr, len);
7489 return native_interpret_vector (type, ptr, len);
7497 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7498 TYPE at compile-time. If we're unable to perform the conversion
7499 return NULL_TREE. */
7502 fold_view_convert_expr (tree type, tree expr)
7504 /* We support up to 512-bit values (for V8DFmode). */
7505 unsigned char buffer[64];
7508 /* Check that the host and target are sane. */
7509 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7512 len = native_encode_expr (expr, buffer, sizeof (buffer));
7516 return native_interpret_expr (type, buffer, len);
7519 /* Build an expression for the address of T. Folds away INDIRECT_REF
7520 to avoid confusing the gimplify process. When IN_FOLD is true
7521 avoid modifications of T. */
7524 build_fold_addr_expr_with_type_1 (tree t, tree ptrtype, bool in_fold)
7526 /* The size of the object is not relevant when talking about its address. */
7527 if (TREE_CODE (t) == WITH_SIZE_EXPR)
7528 t = TREE_OPERAND (t, 0);
7530 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
7531 if (TREE_CODE (t) == INDIRECT_REF
7532 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
7534 t = TREE_OPERAND (t, 0);
7536 if (TREE_TYPE (t) != ptrtype)
7537 t = build1 (NOP_EXPR, ptrtype, t);
7543 while (handled_component_p (base))
7544 base = TREE_OPERAND (base, 0);
7547 TREE_ADDRESSABLE (base) = 1;
7549 t = build1 (ADDR_EXPR, ptrtype, t);
7552 t = build1 (ADDR_EXPR, ptrtype, t);
7557 /* Build an expression for the address of T with type PTRTYPE. This
7558 function modifies the input parameter 'T' by sometimes setting the
7559 TREE_ADDRESSABLE flag. */
7562 build_fold_addr_expr_with_type (tree t, tree ptrtype)
7564 return build_fold_addr_expr_with_type_1 (t, ptrtype, false);
7567 /* Build an expression for the address of T. This function modifies
7568 the input parameter 'T' by sometimes setting the TREE_ADDRESSABLE
7569 flag. When called from fold functions, use fold_addr_expr instead. */
7572 build_fold_addr_expr (tree t)
7574 return build_fold_addr_expr_with_type_1 (t,
7575 build_pointer_type (TREE_TYPE (t)),
7579 /* Same as build_fold_addr_expr, builds an expression for the address
7580 of T, but avoids touching the input node 't'. Fold functions
7581 should use this version. */
7584 fold_addr_expr (tree t)
7586 tree ptrtype = build_pointer_type (TREE_TYPE (t));
7588 return build_fold_addr_expr_with_type_1 (t, ptrtype, true);
7591 /* Fold a unary expression of code CODE and type TYPE with operand
7592 OP0. Return the folded expression if folding is successful.
7593 Otherwise, return NULL_TREE. */
7596 fold_unary (enum tree_code code, tree type, tree op0)
7600 enum tree_code_class kind = TREE_CODE_CLASS (code);
7602 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7603 && TREE_CODE_LENGTH (code) == 1);
7608 if (code == NOP_EXPR || code == CONVERT_EXPR
7609 || code == FLOAT_EXPR || code == ABS_EXPR)
7611 /* Don't use STRIP_NOPS, because signedness of argument type
7613 STRIP_SIGN_NOPS (arg0);
7617 /* Strip any conversions that don't change the mode. This
7618 is safe for every expression, except for a comparison
7619 expression because its signedness is derived from its
7622 Note that this is done as an internal manipulation within
7623 the constant folder, in order to find the simplest
7624 representation of the arguments so that their form can be
7625 studied. In any cases, the appropriate type conversions
7626 should be put back in the tree that will get out of the
7632 if (TREE_CODE_CLASS (code) == tcc_unary)
7634 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7635 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7636 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
7637 else if (TREE_CODE (arg0) == COND_EXPR)
7639 tree arg01 = TREE_OPERAND (arg0, 1);
7640 tree arg02 = TREE_OPERAND (arg0, 2);
7641 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7642 arg01 = fold_build1 (code, type, arg01);
7643 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7644 arg02 = fold_build1 (code, type, arg02);
7645 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
7648 /* If this was a conversion, and all we did was to move into
7649 inside the COND_EXPR, bring it back out. But leave it if
7650 it is a conversion from integer to integer and the
7651 result precision is no wider than a word since such a
7652 conversion is cheap and may be optimized away by combine,
7653 while it couldn't if it were outside the COND_EXPR. Then return
7654 so we don't get into an infinite recursion loop taking the
7655 conversion out and then back in. */
7657 if ((code == NOP_EXPR || code == CONVERT_EXPR
7658 || code == NON_LVALUE_EXPR)
7659 && TREE_CODE (tem) == COND_EXPR
7660 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7661 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7662 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7663 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7664 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7665 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7666 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7668 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7669 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7670 || flag_syntax_only))
7671 tem = build1 (code, type,
7673 TREE_TYPE (TREE_OPERAND
7674 (TREE_OPERAND (tem, 1), 0)),
7675 TREE_OPERAND (tem, 0),
7676 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7677 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
7680 else if (COMPARISON_CLASS_P (arg0))
7682 if (TREE_CODE (type) == BOOLEAN_TYPE)
7684 arg0 = copy_node (arg0);
7685 TREE_TYPE (arg0) = type;
7688 else if (TREE_CODE (type) != INTEGER_TYPE)
7689 return fold_build3 (COND_EXPR, type, arg0,
7690 fold_build1 (code, type,
7692 fold_build1 (code, type,
7693 integer_zero_node));
7700 /* Re-association barriers around constants and other re-association
7701 barriers can be removed. */
7702 if (CONSTANT_CLASS_P (op0)
7703 || TREE_CODE (op0) == PAREN_EXPR)
7704 return fold_convert (type, op0);
7710 case FIX_TRUNC_EXPR:
7711 if (TREE_TYPE (op0) == type)
7714 /* If we have (type) (a CMP b) and type is an integral type, return
7715 new expression involving the new type. */
7716 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
7717 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
7718 TREE_OPERAND (op0, 1));
7720 /* Handle cases of two conversions in a row. */
7721 if (TREE_CODE (op0) == NOP_EXPR
7722 || TREE_CODE (op0) == CONVERT_EXPR)
7724 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
7725 tree inter_type = TREE_TYPE (op0);
7726 int inside_int = INTEGRAL_TYPE_P (inside_type);
7727 int inside_ptr = POINTER_TYPE_P (inside_type);
7728 int inside_float = FLOAT_TYPE_P (inside_type);
7729 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
7730 unsigned int inside_prec = TYPE_PRECISION (inside_type);
7731 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
7732 int inter_int = INTEGRAL_TYPE_P (inter_type);
7733 int inter_ptr = POINTER_TYPE_P (inter_type);
7734 int inter_float = FLOAT_TYPE_P (inter_type);
7735 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
7736 unsigned int inter_prec = TYPE_PRECISION (inter_type);
7737 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
7738 int final_int = INTEGRAL_TYPE_P (type);
7739 int final_ptr = POINTER_TYPE_P (type);
7740 int final_float = FLOAT_TYPE_P (type);
7741 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
7742 unsigned int final_prec = TYPE_PRECISION (type);
7743 int final_unsignedp = TYPE_UNSIGNED (type);
7745 /* In addition to the cases of two conversions in a row
7746 handled below, if we are converting something to its own
7747 type via an object of identical or wider precision, neither
7748 conversion is needed. */
7749 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
7750 && (((inter_int || inter_ptr) && final_int)
7751 || (inter_float && final_float))
7752 && inter_prec >= final_prec)
7753 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7755 /* Likewise, if the intermediate and final types are either both
7756 float or both integer, we don't need the middle conversion if
7757 it is wider than the final type and doesn't change the signedness
7758 (for integers). Avoid this if the final type is a pointer
7759 since then we sometimes need the inner conversion. Likewise if
7760 the outer has a precision not equal to the size of its mode. */
7761 if (((inter_int && inside_int)
7762 || (inter_float && inside_float)
7763 || (inter_vec && inside_vec))
7764 && inter_prec >= inside_prec
7765 && (inter_float || inter_vec
7766 || inter_unsignedp == inside_unsignedp)
7767 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7768 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7770 && (! final_vec || inter_prec == inside_prec))
7771 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7773 /* If we have a sign-extension of a zero-extended value, we can
7774 replace that by a single zero-extension. */
7775 if (inside_int && inter_int && final_int
7776 && inside_prec < inter_prec && inter_prec < final_prec
7777 && inside_unsignedp && !inter_unsignedp)
7778 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7780 /* Two conversions in a row are not needed unless:
7781 - some conversion is floating-point (overstrict for now), or
7782 - some conversion is a vector (overstrict for now), or
7783 - the intermediate type is narrower than both initial and
7785 - the intermediate type and innermost type differ in signedness,
7786 and the outermost type is wider than the intermediate, or
7787 - the initial type is a pointer type and the precisions of the
7788 intermediate and final types differ, or
7789 - the final type is a pointer type and the precisions of the
7790 initial and intermediate types differ. */
7791 if (! inside_float && ! inter_float && ! final_float
7792 && ! inside_vec && ! inter_vec && ! final_vec
7793 && (inter_prec >= inside_prec || inter_prec >= final_prec)
7794 && ! (inside_int && inter_int
7795 && inter_unsignedp != inside_unsignedp
7796 && inter_prec < final_prec)
7797 && ((inter_unsignedp && inter_prec > inside_prec)
7798 == (final_unsignedp && final_prec > inter_prec))
7799 && ! (inside_ptr && inter_prec != final_prec)
7800 && ! (final_ptr && inside_prec != inter_prec)
7801 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7802 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
7803 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7806 /* Handle (T *)&A.B.C for A being of type T and B and C
7807 living at offset zero. This occurs frequently in
7808 C++ upcasting and then accessing the base. */
7809 if (TREE_CODE (op0) == ADDR_EXPR
7810 && POINTER_TYPE_P (type)
7811 && handled_component_p (TREE_OPERAND (op0, 0)))
7813 HOST_WIDE_INT bitsize, bitpos;
7815 enum machine_mode mode;
7816 int unsignedp, volatilep;
7817 tree base = TREE_OPERAND (op0, 0);
7818 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
7819 &mode, &unsignedp, &volatilep, false);
7820 /* If the reference was to a (constant) zero offset, we can use
7821 the address of the base if it has the same base type
7822 as the result type. */
7823 if (! offset && bitpos == 0
7824 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
7825 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
7826 return fold_convert (type, fold_addr_expr (base));
7829 if ((TREE_CODE (op0) == MODIFY_EXPR
7830 || TREE_CODE (op0) == GIMPLE_MODIFY_STMT)
7831 && TREE_CONSTANT (GENERIC_TREE_OPERAND (op0, 1))
7832 /* Detect assigning a bitfield. */
7833 && !(TREE_CODE (GENERIC_TREE_OPERAND (op0, 0)) == COMPONENT_REF
7835 (TREE_OPERAND (GENERIC_TREE_OPERAND (op0, 0), 1))))
7837 /* Don't leave an assignment inside a conversion
7838 unless assigning a bitfield. */
7839 tem = fold_build1 (code, type, GENERIC_TREE_OPERAND (op0, 1));
7840 /* First do the assignment, then return converted constant. */
7841 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
7842 TREE_NO_WARNING (tem) = 1;
7843 TREE_USED (tem) = 1;
7847 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7848 constants (if x has signed type, the sign bit cannot be set
7849 in c). This folds extension into the BIT_AND_EXPR. */
7850 if (INTEGRAL_TYPE_P (type)
7851 && TREE_CODE (type) != BOOLEAN_TYPE
7852 && TREE_CODE (op0) == BIT_AND_EXPR
7853 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
7856 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
7859 if (TYPE_UNSIGNED (TREE_TYPE (and))
7860 || (TYPE_PRECISION (type)
7861 <= TYPE_PRECISION (TREE_TYPE (and))))
7863 else if (TYPE_PRECISION (TREE_TYPE (and1))
7864 <= HOST_BITS_PER_WIDE_INT
7865 && host_integerp (and1, 1))
7867 unsigned HOST_WIDE_INT cst;
7869 cst = tree_low_cst (and1, 1);
7870 cst &= (HOST_WIDE_INT) -1
7871 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
7872 change = (cst == 0);
7873 #ifdef LOAD_EXTEND_OP
7875 && !flag_syntax_only
7876 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
7879 tree uns = unsigned_type_for (TREE_TYPE (and0));
7880 and0 = fold_convert (uns, and0);
7881 and1 = fold_convert (uns, and1);
7887 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
7888 TREE_INT_CST_HIGH (and1), 0,
7889 TREE_OVERFLOW (and1));
7890 return fold_build2 (BIT_AND_EXPR, type,
7891 fold_convert (type, and0), tem);
7895 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
7896 when one of the new casts will fold away. Conservatively we assume
7897 that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
7898 if (POINTER_TYPE_P (type)
7899 && TREE_CODE (arg0) == POINTER_PLUS_EXPR
7900 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7901 || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
7902 || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
7904 tree arg00 = TREE_OPERAND (arg0, 0);
7905 tree arg01 = TREE_OPERAND (arg0, 1);
7907 return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
7908 fold_convert (sizetype, arg01));
7911 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
7912 of the same precision, and X is an integer type not narrower than
7913 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
7914 if (INTEGRAL_TYPE_P (type)
7915 && TREE_CODE (op0) == BIT_NOT_EXPR
7916 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7917 && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
7918 || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
7919 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
7921 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
7922 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7923 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
7924 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
7927 /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the
7928 type of X and Y (integer types only). */
7929 if (INTEGRAL_TYPE_P (type)
7930 && TREE_CODE (op0) == MULT_EXPR
7931 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7932 && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (op0)))
7934 /* Be careful not to introduce new overflows. */
7936 if (TYPE_OVERFLOW_WRAPS (type))
7939 mult_type = unsigned_type_for (type);
7941 tem = fold_build2 (MULT_EXPR, mult_type,
7942 fold_convert (mult_type, TREE_OPERAND (op0, 0)),
7943 fold_convert (mult_type, TREE_OPERAND (op0, 1)));
7944 return fold_convert (type, tem);
7947 tem = fold_convert_const (code, type, op0);
7948 return tem ? tem : NULL_TREE;
7950 case FIXED_CONVERT_EXPR:
7951 tem = fold_convert_const (code, type, arg0);
7952 return tem ? tem : NULL_TREE;
7954 case VIEW_CONVERT_EXPR:
7955 if (TREE_TYPE (op0) == type)
7957 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
7958 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7960 /* For integral conversions with the same precision or pointer
7961 conversions use a NOP_EXPR instead. */
7962 if ((INTEGRAL_TYPE_P (type)
7963 || POINTER_TYPE_P (type))
7964 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
7965 || POINTER_TYPE_P (TREE_TYPE (op0)))
7966 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0))
7967 /* Do not muck with VIEW_CONVERT_EXPRs that convert from
7968 a sub-type to its base type as generated by the Ada FE. */
7969 && !(INTEGRAL_TYPE_P (TREE_TYPE (op0))
7970 && TREE_TYPE (TREE_TYPE (op0))))
7971 return fold_convert (type, op0);
7973 /* Strip inner integral conversions that do not change the precision. */
7974 if ((TREE_CODE (op0) == NOP_EXPR
7975 || TREE_CODE (op0) == CONVERT_EXPR)
7976 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
7977 || POINTER_TYPE_P (TREE_TYPE (op0)))
7978 && (INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
7979 || POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0))))
7980 && (TYPE_PRECISION (TREE_TYPE (op0))
7981 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
7982 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7984 return fold_view_convert_expr (type, op0);
7987 tem = fold_negate_expr (arg0);
7989 return fold_convert (type, tem);
7993 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
7994 return fold_abs_const (arg0, type);
7995 else if (TREE_CODE (arg0) == NEGATE_EXPR)
7996 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
7997 /* Convert fabs((double)float) into (double)fabsf(float). */
7998 else if (TREE_CODE (arg0) == NOP_EXPR
7999 && TREE_CODE (type) == REAL_TYPE)
8001 tree targ0 = strip_float_extensions (arg0);
8003 return fold_convert (type, fold_build1 (ABS_EXPR,
8007 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
8008 else if (TREE_CODE (arg0) == ABS_EXPR)
8010 else if (tree_expr_nonnegative_p (arg0))
8013 /* Strip sign ops from argument. */
8014 if (TREE_CODE (type) == REAL_TYPE)
8016 tem = fold_strip_sign_ops (arg0);
8018 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
8023 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8024 return fold_convert (type, arg0);
8025 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8027 tree itype = TREE_TYPE (type);
8028 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
8029 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
8030 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
8032 if (TREE_CODE (arg0) == COMPLEX_CST)
8034 tree itype = TREE_TYPE (type);
8035 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
8036 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
8037 return build_complex (type, rpart, negate_expr (ipart));
8039 if (TREE_CODE (arg0) == CONJ_EXPR)
8040 return fold_convert (type, TREE_OPERAND (arg0, 0));
8044 if (TREE_CODE (arg0) == INTEGER_CST)
8045 return fold_not_const (arg0, type);
8046 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
8047 return fold_convert (type, TREE_OPERAND (arg0, 0));
8048 /* Convert ~ (-A) to A - 1. */
8049 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
8050 return fold_build2 (MINUS_EXPR, type,
8051 fold_convert (type, TREE_OPERAND (arg0, 0)),
8052 build_int_cst (type, 1));
8053 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
8054 else if (INTEGRAL_TYPE_P (type)
8055 && ((TREE_CODE (arg0) == MINUS_EXPR
8056 && integer_onep (TREE_OPERAND (arg0, 1)))
8057 || (TREE_CODE (arg0) == PLUS_EXPR
8058 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
8059 return fold_build1 (NEGATE_EXPR, type,
8060 fold_convert (type, TREE_OPERAND (arg0, 0)));
8061 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8062 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8063 && (tem = fold_unary (BIT_NOT_EXPR, type,
8065 TREE_OPERAND (arg0, 0)))))
8066 return fold_build2 (BIT_XOR_EXPR, type, tem,
8067 fold_convert (type, TREE_OPERAND (arg0, 1)));
8068 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8069 && (tem = fold_unary (BIT_NOT_EXPR, type,
8071 TREE_OPERAND (arg0, 1)))))
8072 return fold_build2 (BIT_XOR_EXPR, type,
8073 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
8074 /* Perform BIT_NOT_EXPR on each element individually. */
8075 else if (TREE_CODE (arg0) == VECTOR_CST)
8077 tree elements = TREE_VECTOR_CST_ELTS (arg0), elem, list = NULL_TREE;
8078 int count = TYPE_VECTOR_SUBPARTS (type), i;
8080 for (i = 0; i < count; i++)
8084 elem = TREE_VALUE (elements);
8085 elem = fold_unary (BIT_NOT_EXPR, TREE_TYPE (type), elem);
8086 if (elem == NULL_TREE)
8088 elements = TREE_CHAIN (elements);
8091 elem = build_int_cst (TREE_TYPE (type), -1);
8092 list = tree_cons (NULL_TREE, elem, list);
8095 return build_vector (type, nreverse (list));
8100 case TRUTH_NOT_EXPR:
8101 /* The argument to invert_truthvalue must have Boolean type. */
8102 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8103 arg0 = fold_convert (boolean_type_node, arg0);
8105 /* Note that the operand of this must be an int
8106 and its values must be 0 or 1.
8107 ("true" is a fixed value perhaps depending on the language,
8108 but we don't handle values other than 1 correctly yet.) */
8109 tem = fold_truth_not_expr (arg0);
8112 return fold_convert (type, tem);
8115 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8116 return fold_convert (type, arg0);
8117 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8118 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8119 TREE_OPERAND (arg0, 1));
8120 if (TREE_CODE (arg0) == COMPLEX_CST)
8121 return fold_convert (type, TREE_REALPART (arg0));
8122 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8124 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8125 tem = fold_build2 (TREE_CODE (arg0), itype,
8126 fold_build1 (REALPART_EXPR, itype,
8127 TREE_OPERAND (arg0, 0)),
8128 fold_build1 (REALPART_EXPR, itype,
8129 TREE_OPERAND (arg0, 1)));
8130 return fold_convert (type, tem);
8132 if (TREE_CODE (arg0) == CONJ_EXPR)
8134 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8135 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8136 return fold_convert (type, tem);
8138 if (TREE_CODE (arg0) == CALL_EXPR)
8140 tree fn = get_callee_fndecl (arg0);
8141 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8142 switch (DECL_FUNCTION_CODE (fn))
8144 CASE_FLT_FN (BUILT_IN_CEXPI):
8145 fn = mathfn_built_in (type, BUILT_IN_COS);
8147 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8157 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8158 return fold_convert (type, integer_zero_node);
8159 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8160 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8161 TREE_OPERAND (arg0, 0));
8162 if (TREE_CODE (arg0) == COMPLEX_CST)
8163 return fold_convert (type, TREE_IMAGPART (arg0));
8164 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8166 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8167 tem = fold_build2 (TREE_CODE (arg0), itype,
8168 fold_build1 (IMAGPART_EXPR, itype,
8169 TREE_OPERAND (arg0, 0)),
8170 fold_build1 (IMAGPART_EXPR, itype,
8171 TREE_OPERAND (arg0, 1)));
8172 return fold_convert (type, tem);
8174 if (TREE_CODE (arg0) == CONJ_EXPR)
8176 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8177 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8178 return fold_convert (type, negate_expr (tem));
8180 if (TREE_CODE (arg0) == CALL_EXPR)
8182 tree fn = get_callee_fndecl (arg0);
8183 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8184 switch (DECL_FUNCTION_CODE (fn))
8186 CASE_FLT_FN (BUILT_IN_CEXPI):
8187 fn = mathfn_built_in (type, BUILT_IN_SIN);
8189 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8200 } /* switch (code) */
8203 /* Fold a binary expression of code CODE and type TYPE with operands
8204 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8205 Return the folded expression if folding is successful. Otherwise,
8206 return NULL_TREE. */
8209 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8211 enum tree_code compl_code;
8213 if (code == MIN_EXPR)
8214 compl_code = MAX_EXPR;
8215 else if (code == MAX_EXPR)
8216 compl_code = MIN_EXPR;
8220 /* MIN (MAX (a, b), b) == b. */
8221 if (TREE_CODE (op0) == compl_code
8222 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8223 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8225 /* MIN (MAX (b, a), b) == b. */
8226 if (TREE_CODE (op0) == compl_code
8227 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8228 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8229 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8231 /* MIN (a, MAX (a, b)) == a. */
8232 if (TREE_CODE (op1) == compl_code
8233 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8234 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8235 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8237 /* MIN (a, MAX (b, a)) == a. */
8238 if (TREE_CODE (op1) == compl_code
8239 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8240 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8241 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8246 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8247 by changing CODE to reduce the magnitude of constants involved in
8248 ARG0 of the comparison.
8249 Returns a canonicalized comparison tree if a simplification was
8250 possible, otherwise returns NULL_TREE.
8251 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8252 valid if signed overflow is undefined. */
8255 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8256 tree arg0, tree arg1,
8257 bool *strict_overflow_p)
8259 enum tree_code code0 = TREE_CODE (arg0);
8260 tree t, cst0 = NULL_TREE;
8264 /* Match A +- CST code arg1 and CST code arg1. */
8265 if (!(((code0 == MINUS_EXPR
8266 || code0 == PLUS_EXPR)
8267 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8268 || code0 == INTEGER_CST))
8271 /* Identify the constant in arg0 and its sign. */
8272 if (code0 == INTEGER_CST)
8275 cst0 = TREE_OPERAND (arg0, 1);
8276 sgn0 = tree_int_cst_sgn (cst0);
8278 /* Overflowed constants and zero will cause problems. */
8279 if (integer_zerop (cst0)
8280 || TREE_OVERFLOW (cst0))
8283 /* See if we can reduce the magnitude of the constant in
8284 arg0 by changing the comparison code. */
8285 if (code0 == INTEGER_CST)
8287 /* CST <= arg1 -> CST-1 < arg1. */
8288 if (code == LE_EXPR && sgn0 == 1)
8290 /* -CST < arg1 -> -CST-1 <= arg1. */
8291 else if (code == LT_EXPR && sgn0 == -1)
8293 /* CST > arg1 -> CST-1 >= arg1. */
8294 else if (code == GT_EXPR && sgn0 == 1)
8296 /* -CST >= arg1 -> -CST-1 > arg1. */
8297 else if (code == GE_EXPR && sgn0 == -1)
8301 /* arg1 code' CST' might be more canonical. */
8306 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8308 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8310 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8311 else if (code == GT_EXPR
8312 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8314 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8315 else if (code == LE_EXPR
8316 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8318 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8319 else if (code == GE_EXPR
8320 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8324 *strict_overflow_p = true;
8327 /* Now build the constant reduced in magnitude. */
8328 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8329 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8330 if (code0 != INTEGER_CST)
8331 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8333 /* If swapping might yield to a more canonical form, do so. */
8335 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8337 return fold_build2 (code, type, t, arg1);
8340 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8341 overflow further. Try to decrease the magnitude of constants involved
8342 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8343 and put sole constants at the second argument position.
8344 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8347 maybe_canonicalize_comparison (enum tree_code code, tree type,
8348 tree arg0, tree arg1)
8351 bool strict_overflow_p;
8352 const char * const warnmsg = G_("assuming signed overflow does not occur "
8353 "when reducing constant in comparison");
8355 /* In principle pointers also have undefined overflow behavior,
8356 but that causes problems elsewhere. */
8357 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8358 || POINTER_TYPE_P (TREE_TYPE (arg0)))
8361 /* Try canonicalization by simplifying arg0. */
8362 strict_overflow_p = false;
8363 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8364 &strict_overflow_p);
8367 if (strict_overflow_p)
8368 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8372 /* Try canonicalization by simplifying arg1 using the swapped
8374 code = swap_tree_comparison (code);
8375 strict_overflow_p = false;
8376 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8377 &strict_overflow_p);
8378 if (t && strict_overflow_p)
8379 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8383 /* Subroutine of fold_binary. This routine performs all of the
8384 transformations that are common to the equality/inequality
8385 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8386 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8387 fold_binary should call fold_binary. Fold a comparison with
8388 tree code CODE and type TYPE with operands OP0 and OP1. Return
8389 the folded comparison or NULL_TREE. */
8392 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8394 tree arg0, arg1, tem;
8399 STRIP_SIGN_NOPS (arg0);
8400 STRIP_SIGN_NOPS (arg1);
8402 tem = fold_relational_const (code, type, arg0, arg1);
8403 if (tem != NULL_TREE)
8406 /* If one arg is a real or integer constant, put it last. */
8407 if (tree_swap_operands_p (arg0, arg1, true))
8408 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8410 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8411 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8412 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8413 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8414 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8415 && (TREE_CODE (arg1) == INTEGER_CST
8416 && !TREE_OVERFLOW (arg1)))
8418 tree const1 = TREE_OPERAND (arg0, 1);
8420 tree variable = TREE_OPERAND (arg0, 0);
8423 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8425 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8426 TREE_TYPE (arg1), const2, const1);
8428 /* If the constant operation overflowed this can be
8429 simplified as a comparison against INT_MAX/INT_MIN. */
8430 if (TREE_CODE (lhs) == INTEGER_CST
8431 && TREE_OVERFLOW (lhs))
8433 int const1_sgn = tree_int_cst_sgn (const1);
8434 enum tree_code code2 = code;
8436 /* Get the sign of the constant on the lhs if the
8437 operation were VARIABLE + CONST1. */
8438 if (TREE_CODE (arg0) == MINUS_EXPR)
8439 const1_sgn = -const1_sgn;
8441 /* The sign of the constant determines if we overflowed
8442 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8443 Canonicalize to the INT_MIN overflow by swapping the comparison
8445 if (const1_sgn == -1)
8446 code2 = swap_tree_comparison (code);
8448 /* We now can look at the canonicalized case
8449 VARIABLE + 1 CODE2 INT_MIN
8450 and decide on the result. */
8451 if (code2 == LT_EXPR
8453 || code2 == EQ_EXPR)
8454 return omit_one_operand (type, boolean_false_node, variable);
8455 else if (code2 == NE_EXPR
8457 || code2 == GT_EXPR)
8458 return omit_one_operand (type, boolean_true_node, variable);
8461 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8462 && (TREE_CODE (lhs) != INTEGER_CST
8463 || !TREE_OVERFLOW (lhs)))
8465 fold_overflow_warning (("assuming signed overflow does not occur "
8466 "when changing X +- C1 cmp C2 to "
8468 WARN_STRICT_OVERFLOW_COMPARISON);
8469 return fold_build2 (code, type, variable, lhs);
8473 /* For comparisons of pointers we can decompose it to a compile time
8474 comparison of the base objects and the offsets into the object.
8475 This requires at least one operand being an ADDR_EXPR or a
8476 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8477 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8478 && (TREE_CODE (arg0) == ADDR_EXPR
8479 || TREE_CODE (arg1) == ADDR_EXPR
8480 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
8481 || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
8483 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8484 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8485 enum machine_mode mode;
8486 int volatilep, unsignedp;
8487 bool indirect_base0 = false, indirect_base1 = false;
8489 /* Get base and offset for the access. Strip ADDR_EXPR for
8490 get_inner_reference, but put it back by stripping INDIRECT_REF
8491 off the base object if possible. indirect_baseN will be true
8492 if baseN is not an address but refers to the object itself. */
8494 if (TREE_CODE (arg0) == ADDR_EXPR)
8496 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8497 &bitsize, &bitpos0, &offset0, &mode,
8498 &unsignedp, &volatilep, false);
8499 if (TREE_CODE (base0) == INDIRECT_REF)
8500 base0 = TREE_OPERAND (base0, 0);
8502 indirect_base0 = true;
8504 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
8506 base0 = TREE_OPERAND (arg0, 0);
8507 offset0 = TREE_OPERAND (arg0, 1);
8511 if (TREE_CODE (arg1) == ADDR_EXPR)
8513 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8514 &bitsize, &bitpos1, &offset1, &mode,
8515 &unsignedp, &volatilep, false);
8516 if (TREE_CODE (base1) == INDIRECT_REF)
8517 base1 = TREE_OPERAND (base1, 0);
8519 indirect_base1 = true;
8521 else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
8523 base1 = TREE_OPERAND (arg1, 0);
8524 offset1 = TREE_OPERAND (arg1, 1);
8527 /* If we have equivalent bases we might be able to simplify. */
8528 if (indirect_base0 == indirect_base1
8529 && operand_equal_p (base0, base1, 0))
8531 /* We can fold this expression to a constant if the non-constant
8532 offset parts are equal. */
8533 if (offset0 == offset1
8534 || (offset0 && offset1
8535 && operand_equal_p (offset0, offset1, 0)))
8540 return build_int_cst (boolean_type_node, bitpos0 == bitpos1);
8542 return build_int_cst (boolean_type_node, bitpos0 != bitpos1);
8544 return build_int_cst (boolean_type_node, bitpos0 < bitpos1);
8546 return build_int_cst (boolean_type_node, bitpos0 <= bitpos1);
8548 return build_int_cst (boolean_type_node, bitpos0 >= bitpos1);
8550 return build_int_cst (boolean_type_node, bitpos0 > bitpos1);
8554 /* We can simplify the comparison to a comparison of the variable
8555 offset parts if the constant offset parts are equal.
8556 Be careful to use signed size type here because otherwise we
8557 mess with array offsets in the wrong way. This is possible
8558 because pointer arithmetic is restricted to retain within an
8559 object and overflow on pointer differences is undefined as of
8560 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8561 else if (bitpos0 == bitpos1)
8563 tree signed_size_type_node;
8564 signed_size_type_node = signed_type_for (size_type_node);
8566 /* By converting to signed size type we cover middle-end pointer
8567 arithmetic which operates on unsigned pointer types of size
8568 type size and ARRAY_REF offsets which are properly sign or
8569 zero extended from their type in case it is narrower than
8571 if (offset0 == NULL_TREE)
8572 offset0 = build_int_cst (signed_size_type_node, 0);
8574 offset0 = fold_convert (signed_size_type_node, offset0);
8575 if (offset1 == NULL_TREE)
8576 offset1 = build_int_cst (signed_size_type_node, 0);
8578 offset1 = fold_convert (signed_size_type_node, offset1);
8580 return fold_build2 (code, type, offset0, offset1);
8583 /* For non-equal bases we can simplify if they are addresses
8584 of local binding decls or constants. */
8585 else if (indirect_base0 && indirect_base1
8586 /* We know that !operand_equal_p (base0, base1, 0)
8587 because the if condition was false. */
8588 && TREE_CODE (arg0) == ADDR_EXPR
8589 && TREE_CODE (arg1) == ADDR_EXPR
8591 && (targetm.binds_local_p (base0)
8592 || CONSTANT_CLASS_P (base1)))
8593 || CONSTANT_CLASS_P (base0))
8595 && (targetm.binds_local_p (base1)
8596 || CONSTANT_CLASS_P (base0)))
8597 || CONSTANT_CLASS_P (base1)))
8599 if (code == EQ_EXPR)
8600 return omit_two_operands (type, boolean_false_node, arg0, arg1);
8601 else if (code == NE_EXPR)
8602 return omit_two_operands (type, boolean_true_node, arg0, arg1);
8604 /* For equal offsets we can simplify to a comparison of the
8606 else if (bitpos0 == bitpos1
8608 ? base0 != TREE_OPERAND (arg0, 0) : base0 != arg0)
8610 ? base1 != TREE_OPERAND (arg1, 0) : base1 != arg1)
8611 && ((offset0 == offset1)
8612 || (offset0 && offset1
8613 && operand_equal_p (offset0, offset1, 0))))
8616 base0 = fold_addr_expr (base0);
8618 base1 = fold_addr_expr (base1);
8619 return fold_build2 (code, type, base0, base1);
8623 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8624 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8625 the resulting offset is smaller in absolute value than the
8627 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8628 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8629 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8630 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8631 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
8632 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8633 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
8635 tree const1 = TREE_OPERAND (arg0, 1);
8636 tree const2 = TREE_OPERAND (arg1, 1);
8637 tree variable1 = TREE_OPERAND (arg0, 0);
8638 tree variable2 = TREE_OPERAND (arg1, 0);
8640 const char * const warnmsg = G_("assuming signed overflow does not "
8641 "occur when combining constants around "
8644 /* Put the constant on the side where it doesn't overflow and is
8645 of lower absolute value than before. */
8646 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8647 ? MINUS_EXPR : PLUS_EXPR,
8649 if (!TREE_OVERFLOW (cst)
8650 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
8652 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8653 return fold_build2 (code, type,
8655 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
8659 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8660 ? MINUS_EXPR : PLUS_EXPR,
8662 if (!TREE_OVERFLOW (cst)
8663 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
8665 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8666 return fold_build2 (code, type,
8667 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
8673 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
8674 signed arithmetic case. That form is created by the compiler
8675 often enough for folding it to be of value. One example is in
8676 computing loop trip counts after Operator Strength Reduction. */
8677 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8678 && TREE_CODE (arg0) == MULT_EXPR
8679 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8680 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8681 && integer_zerop (arg1))
8683 tree const1 = TREE_OPERAND (arg0, 1);
8684 tree const2 = arg1; /* zero */
8685 tree variable1 = TREE_OPERAND (arg0, 0);
8686 enum tree_code cmp_code = code;
8688 gcc_assert (!integer_zerop (const1));
8690 fold_overflow_warning (("assuming signed overflow does not occur when "
8691 "eliminating multiplication in comparison "
8693 WARN_STRICT_OVERFLOW_COMPARISON);
8695 /* If const1 is negative we swap the sense of the comparison. */
8696 if (tree_int_cst_sgn (const1) < 0)
8697 cmp_code = swap_tree_comparison (cmp_code);
8699 return fold_build2 (cmp_code, type, variable1, const2);
8702 tem = maybe_canonicalize_comparison (code, type, op0, op1);
8706 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8708 tree targ0 = strip_float_extensions (arg0);
8709 tree targ1 = strip_float_extensions (arg1);
8710 tree newtype = TREE_TYPE (targ0);
8712 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8713 newtype = TREE_TYPE (targ1);
8715 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8716 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8717 return fold_build2 (code, type, fold_convert (newtype, targ0),
8718 fold_convert (newtype, targ1));
8720 /* (-a) CMP (-b) -> b CMP a */
8721 if (TREE_CODE (arg0) == NEGATE_EXPR
8722 && TREE_CODE (arg1) == NEGATE_EXPR)
8723 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8724 TREE_OPERAND (arg0, 0));
8726 if (TREE_CODE (arg1) == REAL_CST)
8728 REAL_VALUE_TYPE cst;
8729 cst = TREE_REAL_CST (arg1);
8731 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8732 if (TREE_CODE (arg0) == NEGATE_EXPR)
8733 return fold_build2 (swap_tree_comparison (code), type,
8734 TREE_OPERAND (arg0, 0),
8735 build_real (TREE_TYPE (arg1),
8736 REAL_VALUE_NEGATE (cst)));
8738 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8739 /* a CMP (-0) -> a CMP 0 */
8740 if (REAL_VALUE_MINUS_ZERO (cst))
8741 return fold_build2 (code, type, arg0,
8742 build_real (TREE_TYPE (arg1), dconst0));
8744 /* x != NaN is always true, other ops are always false. */
8745 if (REAL_VALUE_ISNAN (cst)
8746 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8748 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8749 return omit_one_operand (type, tem, arg0);
8752 /* Fold comparisons against infinity. */
8753 if (REAL_VALUE_ISINF (cst))
8755 tem = fold_inf_compare (code, type, arg0, arg1);
8756 if (tem != NULL_TREE)
8761 /* If this is a comparison of a real constant with a PLUS_EXPR
8762 or a MINUS_EXPR of a real constant, we can convert it into a
8763 comparison with a revised real constant as long as no overflow
8764 occurs when unsafe_math_optimizations are enabled. */
8765 if (flag_unsafe_math_optimizations
8766 && TREE_CODE (arg1) == REAL_CST
8767 && (TREE_CODE (arg0) == PLUS_EXPR
8768 || TREE_CODE (arg0) == MINUS_EXPR)
8769 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8770 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8771 ? MINUS_EXPR : PLUS_EXPR,
8772 arg1, TREE_OPERAND (arg0, 1), 0))
8773 && !TREE_OVERFLOW (tem))
8774 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
8776 /* Likewise, we can simplify a comparison of a real constant with
8777 a MINUS_EXPR whose first operand is also a real constant, i.e.
8778 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
8779 floating-point types only if -fassociative-math is set. */
8780 if (flag_associative_math
8781 && TREE_CODE (arg1) == REAL_CST
8782 && TREE_CODE (arg0) == MINUS_EXPR
8783 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8784 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8786 && !TREE_OVERFLOW (tem))
8787 return fold_build2 (swap_tree_comparison (code), type,
8788 TREE_OPERAND (arg0, 1), tem);
8790 /* Fold comparisons against built-in math functions. */
8791 if (TREE_CODE (arg1) == REAL_CST
8792 && flag_unsafe_math_optimizations
8793 && ! flag_errno_math)
8795 enum built_in_function fcode = builtin_mathfn_code (arg0);
8797 if (fcode != END_BUILTINS)
8799 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8800 if (tem != NULL_TREE)
8806 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8807 && (TREE_CODE (arg0) == NOP_EXPR
8808 || TREE_CODE (arg0) == CONVERT_EXPR))
8810 /* If we are widening one operand of an integer comparison,
8811 see if the other operand is similarly being widened. Perhaps we
8812 can do the comparison in the narrower type. */
8813 tem = fold_widened_comparison (code, type, arg0, arg1);
8817 /* Or if we are changing signedness. */
8818 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
8823 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8824 constant, we can simplify it. */
8825 if (TREE_CODE (arg1) == INTEGER_CST
8826 && (TREE_CODE (arg0) == MIN_EXPR
8827 || TREE_CODE (arg0) == MAX_EXPR)
8828 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8830 tem = optimize_minmax_comparison (code, type, op0, op1);
8835 /* Simplify comparison of something with itself. (For IEEE
8836 floating-point, we can only do some of these simplifications.) */
8837 if (operand_equal_p (arg0, arg1, 0))
8842 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8843 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8844 return constant_boolean_node (1, type);
8849 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8850 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8851 return constant_boolean_node (1, type);
8852 return fold_build2 (EQ_EXPR, type, arg0, arg1);
8855 /* For NE, we can only do this simplification if integer
8856 or we don't honor IEEE floating point NaNs. */
8857 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8858 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8860 /* ... fall through ... */
8863 return constant_boolean_node (0, type);
8869 /* If we are comparing an expression that just has comparisons
8870 of two integer values, arithmetic expressions of those comparisons,
8871 and constants, we can simplify it. There are only three cases
8872 to check: the two values can either be equal, the first can be
8873 greater, or the second can be greater. Fold the expression for
8874 those three values. Since each value must be 0 or 1, we have
8875 eight possibilities, each of which corresponds to the constant 0
8876 or 1 or one of the six possible comparisons.
8878 This handles common cases like (a > b) == 0 but also handles
8879 expressions like ((x > y) - (y > x)) > 0, which supposedly
8880 occur in macroized code. */
8882 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8884 tree cval1 = 0, cval2 = 0;
8887 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8888 /* Don't handle degenerate cases here; they should already
8889 have been handled anyway. */
8890 && cval1 != 0 && cval2 != 0
8891 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8892 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8893 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8894 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8895 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8896 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8897 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8899 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8900 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8902 /* We can't just pass T to eval_subst in case cval1 or cval2
8903 was the same as ARG1. */
8906 = fold_build2 (code, type,
8907 eval_subst (arg0, cval1, maxval,
8911 = fold_build2 (code, type,
8912 eval_subst (arg0, cval1, maxval,
8916 = fold_build2 (code, type,
8917 eval_subst (arg0, cval1, minval,
8921 /* All three of these results should be 0 or 1. Confirm they are.
8922 Then use those values to select the proper code to use. */
8924 if (TREE_CODE (high_result) == INTEGER_CST
8925 && TREE_CODE (equal_result) == INTEGER_CST
8926 && TREE_CODE (low_result) == INTEGER_CST)
8928 /* Make a 3-bit mask with the high-order bit being the
8929 value for `>', the next for '=', and the low for '<'. */
8930 switch ((integer_onep (high_result) * 4)
8931 + (integer_onep (equal_result) * 2)
8932 + integer_onep (low_result))
8936 return omit_one_operand (type, integer_zero_node, arg0);
8957 return omit_one_operand (type, integer_one_node, arg0);
8961 return save_expr (build2 (code, type, cval1, cval2));
8962 return fold_build2 (code, type, cval1, cval2);
8967 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8968 into a single range test. */
8969 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
8970 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
8971 && TREE_CODE (arg1) == INTEGER_CST
8972 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8973 && !integer_zerop (TREE_OPERAND (arg0, 1))
8974 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8975 && !TREE_OVERFLOW (arg1))
8977 tem = fold_div_compare (code, type, arg0, arg1);
8978 if (tem != NULL_TREE)
8982 /* Fold ~X op ~Y as Y op X. */
8983 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8984 && TREE_CODE (arg1) == BIT_NOT_EXPR)
8986 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
8987 return fold_build2 (code, type,
8988 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
8989 TREE_OPERAND (arg0, 0));
8992 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
8993 if (TREE_CODE (arg0) == BIT_NOT_EXPR
8994 && TREE_CODE (arg1) == INTEGER_CST)
8996 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
8997 return fold_build2 (swap_tree_comparison (code), type,
8998 TREE_OPERAND (arg0, 0),
8999 fold_build1 (BIT_NOT_EXPR, cmp_type,
9000 fold_convert (cmp_type, arg1)));
9007 /* Subroutine of fold_binary. Optimize complex multiplications of the
9008 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9009 argument EXPR represents the expression "z" of type TYPE. */
9012 fold_mult_zconjz (tree type, tree expr)
9014 tree itype = TREE_TYPE (type);
9015 tree rpart, ipart, tem;
9017 if (TREE_CODE (expr) == COMPLEX_EXPR)
9019 rpart = TREE_OPERAND (expr, 0);
9020 ipart = TREE_OPERAND (expr, 1);
9022 else if (TREE_CODE (expr) == COMPLEX_CST)
9024 rpart = TREE_REALPART (expr);
9025 ipart = TREE_IMAGPART (expr);
9029 expr = save_expr (expr);
9030 rpart = fold_build1 (REALPART_EXPR, itype, expr);
9031 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
9034 rpart = save_expr (rpart);
9035 ipart = save_expr (ipart);
9036 tem = fold_build2 (PLUS_EXPR, itype,
9037 fold_build2 (MULT_EXPR, itype, rpart, rpart),
9038 fold_build2 (MULT_EXPR, itype, ipart, ipart));
9039 return fold_build2 (COMPLEX_EXPR, type, tem,
9040 fold_convert (itype, integer_zero_node));
9044 /* Subroutine of fold_binary. If P is the value of EXPR, computes
9045 power-of-two M and (arbitrary) N such that M divides (P-N). This condition
9046 guarantees that P and N have the same least significant log2(M) bits.
9047 N is not otherwise constrained. In particular, N is not normalized to
9048 0 <= N < M as is common. In general, the precise value of P is unknown.
9049 M is chosen as large as possible such that constant N can be determined.
9051 Returns M and sets *RESIDUE to N. */
9053 static unsigned HOST_WIDE_INT
9054 get_pointer_modulus_and_residue (tree expr, unsigned HOST_WIDE_INT *residue)
9056 enum tree_code code;
9060 code = TREE_CODE (expr);
9061 if (code == ADDR_EXPR)
9063 expr = TREE_OPERAND (expr, 0);
9064 if (handled_component_p (expr))
9066 HOST_WIDE_INT bitsize, bitpos;
9068 enum machine_mode mode;
9069 int unsignedp, volatilep;
9071 expr = get_inner_reference (expr, &bitsize, &bitpos, &offset,
9072 &mode, &unsignedp, &volatilep, false);
9073 *residue = bitpos / BITS_PER_UNIT;
9076 if (TREE_CODE (offset) == INTEGER_CST)
9077 *residue += TREE_INT_CST_LOW (offset);
9079 /* We don't handle more complicated offset expressions. */
9085 return DECL_ALIGN_UNIT (expr);
9087 else if (code == POINTER_PLUS_EXPR)
9090 unsigned HOST_WIDE_INT modulus;
9091 enum tree_code inner_code;
9093 op0 = TREE_OPERAND (expr, 0);
9095 modulus = get_pointer_modulus_and_residue (op0, residue);
9097 op1 = TREE_OPERAND (expr, 1);
9099 inner_code = TREE_CODE (op1);
9100 if (inner_code == INTEGER_CST)
9102 *residue += TREE_INT_CST_LOW (op1);
9105 else if (inner_code == MULT_EXPR)
9107 op1 = TREE_OPERAND (op1, 1);
9108 if (TREE_CODE (op1) == INTEGER_CST)
9110 unsigned HOST_WIDE_INT align;
9112 /* Compute the greatest power-of-2 divisor of op1. */
9113 align = TREE_INT_CST_LOW (op1);
9116 /* If align is non-zero and less than *modulus, replace
9117 *modulus with align., If align is 0, then either op1 is 0
9118 or the greatest power-of-2 divisor of op1 doesn't fit in an
9119 unsigned HOST_WIDE_INT. In either case, no additional
9120 constraint is imposed. */
9122 modulus = MIN (modulus, align);
9129 /* If we get here, we were unable to determine anything useful about the
9135 /* Fold a binary expression of code CODE and type TYPE with operands
9136 OP0 and OP1. Return the folded expression if folding is
9137 successful. Otherwise, return NULL_TREE. */
9140 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
9142 enum tree_code_class kind = TREE_CODE_CLASS (code);
9143 tree arg0, arg1, tem;
9144 tree t1 = NULL_TREE;
9145 bool strict_overflow_p;
9147 gcc_assert ((IS_EXPR_CODE_CLASS (kind)
9148 || IS_GIMPLE_STMT_CODE_CLASS (kind))
9149 && TREE_CODE_LENGTH (code) == 2
9151 && op1 != NULL_TREE);
9156 /* Strip any conversions that don't change the mode. This is
9157 safe for every expression, except for a comparison expression
9158 because its signedness is derived from its operands. So, in
9159 the latter case, only strip conversions that don't change the
9162 Note that this is done as an internal manipulation within the
9163 constant folder, in order to find the simplest representation
9164 of the arguments so that their form can be studied. In any
9165 cases, the appropriate type conversions should be put back in
9166 the tree that will get out of the constant folder. */
9168 if (kind == tcc_comparison)
9170 STRIP_SIGN_NOPS (arg0);
9171 STRIP_SIGN_NOPS (arg1);
9179 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9180 constant but we can't do arithmetic on them. */
9181 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9182 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9183 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == FIXED_CST)
9184 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == INTEGER_CST)
9185 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9186 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9188 if (kind == tcc_binary)
9190 /* Make sure type and arg0 have the same saturating flag. */
9191 gcc_assert (TYPE_SATURATING (type)
9192 == TYPE_SATURATING (TREE_TYPE (arg0)));
9193 tem = const_binop (code, arg0, arg1, 0);
9195 else if (kind == tcc_comparison)
9196 tem = fold_relational_const (code, type, arg0, arg1);
9200 if (tem != NULL_TREE)
9202 if (TREE_TYPE (tem) != type)
9203 tem = fold_convert (type, tem);
9208 /* If this is a commutative operation, and ARG0 is a constant, move it
9209 to ARG1 to reduce the number of tests below. */
9210 if (commutative_tree_code (code)
9211 && tree_swap_operands_p (arg0, arg1, true))
9212 return fold_build2 (code, type, op1, op0);
9214 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9216 First check for cases where an arithmetic operation is applied to a
9217 compound, conditional, or comparison operation. Push the arithmetic
9218 operation inside the compound or conditional to see if any folding
9219 can then be done. Convert comparison to conditional for this purpose.
9220 The also optimizes non-constant cases that used to be done in
9223 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9224 one of the operands is a comparison and the other is a comparison, a
9225 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9226 code below would make the expression more complex. Change it to a
9227 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9228 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9230 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9231 || code == EQ_EXPR || code == NE_EXPR)
9232 && ((truth_value_p (TREE_CODE (arg0))
9233 && (truth_value_p (TREE_CODE (arg1))
9234 || (TREE_CODE (arg1) == BIT_AND_EXPR
9235 && integer_onep (TREE_OPERAND (arg1, 1)))))
9236 || (truth_value_p (TREE_CODE (arg1))
9237 && (truth_value_p (TREE_CODE (arg0))
9238 || (TREE_CODE (arg0) == BIT_AND_EXPR
9239 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9241 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9242 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9245 fold_convert (boolean_type_node, arg0),
9246 fold_convert (boolean_type_node, arg1));
9248 if (code == EQ_EXPR)
9249 tem = invert_truthvalue (tem);
9251 return fold_convert (type, tem);
9254 if (TREE_CODE_CLASS (code) == tcc_binary
9255 || TREE_CODE_CLASS (code) == tcc_comparison)
9257 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9258 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9259 fold_build2 (code, type,
9260 fold_convert (TREE_TYPE (op0),
9261 TREE_OPERAND (arg0, 1)),
9263 if (TREE_CODE (arg1) == COMPOUND_EXPR
9264 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9265 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9266 fold_build2 (code, type, op0,
9267 fold_convert (TREE_TYPE (op1),
9268 TREE_OPERAND (arg1, 1))));
9270 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9272 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9274 /*cond_first_p=*/1);
9275 if (tem != NULL_TREE)
9279 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9281 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9283 /*cond_first_p=*/0);
9284 if (tem != NULL_TREE)
9291 case POINTER_PLUS_EXPR:
9292 /* 0 +p index -> (type)index */
9293 if (integer_zerop (arg0))
9294 return non_lvalue (fold_convert (type, arg1));
9296 /* PTR +p 0 -> PTR */
9297 if (integer_zerop (arg1))
9298 return non_lvalue (fold_convert (type, arg0));
9300 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9301 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9302 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9303 return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
9304 fold_convert (sizetype, arg1),
9305 fold_convert (sizetype, arg0)));
9307 /* index +p PTR -> PTR +p index */
9308 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9309 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9310 return fold_build2 (POINTER_PLUS_EXPR, type,
9311 fold_convert (type, arg1),
9312 fold_convert (sizetype, arg0));
9314 /* (PTR +p B) +p A -> PTR +p (B + A) */
9315 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9318 tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
9319 tree arg00 = TREE_OPERAND (arg0, 0);
9320 inner = fold_build2 (PLUS_EXPR, sizetype,
9321 arg01, fold_convert (sizetype, arg1));
9322 return fold_convert (type,
9323 fold_build2 (POINTER_PLUS_EXPR,
9324 TREE_TYPE (arg00), arg00, inner));
9327 /* PTR_CST +p CST -> CST1 */
9328 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9329 return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
9331 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9332 of the array. Loop optimizer sometimes produce this type of
9334 if (TREE_CODE (arg0) == ADDR_EXPR)
9336 tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
9338 return fold_convert (type, tem);
9344 /* PTR + INT -> (INT)(PTR p+ INT) */
9345 if (POINTER_TYPE_P (TREE_TYPE (arg0))
9346 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9347 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9350 fold_convert (sizetype, arg1)));
9351 /* INT + PTR -> (INT)(PTR p+ INT) */
9352 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9353 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9354 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9357 fold_convert (sizetype, arg0)));
9358 /* A + (-B) -> A - B */
9359 if (TREE_CODE (arg1) == NEGATE_EXPR)
9360 return fold_build2 (MINUS_EXPR, type,
9361 fold_convert (type, arg0),
9362 fold_convert (type, TREE_OPERAND (arg1, 0)));
9363 /* (-A) + B -> B - A */
9364 if (TREE_CODE (arg0) == NEGATE_EXPR
9365 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9366 return fold_build2 (MINUS_EXPR, type,
9367 fold_convert (type, arg1),
9368 fold_convert (type, TREE_OPERAND (arg0, 0)));
9370 if (INTEGRAL_TYPE_P (type))
9372 /* Convert ~A + 1 to -A. */
9373 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9374 && integer_onep (arg1))
9375 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
9378 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9379 && !TYPE_OVERFLOW_TRAPS (type))
9381 tree tem = TREE_OPERAND (arg0, 0);
9384 if (operand_equal_p (tem, arg1, 0))
9386 t1 = build_int_cst_type (type, -1);
9387 return omit_one_operand (type, t1, arg1);
9392 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9393 && !TYPE_OVERFLOW_TRAPS (type))
9395 tree tem = TREE_OPERAND (arg1, 0);
9398 if (operand_equal_p (arg0, tem, 0))
9400 t1 = build_int_cst_type (type, -1);
9401 return omit_one_operand (type, t1, arg0);
9405 /* X + (X / CST) * -CST is X % CST. */
9406 if (TREE_CODE (arg1) == MULT_EXPR
9407 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9408 && operand_equal_p (arg0,
9409 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
9411 tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
9412 tree cst1 = TREE_OPERAND (arg1, 1);
9413 tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
9414 if (sum && integer_zerop (sum))
9415 return fold_convert (type,
9416 fold_build2 (TRUNC_MOD_EXPR,
9417 TREE_TYPE (arg0), arg0, cst0));
9421 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9422 same or one. Make sure type is not saturating.
9423 fold_plusminus_mult_expr will re-associate. */
9424 if ((TREE_CODE (arg0) == MULT_EXPR
9425 || TREE_CODE (arg1) == MULT_EXPR)
9426 && !TYPE_SATURATING (type)
9427 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9429 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9434 if (! FLOAT_TYPE_P (type))
9436 if (integer_zerop (arg1))
9437 return non_lvalue (fold_convert (type, arg0));
9439 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9440 with a constant, and the two constants have no bits in common,
9441 we should treat this as a BIT_IOR_EXPR since this may produce more
9443 if (TREE_CODE (arg0) == BIT_AND_EXPR
9444 && TREE_CODE (arg1) == BIT_AND_EXPR
9445 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9446 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9447 && integer_zerop (const_binop (BIT_AND_EXPR,
9448 TREE_OPERAND (arg0, 1),
9449 TREE_OPERAND (arg1, 1), 0)))
9451 code = BIT_IOR_EXPR;
9455 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9456 (plus (plus (mult) (mult)) (foo)) so that we can
9457 take advantage of the factoring cases below. */
9458 if (((TREE_CODE (arg0) == PLUS_EXPR
9459 || TREE_CODE (arg0) == MINUS_EXPR)
9460 && TREE_CODE (arg1) == MULT_EXPR)
9461 || ((TREE_CODE (arg1) == PLUS_EXPR
9462 || TREE_CODE (arg1) == MINUS_EXPR)
9463 && TREE_CODE (arg0) == MULT_EXPR))
9465 tree parg0, parg1, parg, marg;
9466 enum tree_code pcode;
9468 if (TREE_CODE (arg1) == MULT_EXPR)
9469 parg = arg0, marg = arg1;
9471 parg = arg1, marg = arg0;
9472 pcode = TREE_CODE (parg);
9473 parg0 = TREE_OPERAND (parg, 0);
9474 parg1 = TREE_OPERAND (parg, 1);
9478 if (TREE_CODE (parg0) == MULT_EXPR
9479 && TREE_CODE (parg1) != MULT_EXPR)
9480 return fold_build2 (pcode, type,
9481 fold_build2 (PLUS_EXPR, type,
9482 fold_convert (type, parg0),
9483 fold_convert (type, marg)),
9484 fold_convert (type, parg1));
9485 if (TREE_CODE (parg0) != MULT_EXPR
9486 && TREE_CODE (parg1) == MULT_EXPR)
9487 return fold_build2 (PLUS_EXPR, type,
9488 fold_convert (type, parg0),
9489 fold_build2 (pcode, type,
9490 fold_convert (type, marg),
9497 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9498 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
9499 return non_lvalue (fold_convert (type, arg0));
9501 /* Likewise if the operands are reversed. */
9502 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9503 return non_lvalue (fold_convert (type, arg1));
9505 /* Convert X + -C into X - C. */
9506 if (TREE_CODE (arg1) == REAL_CST
9507 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
9509 tem = fold_negate_const (arg1, type);
9510 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
9511 return fold_build2 (MINUS_EXPR, type,
9512 fold_convert (type, arg0),
9513 fold_convert (type, tem));
9516 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9517 to __complex__ ( x, y ). This is not the same for SNaNs or
9518 if signed zeros are involved. */
9519 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9520 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9521 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9523 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9524 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9525 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9526 bool arg0rz = false, arg0iz = false;
9527 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9528 || (arg0i && (arg0iz = real_zerop (arg0i))))
9530 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9531 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9532 if (arg0rz && arg1i && real_zerop (arg1i))
9534 tree rp = arg1r ? arg1r
9535 : build1 (REALPART_EXPR, rtype, arg1);
9536 tree ip = arg0i ? arg0i
9537 : build1 (IMAGPART_EXPR, rtype, arg0);
9538 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9540 else if (arg0iz && arg1r && real_zerop (arg1r))
9542 tree rp = arg0r ? arg0r
9543 : build1 (REALPART_EXPR, rtype, arg0);
9544 tree ip = arg1i ? arg1i
9545 : build1 (IMAGPART_EXPR, rtype, arg1);
9546 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9551 if (flag_unsafe_math_optimizations
9552 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9553 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9554 && (tem = distribute_real_division (code, type, arg0, arg1)))
9557 /* Convert x+x into x*2.0. */
9558 if (operand_equal_p (arg0, arg1, 0)
9559 && SCALAR_FLOAT_TYPE_P (type))
9560 return fold_build2 (MULT_EXPR, type, arg0,
9561 build_real (type, dconst2));
9563 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
9564 We associate floats only if the user has specified
9565 -fassociative-math. */
9566 if (flag_associative_math
9567 && TREE_CODE (arg1) == PLUS_EXPR
9568 && TREE_CODE (arg0) != MULT_EXPR)
9570 tree tree10 = TREE_OPERAND (arg1, 0);
9571 tree tree11 = TREE_OPERAND (arg1, 1);
9572 if (TREE_CODE (tree11) == MULT_EXPR
9573 && TREE_CODE (tree10) == MULT_EXPR)
9576 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
9577 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
9580 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
9581 We associate floats only if the user has specified
9582 -fassociative-math. */
9583 if (flag_associative_math
9584 && TREE_CODE (arg0) == PLUS_EXPR
9585 && TREE_CODE (arg1) != MULT_EXPR)
9587 tree tree00 = TREE_OPERAND (arg0, 0);
9588 tree tree01 = TREE_OPERAND (arg0, 1);
9589 if (TREE_CODE (tree01) == MULT_EXPR
9590 && TREE_CODE (tree00) == MULT_EXPR)
9593 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
9594 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
9600 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9601 is a rotate of A by C1 bits. */
9602 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9603 is a rotate of A by B bits. */
9605 enum tree_code code0, code1;
9607 code0 = TREE_CODE (arg0);
9608 code1 = TREE_CODE (arg1);
9609 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
9610 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
9611 && operand_equal_p (TREE_OPERAND (arg0, 0),
9612 TREE_OPERAND (arg1, 0), 0)
9613 && (rtype = TREE_TYPE (TREE_OPERAND (arg0, 0)),
9614 TYPE_UNSIGNED (rtype))
9615 /* Only create rotates in complete modes. Other cases are not
9616 expanded properly. */
9617 && TYPE_PRECISION (rtype) == GET_MODE_PRECISION (TYPE_MODE (rtype)))
9619 tree tree01, tree11;
9620 enum tree_code code01, code11;
9622 tree01 = TREE_OPERAND (arg0, 1);
9623 tree11 = TREE_OPERAND (arg1, 1);
9624 STRIP_NOPS (tree01);
9625 STRIP_NOPS (tree11);
9626 code01 = TREE_CODE (tree01);
9627 code11 = TREE_CODE (tree11);
9628 if (code01 == INTEGER_CST
9629 && code11 == INTEGER_CST
9630 && TREE_INT_CST_HIGH (tree01) == 0
9631 && TREE_INT_CST_HIGH (tree11) == 0
9632 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
9633 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
9634 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
9635 code0 == LSHIFT_EXPR ? tree01 : tree11);
9636 else if (code11 == MINUS_EXPR)
9638 tree tree110, tree111;
9639 tree110 = TREE_OPERAND (tree11, 0);
9640 tree111 = TREE_OPERAND (tree11, 1);
9641 STRIP_NOPS (tree110);
9642 STRIP_NOPS (tree111);
9643 if (TREE_CODE (tree110) == INTEGER_CST
9644 && 0 == compare_tree_int (tree110,
9646 (TREE_TYPE (TREE_OPERAND
9648 && operand_equal_p (tree01, tree111, 0))
9649 return build2 ((code0 == LSHIFT_EXPR
9652 type, TREE_OPERAND (arg0, 0), tree01);
9654 else if (code01 == MINUS_EXPR)
9656 tree tree010, tree011;
9657 tree010 = TREE_OPERAND (tree01, 0);
9658 tree011 = TREE_OPERAND (tree01, 1);
9659 STRIP_NOPS (tree010);
9660 STRIP_NOPS (tree011);
9661 if (TREE_CODE (tree010) == INTEGER_CST
9662 && 0 == compare_tree_int (tree010,
9664 (TREE_TYPE (TREE_OPERAND
9666 && operand_equal_p (tree11, tree011, 0))
9667 return build2 ((code0 != LSHIFT_EXPR
9670 type, TREE_OPERAND (arg0, 0), tree11);
9676 /* In most languages, can't associate operations on floats through
9677 parentheses. Rather than remember where the parentheses were, we
9678 don't associate floats at all, unless the user has specified
9680 And, we need to make sure type is not saturating. */
9682 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
9683 && !TYPE_SATURATING (type))
9685 tree var0, con0, lit0, minus_lit0;
9686 tree var1, con1, lit1, minus_lit1;
9689 /* Split both trees into variables, constants, and literals. Then
9690 associate each group together, the constants with literals,
9691 then the result with variables. This increases the chances of
9692 literals being recombined later and of generating relocatable
9693 expressions for the sum of a constant and literal. */
9694 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
9695 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
9696 code == MINUS_EXPR);
9698 /* With undefined overflow we can only associate constants
9699 with one variable. */
9700 if ((POINTER_TYPE_P (type)
9701 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
9707 if (TREE_CODE (tmp0) == NEGATE_EXPR)
9708 tmp0 = TREE_OPERAND (tmp0, 0);
9709 if (TREE_CODE (tmp1) == NEGATE_EXPR)
9710 tmp1 = TREE_OPERAND (tmp1, 0);
9711 /* The only case we can still associate with two variables
9712 is if they are the same, modulo negation. */
9713 if (!operand_equal_p (tmp0, tmp1, 0))
9717 /* Only do something if we found more than two objects. Otherwise,
9718 nothing has changed and we risk infinite recursion. */
9720 && (2 < ((var0 != 0) + (var1 != 0)
9721 + (con0 != 0) + (con1 != 0)
9722 + (lit0 != 0) + (lit1 != 0)
9723 + (minus_lit0 != 0) + (minus_lit1 != 0))))
9725 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9726 if (code == MINUS_EXPR)
9729 var0 = associate_trees (var0, var1, code, type);
9730 con0 = associate_trees (con0, con1, code, type);
9731 lit0 = associate_trees (lit0, lit1, code, type);
9732 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
9734 /* Preserve the MINUS_EXPR if the negative part of the literal is
9735 greater than the positive part. Otherwise, the multiplicative
9736 folding code (i.e extract_muldiv) may be fooled in case
9737 unsigned constants are subtracted, like in the following
9738 example: ((X*2 + 4) - 8U)/2. */
9739 if (minus_lit0 && lit0)
9741 if (TREE_CODE (lit0) == INTEGER_CST
9742 && TREE_CODE (minus_lit0) == INTEGER_CST
9743 && tree_int_cst_lt (lit0, minus_lit0))
9745 minus_lit0 = associate_trees (minus_lit0, lit0,
9751 lit0 = associate_trees (lit0, minus_lit0,
9759 return fold_convert (type,
9760 associate_trees (var0, minus_lit0,
9764 con0 = associate_trees (con0, minus_lit0,
9766 return fold_convert (type,
9767 associate_trees (var0, con0,
9772 con0 = associate_trees (con0, lit0, code, type);
9773 return fold_convert (type, associate_trees (var0, con0,
9781 /* Pointer simplifications for subtraction, simple reassociations. */
9782 if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
9784 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
9785 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
9786 && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
9788 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
9789 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
9790 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
9791 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
9792 return fold_build2 (PLUS_EXPR, type,
9793 fold_build2 (MINUS_EXPR, type, arg00, arg10),
9794 fold_build2 (MINUS_EXPR, type, arg01, arg11));
9796 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
9797 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9799 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
9800 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
9801 tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
9803 return fold_build2 (PLUS_EXPR, type, tmp, arg01);
9806 /* A - (-B) -> A + B */
9807 if (TREE_CODE (arg1) == NEGATE_EXPR)
9808 return fold_build2 (PLUS_EXPR, type, op0,
9809 fold_convert (type, TREE_OPERAND (arg1, 0)));
9810 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
9811 if (TREE_CODE (arg0) == NEGATE_EXPR
9812 && (FLOAT_TYPE_P (type)
9813 || INTEGRAL_TYPE_P (type))
9814 && negate_expr_p (arg1)
9815 && reorder_operands_p (arg0, arg1))
9816 return fold_build2 (MINUS_EXPR, type,
9817 fold_convert (type, negate_expr (arg1)),
9818 fold_convert (type, TREE_OPERAND (arg0, 0)));
9819 /* Convert -A - 1 to ~A. */
9820 if (INTEGRAL_TYPE_P (type)
9821 && TREE_CODE (arg0) == NEGATE_EXPR
9822 && integer_onep (arg1)
9823 && !TYPE_OVERFLOW_TRAPS (type))
9824 return fold_build1 (BIT_NOT_EXPR, type,
9825 fold_convert (type, TREE_OPERAND (arg0, 0)));
9827 /* Convert -1 - A to ~A. */
9828 if (INTEGRAL_TYPE_P (type)
9829 && integer_all_onesp (arg0))
9830 return fold_build1 (BIT_NOT_EXPR, type, op1);
9833 /* X - (X / CST) * CST is X % CST. */
9834 if (INTEGRAL_TYPE_P (type)
9835 && TREE_CODE (arg1) == MULT_EXPR
9836 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9837 && operand_equal_p (arg0,
9838 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
9839 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
9840 TREE_OPERAND (arg1, 1), 0))
9841 return fold_convert (type,
9842 fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
9843 arg0, TREE_OPERAND (arg1, 1)));
9845 if (! FLOAT_TYPE_P (type))
9847 if (integer_zerop (arg0))
9848 return negate_expr (fold_convert (type, arg1));
9849 if (integer_zerop (arg1))
9850 return non_lvalue (fold_convert (type, arg0));
9852 /* Fold A - (A & B) into ~B & A. */
9853 if (!TREE_SIDE_EFFECTS (arg0)
9854 && TREE_CODE (arg1) == BIT_AND_EXPR)
9856 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
9858 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
9859 return fold_build2 (BIT_AND_EXPR, type,
9860 fold_build1 (BIT_NOT_EXPR, type, arg10),
9861 fold_convert (type, arg0));
9863 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9865 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
9866 return fold_build2 (BIT_AND_EXPR, type,
9867 fold_build1 (BIT_NOT_EXPR, type, arg11),
9868 fold_convert (type, arg0));
9872 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
9873 any power of 2 minus 1. */
9874 if (TREE_CODE (arg0) == BIT_AND_EXPR
9875 && TREE_CODE (arg1) == BIT_AND_EXPR
9876 && operand_equal_p (TREE_OPERAND (arg0, 0),
9877 TREE_OPERAND (arg1, 0), 0))
9879 tree mask0 = TREE_OPERAND (arg0, 1);
9880 tree mask1 = TREE_OPERAND (arg1, 1);
9881 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
9883 if (operand_equal_p (tem, mask1, 0))
9885 tem = fold_build2 (BIT_XOR_EXPR, type,
9886 TREE_OPERAND (arg0, 0), mask1);
9887 return fold_build2 (MINUS_EXPR, type, tem, mask1);
9892 /* See if ARG1 is zero and X - ARG1 reduces to X. */
9893 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
9894 return non_lvalue (fold_convert (type, arg0));
9896 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
9897 ARG0 is zero and X + ARG0 reduces to X, since that would mean
9898 (-ARG1 + ARG0) reduces to -ARG1. */
9899 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9900 return negate_expr (fold_convert (type, arg1));
9902 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
9903 __complex__ ( x, -y ). This is not the same for SNaNs or if
9904 signed zeros are involved. */
9905 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9906 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9907 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9909 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9910 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9911 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9912 bool arg0rz = false, arg0iz = false;
9913 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9914 || (arg0i && (arg0iz = real_zerop (arg0i))))
9916 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9917 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9918 if (arg0rz && arg1i && real_zerop (arg1i))
9920 tree rp = fold_build1 (NEGATE_EXPR, rtype,
9922 : build1 (REALPART_EXPR, rtype, arg1));
9923 tree ip = arg0i ? arg0i
9924 : build1 (IMAGPART_EXPR, rtype, arg0);
9925 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9927 else if (arg0iz && arg1r && real_zerop (arg1r))
9929 tree rp = arg0r ? arg0r
9930 : build1 (REALPART_EXPR, rtype, arg0);
9931 tree ip = fold_build1 (NEGATE_EXPR, rtype,
9933 : build1 (IMAGPART_EXPR, rtype, arg1));
9934 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9939 /* Fold &x - &x. This can happen from &x.foo - &x.
9940 This is unsafe for certain floats even in non-IEEE formats.
9941 In IEEE, it is unsafe because it does wrong for NaNs.
9942 Also note that operand_equal_p is always false if an operand
9945 if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
9946 && operand_equal_p (arg0, arg1, 0))
9947 return fold_convert (type, integer_zero_node);
9949 /* A - B -> A + (-B) if B is easily negatable. */
9950 if (negate_expr_p (arg1)
9951 && ((FLOAT_TYPE_P (type)
9952 /* Avoid this transformation if B is a positive REAL_CST. */
9953 && (TREE_CODE (arg1) != REAL_CST
9954 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
9955 || INTEGRAL_TYPE_P (type)))
9956 return fold_build2 (PLUS_EXPR, type,
9957 fold_convert (type, arg0),
9958 fold_convert (type, negate_expr (arg1)));
9960 /* Try folding difference of addresses. */
9964 if ((TREE_CODE (arg0) == ADDR_EXPR
9965 || TREE_CODE (arg1) == ADDR_EXPR)
9966 && ptr_difference_const (arg0, arg1, &diff))
9967 return build_int_cst_type (type, diff);
9970 /* Fold &a[i] - &a[j] to i-j. */
9971 if (TREE_CODE (arg0) == ADDR_EXPR
9972 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
9973 && TREE_CODE (arg1) == ADDR_EXPR
9974 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
9976 tree aref0 = TREE_OPERAND (arg0, 0);
9977 tree aref1 = TREE_OPERAND (arg1, 0);
9978 if (operand_equal_p (TREE_OPERAND (aref0, 0),
9979 TREE_OPERAND (aref1, 0), 0))
9981 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
9982 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
9983 tree esz = array_ref_element_size (aref0);
9984 tree diff = build2 (MINUS_EXPR, type, op0, op1);
9985 return fold_build2 (MULT_EXPR, type, diff,
9986 fold_convert (type, esz));
9991 if (flag_unsafe_math_optimizations
9992 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9993 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9994 && (tem = distribute_real_division (code, type, arg0, arg1)))
9997 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
9998 same or one. Make sure type is not saturating.
9999 fold_plusminus_mult_expr will re-associate. */
10000 if ((TREE_CODE (arg0) == MULT_EXPR
10001 || TREE_CODE (arg1) == MULT_EXPR)
10002 && !TYPE_SATURATING (type)
10003 && (!FLOAT_TYPE_P (type) || flag_associative_math))
10005 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
10013 /* (-A) * (-B) -> A * B */
10014 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10015 return fold_build2 (MULT_EXPR, type,
10016 fold_convert (type, TREE_OPERAND (arg0, 0)),
10017 fold_convert (type, negate_expr (arg1)));
10018 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10019 return fold_build2 (MULT_EXPR, type,
10020 fold_convert (type, negate_expr (arg0)),
10021 fold_convert (type, TREE_OPERAND (arg1, 0)));
10023 if (! FLOAT_TYPE_P (type))
10025 if (integer_zerop (arg1))
10026 return omit_one_operand (type, arg1, arg0);
10027 if (integer_onep (arg1))
10028 return non_lvalue (fold_convert (type, arg0));
10029 /* Transform x * -1 into -x. Make sure to do the negation
10030 on the original operand with conversions not stripped
10031 because we can only strip non-sign-changing conversions. */
10032 if (integer_all_onesp (arg1))
10033 return fold_convert (type, negate_expr (op0));
10034 /* Transform x * -C into -x * C if x is easily negatable. */
10035 if (TREE_CODE (arg1) == INTEGER_CST
10036 && tree_int_cst_sgn (arg1) == -1
10037 && negate_expr_p (arg0)
10038 && (tem = negate_expr (arg1)) != arg1
10039 && !TREE_OVERFLOW (tem))
10040 return fold_build2 (MULT_EXPR, type,
10041 fold_convert (type, negate_expr (arg0)), tem);
10043 /* (a * (1 << b)) is (a << b) */
10044 if (TREE_CODE (arg1) == LSHIFT_EXPR
10045 && integer_onep (TREE_OPERAND (arg1, 0)))
10046 return fold_build2 (LSHIFT_EXPR, type, op0,
10047 TREE_OPERAND (arg1, 1));
10048 if (TREE_CODE (arg0) == LSHIFT_EXPR
10049 && integer_onep (TREE_OPERAND (arg0, 0)))
10050 return fold_build2 (LSHIFT_EXPR, type, op1,
10051 TREE_OPERAND (arg0, 1));
10053 strict_overflow_p = false;
10054 if (TREE_CODE (arg1) == INTEGER_CST
10055 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10056 &strict_overflow_p)))
10058 if (strict_overflow_p)
10059 fold_overflow_warning (("assuming signed overflow does not "
10060 "occur when simplifying "
10062 WARN_STRICT_OVERFLOW_MISC);
10063 return fold_convert (type, tem);
10066 /* Optimize z * conj(z) for integer complex numbers. */
10067 if (TREE_CODE (arg0) == CONJ_EXPR
10068 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10069 return fold_mult_zconjz (type, arg1);
10070 if (TREE_CODE (arg1) == CONJ_EXPR
10071 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10072 return fold_mult_zconjz (type, arg0);
10076 /* Maybe fold x * 0 to 0. The expressions aren't the same
10077 when x is NaN, since x * 0 is also NaN. Nor are they the
10078 same in modes with signed zeros, since multiplying a
10079 negative value by 0 gives -0, not +0. */
10080 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10081 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10082 && real_zerop (arg1))
10083 return omit_one_operand (type, arg1, arg0);
10084 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
10085 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10086 && real_onep (arg1))
10087 return non_lvalue (fold_convert (type, arg0));
10089 /* Transform x * -1.0 into -x. */
10090 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10091 && real_minus_onep (arg1))
10092 return fold_convert (type, negate_expr (arg0));
10094 /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
10095 the result for floating point types due to rounding so it is applied
10096 only if -fassociative-math was specify. */
10097 if (flag_associative_math
10098 && TREE_CODE (arg0) == RDIV_EXPR
10099 && TREE_CODE (arg1) == REAL_CST
10100 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
10102 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
10105 return fold_build2 (RDIV_EXPR, type, tem,
10106 TREE_OPERAND (arg0, 1));
10109 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10110 if (operand_equal_p (arg0, arg1, 0))
10112 tree tem = fold_strip_sign_ops (arg0);
10113 if (tem != NULL_TREE)
10115 tem = fold_convert (type, tem);
10116 return fold_build2 (MULT_EXPR, type, tem, tem);
10120 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10121 This is not the same for NaNs or if signed zeros are
10123 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10124 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10125 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10126 && TREE_CODE (arg1) == COMPLEX_CST
10127 && real_zerop (TREE_REALPART (arg1)))
10129 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10130 if (real_onep (TREE_IMAGPART (arg1)))
10131 return fold_build2 (COMPLEX_EXPR, type,
10132 negate_expr (fold_build1 (IMAGPART_EXPR,
10134 fold_build1 (REALPART_EXPR, rtype, arg0));
10135 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10136 return fold_build2 (COMPLEX_EXPR, type,
10137 fold_build1 (IMAGPART_EXPR, rtype, arg0),
10138 negate_expr (fold_build1 (REALPART_EXPR,
10142 /* Optimize z * conj(z) for floating point complex numbers.
10143 Guarded by flag_unsafe_math_optimizations as non-finite
10144 imaginary components don't produce scalar results. */
10145 if (flag_unsafe_math_optimizations
10146 && TREE_CODE (arg0) == CONJ_EXPR
10147 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10148 return fold_mult_zconjz (type, arg1);
10149 if (flag_unsafe_math_optimizations
10150 && TREE_CODE (arg1) == CONJ_EXPR
10151 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10152 return fold_mult_zconjz (type, arg0);
10154 if (flag_unsafe_math_optimizations)
10156 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10157 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10159 /* Optimizations of root(...)*root(...). */
10160 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
10163 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10164 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10166 /* Optimize sqrt(x)*sqrt(x) as x. */
10167 if (BUILTIN_SQRT_P (fcode0)
10168 && operand_equal_p (arg00, arg10, 0)
10169 && ! HONOR_SNANS (TYPE_MODE (type)))
10172 /* Optimize root(x)*root(y) as root(x*y). */
10173 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10174 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10175 return build_call_expr (rootfn, 1, arg);
10178 /* Optimize expN(x)*expN(y) as expN(x+y). */
10179 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
10181 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10182 tree arg = fold_build2 (PLUS_EXPR, type,
10183 CALL_EXPR_ARG (arg0, 0),
10184 CALL_EXPR_ARG (arg1, 0));
10185 return build_call_expr (expfn, 1, arg);
10188 /* Optimizations of pow(...)*pow(...). */
10189 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
10190 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
10191 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
10193 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10194 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10195 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10196 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10198 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10199 if (operand_equal_p (arg01, arg11, 0))
10201 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10202 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10203 return build_call_expr (powfn, 2, arg, arg01);
10206 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10207 if (operand_equal_p (arg00, arg10, 0))
10209 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10210 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
10211 return build_call_expr (powfn, 2, arg00, arg);
10215 /* Optimize tan(x)*cos(x) as sin(x). */
10216 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
10217 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
10218 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
10219 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
10220 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
10221 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
10222 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10223 CALL_EXPR_ARG (arg1, 0), 0))
10225 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
10227 if (sinfn != NULL_TREE)
10228 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
10231 /* Optimize x*pow(x,c) as pow(x,c+1). */
10232 if (fcode1 == BUILT_IN_POW
10233 || fcode1 == BUILT_IN_POWF
10234 || fcode1 == BUILT_IN_POWL)
10236 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10237 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10238 if (TREE_CODE (arg11) == REAL_CST
10239 && !TREE_OVERFLOW (arg11)
10240 && operand_equal_p (arg0, arg10, 0))
10242 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10246 c = TREE_REAL_CST (arg11);
10247 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10248 arg = build_real (type, c);
10249 return build_call_expr (powfn, 2, arg0, arg);
10253 /* Optimize pow(x,c)*x as pow(x,c+1). */
10254 if (fcode0 == BUILT_IN_POW
10255 || fcode0 == BUILT_IN_POWF
10256 || fcode0 == BUILT_IN_POWL)
10258 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10259 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10260 if (TREE_CODE (arg01) == REAL_CST
10261 && !TREE_OVERFLOW (arg01)
10262 && operand_equal_p (arg1, arg00, 0))
10264 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10268 c = TREE_REAL_CST (arg01);
10269 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10270 arg = build_real (type, c);
10271 return build_call_expr (powfn, 2, arg1, arg);
10275 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10276 if (! optimize_size
10277 && operand_equal_p (arg0, arg1, 0))
10279 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
10283 tree arg = build_real (type, dconst2);
10284 return build_call_expr (powfn, 2, arg0, arg);
10293 if (integer_all_onesp (arg1))
10294 return omit_one_operand (type, arg1, arg0);
10295 if (integer_zerop (arg1))
10296 return non_lvalue (fold_convert (type, arg0));
10297 if (operand_equal_p (arg0, arg1, 0))
10298 return non_lvalue (fold_convert (type, arg0));
10300 /* ~X | X is -1. */
10301 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10302 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10304 t1 = fold_convert (type, integer_zero_node);
10305 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10306 return omit_one_operand (type, t1, arg1);
10309 /* X | ~X is -1. */
10310 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10311 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10313 t1 = fold_convert (type, integer_zero_node);
10314 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10315 return omit_one_operand (type, t1, arg0);
10318 /* Canonicalize (X & C1) | C2. */
10319 if (TREE_CODE (arg0) == BIT_AND_EXPR
10320 && TREE_CODE (arg1) == INTEGER_CST
10321 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10323 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, hi3, lo3, mlo, mhi;
10324 int width = TYPE_PRECISION (type), w;
10325 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10326 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10327 hi2 = TREE_INT_CST_HIGH (arg1);
10328 lo2 = TREE_INT_CST_LOW (arg1);
10330 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10331 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10332 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10334 if (width > HOST_BITS_PER_WIDE_INT)
10336 mhi = (unsigned HOST_WIDE_INT) -1
10337 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10343 mlo = (unsigned HOST_WIDE_INT) -1
10344 >> (HOST_BITS_PER_WIDE_INT - width);
10347 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10348 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10349 return fold_build2 (BIT_IOR_EXPR, type,
10350 TREE_OPERAND (arg0, 0), arg1);
10352 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
10353 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
10354 mode which allows further optimizations. */
10361 for (w = BITS_PER_UNIT;
10362 w <= width && w <= HOST_BITS_PER_WIDE_INT;
10365 unsigned HOST_WIDE_INT mask
10366 = (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
10367 if (((lo1 | lo2) & mask) == mask
10368 && (lo1 & ~mask) == 0 && hi1 == 0)
10375 if (hi3 != hi1 || lo3 != lo1)
10376 return fold_build2 (BIT_IOR_EXPR, type,
10377 fold_build2 (BIT_AND_EXPR, type,
10378 TREE_OPERAND (arg0, 0),
10379 build_int_cst_wide (type,
10384 /* (X & Y) | Y is (X, Y). */
10385 if (TREE_CODE (arg0) == BIT_AND_EXPR
10386 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10387 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10388 /* (X & Y) | X is (Y, X). */
10389 if (TREE_CODE (arg0) == BIT_AND_EXPR
10390 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10391 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10392 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10393 /* X | (X & Y) is (Y, X). */
10394 if (TREE_CODE (arg1) == BIT_AND_EXPR
10395 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10396 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10397 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10398 /* X | (Y & X) is (Y, X). */
10399 if (TREE_CODE (arg1) == BIT_AND_EXPR
10400 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10401 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10402 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10404 t1 = distribute_bit_expr (code, type, arg0, arg1);
10405 if (t1 != NULL_TREE)
10408 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10410 This results in more efficient code for machines without a NAND
10411 instruction. Combine will canonicalize to the first form
10412 which will allow use of NAND instructions provided by the
10413 backend if they exist. */
10414 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10415 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10417 return fold_build1 (BIT_NOT_EXPR, type,
10418 build2 (BIT_AND_EXPR, type,
10419 TREE_OPERAND (arg0, 0),
10420 TREE_OPERAND (arg1, 0)));
10423 /* See if this can be simplified into a rotate first. If that
10424 is unsuccessful continue in the association code. */
10428 if (integer_zerop (arg1))
10429 return non_lvalue (fold_convert (type, arg0));
10430 if (integer_all_onesp (arg1))
10431 return fold_build1 (BIT_NOT_EXPR, type, op0);
10432 if (operand_equal_p (arg0, arg1, 0))
10433 return omit_one_operand (type, integer_zero_node, arg0);
10435 /* ~X ^ X is -1. */
10436 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10437 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10439 t1 = fold_convert (type, integer_zero_node);
10440 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10441 return omit_one_operand (type, t1, arg1);
10444 /* X ^ ~X is -1. */
10445 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10446 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10448 t1 = fold_convert (type, integer_zero_node);
10449 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10450 return omit_one_operand (type, t1, arg0);
10453 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10454 with a constant, and the two constants have no bits in common,
10455 we should treat this as a BIT_IOR_EXPR since this may produce more
10456 simplifications. */
10457 if (TREE_CODE (arg0) == BIT_AND_EXPR
10458 && TREE_CODE (arg1) == BIT_AND_EXPR
10459 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10460 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10461 && integer_zerop (const_binop (BIT_AND_EXPR,
10462 TREE_OPERAND (arg0, 1),
10463 TREE_OPERAND (arg1, 1), 0)))
10465 code = BIT_IOR_EXPR;
10469 /* (X | Y) ^ X -> Y & ~ X*/
10470 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10471 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10473 tree t2 = TREE_OPERAND (arg0, 1);
10474 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10476 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10477 fold_convert (type, t1));
10481 /* (Y | X) ^ X -> Y & ~ X*/
10482 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10483 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10485 tree t2 = TREE_OPERAND (arg0, 0);
10486 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10488 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10489 fold_convert (type, t1));
10493 /* X ^ (X | Y) -> Y & ~ X*/
10494 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10495 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
10497 tree t2 = TREE_OPERAND (arg1, 1);
10498 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10500 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10501 fold_convert (type, t1));
10505 /* X ^ (Y | X) -> Y & ~ X*/
10506 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10507 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
10509 tree t2 = TREE_OPERAND (arg1, 0);
10510 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10512 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10513 fold_convert (type, t1));
10517 /* Convert ~X ^ ~Y to X ^ Y. */
10518 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10519 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10520 return fold_build2 (code, type,
10521 fold_convert (type, TREE_OPERAND (arg0, 0)),
10522 fold_convert (type, TREE_OPERAND (arg1, 0)));
10524 /* Convert ~X ^ C to X ^ ~C. */
10525 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10526 && TREE_CODE (arg1) == INTEGER_CST)
10527 return fold_build2 (code, type,
10528 fold_convert (type, TREE_OPERAND (arg0, 0)),
10529 fold_build1 (BIT_NOT_EXPR, type, arg1));
10531 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10532 if (TREE_CODE (arg0) == BIT_AND_EXPR
10533 && integer_onep (TREE_OPERAND (arg0, 1))
10534 && integer_onep (arg1))
10535 return fold_build2 (EQ_EXPR, type, arg0,
10536 build_int_cst (TREE_TYPE (arg0), 0));
10538 /* Fold (X & Y) ^ Y as ~X & Y. */
10539 if (TREE_CODE (arg0) == BIT_AND_EXPR
10540 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10542 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10543 return fold_build2 (BIT_AND_EXPR, type,
10544 fold_build1 (BIT_NOT_EXPR, type, tem),
10545 fold_convert (type, arg1));
10547 /* Fold (X & Y) ^ X as ~Y & X. */
10548 if (TREE_CODE (arg0) == BIT_AND_EXPR
10549 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10550 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10552 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10553 return fold_build2 (BIT_AND_EXPR, type,
10554 fold_build1 (BIT_NOT_EXPR, type, tem),
10555 fold_convert (type, arg1));
10557 /* Fold X ^ (X & Y) as X & ~Y. */
10558 if (TREE_CODE (arg1) == BIT_AND_EXPR
10559 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10561 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10562 return fold_build2 (BIT_AND_EXPR, type,
10563 fold_convert (type, arg0),
10564 fold_build1 (BIT_NOT_EXPR, type, tem));
10566 /* Fold X ^ (Y & X) as ~Y & X. */
10567 if (TREE_CODE (arg1) == BIT_AND_EXPR
10568 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10569 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10571 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10572 return fold_build2 (BIT_AND_EXPR, type,
10573 fold_build1 (BIT_NOT_EXPR, type, tem),
10574 fold_convert (type, arg0));
10577 /* See if this can be simplified into a rotate first. If that
10578 is unsuccessful continue in the association code. */
10582 if (integer_all_onesp (arg1))
10583 return non_lvalue (fold_convert (type, arg0));
10584 if (integer_zerop (arg1))
10585 return omit_one_operand (type, arg1, arg0);
10586 if (operand_equal_p (arg0, arg1, 0))
10587 return non_lvalue (fold_convert (type, arg0));
10589 /* ~X & X is always zero. */
10590 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10591 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10592 return omit_one_operand (type, integer_zero_node, arg1);
10594 /* X & ~X is always zero. */
10595 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10596 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10597 return omit_one_operand (type, integer_zero_node, arg0);
10599 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
10600 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10601 && TREE_CODE (arg1) == INTEGER_CST
10602 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10604 tree tmp1 = fold_convert (TREE_TYPE (arg0), arg1);
10605 tree tmp2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10606 TREE_OPERAND (arg0, 0), tmp1);
10607 tree tmp3 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10608 TREE_OPERAND (arg0, 1), tmp1);
10609 return fold_convert (type,
10610 fold_build2 (BIT_IOR_EXPR, TREE_TYPE (arg0),
10614 /* (X | Y) & Y is (X, Y). */
10615 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10616 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10617 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10618 /* (X | Y) & X is (Y, X). */
10619 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10620 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10621 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10622 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10623 /* X & (X | Y) is (Y, X). */
10624 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10625 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10626 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10627 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10628 /* X & (Y | X) is (Y, X). */
10629 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10630 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10631 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10632 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10634 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10635 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10636 && integer_onep (TREE_OPERAND (arg0, 1))
10637 && integer_onep (arg1))
10639 tem = TREE_OPERAND (arg0, 0);
10640 return fold_build2 (EQ_EXPR, type,
10641 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10642 build_int_cst (TREE_TYPE (tem), 1)),
10643 build_int_cst (TREE_TYPE (tem), 0));
10645 /* Fold ~X & 1 as (X & 1) == 0. */
10646 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10647 && integer_onep (arg1))
10649 tem = TREE_OPERAND (arg0, 0);
10650 return fold_build2 (EQ_EXPR, type,
10651 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10652 build_int_cst (TREE_TYPE (tem), 1)),
10653 build_int_cst (TREE_TYPE (tem), 0));
10656 /* Fold (X ^ Y) & Y as ~X & Y. */
10657 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10658 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10660 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10661 return fold_build2 (BIT_AND_EXPR, type,
10662 fold_build1 (BIT_NOT_EXPR, type, tem),
10663 fold_convert (type, arg1));
10665 /* Fold (X ^ Y) & X as ~Y & X. */
10666 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10667 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10668 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10670 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10671 return fold_build2 (BIT_AND_EXPR, type,
10672 fold_build1 (BIT_NOT_EXPR, type, tem),
10673 fold_convert (type, arg1));
10675 /* Fold X & (X ^ Y) as X & ~Y. */
10676 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10677 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10679 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10680 return fold_build2 (BIT_AND_EXPR, type,
10681 fold_convert (type, arg0),
10682 fold_build1 (BIT_NOT_EXPR, type, tem));
10684 /* Fold X & (Y ^ X) as ~Y & X. */
10685 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10686 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10687 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10689 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10690 return fold_build2 (BIT_AND_EXPR, type,
10691 fold_build1 (BIT_NOT_EXPR, type, tem),
10692 fold_convert (type, arg0));
10695 t1 = distribute_bit_expr (code, type, arg0, arg1);
10696 if (t1 != NULL_TREE)
10698 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10699 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
10700 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
10703 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
10705 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
10706 && (~TREE_INT_CST_LOW (arg1)
10707 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
10708 return fold_convert (type, TREE_OPERAND (arg0, 0));
10711 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
10713 This results in more efficient code for machines without a NOR
10714 instruction. Combine will canonicalize to the first form
10715 which will allow use of NOR instructions provided by the
10716 backend if they exist. */
10717 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10718 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10720 return fold_build1 (BIT_NOT_EXPR, type,
10721 build2 (BIT_IOR_EXPR, type,
10722 fold_convert (type,
10723 TREE_OPERAND (arg0, 0)),
10724 fold_convert (type,
10725 TREE_OPERAND (arg1, 0))));
10728 /* If arg0 is derived from the address of an object or function, we may
10729 be able to fold this expression using the object or function's
10731 if (POINTER_TYPE_P (TREE_TYPE (arg0)) && host_integerp (arg1, 1))
10733 unsigned HOST_WIDE_INT modulus, residue;
10734 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (arg1);
10736 modulus = get_pointer_modulus_and_residue (arg0, &residue);
10738 /* This works because modulus is a power of 2. If this weren't the
10739 case, we'd have to replace it by its greatest power-of-2
10740 divisor: modulus & -modulus. */
10742 return build_int_cst (type, residue & low);
10745 /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
10746 (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
10747 if the new mask might be further optimized. */
10748 if ((TREE_CODE (arg0) == LSHIFT_EXPR
10749 || TREE_CODE (arg0) == RSHIFT_EXPR)
10750 && host_integerp (TREE_OPERAND (arg0, 1), 1)
10751 && host_integerp (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)))
10752 && tree_low_cst (TREE_OPERAND (arg0, 1), 1)
10753 < TYPE_PRECISION (TREE_TYPE (arg0))
10754 && TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
10755 && tree_low_cst (TREE_OPERAND (arg0, 1), 1) > 0)
10757 unsigned int shiftc = tree_low_cst (TREE_OPERAND (arg0, 1), 1);
10758 unsigned HOST_WIDE_INT mask
10759 = tree_low_cst (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)));
10760 unsigned HOST_WIDE_INT newmask, zerobits = 0;
10761 tree shift_type = TREE_TYPE (arg0);
10763 if (TREE_CODE (arg0) == LSHIFT_EXPR)
10764 zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
10765 else if (TREE_CODE (arg0) == RSHIFT_EXPR
10766 && TYPE_PRECISION (TREE_TYPE (arg0))
10767 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg0))))
10769 unsigned int prec = TYPE_PRECISION (TREE_TYPE (arg0));
10770 tree arg00 = TREE_OPERAND (arg0, 0);
10771 /* See if more bits can be proven as zero because of
10773 if (TREE_CODE (arg00) == NOP_EXPR
10774 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
10776 tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
10777 if (TYPE_PRECISION (inner_type)
10778 == GET_MODE_BITSIZE (TYPE_MODE (inner_type))
10779 && TYPE_PRECISION (inner_type) < prec)
10781 prec = TYPE_PRECISION (inner_type);
10782 /* See if we can shorten the right shift. */
10784 shift_type = inner_type;
10787 zerobits = ~(unsigned HOST_WIDE_INT) 0;
10788 zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
10789 zerobits <<= prec - shiftc;
10790 /* For arithmetic shift if sign bit could be set, zerobits
10791 can contain actually sign bits, so no transformation is
10792 possible, unless MASK masks them all away. In that
10793 case the shift needs to be converted into logical shift. */
10794 if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
10795 && prec == TYPE_PRECISION (TREE_TYPE (arg0)))
10797 if ((mask & zerobits) == 0)
10798 shift_type = unsigned_type_for (TREE_TYPE (arg0));
10804 /* ((X << 16) & 0xff00) is (X, 0). */
10805 if ((mask & zerobits) == mask)
10806 return omit_one_operand (type, build_int_cst (type, 0), arg0);
10808 newmask = mask | zerobits;
10809 if (newmask != mask && (newmask & (newmask + 1)) == 0)
10813 /* Only do the transformation if NEWMASK is some integer
10815 for (prec = BITS_PER_UNIT;
10816 prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
10817 if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
10819 if (prec < HOST_BITS_PER_WIDE_INT
10820 || newmask == ~(unsigned HOST_WIDE_INT) 0)
10822 if (shift_type != TREE_TYPE (arg0))
10824 tem = fold_build2 (TREE_CODE (arg0), shift_type,
10825 fold_convert (shift_type,
10826 TREE_OPERAND (arg0, 0)),
10827 TREE_OPERAND (arg0, 1));
10828 tem = fold_convert (type, tem);
10832 return fold_build2 (BIT_AND_EXPR, type, tem,
10833 build_int_cst_type (TREE_TYPE (op1),
10842 /* Don't touch a floating-point divide by zero unless the mode
10843 of the constant can represent infinity. */
10844 if (TREE_CODE (arg1) == REAL_CST
10845 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
10846 && real_zerop (arg1))
10849 /* Optimize A / A to 1.0 if we don't care about
10850 NaNs or Infinities. Skip the transformation
10851 for non-real operands. */
10852 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
10853 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10854 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
10855 && operand_equal_p (arg0, arg1, 0))
10857 tree r = build_real (TREE_TYPE (arg0), dconst1);
10859 return omit_two_operands (type, r, arg0, arg1);
10862 /* The complex version of the above A / A optimization. */
10863 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10864 && operand_equal_p (arg0, arg1, 0))
10866 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
10867 if (! HONOR_NANS (TYPE_MODE (elem_type))
10868 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
10870 tree r = build_real (elem_type, dconst1);
10871 /* omit_two_operands will call fold_convert for us. */
10872 return omit_two_operands (type, r, arg0, arg1);
10876 /* (-A) / (-B) -> A / B */
10877 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10878 return fold_build2 (RDIV_EXPR, type,
10879 TREE_OPERAND (arg0, 0),
10880 negate_expr (arg1));
10881 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10882 return fold_build2 (RDIV_EXPR, type,
10883 negate_expr (arg0),
10884 TREE_OPERAND (arg1, 0));
10886 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
10887 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10888 && real_onep (arg1))
10889 return non_lvalue (fold_convert (type, arg0));
10891 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
10892 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10893 && real_minus_onep (arg1))
10894 return non_lvalue (fold_convert (type, negate_expr (arg0)));
10896 /* If ARG1 is a constant, we can convert this to a multiply by the
10897 reciprocal. This does not have the same rounding properties,
10898 so only do this if -freciprocal-math. We can actually
10899 always safely do it if ARG1 is a power of two, but it's hard to
10900 tell if it is or not in a portable manner. */
10901 if (TREE_CODE (arg1) == REAL_CST)
10903 if (flag_reciprocal_math
10904 && 0 != (tem = const_binop (code, build_real (type, dconst1),
10906 return fold_build2 (MULT_EXPR, type, arg0, tem);
10907 /* Find the reciprocal if optimizing and the result is exact. */
10911 r = TREE_REAL_CST (arg1);
10912 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
10914 tem = build_real (type, r);
10915 return fold_build2 (MULT_EXPR, type,
10916 fold_convert (type, arg0), tem);
10920 /* Convert A/B/C to A/(B*C). */
10921 if (flag_reciprocal_math
10922 && TREE_CODE (arg0) == RDIV_EXPR)
10923 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
10924 fold_build2 (MULT_EXPR, type,
10925 TREE_OPERAND (arg0, 1), arg1));
10927 /* Convert A/(B/C) to (A/B)*C. */
10928 if (flag_reciprocal_math
10929 && TREE_CODE (arg1) == RDIV_EXPR)
10930 return fold_build2 (MULT_EXPR, type,
10931 fold_build2 (RDIV_EXPR, type, arg0,
10932 TREE_OPERAND (arg1, 0)),
10933 TREE_OPERAND (arg1, 1));
10935 /* Convert C1/(X*C2) into (C1/C2)/X. */
10936 if (flag_reciprocal_math
10937 && TREE_CODE (arg1) == MULT_EXPR
10938 && TREE_CODE (arg0) == REAL_CST
10939 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
10941 tree tem = const_binop (RDIV_EXPR, arg0,
10942 TREE_OPERAND (arg1, 1), 0);
10944 return fold_build2 (RDIV_EXPR, type, tem,
10945 TREE_OPERAND (arg1, 0));
10948 if (flag_unsafe_math_optimizations)
10950 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10951 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10953 /* Optimize sin(x)/cos(x) as tan(x). */
10954 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
10955 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
10956 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
10957 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10958 CALL_EXPR_ARG (arg1, 0), 0))
10960 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
10962 if (tanfn != NULL_TREE)
10963 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
10966 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
10967 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
10968 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
10969 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
10970 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10971 CALL_EXPR_ARG (arg1, 0), 0))
10973 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
10975 if (tanfn != NULL_TREE)
10977 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
10978 return fold_build2 (RDIV_EXPR, type,
10979 build_real (type, dconst1), tmp);
10983 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
10984 NaNs or Infinities. */
10985 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
10986 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
10987 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
10989 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10990 tree arg01 = CALL_EXPR_ARG (arg1, 0);
10992 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
10993 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
10994 && operand_equal_p (arg00, arg01, 0))
10996 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
10998 if (cosfn != NULL_TREE)
10999 return build_call_expr (cosfn, 1, arg00);
11003 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11004 NaNs or Infinities. */
11005 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
11006 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
11007 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
11009 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11010 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11012 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11013 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11014 && operand_equal_p (arg00, arg01, 0))
11016 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11018 if (cosfn != NULL_TREE)
11020 tree tmp = build_call_expr (cosfn, 1, arg00);
11021 return fold_build2 (RDIV_EXPR, type,
11022 build_real (type, dconst1),
11028 /* Optimize pow(x,c)/x as pow(x,c-1). */
11029 if (fcode0 == BUILT_IN_POW
11030 || fcode0 == BUILT_IN_POWF
11031 || fcode0 == BUILT_IN_POWL)
11033 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11034 tree arg01 = CALL_EXPR_ARG (arg0, 1);
11035 if (TREE_CODE (arg01) == REAL_CST
11036 && !TREE_OVERFLOW (arg01)
11037 && operand_equal_p (arg1, arg00, 0))
11039 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
11043 c = TREE_REAL_CST (arg01);
11044 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
11045 arg = build_real (type, c);
11046 return build_call_expr (powfn, 2, arg1, arg);
11050 /* Optimize a/root(b/c) into a*root(c/b). */
11051 if (BUILTIN_ROOT_P (fcode1))
11053 tree rootarg = CALL_EXPR_ARG (arg1, 0);
11055 if (TREE_CODE (rootarg) == RDIV_EXPR)
11057 tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11058 tree b = TREE_OPERAND (rootarg, 0);
11059 tree c = TREE_OPERAND (rootarg, 1);
11061 tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
11063 tmp = build_call_expr (rootfn, 1, tmp);
11064 return fold_build2 (MULT_EXPR, type, arg0, tmp);
11068 /* Optimize x/expN(y) into x*expN(-y). */
11069 if (BUILTIN_EXPONENT_P (fcode1))
11071 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11072 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
11073 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
11074 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11077 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11078 if (fcode1 == BUILT_IN_POW
11079 || fcode1 == BUILT_IN_POWF
11080 || fcode1 == BUILT_IN_POWL)
11082 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11083 tree arg10 = CALL_EXPR_ARG (arg1, 0);
11084 tree arg11 = CALL_EXPR_ARG (arg1, 1);
11085 tree neg11 = fold_convert (type, negate_expr (arg11));
11086 arg1 = build_call_expr (powfn, 2, arg10, neg11);
11087 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11092 case TRUNC_DIV_EXPR:
11093 case FLOOR_DIV_EXPR:
11094 /* Simplify A / (B << N) where A and B are positive and B is
11095 a power of 2, to A >> (N + log2(B)). */
11096 strict_overflow_p = false;
11097 if (TREE_CODE (arg1) == LSHIFT_EXPR
11098 && (TYPE_UNSIGNED (type)
11099 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11101 tree sval = TREE_OPERAND (arg1, 0);
11102 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
11104 tree sh_cnt = TREE_OPERAND (arg1, 1);
11105 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
11107 if (strict_overflow_p)
11108 fold_overflow_warning (("assuming signed overflow does not "
11109 "occur when simplifying A / (B << N)"),
11110 WARN_STRICT_OVERFLOW_MISC);
11112 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
11113 sh_cnt, build_int_cst (NULL_TREE, pow2));
11114 return fold_build2 (RSHIFT_EXPR, type,
11115 fold_convert (type, arg0), sh_cnt);
11119 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
11120 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
11121 if (INTEGRAL_TYPE_P (type)
11122 && TYPE_UNSIGNED (type)
11123 && code == FLOOR_DIV_EXPR)
11124 return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
11128 case ROUND_DIV_EXPR:
11129 case CEIL_DIV_EXPR:
11130 case EXACT_DIV_EXPR:
11131 if (integer_onep (arg1))
11132 return non_lvalue (fold_convert (type, arg0));
11133 if (integer_zerop (arg1))
11135 /* X / -1 is -X. */
11136 if (!TYPE_UNSIGNED (type)
11137 && TREE_CODE (arg1) == INTEGER_CST
11138 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11139 && TREE_INT_CST_HIGH (arg1) == -1)
11140 return fold_convert (type, negate_expr (arg0));
11142 /* Convert -A / -B to A / B when the type is signed and overflow is
11144 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11145 && TREE_CODE (arg0) == NEGATE_EXPR
11146 && negate_expr_p (arg1))
11148 if (INTEGRAL_TYPE_P (type))
11149 fold_overflow_warning (("assuming signed overflow does not occur "
11150 "when distributing negation across "
11152 WARN_STRICT_OVERFLOW_MISC);
11153 return fold_build2 (code, type,
11154 fold_convert (type, TREE_OPERAND (arg0, 0)),
11155 negate_expr (arg1));
11157 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11158 && TREE_CODE (arg1) == NEGATE_EXPR
11159 && negate_expr_p (arg0))
11161 if (INTEGRAL_TYPE_P (type))
11162 fold_overflow_warning (("assuming signed overflow does not occur "
11163 "when distributing negation across "
11165 WARN_STRICT_OVERFLOW_MISC);
11166 return fold_build2 (code, type, negate_expr (arg0),
11167 TREE_OPERAND (arg1, 0));
11170 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11171 operation, EXACT_DIV_EXPR.
11173 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11174 At one time others generated faster code, it's not clear if they do
11175 after the last round to changes to the DIV code in expmed.c. */
11176 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
11177 && multiple_of_p (type, arg0, arg1))
11178 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
11180 strict_overflow_p = false;
11181 if (TREE_CODE (arg1) == INTEGER_CST
11182 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11183 &strict_overflow_p)))
11185 if (strict_overflow_p)
11186 fold_overflow_warning (("assuming signed overflow does not occur "
11187 "when simplifying division"),
11188 WARN_STRICT_OVERFLOW_MISC);
11189 return fold_convert (type, tem);
11194 case CEIL_MOD_EXPR:
11195 case FLOOR_MOD_EXPR:
11196 case ROUND_MOD_EXPR:
11197 case TRUNC_MOD_EXPR:
11198 /* X % 1 is always zero, but be sure to preserve any side
11200 if (integer_onep (arg1))
11201 return omit_one_operand (type, integer_zero_node, arg0);
11203 /* X % 0, return X % 0 unchanged so that we can get the
11204 proper warnings and errors. */
11205 if (integer_zerop (arg1))
11208 /* 0 % X is always zero, but be sure to preserve any side
11209 effects in X. Place this after checking for X == 0. */
11210 if (integer_zerop (arg0))
11211 return omit_one_operand (type, integer_zero_node, arg1);
11213 /* X % -1 is zero. */
11214 if (!TYPE_UNSIGNED (type)
11215 && TREE_CODE (arg1) == INTEGER_CST
11216 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11217 && TREE_INT_CST_HIGH (arg1) == -1)
11218 return omit_one_operand (type, integer_zero_node, arg0);
11220 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11221 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11222 strict_overflow_p = false;
11223 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
11224 && (TYPE_UNSIGNED (type)
11225 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11228 /* Also optimize A % (C << N) where C is a power of 2,
11229 to A & ((C << N) - 1). */
11230 if (TREE_CODE (arg1) == LSHIFT_EXPR)
11231 c = TREE_OPERAND (arg1, 0);
11233 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
11235 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
11236 build_int_cst (TREE_TYPE (arg1), 1));
11237 if (strict_overflow_p)
11238 fold_overflow_warning (("assuming signed overflow does not "
11239 "occur when simplifying "
11240 "X % (power of two)"),
11241 WARN_STRICT_OVERFLOW_MISC);
11242 return fold_build2 (BIT_AND_EXPR, type,
11243 fold_convert (type, arg0),
11244 fold_convert (type, mask));
11248 /* X % -C is the same as X % C. */
11249 if (code == TRUNC_MOD_EXPR
11250 && !TYPE_UNSIGNED (type)
11251 && TREE_CODE (arg1) == INTEGER_CST
11252 && !TREE_OVERFLOW (arg1)
11253 && TREE_INT_CST_HIGH (arg1) < 0
11254 && !TYPE_OVERFLOW_TRAPS (type)
11255 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11256 && !sign_bit_p (arg1, arg1))
11257 return fold_build2 (code, type, fold_convert (type, arg0),
11258 fold_convert (type, negate_expr (arg1)));
11260 /* X % -Y is the same as X % Y. */
11261 if (code == TRUNC_MOD_EXPR
11262 && !TYPE_UNSIGNED (type)
11263 && TREE_CODE (arg1) == NEGATE_EXPR
11264 && !TYPE_OVERFLOW_TRAPS (type))
11265 return fold_build2 (code, type, fold_convert (type, arg0),
11266 fold_convert (type, TREE_OPERAND (arg1, 0)));
11268 if (TREE_CODE (arg1) == INTEGER_CST
11269 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11270 &strict_overflow_p)))
11272 if (strict_overflow_p)
11273 fold_overflow_warning (("assuming signed overflow does not occur "
11274 "when simplifying modulos"),
11275 WARN_STRICT_OVERFLOW_MISC);
11276 return fold_convert (type, tem);
11283 if (integer_all_onesp (arg0))
11284 return omit_one_operand (type, arg0, arg1);
11288 /* Optimize -1 >> x for arithmetic right shifts. */
11289 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
11290 return omit_one_operand (type, arg0, arg1);
11291 /* ... fall through ... */
11295 if (integer_zerop (arg1))
11296 return non_lvalue (fold_convert (type, arg0));
11297 if (integer_zerop (arg0))
11298 return omit_one_operand (type, arg0, arg1);
11300 /* Since negative shift count is not well-defined,
11301 don't try to compute it in the compiler. */
11302 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
11305 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11306 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
11307 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11308 && host_integerp (TREE_OPERAND (arg0, 1), false)
11309 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11311 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
11312 + TREE_INT_CST_LOW (arg1));
11314 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11315 being well defined. */
11316 if (low >= TYPE_PRECISION (type))
11318 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
11319 low = low % TYPE_PRECISION (type);
11320 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
11321 return build_int_cst (type, 0);
11323 low = TYPE_PRECISION (type) - 1;
11326 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11327 build_int_cst (type, low));
11330 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11331 into x & ((unsigned)-1 >> c) for unsigned types. */
11332 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
11333 || (TYPE_UNSIGNED (type)
11334 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
11335 && host_integerp (arg1, false)
11336 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11337 && host_integerp (TREE_OPERAND (arg0, 1), false)
11338 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11340 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
11341 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
11347 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
11349 lshift = build_int_cst (type, -1);
11350 lshift = int_const_binop (code, lshift, arg1, 0);
11352 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
11356 /* Rewrite an LROTATE_EXPR by a constant into an
11357 RROTATE_EXPR by a new constant. */
11358 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
11360 tree tem = build_int_cst (TREE_TYPE (arg1),
11361 TYPE_PRECISION (type));
11362 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
11363 return fold_build2 (RROTATE_EXPR, type, op0, tem);
11366 /* If we have a rotate of a bit operation with the rotate count and
11367 the second operand of the bit operation both constant,
11368 permute the two operations. */
11369 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11370 && (TREE_CODE (arg0) == BIT_AND_EXPR
11371 || TREE_CODE (arg0) == BIT_IOR_EXPR
11372 || TREE_CODE (arg0) == BIT_XOR_EXPR)
11373 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11374 return fold_build2 (TREE_CODE (arg0), type,
11375 fold_build2 (code, type,
11376 TREE_OPERAND (arg0, 0), arg1),
11377 fold_build2 (code, type,
11378 TREE_OPERAND (arg0, 1), arg1));
11380 /* Two consecutive rotates adding up to the precision of the
11381 type can be ignored. */
11382 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11383 && TREE_CODE (arg0) == RROTATE_EXPR
11384 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11385 && TREE_INT_CST_HIGH (arg1) == 0
11386 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
11387 && ((TREE_INT_CST_LOW (arg1)
11388 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
11389 == (unsigned int) TYPE_PRECISION (type)))
11390 return TREE_OPERAND (arg0, 0);
11392 /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
11393 (X & C2) >> C1 into (X >> C1) & (C2 >> C1)
11394 if the latter can be further optimized. */
11395 if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
11396 && TREE_CODE (arg0) == BIT_AND_EXPR
11397 && TREE_CODE (arg1) == INTEGER_CST
11398 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11400 tree mask = fold_build2 (code, type,
11401 fold_convert (type, TREE_OPERAND (arg0, 1)),
11403 tree shift = fold_build2 (code, type,
11404 fold_convert (type, TREE_OPERAND (arg0, 0)),
11406 tem = fold_binary (BIT_AND_EXPR, type, shift, mask);
11414 if (operand_equal_p (arg0, arg1, 0))
11415 return omit_one_operand (type, arg0, arg1);
11416 if (INTEGRAL_TYPE_P (type)
11417 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
11418 return omit_one_operand (type, arg1, arg0);
11419 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
11425 if (operand_equal_p (arg0, arg1, 0))
11426 return omit_one_operand (type, arg0, arg1);
11427 if (INTEGRAL_TYPE_P (type)
11428 && TYPE_MAX_VALUE (type)
11429 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
11430 return omit_one_operand (type, arg1, arg0);
11431 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
11436 case TRUTH_ANDIF_EXPR:
11437 /* Note that the operands of this must be ints
11438 and their values must be 0 or 1.
11439 ("true" is a fixed value perhaps depending on the language.) */
11440 /* If first arg is constant zero, return it. */
11441 if (integer_zerop (arg0))
11442 return fold_convert (type, arg0);
11443 case TRUTH_AND_EXPR:
11444 /* If either arg is constant true, drop it. */
11445 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11446 return non_lvalue (fold_convert (type, arg1));
11447 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
11448 /* Preserve sequence points. */
11449 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11450 return non_lvalue (fold_convert (type, arg0));
11451 /* If second arg is constant zero, result is zero, but first arg
11452 must be evaluated. */
11453 if (integer_zerop (arg1))
11454 return omit_one_operand (type, arg1, arg0);
11455 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11456 case will be handled here. */
11457 if (integer_zerop (arg0))
11458 return omit_one_operand (type, arg0, arg1);
11460 /* !X && X is always false. */
11461 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11462 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11463 return omit_one_operand (type, integer_zero_node, arg1);
11464 /* X && !X is always false. */
11465 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11466 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11467 return omit_one_operand (type, integer_zero_node, arg0);
11469 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
11470 means A >= Y && A != MAX, but in this case we know that
11473 if (!TREE_SIDE_EFFECTS (arg0)
11474 && !TREE_SIDE_EFFECTS (arg1))
11476 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
11477 if (tem && !operand_equal_p (tem, arg0, 0))
11478 return fold_build2 (code, type, tem, arg1);
11480 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
11481 if (tem && !operand_equal_p (tem, arg1, 0))
11482 return fold_build2 (code, type, arg0, tem);
11486 /* We only do these simplifications if we are optimizing. */
11490 /* Check for things like (A || B) && (A || C). We can convert this
11491 to A || (B && C). Note that either operator can be any of the four
11492 truth and/or operations and the transformation will still be
11493 valid. Also note that we only care about order for the
11494 ANDIF and ORIF operators. If B contains side effects, this
11495 might change the truth-value of A. */
11496 if (TREE_CODE (arg0) == TREE_CODE (arg1)
11497 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
11498 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
11499 || TREE_CODE (arg0) == TRUTH_AND_EXPR
11500 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
11501 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
11503 tree a00 = TREE_OPERAND (arg0, 0);
11504 tree a01 = TREE_OPERAND (arg0, 1);
11505 tree a10 = TREE_OPERAND (arg1, 0);
11506 tree a11 = TREE_OPERAND (arg1, 1);
11507 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
11508 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
11509 && (code == TRUTH_AND_EXPR
11510 || code == TRUTH_OR_EXPR));
11512 if (operand_equal_p (a00, a10, 0))
11513 return fold_build2 (TREE_CODE (arg0), type, a00,
11514 fold_build2 (code, type, a01, a11));
11515 else if (commutative && operand_equal_p (a00, a11, 0))
11516 return fold_build2 (TREE_CODE (arg0), type, a00,
11517 fold_build2 (code, type, a01, a10));
11518 else if (commutative && operand_equal_p (a01, a10, 0))
11519 return fold_build2 (TREE_CODE (arg0), type, a01,
11520 fold_build2 (code, type, a00, a11));
11522 /* This case if tricky because we must either have commutative
11523 operators or else A10 must not have side-effects. */
11525 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
11526 && operand_equal_p (a01, a11, 0))
11527 return fold_build2 (TREE_CODE (arg0), type,
11528 fold_build2 (code, type, a00, a10),
11532 /* See if we can build a range comparison. */
11533 if (0 != (tem = fold_range_test (code, type, op0, op1)))
11536 /* Check for the possibility of merging component references. If our
11537 lhs is another similar operation, try to merge its rhs with our
11538 rhs. Then try to merge our lhs and rhs. */
11539 if (TREE_CODE (arg0) == code
11540 && 0 != (tem = fold_truthop (code, type,
11541 TREE_OPERAND (arg0, 1), arg1)))
11542 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11544 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
11549 case TRUTH_ORIF_EXPR:
11550 /* Note that the operands of this must be ints
11551 and their values must be 0 or true.
11552 ("true" is a fixed value perhaps depending on the language.) */
11553 /* If first arg is constant true, return it. */
11554 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11555 return fold_convert (type, arg0);
11556 case TRUTH_OR_EXPR:
11557 /* If either arg is constant zero, drop it. */
11558 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
11559 return non_lvalue (fold_convert (type, arg1));
11560 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
11561 /* Preserve sequence points. */
11562 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11563 return non_lvalue (fold_convert (type, arg0));
11564 /* If second arg is constant true, result is true, but we must
11565 evaluate first arg. */
11566 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
11567 return omit_one_operand (type, arg1, arg0);
11568 /* Likewise for first arg, but note this only occurs here for
11570 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11571 return omit_one_operand (type, arg0, arg1);
11573 /* !X || X is always true. */
11574 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11575 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11576 return omit_one_operand (type, integer_one_node, arg1);
11577 /* X || !X is always true. */
11578 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11579 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11580 return omit_one_operand (type, integer_one_node, arg0);
11584 case TRUTH_XOR_EXPR:
11585 /* If the second arg is constant zero, drop it. */
11586 if (integer_zerop (arg1))
11587 return non_lvalue (fold_convert (type, arg0));
11588 /* If the second arg is constant true, this is a logical inversion. */
11589 if (integer_onep (arg1))
11591 /* Only call invert_truthvalue if operand is a truth value. */
11592 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
11593 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
11595 tem = invert_truthvalue (arg0);
11596 return non_lvalue (fold_convert (type, tem));
11598 /* Identical arguments cancel to zero. */
11599 if (operand_equal_p (arg0, arg1, 0))
11600 return omit_one_operand (type, integer_zero_node, arg0);
11602 /* !X ^ X is always true. */
11603 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11604 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11605 return omit_one_operand (type, integer_one_node, arg1);
11607 /* X ^ !X is always true. */
11608 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11609 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11610 return omit_one_operand (type, integer_one_node, arg0);
11616 tem = fold_comparison (code, type, op0, op1);
11617 if (tem != NULL_TREE)
11620 /* bool_var != 0 becomes bool_var. */
11621 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11622 && code == NE_EXPR)
11623 return non_lvalue (fold_convert (type, arg0));
11625 /* bool_var == 1 becomes bool_var. */
11626 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11627 && code == EQ_EXPR)
11628 return non_lvalue (fold_convert (type, arg0));
11630 /* bool_var != 1 becomes !bool_var. */
11631 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11632 && code == NE_EXPR)
11633 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11635 /* bool_var == 0 becomes !bool_var. */
11636 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11637 && code == EQ_EXPR)
11638 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11640 /* If this is an equality comparison of the address of two non-weak,
11641 unaliased symbols neither of which are extern (since we do not
11642 have access to attributes for externs), then we know the result. */
11643 if (TREE_CODE (arg0) == ADDR_EXPR
11644 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
11645 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
11646 && ! lookup_attribute ("alias",
11647 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
11648 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
11649 && TREE_CODE (arg1) == ADDR_EXPR
11650 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
11651 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
11652 && ! lookup_attribute ("alias",
11653 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
11654 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
11656 /* We know that we're looking at the address of two
11657 non-weak, unaliased, static _DECL nodes.
11659 It is both wasteful and incorrect to call operand_equal_p
11660 to compare the two ADDR_EXPR nodes. It is wasteful in that
11661 all we need to do is test pointer equality for the arguments
11662 to the two ADDR_EXPR nodes. It is incorrect to use
11663 operand_equal_p as that function is NOT equivalent to a
11664 C equality test. It can in fact return false for two
11665 objects which would test as equal using the C equality
11667 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
11668 return constant_boolean_node (equal
11669 ? code == EQ_EXPR : code != EQ_EXPR,
11673 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
11674 a MINUS_EXPR of a constant, we can convert it into a comparison with
11675 a revised constant as long as no overflow occurs. */
11676 if (TREE_CODE (arg1) == INTEGER_CST
11677 && (TREE_CODE (arg0) == PLUS_EXPR
11678 || TREE_CODE (arg0) == MINUS_EXPR)
11679 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11680 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
11681 ? MINUS_EXPR : PLUS_EXPR,
11682 fold_convert (TREE_TYPE (arg0), arg1),
11683 TREE_OPERAND (arg0, 1), 0))
11684 && !TREE_OVERFLOW (tem))
11685 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11687 /* Similarly for a NEGATE_EXPR. */
11688 if (TREE_CODE (arg0) == NEGATE_EXPR
11689 && TREE_CODE (arg1) == INTEGER_CST
11690 && 0 != (tem = negate_expr (arg1))
11691 && TREE_CODE (tem) == INTEGER_CST
11692 && !TREE_OVERFLOW (tem))
11693 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11695 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
11696 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11697 && TREE_CODE (arg1) == INTEGER_CST
11698 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11699 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11700 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
11701 fold_convert (TREE_TYPE (arg0), arg1),
11702 TREE_OPERAND (arg0, 1)));
11704 /* Transform comparisons of the form X +- C CMP X. */
11705 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11706 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11707 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11708 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
11709 || POINTER_TYPE_P (TREE_TYPE (arg0))))
11711 tree cst = TREE_OPERAND (arg0, 1);
11713 if (code == EQ_EXPR
11714 && !integer_zerop (cst))
11715 return omit_two_operands (type, boolean_false_node,
11716 TREE_OPERAND (arg0, 0), arg1);
11718 return omit_two_operands (type, boolean_true_node,
11719 TREE_OPERAND (arg0, 0), arg1);
11722 /* If we have X - Y == 0, we can convert that to X == Y and similarly
11723 for !=. Don't do this for ordered comparisons due to overflow. */
11724 if (TREE_CODE (arg0) == MINUS_EXPR
11725 && integer_zerop (arg1))
11726 return fold_build2 (code, type,
11727 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
11729 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
11730 if (TREE_CODE (arg0) == ABS_EXPR
11731 && (integer_zerop (arg1) || real_zerop (arg1)))
11732 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
11734 /* If this is an EQ or NE comparison with zero and ARG0 is
11735 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
11736 two operations, but the latter can be done in one less insn
11737 on machines that have only two-operand insns or on which a
11738 constant cannot be the first operand. */
11739 if (TREE_CODE (arg0) == BIT_AND_EXPR
11740 && integer_zerop (arg1))
11742 tree arg00 = TREE_OPERAND (arg0, 0);
11743 tree arg01 = TREE_OPERAND (arg0, 1);
11744 if (TREE_CODE (arg00) == LSHIFT_EXPR
11745 && integer_onep (TREE_OPERAND (arg00, 0)))
11747 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
11748 arg01, TREE_OPERAND (arg00, 1));
11749 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11750 build_int_cst (TREE_TYPE (arg0), 1));
11751 return fold_build2 (code, type,
11752 fold_convert (TREE_TYPE (arg1), tem), arg1);
11754 else if (TREE_CODE (arg01) == LSHIFT_EXPR
11755 && integer_onep (TREE_OPERAND (arg01, 0)))
11757 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
11758 arg00, TREE_OPERAND (arg01, 1));
11759 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11760 build_int_cst (TREE_TYPE (arg0), 1));
11761 return fold_build2 (code, type,
11762 fold_convert (TREE_TYPE (arg1), tem), arg1);
11766 /* If this is an NE or EQ comparison of zero against the result of a
11767 signed MOD operation whose second operand is a power of 2, make
11768 the MOD operation unsigned since it is simpler and equivalent. */
11769 if (integer_zerop (arg1)
11770 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
11771 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
11772 || TREE_CODE (arg0) == CEIL_MOD_EXPR
11773 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
11774 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
11775 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11777 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
11778 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
11779 fold_convert (newtype,
11780 TREE_OPERAND (arg0, 0)),
11781 fold_convert (newtype,
11782 TREE_OPERAND (arg0, 1)));
11784 return fold_build2 (code, type, newmod,
11785 fold_convert (newtype, arg1));
11788 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
11789 C1 is a valid shift constant, and C2 is a power of two, i.e.
11791 if (TREE_CODE (arg0) == BIT_AND_EXPR
11792 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
11793 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
11795 && integer_pow2p (TREE_OPERAND (arg0, 1))
11796 && integer_zerop (arg1))
11798 tree itype = TREE_TYPE (arg0);
11799 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
11800 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
11802 /* Check for a valid shift count. */
11803 if (TREE_INT_CST_HIGH (arg001) == 0
11804 && TREE_INT_CST_LOW (arg001) < prec)
11806 tree arg01 = TREE_OPERAND (arg0, 1);
11807 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11808 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
11809 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
11810 can be rewritten as (X & (C2 << C1)) != 0. */
11811 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
11813 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
11814 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
11815 return fold_build2 (code, type, tem, arg1);
11817 /* Otherwise, for signed (arithmetic) shifts,
11818 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
11819 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
11820 else if (!TYPE_UNSIGNED (itype))
11821 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
11822 arg000, build_int_cst (itype, 0));
11823 /* Otherwise, of unsigned (logical) shifts,
11824 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
11825 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
11827 return omit_one_operand (type,
11828 code == EQ_EXPR ? integer_one_node
11829 : integer_zero_node,
11834 /* If this is an NE comparison of zero with an AND of one, remove the
11835 comparison since the AND will give the correct value. */
11836 if (code == NE_EXPR
11837 && integer_zerop (arg1)
11838 && TREE_CODE (arg0) == BIT_AND_EXPR
11839 && integer_onep (TREE_OPERAND (arg0, 1)))
11840 return fold_convert (type, arg0);
11842 /* If we have (A & C) == C where C is a power of 2, convert this into
11843 (A & C) != 0. Similarly for NE_EXPR. */
11844 if (TREE_CODE (arg0) == BIT_AND_EXPR
11845 && integer_pow2p (TREE_OPERAND (arg0, 1))
11846 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11847 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11848 arg0, fold_convert (TREE_TYPE (arg0),
11849 integer_zero_node));
11851 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
11852 bit, then fold the expression into A < 0 or A >= 0. */
11853 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
11857 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
11858 Similarly for NE_EXPR. */
11859 if (TREE_CODE (arg0) == BIT_AND_EXPR
11860 && TREE_CODE (arg1) == INTEGER_CST
11861 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11863 tree notc = fold_build1 (BIT_NOT_EXPR,
11864 TREE_TYPE (TREE_OPERAND (arg0, 1)),
11865 TREE_OPERAND (arg0, 1));
11866 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11868 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11869 if (integer_nonzerop (dandnotc))
11870 return omit_one_operand (type, rslt, arg0);
11873 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
11874 Similarly for NE_EXPR. */
11875 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11876 && TREE_CODE (arg1) == INTEGER_CST
11877 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11879 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
11880 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11881 TREE_OPERAND (arg0, 1), notd);
11882 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11883 if (integer_nonzerop (candnotd))
11884 return omit_one_operand (type, rslt, arg0);
11887 /* Optimize comparisons of strlen vs zero to a compare of the
11888 first character of the string vs zero. To wit,
11889 strlen(ptr) == 0 => *ptr == 0
11890 strlen(ptr) != 0 => *ptr != 0
11891 Other cases should reduce to one of these two (or a constant)
11892 due to the return value of strlen being unsigned. */
11893 if (TREE_CODE (arg0) == CALL_EXPR
11894 && integer_zerop (arg1))
11896 tree fndecl = get_callee_fndecl (arg0);
11899 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
11900 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
11901 && call_expr_nargs (arg0) == 1
11902 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
11904 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
11905 return fold_build2 (code, type, iref,
11906 build_int_cst (TREE_TYPE (iref), 0));
11910 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
11911 of X. Similarly fold (X >> C) == 0 into X >= 0. */
11912 if (TREE_CODE (arg0) == RSHIFT_EXPR
11913 && integer_zerop (arg1)
11914 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11916 tree arg00 = TREE_OPERAND (arg0, 0);
11917 tree arg01 = TREE_OPERAND (arg0, 1);
11918 tree itype = TREE_TYPE (arg00);
11919 if (TREE_INT_CST_HIGH (arg01) == 0
11920 && TREE_INT_CST_LOW (arg01)
11921 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
11923 if (TYPE_UNSIGNED (itype))
11925 itype = signed_type_for (itype);
11926 arg00 = fold_convert (itype, arg00);
11928 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
11929 type, arg00, build_int_cst (itype, 0));
11933 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
11934 if (integer_zerop (arg1)
11935 && TREE_CODE (arg0) == BIT_XOR_EXPR)
11936 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11937 TREE_OPERAND (arg0, 1));
11939 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
11940 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11941 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11942 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11943 build_int_cst (TREE_TYPE (arg1), 0));
11944 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
11945 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11946 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11947 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11948 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
11949 build_int_cst (TREE_TYPE (arg1), 0));
11951 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
11952 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11953 && TREE_CODE (arg1) == INTEGER_CST
11954 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11955 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11956 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
11957 TREE_OPERAND (arg0, 1), arg1));
11959 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
11960 (X & C) == 0 when C is a single bit. */
11961 if (TREE_CODE (arg0) == BIT_AND_EXPR
11962 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
11963 && integer_zerop (arg1)
11964 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11966 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11967 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
11968 TREE_OPERAND (arg0, 1));
11969 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
11973 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
11974 constant C is a power of two, i.e. a single bit. */
11975 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11976 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
11977 && integer_zerop (arg1)
11978 && integer_pow2p (TREE_OPERAND (arg0, 1))
11979 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
11980 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
11982 tree arg00 = TREE_OPERAND (arg0, 0);
11983 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11984 arg00, build_int_cst (TREE_TYPE (arg00), 0));
11987 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
11988 when is C is a power of two, i.e. a single bit. */
11989 if (TREE_CODE (arg0) == BIT_AND_EXPR
11990 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
11991 && integer_zerop (arg1)
11992 && integer_pow2p (TREE_OPERAND (arg0, 1))
11993 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
11994 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
11996 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11997 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
11998 arg000, TREE_OPERAND (arg0, 1));
11999 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12000 tem, build_int_cst (TREE_TYPE (tem), 0));
12003 if (integer_zerop (arg1)
12004 && tree_expr_nonzero_p (arg0))
12006 tree res = constant_boolean_node (code==NE_EXPR, type);
12007 return omit_one_operand (type, res, arg0);
12010 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12011 if (TREE_CODE (arg0) == NEGATE_EXPR
12012 && TREE_CODE (arg1) == NEGATE_EXPR)
12013 return fold_build2 (code, type,
12014 TREE_OPERAND (arg0, 0),
12015 TREE_OPERAND (arg1, 0));
12017 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12018 if (TREE_CODE (arg0) == BIT_AND_EXPR
12019 && TREE_CODE (arg1) == BIT_AND_EXPR)
12021 tree arg00 = TREE_OPERAND (arg0, 0);
12022 tree arg01 = TREE_OPERAND (arg0, 1);
12023 tree arg10 = TREE_OPERAND (arg1, 0);
12024 tree arg11 = TREE_OPERAND (arg1, 1);
12025 tree itype = TREE_TYPE (arg0);
12027 if (operand_equal_p (arg01, arg11, 0))
12028 return fold_build2 (code, type,
12029 fold_build2 (BIT_AND_EXPR, itype,
12030 fold_build2 (BIT_XOR_EXPR, itype,
12033 build_int_cst (itype, 0));
12035 if (operand_equal_p (arg01, arg10, 0))
12036 return fold_build2 (code, type,
12037 fold_build2 (BIT_AND_EXPR, itype,
12038 fold_build2 (BIT_XOR_EXPR, itype,
12041 build_int_cst (itype, 0));
12043 if (operand_equal_p (arg00, arg11, 0))
12044 return fold_build2 (code, type,
12045 fold_build2 (BIT_AND_EXPR, itype,
12046 fold_build2 (BIT_XOR_EXPR, itype,
12049 build_int_cst (itype, 0));
12051 if (operand_equal_p (arg00, arg10, 0))
12052 return fold_build2 (code, type,
12053 fold_build2 (BIT_AND_EXPR, itype,
12054 fold_build2 (BIT_XOR_EXPR, itype,
12057 build_int_cst (itype, 0));
12060 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12061 && TREE_CODE (arg1) == BIT_XOR_EXPR)
12063 tree arg00 = TREE_OPERAND (arg0, 0);
12064 tree arg01 = TREE_OPERAND (arg0, 1);
12065 tree arg10 = TREE_OPERAND (arg1, 0);
12066 tree arg11 = TREE_OPERAND (arg1, 1);
12067 tree itype = TREE_TYPE (arg0);
12069 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12070 operand_equal_p guarantees no side-effects so we don't need
12071 to use omit_one_operand on Z. */
12072 if (operand_equal_p (arg01, arg11, 0))
12073 return fold_build2 (code, type, arg00, arg10);
12074 if (operand_equal_p (arg01, arg10, 0))
12075 return fold_build2 (code, type, arg00, arg11);
12076 if (operand_equal_p (arg00, arg11, 0))
12077 return fold_build2 (code, type, arg01, arg10);
12078 if (operand_equal_p (arg00, arg10, 0))
12079 return fold_build2 (code, type, arg01, arg11);
12081 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12082 if (TREE_CODE (arg01) == INTEGER_CST
12083 && TREE_CODE (arg11) == INTEGER_CST)
12084 return fold_build2 (code, type,
12085 fold_build2 (BIT_XOR_EXPR, itype, arg00,
12086 fold_build2 (BIT_XOR_EXPR, itype,
12091 /* Attempt to simplify equality/inequality comparisons of complex
12092 values. Only lower the comparison if the result is known or
12093 can be simplified to a single scalar comparison. */
12094 if ((TREE_CODE (arg0) == COMPLEX_EXPR
12095 || TREE_CODE (arg0) == COMPLEX_CST)
12096 && (TREE_CODE (arg1) == COMPLEX_EXPR
12097 || TREE_CODE (arg1) == COMPLEX_CST))
12099 tree real0, imag0, real1, imag1;
12102 if (TREE_CODE (arg0) == COMPLEX_EXPR)
12104 real0 = TREE_OPERAND (arg0, 0);
12105 imag0 = TREE_OPERAND (arg0, 1);
12109 real0 = TREE_REALPART (arg0);
12110 imag0 = TREE_IMAGPART (arg0);
12113 if (TREE_CODE (arg1) == COMPLEX_EXPR)
12115 real1 = TREE_OPERAND (arg1, 0);
12116 imag1 = TREE_OPERAND (arg1, 1);
12120 real1 = TREE_REALPART (arg1);
12121 imag1 = TREE_IMAGPART (arg1);
12124 rcond = fold_binary (code, type, real0, real1);
12125 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
12127 if (integer_zerop (rcond))
12129 if (code == EQ_EXPR)
12130 return omit_two_operands (type, boolean_false_node,
12132 return fold_build2 (NE_EXPR, type, imag0, imag1);
12136 if (code == NE_EXPR)
12137 return omit_two_operands (type, boolean_true_node,
12139 return fold_build2 (EQ_EXPR, type, imag0, imag1);
12143 icond = fold_binary (code, type, imag0, imag1);
12144 if (icond && TREE_CODE (icond) == INTEGER_CST)
12146 if (integer_zerop (icond))
12148 if (code == EQ_EXPR)
12149 return omit_two_operands (type, boolean_false_node,
12151 return fold_build2 (NE_EXPR, type, real0, real1);
12155 if (code == NE_EXPR)
12156 return omit_two_operands (type, boolean_true_node,
12158 return fold_build2 (EQ_EXPR, type, real0, real1);
12169 tem = fold_comparison (code, type, op0, op1);
12170 if (tem != NULL_TREE)
12173 /* Transform comparisons of the form X +- C CMP X. */
12174 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12175 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12176 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
12177 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
12178 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12179 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
12181 tree arg01 = TREE_OPERAND (arg0, 1);
12182 enum tree_code code0 = TREE_CODE (arg0);
12185 if (TREE_CODE (arg01) == REAL_CST)
12186 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
12188 is_positive = tree_int_cst_sgn (arg01);
12190 /* (X - c) > X becomes false. */
12191 if (code == GT_EXPR
12192 && ((code0 == MINUS_EXPR && is_positive >= 0)
12193 || (code0 == PLUS_EXPR && is_positive <= 0)))
12195 if (TREE_CODE (arg01) == INTEGER_CST
12196 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12197 fold_overflow_warning (("assuming signed overflow does not "
12198 "occur when assuming that (X - c) > X "
12199 "is always false"),
12200 WARN_STRICT_OVERFLOW_ALL);
12201 return constant_boolean_node (0, type);
12204 /* Likewise (X + c) < X becomes false. */
12205 if (code == LT_EXPR
12206 && ((code0 == PLUS_EXPR && is_positive >= 0)
12207 || (code0 == MINUS_EXPR && is_positive <= 0)))
12209 if (TREE_CODE (arg01) == INTEGER_CST
12210 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12211 fold_overflow_warning (("assuming signed overflow does not "
12212 "occur when assuming that "
12213 "(X + c) < X is always false"),
12214 WARN_STRICT_OVERFLOW_ALL);
12215 return constant_boolean_node (0, type);
12218 /* Convert (X - c) <= X to true. */
12219 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12221 && ((code0 == MINUS_EXPR && is_positive >= 0)
12222 || (code0 == PLUS_EXPR && is_positive <= 0)))
12224 if (TREE_CODE (arg01) == INTEGER_CST
12225 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12226 fold_overflow_warning (("assuming signed overflow does not "
12227 "occur when assuming that "
12228 "(X - c) <= X is always true"),
12229 WARN_STRICT_OVERFLOW_ALL);
12230 return constant_boolean_node (1, type);
12233 /* Convert (X + c) >= X to true. */
12234 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12236 && ((code0 == PLUS_EXPR && is_positive >= 0)
12237 || (code0 == MINUS_EXPR && is_positive <= 0)))
12239 if (TREE_CODE (arg01) == INTEGER_CST
12240 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12241 fold_overflow_warning (("assuming signed overflow does not "
12242 "occur when assuming that "
12243 "(X + c) >= X is always true"),
12244 WARN_STRICT_OVERFLOW_ALL);
12245 return constant_boolean_node (1, type);
12248 if (TREE_CODE (arg01) == INTEGER_CST)
12250 /* Convert X + c > X and X - c < X to true for integers. */
12251 if (code == GT_EXPR
12252 && ((code0 == PLUS_EXPR && is_positive > 0)
12253 || (code0 == MINUS_EXPR && is_positive < 0)))
12255 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12256 fold_overflow_warning (("assuming signed overflow does "
12257 "not occur when assuming that "
12258 "(X + c) > X is always true"),
12259 WARN_STRICT_OVERFLOW_ALL);
12260 return constant_boolean_node (1, type);
12263 if (code == LT_EXPR
12264 && ((code0 == MINUS_EXPR && is_positive > 0)
12265 || (code0 == PLUS_EXPR && is_positive < 0)))
12267 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12268 fold_overflow_warning (("assuming signed overflow does "
12269 "not occur when assuming that "
12270 "(X - c) < X is always true"),
12271 WARN_STRICT_OVERFLOW_ALL);
12272 return constant_boolean_node (1, type);
12275 /* Convert X + c <= X and X - c >= X to false for integers. */
12276 if (code == LE_EXPR
12277 && ((code0 == PLUS_EXPR && is_positive > 0)
12278 || (code0 == MINUS_EXPR && is_positive < 0)))
12280 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12281 fold_overflow_warning (("assuming signed overflow does "
12282 "not occur when assuming that "
12283 "(X + c) <= X is always false"),
12284 WARN_STRICT_OVERFLOW_ALL);
12285 return constant_boolean_node (0, type);
12288 if (code == GE_EXPR
12289 && ((code0 == MINUS_EXPR && is_positive > 0)
12290 || (code0 == PLUS_EXPR && is_positive < 0)))
12292 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12293 fold_overflow_warning (("assuming signed overflow does "
12294 "not occur when assuming that "
12295 "(X - c) >= X is always false"),
12296 WARN_STRICT_OVERFLOW_ALL);
12297 return constant_boolean_node (0, type);
12302 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
12303 This transformation affects the cases which are handled in later
12304 optimizations involving comparisons with non-negative constants. */
12305 if (TREE_CODE (arg1) == INTEGER_CST
12306 && TREE_CODE (arg0) != INTEGER_CST
12307 && tree_int_cst_sgn (arg1) > 0)
12309 if (code == GE_EXPR)
12311 arg1 = const_binop (MINUS_EXPR, arg1,
12312 build_int_cst (TREE_TYPE (arg1), 1), 0);
12313 return fold_build2 (GT_EXPR, type, arg0,
12314 fold_convert (TREE_TYPE (arg0), arg1));
12316 if (code == LT_EXPR)
12318 arg1 = const_binop (MINUS_EXPR, arg1,
12319 build_int_cst (TREE_TYPE (arg1), 1), 0);
12320 return fold_build2 (LE_EXPR, type, arg0,
12321 fold_convert (TREE_TYPE (arg0), arg1));
12325 /* Comparisons with the highest or lowest possible integer of
12326 the specified precision will have known values. */
12328 tree arg1_type = TREE_TYPE (arg1);
12329 unsigned int width = TYPE_PRECISION (arg1_type);
12331 if (TREE_CODE (arg1) == INTEGER_CST
12332 && !TREE_OVERFLOW (arg1)
12333 && width <= 2 * HOST_BITS_PER_WIDE_INT
12334 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
12336 HOST_WIDE_INT signed_max_hi;
12337 unsigned HOST_WIDE_INT signed_max_lo;
12338 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
12340 if (width <= HOST_BITS_PER_WIDE_INT)
12342 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12347 if (TYPE_UNSIGNED (arg1_type))
12349 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12355 max_lo = signed_max_lo;
12356 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12362 width -= HOST_BITS_PER_WIDE_INT;
12363 signed_max_lo = -1;
12364 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12369 if (TYPE_UNSIGNED (arg1_type))
12371 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12376 max_hi = signed_max_hi;
12377 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12381 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
12382 && TREE_INT_CST_LOW (arg1) == max_lo)
12386 return omit_one_operand (type, integer_zero_node, arg0);
12389 return fold_build2 (EQ_EXPR, type, op0, op1);
12392 return omit_one_operand (type, integer_one_node, arg0);
12395 return fold_build2 (NE_EXPR, type, op0, op1);
12397 /* The GE_EXPR and LT_EXPR cases above are not normally
12398 reached because of previous transformations. */
12403 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12405 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
12409 arg1 = const_binop (PLUS_EXPR, arg1,
12410 build_int_cst (TREE_TYPE (arg1), 1), 0);
12411 return fold_build2 (EQ_EXPR, type,
12412 fold_convert (TREE_TYPE (arg1), arg0),
12415 arg1 = const_binop (PLUS_EXPR, arg1,
12416 build_int_cst (TREE_TYPE (arg1), 1), 0);
12417 return fold_build2 (NE_EXPR, type,
12418 fold_convert (TREE_TYPE (arg1), arg0),
12423 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12425 && TREE_INT_CST_LOW (arg1) == min_lo)
12429 return omit_one_operand (type, integer_zero_node, arg0);
12432 return fold_build2 (EQ_EXPR, type, op0, op1);
12435 return omit_one_operand (type, integer_one_node, arg0);
12438 return fold_build2 (NE_EXPR, type, op0, op1);
12443 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12445 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
12449 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12450 return fold_build2 (NE_EXPR, type,
12451 fold_convert (TREE_TYPE (arg1), arg0),
12454 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12455 return fold_build2 (EQ_EXPR, type,
12456 fold_convert (TREE_TYPE (arg1), arg0),
12462 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
12463 && TREE_INT_CST_LOW (arg1) == signed_max_lo
12464 && TYPE_UNSIGNED (arg1_type)
12465 /* We will flip the signedness of the comparison operator
12466 associated with the mode of arg1, so the sign bit is
12467 specified by this mode. Check that arg1 is the signed
12468 max associated with this sign bit. */
12469 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
12470 /* signed_type does not work on pointer types. */
12471 && INTEGRAL_TYPE_P (arg1_type))
12473 /* The following case also applies to X < signed_max+1
12474 and X >= signed_max+1 because previous transformations. */
12475 if (code == LE_EXPR || code == GT_EXPR)
12478 st = signed_type_for (TREE_TYPE (arg1));
12479 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
12480 type, fold_convert (st, arg0),
12481 build_int_cst (st, 0));
12487 /* If we are comparing an ABS_EXPR with a constant, we can
12488 convert all the cases into explicit comparisons, but they may
12489 well not be faster than doing the ABS and one comparison.
12490 But ABS (X) <= C is a range comparison, which becomes a subtraction
12491 and a comparison, and is probably faster. */
12492 if (code == LE_EXPR
12493 && TREE_CODE (arg1) == INTEGER_CST
12494 && TREE_CODE (arg0) == ABS_EXPR
12495 && ! TREE_SIDE_EFFECTS (arg0)
12496 && (0 != (tem = negate_expr (arg1)))
12497 && TREE_CODE (tem) == INTEGER_CST
12498 && !TREE_OVERFLOW (tem))
12499 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12500 build2 (GE_EXPR, type,
12501 TREE_OPERAND (arg0, 0), tem),
12502 build2 (LE_EXPR, type,
12503 TREE_OPERAND (arg0, 0), arg1));
12505 /* Convert ABS_EXPR<x> >= 0 to true. */
12506 strict_overflow_p = false;
12507 if (code == GE_EXPR
12508 && (integer_zerop (arg1)
12509 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
12510 && real_zerop (arg1)))
12511 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12513 if (strict_overflow_p)
12514 fold_overflow_warning (("assuming signed overflow does not occur "
12515 "when simplifying comparison of "
12516 "absolute value and zero"),
12517 WARN_STRICT_OVERFLOW_CONDITIONAL);
12518 return omit_one_operand (type, integer_one_node, arg0);
12521 /* Convert ABS_EXPR<x> < 0 to false. */
12522 strict_overflow_p = false;
12523 if (code == LT_EXPR
12524 && (integer_zerop (arg1) || real_zerop (arg1))
12525 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12527 if (strict_overflow_p)
12528 fold_overflow_warning (("assuming signed overflow does not occur "
12529 "when simplifying comparison of "
12530 "absolute value and zero"),
12531 WARN_STRICT_OVERFLOW_CONDITIONAL);
12532 return omit_one_operand (type, integer_zero_node, arg0);
12535 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
12536 and similarly for >= into !=. */
12537 if ((code == LT_EXPR || code == GE_EXPR)
12538 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12539 && TREE_CODE (arg1) == LSHIFT_EXPR
12540 && integer_onep (TREE_OPERAND (arg1, 0)))
12541 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12542 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12543 TREE_OPERAND (arg1, 1)),
12544 build_int_cst (TREE_TYPE (arg0), 0));
12546 if ((code == LT_EXPR || code == GE_EXPR)
12547 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12548 && (TREE_CODE (arg1) == NOP_EXPR
12549 || TREE_CODE (arg1) == CONVERT_EXPR)
12550 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
12551 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
12553 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12554 fold_convert (TREE_TYPE (arg0),
12555 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12556 TREE_OPERAND (TREE_OPERAND (arg1, 0),
12558 build_int_cst (TREE_TYPE (arg0), 0));
12562 case UNORDERED_EXPR:
12570 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
12572 t1 = fold_relational_const (code, type, arg0, arg1);
12573 if (t1 != NULL_TREE)
12577 /* If the first operand is NaN, the result is constant. */
12578 if (TREE_CODE (arg0) == REAL_CST
12579 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
12580 && (code != LTGT_EXPR || ! flag_trapping_math))
12582 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12583 ? integer_zero_node
12584 : integer_one_node;
12585 return omit_one_operand (type, t1, arg1);
12588 /* If the second operand is NaN, the result is constant. */
12589 if (TREE_CODE (arg1) == REAL_CST
12590 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
12591 && (code != LTGT_EXPR || ! flag_trapping_math))
12593 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12594 ? integer_zero_node
12595 : integer_one_node;
12596 return omit_one_operand (type, t1, arg0);
12599 /* Simplify unordered comparison of something with itself. */
12600 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
12601 && operand_equal_p (arg0, arg1, 0))
12602 return constant_boolean_node (1, type);
12604 if (code == LTGT_EXPR
12605 && !flag_trapping_math
12606 && operand_equal_p (arg0, arg1, 0))
12607 return constant_boolean_node (0, type);
12609 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12611 tree targ0 = strip_float_extensions (arg0);
12612 tree targ1 = strip_float_extensions (arg1);
12613 tree newtype = TREE_TYPE (targ0);
12615 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
12616 newtype = TREE_TYPE (targ1);
12618 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
12619 return fold_build2 (code, type, fold_convert (newtype, targ0),
12620 fold_convert (newtype, targ1));
12625 case COMPOUND_EXPR:
12626 /* When pedantic, a compound expression can be neither an lvalue
12627 nor an integer constant expression. */
12628 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
12630 /* Don't let (0, 0) be null pointer constant. */
12631 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
12632 : fold_convert (type, arg1);
12633 return pedantic_non_lvalue (tem);
12636 if ((TREE_CODE (arg0) == REAL_CST
12637 && TREE_CODE (arg1) == REAL_CST)
12638 || (TREE_CODE (arg0) == INTEGER_CST
12639 && TREE_CODE (arg1) == INTEGER_CST))
12640 return build_complex (type, arg0, arg1);
12644 /* An ASSERT_EXPR should never be passed to fold_binary. */
12645 gcc_unreachable ();
12649 } /* switch (code) */
12652 /* Callback for walk_tree, looking for LABEL_EXPR.
12653 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
12654 Do not check the sub-tree of GOTO_EXPR. */
12657 contains_label_1 (tree *tp,
12658 int *walk_subtrees,
12659 void *data ATTRIBUTE_UNUSED)
12661 switch (TREE_CODE (*tp))
12666 *walk_subtrees = 0;
12673 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
12674 accessible from outside the sub-tree. Returns NULL_TREE if no
12675 addressable label is found. */
12678 contains_label_p (tree st)
12680 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
12683 /* Fold a ternary expression of code CODE and type TYPE with operands
12684 OP0, OP1, and OP2. Return the folded expression if folding is
12685 successful. Otherwise, return NULL_TREE. */
12688 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
12691 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
12692 enum tree_code_class kind = TREE_CODE_CLASS (code);
12694 gcc_assert (IS_EXPR_CODE_CLASS (kind)
12695 && TREE_CODE_LENGTH (code) == 3);
12697 /* Strip any conversions that don't change the mode. This is safe
12698 for every expression, except for a comparison expression because
12699 its signedness is derived from its operands. So, in the latter
12700 case, only strip conversions that don't change the signedness.
12702 Note that this is done as an internal manipulation within the
12703 constant folder, in order to find the simplest representation of
12704 the arguments so that their form can be studied. In any cases,
12705 the appropriate type conversions should be put back in the tree
12706 that will get out of the constant folder. */
12721 case COMPONENT_REF:
12722 if (TREE_CODE (arg0) == CONSTRUCTOR
12723 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
12725 unsigned HOST_WIDE_INT idx;
12727 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
12734 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
12735 so all simple results must be passed through pedantic_non_lvalue. */
12736 if (TREE_CODE (arg0) == INTEGER_CST)
12738 tree unused_op = integer_zerop (arg0) ? op1 : op2;
12739 tem = integer_zerop (arg0) ? op2 : op1;
12740 /* Only optimize constant conditions when the selected branch
12741 has the same type as the COND_EXPR. This avoids optimizing
12742 away "c ? x : throw", where the throw has a void type.
12743 Avoid throwing away that operand which contains label. */
12744 if ((!TREE_SIDE_EFFECTS (unused_op)
12745 || !contains_label_p (unused_op))
12746 && (! VOID_TYPE_P (TREE_TYPE (tem))
12747 || VOID_TYPE_P (type)))
12748 return pedantic_non_lvalue (tem);
12751 if (operand_equal_p (arg1, op2, 0))
12752 return pedantic_omit_one_operand (type, arg1, arg0);
12754 /* If we have A op B ? A : C, we may be able to convert this to a
12755 simpler expression, depending on the operation and the values
12756 of B and C. Signed zeros prevent all of these transformations,
12757 for reasons given above each one.
12759 Also try swapping the arguments and inverting the conditional. */
12760 if (COMPARISON_CLASS_P (arg0)
12761 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12762 arg1, TREE_OPERAND (arg0, 1))
12763 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
12765 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
12770 if (COMPARISON_CLASS_P (arg0)
12771 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12773 TREE_OPERAND (arg0, 1))
12774 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
12776 tem = fold_truth_not_expr (arg0);
12777 if (tem && COMPARISON_CLASS_P (tem))
12779 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
12785 /* If the second operand is simpler than the third, swap them
12786 since that produces better jump optimization results. */
12787 if (truth_value_p (TREE_CODE (arg0))
12788 && tree_swap_operands_p (op1, op2, false))
12790 /* See if this can be inverted. If it can't, possibly because
12791 it was a floating-point inequality comparison, don't do
12793 tem = fold_truth_not_expr (arg0);
12795 return fold_build3 (code, type, tem, op2, op1);
12798 /* Convert A ? 1 : 0 to simply A. */
12799 if (integer_onep (op1)
12800 && integer_zerop (op2)
12801 /* If we try to convert OP0 to our type, the
12802 call to fold will try to move the conversion inside
12803 a COND, which will recurse. In that case, the COND_EXPR
12804 is probably the best choice, so leave it alone. */
12805 && type == TREE_TYPE (arg0))
12806 return pedantic_non_lvalue (arg0);
12808 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
12809 over COND_EXPR in cases such as floating point comparisons. */
12810 if (integer_zerop (op1)
12811 && integer_onep (op2)
12812 && truth_value_p (TREE_CODE (arg0)))
12813 return pedantic_non_lvalue (fold_convert (type,
12814 invert_truthvalue (arg0)));
12816 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
12817 if (TREE_CODE (arg0) == LT_EXPR
12818 && integer_zerop (TREE_OPERAND (arg0, 1))
12819 && integer_zerop (op2)
12820 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
12822 /* sign_bit_p only checks ARG1 bits within A's precision.
12823 If <sign bit of A> has wider type than A, bits outside
12824 of A's precision in <sign bit of A> need to be checked.
12825 If they are all 0, this optimization needs to be done
12826 in unsigned A's type, if they are all 1 in signed A's type,
12827 otherwise this can't be done. */
12828 if (TYPE_PRECISION (TREE_TYPE (tem))
12829 < TYPE_PRECISION (TREE_TYPE (arg1))
12830 && TYPE_PRECISION (TREE_TYPE (tem))
12831 < TYPE_PRECISION (type))
12833 unsigned HOST_WIDE_INT mask_lo;
12834 HOST_WIDE_INT mask_hi;
12835 int inner_width, outer_width;
12838 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
12839 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
12840 if (outer_width > TYPE_PRECISION (type))
12841 outer_width = TYPE_PRECISION (type);
12843 if (outer_width > HOST_BITS_PER_WIDE_INT)
12845 mask_hi = ((unsigned HOST_WIDE_INT) -1
12846 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
12852 mask_lo = ((unsigned HOST_WIDE_INT) -1
12853 >> (HOST_BITS_PER_WIDE_INT - outer_width));
12855 if (inner_width > HOST_BITS_PER_WIDE_INT)
12857 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
12858 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12862 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
12863 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12865 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
12866 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
12868 tem_type = signed_type_for (TREE_TYPE (tem));
12869 tem = fold_convert (tem_type, tem);
12871 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
12872 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
12874 tem_type = unsigned_type_for (TREE_TYPE (tem));
12875 tem = fold_convert (tem_type, tem);
12882 return fold_convert (type,
12883 fold_build2 (BIT_AND_EXPR,
12884 TREE_TYPE (tem), tem,
12885 fold_convert (TREE_TYPE (tem),
12889 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
12890 already handled above. */
12891 if (TREE_CODE (arg0) == BIT_AND_EXPR
12892 && integer_onep (TREE_OPERAND (arg0, 1))
12893 && integer_zerop (op2)
12894 && integer_pow2p (arg1))
12896 tree tem = TREE_OPERAND (arg0, 0);
12898 if (TREE_CODE (tem) == RSHIFT_EXPR
12899 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
12900 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
12901 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
12902 return fold_build2 (BIT_AND_EXPR, type,
12903 TREE_OPERAND (tem, 0), arg1);
12906 /* A & N ? N : 0 is simply A & N if N is a power of two. This
12907 is probably obsolete because the first operand should be a
12908 truth value (that's why we have the two cases above), but let's
12909 leave it in until we can confirm this for all front-ends. */
12910 if (integer_zerop (op2)
12911 && TREE_CODE (arg0) == NE_EXPR
12912 && integer_zerop (TREE_OPERAND (arg0, 1))
12913 && integer_pow2p (arg1)
12914 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12915 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12916 arg1, OEP_ONLY_CONST))
12917 return pedantic_non_lvalue (fold_convert (type,
12918 TREE_OPERAND (arg0, 0)));
12920 /* Convert A ? B : 0 into A && B if A and B are truth values. */
12921 if (integer_zerop (op2)
12922 && truth_value_p (TREE_CODE (arg0))
12923 && truth_value_p (TREE_CODE (arg1)))
12924 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12925 fold_convert (type, arg0),
12928 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
12929 if (integer_onep (op2)
12930 && truth_value_p (TREE_CODE (arg0))
12931 && truth_value_p (TREE_CODE (arg1)))
12933 /* Only perform transformation if ARG0 is easily inverted. */
12934 tem = fold_truth_not_expr (arg0);
12936 return fold_build2 (TRUTH_ORIF_EXPR, type,
12937 fold_convert (type, tem),
12941 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
12942 if (integer_zerop (arg1)
12943 && truth_value_p (TREE_CODE (arg0))
12944 && truth_value_p (TREE_CODE (op2)))
12946 /* Only perform transformation if ARG0 is easily inverted. */
12947 tem = fold_truth_not_expr (arg0);
12949 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12950 fold_convert (type, tem),
12954 /* Convert A ? 1 : B into A || B if A and B are truth values. */
12955 if (integer_onep (arg1)
12956 && truth_value_p (TREE_CODE (arg0))
12957 && truth_value_p (TREE_CODE (op2)))
12958 return fold_build2 (TRUTH_ORIF_EXPR, type,
12959 fold_convert (type, arg0),
12965 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
12966 of fold_ternary on them. */
12967 gcc_unreachable ();
12969 case BIT_FIELD_REF:
12970 if ((TREE_CODE (arg0) == VECTOR_CST
12971 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
12972 && type == TREE_TYPE (TREE_TYPE (arg0)))
12974 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
12975 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
12978 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
12979 && (idx % width) == 0
12980 && (idx = idx / width)
12981 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
12983 tree elements = NULL_TREE;
12985 if (TREE_CODE (arg0) == VECTOR_CST)
12986 elements = TREE_VECTOR_CST_ELTS (arg0);
12989 unsigned HOST_WIDE_INT idx;
12992 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
12993 elements = tree_cons (NULL_TREE, value, elements);
12995 while (idx-- > 0 && elements)
12996 elements = TREE_CHAIN (elements);
12998 return TREE_VALUE (elements);
13000 return fold_convert (type, integer_zero_node);
13007 } /* switch (code) */
13010 /* Perform constant folding and related simplification of EXPR.
13011 The related simplifications include x*1 => x, x*0 => 0, etc.,
13012 and application of the associative law.
13013 NOP_EXPR conversions may be removed freely (as long as we
13014 are careful not to change the type of the overall expression).
13015 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13016 but we can constant-fold them if they have constant operands. */
13018 #ifdef ENABLE_FOLD_CHECKING
13019 # define fold(x) fold_1 (x)
13020 static tree fold_1 (tree);
13026 const tree t = expr;
13027 enum tree_code code = TREE_CODE (t);
13028 enum tree_code_class kind = TREE_CODE_CLASS (code);
13031 /* Return right away if a constant. */
13032 if (kind == tcc_constant)
13035 /* CALL_EXPR-like objects with variable numbers of operands are
13036 treated specially. */
13037 if (kind == tcc_vl_exp)
13039 if (code == CALL_EXPR)
13041 tem = fold_call_expr (expr, false);
13042 return tem ? tem : expr;
13047 if (IS_EXPR_CODE_CLASS (kind)
13048 || IS_GIMPLE_STMT_CODE_CLASS (kind))
13050 tree type = TREE_TYPE (t);
13051 tree op0, op1, op2;
13053 switch (TREE_CODE_LENGTH (code))
13056 op0 = TREE_OPERAND (t, 0);
13057 tem = fold_unary (code, type, op0);
13058 return tem ? tem : expr;
13060 op0 = TREE_OPERAND (t, 0);
13061 op1 = TREE_OPERAND (t, 1);
13062 tem = fold_binary (code, type, op0, op1);
13063 return tem ? tem : expr;
13065 op0 = TREE_OPERAND (t, 0);
13066 op1 = TREE_OPERAND (t, 1);
13067 op2 = TREE_OPERAND (t, 2);
13068 tem = fold_ternary (code, type, op0, op1, op2);
13069 return tem ? tem : expr;
13078 return fold (DECL_INITIAL (t));
13082 } /* switch (code) */
13085 #ifdef ENABLE_FOLD_CHECKING
13088 static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
13089 static void fold_check_failed (const_tree, const_tree);
13090 void print_fold_checksum (const_tree);
13092 /* When --enable-checking=fold, compute a digest of expr before
13093 and after actual fold call to see if fold did not accidentally
13094 change original expr. */
13100 struct md5_ctx ctx;
13101 unsigned char checksum_before[16], checksum_after[16];
13104 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13105 md5_init_ctx (&ctx);
13106 fold_checksum_tree (expr, &ctx, ht);
13107 md5_finish_ctx (&ctx, checksum_before);
13110 ret = fold_1 (expr);
13112 md5_init_ctx (&ctx);
13113 fold_checksum_tree (expr, &ctx, ht);
13114 md5_finish_ctx (&ctx, checksum_after);
13117 if (memcmp (checksum_before, checksum_after, 16))
13118 fold_check_failed (expr, ret);
13124 print_fold_checksum (const_tree expr)
13126 struct md5_ctx ctx;
13127 unsigned char checksum[16], cnt;
13130 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13131 md5_init_ctx (&ctx);
13132 fold_checksum_tree (expr, &ctx, ht);
13133 md5_finish_ctx (&ctx, checksum);
13135 for (cnt = 0; cnt < 16; ++cnt)
13136 fprintf (stderr, "%02x", checksum[cnt]);
13137 putc ('\n', stderr);
13141 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
13143 internal_error ("fold check: original tree changed by fold");
13147 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
13150 enum tree_code code;
13151 struct tree_function_decl buf;
13156 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
13157 <= sizeof (struct tree_function_decl))
13158 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
13161 slot = (const void **) htab_find_slot (ht, expr, INSERT);
13165 code = TREE_CODE (expr);
13166 if (TREE_CODE_CLASS (code) == tcc_declaration
13167 && DECL_ASSEMBLER_NAME_SET_P (expr))
13169 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13170 memcpy ((char *) &buf, expr, tree_size (expr));
13171 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
13172 expr = (tree) &buf;
13174 else if (TREE_CODE_CLASS (code) == tcc_type
13175 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
13176 || TYPE_CACHED_VALUES_P (expr)
13177 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
13179 /* Allow these fields to be modified. */
13181 memcpy ((char *) &buf, expr, tree_size (expr));
13182 expr = tmp = (tree) &buf;
13183 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
13184 TYPE_POINTER_TO (tmp) = NULL;
13185 TYPE_REFERENCE_TO (tmp) = NULL;
13186 if (TYPE_CACHED_VALUES_P (tmp))
13188 TYPE_CACHED_VALUES_P (tmp) = 0;
13189 TYPE_CACHED_VALUES (tmp) = NULL;
13192 md5_process_bytes (expr, tree_size (expr), ctx);
13193 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
13194 if (TREE_CODE_CLASS (code) != tcc_type
13195 && TREE_CODE_CLASS (code) != tcc_declaration
13196 && code != TREE_LIST
13197 && code != SSA_NAME)
13198 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
13199 switch (TREE_CODE_CLASS (code))
13205 md5_process_bytes (TREE_STRING_POINTER (expr),
13206 TREE_STRING_LENGTH (expr), ctx);
13209 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
13210 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
13213 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
13219 case tcc_exceptional:
13223 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
13224 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
13225 expr = TREE_CHAIN (expr);
13226 goto recursive_label;
13229 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
13230 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
13236 case tcc_expression:
13237 case tcc_reference:
13238 case tcc_comparison:
13241 case tcc_statement:
13243 len = TREE_OPERAND_LENGTH (expr);
13244 for (i = 0; i < len; ++i)
13245 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
13247 case tcc_declaration:
13248 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
13249 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
13250 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
13252 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
13253 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
13254 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
13255 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
13256 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
13258 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
13259 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
13261 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
13263 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
13264 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
13265 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
13269 if (TREE_CODE (expr) == ENUMERAL_TYPE)
13270 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
13271 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
13272 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
13273 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
13274 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
13275 if (INTEGRAL_TYPE_P (expr)
13276 || SCALAR_FLOAT_TYPE_P (expr))
13278 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
13279 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
13281 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
13282 if (TREE_CODE (expr) == RECORD_TYPE
13283 || TREE_CODE (expr) == UNION_TYPE
13284 || TREE_CODE (expr) == QUAL_UNION_TYPE)
13285 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
13286 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
13293 /* Helper function for outputting the checksum of a tree T. When
13294 debugging with gdb, you can "define mynext" to be "next" followed
13295 by "call debug_fold_checksum (op0)", then just trace down till the
13299 debug_fold_checksum (const_tree t)
13302 unsigned char checksum[16];
13303 struct md5_ctx ctx;
13304 htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13306 md5_init_ctx (&ctx);
13307 fold_checksum_tree (t, &ctx, ht);
13308 md5_finish_ctx (&ctx, checksum);
13311 for (i = 0; i < 16; i++)
13312 fprintf (stderr, "%d ", checksum[i]);
13314 fprintf (stderr, "\n");
13319 /* Fold a unary tree expression with code CODE of type TYPE with an
13320 operand OP0. Return a folded expression if successful. Otherwise,
13321 return a tree expression with code CODE of type TYPE with an
13325 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
13328 #ifdef ENABLE_FOLD_CHECKING
13329 unsigned char checksum_before[16], checksum_after[16];
13330 struct md5_ctx ctx;
13333 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13334 md5_init_ctx (&ctx);
13335 fold_checksum_tree (op0, &ctx, ht);
13336 md5_finish_ctx (&ctx, checksum_before);
13340 tem = fold_unary (code, type, op0);
13342 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
13344 #ifdef ENABLE_FOLD_CHECKING
13345 md5_init_ctx (&ctx);
13346 fold_checksum_tree (op0, &ctx, ht);
13347 md5_finish_ctx (&ctx, checksum_after);
13350 if (memcmp (checksum_before, checksum_after, 16))
13351 fold_check_failed (op0, tem);
13356 /* Fold a binary tree expression with code CODE of type TYPE with
13357 operands OP0 and OP1. Return a folded expression if successful.
13358 Otherwise, return a tree expression with code CODE of type TYPE
13359 with operands OP0 and OP1. */
13362 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
13366 #ifdef ENABLE_FOLD_CHECKING
13367 unsigned char checksum_before_op0[16],
13368 checksum_before_op1[16],
13369 checksum_after_op0[16],
13370 checksum_after_op1[16];
13371 struct md5_ctx ctx;
13374 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13375 md5_init_ctx (&ctx);
13376 fold_checksum_tree (op0, &ctx, ht);
13377 md5_finish_ctx (&ctx, checksum_before_op0);
13380 md5_init_ctx (&ctx);
13381 fold_checksum_tree (op1, &ctx, ht);
13382 md5_finish_ctx (&ctx, checksum_before_op1);
13386 tem = fold_binary (code, type, op0, op1);
13388 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
13390 #ifdef ENABLE_FOLD_CHECKING
13391 md5_init_ctx (&ctx);
13392 fold_checksum_tree (op0, &ctx, ht);
13393 md5_finish_ctx (&ctx, checksum_after_op0);
13396 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13397 fold_check_failed (op0, tem);
13399 md5_init_ctx (&ctx);
13400 fold_checksum_tree (op1, &ctx, ht);
13401 md5_finish_ctx (&ctx, checksum_after_op1);
13404 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13405 fold_check_failed (op1, tem);
13410 /* Fold a ternary tree expression with code CODE of type TYPE with
13411 operands OP0, OP1, and OP2. Return a folded expression if
13412 successful. Otherwise, return a tree expression with code CODE of
13413 type TYPE with operands OP0, OP1, and OP2. */
13416 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
13420 #ifdef ENABLE_FOLD_CHECKING
13421 unsigned char checksum_before_op0[16],
13422 checksum_before_op1[16],
13423 checksum_before_op2[16],
13424 checksum_after_op0[16],
13425 checksum_after_op1[16],
13426 checksum_after_op2[16];
13427 struct md5_ctx ctx;
13430 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13431 md5_init_ctx (&ctx);
13432 fold_checksum_tree (op0, &ctx, ht);
13433 md5_finish_ctx (&ctx, checksum_before_op0);
13436 md5_init_ctx (&ctx);
13437 fold_checksum_tree (op1, &ctx, ht);
13438 md5_finish_ctx (&ctx, checksum_before_op1);
13441 md5_init_ctx (&ctx);
13442 fold_checksum_tree (op2, &ctx, ht);
13443 md5_finish_ctx (&ctx, checksum_before_op2);
13447 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
13448 tem = fold_ternary (code, type, op0, op1, op2);
13450 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
13452 #ifdef ENABLE_FOLD_CHECKING
13453 md5_init_ctx (&ctx);
13454 fold_checksum_tree (op0, &ctx, ht);
13455 md5_finish_ctx (&ctx, checksum_after_op0);
13458 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13459 fold_check_failed (op0, tem);
13461 md5_init_ctx (&ctx);
13462 fold_checksum_tree (op1, &ctx, ht);
13463 md5_finish_ctx (&ctx, checksum_after_op1);
13466 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13467 fold_check_failed (op1, tem);
13469 md5_init_ctx (&ctx);
13470 fold_checksum_tree (op2, &ctx, ht);
13471 md5_finish_ctx (&ctx, checksum_after_op2);
13474 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
13475 fold_check_failed (op2, tem);
13480 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
13481 arguments in ARGARRAY, and a null static chain.
13482 Return a folded expression if successful. Otherwise, return a CALL_EXPR
13483 of type TYPE from the given operands as constructed by build_call_array. */
13486 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
13489 #ifdef ENABLE_FOLD_CHECKING
13490 unsigned char checksum_before_fn[16],
13491 checksum_before_arglist[16],
13492 checksum_after_fn[16],
13493 checksum_after_arglist[16];
13494 struct md5_ctx ctx;
13498 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13499 md5_init_ctx (&ctx);
13500 fold_checksum_tree (fn, &ctx, ht);
13501 md5_finish_ctx (&ctx, checksum_before_fn);
13504 md5_init_ctx (&ctx);
13505 for (i = 0; i < nargs; i++)
13506 fold_checksum_tree (argarray[i], &ctx, ht);
13507 md5_finish_ctx (&ctx, checksum_before_arglist);
13511 tem = fold_builtin_call_array (type, fn, nargs, argarray);
13513 #ifdef ENABLE_FOLD_CHECKING
13514 md5_init_ctx (&ctx);
13515 fold_checksum_tree (fn, &ctx, ht);
13516 md5_finish_ctx (&ctx, checksum_after_fn);
13519 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
13520 fold_check_failed (fn, tem);
13522 md5_init_ctx (&ctx);
13523 for (i = 0; i < nargs; i++)
13524 fold_checksum_tree (argarray[i], &ctx, ht);
13525 md5_finish_ctx (&ctx, checksum_after_arglist);
13528 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
13529 fold_check_failed (NULL_TREE, tem);
13534 /* Perform constant folding and related simplification of initializer
13535 expression EXPR. These behave identically to "fold_buildN" but ignore
13536 potential run-time traps and exceptions that fold must preserve. */
13538 #define START_FOLD_INIT \
13539 int saved_signaling_nans = flag_signaling_nans;\
13540 int saved_trapping_math = flag_trapping_math;\
13541 int saved_rounding_math = flag_rounding_math;\
13542 int saved_trapv = flag_trapv;\
13543 int saved_folding_initializer = folding_initializer;\
13544 flag_signaling_nans = 0;\
13545 flag_trapping_math = 0;\
13546 flag_rounding_math = 0;\
13548 folding_initializer = 1;
13550 #define END_FOLD_INIT \
13551 flag_signaling_nans = saved_signaling_nans;\
13552 flag_trapping_math = saved_trapping_math;\
13553 flag_rounding_math = saved_rounding_math;\
13554 flag_trapv = saved_trapv;\
13555 folding_initializer = saved_folding_initializer;
13558 fold_build1_initializer (enum tree_code code, tree type, tree op)
13563 result = fold_build1 (code, type, op);
13570 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
13575 result = fold_build2 (code, type, op0, op1);
13582 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
13588 result = fold_build3 (code, type, op0, op1, op2);
13595 fold_build_call_array_initializer (tree type, tree fn,
13596 int nargs, tree *argarray)
13601 result = fold_build_call_array (type, fn, nargs, argarray);
13607 #undef START_FOLD_INIT
13608 #undef END_FOLD_INIT
13610 /* Determine if first argument is a multiple of second argument. Return 0 if
13611 it is not, or we cannot easily determined it to be.
13613 An example of the sort of thing we care about (at this point; this routine
13614 could surely be made more general, and expanded to do what the *_DIV_EXPR's
13615 fold cases do now) is discovering that
13617 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13623 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
13625 This code also handles discovering that
13627 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13629 is a multiple of 8 so we don't have to worry about dealing with a
13630 possible remainder.
13632 Note that we *look* inside a SAVE_EXPR only to determine how it was
13633 calculated; it is not safe for fold to do much of anything else with the
13634 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
13635 at run time. For example, the latter example above *cannot* be implemented
13636 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
13637 evaluation time of the original SAVE_EXPR is not necessarily the same at
13638 the time the new expression is evaluated. The only optimization of this
13639 sort that would be valid is changing
13641 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
13645 SAVE_EXPR (I) * SAVE_EXPR (J)
13647 (where the same SAVE_EXPR (J) is used in the original and the
13648 transformed version). */
13651 multiple_of_p (tree type, const_tree top, const_tree bottom)
13653 if (operand_equal_p (top, bottom, 0))
13656 if (TREE_CODE (type) != INTEGER_TYPE)
13659 switch (TREE_CODE (top))
13662 /* Bitwise and provides a power of two multiple. If the mask is
13663 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
13664 if (!integer_pow2p (bottom))
13669 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13670 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13674 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13675 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13678 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
13682 op1 = TREE_OPERAND (top, 1);
13683 /* const_binop may not detect overflow correctly,
13684 so check for it explicitly here. */
13685 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
13686 > TREE_INT_CST_LOW (op1)
13687 && TREE_INT_CST_HIGH (op1) == 0
13688 && 0 != (t1 = fold_convert (type,
13689 const_binop (LSHIFT_EXPR,
13692 && !TREE_OVERFLOW (t1))
13693 return multiple_of_p (type, t1, bottom);
13698 /* Can't handle conversions from non-integral or wider integral type. */
13699 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
13700 || (TYPE_PRECISION (type)
13701 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
13704 /* .. fall through ... */
13707 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
13710 if (TREE_CODE (bottom) != INTEGER_CST
13711 || integer_zerop (bottom)
13712 || (TYPE_UNSIGNED (type)
13713 && (tree_int_cst_sgn (top) < 0
13714 || tree_int_cst_sgn (bottom) < 0)))
13716 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
13724 /* Return true if CODE or TYPE is known to be non-negative. */
13727 tree_simple_nonnegative_warnv_p (enum tree_code code, tree type)
13729 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
13730 && truth_value_p (code))
13731 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
13732 have a signed:1 type (where the value is -1 and 0). */
13737 /* Return true if (CODE OP0) is known to be non-negative. If the return
13738 value is based on the assumption that signed overflow is undefined,
13739 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13740 *STRICT_OVERFLOW_P. */
13743 tree_unary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
13744 bool *strict_overflow_p)
13746 if (TYPE_UNSIGNED (type))
13752 /* We can't return 1 if flag_wrapv is set because
13753 ABS_EXPR<INT_MIN> = INT_MIN. */
13754 if (!INTEGRAL_TYPE_P (type))
13756 if (TYPE_OVERFLOW_UNDEFINED (type))
13758 *strict_overflow_p = true;
13763 case NON_LVALUE_EXPR:
13765 case FIX_TRUNC_EXPR:
13766 return tree_expr_nonnegative_warnv_p (op0,
13767 strict_overflow_p);
13771 tree inner_type = TREE_TYPE (op0);
13772 tree outer_type = type;
13774 if (TREE_CODE (outer_type) == REAL_TYPE)
13776 if (TREE_CODE (inner_type) == REAL_TYPE)
13777 return tree_expr_nonnegative_warnv_p (op0,
13778 strict_overflow_p);
13779 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13781 if (TYPE_UNSIGNED (inner_type))
13783 return tree_expr_nonnegative_warnv_p (op0,
13784 strict_overflow_p);
13787 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
13789 if (TREE_CODE (inner_type) == REAL_TYPE)
13790 return tree_expr_nonnegative_warnv_p (op0,
13791 strict_overflow_p);
13792 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13793 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
13794 && TYPE_UNSIGNED (inner_type);
13800 return tree_simple_nonnegative_warnv_p (code, type);
13803 /* We don't know sign of `t', so be conservative and return false. */
13807 /* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
13808 value is based on the assumption that signed overflow is undefined,
13809 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13810 *STRICT_OVERFLOW_P. */
13813 tree_binary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
13814 tree op1, bool *strict_overflow_p)
13816 if (TYPE_UNSIGNED (type))
13821 case POINTER_PLUS_EXPR:
13823 if (FLOAT_TYPE_P (type))
13824 return (tree_expr_nonnegative_warnv_p (op0,
13826 && tree_expr_nonnegative_warnv_p (op1,
13827 strict_overflow_p));
13829 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
13830 both unsigned and at least 2 bits shorter than the result. */
13831 if (TREE_CODE (type) == INTEGER_TYPE
13832 && TREE_CODE (op0) == NOP_EXPR
13833 && TREE_CODE (op1) == NOP_EXPR)
13835 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
13836 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
13837 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13838 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13840 unsigned int prec = MAX (TYPE_PRECISION (inner1),
13841 TYPE_PRECISION (inner2)) + 1;
13842 return prec < TYPE_PRECISION (type);
13848 if (FLOAT_TYPE_P (type))
13850 /* x * x for floating point x is always non-negative. */
13851 if (operand_equal_p (op0, op1, 0))
13853 return (tree_expr_nonnegative_warnv_p (op0,
13855 && tree_expr_nonnegative_warnv_p (op1,
13856 strict_overflow_p));
13859 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
13860 both unsigned and their total bits is shorter than the result. */
13861 if (TREE_CODE (type) == INTEGER_TYPE
13862 && TREE_CODE (op0) == NOP_EXPR
13863 && TREE_CODE (op1) == NOP_EXPR)
13865 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
13866 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
13867 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13868 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13869 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
13870 < TYPE_PRECISION (type);
13876 return (tree_expr_nonnegative_warnv_p (op0,
13878 || tree_expr_nonnegative_warnv_p (op1,
13879 strict_overflow_p));
13885 case TRUNC_DIV_EXPR:
13886 case CEIL_DIV_EXPR:
13887 case FLOOR_DIV_EXPR:
13888 case ROUND_DIV_EXPR:
13889 return (tree_expr_nonnegative_warnv_p (op0,
13891 && tree_expr_nonnegative_warnv_p (op1,
13892 strict_overflow_p));
13894 case TRUNC_MOD_EXPR:
13895 case CEIL_MOD_EXPR:
13896 case FLOOR_MOD_EXPR:
13897 case ROUND_MOD_EXPR:
13898 return tree_expr_nonnegative_warnv_p (op0,
13899 strict_overflow_p);
13901 return tree_simple_nonnegative_warnv_p (code, type);
13904 /* We don't know sign of `t', so be conservative and return false. */
13908 /* Return true if T is known to be non-negative. If the return
13909 value is based on the assumption that signed overflow is undefined,
13910 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13911 *STRICT_OVERFLOW_P. */
13914 tree_single_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
13916 if (TYPE_UNSIGNED (TREE_TYPE (t)))
13919 switch (TREE_CODE (t))
13922 /* Query VRP to see if it has recorded any information about
13923 the range of this object. */
13924 return ssa_name_nonnegative_p (t);
13927 return tree_int_cst_sgn (t) >= 0;
13930 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
13933 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
13936 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
13938 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
13939 strict_overflow_p));
13941 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
13944 /* We don't know sign of `t', so be conservative and return false. */
13948 /* Return true if T is known to be non-negative. If the return
13949 value is based on the assumption that signed overflow is undefined,
13950 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13951 *STRICT_OVERFLOW_P. */
13954 tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
13956 enum tree_code code = TREE_CODE (t);
13957 if (TYPE_UNSIGNED (TREE_TYPE (t)))
13964 tree temp = TARGET_EXPR_SLOT (t);
13965 t = TARGET_EXPR_INITIAL (t);
13967 /* If the initializer is non-void, then it's a normal expression
13968 that will be assigned to the slot. */
13969 if (!VOID_TYPE_P (t))
13970 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
13972 /* Otherwise, the initializer sets the slot in some way. One common
13973 way is an assignment statement at the end of the initializer. */
13976 if (TREE_CODE (t) == BIND_EXPR)
13977 t = expr_last (BIND_EXPR_BODY (t));
13978 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
13979 || TREE_CODE (t) == TRY_CATCH_EXPR)
13980 t = expr_last (TREE_OPERAND (t, 0));
13981 else if (TREE_CODE (t) == STATEMENT_LIST)
13986 if ((TREE_CODE (t) == MODIFY_EXPR
13987 || TREE_CODE (t) == GIMPLE_MODIFY_STMT)
13988 && GENERIC_TREE_OPERAND (t, 0) == temp)
13989 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
13990 strict_overflow_p);
13997 tree fndecl = get_callee_fndecl (t);
13998 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
13999 switch (DECL_FUNCTION_CODE (fndecl))
14001 CASE_FLT_FN (BUILT_IN_ACOS):
14002 CASE_FLT_FN (BUILT_IN_ACOSH):
14003 CASE_FLT_FN (BUILT_IN_CABS):
14004 CASE_FLT_FN (BUILT_IN_COSH):
14005 CASE_FLT_FN (BUILT_IN_ERFC):
14006 CASE_FLT_FN (BUILT_IN_EXP):
14007 CASE_FLT_FN (BUILT_IN_EXP10):
14008 CASE_FLT_FN (BUILT_IN_EXP2):
14009 CASE_FLT_FN (BUILT_IN_FABS):
14010 CASE_FLT_FN (BUILT_IN_FDIM):
14011 CASE_FLT_FN (BUILT_IN_HYPOT):
14012 CASE_FLT_FN (BUILT_IN_POW10):
14013 CASE_INT_FN (BUILT_IN_FFS):
14014 CASE_INT_FN (BUILT_IN_PARITY):
14015 CASE_INT_FN (BUILT_IN_POPCOUNT):
14016 case BUILT_IN_BSWAP32:
14017 case BUILT_IN_BSWAP64:
14021 CASE_FLT_FN (BUILT_IN_SQRT):
14022 /* sqrt(-0.0) is -0.0. */
14023 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
14025 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14026 strict_overflow_p);
14028 CASE_FLT_FN (BUILT_IN_ASINH):
14029 CASE_FLT_FN (BUILT_IN_ATAN):
14030 CASE_FLT_FN (BUILT_IN_ATANH):
14031 CASE_FLT_FN (BUILT_IN_CBRT):
14032 CASE_FLT_FN (BUILT_IN_CEIL):
14033 CASE_FLT_FN (BUILT_IN_ERF):
14034 CASE_FLT_FN (BUILT_IN_EXPM1):
14035 CASE_FLT_FN (BUILT_IN_FLOOR):
14036 CASE_FLT_FN (BUILT_IN_FMOD):
14037 CASE_FLT_FN (BUILT_IN_FREXP):
14038 CASE_FLT_FN (BUILT_IN_LCEIL):
14039 CASE_FLT_FN (BUILT_IN_LDEXP):
14040 CASE_FLT_FN (BUILT_IN_LFLOOR):
14041 CASE_FLT_FN (BUILT_IN_LLCEIL):
14042 CASE_FLT_FN (BUILT_IN_LLFLOOR):
14043 CASE_FLT_FN (BUILT_IN_LLRINT):
14044 CASE_FLT_FN (BUILT_IN_LLROUND):
14045 CASE_FLT_FN (BUILT_IN_LRINT):
14046 CASE_FLT_FN (BUILT_IN_LROUND):
14047 CASE_FLT_FN (BUILT_IN_MODF):
14048 CASE_FLT_FN (BUILT_IN_NEARBYINT):
14049 CASE_FLT_FN (BUILT_IN_RINT):
14050 CASE_FLT_FN (BUILT_IN_ROUND):
14051 CASE_FLT_FN (BUILT_IN_SCALB):
14052 CASE_FLT_FN (BUILT_IN_SCALBLN):
14053 CASE_FLT_FN (BUILT_IN_SCALBN):
14054 CASE_FLT_FN (BUILT_IN_SIGNBIT):
14055 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
14056 CASE_FLT_FN (BUILT_IN_SINH):
14057 CASE_FLT_FN (BUILT_IN_TANH):
14058 CASE_FLT_FN (BUILT_IN_TRUNC):
14059 /* True if the 1st argument is nonnegative. */
14060 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14061 strict_overflow_p);
14063 CASE_FLT_FN (BUILT_IN_FMAX):
14064 /* True if the 1st OR 2nd arguments are nonnegative. */
14065 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14067 || (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14068 strict_overflow_p)));
14070 CASE_FLT_FN (BUILT_IN_FMIN):
14071 /* True if the 1st AND 2nd arguments are nonnegative. */
14072 return (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14074 && (tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14075 strict_overflow_p)));
14077 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14078 /* True if the 2nd argument is nonnegative. */
14079 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 1),
14080 strict_overflow_p);
14082 CASE_FLT_FN (BUILT_IN_POWI):
14083 /* True if the 1st argument is nonnegative or the second
14084 argument is an even integer. */
14085 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == INTEGER_CST)
14087 tree arg1 = CALL_EXPR_ARG (t, 1);
14088 if ((TREE_INT_CST_LOW (arg1) & 1) == 0)
14091 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14092 strict_overflow_p);
14094 CASE_FLT_FN (BUILT_IN_POW):
14095 /* True if the 1st argument is nonnegative or the second
14096 argument is an even integer valued real. */
14097 if (TREE_CODE (CALL_EXPR_ARG (t, 1)) == REAL_CST)
14102 c = TREE_REAL_CST (CALL_EXPR_ARG (t, 1));
14103 n = real_to_integer (&c);
14106 REAL_VALUE_TYPE cint;
14107 real_from_integer (&cint, VOIDmode, n,
14108 n < 0 ? -1 : 0, 0);
14109 if (real_identical (&c, &cint))
14113 return tree_expr_nonnegative_warnv_p (CALL_EXPR_ARG (t, 0),
14114 strict_overflow_p);
14119 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14124 case COMPOUND_EXPR:
14126 case GIMPLE_MODIFY_STMT:
14127 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14128 strict_overflow_p);
14130 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
14131 strict_overflow_p);
14133 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14134 strict_overflow_p);
14137 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14141 /* We don't know sign of `t', so be conservative and return false. */
14145 /* Return true if T is known to be non-negative. If the return
14146 value is based on the assumption that signed overflow is undefined,
14147 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14148 *STRICT_OVERFLOW_P. */
14151 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14153 enum tree_code code;
14154 if (t == error_mark_node)
14157 code = TREE_CODE (t);
14158 switch (TREE_CODE_CLASS (code))
14161 case tcc_comparison:
14162 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14164 TREE_OPERAND (t, 0),
14165 TREE_OPERAND (t, 1),
14166 strict_overflow_p);
14169 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14171 TREE_OPERAND (t, 0),
14172 strict_overflow_p);
14175 case tcc_declaration:
14176 case tcc_reference:
14177 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14185 case TRUTH_AND_EXPR:
14186 case TRUTH_OR_EXPR:
14187 case TRUTH_XOR_EXPR:
14188 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14190 TREE_OPERAND (t, 0),
14191 TREE_OPERAND (t, 1),
14192 strict_overflow_p);
14193 case TRUTH_NOT_EXPR:
14194 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14196 TREE_OPERAND (t, 0),
14197 strict_overflow_p);
14204 case WITH_SIZE_EXPR:
14208 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14211 return tree_invalid_nonnegative_warnv_p (t, strict_overflow_p);
14215 /* Return true if `t' is known to be non-negative. Handle warnings
14216 about undefined signed overflow. */
14219 tree_expr_nonnegative_p (tree t)
14221 bool ret, strict_overflow_p;
14223 strict_overflow_p = false;
14224 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
14225 if (strict_overflow_p)
14226 fold_overflow_warning (("assuming signed overflow does not occur when "
14227 "determining that expression is always "
14229 WARN_STRICT_OVERFLOW_MISC);
14234 /* Return true when (CODE OP0) is an address and is known to be nonzero.
14235 For floating point we further ensure that T is not denormal.
14236 Similar logic is present in nonzero_address in rtlanal.h.
14238 If the return value is based on the assumption that signed overflow
14239 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14240 change *STRICT_OVERFLOW_P. */
14243 tree_unary_nonzero_warnv_p (enum tree_code code, tree type, tree op0,
14244 bool *strict_overflow_p)
14249 return tree_expr_nonzero_warnv_p (op0,
14250 strict_overflow_p);
14254 tree inner_type = TREE_TYPE (op0);
14255 tree outer_type = type;
14257 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
14258 && tree_expr_nonzero_warnv_p (op0,
14259 strict_overflow_p));
14263 case NON_LVALUE_EXPR:
14264 return tree_expr_nonzero_warnv_p (op0,
14265 strict_overflow_p);
14274 /* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
14275 For floating point we further ensure that T is not denormal.
14276 Similar logic is present in nonzero_address in rtlanal.h.
14278 If the return value is based on the assumption that signed overflow
14279 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14280 change *STRICT_OVERFLOW_P. */
14283 tree_binary_nonzero_warnv_p (enum tree_code code,
14286 tree op1, bool *strict_overflow_p)
14288 bool sub_strict_overflow_p;
14291 case POINTER_PLUS_EXPR:
14293 if (TYPE_OVERFLOW_UNDEFINED (type))
14295 /* With the presence of negative values it is hard
14296 to say something. */
14297 sub_strict_overflow_p = false;
14298 if (!tree_expr_nonnegative_warnv_p (op0,
14299 &sub_strict_overflow_p)
14300 || !tree_expr_nonnegative_warnv_p (op1,
14301 &sub_strict_overflow_p))
14303 /* One of operands must be positive and the other non-negative. */
14304 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14305 overflows, on a twos-complement machine the sum of two
14306 nonnegative numbers can never be zero. */
14307 return (tree_expr_nonzero_warnv_p (op0,
14309 || tree_expr_nonzero_warnv_p (op1,
14310 strict_overflow_p));
14315 if (TYPE_OVERFLOW_UNDEFINED (type))
14317 if (tree_expr_nonzero_warnv_p (op0,
14319 && tree_expr_nonzero_warnv_p (op1,
14320 strict_overflow_p))
14322 *strict_overflow_p = true;
14329 sub_strict_overflow_p = false;
14330 if (tree_expr_nonzero_warnv_p (op0,
14331 &sub_strict_overflow_p)
14332 && tree_expr_nonzero_warnv_p (op1,
14333 &sub_strict_overflow_p))
14335 if (sub_strict_overflow_p)
14336 *strict_overflow_p = true;
14341 sub_strict_overflow_p = false;
14342 if (tree_expr_nonzero_warnv_p (op0,
14343 &sub_strict_overflow_p))
14345 if (sub_strict_overflow_p)
14346 *strict_overflow_p = true;
14348 /* When both operands are nonzero, then MAX must be too. */
14349 if (tree_expr_nonzero_warnv_p (op1,
14350 strict_overflow_p))
14353 /* MAX where operand 0 is positive is positive. */
14354 return tree_expr_nonnegative_warnv_p (op0,
14355 strict_overflow_p);
14357 /* MAX where operand 1 is positive is positive. */
14358 else if (tree_expr_nonzero_warnv_p (op1,
14359 &sub_strict_overflow_p)
14360 && tree_expr_nonnegative_warnv_p (op1,
14361 &sub_strict_overflow_p))
14363 if (sub_strict_overflow_p)
14364 *strict_overflow_p = true;
14370 return (tree_expr_nonzero_warnv_p (op1,
14372 || tree_expr_nonzero_warnv_p (op0,
14373 strict_overflow_p));
14382 /* Return true when T is an address and is known to be nonzero.
14383 For floating point we further ensure that T is not denormal.
14384 Similar logic is present in nonzero_address in rtlanal.h.
14386 If the return value is based on the assumption that signed overflow
14387 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14388 change *STRICT_OVERFLOW_P. */
14391 tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14393 bool sub_strict_overflow_p;
14394 switch (TREE_CODE (t))
14397 /* Query VRP to see if it has recorded any information about
14398 the range of this object. */
14399 return ssa_name_nonzero_p (t);
14402 return !integer_zerop (t);
14406 tree base = get_base_address (TREE_OPERAND (t, 0));
14411 /* Weak declarations may link to NULL. */
14412 if (VAR_OR_FUNCTION_DECL_P (base))
14413 return !DECL_WEAK (base);
14415 /* Constants are never weak. */
14416 if (CONSTANT_CLASS_P (base))
14423 sub_strict_overflow_p = false;
14424 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14425 &sub_strict_overflow_p)
14426 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
14427 &sub_strict_overflow_p))
14429 if (sub_strict_overflow_p)
14430 *strict_overflow_p = true;
14441 /* Return true when T 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_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14452 tree type = TREE_TYPE (t);
14453 enum tree_code code;
14455 /* Doing something useful for floating point would need more work. */
14456 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
14459 code = TREE_CODE (t);
14460 switch (TREE_CODE_CLASS (code))
14463 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
14464 strict_overflow_p);
14466 case tcc_comparison:
14467 return tree_binary_nonzero_warnv_p (code, type,
14468 TREE_OPERAND (t, 0),
14469 TREE_OPERAND (t, 1),
14470 strict_overflow_p);
14472 case tcc_declaration:
14473 case tcc_reference:
14474 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
14482 case TRUTH_NOT_EXPR:
14483 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
14484 strict_overflow_p);
14486 case TRUTH_AND_EXPR:
14487 case TRUTH_OR_EXPR:
14488 case TRUTH_XOR_EXPR:
14489 return tree_binary_nonzero_warnv_p (code, type,
14490 TREE_OPERAND (t, 0),
14491 TREE_OPERAND (t, 1),
14492 strict_overflow_p);
14499 case WITH_SIZE_EXPR:
14503 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
14505 case COMPOUND_EXPR:
14507 case GIMPLE_MODIFY_STMT:
14509 return tree_expr_nonzero_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14510 strict_overflow_p);
14513 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14514 strict_overflow_p);
14517 return alloca_call_p (t);
14525 /* Return true when T is an address and is known to be nonzero.
14526 Handle warnings about undefined signed overflow. */
14529 tree_expr_nonzero_p (tree t)
14531 bool ret, strict_overflow_p;
14533 strict_overflow_p = false;
14534 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
14535 if (strict_overflow_p)
14536 fold_overflow_warning (("assuming signed overflow does not occur when "
14537 "determining that expression is always "
14539 WARN_STRICT_OVERFLOW_MISC);
14543 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
14544 attempt to fold the expression to a constant without modifying TYPE,
14547 If the expression could be simplified to a constant, then return
14548 the constant. If the expression would not be simplified to a
14549 constant, then return NULL_TREE. */
14552 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
14554 tree tem = fold_binary (code, type, op0, op1);
14555 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14558 /* Given the components of a unary expression CODE, TYPE and OP0,
14559 attempt to fold the expression to a constant without modifying
14562 If the expression could be simplified to a constant, then return
14563 the constant. If the expression would not be simplified to a
14564 constant, then return NULL_TREE. */
14567 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
14569 tree tem = fold_unary (code, type, op0);
14570 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14573 /* If EXP represents referencing an element in a constant string
14574 (either via pointer arithmetic or array indexing), return the
14575 tree representing the value accessed, otherwise return NULL. */
14578 fold_read_from_constant_string (tree exp)
14580 if ((TREE_CODE (exp) == INDIRECT_REF
14581 || TREE_CODE (exp) == ARRAY_REF)
14582 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
14584 tree exp1 = TREE_OPERAND (exp, 0);
14588 if (TREE_CODE (exp) == INDIRECT_REF)
14589 string = string_constant (exp1, &index);
14592 tree low_bound = array_ref_low_bound (exp);
14593 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
14595 /* Optimize the special-case of a zero lower bound.
14597 We convert the low_bound to sizetype to avoid some problems
14598 with constant folding. (E.g. suppose the lower bound is 1,
14599 and its mode is QI. Without the conversion,l (ARRAY
14600 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
14601 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
14602 if (! integer_zerop (low_bound))
14603 index = size_diffop (index, fold_convert (sizetype, low_bound));
14609 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
14610 && TREE_CODE (string) == STRING_CST
14611 && TREE_CODE (index) == INTEGER_CST
14612 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
14613 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
14615 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
14616 return build_int_cst_type (TREE_TYPE (exp),
14617 (TREE_STRING_POINTER (string)
14618 [TREE_INT_CST_LOW (index)]));
14623 /* Return the tree for neg (ARG0) when ARG0 is known to be either
14624 an integer constant, real, or fixed-point constant.
14626 TYPE is the type of the result. */
14629 fold_negate_const (tree arg0, tree type)
14631 tree t = NULL_TREE;
14633 switch (TREE_CODE (arg0))
14637 unsigned HOST_WIDE_INT low;
14638 HOST_WIDE_INT high;
14639 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14640 TREE_INT_CST_HIGH (arg0),
14642 t = force_fit_type_double (type, low, high, 1,
14643 (overflow | TREE_OVERFLOW (arg0))
14644 && !TYPE_UNSIGNED (type));
14649 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14654 FIXED_VALUE_TYPE f;
14655 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
14656 &(TREE_FIXED_CST (arg0)), NULL,
14657 TYPE_SATURATING (type));
14658 t = build_fixed (type, f);
14659 /* Propagate overflow flags. */
14660 if (overflow_p | TREE_OVERFLOW (arg0))
14662 TREE_OVERFLOW (t) = 1;
14663 TREE_CONSTANT_OVERFLOW (t) = 1;
14665 else if (TREE_CONSTANT_OVERFLOW (arg0))
14666 TREE_CONSTANT_OVERFLOW (t) = 1;
14671 gcc_unreachable ();
14677 /* Return the tree for abs (ARG0) when ARG0 is known to be either
14678 an integer constant or real constant.
14680 TYPE is the type of the result. */
14683 fold_abs_const (tree arg0, tree type)
14685 tree t = NULL_TREE;
14687 switch (TREE_CODE (arg0))
14690 /* If the value is unsigned, then the absolute value is
14691 the same as the ordinary value. */
14692 if (TYPE_UNSIGNED (type))
14694 /* Similarly, if the value is non-negative. */
14695 else if (INT_CST_LT (integer_minus_one_node, arg0))
14697 /* If the value is negative, then the absolute value is
14701 unsigned HOST_WIDE_INT low;
14702 HOST_WIDE_INT high;
14703 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14704 TREE_INT_CST_HIGH (arg0),
14706 t = force_fit_type_double (type, low, high, -1,
14707 overflow | TREE_OVERFLOW (arg0));
14712 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
14713 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14719 gcc_unreachable ();
14725 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
14726 constant. TYPE is the type of the result. */
14729 fold_not_const (tree arg0, tree type)
14731 tree t = NULL_TREE;
14733 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
14735 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
14736 ~TREE_INT_CST_HIGH (arg0), 0,
14737 TREE_OVERFLOW (arg0));
14742 /* Given CODE, a relational operator, the target type, TYPE and two
14743 constant operands OP0 and OP1, return the result of the
14744 relational operation. If the result is not a compile time
14745 constant, then return NULL_TREE. */
14748 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
14750 int result, invert;
14752 /* From here on, the only cases we handle are when the result is
14753 known to be a constant. */
14755 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
14757 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
14758 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
14760 /* Handle the cases where either operand is a NaN. */
14761 if (real_isnan (c0) || real_isnan (c1))
14771 case UNORDERED_EXPR:
14785 if (flag_trapping_math)
14791 gcc_unreachable ();
14794 return constant_boolean_node (result, type);
14797 return constant_boolean_node (real_compare (code, c0, c1), type);
14800 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
14802 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
14803 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
14804 return constant_boolean_node (fixed_compare (code, c0, c1), type);
14807 /* Handle equality/inequality of complex constants. */
14808 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
14810 tree rcond = fold_relational_const (code, type,
14811 TREE_REALPART (op0),
14812 TREE_REALPART (op1));
14813 tree icond = fold_relational_const (code, type,
14814 TREE_IMAGPART (op0),
14815 TREE_IMAGPART (op1));
14816 if (code == EQ_EXPR)
14817 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
14818 else if (code == NE_EXPR)
14819 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
14824 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14826 To compute GT, swap the arguments and do LT.
14827 To compute GE, do LT and invert the result.
14828 To compute LE, swap the arguments, do LT and invert the result.
14829 To compute NE, do EQ and invert the result.
14831 Therefore, the code below must handle only EQ and LT. */
14833 if (code == LE_EXPR || code == GT_EXPR)
14838 code = swap_tree_comparison (code);
14841 /* Note that it is safe to invert for real values here because we
14842 have already handled the one case that it matters. */
14845 if (code == NE_EXPR || code == GE_EXPR)
14848 code = invert_tree_comparison (code, false);
14851 /* Compute a result for LT or EQ if args permit;
14852 Otherwise return T. */
14853 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
14855 if (code == EQ_EXPR)
14856 result = tree_int_cst_equal (op0, op1);
14857 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
14858 result = INT_CST_LT_UNSIGNED (op0, op1);
14860 result = INT_CST_LT (op0, op1);
14867 return constant_boolean_node (result, type);
14870 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
14871 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
14875 fold_build_cleanup_point_expr (tree type, tree expr)
14877 /* If the expression does not have side effects then we don't have to wrap
14878 it with a cleanup point expression. */
14879 if (!TREE_SIDE_EFFECTS (expr))
14882 /* If the expression is a return, check to see if the expression inside the
14883 return has no side effects or the right hand side of the modify expression
14884 inside the return. If either don't have side effects set we don't need to
14885 wrap the expression in a cleanup point expression. Note we don't check the
14886 left hand side of the modify because it should always be a return decl. */
14887 if (TREE_CODE (expr) == RETURN_EXPR)
14889 tree op = TREE_OPERAND (expr, 0);
14890 if (!op || !TREE_SIDE_EFFECTS (op))
14892 op = TREE_OPERAND (op, 1);
14893 if (!TREE_SIDE_EFFECTS (op))
14897 return build1 (CLEANUP_POINT_EXPR, type, expr);
14900 /* Given a pointer value OP0 and a type TYPE, return a simplified version
14901 of an indirection through OP0, or NULL_TREE if no simplification is
14905 fold_indirect_ref_1 (tree type, tree op0)
14911 subtype = TREE_TYPE (sub);
14912 if (!POINTER_TYPE_P (subtype))
14915 if (TREE_CODE (sub) == ADDR_EXPR)
14917 tree op = TREE_OPERAND (sub, 0);
14918 tree optype = TREE_TYPE (op);
14919 /* *&CONST_DECL -> to the value of the const decl. */
14920 if (TREE_CODE (op) == CONST_DECL)
14921 return DECL_INITIAL (op);
14922 /* *&p => p; make sure to handle *&"str"[cst] here. */
14923 if (type == optype)
14925 tree fop = fold_read_from_constant_string (op);
14931 /* *(foo *)&fooarray => fooarray[0] */
14932 else if (TREE_CODE (optype) == ARRAY_TYPE
14933 && type == TREE_TYPE (optype))
14935 tree type_domain = TYPE_DOMAIN (optype);
14936 tree min_val = size_zero_node;
14937 if (type_domain && TYPE_MIN_VALUE (type_domain))
14938 min_val = TYPE_MIN_VALUE (type_domain);
14939 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
14941 /* *(foo *)&complexfoo => __real__ complexfoo */
14942 else if (TREE_CODE (optype) == COMPLEX_TYPE
14943 && type == TREE_TYPE (optype))
14944 return fold_build1 (REALPART_EXPR, type, op);
14945 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
14946 else if (TREE_CODE (optype) == VECTOR_TYPE
14947 && type == TREE_TYPE (optype))
14949 tree part_width = TYPE_SIZE (type);
14950 tree index = bitsize_int (0);
14951 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
14955 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
14956 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
14957 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
14959 tree op00 = TREE_OPERAND (sub, 0);
14960 tree op01 = TREE_OPERAND (sub, 1);
14964 op00type = TREE_TYPE (op00);
14965 if (TREE_CODE (op00) == ADDR_EXPR
14966 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
14967 && type == TREE_TYPE (TREE_TYPE (op00type)))
14969 tree size = TYPE_SIZE_UNIT (type);
14970 if (tree_int_cst_equal (size, op01))
14971 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
14975 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
14976 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
14977 && type == TREE_TYPE (TREE_TYPE (subtype)))
14980 tree min_val = size_zero_node;
14981 sub = build_fold_indirect_ref (sub);
14982 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
14983 if (type_domain && TYPE_MIN_VALUE (type_domain))
14984 min_val = TYPE_MIN_VALUE (type_domain);
14985 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
14991 /* Builds an expression for an indirection through T, simplifying some
14995 build_fold_indirect_ref (tree t)
14997 tree type = TREE_TYPE (TREE_TYPE (t));
14998 tree sub = fold_indirect_ref_1 (type, t);
15003 return build1 (INDIRECT_REF, type, t);
15006 /* Given an INDIRECT_REF T, return either T or a simplified version. */
15009 fold_indirect_ref (tree t)
15011 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
15019 /* Strip non-trapping, non-side-effecting tree nodes from an expression
15020 whose result is ignored. The type of the returned tree need not be
15021 the same as the original expression. */
15024 fold_ignored_result (tree t)
15026 if (!TREE_SIDE_EFFECTS (t))
15027 return integer_zero_node;
15030 switch (TREE_CODE_CLASS (TREE_CODE (t)))
15033 t = TREE_OPERAND (t, 0);
15037 case tcc_comparison:
15038 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15039 t = TREE_OPERAND (t, 0);
15040 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
15041 t = TREE_OPERAND (t, 1);
15046 case tcc_expression:
15047 switch (TREE_CODE (t))
15049 case COMPOUND_EXPR:
15050 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15052 t = TREE_OPERAND (t, 0);
15056 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
15057 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
15059 t = TREE_OPERAND (t, 0);
15072 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
15073 This can only be applied to objects of a sizetype. */
15076 round_up (tree value, int divisor)
15078 tree div = NULL_TREE;
15080 gcc_assert (divisor > 0);
15084 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15085 have to do anything. Only do this when we are not given a const,
15086 because in that case, this check is more expensive than just
15088 if (TREE_CODE (value) != INTEGER_CST)
15090 div = build_int_cst (TREE_TYPE (value), divisor);
15092 if (multiple_of_p (TREE_TYPE (value), value, div))
15096 /* If divisor is a power of two, simplify this to bit manipulation. */
15097 if (divisor == (divisor & -divisor))
15099 if (TREE_CODE (value) == INTEGER_CST)
15101 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
15102 unsigned HOST_WIDE_INT high;
15105 if ((low & (divisor - 1)) == 0)
15108 overflow_p = TREE_OVERFLOW (value);
15109 high = TREE_INT_CST_HIGH (value);
15110 low &= ~(divisor - 1);
15119 return force_fit_type_double (TREE_TYPE (value), low, high,
15126 t = build_int_cst (TREE_TYPE (value), divisor - 1);
15127 value = size_binop (PLUS_EXPR, value, t);
15128 t = build_int_cst (TREE_TYPE (value), -divisor);
15129 value = size_binop (BIT_AND_EXPR, value, t);
15135 div = build_int_cst (TREE_TYPE (value), divisor);
15136 value = size_binop (CEIL_DIV_EXPR, value, div);
15137 value = size_binop (MULT_EXPR, value, div);
15143 /* Likewise, but round down. */
15146 round_down (tree value, int divisor)
15148 tree div = NULL_TREE;
15150 gcc_assert (divisor > 0);
15154 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15155 have to do anything. Only do this when we are not given a const,
15156 because in that case, this check is more expensive than just
15158 if (TREE_CODE (value) != INTEGER_CST)
15160 div = build_int_cst (TREE_TYPE (value), divisor);
15162 if (multiple_of_p (TREE_TYPE (value), value, div))
15166 /* If divisor is a power of two, simplify this to bit manipulation. */
15167 if (divisor == (divisor & -divisor))
15171 t = build_int_cst (TREE_TYPE (value), -divisor);
15172 value = size_binop (BIT_AND_EXPR, value, t);
15177 div = build_int_cst (TREE_TYPE (value), divisor);
15178 value = size_binop (FLOOR_DIV_EXPR, value, div);
15179 value = size_binop (MULT_EXPR, value, div);
15185 /* Returns the pointer to the base of the object addressed by EXP and
15186 extracts the information about the offset of the access, storing it
15187 to PBITPOS and POFFSET. */
15190 split_address_to_core_and_offset (tree exp,
15191 HOST_WIDE_INT *pbitpos, tree *poffset)
15194 enum machine_mode mode;
15195 int unsignedp, volatilep;
15196 HOST_WIDE_INT bitsize;
15198 if (TREE_CODE (exp) == ADDR_EXPR)
15200 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
15201 poffset, &mode, &unsignedp, &volatilep,
15203 core = fold_addr_expr (core);
15209 *poffset = NULL_TREE;
15215 /* Returns true if addresses of E1 and E2 differ by a constant, false
15216 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15219 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
15222 HOST_WIDE_INT bitpos1, bitpos2;
15223 tree toffset1, toffset2, tdiff, type;
15225 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
15226 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
15228 if (bitpos1 % BITS_PER_UNIT != 0
15229 || bitpos2 % BITS_PER_UNIT != 0
15230 || !operand_equal_p (core1, core2, 0))
15233 if (toffset1 && toffset2)
15235 type = TREE_TYPE (toffset1);
15236 if (type != TREE_TYPE (toffset2))
15237 toffset2 = fold_convert (type, toffset2);
15239 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
15240 if (!cst_and_fits_in_hwi (tdiff))
15243 *diff = int_cst_value (tdiff);
15245 else if (toffset1 || toffset2)
15247 /* If only one of the offsets is non-constant, the difference cannot
15254 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
15258 /* Simplify the floating point expression EXP when the sign of the
15259 result is not significant. Return NULL_TREE if no simplification
15263 fold_strip_sign_ops (tree exp)
15267 switch (TREE_CODE (exp))
15271 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15272 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
15276 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
15278 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15279 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15280 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
15281 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
15282 arg0 ? arg0 : TREE_OPERAND (exp, 0),
15283 arg1 ? arg1 : TREE_OPERAND (exp, 1));
15286 case COMPOUND_EXPR:
15287 arg0 = TREE_OPERAND (exp, 0);
15288 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15290 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
15294 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15295 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
15297 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
15298 arg0 ? arg0 : TREE_OPERAND (exp, 1),
15299 arg1 ? arg1 : TREE_OPERAND (exp, 2));
15304 const enum built_in_function fcode = builtin_mathfn_code (exp);
15307 CASE_FLT_FN (BUILT_IN_COPYSIGN):
15308 /* Strip copysign function call, return the 1st argument. */
15309 arg0 = CALL_EXPR_ARG (exp, 0);
15310 arg1 = CALL_EXPR_ARG (exp, 1);
15311 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
15314 /* Strip sign ops from the argument of "odd" math functions. */
15315 if (negate_mathfn_p (fcode))
15317 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
15319 return build_call_expr (get_callee_fndecl (exp), 1, arg0);