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 if (fold_deferring_overflow_warnings > 0)
1017 if (fold_deferred_overflow_warning == NULL
1018 || wc < fold_deferred_overflow_code)
1020 fold_deferred_overflow_warning = gmsgid;
1021 fold_deferred_overflow_code = wc;
1024 else if (issue_strict_overflow_warning (wc))
1025 warning (OPT_Wstrict_overflow, gmsgid);
1028 /* Return true if the built-in mathematical function specified by CODE
1029 is odd, i.e. -f(x) == f(-x). */
1032 negate_mathfn_p (enum built_in_function code)
1036 CASE_FLT_FN (BUILT_IN_ASIN):
1037 CASE_FLT_FN (BUILT_IN_ASINH):
1038 CASE_FLT_FN (BUILT_IN_ATAN):
1039 CASE_FLT_FN (BUILT_IN_ATANH):
1040 CASE_FLT_FN (BUILT_IN_CASIN):
1041 CASE_FLT_FN (BUILT_IN_CASINH):
1042 CASE_FLT_FN (BUILT_IN_CATAN):
1043 CASE_FLT_FN (BUILT_IN_CATANH):
1044 CASE_FLT_FN (BUILT_IN_CBRT):
1045 CASE_FLT_FN (BUILT_IN_CPROJ):
1046 CASE_FLT_FN (BUILT_IN_CSIN):
1047 CASE_FLT_FN (BUILT_IN_CSINH):
1048 CASE_FLT_FN (BUILT_IN_CTAN):
1049 CASE_FLT_FN (BUILT_IN_CTANH):
1050 CASE_FLT_FN (BUILT_IN_ERF):
1051 CASE_FLT_FN (BUILT_IN_LLROUND):
1052 CASE_FLT_FN (BUILT_IN_LROUND):
1053 CASE_FLT_FN (BUILT_IN_ROUND):
1054 CASE_FLT_FN (BUILT_IN_SIN):
1055 CASE_FLT_FN (BUILT_IN_SINH):
1056 CASE_FLT_FN (BUILT_IN_TAN):
1057 CASE_FLT_FN (BUILT_IN_TANH):
1058 CASE_FLT_FN (BUILT_IN_TRUNC):
1061 CASE_FLT_FN (BUILT_IN_LLRINT):
1062 CASE_FLT_FN (BUILT_IN_LRINT):
1063 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1064 CASE_FLT_FN (BUILT_IN_RINT):
1065 return !flag_rounding_math;
1073 /* Check whether we may negate an integer constant T without causing
1077 may_negate_without_overflow_p (const_tree t)
1079 unsigned HOST_WIDE_INT val;
1083 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1085 type = TREE_TYPE (t);
1086 if (TYPE_UNSIGNED (type))
1089 prec = TYPE_PRECISION (type);
1090 if (prec > HOST_BITS_PER_WIDE_INT)
1092 if (TREE_INT_CST_LOW (t) != 0)
1094 prec -= HOST_BITS_PER_WIDE_INT;
1095 val = TREE_INT_CST_HIGH (t);
1098 val = TREE_INT_CST_LOW (t);
1099 if (prec < HOST_BITS_PER_WIDE_INT)
1100 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1101 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1104 /* Determine whether an expression T can be cheaply negated using
1105 the function negate_expr without introducing undefined overflow. */
1108 negate_expr_p (tree t)
1115 type = TREE_TYPE (t);
1117 STRIP_SIGN_NOPS (t);
1118 switch (TREE_CODE (t))
1121 if (TYPE_OVERFLOW_WRAPS (type))
1124 /* Check that -CST will not overflow type. */
1125 return may_negate_without_overflow_p (t);
1127 return (INTEGRAL_TYPE_P (type)
1128 && TYPE_OVERFLOW_WRAPS (type));
1136 return negate_expr_p (TREE_REALPART (t))
1137 && negate_expr_p (TREE_IMAGPART (t));
1140 return negate_expr_p (TREE_OPERAND (t, 0))
1141 && negate_expr_p (TREE_OPERAND (t, 1));
1144 return negate_expr_p (TREE_OPERAND (t, 0));
1147 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1148 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1150 /* -(A + B) -> (-B) - A. */
1151 if (negate_expr_p (TREE_OPERAND (t, 1))
1152 && reorder_operands_p (TREE_OPERAND (t, 0),
1153 TREE_OPERAND (t, 1)))
1155 /* -(A + B) -> (-A) - B. */
1156 return negate_expr_p (TREE_OPERAND (t, 0));
1159 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1160 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1161 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1162 && reorder_operands_p (TREE_OPERAND (t, 0),
1163 TREE_OPERAND (t, 1));
1166 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1172 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1173 return negate_expr_p (TREE_OPERAND (t, 1))
1174 || negate_expr_p (TREE_OPERAND (t, 0));
1177 case TRUNC_DIV_EXPR:
1178 case ROUND_DIV_EXPR:
1179 case FLOOR_DIV_EXPR:
1181 case EXACT_DIV_EXPR:
1182 /* In general we can't negate A / B, because if A is INT_MIN and
1183 B is 1, we may turn this into INT_MIN / -1 which is undefined
1184 and actually traps on some architectures. But if overflow is
1185 undefined, we can negate, because - (INT_MIN / 1) is an
1187 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1188 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1190 return negate_expr_p (TREE_OPERAND (t, 1))
1191 || negate_expr_p (TREE_OPERAND (t, 0));
1194 /* Negate -((double)float) as (double)(-float). */
1195 if (TREE_CODE (type) == REAL_TYPE)
1197 tree tem = strip_float_extensions (t);
1199 return negate_expr_p (tem);
1204 /* Negate -f(x) as f(-x). */
1205 if (negate_mathfn_p (builtin_mathfn_code (t)))
1206 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1210 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1211 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1213 tree op1 = TREE_OPERAND (t, 1);
1214 if (TREE_INT_CST_HIGH (op1) == 0
1215 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1216 == TREE_INT_CST_LOW (op1))
1227 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1228 simplification is possible.
1229 If negate_expr_p would return true for T, NULL_TREE will never be
1233 fold_negate_expr (tree t)
1235 tree type = TREE_TYPE (t);
1238 switch (TREE_CODE (t))
1240 /* Convert - (~A) to A + 1. */
1242 if (INTEGRAL_TYPE_P (type))
1243 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1244 build_int_cst (type, 1));
1248 tem = fold_negate_const (t, type);
1249 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1250 || !TYPE_OVERFLOW_TRAPS (type))
1255 tem = fold_negate_const (t, type);
1256 /* Two's complement FP formats, such as c4x, may overflow. */
1257 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1262 tem = fold_negate_const (t, type);
1267 tree rpart = negate_expr (TREE_REALPART (t));
1268 tree ipart = negate_expr (TREE_IMAGPART (t));
1270 if ((TREE_CODE (rpart) == REAL_CST
1271 && TREE_CODE (ipart) == REAL_CST)
1272 || (TREE_CODE (rpart) == INTEGER_CST
1273 && TREE_CODE (ipart) == INTEGER_CST))
1274 return build_complex (type, rpart, ipart);
1279 if (negate_expr_p (t))
1280 return fold_build2 (COMPLEX_EXPR, type,
1281 fold_negate_expr (TREE_OPERAND (t, 0)),
1282 fold_negate_expr (TREE_OPERAND (t, 1)));
1286 if (negate_expr_p (t))
1287 return fold_build1 (CONJ_EXPR, type,
1288 fold_negate_expr (TREE_OPERAND (t, 0)));
1292 return TREE_OPERAND (t, 0);
1295 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1296 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1298 /* -(A + B) -> (-B) - A. */
1299 if (negate_expr_p (TREE_OPERAND (t, 1))
1300 && reorder_operands_p (TREE_OPERAND (t, 0),
1301 TREE_OPERAND (t, 1)))
1303 tem = negate_expr (TREE_OPERAND (t, 1));
1304 return fold_build2 (MINUS_EXPR, type,
1305 tem, TREE_OPERAND (t, 0));
1308 /* -(A + B) -> (-A) - B. */
1309 if (negate_expr_p (TREE_OPERAND (t, 0)))
1311 tem = negate_expr (TREE_OPERAND (t, 0));
1312 return fold_build2 (MINUS_EXPR, type,
1313 tem, TREE_OPERAND (t, 1));
1319 /* - (A - B) -> B - A */
1320 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1321 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1322 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1323 return fold_build2 (MINUS_EXPR, type,
1324 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1328 if (TYPE_UNSIGNED (type))
1334 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1336 tem = TREE_OPERAND (t, 1);
1337 if (negate_expr_p (tem))
1338 return fold_build2 (TREE_CODE (t), type,
1339 TREE_OPERAND (t, 0), negate_expr (tem));
1340 tem = TREE_OPERAND (t, 0);
1341 if (negate_expr_p (tem))
1342 return fold_build2 (TREE_CODE (t), type,
1343 negate_expr (tem), TREE_OPERAND (t, 1));
1347 case TRUNC_DIV_EXPR:
1348 case ROUND_DIV_EXPR:
1349 case FLOOR_DIV_EXPR:
1351 case EXACT_DIV_EXPR:
1352 /* In general we can't negate A / B, because if A is INT_MIN and
1353 B is 1, we may turn this into INT_MIN / -1 which is undefined
1354 and actually traps on some architectures. But if overflow is
1355 undefined, we can negate, because - (INT_MIN / 1) is an
1357 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1359 const char * const warnmsg = G_("assuming signed overflow does not "
1360 "occur when negating a division");
1361 tem = TREE_OPERAND (t, 1);
1362 if (negate_expr_p (tem))
1364 if (INTEGRAL_TYPE_P (type)
1365 && (TREE_CODE (tem) != INTEGER_CST
1366 || integer_onep (tem)))
1367 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1368 return fold_build2 (TREE_CODE (t), type,
1369 TREE_OPERAND (t, 0), negate_expr (tem));
1371 tem = TREE_OPERAND (t, 0);
1372 if (negate_expr_p (tem))
1374 if (INTEGRAL_TYPE_P (type)
1375 && (TREE_CODE (tem) != INTEGER_CST
1376 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1377 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1378 return fold_build2 (TREE_CODE (t), type,
1379 negate_expr (tem), TREE_OPERAND (t, 1));
1385 /* Convert -((double)float) into (double)(-float). */
1386 if (TREE_CODE (type) == REAL_TYPE)
1388 tem = strip_float_extensions (t);
1389 if (tem != t && negate_expr_p (tem))
1390 return fold_convert (type, negate_expr (tem));
1395 /* Negate -f(x) as f(-x). */
1396 if (negate_mathfn_p (builtin_mathfn_code (t))
1397 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1401 fndecl = get_callee_fndecl (t);
1402 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1403 return build_call_expr (fndecl, 1, arg);
1408 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1409 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1411 tree op1 = TREE_OPERAND (t, 1);
1412 if (TREE_INT_CST_HIGH (op1) == 0
1413 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1414 == TREE_INT_CST_LOW (op1))
1416 tree ntype = TYPE_UNSIGNED (type)
1417 ? signed_type_for (type)
1418 : unsigned_type_for (type);
1419 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1420 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1421 return fold_convert (type, temp);
1433 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1434 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1435 return NULL_TREE. */
1438 negate_expr (tree t)
1445 type = TREE_TYPE (t);
1446 STRIP_SIGN_NOPS (t);
1448 tem = fold_negate_expr (t);
1450 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1451 return fold_convert (type, tem);
1454 /* Split a tree IN into a constant, literal and variable parts that could be
1455 combined with CODE to make IN. "constant" means an expression with
1456 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1457 commutative arithmetic operation. Store the constant part into *CONP,
1458 the literal in *LITP and return the variable part. If a part isn't
1459 present, set it to null. If the tree does not decompose in this way,
1460 return the entire tree as the variable part and the other parts as null.
1462 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1463 case, we negate an operand that was subtracted. Except if it is a
1464 literal for which we use *MINUS_LITP instead.
1466 If NEGATE_P is true, we are negating all of IN, again except a literal
1467 for which we use *MINUS_LITP instead.
1469 If IN is itself a literal or constant, return it as appropriate.
1471 Note that we do not guarantee that any of the three values will be the
1472 same type as IN, but they will have the same signedness and mode. */
1475 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1476 tree *minus_litp, int negate_p)
1484 /* Strip any conversions that don't change the machine mode or signedness. */
1485 STRIP_SIGN_NOPS (in);
1487 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
1488 || TREE_CODE (in) == FIXED_CST)
1490 else if (TREE_CODE (in) == code
1491 || ((! FLOAT_TYPE_P (TREE_TYPE (in)) || flag_associative_math)
1492 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
1493 /* We can associate addition and subtraction together (even
1494 though the C standard doesn't say so) for integers because
1495 the value is not affected. For reals, the value might be
1496 affected, so we can't. */
1497 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1498 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1500 tree op0 = TREE_OPERAND (in, 0);
1501 tree op1 = TREE_OPERAND (in, 1);
1502 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1503 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1505 /* First see if either of the operands is a literal, then a constant. */
1506 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
1507 || TREE_CODE (op0) == FIXED_CST)
1508 *litp = op0, op0 = 0;
1509 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
1510 || TREE_CODE (op1) == FIXED_CST)
1511 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1513 if (op0 != 0 && TREE_CONSTANT (op0))
1514 *conp = op0, op0 = 0;
1515 else if (op1 != 0 && TREE_CONSTANT (op1))
1516 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1518 /* If we haven't dealt with either operand, this is not a case we can
1519 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1520 if (op0 != 0 && op1 != 0)
1525 var = op1, neg_var_p = neg1_p;
1527 /* Now do any needed negations. */
1529 *minus_litp = *litp, *litp = 0;
1531 *conp = negate_expr (*conp);
1533 var = negate_expr (var);
1535 else if (TREE_CONSTANT (in))
1543 *minus_litp = *litp, *litp = 0;
1544 else if (*minus_litp)
1545 *litp = *minus_litp, *minus_litp = 0;
1546 *conp = negate_expr (*conp);
1547 var = negate_expr (var);
1553 /* Re-associate trees split by the above function. T1 and T2 are either
1554 expressions to associate or null. Return the new expression, if any. If
1555 we build an operation, do it in TYPE and with CODE. */
1558 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1565 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1566 try to fold this since we will have infinite recursion. But do
1567 deal with any NEGATE_EXPRs. */
1568 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1569 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1571 if (code == PLUS_EXPR)
1573 if (TREE_CODE (t1) == NEGATE_EXPR)
1574 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1575 fold_convert (type, TREE_OPERAND (t1, 0)));
1576 else if (TREE_CODE (t2) == NEGATE_EXPR)
1577 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1578 fold_convert (type, TREE_OPERAND (t2, 0)));
1579 else if (integer_zerop (t2))
1580 return fold_convert (type, t1);
1582 else if (code == MINUS_EXPR)
1584 if (integer_zerop (t2))
1585 return fold_convert (type, t1);
1588 return build2 (code, type, fold_convert (type, t1),
1589 fold_convert (type, t2));
1592 return fold_build2 (code, type, fold_convert (type, t1),
1593 fold_convert (type, t2));
1596 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1597 for use in int_const_binop, size_binop and size_diffop. */
1600 int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
1602 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1604 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1619 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1620 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1621 && TYPE_MODE (type1) == TYPE_MODE (type2);
1625 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1626 to produce a new constant. Return NULL_TREE if we don't know how
1627 to evaluate CODE at compile-time.
1629 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1632 int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2, int notrunc)
1634 unsigned HOST_WIDE_INT int1l, int2l;
1635 HOST_WIDE_INT int1h, int2h;
1636 unsigned HOST_WIDE_INT low;
1638 unsigned HOST_WIDE_INT garbagel;
1639 HOST_WIDE_INT garbageh;
1641 tree type = TREE_TYPE (arg1);
1642 int uns = TYPE_UNSIGNED (type);
1644 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1647 int1l = TREE_INT_CST_LOW (arg1);
1648 int1h = TREE_INT_CST_HIGH (arg1);
1649 int2l = TREE_INT_CST_LOW (arg2);
1650 int2h = TREE_INT_CST_HIGH (arg2);
1655 low = int1l | int2l, hi = int1h | int2h;
1659 low = int1l ^ int2l, hi = int1h ^ int2h;
1663 low = int1l & int2l, hi = int1h & int2h;
1669 /* It's unclear from the C standard whether shifts can overflow.
1670 The following code ignores overflow; perhaps a C standard
1671 interpretation ruling is needed. */
1672 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1679 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1684 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1688 neg_double (int2l, int2h, &low, &hi);
1689 add_double (int1l, int1h, low, hi, &low, &hi);
1690 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1694 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1697 case TRUNC_DIV_EXPR:
1698 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1699 case EXACT_DIV_EXPR:
1700 /* This is a shortcut for a common special case. */
1701 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1702 && !TREE_OVERFLOW (arg1)
1703 && !TREE_OVERFLOW (arg2)
1704 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1706 if (code == CEIL_DIV_EXPR)
1709 low = int1l / int2l, hi = 0;
1713 /* ... fall through ... */
1715 case ROUND_DIV_EXPR:
1716 if (int2h == 0 && int2l == 0)
1718 if (int2h == 0 && int2l == 1)
1720 low = int1l, hi = int1h;
1723 if (int1l == int2l && int1h == int2h
1724 && ! (int1l == 0 && int1h == 0))
1729 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1730 &low, &hi, &garbagel, &garbageh);
1733 case TRUNC_MOD_EXPR:
1734 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1735 /* This is a shortcut for a common special case. */
1736 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1737 && !TREE_OVERFLOW (arg1)
1738 && !TREE_OVERFLOW (arg2)
1739 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1741 if (code == CEIL_MOD_EXPR)
1743 low = int1l % int2l, hi = 0;
1747 /* ... fall through ... */
1749 case ROUND_MOD_EXPR:
1750 if (int2h == 0 && int2l == 0)
1752 overflow = div_and_round_double (code, uns,
1753 int1l, int1h, int2l, int2h,
1754 &garbagel, &garbageh, &low, &hi);
1760 low = (((unsigned HOST_WIDE_INT) int1h
1761 < (unsigned HOST_WIDE_INT) int2h)
1762 || (((unsigned HOST_WIDE_INT) int1h
1763 == (unsigned HOST_WIDE_INT) int2h)
1766 low = (int1h < int2h
1767 || (int1h == int2h && int1l < int2l));
1769 if (low == (code == MIN_EXPR))
1770 low = int1l, hi = int1h;
1772 low = int2l, hi = int2h;
1781 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1783 /* Propagate overflow flags ourselves. */
1784 if (((!uns || is_sizetype) && overflow)
1785 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1788 TREE_OVERFLOW (t) = 1;
1792 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1793 ((!uns || is_sizetype) && overflow)
1794 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1799 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1800 constant. We assume ARG1 and ARG2 have the same data type, or at least
1801 are the same kind of constant and the same machine mode. Return zero if
1802 combining the constants is not allowed in the current operating mode.
1804 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1807 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1809 /* Sanity check for the recursive cases. */
1816 if (TREE_CODE (arg1) == INTEGER_CST)
1817 return int_const_binop (code, arg1, arg2, notrunc);
1819 if (TREE_CODE (arg1) == REAL_CST)
1821 enum machine_mode mode;
1824 REAL_VALUE_TYPE value;
1825 REAL_VALUE_TYPE result;
1829 /* The following codes are handled by real_arithmetic. */
1844 d1 = TREE_REAL_CST (arg1);
1845 d2 = TREE_REAL_CST (arg2);
1847 type = TREE_TYPE (arg1);
1848 mode = TYPE_MODE (type);
1850 /* Don't perform operation if we honor signaling NaNs and
1851 either operand is a NaN. */
1852 if (HONOR_SNANS (mode)
1853 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1856 /* Don't perform operation if it would raise a division
1857 by zero exception. */
1858 if (code == RDIV_EXPR
1859 && REAL_VALUES_EQUAL (d2, dconst0)
1860 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1863 /* If either operand is a NaN, just return it. Otherwise, set up
1864 for floating-point trap; we return an overflow. */
1865 if (REAL_VALUE_ISNAN (d1))
1867 else if (REAL_VALUE_ISNAN (d2))
1870 inexact = real_arithmetic (&value, code, &d1, &d2);
1871 real_convert (&result, mode, &value);
1873 /* Don't constant fold this floating point operation if
1874 the result has overflowed and flag_trapping_math. */
1875 if (flag_trapping_math
1876 && MODE_HAS_INFINITIES (mode)
1877 && REAL_VALUE_ISINF (result)
1878 && !REAL_VALUE_ISINF (d1)
1879 && !REAL_VALUE_ISINF (d2))
1882 /* Don't constant fold this floating point operation if the
1883 result may dependent upon the run-time rounding mode and
1884 flag_rounding_math is set, or if GCC's software emulation
1885 is unable to accurately represent the result. */
1886 if ((flag_rounding_math
1887 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1888 && !flag_unsafe_math_optimizations))
1889 && (inexact || !real_identical (&result, &value)))
1892 t = build_real (type, result);
1894 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1898 if (TREE_CODE (arg1) == FIXED_CST)
1900 FIXED_VALUE_TYPE f1;
1901 FIXED_VALUE_TYPE f2;
1902 FIXED_VALUE_TYPE result;
1907 /* The following codes are handled by fixed_arithmetic. */
1913 case TRUNC_DIV_EXPR:
1914 f2 = TREE_FIXED_CST (arg2);
1919 f2.data.high = TREE_INT_CST_HIGH (arg2);
1920 f2.data.low = TREE_INT_CST_LOW (arg2);
1928 f1 = TREE_FIXED_CST (arg1);
1929 type = TREE_TYPE (arg1);
1930 sat_p = TYPE_SATURATING (type);
1931 overflow_p = fixed_arithmetic (&result, code, &f1, &f2, sat_p);
1932 t = build_fixed (type, result);
1933 /* Propagate overflow flags. */
1934 if (overflow_p | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1936 TREE_OVERFLOW (t) = 1;
1937 TREE_CONSTANT_OVERFLOW (t) = 1;
1939 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1940 TREE_CONSTANT_OVERFLOW (t) = 1;
1944 if (TREE_CODE (arg1) == COMPLEX_CST)
1946 tree type = TREE_TYPE (arg1);
1947 tree r1 = TREE_REALPART (arg1);
1948 tree i1 = TREE_IMAGPART (arg1);
1949 tree r2 = TREE_REALPART (arg2);
1950 tree i2 = TREE_IMAGPART (arg2);
1957 real = const_binop (code, r1, r2, notrunc);
1958 imag = const_binop (code, i1, i2, notrunc);
1962 real = const_binop (MINUS_EXPR,
1963 const_binop (MULT_EXPR, r1, r2, notrunc),
1964 const_binop (MULT_EXPR, i1, i2, notrunc),
1966 imag = const_binop (PLUS_EXPR,
1967 const_binop (MULT_EXPR, r1, i2, notrunc),
1968 const_binop (MULT_EXPR, i1, r2, notrunc),
1975 = const_binop (PLUS_EXPR,
1976 const_binop (MULT_EXPR, r2, r2, notrunc),
1977 const_binop (MULT_EXPR, i2, i2, notrunc),
1980 = const_binop (PLUS_EXPR,
1981 const_binop (MULT_EXPR, r1, r2, notrunc),
1982 const_binop (MULT_EXPR, i1, i2, notrunc),
1985 = const_binop (MINUS_EXPR,
1986 const_binop (MULT_EXPR, i1, r2, notrunc),
1987 const_binop (MULT_EXPR, r1, i2, notrunc),
1990 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
1991 code = TRUNC_DIV_EXPR;
1993 real = const_binop (code, t1, magsquared, notrunc);
1994 imag = const_binop (code, t2, magsquared, notrunc);
2003 return build_complex (type, real, imag);
2009 /* Create a size type INT_CST node with NUMBER sign extended. KIND
2010 indicates which particular sizetype to create. */
2013 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
2015 return build_int_cst (sizetype_tab[(int) kind], number);
2018 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
2019 is a tree code. The type of the result is taken from the operands.
2020 Both must be equivalent integer types, ala int_binop_types_match_p.
2021 If the operands are constant, so is the result. */
2024 size_binop (enum tree_code code, tree arg0, tree arg1)
2026 tree type = TREE_TYPE (arg0);
2028 if (arg0 == error_mark_node || arg1 == error_mark_node)
2029 return error_mark_node;
2031 gcc_assert (int_binop_types_match_p (code, TREE_TYPE (arg0),
2034 /* Handle the special case of two integer constants faster. */
2035 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
2037 /* And some specific cases even faster than that. */
2038 if (code == PLUS_EXPR)
2040 if (integer_zerop (arg0) && !TREE_OVERFLOW (arg0))
2042 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2045 else if (code == MINUS_EXPR)
2047 if (integer_zerop (arg1) && !TREE_OVERFLOW (arg1))
2050 else if (code == MULT_EXPR)
2052 if (integer_onep (arg0) && !TREE_OVERFLOW (arg0))
2056 /* Handle general case of two integer constants. */
2057 return int_const_binop (code, arg0, arg1, 0);
2060 return fold_build2 (code, type, arg0, arg1);
2063 /* Given two values, either both of sizetype or both of bitsizetype,
2064 compute the difference between the two values. Return the value
2065 in signed type corresponding to the type of the operands. */
2068 size_diffop (tree arg0, tree arg1)
2070 tree type = TREE_TYPE (arg0);
2073 gcc_assert (int_binop_types_match_p (MINUS_EXPR, TREE_TYPE (arg0),
2076 /* If the type is already signed, just do the simple thing. */
2077 if (!TYPE_UNSIGNED (type))
2078 return size_binop (MINUS_EXPR, arg0, arg1);
2080 if (type == sizetype)
2082 else if (type == bitsizetype)
2083 ctype = sbitsizetype;
2085 ctype = signed_type_for (type);
2087 /* If either operand is not a constant, do the conversions to the signed
2088 type and subtract. The hardware will do the right thing with any
2089 overflow in the subtraction. */
2090 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
2091 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
2092 fold_convert (ctype, arg1));
2094 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
2095 Otherwise, subtract the other way, convert to CTYPE (we know that can't
2096 overflow) and negate (which can't either). Special-case a result
2097 of zero while we're here. */
2098 if (tree_int_cst_equal (arg0, arg1))
2099 return build_int_cst (ctype, 0);
2100 else if (tree_int_cst_lt (arg1, arg0))
2101 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
2103 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
2104 fold_convert (ctype, size_binop (MINUS_EXPR,
2108 /* A subroutine of fold_convert_const handling conversions of an
2109 INTEGER_CST to another integer type. */
2112 fold_convert_const_int_from_int (tree type, const_tree arg1)
2116 /* Given an integer constant, make new constant with new type,
2117 appropriately sign-extended or truncated. */
2118 t = force_fit_type_double (type, TREE_INT_CST_LOW (arg1),
2119 TREE_INT_CST_HIGH (arg1),
2120 /* Don't set the overflow when
2121 converting from a pointer, */
2122 !POINTER_TYPE_P (TREE_TYPE (arg1))
2123 /* or to a sizetype with same signedness
2124 and the precision is unchanged.
2125 ??? sizetype is always sign-extended,
2126 but its signedness depends on the
2127 frontend. Thus we see spurious overflows
2128 here if we do not check this. */
2129 && !((TYPE_PRECISION (TREE_TYPE (arg1))
2130 == TYPE_PRECISION (type))
2131 && (TYPE_UNSIGNED (TREE_TYPE (arg1))
2132 == TYPE_UNSIGNED (type))
2133 && ((TREE_CODE (TREE_TYPE (arg1)) == INTEGER_TYPE
2134 && TYPE_IS_SIZETYPE (TREE_TYPE (arg1)))
2135 || (TREE_CODE (type) == INTEGER_TYPE
2136 && TYPE_IS_SIZETYPE (type)))),
2137 (TREE_INT_CST_HIGH (arg1) < 0
2138 && (TYPE_UNSIGNED (type)
2139 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2140 | TREE_OVERFLOW (arg1));
2145 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2146 to an integer type. */
2149 fold_convert_const_int_from_real (enum tree_code code, tree type, const_tree arg1)
2154 /* The following code implements the floating point to integer
2155 conversion rules required by the Java Language Specification,
2156 that IEEE NaNs are mapped to zero and values that overflow
2157 the target precision saturate, i.e. values greater than
2158 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
2159 are mapped to INT_MIN. These semantics are allowed by the
2160 C and C++ standards that simply state that the behavior of
2161 FP-to-integer conversion is unspecified upon overflow. */
2163 HOST_WIDE_INT high, low;
2165 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
2169 case FIX_TRUNC_EXPR:
2170 real_trunc (&r, VOIDmode, &x);
2177 /* If R is NaN, return zero and show we have an overflow. */
2178 if (REAL_VALUE_ISNAN (r))
2185 /* See if R is less than the lower bound or greater than the
2190 tree lt = TYPE_MIN_VALUE (type);
2191 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
2192 if (REAL_VALUES_LESS (r, l))
2195 high = TREE_INT_CST_HIGH (lt);
2196 low = TREE_INT_CST_LOW (lt);
2202 tree ut = TYPE_MAX_VALUE (type);
2205 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
2206 if (REAL_VALUES_LESS (u, r))
2209 high = TREE_INT_CST_HIGH (ut);
2210 low = TREE_INT_CST_LOW (ut);
2216 REAL_VALUE_TO_INT (&low, &high, r);
2218 t = force_fit_type_double (type, low, high, -1,
2219 overflow | TREE_OVERFLOW (arg1));
2223 /* A subroutine of fold_convert_const handling conversions of a
2224 FIXED_CST to an integer type. */
2227 fold_convert_const_int_from_fixed (tree type, const_tree arg1)
2230 double_int temp, temp_trunc;
2233 /* Right shift FIXED_CST to temp by fbit. */
2234 temp = TREE_FIXED_CST (arg1).data;
2235 mode = TREE_FIXED_CST (arg1).mode;
2236 if (GET_MODE_FBIT (mode) < 2 * HOST_BITS_PER_WIDE_INT)
2238 lshift_double (temp.low, temp.high,
2239 - GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2240 &temp.low, &temp.high, SIGNED_FIXED_POINT_MODE_P (mode));
2242 /* Left shift temp to temp_trunc by fbit. */
2243 lshift_double (temp.low, temp.high,
2244 GET_MODE_FBIT (mode), 2 * HOST_BITS_PER_WIDE_INT,
2245 &temp_trunc.low, &temp_trunc.high,
2246 SIGNED_FIXED_POINT_MODE_P (mode));
2253 temp_trunc.high = 0;
2256 /* If FIXED_CST is negative, we need to round the value toward 0.
2257 By checking if the fractional bits are not zero to add 1 to temp. */
2258 if (SIGNED_FIXED_POINT_MODE_P (mode) && temp_trunc.high < 0
2259 && !double_int_equal_p (TREE_FIXED_CST (arg1).data, temp_trunc))
2264 temp = double_int_add (temp, one);
2267 /* Given a fixed-point constant, make new constant with new type,
2268 appropriately sign-extended or truncated. */
2269 t = force_fit_type_double (type, temp.low, temp.high, -1,
2271 && (TYPE_UNSIGNED (type)
2272 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
2273 | TREE_OVERFLOW (arg1));
2278 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2279 to another floating point type. */
2282 fold_convert_const_real_from_real (tree type, const_tree arg1)
2284 REAL_VALUE_TYPE value;
2287 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
2288 t = build_real (type, value);
2290 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2294 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2295 to a floating point type. */
2298 fold_convert_const_real_from_fixed (tree type, const_tree arg1)
2300 REAL_VALUE_TYPE value;
2303 real_convert_from_fixed (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1));
2304 t = build_real (type, value);
2306 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
2307 TREE_CONSTANT_OVERFLOW (t)
2308 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
2312 /* A subroutine of fold_convert_const handling conversions a FIXED_CST
2313 to another fixed-point type. */
2316 fold_convert_const_fixed_from_fixed (tree type, const_tree arg1)
2318 FIXED_VALUE_TYPE value;
2322 overflow_p = fixed_convert (&value, TYPE_MODE (type), &TREE_FIXED_CST (arg1),
2323 TYPE_SATURATING (type));
2324 t = build_fixed (type, value);
2326 /* Propagate overflow flags. */
2327 if (overflow_p | TREE_OVERFLOW (arg1))
2329 TREE_OVERFLOW (t) = 1;
2330 TREE_CONSTANT_OVERFLOW (t) = 1;
2332 else if (TREE_CONSTANT_OVERFLOW (arg1))
2333 TREE_CONSTANT_OVERFLOW (t) = 1;
2337 /* A subroutine of fold_convert_const handling conversions an INTEGER_CST
2338 to a fixed-point type. */
2341 fold_convert_const_fixed_from_int (tree type, const_tree arg1)
2343 FIXED_VALUE_TYPE value;
2347 overflow_p = fixed_convert_from_int (&value, TYPE_MODE (type),
2348 TREE_INT_CST (arg1),
2349 TYPE_UNSIGNED (TREE_TYPE (arg1)),
2350 TYPE_SATURATING (type));
2351 t = build_fixed (type, value);
2353 /* Propagate overflow flags. */
2354 if (overflow_p | TREE_OVERFLOW (arg1))
2356 TREE_OVERFLOW (t) = 1;
2357 TREE_CONSTANT_OVERFLOW (t) = 1;
2359 else if (TREE_CONSTANT_OVERFLOW (arg1))
2360 TREE_CONSTANT_OVERFLOW (t) = 1;
2364 /* A subroutine of fold_convert_const handling conversions a REAL_CST
2365 to a fixed-point type. */
2368 fold_convert_const_fixed_from_real (tree type, const_tree arg1)
2370 FIXED_VALUE_TYPE value;
2374 overflow_p = fixed_convert_from_real (&value, TYPE_MODE (type),
2375 &TREE_REAL_CST (arg1),
2376 TYPE_SATURATING (type));
2377 t = build_fixed (type, value);
2379 /* Propagate overflow flags. */
2380 if (overflow_p | TREE_OVERFLOW (arg1))
2382 TREE_OVERFLOW (t) = 1;
2383 TREE_CONSTANT_OVERFLOW (t) = 1;
2385 else if (TREE_CONSTANT_OVERFLOW (arg1))
2386 TREE_CONSTANT_OVERFLOW (t) = 1;
2390 /* Attempt to fold type conversion operation CODE of expression ARG1 to
2391 type TYPE. If no simplification can be done return NULL_TREE. */
2394 fold_convert_const (enum tree_code code, tree type, tree arg1)
2396 if (TREE_TYPE (arg1) == type)
2399 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
2401 if (TREE_CODE (arg1) == INTEGER_CST)
2402 return fold_convert_const_int_from_int (type, arg1);
2403 else if (TREE_CODE (arg1) == REAL_CST)
2404 return fold_convert_const_int_from_real (code, type, arg1);
2405 else if (TREE_CODE (arg1) == FIXED_CST)
2406 return fold_convert_const_int_from_fixed (type, arg1);
2408 else if (TREE_CODE (type) == REAL_TYPE)
2410 if (TREE_CODE (arg1) == INTEGER_CST)
2411 return build_real_from_int_cst (type, arg1);
2412 else if (TREE_CODE (arg1) == REAL_CST)
2413 return fold_convert_const_real_from_real (type, arg1);
2414 else if (TREE_CODE (arg1) == FIXED_CST)
2415 return fold_convert_const_real_from_fixed (type, arg1);
2417 else if (TREE_CODE (type) == FIXED_POINT_TYPE)
2419 if (TREE_CODE (arg1) == FIXED_CST)
2420 return fold_convert_const_fixed_from_fixed (type, arg1);
2421 else if (TREE_CODE (arg1) == INTEGER_CST)
2422 return fold_convert_const_fixed_from_int (type, arg1);
2423 else if (TREE_CODE (arg1) == REAL_CST)
2424 return fold_convert_const_fixed_from_real (type, arg1);
2429 /* Construct a vector of zero elements of vector type TYPE. */
2432 build_zero_vector (tree type)
2437 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2438 units = TYPE_VECTOR_SUBPARTS (type);
2441 for (i = 0; i < units; i++)
2442 list = tree_cons (NULL_TREE, elem, list);
2443 return build_vector (type, list);
2446 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2449 fold_convertible_p (const_tree type, const_tree arg)
2451 tree orig = TREE_TYPE (arg);
2456 if (TREE_CODE (arg) == ERROR_MARK
2457 || TREE_CODE (type) == ERROR_MARK
2458 || TREE_CODE (orig) == ERROR_MARK)
2461 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2464 switch (TREE_CODE (type))
2466 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2467 case POINTER_TYPE: case REFERENCE_TYPE:
2469 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2470 || TREE_CODE (orig) == OFFSET_TYPE)
2472 return (TREE_CODE (orig) == VECTOR_TYPE
2473 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2476 case FIXED_POINT_TYPE:
2480 return TREE_CODE (type) == TREE_CODE (orig);
2487 /* Convert expression ARG to type TYPE. Used by the middle-end for
2488 simple conversions in preference to calling the front-end's convert. */
2491 fold_convert (tree type, tree arg)
2493 tree orig = TREE_TYPE (arg);
2499 if (TREE_CODE (arg) == ERROR_MARK
2500 || TREE_CODE (type) == ERROR_MARK
2501 || TREE_CODE (orig) == ERROR_MARK)
2502 return error_mark_node;
2504 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2505 return fold_build1 (NOP_EXPR, type, arg);
2507 switch (TREE_CODE (type))
2509 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2510 case POINTER_TYPE: case REFERENCE_TYPE:
2512 if (TREE_CODE (arg) == INTEGER_CST)
2514 tem = fold_convert_const (NOP_EXPR, type, arg);
2515 if (tem != NULL_TREE)
2518 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2519 || TREE_CODE (orig) == OFFSET_TYPE)
2520 return fold_build1 (NOP_EXPR, type, arg);
2521 if (TREE_CODE (orig) == COMPLEX_TYPE)
2523 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2524 return fold_convert (type, tem);
2526 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2527 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2528 return fold_build1 (NOP_EXPR, type, arg);
2531 if (TREE_CODE (arg) == INTEGER_CST)
2533 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2534 if (tem != NULL_TREE)
2537 else if (TREE_CODE (arg) == REAL_CST)
2539 tem = fold_convert_const (NOP_EXPR, type, arg);
2540 if (tem != NULL_TREE)
2543 else if (TREE_CODE (arg) == FIXED_CST)
2545 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2546 if (tem != NULL_TREE)
2550 switch (TREE_CODE (orig))
2553 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2554 case POINTER_TYPE: case REFERENCE_TYPE:
2555 return fold_build1 (FLOAT_EXPR, type, arg);
2558 return fold_build1 (NOP_EXPR, type, arg);
2560 case FIXED_POINT_TYPE:
2561 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2564 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2565 return fold_convert (type, tem);
2571 case FIXED_POINT_TYPE:
2572 if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
2573 || TREE_CODE (arg) == REAL_CST)
2575 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2576 if (tem != NULL_TREE)
2580 switch (TREE_CODE (orig))
2582 case FIXED_POINT_TYPE:
2587 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2590 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2591 return fold_convert (type, tem);
2598 switch (TREE_CODE (orig))
2601 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2602 case POINTER_TYPE: case REFERENCE_TYPE:
2604 case FIXED_POINT_TYPE:
2605 return build2 (COMPLEX_EXPR, type,
2606 fold_convert (TREE_TYPE (type), arg),
2607 fold_convert (TREE_TYPE (type), integer_zero_node));
2612 if (TREE_CODE (arg) == COMPLEX_EXPR)
2614 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2615 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2616 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2619 arg = save_expr (arg);
2620 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2621 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2622 rpart = fold_convert (TREE_TYPE (type), rpart);
2623 ipart = fold_convert (TREE_TYPE (type), ipart);
2624 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2632 if (integer_zerop (arg))
2633 return build_zero_vector (type);
2634 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2635 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2636 || TREE_CODE (orig) == VECTOR_TYPE);
2637 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2640 tem = fold_ignored_result (arg);
2641 if (TREE_CODE (tem) == GIMPLE_MODIFY_STMT)
2643 return fold_build1 (NOP_EXPR, type, tem);
2650 /* Return false if expr can be assumed not to be an lvalue, true
2654 maybe_lvalue_p (const_tree x)
2656 /* We only need to wrap lvalue tree codes. */
2657 switch (TREE_CODE (x))
2668 case ALIGN_INDIRECT_REF:
2669 case MISALIGNED_INDIRECT_REF:
2671 case ARRAY_RANGE_REF:
2677 case PREINCREMENT_EXPR:
2678 case PREDECREMENT_EXPR:
2680 case TRY_CATCH_EXPR:
2681 case WITH_CLEANUP_EXPR:
2684 case GIMPLE_MODIFY_STMT:
2693 /* Assume the worst for front-end tree codes. */
2694 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2702 /* Return an expr equal to X but certainly not valid as an lvalue. */
2707 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2712 if (! maybe_lvalue_p (x))
2714 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2717 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2718 Zero means allow extended lvalues. */
2720 int pedantic_lvalues;
2722 /* When pedantic, return an expr equal to X but certainly not valid as a
2723 pedantic lvalue. Otherwise, return X. */
2726 pedantic_non_lvalue (tree x)
2728 if (pedantic_lvalues)
2729 return non_lvalue (x);
2734 /* Given a tree comparison code, return the code that is the logical inverse
2735 of the given code. It is not safe to do this for floating-point
2736 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2737 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2740 invert_tree_comparison (enum tree_code code, bool honor_nans)
2742 if (honor_nans && flag_trapping_math)
2752 return honor_nans ? UNLE_EXPR : LE_EXPR;
2754 return honor_nans ? UNLT_EXPR : LT_EXPR;
2756 return honor_nans ? UNGE_EXPR : GE_EXPR;
2758 return honor_nans ? UNGT_EXPR : GT_EXPR;
2772 return UNORDERED_EXPR;
2773 case UNORDERED_EXPR:
2774 return ORDERED_EXPR;
2780 /* Similar, but return the comparison that results if the operands are
2781 swapped. This is safe for floating-point. */
2784 swap_tree_comparison (enum tree_code code)
2791 case UNORDERED_EXPR:
2817 /* Convert a comparison tree code from an enum tree_code representation
2818 into a compcode bit-based encoding. This function is the inverse of
2819 compcode_to_comparison. */
2821 static enum comparison_code
2822 comparison_to_compcode (enum tree_code code)
2839 return COMPCODE_ORD;
2840 case UNORDERED_EXPR:
2841 return COMPCODE_UNORD;
2843 return COMPCODE_UNLT;
2845 return COMPCODE_UNEQ;
2847 return COMPCODE_UNLE;
2849 return COMPCODE_UNGT;
2851 return COMPCODE_LTGT;
2853 return COMPCODE_UNGE;
2859 /* Convert a compcode bit-based encoding of a comparison operator back
2860 to GCC's enum tree_code representation. This function is the
2861 inverse of comparison_to_compcode. */
2863 static enum tree_code
2864 compcode_to_comparison (enum comparison_code code)
2881 return ORDERED_EXPR;
2882 case COMPCODE_UNORD:
2883 return UNORDERED_EXPR;
2901 /* Return a tree for the comparison which is the combination of
2902 doing the AND or OR (depending on CODE) of the two operations LCODE
2903 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2904 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2905 if this makes the transformation invalid. */
2908 combine_comparisons (enum tree_code code, enum tree_code lcode,
2909 enum tree_code rcode, tree truth_type,
2910 tree ll_arg, tree lr_arg)
2912 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2913 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2914 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2915 enum comparison_code compcode;
2919 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2920 compcode = lcompcode & rcompcode;
2923 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2924 compcode = lcompcode | rcompcode;
2933 /* Eliminate unordered comparisons, as well as LTGT and ORD
2934 which are not used unless the mode has NaNs. */
2935 compcode &= ~COMPCODE_UNORD;
2936 if (compcode == COMPCODE_LTGT)
2937 compcode = COMPCODE_NE;
2938 else if (compcode == COMPCODE_ORD)
2939 compcode = COMPCODE_TRUE;
2941 else if (flag_trapping_math)
2943 /* Check that the original operation and the optimized ones will trap
2944 under the same condition. */
2945 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2946 && (lcompcode != COMPCODE_EQ)
2947 && (lcompcode != COMPCODE_ORD);
2948 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2949 && (rcompcode != COMPCODE_EQ)
2950 && (rcompcode != COMPCODE_ORD);
2951 bool trap = (compcode & COMPCODE_UNORD) == 0
2952 && (compcode != COMPCODE_EQ)
2953 && (compcode != COMPCODE_ORD);
2955 /* In a short-circuited boolean expression the LHS might be
2956 such that the RHS, if evaluated, will never trap. For
2957 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2958 if neither x nor y is NaN. (This is a mixed blessing: for
2959 example, the expression above will never trap, hence
2960 optimizing it to x < y would be invalid). */
2961 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2962 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2965 /* If the comparison was short-circuited, and only the RHS
2966 trapped, we may now generate a spurious trap. */
2968 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2971 /* If we changed the conditions that cause a trap, we lose. */
2972 if ((ltrap || rtrap) != trap)
2976 if (compcode == COMPCODE_TRUE)
2977 return constant_boolean_node (true, truth_type);
2978 else if (compcode == COMPCODE_FALSE)
2979 return constant_boolean_node (false, truth_type);
2981 return fold_build2 (compcode_to_comparison (compcode),
2982 truth_type, ll_arg, lr_arg);
2985 /* Return nonzero if CODE is a tree code that represents a truth value. */
2988 truth_value_p (enum tree_code code)
2990 return (TREE_CODE_CLASS (code) == tcc_comparison
2991 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2992 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2993 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2996 /* Return nonzero if two operands (typically of the same tree node)
2997 are necessarily equal. If either argument has side-effects this
2998 function returns zero. FLAGS modifies behavior as follows:
3000 If OEP_ONLY_CONST is set, only return nonzero for constants.
3001 This function tests whether the operands are indistinguishable;
3002 it does not test whether they are equal using C's == operation.
3003 The distinction is important for IEEE floating point, because
3004 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
3005 (2) two NaNs may be indistinguishable, but NaN!=NaN.
3007 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
3008 even though it may hold multiple values during a function.
3009 This is because a GCC tree node guarantees that nothing else is
3010 executed between the evaluation of its "operands" (which may often
3011 be evaluated in arbitrary order). Hence if the operands themselves
3012 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
3013 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
3014 unset means assuming isochronic (or instantaneous) tree equivalence.
3015 Unless comparing arbitrary expression trees, such as from different
3016 statements, this flag can usually be left unset.
3018 If OEP_PURE_SAME is set, then pure functions with identical arguments
3019 are considered the same. It is used when the caller has other ways
3020 to ensure that global memory is unchanged in between. */
3023 operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
3025 /* If either is ERROR_MARK, they aren't equal. */
3026 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
3029 /* Check equality of integer constants before bailing out due to
3030 precision differences. */
3031 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
3032 return tree_int_cst_equal (arg0, arg1);
3034 /* If both types don't have the same signedness, then we can't consider
3035 them equal. We must check this before the STRIP_NOPS calls
3036 because they may change the signedness of the arguments. */
3037 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3040 /* If both types don't have the same precision, then it is not safe
3042 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
3048 /* In case both args are comparisons but with different comparison
3049 code, try to swap the comparison operands of one arg to produce
3050 a match and compare that variant. */
3051 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3052 && COMPARISON_CLASS_P (arg0)
3053 && COMPARISON_CLASS_P (arg1))
3055 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
3057 if (TREE_CODE (arg0) == swap_code)
3058 return operand_equal_p (TREE_OPERAND (arg0, 0),
3059 TREE_OPERAND (arg1, 1), flags)
3060 && operand_equal_p (TREE_OPERAND (arg0, 1),
3061 TREE_OPERAND (arg1, 0), flags);
3064 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3065 /* This is needed for conversions and for COMPONENT_REF.
3066 Might as well play it safe and always test this. */
3067 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
3068 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
3069 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
3072 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3073 We don't care about side effects in that case because the SAVE_EXPR
3074 takes care of that for us. In all other cases, two expressions are
3075 equal if they have no side effects. If we have two identical
3076 expressions with side effects that should be treated the same due
3077 to the only side effects being identical SAVE_EXPR's, that will
3078 be detected in the recursive calls below. */
3079 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
3080 && (TREE_CODE (arg0) == SAVE_EXPR
3081 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
3084 /* Next handle constant cases, those for which we can return 1 even
3085 if ONLY_CONST is set. */
3086 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
3087 switch (TREE_CODE (arg0))
3090 return tree_int_cst_equal (arg0, arg1);
3093 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
3094 TREE_FIXED_CST (arg1));
3097 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
3098 TREE_REAL_CST (arg1)))
3102 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
3104 /* If we do not distinguish between signed and unsigned zero,
3105 consider them equal. */
3106 if (real_zerop (arg0) && real_zerop (arg1))
3115 v1 = TREE_VECTOR_CST_ELTS (arg0);
3116 v2 = TREE_VECTOR_CST_ELTS (arg1);
3119 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
3122 v1 = TREE_CHAIN (v1);
3123 v2 = TREE_CHAIN (v2);
3130 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
3132 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
3136 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
3137 && ! memcmp (TREE_STRING_POINTER (arg0),
3138 TREE_STRING_POINTER (arg1),
3139 TREE_STRING_LENGTH (arg0)));
3142 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
3148 if (flags & OEP_ONLY_CONST)
3151 /* Define macros to test an operand from arg0 and arg1 for equality and a
3152 variant that allows null and views null as being different from any
3153 non-null value. In the latter case, if either is null, the both
3154 must be; otherwise, do the normal comparison. */
3155 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3156 TREE_OPERAND (arg1, N), flags)
3158 #define OP_SAME_WITH_NULL(N) \
3159 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3160 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3162 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
3165 /* Two conversions are equal only if signedness and modes match. */
3166 switch (TREE_CODE (arg0))
3170 case FIX_TRUNC_EXPR:
3171 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
3172 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3182 case tcc_comparison:
3184 if (OP_SAME (0) && OP_SAME (1))
3187 /* For commutative ops, allow the other order. */
3188 return (commutative_tree_code (TREE_CODE (arg0))
3189 && operand_equal_p (TREE_OPERAND (arg0, 0),
3190 TREE_OPERAND (arg1, 1), flags)
3191 && operand_equal_p (TREE_OPERAND (arg0, 1),
3192 TREE_OPERAND (arg1, 0), flags));
3195 /* If either of the pointer (or reference) expressions we are
3196 dereferencing contain a side effect, these cannot be equal. */
3197 if (TREE_SIDE_EFFECTS (arg0)
3198 || TREE_SIDE_EFFECTS (arg1))
3201 switch (TREE_CODE (arg0))
3204 case ALIGN_INDIRECT_REF:
3205 case MISALIGNED_INDIRECT_REF:
3211 case ARRAY_RANGE_REF:
3212 /* Operands 2 and 3 may be null.
3213 Compare the array index by value if it is constant first as we
3214 may have different types but same value here. */
3216 && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
3217 TREE_OPERAND (arg1, 1))
3219 && OP_SAME_WITH_NULL (2)
3220 && OP_SAME_WITH_NULL (3));
3223 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3224 may be NULL when we're called to compare MEM_EXPRs. */
3225 return OP_SAME_WITH_NULL (0)
3227 && OP_SAME_WITH_NULL (2);
3230 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3236 case tcc_expression:
3237 switch (TREE_CODE (arg0))
3240 case TRUTH_NOT_EXPR:
3243 case TRUTH_ANDIF_EXPR:
3244 case TRUTH_ORIF_EXPR:
3245 return OP_SAME (0) && OP_SAME (1);
3247 case TRUTH_AND_EXPR:
3249 case TRUTH_XOR_EXPR:
3250 if (OP_SAME (0) && OP_SAME (1))
3253 /* Otherwise take into account this is a commutative operation. */
3254 return (operand_equal_p (TREE_OPERAND (arg0, 0),
3255 TREE_OPERAND (arg1, 1), flags)
3256 && operand_equal_p (TREE_OPERAND (arg0, 1),
3257 TREE_OPERAND (arg1, 0), flags));
3264 switch (TREE_CODE (arg0))
3267 /* If the CALL_EXPRs call different functions, then they
3268 clearly can not be equal. */
3269 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
3274 unsigned int cef = call_expr_flags (arg0);
3275 if (flags & OEP_PURE_SAME)
3276 cef &= ECF_CONST | ECF_PURE;
3283 /* Now see if all the arguments are the same. */
3285 const_call_expr_arg_iterator iter0, iter1;
3287 for (a0 = first_const_call_expr_arg (arg0, &iter0),
3288 a1 = first_const_call_expr_arg (arg1, &iter1);
3290 a0 = next_const_call_expr_arg (&iter0),
3291 a1 = next_const_call_expr_arg (&iter1))
3292 if (! operand_equal_p (a0, a1, flags))
3295 /* If we get here and both argument lists are exhausted
3296 then the CALL_EXPRs are equal. */
3297 return ! (a0 || a1);
3303 case tcc_declaration:
3304 /* Consider __builtin_sqrt equal to sqrt. */
3305 return (TREE_CODE (arg0) == FUNCTION_DECL
3306 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
3307 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
3308 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
3315 #undef OP_SAME_WITH_NULL
3318 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3319 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3321 When in doubt, return 0. */
3324 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
3326 int unsignedp1, unsignedpo;
3327 tree primarg0, primarg1, primother;
3328 unsigned int correct_width;
3330 if (operand_equal_p (arg0, arg1, 0))
3333 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3334 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3337 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3338 and see if the inner values are the same. This removes any
3339 signedness comparison, which doesn't matter here. */
3340 primarg0 = arg0, primarg1 = arg1;
3341 STRIP_NOPS (primarg0);
3342 STRIP_NOPS (primarg1);
3343 if (operand_equal_p (primarg0, primarg1, 0))
3346 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3347 actual comparison operand, ARG0.
3349 First throw away any conversions to wider types
3350 already present in the operands. */
3352 primarg1 = get_narrower (arg1, &unsignedp1);
3353 primother = get_narrower (other, &unsignedpo);
3355 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3356 if (unsignedp1 == unsignedpo
3357 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3358 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3360 tree type = TREE_TYPE (arg0);
3362 /* Make sure shorter operand is extended the right way
3363 to match the longer operand. */
3364 primarg1 = fold_convert (signed_or_unsigned_type_for
3365 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3367 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3374 /* See if ARG is an expression that is either a comparison or is performing
3375 arithmetic on comparisons. The comparisons must only be comparing
3376 two different values, which will be stored in *CVAL1 and *CVAL2; if
3377 they are nonzero it means that some operands have already been found.
3378 No variables may be used anywhere else in the expression except in the
3379 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3380 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3382 If this is true, return 1. Otherwise, return zero. */
3385 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3387 enum tree_code code = TREE_CODE (arg);
3388 enum tree_code_class class = TREE_CODE_CLASS (code);
3390 /* We can handle some of the tcc_expression cases here. */
3391 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3393 else if (class == tcc_expression
3394 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3395 || code == COMPOUND_EXPR))
3398 else if (class == tcc_expression && code == SAVE_EXPR
3399 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3401 /* If we've already found a CVAL1 or CVAL2, this expression is
3402 two complex to handle. */
3403 if (*cval1 || *cval2)
3413 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3416 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3417 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3418 cval1, cval2, save_p));
3423 case tcc_expression:
3424 if (code == COND_EXPR)
3425 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3426 cval1, cval2, save_p)
3427 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3428 cval1, cval2, save_p)
3429 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3430 cval1, cval2, save_p));
3433 case tcc_comparison:
3434 /* First see if we can handle the first operand, then the second. For
3435 the second operand, we know *CVAL1 can't be zero. It must be that
3436 one side of the comparison is each of the values; test for the
3437 case where this isn't true by failing if the two operands
3440 if (operand_equal_p (TREE_OPERAND (arg, 0),
3441 TREE_OPERAND (arg, 1), 0))
3445 *cval1 = TREE_OPERAND (arg, 0);
3446 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3448 else if (*cval2 == 0)
3449 *cval2 = TREE_OPERAND (arg, 0);
3450 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3455 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3457 else if (*cval2 == 0)
3458 *cval2 = TREE_OPERAND (arg, 1);
3459 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3471 /* ARG is a tree that is known to contain just arithmetic operations and
3472 comparisons. Evaluate the operations in the tree substituting NEW0 for
3473 any occurrence of OLD0 as an operand of a comparison and likewise for
3477 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3479 tree type = TREE_TYPE (arg);
3480 enum tree_code code = TREE_CODE (arg);
3481 enum tree_code_class class = TREE_CODE_CLASS (code);
3483 /* We can handle some of the tcc_expression cases here. */
3484 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
3486 else if (class == tcc_expression
3487 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3493 return fold_build1 (code, type,
3494 eval_subst (TREE_OPERAND (arg, 0),
3495 old0, new0, old1, new1));
3498 return fold_build2 (code, type,
3499 eval_subst (TREE_OPERAND (arg, 0),
3500 old0, new0, old1, new1),
3501 eval_subst (TREE_OPERAND (arg, 1),
3502 old0, new0, old1, new1));
3504 case tcc_expression:
3508 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3511 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3514 return fold_build3 (code, type,
3515 eval_subst (TREE_OPERAND (arg, 0),
3516 old0, new0, old1, new1),
3517 eval_subst (TREE_OPERAND (arg, 1),
3518 old0, new0, old1, new1),
3519 eval_subst (TREE_OPERAND (arg, 2),
3520 old0, new0, old1, new1));
3524 /* Fall through - ??? */
3526 case tcc_comparison:
3528 tree arg0 = TREE_OPERAND (arg, 0);
3529 tree arg1 = TREE_OPERAND (arg, 1);
3531 /* We need to check both for exact equality and tree equality. The
3532 former will be true if the operand has a side-effect. In that
3533 case, we know the operand occurred exactly once. */
3535 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3537 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3540 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3542 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3545 return fold_build2 (code, type, arg0, arg1);
3553 /* Return a tree for the case when the result of an expression is RESULT
3554 converted to TYPE and OMITTED was previously an operand of the expression
3555 but is now not needed (e.g., we folded OMITTED * 0).
3557 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3558 the conversion of RESULT to TYPE. */
3561 omit_one_operand (tree type, tree result, tree omitted)
3563 tree t = fold_convert (type, result);
3565 /* If the resulting operand is an empty statement, just return the omitted
3566 statement casted to void. */
3567 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3568 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3570 if (TREE_SIDE_EFFECTS (omitted))
3571 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3573 return non_lvalue (t);
3576 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3579 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3581 tree t = fold_convert (type, result);
3583 /* If the resulting operand is an empty statement, just return the omitted
3584 statement casted to void. */
3585 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3586 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3588 if (TREE_SIDE_EFFECTS (omitted))
3589 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3591 return pedantic_non_lvalue (t);
3594 /* Return a tree for the case when the result of an expression is RESULT
3595 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3596 of the expression but are now not needed.
3598 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3599 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3600 evaluated before OMITTED2. Otherwise, if neither has side effects,
3601 just do the conversion of RESULT to TYPE. */
3604 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3606 tree t = fold_convert (type, result);
3608 if (TREE_SIDE_EFFECTS (omitted2))
3609 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3610 if (TREE_SIDE_EFFECTS (omitted1))
3611 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3613 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3617 /* Return a simplified tree node for the truth-negation of ARG. This
3618 never alters ARG itself. We assume that ARG is an operation that
3619 returns a truth value (0 or 1).
3621 FIXME: one would think we would fold the result, but it causes
3622 problems with the dominator optimizer. */
3625 fold_truth_not_expr (tree arg)
3627 tree type = TREE_TYPE (arg);
3628 enum tree_code code = TREE_CODE (arg);
3630 /* If this is a comparison, we can simply invert it, except for
3631 floating-point non-equality comparisons, in which case we just
3632 enclose a TRUTH_NOT_EXPR around what we have. */
3634 if (TREE_CODE_CLASS (code) == tcc_comparison)
3636 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3637 if (FLOAT_TYPE_P (op_type)
3638 && flag_trapping_math
3639 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3640 && code != NE_EXPR && code != EQ_EXPR)
3644 code = invert_tree_comparison (code,
3645 HONOR_NANS (TYPE_MODE (op_type)));
3646 if (code == ERROR_MARK)
3649 return build2 (code, type,
3650 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3657 return constant_boolean_node (integer_zerop (arg), type);
3659 case TRUTH_AND_EXPR:
3660 return build2 (TRUTH_OR_EXPR, type,
3661 invert_truthvalue (TREE_OPERAND (arg, 0)),
3662 invert_truthvalue (TREE_OPERAND (arg, 1)));
3665 return build2 (TRUTH_AND_EXPR, type,
3666 invert_truthvalue (TREE_OPERAND (arg, 0)),
3667 invert_truthvalue (TREE_OPERAND (arg, 1)));
3669 case TRUTH_XOR_EXPR:
3670 /* Here we can invert either operand. We invert the first operand
3671 unless the second operand is a TRUTH_NOT_EXPR in which case our
3672 result is the XOR of the first operand with the inside of the
3673 negation of the second operand. */
3675 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3676 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3677 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3679 return build2 (TRUTH_XOR_EXPR, type,
3680 invert_truthvalue (TREE_OPERAND (arg, 0)),
3681 TREE_OPERAND (arg, 1));
3683 case TRUTH_ANDIF_EXPR:
3684 return build2 (TRUTH_ORIF_EXPR, type,
3685 invert_truthvalue (TREE_OPERAND (arg, 0)),
3686 invert_truthvalue (TREE_OPERAND (arg, 1)));
3688 case TRUTH_ORIF_EXPR:
3689 return build2 (TRUTH_ANDIF_EXPR, type,
3690 invert_truthvalue (TREE_OPERAND (arg, 0)),
3691 invert_truthvalue (TREE_OPERAND (arg, 1)));
3693 case TRUTH_NOT_EXPR:
3694 return TREE_OPERAND (arg, 0);
3698 tree arg1 = TREE_OPERAND (arg, 1);
3699 tree arg2 = TREE_OPERAND (arg, 2);
3700 /* A COND_EXPR may have a throw as one operand, which
3701 then has void type. Just leave void operands
3703 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3704 VOID_TYPE_P (TREE_TYPE (arg1))
3705 ? arg1 : invert_truthvalue (arg1),
3706 VOID_TYPE_P (TREE_TYPE (arg2))
3707 ? arg2 : invert_truthvalue (arg2));
3711 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3712 invert_truthvalue (TREE_OPERAND (arg, 1)));
3714 case NON_LVALUE_EXPR:
3715 return invert_truthvalue (TREE_OPERAND (arg, 0));
3718 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3719 return build1 (TRUTH_NOT_EXPR, type, arg);
3723 return build1 (TREE_CODE (arg), type,
3724 invert_truthvalue (TREE_OPERAND (arg, 0)));
3727 if (!integer_onep (TREE_OPERAND (arg, 1)))
3729 return build2 (EQ_EXPR, type, arg,
3730 build_int_cst (type, 0));
3733 return build1 (TRUTH_NOT_EXPR, type, arg);
3735 case CLEANUP_POINT_EXPR:
3736 return build1 (CLEANUP_POINT_EXPR, type,
3737 invert_truthvalue (TREE_OPERAND (arg, 0)));
3746 /* Return a simplified tree node for the truth-negation of ARG. This
3747 never alters ARG itself. We assume that ARG is an operation that
3748 returns a truth value (0 or 1).
3750 FIXME: one would think we would fold the result, but it causes
3751 problems with the dominator optimizer. */
3754 invert_truthvalue (tree arg)
3758 if (TREE_CODE (arg) == ERROR_MARK)
3761 tem = fold_truth_not_expr (arg);
3763 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3768 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3769 operands are another bit-wise operation with a common input. If so,
3770 distribute the bit operations to save an operation and possibly two if
3771 constants are involved. For example, convert
3772 (A | B) & (A | C) into A | (B & C)
3773 Further simplification will occur if B and C are constants.
3775 If this optimization cannot be done, 0 will be returned. */
3778 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3783 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3784 || TREE_CODE (arg0) == code
3785 || (TREE_CODE (arg0) != BIT_AND_EXPR
3786 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3789 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3791 common = TREE_OPERAND (arg0, 0);
3792 left = TREE_OPERAND (arg0, 1);
3793 right = TREE_OPERAND (arg1, 1);
3795 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3797 common = TREE_OPERAND (arg0, 0);
3798 left = TREE_OPERAND (arg0, 1);
3799 right = TREE_OPERAND (arg1, 0);
3801 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3803 common = TREE_OPERAND (arg0, 1);
3804 left = TREE_OPERAND (arg0, 0);
3805 right = TREE_OPERAND (arg1, 1);
3807 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3809 common = TREE_OPERAND (arg0, 1);
3810 left = TREE_OPERAND (arg0, 0);
3811 right = TREE_OPERAND (arg1, 0);
3816 return fold_build2 (TREE_CODE (arg0), type, common,
3817 fold_build2 (code, type, left, right));
3820 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3821 with code CODE. This optimization is unsafe. */
3823 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3825 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3826 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3828 /* (A / C) +- (B / C) -> (A +- B) / C. */
3830 && operand_equal_p (TREE_OPERAND (arg0, 1),
3831 TREE_OPERAND (arg1, 1), 0))
3832 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3833 fold_build2 (code, type,
3834 TREE_OPERAND (arg0, 0),
3835 TREE_OPERAND (arg1, 0)),
3836 TREE_OPERAND (arg0, 1));
3838 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3839 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3840 TREE_OPERAND (arg1, 0), 0)
3841 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3842 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3844 REAL_VALUE_TYPE r0, r1;
3845 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3846 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3848 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3850 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3851 real_arithmetic (&r0, code, &r0, &r1);
3852 return fold_build2 (MULT_EXPR, type,
3853 TREE_OPERAND (arg0, 0),
3854 build_real (type, r0));
3860 /* Subroutine for fold_truthop: decode a field reference.
3862 If EXP is a comparison reference, we return the innermost reference.
3864 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3865 set to the starting bit number.
3867 If the innermost field can be completely contained in a mode-sized
3868 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3870 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3871 otherwise it is not changed.
3873 *PUNSIGNEDP is set to the signedness of the field.
3875 *PMASK is set to the mask used. This is either contained in a
3876 BIT_AND_EXPR or derived from the width of the field.
3878 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3880 Return 0 if this is not a component reference or is one that we can't
3881 do anything with. */
3884 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3885 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3886 int *punsignedp, int *pvolatilep,
3887 tree *pmask, tree *pand_mask)
3889 tree outer_type = 0;
3891 tree mask, inner, offset;
3893 unsigned int precision;
3895 /* All the optimizations using this function assume integer fields.
3896 There are problems with FP fields since the type_for_size call
3897 below can fail for, e.g., XFmode. */
3898 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3901 /* We are interested in the bare arrangement of bits, so strip everything
3902 that doesn't affect the machine mode. However, record the type of the
3903 outermost expression if it may matter below. */
3904 if (TREE_CODE (exp) == NOP_EXPR
3905 || TREE_CODE (exp) == CONVERT_EXPR
3906 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3907 outer_type = TREE_TYPE (exp);
3910 if (TREE_CODE (exp) == BIT_AND_EXPR)
3912 and_mask = TREE_OPERAND (exp, 1);
3913 exp = TREE_OPERAND (exp, 0);
3914 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3915 if (TREE_CODE (and_mask) != INTEGER_CST)
3919 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3920 punsignedp, pvolatilep, false);
3921 if ((inner == exp && and_mask == 0)
3922 || *pbitsize < 0 || offset != 0
3923 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3926 /* If the number of bits in the reference is the same as the bitsize of
3927 the outer type, then the outer type gives the signedness. Otherwise
3928 (in case of a small bitfield) the signedness is unchanged. */
3929 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3930 *punsignedp = TYPE_UNSIGNED (outer_type);
3932 /* Compute the mask to access the bitfield. */
3933 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3934 precision = TYPE_PRECISION (unsigned_type);
3936 mask = build_int_cst_type (unsigned_type, -1);
3938 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3939 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3941 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3943 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
3944 fold_convert (unsigned_type, and_mask), mask);
3947 *pand_mask = and_mask;
3951 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3952 represents the sign bit of EXP's type. If EXP represents a sign
3953 or zero extension, also test VAL against the unextended type.
3954 The return value is the (sub)expression whose sign bit is VAL,
3955 or NULL_TREE otherwise. */
3958 sign_bit_p (tree exp, const_tree val)
3960 unsigned HOST_WIDE_INT mask_lo, lo;
3961 HOST_WIDE_INT mask_hi, hi;
3965 /* Tree EXP must have an integral type. */
3966 t = TREE_TYPE (exp);
3967 if (! INTEGRAL_TYPE_P (t))
3970 /* Tree VAL must be an integer constant. */
3971 if (TREE_CODE (val) != INTEGER_CST
3972 || TREE_OVERFLOW (val))
3975 width = TYPE_PRECISION (t);
3976 if (width > HOST_BITS_PER_WIDE_INT)
3978 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3981 mask_hi = ((unsigned HOST_WIDE_INT) -1
3982 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3988 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3991 mask_lo = ((unsigned HOST_WIDE_INT) -1
3992 >> (HOST_BITS_PER_WIDE_INT - width));
3995 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3996 treat VAL as if it were unsigned. */
3997 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3998 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
4001 /* Handle extension from a narrower type. */
4002 if (TREE_CODE (exp) == NOP_EXPR
4003 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
4004 return sign_bit_p (TREE_OPERAND (exp, 0), val);
4009 /* Subroutine for fold_truthop: determine if an operand is simple enough
4010 to be evaluated unconditionally. */
4013 simple_operand_p (const_tree exp)
4015 /* Strip any conversions that don't change the machine mode. */
4018 return (CONSTANT_CLASS_P (exp)
4019 || TREE_CODE (exp) == SSA_NAME
4021 && ! TREE_ADDRESSABLE (exp)
4022 && ! TREE_THIS_VOLATILE (exp)
4023 && ! DECL_NONLOCAL (exp)
4024 /* Don't regard global variables as simple. They may be
4025 allocated in ways unknown to the compiler (shared memory,
4026 #pragma weak, etc). */
4027 && ! TREE_PUBLIC (exp)
4028 && ! DECL_EXTERNAL (exp)
4029 /* Loading a static variable is unduly expensive, but global
4030 registers aren't expensive. */
4031 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
4034 /* The following functions are subroutines to fold_range_test and allow it to
4035 try to change a logical combination of comparisons into a range test.
4038 X == 2 || X == 3 || X == 4 || X == 5
4042 (unsigned) (X - 2) <= 3
4044 We describe each set of comparisons as being either inside or outside
4045 a range, using a variable named like IN_P, and then describe the
4046 range with a lower and upper bound. If one of the bounds is omitted,
4047 it represents either the highest or lowest value of the type.
4049 In the comments below, we represent a range by two numbers in brackets
4050 preceded by a "+" to designate being inside that range, or a "-" to
4051 designate being outside that range, so the condition can be inverted by
4052 flipping the prefix. An omitted bound is represented by a "-". For
4053 example, "- [-, 10]" means being outside the range starting at the lowest
4054 possible value and ending at 10, in other words, being greater than 10.
4055 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4058 We set up things so that the missing bounds are handled in a consistent
4059 manner so neither a missing bound nor "true" and "false" need to be
4060 handled using a special case. */
4062 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4063 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4064 and UPPER1_P are nonzero if the respective argument is an upper bound
4065 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4066 must be specified for a comparison. ARG1 will be converted to ARG0's
4067 type if both are specified. */
4070 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
4071 tree arg1, int upper1_p)
4077 /* If neither arg represents infinity, do the normal operation.
4078 Else, if not a comparison, return infinity. Else handle the special
4079 comparison rules. Note that most of the cases below won't occur, but
4080 are handled for consistency. */
4082 if (arg0 != 0 && arg1 != 0)
4084 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
4085 arg0, fold_convert (TREE_TYPE (arg0), arg1));
4087 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
4090 if (TREE_CODE_CLASS (code) != tcc_comparison)
4093 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4094 for neither. In real maths, we cannot assume open ended ranges are
4095 the same. But, this is computer arithmetic, where numbers are finite.
4096 We can therefore make the transformation of any unbounded range with
4097 the value Z, Z being greater than any representable number. This permits
4098 us to treat unbounded ranges as equal. */
4099 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
4100 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
4104 result = sgn0 == sgn1;
4107 result = sgn0 != sgn1;
4110 result = sgn0 < sgn1;
4113 result = sgn0 <= sgn1;
4116 result = sgn0 > sgn1;
4119 result = sgn0 >= sgn1;
4125 return constant_boolean_node (result, type);
4128 /* Given EXP, a logical expression, set the range it is testing into
4129 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4130 actually being tested. *PLOW and *PHIGH will be made of the same
4131 type as the returned expression. If EXP is not a comparison, we
4132 will most likely not be returning a useful value and range. Set
4133 *STRICT_OVERFLOW_P to true if the return value is only valid
4134 because signed overflow is undefined; otherwise, do not change
4135 *STRICT_OVERFLOW_P. */
4138 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4139 bool *strict_overflow_p)
4141 enum tree_code code;
4142 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4143 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4145 tree low, high, n_low, n_high;
4147 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4148 and see if we can refine the range. Some of the cases below may not
4149 happen, but it doesn't seem worth worrying about this. We "continue"
4150 the outer loop when we've changed something; otherwise we "break"
4151 the switch, which will "break" the while. */
4154 low = high = build_int_cst (TREE_TYPE (exp), 0);
4158 code = TREE_CODE (exp);
4159 exp_type = TREE_TYPE (exp);
4161 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4163 if (TREE_OPERAND_LENGTH (exp) > 0)
4164 arg0 = TREE_OPERAND (exp, 0);
4165 if (TREE_CODE_CLASS (code) == tcc_comparison
4166 || TREE_CODE_CLASS (code) == tcc_unary
4167 || TREE_CODE_CLASS (code) == tcc_binary)
4168 arg0_type = TREE_TYPE (arg0);
4169 if (TREE_CODE_CLASS (code) == tcc_binary
4170 || TREE_CODE_CLASS (code) == tcc_comparison
4171 || (TREE_CODE_CLASS (code) == tcc_expression
4172 && TREE_OPERAND_LENGTH (exp) > 1))
4173 arg1 = TREE_OPERAND (exp, 1);
4178 case TRUTH_NOT_EXPR:
4179 in_p = ! in_p, exp = arg0;
4182 case EQ_EXPR: case NE_EXPR:
4183 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4184 /* We can only do something if the range is testing for zero
4185 and if the second operand is an integer constant. Note that
4186 saying something is "in" the range we make is done by
4187 complementing IN_P since it will set in the initial case of
4188 being not equal to zero; "out" is leaving it alone. */
4189 if (low == 0 || high == 0
4190 || ! integer_zerop (low) || ! integer_zerop (high)
4191 || TREE_CODE (arg1) != INTEGER_CST)
4196 case NE_EXPR: /* - [c, c] */
4199 case EQ_EXPR: /* + [c, c] */
4200 in_p = ! in_p, low = high = arg1;
4202 case GT_EXPR: /* - [-, c] */
4203 low = 0, high = arg1;
4205 case GE_EXPR: /* + [c, -] */
4206 in_p = ! in_p, low = arg1, high = 0;
4208 case LT_EXPR: /* - [c, -] */
4209 low = arg1, high = 0;
4211 case LE_EXPR: /* + [-, c] */
4212 in_p = ! in_p, low = 0, high = arg1;
4218 /* If this is an unsigned comparison, we also know that EXP is
4219 greater than or equal to zero. We base the range tests we make
4220 on that fact, so we record it here so we can parse existing
4221 range tests. We test arg0_type since often the return type
4222 of, e.g. EQ_EXPR, is boolean. */
4223 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4225 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4227 build_int_cst (arg0_type, 0),
4231 in_p = n_in_p, low = n_low, high = n_high;
4233 /* If the high bound is missing, but we have a nonzero low
4234 bound, reverse the range so it goes from zero to the low bound
4236 if (high == 0 && low && ! integer_zerop (low))
4239 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4240 integer_one_node, 0);
4241 low = build_int_cst (arg0_type, 0);
4249 /* (-x) IN [a,b] -> x in [-b, -a] */
4250 n_low = range_binop (MINUS_EXPR, exp_type,
4251 build_int_cst (exp_type, 0),
4253 n_high = range_binop (MINUS_EXPR, exp_type,
4254 build_int_cst (exp_type, 0),
4256 low = n_low, high = n_high;
4262 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4263 build_int_cst (exp_type, 1));
4266 case PLUS_EXPR: case MINUS_EXPR:
4267 if (TREE_CODE (arg1) != INTEGER_CST)
4270 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4271 move a constant to the other side. */
4272 if (!TYPE_UNSIGNED (arg0_type)
4273 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4276 /* If EXP is signed, any overflow in the computation is undefined,
4277 so we don't worry about it so long as our computations on
4278 the bounds don't overflow. For unsigned, overflow is defined
4279 and this is exactly the right thing. */
4280 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4281 arg0_type, low, 0, arg1, 0);
4282 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4283 arg0_type, high, 1, arg1, 0);
4284 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4285 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4288 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4289 *strict_overflow_p = true;
4291 /* Check for an unsigned range which has wrapped around the maximum
4292 value thus making n_high < n_low, and normalize it. */
4293 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4295 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4296 integer_one_node, 0);
4297 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4298 integer_one_node, 0);
4300 /* If the range is of the form +/- [ x+1, x ], we won't
4301 be able to normalize it. But then, it represents the
4302 whole range or the empty set, so make it
4304 if (tree_int_cst_equal (n_low, low)
4305 && tree_int_cst_equal (n_high, high))
4311 low = n_low, high = n_high;
4316 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
4317 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4320 if (! INTEGRAL_TYPE_P (arg0_type)
4321 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4322 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4325 n_low = low, n_high = high;
4328 n_low = fold_convert (arg0_type, n_low);
4331 n_high = fold_convert (arg0_type, n_high);
4334 /* If we're converting arg0 from an unsigned type, to exp,
4335 a signed type, we will be doing the comparison as unsigned.
4336 The tests above have already verified that LOW and HIGH
4339 So we have to ensure that we will handle large unsigned
4340 values the same way that the current signed bounds treat
4343 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4347 /* For fixed-point modes, we need to pass the saturating flag
4348 as the 2nd parameter. */
4349 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
4350 equiv_type = lang_hooks.types.type_for_mode
4351 (TYPE_MODE (arg0_type),
4352 TYPE_SATURATING (arg0_type));
4354 equiv_type = lang_hooks.types.type_for_mode
4355 (TYPE_MODE (arg0_type), 1);
4357 /* A range without an upper bound is, naturally, unbounded.
4358 Since convert would have cropped a very large value, use
4359 the max value for the destination type. */
4361 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4362 : TYPE_MAX_VALUE (arg0_type);
4364 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4365 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4366 fold_convert (arg0_type,
4368 build_int_cst (arg0_type, 1));
4370 /* If the low bound is specified, "and" the range with the
4371 range for which the original unsigned value will be
4375 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4376 1, n_low, n_high, 1,
4377 fold_convert (arg0_type,
4382 in_p = (n_in_p == in_p);
4386 /* Otherwise, "or" the range with the range of the input
4387 that will be interpreted as negative. */
4388 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4389 0, n_low, n_high, 1,
4390 fold_convert (arg0_type,
4395 in_p = (in_p != n_in_p);
4400 low = n_low, high = n_high;
4410 /* If EXP is a constant, we can evaluate whether this is true or false. */
4411 if (TREE_CODE (exp) == INTEGER_CST)
4413 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4415 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4421 *pin_p = in_p, *plow = low, *phigh = high;
4425 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4426 type, TYPE, return an expression to test if EXP is in (or out of, depending
4427 on IN_P) the range. Return 0 if the test couldn't be created. */
4430 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4432 tree etype = TREE_TYPE (exp);
4435 #ifdef HAVE_canonicalize_funcptr_for_compare
4436 /* Disable this optimization for function pointer expressions
4437 on targets that require function pointer canonicalization. */
4438 if (HAVE_canonicalize_funcptr_for_compare
4439 && TREE_CODE (etype) == POINTER_TYPE
4440 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4446 value = build_range_check (type, exp, 1, low, high);
4448 return invert_truthvalue (value);
4453 if (low == 0 && high == 0)
4454 return build_int_cst (type, 1);
4457 return fold_build2 (LE_EXPR, type, exp,
4458 fold_convert (etype, high));
4461 return fold_build2 (GE_EXPR, type, exp,
4462 fold_convert (etype, low));
4464 if (operand_equal_p (low, high, 0))
4465 return fold_build2 (EQ_EXPR, type, exp,
4466 fold_convert (etype, low));
4468 if (integer_zerop (low))
4470 if (! TYPE_UNSIGNED (etype))
4472 etype = unsigned_type_for (etype);
4473 high = fold_convert (etype, high);
4474 exp = fold_convert (etype, exp);
4476 return build_range_check (type, exp, 1, 0, high);
4479 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4480 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4482 unsigned HOST_WIDE_INT lo;
4486 prec = TYPE_PRECISION (etype);
4487 if (prec <= HOST_BITS_PER_WIDE_INT)
4490 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4494 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4495 lo = (unsigned HOST_WIDE_INT) -1;
4498 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4500 if (TYPE_UNSIGNED (etype))
4502 etype = signed_type_for (etype);
4503 exp = fold_convert (etype, exp);
4505 return fold_build2 (GT_EXPR, type, exp,
4506 build_int_cst (etype, 0));
4510 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4511 This requires wrap-around arithmetics for the type of the expression. */
4512 switch (TREE_CODE (etype))
4515 /* There is no requirement that LOW be within the range of ETYPE
4516 if the latter is a subtype. It must, however, be within the base
4517 type of ETYPE. So be sure we do the subtraction in that type. */
4518 if (TREE_TYPE (etype))
4519 etype = TREE_TYPE (etype);
4524 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4525 TYPE_UNSIGNED (etype));
4532 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4533 if (TREE_CODE (etype) == INTEGER_TYPE
4534 && !TYPE_OVERFLOW_WRAPS (etype))
4536 tree utype, minv, maxv;
4538 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4539 for the type in question, as we rely on this here. */
4540 utype = unsigned_type_for (etype);
4541 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4542 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4543 integer_one_node, 1);
4544 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4546 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4553 high = fold_convert (etype, high);
4554 low = fold_convert (etype, low);
4555 exp = fold_convert (etype, exp);
4557 value = const_binop (MINUS_EXPR, high, low, 0);
4560 if (POINTER_TYPE_P (etype))
4562 if (value != 0 && !TREE_OVERFLOW (value))
4564 low = fold_convert (sizetype, low);
4565 low = fold_build1 (NEGATE_EXPR, sizetype, low);
4566 return build_range_check (type,
4567 fold_build2 (POINTER_PLUS_EXPR, etype, exp, low),
4568 1, build_int_cst (etype, 0), value);
4573 if (value != 0 && !TREE_OVERFLOW (value))
4574 return build_range_check (type,
4575 fold_build2 (MINUS_EXPR, etype, exp, low),
4576 1, build_int_cst (etype, 0), value);
4581 /* Return the predecessor of VAL in its type, handling the infinite case. */
4584 range_predecessor (tree val)
4586 tree type = TREE_TYPE (val);
4588 if (INTEGRAL_TYPE_P (type)
4589 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4592 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4595 /* Return the successor of VAL in its type, handling the infinite case. */
4598 range_successor (tree val)
4600 tree type = TREE_TYPE (val);
4602 if (INTEGRAL_TYPE_P (type)
4603 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4606 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4609 /* Given two ranges, see if we can merge them into one. Return 1 if we
4610 can, 0 if we can't. Set the output range into the specified parameters. */
4613 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4614 tree high0, int in1_p, tree low1, tree high1)
4622 int lowequal = ((low0 == 0 && low1 == 0)
4623 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4624 low0, 0, low1, 0)));
4625 int highequal = ((high0 == 0 && high1 == 0)
4626 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4627 high0, 1, high1, 1)));
4629 /* Make range 0 be the range that starts first, or ends last if they
4630 start at the same value. Swap them if it isn't. */
4631 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4634 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4635 high1, 1, high0, 1))))
4637 temp = in0_p, in0_p = in1_p, in1_p = temp;
4638 tem = low0, low0 = low1, low1 = tem;
4639 tem = high0, high0 = high1, high1 = tem;
4642 /* Now flag two cases, whether the ranges are disjoint or whether the
4643 second range is totally subsumed in the first. Note that the tests
4644 below are simplified by the ones above. */
4645 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4646 high0, 1, low1, 0));
4647 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4648 high1, 1, high0, 1));
4650 /* We now have four cases, depending on whether we are including or
4651 excluding the two ranges. */
4654 /* If they don't overlap, the result is false. If the second range
4655 is a subset it is the result. Otherwise, the range is from the start
4656 of the second to the end of the first. */
4658 in_p = 0, low = high = 0;
4660 in_p = 1, low = low1, high = high1;
4662 in_p = 1, low = low1, high = high0;
4665 else if (in0_p && ! in1_p)
4667 /* If they don't overlap, the result is the first range. If they are
4668 equal, the result is false. If the second range is a subset of the
4669 first, and the ranges begin at the same place, we go from just after
4670 the end of the second range to the end of the first. If the second
4671 range is not a subset of the first, or if it is a subset and both
4672 ranges end at the same place, the range starts at the start of the
4673 first range and ends just before the second range.
4674 Otherwise, we can't describe this as a single range. */
4676 in_p = 1, low = low0, high = high0;
4677 else if (lowequal && highequal)
4678 in_p = 0, low = high = 0;
4679 else if (subset && lowequal)
4681 low = range_successor (high1);
4686 /* We are in the weird situation where high0 > high1 but
4687 high1 has no successor. Punt. */
4691 else if (! subset || highequal)
4694 high = range_predecessor (low1);
4698 /* low0 < low1 but low1 has no predecessor. Punt. */
4706 else if (! in0_p && in1_p)
4708 /* If they don't overlap, the result is the second range. If the second
4709 is a subset of the first, the result is false. Otherwise,
4710 the range starts just after the first range and ends at the
4711 end of the second. */
4713 in_p = 1, low = low1, high = high1;
4714 else if (subset || highequal)
4715 in_p = 0, low = high = 0;
4718 low = range_successor (high0);
4723 /* high1 > high0 but high0 has no successor. Punt. */
4731 /* The case where we are excluding both ranges. Here the complex case
4732 is if they don't overlap. In that case, the only time we have a
4733 range is if they are adjacent. If the second is a subset of the
4734 first, the result is the first. Otherwise, the range to exclude
4735 starts at the beginning of the first range and ends at the end of the
4739 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4740 range_successor (high0),
4742 in_p = 0, low = low0, high = high1;
4745 /* Canonicalize - [min, x] into - [-, x]. */
4746 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4747 switch (TREE_CODE (TREE_TYPE (low0)))
4750 if (TYPE_PRECISION (TREE_TYPE (low0))
4751 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4755 if (tree_int_cst_equal (low0,
4756 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4760 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4761 && integer_zerop (low0))
4768 /* Canonicalize - [x, max] into - [x, -]. */
4769 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4770 switch (TREE_CODE (TREE_TYPE (high1)))
4773 if (TYPE_PRECISION (TREE_TYPE (high1))
4774 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4778 if (tree_int_cst_equal (high1,
4779 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4783 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4784 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4786 integer_one_node, 1)))
4793 /* The ranges might be also adjacent between the maximum and
4794 minimum values of the given type. For
4795 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4796 return + [x + 1, y - 1]. */
4797 if (low0 == 0 && high1 == 0)
4799 low = range_successor (high0);
4800 high = range_predecessor (low1);
4801 if (low == 0 || high == 0)
4811 in_p = 0, low = low0, high = high0;
4813 in_p = 0, low = low0, high = high1;
4816 *pin_p = in_p, *plow = low, *phigh = high;
4821 /* Subroutine of fold, looking inside expressions of the form
4822 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4823 of the COND_EXPR. This function is being used also to optimize
4824 A op B ? C : A, by reversing the comparison first.
4826 Return a folded expression whose code is not a COND_EXPR
4827 anymore, or NULL_TREE if no folding opportunity is found. */
4830 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4832 enum tree_code comp_code = TREE_CODE (arg0);
4833 tree arg00 = TREE_OPERAND (arg0, 0);
4834 tree arg01 = TREE_OPERAND (arg0, 1);
4835 tree arg1_type = TREE_TYPE (arg1);
4841 /* If we have A op 0 ? A : -A, consider applying the following
4844 A == 0? A : -A same as -A
4845 A != 0? A : -A same as A
4846 A >= 0? A : -A same as abs (A)
4847 A > 0? A : -A same as abs (A)
4848 A <= 0? A : -A same as -abs (A)
4849 A < 0? A : -A same as -abs (A)
4851 None of these transformations work for modes with signed
4852 zeros. If A is +/-0, the first two transformations will
4853 change the sign of the result (from +0 to -0, or vice
4854 versa). The last four will fix the sign of the result,
4855 even though the original expressions could be positive or
4856 negative, depending on the sign of A.
4858 Note that all these transformations are correct if A is
4859 NaN, since the two alternatives (A and -A) are also NaNs. */
4860 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4861 && (FLOAT_TYPE_P (TREE_TYPE (arg01))
4862 ? real_zerop (arg01)
4863 : integer_zerop (arg01))
4864 && ((TREE_CODE (arg2) == NEGATE_EXPR
4865 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4866 /* In the case that A is of the form X-Y, '-A' (arg2) may
4867 have already been folded to Y-X, check for that. */
4868 || (TREE_CODE (arg1) == MINUS_EXPR
4869 && TREE_CODE (arg2) == MINUS_EXPR
4870 && operand_equal_p (TREE_OPERAND (arg1, 0),
4871 TREE_OPERAND (arg2, 1), 0)
4872 && operand_equal_p (TREE_OPERAND (arg1, 1),
4873 TREE_OPERAND (arg2, 0), 0))))
4878 tem = fold_convert (arg1_type, arg1);
4879 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4882 return pedantic_non_lvalue (fold_convert (type, arg1));
4885 if (flag_trapping_math)
4890 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4891 arg1 = fold_convert (signed_type_for
4892 (TREE_TYPE (arg1)), arg1);
4893 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4894 return pedantic_non_lvalue (fold_convert (type, tem));
4897 if (flag_trapping_math)
4901 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4902 arg1 = fold_convert (signed_type_for
4903 (TREE_TYPE (arg1)), arg1);
4904 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4905 return negate_expr (fold_convert (type, tem));
4907 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4911 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4912 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4913 both transformations are correct when A is NaN: A != 0
4914 is then true, and A == 0 is false. */
4916 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4917 && integer_zerop (arg01) && integer_zerop (arg2))
4919 if (comp_code == NE_EXPR)
4920 return pedantic_non_lvalue (fold_convert (type, arg1));
4921 else if (comp_code == EQ_EXPR)
4922 return build_int_cst (type, 0);
4925 /* Try some transformations of A op B ? A : B.
4927 A == B? A : B same as B
4928 A != B? A : B same as A
4929 A >= B? A : B same as max (A, B)
4930 A > B? A : B same as max (B, A)
4931 A <= B? A : B same as min (A, B)
4932 A < B? A : B same as min (B, A)
4934 As above, these transformations don't work in the presence
4935 of signed zeros. For example, if A and B are zeros of
4936 opposite sign, the first two transformations will change
4937 the sign of the result. In the last four, the original
4938 expressions give different results for (A=+0, B=-0) and
4939 (A=-0, B=+0), but the transformed expressions do not.
4941 The first two transformations are correct if either A or B
4942 is a NaN. In the first transformation, the condition will
4943 be false, and B will indeed be chosen. In the case of the
4944 second transformation, the condition A != B will be true,
4945 and A will be chosen.
4947 The conversions to max() and min() are not correct if B is
4948 a number and A is not. The conditions in the original
4949 expressions will be false, so all four give B. The min()
4950 and max() versions would give a NaN instead. */
4951 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4952 && operand_equal_for_comparison_p (arg01, arg2, arg00)
4953 /* Avoid these transformations if the COND_EXPR may be used
4954 as an lvalue in the C++ front-end. PR c++/19199. */
4956 || (strcmp (lang_hooks.name, "GNU C++") != 0
4957 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
4958 || ! maybe_lvalue_p (arg1)
4959 || ! maybe_lvalue_p (arg2)))
4961 tree comp_op0 = arg00;
4962 tree comp_op1 = arg01;
4963 tree comp_type = TREE_TYPE (comp_op0);
4965 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4966 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4976 return pedantic_non_lvalue (fold_convert (type, arg2));
4978 return pedantic_non_lvalue (fold_convert (type, arg1));
4983 /* In C++ a ?: expression can be an lvalue, so put the
4984 operand which will be used if they are equal first
4985 so that we can convert this back to the
4986 corresponding COND_EXPR. */
4987 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4989 comp_op0 = fold_convert (comp_type, comp_op0);
4990 comp_op1 = fold_convert (comp_type, comp_op1);
4991 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4992 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
4993 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
4994 return pedantic_non_lvalue (fold_convert (type, tem));
5001 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5003 comp_op0 = fold_convert (comp_type, comp_op0);
5004 comp_op1 = fold_convert (comp_type, comp_op1);
5005 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
5006 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
5007 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
5008 return pedantic_non_lvalue (fold_convert (type, tem));
5012 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5013 return pedantic_non_lvalue (fold_convert (type, arg2));
5016 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5017 return pedantic_non_lvalue (fold_convert (type, arg1));
5020 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5025 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
5026 we might still be able to simplify this. For example,
5027 if C1 is one less or one more than C2, this might have started
5028 out as a MIN or MAX and been transformed by this function.
5029 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
5031 if (INTEGRAL_TYPE_P (type)
5032 && TREE_CODE (arg01) == INTEGER_CST
5033 && TREE_CODE (arg2) == INTEGER_CST)
5037 /* We can replace A with C1 in this case. */
5038 arg1 = fold_convert (type, arg01);
5039 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
5042 /* If C1 is C2 + 1, this is min(A, C2). */
5043 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5045 && operand_equal_p (arg01,
5046 const_binop (PLUS_EXPR, arg2,
5047 build_int_cst (type, 1), 0),
5049 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5051 fold_convert (type, arg1),
5056 /* If C1 is C2 - 1, this is min(A, C2). */
5057 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5059 && operand_equal_p (arg01,
5060 const_binop (MINUS_EXPR, arg2,
5061 build_int_cst (type, 1), 0),
5063 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5065 fold_convert (type, arg1),
5070 /* If C1 is C2 - 1, this is max(A, C2). */
5071 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5073 && operand_equal_p (arg01,
5074 const_binop (MINUS_EXPR, arg2,
5075 build_int_cst (type, 1), 0),
5077 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5079 fold_convert (type, arg1),
5084 /* If C1 is C2 + 1, this is max(A, C2). */
5085 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5087 && operand_equal_p (arg01,
5088 const_binop (PLUS_EXPR, arg2,
5089 build_int_cst (type, 1), 0),
5091 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5093 fold_convert (type, arg1),
5107 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5108 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
5111 /* EXP is some logical combination of boolean tests. See if we can
5112 merge it into some range test. Return the new tree if so. */
5115 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
5117 int or_op = (code == TRUTH_ORIF_EXPR
5118 || code == TRUTH_OR_EXPR);
5119 int in0_p, in1_p, in_p;
5120 tree low0, low1, low, high0, high1, high;
5121 bool strict_overflow_p = false;
5122 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
5123 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
5125 const char * const warnmsg = G_("assuming signed overflow does not occur "
5126 "when simplifying range test");
5128 /* If this is an OR operation, invert both sides; we will invert
5129 again at the end. */
5131 in0_p = ! in0_p, in1_p = ! in1_p;
5133 /* If both expressions are the same, if we can merge the ranges, and we
5134 can build the range test, return it or it inverted. If one of the
5135 ranges is always true or always false, consider it to be the same
5136 expression as the other. */
5137 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
5138 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
5140 && 0 != (tem = (build_range_check (type,
5142 : rhs != 0 ? rhs : integer_zero_node,
5145 if (strict_overflow_p)
5146 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
5147 return or_op ? invert_truthvalue (tem) : tem;
5150 /* On machines where the branch cost is expensive, if this is a
5151 short-circuited branch and the underlying object on both sides
5152 is the same, make a non-short-circuit operation. */
5153 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5154 && lhs != 0 && rhs != 0
5155 && (code == TRUTH_ANDIF_EXPR
5156 || code == TRUTH_ORIF_EXPR)
5157 && operand_equal_p (lhs, rhs, 0))
5159 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5160 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5161 which cases we can't do this. */
5162 if (simple_operand_p (lhs))
5163 return build2 (code == TRUTH_ANDIF_EXPR
5164 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5167 else if (lang_hooks.decls.global_bindings_p () == 0
5168 && ! CONTAINS_PLACEHOLDER_P (lhs))
5170 tree common = save_expr (lhs);
5172 if (0 != (lhs = build_range_check (type, common,
5173 or_op ? ! in0_p : in0_p,
5175 && (0 != (rhs = build_range_check (type, common,
5176 or_op ? ! in1_p : in1_p,
5179 if (strict_overflow_p)
5180 fold_overflow_warning (warnmsg,
5181 WARN_STRICT_OVERFLOW_COMPARISON);
5182 return build2 (code == TRUTH_ANDIF_EXPR
5183 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5192 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5193 bit value. Arrange things so the extra bits will be set to zero if and
5194 only if C is signed-extended to its full width. If MASK is nonzero,
5195 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5198 unextend (tree c, int p, int unsignedp, tree mask)
5200 tree type = TREE_TYPE (c);
5201 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5204 if (p == modesize || unsignedp)
5207 /* We work by getting just the sign bit into the low-order bit, then
5208 into the high-order bit, then sign-extend. We then XOR that value
5210 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5211 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5213 /* We must use a signed type in order to get an arithmetic right shift.
5214 However, we must also avoid introducing accidental overflows, so that
5215 a subsequent call to integer_zerop will work. Hence we must
5216 do the type conversion here. At this point, the constant is either
5217 zero or one, and the conversion to a signed type can never overflow.
5218 We could get an overflow if this conversion is done anywhere else. */
5219 if (TYPE_UNSIGNED (type))
5220 temp = fold_convert (signed_type_for (type), temp);
5222 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5223 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5225 temp = const_binop (BIT_AND_EXPR, temp,
5226 fold_convert (TREE_TYPE (c), mask), 0);
5227 /* If necessary, convert the type back to match the type of C. */
5228 if (TYPE_UNSIGNED (type))
5229 temp = fold_convert (type, temp);
5231 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5234 /* Find ways of folding logical expressions of LHS and RHS:
5235 Try to merge two comparisons to the same innermost item.
5236 Look for range tests like "ch >= '0' && ch <= '9'".
5237 Look for combinations of simple terms on machines with expensive branches
5238 and evaluate the RHS unconditionally.
5240 For example, if we have p->a == 2 && p->b == 4 and we can make an
5241 object large enough to span both A and B, we can do this with a comparison
5242 against the object ANDed with the a mask.
5244 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5245 operations to do this with one comparison.
5247 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5248 function and the one above.
5250 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5251 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5253 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5256 We return the simplified tree or 0 if no optimization is possible. */
5259 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5261 /* If this is the "or" of two comparisons, we can do something if
5262 the comparisons are NE_EXPR. If this is the "and", we can do something
5263 if the comparisons are EQ_EXPR. I.e.,
5264 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5266 WANTED_CODE is this operation code. For single bit fields, we can
5267 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5268 comparison for one-bit fields. */
5270 enum tree_code wanted_code;
5271 enum tree_code lcode, rcode;
5272 tree ll_arg, lr_arg, rl_arg, rr_arg;
5273 tree ll_inner, lr_inner, rl_inner, rr_inner;
5274 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5275 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5276 HOST_WIDE_INT xll_bitpos, xrl_bitpos;
5277 HOST_WIDE_INT lnbitsize, lnbitpos;
5278 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5279 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5280 enum machine_mode lnmode;
5281 tree ll_mask, lr_mask, rl_mask, rr_mask;
5282 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5283 tree l_const, r_const;
5284 tree lntype, result;
5285 int first_bit, end_bit;
5287 tree orig_lhs = lhs, orig_rhs = rhs;
5288 enum tree_code orig_code = code;
5290 /* Start by getting the comparison codes. Fail if anything is volatile.
5291 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5292 it were surrounded with a NE_EXPR. */
5294 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5297 lcode = TREE_CODE (lhs);
5298 rcode = TREE_CODE (rhs);
5300 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5302 lhs = build2 (NE_EXPR, truth_type, lhs,
5303 build_int_cst (TREE_TYPE (lhs), 0));
5307 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5309 rhs = build2 (NE_EXPR, truth_type, rhs,
5310 build_int_cst (TREE_TYPE (rhs), 0));
5314 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5315 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5318 ll_arg = TREE_OPERAND (lhs, 0);
5319 lr_arg = TREE_OPERAND (lhs, 1);
5320 rl_arg = TREE_OPERAND (rhs, 0);
5321 rr_arg = TREE_OPERAND (rhs, 1);
5323 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5324 if (simple_operand_p (ll_arg)
5325 && simple_operand_p (lr_arg))
5328 if (operand_equal_p (ll_arg, rl_arg, 0)
5329 && operand_equal_p (lr_arg, rr_arg, 0))
5331 result = combine_comparisons (code, lcode, rcode,
5332 truth_type, ll_arg, lr_arg);
5336 else if (operand_equal_p (ll_arg, rr_arg, 0)
5337 && operand_equal_p (lr_arg, rl_arg, 0))
5339 result = combine_comparisons (code, lcode,
5340 swap_tree_comparison (rcode),
5341 truth_type, ll_arg, lr_arg);
5347 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5348 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5350 /* If the RHS can be evaluated unconditionally and its operands are
5351 simple, it wins to evaluate the RHS unconditionally on machines
5352 with expensive branches. In this case, this isn't a comparison
5353 that can be merged. Avoid doing this if the RHS is a floating-point
5354 comparison since those can trap. */
5356 if (BRANCH_COST >= 2
5357 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5358 && simple_operand_p (rl_arg)
5359 && simple_operand_p (rr_arg))
5361 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5362 if (code == TRUTH_OR_EXPR
5363 && lcode == NE_EXPR && integer_zerop (lr_arg)
5364 && rcode == NE_EXPR && integer_zerop (rr_arg)
5365 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5366 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5367 return build2 (NE_EXPR, truth_type,
5368 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5370 build_int_cst (TREE_TYPE (ll_arg), 0));
5372 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5373 if (code == TRUTH_AND_EXPR
5374 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5375 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5376 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5377 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5378 return build2 (EQ_EXPR, truth_type,
5379 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5381 build_int_cst (TREE_TYPE (ll_arg), 0));
5383 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5385 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5386 return build2 (code, truth_type, lhs, rhs);
5391 /* See if the comparisons can be merged. Then get all the parameters for
5394 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5395 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5399 ll_inner = decode_field_reference (ll_arg,
5400 &ll_bitsize, &ll_bitpos, &ll_mode,
5401 &ll_unsignedp, &volatilep, &ll_mask,
5403 lr_inner = decode_field_reference (lr_arg,
5404 &lr_bitsize, &lr_bitpos, &lr_mode,
5405 &lr_unsignedp, &volatilep, &lr_mask,
5407 rl_inner = decode_field_reference (rl_arg,
5408 &rl_bitsize, &rl_bitpos, &rl_mode,
5409 &rl_unsignedp, &volatilep, &rl_mask,
5411 rr_inner = decode_field_reference (rr_arg,
5412 &rr_bitsize, &rr_bitpos, &rr_mode,
5413 &rr_unsignedp, &volatilep, &rr_mask,
5416 /* It must be true that the inner operation on the lhs of each
5417 comparison must be the same if we are to be able to do anything.
5418 Then see if we have constants. If not, the same must be true for
5420 if (volatilep || ll_inner == 0 || rl_inner == 0
5421 || ! operand_equal_p (ll_inner, rl_inner, 0))
5424 if (TREE_CODE (lr_arg) == INTEGER_CST
5425 && TREE_CODE (rr_arg) == INTEGER_CST)
5426 l_const = lr_arg, r_const = rr_arg;
5427 else if (lr_inner == 0 || rr_inner == 0
5428 || ! operand_equal_p (lr_inner, rr_inner, 0))
5431 l_const = r_const = 0;
5433 /* If either comparison code is not correct for our logical operation,
5434 fail. However, we can convert a one-bit comparison against zero into
5435 the opposite comparison against that bit being set in the field. */
5437 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5438 if (lcode != wanted_code)
5440 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5442 /* Make the left operand unsigned, since we are only interested
5443 in the value of one bit. Otherwise we are doing the wrong
5452 /* This is analogous to the code for l_const above. */
5453 if (rcode != wanted_code)
5455 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5464 /* See if we can find a mode that contains both fields being compared on
5465 the left. If we can't, fail. Otherwise, update all constants and masks
5466 to be relative to a field of that size. */
5467 first_bit = MIN (ll_bitpos, rl_bitpos);
5468 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5469 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5470 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5472 if (lnmode == VOIDmode)
5475 lnbitsize = GET_MODE_BITSIZE (lnmode);
5476 lnbitpos = first_bit & ~ (lnbitsize - 1);
5477 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5478 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5480 if (BYTES_BIG_ENDIAN)
5482 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5483 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5486 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5487 size_int (xll_bitpos), 0);
5488 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5489 size_int (xrl_bitpos), 0);
5493 l_const = fold_convert (lntype, l_const);
5494 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5495 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5496 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5497 fold_build1 (BIT_NOT_EXPR,
5501 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5503 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5508 r_const = fold_convert (lntype, r_const);
5509 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5510 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5511 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5512 fold_build1 (BIT_NOT_EXPR,
5516 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5518 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5522 /* Handle the case of comparisons with constants. If there is something in
5523 common between the masks, those bits of the constants must be the same.
5524 If not, the condition is always false. Test for this to avoid generating
5525 incorrect code below. */
5526 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5527 if (! integer_zerop (result)
5528 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5529 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5531 if (wanted_code == NE_EXPR)
5533 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5534 return constant_boolean_node (true, truth_type);
5538 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5539 return constant_boolean_node (false, truth_type);
5546 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5550 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5553 enum tree_code op_code;
5556 int consts_equal, consts_lt;
5559 STRIP_SIGN_NOPS (arg0);
5561 op_code = TREE_CODE (arg0);
5562 minmax_const = TREE_OPERAND (arg0, 1);
5563 comp_const = fold_convert (TREE_TYPE (arg0), op1);
5564 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5565 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5566 inner = TREE_OPERAND (arg0, 0);
5568 /* If something does not permit us to optimize, return the original tree. */
5569 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5570 || TREE_CODE (comp_const) != INTEGER_CST
5571 || TREE_OVERFLOW (comp_const)
5572 || TREE_CODE (minmax_const) != INTEGER_CST
5573 || TREE_OVERFLOW (minmax_const))
5576 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5577 and GT_EXPR, doing the rest with recursive calls using logical
5581 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5583 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5586 return invert_truthvalue (tem);
5592 fold_build2 (TRUTH_ORIF_EXPR, type,
5593 optimize_minmax_comparison
5594 (EQ_EXPR, type, arg0, comp_const),
5595 optimize_minmax_comparison
5596 (GT_EXPR, type, arg0, comp_const));
5599 if (op_code == MAX_EXPR && consts_equal)
5600 /* MAX (X, 0) == 0 -> X <= 0 */
5601 return fold_build2 (LE_EXPR, type, inner, comp_const);
5603 else if (op_code == MAX_EXPR && consts_lt)
5604 /* MAX (X, 0) == 5 -> X == 5 */
5605 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5607 else if (op_code == MAX_EXPR)
5608 /* MAX (X, 0) == -1 -> false */
5609 return omit_one_operand (type, integer_zero_node, inner);
5611 else if (consts_equal)
5612 /* MIN (X, 0) == 0 -> X >= 0 */
5613 return fold_build2 (GE_EXPR, type, inner, comp_const);
5616 /* MIN (X, 0) == 5 -> false */
5617 return omit_one_operand (type, integer_zero_node, inner);
5620 /* MIN (X, 0) == -1 -> X == -1 */
5621 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5624 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5625 /* MAX (X, 0) > 0 -> X > 0
5626 MAX (X, 0) > 5 -> X > 5 */
5627 return fold_build2 (GT_EXPR, type, inner, comp_const);
5629 else if (op_code == MAX_EXPR)
5630 /* MAX (X, 0) > -1 -> true */
5631 return omit_one_operand (type, integer_one_node, inner);
5633 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5634 /* MIN (X, 0) > 0 -> false
5635 MIN (X, 0) > 5 -> false */
5636 return omit_one_operand (type, integer_zero_node, inner);
5639 /* MIN (X, 0) > -1 -> X > -1 */
5640 return fold_build2 (GT_EXPR, type, inner, comp_const);
5647 /* T is an integer expression that is being multiplied, divided, or taken a
5648 modulus (CODE says which and what kind of divide or modulus) by a
5649 constant C. See if we can eliminate that operation by folding it with
5650 other operations already in T. WIDE_TYPE, if non-null, is a type that
5651 should be used for the computation if wider than our type.
5653 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5654 (X * 2) + (Y * 4). We must, however, be assured that either the original
5655 expression would not overflow or that overflow is undefined for the type
5656 in the language in question.
5658 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5659 the machine has a multiply-accumulate insn or that this is part of an
5660 addressing calculation.
5662 If we return a non-null expression, it is an equivalent form of the
5663 original computation, but need not be in the original type.
5665 We set *STRICT_OVERFLOW_P to true if the return values depends on
5666 signed overflow being undefined. Otherwise we do not change
5667 *STRICT_OVERFLOW_P. */
5670 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
5671 bool *strict_overflow_p)
5673 /* To avoid exponential search depth, refuse to allow recursion past
5674 three levels. Beyond that (1) it's highly unlikely that we'll find
5675 something interesting and (2) we've probably processed it before
5676 when we built the inner expression. */
5685 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
5692 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
5693 bool *strict_overflow_p)
5695 tree type = TREE_TYPE (t);
5696 enum tree_code tcode = TREE_CODE (t);
5697 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5698 > GET_MODE_SIZE (TYPE_MODE (type)))
5699 ? wide_type : type);
5701 int same_p = tcode == code;
5702 tree op0 = NULL_TREE, op1 = NULL_TREE;
5703 bool sub_strict_overflow_p;
5705 /* Don't deal with constants of zero here; they confuse the code below. */
5706 if (integer_zerop (c))
5709 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5710 op0 = TREE_OPERAND (t, 0);
5712 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5713 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5715 /* Note that we need not handle conditional operations here since fold
5716 already handles those cases. So just do arithmetic here. */
5720 /* For a constant, we can always simplify if we are a multiply
5721 or (for divide and modulus) if it is a multiple of our constant. */
5722 if (code == MULT_EXPR
5723 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5724 return const_binop (code, fold_convert (ctype, t),
5725 fold_convert (ctype, c), 0);
5728 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5729 /* If op0 is an expression ... */
5730 if ((COMPARISON_CLASS_P (op0)
5731 || UNARY_CLASS_P (op0)
5732 || BINARY_CLASS_P (op0)
5733 || VL_EXP_CLASS_P (op0)
5734 || EXPRESSION_CLASS_P (op0))
5735 /* ... and is unsigned, and its type is smaller than ctype,
5736 then we cannot pass through as widening. */
5737 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5738 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5739 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5740 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5741 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5742 /* ... or this is a truncation (t is narrower than op0),
5743 then we cannot pass through this narrowing. */
5744 || (GET_MODE_SIZE (TYPE_MODE (type))
5745 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5746 /* ... or signedness changes for division or modulus,
5747 then we cannot pass through this conversion. */
5748 || (code != MULT_EXPR
5749 && (TYPE_UNSIGNED (ctype)
5750 != TYPE_UNSIGNED (TREE_TYPE (op0))))
5751 /* ... or has undefined overflow while the converted to
5752 type has not, we cannot do the operation in the inner type
5753 as that would introduce undefined overflow. */
5754 || (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))
5755 && !TYPE_OVERFLOW_UNDEFINED (type))))
5758 /* Pass the constant down and see if we can make a simplification. If
5759 we can, replace this expression with the inner simplification for
5760 possible later conversion to our or some other type. */
5761 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5762 && TREE_CODE (t2) == INTEGER_CST
5763 && !TREE_OVERFLOW (t2)
5764 && (0 != (t1 = extract_muldiv (op0, t2, code,
5766 ? ctype : NULL_TREE,
5767 strict_overflow_p))))
5772 /* If widening the type changes it from signed to unsigned, then we
5773 must avoid building ABS_EXPR itself as unsigned. */
5774 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5776 tree cstype = (*signed_type_for) (ctype);
5777 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
5780 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
5781 return fold_convert (ctype, t1);
5785 /* If the constant is negative, we cannot simplify this. */
5786 if (tree_int_cst_sgn (c) == -1)
5790 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
5792 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
5795 case MIN_EXPR: case MAX_EXPR:
5796 /* If widening the type changes the signedness, then we can't perform
5797 this optimization as that changes the result. */
5798 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5801 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5802 sub_strict_overflow_p = false;
5803 if ((t1 = extract_muldiv (op0, c, code, wide_type,
5804 &sub_strict_overflow_p)) != 0
5805 && (t2 = extract_muldiv (op1, c, code, wide_type,
5806 &sub_strict_overflow_p)) != 0)
5808 if (tree_int_cst_sgn (c) < 0)
5809 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5810 if (sub_strict_overflow_p)
5811 *strict_overflow_p = true;
5812 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5813 fold_convert (ctype, t2));
5817 case LSHIFT_EXPR: case RSHIFT_EXPR:
5818 /* If the second operand is constant, this is a multiplication
5819 or floor division, by a power of two, so we can treat it that
5820 way unless the multiplier or divisor overflows. Signed
5821 left-shift overflow is implementation-defined rather than
5822 undefined in C90, so do not convert signed left shift into
5824 if (TREE_CODE (op1) == INTEGER_CST
5825 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5826 /* const_binop may not detect overflow correctly,
5827 so check for it explicitly here. */
5828 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5829 && TREE_INT_CST_HIGH (op1) == 0
5830 && 0 != (t1 = fold_convert (ctype,
5831 const_binop (LSHIFT_EXPR,
5834 && !TREE_OVERFLOW (t1))
5835 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5836 ? MULT_EXPR : FLOOR_DIV_EXPR,
5837 ctype, fold_convert (ctype, op0), t1),
5838 c, code, wide_type, strict_overflow_p);
5841 case PLUS_EXPR: case MINUS_EXPR:
5842 /* See if we can eliminate the operation on both sides. If we can, we
5843 can return a new PLUS or MINUS. If we can't, the only remaining
5844 cases where we can do anything are if the second operand is a
5846 sub_strict_overflow_p = false;
5847 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
5848 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
5849 if (t1 != 0 && t2 != 0
5850 && (code == MULT_EXPR
5851 /* If not multiplication, we can only do this if both operands
5852 are divisible by c. */
5853 || (multiple_of_p (ctype, op0, c)
5854 && multiple_of_p (ctype, op1, c))))
5856 if (sub_strict_overflow_p)
5857 *strict_overflow_p = true;
5858 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5859 fold_convert (ctype, t2));
5862 /* If this was a subtraction, negate OP1 and set it to be an addition.
5863 This simplifies the logic below. */
5864 if (tcode == MINUS_EXPR)
5865 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5867 if (TREE_CODE (op1) != INTEGER_CST)
5870 /* If either OP1 or C are negative, this optimization is not safe for
5871 some of the division and remainder types while for others we need
5872 to change the code. */
5873 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5875 if (code == CEIL_DIV_EXPR)
5876 code = FLOOR_DIV_EXPR;
5877 else if (code == FLOOR_DIV_EXPR)
5878 code = CEIL_DIV_EXPR;
5879 else if (code != MULT_EXPR
5880 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5884 /* If it's a multiply or a division/modulus operation of a multiple
5885 of our constant, do the operation and verify it doesn't overflow. */
5886 if (code == MULT_EXPR
5887 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5889 op1 = const_binop (code, fold_convert (ctype, op1),
5890 fold_convert (ctype, c), 0);
5891 /* We allow the constant to overflow with wrapping semantics. */
5893 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
5899 /* If we have an unsigned type is not a sizetype, we cannot widen
5900 the operation since it will change the result if the original
5901 computation overflowed. */
5902 if (TYPE_UNSIGNED (ctype)
5903 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5907 /* If we were able to eliminate our operation from the first side,
5908 apply our operation to the second side and reform the PLUS. */
5909 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5910 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
5912 /* The last case is if we are a multiply. In that case, we can
5913 apply the distributive law to commute the multiply and addition
5914 if the multiplication of the constants doesn't overflow. */
5915 if (code == MULT_EXPR)
5916 return fold_build2 (tcode, ctype,
5917 fold_build2 (code, ctype,
5918 fold_convert (ctype, op0),
5919 fold_convert (ctype, c)),
5925 /* We have a special case here if we are doing something like
5926 (C * 8) % 4 since we know that's zero. */
5927 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5928 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5929 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5930 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5931 return omit_one_operand (type, integer_zero_node, op0);
5933 /* ... fall through ... */
5935 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5936 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5937 /* If we can extract our operation from the LHS, do so and return a
5938 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5939 do something only if the second operand is a constant. */
5941 && (t1 = extract_muldiv (op0, c, code, wide_type,
5942 strict_overflow_p)) != 0)
5943 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5944 fold_convert (ctype, op1));
5945 else if (tcode == MULT_EXPR && code == MULT_EXPR
5946 && (t1 = extract_muldiv (op1, c, code, wide_type,
5947 strict_overflow_p)) != 0)
5948 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5949 fold_convert (ctype, t1));
5950 else if (TREE_CODE (op1) != INTEGER_CST)
5953 /* If these are the same operation types, we can associate them
5954 assuming no overflow. */
5956 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5957 fold_convert (ctype, c), 0))
5958 && !TREE_OVERFLOW (t1))
5959 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
5961 /* If these operations "cancel" each other, we have the main
5962 optimizations of this pass, which occur when either constant is a
5963 multiple of the other, in which case we replace this with either an
5964 operation or CODE or TCODE.
5966 If we have an unsigned type that is not a sizetype, we cannot do
5967 this since it will change the result if the original computation
5969 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
5970 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5971 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5972 || (tcode == MULT_EXPR
5973 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5974 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
5975 && code != MULT_EXPR)))
5977 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5979 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5980 *strict_overflow_p = true;
5981 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5982 fold_convert (ctype,
5983 const_binop (TRUNC_DIV_EXPR,
5986 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5988 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5989 *strict_overflow_p = true;
5990 return fold_build2 (code, ctype, fold_convert (ctype, op0),
5991 fold_convert (ctype,
5992 const_binop (TRUNC_DIV_EXPR,
6005 /* Return a node which has the indicated constant VALUE (either 0 or
6006 1), and is of the indicated TYPE. */
6009 constant_boolean_node (int value, tree type)
6011 if (type == integer_type_node)
6012 return value ? integer_one_node : integer_zero_node;
6013 else if (type == boolean_type_node)
6014 return value ? boolean_true_node : boolean_false_node;
6016 return build_int_cst (type, value);
6020 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6021 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6022 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6023 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6024 COND is the first argument to CODE; otherwise (as in the example
6025 given here), it is the second argument. TYPE is the type of the
6026 original expression. Return NULL_TREE if no simplification is
6030 fold_binary_op_with_conditional_arg (enum tree_code code,
6031 tree type, tree op0, tree op1,
6032 tree cond, tree arg, int cond_first_p)
6034 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6035 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6036 tree test, true_value, false_value;
6037 tree lhs = NULL_TREE;
6038 tree rhs = NULL_TREE;
6040 /* This transformation is only worthwhile if we don't have to wrap
6041 arg in a SAVE_EXPR, and the operation can be simplified on at least
6042 one of the branches once its pushed inside the COND_EXPR. */
6043 if (!TREE_CONSTANT (arg))
6046 if (TREE_CODE (cond) == COND_EXPR)
6048 test = TREE_OPERAND (cond, 0);
6049 true_value = TREE_OPERAND (cond, 1);
6050 false_value = TREE_OPERAND (cond, 2);
6051 /* If this operand throws an expression, then it does not make
6052 sense to try to perform a logical or arithmetic operation
6054 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6056 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6061 tree testtype = TREE_TYPE (cond);
6063 true_value = constant_boolean_node (true, testtype);
6064 false_value = constant_boolean_node (false, testtype);
6067 arg = fold_convert (arg_type, arg);
6070 true_value = fold_convert (cond_type, true_value);
6072 lhs = fold_build2 (code, type, true_value, arg);
6074 lhs = fold_build2 (code, type, arg, true_value);
6078 false_value = fold_convert (cond_type, false_value);
6080 rhs = fold_build2 (code, type, false_value, arg);
6082 rhs = fold_build2 (code, type, arg, false_value);
6085 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6086 return fold_convert (type, test);
6090 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6092 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6093 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6094 ADDEND is the same as X.
6096 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6097 and finite. The problematic cases are when X is zero, and its mode
6098 has signed zeros. In the case of rounding towards -infinity,
6099 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6100 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6103 fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
6105 if (!real_zerop (addend))
6108 /* Don't allow the fold with -fsignaling-nans. */
6109 if (HONOR_SNANS (TYPE_MODE (type)))
6112 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6113 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6116 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6117 if (TREE_CODE (addend) == REAL_CST
6118 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6121 /* The mode has signed zeros, and we have to honor their sign.
6122 In this situation, there is only one case we can return true for.
6123 X - 0 is the same as X unless rounding towards -infinity is
6125 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6128 /* Subroutine of fold() that checks comparisons of built-in math
6129 functions against real constants.
6131 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6132 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6133 is the type of the result and ARG0 and ARG1 are the operands of the
6134 comparison. ARG1 must be a TREE_REAL_CST.
6136 The function returns the constant folded tree if a simplification
6137 can be made, and NULL_TREE otherwise. */
6140 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6141 tree type, tree arg0, tree arg1)
6145 if (BUILTIN_SQRT_P (fcode))
6147 tree arg = CALL_EXPR_ARG (arg0, 0);
6148 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6150 c = TREE_REAL_CST (arg1);
6151 if (REAL_VALUE_NEGATIVE (c))
6153 /* sqrt(x) < y is always false, if y is negative. */
6154 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6155 return omit_one_operand (type, integer_zero_node, arg);
6157 /* sqrt(x) > y is always true, if y is negative and we
6158 don't care about NaNs, i.e. negative values of x. */
6159 if (code == NE_EXPR || !HONOR_NANS (mode))
6160 return omit_one_operand (type, integer_one_node, arg);
6162 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6163 return fold_build2 (GE_EXPR, type, arg,
6164 build_real (TREE_TYPE (arg), dconst0));
6166 else if (code == GT_EXPR || code == GE_EXPR)
6170 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6171 real_convert (&c2, mode, &c2);
6173 if (REAL_VALUE_ISINF (c2))
6175 /* sqrt(x) > y is x == +Inf, when y is very large. */
6176 if (HONOR_INFINITIES (mode))
6177 return fold_build2 (EQ_EXPR, type, arg,
6178 build_real (TREE_TYPE (arg), c2));
6180 /* sqrt(x) > y is always false, when y is very large
6181 and we don't care about infinities. */
6182 return omit_one_operand (type, integer_zero_node, arg);
6185 /* sqrt(x) > c is the same as x > c*c. */
6186 return fold_build2 (code, type, arg,
6187 build_real (TREE_TYPE (arg), c2));
6189 else if (code == LT_EXPR || code == LE_EXPR)
6193 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6194 real_convert (&c2, mode, &c2);
6196 if (REAL_VALUE_ISINF (c2))
6198 /* sqrt(x) < y is always true, when y is a very large
6199 value and we don't care about NaNs or Infinities. */
6200 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6201 return omit_one_operand (type, integer_one_node, arg);
6203 /* sqrt(x) < y is x != +Inf when y is very large and we
6204 don't care about NaNs. */
6205 if (! HONOR_NANS (mode))
6206 return fold_build2 (NE_EXPR, type, arg,
6207 build_real (TREE_TYPE (arg), c2));
6209 /* sqrt(x) < y is x >= 0 when y is very large and we
6210 don't care about Infinities. */
6211 if (! HONOR_INFINITIES (mode))
6212 return fold_build2 (GE_EXPR, type, arg,
6213 build_real (TREE_TYPE (arg), dconst0));
6215 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6216 if (lang_hooks.decls.global_bindings_p () != 0
6217 || CONTAINS_PLACEHOLDER_P (arg))
6220 arg = save_expr (arg);
6221 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6222 fold_build2 (GE_EXPR, type, arg,
6223 build_real (TREE_TYPE (arg),
6225 fold_build2 (NE_EXPR, type, arg,
6226 build_real (TREE_TYPE (arg),
6230 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6231 if (! HONOR_NANS (mode))
6232 return fold_build2 (code, type, arg,
6233 build_real (TREE_TYPE (arg), c2));
6235 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6236 if (lang_hooks.decls.global_bindings_p () == 0
6237 && ! CONTAINS_PLACEHOLDER_P (arg))
6239 arg = save_expr (arg);
6240 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6241 fold_build2 (GE_EXPR, type, arg,
6242 build_real (TREE_TYPE (arg),
6244 fold_build2 (code, type, arg,
6245 build_real (TREE_TYPE (arg),
6254 /* Subroutine of fold() that optimizes comparisons against Infinities,
6255 either +Inf or -Inf.
6257 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6258 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6259 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6261 The function returns the constant folded tree if a simplification
6262 can be made, and NULL_TREE otherwise. */
6265 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6267 enum machine_mode mode;
6268 REAL_VALUE_TYPE max;
6272 mode = TYPE_MODE (TREE_TYPE (arg0));
6274 /* For negative infinity swap the sense of the comparison. */
6275 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6277 code = swap_tree_comparison (code);
6282 /* x > +Inf is always false, if with ignore sNANs. */
6283 if (HONOR_SNANS (mode))
6285 return omit_one_operand (type, integer_zero_node, arg0);
6288 /* x <= +Inf is always true, if we don't case about NaNs. */
6289 if (! HONOR_NANS (mode))
6290 return omit_one_operand (type, integer_one_node, arg0);
6292 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6293 if (lang_hooks.decls.global_bindings_p () == 0
6294 && ! CONTAINS_PLACEHOLDER_P (arg0))
6296 arg0 = save_expr (arg0);
6297 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6303 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6304 real_maxval (&max, neg, mode);
6305 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6306 arg0, build_real (TREE_TYPE (arg0), max));
6309 /* x < +Inf is always equal to x <= DBL_MAX. */
6310 real_maxval (&max, neg, mode);
6311 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6312 arg0, build_real (TREE_TYPE (arg0), max));
6315 /* x != +Inf is always equal to !(x > DBL_MAX). */
6316 real_maxval (&max, neg, mode);
6317 if (! HONOR_NANS (mode))
6318 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6319 arg0, build_real (TREE_TYPE (arg0), max));
6321 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6322 arg0, build_real (TREE_TYPE (arg0), max));
6323 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6332 /* Subroutine of fold() that optimizes comparisons of a division by
6333 a nonzero integer constant against an integer constant, i.e.
6336 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6337 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6338 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6340 The function returns the constant folded tree if a simplification
6341 can be made, and NULL_TREE otherwise. */
6344 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6346 tree prod, tmp, hi, lo;
6347 tree arg00 = TREE_OPERAND (arg0, 0);
6348 tree arg01 = TREE_OPERAND (arg0, 1);
6349 unsigned HOST_WIDE_INT lpart;
6350 HOST_WIDE_INT hpart;
6351 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6355 /* We have to do this the hard way to detect unsigned overflow.
6356 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6357 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6358 TREE_INT_CST_HIGH (arg01),
6359 TREE_INT_CST_LOW (arg1),
6360 TREE_INT_CST_HIGH (arg1),
6361 &lpart, &hpart, unsigned_p);
6362 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6364 neg_overflow = false;
6368 tmp = int_const_binop (MINUS_EXPR, arg01,
6369 build_int_cst (TREE_TYPE (arg01), 1), 0);
6372 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6373 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6374 TREE_INT_CST_HIGH (prod),
6375 TREE_INT_CST_LOW (tmp),
6376 TREE_INT_CST_HIGH (tmp),
6377 &lpart, &hpart, unsigned_p);
6378 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6379 -1, overflow | TREE_OVERFLOW (prod));
6381 else if (tree_int_cst_sgn (arg01) >= 0)
6383 tmp = int_const_binop (MINUS_EXPR, arg01,
6384 build_int_cst (TREE_TYPE (arg01), 1), 0);
6385 switch (tree_int_cst_sgn (arg1))
6388 neg_overflow = true;
6389 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6394 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6399 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6409 /* A negative divisor reverses the relational operators. */
6410 code = swap_tree_comparison (code);
6412 tmp = int_const_binop (PLUS_EXPR, arg01,
6413 build_int_cst (TREE_TYPE (arg01), 1), 0);
6414 switch (tree_int_cst_sgn (arg1))
6417 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6422 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6427 neg_overflow = true;
6428 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6440 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6441 return omit_one_operand (type, integer_zero_node, arg00);
6442 if (TREE_OVERFLOW (hi))
6443 return fold_build2 (GE_EXPR, type, arg00, lo);
6444 if (TREE_OVERFLOW (lo))
6445 return fold_build2 (LE_EXPR, type, arg00, hi);
6446 return build_range_check (type, arg00, 1, lo, hi);
6449 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6450 return omit_one_operand (type, integer_one_node, arg00);
6451 if (TREE_OVERFLOW (hi))
6452 return fold_build2 (LT_EXPR, type, arg00, lo);
6453 if (TREE_OVERFLOW (lo))
6454 return fold_build2 (GT_EXPR, type, arg00, hi);
6455 return build_range_check (type, arg00, 0, lo, hi);
6458 if (TREE_OVERFLOW (lo))
6460 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6461 return omit_one_operand (type, tmp, arg00);
6463 return fold_build2 (LT_EXPR, type, arg00, lo);
6466 if (TREE_OVERFLOW (hi))
6468 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6469 return omit_one_operand (type, tmp, arg00);
6471 return fold_build2 (LE_EXPR, type, arg00, hi);
6474 if (TREE_OVERFLOW (hi))
6476 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6477 return omit_one_operand (type, tmp, arg00);
6479 return fold_build2 (GT_EXPR, type, arg00, hi);
6482 if (TREE_OVERFLOW (lo))
6484 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6485 return omit_one_operand (type, tmp, arg00);
6487 return fold_build2 (GE_EXPR, type, arg00, lo);
6497 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6498 equality/inequality test, then return a simplified form of the test
6499 using a sign testing. Otherwise return NULL. TYPE is the desired
6503 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6506 /* If this is testing a single bit, we can optimize the test. */
6507 if ((code == NE_EXPR || code == EQ_EXPR)
6508 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6509 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6511 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6512 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6513 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6515 if (arg00 != NULL_TREE
6516 /* This is only a win if casting to a signed type is cheap,
6517 i.e. when arg00's type is not a partial mode. */
6518 && TYPE_PRECISION (TREE_TYPE (arg00))
6519 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6521 tree stype = signed_type_for (TREE_TYPE (arg00));
6522 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6523 result_type, fold_convert (stype, arg00),
6524 build_int_cst (stype, 0));
6531 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6532 equality/inequality test, then return a simplified form of
6533 the test using shifts and logical operations. Otherwise return
6534 NULL. TYPE is the desired result type. */
6537 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6540 /* If this is testing a single bit, we can optimize the test. */
6541 if ((code == NE_EXPR || code == EQ_EXPR)
6542 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6543 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6545 tree inner = TREE_OPERAND (arg0, 0);
6546 tree type = TREE_TYPE (arg0);
6547 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6548 enum machine_mode operand_mode = TYPE_MODE (type);
6550 tree signed_type, unsigned_type, intermediate_type;
6553 /* First, see if we can fold the single bit test into a sign-bit
6555 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6560 /* Otherwise we have (A & C) != 0 where C is a single bit,
6561 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6562 Similarly for (A & C) == 0. */
6564 /* If INNER is a right shift of a constant and it plus BITNUM does
6565 not overflow, adjust BITNUM and INNER. */
6566 if (TREE_CODE (inner) == RSHIFT_EXPR
6567 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6568 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6569 && bitnum < TYPE_PRECISION (type)
6570 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6571 bitnum - TYPE_PRECISION (type)))
6573 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6574 inner = TREE_OPERAND (inner, 0);
6577 /* If we are going to be able to omit the AND below, we must do our
6578 operations as unsigned. If we must use the AND, we have a choice.
6579 Normally unsigned is faster, but for some machines signed is. */
6580 #ifdef LOAD_EXTEND_OP
6581 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6582 && !flag_syntax_only) ? 0 : 1;
6587 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6588 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6589 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6590 inner = fold_convert (intermediate_type, inner);
6593 inner = build2 (RSHIFT_EXPR, intermediate_type,
6594 inner, size_int (bitnum));
6596 one = build_int_cst (intermediate_type, 1);
6598 if (code == EQ_EXPR)
6599 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6601 /* Put the AND last so it can combine with more things. */
6602 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6604 /* Make sure to return the proper type. */
6605 inner = fold_convert (result_type, inner);
6612 /* Check whether we are allowed to reorder operands arg0 and arg1,
6613 such that the evaluation of arg1 occurs before arg0. */
6616 reorder_operands_p (const_tree arg0, const_tree arg1)
6618 if (! flag_evaluation_order)
6620 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6622 return ! TREE_SIDE_EFFECTS (arg0)
6623 && ! TREE_SIDE_EFFECTS (arg1);
6626 /* Test whether it is preferable two swap two operands, ARG0 and
6627 ARG1, for example because ARG0 is an integer constant and ARG1
6628 isn't. If REORDER is true, only recommend swapping if we can
6629 evaluate the operands in reverse order. */
6632 tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
6634 STRIP_SIGN_NOPS (arg0);
6635 STRIP_SIGN_NOPS (arg1);
6637 if (TREE_CODE (arg1) == INTEGER_CST)
6639 if (TREE_CODE (arg0) == INTEGER_CST)
6642 if (TREE_CODE (arg1) == REAL_CST)
6644 if (TREE_CODE (arg0) == REAL_CST)
6647 if (TREE_CODE (arg1) == FIXED_CST)
6649 if (TREE_CODE (arg0) == FIXED_CST)
6652 if (TREE_CODE (arg1) == COMPLEX_CST)
6654 if (TREE_CODE (arg0) == COMPLEX_CST)
6657 if (TREE_CONSTANT (arg1))
6659 if (TREE_CONSTANT (arg0))
6665 if (reorder && flag_evaluation_order
6666 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6669 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6670 for commutative and comparison operators. Ensuring a canonical
6671 form allows the optimizers to find additional redundancies without
6672 having to explicitly check for both orderings. */
6673 if (TREE_CODE (arg0) == SSA_NAME
6674 && TREE_CODE (arg1) == SSA_NAME
6675 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6678 /* Put SSA_NAMEs last. */
6679 if (TREE_CODE (arg1) == SSA_NAME)
6681 if (TREE_CODE (arg0) == SSA_NAME)
6684 /* Put variables last. */
6693 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6694 ARG0 is extended to a wider type. */
6697 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6699 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6701 tree shorter_type, outer_type;
6705 if (arg0_unw == arg0)
6707 shorter_type = TREE_TYPE (arg0_unw);
6709 #ifdef HAVE_canonicalize_funcptr_for_compare
6710 /* Disable this optimization if we're casting a function pointer
6711 type on targets that require function pointer canonicalization. */
6712 if (HAVE_canonicalize_funcptr_for_compare
6713 && TREE_CODE (shorter_type) == POINTER_TYPE
6714 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
6718 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6721 arg1_unw = get_unwidened (arg1, NULL_TREE);
6723 /* If possible, express the comparison in the shorter mode. */
6724 if ((code == EQ_EXPR || code == NE_EXPR
6725 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6726 && (TREE_TYPE (arg1_unw) == shorter_type
6727 || (TYPE_PRECISION (shorter_type)
6728 > TYPE_PRECISION (TREE_TYPE (arg1_unw)))
6729 || ((TYPE_PRECISION (shorter_type)
6730 == TYPE_PRECISION (TREE_TYPE (arg1_unw)))
6731 && (TYPE_UNSIGNED (shorter_type)
6732 == TYPE_UNSIGNED (TREE_TYPE (arg1_unw))))
6733 || (TREE_CODE (arg1_unw) == INTEGER_CST
6734 && (TREE_CODE (shorter_type) == INTEGER_TYPE
6735 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
6736 && int_fits_type_p (arg1_unw, shorter_type))))
6737 return fold_build2 (code, type, arg0_unw,
6738 fold_convert (shorter_type, arg1_unw));
6740 if (TREE_CODE (arg1_unw) != INTEGER_CST
6741 || TREE_CODE (shorter_type) != INTEGER_TYPE
6742 || !int_fits_type_p (arg1_unw, shorter_type))
6745 /* If we are comparing with the integer that does not fit into the range
6746 of the shorter type, the result is known. */
6747 outer_type = TREE_TYPE (arg1_unw);
6748 min = lower_bound_in_type (outer_type, shorter_type);
6749 max = upper_bound_in_type (outer_type, shorter_type);
6751 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6753 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6760 return omit_one_operand (type, integer_zero_node, arg0);
6765 return omit_one_operand (type, integer_one_node, arg0);
6771 return omit_one_operand (type, integer_one_node, arg0);
6773 return omit_one_operand (type, integer_zero_node, arg0);
6778 return omit_one_operand (type, integer_zero_node, arg0);
6780 return omit_one_operand (type, integer_one_node, arg0);
6789 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6790 ARG0 just the signedness is changed. */
6793 fold_sign_changed_comparison (enum tree_code code, tree type,
6794 tree arg0, tree arg1)
6797 tree inner_type, outer_type;
6799 if (TREE_CODE (arg0) != NOP_EXPR
6800 && TREE_CODE (arg0) != CONVERT_EXPR)
6803 outer_type = TREE_TYPE (arg0);
6804 arg0_inner = TREE_OPERAND (arg0, 0);
6805 inner_type = TREE_TYPE (arg0_inner);
6807 #ifdef HAVE_canonicalize_funcptr_for_compare
6808 /* Disable this optimization if we're casting a function pointer
6809 type on targets that require function pointer canonicalization. */
6810 if (HAVE_canonicalize_funcptr_for_compare
6811 && TREE_CODE (inner_type) == POINTER_TYPE
6812 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
6816 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6819 /* If the conversion is from an integral subtype to its basetype
6821 if (TREE_TYPE (inner_type) == outer_type)
6824 if (TREE_CODE (arg1) != INTEGER_CST
6825 && !((TREE_CODE (arg1) == NOP_EXPR
6826 || TREE_CODE (arg1) == CONVERT_EXPR)
6827 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6830 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6835 if (TREE_CODE (arg1) == INTEGER_CST)
6836 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
6837 TREE_INT_CST_HIGH (arg1), 0,
6838 TREE_OVERFLOW (arg1));
6840 arg1 = fold_convert (inner_type, arg1);
6842 return fold_build2 (code, type, arg0_inner, arg1);
6845 /* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
6846 step of the array. Reconstructs s and delta in the case of s * delta
6847 being an integer constant (and thus already folded).
6848 ADDR is the address. MULT is the multiplicative expression.
6849 If the function succeeds, the new address expression is returned. Otherwise
6850 NULL_TREE is returned. */
6853 try_move_mult_to_index (tree addr, tree op1)
6855 tree s, delta, step;
6856 tree ref = TREE_OPERAND (addr, 0), pref;
6861 /* Strip the nops that might be added when converting op1 to sizetype. */
6864 /* Canonicalize op1 into a possibly non-constant delta
6865 and an INTEGER_CST s. */
6866 if (TREE_CODE (op1) == MULT_EXPR)
6868 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
6873 if (TREE_CODE (arg0) == INTEGER_CST)
6878 else if (TREE_CODE (arg1) == INTEGER_CST)
6886 else if (TREE_CODE (op1) == INTEGER_CST)
6893 /* Simulate we are delta * 1. */
6895 s = integer_one_node;
6898 for (;; ref = TREE_OPERAND (ref, 0))
6900 if (TREE_CODE (ref) == ARRAY_REF)
6902 /* Remember if this was a multi-dimensional array. */
6903 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
6906 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
6910 step = array_ref_element_size (ref);
6911 if (TREE_CODE (step) != INTEGER_CST)
6916 if (! tree_int_cst_equal (step, s))
6921 /* Try if delta is a multiple of step. */
6922 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
6928 /* Only fold here if we can verify we do not overflow one
6929 dimension of a multi-dimensional array. */
6934 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
6935 || !INTEGRAL_TYPE_P (itype)
6936 || !TYPE_MAX_VALUE (itype)
6937 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
6940 tmp = fold_binary (PLUS_EXPR, itype,
6941 fold_convert (itype,
6942 TREE_OPERAND (ref, 1)),
6943 fold_convert (itype, delta));
6945 || TREE_CODE (tmp) != INTEGER_CST
6946 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
6955 if (!handled_component_p (ref))
6959 /* We found the suitable array reference. So copy everything up to it,
6960 and replace the index. */
6962 pref = TREE_OPERAND (addr, 0);
6963 ret = copy_node (pref);
6968 pref = TREE_OPERAND (pref, 0);
6969 TREE_OPERAND (pos, 0) = copy_node (pref);
6970 pos = TREE_OPERAND (pos, 0);
6973 TREE_OPERAND (pos, 1) = fold_build2 (PLUS_EXPR, itype,
6974 fold_convert (itype,
6975 TREE_OPERAND (pos, 1)),
6976 fold_convert (itype, delta));
6978 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6982 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6983 means A >= Y && A != MAX, but in this case we know that
6984 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6987 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6989 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6991 if (TREE_CODE (bound) == LT_EXPR)
6992 a = TREE_OPERAND (bound, 0);
6993 else if (TREE_CODE (bound) == GT_EXPR)
6994 a = TREE_OPERAND (bound, 1);
6998 typea = TREE_TYPE (a);
6999 if (!INTEGRAL_TYPE_P (typea)
7000 && !POINTER_TYPE_P (typea))
7003 if (TREE_CODE (ineq) == LT_EXPR)
7005 a1 = TREE_OPERAND (ineq, 1);
7006 y = TREE_OPERAND (ineq, 0);
7008 else if (TREE_CODE (ineq) == GT_EXPR)
7010 a1 = TREE_OPERAND (ineq, 0);
7011 y = TREE_OPERAND (ineq, 1);
7016 if (TREE_TYPE (a1) != typea)
7019 if (POINTER_TYPE_P (typea))
7021 /* Convert the pointer types into integer before taking the difference. */
7022 tree ta = fold_convert (ssizetype, a);
7023 tree ta1 = fold_convert (ssizetype, a1);
7024 diff = fold_binary (MINUS_EXPR, ssizetype, ta1, ta);
7027 diff = fold_binary (MINUS_EXPR, typea, a1, a);
7029 if (!diff || !integer_onep (diff))
7032 return fold_build2 (GE_EXPR, type, a, y);
7035 /* Fold a sum or difference of at least one multiplication.
7036 Returns the folded tree or NULL if no simplification could be made. */
7039 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7041 tree arg00, arg01, arg10, arg11;
7042 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7044 /* (A * C) +- (B * C) -> (A+-B) * C.
7045 (A * C) +- A -> A * (C+-1).
7046 We are most concerned about the case where C is a constant,
7047 but other combinations show up during loop reduction. Since
7048 it is not difficult, try all four possibilities. */
7050 if (TREE_CODE (arg0) == MULT_EXPR)
7052 arg00 = TREE_OPERAND (arg0, 0);
7053 arg01 = TREE_OPERAND (arg0, 1);
7055 else if (TREE_CODE (arg0) == INTEGER_CST)
7057 arg00 = build_one_cst (type);
7062 /* We cannot generate constant 1 for fract. */
7063 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7066 arg01 = build_one_cst (type);
7068 if (TREE_CODE (arg1) == MULT_EXPR)
7070 arg10 = TREE_OPERAND (arg1, 0);
7071 arg11 = TREE_OPERAND (arg1, 1);
7073 else if (TREE_CODE (arg1) == INTEGER_CST)
7075 arg10 = build_one_cst (type);
7080 /* We cannot generate constant 1 for fract. */
7081 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7084 arg11 = build_one_cst (type);
7088 if (operand_equal_p (arg01, arg11, 0))
7089 same = arg01, alt0 = arg00, alt1 = arg10;
7090 else if (operand_equal_p (arg00, arg10, 0))
7091 same = arg00, alt0 = arg01, alt1 = arg11;
7092 else if (operand_equal_p (arg00, arg11, 0))
7093 same = arg00, alt0 = arg01, alt1 = arg10;
7094 else if (operand_equal_p (arg01, arg10, 0))
7095 same = arg01, alt0 = arg00, alt1 = arg11;
7097 /* No identical multiplicands; see if we can find a common
7098 power-of-two factor in non-power-of-two multiplies. This
7099 can help in multi-dimensional array access. */
7100 else if (host_integerp (arg01, 0)
7101 && host_integerp (arg11, 0))
7103 HOST_WIDE_INT int01, int11, tmp;
7106 int01 = TREE_INT_CST_LOW (arg01);
7107 int11 = TREE_INT_CST_LOW (arg11);
7109 /* Move min of absolute values to int11. */
7110 if ((int01 >= 0 ? int01 : -int01)
7111 < (int11 >= 0 ? int11 : -int11))
7113 tmp = int01, int01 = int11, int11 = tmp;
7114 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7121 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
7123 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7124 build_int_cst (TREE_TYPE (arg00),
7129 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7134 return fold_build2 (MULT_EXPR, type,
7135 fold_build2 (code, type,
7136 fold_convert (type, alt0),
7137 fold_convert (type, alt1)),
7138 fold_convert (type, same));
7143 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7144 specified by EXPR into the buffer PTR of length LEN bytes.
7145 Return the number of bytes placed in the buffer, or zero
7149 native_encode_int (const_tree expr, unsigned char *ptr, int len)
7151 tree type = TREE_TYPE (expr);
7152 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7153 int byte, offset, word, words;
7154 unsigned char value;
7156 if (total_bytes > len)
7158 words = total_bytes / UNITS_PER_WORD;
7160 for (byte = 0; byte < total_bytes; byte++)
7162 int bitpos = byte * BITS_PER_UNIT;
7163 if (bitpos < HOST_BITS_PER_WIDE_INT)
7164 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7166 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7167 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7169 if (total_bytes > UNITS_PER_WORD)
7171 word = byte / UNITS_PER_WORD;
7172 if (WORDS_BIG_ENDIAN)
7173 word = (words - 1) - word;
7174 offset = word * UNITS_PER_WORD;
7175 if (BYTES_BIG_ENDIAN)
7176 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7178 offset += byte % UNITS_PER_WORD;
7181 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7182 ptr[offset] = value;
7188 /* Subroutine of native_encode_expr. Encode the REAL_CST
7189 specified by EXPR into the buffer PTR of length LEN bytes.
7190 Return the number of bytes placed in the buffer, or zero
7194 native_encode_real (const_tree expr, unsigned char *ptr, int len)
7196 tree type = TREE_TYPE (expr);
7197 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7198 int byte, offset, word, words, bitpos;
7199 unsigned char value;
7201 /* There are always 32 bits in each long, no matter the size of
7202 the hosts long. We handle floating point representations with
7206 if (total_bytes > len)
7208 words = 32 / UNITS_PER_WORD;
7210 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7212 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7213 bitpos += BITS_PER_UNIT)
7215 byte = (bitpos / BITS_PER_UNIT) & 3;
7216 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7218 if (UNITS_PER_WORD < 4)
7220 word = byte / UNITS_PER_WORD;
7221 if (WORDS_BIG_ENDIAN)
7222 word = (words - 1) - word;
7223 offset = word * UNITS_PER_WORD;
7224 if (BYTES_BIG_ENDIAN)
7225 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7227 offset += byte % UNITS_PER_WORD;
7230 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7231 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7236 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7237 specified by EXPR into the buffer PTR of length LEN bytes.
7238 Return the number of bytes placed in the buffer, or zero
7242 native_encode_complex (const_tree expr, unsigned char *ptr, int len)
7247 part = TREE_REALPART (expr);
7248 rsize = native_encode_expr (part, ptr, len);
7251 part = TREE_IMAGPART (expr);
7252 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7255 return rsize + isize;
7259 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7260 specified by EXPR into the buffer PTR of length LEN bytes.
7261 Return the number of bytes placed in the buffer, or zero
7265 native_encode_vector (const_tree expr, unsigned char *ptr, int len)
7267 int i, size, offset, count;
7268 tree itype, elem, elements;
7271 elements = TREE_VECTOR_CST_ELTS (expr);
7272 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7273 itype = TREE_TYPE (TREE_TYPE (expr));
7274 size = GET_MODE_SIZE (TYPE_MODE (itype));
7275 for (i = 0; i < count; i++)
7279 elem = TREE_VALUE (elements);
7280 elements = TREE_CHAIN (elements);
7287 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7292 if (offset + size > len)
7294 memset (ptr+offset, 0, size);
7302 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7303 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7304 buffer PTR of length LEN bytes. Return the number of bytes
7305 placed in the buffer, or zero upon failure. */
7308 native_encode_expr (const_tree expr, unsigned char *ptr, int len)
7310 switch (TREE_CODE (expr))
7313 return native_encode_int (expr, ptr, len);
7316 return native_encode_real (expr, ptr, len);
7319 return native_encode_complex (expr, ptr, len);
7322 return native_encode_vector (expr, ptr, len);
7330 /* Subroutine of native_interpret_expr. Interpret the contents of
7331 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7332 If the buffer cannot be interpreted, return NULL_TREE. */
7335 native_interpret_int (tree type, const unsigned char *ptr, int len)
7337 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7338 int byte, offset, word, words;
7339 unsigned char value;
7340 unsigned int HOST_WIDE_INT lo = 0;
7341 HOST_WIDE_INT hi = 0;
7343 if (total_bytes > len)
7345 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7347 words = total_bytes / UNITS_PER_WORD;
7349 for (byte = 0; byte < total_bytes; byte++)
7351 int bitpos = byte * BITS_PER_UNIT;
7352 if (total_bytes > UNITS_PER_WORD)
7354 word = byte / UNITS_PER_WORD;
7355 if (WORDS_BIG_ENDIAN)
7356 word = (words - 1) - word;
7357 offset = word * UNITS_PER_WORD;
7358 if (BYTES_BIG_ENDIAN)
7359 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7361 offset += byte % UNITS_PER_WORD;
7364 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7365 value = ptr[offset];
7367 if (bitpos < HOST_BITS_PER_WIDE_INT)
7368 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7370 hi |= (unsigned HOST_WIDE_INT) value
7371 << (bitpos - HOST_BITS_PER_WIDE_INT);
7374 return build_int_cst_wide_type (type, lo, hi);
7378 /* Subroutine of native_interpret_expr. Interpret the contents of
7379 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7380 If the buffer cannot be interpreted, return NULL_TREE. */
7383 native_interpret_real (tree type, const unsigned char *ptr, int len)
7385 enum machine_mode mode = TYPE_MODE (type);
7386 int total_bytes = GET_MODE_SIZE (mode);
7387 int byte, offset, word, words, bitpos;
7388 unsigned char value;
7389 /* There are always 32 bits in each long, no matter the size of
7390 the hosts long. We handle floating point representations with
7395 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7396 if (total_bytes > len || total_bytes > 24)
7398 words = 32 / UNITS_PER_WORD;
7400 memset (tmp, 0, sizeof (tmp));
7401 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7402 bitpos += BITS_PER_UNIT)
7404 byte = (bitpos / BITS_PER_UNIT) & 3;
7405 if (UNITS_PER_WORD < 4)
7407 word = byte / UNITS_PER_WORD;
7408 if (WORDS_BIG_ENDIAN)
7409 word = (words - 1) - word;
7410 offset = word * UNITS_PER_WORD;
7411 if (BYTES_BIG_ENDIAN)
7412 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7414 offset += byte % UNITS_PER_WORD;
7417 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7418 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7420 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7423 real_from_target (&r, tmp, mode);
7424 return build_real (type, r);
7428 /* Subroutine of native_interpret_expr. Interpret the contents of
7429 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7430 If the buffer cannot be interpreted, return NULL_TREE. */
7433 native_interpret_complex (tree type, const unsigned char *ptr, int len)
7435 tree etype, rpart, ipart;
7438 etype = TREE_TYPE (type);
7439 size = GET_MODE_SIZE (TYPE_MODE (etype));
7442 rpart = native_interpret_expr (etype, ptr, size);
7445 ipart = native_interpret_expr (etype, ptr+size, size);
7448 return build_complex (type, rpart, ipart);
7452 /* Subroutine of native_interpret_expr. Interpret the contents of
7453 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7454 If the buffer cannot be interpreted, return NULL_TREE. */
7457 native_interpret_vector (tree type, const unsigned char *ptr, int len)
7459 tree etype, elem, elements;
7462 etype = TREE_TYPE (type);
7463 size = GET_MODE_SIZE (TYPE_MODE (etype));
7464 count = TYPE_VECTOR_SUBPARTS (type);
7465 if (size * count > len)
7468 elements = NULL_TREE;
7469 for (i = count - 1; i >= 0; i--)
7471 elem = native_interpret_expr (etype, ptr+(i*size), size);
7474 elements = tree_cons (NULL_TREE, elem, elements);
7476 return build_vector (type, elements);
7480 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7481 the buffer PTR of length LEN as a constant of type TYPE. For
7482 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7483 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7484 return NULL_TREE. */
7487 native_interpret_expr (tree type, const unsigned char *ptr, int len)
7489 switch (TREE_CODE (type))
7494 return native_interpret_int (type, ptr, len);
7497 return native_interpret_real (type, ptr, len);
7500 return native_interpret_complex (type, ptr, len);
7503 return native_interpret_vector (type, ptr, len);
7511 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7512 TYPE at compile-time. If we're unable to perform the conversion
7513 return NULL_TREE. */
7516 fold_view_convert_expr (tree type, tree expr)
7518 /* We support up to 512-bit values (for V8DFmode). */
7519 unsigned char buffer[64];
7522 /* Check that the host and target are sane. */
7523 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7526 len = native_encode_expr (expr, buffer, sizeof (buffer));
7530 return native_interpret_expr (type, buffer, len);
7533 /* Build an expression for the address of T. Folds away INDIRECT_REF
7534 to avoid confusing the gimplify process. When IN_FOLD is true
7535 avoid modifications of T. */
7538 build_fold_addr_expr_with_type_1 (tree t, tree ptrtype, bool in_fold)
7540 /* The size of the object is not relevant when talking about its address. */
7541 if (TREE_CODE (t) == WITH_SIZE_EXPR)
7542 t = TREE_OPERAND (t, 0);
7544 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
7545 if (TREE_CODE (t) == INDIRECT_REF
7546 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
7548 t = TREE_OPERAND (t, 0);
7550 if (TREE_TYPE (t) != ptrtype)
7551 t = build1 (NOP_EXPR, ptrtype, t);
7557 while (handled_component_p (base))
7558 base = TREE_OPERAND (base, 0);
7561 TREE_ADDRESSABLE (base) = 1;
7563 t = build1 (ADDR_EXPR, ptrtype, t);
7566 t = build1 (ADDR_EXPR, ptrtype, t);
7571 /* Build an expression for the address of T with type PTRTYPE. This
7572 function modifies the input parameter 'T' by sometimes setting the
7573 TREE_ADDRESSABLE flag. */
7576 build_fold_addr_expr_with_type (tree t, tree ptrtype)
7578 return build_fold_addr_expr_with_type_1 (t, ptrtype, false);
7581 /* Build an expression for the address of T. This function modifies
7582 the input parameter 'T' by sometimes setting the TREE_ADDRESSABLE
7583 flag. When called from fold functions, use fold_addr_expr instead. */
7586 build_fold_addr_expr (tree t)
7588 return build_fold_addr_expr_with_type_1 (t,
7589 build_pointer_type (TREE_TYPE (t)),
7593 /* Same as build_fold_addr_expr, builds an expression for the address
7594 of T, but avoids touching the input node 't'. Fold functions
7595 should use this version. */
7598 fold_addr_expr (tree t)
7600 tree ptrtype = build_pointer_type (TREE_TYPE (t));
7602 return build_fold_addr_expr_with_type_1 (t, ptrtype, true);
7605 /* Fold a unary expression of code CODE and type TYPE with operand
7606 OP0. Return the folded expression if folding is successful.
7607 Otherwise, return NULL_TREE. */
7610 fold_unary (enum tree_code code, tree type, tree op0)
7614 enum tree_code_class kind = TREE_CODE_CLASS (code);
7616 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7617 && TREE_CODE_LENGTH (code) == 1);
7622 if (code == NOP_EXPR || code == CONVERT_EXPR
7623 || code == FLOAT_EXPR || code == ABS_EXPR)
7625 /* Don't use STRIP_NOPS, because signedness of argument type
7627 STRIP_SIGN_NOPS (arg0);
7631 /* Strip any conversions that don't change the mode. This
7632 is safe for every expression, except for a comparison
7633 expression because its signedness is derived from its
7636 Note that this is done as an internal manipulation within
7637 the constant folder, in order to find the simplest
7638 representation of the arguments so that their form can be
7639 studied. In any cases, the appropriate type conversions
7640 should be put back in the tree that will get out of the
7646 if (TREE_CODE_CLASS (code) == tcc_unary)
7648 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7649 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7650 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
7651 else if (TREE_CODE (arg0) == COND_EXPR)
7653 tree arg01 = TREE_OPERAND (arg0, 1);
7654 tree arg02 = TREE_OPERAND (arg0, 2);
7655 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7656 arg01 = fold_build1 (code, type, arg01);
7657 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7658 arg02 = fold_build1 (code, type, arg02);
7659 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
7662 /* If this was a conversion, and all we did was to move into
7663 inside the COND_EXPR, bring it back out. But leave it if
7664 it is a conversion from integer to integer and the
7665 result precision is no wider than a word since such a
7666 conversion is cheap and may be optimized away by combine,
7667 while it couldn't if it were outside the COND_EXPR. Then return
7668 so we don't get into an infinite recursion loop taking the
7669 conversion out and then back in. */
7671 if ((code == NOP_EXPR || code == CONVERT_EXPR
7672 || code == NON_LVALUE_EXPR)
7673 && TREE_CODE (tem) == COND_EXPR
7674 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7675 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7676 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7677 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7678 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7679 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7680 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7682 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7683 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7684 || flag_syntax_only))
7685 tem = build1 (code, type,
7687 TREE_TYPE (TREE_OPERAND
7688 (TREE_OPERAND (tem, 1), 0)),
7689 TREE_OPERAND (tem, 0),
7690 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7691 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
7694 else if (COMPARISON_CLASS_P (arg0))
7696 if (TREE_CODE (type) == BOOLEAN_TYPE)
7698 arg0 = copy_node (arg0);
7699 TREE_TYPE (arg0) = type;
7702 else if (TREE_CODE (type) != INTEGER_TYPE)
7703 return fold_build3 (COND_EXPR, type, arg0,
7704 fold_build1 (code, type,
7706 fold_build1 (code, type,
7707 integer_zero_node));
7714 /* Re-association barriers around constants and other re-association
7715 barriers can be removed. */
7716 if (CONSTANT_CLASS_P (op0)
7717 || TREE_CODE (op0) == PAREN_EXPR)
7718 return fold_convert (type, op0);
7724 case FIX_TRUNC_EXPR:
7725 if (TREE_TYPE (op0) == type)
7728 /* If we have (type) (a CMP b) and type is an integral type, return
7729 new expression involving the new type. */
7730 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
7731 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
7732 TREE_OPERAND (op0, 1));
7734 /* Handle cases of two conversions in a row. */
7735 if (TREE_CODE (op0) == NOP_EXPR
7736 || TREE_CODE (op0) == CONVERT_EXPR)
7738 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
7739 tree inter_type = TREE_TYPE (op0);
7740 int inside_int = INTEGRAL_TYPE_P (inside_type);
7741 int inside_ptr = POINTER_TYPE_P (inside_type);
7742 int inside_float = FLOAT_TYPE_P (inside_type);
7743 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
7744 unsigned int inside_prec = TYPE_PRECISION (inside_type);
7745 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
7746 int inter_int = INTEGRAL_TYPE_P (inter_type);
7747 int inter_ptr = POINTER_TYPE_P (inter_type);
7748 int inter_float = FLOAT_TYPE_P (inter_type);
7749 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
7750 unsigned int inter_prec = TYPE_PRECISION (inter_type);
7751 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
7752 int final_int = INTEGRAL_TYPE_P (type);
7753 int final_ptr = POINTER_TYPE_P (type);
7754 int final_float = FLOAT_TYPE_P (type);
7755 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
7756 unsigned int final_prec = TYPE_PRECISION (type);
7757 int final_unsignedp = TYPE_UNSIGNED (type);
7759 /* In addition to the cases of two conversions in a row
7760 handled below, if we are converting something to its own
7761 type via an object of identical or wider precision, neither
7762 conversion is needed. */
7763 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
7764 && (((inter_int || inter_ptr) && final_int)
7765 || (inter_float && final_float))
7766 && inter_prec >= final_prec)
7767 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7769 /* Likewise, if the intermediate and final types are either both
7770 float or both integer, we don't need the middle conversion if
7771 it is wider than the final type and doesn't change the signedness
7772 (for integers). Avoid this if the final type is a pointer
7773 since then we sometimes need the inner conversion. Likewise if
7774 the outer has a precision not equal to the size of its mode. */
7775 if (((inter_int && inside_int)
7776 || (inter_float && inside_float)
7777 || (inter_vec && inside_vec))
7778 && inter_prec >= inside_prec
7779 && (inter_float || inter_vec
7780 || inter_unsignedp == inside_unsignedp)
7781 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7782 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7784 && (! final_vec || inter_prec == inside_prec))
7785 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7787 /* If we have a sign-extension of a zero-extended value, we can
7788 replace that by a single zero-extension. */
7789 if (inside_int && inter_int && final_int
7790 && inside_prec < inter_prec && inter_prec < final_prec
7791 && inside_unsignedp && !inter_unsignedp)
7792 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7794 /* Two conversions in a row are not needed unless:
7795 - some conversion is floating-point (overstrict for now), or
7796 - some conversion is a vector (overstrict for now), or
7797 - the intermediate type is narrower than both initial and
7799 - the intermediate type and innermost type differ in signedness,
7800 and the outermost type is wider than the intermediate, or
7801 - the initial type is a pointer type and the precisions of the
7802 intermediate and final types differ, or
7803 - the final type is a pointer type and the precisions of the
7804 initial and intermediate types differ. */
7805 if (! inside_float && ! inter_float && ! final_float
7806 && ! inside_vec && ! inter_vec && ! final_vec
7807 && (inter_prec >= inside_prec || inter_prec >= final_prec)
7808 && ! (inside_int && inter_int
7809 && inter_unsignedp != inside_unsignedp
7810 && inter_prec < final_prec)
7811 && ((inter_unsignedp && inter_prec > inside_prec)
7812 == (final_unsignedp && final_prec > inter_prec))
7813 && ! (inside_ptr && inter_prec != final_prec)
7814 && ! (final_ptr && inside_prec != inter_prec)
7815 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7816 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
7817 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7820 /* Handle (T *)&A.B.C for A being of type T and B and C
7821 living at offset zero. This occurs frequently in
7822 C++ upcasting and then accessing the base. */
7823 if (TREE_CODE (op0) == ADDR_EXPR
7824 && POINTER_TYPE_P (type)
7825 && handled_component_p (TREE_OPERAND (op0, 0)))
7827 HOST_WIDE_INT bitsize, bitpos;
7829 enum machine_mode mode;
7830 int unsignedp, volatilep;
7831 tree base = TREE_OPERAND (op0, 0);
7832 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
7833 &mode, &unsignedp, &volatilep, false);
7834 /* If the reference was to a (constant) zero offset, we can use
7835 the address of the base if it has the same base type
7836 as the result type. */
7837 if (! offset && bitpos == 0
7838 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
7839 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
7840 return fold_convert (type, fold_addr_expr (base));
7843 if ((TREE_CODE (op0) == MODIFY_EXPR
7844 || TREE_CODE (op0) == GIMPLE_MODIFY_STMT)
7845 && TREE_CONSTANT (GENERIC_TREE_OPERAND (op0, 1))
7846 /* Detect assigning a bitfield. */
7847 && !(TREE_CODE (GENERIC_TREE_OPERAND (op0, 0)) == COMPONENT_REF
7849 (TREE_OPERAND (GENERIC_TREE_OPERAND (op0, 0), 1))))
7851 /* Don't leave an assignment inside a conversion
7852 unless assigning a bitfield. */
7853 tem = fold_build1 (code, type, GENERIC_TREE_OPERAND (op0, 1));
7854 /* First do the assignment, then return converted constant. */
7855 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
7856 TREE_NO_WARNING (tem) = 1;
7857 TREE_USED (tem) = 1;
7861 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7862 constants (if x has signed type, the sign bit cannot be set
7863 in c). This folds extension into the BIT_AND_EXPR. */
7864 if (INTEGRAL_TYPE_P (type)
7865 && TREE_CODE (type) != BOOLEAN_TYPE
7866 && TREE_CODE (op0) == BIT_AND_EXPR
7867 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
7870 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
7873 if (TYPE_UNSIGNED (TREE_TYPE (and))
7874 || (TYPE_PRECISION (type)
7875 <= TYPE_PRECISION (TREE_TYPE (and))))
7877 else if (TYPE_PRECISION (TREE_TYPE (and1))
7878 <= HOST_BITS_PER_WIDE_INT
7879 && host_integerp (and1, 1))
7881 unsigned HOST_WIDE_INT cst;
7883 cst = tree_low_cst (and1, 1);
7884 cst &= (HOST_WIDE_INT) -1
7885 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
7886 change = (cst == 0);
7887 #ifdef LOAD_EXTEND_OP
7889 && !flag_syntax_only
7890 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
7893 tree uns = unsigned_type_for (TREE_TYPE (and0));
7894 and0 = fold_convert (uns, and0);
7895 and1 = fold_convert (uns, and1);
7901 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
7902 TREE_INT_CST_HIGH (and1), 0,
7903 TREE_OVERFLOW (and1));
7904 return fold_build2 (BIT_AND_EXPR, type,
7905 fold_convert (type, and0), tem);
7909 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
7910 when one of the new casts will fold away. Conservatively we assume
7911 that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
7912 if (POINTER_TYPE_P (type)
7913 && TREE_CODE (arg0) == POINTER_PLUS_EXPR
7914 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7915 || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
7916 || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
7918 tree arg00 = TREE_OPERAND (arg0, 0);
7919 tree arg01 = TREE_OPERAND (arg0, 1);
7921 return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
7922 fold_convert (sizetype, arg01));
7925 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
7926 of the same precision, and X is an integer type not narrower than
7927 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
7928 if (INTEGRAL_TYPE_P (type)
7929 && TREE_CODE (op0) == BIT_NOT_EXPR
7930 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7931 && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
7932 || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
7933 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
7935 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
7936 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7937 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
7938 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
7941 /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the
7942 type of X and Y (integer types only). */
7943 if (INTEGRAL_TYPE_P (type)
7944 && TREE_CODE (op0) == MULT_EXPR
7945 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7946 && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (op0)))
7948 /* Be careful not to introduce new overflows. */
7950 if (TYPE_OVERFLOW_WRAPS (type))
7953 mult_type = unsigned_type_for (type);
7955 tem = fold_build2 (MULT_EXPR, mult_type,
7956 fold_convert (mult_type, TREE_OPERAND (op0, 0)),
7957 fold_convert (mult_type, TREE_OPERAND (op0, 1)));
7958 return fold_convert (type, tem);
7961 tem = fold_convert_const (code, type, op0);
7962 return tem ? tem : NULL_TREE;
7964 case FIXED_CONVERT_EXPR:
7965 tem = fold_convert_const (code, type, arg0);
7966 return tem ? tem : NULL_TREE;
7968 case VIEW_CONVERT_EXPR:
7969 if (TREE_TYPE (op0) == type)
7971 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
7972 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7974 /* For integral conversions with the same precision or pointer
7975 conversions use a NOP_EXPR instead. */
7976 if ((INTEGRAL_TYPE_P (type)
7977 || POINTER_TYPE_P (type))
7978 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
7979 || POINTER_TYPE_P (TREE_TYPE (op0)))
7980 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0))
7981 /* Do not muck with VIEW_CONVERT_EXPRs that convert from
7982 a sub-type to its base type as generated by the Ada FE. */
7983 && !(INTEGRAL_TYPE_P (TREE_TYPE (op0))
7984 && TREE_TYPE (TREE_TYPE (op0))))
7985 return fold_convert (type, op0);
7987 /* Strip inner integral conversions that do not change the precision. */
7988 if ((TREE_CODE (op0) == NOP_EXPR
7989 || TREE_CODE (op0) == CONVERT_EXPR)
7990 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
7991 || POINTER_TYPE_P (TREE_TYPE (op0)))
7992 && (INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
7993 || POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0))))
7994 && (TYPE_PRECISION (TREE_TYPE (op0))
7995 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
7996 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7998 return fold_view_convert_expr (type, op0);
8001 tem = fold_negate_expr (arg0);
8003 return fold_convert (type, tem);
8007 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
8008 return fold_abs_const (arg0, type);
8009 else if (TREE_CODE (arg0) == NEGATE_EXPR)
8010 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
8011 /* Convert fabs((double)float) into (double)fabsf(float). */
8012 else if (TREE_CODE (arg0) == NOP_EXPR
8013 && TREE_CODE (type) == REAL_TYPE)
8015 tree targ0 = strip_float_extensions (arg0);
8017 return fold_convert (type, fold_build1 (ABS_EXPR,
8021 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
8022 else if (TREE_CODE (arg0) == ABS_EXPR)
8024 else if (tree_expr_nonnegative_p (arg0))
8027 /* Strip sign ops from argument. */
8028 if (TREE_CODE (type) == REAL_TYPE)
8030 tem = fold_strip_sign_ops (arg0);
8032 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
8037 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8038 return fold_convert (type, arg0);
8039 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8041 tree itype = TREE_TYPE (type);
8042 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
8043 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
8044 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
8046 if (TREE_CODE (arg0) == COMPLEX_CST)
8048 tree itype = TREE_TYPE (type);
8049 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
8050 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
8051 return build_complex (type, rpart, negate_expr (ipart));
8053 if (TREE_CODE (arg0) == CONJ_EXPR)
8054 return fold_convert (type, TREE_OPERAND (arg0, 0));
8058 if (TREE_CODE (arg0) == INTEGER_CST)
8059 return fold_not_const (arg0, type);
8060 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
8061 return fold_convert (type, TREE_OPERAND (arg0, 0));
8062 /* Convert ~ (-A) to A - 1. */
8063 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
8064 return fold_build2 (MINUS_EXPR, type,
8065 fold_convert (type, TREE_OPERAND (arg0, 0)),
8066 build_int_cst (type, 1));
8067 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
8068 else if (INTEGRAL_TYPE_P (type)
8069 && ((TREE_CODE (arg0) == MINUS_EXPR
8070 && integer_onep (TREE_OPERAND (arg0, 1)))
8071 || (TREE_CODE (arg0) == PLUS_EXPR
8072 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
8073 return fold_build1 (NEGATE_EXPR, type,
8074 fold_convert (type, TREE_OPERAND (arg0, 0)));
8075 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8076 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8077 && (tem = fold_unary (BIT_NOT_EXPR, type,
8079 TREE_OPERAND (arg0, 0)))))
8080 return fold_build2 (BIT_XOR_EXPR, type, tem,
8081 fold_convert (type, TREE_OPERAND (arg0, 1)));
8082 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8083 && (tem = fold_unary (BIT_NOT_EXPR, type,
8085 TREE_OPERAND (arg0, 1)))))
8086 return fold_build2 (BIT_XOR_EXPR, type,
8087 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
8088 /* Perform BIT_NOT_EXPR on each element individually. */
8089 else if (TREE_CODE (arg0) == VECTOR_CST)
8091 tree elements = TREE_VECTOR_CST_ELTS (arg0), elem, list = NULL_TREE;
8092 int count = TYPE_VECTOR_SUBPARTS (type), i;
8094 for (i = 0; i < count; i++)
8098 elem = TREE_VALUE (elements);
8099 elem = fold_unary (BIT_NOT_EXPR, TREE_TYPE (type), elem);
8100 if (elem == NULL_TREE)
8102 elements = TREE_CHAIN (elements);
8105 elem = build_int_cst (TREE_TYPE (type), -1);
8106 list = tree_cons (NULL_TREE, elem, list);
8109 return build_vector (type, nreverse (list));
8114 case TRUTH_NOT_EXPR:
8115 /* The argument to invert_truthvalue must have Boolean type. */
8116 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8117 arg0 = fold_convert (boolean_type_node, arg0);
8119 /* Note that the operand of this must be an int
8120 and its values must be 0 or 1.
8121 ("true" is a fixed value perhaps depending on the language,
8122 but we don't handle values other than 1 correctly yet.) */
8123 tem = fold_truth_not_expr (arg0);
8126 return fold_convert (type, tem);
8129 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8130 return fold_convert (type, arg0);
8131 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8132 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8133 TREE_OPERAND (arg0, 1));
8134 if (TREE_CODE (arg0) == COMPLEX_CST)
8135 return fold_convert (type, TREE_REALPART (arg0));
8136 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8138 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8139 tem = fold_build2 (TREE_CODE (arg0), itype,
8140 fold_build1 (REALPART_EXPR, itype,
8141 TREE_OPERAND (arg0, 0)),
8142 fold_build1 (REALPART_EXPR, itype,
8143 TREE_OPERAND (arg0, 1)));
8144 return fold_convert (type, tem);
8146 if (TREE_CODE (arg0) == CONJ_EXPR)
8148 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8149 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8150 return fold_convert (type, tem);
8152 if (TREE_CODE (arg0) == CALL_EXPR)
8154 tree fn = get_callee_fndecl (arg0);
8155 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8156 switch (DECL_FUNCTION_CODE (fn))
8158 CASE_FLT_FN (BUILT_IN_CEXPI):
8159 fn = mathfn_built_in (type, BUILT_IN_COS);
8161 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8171 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8172 return fold_convert (type, integer_zero_node);
8173 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8174 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8175 TREE_OPERAND (arg0, 0));
8176 if (TREE_CODE (arg0) == COMPLEX_CST)
8177 return fold_convert (type, TREE_IMAGPART (arg0));
8178 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8180 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8181 tem = fold_build2 (TREE_CODE (arg0), itype,
8182 fold_build1 (IMAGPART_EXPR, itype,
8183 TREE_OPERAND (arg0, 0)),
8184 fold_build1 (IMAGPART_EXPR, itype,
8185 TREE_OPERAND (arg0, 1)));
8186 return fold_convert (type, tem);
8188 if (TREE_CODE (arg0) == CONJ_EXPR)
8190 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8191 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8192 return fold_convert (type, negate_expr (tem));
8194 if (TREE_CODE (arg0) == CALL_EXPR)
8196 tree fn = get_callee_fndecl (arg0);
8197 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8198 switch (DECL_FUNCTION_CODE (fn))
8200 CASE_FLT_FN (BUILT_IN_CEXPI):
8201 fn = mathfn_built_in (type, BUILT_IN_SIN);
8203 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8214 } /* switch (code) */
8217 /* Fold a binary expression of code CODE and type TYPE with operands
8218 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8219 Return the folded expression if folding is successful. Otherwise,
8220 return NULL_TREE. */
8223 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8225 enum tree_code compl_code;
8227 if (code == MIN_EXPR)
8228 compl_code = MAX_EXPR;
8229 else if (code == MAX_EXPR)
8230 compl_code = MIN_EXPR;
8234 /* MIN (MAX (a, b), b) == b. */
8235 if (TREE_CODE (op0) == compl_code
8236 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8237 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8239 /* MIN (MAX (b, a), b) == b. */
8240 if (TREE_CODE (op0) == compl_code
8241 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8242 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8243 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8245 /* MIN (a, MAX (a, b)) == a. */
8246 if (TREE_CODE (op1) == compl_code
8247 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8248 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8249 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8251 /* MIN (a, MAX (b, a)) == a. */
8252 if (TREE_CODE (op1) == compl_code
8253 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8254 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8255 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8260 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8261 by changing CODE to reduce the magnitude of constants involved in
8262 ARG0 of the comparison.
8263 Returns a canonicalized comparison tree if a simplification was
8264 possible, otherwise returns NULL_TREE.
8265 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8266 valid if signed overflow is undefined. */
8269 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8270 tree arg0, tree arg1,
8271 bool *strict_overflow_p)
8273 enum tree_code code0 = TREE_CODE (arg0);
8274 tree t, cst0 = NULL_TREE;
8278 /* Match A +- CST code arg1 and CST code arg1. */
8279 if (!(((code0 == MINUS_EXPR
8280 || code0 == PLUS_EXPR)
8281 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8282 || code0 == INTEGER_CST))
8285 /* Identify the constant in arg0 and its sign. */
8286 if (code0 == INTEGER_CST)
8289 cst0 = TREE_OPERAND (arg0, 1);
8290 sgn0 = tree_int_cst_sgn (cst0);
8292 /* Overflowed constants and zero will cause problems. */
8293 if (integer_zerop (cst0)
8294 || TREE_OVERFLOW (cst0))
8297 /* See if we can reduce the magnitude of the constant in
8298 arg0 by changing the comparison code. */
8299 if (code0 == INTEGER_CST)
8301 /* CST <= arg1 -> CST-1 < arg1. */
8302 if (code == LE_EXPR && sgn0 == 1)
8304 /* -CST < arg1 -> -CST-1 <= arg1. */
8305 else if (code == LT_EXPR && sgn0 == -1)
8307 /* CST > arg1 -> CST-1 >= arg1. */
8308 else if (code == GT_EXPR && sgn0 == 1)
8310 /* -CST >= arg1 -> -CST-1 > arg1. */
8311 else if (code == GE_EXPR && sgn0 == -1)
8315 /* arg1 code' CST' might be more canonical. */
8320 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8322 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8324 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8325 else if (code == GT_EXPR
8326 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8328 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8329 else if (code == LE_EXPR
8330 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8332 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8333 else if (code == GE_EXPR
8334 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8338 *strict_overflow_p = true;
8341 /* Now build the constant reduced in magnitude. */
8342 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8343 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8344 if (code0 != INTEGER_CST)
8345 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8347 /* If swapping might yield to a more canonical form, do so. */
8349 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8351 return fold_build2 (code, type, t, arg1);
8354 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8355 overflow further. Try to decrease the magnitude of constants involved
8356 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8357 and put sole constants at the second argument position.
8358 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8361 maybe_canonicalize_comparison (enum tree_code code, tree type,
8362 tree arg0, tree arg1)
8365 bool strict_overflow_p;
8366 const char * const warnmsg = G_("assuming signed overflow does not occur "
8367 "when reducing constant in comparison");
8369 /* In principle pointers also have undefined overflow behavior,
8370 but that causes problems elsewhere. */
8371 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8372 || POINTER_TYPE_P (TREE_TYPE (arg0)))
8375 /* Try canonicalization by simplifying arg0. */
8376 strict_overflow_p = false;
8377 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8378 &strict_overflow_p);
8381 if (strict_overflow_p)
8382 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8386 /* Try canonicalization by simplifying arg1 using the swapped
8388 code = swap_tree_comparison (code);
8389 strict_overflow_p = false;
8390 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8391 &strict_overflow_p);
8392 if (t && strict_overflow_p)
8393 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8397 /* Return whether BASE + OFFSET + BITPOS may wrap around the address
8398 space. This is used to avoid issuing overflow warnings for
8399 expressions like &p->x which can not wrap. */
8402 pointer_may_wrap_p (tree base, tree offset, HOST_WIDE_INT bitpos)
8404 unsigned HOST_WIDE_INT offset_low, total_low;
8405 HOST_WIDE_INT size, offset_high, total_high;
8407 if (!POINTER_TYPE_P (TREE_TYPE (base)))
8413 if (offset == NULL_TREE)
8418 else if (TREE_CODE (offset) != INTEGER_CST || TREE_OVERFLOW (offset))
8422 offset_low = TREE_INT_CST_LOW (offset);
8423 offset_high = TREE_INT_CST_HIGH (offset);
8426 if (add_double_with_sign (offset_low, offset_high,
8427 bitpos / BITS_PER_UNIT, 0,
8428 &total_low, &total_high,
8432 if (total_high != 0)
8435 size = int_size_in_bytes (TREE_TYPE (TREE_TYPE (base)));
8439 /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
8441 if (TREE_CODE (base) == ADDR_EXPR)
8443 HOST_WIDE_INT base_size;
8445 base_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (base, 0)));
8446 if (base_size > 0 && size < base_size)
8450 return total_low > (unsigned HOST_WIDE_INT) size;
8453 /* Subroutine of fold_binary. This routine performs all of the
8454 transformations that are common to the equality/inequality
8455 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8456 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8457 fold_binary should call fold_binary. Fold a comparison with
8458 tree code CODE and type TYPE with operands OP0 and OP1. Return
8459 the folded comparison or NULL_TREE. */
8462 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8464 tree arg0, arg1, tem;
8469 STRIP_SIGN_NOPS (arg0);
8470 STRIP_SIGN_NOPS (arg1);
8472 tem = fold_relational_const (code, type, arg0, arg1);
8473 if (tem != NULL_TREE)
8476 /* If one arg is a real or integer constant, put it last. */
8477 if (tree_swap_operands_p (arg0, arg1, true))
8478 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8480 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8481 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8482 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8483 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8484 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8485 && (TREE_CODE (arg1) == INTEGER_CST
8486 && !TREE_OVERFLOW (arg1)))
8488 tree const1 = TREE_OPERAND (arg0, 1);
8490 tree variable = TREE_OPERAND (arg0, 0);
8493 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8495 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8496 TREE_TYPE (arg1), const2, const1);
8498 /* If the constant operation overflowed this can be
8499 simplified as a comparison against INT_MAX/INT_MIN. */
8500 if (TREE_CODE (lhs) == INTEGER_CST
8501 && TREE_OVERFLOW (lhs))
8503 int const1_sgn = tree_int_cst_sgn (const1);
8504 enum tree_code code2 = code;
8506 /* Get the sign of the constant on the lhs if the
8507 operation were VARIABLE + CONST1. */
8508 if (TREE_CODE (arg0) == MINUS_EXPR)
8509 const1_sgn = -const1_sgn;
8511 /* The sign of the constant determines if we overflowed
8512 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8513 Canonicalize to the INT_MIN overflow by swapping the comparison
8515 if (const1_sgn == -1)
8516 code2 = swap_tree_comparison (code);
8518 /* We now can look at the canonicalized case
8519 VARIABLE + 1 CODE2 INT_MIN
8520 and decide on the result. */
8521 if (code2 == LT_EXPR
8523 || code2 == EQ_EXPR)
8524 return omit_one_operand (type, boolean_false_node, variable);
8525 else if (code2 == NE_EXPR
8527 || code2 == GT_EXPR)
8528 return omit_one_operand (type, boolean_true_node, variable);
8531 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8532 && (TREE_CODE (lhs) != INTEGER_CST
8533 || !TREE_OVERFLOW (lhs)))
8535 fold_overflow_warning (("assuming signed overflow does not occur "
8536 "when changing X +- C1 cmp C2 to "
8538 WARN_STRICT_OVERFLOW_COMPARISON);
8539 return fold_build2 (code, type, variable, lhs);
8543 /* For comparisons of pointers we can decompose it to a compile time
8544 comparison of the base objects and the offsets into the object.
8545 This requires at least one operand being an ADDR_EXPR or a
8546 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8547 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8548 && (TREE_CODE (arg0) == ADDR_EXPR
8549 || TREE_CODE (arg1) == ADDR_EXPR
8550 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
8551 || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
8553 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8554 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8555 enum machine_mode mode;
8556 int volatilep, unsignedp;
8557 bool indirect_base0 = false, indirect_base1 = false;
8559 /* Get base and offset for the access. Strip ADDR_EXPR for
8560 get_inner_reference, but put it back by stripping INDIRECT_REF
8561 off the base object if possible. indirect_baseN will be true
8562 if baseN is not an address but refers to the object itself. */
8564 if (TREE_CODE (arg0) == ADDR_EXPR)
8566 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8567 &bitsize, &bitpos0, &offset0, &mode,
8568 &unsignedp, &volatilep, false);
8569 if (TREE_CODE (base0) == INDIRECT_REF)
8570 base0 = TREE_OPERAND (base0, 0);
8572 indirect_base0 = true;
8574 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
8576 base0 = TREE_OPERAND (arg0, 0);
8577 offset0 = TREE_OPERAND (arg0, 1);
8581 if (TREE_CODE (arg1) == ADDR_EXPR)
8583 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8584 &bitsize, &bitpos1, &offset1, &mode,
8585 &unsignedp, &volatilep, false);
8586 if (TREE_CODE (base1) == INDIRECT_REF)
8587 base1 = TREE_OPERAND (base1, 0);
8589 indirect_base1 = true;
8591 else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
8593 base1 = TREE_OPERAND (arg1, 0);
8594 offset1 = TREE_OPERAND (arg1, 1);
8597 /* If we have equivalent bases we might be able to simplify. */
8598 if (indirect_base0 == indirect_base1
8599 && operand_equal_p (base0, base1, 0))
8601 /* We can fold this expression to a constant if the non-constant
8602 offset parts are equal. */
8603 if ((offset0 == offset1
8604 || (offset0 && offset1
8605 && operand_equal_p (offset0, offset1, 0)))
8608 || POINTER_TYPE_OVERFLOW_UNDEFINED))
8613 && bitpos0 != bitpos1
8614 && (pointer_may_wrap_p (base0, offset0, bitpos0)
8615 || pointer_may_wrap_p (base1, offset1, bitpos1)))
8616 fold_overflow_warning (("assuming pointer wraparound does not "
8617 "occur when comparing P +- C1 with "
8619 WARN_STRICT_OVERFLOW_CONDITIONAL);
8624 return build_int_cst (boolean_type_node, bitpos0 == bitpos1);
8626 return build_int_cst (boolean_type_node, bitpos0 != bitpos1);
8628 return build_int_cst (boolean_type_node, bitpos0 < bitpos1);
8630 return build_int_cst (boolean_type_node, bitpos0 <= bitpos1);
8632 return build_int_cst (boolean_type_node, bitpos0 >= bitpos1);
8634 return build_int_cst (boolean_type_node, bitpos0 > bitpos1);
8638 /* We can simplify the comparison to a comparison of the variable
8639 offset parts if the constant offset parts are equal.
8640 Be careful to use signed size type here because otherwise we
8641 mess with array offsets in the wrong way. This is possible
8642 because pointer arithmetic is restricted to retain within an
8643 object and overflow on pointer differences is undefined as of
8644 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8645 else if (bitpos0 == bitpos1
8646 && ((code == EQ_EXPR || code == NE_EXPR)
8647 || POINTER_TYPE_OVERFLOW_UNDEFINED))
8649 tree signed_size_type_node;
8650 signed_size_type_node = signed_type_for (size_type_node);
8652 /* By converting to signed size type we cover middle-end pointer
8653 arithmetic which operates on unsigned pointer types of size
8654 type size and ARRAY_REF offsets which are properly sign or
8655 zero extended from their type in case it is narrower than
8657 if (offset0 == NULL_TREE)
8658 offset0 = build_int_cst (signed_size_type_node, 0);
8660 offset0 = fold_convert (signed_size_type_node, offset0);
8661 if (offset1 == NULL_TREE)
8662 offset1 = build_int_cst (signed_size_type_node, 0);
8664 offset1 = fold_convert (signed_size_type_node, offset1);
8668 && (pointer_may_wrap_p (base0, offset0, bitpos0)
8669 || pointer_may_wrap_p (base1, offset1, bitpos1)))
8670 fold_overflow_warning (("assuming pointer wraparound does not "
8671 "occur when comparing P +- C1 with "
8673 WARN_STRICT_OVERFLOW_COMPARISON);
8675 return fold_build2 (code, type, offset0, offset1);
8678 /* For non-equal bases we can simplify if they are addresses
8679 of local binding decls or constants. */
8680 else if (indirect_base0 && indirect_base1
8681 /* We know that !operand_equal_p (base0, base1, 0)
8682 because the if condition was false. But make
8683 sure two decls are not the same. */
8685 && TREE_CODE (arg0) == ADDR_EXPR
8686 && TREE_CODE (arg1) == ADDR_EXPR
8687 && (((TREE_CODE (base0) == VAR_DECL
8688 || TREE_CODE (base0) == PARM_DECL)
8689 && (targetm.binds_local_p (base0)
8690 || CONSTANT_CLASS_P (base1)))
8691 || CONSTANT_CLASS_P (base0))
8692 && (((TREE_CODE (base1) == VAR_DECL
8693 || TREE_CODE (base1) == PARM_DECL)
8694 && (targetm.binds_local_p (base1)
8695 || CONSTANT_CLASS_P (base0)))
8696 || CONSTANT_CLASS_P (base1)))
8698 if (code == EQ_EXPR)
8699 return omit_two_operands (type, boolean_false_node, arg0, arg1);
8700 else if (code == NE_EXPR)
8701 return omit_two_operands (type, boolean_true_node, arg0, arg1);
8703 /* For equal offsets we can simplify to a comparison of the
8705 else if (bitpos0 == bitpos1
8707 ? base0 != TREE_OPERAND (arg0, 0) : base0 != arg0)
8709 ? base1 != TREE_OPERAND (arg1, 0) : base1 != arg1)
8710 && ((offset0 == offset1)
8711 || (offset0 && offset1
8712 && operand_equal_p (offset0, offset1, 0))))
8715 base0 = fold_addr_expr (base0);
8717 base1 = fold_addr_expr (base1);
8718 return fold_build2 (code, type, base0, base1);
8722 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8723 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8724 the resulting offset is smaller in absolute value than the
8726 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8727 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8728 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8729 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8730 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
8731 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8732 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
8734 tree const1 = TREE_OPERAND (arg0, 1);
8735 tree const2 = TREE_OPERAND (arg1, 1);
8736 tree variable1 = TREE_OPERAND (arg0, 0);
8737 tree variable2 = TREE_OPERAND (arg1, 0);
8739 const char * const warnmsg = G_("assuming signed overflow does not "
8740 "occur when combining constants around "
8743 /* Put the constant on the side where it doesn't overflow and is
8744 of lower absolute value than before. */
8745 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8746 ? MINUS_EXPR : PLUS_EXPR,
8748 if (!TREE_OVERFLOW (cst)
8749 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
8751 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8752 return fold_build2 (code, type,
8754 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
8758 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8759 ? MINUS_EXPR : PLUS_EXPR,
8761 if (!TREE_OVERFLOW (cst)
8762 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
8764 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8765 return fold_build2 (code, type,
8766 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
8772 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
8773 signed arithmetic case. That form is created by the compiler
8774 often enough for folding it to be of value. One example is in
8775 computing loop trip counts after Operator Strength Reduction. */
8776 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8777 && TREE_CODE (arg0) == MULT_EXPR
8778 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8779 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8780 && integer_zerop (arg1))
8782 tree const1 = TREE_OPERAND (arg0, 1);
8783 tree const2 = arg1; /* zero */
8784 tree variable1 = TREE_OPERAND (arg0, 0);
8785 enum tree_code cmp_code = code;
8787 gcc_assert (!integer_zerop (const1));
8789 fold_overflow_warning (("assuming signed overflow does not occur when "
8790 "eliminating multiplication in comparison "
8792 WARN_STRICT_OVERFLOW_COMPARISON);
8794 /* If const1 is negative we swap the sense of the comparison. */
8795 if (tree_int_cst_sgn (const1) < 0)
8796 cmp_code = swap_tree_comparison (cmp_code);
8798 return fold_build2 (cmp_code, type, variable1, const2);
8801 tem = maybe_canonicalize_comparison (code, type, op0, op1);
8805 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8807 tree targ0 = strip_float_extensions (arg0);
8808 tree targ1 = strip_float_extensions (arg1);
8809 tree newtype = TREE_TYPE (targ0);
8811 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8812 newtype = TREE_TYPE (targ1);
8814 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8815 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8816 return fold_build2 (code, type, fold_convert (newtype, targ0),
8817 fold_convert (newtype, targ1));
8819 /* (-a) CMP (-b) -> b CMP a */
8820 if (TREE_CODE (arg0) == NEGATE_EXPR
8821 && TREE_CODE (arg1) == NEGATE_EXPR)
8822 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8823 TREE_OPERAND (arg0, 0));
8825 if (TREE_CODE (arg1) == REAL_CST)
8827 REAL_VALUE_TYPE cst;
8828 cst = TREE_REAL_CST (arg1);
8830 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8831 if (TREE_CODE (arg0) == NEGATE_EXPR)
8832 return fold_build2 (swap_tree_comparison (code), type,
8833 TREE_OPERAND (arg0, 0),
8834 build_real (TREE_TYPE (arg1),
8835 REAL_VALUE_NEGATE (cst)));
8837 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8838 /* a CMP (-0) -> a CMP 0 */
8839 if (REAL_VALUE_MINUS_ZERO (cst))
8840 return fold_build2 (code, type, arg0,
8841 build_real (TREE_TYPE (arg1), dconst0));
8843 /* x != NaN is always true, other ops are always false. */
8844 if (REAL_VALUE_ISNAN (cst)
8845 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8847 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8848 return omit_one_operand (type, tem, arg0);
8851 /* Fold comparisons against infinity. */
8852 if (REAL_VALUE_ISINF (cst))
8854 tem = fold_inf_compare (code, type, arg0, arg1);
8855 if (tem != NULL_TREE)
8860 /* If this is a comparison of a real constant with a PLUS_EXPR
8861 or a MINUS_EXPR of a real constant, we can convert it into a
8862 comparison with a revised real constant as long as no overflow
8863 occurs when unsafe_math_optimizations are enabled. */
8864 if (flag_unsafe_math_optimizations
8865 && TREE_CODE (arg1) == REAL_CST
8866 && (TREE_CODE (arg0) == PLUS_EXPR
8867 || TREE_CODE (arg0) == MINUS_EXPR)
8868 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8869 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8870 ? MINUS_EXPR : PLUS_EXPR,
8871 arg1, TREE_OPERAND (arg0, 1), 0))
8872 && !TREE_OVERFLOW (tem))
8873 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
8875 /* Likewise, we can simplify a comparison of a real constant with
8876 a MINUS_EXPR whose first operand is also a real constant, i.e.
8877 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
8878 floating-point types only if -fassociative-math is set. */
8879 if (flag_associative_math
8880 && TREE_CODE (arg1) == REAL_CST
8881 && TREE_CODE (arg0) == MINUS_EXPR
8882 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8883 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8885 && !TREE_OVERFLOW (tem))
8886 return fold_build2 (swap_tree_comparison (code), type,
8887 TREE_OPERAND (arg0, 1), tem);
8889 /* Fold comparisons against built-in math functions. */
8890 if (TREE_CODE (arg1) == REAL_CST
8891 && flag_unsafe_math_optimizations
8892 && ! flag_errno_math)
8894 enum built_in_function fcode = builtin_mathfn_code (arg0);
8896 if (fcode != END_BUILTINS)
8898 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8899 if (tem != NULL_TREE)
8905 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8906 && (TREE_CODE (arg0) == NOP_EXPR
8907 || TREE_CODE (arg0) == CONVERT_EXPR))
8909 /* If we are widening one operand of an integer comparison,
8910 see if the other operand is similarly being widened. Perhaps we
8911 can do the comparison in the narrower type. */
8912 tem = fold_widened_comparison (code, type, arg0, arg1);
8916 /* Or if we are changing signedness. */
8917 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
8922 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8923 constant, we can simplify it. */
8924 if (TREE_CODE (arg1) == INTEGER_CST
8925 && (TREE_CODE (arg0) == MIN_EXPR
8926 || TREE_CODE (arg0) == MAX_EXPR)
8927 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8929 tem = optimize_minmax_comparison (code, type, op0, op1);
8934 /* Simplify comparison of something with itself. (For IEEE
8935 floating-point, we can only do some of these simplifications.) */
8936 if (operand_equal_p (arg0, arg1, 0))
8941 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8942 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8943 return constant_boolean_node (1, type);
8948 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8949 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8950 return constant_boolean_node (1, type);
8951 return fold_build2 (EQ_EXPR, type, arg0, arg1);
8954 /* For NE, we can only do this simplification if integer
8955 or we don't honor IEEE floating point NaNs. */
8956 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8957 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8959 /* ... fall through ... */
8962 return constant_boolean_node (0, type);
8968 /* If we are comparing an expression that just has comparisons
8969 of two integer values, arithmetic expressions of those comparisons,
8970 and constants, we can simplify it. There are only three cases
8971 to check: the two values can either be equal, the first can be
8972 greater, or the second can be greater. Fold the expression for
8973 those three values. Since each value must be 0 or 1, we have
8974 eight possibilities, each of which corresponds to the constant 0
8975 or 1 or one of the six possible comparisons.
8977 This handles common cases like (a > b) == 0 but also handles
8978 expressions like ((x > y) - (y > x)) > 0, which supposedly
8979 occur in macroized code. */
8981 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8983 tree cval1 = 0, cval2 = 0;
8986 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8987 /* Don't handle degenerate cases here; they should already
8988 have been handled anyway. */
8989 && cval1 != 0 && cval2 != 0
8990 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8991 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8992 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8993 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8994 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8995 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8996 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8998 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8999 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9001 /* We can't just pass T to eval_subst in case cval1 or cval2
9002 was the same as ARG1. */
9005 = fold_build2 (code, type,
9006 eval_subst (arg0, cval1, maxval,
9010 = fold_build2 (code, type,
9011 eval_subst (arg0, cval1, maxval,
9015 = fold_build2 (code, type,
9016 eval_subst (arg0, cval1, minval,
9020 /* All three of these results should be 0 or 1. Confirm they are.
9021 Then use those values to select the proper code to use. */
9023 if (TREE_CODE (high_result) == INTEGER_CST
9024 && TREE_CODE (equal_result) == INTEGER_CST
9025 && TREE_CODE (low_result) == INTEGER_CST)
9027 /* Make a 3-bit mask with the high-order bit being the
9028 value for `>', the next for '=', and the low for '<'. */
9029 switch ((integer_onep (high_result) * 4)
9030 + (integer_onep (equal_result) * 2)
9031 + integer_onep (low_result))
9035 return omit_one_operand (type, integer_zero_node, arg0);
9056 return omit_one_operand (type, integer_one_node, arg0);
9060 return save_expr (build2 (code, type, cval1, cval2));
9061 return fold_build2 (code, type, cval1, cval2);
9066 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9067 into a single range test. */
9068 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9069 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9070 && TREE_CODE (arg1) == INTEGER_CST
9071 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9072 && !integer_zerop (TREE_OPERAND (arg0, 1))
9073 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9074 && !TREE_OVERFLOW (arg1))
9076 tem = fold_div_compare (code, type, arg0, arg1);
9077 if (tem != NULL_TREE)
9081 /* Fold ~X op ~Y as Y op X. */
9082 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9083 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9085 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9086 return fold_build2 (code, type,
9087 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
9088 TREE_OPERAND (arg0, 0));
9091 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
9092 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9093 && TREE_CODE (arg1) == INTEGER_CST)
9095 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9096 return fold_build2 (swap_tree_comparison (code), type,
9097 TREE_OPERAND (arg0, 0),
9098 fold_build1 (BIT_NOT_EXPR, cmp_type,
9099 fold_convert (cmp_type, arg1)));
9106 /* Subroutine of fold_binary. Optimize complex multiplications of the
9107 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9108 argument EXPR represents the expression "z" of type TYPE. */
9111 fold_mult_zconjz (tree type, tree expr)
9113 tree itype = TREE_TYPE (type);
9114 tree rpart, ipart, tem;
9116 if (TREE_CODE (expr) == COMPLEX_EXPR)
9118 rpart = TREE_OPERAND (expr, 0);
9119 ipart = TREE_OPERAND (expr, 1);
9121 else if (TREE_CODE (expr) == COMPLEX_CST)
9123 rpart = TREE_REALPART (expr);
9124 ipart = TREE_IMAGPART (expr);
9128 expr = save_expr (expr);
9129 rpart = fold_build1 (REALPART_EXPR, itype, expr);
9130 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
9133 rpart = save_expr (rpart);
9134 ipart = save_expr (ipart);
9135 tem = fold_build2 (PLUS_EXPR, itype,
9136 fold_build2 (MULT_EXPR, itype, rpart, rpart),
9137 fold_build2 (MULT_EXPR, itype, ipart, ipart));
9138 return fold_build2 (COMPLEX_EXPR, type, tem,
9139 fold_convert (itype, integer_zero_node));
9143 /* Subroutine of fold_binary. If P is the value of EXPR, computes
9144 power-of-two M and (arbitrary) N such that M divides (P-N). This condition
9145 guarantees that P and N have the same least significant log2(M) bits.
9146 N is not otherwise constrained. In particular, N is not normalized to
9147 0 <= N < M as is common. In general, the precise value of P is unknown.
9148 M is chosen as large as possible such that constant N can be determined.
9150 Returns M and sets *RESIDUE to N. */
9152 static unsigned HOST_WIDE_INT
9153 get_pointer_modulus_and_residue (tree expr, unsigned HOST_WIDE_INT *residue)
9155 enum tree_code code;
9159 code = TREE_CODE (expr);
9160 if (code == ADDR_EXPR)
9162 expr = TREE_OPERAND (expr, 0);
9163 if (handled_component_p (expr))
9165 HOST_WIDE_INT bitsize, bitpos;
9167 enum machine_mode mode;
9168 int unsignedp, volatilep;
9170 expr = get_inner_reference (expr, &bitsize, &bitpos, &offset,
9171 &mode, &unsignedp, &volatilep, false);
9172 *residue = bitpos / BITS_PER_UNIT;
9175 if (TREE_CODE (offset) == INTEGER_CST)
9176 *residue += TREE_INT_CST_LOW (offset);
9178 /* We don't handle more complicated offset expressions. */
9183 if (DECL_P (expr) && TREE_CODE (expr) != FUNCTION_DECL)
9184 return DECL_ALIGN_UNIT (expr);
9186 else if (code == POINTER_PLUS_EXPR)
9189 unsigned HOST_WIDE_INT modulus;
9190 enum tree_code inner_code;
9192 op0 = TREE_OPERAND (expr, 0);
9194 modulus = get_pointer_modulus_and_residue (op0, residue);
9196 op1 = TREE_OPERAND (expr, 1);
9198 inner_code = TREE_CODE (op1);
9199 if (inner_code == INTEGER_CST)
9201 *residue += TREE_INT_CST_LOW (op1);
9204 else if (inner_code == MULT_EXPR)
9206 op1 = TREE_OPERAND (op1, 1);
9207 if (TREE_CODE (op1) == INTEGER_CST)
9209 unsigned HOST_WIDE_INT align;
9211 /* Compute the greatest power-of-2 divisor of op1. */
9212 align = TREE_INT_CST_LOW (op1);
9215 /* If align is non-zero and less than *modulus, replace
9216 *modulus with align., If align is 0, then either op1 is 0
9217 or the greatest power-of-2 divisor of op1 doesn't fit in an
9218 unsigned HOST_WIDE_INT. In either case, no additional
9219 constraint is imposed. */
9221 modulus = MIN (modulus, align);
9228 /* If we get here, we were unable to determine anything useful about the
9234 /* Fold a binary expression of code CODE and type TYPE with operands
9235 OP0 and OP1. Return the folded expression if folding is
9236 successful. Otherwise, return NULL_TREE. */
9239 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
9241 enum tree_code_class kind = TREE_CODE_CLASS (code);
9242 tree arg0, arg1, tem;
9243 tree t1 = NULL_TREE;
9244 bool strict_overflow_p;
9246 gcc_assert ((IS_EXPR_CODE_CLASS (kind)
9247 || IS_GIMPLE_STMT_CODE_CLASS (kind))
9248 && TREE_CODE_LENGTH (code) == 2
9250 && op1 != NULL_TREE);
9255 /* Strip any conversions that don't change the mode. This is
9256 safe for every expression, except for a comparison expression
9257 because its signedness is derived from its operands. So, in
9258 the latter case, only strip conversions that don't change the
9261 Note that this is done as an internal manipulation within the
9262 constant folder, in order to find the simplest representation
9263 of the arguments so that their form can be studied. In any
9264 cases, the appropriate type conversions should be put back in
9265 the tree that will get out of the constant folder. */
9267 if (kind == tcc_comparison)
9269 STRIP_SIGN_NOPS (arg0);
9270 STRIP_SIGN_NOPS (arg1);
9278 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9279 constant but we can't do arithmetic on them. */
9280 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9281 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9282 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == FIXED_CST)
9283 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == INTEGER_CST)
9284 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9285 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9287 if (kind == tcc_binary)
9289 /* Make sure type and arg0 have the same saturating flag. */
9290 gcc_assert (TYPE_SATURATING (type)
9291 == TYPE_SATURATING (TREE_TYPE (arg0)));
9292 tem = const_binop (code, arg0, arg1, 0);
9294 else if (kind == tcc_comparison)
9295 tem = fold_relational_const (code, type, arg0, arg1);
9299 if (tem != NULL_TREE)
9301 if (TREE_TYPE (tem) != type)
9302 tem = fold_convert (type, tem);
9307 /* If this is a commutative operation, and ARG0 is a constant, move it
9308 to ARG1 to reduce the number of tests below. */
9309 if (commutative_tree_code (code)
9310 && tree_swap_operands_p (arg0, arg1, true))
9311 return fold_build2 (code, type, op1, op0);
9313 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9315 First check for cases where an arithmetic operation is applied to a
9316 compound, conditional, or comparison operation. Push the arithmetic
9317 operation inside the compound or conditional to see if any folding
9318 can then be done. Convert comparison to conditional for this purpose.
9319 The also optimizes non-constant cases that used to be done in
9322 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9323 one of the operands is a comparison and the other is a comparison, a
9324 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9325 code below would make the expression more complex. Change it to a
9326 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9327 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9329 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9330 || code == EQ_EXPR || code == NE_EXPR)
9331 && ((truth_value_p (TREE_CODE (arg0))
9332 && (truth_value_p (TREE_CODE (arg1))
9333 || (TREE_CODE (arg1) == BIT_AND_EXPR
9334 && integer_onep (TREE_OPERAND (arg1, 1)))))
9335 || (truth_value_p (TREE_CODE (arg1))
9336 && (truth_value_p (TREE_CODE (arg0))
9337 || (TREE_CODE (arg0) == BIT_AND_EXPR
9338 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9340 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9341 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9344 fold_convert (boolean_type_node, arg0),
9345 fold_convert (boolean_type_node, arg1));
9347 if (code == EQ_EXPR)
9348 tem = invert_truthvalue (tem);
9350 return fold_convert (type, tem);
9353 if (TREE_CODE_CLASS (code) == tcc_binary
9354 || TREE_CODE_CLASS (code) == tcc_comparison)
9356 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9357 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9358 fold_build2 (code, type,
9359 fold_convert (TREE_TYPE (op0),
9360 TREE_OPERAND (arg0, 1)),
9362 if (TREE_CODE (arg1) == COMPOUND_EXPR
9363 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9364 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9365 fold_build2 (code, type, op0,
9366 fold_convert (TREE_TYPE (op1),
9367 TREE_OPERAND (arg1, 1))));
9369 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9371 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9373 /*cond_first_p=*/1);
9374 if (tem != NULL_TREE)
9378 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9380 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9382 /*cond_first_p=*/0);
9383 if (tem != NULL_TREE)
9390 case POINTER_PLUS_EXPR:
9391 /* 0 +p index -> (type)index */
9392 if (integer_zerop (arg0))
9393 return non_lvalue (fold_convert (type, arg1));
9395 /* PTR +p 0 -> PTR */
9396 if (integer_zerop (arg1))
9397 return non_lvalue (fold_convert (type, arg0));
9399 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9400 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9401 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9402 return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
9403 fold_convert (sizetype, arg1),
9404 fold_convert (sizetype, arg0)));
9406 /* index +p PTR -> PTR +p index */
9407 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9408 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9409 return fold_build2 (POINTER_PLUS_EXPR, type,
9410 fold_convert (type, arg1),
9411 fold_convert (sizetype, arg0));
9413 /* (PTR +p B) +p A -> PTR +p (B + A) */
9414 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9417 tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
9418 tree arg00 = TREE_OPERAND (arg0, 0);
9419 inner = fold_build2 (PLUS_EXPR, sizetype,
9420 arg01, fold_convert (sizetype, arg1));
9421 return fold_convert (type,
9422 fold_build2 (POINTER_PLUS_EXPR,
9423 TREE_TYPE (arg00), arg00, inner));
9426 /* PTR_CST +p CST -> CST1 */
9427 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9428 return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
9430 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9431 of the array. Loop optimizer sometimes produce this type of
9433 if (TREE_CODE (arg0) == ADDR_EXPR)
9435 tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
9437 return fold_convert (type, tem);
9443 /* PTR + INT -> (INT)(PTR p+ INT) */
9444 if (POINTER_TYPE_P (TREE_TYPE (arg0))
9445 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9446 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9449 fold_convert (sizetype, arg1)));
9450 /* INT + PTR -> (INT)(PTR p+ INT) */
9451 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9452 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9453 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9456 fold_convert (sizetype, arg0)));
9457 /* A + (-B) -> A - B */
9458 if (TREE_CODE (arg1) == NEGATE_EXPR)
9459 return fold_build2 (MINUS_EXPR, type,
9460 fold_convert (type, arg0),
9461 fold_convert (type, TREE_OPERAND (arg1, 0)));
9462 /* (-A) + B -> B - A */
9463 if (TREE_CODE (arg0) == NEGATE_EXPR
9464 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9465 return fold_build2 (MINUS_EXPR, type,
9466 fold_convert (type, arg1),
9467 fold_convert (type, TREE_OPERAND (arg0, 0)));
9469 if (INTEGRAL_TYPE_P (type))
9471 /* Convert ~A + 1 to -A. */
9472 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9473 && integer_onep (arg1))
9474 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
9477 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9478 && !TYPE_OVERFLOW_TRAPS (type))
9480 tree tem = TREE_OPERAND (arg0, 0);
9483 if (operand_equal_p (tem, arg1, 0))
9485 t1 = build_int_cst_type (type, -1);
9486 return omit_one_operand (type, t1, arg1);
9491 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9492 && !TYPE_OVERFLOW_TRAPS (type))
9494 tree tem = TREE_OPERAND (arg1, 0);
9497 if (operand_equal_p (arg0, tem, 0))
9499 t1 = build_int_cst_type (type, -1);
9500 return omit_one_operand (type, t1, arg0);
9504 /* X + (X / CST) * -CST is X % CST. */
9505 if (TREE_CODE (arg1) == MULT_EXPR
9506 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9507 && operand_equal_p (arg0,
9508 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
9510 tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
9511 tree cst1 = TREE_OPERAND (arg1, 1);
9512 tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
9513 if (sum && integer_zerop (sum))
9514 return fold_convert (type,
9515 fold_build2 (TRUNC_MOD_EXPR,
9516 TREE_TYPE (arg0), arg0, cst0));
9520 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9521 same or one. Make sure type is not saturating.
9522 fold_plusminus_mult_expr will re-associate. */
9523 if ((TREE_CODE (arg0) == MULT_EXPR
9524 || TREE_CODE (arg1) == MULT_EXPR)
9525 && !TYPE_SATURATING (type)
9526 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9528 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9533 if (! FLOAT_TYPE_P (type))
9535 if (integer_zerop (arg1))
9536 return non_lvalue (fold_convert (type, arg0));
9538 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9539 with a constant, and the two constants have no bits in common,
9540 we should treat this as a BIT_IOR_EXPR since this may produce more
9542 if (TREE_CODE (arg0) == BIT_AND_EXPR
9543 && TREE_CODE (arg1) == BIT_AND_EXPR
9544 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9545 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9546 && integer_zerop (const_binop (BIT_AND_EXPR,
9547 TREE_OPERAND (arg0, 1),
9548 TREE_OPERAND (arg1, 1), 0)))
9550 code = BIT_IOR_EXPR;
9554 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9555 (plus (plus (mult) (mult)) (foo)) so that we can
9556 take advantage of the factoring cases below. */
9557 if (((TREE_CODE (arg0) == PLUS_EXPR
9558 || TREE_CODE (arg0) == MINUS_EXPR)
9559 && TREE_CODE (arg1) == MULT_EXPR)
9560 || ((TREE_CODE (arg1) == PLUS_EXPR
9561 || TREE_CODE (arg1) == MINUS_EXPR)
9562 && TREE_CODE (arg0) == MULT_EXPR))
9564 tree parg0, parg1, parg, marg;
9565 enum tree_code pcode;
9567 if (TREE_CODE (arg1) == MULT_EXPR)
9568 parg = arg0, marg = arg1;
9570 parg = arg1, marg = arg0;
9571 pcode = TREE_CODE (parg);
9572 parg0 = TREE_OPERAND (parg, 0);
9573 parg1 = TREE_OPERAND (parg, 1);
9577 if (TREE_CODE (parg0) == MULT_EXPR
9578 && TREE_CODE (parg1) != MULT_EXPR)
9579 return fold_build2 (pcode, type,
9580 fold_build2 (PLUS_EXPR, type,
9581 fold_convert (type, parg0),
9582 fold_convert (type, marg)),
9583 fold_convert (type, parg1));
9584 if (TREE_CODE (parg0) != MULT_EXPR
9585 && TREE_CODE (parg1) == MULT_EXPR)
9586 return fold_build2 (PLUS_EXPR, type,
9587 fold_convert (type, parg0),
9588 fold_build2 (pcode, type,
9589 fold_convert (type, marg),
9596 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9597 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
9598 return non_lvalue (fold_convert (type, arg0));
9600 /* Likewise if the operands are reversed. */
9601 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9602 return non_lvalue (fold_convert (type, arg1));
9604 /* Convert X + -C into X - C. */
9605 if (TREE_CODE (arg1) == REAL_CST
9606 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
9608 tem = fold_negate_const (arg1, type);
9609 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
9610 return fold_build2 (MINUS_EXPR, type,
9611 fold_convert (type, arg0),
9612 fold_convert (type, tem));
9615 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9616 to __complex__ ( x, y ). This is not the same for SNaNs or
9617 if signed zeros are involved. */
9618 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9619 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9620 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9622 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9623 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9624 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9625 bool arg0rz = false, arg0iz = false;
9626 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9627 || (arg0i && (arg0iz = real_zerop (arg0i))))
9629 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9630 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9631 if (arg0rz && arg1i && real_zerop (arg1i))
9633 tree rp = arg1r ? arg1r
9634 : build1 (REALPART_EXPR, rtype, arg1);
9635 tree ip = arg0i ? arg0i
9636 : build1 (IMAGPART_EXPR, rtype, arg0);
9637 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9639 else if (arg0iz && arg1r && real_zerop (arg1r))
9641 tree rp = arg0r ? arg0r
9642 : build1 (REALPART_EXPR, rtype, arg0);
9643 tree ip = arg1i ? arg1i
9644 : build1 (IMAGPART_EXPR, rtype, arg1);
9645 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9650 if (flag_unsafe_math_optimizations
9651 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9652 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9653 && (tem = distribute_real_division (code, type, arg0, arg1)))
9656 /* Convert x+x into x*2.0. */
9657 if (operand_equal_p (arg0, arg1, 0)
9658 && SCALAR_FLOAT_TYPE_P (type))
9659 return fold_build2 (MULT_EXPR, type, arg0,
9660 build_real (type, dconst2));
9662 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
9663 We associate floats only if the user has specified
9664 -fassociative-math. */
9665 if (flag_associative_math
9666 && TREE_CODE (arg1) == PLUS_EXPR
9667 && TREE_CODE (arg0) != MULT_EXPR)
9669 tree tree10 = TREE_OPERAND (arg1, 0);
9670 tree tree11 = TREE_OPERAND (arg1, 1);
9671 if (TREE_CODE (tree11) == MULT_EXPR
9672 && TREE_CODE (tree10) == MULT_EXPR)
9675 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
9676 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
9679 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
9680 We associate floats only if the user has specified
9681 -fassociative-math. */
9682 if (flag_associative_math
9683 && TREE_CODE (arg0) == PLUS_EXPR
9684 && TREE_CODE (arg1) != MULT_EXPR)
9686 tree tree00 = TREE_OPERAND (arg0, 0);
9687 tree tree01 = TREE_OPERAND (arg0, 1);
9688 if (TREE_CODE (tree01) == MULT_EXPR
9689 && TREE_CODE (tree00) == MULT_EXPR)
9692 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
9693 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
9699 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9700 is a rotate of A by C1 bits. */
9701 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9702 is a rotate of A by B bits. */
9704 enum tree_code code0, code1;
9706 code0 = TREE_CODE (arg0);
9707 code1 = TREE_CODE (arg1);
9708 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
9709 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
9710 && operand_equal_p (TREE_OPERAND (arg0, 0),
9711 TREE_OPERAND (arg1, 0), 0)
9712 && (rtype = TREE_TYPE (TREE_OPERAND (arg0, 0)),
9713 TYPE_UNSIGNED (rtype))
9714 /* Only create rotates in complete modes. Other cases are not
9715 expanded properly. */
9716 && TYPE_PRECISION (rtype) == GET_MODE_PRECISION (TYPE_MODE (rtype)))
9718 tree tree01, tree11;
9719 enum tree_code code01, code11;
9721 tree01 = TREE_OPERAND (arg0, 1);
9722 tree11 = TREE_OPERAND (arg1, 1);
9723 STRIP_NOPS (tree01);
9724 STRIP_NOPS (tree11);
9725 code01 = TREE_CODE (tree01);
9726 code11 = TREE_CODE (tree11);
9727 if (code01 == INTEGER_CST
9728 && code11 == INTEGER_CST
9729 && TREE_INT_CST_HIGH (tree01) == 0
9730 && TREE_INT_CST_HIGH (tree11) == 0
9731 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
9732 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
9733 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
9734 code0 == LSHIFT_EXPR ? tree01 : tree11);
9735 else if (code11 == MINUS_EXPR)
9737 tree tree110, tree111;
9738 tree110 = TREE_OPERAND (tree11, 0);
9739 tree111 = TREE_OPERAND (tree11, 1);
9740 STRIP_NOPS (tree110);
9741 STRIP_NOPS (tree111);
9742 if (TREE_CODE (tree110) == INTEGER_CST
9743 && 0 == compare_tree_int (tree110,
9745 (TREE_TYPE (TREE_OPERAND
9747 && operand_equal_p (tree01, tree111, 0))
9748 return build2 ((code0 == LSHIFT_EXPR
9751 type, TREE_OPERAND (arg0, 0), tree01);
9753 else if (code01 == MINUS_EXPR)
9755 tree tree010, tree011;
9756 tree010 = TREE_OPERAND (tree01, 0);
9757 tree011 = TREE_OPERAND (tree01, 1);
9758 STRIP_NOPS (tree010);
9759 STRIP_NOPS (tree011);
9760 if (TREE_CODE (tree010) == INTEGER_CST
9761 && 0 == compare_tree_int (tree010,
9763 (TREE_TYPE (TREE_OPERAND
9765 && operand_equal_p (tree11, tree011, 0))
9766 return build2 ((code0 != LSHIFT_EXPR
9769 type, TREE_OPERAND (arg0, 0), tree11);
9775 /* In most languages, can't associate operations on floats through
9776 parentheses. Rather than remember where the parentheses were, we
9777 don't associate floats at all, unless the user has specified
9779 And, we need to make sure type is not saturating. */
9781 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
9782 && !TYPE_SATURATING (type))
9784 tree var0, con0, lit0, minus_lit0;
9785 tree var1, con1, lit1, minus_lit1;
9788 /* Split both trees into variables, constants, and literals. Then
9789 associate each group together, the constants with literals,
9790 then the result with variables. This increases the chances of
9791 literals being recombined later and of generating relocatable
9792 expressions for the sum of a constant and literal. */
9793 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
9794 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
9795 code == MINUS_EXPR);
9797 /* With undefined overflow we can only associate constants
9798 with one variable. */
9799 if (((POINTER_TYPE_P (type) && POINTER_TYPE_OVERFLOW_UNDEFINED)
9800 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
9806 if (TREE_CODE (tmp0) == NEGATE_EXPR)
9807 tmp0 = TREE_OPERAND (tmp0, 0);
9808 if (TREE_CODE (tmp1) == NEGATE_EXPR)
9809 tmp1 = TREE_OPERAND (tmp1, 0);
9810 /* The only case we can still associate with two variables
9811 is if they are the same, modulo negation. */
9812 if (!operand_equal_p (tmp0, tmp1, 0))
9816 /* Only do something if we found more than two objects. Otherwise,
9817 nothing has changed and we risk infinite recursion. */
9819 && (2 < ((var0 != 0) + (var1 != 0)
9820 + (con0 != 0) + (con1 != 0)
9821 + (lit0 != 0) + (lit1 != 0)
9822 + (minus_lit0 != 0) + (minus_lit1 != 0))))
9824 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9825 if (code == MINUS_EXPR)
9828 var0 = associate_trees (var0, var1, code, type);
9829 con0 = associate_trees (con0, con1, code, type);
9830 lit0 = associate_trees (lit0, lit1, code, type);
9831 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
9833 /* Preserve the MINUS_EXPR if the negative part of the literal is
9834 greater than the positive part. Otherwise, the multiplicative
9835 folding code (i.e extract_muldiv) may be fooled in case
9836 unsigned constants are subtracted, like in the following
9837 example: ((X*2 + 4) - 8U)/2. */
9838 if (minus_lit0 && lit0)
9840 if (TREE_CODE (lit0) == INTEGER_CST
9841 && TREE_CODE (minus_lit0) == INTEGER_CST
9842 && tree_int_cst_lt (lit0, minus_lit0))
9844 minus_lit0 = associate_trees (minus_lit0, lit0,
9850 lit0 = associate_trees (lit0, minus_lit0,
9858 return fold_convert (type,
9859 associate_trees (var0, minus_lit0,
9863 con0 = associate_trees (con0, minus_lit0,
9865 return fold_convert (type,
9866 associate_trees (var0, con0,
9871 con0 = associate_trees (con0, lit0, code, type);
9872 return fold_convert (type, associate_trees (var0, con0,
9880 /* Pointer simplifications for subtraction, simple reassociations. */
9881 if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
9883 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
9884 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
9885 && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
9887 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
9888 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
9889 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
9890 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
9891 return fold_build2 (PLUS_EXPR, type,
9892 fold_build2 (MINUS_EXPR, type, arg00, arg10),
9893 fold_build2 (MINUS_EXPR, type, arg01, arg11));
9895 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
9896 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9898 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
9899 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
9900 tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
9902 return fold_build2 (PLUS_EXPR, type, tmp, arg01);
9905 /* A - (-B) -> A + B */
9906 if (TREE_CODE (arg1) == NEGATE_EXPR)
9907 return fold_build2 (PLUS_EXPR, type, op0,
9908 fold_convert (type, TREE_OPERAND (arg1, 0)));
9909 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
9910 if (TREE_CODE (arg0) == NEGATE_EXPR
9911 && (FLOAT_TYPE_P (type)
9912 || INTEGRAL_TYPE_P (type))
9913 && negate_expr_p (arg1)
9914 && reorder_operands_p (arg0, arg1))
9915 return fold_build2 (MINUS_EXPR, type,
9916 fold_convert (type, negate_expr (arg1)),
9917 fold_convert (type, TREE_OPERAND (arg0, 0)));
9918 /* Convert -A - 1 to ~A. */
9919 if (INTEGRAL_TYPE_P (type)
9920 && TREE_CODE (arg0) == NEGATE_EXPR
9921 && integer_onep (arg1)
9922 && !TYPE_OVERFLOW_TRAPS (type))
9923 return fold_build1 (BIT_NOT_EXPR, type,
9924 fold_convert (type, TREE_OPERAND (arg0, 0)));
9926 /* Convert -1 - A to ~A. */
9927 if (INTEGRAL_TYPE_P (type)
9928 && integer_all_onesp (arg0))
9929 return fold_build1 (BIT_NOT_EXPR, type, op1);
9932 /* X - (X / CST) * CST is X % CST. */
9933 if (INTEGRAL_TYPE_P (type)
9934 && TREE_CODE (arg1) == MULT_EXPR
9935 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9936 && operand_equal_p (arg0,
9937 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
9938 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
9939 TREE_OPERAND (arg1, 1), 0))
9940 return fold_convert (type,
9941 fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
9942 arg0, TREE_OPERAND (arg1, 1)));
9944 if (! FLOAT_TYPE_P (type))
9946 if (integer_zerop (arg0))
9947 return negate_expr (fold_convert (type, arg1));
9948 if (integer_zerop (arg1))
9949 return non_lvalue (fold_convert (type, arg0));
9951 /* Fold A - (A & B) into ~B & A. */
9952 if (!TREE_SIDE_EFFECTS (arg0)
9953 && TREE_CODE (arg1) == BIT_AND_EXPR)
9955 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
9957 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
9958 return fold_build2 (BIT_AND_EXPR, type,
9959 fold_build1 (BIT_NOT_EXPR, type, arg10),
9960 fold_convert (type, arg0));
9962 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9964 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
9965 return fold_build2 (BIT_AND_EXPR, type,
9966 fold_build1 (BIT_NOT_EXPR, type, arg11),
9967 fold_convert (type, arg0));
9971 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
9972 any power of 2 minus 1. */
9973 if (TREE_CODE (arg0) == BIT_AND_EXPR
9974 && TREE_CODE (arg1) == BIT_AND_EXPR
9975 && operand_equal_p (TREE_OPERAND (arg0, 0),
9976 TREE_OPERAND (arg1, 0), 0))
9978 tree mask0 = TREE_OPERAND (arg0, 1);
9979 tree mask1 = TREE_OPERAND (arg1, 1);
9980 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
9982 if (operand_equal_p (tem, mask1, 0))
9984 tem = fold_build2 (BIT_XOR_EXPR, type,
9985 TREE_OPERAND (arg0, 0), mask1);
9986 return fold_build2 (MINUS_EXPR, type, tem, mask1);
9991 /* See if ARG1 is zero and X - ARG1 reduces to X. */
9992 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
9993 return non_lvalue (fold_convert (type, arg0));
9995 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
9996 ARG0 is zero and X + ARG0 reduces to X, since that would mean
9997 (-ARG1 + ARG0) reduces to -ARG1. */
9998 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9999 return negate_expr (fold_convert (type, arg1));
10001 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
10002 __complex__ ( x, -y ). This is not the same for SNaNs or if
10003 signed zeros are involved. */
10004 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10005 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10006 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10008 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10009 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10010 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10011 bool arg0rz = false, arg0iz = false;
10012 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10013 || (arg0i && (arg0iz = real_zerop (arg0i))))
10015 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10016 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10017 if (arg0rz && arg1i && real_zerop (arg1i))
10019 tree rp = fold_build1 (NEGATE_EXPR, rtype,
10021 : build1 (REALPART_EXPR, rtype, arg1));
10022 tree ip = arg0i ? arg0i
10023 : build1 (IMAGPART_EXPR, rtype, arg0);
10024 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10026 else if (arg0iz && arg1r && real_zerop (arg1r))
10028 tree rp = arg0r ? arg0r
10029 : build1 (REALPART_EXPR, rtype, arg0);
10030 tree ip = fold_build1 (NEGATE_EXPR, rtype,
10032 : build1 (IMAGPART_EXPR, rtype, arg1));
10033 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10038 /* Fold &x - &x. This can happen from &x.foo - &x.
10039 This is unsafe for certain floats even in non-IEEE formats.
10040 In IEEE, it is unsafe because it does wrong for NaNs.
10041 Also note that operand_equal_p is always false if an operand
10044 if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
10045 && operand_equal_p (arg0, arg1, 0))
10046 return fold_convert (type, integer_zero_node);
10048 /* A - B -> A + (-B) if B is easily negatable. */
10049 if (negate_expr_p (arg1)
10050 && ((FLOAT_TYPE_P (type)
10051 /* Avoid this transformation if B is a positive REAL_CST. */
10052 && (TREE_CODE (arg1) != REAL_CST
10053 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
10054 || INTEGRAL_TYPE_P (type)))
10055 return fold_build2 (PLUS_EXPR, type,
10056 fold_convert (type, arg0),
10057 fold_convert (type, negate_expr (arg1)));
10059 /* Try folding difference of addresses. */
10061 HOST_WIDE_INT diff;
10063 if ((TREE_CODE (arg0) == ADDR_EXPR
10064 || TREE_CODE (arg1) == ADDR_EXPR)
10065 && ptr_difference_const (arg0, arg1, &diff))
10066 return build_int_cst_type (type, diff);
10069 /* Fold &a[i] - &a[j] to i-j. */
10070 if (TREE_CODE (arg0) == ADDR_EXPR
10071 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
10072 && TREE_CODE (arg1) == ADDR_EXPR
10073 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
10075 tree aref0 = TREE_OPERAND (arg0, 0);
10076 tree aref1 = TREE_OPERAND (arg1, 0);
10077 if (operand_equal_p (TREE_OPERAND (aref0, 0),
10078 TREE_OPERAND (aref1, 0), 0))
10080 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
10081 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
10082 tree esz = array_ref_element_size (aref0);
10083 tree diff = build2 (MINUS_EXPR, type, op0, op1);
10084 return fold_build2 (MULT_EXPR, type, diff,
10085 fold_convert (type, esz));
10090 if (flag_unsafe_math_optimizations
10091 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10092 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10093 && (tem = distribute_real_division (code, type, arg0, arg1)))
10096 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
10097 same or one. Make sure type is not saturating.
10098 fold_plusminus_mult_expr will re-associate. */
10099 if ((TREE_CODE (arg0) == MULT_EXPR
10100 || TREE_CODE (arg1) == MULT_EXPR)
10101 && !TYPE_SATURATING (type)
10102 && (!FLOAT_TYPE_P (type) || flag_associative_math))
10104 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
10112 /* (-A) * (-B) -> A * B */
10113 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10114 return fold_build2 (MULT_EXPR, type,
10115 fold_convert (type, TREE_OPERAND (arg0, 0)),
10116 fold_convert (type, negate_expr (arg1)));
10117 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10118 return fold_build2 (MULT_EXPR, type,
10119 fold_convert (type, negate_expr (arg0)),
10120 fold_convert (type, TREE_OPERAND (arg1, 0)));
10122 if (! FLOAT_TYPE_P (type))
10124 if (integer_zerop (arg1))
10125 return omit_one_operand (type, arg1, arg0);
10126 if (integer_onep (arg1))
10127 return non_lvalue (fold_convert (type, arg0));
10128 /* Transform x * -1 into -x. Make sure to do the negation
10129 on the original operand with conversions not stripped
10130 because we can only strip non-sign-changing conversions. */
10131 if (integer_all_onesp (arg1))
10132 return fold_convert (type, negate_expr (op0));
10133 /* Transform x * -C into -x * C if x is easily negatable. */
10134 if (TREE_CODE (arg1) == INTEGER_CST
10135 && tree_int_cst_sgn (arg1) == -1
10136 && negate_expr_p (arg0)
10137 && (tem = negate_expr (arg1)) != arg1
10138 && !TREE_OVERFLOW (tem))
10139 return fold_build2 (MULT_EXPR, type,
10140 fold_convert (type, negate_expr (arg0)), tem);
10142 /* (a * (1 << b)) is (a << b) */
10143 if (TREE_CODE (arg1) == LSHIFT_EXPR
10144 && integer_onep (TREE_OPERAND (arg1, 0)))
10145 return fold_build2 (LSHIFT_EXPR, type, op0,
10146 TREE_OPERAND (arg1, 1));
10147 if (TREE_CODE (arg0) == LSHIFT_EXPR
10148 && integer_onep (TREE_OPERAND (arg0, 0)))
10149 return fold_build2 (LSHIFT_EXPR, type, op1,
10150 TREE_OPERAND (arg0, 1));
10152 strict_overflow_p = false;
10153 if (TREE_CODE (arg1) == INTEGER_CST
10154 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10155 &strict_overflow_p)))
10157 if (strict_overflow_p)
10158 fold_overflow_warning (("assuming signed overflow does not "
10159 "occur when simplifying "
10161 WARN_STRICT_OVERFLOW_MISC);
10162 return fold_convert (type, tem);
10165 /* Optimize z * conj(z) for integer complex numbers. */
10166 if (TREE_CODE (arg0) == CONJ_EXPR
10167 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10168 return fold_mult_zconjz (type, arg1);
10169 if (TREE_CODE (arg1) == CONJ_EXPR
10170 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10171 return fold_mult_zconjz (type, arg0);
10175 /* Maybe fold x * 0 to 0. The expressions aren't the same
10176 when x is NaN, since x * 0 is also NaN. Nor are they the
10177 same in modes with signed zeros, since multiplying a
10178 negative value by 0 gives -0, not +0. */
10179 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10180 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10181 && real_zerop (arg1))
10182 return omit_one_operand (type, arg1, arg0);
10183 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
10184 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10185 && real_onep (arg1))
10186 return non_lvalue (fold_convert (type, arg0));
10188 /* Transform x * -1.0 into -x. */
10189 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10190 && real_minus_onep (arg1))
10191 return fold_convert (type, negate_expr (arg0));
10193 /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
10194 the result for floating point types due to rounding so it is applied
10195 only if -fassociative-math was specify. */
10196 if (flag_associative_math
10197 && TREE_CODE (arg0) == RDIV_EXPR
10198 && TREE_CODE (arg1) == REAL_CST
10199 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
10201 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
10204 return fold_build2 (RDIV_EXPR, type, tem,
10205 TREE_OPERAND (arg0, 1));
10208 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10209 if (operand_equal_p (arg0, arg1, 0))
10211 tree tem = fold_strip_sign_ops (arg0);
10212 if (tem != NULL_TREE)
10214 tem = fold_convert (type, tem);
10215 return fold_build2 (MULT_EXPR, type, tem, tem);
10219 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10220 This is not the same for NaNs or if signed zeros are
10222 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10223 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10224 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10225 && TREE_CODE (arg1) == COMPLEX_CST
10226 && real_zerop (TREE_REALPART (arg1)))
10228 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10229 if (real_onep (TREE_IMAGPART (arg1)))
10230 return fold_build2 (COMPLEX_EXPR, type,
10231 negate_expr (fold_build1 (IMAGPART_EXPR,
10233 fold_build1 (REALPART_EXPR, rtype, arg0));
10234 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10235 return fold_build2 (COMPLEX_EXPR, type,
10236 fold_build1 (IMAGPART_EXPR, rtype, arg0),
10237 negate_expr (fold_build1 (REALPART_EXPR,
10241 /* Optimize z * conj(z) for floating point complex numbers.
10242 Guarded by flag_unsafe_math_optimizations as non-finite
10243 imaginary components don't produce scalar results. */
10244 if (flag_unsafe_math_optimizations
10245 && TREE_CODE (arg0) == CONJ_EXPR
10246 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10247 return fold_mult_zconjz (type, arg1);
10248 if (flag_unsafe_math_optimizations
10249 && TREE_CODE (arg1) == CONJ_EXPR
10250 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10251 return fold_mult_zconjz (type, arg0);
10253 if (flag_unsafe_math_optimizations)
10255 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10256 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10258 /* Optimizations of root(...)*root(...). */
10259 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
10262 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10263 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10265 /* Optimize sqrt(x)*sqrt(x) as x. */
10266 if (BUILTIN_SQRT_P (fcode0)
10267 && operand_equal_p (arg00, arg10, 0)
10268 && ! HONOR_SNANS (TYPE_MODE (type)))
10271 /* Optimize root(x)*root(y) as root(x*y). */
10272 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10273 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10274 return build_call_expr (rootfn, 1, arg);
10277 /* Optimize expN(x)*expN(y) as expN(x+y). */
10278 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
10280 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10281 tree arg = fold_build2 (PLUS_EXPR, type,
10282 CALL_EXPR_ARG (arg0, 0),
10283 CALL_EXPR_ARG (arg1, 0));
10284 return build_call_expr (expfn, 1, arg);
10287 /* Optimizations of pow(...)*pow(...). */
10288 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
10289 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
10290 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
10292 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10293 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10294 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10295 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10297 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10298 if (operand_equal_p (arg01, arg11, 0))
10300 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10301 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10302 return build_call_expr (powfn, 2, arg, arg01);
10305 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10306 if (operand_equal_p (arg00, arg10, 0))
10308 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10309 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
10310 return build_call_expr (powfn, 2, arg00, arg);
10314 /* Optimize tan(x)*cos(x) as sin(x). */
10315 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
10316 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
10317 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
10318 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
10319 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
10320 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
10321 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10322 CALL_EXPR_ARG (arg1, 0), 0))
10324 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
10326 if (sinfn != NULL_TREE)
10327 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
10330 /* Optimize x*pow(x,c) as pow(x,c+1). */
10331 if (fcode1 == BUILT_IN_POW
10332 || fcode1 == BUILT_IN_POWF
10333 || fcode1 == BUILT_IN_POWL)
10335 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10336 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10337 if (TREE_CODE (arg11) == REAL_CST
10338 && !TREE_OVERFLOW (arg11)
10339 && operand_equal_p (arg0, arg10, 0))
10341 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10345 c = TREE_REAL_CST (arg11);
10346 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10347 arg = build_real (type, c);
10348 return build_call_expr (powfn, 2, arg0, arg);
10352 /* Optimize pow(x,c)*x as pow(x,c+1). */
10353 if (fcode0 == BUILT_IN_POW
10354 || fcode0 == BUILT_IN_POWF
10355 || fcode0 == BUILT_IN_POWL)
10357 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10358 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10359 if (TREE_CODE (arg01) == REAL_CST
10360 && !TREE_OVERFLOW (arg01)
10361 && operand_equal_p (arg1, arg00, 0))
10363 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10367 c = TREE_REAL_CST (arg01);
10368 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10369 arg = build_real (type, c);
10370 return build_call_expr (powfn, 2, arg1, arg);
10374 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10375 if (! optimize_size
10376 && operand_equal_p (arg0, arg1, 0))
10378 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
10382 tree arg = build_real (type, dconst2);
10383 return build_call_expr (powfn, 2, arg0, arg);
10392 if (integer_all_onesp (arg1))
10393 return omit_one_operand (type, arg1, arg0);
10394 if (integer_zerop (arg1))
10395 return non_lvalue (fold_convert (type, arg0));
10396 if (operand_equal_p (arg0, arg1, 0))
10397 return non_lvalue (fold_convert (type, arg0));
10399 /* ~X | X is -1. */
10400 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10401 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10403 t1 = fold_convert (type, integer_zero_node);
10404 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10405 return omit_one_operand (type, t1, arg1);
10408 /* X | ~X is -1. */
10409 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10410 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10412 t1 = fold_convert (type, integer_zero_node);
10413 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10414 return omit_one_operand (type, t1, arg0);
10417 /* Canonicalize (X & C1) | C2. */
10418 if (TREE_CODE (arg0) == BIT_AND_EXPR
10419 && TREE_CODE (arg1) == INTEGER_CST
10420 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10422 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, hi3, lo3, mlo, mhi;
10423 int width = TYPE_PRECISION (type), w;
10424 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10425 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10426 hi2 = TREE_INT_CST_HIGH (arg1);
10427 lo2 = TREE_INT_CST_LOW (arg1);
10429 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10430 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10431 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10433 if (width > HOST_BITS_PER_WIDE_INT)
10435 mhi = (unsigned HOST_WIDE_INT) -1
10436 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10442 mlo = (unsigned HOST_WIDE_INT) -1
10443 >> (HOST_BITS_PER_WIDE_INT - width);
10446 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10447 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10448 return fold_build2 (BIT_IOR_EXPR, type,
10449 TREE_OPERAND (arg0, 0), arg1);
10451 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
10452 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
10453 mode which allows further optimizations. */
10460 for (w = BITS_PER_UNIT;
10461 w <= width && w <= HOST_BITS_PER_WIDE_INT;
10464 unsigned HOST_WIDE_INT mask
10465 = (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
10466 if (((lo1 | lo2) & mask) == mask
10467 && (lo1 & ~mask) == 0 && hi1 == 0)
10474 if (hi3 != hi1 || lo3 != lo1)
10475 return fold_build2 (BIT_IOR_EXPR, type,
10476 fold_build2 (BIT_AND_EXPR, type,
10477 TREE_OPERAND (arg0, 0),
10478 build_int_cst_wide (type,
10483 /* (X & Y) | Y is (X, Y). */
10484 if (TREE_CODE (arg0) == BIT_AND_EXPR
10485 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10486 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10487 /* (X & Y) | X is (Y, X). */
10488 if (TREE_CODE (arg0) == BIT_AND_EXPR
10489 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10490 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10491 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10492 /* X | (X & Y) is (Y, X). */
10493 if (TREE_CODE (arg1) == BIT_AND_EXPR
10494 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10495 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10496 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10497 /* X | (Y & X) is (Y, X). */
10498 if (TREE_CODE (arg1) == BIT_AND_EXPR
10499 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10500 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10501 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10503 t1 = distribute_bit_expr (code, type, arg0, arg1);
10504 if (t1 != NULL_TREE)
10507 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10509 This results in more efficient code for machines without a NAND
10510 instruction. Combine will canonicalize to the first form
10511 which will allow use of NAND instructions provided by the
10512 backend if they exist. */
10513 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10514 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10516 return fold_build1 (BIT_NOT_EXPR, type,
10517 build2 (BIT_AND_EXPR, type,
10518 fold_convert (type,
10519 TREE_OPERAND (arg0, 0)),
10520 fold_convert (type,
10521 TREE_OPERAND (arg1, 0))));
10524 /* See if this can be simplified into a rotate first. If that
10525 is unsuccessful continue in the association code. */
10529 if (integer_zerop (arg1))
10530 return non_lvalue (fold_convert (type, arg0));
10531 if (integer_all_onesp (arg1))
10532 return fold_build1 (BIT_NOT_EXPR, type, op0);
10533 if (operand_equal_p (arg0, arg1, 0))
10534 return omit_one_operand (type, integer_zero_node, arg0);
10536 /* ~X ^ X is -1. */
10537 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10538 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10540 t1 = fold_convert (type, integer_zero_node);
10541 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10542 return omit_one_operand (type, t1, arg1);
10545 /* X ^ ~X is -1. */
10546 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10547 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10549 t1 = fold_convert (type, integer_zero_node);
10550 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10551 return omit_one_operand (type, t1, arg0);
10554 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10555 with a constant, and the two constants have no bits in common,
10556 we should treat this as a BIT_IOR_EXPR since this may produce more
10557 simplifications. */
10558 if (TREE_CODE (arg0) == BIT_AND_EXPR
10559 && TREE_CODE (arg1) == BIT_AND_EXPR
10560 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10561 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10562 && integer_zerop (const_binop (BIT_AND_EXPR,
10563 TREE_OPERAND (arg0, 1),
10564 TREE_OPERAND (arg1, 1), 0)))
10566 code = BIT_IOR_EXPR;
10570 /* (X | Y) ^ X -> Y & ~ X*/
10571 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10572 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10574 tree t2 = TREE_OPERAND (arg0, 1);
10575 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10577 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10578 fold_convert (type, t1));
10582 /* (Y | X) ^ X -> Y & ~ X*/
10583 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10584 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10586 tree t2 = TREE_OPERAND (arg0, 0);
10587 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10589 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10590 fold_convert (type, t1));
10594 /* X ^ (X | Y) -> Y & ~ X*/
10595 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10596 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
10598 tree t2 = TREE_OPERAND (arg1, 1);
10599 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10601 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10602 fold_convert (type, t1));
10606 /* X ^ (Y | X) -> Y & ~ X*/
10607 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10608 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
10610 tree t2 = TREE_OPERAND (arg1, 0);
10611 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10613 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10614 fold_convert (type, t1));
10618 /* Convert ~X ^ ~Y to X ^ Y. */
10619 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10620 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10621 return fold_build2 (code, type,
10622 fold_convert (type, TREE_OPERAND (arg0, 0)),
10623 fold_convert (type, TREE_OPERAND (arg1, 0)));
10625 /* Convert ~X ^ C to X ^ ~C. */
10626 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10627 && TREE_CODE (arg1) == INTEGER_CST)
10628 return fold_build2 (code, type,
10629 fold_convert (type, TREE_OPERAND (arg0, 0)),
10630 fold_build1 (BIT_NOT_EXPR, type, arg1));
10632 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10633 if (TREE_CODE (arg0) == BIT_AND_EXPR
10634 && integer_onep (TREE_OPERAND (arg0, 1))
10635 && integer_onep (arg1))
10636 return fold_build2 (EQ_EXPR, type, arg0,
10637 build_int_cst (TREE_TYPE (arg0), 0));
10639 /* Fold (X & Y) ^ Y as ~X & Y. */
10640 if (TREE_CODE (arg0) == BIT_AND_EXPR
10641 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10643 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10644 return fold_build2 (BIT_AND_EXPR, type,
10645 fold_build1 (BIT_NOT_EXPR, type, tem),
10646 fold_convert (type, arg1));
10648 /* Fold (X & Y) ^ X as ~Y & X. */
10649 if (TREE_CODE (arg0) == BIT_AND_EXPR
10650 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10651 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10653 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10654 return fold_build2 (BIT_AND_EXPR, type,
10655 fold_build1 (BIT_NOT_EXPR, type, tem),
10656 fold_convert (type, arg1));
10658 /* Fold X ^ (X & Y) as X & ~Y. */
10659 if (TREE_CODE (arg1) == BIT_AND_EXPR
10660 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10662 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10663 return fold_build2 (BIT_AND_EXPR, type,
10664 fold_convert (type, arg0),
10665 fold_build1 (BIT_NOT_EXPR, type, tem));
10667 /* Fold X ^ (Y & X) as ~Y & X. */
10668 if (TREE_CODE (arg1) == BIT_AND_EXPR
10669 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10670 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10672 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10673 return fold_build2 (BIT_AND_EXPR, type,
10674 fold_build1 (BIT_NOT_EXPR, type, tem),
10675 fold_convert (type, arg0));
10678 /* See if this can be simplified into a rotate first. If that
10679 is unsuccessful continue in the association code. */
10683 if (integer_all_onesp (arg1))
10684 return non_lvalue (fold_convert (type, arg0));
10685 if (integer_zerop (arg1))
10686 return omit_one_operand (type, arg1, arg0);
10687 if (operand_equal_p (arg0, arg1, 0))
10688 return non_lvalue (fold_convert (type, arg0));
10690 /* ~X & X is always zero. */
10691 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10692 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10693 return omit_one_operand (type, integer_zero_node, arg1);
10695 /* X & ~X is always zero. */
10696 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10697 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10698 return omit_one_operand (type, integer_zero_node, arg0);
10700 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
10701 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10702 && TREE_CODE (arg1) == INTEGER_CST
10703 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10705 tree tmp1 = fold_convert (TREE_TYPE (arg0), arg1);
10706 tree tmp2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10707 TREE_OPERAND (arg0, 0), tmp1);
10708 tree tmp3 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10709 TREE_OPERAND (arg0, 1), tmp1);
10710 return fold_convert (type,
10711 fold_build2 (BIT_IOR_EXPR, TREE_TYPE (arg0),
10715 /* (X | Y) & Y is (X, Y). */
10716 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10717 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10718 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10719 /* (X | Y) & X is (Y, X). */
10720 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10721 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10722 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10723 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10724 /* X & (X | Y) is (Y, X). */
10725 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10726 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10727 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10728 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10729 /* X & (Y | X) is (Y, X). */
10730 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10731 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10732 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10733 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10735 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10736 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10737 && integer_onep (TREE_OPERAND (arg0, 1))
10738 && integer_onep (arg1))
10740 tem = TREE_OPERAND (arg0, 0);
10741 return fold_build2 (EQ_EXPR, type,
10742 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10743 build_int_cst (TREE_TYPE (tem), 1)),
10744 build_int_cst (TREE_TYPE (tem), 0));
10746 /* Fold ~X & 1 as (X & 1) == 0. */
10747 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10748 && integer_onep (arg1))
10750 tem = TREE_OPERAND (arg0, 0);
10751 return fold_build2 (EQ_EXPR, type,
10752 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10753 build_int_cst (TREE_TYPE (tem), 1)),
10754 build_int_cst (TREE_TYPE (tem), 0));
10757 /* Fold (X ^ Y) & Y as ~X & Y. */
10758 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10759 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10761 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10762 return fold_build2 (BIT_AND_EXPR, type,
10763 fold_build1 (BIT_NOT_EXPR, type, tem),
10764 fold_convert (type, arg1));
10766 /* Fold (X ^ Y) & X as ~Y & X. */
10767 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10768 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10769 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10771 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10772 return fold_build2 (BIT_AND_EXPR, type,
10773 fold_build1 (BIT_NOT_EXPR, type, tem),
10774 fold_convert (type, arg1));
10776 /* Fold X & (X ^ Y) as X & ~Y. */
10777 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10778 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10780 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10781 return fold_build2 (BIT_AND_EXPR, type,
10782 fold_convert (type, arg0),
10783 fold_build1 (BIT_NOT_EXPR, type, tem));
10785 /* Fold X & (Y ^ X) as ~Y & X. */
10786 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10787 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10788 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10790 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10791 return fold_build2 (BIT_AND_EXPR, type,
10792 fold_build1 (BIT_NOT_EXPR, type, tem),
10793 fold_convert (type, arg0));
10796 t1 = distribute_bit_expr (code, type, arg0, arg1);
10797 if (t1 != NULL_TREE)
10799 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10800 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
10801 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
10804 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
10806 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
10807 && (~TREE_INT_CST_LOW (arg1)
10808 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
10809 return fold_convert (type, TREE_OPERAND (arg0, 0));
10812 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
10814 This results in more efficient code for machines without a NOR
10815 instruction. Combine will canonicalize to the first form
10816 which will allow use of NOR instructions provided by the
10817 backend if they exist. */
10818 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10819 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10821 return fold_build1 (BIT_NOT_EXPR, type,
10822 build2 (BIT_IOR_EXPR, type,
10823 fold_convert (type,
10824 TREE_OPERAND (arg0, 0)),
10825 fold_convert (type,
10826 TREE_OPERAND (arg1, 0))));
10829 /* If arg0 is derived from the address of an object or function, we may
10830 be able to fold this expression using the object or function's
10832 if (POINTER_TYPE_P (TREE_TYPE (arg0)) && host_integerp (arg1, 1))
10834 unsigned HOST_WIDE_INT modulus, residue;
10835 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (arg1);
10837 modulus = get_pointer_modulus_and_residue (arg0, &residue);
10839 /* This works because modulus is a power of 2. If this weren't the
10840 case, we'd have to replace it by its greatest power-of-2
10841 divisor: modulus & -modulus. */
10843 return build_int_cst (type, residue & low);
10846 /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
10847 (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
10848 if the new mask might be further optimized. */
10849 if ((TREE_CODE (arg0) == LSHIFT_EXPR
10850 || TREE_CODE (arg0) == RSHIFT_EXPR)
10851 && host_integerp (TREE_OPERAND (arg0, 1), 1)
10852 && host_integerp (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)))
10853 && tree_low_cst (TREE_OPERAND (arg0, 1), 1)
10854 < TYPE_PRECISION (TREE_TYPE (arg0))
10855 && TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
10856 && tree_low_cst (TREE_OPERAND (arg0, 1), 1) > 0)
10858 unsigned int shiftc = tree_low_cst (TREE_OPERAND (arg0, 1), 1);
10859 unsigned HOST_WIDE_INT mask
10860 = tree_low_cst (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)));
10861 unsigned HOST_WIDE_INT newmask, zerobits = 0;
10862 tree shift_type = TREE_TYPE (arg0);
10864 if (TREE_CODE (arg0) == LSHIFT_EXPR)
10865 zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
10866 else if (TREE_CODE (arg0) == RSHIFT_EXPR
10867 && TYPE_PRECISION (TREE_TYPE (arg0))
10868 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg0))))
10870 unsigned int prec = TYPE_PRECISION (TREE_TYPE (arg0));
10871 tree arg00 = TREE_OPERAND (arg0, 0);
10872 /* See if more bits can be proven as zero because of
10874 if (TREE_CODE (arg00) == NOP_EXPR
10875 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
10877 tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
10878 if (TYPE_PRECISION (inner_type)
10879 == GET_MODE_BITSIZE (TYPE_MODE (inner_type))
10880 && TYPE_PRECISION (inner_type) < prec)
10882 prec = TYPE_PRECISION (inner_type);
10883 /* See if we can shorten the right shift. */
10885 shift_type = inner_type;
10888 zerobits = ~(unsigned HOST_WIDE_INT) 0;
10889 zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
10890 zerobits <<= prec - shiftc;
10891 /* For arithmetic shift if sign bit could be set, zerobits
10892 can contain actually sign bits, so no transformation is
10893 possible, unless MASK masks them all away. In that
10894 case the shift needs to be converted into logical shift. */
10895 if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
10896 && prec == TYPE_PRECISION (TREE_TYPE (arg0)))
10898 if ((mask & zerobits) == 0)
10899 shift_type = unsigned_type_for (TREE_TYPE (arg0));
10905 /* ((X << 16) & 0xff00) is (X, 0). */
10906 if ((mask & zerobits) == mask)
10907 return omit_one_operand (type, build_int_cst (type, 0), arg0);
10909 newmask = mask | zerobits;
10910 if (newmask != mask && (newmask & (newmask + 1)) == 0)
10914 /* Only do the transformation if NEWMASK is some integer
10916 for (prec = BITS_PER_UNIT;
10917 prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
10918 if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
10920 if (prec < HOST_BITS_PER_WIDE_INT
10921 || newmask == ~(unsigned HOST_WIDE_INT) 0)
10923 if (shift_type != TREE_TYPE (arg0))
10925 tem = fold_build2 (TREE_CODE (arg0), shift_type,
10926 fold_convert (shift_type,
10927 TREE_OPERAND (arg0, 0)),
10928 TREE_OPERAND (arg0, 1));
10929 tem = fold_convert (type, tem);
10933 return fold_build2 (BIT_AND_EXPR, type, tem,
10934 build_int_cst_type (TREE_TYPE (op1),
10943 /* Don't touch a floating-point divide by zero unless the mode
10944 of the constant can represent infinity. */
10945 if (TREE_CODE (arg1) == REAL_CST
10946 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
10947 && real_zerop (arg1))
10950 /* Optimize A / A to 1.0 if we don't care about
10951 NaNs or Infinities. Skip the transformation
10952 for non-real operands. */
10953 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
10954 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10955 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
10956 && operand_equal_p (arg0, arg1, 0))
10958 tree r = build_real (TREE_TYPE (arg0), dconst1);
10960 return omit_two_operands (type, r, arg0, arg1);
10963 /* The complex version of the above A / A optimization. */
10964 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10965 && operand_equal_p (arg0, arg1, 0))
10967 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
10968 if (! HONOR_NANS (TYPE_MODE (elem_type))
10969 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
10971 tree r = build_real (elem_type, dconst1);
10972 /* omit_two_operands will call fold_convert for us. */
10973 return omit_two_operands (type, r, arg0, arg1);
10977 /* (-A) / (-B) -> A / B */
10978 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10979 return fold_build2 (RDIV_EXPR, type,
10980 TREE_OPERAND (arg0, 0),
10981 negate_expr (arg1));
10982 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10983 return fold_build2 (RDIV_EXPR, type,
10984 negate_expr (arg0),
10985 TREE_OPERAND (arg1, 0));
10987 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
10988 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10989 && real_onep (arg1))
10990 return non_lvalue (fold_convert (type, arg0));
10992 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
10993 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10994 && real_minus_onep (arg1))
10995 return non_lvalue (fold_convert (type, negate_expr (arg0)));
10997 /* If ARG1 is a constant, we can convert this to a multiply by the
10998 reciprocal. This does not have the same rounding properties,
10999 so only do this if -freciprocal-math. We can actually
11000 always safely do it if ARG1 is a power of two, but it's hard to
11001 tell if it is or not in a portable manner. */
11002 if (TREE_CODE (arg1) == REAL_CST)
11004 if (flag_reciprocal_math
11005 && 0 != (tem = const_binop (code, build_real (type, dconst1),
11007 return fold_build2 (MULT_EXPR, type, arg0, tem);
11008 /* Find the reciprocal if optimizing and the result is exact. */
11012 r = TREE_REAL_CST (arg1);
11013 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
11015 tem = build_real (type, r);
11016 return fold_build2 (MULT_EXPR, type,
11017 fold_convert (type, arg0), tem);
11021 /* Convert A/B/C to A/(B*C). */
11022 if (flag_reciprocal_math
11023 && TREE_CODE (arg0) == RDIV_EXPR)
11024 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
11025 fold_build2 (MULT_EXPR, type,
11026 TREE_OPERAND (arg0, 1), arg1));
11028 /* Convert A/(B/C) to (A/B)*C. */
11029 if (flag_reciprocal_math
11030 && TREE_CODE (arg1) == RDIV_EXPR)
11031 return fold_build2 (MULT_EXPR, type,
11032 fold_build2 (RDIV_EXPR, type, arg0,
11033 TREE_OPERAND (arg1, 0)),
11034 TREE_OPERAND (arg1, 1));
11036 /* Convert C1/(X*C2) into (C1/C2)/X. */
11037 if (flag_reciprocal_math
11038 && TREE_CODE (arg1) == MULT_EXPR
11039 && TREE_CODE (arg0) == REAL_CST
11040 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
11042 tree tem = const_binop (RDIV_EXPR, arg0,
11043 TREE_OPERAND (arg1, 1), 0);
11045 return fold_build2 (RDIV_EXPR, type, tem,
11046 TREE_OPERAND (arg1, 0));
11049 if (flag_unsafe_math_optimizations)
11051 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
11052 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
11054 /* Optimize sin(x)/cos(x) as tan(x). */
11055 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
11056 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
11057 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
11058 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11059 CALL_EXPR_ARG (arg1, 0), 0))
11061 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11063 if (tanfn != NULL_TREE)
11064 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11067 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
11068 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
11069 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
11070 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
11071 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11072 CALL_EXPR_ARG (arg1, 0), 0))
11074 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11076 if (tanfn != NULL_TREE)
11078 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11079 return fold_build2 (RDIV_EXPR, type,
11080 build_real (type, dconst1), tmp);
11084 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
11085 NaNs or Infinities. */
11086 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
11087 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
11088 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
11090 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11091 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11093 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11094 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11095 && operand_equal_p (arg00, arg01, 0))
11097 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11099 if (cosfn != NULL_TREE)
11100 return build_call_expr (cosfn, 1, arg00);
11104 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11105 NaNs or Infinities. */
11106 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
11107 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
11108 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
11110 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11111 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11113 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11114 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11115 && operand_equal_p (arg00, arg01, 0))
11117 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11119 if (cosfn != NULL_TREE)
11121 tree tmp = build_call_expr (cosfn, 1, arg00);
11122 return fold_build2 (RDIV_EXPR, type,
11123 build_real (type, dconst1),
11129 /* Optimize pow(x,c)/x as pow(x,c-1). */
11130 if (fcode0 == BUILT_IN_POW
11131 || fcode0 == BUILT_IN_POWF
11132 || fcode0 == BUILT_IN_POWL)
11134 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11135 tree arg01 = CALL_EXPR_ARG (arg0, 1);
11136 if (TREE_CODE (arg01) == REAL_CST
11137 && !TREE_OVERFLOW (arg01)
11138 && operand_equal_p (arg1, arg00, 0))
11140 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
11144 c = TREE_REAL_CST (arg01);
11145 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
11146 arg = build_real (type, c);
11147 return build_call_expr (powfn, 2, arg1, arg);
11151 /* Optimize a/root(b/c) into a*root(c/b). */
11152 if (BUILTIN_ROOT_P (fcode1))
11154 tree rootarg = CALL_EXPR_ARG (arg1, 0);
11156 if (TREE_CODE (rootarg) == RDIV_EXPR)
11158 tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11159 tree b = TREE_OPERAND (rootarg, 0);
11160 tree c = TREE_OPERAND (rootarg, 1);
11162 tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
11164 tmp = build_call_expr (rootfn, 1, tmp);
11165 return fold_build2 (MULT_EXPR, type, arg0, tmp);
11169 /* Optimize x/expN(y) into x*expN(-y). */
11170 if (BUILTIN_EXPONENT_P (fcode1))
11172 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11173 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
11174 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
11175 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11178 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11179 if (fcode1 == BUILT_IN_POW
11180 || fcode1 == BUILT_IN_POWF
11181 || fcode1 == BUILT_IN_POWL)
11183 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11184 tree arg10 = CALL_EXPR_ARG (arg1, 0);
11185 tree arg11 = CALL_EXPR_ARG (arg1, 1);
11186 tree neg11 = fold_convert (type, negate_expr (arg11));
11187 arg1 = build_call_expr (powfn, 2, arg10, neg11);
11188 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11193 case TRUNC_DIV_EXPR:
11194 case FLOOR_DIV_EXPR:
11195 /* Simplify A / (B << N) where A and B are positive and B is
11196 a power of 2, to A >> (N + log2(B)). */
11197 strict_overflow_p = false;
11198 if (TREE_CODE (arg1) == LSHIFT_EXPR
11199 && (TYPE_UNSIGNED (type)
11200 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11202 tree sval = TREE_OPERAND (arg1, 0);
11203 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
11205 tree sh_cnt = TREE_OPERAND (arg1, 1);
11206 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
11208 if (strict_overflow_p)
11209 fold_overflow_warning (("assuming signed overflow does not "
11210 "occur when simplifying A / (B << N)"),
11211 WARN_STRICT_OVERFLOW_MISC);
11213 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
11214 sh_cnt, build_int_cst (NULL_TREE, pow2));
11215 return fold_build2 (RSHIFT_EXPR, type,
11216 fold_convert (type, arg0), sh_cnt);
11220 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
11221 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
11222 if (INTEGRAL_TYPE_P (type)
11223 && TYPE_UNSIGNED (type)
11224 && code == FLOOR_DIV_EXPR)
11225 return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
11229 case ROUND_DIV_EXPR:
11230 case CEIL_DIV_EXPR:
11231 case EXACT_DIV_EXPR:
11232 if (integer_onep (arg1))
11233 return non_lvalue (fold_convert (type, arg0));
11234 if (integer_zerop (arg1))
11236 /* X / -1 is -X. */
11237 if (!TYPE_UNSIGNED (type)
11238 && TREE_CODE (arg1) == INTEGER_CST
11239 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11240 && TREE_INT_CST_HIGH (arg1) == -1)
11241 return fold_convert (type, negate_expr (arg0));
11243 /* Convert -A / -B to A / B when the type is signed and overflow is
11245 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11246 && TREE_CODE (arg0) == NEGATE_EXPR
11247 && negate_expr_p (arg1))
11249 if (INTEGRAL_TYPE_P (type))
11250 fold_overflow_warning (("assuming signed overflow does not occur "
11251 "when distributing negation across "
11253 WARN_STRICT_OVERFLOW_MISC);
11254 return fold_build2 (code, type,
11255 fold_convert (type, TREE_OPERAND (arg0, 0)),
11256 negate_expr (arg1));
11258 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11259 && TREE_CODE (arg1) == NEGATE_EXPR
11260 && negate_expr_p (arg0))
11262 if (INTEGRAL_TYPE_P (type))
11263 fold_overflow_warning (("assuming signed overflow does not occur "
11264 "when distributing negation across "
11266 WARN_STRICT_OVERFLOW_MISC);
11267 return fold_build2 (code, type, negate_expr (arg0),
11268 TREE_OPERAND (arg1, 0));
11271 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11272 operation, EXACT_DIV_EXPR.
11274 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11275 At one time others generated faster code, it's not clear if they do
11276 after the last round to changes to the DIV code in expmed.c. */
11277 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
11278 && multiple_of_p (type, arg0, arg1))
11279 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
11281 strict_overflow_p = false;
11282 if (TREE_CODE (arg1) == INTEGER_CST
11283 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11284 &strict_overflow_p)))
11286 if (strict_overflow_p)
11287 fold_overflow_warning (("assuming signed overflow does not occur "
11288 "when simplifying division"),
11289 WARN_STRICT_OVERFLOW_MISC);
11290 return fold_convert (type, tem);
11295 case CEIL_MOD_EXPR:
11296 case FLOOR_MOD_EXPR:
11297 case ROUND_MOD_EXPR:
11298 case TRUNC_MOD_EXPR:
11299 /* X % 1 is always zero, but be sure to preserve any side
11301 if (integer_onep (arg1))
11302 return omit_one_operand (type, integer_zero_node, arg0);
11304 /* X % 0, return X % 0 unchanged so that we can get the
11305 proper warnings and errors. */
11306 if (integer_zerop (arg1))
11309 /* 0 % X is always zero, but be sure to preserve any side
11310 effects in X. Place this after checking for X == 0. */
11311 if (integer_zerop (arg0))
11312 return omit_one_operand (type, integer_zero_node, arg1);
11314 /* X % -1 is zero. */
11315 if (!TYPE_UNSIGNED (type)
11316 && TREE_CODE (arg1) == INTEGER_CST
11317 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11318 && TREE_INT_CST_HIGH (arg1) == -1)
11319 return omit_one_operand (type, integer_zero_node, arg0);
11321 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11322 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11323 strict_overflow_p = false;
11324 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
11325 && (TYPE_UNSIGNED (type)
11326 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11329 /* Also optimize A % (C << N) where C is a power of 2,
11330 to A & ((C << N) - 1). */
11331 if (TREE_CODE (arg1) == LSHIFT_EXPR)
11332 c = TREE_OPERAND (arg1, 0);
11334 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
11336 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
11337 build_int_cst (TREE_TYPE (arg1), 1));
11338 if (strict_overflow_p)
11339 fold_overflow_warning (("assuming signed overflow does not "
11340 "occur when simplifying "
11341 "X % (power of two)"),
11342 WARN_STRICT_OVERFLOW_MISC);
11343 return fold_build2 (BIT_AND_EXPR, type,
11344 fold_convert (type, arg0),
11345 fold_convert (type, mask));
11349 /* X % -C is the same as X % C. */
11350 if (code == TRUNC_MOD_EXPR
11351 && !TYPE_UNSIGNED (type)
11352 && TREE_CODE (arg1) == INTEGER_CST
11353 && !TREE_OVERFLOW (arg1)
11354 && TREE_INT_CST_HIGH (arg1) < 0
11355 && !TYPE_OVERFLOW_TRAPS (type)
11356 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11357 && !sign_bit_p (arg1, arg1))
11358 return fold_build2 (code, type, fold_convert (type, arg0),
11359 fold_convert (type, negate_expr (arg1)));
11361 /* X % -Y is the same as X % Y. */
11362 if (code == TRUNC_MOD_EXPR
11363 && !TYPE_UNSIGNED (type)
11364 && TREE_CODE (arg1) == NEGATE_EXPR
11365 && !TYPE_OVERFLOW_TRAPS (type))
11366 return fold_build2 (code, type, fold_convert (type, arg0),
11367 fold_convert (type, TREE_OPERAND (arg1, 0)));
11369 if (TREE_CODE (arg1) == INTEGER_CST
11370 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11371 &strict_overflow_p)))
11373 if (strict_overflow_p)
11374 fold_overflow_warning (("assuming signed overflow does not occur "
11375 "when simplifying modulos"),
11376 WARN_STRICT_OVERFLOW_MISC);
11377 return fold_convert (type, tem);
11384 if (integer_all_onesp (arg0))
11385 return omit_one_operand (type, arg0, arg1);
11389 /* Optimize -1 >> x for arithmetic right shifts. */
11390 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
11391 return omit_one_operand (type, arg0, arg1);
11392 /* ... fall through ... */
11396 if (integer_zerop (arg1))
11397 return non_lvalue (fold_convert (type, arg0));
11398 if (integer_zerop (arg0))
11399 return omit_one_operand (type, arg0, arg1);
11401 /* Since negative shift count is not well-defined,
11402 don't try to compute it in the compiler. */
11403 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
11406 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11407 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
11408 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11409 && host_integerp (TREE_OPERAND (arg0, 1), false)
11410 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11412 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
11413 + TREE_INT_CST_LOW (arg1));
11415 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11416 being well defined. */
11417 if (low >= TYPE_PRECISION (type))
11419 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
11420 low = low % TYPE_PRECISION (type);
11421 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
11422 return build_int_cst (type, 0);
11424 low = TYPE_PRECISION (type) - 1;
11427 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11428 build_int_cst (type, low));
11431 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11432 into x & ((unsigned)-1 >> c) for unsigned types. */
11433 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
11434 || (TYPE_UNSIGNED (type)
11435 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
11436 && host_integerp (arg1, false)
11437 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11438 && host_integerp (TREE_OPERAND (arg0, 1), false)
11439 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11441 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
11442 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
11448 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
11450 lshift = build_int_cst (type, -1);
11451 lshift = int_const_binop (code, lshift, arg1, 0);
11453 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
11457 /* Rewrite an LROTATE_EXPR by a constant into an
11458 RROTATE_EXPR by a new constant. */
11459 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
11461 tree tem = build_int_cst (TREE_TYPE (arg1),
11462 TYPE_PRECISION (type));
11463 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
11464 return fold_build2 (RROTATE_EXPR, type, op0, tem);
11467 /* If we have a rotate of a bit operation with the rotate count and
11468 the second operand of the bit operation both constant,
11469 permute the two operations. */
11470 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11471 && (TREE_CODE (arg0) == BIT_AND_EXPR
11472 || TREE_CODE (arg0) == BIT_IOR_EXPR
11473 || TREE_CODE (arg0) == BIT_XOR_EXPR)
11474 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11475 return fold_build2 (TREE_CODE (arg0), type,
11476 fold_build2 (code, type,
11477 TREE_OPERAND (arg0, 0), arg1),
11478 fold_build2 (code, type,
11479 TREE_OPERAND (arg0, 1), arg1));
11481 /* Two consecutive rotates adding up to the precision of the
11482 type can be ignored. */
11483 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11484 && TREE_CODE (arg0) == RROTATE_EXPR
11485 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11486 && TREE_INT_CST_HIGH (arg1) == 0
11487 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
11488 && ((TREE_INT_CST_LOW (arg1)
11489 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
11490 == (unsigned int) TYPE_PRECISION (type)))
11491 return TREE_OPERAND (arg0, 0);
11493 /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
11494 (X & C2) >> C1 into (X >> C1) & (C2 >> C1)
11495 if the latter can be further optimized. */
11496 if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
11497 && TREE_CODE (arg0) == BIT_AND_EXPR
11498 && TREE_CODE (arg1) == INTEGER_CST
11499 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11501 tree mask = fold_build2 (code, type,
11502 fold_convert (type, TREE_OPERAND (arg0, 1)),
11504 tree shift = fold_build2 (code, type,
11505 fold_convert (type, TREE_OPERAND (arg0, 0)),
11507 tem = fold_binary (BIT_AND_EXPR, type, shift, mask);
11515 if (operand_equal_p (arg0, arg1, 0))
11516 return omit_one_operand (type, arg0, arg1);
11517 if (INTEGRAL_TYPE_P (type)
11518 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
11519 return omit_one_operand (type, arg1, arg0);
11520 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
11526 if (operand_equal_p (arg0, arg1, 0))
11527 return omit_one_operand (type, arg0, arg1);
11528 if (INTEGRAL_TYPE_P (type)
11529 && TYPE_MAX_VALUE (type)
11530 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
11531 return omit_one_operand (type, arg1, arg0);
11532 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
11537 case TRUTH_ANDIF_EXPR:
11538 /* Note that the operands of this must be ints
11539 and their values must be 0 or 1.
11540 ("true" is a fixed value perhaps depending on the language.) */
11541 /* If first arg is constant zero, return it. */
11542 if (integer_zerop (arg0))
11543 return fold_convert (type, arg0);
11544 case TRUTH_AND_EXPR:
11545 /* If either arg is constant true, drop it. */
11546 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11547 return non_lvalue (fold_convert (type, arg1));
11548 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
11549 /* Preserve sequence points. */
11550 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11551 return non_lvalue (fold_convert (type, arg0));
11552 /* If second arg is constant zero, result is zero, but first arg
11553 must be evaluated. */
11554 if (integer_zerop (arg1))
11555 return omit_one_operand (type, arg1, arg0);
11556 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11557 case will be handled here. */
11558 if (integer_zerop (arg0))
11559 return omit_one_operand (type, arg0, arg1);
11561 /* !X && X is always false. */
11562 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11563 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11564 return omit_one_operand (type, integer_zero_node, arg1);
11565 /* X && !X is always false. */
11566 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11567 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11568 return omit_one_operand (type, integer_zero_node, arg0);
11570 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
11571 means A >= Y && A != MAX, but in this case we know that
11574 if (!TREE_SIDE_EFFECTS (arg0)
11575 && !TREE_SIDE_EFFECTS (arg1))
11577 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
11578 if (tem && !operand_equal_p (tem, arg0, 0))
11579 return fold_build2 (code, type, tem, arg1);
11581 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
11582 if (tem && !operand_equal_p (tem, arg1, 0))
11583 return fold_build2 (code, type, arg0, tem);
11587 /* We only do these simplifications if we are optimizing. */
11591 /* Check for things like (A || B) && (A || C). We can convert this
11592 to A || (B && C). Note that either operator can be any of the four
11593 truth and/or operations and the transformation will still be
11594 valid. Also note that we only care about order for the
11595 ANDIF and ORIF operators. If B contains side effects, this
11596 might change the truth-value of A. */
11597 if (TREE_CODE (arg0) == TREE_CODE (arg1)
11598 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
11599 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
11600 || TREE_CODE (arg0) == TRUTH_AND_EXPR
11601 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
11602 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
11604 tree a00 = TREE_OPERAND (arg0, 0);
11605 tree a01 = TREE_OPERAND (arg0, 1);
11606 tree a10 = TREE_OPERAND (arg1, 0);
11607 tree a11 = TREE_OPERAND (arg1, 1);
11608 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
11609 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
11610 && (code == TRUTH_AND_EXPR
11611 || code == TRUTH_OR_EXPR));
11613 if (operand_equal_p (a00, a10, 0))
11614 return fold_build2 (TREE_CODE (arg0), type, a00,
11615 fold_build2 (code, type, a01, a11));
11616 else if (commutative && operand_equal_p (a00, a11, 0))
11617 return fold_build2 (TREE_CODE (arg0), type, a00,
11618 fold_build2 (code, type, a01, a10));
11619 else if (commutative && operand_equal_p (a01, a10, 0))
11620 return fold_build2 (TREE_CODE (arg0), type, a01,
11621 fold_build2 (code, type, a00, a11));
11623 /* This case if tricky because we must either have commutative
11624 operators or else A10 must not have side-effects. */
11626 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
11627 && operand_equal_p (a01, a11, 0))
11628 return fold_build2 (TREE_CODE (arg0), type,
11629 fold_build2 (code, type, a00, a10),
11633 /* See if we can build a range comparison. */
11634 if (0 != (tem = fold_range_test (code, type, op0, op1)))
11637 /* Check for the possibility of merging component references. If our
11638 lhs is another similar operation, try to merge its rhs with our
11639 rhs. Then try to merge our lhs and rhs. */
11640 if (TREE_CODE (arg0) == code
11641 && 0 != (tem = fold_truthop (code, type,
11642 TREE_OPERAND (arg0, 1), arg1)))
11643 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11645 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
11650 case TRUTH_ORIF_EXPR:
11651 /* Note that the operands of this must be ints
11652 and their values must be 0 or true.
11653 ("true" is a fixed value perhaps depending on the language.) */
11654 /* If first arg is constant true, return it. */
11655 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11656 return fold_convert (type, arg0);
11657 case TRUTH_OR_EXPR:
11658 /* If either arg is constant zero, drop it. */
11659 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
11660 return non_lvalue (fold_convert (type, arg1));
11661 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
11662 /* Preserve sequence points. */
11663 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11664 return non_lvalue (fold_convert (type, arg0));
11665 /* If second arg is constant true, result is true, but we must
11666 evaluate first arg. */
11667 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
11668 return omit_one_operand (type, arg1, arg0);
11669 /* Likewise for first arg, but note this only occurs here for
11671 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11672 return omit_one_operand (type, arg0, arg1);
11674 /* !X || X is always true. */
11675 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11676 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11677 return omit_one_operand (type, integer_one_node, arg1);
11678 /* X || !X is always true. */
11679 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11680 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11681 return omit_one_operand (type, integer_one_node, arg0);
11685 case TRUTH_XOR_EXPR:
11686 /* If the second arg is constant zero, drop it. */
11687 if (integer_zerop (arg1))
11688 return non_lvalue (fold_convert (type, arg0));
11689 /* If the second arg is constant true, this is a logical inversion. */
11690 if (integer_onep (arg1))
11692 /* Only call invert_truthvalue if operand is a truth value. */
11693 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
11694 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
11696 tem = invert_truthvalue (arg0);
11697 return non_lvalue (fold_convert (type, tem));
11699 /* Identical arguments cancel to zero. */
11700 if (operand_equal_p (arg0, arg1, 0))
11701 return omit_one_operand (type, integer_zero_node, arg0);
11703 /* !X ^ X is always true. */
11704 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11705 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11706 return omit_one_operand (type, integer_one_node, arg1);
11708 /* X ^ !X is always true. */
11709 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11710 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11711 return omit_one_operand (type, integer_one_node, arg0);
11717 tem = fold_comparison (code, type, op0, op1);
11718 if (tem != NULL_TREE)
11721 /* bool_var != 0 becomes bool_var. */
11722 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11723 && code == NE_EXPR)
11724 return non_lvalue (fold_convert (type, arg0));
11726 /* bool_var == 1 becomes bool_var. */
11727 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11728 && code == EQ_EXPR)
11729 return non_lvalue (fold_convert (type, arg0));
11731 /* bool_var != 1 becomes !bool_var. */
11732 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11733 && code == NE_EXPR)
11734 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11736 /* bool_var == 0 becomes !bool_var. */
11737 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11738 && code == EQ_EXPR)
11739 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11741 /* If this is an equality comparison of the address of two non-weak,
11742 unaliased symbols neither of which are extern (since we do not
11743 have access to attributes for externs), then we know the result. */
11744 if (TREE_CODE (arg0) == ADDR_EXPR
11745 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
11746 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
11747 && ! lookup_attribute ("alias",
11748 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
11749 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
11750 && TREE_CODE (arg1) == ADDR_EXPR
11751 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
11752 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
11753 && ! lookup_attribute ("alias",
11754 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
11755 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
11757 /* We know that we're looking at the address of two
11758 non-weak, unaliased, static _DECL nodes.
11760 It is both wasteful and incorrect to call operand_equal_p
11761 to compare the two ADDR_EXPR nodes. It is wasteful in that
11762 all we need to do is test pointer equality for the arguments
11763 to the two ADDR_EXPR nodes. It is incorrect to use
11764 operand_equal_p as that function is NOT equivalent to a
11765 C equality test. It can in fact return false for two
11766 objects which would test as equal using the C equality
11768 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
11769 return constant_boolean_node (equal
11770 ? code == EQ_EXPR : code != EQ_EXPR,
11774 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
11775 a MINUS_EXPR of a constant, we can convert it into a comparison with
11776 a revised constant as long as no overflow occurs. */
11777 if (TREE_CODE (arg1) == INTEGER_CST
11778 && (TREE_CODE (arg0) == PLUS_EXPR
11779 || TREE_CODE (arg0) == MINUS_EXPR)
11780 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11781 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
11782 ? MINUS_EXPR : PLUS_EXPR,
11783 fold_convert (TREE_TYPE (arg0), arg1),
11784 TREE_OPERAND (arg0, 1), 0))
11785 && !TREE_OVERFLOW (tem))
11786 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11788 /* Similarly for a NEGATE_EXPR. */
11789 if (TREE_CODE (arg0) == NEGATE_EXPR
11790 && TREE_CODE (arg1) == INTEGER_CST
11791 && 0 != (tem = negate_expr (arg1))
11792 && TREE_CODE (tem) == INTEGER_CST
11793 && !TREE_OVERFLOW (tem))
11794 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11796 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
11797 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11798 && TREE_CODE (arg1) == INTEGER_CST
11799 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11800 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11801 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
11802 fold_convert (TREE_TYPE (arg0), arg1),
11803 TREE_OPERAND (arg0, 1)));
11805 /* Transform comparisons of the form X +- C CMP X. */
11806 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11807 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11808 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11809 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
11810 || POINTER_TYPE_P (TREE_TYPE (arg0))))
11812 tree cst = TREE_OPERAND (arg0, 1);
11814 if (code == EQ_EXPR
11815 && !integer_zerop (cst))
11816 return omit_two_operands (type, boolean_false_node,
11817 TREE_OPERAND (arg0, 0), arg1);
11819 return omit_two_operands (type, boolean_true_node,
11820 TREE_OPERAND (arg0, 0), arg1);
11823 /* If we have X - Y == 0, we can convert that to X == Y and similarly
11824 for !=. Don't do this for ordered comparisons due to overflow. */
11825 if (TREE_CODE (arg0) == MINUS_EXPR
11826 && integer_zerop (arg1))
11827 return fold_build2 (code, type,
11828 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
11830 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
11831 if (TREE_CODE (arg0) == ABS_EXPR
11832 && (integer_zerop (arg1) || real_zerop (arg1)))
11833 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
11835 /* If this is an EQ or NE comparison with zero and ARG0 is
11836 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
11837 two operations, but the latter can be done in one less insn
11838 on machines that have only two-operand insns or on which a
11839 constant cannot be the first operand. */
11840 if (TREE_CODE (arg0) == BIT_AND_EXPR
11841 && integer_zerop (arg1))
11843 tree arg00 = TREE_OPERAND (arg0, 0);
11844 tree arg01 = TREE_OPERAND (arg0, 1);
11845 if (TREE_CODE (arg00) == LSHIFT_EXPR
11846 && integer_onep (TREE_OPERAND (arg00, 0)))
11848 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
11849 arg01, TREE_OPERAND (arg00, 1));
11850 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11851 build_int_cst (TREE_TYPE (arg0), 1));
11852 return fold_build2 (code, type,
11853 fold_convert (TREE_TYPE (arg1), tem), arg1);
11855 else if (TREE_CODE (arg01) == LSHIFT_EXPR
11856 && integer_onep (TREE_OPERAND (arg01, 0)))
11858 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
11859 arg00, TREE_OPERAND (arg01, 1));
11860 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11861 build_int_cst (TREE_TYPE (arg0), 1));
11862 return fold_build2 (code, type,
11863 fold_convert (TREE_TYPE (arg1), tem), arg1);
11867 /* If this is an NE or EQ comparison of zero against the result of a
11868 signed MOD operation whose second operand is a power of 2, make
11869 the MOD operation unsigned since it is simpler and equivalent. */
11870 if (integer_zerop (arg1)
11871 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
11872 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
11873 || TREE_CODE (arg0) == CEIL_MOD_EXPR
11874 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
11875 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
11876 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11878 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
11879 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
11880 fold_convert (newtype,
11881 TREE_OPERAND (arg0, 0)),
11882 fold_convert (newtype,
11883 TREE_OPERAND (arg0, 1)));
11885 return fold_build2 (code, type, newmod,
11886 fold_convert (newtype, arg1));
11889 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
11890 C1 is a valid shift constant, and C2 is a power of two, i.e.
11892 if (TREE_CODE (arg0) == BIT_AND_EXPR
11893 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
11894 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
11896 && integer_pow2p (TREE_OPERAND (arg0, 1))
11897 && integer_zerop (arg1))
11899 tree itype = TREE_TYPE (arg0);
11900 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
11901 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
11903 /* Check for a valid shift count. */
11904 if (TREE_INT_CST_HIGH (arg001) == 0
11905 && TREE_INT_CST_LOW (arg001) < prec)
11907 tree arg01 = TREE_OPERAND (arg0, 1);
11908 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11909 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
11910 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
11911 can be rewritten as (X & (C2 << C1)) != 0. */
11912 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
11914 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
11915 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
11916 return fold_build2 (code, type, tem, arg1);
11918 /* Otherwise, for signed (arithmetic) shifts,
11919 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
11920 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
11921 else if (!TYPE_UNSIGNED (itype))
11922 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
11923 arg000, build_int_cst (itype, 0));
11924 /* Otherwise, of unsigned (logical) shifts,
11925 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
11926 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
11928 return omit_one_operand (type,
11929 code == EQ_EXPR ? integer_one_node
11930 : integer_zero_node,
11935 /* If this is an NE comparison of zero with an AND of one, remove the
11936 comparison since the AND will give the correct value. */
11937 if (code == NE_EXPR
11938 && integer_zerop (arg1)
11939 && TREE_CODE (arg0) == BIT_AND_EXPR
11940 && integer_onep (TREE_OPERAND (arg0, 1)))
11941 return fold_convert (type, arg0);
11943 /* If we have (A & C) == C where C is a power of 2, convert this into
11944 (A & C) != 0. Similarly for NE_EXPR. */
11945 if (TREE_CODE (arg0) == BIT_AND_EXPR
11946 && integer_pow2p (TREE_OPERAND (arg0, 1))
11947 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11948 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11949 arg0, fold_convert (TREE_TYPE (arg0),
11950 integer_zero_node));
11952 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
11953 bit, then fold the expression into A < 0 or A >= 0. */
11954 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
11958 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
11959 Similarly for NE_EXPR. */
11960 if (TREE_CODE (arg0) == BIT_AND_EXPR
11961 && TREE_CODE (arg1) == INTEGER_CST
11962 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11964 tree notc = fold_build1 (BIT_NOT_EXPR,
11965 TREE_TYPE (TREE_OPERAND (arg0, 1)),
11966 TREE_OPERAND (arg0, 1));
11967 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11969 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11970 if (integer_nonzerop (dandnotc))
11971 return omit_one_operand (type, rslt, arg0);
11974 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
11975 Similarly for NE_EXPR. */
11976 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11977 && TREE_CODE (arg1) == INTEGER_CST
11978 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11980 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
11981 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11982 TREE_OPERAND (arg0, 1), notd);
11983 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11984 if (integer_nonzerop (candnotd))
11985 return omit_one_operand (type, rslt, arg0);
11988 /* Optimize comparisons of strlen vs zero to a compare of the
11989 first character of the string vs zero. To wit,
11990 strlen(ptr) == 0 => *ptr == 0
11991 strlen(ptr) != 0 => *ptr != 0
11992 Other cases should reduce to one of these two (or a constant)
11993 due to the return value of strlen being unsigned. */
11994 if (TREE_CODE (arg0) == CALL_EXPR
11995 && integer_zerop (arg1))
11997 tree fndecl = get_callee_fndecl (arg0);
12000 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
12001 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
12002 && call_expr_nargs (arg0) == 1
12003 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
12005 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
12006 return fold_build2 (code, type, iref,
12007 build_int_cst (TREE_TYPE (iref), 0));
12011 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
12012 of X. Similarly fold (X >> C) == 0 into X >= 0. */
12013 if (TREE_CODE (arg0) == RSHIFT_EXPR
12014 && integer_zerop (arg1)
12015 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12017 tree arg00 = TREE_OPERAND (arg0, 0);
12018 tree arg01 = TREE_OPERAND (arg0, 1);
12019 tree itype = TREE_TYPE (arg00);
12020 if (TREE_INT_CST_HIGH (arg01) == 0
12021 && TREE_INT_CST_LOW (arg01)
12022 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
12024 if (TYPE_UNSIGNED (itype))
12026 itype = signed_type_for (itype);
12027 arg00 = fold_convert (itype, arg00);
12029 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
12030 type, arg00, build_int_cst (itype, 0));
12034 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
12035 if (integer_zerop (arg1)
12036 && TREE_CODE (arg0) == BIT_XOR_EXPR)
12037 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12038 TREE_OPERAND (arg0, 1));
12040 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
12041 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12042 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12043 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12044 build_int_cst (TREE_TYPE (arg1), 0));
12045 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
12046 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12047 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12048 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
12049 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
12050 build_int_cst (TREE_TYPE (arg1), 0));
12052 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
12053 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12054 && TREE_CODE (arg1) == INTEGER_CST
12055 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12056 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12057 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
12058 TREE_OPERAND (arg0, 1), arg1));
12060 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
12061 (X & C) == 0 when C is a single bit. */
12062 if (TREE_CODE (arg0) == BIT_AND_EXPR
12063 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
12064 && integer_zerop (arg1)
12065 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12067 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12068 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
12069 TREE_OPERAND (arg0, 1));
12070 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
12074 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12075 constant C is a power of two, i.e. a single bit. */
12076 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12077 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12078 && integer_zerop (arg1)
12079 && integer_pow2p (TREE_OPERAND (arg0, 1))
12080 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12081 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12083 tree arg00 = TREE_OPERAND (arg0, 0);
12084 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12085 arg00, build_int_cst (TREE_TYPE (arg00), 0));
12088 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12089 when is C is a power of two, i.e. a single bit. */
12090 if (TREE_CODE (arg0) == BIT_AND_EXPR
12091 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
12092 && integer_zerop (arg1)
12093 && integer_pow2p (TREE_OPERAND (arg0, 1))
12094 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12095 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12097 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12098 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
12099 arg000, TREE_OPERAND (arg0, 1));
12100 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12101 tem, build_int_cst (TREE_TYPE (tem), 0));
12104 if (integer_zerop (arg1)
12105 && tree_expr_nonzero_p (arg0))
12107 tree res = constant_boolean_node (code==NE_EXPR, type);
12108 return omit_one_operand (type, res, arg0);
12111 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12112 if (TREE_CODE (arg0) == NEGATE_EXPR
12113 && TREE_CODE (arg1) == NEGATE_EXPR)
12114 return fold_build2 (code, type,
12115 TREE_OPERAND (arg0, 0),
12116 TREE_OPERAND (arg1, 0));
12118 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12119 if (TREE_CODE (arg0) == BIT_AND_EXPR
12120 && TREE_CODE (arg1) == BIT_AND_EXPR)
12122 tree arg00 = TREE_OPERAND (arg0, 0);
12123 tree arg01 = TREE_OPERAND (arg0, 1);
12124 tree arg10 = TREE_OPERAND (arg1, 0);
12125 tree arg11 = TREE_OPERAND (arg1, 1);
12126 tree itype = TREE_TYPE (arg0);
12128 if (operand_equal_p (arg01, arg11, 0))
12129 return fold_build2 (code, type,
12130 fold_build2 (BIT_AND_EXPR, itype,
12131 fold_build2 (BIT_XOR_EXPR, itype,
12134 build_int_cst (itype, 0));
12136 if (operand_equal_p (arg01, arg10, 0))
12137 return fold_build2 (code, type,
12138 fold_build2 (BIT_AND_EXPR, itype,
12139 fold_build2 (BIT_XOR_EXPR, itype,
12142 build_int_cst (itype, 0));
12144 if (operand_equal_p (arg00, arg11, 0))
12145 return fold_build2 (code, type,
12146 fold_build2 (BIT_AND_EXPR, itype,
12147 fold_build2 (BIT_XOR_EXPR, itype,
12150 build_int_cst (itype, 0));
12152 if (operand_equal_p (arg00, arg10, 0))
12153 return fold_build2 (code, type,
12154 fold_build2 (BIT_AND_EXPR, itype,
12155 fold_build2 (BIT_XOR_EXPR, itype,
12158 build_int_cst (itype, 0));
12161 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12162 && TREE_CODE (arg1) == BIT_XOR_EXPR)
12164 tree arg00 = TREE_OPERAND (arg0, 0);
12165 tree arg01 = TREE_OPERAND (arg0, 1);
12166 tree arg10 = TREE_OPERAND (arg1, 0);
12167 tree arg11 = TREE_OPERAND (arg1, 1);
12168 tree itype = TREE_TYPE (arg0);
12170 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12171 operand_equal_p guarantees no side-effects so we don't need
12172 to use omit_one_operand on Z. */
12173 if (operand_equal_p (arg01, arg11, 0))
12174 return fold_build2 (code, type, arg00, arg10);
12175 if (operand_equal_p (arg01, arg10, 0))
12176 return fold_build2 (code, type, arg00, arg11);
12177 if (operand_equal_p (arg00, arg11, 0))
12178 return fold_build2 (code, type, arg01, arg10);
12179 if (operand_equal_p (arg00, arg10, 0))
12180 return fold_build2 (code, type, arg01, arg11);
12182 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12183 if (TREE_CODE (arg01) == INTEGER_CST
12184 && TREE_CODE (arg11) == INTEGER_CST)
12185 return fold_build2 (code, type,
12186 fold_build2 (BIT_XOR_EXPR, itype, arg00,
12187 fold_build2 (BIT_XOR_EXPR, itype,
12192 /* Attempt to simplify equality/inequality comparisons of complex
12193 values. Only lower the comparison if the result is known or
12194 can be simplified to a single scalar comparison. */
12195 if ((TREE_CODE (arg0) == COMPLEX_EXPR
12196 || TREE_CODE (arg0) == COMPLEX_CST)
12197 && (TREE_CODE (arg1) == COMPLEX_EXPR
12198 || TREE_CODE (arg1) == COMPLEX_CST))
12200 tree real0, imag0, real1, imag1;
12203 if (TREE_CODE (arg0) == COMPLEX_EXPR)
12205 real0 = TREE_OPERAND (arg0, 0);
12206 imag0 = TREE_OPERAND (arg0, 1);
12210 real0 = TREE_REALPART (arg0);
12211 imag0 = TREE_IMAGPART (arg0);
12214 if (TREE_CODE (arg1) == COMPLEX_EXPR)
12216 real1 = TREE_OPERAND (arg1, 0);
12217 imag1 = TREE_OPERAND (arg1, 1);
12221 real1 = TREE_REALPART (arg1);
12222 imag1 = TREE_IMAGPART (arg1);
12225 rcond = fold_binary (code, type, real0, real1);
12226 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
12228 if (integer_zerop (rcond))
12230 if (code == EQ_EXPR)
12231 return omit_two_operands (type, boolean_false_node,
12233 return fold_build2 (NE_EXPR, type, imag0, imag1);
12237 if (code == NE_EXPR)
12238 return omit_two_operands (type, boolean_true_node,
12240 return fold_build2 (EQ_EXPR, type, imag0, imag1);
12244 icond = fold_binary (code, type, imag0, imag1);
12245 if (icond && TREE_CODE (icond) == INTEGER_CST)
12247 if (integer_zerop (icond))
12249 if (code == EQ_EXPR)
12250 return omit_two_operands (type, boolean_false_node,
12252 return fold_build2 (NE_EXPR, type, real0, real1);
12256 if (code == NE_EXPR)
12257 return omit_two_operands (type, boolean_true_node,
12259 return fold_build2 (EQ_EXPR, type, real0, real1);
12270 tem = fold_comparison (code, type, op0, op1);
12271 if (tem != NULL_TREE)
12274 /* Transform comparisons of the form X +- C CMP X. */
12275 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12276 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12277 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
12278 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
12279 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12280 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
12282 tree arg01 = TREE_OPERAND (arg0, 1);
12283 enum tree_code code0 = TREE_CODE (arg0);
12286 if (TREE_CODE (arg01) == REAL_CST)
12287 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
12289 is_positive = tree_int_cst_sgn (arg01);
12291 /* (X - c) > X becomes false. */
12292 if (code == GT_EXPR
12293 && ((code0 == MINUS_EXPR && is_positive >= 0)
12294 || (code0 == PLUS_EXPR && is_positive <= 0)))
12296 if (TREE_CODE (arg01) == INTEGER_CST
12297 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12298 fold_overflow_warning (("assuming signed overflow does not "
12299 "occur when assuming that (X - c) > X "
12300 "is always false"),
12301 WARN_STRICT_OVERFLOW_ALL);
12302 return constant_boolean_node (0, type);
12305 /* Likewise (X + c) < X becomes false. */
12306 if (code == LT_EXPR
12307 && ((code0 == PLUS_EXPR && is_positive >= 0)
12308 || (code0 == MINUS_EXPR && is_positive <= 0)))
12310 if (TREE_CODE (arg01) == INTEGER_CST
12311 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12312 fold_overflow_warning (("assuming signed overflow does not "
12313 "occur when assuming that "
12314 "(X + c) < X is always false"),
12315 WARN_STRICT_OVERFLOW_ALL);
12316 return constant_boolean_node (0, type);
12319 /* Convert (X - c) <= X to true. */
12320 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12322 && ((code0 == MINUS_EXPR && is_positive >= 0)
12323 || (code0 == PLUS_EXPR && is_positive <= 0)))
12325 if (TREE_CODE (arg01) == INTEGER_CST
12326 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12327 fold_overflow_warning (("assuming signed overflow does not "
12328 "occur when assuming that "
12329 "(X - c) <= X is always true"),
12330 WARN_STRICT_OVERFLOW_ALL);
12331 return constant_boolean_node (1, type);
12334 /* Convert (X + c) >= X to true. */
12335 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12337 && ((code0 == PLUS_EXPR && is_positive >= 0)
12338 || (code0 == MINUS_EXPR && is_positive <= 0)))
12340 if (TREE_CODE (arg01) == INTEGER_CST
12341 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12342 fold_overflow_warning (("assuming signed overflow does not "
12343 "occur when assuming that "
12344 "(X + c) >= X is always true"),
12345 WARN_STRICT_OVERFLOW_ALL);
12346 return constant_boolean_node (1, type);
12349 if (TREE_CODE (arg01) == INTEGER_CST)
12351 /* Convert X + c > X and X - c < X to true for integers. */
12352 if (code == GT_EXPR
12353 && ((code0 == PLUS_EXPR && is_positive > 0)
12354 || (code0 == MINUS_EXPR && is_positive < 0)))
12356 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12357 fold_overflow_warning (("assuming signed overflow does "
12358 "not occur when assuming that "
12359 "(X + c) > X is always true"),
12360 WARN_STRICT_OVERFLOW_ALL);
12361 return constant_boolean_node (1, type);
12364 if (code == LT_EXPR
12365 && ((code0 == MINUS_EXPR && is_positive > 0)
12366 || (code0 == PLUS_EXPR && is_positive < 0)))
12368 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12369 fold_overflow_warning (("assuming signed overflow does "
12370 "not occur when assuming that "
12371 "(X - c) < X is always true"),
12372 WARN_STRICT_OVERFLOW_ALL);
12373 return constant_boolean_node (1, type);
12376 /* Convert X + c <= X and X - c >= X to false for integers. */
12377 if (code == LE_EXPR
12378 && ((code0 == PLUS_EXPR && is_positive > 0)
12379 || (code0 == MINUS_EXPR && is_positive < 0)))
12381 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12382 fold_overflow_warning (("assuming signed overflow does "
12383 "not occur when assuming that "
12384 "(X + c) <= X is always false"),
12385 WARN_STRICT_OVERFLOW_ALL);
12386 return constant_boolean_node (0, type);
12389 if (code == GE_EXPR
12390 && ((code0 == MINUS_EXPR && is_positive > 0)
12391 || (code0 == PLUS_EXPR && is_positive < 0)))
12393 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12394 fold_overflow_warning (("assuming signed overflow does "
12395 "not occur when assuming that "
12396 "(X - c) >= X is always false"),
12397 WARN_STRICT_OVERFLOW_ALL);
12398 return constant_boolean_node (0, type);
12403 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
12404 This transformation affects the cases which are handled in later
12405 optimizations involving comparisons with non-negative constants. */
12406 if (TREE_CODE (arg1) == INTEGER_CST
12407 && TREE_CODE (arg0) != INTEGER_CST
12408 && tree_int_cst_sgn (arg1) > 0)
12410 if (code == GE_EXPR)
12412 arg1 = const_binop (MINUS_EXPR, arg1,
12413 build_int_cst (TREE_TYPE (arg1), 1), 0);
12414 return fold_build2 (GT_EXPR, type, arg0,
12415 fold_convert (TREE_TYPE (arg0), arg1));
12417 if (code == LT_EXPR)
12419 arg1 = const_binop (MINUS_EXPR, arg1,
12420 build_int_cst (TREE_TYPE (arg1), 1), 0);
12421 return fold_build2 (LE_EXPR, type, arg0,
12422 fold_convert (TREE_TYPE (arg0), arg1));
12426 /* Comparisons with the highest or lowest possible integer of
12427 the specified precision will have known values. */
12429 tree arg1_type = TREE_TYPE (arg1);
12430 unsigned int width = TYPE_PRECISION (arg1_type);
12432 if (TREE_CODE (arg1) == INTEGER_CST
12433 && !TREE_OVERFLOW (arg1)
12434 && width <= 2 * HOST_BITS_PER_WIDE_INT
12435 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
12437 HOST_WIDE_INT signed_max_hi;
12438 unsigned HOST_WIDE_INT signed_max_lo;
12439 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
12441 if (width <= HOST_BITS_PER_WIDE_INT)
12443 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12448 if (TYPE_UNSIGNED (arg1_type))
12450 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12456 max_lo = signed_max_lo;
12457 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12463 width -= HOST_BITS_PER_WIDE_INT;
12464 signed_max_lo = -1;
12465 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12470 if (TYPE_UNSIGNED (arg1_type))
12472 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12477 max_hi = signed_max_hi;
12478 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12482 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
12483 && TREE_INT_CST_LOW (arg1) == max_lo)
12487 return omit_one_operand (type, integer_zero_node, arg0);
12490 return fold_build2 (EQ_EXPR, type, op0, op1);
12493 return omit_one_operand (type, integer_one_node, arg0);
12496 return fold_build2 (NE_EXPR, type, op0, op1);
12498 /* The GE_EXPR and LT_EXPR cases above are not normally
12499 reached because of previous transformations. */
12504 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12506 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
12510 arg1 = const_binop (PLUS_EXPR, arg1,
12511 build_int_cst (TREE_TYPE (arg1), 1), 0);
12512 return fold_build2 (EQ_EXPR, type,
12513 fold_convert (TREE_TYPE (arg1), arg0),
12516 arg1 = const_binop (PLUS_EXPR, arg1,
12517 build_int_cst (TREE_TYPE (arg1), 1), 0);
12518 return fold_build2 (NE_EXPR, type,
12519 fold_convert (TREE_TYPE (arg1), arg0),
12524 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12526 && TREE_INT_CST_LOW (arg1) == min_lo)
12530 return omit_one_operand (type, integer_zero_node, arg0);
12533 return fold_build2 (EQ_EXPR, type, op0, op1);
12536 return omit_one_operand (type, integer_one_node, arg0);
12539 return fold_build2 (NE_EXPR, type, op0, op1);
12544 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12546 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
12550 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12551 return fold_build2 (NE_EXPR, type,
12552 fold_convert (TREE_TYPE (arg1), arg0),
12555 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12556 return fold_build2 (EQ_EXPR, type,
12557 fold_convert (TREE_TYPE (arg1), arg0),
12563 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
12564 && TREE_INT_CST_LOW (arg1) == signed_max_lo
12565 && TYPE_UNSIGNED (arg1_type)
12566 /* We will flip the signedness of the comparison operator
12567 associated with the mode of arg1, so the sign bit is
12568 specified by this mode. Check that arg1 is the signed
12569 max associated with this sign bit. */
12570 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
12571 /* signed_type does not work on pointer types. */
12572 && INTEGRAL_TYPE_P (arg1_type))
12574 /* The following case also applies to X < signed_max+1
12575 and X >= signed_max+1 because previous transformations. */
12576 if (code == LE_EXPR || code == GT_EXPR)
12579 st = signed_type_for (TREE_TYPE (arg1));
12580 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
12581 type, fold_convert (st, arg0),
12582 build_int_cst (st, 0));
12588 /* If we are comparing an ABS_EXPR with a constant, we can
12589 convert all the cases into explicit comparisons, but they may
12590 well not be faster than doing the ABS and one comparison.
12591 But ABS (X) <= C is a range comparison, which becomes a subtraction
12592 and a comparison, and is probably faster. */
12593 if (code == LE_EXPR
12594 && TREE_CODE (arg1) == INTEGER_CST
12595 && TREE_CODE (arg0) == ABS_EXPR
12596 && ! TREE_SIDE_EFFECTS (arg0)
12597 && (0 != (tem = negate_expr (arg1)))
12598 && TREE_CODE (tem) == INTEGER_CST
12599 && !TREE_OVERFLOW (tem))
12600 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12601 build2 (GE_EXPR, type,
12602 TREE_OPERAND (arg0, 0), tem),
12603 build2 (LE_EXPR, type,
12604 TREE_OPERAND (arg0, 0), arg1));
12606 /* Convert ABS_EXPR<x> >= 0 to true. */
12607 strict_overflow_p = false;
12608 if (code == GE_EXPR
12609 && (integer_zerop (arg1)
12610 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
12611 && real_zerop (arg1)))
12612 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12614 if (strict_overflow_p)
12615 fold_overflow_warning (("assuming signed overflow does not occur "
12616 "when simplifying comparison of "
12617 "absolute value and zero"),
12618 WARN_STRICT_OVERFLOW_CONDITIONAL);
12619 return omit_one_operand (type, integer_one_node, arg0);
12622 /* Convert ABS_EXPR<x> < 0 to false. */
12623 strict_overflow_p = false;
12624 if (code == LT_EXPR
12625 && (integer_zerop (arg1) || real_zerop (arg1))
12626 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12628 if (strict_overflow_p)
12629 fold_overflow_warning (("assuming signed overflow does not occur "
12630 "when simplifying comparison of "
12631 "absolute value and zero"),
12632 WARN_STRICT_OVERFLOW_CONDITIONAL);
12633 return omit_one_operand (type, integer_zero_node, arg0);
12636 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
12637 and similarly for >= into !=. */
12638 if ((code == LT_EXPR || code == GE_EXPR)
12639 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12640 && TREE_CODE (arg1) == LSHIFT_EXPR
12641 && integer_onep (TREE_OPERAND (arg1, 0)))
12642 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12643 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12644 TREE_OPERAND (arg1, 1)),
12645 build_int_cst (TREE_TYPE (arg0), 0));
12647 if ((code == LT_EXPR || code == GE_EXPR)
12648 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12649 && (TREE_CODE (arg1) == NOP_EXPR
12650 || TREE_CODE (arg1) == CONVERT_EXPR)
12651 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
12652 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
12654 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12655 fold_convert (TREE_TYPE (arg0),
12656 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12657 TREE_OPERAND (TREE_OPERAND (arg1, 0),
12659 build_int_cst (TREE_TYPE (arg0), 0));
12663 case UNORDERED_EXPR:
12671 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
12673 t1 = fold_relational_const (code, type, arg0, arg1);
12674 if (t1 != NULL_TREE)
12678 /* If the first operand is NaN, the result is constant. */
12679 if (TREE_CODE (arg0) == REAL_CST
12680 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
12681 && (code != LTGT_EXPR || ! flag_trapping_math))
12683 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12684 ? integer_zero_node
12685 : integer_one_node;
12686 return omit_one_operand (type, t1, arg1);
12689 /* If the second operand is NaN, the result is constant. */
12690 if (TREE_CODE (arg1) == REAL_CST
12691 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
12692 && (code != LTGT_EXPR || ! flag_trapping_math))
12694 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12695 ? integer_zero_node
12696 : integer_one_node;
12697 return omit_one_operand (type, t1, arg0);
12700 /* Simplify unordered comparison of something with itself. */
12701 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
12702 && operand_equal_p (arg0, arg1, 0))
12703 return constant_boolean_node (1, type);
12705 if (code == LTGT_EXPR
12706 && !flag_trapping_math
12707 && operand_equal_p (arg0, arg1, 0))
12708 return constant_boolean_node (0, type);
12710 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12712 tree targ0 = strip_float_extensions (arg0);
12713 tree targ1 = strip_float_extensions (arg1);
12714 tree newtype = TREE_TYPE (targ0);
12716 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
12717 newtype = TREE_TYPE (targ1);
12719 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
12720 return fold_build2 (code, type, fold_convert (newtype, targ0),
12721 fold_convert (newtype, targ1));
12726 case COMPOUND_EXPR:
12727 /* When pedantic, a compound expression can be neither an lvalue
12728 nor an integer constant expression. */
12729 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
12731 /* Don't let (0, 0) be null pointer constant. */
12732 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
12733 : fold_convert (type, arg1);
12734 return pedantic_non_lvalue (tem);
12737 if ((TREE_CODE (arg0) == REAL_CST
12738 && TREE_CODE (arg1) == REAL_CST)
12739 || (TREE_CODE (arg0) == INTEGER_CST
12740 && TREE_CODE (arg1) == INTEGER_CST))
12741 return build_complex (type, arg0, arg1);
12745 /* An ASSERT_EXPR should never be passed to fold_binary. */
12746 gcc_unreachable ();
12750 } /* switch (code) */
12753 /* Callback for walk_tree, looking for LABEL_EXPR.
12754 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
12755 Do not check the sub-tree of GOTO_EXPR. */
12758 contains_label_1 (tree *tp,
12759 int *walk_subtrees,
12760 void *data ATTRIBUTE_UNUSED)
12762 switch (TREE_CODE (*tp))
12767 *walk_subtrees = 0;
12774 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
12775 accessible from outside the sub-tree. Returns NULL_TREE if no
12776 addressable label is found. */
12779 contains_label_p (tree st)
12781 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
12784 /* Fold a ternary expression of code CODE and type TYPE with operands
12785 OP0, OP1, and OP2. Return the folded expression if folding is
12786 successful. Otherwise, return NULL_TREE. */
12789 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
12792 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
12793 enum tree_code_class kind = TREE_CODE_CLASS (code);
12795 gcc_assert (IS_EXPR_CODE_CLASS (kind)
12796 && TREE_CODE_LENGTH (code) == 3);
12798 /* Strip any conversions that don't change the mode. This is safe
12799 for every expression, except for a comparison expression because
12800 its signedness is derived from its operands. So, in the latter
12801 case, only strip conversions that don't change the signedness.
12803 Note that this is done as an internal manipulation within the
12804 constant folder, in order to find the simplest representation of
12805 the arguments so that their form can be studied. In any cases,
12806 the appropriate type conversions should be put back in the tree
12807 that will get out of the constant folder. */
12822 case COMPONENT_REF:
12823 if (TREE_CODE (arg0) == CONSTRUCTOR
12824 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
12826 unsigned HOST_WIDE_INT idx;
12828 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
12835 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
12836 so all simple results must be passed through pedantic_non_lvalue. */
12837 if (TREE_CODE (arg0) == INTEGER_CST)
12839 tree unused_op = integer_zerop (arg0) ? op1 : op2;
12840 tem = integer_zerop (arg0) ? op2 : op1;
12841 /* Only optimize constant conditions when the selected branch
12842 has the same type as the COND_EXPR. This avoids optimizing
12843 away "c ? x : throw", where the throw has a void type.
12844 Avoid throwing away that operand which contains label. */
12845 if ((!TREE_SIDE_EFFECTS (unused_op)
12846 || !contains_label_p (unused_op))
12847 && (! VOID_TYPE_P (TREE_TYPE (tem))
12848 || VOID_TYPE_P (type)))
12849 return pedantic_non_lvalue (tem);
12852 if (operand_equal_p (arg1, op2, 0))
12853 return pedantic_omit_one_operand (type, arg1, arg0);
12855 /* If we have A op B ? A : C, we may be able to convert this to a
12856 simpler expression, depending on the operation and the values
12857 of B and C. Signed zeros prevent all of these transformations,
12858 for reasons given above each one.
12860 Also try swapping the arguments and inverting the conditional. */
12861 if (COMPARISON_CLASS_P (arg0)
12862 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12863 arg1, TREE_OPERAND (arg0, 1))
12864 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
12866 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
12871 if (COMPARISON_CLASS_P (arg0)
12872 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12874 TREE_OPERAND (arg0, 1))
12875 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
12877 tem = fold_truth_not_expr (arg0);
12878 if (tem && COMPARISON_CLASS_P (tem))
12880 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
12886 /* If the second operand is simpler than the third, swap them
12887 since that produces better jump optimization results. */
12888 if (truth_value_p (TREE_CODE (arg0))
12889 && tree_swap_operands_p (op1, op2, false))
12891 /* See if this can be inverted. If it can't, possibly because
12892 it was a floating-point inequality comparison, don't do
12894 tem = fold_truth_not_expr (arg0);
12896 return fold_build3 (code, type, tem, op2, op1);
12899 /* Convert A ? 1 : 0 to simply A. */
12900 if (integer_onep (op1)
12901 && integer_zerop (op2)
12902 /* If we try to convert OP0 to our type, the
12903 call to fold will try to move the conversion inside
12904 a COND, which will recurse. In that case, the COND_EXPR
12905 is probably the best choice, so leave it alone. */
12906 && type == TREE_TYPE (arg0))
12907 return pedantic_non_lvalue (arg0);
12909 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
12910 over COND_EXPR in cases such as floating point comparisons. */
12911 if (integer_zerop (op1)
12912 && integer_onep (op2)
12913 && truth_value_p (TREE_CODE (arg0)))
12914 return pedantic_non_lvalue (fold_convert (type,
12915 invert_truthvalue (arg0)));
12917 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
12918 if (TREE_CODE (arg0) == LT_EXPR
12919 && integer_zerop (TREE_OPERAND (arg0, 1))
12920 && integer_zerop (op2)
12921 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
12923 /* sign_bit_p only checks ARG1 bits within A's precision.
12924 If <sign bit of A> has wider type than A, bits outside
12925 of A's precision in <sign bit of A> need to be checked.
12926 If they are all 0, this optimization needs to be done
12927 in unsigned A's type, if they are all 1 in signed A's type,
12928 otherwise this can't be done. */
12929 if (TYPE_PRECISION (TREE_TYPE (tem))
12930 < TYPE_PRECISION (TREE_TYPE (arg1))
12931 && TYPE_PRECISION (TREE_TYPE (tem))
12932 < TYPE_PRECISION (type))
12934 unsigned HOST_WIDE_INT mask_lo;
12935 HOST_WIDE_INT mask_hi;
12936 int inner_width, outer_width;
12939 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
12940 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
12941 if (outer_width > TYPE_PRECISION (type))
12942 outer_width = TYPE_PRECISION (type);
12944 if (outer_width > HOST_BITS_PER_WIDE_INT)
12946 mask_hi = ((unsigned HOST_WIDE_INT) -1
12947 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
12953 mask_lo = ((unsigned HOST_WIDE_INT) -1
12954 >> (HOST_BITS_PER_WIDE_INT - outer_width));
12956 if (inner_width > HOST_BITS_PER_WIDE_INT)
12958 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
12959 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12963 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
12964 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12966 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
12967 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
12969 tem_type = signed_type_for (TREE_TYPE (tem));
12970 tem = fold_convert (tem_type, tem);
12972 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
12973 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
12975 tem_type = unsigned_type_for (TREE_TYPE (tem));
12976 tem = fold_convert (tem_type, tem);
12983 return fold_convert (type,
12984 fold_build2 (BIT_AND_EXPR,
12985 TREE_TYPE (tem), tem,
12986 fold_convert (TREE_TYPE (tem),
12990 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
12991 already handled above. */
12992 if (TREE_CODE (arg0) == BIT_AND_EXPR
12993 && integer_onep (TREE_OPERAND (arg0, 1))
12994 && integer_zerop (op2)
12995 && integer_pow2p (arg1))
12997 tree tem = TREE_OPERAND (arg0, 0);
12999 if (TREE_CODE (tem) == RSHIFT_EXPR
13000 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
13001 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
13002 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
13003 return fold_build2 (BIT_AND_EXPR, type,
13004 TREE_OPERAND (tem, 0), arg1);
13007 /* A & N ? N : 0 is simply A & N if N is a power of two. This
13008 is probably obsolete because the first operand should be a
13009 truth value (that's why we have the two cases above), but let's
13010 leave it in until we can confirm this for all front-ends. */
13011 if (integer_zerop (op2)
13012 && TREE_CODE (arg0) == NE_EXPR
13013 && integer_zerop (TREE_OPERAND (arg0, 1))
13014 && integer_pow2p (arg1)
13015 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
13016 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
13017 arg1, OEP_ONLY_CONST))
13018 return pedantic_non_lvalue (fold_convert (type,
13019 TREE_OPERAND (arg0, 0)));
13021 /* Convert A ? B : 0 into A && B if A and B are truth values. */
13022 if (integer_zerop (op2)
13023 && truth_value_p (TREE_CODE (arg0))
13024 && truth_value_p (TREE_CODE (arg1)))
13025 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13026 fold_convert (type, arg0),
13029 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
13030 if (integer_onep (op2)
13031 && truth_value_p (TREE_CODE (arg0))
13032 && truth_value_p (TREE_CODE (arg1)))
13034 /* Only perform transformation if ARG0 is easily inverted. */
13035 tem = fold_truth_not_expr (arg0);
13037 return fold_build2 (TRUTH_ORIF_EXPR, type,
13038 fold_convert (type, tem),
13042 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
13043 if (integer_zerop (arg1)
13044 && truth_value_p (TREE_CODE (arg0))
13045 && truth_value_p (TREE_CODE (op2)))
13047 /* Only perform transformation if ARG0 is easily inverted. */
13048 tem = fold_truth_not_expr (arg0);
13050 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13051 fold_convert (type, tem),
13055 /* Convert A ? 1 : B into A || B if A and B are truth values. */
13056 if (integer_onep (arg1)
13057 && truth_value_p (TREE_CODE (arg0))
13058 && truth_value_p (TREE_CODE (op2)))
13059 return fold_build2 (TRUTH_ORIF_EXPR, type,
13060 fold_convert (type, arg0),
13066 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
13067 of fold_ternary on them. */
13068 gcc_unreachable ();
13070 case BIT_FIELD_REF:
13071 if ((TREE_CODE (arg0) == VECTOR_CST
13072 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
13073 && type == TREE_TYPE (TREE_TYPE (arg0)))
13075 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
13076 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
13079 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
13080 && (idx % width) == 0
13081 && (idx = idx / width)
13082 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
13084 tree elements = NULL_TREE;
13086 if (TREE_CODE (arg0) == VECTOR_CST)
13087 elements = TREE_VECTOR_CST_ELTS (arg0);
13090 unsigned HOST_WIDE_INT idx;
13093 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
13094 elements = tree_cons (NULL_TREE, value, elements);
13096 while (idx-- > 0 && elements)
13097 elements = TREE_CHAIN (elements);
13099 return TREE_VALUE (elements);
13101 return fold_convert (type, integer_zero_node);
13108 } /* switch (code) */
13111 /* Perform constant folding and related simplification of EXPR.
13112 The related simplifications include x*1 => x, x*0 => 0, etc.,
13113 and application of the associative law.
13114 NOP_EXPR conversions may be removed freely (as long as we
13115 are careful not to change the type of the overall expression).
13116 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13117 but we can constant-fold them if they have constant operands. */
13119 #ifdef ENABLE_FOLD_CHECKING
13120 # define fold(x) fold_1 (x)
13121 static tree fold_1 (tree);
13127 const tree t = expr;
13128 enum tree_code code = TREE_CODE (t);
13129 enum tree_code_class kind = TREE_CODE_CLASS (code);
13132 /* Return right away if a constant. */
13133 if (kind == tcc_constant)
13136 /* CALL_EXPR-like objects with variable numbers of operands are
13137 treated specially. */
13138 if (kind == tcc_vl_exp)
13140 if (code == CALL_EXPR)
13142 tem = fold_call_expr (expr, false);
13143 return tem ? tem : expr;
13148 if (IS_EXPR_CODE_CLASS (kind)
13149 || IS_GIMPLE_STMT_CODE_CLASS (kind))
13151 tree type = TREE_TYPE (t);
13152 tree op0, op1, op2;
13154 switch (TREE_CODE_LENGTH (code))
13157 op0 = TREE_OPERAND (t, 0);
13158 tem = fold_unary (code, type, op0);
13159 return tem ? tem : expr;
13161 op0 = TREE_OPERAND (t, 0);
13162 op1 = TREE_OPERAND (t, 1);
13163 tem = fold_binary (code, type, op0, op1);
13164 return tem ? tem : expr;
13166 op0 = TREE_OPERAND (t, 0);
13167 op1 = TREE_OPERAND (t, 1);
13168 op2 = TREE_OPERAND (t, 2);
13169 tem = fold_ternary (code, type, op0, op1, op2);
13170 return tem ? tem : expr;
13180 tree op0 = TREE_OPERAND (t, 0);
13181 tree op1 = TREE_OPERAND (t, 1);
13183 if (TREE_CODE (op1) == INTEGER_CST
13184 && TREE_CODE (op0) == CONSTRUCTOR
13185 && ! type_contains_placeholder_p (TREE_TYPE (op0)))
13187 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (op0);
13188 unsigned HOST_WIDE_INT end = VEC_length (constructor_elt, elts);
13189 unsigned HOST_WIDE_INT begin = 0;
13191 /* Find a matching index by means of a binary search. */
13192 while (begin != end)
13194 unsigned HOST_WIDE_INT middle = (begin + end) / 2;
13195 tree index = VEC_index (constructor_elt, elts, middle)->index;
13197 if (TREE_CODE (index) == INTEGER_CST
13198 && tree_int_cst_lt (index, op1))
13199 begin = middle + 1;
13200 else if (TREE_CODE (index) == INTEGER_CST
13201 && tree_int_cst_lt (op1, index))
13203 else if (TREE_CODE (index) == RANGE_EXPR
13204 && tree_int_cst_lt (TREE_OPERAND (index, 1), op1))
13205 begin = middle + 1;
13206 else if (TREE_CODE (index) == RANGE_EXPR
13207 && tree_int_cst_lt (op1, TREE_OPERAND (index, 0)))
13210 return VEC_index (constructor_elt, elts, middle)->value;
13218 return fold (DECL_INITIAL (t));
13222 } /* switch (code) */
13225 #ifdef ENABLE_FOLD_CHECKING
13228 static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
13229 static void fold_check_failed (const_tree, const_tree);
13230 void print_fold_checksum (const_tree);
13232 /* When --enable-checking=fold, compute a digest of expr before
13233 and after actual fold call to see if fold did not accidentally
13234 change original expr. */
13240 struct md5_ctx ctx;
13241 unsigned char checksum_before[16], checksum_after[16];
13244 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13245 md5_init_ctx (&ctx);
13246 fold_checksum_tree (expr, &ctx, ht);
13247 md5_finish_ctx (&ctx, checksum_before);
13250 ret = fold_1 (expr);
13252 md5_init_ctx (&ctx);
13253 fold_checksum_tree (expr, &ctx, ht);
13254 md5_finish_ctx (&ctx, checksum_after);
13257 if (memcmp (checksum_before, checksum_after, 16))
13258 fold_check_failed (expr, ret);
13264 print_fold_checksum (const_tree expr)
13266 struct md5_ctx ctx;
13267 unsigned char checksum[16], cnt;
13270 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13271 md5_init_ctx (&ctx);
13272 fold_checksum_tree (expr, &ctx, ht);
13273 md5_finish_ctx (&ctx, checksum);
13275 for (cnt = 0; cnt < 16; ++cnt)
13276 fprintf (stderr, "%02x", checksum[cnt]);
13277 putc ('\n', stderr);
13281 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
13283 internal_error ("fold check: original tree changed by fold");
13287 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
13290 enum tree_code code;
13291 struct tree_function_decl buf;
13296 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
13297 <= sizeof (struct tree_function_decl))
13298 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
13301 slot = (const void **) htab_find_slot (ht, expr, INSERT);
13305 code = TREE_CODE (expr);
13306 if (TREE_CODE_CLASS (code) == tcc_declaration
13307 && DECL_ASSEMBLER_NAME_SET_P (expr))
13309 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13310 memcpy ((char *) &buf, expr, tree_size (expr));
13311 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
13312 expr = (tree) &buf;
13314 else if (TREE_CODE_CLASS (code) == tcc_type
13315 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
13316 || TYPE_CACHED_VALUES_P (expr)
13317 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
13319 /* Allow these fields to be modified. */
13321 memcpy ((char *) &buf, expr, tree_size (expr));
13322 expr = tmp = (tree) &buf;
13323 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
13324 TYPE_POINTER_TO (tmp) = NULL;
13325 TYPE_REFERENCE_TO (tmp) = NULL;
13326 if (TYPE_CACHED_VALUES_P (tmp))
13328 TYPE_CACHED_VALUES_P (tmp) = 0;
13329 TYPE_CACHED_VALUES (tmp) = NULL;
13332 md5_process_bytes (expr, tree_size (expr), ctx);
13333 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
13334 if (TREE_CODE_CLASS (code) != tcc_type
13335 && TREE_CODE_CLASS (code) != tcc_declaration
13336 && code != TREE_LIST
13337 && code != SSA_NAME)
13338 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
13339 switch (TREE_CODE_CLASS (code))
13345 md5_process_bytes (TREE_STRING_POINTER (expr),
13346 TREE_STRING_LENGTH (expr), ctx);
13349 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
13350 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
13353 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
13359 case tcc_exceptional:
13363 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
13364 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
13365 expr = TREE_CHAIN (expr);
13366 goto recursive_label;
13369 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
13370 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
13376 case tcc_expression:
13377 case tcc_reference:
13378 case tcc_comparison:
13381 case tcc_statement:
13383 len = TREE_OPERAND_LENGTH (expr);
13384 for (i = 0; i < len; ++i)
13385 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
13387 case tcc_declaration:
13388 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
13389 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
13390 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
13392 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
13393 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
13394 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
13395 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
13396 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
13398 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
13399 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
13401 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
13403 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
13404 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
13405 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
13409 if (TREE_CODE (expr) == ENUMERAL_TYPE)
13410 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
13411 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
13412 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
13413 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
13414 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
13415 if (INTEGRAL_TYPE_P (expr)
13416 || SCALAR_FLOAT_TYPE_P (expr))
13418 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
13419 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
13421 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
13422 if (TREE_CODE (expr) == RECORD_TYPE
13423 || TREE_CODE (expr) == UNION_TYPE
13424 || TREE_CODE (expr) == QUAL_UNION_TYPE)
13425 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
13426 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
13433 /* Helper function for outputting the checksum of a tree T. When
13434 debugging with gdb, you can "define mynext" to be "next" followed
13435 by "call debug_fold_checksum (op0)", then just trace down till the
13439 debug_fold_checksum (const_tree t)
13442 unsigned char checksum[16];
13443 struct md5_ctx ctx;
13444 htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13446 md5_init_ctx (&ctx);
13447 fold_checksum_tree (t, &ctx, ht);
13448 md5_finish_ctx (&ctx, checksum);
13451 for (i = 0; i < 16; i++)
13452 fprintf (stderr, "%d ", checksum[i]);
13454 fprintf (stderr, "\n");
13459 /* Fold a unary tree expression with code CODE of type TYPE with an
13460 operand OP0. Return a folded expression if successful. Otherwise,
13461 return a tree expression with code CODE of type TYPE with an
13465 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
13468 #ifdef ENABLE_FOLD_CHECKING
13469 unsigned char checksum_before[16], checksum_after[16];
13470 struct md5_ctx ctx;
13473 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13474 md5_init_ctx (&ctx);
13475 fold_checksum_tree (op0, &ctx, ht);
13476 md5_finish_ctx (&ctx, checksum_before);
13480 tem = fold_unary (code, type, op0);
13482 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
13484 #ifdef ENABLE_FOLD_CHECKING
13485 md5_init_ctx (&ctx);
13486 fold_checksum_tree (op0, &ctx, ht);
13487 md5_finish_ctx (&ctx, checksum_after);
13490 if (memcmp (checksum_before, checksum_after, 16))
13491 fold_check_failed (op0, tem);
13496 /* Fold a binary tree expression with code CODE of type TYPE with
13497 operands OP0 and OP1. Return a folded expression if successful.
13498 Otherwise, return a tree expression with code CODE of type TYPE
13499 with operands OP0 and OP1. */
13502 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
13506 #ifdef ENABLE_FOLD_CHECKING
13507 unsigned char checksum_before_op0[16],
13508 checksum_before_op1[16],
13509 checksum_after_op0[16],
13510 checksum_after_op1[16];
13511 struct md5_ctx ctx;
13514 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13515 md5_init_ctx (&ctx);
13516 fold_checksum_tree (op0, &ctx, ht);
13517 md5_finish_ctx (&ctx, checksum_before_op0);
13520 md5_init_ctx (&ctx);
13521 fold_checksum_tree (op1, &ctx, ht);
13522 md5_finish_ctx (&ctx, checksum_before_op1);
13526 tem = fold_binary (code, type, op0, op1);
13528 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
13530 #ifdef ENABLE_FOLD_CHECKING
13531 md5_init_ctx (&ctx);
13532 fold_checksum_tree (op0, &ctx, ht);
13533 md5_finish_ctx (&ctx, checksum_after_op0);
13536 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13537 fold_check_failed (op0, tem);
13539 md5_init_ctx (&ctx);
13540 fold_checksum_tree (op1, &ctx, ht);
13541 md5_finish_ctx (&ctx, checksum_after_op1);
13544 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13545 fold_check_failed (op1, tem);
13550 /* Fold a ternary tree expression with code CODE of type TYPE with
13551 operands OP0, OP1, and OP2. Return a folded expression if
13552 successful. Otherwise, return a tree expression with code CODE of
13553 type TYPE with operands OP0, OP1, and OP2. */
13556 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
13560 #ifdef ENABLE_FOLD_CHECKING
13561 unsigned char checksum_before_op0[16],
13562 checksum_before_op1[16],
13563 checksum_before_op2[16],
13564 checksum_after_op0[16],
13565 checksum_after_op1[16],
13566 checksum_after_op2[16];
13567 struct md5_ctx ctx;
13570 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13571 md5_init_ctx (&ctx);
13572 fold_checksum_tree (op0, &ctx, ht);
13573 md5_finish_ctx (&ctx, checksum_before_op0);
13576 md5_init_ctx (&ctx);
13577 fold_checksum_tree (op1, &ctx, ht);
13578 md5_finish_ctx (&ctx, checksum_before_op1);
13581 md5_init_ctx (&ctx);
13582 fold_checksum_tree (op2, &ctx, ht);
13583 md5_finish_ctx (&ctx, checksum_before_op2);
13587 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
13588 tem = fold_ternary (code, type, op0, op1, op2);
13590 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
13592 #ifdef ENABLE_FOLD_CHECKING
13593 md5_init_ctx (&ctx);
13594 fold_checksum_tree (op0, &ctx, ht);
13595 md5_finish_ctx (&ctx, checksum_after_op0);
13598 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13599 fold_check_failed (op0, tem);
13601 md5_init_ctx (&ctx);
13602 fold_checksum_tree (op1, &ctx, ht);
13603 md5_finish_ctx (&ctx, checksum_after_op1);
13606 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13607 fold_check_failed (op1, tem);
13609 md5_init_ctx (&ctx);
13610 fold_checksum_tree (op2, &ctx, ht);
13611 md5_finish_ctx (&ctx, checksum_after_op2);
13614 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
13615 fold_check_failed (op2, tem);
13620 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
13621 arguments in ARGARRAY, and a null static chain.
13622 Return a folded expression if successful. Otherwise, return a CALL_EXPR
13623 of type TYPE from the given operands as constructed by build_call_array. */
13626 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
13629 #ifdef ENABLE_FOLD_CHECKING
13630 unsigned char checksum_before_fn[16],
13631 checksum_before_arglist[16],
13632 checksum_after_fn[16],
13633 checksum_after_arglist[16];
13634 struct md5_ctx ctx;
13638 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13639 md5_init_ctx (&ctx);
13640 fold_checksum_tree (fn, &ctx, ht);
13641 md5_finish_ctx (&ctx, checksum_before_fn);
13644 md5_init_ctx (&ctx);
13645 for (i = 0; i < nargs; i++)
13646 fold_checksum_tree (argarray[i], &ctx, ht);
13647 md5_finish_ctx (&ctx, checksum_before_arglist);
13651 tem = fold_builtin_call_array (type, fn, nargs, argarray);
13653 #ifdef ENABLE_FOLD_CHECKING
13654 md5_init_ctx (&ctx);
13655 fold_checksum_tree (fn, &ctx, ht);
13656 md5_finish_ctx (&ctx, checksum_after_fn);
13659 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
13660 fold_check_failed (fn, tem);
13662 md5_init_ctx (&ctx);
13663 for (i = 0; i < nargs; i++)
13664 fold_checksum_tree (argarray[i], &ctx, ht);
13665 md5_finish_ctx (&ctx, checksum_after_arglist);
13668 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
13669 fold_check_failed (NULL_TREE, tem);
13674 /* Perform constant folding and related simplification of initializer
13675 expression EXPR. These behave identically to "fold_buildN" but ignore
13676 potential run-time traps and exceptions that fold must preserve. */
13678 #define START_FOLD_INIT \
13679 int saved_signaling_nans = flag_signaling_nans;\
13680 int saved_trapping_math = flag_trapping_math;\
13681 int saved_rounding_math = flag_rounding_math;\
13682 int saved_trapv = flag_trapv;\
13683 int saved_folding_initializer = folding_initializer;\
13684 flag_signaling_nans = 0;\
13685 flag_trapping_math = 0;\
13686 flag_rounding_math = 0;\
13688 folding_initializer = 1;
13690 #define END_FOLD_INIT \
13691 flag_signaling_nans = saved_signaling_nans;\
13692 flag_trapping_math = saved_trapping_math;\
13693 flag_rounding_math = saved_rounding_math;\
13694 flag_trapv = saved_trapv;\
13695 folding_initializer = saved_folding_initializer;
13698 fold_build1_initializer (enum tree_code code, tree type, tree op)
13703 result = fold_build1 (code, type, op);
13710 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
13715 result = fold_build2 (code, type, op0, op1);
13722 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
13728 result = fold_build3 (code, type, op0, op1, op2);
13735 fold_build_call_array_initializer (tree type, tree fn,
13736 int nargs, tree *argarray)
13741 result = fold_build_call_array (type, fn, nargs, argarray);
13747 #undef START_FOLD_INIT
13748 #undef END_FOLD_INIT
13750 /* Determine if first argument is a multiple of second argument. Return 0 if
13751 it is not, or we cannot easily determined it to be.
13753 An example of the sort of thing we care about (at this point; this routine
13754 could surely be made more general, and expanded to do what the *_DIV_EXPR's
13755 fold cases do now) is discovering that
13757 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13763 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
13765 This code also handles discovering that
13767 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13769 is a multiple of 8 so we don't have to worry about dealing with a
13770 possible remainder.
13772 Note that we *look* inside a SAVE_EXPR only to determine how it was
13773 calculated; it is not safe for fold to do much of anything else with the
13774 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
13775 at run time. For example, the latter example above *cannot* be implemented
13776 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
13777 evaluation time of the original SAVE_EXPR is not necessarily the same at
13778 the time the new expression is evaluated. The only optimization of this
13779 sort that would be valid is changing
13781 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
13785 SAVE_EXPR (I) * SAVE_EXPR (J)
13787 (where the same SAVE_EXPR (J) is used in the original and the
13788 transformed version). */
13791 multiple_of_p (tree type, const_tree top, const_tree bottom)
13793 if (operand_equal_p (top, bottom, 0))
13796 if (TREE_CODE (type) != INTEGER_TYPE)
13799 switch (TREE_CODE (top))
13802 /* Bitwise and provides a power of two multiple. If the mask is
13803 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
13804 if (!integer_pow2p (bottom))
13809 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13810 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13814 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13815 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13818 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
13822 op1 = TREE_OPERAND (top, 1);
13823 /* const_binop may not detect overflow correctly,
13824 so check for it explicitly here. */
13825 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
13826 > TREE_INT_CST_LOW (op1)
13827 && TREE_INT_CST_HIGH (op1) == 0
13828 && 0 != (t1 = fold_convert (type,
13829 const_binop (LSHIFT_EXPR,
13832 && !TREE_OVERFLOW (t1))
13833 return multiple_of_p (type, t1, bottom);
13838 /* Can't handle conversions from non-integral or wider integral type. */
13839 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
13840 || (TYPE_PRECISION (type)
13841 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
13844 /* .. fall through ... */
13847 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
13850 if (TREE_CODE (bottom) != INTEGER_CST
13851 || integer_zerop (bottom)
13852 || (TYPE_UNSIGNED (type)
13853 && (tree_int_cst_sgn (top) < 0
13854 || tree_int_cst_sgn (bottom) < 0)))
13856 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
13864 /* Return true if CODE or TYPE is known to be non-negative. */
13867 tree_simple_nonnegative_warnv_p (enum tree_code code, tree type)
13869 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
13870 && truth_value_p (code))
13871 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
13872 have a signed:1 type (where the value is -1 and 0). */
13877 /* Return true if (CODE OP0) is known to be non-negative. If the return
13878 value is based on the assumption that signed overflow is undefined,
13879 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13880 *STRICT_OVERFLOW_P. */
13883 tree_unary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
13884 bool *strict_overflow_p)
13886 if (TYPE_UNSIGNED (type))
13892 /* We can't return 1 if flag_wrapv is set because
13893 ABS_EXPR<INT_MIN> = INT_MIN. */
13894 if (!INTEGRAL_TYPE_P (type))
13896 if (TYPE_OVERFLOW_UNDEFINED (type))
13898 *strict_overflow_p = true;
13903 case NON_LVALUE_EXPR:
13905 case FIX_TRUNC_EXPR:
13906 return tree_expr_nonnegative_warnv_p (op0,
13907 strict_overflow_p);
13911 tree inner_type = TREE_TYPE (op0);
13912 tree outer_type = type;
13914 if (TREE_CODE (outer_type) == REAL_TYPE)
13916 if (TREE_CODE (inner_type) == REAL_TYPE)
13917 return tree_expr_nonnegative_warnv_p (op0,
13918 strict_overflow_p);
13919 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13921 if (TYPE_UNSIGNED (inner_type))
13923 return tree_expr_nonnegative_warnv_p (op0,
13924 strict_overflow_p);
13927 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
13929 if (TREE_CODE (inner_type) == REAL_TYPE)
13930 return tree_expr_nonnegative_warnv_p (op0,
13931 strict_overflow_p);
13932 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13933 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
13934 && TYPE_UNSIGNED (inner_type);
13940 return tree_simple_nonnegative_warnv_p (code, type);
13943 /* We don't know sign of `t', so be conservative and return false. */
13947 /* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
13948 value is based on the assumption that signed overflow is undefined,
13949 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13950 *STRICT_OVERFLOW_P. */
13953 tree_binary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
13954 tree op1, bool *strict_overflow_p)
13956 if (TYPE_UNSIGNED (type))
13961 case POINTER_PLUS_EXPR:
13963 if (FLOAT_TYPE_P (type))
13964 return (tree_expr_nonnegative_warnv_p (op0,
13966 && tree_expr_nonnegative_warnv_p (op1,
13967 strict_overflow_p));
13969 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
13970 both unsigned and at least 2 bits shorter than the result. */
13971 if (TREE_CODE (type) == INTEGER_TYPE
13972 && TREE_CODE (op0) == NOP_EXPR
13973 && TREE_CODE (op1) == NOP_EXPR)
13975 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
13976 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
13977 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13978 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13980 unsigned int prec = MAX (TYPE_PRECISION (inner1),
13981 TYPE_PRECISION (inner2)) + 1;
13982 return prec < TYPE_PRECISION (type);
13988 if (FLOAT_TYPE_P (type))
13990 /* x * x for floating point x is always non-negative. */
13991 if (operand_equal_p (op0, op1, 0))
13993 return (tree_expr_nonnegative_warnv_p (op0,
13995 && tree_expr_nonnegative_warnv_p (op1,
13996 strict_overflow_p));
13999 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
14000 both unsigned and their total bits is shorter than the result. */
14001 if (TREE_CODE (type) == INTEGER_TYPE
14002 && TREE_CODE (op0) == NOP_EXPR
14003 && TREE_CODE (op1) == NOP_EXPR)
14005 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
14006 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
14007 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
14008 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
14009 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
14010 < TYPE_PRECISION (type);
14016 return (tree_expr_nonnegative_warnv_p (op0,
14018 || tree_expr_nonnegative_warnv_p (op1,
14019 strict_overflow_p));
14025 case TRUNC_DIV_EXPR:
14026 case CEIL_DIV_EXPR:
14027 case FLOOR_DIV_EXPR:
14028 case ROUND_DIV_EXPR:
14029 return (tree_expr_nonnegative_warnv_p (op0,
14031 && tree_expr_nonnegative_warnv_p (op1,
14032 strict_overflow_p));
14034 case TRUNC_MOD_EXPR:
14035 case CEIL_MOD_EXPR:
14036 case FLOOR_MOD_EXPR:
14037 case ROUND_MOD_EXPR:
14038 return tree_expr_nonnegative_warnv_p (op0,
14039 strict_overflow_p);
14041 return tree_simple_nonnegative_warnv_p (code, type);
14044 /* We don't know sign of `t', so be conservative and return false. */
14048 /* Return true if T is known to be non-negative. If the return
14049 value is based on the assumption that signed overflow is undefined,
14050 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14051 *STRICT_OVERFLOW_P. */
14054 tree_single_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14056 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14059 switch (TREE_CODE (t))
14062 /* Query VRP to see if it has recorded any information about
14063 the range of this object. */
14064 return ssa_name_nonnegative_p (t);
14067 return tree_int_cst_sgn (t) >= 0;
14070 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
14073 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
14076 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14078 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
14079 strict_overflow_p));
14081 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14084 /* We don't know sign of `t', so be conservative and return false. */
14088 /* Return true if T is known to be non-negative. If the return
14089 value is based on the assumption that signed overflow is undefined,
14090 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14091 *STRICT_OVERFLOW_P. */
14094 tree_call_nonnegative_warnv_p (enum tree_code code, tree type, tree fndecl,
14095 tree arg0, tree arg1, bool *strict_overflow_p)
14097 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
14098 switch (DECL_FUNCTION_CODE (fndecl))
14100 CASE_FLT_FN (BUILT_IN_ACOS):
14101 CASE_FLT_FN (BUILT_IN_ACOSH):
14102 CASE_FLT_FN (BUILT_IN_CABS):
14103 CASE_FLT_FN (BUILT_IN_COSH):
14104 CASE_FLT_FN (BUILT_IN_ERFC):
14105 CASE_FLT_FN (BUILT_IN_EXP):
14106 CASE_FLT_FN (BUILT_IN_EXP10):
14107 CASE_FLT_FN (BUILT_IN_EXP2):
14108 CASE_FLT_FN (BUILT_IN_FABS):
14109 CASE_FLT_FN (BUILT_IN_FDIM):
14110 CASE_FLT_FN (BUILT_IN_HYPOT):
14111 CASE_FLT_FN (BUILT_IN_POW10):
14112 CASE_INT_FN (BUILT_IN_FFS):
14113 CASE_INT_FN (BUILT_IN_PARITY):
14114 CASE_INT_FN (BUILT_IN_POPCOUNT):
14115 case BUILT_IN_BSWAP32:
14116 case BUILT_IN_BSWAP64:
14120 CASE_FLT_FN (BUILT_IN_SQRT):
14121 /* sqrt(-0.0) is -0.0. */
14122 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
14124 return tree_expr_nonnegative_warnv_p (arg0,
14125 strict_overflow_p);
14127 CASE_FLT_FN (BUILT_IN_ASINH):
14128 CASE_FLT_FN (BUILT_IN_ATAN):
14129 CASE_FLT_FN (BUILT_IN_ATANH):
14130 CASE_FLT_FN (BUILT_IN_CBRT):
14131 CASE_FLT_FN (BUILT_IN_CEIL):
14132 CASE_FLT_FN (BUILT_IN_ERF):
14133 CASE_FLT_FN (BUILT_IN_EXPM1):
14134 CASE_FLT_FN (BUILT_IN_FLOOR):
14135 CASE_FLT_FN (BUILT_IN_FMOD):
14136 CASE_FLT_FN (BUILT_IN_FREXP):
14137 CASE_FLT_FN (BUILT_IN_LCEIL):
14138 CASE_FLT_FN (BUILT_IN_LDEXP):
14139 CASE_FLT_FN (BUILT_IN_LFLOOR):
14140 CASE_FLT_FN (BUILT_IN_LLCEIL):
14141 CASE_FLT_FN (BUILT_IN_LLFLOOR):
14142 CASE_FLT_FN (BUILT_IN_LLRINT):
14143 CASE_FLT_FN (BUILT_IN_LLROUND):
14144 CASE_FLT_FN (BUILT_IN_LRINT):
14145 CASE_FLT_FN (BUILT_IN_LROUND):
14146 CASE_FLT_FN (BUILT_IN_MODF):
14147 CASE_FLT_FN (BUILT_IN_NEARBYINT):
14148 CASE_FLT_FN (BUILT_IN_RINT):
14149 CASE_FLT_FN (BUILT_IN_ROUND):
14150 CASE_FLT_FN (BUILT_IN_SCALB):
14151 CASE_FLT_FN (BUILT_IN_SCALBLN):
14152 CASE_FLT_FN (BUILT_IN_SCALBN):
14153 CASE_FLT_FN (BUILT_IN_SIGNBIT):
14154 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
14155 CASE_FLT_FN (BUILT_IN_SINH):
14156 CASE_FLT_FN (BUILT_IN_TANH):
14157 CASE_FLT_FN (BUILT_IN_TRUNC):
14158 /* True if the 1st argument is nonnegative. */
14159 return tree_expr_nonnegative_warnv_p (arg0,
14160 strict_overflow_p);
14162 CASE_FLT_FN (BUILT_IN_FMAX):
14163 /* True if the 1st OR 2nd arguments are nonnegative. */
14164 return (tree_expr_nonnegative_warnv_p (arg0,
14166 || (tree_expr_nonnegative_warnv_p (arg1,
14167 strict_overflow_p)));
14169 CASE_FLT_FN (BUILT_IN_FMIN):
14170 /* True if the 1st AND 2nd arguments are nonnegative. */
14171 return (tree_expr_nonnegative_warnv_p (arg0,
14173 && (tree_expr_nonnegative_warnv_p (arg1,
14174 strict_overflow_p)));
14176 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14177 /* True if the 2nd argument is nonnegative. */
14178 return tree_expr_nonnegative_warnv_p (arg1,
14179 strict_overflow_p);
14181 CASE_FLT_FN (BUILT_IN_POWI):
14182 /* True if the 1st argument is nonnegative or the second
14183 argument is an even integer. */
14184 if (TREE_CODE (arg1) == INTEGER_CST
14185 && (TREE_INT_CST_LOW (arg1) & 1) == 0)
14187 return tree_expr_nonnegative_warnv_p (arg0,
14188 strict_overflow_p);
14190 CASE_FLT_FN (BUILT_IN_POW):
14191 /* True if the 1st argument is nonnegative or the second
14192 argument is an even integer valued real. */
14193 if (TREE_CODE (arg1) == REAL_CST)
14198 c = TREE_REAL_CST (arg1);
14199 n = real_to_integer (&c);
14202 REAL_VALUE_TYPE cint;
14203 real_from_integer (&cint, VOIDmode, n,
14204 n < 0 ? -1 : 0, 0);
14205 if (real_identical (&c, &cint))
14209 return tree_expr_nonnegative_warnv_p (arg0,
14210 strict_overflow_p);
14215 return tree_simple_nonnegative_warnv_p (code,
14219 /* Return true if T is known to be non-negative. If the return
14220 value is based on the assumption that signed overflow is undefined,
14221 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14222 *STRICT_OVERFLOW_P. */
14225 tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14227 enum tree_code code = TREE_CODE (t);
14228 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14235 tree temp = TARGET_EXPR_SLOT (t);
14236 t = TARGET_EXPR_INITIAL (t);
14238 /* If the initializer is non-void, then it's a normal expression
14239 that will be assigned to the slot. */
14240 if (!VOID_TYPE_P (t))
14241 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
14243 /* Otherwise, the initializer sets the slot in some way. One common
14244 way is an assignment statement at the end of the initializer. */
14247 if (TREE_CODE (t) == BIND_EXPR)
14248 t = expr_last (BIND_EXPR_BODY (t));
14249 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
14250 || TREE_CODE (t) == TRY_CATCH_EXPR)
14251 t = expr_last (TREE_OPERAND (t, 0));
14252 else if (TREE_CODE (t) == STATEMENT_LIST)
14257 if ((TREE_CODE (t) == MODIFY_EXPR
14258 || TREE_CODE (t) == GIMPLE_MODIFY_STMT)
14259 && GENERIC_TREE_OPERAND (t, 0) == temp)
14260 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14261 strict_overflow_p);
14268 tree arg0 = call_expr_nargs (t) > 0 ? CALL_EXPR_ARG (t, 0) : NULL_TREE;
14269 tree arg1 = call_expr_nargs (t) > 1 ? CALL_EXPR_ARG (t, 1) : NULL_TREE;
14271 return tree_call_nonnegative_warnv_p (TREE_CODE (t),
14273 get_callee_fndecl (t),
14276 strict_overflow_p);
14278 case COMPOUND_EXPR:
14280 case GIMPLE_MODIFY_STMT:
14281 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14282 strict_overflow_p);
14284 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
14285 strict_overflow_p);
14287 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14288 strict_overflow_p);
14291 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14295 /* We don't know sign of `t', so be conservative and return false. */
14299 /* Return true if T is known to be non-negative. If the return
14300 value is based on the assumption that signed overflow is undefined,
14301 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14302 *STRICT_OVERFLOW_P. */
14305 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14307 enum tree_code code;
14308 if (t == error_mark_node)
14311 code = TREE_CODE (t);
14312 switch (TREE_CODE_CLASS (code))
14315 case tcc_comparison:
14316 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14318 TREE_OPERAND (t, 0),
14319 TREE_OPERAND (t, 1),
14320 strict_overflow_p);
14323 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14325 TREE_OPERAND (t, 0),
14326 strict_overflow_p);
14329 case tcc_declaration:
14330 case tcc_reference:
14331 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14339 case TRUTH_AND_EXPR:
14340 case TRUTH_OR_EXPR:
14341 case TRUTH_XOR_EXPR:
14342 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14344 TREE_OPERAND (t, 0),
14345 TREE_OPERAND (t, 1),
14346 strict_overflow_p);
14347 case TRUTH_NOT_EXPR:
14348 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14350 TREE_OPERAND (t, 0),
14351 strict_overflow_p);
14358 case WITH_SIZE_EXPR:
14362 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14365 return tree_invalid_nonnegative_warnv_p (t, strict_overflow_p);
14369 /* Return true if `t' is known to be non-negative. Handle warnings
14370 about undefined signed overflow. */
14373 tree_expr_nonnegative_p (tree t)
14375 bool ret, strict_overflow_p;
14377 strict_overflow_p = false;
14378 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
14379 if (strict_overflow_p)
14380 fold_overflow_warning (("assuming signed overflow does not occur when "
14381 "determining that expression is always "
14383 WARN_STRICT_OVERFLOW_MISC);
14388 /* Return true when (CODE OP0) is an address and is known to be nonzero.
14389 For floating point we further ensure that T is not denormal.
14390 Similar logic is present in nonzero_address in rtlanal.h.
14392 If the return value is based on the assumption that signed overflow
14393 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14394 change *STRICT_OVERFLOW_P. */
14397 tree_unary_nonzero_warnv_p (enum tree_code code, tree type, tree op0,
14398 bool *strict_overflow_p)
14403 return tree_expr_nonzero_warnv_p (op0,
14404 strict_overflow_p);
14408 tree inner_type = TREE_TYPE (op0);
14409 tree outer_type = type;
14411 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
14412 && tree_expr_nonzero_warnv_p (op0,
14413 strict_overflow_p));
14417 case NON_LVALUE_EXPR:
14418 return tree_expr_nonzero_warnv_p (op0,
14419 strict_overflow_p);
14428 /* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
14429 For floating point we further ensure that T is not denormal.
14430 Similar logic is present in nonzero_address in rtlanal.h.
14432 If the return value is based on the assumption that signed overflow
14433 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14434 change *STRICT_OVERFLOW_P. */
14437 tree_binary_nonzero_warnv_p (enum tree_code code,
14440 tree op1, bool *strict_overflow_p)
14442 bool sub_strict_overflow_p;
14445 case POINTER_PLUS_EXPR:
14447 if (TYPE_OVERFLOW_UNDEFINED (type))
14449 /* With the presence of negative values it is hard
14450 to say something. */
14451 sub_strict_overflow_p = false;
14452 if (!tree_expr_nonnegative_warnv_p (op0,
14453 &sub_strict_overflow_p)
14454 || !tree_expr_nonnegative_warnv_p (op1,
14455 &sub_strict_overflow_p))
14457 /* One of operands must be positive and the other non-negative. */
14458 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14459 overflows, on a twos-complement machine the sum of two
14460 nonnegative numbers can never be zero. */
14461 return (tree_expr_nonzero_warnv_p (op0,
14463 || tree_expr_nonzero_warnv_p (op1,
14464 strict_overflow_p));
14469 if (TYPE_OVERFLOW_UNDEFINED (type))
14471 if (tree_expr_nonzero_warnv_p (op0,
14473 && tree_expr_nonzero_warnv_p (op1,
14474 strict_overflow_p))
14476 *strict_overflow_p = true;
14483 sub_strict_overflow_p = false;
14484 if (tree_expr_nonzero_warnv_p (op0,
14485 &sub_strict_overflow_p)
14486 && tree_expr_nonzero_warnv_p (op1,
14487 &sub_strict_overflow_p))
14489 if (sub_strict_overflow_p)
14490 *strict_overflow_p = true;
14495 sub_strict_overflow_p = false;
14496 if (tree_expr_nonzero_warnv_p (op0,
14497 &sub_strict_overflow_p))
14499 if (sub_strict_overflow_p)
14500 *strict_overflow_p = true;
14502 /* When both operands are nonzero, then MAX must be too. */
14503 if (tree_expr_nonzero_warnv_p (op1,
14504 strict_overflow_p))
14507 /* MAX where operand 0 is positive is positive. */
14508 return tree_expr_nonnegative_warnv_p (op0,
14509 strict_overflow_p);
14511 /* MAX where operand 1 is positive is positive. */
14512 else if (tree_expr_nonzero_warnv_p (op1,
14513 &sub_strict_overflow_p)
14514 && tree_expr_nonnegative_warnv_p (op1,
14515 &sub_strict_overflow_p))
14517 if (sub_strict_overflow_p)
14518 *strict_overflow_p = true;
14524 return (tree_expr_nonzero_warnv_p (op1,
14526 || tree_expr_nonzero_warnv_p (op0,
14527 strict_overflow_p));
14536 /* Return true when T is an address and is known to be nonzero.
14537 For floating point we further ensure that T is not denormal.
14538 Similar logic is present in nonzero_address in rtlanal.h.
14540 If the return value is based on the assumption that signed overflow
14541 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14542 change *STRICT_OVERFLOW_P. */
14545 tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14547 bool sub_strict_overflow_p;
14548 switch (TREE_CODE (t))
14551 /* Query VRP to see if it has recorded any information about
14552 the range of this object. */
14553 return ssa_name_nonzero_p (t);
14556 return !integer_zerop (t);
14560 tree base = get_base_address (TREE_OPERAND (t, 0));
14565 /* Weak declarations may link to NULL. */
14566 if (VAR_OR_FUNCTION_DECL_P (base))
14567 return !DECL_WEAK (base);
14569 /* Constants are never weak. */
14570 if (CONSTANT_CLASS_P (base))
14577 sub_strict_overflow_p = false;
14578 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14579 &sub_strict_overflow_p)
14580 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
14581 &sub_strict_overflow_p))
14583 if (sub_strict_overflow_p)
14584 *strict_overflow_p = true;
14595 /* Return true when T is an address and is known to be nonzero.
14596 For floating point we further ensure that T is not denormal.
14597 Similar logic is present in nonzero_address in rtlanal.h.
14599 If the return value is based on the assumption that signed overflow
14600 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14601 change *STRICT_OVERFLOW_P. */
14604 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14606 tree type = TREE_TYPE (t);
14607 enum tree_code code;
14609 /* Doing something useful for floating point would need more work. */
14610 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
14613 code = TREE_CODE (t);
14614 switch (TREE_CODE_CLASS (code))
14617 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
14618 strict_overflow_p);
14620 case tcc_comparison:
14621 return tree_binary_nonzero_warnv_p (code, type,
14622 TREE_OPERAND (t, 0),
14623 TREE_OPERAND (t, 1),
14624 strict_overflow_p);
14626 case tcc_declaration:
14627 case tcc_reference:
14628 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
14636 case TRUTH_NOT_EXPR:
14637 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
14638 strict_overflow_p);
14640 case TRUTH_AND_EXPR:
14641 case TRUTH_OR_EXPR:
14642 case TRUTH_XOR_EXPR:
14643 return tree_binary_nonzero_warnv_p (code, type,
14644 TREE_OPERAND (t, 0),
14645 TREE_OPERAND (t, 1),
14646 strict_overflow_p);
14653 case WITH_SIZE_EXPR:
14657 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
14659 case COMPOUND_EXPR:
14661 case GIMPLE_MODIFY_STMT:
14663 return tree_expr_nonzero_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14664 strict_overflow_p);
14667 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14668 strict_overflow_p);
14671 return alloca_call_p (t);
14679 /* Return true when T is an address and is known to be nonzero.
14680 Handle warnings about undefined signed overflow. */
14683 tree_expr_nonzero_p (tree t)
14685 bool ret, strict_overflow_p;
14687 strict_overflow_p = false;
14688 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
14689 if (strict_overflow_p)
14690 fold_overflow_warning (("assuming signed overflow does not occur when "
14691 "determining that expression is always "
14693 WARN_STRICT_OVERFLOW_MISC);
14697 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
14698 attempt to fold the expression to a constant without modifying TYPE,
14701 If the expression could be simplified to a constant, then return
14702 the constant. If the expression would not be simplified to a
14703 constant, then return NULL_TREE. */
14706 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
14708 tree tem = fold_binary (code, type, op0, op1);
14709 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14712 /* Given the components of a unary expression CODE, TYPE and OP0,
14713 attempt to fold the expression to a constant without modifying
14716 If the expression could be simplified to a constant, then return
14717 the constant. If the expression would not be simplified to a
14718 constant, then return NULL_TREE. */
14721 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
14723 tree tem = fold_unary (code, type, op0);
14724 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14727 /* If EXP represents referencing an element in a constant string
14728 (either via pointer arithmetic or array indexing), return the
14729 tree representing the value accessed, otherwise return NULL. */
14732 fold_read_from_constant_string (tree exp)
14734 if ((TREE_CODE (exp) == INDIRECT_REF
14735 || TREE_CODE (exp) == ARRAY_REF)
14736 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
14738 tree exp1 = TREE_OPERAND (exp, 0);
14742 if (TREE_CODE (exp) == INDIRECT_REF)
14743 string = string_constant (exp1, &index);
14746 tree low_bound = array_ref_low_bound (exp);
14747 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
14749 /* Optimize the special-case of a zero lower bound.
14751 We convert the low_bound to sizetype to avoid some problems
14752 with constant folding. (E.g. suppose the lower bound is 1,
14753 and its mode is QI. Without the conversion,l (ARRAY
14754 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
14755 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
14756 if (! integer_zerop (low_bound))
14757 index = size_diffop (index, fold_convert (sizetype, low_bound));
14763 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
14764 && TREE_CODE (string) == STRING_CST
14765 && TREE_CODE (index) == INTEGER_CST
14766 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
14767 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
14769 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
14770 return build_int_cst_type (TREE_TYPE (exp),
14771 (TREE_STRING_POINTER (string)
14772 [TREE_INT_CST_LOW (index)]));
14777 /* Return the tree for neg (ARG0) when ARG0 is known to be either
14778 an integer constant, real, or fixed-point constant.
14780 TYPE is the type of the result. */
14783 fold_negate_const (tree arg0, tree type)
14785 tree t = NULL_TREE;
14787 switch (TREE_CODE (arg0))
14791 unsigned HOST_WIDE_INT low;
14792 HOST_WIDE_INT high;
14793 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14794 TREE_INT_CST_HIGH (arg0),
14796 t = force_fit_type_double (type, low, high, 1,
14797 (overflow | TREE_OVERFLOW (arg0))
14798 && !TYPE_UNSIGNED (type));
14803 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14808 FIXED_VALUE_TYPE f;
14809 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
14810 &(TREE_FIXED_CST (arg0)), NULL,
14811 TYPE_SATURATING (type));
14812 t = build_fixed (type, f);
14813 /* Propagate overflow flags. */
14814 if (overflow_p | TREE_OVERFLOW (arg0))
14816 TREE_OVERFLOW (t) = 1;
14817 TREE_CONSTANT_OVERFLOW (t) = 1;
14819 else if (TREE_CONSTANT_OVERFLOW (arg0))
14820 TREE_CONSTANT_OVERFLOW (t) = 1;
14825 gcc_unreachable ();
14831 /* Return the tree for abs (ARG0) when ARG0 is known to be either
14832 an integer constant or real constant.
14834 TYPE is the type of the result. */
14837 fold_abs_const (tree arg0, tree type)
14839 tree t = NULL_TREE;
14841 switch (TREE_CODE (arg0))
14844 /* If the value is unsigned, then the absolute value is
14845 the same as the ordinary value. */
14846 if (TYPE_UNSIGNED (type))
14848 /* Similarly, if the value is non-negative. */
14849 else if (INT_CST_LT (integer_minus_one_node, arg0))
14851 /* If the value is negative, then the absolute value is
14855 unsigned HOST_WIDE_INT low;
14856 HOST_WIDE_INT high;
14857 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14858 TREE_INT_CST_HIGH (arg0),
14860 t = force_fit_type_double (type, low, high, -1,
14861 overflow | TREE_OVERFLOW (arg0));
14866 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
14867 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14873 gcc_unreachable ();
14879 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
14880 constant. TYPE is the type of the result. */
14883 fold_not_const (tree arg0, tree type)
14885 tree t = NULL_TREE;
14887 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
14889 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
14890 ~TREE_INT_CST_HIGH (arg0), 0,
14891 TREE_OVERFLOW (arg0));
14896 /* Given CODE, a relational operator, the target type, TYPE and two
14897 constant operands OP0 and OP1, return the result of the
14898 relational operation. If the result is not a compile time
14899 constant, then return NULL_TREE. */
14902 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
14904 int result, invert;
14906 /* From here on, the only cases we handle are when the result is
14907 known to be a constant. */
14909 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
14911 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
14912 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
14914 /* Handle the cases where either operand is a NaN. */
14915 if (real_isnan (c0) || real_isnan (c1))
14925 case UNORDERED_EXPR:
14939 if (flag_trapping_math)
14945 gcc_unreachable ();
14948 return constant_boolean_node (result, type);
14951 return constant_boolean_node (real_compare (code, c0, c1), type);
14954 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
14956 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
14957 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
14958 return constant_boolean_node (fixed_compare (code, c0, c1), type);
14961 /* Handle equality/inequality of complex constants. */
14962 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
14964 tree rcond = fold_relational_const (code, type,
14965 TREE_REALPART (op0),
14966 TREE_REALPART (op1));
14967 tree icond = fold_relational_const (code, type,
14968 TREE_IMAGPART (op0),
14969 TREE_IMAGPART (op1));
14970 if (code == EQ_EXPR)
14971 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
14972 else if (code == NE_EXPR)
14973 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
14978 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14980 To compute GT, swap the arguments and do LT.
14981 To compute GE, do LT and invert the result.
14982 To compute LE, swap the arguments, do LT and invert the result.
14983 To compute NE, do EQ and invert the result.
14985 Therefore, the code below must handle only EQ and LT. */
14987 if (code == LE_EXPR || code == GT_EXPR)
14992 code = swap_tree_comparison (code);
14995 /* Note that it is safe to invert for real values here because we
14996 have already handled the one case that it matters. */
14999 if (code == NE_EXPR || code == GE_EXPR)
15002 code = invert_tree_comparison (code, false);
15005 /* Compute a result for LT or EQ if args permit;
15006 Otherwise return T. */
15007 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
15009 if (code == EQ_EXPR)
15010 result = tree_int_cst_equal (op0, op1);
15011 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
15012 result = INT_CST_LT_UNSIGNED (op0, op1);
15014 result = INT_CST_LT (op0, op1);
15021 return constant_boolean_node (result, type);
15024 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
15025 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
15029 fold_build_cleanup_point_expr (tree type, tree expr)
15031 /* If the expression does not have side effects then we don't have to wrap
15032 it with a cleanup point expression. */
15033 if (!TREE_SIDE_EFFECTS (expr))
15036 /* If the expression is a return, check to see if the expression inside the
15037 return has no side effects or the right hand side of the modify expression
15038 inside the return. If either don't have side effects set we don't need to
15039 wrap the expression in a cleanup point expression. Note we don't check the
15040 left hand side of the modify because it should always be a return decl. */
15041 if (TREE_CODE (expr) == RETURN_EXPR)
15043 tree op = TREE_OPERAND (expr, 0);
15044 if (!op || !TREE_SIDE_EFFECTS (op))
15046 op = TREE_OPERAND (op, 1);
15047 if (!TREE_SIDE_EFFECTS (op))
15051 return build1 (CLEANUP_POINT_EXPR, type, expr);
15054 /* Given a pointer value OP0 and a type TYPE, return a simplified version
15055 of an indirection through OP0, or NULL_TREE if no simplification is
15059 fold_indirect_ref_1 (tree type, tree op0)
15065 subtype = TREE_TYPE (sub);
15066 if (!POINTER_TYPE_P (subtype))
15069 if (TREE_CODE (sub) == ADDR_EXPR)
15071 tree op = TREE_OPERAND (sub, 0);
15072 tree optype = TREE_TYPE (op);
15073 /* *&CONST_DECL -> to the value of the const decl. */
15074 if (TREE_CODE (op) == CONST_DECL)
15075 return DECL_INITIAL (op);
15076 /* *&p => p; make sure to handle *&"str"[cst] here. */
15077 if (type == optype)
15079 tree fop = fold_read_from_constant_string (op);
15085 /* *(foo *)&fooarray => fooarray[0] */
15086 else if (TREE_CODE (optype) == ARRAY_TYPE
15087 && type == TREE_TYPE (optype))
15089 tree type_domain = TYPE_DOMAIN (optype);
15090 tree min_val = size_zero_node;
15091 if (type_domain && TYPE_MIN_VALUE (type_domain))
15092 min_val = TYPE_MIN_VALUE (type_domain);
15093 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
15095 /* *(foo *)&complexfoo => __real__ complexfoo */
15096 else if (TREE_CODE (optype) == COMPLEX_TYPE
15097 && type == TREE_TYPE (optype))
15098 return fold_build1 (REALPART_EXPR, type, op);
15099 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
15100 else if (TREE_CODE (optype) == VECTOR_TYPE
15101 && type == TREE_TYPE (optype))
15103 tree part_width = TYPE_SIZE (type);
15104 tree index = bitsize_int (0);
15105 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
15109 /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
15110 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15111 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15113 tree op00 = TREE_OPERAND (sub, 0);
15114 tree op01 = TREE_OPERAND (sub, 1);
15118 op00type = TREE_TYPE (op00);
15119 if (TREE_CODE (op00) == ADDR_EXPR
15120 && TREE_CODE (TREE_TYPE (op00type)) == VECTOR_TYPE
15121 && type == TREE_TYPE (TREE_TYPE (op00type)))
15123 HOST_WIDE_INT offset = tree_low_cst (op01, 0);
15124 tree part_width = TYPE_SIZE (type);
15125 unsigned HOST_WIDE_INT part_widthi = tree_low_cst (part_width, 0)/BITS_PER_UNIT;
15126 unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
15127 tree index = bitsize_int (indexi);
15129 if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (op00type)))
15130 return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (op00, 0),
15131 part_width, index);
15137 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
15138 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15139 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15141 tree op00 = TREE_OPERAND (sub, 0);
15142 tree op01 = TREE_OPERAND (sub, 1);
15146 op00type = TREE_TYPE (op00);
15147 if (TREE_CODE (op00) == ADDR_EXPR
15148 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
15149 && type == TREE_TYPE (TREE_TYPE (op00type)))
15151 tree size = TYPE_SIZE_UNIT (type);
15152 if (tree_int_cst_equal (size, op01))
15153 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
15157 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
15158 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
15159 && type == TREE_TYPE (TREE_TYPE (subtype)))
15162 tree min_val = size_zero_node;
15163 sub = build_fold_indirect_ref (sub);
15164 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
15165 if (type_domain && TYPE_MIN_VALUE (type_domain))
15166 min_val = TYPE_MIN_VALUE (type_domain);
15167 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
15173 /* Builds an expression for an indirection through T, simplifying some
15177 build_fold_indirect_ref (tree t)
15179 tree type = TREE_TYPE (TREE_TYPE (t));
15180 tree sub = fold_indirect_ref_1 (type, t);
15185 return build1 (INDIRECT_REF, type, t);
15188 /* Given an INDIRECT_REF T, return either T or a simplified version. */
15191 fold_indirect_ref (tree t)
15193 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
15201 /* Strip non-trapping, non-side-effecting tree nodes from an expression
15202 whose result is ignored. The type of the returned tree need not be
15203 the same as the original expression. */
15206 fold_ignored_result (tree t)
15208 if (!TREE_SIDE_EFFECTS (t))
15209 return integer_zero_node;
15212 switch (TREE_CODE_CLASS (TREE_CODE (t)))
15215 t = TREE_OPERAND (t, 0);
15219 case tcc_comparison:
15220 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15221 t = TREE_OPERAND (t, 0);
15222 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
15223 t = TREE_OPERAND (t, 1);
15228 case tcc_expression:
15229 switch (TREE_CODE (t))
15231 case COMPOUND_EXPR:
15232 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15234 t = TREE_OPERAND (t, 0);
15238 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
15239 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
15241 t = TREE_OPERAND (t, 0);
15254 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
15255 This can only be applied to objects of a sizetype. */
15258 round_up (tree value, int divisor)
15260 tree div = NULL_TREE;
15262 gcc_assert (divisor > 0);
15266 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15267 have to do anything. Only do this when we are not given a const,
15268 because in that case, this check is more expensive than just
15270 if (TREE_CODE (value) != INTEGER_CST)
15272 div = build_int_cst (TREE_TYPE (value), divisor);
15274 if (multiple_of_p (TREE_TYPE (value), value, div))
15278 /* If divisor is a power of two, simplify this to bit manipulation. */
15279 if (divisor == (divisor & -divisor))
15281 if (TREE_CODE (value) == INTEGER_CST)
15283 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
15284 unsigned HOST_WIDE_INT high;
15287 if ((low & (divisor - 1)) == 0)
15290 overflow_p = TREE_OVERFLOW (value);
15291 high = TREE_INT_CST_HIGH (value);
15292 low &= ~(divisor - 1);
15301 return force_fit_type_double (TREE_TYPE (value), low, high,
15308 t = build_int_cst (TREE_TYPE (value), divisor - 1);
15309 value = size_binop (PLUS_EXPR, value, t);
15310 t = build_int_cst (TREE_TYPE (value), -divisor);
15311 value = size_binop (BIT_AND_EXPR, value, t);
15317 div = build_int_cst (TREE_TYPE (value), divisor);
15318 value = size_binop (CEIL_DIV_EXPR, value, div);
15319 value = size_binop (MULT_EXPR, value, div);
15325 /* Likewise, but round down. */
15328 round_down (tree value, int divisor)
15330 tree div = NULL_TREE;
15332 gcc_assert (divisor > 0);
15336 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15337 have to do anything. Only do this when we are not given a const,
15338 because in that case, this check is more expensive than just
15340 if (TREE_CODE (value) != INTEGER_CST)
15342 div = build_int_cst (TREE_TYPE (value), divisor);
15344 if (multiple_of_p (TREE_TYPE (value), value, div))
15348 /* If divisor is a power of two, simplify this to bit manipulation. */
15349 if (divisor == (divisor & -divisor))
15353 t = build_int_cst (TREE_TYPE (value), -divisor);
15354 value = size_binop (BIT_AND_EXPR, value, t);
15359 div = build_int_cst (TREE_TYPE (value), divisor);
15360 value = size_binop (FLOOR_DIV_EXPR, value, div);
15361 value = size_binop (MULT_EXPR, value, div);
15367 /* Returns the pointer to the base of the object addressed by EXP and
15368 extracts the information about the offset of the access, storing it
15369 to PBITPOS and POFFSET. */
15372 split_address_to_core_and_offset (tree exp,
15373 HOST_WIDE_INT *pbitpos, tree *poffset)
15376 enum machine_mode mode;
15377 int unsignedp, volatilep;
15378 HOST_WIDE_INT bitsize;
15380 if (TREE_CODE (exp) == ADDR_EXPR)
15382 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
15383 poffset, &mode, &unsignedp, &volatilep,
15385 core = fold_addr_expr (core);
15391 *poffset = NULL_TREE;
15397 /* Returns true if addresses of E1 and E2 differ by a constant, false
15398 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15401 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
15404 HOST_WIDE_INT bitpos1, bitpos2;
15405 tree toffset1, toffset2, tdiff, type;
15407 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
15408 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
15410 if (bitpos1 % BITS_PER_UNIT != 0
15411 || bitpos2 % BITS_PER_UNIT != 0
15412 || !operand_equal_p (core1, core2, 0))
15415 if (toffset1 && toffset2)
15417 type = TREE_TYPE (toffset1);
15418 if (type != TREE_TYPE (toffset2))
15419 toffset2 = fold_convert (type, toffset2);
15421 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
15422 if (!cst_and_fits_in_hwi (tdiff))
15425 *diff = int_cst_value (tdiff);
15427 else if (toffset1 || toffset2)
15429 /* If only one of the offsets is non-constant, the difference cannot
15436 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
15440 /* Simplify the floating point expression EXP when the sign of the
15441 result is not significant. Return NULL_TREE if no simplification
15445 fold_strip_sign_ops (tree exp)
15449 switch (TREE_CODE (exp))
15453 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15454 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
15458 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
15460 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15461 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15462 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
15463 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
15464 arg0 ? arg0 : TREE_OPERAND (exp, 0),
15465 arg1 ? arg1 : TREE_OPERAND (exp, 1));
15468 case COMPOUND_EXPR:
15469 arg0 = TREE_OPERAND (exp, 0);
15470 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15472 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
15476 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15477 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
15479 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
15480 arg0 ? arg0 : TREE_OPERAND (exp, 1),
15481 arg1 ? arg1 : TREE_OPERAND (exp, 2));
15486 const enum built_in_function fcode = builtin_mathfn_code (exp);
15489 CASE_FLT_FN (BUILT_IN_COPYSIGN):
15490 /* Strip copysign function call, return the 1st argument. */
15491 arg0 = CALL_EXPR_ARG (exp, 0);
15492 arg1 = CALL_EXPR_ARG (exp, 1);
15493 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
15496 /* Strip sign ops from the argument of "odd" math functions. */
15497 if (negate_mathfn_p (fcode))
15499 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
15501 return build_call_expr (get_callee_fndecl (exp), 1, arg0);