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 /* Subroutine of fold_binary. This routine performs all of the
8398 transformations that are common to the equality/inequality
8399 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8400 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8401 fold_binary should call fold_binary. Fold a comparison with
8402 tree code CODE and type TYPE with operands OP0 and OP1. Return
8403 the folded comparison or NULL_TREE. */
8406 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8408 tree arg0, arg1, tem;
8413 STRIP_SIGN_NOPS (arg0);
8414 STRIP_SIGN_NOPS (arg1);
8416 tem = fold_relational_const (code, type, arg0, arg1);
8417 if (tem != NULL_TREE)
8420 /* If one arg is a real or integer constant, put it last. */
8421 if (tree_swap_operands_p (arg0, arg1, true))
8422 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8424 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8425 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8426 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8427 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8428 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8429 && (TREE_CODE (arg1) == INTEGER_CST
8430 && !TREE_OVERFLOW (arg1)))
8432 tree const1 = TREE_OPERAND (arg0, 1);
8434 tree variable = TREE_OPERAND (arg0, 0);
8437 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8439 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8440 TREE_TYPE (arg1), const2, const1);
8442 /* If the constant operation overflowed this can be
8443 simplified as a comparison against INT_MAX/INT_MIN. */
8444 if (TREE_CODE (lhs) == INTEGER_CST
8445 && TREE_OVERFLOW (lhs))
8447 int const1_sgn = tree_int_cst_sgn (const1);
8448 enum tree_code code2 = code;
8450 /* Get the sign of the constant on the lhs if the
8451 operation were VARIABLE + CONST1. */
8452 if (TREE_CODE (arg0) == MINUS_EXPR)
8453 const1_sgn = -const1_sgn;
8455 /* The sign of the constant determines if we overflowed
8456 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8457 Canonicalize to the INT_MIN overflow by swapping the comparison
8459 if (const1_sgn == -1)
8460 code2 = swap_tree_comparison (code);
8462 /* We now can look at the canonicalized case
8463 VARIABLE + 1 CODE2 INT_MIN
8464 and decide on the result. */
8465 if (code2 == LT_EXPR
8467 || code2 == EQ_EXPR)
8468 return omit_one_operand (type, boolean_false_node, variable);
8469 else if (code2 == NE_EXPR
8471 || code2 == GT_EXPR)
8472 return omit_one_operand (type, boolean_true_node, variable);
8475 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8476 && (TREE_CODE (lhs) != INTEGER_CST
8477 || !TREE_OVERFLOW (lhs)))
8479 fold_overflow_warning (("assuming signed overflow does not occur "
8480 "when changing X +- C1 cmp C2 to "
8482 WARN_STRICT_OVERFLOW_COMPARISON);
8483 return fold_build2 (code, type, variable, lhs);
8487 /* For comparisons of pointers we can decompose it to a compile time
8488 comparison of the base objects and the offsets into the object.
8489 This requires at least one operand being an ADDR_EXPR or a
8490 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8491 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8492 && (TREE_CODE (arg0) == ADDR_EXPR
8493 || TREE_CODE (arg1) == ADDR_EXPR
8494 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
8495 || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
8497 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8498 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8499 enum machine_mode mode;
8500 int volatilep, unsignedp;
8501 bool indirect_base0 = false, indirect_base1 = false;
8503 /* Get base and offset for the access. Strip ADDR_EXPR for
8504 get_inner_reference, but put it back by stripping INDIRECT_REF
8505 off the base object if possible. indirect_baseN will be true
8506 if baseN is not an address but refers to the object itself. */
8508 if (TREE_CODE (arg0) == ADDR_EXPR)
8510 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8511 &bitsize, &bitpos0, &offset0, &mode,
8512 &unsignedp, &volatilep, false);
8513 if (TREE_CODE (base0) == INDIRECT_REF)
8514 base0 = TREE_OPERAND (base0, 0);
8516 indirect_base0 = true;
8518 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
8520 base0 = TREE_OPERAND (arg0, 0);
8521 offset0 = TREE_OPERAND (arg0, 1);
8525 if (TREE_CODE (arg1) == ADDR_EXPR)
8527 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8528 &bitsize, &bitpos1, &offset1, &mode,
8529 &unsignedp, &volatilep, false);
8530 if (TREE_CODE (base1) == INDIRECT_REF)
8531 base1 = TREE_OPERAND (base1, 0);
8533 indirect_base1 = true;
8535 else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
8537 base1 = TREE_OPERAND (arg1, 0);
8538 offset1 = TREE_OPERAND (arg1, 1);
8541 /* If we have equivalent bases we might be able to simplify. */
8542 if (indirect_base0 == indirect_base1
8543 && operand_equal_p (base0, base1, 0))
8545 /* We can fold this expression to a constant if the non-constant
8546 offset parts are equal. */
8547 if (offset0 == offset1
8548 || (offset0 && offset1
8549 && operand_equal_p (offset0, offset1, 0)))
8554 return build_int_cst (boolean_type_node, bitpos0 == bitpos1);
8556 return build_int_cst (boolean_type_node, bitpos0 != bitpos1);
8558 return build_int_cst (boolean_type_node, bitpos0 < bitpos1);
8560 return build_int_cst (boolean_type_node, bitpos0 <= bitpos1);
8562 return build_int_cst (boolean_type_node, bitpos0 >= bitpos1);
8564 return build_int_cst (boolean_type_node, bitpos0 > bitpos1);
8568 /* We can simplify the comparison to a comparison of the variable
8569 offset parts if the constant offset parts are equal.
8570 Be careful to use signed size type here because otherwise we
8571 mess with array offsets in the wrong way. This is possible
8572 because pointer arithmetic is restricted to retain within an
8573 object and overflow on pointer differences is undefined as of
8574 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8575 else if (bitpos0 == bitpos1
8576 && ((code == EQ_EXPR || code == NE_EXPR)
8577 || POINTER_TYPE_OVERFLOW_UNDEFINED))
8579 tree signed_size_type_node;
8580 signed_size_type_node = signed_type_for (size_type_node);
8582 /* By converting to signed size type we cover middle-end pointer
8583 arithmetic which operates on unsigned pointer types of size
8584 type size and ARRAY_REF offsets which are properly sign or
8585 zero extended from their type in case it is narrower than
8587 if (offset0 == NULL_TREE)
8588 offset0 = build_int_cst (signed_size_type_node, 0);
8590 offset0 = fold_convert (signed_size_type_node, offset0);
8591 if (offset1 == NULL_TREE)
8592 offset1 = build_int_cst (signed_size_type_node, 0);
8594 offset1 = fold_convert (signed_size_type_node, offset1);
8596 if (code != EQ_EXPR && code != NE_EXPR)
8597 fold_overflow_warning (("assuming pointer wraparound does not "
8598 "occur when comparing P +- C1 with "
8600 WARN_STRICT_OVERFLOW_COMPARISON);
8602 return fold_build2 (code, type, offset0, offset1);
8605 /* For non-equal bases we can simplify if they are addresses
8606 of local binding decls or constants. */
8607 else if (indirect_base0 && indirect_base1
8608 /* We know that !operand_equal_p (base0, base1, 0)
8609 because the if condition was false. But make
8610 sure two decls are not the same. */
8612 && TREE_CODE (arg0) == ADDR_EXPR
8613 && TREE_CODE (arg1) == ADDR_EXPR
8614 && (((TREE_CODE (base0) == VAR_DECL
8615 || TREE_CODE (base0) == PARM_DECL)
8616 && (targetm.binds_local_p (base0)
8617 || CONSTANT_CLASS_P (base1)))
8618 || CONSTANT_CLASS_P (base0))
8619 && (((TREE_CODE (base1) == VAR_DECL
8620 || TREE_CODE (base1) == PARM_DECL)
8621 && (targetm.binds_local_p (base1)
8622 || CONSTANT_CLASS_P (base0)))
8623 || CONSTANT_CLASS_P (base1)))
8625 if (code == EQ_EXPR)
8626 return omit_two_operands (type, boolean_false_node, arg0, arg1);
8627 else if (code == NE_EXPR)
8628 return omit_two_operands (type, boolean_true_node, arg0, arg1);
8630 /* For equal offsets we can simplify to a comparison of the
8632 else if (bitpos0 == bitpos1
8634 ? base0 != TREE_OPERAND (arg0, 0) : base0 != arg0)
8636 ? base1 != TREE_OPERAND (arg1, 0) : base1 != arg1)
8637 && ((offset0 == offset1)
8638 || (offset0 && offset1
8639 && operand_equal_p (offset0, offset1, 0))))
8642 base0 = fold_addr_expr (base0);
8644 base1 = fold_addr_expr (base1);
8645 return fold_build2 (code, type, base0, base1);
8649 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8650 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8651 the resulting offset is smaller in absolute value than the
8653 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8654 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8655 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8656 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8657 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
8658 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8659 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
8661 tree const1 = TREE_OPERAND (arg0, 1);
8662 tree const2 = TREE_OPERAND (arg1, 1);
8663 tree variable1 = TREE_OPERAND (arg0, 0);
8664 tree variable2 = TREE_OPERAND (arg1, 0);
8666 const char * const warnmsg = G_("assuming signed overflow does not "
8667 "occur when combining constants around "
8670 /* Put the constant on the side where it doesn't overflow and is
8671 of lower absolute value than before. */
8672 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8673 ? MINUS_EXPR : PLUS_EXPR,
8675 if (!TREE_OVERFLOW (cst)
8676 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
8678 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8679 return fold_build2 (code, type,
8681 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
8685 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8686 ? MINUS_EXPR : PLUS_EXPR,
8688 if (!TREE_OVERFLOW (cst)
8689 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
8691 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8692 return fold_build2 (code, type,
8693 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
8699 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
8700 signed arithmetic case. That form is created by the compiler
8701 often enough for folding it to be of value. One example is in
8702 computing loop trip counts after Operator Strength Reduction. */
8703 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8704 && TREE_CODE (arg0) == MULT_EXPR
8705 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8706 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8707 && integer_zerop (arg1))
8709 tree const1 = TREE_OPERAND (arg0, 1);
8710 tree const2 = arg1; /* zero */
8711 tree variable1 = TREE_OPERAND (arg0, 0);
8712 enum tree_code cmp_code = code;
8714 gcc_assert (!integer_zerop (const1));
8716 fold_overflow_warning (("assuming signed overflow does not occur when "
8717 "eliminating multiplication in comparison "
8719 WARN_STRICT_OVERFLOW_COMPARISON);
8721 /* If const1 is negative we swap the sense of the comparison. */
8722 if (tree_int_cst_sgn (const1) < 0)
8723 cmp_code = swap_tree_comparison (cmp_code);
8725 return fold_build2 (cmp_code, type, variable1, const2);
8728 tem = maybe_canonicalize_comparison (code, type, op0, op1);
8732 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8734 tree targ0 = strip_float_extensions (arg0);
8735 tree targ1 = strip_float_extensions (arg1);
8736 tree newtype = TREE_TYPE (targ0);
8738 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8739 newtype = TREE_TYPE (targ1);
8741 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8742 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8743 return fold_build2 (code, type, fold_convert (newtype, targ0),
8744 fold_convert (newtype, targ1));
8746 /* (-a) CMP (-b) -> b CMP a */
8747 if (TREE_CODE (arg0) == NEGATE_EXPR
8748 && TREE_CODE (arg1) == NEGATE_EXPR)
8749 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8750 TREE_OPERAND (arg0, 0));
8752 if (TREE_CODE (arg1) == REAL_CST)
8754 REAL_VALUE_TYPE cst;
8755 cst = TREE_REAL_CST (arg1);
8757 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8758 if (TREE_CODE (arg0) == NEGATE_EXPR)
8759 return fold_build2 (swap_tree_comparison (code), type,
8760 TREE_OPERAND (arg0, 0),
8761 build_real (TREE_TYPE (arg1),
8762 REAL_VALUE_NEGATE (cst)));
8764 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8765 /* a CMP (-0) -> a CMP 0 */
8766 if (REAL_VALUE_MINUS_ZERO (cst))
8767 return fold_build2 (code, type, arg0,
8768 build_real (TREE_TYPE (arg1), dconst0));
8770 /* x != NaN is always true, other ops are always false. */
8771 if (REAL_VALUE_ISNAN (cst)
8772 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8774 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8775 return omit_one_operand (type, tem, arg0);
8778 /* Fold comparisons against infinity. */
8779 if (REAL_VALUE_ISINF (cst))
8781 tem = fold_inf_compare (code, type, arg0, arg1);
8782 if (tem != NULL_TREE)
8787 /* If this is a comparison of a real constant with a PLUS_EXPR
8788 or a MINUS_EXPR of a real constant, we can convert it into a
8789 comparison with a revised real constant as long as no overflow
8790 occurs when unsafe_math_optimizations are enabled. */
8791 if (flag_unsafe_math_optimizations
8792 && TREE_CODE (arg1) == REAL_CST
8793 && (TREE_CODE (arg0) == PLUS_EXPR
8794 || TREE_CODE (arg0) == MINUS_EXPR)
8795 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8796 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8797 ? MINUS_EXPR : PLUS_EXPR,
8798 arg1, TREE_OPERAND (arg0, 1), 0))
8799 && !TREE_OVERFLOW (tem))
8800 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
8802 /* Likewise, we can simplify a comparison of a real constant with
8803 a MINUS_EXPR whose first operand is also a real constant, i.e.
8804 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
8805 floating-point types only if -fassociative-math is set. */
8806 if (flag_associative_math
8807 && TREE_CODE (arg1) == REAL_CST
8808 && TREE_CODE (arg0) == MINUS_EXPR
8809 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8810 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8812 && !TREE_OVERFLOW (tem))
8813 return fold_build2 (swap_tree_comparison (code), type,
8814 TREE_OPERAND (arg0, 1), tem);
8816 /* Fold comparisons against built-in math functions. */
8817 if (TREE_CODE (arg1) == REAL_CST
8818 && flag_unsafe_math_optimizations
8819 && ! flag_errno_math)
8821 enum built_in_function fcode = builtin_mathfn_code (arg0);
8823 if (fcode != END_BUILTINS)
8825 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8826 if (tem != NULL_TREE)
8832 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8833 && (TREE_CODE (arg0) == NOP_EXPR
8834 || TREE_CODE (arg0) == CONVERT_EXPR))
8836 /* If we are widening one operand of an integer comparison,
8837 see if the other operand is similarly being widened. Perhaps we
8838 can do the comparison in the narrower type. */
8839 tem = fold_widened_comparison (code, type, arg0, arg1);
8843 /* Or if we are changing signedness. */
8844 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
8849 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8850 constant, we can simplify it. */
8851 if (TREE_CODE (arg1) == INTEGER_CST
8852 && (TREE_CODE (arg0) == MIN_EXPR
8853 || TREE_CODE (arg0) == MAX_EXPR)
8854 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8856 tem = optimize_minmax_comparison (code, type, op0, op1);
8861 /* Simplify comparison of something with itself. (For IEEE
8862 floating-point, we can only do some of these simplifications.) */
8863 if (operand_equal_p (arg0, arg1, 0))
8868 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8869 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8870 return constant_boolean_node (1, type);
8875 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8876 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8877 return constant_boolean_node (1, type);
8878 return fold_build2 (EQ_EXPR, type, arg0, arg1);
8881 /* For NE, we can only do this simplification if integer
8882 or we don't honor IEEE floating point NaNs. */
8883 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8884 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8886 /* ... fall through ... */
8889 return constant_boolean_node (0, type);
8895 /* If we are comparing an expression that just has comparisons
8896 of two integer values, arithmetic expressions of those comparisons,
8897 and constants, we can simplify it. There are only three cases
8898 to check: the two values can either be equal, the first can be
8899 greater, or the second can be greater. Fold the expression for
8900 those three values. Since each value must be 0 or 1, we have
8901 eight possibilities, each of which corresponds to the constant 0
8902 or 1 or one of the six possible comparisons.
8904 This handles common cases like (a > b) == 0 but also handles
8905 expressions like ((x > y) - (y > x)) > 0, which supposedly
8906 occur in macroized code. */
8908 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8910 tree cval1 = 0, cval2 = 0;
8913 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8914 /* Don't handle degenerate cases here; they should already
8915 have been handled anyway. */
8916 && cval1 != 0 && cval2 != 0
8917 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8918 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8919 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8920 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8921 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8922 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8923 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8925 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8926 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8928 /* We can't just pass T to eval_subst in case cval1 or cval2
8929 was the same as ARG1. */
8932 = fold_build2 (code, type,
8933 eval_subst (arg0, cval1, maxval,
8937 = fold_build2 (code, type,
8938 eval_subst (arg0, cval1, maxval,
8942 = fold_build2 (code, type,
8943 eval_subst (arg0, cval1, minval,
8947 /* All three of these results should be 0 or 1. Confirm they are.
8948 Then use those values to select the proper code to use. */
8950 if (TREE_CODE (high_result) == INTEGER_CST
8951 && TREE_CODE (equal_result) == INTEGER_CST
8952 && TREE_CODE (low_result) == INTEGER_CST)
8954 /* Make a 3-bit mask with the high-order bit being the
8955 value for `>', the next for '=', and the low for '<'. */
8956 switch ((integer_onep (high_result) * 4)
8957 + (integer_onep (equal_result) * 2)
8958 + integer_onep (low_result))
8962 return omit_one_operand (type, integer_zero_node, arg0);
8983 return omit_one_operand (type, integer_one_node, arg0);
8987 return save_expr (build2 (code, type, cval1, cval2));
8988 return fold_build2 (code, type, cval1, cval2);
8993 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8994 into a single range test. */
8995 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
8996 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
8997 && TREE_CODE (arg1) == INTEGER_CST
8998 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8999 && !integer_zerop (TREE_OPERAND (arg0, 1))
9000 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9001 && !TREE_OVERFLOW (arg1))
9003 tem = fold_div_compare (code, type, arg0, arg1);
9004 if (tem != NULL_TREE)
9008 /* Fold ~X op ~Y as Y op X. */
9009 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9010 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9012 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9013 return fold_build2 (code, type,
9014 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
9015 TREE_OPERAND (arg0, 0));
9018 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
9019 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9020 && TREE_CODE (arg1) == INTEGER_CST)
9022 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9023 return fold_build2 (swap_tree_comparison (code), type,
9024 TREE_OPERAND (arg0, 0),
9025 fold_build1 (BIT_NOT_EXPR, cmp_type,
9026 fold_convert (cmp_type, arg1)));
9033 /* Subroutine of fold_binary. Optimize complex multiplications of the
9034 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9035 argument EXPR represents the expression "z" of type TYPE. */
9038 fold_mult_zconjz (tree type, tree expr)
9040 tree itype = TREE_TYPE (type);
9041 tree rpart, ipart, tem;
9043 if (TREE_CODE (expr) == COMPLEX_EXPR)
9045 rpart = TREE_OPERAND (expr, 0);
9046 ipart = TREE_OPERAND (expr, 1);
9048 else if (TREE_CODE (expr) == COMPLEX_CST)
9050 rpart = TREE_REALPART (expr);
9051 ipart = TREE_IMAGPART (expr);
9055 expr = save_expr (expr);
9056 rpart = fold_build1 (REALPART_EXPR, itype, expr);
9057 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
9060 rpart = save_expr (rpart);
9061 ipart = save_expr (ipart);
9062 tem = fold_build2 (PLUS_EXPR, itype,
9063 fold_build2 (MULT_EXPR, itype, rpart, rpart),
9064 fold_build2 (MULT_EXPR, itype, ipart, ipart));
9065 return fold_build2 (COMPLEX_EXPR, type, tem,
9066 fold_convert (itype, integer_zero_node));
9070 /* Subroutine of fold_binary. If P is the value of EXPR, computes
9071 power-of-two M and (arbitrary) N such that M divides (P-N). This condition
9072 guarantees that P and N have the same least significant log2(M) bits.
9073 N is not otherwise constrained. In particular, N is not normalized to
9074 0 <= N < M as is common. In general, the precise value of P is unknown.
9075 M is chosen as large as possible such that constant N can be determined.
9077 Returns M and sets *RESIDUE to N. */
9079 static unsigned HOST_WIDE_INT
9080 get_pointer_modulus_and_residue (tree expr, unsigned HOST_WIDE_INT *residue)
9082 enum tree_code code;
9086 code = TREE_CODE (expr);
9087 if (code == ADDR_EXPR)
9089 expr = TREE_OPERAND (expr, 0);
9090 if (handled_component_p (expr))
9092 HOST_WIDE_INT bitsize, bitpos;
9094 enum machine_mode mode;
9095 int unsignedp, volatilep;
9097 expr = get_inner_reference (expr, &bitsize, &bitpos, &offset,
9098 &mode, &unsignedp, &volatilep, false);
9099 *residue = bitpos / BITS_PER_UNIT;
9102 if (TREE_CODE (offset) == INTEGER_CST)
9103 *residue += TREE_INT_CST_LOW (offset);
9105 /* We don't handle more complicated offset expressions. */
9110 if (DECL_P (expr) && TREE_CODE (expr) != FUNCTION_DECL)
9111 return DECL_ALIGN_UNIT (expr);
9113 else if (code == POINTER_PLUS_EXPR)
9116 unsigned HOST_WIDE_INT modulus;
9117 enum tree_code inner_code;
9119 op0 = TREE_OPERAND (expr, 0);
9121 modulus = get_pointer_modulus_and_residue (op0, residue);
9123 op1 = TREE_OPERAND (expr, 1);
9125 inner_code = TREE_CODE (op1);
9126 if (inner_code == INTEGER_CST)
9128 *residue += TREE_INT_CST_LOW (op1);
9131 else if (inner_code == MULT_EXPR)
9133 op1 = TREE_OPERAND (op1, 1);
9134 if (TREE_CODE (op1) == INTEGER_CST)
9136 unsigned HOST_WIDE_INT align;
9138 /* Compute the greatest power-of-2 divisor of op1. */
9139 align = TREE_INT_CST_LOW (op1);
9142 /* If align is non-zero and less than *modulus, replace
9143 *modulus with align., If align is 0, then either op1 is 0
9144 or the greatest power-of-2 divisor of op1 doesn't fit in an
9145 unsigned HOST_WIDE_INT. In either case, no additional
9146 constraint is imposed. */
9148 modulus = MIN (modulus, align);
9155 /* If we get here, we were unable to determine anything useful about the
9161 /* Fold a binary expression of code CODE and type TYPE with operands
9162 OP0 and OP1. Return the folded expression if folding is
9163 successful. Otherwise, return NULL_TREE. */
9166 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
9168 enum tree_code_class kind = TREE_CODE_CLASS (code);
9169 tree arg0, arg1, tem;
9170 tree t1 = NULL_TREE;
9171 bool strict_overflow_p;
9173 gcc_assert ((IS_EXPR_CODE_CLASS (kind)
9174 || IS_GIMPLE_STMT_CODE_CLASS (kind))
9175 && TREE_CODE_LENGTH (code) == 2
9177 && op1 != NULL_TREE);
9182 /* Strip any conversions that don't change the mode. This is
9183 safe for every expression, except for a comparison expression
9184 because its signedness is derived from its operands. So, in
9185 the latter case, only strip conversions that don't change the
9188 Note that this is done as an internal manipulation within the
9189 constant folder, in order to find the simplest representation
9190 of the arguments so that their form can be studied. In any
9191 cases, the appropriate type conversions should be put back in
9192 the tree that will get out of the constant folder. */
9194 if (kind == tcc_comparison)
9196 STRIP_SIGN_NOPS (arg0);
9197 STRIP_SIGN_NOPS (arg1);
9205 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9206 constant but we can't do arithmetic on them. */
9207 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9208 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9209 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == FIXED_CST)
9210 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == INTEGER_CST)
9211 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9212 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9214 if (kind == tcc_binary)
9216 /* Make sure type and arg0 have the same saturating flag. */
9217 gcc_assert (TYPE_SATURATING (type)
9218 == TYPE_SATURATING (TREE_TYPE (arg0)));
9219 tem = const_binop (code, arg0, arg1, 0);
9221 else if (kind == tcc_comparison)
9222 tem = fold_relational_const (code, type, arg0, arg1);
9226 if (tem != NULL_TREE)
9228 if (TREE_TYPE (tem) != type)
9229 tem = fold_convert (type, tem);
9234 /* If this is a commutative operation, and ARG0 is a constant, move it
9235 to ARG1 to reduce the number of tests below. */
9236 if (commutative_tree_code (code)
9237 && tree_swap_operands_p (arg0, arg1, true))
9238 return fold_build2 (code, type, op1, op0);
9240 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9242 First check for cases where an arithmetic operation is applied to a
9243 compound, conditional, or comparison operation. Push the arithmetic
9244 operation inside the compound or conditional to see if any folding
9245 can then be done. Convert comparison to conditional for this purpose.
9246 The also optimizes non-constant cases that used to be done in
9249 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9250 one of the operands is a comparison and the other is a comparison, a
9251 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9252 code below would make the expression more complex. Change it to a
9253 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9254 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9256 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9257 || code == EQ_EXPR || code == NE_EXPR)
9258 && ((truth_value_p (TREE_CODE (arg0))
9259 && (truth_value_p (TREE_CODE (arg1))
9260 || (TREE_CODE (arg1) == BIT_AND_EXPR
9261 && integer_onep (TREE_OPERAND (arg1, 1)))))
9262 || (truth_value_p (TREE_CODE (arg1))
9263 && (truth_value_p (TREE_CODE (arg0))
9264 || (TREE_CODE (arg0) == BIT_AND_EXPR
9265 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9267 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9268 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9271 fold_convert (boolean_type_node, arg0),
9272 fold_convert (boolean_type_node, arg1));
9274 if (code == EQ_EXPR)
9275 tem = invert_truthvalue (tem);
9277 return fold_convert (type, tem);
9280 if (TREE_CODE_CLASS (code) == tcc_binary
9281 || TREE_CODE_CLASS (code) == tcc_comparison)
9283 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9284 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9285 fold_build2 (code, type,
9286 fold_convert (TREE_TYPE (op0),
9287 TREE_OPERAND (arg0, 1)),
9289 if (TREE_CODE (arg1) == COMPOUND_EXPR
9290 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9291 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9292 fold_build2 (code, type, op0,
9293 fold_convert (TREE_TYPE (op1),
9294 TREE_OPERAND (arg1, 1))));
9296 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9298 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9300 /*cond_first_p=*/1);
9301 if (tem != NULL_TREE)
9305 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9307 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9309 /*cond_first_p=*/0);
9310 if (tem != NULL_TREE)
9317 case POINTER_PLUS_EXPR:
9318 /* 0 +p index -> (type)index */
9319 if (integer_zerop (arg0))
9320 return non_lvalue (fold_convert (type, arg1));
9322 /* PTR +p 0 -> PTR */
9323 if (integer_zerop (arg1))
9324 return non_lvalue (fold_convert (type, arg0));
9326 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9327 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9328 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9329 return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
9330 fold_convert (sizetype, arg1),
9331 fold_convert (sizetype, arg0)));
9333 /* index +p PTR -> PTR +p index */
9334 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9335 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9336 return fold_build2 (POINTER_PLUS_EXPR, type,
9337 fold_convert (type, arg1),
9338 fold_convert (sizetype, arg0));
9340 /* (PTR +p B) +p A -> PTR +p (B + A) */
9341 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9344 tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
9345 tree arg00 = TREE_OPERAND (arg0, 0);
9346 inner = fold_build2 (PLUS_EXPR, sizetype,
9347 arg01, fold_convert (sizetype, arg1));
9348 return fold_convert (type,
9349 fold_build2 (POINTER_PLUS_EXPR,
9350 TREE_TYPE (arg00), arg00, inner));
9353 /* PTR_CST +p CST -> CST1 */
9354 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9355 return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
9357 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9358 of the array. Loop optimizer sometimes produce this type of
9360 if (TREE_CODE (arg0) == ADDR_EXPR)
9362 tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
9364 return fold_convert (type, tem);
9370 /* PTR + INT -> (INT)(PTR p+ INT) */
9371 if (POINTER_TYPE_P (TREE_TYPE (arg0))
9372 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9373 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9376 fold_convert (sizetype, arg1)));
9377 /* INT + PTR -> (INT)(PTR p+ INT) */
9378 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9379 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9380 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9383 fold_convert (sizetype, arg0)));
9384 /* A + (-B) -> A - B */
9385 if (TREE_CODE (arg1) == NEGATE_EXPR)
9386 return fold_build2 (MINUS_EXPR, type,
9387 fold_convert (type, arg0),
9388 fold_convert (type, TREE_OPERAND (arg1, 0)));
9389 /* (-A) + B -> B - A */
9390 if (TREE_CODE (arg0) == NEGATE_EXPR
9391 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9392 return fold_build2 (MINUS_EXPR, type,
9393 fold_convert (type, arg1),
9394 fold_convert (type, TREE_OPERAND (arg0, 0)));
9396 if (INTEGRAL_TYPE_P (type))
9398 /* Convert ~A + 1 to -A. */
9399 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9400 && integer_onep (arg1))
9401 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
9404 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9405 && !TYPE_OVERFLOW_TRAPS (type))
9407 tree tem = TREE_OPERAND (arg0, 0);
9410 if (operand_equal_p (tem, arg1, 0))
9412 t1 = build_int_cst_type (type, -1);
9413 return omit_one_operand (type, t1, arg1);
9418 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9419 && !TYPE_OVERFLOW_TRAPS (type))
9421 tree tem = TREE_OPERAND (arg1, 0);
9424 if (operand_equal_p (arg0, tem, 0))
9426 t1 = build_int_cst_type (type, -1);
9427 return omit_one_operand (type, t1, arg0);
9431 /* X + (X / CST) * -CST is X % CST. */
9432 if (TREE_CODE (arg1) == MULT_EXPR
9433 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9434 && operand_equal_p (arg0,
9435 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
9437 tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
9438 tree cst1 = TREE_OPERAND (arg1, 1);
9439 tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
9440 if (sum && integer_zerop (sum))
9441 return fold_convert (type,
9442 fold_build2 (TRUNC_MOD_EXPR,
9443 TREE_TYPE (arg0), arg0, cst0));
9447 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9448 same or one. Make sure type is not saturating.
9449 fold_plusminus_mult_expr will re-associate. */
9450 if ((TREE_CODE (arg0) == MULT_EXPR
9451 || TREE_CODE (arg1) == MULT_EXPR)
9452 && !TYPE_SATURATING (type)
9453 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9455 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9460 if (! FLOAT_TYPE_P (type))
9462 if (integer_zerop (arg1))
9463 return non_lvalue (fold_convert (type, arg0));
9465 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9466 with a constant, and the two constants have no bits in common,
9467 we should treat this as a BIT_IOR_EXPR since this may produce more
9469 if (TREE_CODE (arg0) == BIT_AND_EXPR
9470 && TREE_CODE (arg1) == BIT_AND_EXPR
9471 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9472 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9473 && integer_zerop (const_binop (BIT_AND_EXPR,
9474 TREE_OPERAND (arg0, 1),
9475 TREE_OPERAND (arg1, 1), 0)))
9477 code = BIT_IOR_EXPR;
9481 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9482 (plus (plus (mult) (mult)) (foo)) so that we can
9483 take advantage of the factoring cases below. */
9484 if (((TREE_CODE (arg0) == PLUS_EXPR
9485 || TREE_CODE (arg0) == MINUS_EXPR)
9486 && TREE_CODE (arg1) == MULT_EXPR)
9487 || ((TREE_CODE (arg1) == PLUS_EXPR
9488 || TREE_CODE (arg1) == MINUS_EXPR)
9489 && TREE_CODE (arg0) == MULT_EXPR))
9491 tree parg0, parg1, parg, marg;
9492 enum tree_code pcode;
9494 if (TREE_CODE (arg1) == MULT_EXPR)
9495 parg = arg0, marg = arg1;
9497 parg = arg1, marg = arg0;
9498 pcode = TREE_CODE (parg);
9499 parg0 = TREE_OPERAND (parg, 0);
9500 parg1 = TREE_OPERAND (parg, 1);
9504 if (TREE_CODE (parg0) == MULT_EXPR
9505 && TREE_CODE (parg1) != MULT_EXPR)
9506 return fold_build2 (pcode, type,
9507 fold_build2 (PLUS_EXPR, type,
9508 fold_convert (type, parg0),
9509 fold_convert (type, marg)),
9510 fold_convert (type, parg1));
9511 if (TREE_CODE (parg0) != MULT_EXPR
9512 && TREE_CODE (parg1) == MULT_EXPR)
9513 return fold_build2 (PLUS_EXPR, type,
9514 fold_convert (type, parg0),
9515 fold_build2 (pcode, type,
9516 fold_convert (type, marg),
9523 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9524 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
9525 return non_lvalue (fold_convert (type, arg0));
9527 /* Likewise if the operands are reversed. */
9528 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9529 return non_lvalue (fold_convert (type, arg1));
9531 /* Convert X + -C into X - C. */
9532 if (TREE_CODE (arg1) == REAL_CST
9533 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
9535 tem = fold_negate_const (arg1, type);
9536 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
9537 return fold_build2 (MINUS_EXPR, type,
9538 fold_convert (type, arg0),
9539 fold_convert (type, tem));
9542 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9543 to __complex__ ( x, y ). This is not the same for SNaNs or
9544 if signed zeros are involved. */
9545 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9546 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9547 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9549 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9550 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9551 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9552 bool arg0rz = false, arg0iz = false;
9553 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9554 || (arg0i && (arg0iz = real_zerop (arg0i))))
9556 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9557 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9558 if (arg0rz && arg1i && real_zerop (arg1i))
9560 tree rp = arg1r ? arg1r
9561 : build1 (REALPART_EXPR, rtype, arg1);
9562 tree ip = arg0i ? arg0i
9563 : build1 (IMAGPART_EXPR, rtype, arg0);
9564 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9566 else if (arg0iz && arg1r && real_zerop (arg1r))
9568 tree rp = arg0r ? arg0r
9569 : build1 (REALPART_EXPR, rtype, arg0);
9570 tree ip = arg1i ? arg1i
9571 : build1 (IMAGPART_EXPR, rtype, arg1);
9572 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9577 if (flag_unsafe_math_optimizations
9578 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9579 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9580 && (tem = distribute_real_division (code, type, arg0, arg1)))
9583 /* Convert x+x into x*2.0. */
9584 if (operand_equal_p (arg0, arg1, 0)
9585 && SCALAR_FLOAT_TYPE_P (type))
9586 return fold_build2 (MULT_EXPR, type, arg0,
9587 build_real (type, dconst2));
9589 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
9590 We associate floats only if the user has specified
9591 -fassociative-math. */
9592 if (flag_associative_math
9593 && TREE_CODE (arg1) == PLUS_EXPR
9594 && TREE_CODE (arg0) != MULT_EXPR)
9596 tree tree10 = TREE_OPERAND (arg1, 0);
9597 tree tree11 = TREE_OPERAND (arg1, 1);
9598 if (TREE_CODE (tree11) == MULT_EXPR
9599 && TREE_CODE (tree10) == MULT_EXPR)
9602 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
9603 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
9606 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
9607 We associate floats only if the user has specified
9608 -fassociative-math. */
9609 if (flag_associative_math
9610 && TREE_CODE (arg0) == PLUS_EXPR
9611 && TREE_CODE (arg1) != MULT_EXPR)
9613 tree tree00 = TREE_OPERAND (arg0, 0);
9614 tree tree01 = TREE_OPERAND (arg0, 1);
9615 if (TREE_CODE (tree01) == MULT_EXPR
9616 && TREE_CODE (tree00) == MULT_EXPR)
9619 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
9620 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
9626 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9627 is a rotate of A by C1 bits. */
9628 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9629 is a rotate of A by B bits. */
9631 enum tree_code code0, code1;
9633 code0 = TREE_CODE (arg0);
9634 code1 = TREE_CODE (arg1);
9635 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
9636 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
9637 && operand_equal_p (TREE_OPERAND (arg0, 0),
9638 TREE_OPERAND (arg1, 0), 0)
9639 && (rtype = TREE_TYPE (TREE_OPERAND (arg0, 0)),
9640 TYPE_UNSIGNED (rtype))
9641 /* Only create rotates in complete modes. Other cases are not
9642 expanded properly. */
9643 && TYPE_PRECISION (rtype) == GET_MODE_PRECISION (TYPE_MODE (rtype)))
9645 tree tree01, tree11;
9646 enum tree_code code01, code11;
9648 tree01 = TREE_OPERAND (arg0, 1);
9649 tree11 = TREE_OPERAND (arg1, 1);
9650 STRIP_NOPS (tree01);
9651 STRIP_NOPS (tree11);
9652 code01 = TREE_CODE (tree01);
9653 code11 = TREE_CODE (tree11);
9654 if (code01 == INTEGER_CST
9655 && code11 == INTEGER_CST
9656 && TREE_INT_CST_HIGH (tree01) == 0
9657 && TREE_INT_CST_HIGH (tree11) == 0
9658 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
9659 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
9660 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
9661 code0 == LSHIFT_EXPR ? tree01 : tree11);
9662 else if (code11 == MINUS_EXPR)
9664 tree tree110, tree111;
9665 tree110 = TREE_OPERAND (tree11, 0);
9666 tree111 = TREE_OPERAND (tree11, 1);
9667 STRIP_NOPS (tree110);
9668 STRIP_NOPS (tree111);
9669 if (TREE_CODE (tree110) == INTEGER_CST
9670 && 0 == compare_tree_int (tree110,
9672 (TREE_TYPE (TREE_OPERAND
9674 && operand_equal_p (tree01, tree111, 0))
9675 return build2 ((code0 == LSHIFT_EXPR
9678 type, TREE_OPERAND (arg0, 0), tree01);
9680 else if (code01 == MINUS_EXPR)
9682 tree tree010, tree011;
9683 tree010 = TREE_OPERAND (tree01, 0);
9684 tree011 = TREE_OPERAND (tree01, 1);
9685 STRIP_NOPS (tree010);
9686 STRIP_NOPS (tree011);
9687 if (TREE_CODE (tree010) == INTEGER_CST
9688 && 0 == compare_tree_int (tree010,
9690 (TREE_TYPE (TREE_OPERAND
9692 && operand_equal_p (tree11, tree011, 0))
9693 return build2 ((code0 != LSHIFT_EXPR
9696 type, TREE_OPERAND (arg0, 0), tree11);
9702 /* In most languages, can't associate operations on floats through
9703 parentheses. Rather than remember where the parentheses were, we
9704 don't associate floats at all, unless the user has specified
9706 And, we need to make sure type is not saturating. */
9708 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
9709 && !TYPE_SATURATING (type))
9711 tree var0, con0, lit0, minus_lit0;
9712 tree var1, con1, lit1, minus_lit1;
9715 /* Split both trees into variables, constants, and literals. Then
9716 associate each group together, the constants with literals,
9717 then the result with variables. This increases the chances of
9718 literals being recombined later and of generating relocatable
9719 expressions for the sum of a constant and literal. */
9720 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
9721 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
9722 code == MINUS_EXPR);
9724 /* With undefined overflow we can only associate constants
9725 with one variable. */
9726 if (((POINTER_TYPE_P (type) && POINTER_TYPE_OVERFLOW_UNDEFINED)
9727 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
9733 if (TREE_CODE (tmp0) == NEGATE_EXPR)
9734 tmp0 = TREE_OPERAND (tmp0, 0);
9735 if (TREE_CODE (tmp1) == NEGATE_EXPR)
9736 tmp1 = TREE_OPERAND (tmp1, 0);
9737 /* The only case we can still associate with two variables
9738 is if they are the same, modulo negation. */
9739 if (!operand_equal_p (tmp0, tmp1, 0))
9743 /* Only do something if we found more than two objects. Otherwise,
9744 nothing has changed and we risk infinite recursion. */
9746 && (2 < ((var0 != 0) + (var1 != 0)
9747 + (con0 != 0) + (con1 != 0)
9748 + (lit0 != 0) + (lit1 != 0)
9749 + (minus_lit0 != 0) + (minus_lit1 != 0))))
9751 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9752 if (code == MINUS_EXPR)
9755 var0 = associate_trees (var0, var1, code, type);
9756 con0 = associate_trees (con0, con1, code, type);
9757 lit0 = associate_trees (lit0, lit1, code, type);
9758 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
9760 /* Preserve the MINUS_EXPR if the negative part of the literal is
9761 greater than the positive part. Otherwise, the multiplicative
9762 folding code (i.e extract_muldiv) may be fooled in case
9763 unsigned constants are subtracted, like in the following
9764 example: ((X*2 + 4) - 8U)/2. */
9765 if (minus_lit0 && lit0)
9767 if (TREE_CODE (lit0) == INTEGER_CST
9768 && TREE_CODE (minus_lit0) == INTEGER_CST
9769 && tree_int_cst_lt (lit0, minus_lit0))
9771 minus_lit0 = associate_trees (minus_lit0, lit0,
9777 lit0 = associate_trees (lit0, minus_lit0,
9785 return fold_convert (type,
9786 associate_trees (var0, minus_lit0,
9790 con0 = associate_trees (con0, minus_lit0,
9792 return fold_convert (type,
9793 associate_trees (var0, con0,
9798 con0 = associate_trees (con0, lit0, code, type);
9799 return fold_convert (type, associate_trees (var0, con0,
9807 /* Pointer simplifications for subtraction, simple reassociations. */
9808 if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
9810 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
9811 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
9812 && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
9814 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
9815 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
9816 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
9817 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
9818 return fold_build2 (PLUS_EXPR, type,
9819 fold_build2 (MINUS_EXPR, type, arg00, arg10),
9820 fold_build2 (MINUS_EXPR, type, arg01, arg11));
9822 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
9823 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9825 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
9826 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
9827 tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
9829 return fold_build2 (PLUS_EXPR, type, tmp, arg01);
9832 /* A - (-B) -> A + B */
9833 if (TREE_CODE (arg1) == NEGATE_EXPR)
9834 return fold_build2 (PLUS_EXPR, type, op0,
9835 fold_convert (type, TREE_OPERAND (arg1, 0)));
9836 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
9837 if (TREE_CODE (arg0) == NEGATE_EXPR
9838 && (FLOAT_TYPE_P (type)
9839 || INTEGRAL_TYPE_P (type))
9840 && negate_expr_p (arg1)
9841 && reorder_operands_p (arg0, arg1))
9842 return fold_build2 (MINUS_EXPR, type,
9843 fold_convert (type, negate_expr (arg1)),
9844 fold_convert (type, TREE_OPERAND (arg0, 0)));
9845 /* Convert -A - 1 to ~A. */
9846 if (INTEGRAL_TYPE_P (type)
9847 && TREE_CODE (arg0) == NEGATE_EXPR
9848 && integer_onep (arg1)
9849 && !TYPE_OVERFLOW_TRAPS (type))
9850 return fold_build1 (BIT_NOT_EXPR, type,
9851 fold_convert (type, TREE_OPERAND (arg0, 0)));
9853 /* Convert -1 - A to ~A. */
9854 if (INTEGRAL_TYPE_P (type)
9855 && integer_all_onesp (arg0))
9856 return fold_build1 (BIT_NOT_EXPR, type, op1);
9859 /* X - (X / CST) * CST is X % CST. */
9860 if (INTEGRAL_TYPE_P (type)
9861 && TREE_CODE (arg1) == MULT_EXPR
9862 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9863 && operand_equal_p (arg0,
9864 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
9865 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
9866 TREE_OPERAND (arg1, 1), 0))
9867 return fold_convert (type,
9868 fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
9869 arg0, TREE_OPERAND (arg1, 1)));
9871 if (! FLOAT_TYPE_P (type))
9873 if (integer_zerop (arg0))
9874 return negate_expr (fold_convert (type, arg1));
9875 if (integer_zerop (arg1))
9876 return non_lvalue (fold_convert (type, arg0));
9878 /* Fold A - (A & B) into ~B & A. */
9879 if (!TREE_SIDE_EFFECTS (arg0)
9880 && TREE_CODE (arg1) == BIT_AND_EXPR)
9882 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
9884 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
9885 return fold_build2 (BIT_AND_EXPR, type,
9886 fold_build1 (BIT_NOT_EXPR, type, arg10),
9887 fold_convert (type, arg0));
9889 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9891 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
9892 return fold_build2 (BIT_AND_EXPR, type,
9893 fold_build1 (BIT_NOT_EXPR, type, arg11),
9894 fold_convert (type, arg0));
9898 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
9899 any power of 2 minus 1. */
9900 if (TREE_CODE (arg0) == BIT_AND_EXPR
9901 && TREE_CODE (arg1) == BIT_AND_EXPR
9902 && operand_equal_p (TREE_OPERAND (arg0, 0),
9903 TREE_OPERAND (arg1, 0), 0))
9905 tree mask0 = TREE_OPERAND (arg0, 1);
9906 tree mask1 = TREE_OPERAND (arg1, 1);
9907 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
9909 if (operand_equal_p (tem, mask1, 0))
9911 tem = fold_build2 (BIT_XOR_EXPR, type,
9912 TREE_OPERAND (arg0, 0), mask1);
9913 return fold_build2 (MINUS_EXPR, type, tem, mask1);
9918 /* See if ARG1 is zero and X - ARG1 reduces to X. */
9919 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
9920 return non_lvalue (fold_convert (type, arg0));
9922 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
9923 ARG0 is zero and X + ARG0 reduces to X, since that would mean
9924 (-ARG1 + ARG0) reduces to -ARG1. */
9925 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9926 return negate_expr (fold_convert (type, arg1));
9928 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
9929 __complex__ ( x, -y ). This is not the same for SNaNs or if
9930 signed zeros are involved. */
9931 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9932 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9933 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9935 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9936 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9937 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9938 bool arg0rz = false, arg0iz = false;
9939 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9940 || (arg0i && (arg0iz = real_zerop (arg0i))))
9942 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9943 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9944 if (arg0rz && arg1i && real_zerop (arg1i))
9946 tree rp = fold_build1 (NEGATE_EXPR, rtype,
9948 : build1 (REALPART_EXPR, rtype, arg1));
9949 tree ip = arg0i ? arg0i
9950 : build1 (IMAGPART_EXPR, rtype, arg0);
9951 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9953 else if (arg0iz && arg1r && real_zerop (arg1r))
9955 tree rp = arg0r ? arg0r
9956 : build1 (REALPART_EXPR, rtype, arg0);
9957 tree ip = fold_build1 (NEGATE_EXPR, rtype,
9959 : build1 (IMAGPART_EXPR, rtype, arg1));
9960 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9965 /* Fold &x - &x. This can happen from &x.foo - &x.
9966 This is unsafe for certain floats even in non-IEEE formats.
9967 In IEEE, it is unsafe because it does wrong for NaNs.
9968 Also note that operand_equal_p is always false if an operand
9971 if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
9972 && operand_equal_p (arg0, arg1, 0))
9973 return fold_convert (type, integer_zero_node);
9975 /* A - B -> A + (-B) if B is easily negatable. */
9976 if (negate_expr_p (arg1)
9977 && ((FLOAT_TYPE_P (type)
9978 /* Avoid this transformation if B is a positive REAL_CST. */
9979 && (TREE_CODE (arg1) != REAL_CST
9980 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
9981 || INTEGRAL_TYPE_P (type)))
9982 return fold_build2 (PLUS_EXPR, type,
9983 fold_convert (type, arg0),
9984 fold_convert (type, negate_expr (arg1)));
9986 /* Try folding difference of addresses. */
9990 if ((TREE_CODE (arg0) == ADDR_EXPR
9991 || TREE_CODE (arg1) == ADDR_EXPR)
9992 && ptr_difference_const (arg0, arg1, &diff))
9993 return build_int_cst_type (type, diff);
9996 /* Fold &a[i] - &a[j] to i-j. */
9997 if (TREE_CODE (arg0) == ADDR_EXPR
9998 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
9999 && TREE_CODE (arg1) == ADDR_EXPR
10000 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
10002 tree aref0 = TREE_OPERAND (arg0, 0);
10003 tree aref1 = TREE_OPERAND (arg1, 0);
10004 if (operand_equal_p (TREE_OPERAND (aref0, 0),
10005 TREE_OPERAND (aref1, 0), 0))
10007 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
10008 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
10009 tree esz = array_ref_element_size (aref0);
10010 tree diff = build2 (MINUS_EXPR, type, op0, op1);
10011 return fold_build2 (MULT_EXPR, type, diff,
10012 fold_convert (type, esz));
10017 if (flag_unsafe_math_optimizations
10018 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10019 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10020 && (tem = distribute_real_division (code, type, arg0, arg1)))
10023 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
10024 same or one. Make sure type is not saturating.
10025 fold_plusminus_mult_expr will re-associate. */
10026 if ((TREE_CODE (arg0) == MULT_EXPR
10027 || TREE_CODE (arg1) == MULT_EXPR)
10028 && !TYPE_SATURATING (type)
10029 && (!FLOAT_TYPE_P (type) || flag_associative_math))
10031 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
10039 /* (-A) * (-B) -> A * B */
10040 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10041 return fold_build2 (MULT_EXPR, type,
10042 fold_convert (type, TREE_OPERAND (arg0, 0)),
10043 fold_convert (type, negate_expr (arg1)));
10044 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10045 return fold_build2 (MULT_EXPR, type,
10046 fold_convert (type, negate_expr (arg0)),
10047 fold_convert (type, TREE_OPERAND (arg1, 0)));
10049 if (! FLOAT_TYPE_P (type))
10051 if (integer_zerop (arg1))
10052 return omit_one_operand (type, arg1, arg0);
10053 if (integer_onep (arg1))
10054 return non_lvalue (fold_convert (type, arg0));
10055 /* Transform x * -1 into -x. Make sure to do the negation
10056 on the original operand with conversions not stripped
10057 because we can only strip non-sign-changing conversions. */
10058 if (integer_all_onesp (arg1))
10059 return fold_convert (type, negate_expr (op0));
10060 /* Transform x * -C into -x * C if x is easily negatable. */
10061 if (TREE_CODE (arg1) == INTEGER_CST
10062 && tree_int_cst_sgn (arg1) == -1
10063 && negate_expr_p (arg0)
10064 && (tem = negate_expr (arg1)) != arg1
10065 && !TREE_OVERFLOW (tem))
10066 return fold_build2 (MULT_EXPR, type,
10067 fold_convert (type, negate_expr (arg0)), tem);
10069 /* (a * (1 << b)) is (a << b) */
10070 if (TREE_CODE (arg1) == LSHIFT_EXPR
10071 && integer_onep (TREE_OPERAND (arg1, 0)))
10072 return fold_build2 (LSHIFT_EXPR, type, op0,
10073 TREE_OPERAND (arg1, 1));
10074 if (TREE_CODE (arg0) == LSHIFT_EXPR
10075 && integer_onep (TREE_OPERAND (arg0, 0)))
10076 return fold_build2 (LSHIFT_EXPR, type, op1,
10077 TREE_OPERAND (arg0, 1));
10079 strict_overflow_p = false;
10080 if (TREE_CODE (arg1) == INTEGER_CST
10081 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10082 &strict_overflow_p)))
10084 if (strict_overflow_p)
10085 fold_overflow_warning (("assuming signed overflow does not "
10086 "occur when simplifying "
10088 WARN_STRICT_OVERFLOW_MISC);
10089 return fold_convert (type, tem);
10092 /* Optimize z * conj(z) for integer complex numbers. */
10093 if (TREE_CODE (arg0) == CONJ_EXPR
10094 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10095 return fold_mult_zconjz (type, arg1);
10096 if (TREE_CODE (arg1) == CONJ_EXPR
10097 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10098 return fold_mult_zconjz (type, arg0);
10102 /* Maybe fold x * 0 to 0. The expressions aren't the same
10103 when x is NaN, since x * 0 is also NaN. Nor are they the
10104 same in modes with signed zeros, since multiplying a
10105 negative value by 0 gives -0, not +0. */
10106 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10107 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10108 && real_zerop (arg1))
10109 return omit_one_operand (type, arg1, arg0);
10110 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
10111 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10112 && real_onep (arg1))
10113 return non_lvalue (fold_convert (type, arg0));
10115 /* Transform x * -1.0 into -x. */
10116 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10117 && real_minus_onep (arg1))
10118 return fold_convert (type, negate_expr (arg0));
10120 /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
10121 the result for floating point types due to rounding so it is applied
10122 only if -fassociative-math was specify. */
10123 if (flag_associative_math
10124 && TREE_CODE (arg0) == RDIV_EXPR
10125 && TREE_CODE (arg1) == REAL_CST
10126 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
10128 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
10131 return fold_build2 (RDIV_EXPR, type, tem,
10132 TREE_OPERAND (arg0, 1));
10135 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10136 if (operand_equal_p (arg0, arg1, 0))
10138 tree tem = fold_strip_sign_ops (arg0);
10139 if (tem != NULL_TREE)
10141 tem = fold_convert (type, tem);
10142 return fold_build2 (MULT_EXPR, type, tem, tem);
10146 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10147 This is not the same for NaNs or if signed zeros are
10149 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10150 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10151 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10152 && TREE_CODE (arg1) == COMPLEX_CST
10153 && real_zerop (TREE_REALPART (arg1)))
10155 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10156 if (real_onep (TREE_IMAGPART (arg1)))
10157 return fold_build2 (COMPLEX_EXPR, type,
10158 negate_expr (fold_build1 (IMAGPART_EXPR,
10160 fold_build1 (REALPART_EXPR, rtype, arg0));
10161 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10162 return fold_build2 (COMPLEX_EXPR, type,
10163 fold_build1 (IMAGPART_EXPR, rtype, arg0),
10164 negate_expr (fold_build1 (REALPART_EXPR,
10168 /* Optimize z * conj(z) for floating point complex numbers.
10169 Guarded by flag_unsafe_math_optimizations as non-finite
10170 imaginary components don't produce scalar results. */
10171 if (flag_unsafe_math_optimizations
10172 && TREE_CODE (arg0) == CONJ_EXPR
10173 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10174 return fold_mult_zconjz (type, arg1);
10175 if (flag_unsafe_math_optimizations
10176 && TREE_CODE (arg1) == CONJ_EXPR
10177 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10178 return fold_mult_zconjz (type, arg0);
10180 if (flag_unsafe_math_optimizations)
10182 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10183 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10185 /* Optimizations of root(...)*root(...). */
10186 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
10189 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10190 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10192 /* Optimize sqrt(x)*sqrt(x) as x. */
10193 if (BUILTIN_SQRT_P (fcode0)
10194 && operand_equal_p (arg00, arg10, 0)
10195 && ! HONOR_SNANS (TYPE_MODE (type)))
10198 /* Optimize root(x)*root(y) as root(x*y). */
10199 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10200 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10201 return build_call_expr (rootfn, 1, arg);
10204 /* Optimize expN(x)*expN(y) as expN(x+y). */
10205 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
10207 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10208 tree arg = fold_build2 (PLUS_EXPR, type,
10209 CALL_EXPR_ARG (arg0, 0),
10210 CALL_EXPR_ARG (arg1, 0));
10211 return build_call_expr (expfn, 1, arg);
10214 /* Optimizations of pow(...)*pow(...). */
10215 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
10216 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
10217 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
10219 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10220 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10221 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10222 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10224 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10225 if (operand_equal_p (arg01, arg11, 0))
10227 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10228 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10229 return build_call_expr (powfn, 2, arg, arg01);
10232 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10233 if (operand_equal_p (arg00, arg10, 0))
10235 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10236 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
10237 return build_call_expr (powfn, 2, arg00, arg);
10241 /* Optimize tan(x)*cos(x) as sin(x). */
10242 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
10243 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
10244 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
10245 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
10246 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
10247 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
10248 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10249 CALL_EXPR_ARG (arg1, 0), 0))
10251 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
10253 if (sinfn != NULL_TREE)
10254 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
10257 /* Optimize x*pow(x,c) as pow(x,c+1). */
10258 if (fcode1 == BUILT_IN_POW
10259 || fcode1 == BUILT_IN_POWF
10260 || fcode1 == BUILT_IN_POWL)
10262 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10263 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10264 if (TREE_CODE (arg11) == REAL_CST
10265 && !TREE_OVERFLOW (arg11)
10266 && operand_equal_p (arg0, arg10, 0))
10268 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10272 c = TREE_REAL_CST (arg11);
10273 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10274 arg = build_real (type, c);
10275 return build_call_expr (powfn, 2, arg0, arg);
10279 /* Optimize pow(x,c)*x as pow(x,c+1). */
10280 if (fcode0 == BUILT_IN_POW
10281 || fcode0 == BUILT_IN_POWF
10282 || fcode0 == BUILT_IN_POWL)
10284 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10285 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10286 if (TREE_CODE (arg01) == REAL_CST
10287 && !TREE_OVERFLOW (arg01)
10288 && operand_equal_p (arg1, arg00, 0))
10290 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10294 c = TREE_REAL_CST (arg01);
10295 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10296 arg = build_real (type, c);
10297 return build_call_expr (powfn, 2, arg1, arg);
10301 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10302 if (! optimize_size
10303 && operand_equal_p (arg0, arg1, 0))
10305 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
10309 tree arg = build_real (type, dconst2);
10310 return build_call_expr (powfn, 2, arg0, arg);
10319 if (integer_all_onesp (arg1))
10320 return omit_one_operand (type, arg1, arg0);
10321 if (integer_zerop (arg1))
10322 return non_lvalue (fold_convert (type, arg0));
10323 if (operand_equal_p (arg0, arg1, 0))
10324 return non_lvalue (fold_convert (type, arg0));
10326 /* ~X | X is -1. */
10327 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10328 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10330 t1 = fold_convert (type, integer_zero_node);
10331 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10332 return omit_one_operand (type, t1, arg1);
10335 /* X | ~X is -1. */
10336 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10337 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10339 t1 = fold_convert (type, integer_zero_node);
10340 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10341 return omit_one_operand (type, t1, arg0);
10344 /* Canonicalize (X & C1) | C2. */
10345 if (TREE_CODE (arg0) == BIT_AND_EXPR
10346 && TREE_CODE (arg1) == INTEGER_CST
10347 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10349 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, hi3, lo3, mlo, mhi;
10350 int width = TYPE_PRECISION (type), w;
10351 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10352 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10353 hi2 = TREE_INT_CST_HIGH (arg1);
10354 lo2 = TREE_INT_CST_LOW (arg1);
10356 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10357 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10358 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10360 if (width > HOST_BITS_PER_WIDE_INT)
10362 mhi = (unsigned HOST_WIDE_INT) -1
10363 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10369 mlo = (unsigned HOST_WIDE_INT) -1
10370 >> (HOST_BITS_PER_WIDE_INT - width);
10373 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10374 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10375 return fold_build2 (BIT_IOR_EXPR, type,
10376 TREE_OPERAND (arg0, 0), arg1);
10378 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
10379 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
10380 mode which allows further optimizations. */
10387 for (w = BITS_PER_UNIT;
10388 w <= width && w <= HOST_BITS_PER_WIDE_INT;
10391 unsigned HOST_WIDE_INT mask
10392 = (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
10393 if (((lo1 | lo2) & mask) == mask
10394 && (lo1 & ~mask) == 0 && hi1 == 0)
10401 if (hi3 != hi1 || lo3 != lo1)
10402 return fold_build2 (BIT_IOR_EXPR, type,
10403 fold_build2 (BIT_AND_EXPR, type,
10404 TREE_OPERAND (arg0, 0),
10405 build_int_cst_wide (type,
10410 /* (X & Y) | Y is (X, Y). */
10411 if (TREE_CODE (arg0) == BIT_AND_EXPR
10412 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10413 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10414 /* (X & Y) | X is (Y, X). */
10415 if (TREE_CODE (arg0) == BIT_AND_EXPR
10416 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10417 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10418 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10419 /* X | (X & Y) is (Y, X). */
10420 if (TREE_CODE (arg1) == BIT_AND_EXPR
10421 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10422 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10423 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10424 /* X | (Y & X) is (Y, X). */
10425 if (TREE_CODE (arg1) == BIT_AND_EXPR
10426 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10427 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10428 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10430 t1 = distribute_bit_expr (code, type, arg0, arg1);
10431 if (t1 != NULL_TREE)
10434 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10436 This results in more efficient code for machines without a NAND
10437 instruction. Combine will canonicalize to the first form
10438 which will allow use of NAND instructions provided by the
10439 backend if they exist. */
10440 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10441 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10443 return fold_build1 (BIT_NOT_EXPR, type,
10444 build2 (BIT_AND_EXPR, type,
10445 fold_convert (type,
10446 TREE_OPERAND (arg0, 0)),
10447 fold_convert (type,
10448 TREE_OPERAND (arg1, 0))));
10451 /* See if this can be simplified into a rotate first. If that
10452 is unsuccessful continue in the association code. */
10456 if (integer_zerop (arg1))
10457 return non_lvalue (fold_convert (type, arg0));
10458 if (integer_all_onesp (arg1))
10459 return fold_build1 (BIT_NOT_EXPR, type, op0);
10460 if (operand_equal_p (arg0, arg1, 0))
10461 return omit_one_operand (type, integer_zero_node, arg0);
10463 /* ~X ^ X is -1. */
10464 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10465 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10467 t1 = fold_convert (type, integer_zero_node);
10468 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10469 return omit_one_operand (type, t1, arg1);
10472 /* X ^ ~X is -1. */
10473 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10474 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10476 t1 = fold_convert (type, integer_zero_node);
10477 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10478 return omit_one_operand (type, t1, arg0);
10481 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10482 with a constant, and the two constants have no bits in common,
10483 we should treat this as a BIT_IOR_EXPR since this may produce more
10484 simplifications. */
10485 if (TREE_CODE (arg0) == BIT_AND_EXPR
10486 && TREE_CODE (arg1) == BIT_AND_EXPR
10487 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10488 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10489 && integer_zerop (const_binop (BIT_AND_EXPR,
10490 TREE_OPERAND (arg0, 1),
10491 TREE_OPERAND (arg1, 1), 0)))
10493 code = BIT_IOR_EXPR;
10497 /* (X | Y) ^ X -> Y & ~ X*/
10498 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10499 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10501 tree t2 = TREE_OPERAND (arg0, 1);
10502 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10504 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10505 fold_convert (type, t1));
10509 /* (Y | X) ^ X -> Y & ~ X*/
10510 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10511 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10513 tree t2 = TREE_OPERAND (arg0, 0);
10514 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10516 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10517 fold_convert (type, t1));
10521 /* X ^ (X | Y) -> Y & ~ X*/
10522 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10523 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
10525 tree t2 = TREE_OPERAND (arg1, 1);
10526 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10528 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10529 fold_convert (type, t1));
10533 /* X ^ (Y | X) -> Y & ~ X*/
10534 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10535 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
10537 tree t2 = TREE_OPERAND (arg1, 0);
10538 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10540 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10541 fold_convert (type, t1));
10545 /* Convert ~X ^ ~Y to X ^ Y. */
10546 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10547 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10548 return fold_build2 (code, type,
10549 fold_convert (type, TREE_OPERAND (arg0, 0)),
10550 fold_convert (type, TREE_OPERAND (arg1, 0)));
10552 /* Convert ~X ^ C to X ^ ~C. */
10553 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10554 && TREE_CODE (arg1) == INTEGER_CST)
10555 return fold_build2 (code, type,
10556 fold_convert (type, TREE_OPERAND (arg0, 0)),
10557 fold_build1 (BIT_NOT_EXPR, type, arg1));
10559 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10560 if (TREE_CODE (arg0) == BIT_AND_EXPR
10561 && integer_onep (TREE_OPERAND (arg0, 1))
10562 && integer_onep (arg1))
10563 return fold_build2 (EQ_EXPR, type, arg0,
10564 build_int_cst (TREE_TYPE (arg0), 0));
10566 /* Fold (X & Y) ^ Y as ~X & Y. */
10567 if (TREE_CODE (arg0) == BIT_AND_EXPR
10568 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10570 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10571 return fold_build2 (BIT_AND_EXPR, type,
10572 fold_build1 (BIT_NOT_EXPR, type, tem),
10573 fold_convert (type, arg1));
10575 /* Fold (X & Y) ^ X as ~Y & X. */
10576 if (TREE_CODE (arg0) == BIT_AND_EXPR
10577 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10578 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10580 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10581 return fold_build2 (BIT_AND_EXPR, type,
10582 fold_build1 (BIT_NOT_EXPR, type, tem),
10583 fold_convert (type, arg1));
10585 /* Fold X ^ (X & Y) as X & ~Y. */
10586 if (TREE_CODE (arg1) == BIT_AND_EXPR
10587 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10589 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10590 return fold_build2 (BIT_AND_EXPR, type,
10591 fold_convert (type, arg0),
10592 fold_build1 (BIT_NOT_EXPR, type, tem));
10594 /* Fold X ^ (Y & X) as ~Y & X. */
10595 if (TREE_CODE (arg1) == BIT_AND_EXPR
10596 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10597 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10599 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10600 return fold_build2 (BIT_AND_EXPR, type,
10601 fold_build1 (BIT_NOT_EXPR, type, tem),
10602 fold_convert (type, arg0));
10605 /* See if this can be simplified into a rotate first. If that
10606 is unsuccessful continue in the association code. */
10610 if (integer_all_onesp (arg1))
10611 return non_lvalue (fold_convert (type, arg0));
10612 if (integer_zerop (arg1))
10613 return omit_one_operand (type, arg1, arg0);
10614 if (operand_equal_p (arg0, arg1, 0))
10615 return non_lvalue (fold_convert (type, arg0));
10617 /* ~X & X is always zero. */
10618 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10619 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10620 return omit_one_operand (type, integer_zero_node, arg1);
10622 /* X & ~X is always zero. */
10623 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10624 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10625 return omit_one_operand (type, integer_zero_node, arg0);
10627 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
10628 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10629 && TREE_CODE (arg1) == INTEGER_CST
10630 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10632 tree tmp1 = fold_convert (TREE_TYPE (arg0), arg1);
10633 tree tmp2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10634 TREE_OPERAND (arg0, 0), tmp1);
10635 tree tmp3 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10636 TREE_OPERAND (arg0, 1), tmp1);
10637 return fold_convert (type,
10638 fold_build2 (BIT_IOR_EXPR, TREE_TYPE (arg0),
10642 /* (X | Y) & Y is (X, Y). */
10643 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10644 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10645 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10646 /* (X | Y) & X is (Y, X). */
10647 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10648 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10649 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10650 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10651 /* X & (X | Y) is (Y, X). */
10652 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10653 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10654 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10655 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10656 /* X & (Y | X) is (Y, X). */
10657 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10658 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10659 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10660 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10662 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10663 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10664 && integer_onep (TREE_OPERAND (arg0, 1))
10665 && integer_onep (arg1))
10667 tem = TREE_OPERAND (arg0, 0);
10668 return fold_build2 (EQ_EXPR, type,
10669 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10670 build_int_cst (TREE_TYPE (tem), 1)),
10671 build_int_cst (TREE_TYPE (tem), 0));
10673 /* Fold ~X & 1 as (X & 1) == 0. */
10674 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10675 && integer_onep (arg1))
10677 tem = TREE_OPERAND (arg0, 0);
10678 return fold_build2 (EQ_EXPR, type,
10679 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10680 build_int_cst (TREE_TYPE (tem), 1)),
10681 build_int_cst (TREE_TYPE (tem), 0));
10684 /* Fold (X ^ Y) & Y as ~X & Y. */
10685 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10686 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10688 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10689 return fold_build2 (BIT_AND_EXPR, type,
10690 fold_build1 (BIT_NOT_EXPR, type, tem),
10691 fold_convert (type, arg1));
10693 /* Fold (X ^ Y) & X as ~Y & X. */
10694 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10695 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10696 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10698 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10699 return fold_build2 (BIT_AND_EXPR, type,
10700 fold_build1 (BIT_NOT_EXPR, type, tem),
10701 fold_convert (type, arg1));
10703 /* Fold X & (X ^ Y) as X & ~Y. */
10704 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10705 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10707 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10708 return fold_build2 (BIT_AND_EXPR, type,
10709 fold_convert (type, arg0),
10710 fold_build1 (BIT_NOT_EXPR, type, tem));
10712 /* Fold X & (Y ^ X) as ~Y & X. */
10713 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10714 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10715 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10717 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10718 return fold_build2 (BIT_AND_EXPR, type,
10719 fold_build1 (BIT_NOT_EXPR, type, tem),
10720 fold_convert (type, arg0));
10723 t1 = distribute_bit_expr (code, type, arg0, arg1);
10724 if (t1 != NULL_TREE)
10726 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10727 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
10728 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
10731 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
10733 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
10734 && (~TREE_INT_CST_LOW (arg1)
10735 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
10736 return fold_convert (type, TREE_OPERAND (arg0, 0));
10739 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
10741 This results in more efficient code for machines without a NOR
10742 instruction. Combine will canonicalize to the first form
10743 which will allow use of NOR instructions provided by the
10744 backend if they exist. */
10745 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10746 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10748 return fold_build1 (BIT_NOT_EXPR, type,
10749 build2 (BIT_IOR_EXPR, type,
10750 fold_convert (type,
10751 TREE_OPERAND (arg0, 0)),
10752 fold_convert (type,
10753 TREE_OPERAND (arg1, 0))));
10756 /* If arg0 is derived from the address of an object or function, we may
10757 be able to fold this expression using the object or function's
10759 if (POINTER_TYPE_P (TREE_TYPE (arg0)) && host_integerp (arg1, 1))
10761 unsigned HOST_WIDE_INT modulus, residue;
10762 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (arg1);
10764 modulus = get_pointer_modulus_and_residue (arg0, &residue);
10766 /* This works because modulus is a power of 2. If this weren't the
10767 case, we'd have to replace it by its greatest power-of-2
10768 divisor: modulus & -modulus. */
10770 return build_int_cst (type, residue & low);
10773 /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
10774 (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
10775 if the new mask might be further optimized. */
10776 if ((TREE_CODE (arg0) == LSHIFT_EXPR
10777 || TREE_CODE (arg0) == RSHIFT_EXPR)
10778 && host_integerp (TREE_OPERAND (arg0, 1), 1)
10779 && host_integerp (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)))
10780 && tree_low_cst (TREE_OPERAND (arg0, 1), 1)
10781 < TYPE_PRECISION (TREE_TYPE (arg0))
10782 && TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
10783 && tree_low_cst (TREE_OPERAND (arg0, 1), 1) > 0)
10785 unsigned int shiftc = tree_low_cst (TREE_OPERAND (arg0, 1), 1);
10786 unsigned HOST_WIDE_INT mask
10787 = tree_low_cst (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)));
10788 unsigned HOST_WIDE_INT newmask, zerobits = 0;
10789 tree shift_type = TREE_TYPE (arg0);
10791 if (TREE_CODE (arg0) == LSHIFT_EXPR)
10792 zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
10793 else if (TREE_CODE (arg0) == RSHIFT_EXPR
10794 && TYPE_PRECISION (TREE_TYPE (arg0))
10795 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg0))))
10797 unsigned int prec = TYPE_PRECISION (TREE_TYPE (arg0));
10798 tree arg00 = TREE_OPERAND (arg0, 0);
10799 /* See if more bits can be proven as zero because of
10801 if (TREE_CODE (arg00) == NOP_EXPR
10802 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
10804 tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
10805 if (TYPE_PRECISION (inner_type)
10806 == GET_MODE_BITSIZE (TYPE_MODE (inner_type))
10807 && TYPE_PRECISION (inner_type) < prec)
10809 prec = TYPE_PRECISION (inner_type);
10810 /* See if we can shorten the right shift. */
10812 shift_type = inner_type;
10815 zerobits = ~(unsigned HOST_WIDE_INT) 0;
10816 zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
10817 zerobits <<= prec - shiftc;
10818 /* For arithmetic shift if sign bit could be set, zerobits
10819 can contain actually sign bits, so no transformation is
10820 possible, unless MASK masks them all away. In that
10821 case the shift needs to be converted into logical shift. */
10822 if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
10823 && prec == TYPE_PRECISION (TREE_TYPE (arg0)))
10825 if ((mask & zerobits) == 0)
10826 shift_type = unsigned_type_for (TREE_TYPE (arg0));
10832 /* ((X << 16) & 0xff00) is (X, 0). */
10833 if ((mask & zerobits) == mask)
10834 return omit_one_operand (type, build_int_cst (type, 0), arg0);
10836 newmask = mask | zerobits;
10837 if (newmask != mask && (newmask & (newmask + 1)) == 0)
10841 /* Only do the transformation if NEWMASK is some integer
10843 for (prec = BITS_PER_UNIT;
10844 prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
10845 if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
10847 if (prec < HOST_BITS_PER_WIDE_INT
10848 || newmask == ~(unsigned HOST_WIDE_INT) 0)
10850 if (shift_type != TREE_TYPE (arg0))
10852 tem = fold_build2 (TREE_CODE (arg0), shift_type,
10853 fold_convert (shift_type,
10854 TREE_OPERAND (arg0, 0)),
10855 TREE_OPERAND (arg0, 1));
10856 tem = fold_convert (type, tem);
10860 return fold_build2 (BIT_AND_EXPR, type, tem,
10861 build_int_cst_type (TREE_TYPE (op1),
10870 /* Don't touch a floating-point divide by zero unless the mode
10871 of the constant can represent infinity. */
10872 if (TREE_CODE (arg1) == REAL_CST
10873 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
10874 && real_zerop (arg1))
10877 /* Optimize A / A to 1.0 if we don't care about
10878 NaNs or Infinities. Skip the transformation
10879 for non-real operands. */
10880 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
10881 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10882 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
10883 && operand_equal_p (arg0, arg1, 0))
10885 tree r = build_real (TREE_TYPE (arg0), dconst1);
10887 return omit_two_operands (type, r, arg0, arg1);
10890 /* The complex version of the above A / A optimization. */
10891 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10892 && operand_equal_p (arg0, arg1, 0))
10894 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
10895 if (! HONOR_NANS (TYPE_MODE (elem_type))
10896 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
10898 tree r = build_real (elem_type, dconst1);
10899 /* omit_two_operands will call fold_convert for us. */
10900 return omit_two_operands (type, r, arg0, arg1);
10904 /* (-A) / (-B) -> A / B */
10905 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10906 return fold_build2 (RDIV_EXPR, type,
10907 TREE_OPERAND (arg0, 0),
10908 negate_expr (arg1));
10909 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10910 return fold_build2 (RDIV_EXPR, type,
10911 negate_expr (arg0),
10912 TREE_OPERAND (arg1, 0));
10914 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
10915 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10916 && real_onep (arg1))
10917 return non_lvalue (fold_convert (type, arg0));
10919 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
10920 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10921 && real_minus_onep (arg1))
10922 return non_lvalue (fold_convert (type, negate_expr (arg0)));
10924 /* If ARG1 is a constant, we can convert this to a multiply by the
10925 reciprocal. This does not have the same rounding properties,
10926 so only do this if -freciprocal-math. We can actually
10927 always safely do it if ARG1 is a power of two, but it's hard to
10928 tell if it is or not in a portable manner. */
10929 if (TREE_CODE (arg1) == REAL_CST)
10931 if (flag_reciprocal_math
10932 && 0 != (tem = const_binop (code, build_real (type, dconst1),
10934 return fold_build2 (MULT_EXPR, type, arg0, tem);
10935 /* Find the reciprocal if optimizing and the result is exact. */
10939 r = TREE_REAL_CST (arg1);
10940 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
10942 tem = build_real (type, r);
10943 return fold_build2 (MULT_EXPR, type,
10944 fold_convert (type, arg0), tem);
10948 /* Convert A/B/C to A/(B*C). */
10949 if (flag_reciprocal_math
10950 && TREE_CODE (arg0) == RDIV_EXPR)
10951 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
10952 fold_build2 (MULT_EXPR, type,
10953 TREE_OPERAND (arg0, 1), arg1));
10955 /* Convert A/(B/C) to (A/B)*C. */
10956 if (flag_reciprocal_math
10957 && TREE_CODE (arg1) == RDIV_EXPR)
10958 return fold_build2 (MULT_EXPR, type,
10959 fold_build2 (RDIV_EXPR, type, arg0,
10960 TREE_OPERAND (arg1, 0)),
10961 TREE_OPERAND (arg1, 1));
10963 /* Convert C1/(X*C2) into (C1/C2)/X. */
10964 if (flag_reciprocal_math
10965 && TREE_CODE (arg1) == MULT_EXPR
10966 && TREE_CODE (arg0) == REAL_CST
10967 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
10969 tree tem = const_binop (RDIV_EXPR, arg0,
10970 TREE_OPERAND (arg1, 1), 0);
10972 return fold_build2 (RDIV_EXPR, type, tem,
10973 TREE_OPERAND (arg1, 0));
10976 if (flag_unsafe_math_optimizations)
10978 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10979 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10981 /* Optimize sin(x)/cos(x) as tan(x). */
10982 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
10983 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
10984 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
10985 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10986 CALL_EXPR_ARG (arg1, 0), 0))
10988 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
10990 if (tanfn != NULL_TREE)
10991 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
10994 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
10995 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
10996 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
10997 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
10998 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10999 CALL_EXPR_ARG (arg1, 0), 0))
11001 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11003 if (tanfn != NULL_TREE)
11005 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11006 return fold_build2 (RDIV_EXPR, type,
11007 build_real (type, dconst1), tmp);
11011 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
11012 NaNs or Infinities. */
11013 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
11014 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
11015 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
11017 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11018 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11020 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11021 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11022 && operand_equal_p (arg00, arg01, 0))
11024 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11026 if (cosfn != NULL_TREE)
11027 return build_call_expr (cosfn, 1, arg00);
11031 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11032 NaNs or Infinities. */
11033 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
11034 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
11035 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
11037 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11038 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11040 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11041 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11042 && operand_equal_p (arg00, arg01, 0))
11044 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11046 if (cosfn != NULL_TREE)
11048 tree tmp = build_call_expr (cosfn, 1, arg00);
11049 return fold_build2 (RDIV_EXPR, type,
11050 build_real (type, dconst1),
11056 /* Optimize pow(x,c)/x as pow(x,c-1). */
11057 if (fcode0 == BUILT_IN_POW
11058 || fcode0 == BUILT_IN_POWF
11059 || fcode0 == BUILT_IN_POWL)
11061 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11062 tree arg01 = CALL_EXPR_ARG (arg0, 1);
11063 if (TREE_CODE (arg01) == REAL_CST
11064 && !TREE_OVERFLOW (arg01)
11065 && operand_equal_p (arg1, arg00, 0))
11067 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
11071 c = TREE_REAL_CST (arg01);
11072 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
11073 arg = build_real (type, c);
11074 return build_call_expr (powfn, 2, arg1, arg);
11078 /* Optimize a/root(b/c) into a*root(c/b). */
11079 if (BUILTIN_ROOT_P (fcode1))
11081 tree rootarg = CALL_EXPR_ARG (arg1, 0);
11083 if (TREE_CODE (rootarg) == RDIV_EXPR)
11085 tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11086 tree b = TREE_OPERAND (rootarg, 0);
11087 tree c = TREE_OPERAND (rootarg, 1);
11089 tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
11091 tmp = build_call_expr (rootfn, 1, tmp);
11092 return fold_build2 (MULT_EXPR, type, arg0, tmp);
11096 /* Optimize x/expN(y) into x*expN(-y). */
11097 if (BUILTIN_EXPONENT_P (fcode1))
11099 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11100 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
11101 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
11102 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11105 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11106 if (fcode1 == BUILT_IN_POW
11107 || fcode1 == BUILT_IN_POWF
11108 || fcode1 == BUILT_IN_POWL)
11110 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11111 tree arg10 = CALL_EXPR_ARG (arg1, 0);
11112 tree arg11 = CALL_EXPR_ARG (arg1, 1);
11113 tree neg11 = fold_convert (type, negate_expr (arg11));
11114 arg1 = build_call_expr (powfn, 2, arg10, neg11);
11115 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11120 case TRUNC_DIV_EXPR:
11121 case FLOOR_DIV_EXPR:
11122 /* Simplify A / (B << N) where A and B are positive and B is
11123 a power of 2, to A >> (N + log2(B)). */
11124 strict_overflow_p = false;
11125 if (TREE_CODE (arg1) == LSHIFT_EXPR
11126 && (TYPE_UNSIGNED (type)
11127 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11129 tree sval = TREE_OPERAND (arg1, 0);
11130 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
11132 tree sh_cnt = TREE_OPERAND (arg1, 1);
11133 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
11135 if (strict_overflow_p)
11136 fold_overflow_warning (("assuming signed overflow does not "
11137 "occur when simplifying A / (B << N)"),
11138 WARN_STRICT_OVERFLOW_MISC);
11140 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
11141 sh_cnt, build_int_cst (NULL_TREE, pow2));
11142 return fold_build2 (RSHIFT_EXPR, type,
11143 fold_convert (type, arg0), sh_cnt);
11147 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
11148 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
11149 if (INTEGRAL_TYPE_P (type)
11150 && TYPE_UNSIGNED (type)
11151 && code == FLOOR_DIV_EXPR)
11152 return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
11156 case ROUND_DIV_EXPR:
11157 case CEIL_DIV_EXPR:
11158 case EXACT_DIV_EXPR:
11159 if (integer_onep (arg1))
11160 return non_lvalue (fold_convert (type, arg0));
11161 if (integer_zerop (arg1))
11163 /* X / -1 is -X. */
11164 if (!TYPE_UNSIGNED (type)
11165 && TREE_CODE (arg1) == INTEGER_CST
11166 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11167 && TREE_INT_CST_HIGH (arg1) == -1)
11168 return fold_convert (type, negate_expr (arg0));
11170 /* Convert -A / -B to A / B when the type is signed and overflow is
11172 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11173 && TREE_CODE (arg0) == NEGATE_EXPR
11174 && negate_expr_p (arg1))
11176 if (INTEGRAL_TYPE_P (type))
11177 fold_overflow_warning (("assuming signed overflow does not occur "
11178 "when distributing negation across "
11180 WARN_STRICT_OVERFLOW_MISC);
11181 return fold_build2 (code, type,
11182 fold_convert (type, TREE_OPERAND (arg0, 0)),
11183 negate_expr (arg1));
11185 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11186 && TREE_CODE (arg1) == NEGATE_EXPR
11187 && negate_expr_p (arg0))
11189 if (INTEGRAL_TYPE_P (type))
11190 fold_overflow_warning (("assuming signed overflow does not occur "
11191 "when distributing negation across "
11193 WARN_STRICT_OVERFLOW_MISC);
11194 return fold_build2 (code, type, negate_expr (arg0),
11195 TREE_OPERAND (arg1, 0));
11198 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11199 operation, EXACT_DIV_EXPR.
11201 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11202 At one time others generated faster code, it's not clear if they do
11203 after the last round to changes to the DIV code in expmed.c. */
11204 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
11205 && multiple_of_p (type, arg0, arg1))
11206 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
11208 strict_overflow_p = false;
11209 if (TREE_CODE (arg1) == INTEGER_CST
11210 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11211 &strict_overflow_p)))
11213 if (strict_overflow_p)
11214 fold_overflow_warning (("assuming signed overflow does not occur "
11215 "when simplifying division"),
11216 WARN_STRICT_OVERFLOW_MISC);
11217 return fold_convert (type, tem);
11222 case CEIL_MOD_EXPR:
11223 case FLOOR_MOD_EXPR:
11224 case ROUND_MOD_EXPR:
11225 case TRUNC_MOD_EXPR:
11226 /* X % 1 is always zero, but be sure to preserve any side
11228 if (integer_onep (arg1))
11229 return omit_one_operand (type, integer_zero_node, arg0);
11231 /* X % 0, return X % 0 unchanged so that we can get the
11232 proper warnings and errors. */
11233 if (integer_zerop (arg1))
11236 /* 0 % X is always zero, but be sure to preserve any side
11237 effects in X. Place this after checking for X == 0. */
11238 if (integer_zerop (arg0))
11239 return omit_one_operand (type, integer_zero_node, arg1);
11241 /* X % -1 is zero. */
11242 if (!TYPE_UNSIGNED (type)
11243 && TREE_CODE (arg1) == INTEGER_CST
11244 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11245 && TREE_INT_CST_HIGH (arg1) == -1)
11246 return omit_one_operand (type, integer_zero_node, arg0);
11248 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11249 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11250 strict_overflow_p = false;
11251 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
11252 && (TYPE_UNSIGNED (type)
11253 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11256 /* Also optimize A % (C << N) where C is a power of 2,
11257 to A & ((C << N) - 1). */
11258 if (TREE_CODE (arg1) == LSHIFT_EXPR)
11259 c = TREE_OPERAND (arg1, 0);
11261 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
11263 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
11264 build_int_cst (TREE_TYPE (arg1), 1));
11265 if (strict_overflow_p)
11266 fold_overflow_warning (("assuming signed overflow does not "
11267 "occur when simplifying "
11268 "X % (power of two)"),
11269 WARN_STRICT_OVERFLOW_MISC);
11270 return fold_build2 (BIT_AND_EXPR, type,
11271 fold_convert (type, arg0),
11272 fold_convert (type, mask));
11276 /* X % -C is the same as X % C. */
11277 if (code == TRUNC_MOD_EXPR
11278 && !TYPE_UNSIGNED (type)
11279 && TREE_CODE (arg1) == INTEGER_CST
11280 && !TREE_OVERFLOW (arg1)
11281 && TREE_INT_CST_HIGH (arg1) < 0
11282 && !TYPE_OVERFLOW_TRAPS (type)
11283 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11284 && !sign_bit_p (arg1, arg1))
11285 return fold_build2 (code, type, fold_convert (type, arg0),
11286 fold_convert (type, negate_expr (arg1)));
11288 /* X % -Y is the same as X % Y. */
11289 if (code == TRUNC_MOD_EXPR
11290 && !TYPE_UNSIGNED (type)
11291 && TREE_CODE (arg1) == NEGATE_EXPR
11292 && !TYPE_OVERFLOW_TRAPS (type))
11293 return fold_build2 (code, type, fold_convert (type, arg0),
11294 fold_convert (type, TREE_OPERAND (arg1, 0)));
11296 if (TREE_CODE (arg1) == INTEGER_CST
11297 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11298 &strict_overflow_p)))
11300 if (strict_overflow_p)
11301 fold_overflow_warning (("assuming signed overflow does not occur "
11302 "when simplifying modulos"),
11303 WARN_STRICT_OVERFLOW_MISC);
11304 return fold_convert (type, tem);
11311 if (integer_all_onesp (arg0))
11312 return omit_one_operand (type, arg0, arg1);
11316 /* Optimize -1 >> x for arithmetic right shifts. */
11317 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
11318 return omit_one_operand (type, arg0, arg1);
11319 /* ... fall through ... */
11323 if (integer_zerop (arg1))
11324 return non_lvalue (fold_convert (type, arg0));
11325 if (integer_zerop (arg0))
11326 return omit_one_operand (type, arg0, arg1);
11328 /* Since negative shift count is not well-defined,
11329 don't try to compute it in the compiler. */
11330 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
11333 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11334 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
11335 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11336 && host_integerp (TREE_OPERAND (arg0, 1), false)
11337 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11339 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
11340 + TREE_INT_CST_LOW (arg1));
11342 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11343 being well defined. */
11344 if (low >= TYPE_PRECISION (type))
11346 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
11347 low = low % TYPE_PRECISION (type);
11348 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
11349 return build_int_cst (type, 0);
11351 low = TYPE_PRECISION (type) - 1;
11354 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11355 build_int_cst (type, low));
11358 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11359 into x & ((unsigned)-1 >> c) for unsigned types. */
11360 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
11361 || (TYPE_UNSIGNED (type)
11362 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
11363 && host_integerp (arg1, false)
11364 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11365 && host_integerp (TREE_OPERAND (arg0, 1), false)
11366 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11368 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
11369 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
11375 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
11377 lshift = build_int_cst (type, -1);
11378 lshift = int_const_binop (code, lshift, arg1, 0);
11380 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
11384 /* Rewrite an LROTATE_EXPR by a constant into an
11385 RROTATE_EXPR by a new constant. */
11386 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
11388 tree tem = build_int_cst (TREE_TYPE (arg1),
11389 TYPE_PRECISION (type));
11390 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
11391 return fold_build2 (RROTATE_EXPR, type, op0, tem);
11394 /* If we have a rotate of a bit operation with the rotate count and
11395 the second operand of the bit operation both constant,
11396 permute the two operations. */
11397 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11398 && (TREE_CODE (arg0) == BIT_AND_EXPR
11399 || TREE_CODE (arg0) == BIT_IOR_EXPR
11400 || TREE_CODE (arg0) == BIT_XOR_EXPR)
11401 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11402 return fold_build2 (TREE_CODE (arg0), type,
11403 fold_build2 (code, type,
11404 TREE_OPERAND (arg0, 0), arg1),
11405 fold_build2 (code, type,
11406 TREE_OPERAND (arg0, 1), arg1));
11408 /* Two consecutive rotates adding up to the precision of the
11409 type can be ignored. */
11410 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11411 && TREE_CODE (arg0) == RROTATE_EXPR
11412 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11413 && TREE_INT_CST_HIGH (arg1) == 0
11414 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
11415 && ((TREE_INT_CST_LOW (arg1)
11416 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
11417 == (unsigned int) TYPE_PRECISION (type)))
11418 return TREE_OPERAND (arg0, 0);
11420 /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
11421 (X & C2) >> C1 into (X >> C1) & (C2 >> C1)
11422 if the latter can be further optimized. */
11423 if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
11424 && TREE_CODE (arg0) == BIT_AND_EXPR
11425 && TREE_CODE (arg1) == INTEGER_CST
11426 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11428 tree mask = fold_build2 (code, type,
11429 fold_convert (type, TREE_OPERAND (arg0, 1)),
11431 tree shift = fold_build2 (code, type,
11432 fold_convert (type, TREE_OPERAND (arg0, 0)),
11434 tem = fold_binary (BIT_AND_EXPR, type, shift, mask);
11442 if (operand_equal_p (arg0, arg1, 0))
11443 return omit_one_operand (type, arg0, arg1);
11444 if (INTEGRAL_TYPE_P (type)
11445 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
11446 return omit_one_operand (type, arg1, arg0);
11447 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
11453 if (operand_equal_p (arg0, arg1, 0))
11454 return omit_one_operand (type, arg0, arg1);
11455 if (INTEGRAL_TYPE_P (type)
11456 && TYPE_MAX_VALUE (type)
11457 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
11458 return omit_one_operand (type, arg1, arg0);
11459 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
11464 case TRUTH_ANDIF_EXPR:
11465 /* Note that the operands of this must be ints
11466 and their values must be 0 or 1.
11467 ("true" is a fixed value perhaps depending on the language.) */
11468 /* If first arg is constant zero, return it. */
11469 if (integer_zerop (arg0))
11470 return fold_convert (type, arg0);
11471 case TRUTH_AND_EXPR:
11472 /* If either arg is constant true, drop it. */
11473 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11474 return non_lvalue (fold_convert (type, arg1));
11475 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
11476 /* Preserve sequence points. */
11477 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11478 return non_lvalue (fold_convert (type, arg0));
11479 /* If second arg is constant zero, result is zero, but first arg
11480 must be evaluated. */
11481 if (integer_zerop (arg1))
11482 return omit_one_operand (type, arg1, arg0);
11483 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11484 case will be handled here. */
11485 if (integer_zerop (arg0))
11486 return omit_one_operand (type, arg0, arg1);
11488 /* !X && X is always false. */
11489 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11490 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11491 return omit_one_operand (type, integer_zero_node, arg1);
11492 /* X && !X is always false. */
11493 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11494 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11495 return omit_one_operand (type, integer_zero_node, arg0);
11497 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
11498 means A >= Y && A != MAX, but in this case we know that
11501 if (!TREE_SIDE_EFFECTS (arg0)
11502 && !TREE_SIDE_EFFECTS (arg1))
11504 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
11505 if (tem && !operand_equal_p (tem, arg0, 0))
11506 return fold_build2 (code, type, tem, arg1);
11508 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
11509 if (tem && !operand_equal_p (tem, arg1, 0))
11510 return fold_build2 (code, type, arg0, tem);
11514 /* We only do these simplifications if we are optimizing. */
11518 /* Check for things like (A || B) && (A || C). We can convert this
11519 to A || (B && C). Note that either operator can be any of the four
11520 truth and/or operations and the transformation will still be
11521 valid. Also note that we only care about order for the
11522 ANDIF and ORIF operators. If B contains side effects, this
11523 might change the truth-value of A. */
11524 if (TREE_CODE (arg0) == TREE_CODE (arg1)
11525 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
11526 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
11527 || TREE_CODE (arg0) == TRUTH_AND_EXPR
11528 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
11529 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
11531 tree a00 = TREE_OPERAND (arg0, 0);
11532 tree a01 = TREE_OPERAND (arg0, 1);
11533 tree a10 = TREE_OPERAND (arg1, 0);
11534 tree a11 = TREE_OPERAND (arg1, 1);
11535 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
11536 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
11537 && (code == TRUTH_AND_EXPR
11538 || code == TRUTH_OR_EXPR));
11540 if (operand_equal_p (a00, a10, 0))
11541 return fold_build2 (TREE_CODE (arg0), type, a00,
11542 fold_build2 (code, type, a01, a11));
11543 else if (commutative && operand_equal_p (a00, a11, 0))
11544 return fold_build2 (TREE_CODE (arg0), type, a00,
11545 fold_build2 (code, type, a01, a10));
11546 else if (commutative && operand_equal_p (a01, a10, 0))
11547 return fold_build2 (TREE_CODE (arg0), type, a01,
11548 fold_build2 (code, type, a00, a11));
11550 /* This case if tricky because we must either have commutative
11551 operators or else A10 must not have side-effects. */
11553 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
11554 && operand_equal_p (a01, a11, 0))
11555 return fold_build2 (TREE_CODE (arg0), type,
11556 fold_build2 (code, type, a00, a10),
11560 /* See if we can build a range comparison. */
11561 if (0 != (tem = fold_range_test (code, type, op0, op1)))
11564 /* Check for the possibility of merging component references. If our
11565 lhs is another similar operation, try to merge its rhs with our
11566 rhs. Then try to merge our lhs and rhs. */
11567 if (TREE_CODE (arg0) == code
11568 && 0 != (tem = fold_truthop (code, type,
11569 TREE_OPERAND (arg0, 1), arg1)))
11570 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11572 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
11577 case TRUTH_ORIF_EXPR:
11578 /* Note that the operands of this must be ints
11579 and their values must be 0 or true.
11580 ("true" is a fixed value perhaps depending on the language.) */
11581 /* If first arg is constant true, return it. */
11582 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11583 return fold_convert (type, arg0);
11584 case TRUTH_OR_EXPR:
11585 /* If either arg is constant zero, drop it. */
11586 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
11587 return non_lvalue (fold_convert (type, arg1));
11588 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
11589 /* Preserve sequence points. */
11590 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11591 return non_lvalue (fold_convert (type, arg0));
11592 /* If second arg is constant true, result is true, but we must
11593 evaluate first arg. */
11594 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
11595 return omit_one_operand (type, arg1, arg0);
11596 /* Likewise for first arg, but note this only occurs here for
11598 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11599 return omit_one_operand (type, arg0, arg1);
11601 /* !X || X is always true. */
11602 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11603 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11604 return omit_one_operand (type, integer_one_node, arg1);
11605 /* X || !X is always true. */
11606 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11607 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11608 return omit_one_operand (type, integer_one_node, arg0);
11612 case TRUTH_XOR_EXPR:
11613 /* If the second arg is constant zero, drop it. */
11614 if (integer_zerop (arg1))
11615 return non_lvalue (fold_convert (type, arg0));
11616 /* If the second arg is constant true, this is a logical inversion. */
11617 if (integer_onep (arg1))
11619 /* Only call invert_truthvalue if operand is a truth value. */
11620 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
11621 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
11623 tem = invert_truthvalue (arg0);
11624 return non_lvalue (fold_convert (type, tem));
11626 /* Identical arguments cancel to zero. */
11627 if (operand_equal_p (arg0, arg1, 0))
11628 return omit_one_operand (type, integer_zero_node, arg0);
11630 /* !X ^ X is always true. */
11631 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11632 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11633 return omit_one_operand (type, integer_one_node, arg1);
11635 /* X ^ !X is always true. */
11636 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11637 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11638 return omit_one_operand (type, integer_one_node, arg0);
11644 tem = fold_comparison (code, type, op0, op1);
11645 if (tem != NULL_TREE)
11648 /* bool_var != 0 becomes bool_var. */
11649 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11650 && code == NE_EXPR)
11651 return non_lvalue (fold_convert (type, arg0));
11653 /* bool_var == 1 becomes bool_var. */
11654 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11655 && code == EQ_EXPR)
11656 return non_lvalue (fold_convert (type, arg0));
11658 /* bool_var != 1 becomes !bool_var. */
11659 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11660 && code == NE_EXPR)
11661 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11663 /* bool_var == 0 becomes !bool_var. */
11664 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11665 && code == EQ_EXPR)
11666 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11668 /* If this is an equality comparison of the address of two non-weak,
11669 unaliased symbols neither of which are extern (since we do not
11670 have access to attributes for externs), then we know the result. */
11671 if (TREE_CODE (arg0) == ADDR_EXPR
11672 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
11673 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
11674 && ! lookup_attribute ("alias",
11675 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
11676 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
11677 && TREE_CODE (arg1) == ADDR_EXPR
11678 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
11679 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
11680 && ! lookup_attribute ("alias",
11681 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
11682 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
11684 /* We know that we're looking at the address of two
11685 non-weak, unaliased, static _DECL nodes.
11687 It is both wasteful and incorrect to call operand_equal_p
11688 to compare the two ADDR_EXPR nodes. It is wasteful in that
11689 all we need to do is test pointer equality for the arguments
11690 to the two ADDR_EXPR nodes. It is incorrect to use
11691 operand_equal_p as that function is NOT equivalent to a
11692 C equality test. It can in fact return false for two
11693 objects which would test as equal using the C equality
11695 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
11696 return constant_boolean_node (equal
11697 ? code == EQ_EXPR : code != EQ_EXPR,
11701 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
11702 a MINUS_EXPR of a constant, we can convert it into a comparison with
11703 a revised constant as long as no overflow occurs. */
11704 if (TREE_CODE (arg1) == INTEGER_CST
11705 && (TREE_CODE (arg0) == PLUS_EXPR
11706 || TREE_CODE (arg0) == MINUS_EXPR)
11707 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11708 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
11709 ? MINUS_EXPR : PLUS_EXPR,
11710 fold_convert (TREE_TYPE (arg0), arg1),
11711 TREE_OPERAND (arg0, 1), 0))
11712 && !TREE_OVERFLOW (tem))
11713 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11715 /* Similarly for a NEGATE_EXPR. */
11716 if (TREE_CODE (arg0) == NEGATE_EXPR
11717 && TREE_CODE (arg1) == INTEGER_CST
11718 && 0 != (tem = negate_expr (arg1))
11719 && TREE_CODE (tem) == INTEGER_CST
11720 && !TREE_OVERFLOW (tem))
11721 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11723 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
11724 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11725 && TREE_CODE (arg1) == INTEGER_CST
11726 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11727 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11728 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
11729 fold_convert (TREE_TYPE (arg0), arg1),
11730 TREE_OPERAND (arg0, 1)));
11732 /* Transform comparisons of the form X +- C CMP X. */
11733 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11734 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11735 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11736 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
11737 || POINTER_TYPE_P (TREE_TYPE (arg0))))
11739 tree cst = TREE_OPERAND (arg0, 1);
11741 if (code == EQ_EXPR
11742 && !integer_zerop (cst))
11743 return omit_two_operands (type, boolean_false_node,
11744 TREE_OPERAND (arg0, 0), arg1);
11746 return omit_two_operands (type, boolean_true_node,
11747 TREE_OPERAND (arg0, 0), arg1);
11750 /* If we have X - Y == 0, we can convert that to X == Y and similarly
11751 for !=. Don't do this for ordered comparisons due to overflow. */
11752 if (TREE_CODE (arg0) == MINUS_EXPR
11753 && integer_zerop (arg1))
11754 return fold_build2 (code, type,
11755 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
11757 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
11758 if (TREE_CODE (arg0) == ABS_EXPR
11759 && (integer_zerop (arg1) || real_zerop (arg1)))
11760 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
11762 /* If this is an EQ or NE comparison with zero and ARG0 is
11763 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
11764 two operations, but the latter can be done in one less insn
11765 on machines that have only two-operand insns or on which a
11766 constant cannot be the first operand. */
11767 if (TREE_CODE (arg0) == BIT_AND_EXPR
11768 && integer_zerop (arg1))
11770 tree arg00 = TREE_OPERAND (arg0, 0);
11771 tree arg01 = TREE_OPERAND (arg0, 1);
11772 if (TREE_CODE (arg00) == LSHIFT_EXPR
11773 && integer_onep (TREE_OPERAND (arg00, 0)))
11775 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
11776 arg01, TREE_OPERAND (arg00, 1));
11777 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11778 build_int_cst (TREE_TYPE (arg0), 1));
11779 return fold_build2 (code, type,
11780 fold_convert (TREE_TYPE (arg1), tem), arg1);
11782 else if (TREE_CODE (arg01) == LSHIFT_EXPR
11783 && integer_onep (TREE_OPERAND (arg01, 0)))
11785 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
11786 arg00, TREE_OPERAND (arg01, 1));
11787 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11788 build_int_cst (TREE_TYPE (arg0), 1));
11789 return fold_build2 (code, type,
11790 fold_convert (TREE_TYPE (arg1), tem), arg1);
11794 /* If this is an NE or EQ comparison of zero against the result of a
11795 signed MOD operation whose second operand is a power of 2, make
11796 the MOD operation unsigned since it is simpler and equivalent. */
11797 if (integer_zerop (arg1)
11798 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
11799 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
11800 || TREE_CODE (arg0) == CEIL_MOD_EXPR
11801 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
11802 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
11803 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11805 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
11806 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
11807 fold_convert (newtype,
11808 TREE_OPERAND (arg0, 0)),
11809 fold_convert (newtype,
11810 TREE_OPERAND (arg0, 1)));
11812 return fold_build2 (code, type, newmod,
11813 fold_convert (newtype, arg1));
11816 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
11817 C1 is a valid shift constant, and C2 is a power of two, i.e.
11819 if (TREE_CODE (arg0) == BIT_AND_EXPR
11820 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
11821 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
11823 && integer_pow2p (TREE_OPERAND (arg0, 1))
11824 && integer_zerop (arg1))
11826 tree itype = TREE_TYPE (arg0);
11827 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
11828 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
11830 /* Check for a valid shift count. */
11831 if (TREE_INT_CST_HIGH (arg001) == 0
11832 && TREE_INT_CST_LOW (arg001) < prec)
11834 tree arg01 = TREE_OPERAND (arg0, 1);
11835 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11836 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
11837 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
11838 can be rewritten as (X & (C2 << C1)) != 0. */
11839 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
11841 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
11842 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
11843 return fold_build2 (code, type, tem, arg1);
11845 /* Otherwise, for signed (arithmetic) shifts,
11846 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
11847 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
11848 else if (!TYPE_UNSIGNED (itype))
11849 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
11850 arg000, build_int_cst (itype, 0));
11851 /* Otherwise, of unsigned (logical) shifts,
11852 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
11853 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
11855 return omit_one_operand (type,
11856 code == EQ_EXPR ? integer_one_node
11857 : integer_zero_node,
11862 /* If this is an NE comparison of zero with an AND of one, remove the
11863 comparison since the AND will give the correct value. */
11864 if (code == NE_EXPR
11865 && integer_zerop (arg1)
11866 && TREE_CODE (arg0) == BIT_AND_EXPR
11867 && integer_onep (TREE_OPERAND (arg0, 1)))
11868 return fold_convert (type, arg0);
11870 /* If we have (A & C) == C where C is a power of 2, convert this into
11871 (A & C) != 0. Similarly for NE_EXPR. */
11872 if (TREE_CODE (arg0) == BIT_AND_EXPR
11873 && integer_pow2p (TREE_OPERAND (arg0, 1))
11874 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11875 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11876 arg0, fold_convert (TREE_TYPE (arg0),
11877 integer_zero_node));
11879 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
11880 bit, then fold the expression into A < 0 or A >= 0. */
11881 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
11885 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
11886 Similarly for NE_EXPR. */
11887 if (TREE_CODE (arg0) == BIT_AND_EXPR
11888 && TREE_CODE (arg1) == INTEGER_CST
11889 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11891 tree notc = fold_build1 (BIT_NOT_EXPR,
11892 TREE_TYPE (TREE_OPERAND (arg0, 1)),
11893 TREE_OPERAND (arg0, 1));
11894 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11896 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11897 if (integer_nonzerop (dandnotc))
11898 return omit_one_operand (type, rslt, arg0);
11901 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
11902 Similarly for NE_EXPR. */
11903 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11904 && TREE_CODE (arg1) == INTEGER_CST
11905 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11907 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
11908 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11909 TREE_OPERAND (arg0, 1), notd);
11910 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11911 if (integer_nonzerop (candnotd))
11912 return omit_one_operand (type, rslt, arg0);
11915 /* Optimize comparisons of strlen vs zero to a compare of the
11916 first character of the string vs zero. To wit,
11917 strlen(ptr) == 0 => *ptr == 0
11918 strlen(ptr) != 0 => *ptr != 0
11919 Other cases should reduce to one of these two (or a constant)
11920 due to the return value of strlen being unsigned. */
11921 if (TREE_CODE (arg0) == CALL_EXPR
11922 && integer_zerop (arg1))
11924 tree fndecl = get_callee_fndecl (arg0);
11927 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
11928 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
11929 && call_expr_nargs (arg0) == 1
11930 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
11932 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
11933 return fold_build2 (code, type, iref,
11934 build_int_cst (TREE_TYPE (iref), 0));
11938 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
11939 of X. Similarly fold (X >> C) == 0 into X >= 0. */
11940 if (TREE_CODE (arg0) == RSHIFT_EXPR
11941 && integer_zerop (arg1)
11942 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11944 tree arg00 = TREE_OPERAND (arg0, 0);
11945 tree arg01 = TREE_OPERAND (arg0, 1);
11946 tree itype = TREE_TYPE (arg00);
11947 if (TREE_INT_CST_HIGH (arg01) == 0
11948 && TREE_INT_CST_LOW (arg01)
11949 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
11951 if (TYPE_UNSIGNED (itype))
11953 itype = signed_type_for (itype);
11954 arg00 = fold_convert (itype, arg00);
11956 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
11957 type, arg00, build_int_cst (itype, 0));
11961 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
11962 if (integer_zerop (arg1)
11963 && TREE_CODE (arg0) == BIT_XOR_EXPR)
11964 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11965 TREE_OPERAND (arg0, 1));
11967 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
11968 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11969 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11970 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11971 build_int_cst (TREE_TYPE (arg1), 0));
11972 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
11973 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11974 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11975 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
11976 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
11977 build_int_cst (TREE_TYPE (arg1), 0));
11979 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
11980 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11981 && TREE_CODE (arg1) == INTEGER_CST
11982 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11983 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11984 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
11985 TREE_OPERAND (arg0, 1), arg1));
11987 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
11988 (X & C) == 0 when C is a single bit. */
11989 if (TREE_CODE (arg0) == BIT_AND_EXPR
11990 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
11991 && integer_zerop (arg1)
11992 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11994 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11995 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
11996 TREE_OPERAND (arg0, 1));
11997 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
12001 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12002 constant C is a power of two, i.e. a single bit. */
12003 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12004 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12005 && integer_zerop (arg1)
12006 && integer_pow2p (TREE_OPERAND (arg0, 1))
12007 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12008 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12010 tree arg00 = TREE_OPERAND (arg0, 0);
12011 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12012 arg00, build_int_cst (TREE_TYPE (arg00), 0));
12015 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12016 when is C is a power of two, i.e. a single bit. */
12017 if (TREE_CODE (arg0) == BIT_AND_EXPR
12018 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
12019 && integer_zerop (arg1)
12020 && integer_pow2p (TREE_OPERAND (arg0, 1))
12021 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12022 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12024 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12025 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
12026 arg000, TREE_OPERAND (arg0, 1));
12027 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12028 tem, build_int_cst (TREE_TYPE (tem), 0));
12031 if (integer_zerop (arg1)
12032 && tree_expr_nonzero_p (arg0))
12034 tree res = constant_boolean_node (code==NE_EXPR, type);
12035 return omit_one_operand (type, res, arg0);
12038 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12039 if (TREE_CODE (arg0) == NEGATE_EXPR
12040 && TREE_CODE (arg1) == NEGATE_EXPR)
12041 return fold_build2 (code, type,
12042 TREE_OPERAND (arg0, 0),
12043 TREE_OPERAND (arg1, 0));
12045 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12046 if (TREE_CODE (arg0) == BIT_AND_EXPR
12047 && TREE_CODE (arg1) == BIT_AND_EXPR)
12049 tree arg00 = TREE_OPERAND (arg0, 0);
12050 tree arg01 = TREE_OPERAND (arg0, 1);
12051 tree arg10 = TREE_OPERAND (arg1, 0);
12052 tree arg11 = TREE_OPERAND (arg1, 1);
12053 tree itype = TREE_TYPE (arg0);
12055 if (operand_equal_p (arg01, arg11, 0))
12056 return fold_build2 (code, type,
12057 fold_build2 (BIT_AND_EXPR, itype,
12058 fold_build2 (BIT_XOR_EXPR, itype,
12061 build_int_cst (itype, 0));
12063 if (operand_equal_p (arg01, arg10, 0))
12064 return fold_build2 (code, type,
12065 fold_build2 (BIT_AND_EXPR, itype,
12066 fold_build2 (BIT_XOR_EXPR, itype,
12069 build_int_cst (itype, 0));
12071 if (operand_equal_p (arg00, arg11, 0))
12072 return fold_build2 (code, type,
12073 fold_build2 (BIT_AND_EXPR, itype,
12074 fold_build2 (BIT_XOR_EXPR, itype,
12077 build_int_cst (itype, 0));
12079 if (operand_equal_p (arg00, arg10, 0))
12080 return fold_build2 (code, type,
12081 fold_build2 (BIT_AND_EXPR, itype,
12082 fold_build2 (BIT_XOR_EXPR, itype,
12085 build_int_cst (itype, 0));
12088 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12089 && TREE_CODE (arg1) == BIT_XOR_EXPR)
12091 tree arg00 = TREE_OPERAND (arg0, 0);
12092 tree arg01 = TREE_OPERAND (arg0, 1);
12093 tree arg10 = TREE_OPERAND (arg1, 0);
12094 tree arg11 = TREE_OPERAND (arg1, 1);
12095 tree itype = TREE_TYPE (arg0);
12097 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12098 operand_equal_p guarantees no side-effects so we don't need
12099 to use omit_one_operand on Z. */
12100 if (operand_equal_p (arg01, arg11, 0))
12101 return fold_build2 (code, type, arg00, arg10);
12102 if (operand_equal_p (arg01, arg10, 0))
12103 return fold_build2 (code, type, arg00, arg11);
12104 if (operand_equal_p (arg00, arg11, 0))
12105 return fold_build2 (code, type, arg01, arg10);
12106 if (operand_equal_p (arg00, arg10, 0))
12107 return fold_build2 (code, type, arg01, arg11);
12109 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12110 if (TREE_CODE (arg01) == INTEGER_CST
12111 && TREE_CODE (arg11) == INTEGER_CST)
12112 return fold_build2 (code, type,
12113 fold_build2 (BIT_XOR_EXPR, itype, arg00,
12114 fold_build2 (BIT_XOR_EXPR, itype,
12119 /* Attempt to simplify equality/inequality comparisons of complex
12120 values. Only lower the comparison if the result is known or
12121 can be simplified to a single scalar comparison. */
12122 if ((TREE_CODE (arg0) == COMPLEX_EXPR
12123 || TREE_CODE (arg0) == COMPLEX_CST)
12124 && (TREE_CODE (arg1) == COMPLEX_EXPR
12125 || TREE_CODE (arg1) == COMPLEX_CST))
12127 tree real0, imag0, real1, imag1;
12130 if (TREE_CODE (arg0) == COMPLEX_EXPR)
12132 real0 = TREE_OPERAND (arg0, 0);
12133 imag0 = TREE_OPERAND (arg0, 1);
12137 real0 = TREE_REALPART (arg0);
12138 imag0 = TREE_IMAGPART (arg0);
12141 if (TREE_CODE (arg1) == COMPLEX_EXPR)
12143 real1 = TREE_OPERAND (arg1, 0);
12144 imag1 = TREE_OPERAND (arg1, 1);
12148 real1 = TREE_REALPART (arg1);
12149 imag1 = TREE_IMAGPART (arg1);
12152 rcond = fold_binary (code, type, real0, real1);
12153 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
12155 if (integer_zerop (rcond))
12157 if (code == EQ_EXPR)
12158 return omit_two_operands (type, boolean_false_node,
12160 return fold_build2 (NE_EXPR, type, imag0, imag1);
12164 if (code == NE_EXPR)
12165 return omit_two_operands (type, boolean_true_node,
12167 return fold_build2 (EQ_EXPR, type, imag0, imag1);
12171 icond = fold_binary (code, type, imag0, imag1);
12172 if (icond && TREE_CODE (icond) == INTEGER_CST)
12174 if (integer_zerop (icond))
12176 if (code == EQ_EXPR)
12177 return omit_two_operands (type, boolean_false_node,
12179 return fold_build2 (NE_EXPR, type, real0, real1);
12183 if (code == NE_EXPR)
12184 return omit_two_operands (type, boolean_true_node,
12186 return fold_build2 (EQ_EXPR, type, real0, real1);
12197 tem = fold_comparison (code, type, op0, op1);
12198 if (tem != NULL_TREE)
12201 /* Transform comparisons of the form X +- C CMP X. */
12202 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12203 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12204 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
12205 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
12206 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12207 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
12209 tree arg01 = TREE_OPERAND (arg0, 1);
12210 enum tree_code code0 = TREE_CODE (arg0);
12213 if (TREE_CODE (arg01) == REAL_CST)
12214 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
12216 is_positive = tree_int_cst_sgn (arg01);
12218 /* (X - c) > X becomes false. */
12219 if (code == GT_EXPR
12220 && ((code0 == MINUS_EXPR && is_positive >= 0)
12221 || (code0 == PLUS_EXPR && is_positive <= 0)))
12223 if (TREE_CODE (arg01) == INTEGER_CST
12224 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12225 fold_overflow_warning (("assuming signed overflow does not "
12226 "occur when assuming that (X - c) > X "
12227 "is always false"),
12228 WARN_STRICT_OVERFLOW_ALL);
12229 return constant_boolean_node (0, type);
12232 /* Likewise (X + c) < X becomes false. */
12233 if (code == LT_EXPR
12234 && ((code0 == PLUS_EXPR && is_positive >= 0)
12235 || (code0 == MINUS_EXPR && is_positive <= 0)))
12237 if (TREE_CODE (arg01) == INTEGER_CST
12238 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12239 fold_overflow_warning (("assuming signed overflow does not "
12240 "occur when assuming that "
12241 "(X + c) < X is always false"),
12242 WARN_STRICT_OVERFLOW_ALL);
12243 return constant_boolean_node (0, type);
12246 /* Convert (X - c) <= X to true. */
12247 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12249 && ((code0 == MINUS_EXPR && is_positive >= 0)
12250 || (code0 == PLUS_EXPR && is_positive <= 0)))
12252 if (TREE_CODE (arg01) == INTEGER_CST
12253 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12254 fold_overflow_warning (("assuming signed overflow does not "
12255 "occur when assuming that "
12256 "(X - c) <= X is always true"),
12257 WARN_STRICT_OVERFLOW_ALL);
12258 return constant_boolean_node (1, type);
12261 /* Convert (X + c) >= X to true. */
12262 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12264 && ((code0 == PLUS_EXPR && is_positive >= 0)
12265 || (code0 == MINUS_EXPR && is_positive <= 0)))
12267 if (TREE_CODE (arg01) == INTEGER_CST
12268 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12269 fold_overflow_warning (("assuming signed overflow does not "
12270 "occur when assuming that "
12271 "(X + c) >= X is always true"),
12272 WARN_STRICT_OVERFLOW_ALL);
12273 return constant_boolean_node (1, type);
12276 if (TREE_CODE (arg01) == INTEGER_CST)
12278 /* Convert X + c > X and X - c < X to true for integers. */
12279 if (code == GT_EXPR
12280 && ((code0 == PLUS_EXPR && is_positive > 0)
12281 || (code0 == MINUS_EXPR && is_positive < 0)))
12283 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12284 fold_overflow_warning (("assuming signed overflow does "
12285 "not occur when assuming that "
12286 "(X + c) > X is always true"),
12287 WARN_STRICT_OVERFLOW_ALL);
12288 return constant_boolean_node (1, type);
12291 if (code == LT_EXPR
12292 && ((code0 == MINUS_EXPR && is_positive > 0)
12293 || (code0 == PLUS_EXPR && is_positive < 0)))
12295 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12296 fold_overflow_warning (("assuming signed overflow does "
12297 "not occur when assuming that "
12298 "(X - c) < X is always true"),
12299 WARN_STRICT_OVERFLOW_ALL);
12300 return constant_boolean_node (1, type);
12303 /* Convert X + c <= X and X - c >= X to false for integers. */
12304 if (code == LE_EXPR
12305 && ((code0 == PLUS_EXPR && is_positive > 0)
12306 || (code0 == MINUS_EXPR && is_positive < 0)))
12308 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12309 fold_overflow_warning (("assuming signed overflow does "
12310 "not occur when assuming that "
12311 "(X + c) <= X is always false"),
12312 WARN_STRICT_OVERFLOW_ALL);
12313 return constant_boolean_node (0, type);
12316 if (code == GE_EXPR
12317 && ((code0 == MINUS_EXPR && is_positive > 0)
12318 || (code0 == PLUS_EXPR && is_positive < 0)))
12320 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12321 fold_overflow_warning (("assuming signed overflow does "
12322 "not occur when assuming that "
12323 "(X - c) >= X is always false"),
12324 WARN_STRICT_OVERFLOW_ALL);
12325 return constant_boolean_node (0, type);
12330 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
12331 This transformation affects the cases which are handled in later
12332 optimizations involving comparisons with non-negative constants. */
12333 if (TREE_CODE (arg1) == INTEGER_CST
12334 && TREE_CODE (arg0) != INTEGER_CST
12335 && tree_int_cst_sgn (arg1) > 0)
12337 if (code == GE_EXPR)
12339 arg1 = const_binop (MINUS_EXPR, arg1,
12340 build_int_cst (TREE_TYPE (arg1), 1), 0);
12341 return fold_build2 (GT_EXPR, type, arg0,
12342 fold_convert (TREE_TYPE (arg0), arg1));
12344 if (code == LT_EXPR)
12346 arg1 = const_binop (MINUS_EXPR, arg1,
12347 build_int_cst (TREE_TYPE (arg1), 1), 0);
12348 return fold_build2 (LE_EXPR, type, arg0,
12349 fold_convert (TREE_TYPE (arg0), arg1));
12353 /* Comparisons with the highest or lowest possible integer of
12354 the specified precision will have known values. */
12356 tree arg1_type = TREE_TYPE (arg1);
12357 unsigned int width = TYPE_PRECISION (arg1_type);
12359 if (TREE_CODE (arg1) == INTEGER_CST
12360 && !TREE_OVERFLOW (arg1)
12361 && width <= 2 * HOST_BITS_PER_WIDE_INT
12362 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
12364 HOST_WIDE_INT signed_max_hi;
12365 unsigned HOST_WIDE_INT signed_max_lo;
12366 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
12368 if (width <= HOST_BITS_PER_WIDE_INT)
12370 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12375 if (TYPE_UNSIGNED (arg1_type))
12377 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12383 max_lo = signed_max_lo;
12384 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12390 width -= HOST_BITS_PER_WIDE_INT;
12391 signed_max_lo = -1;
12392 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12397 if (TYPE_UNSIGNED (arg1_type))
12399 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12404 max_hi = signed_max_hi;
12405 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12409 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
12410 && TREE_INT_CST_LOW (arg1) == max_lo)
12414 return omit_one_operand (type, integer_zero_node, arg0);
12417 return fold_build2 (EQ_EXPR, type, op0, op1);
12420 return omit_one_operand (type, integer_one_node, arg0);
12423 return fold_build2 (NE_EXPR, type, op0, op1);
12425 /* The GE_EXPR and LT_EXPR cases above are not normally
12426 reached because of previous transformations. */
12431 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12433 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
12437 arg1 = const_binop (PLUS_EXPR, arg1,
12438 build_int_cst (TREE_TYPE (arg1), 1), 0);
12439 return fold_build2 (EQ_EXPR, type,
12440 fold_convert (TREE_TYPE (arg1), arg0),
12443 arg1 = const_binop (PLUS_EXPR, arg1,
12444 build_int_cst (TREE_TYPE (arg1), 1), 0);
12445 return fold_build2 (NE_EXPR, type,
12446 fold_convert (TREE_TYPE (arg1), arg0),
12451 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12453 && TREE_INT_CST_LOW (arg1) == min_lo)
12457 return omit_one_operand (type, integer_zero_node, arg0);
12460 return fold_build2 (EQ_EXPR, type, op0, op1);
12463 return omit_one_operand (type, integer_one_node, arg0);
12466 return fold_build2 (NE_EXPR, type, op0, op1);
12471 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12473 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
12477 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12478 return fold_build2 (NE_EXPR, type,
12479 fold_convert (TREE_TYPE (arg1), arg0),
12482 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12483 return fold_build2 (EQ_EXPR, type,
12484 fold_convert (TREE_TYPE (arg1), arg0),
12490 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
12491 && TREE_INT_CST_LOW (arg1) == signed_max_lo
12492 && TYPE_UNSIGNED (arg1_type)
12493 /* We will flip the signedness of the comparison operator
12494 associated with the mode of arg1, so the sign bit is
12495 specified by this mode. Check that arg1 is the signed
12496 max associated with this sign bit. */
12497 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
12498 /* signed_type does not work on pointer types. */
12499 && INTEGRAL_TYPE_P (arg1_type))
12501 /* The following case also applies to X < signed_max+1
12502 and X >= signed_max+1 because previous transformations. */
12503 if (code == LE_EXPR || code == GT_EXPR)
12506 st = signed_type_for (TREE_TYPE (arg1));
12507 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
12508 type, fold_convert (st, arg0),
12509 build_int_cst (st, 0));
12515 /* If we are comparing an ABS_EXPR with a constant, we can
12516 convert all the cases into explicit comparisons, but they may
12517 well not be faster than doing the ABS and one comparison.
12518 But ABS (X) <= C is a range comparison, which becomes a subtraction
12519 and a comparison, and is probably faster. */
12520 if (code == LE_EXPR
12521 && TREE_CODE (arg1) == INTEGER_CST
12522 && TREE_CODE (arg0) == ABS_EXPR
12523 && ! TREE_SIDE_EFFECTS (arg0)
12524 && (0 != (tem = negate_expr (arg1)))
12525 && TREE_CODE (tem) == INTEGER_CST
12526 && !TREE_OVERFLOW (tem))
12527 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12528 build2 (GE_EXPR, type,
12529 TREE_OPERAND (arg0, 0), tem),
12530 build2 (LE_EXPR, type,
12531 TREE_OPERAND (arg0, 0), arg1));
12533 /* Convert ABS_EXPR<x> >= 0 to true. */
12534 strict_overflow_p = false;
12535 if (code == GE_EXPR
12536 && (integer_zerop (arg1)
12537 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
12538 && real_zerop (arg1)))
12539 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12541 if (strict_overflow_p)
12542 fold_overflow_warning (("assuming signed overflow does not occur "
12543 "when simplifying comparison of "
12544 "absolute value and zero"),
12545 WARN_STRICT_OVERFLOW_CONDITIONAL);
12546 return omit_one_operand (type, integer_one_node, arg0);
12549 /* Convert ABS_EXPR<x> < 0 to false. */
12550 strict_overflow_p = false;
12551 if (code == LT_EXPR
12552 && (integer_zerop (arg1) || real_zerop (arg1))
12553 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12555 if (strict_overflow_p)
12556 fold_overflow_warning (("assuming signed overflow does not occur "
12557 "when simplifying comparison of "
12558 "absolute value and zero"),
12559 WARN_STRICT_OVERFLOW_CONDITIONAL);
12560 return omit_one_operand (type, integer_zero_node, arg0);
12563 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
12564 and similarly for >= into !=. */
12565 if ((code == LT_EXPR || code == GE_EXPR)
12566 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12567 && TREE_CODE (arg1) == LSHIFT_EXPR
12568 && integer_onep (TREE_OPERAND (arg1, 0)))
12569 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12570 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12571 TREE_OPERAND (arg1, 1)),
12572 build_int_cst (TREE_TYPE (arg0), 0));
12574 if ((code == LT_EXPR || code == GE_EXPR)
12575 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12576 && (TREE_CODE (arg1) == NOP_EXPR
12577 || TREE_CODE (arg1) == CONVERT_EXPR)
12578 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
12579 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
12581 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12582 fold_convert (TREE_TYPE (arg0),
12583 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12584 TREE_OPERAND (TREE_OPERAND (arg1, 0),
12586 build_int_cst (TREE_TYPE (arg0), 0));
12590 case UNORDERED_EXPR:
12598 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
12600 t1 = fold_relational_const (code, type, arg0, arg1);
12601 if (t1 != NULL_TREE)
12605 /* If the first operand is NaN, the result is constant. */
12606 if (TREE_CODE (arg0) == REAL_CST
12607 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
12608 && (code != LTGT_EXPR || ! flag_trapping_math))
12610 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12611 ? integer_zero_node
12612 : integer_one_node;
12613 return omit_one_operand (type, t1, arg1);
12616 /* If the second operand is NaN, the result is constant. */
12617 if (TREE_CODE (arg1) == REAL_CST
12618 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
12619 && (code != LTGT_EXPR || ! flag_trapping_math))
12621 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12622 ? integer_zero_node
12623 : integer_one_node;
12624 return omit_one_operand (type, t1, arg0);
12627 /* Simplify unordered comparison of something with itself. */
12628 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
12629 && operand_equal_p (arg0, arg1, 0))
12630 return constant_boolean_node (1, type);
12632 if (code == LTGT_EXPR
12633 && !flag_trapping_math
12634 && operand_equal_p (arg0, arg1, 0))
12635 return constant_boolean_node (0, type);
12637 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12639 tree targ0 = strip_float_extensions (arg0);
12640 tree targ1 = strip_float_extensions (arg1);
12641 tree newtype = TREE_TYPE (targ0);
12643 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
12644 newtype = TREE_TYPE (targ1);
12646 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
12647 return fold_build2 (code, type, fold_convert (newtype, targ0),
12648 fold_convert (newtype, targ1));
12653 case COMPOUND_EXPR:
12654 /* When pedantic, a compound expression can be neither an lvalue
12655 nor an integer constant expression. */
12656 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
12658 /* Don't let (0, 0) be null pointer constant. */
12659 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
12660 : fold_convert (type, arg1);
12661 return pedantic_non_lvalue (tem);
12664 if ((TREE_CODE (arg0) == REAL_CST
12665 && TREE_CODE (arg1) == REAL_CST)
12666 || (TREE_CODE (arg0) == INTEGER_CST
12667 && TREE_CODE (arg1) == INTEGER_CST))
12668 return build_complex (type, arg0, arg1);
12672 /* An ASSERT_EXPR should never be passed to fold_binary. */
12673 gcc_unreachable ();
12677 } /* switch (code) */
12680 /* Callback for walk_tree, looking for LABEL_EXPR.
12681 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
12682 Do not check the sub-tree of GOTO_EXPR. */
12685 contains_label_1 (tree *tp,
12686 int *walk_subtrees,
12687 void *data ATTRIBUTE_UNUSED)
12689 switch (TREE_CODE (*tp))
12694 *walk_subtrees = 0;
12701 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
12702 accessible from outside the sub-tree. Returns NULL_TREE if no
12703 addressable label is found. */
12706 contains_label_p (tree st)
12708 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
12711 /* Fold a ternary expression of code CODE and type TYPE with operands
12712 OP0, OP1, and OP2. Return the folded expression if folding is
12713 successful. Otherwise, return NULL_TREE. */
12716 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
12719 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
12720 enum tree_code_class kind = TREE_CODE_CLASS (code);
12722 gcc_assert (IS_EXPR_CODE_CLASS (kind)
12723 && TREE_CODE_LENGTH (code) == 3);
12725 /* Strip any conversions that don't change the mode. This is safe
12726 for every expression, except for a comparison expression because
12727 its signedness is derived from its operands. So, in the latter
12728 case, only strip conversions that don't change the signedness.
12730 Note that this is done as an internal manipulation within the
12731 constant folder, in order to find the simplest representation of
12732 the arguments so that their form can be studied. In any cases,
12733 the appropriate type conversions should be put back in the tree
12734 that will get out of the constant folder. */
12749 case COMPONENT_REF:
12750 if (TREE_CODE (arg0) == CONSTRUCTOR
12751 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
12753 unsigned HOST_WIDE_INT idx;
12755 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
12762 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
12763 so all simple results must be passed through pedantic_non_lvalue. */
12764 if (TREE_CODE (arg0) == INTEGER_CST)
12766 tree unused_op = integer_zerop (arg0) ? op1 : op2;
12767 tem = integer_zerop (arg0) ? op2 : op1;
12768 /* Only optimize constant conditions when the selected branch
12769 has the same type as the COND_EXPR. This avoids optimizing
12770 away "c ? x : throw", where the throw has a void type.
12771 Avoid throwing away that operand which contains label. */
12772 if ((!TREE_SIDE_EFFECTS (unused_op)
12773 || !contains_label_p (unused_op))
12774 && (! VOID_TYPE_P (TREE_TYPE (tem))
12775 || VOID_TYPE_P (type)))
12776 return pedantic_non_lvalue (tem);
12779 if (operand_equal_p (arg1, op2, 0))
12780 return pedantic_omit_one_operand (type, arg1, arg0);
12782 /* If we have A op B ? A : C, we may be able to convert this to a
12783 simpler expression, depending on the operation and the values
12784 of B and C. Signed zeros prevent all of these transformations,
12785 for reasons given above each one.
12787 Also try swapping the arguments and inverting the conditional. */
12788 if (COMPARISON_CLASS_P (arg0)
12789 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12790 arg1, TREE_OPERAND (arg0, 1))
12791 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
12793 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
12798 if (COMPARISON_CLASS_P (arg0)
12799 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12801 TREE_OPERAND (arg0, 1))
12802 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
12804 tem = fold_truth_not_expr (arg0);
12805 if (tem && COMPARISON_CLASS_P (tem))
12807 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
12813 /* If the second operand is simpler than the third, swap them
12814 since that produces better jump optimization results. */
12815 if (truth_value_p (TREE_CODE (arg0))
12816 && tree_swap_operands_p (op1, op2, false))
12818 /* See if this can be inverted. If it can't, possibly because
12819 it was a floating-point inequality comparison, don't do
12821 tem = fold_truth_not_expr (arg0);
12823 return fold_build3 (code, type, tem, op2, op1);
12826 /* Convert A ? 1 : 0 to simply A. */
12827 if (integer_onep (op1)
12828 && integer_zerop (op2)
12829 /* If we try to convert OP0 to our type, the
12830 call to fold will try to move the conversion inside
12831 a COND, which will recurse. In that case, the COND_EXPR
12832 is probably the best choice, so leave it alone. */
12833 && type == TREE_TYPE (arg0))
12834 return pedantic_non_lvalue (arg0);
12836 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
12837 over COND_EXPR in cases such as floating point comparisons. */
12838 if (integer_zerop (op1)
12839 && integer_onep (op2)
12840 && truth_value_p (TREE_CODE (arg0)))
12841 return pedantic_non_lvalue (fold_convert (type,
12842 invert_truthvalue (arg0)));
12844 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
12845 if (TREE_CODE (arg0) == LT_EXPR
12846 && integer_zerop (TREE_OPERAND (arg0, 1))
12847 && integer_zerop (op2)
12848 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
12850 /* sign_bit_p only checks ARG1 bits within A's precision.
12851 If <sign bit of A> has wider type than A, bits outside
12852 of A's precision in <sign bit of A> need to be checked.
12853 If they are all 0, this optimization needs to be done
12854 in unsigned A's type, if they are all 1 in signed A's type,
12855 otherwise this can't be done. */
12856 if (TYPE_PRECISION (TREE_TYPE (tem))
12857 < TYPE_PRECISION (TREE_TYPE (arg1))
12858 && TYPE_PRECISION (TREE_TYPE (tem))
12859 < TYPE_PRECISION (type))
12861 unsigned HOST_WIDE_INT mask_lo;
12862 HOST_WIDE_INT mask_hi;
12863 int inner_width, outer_width;
12866 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
12867 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
12868 if (outer_width > TYPE_PRECISION (type))
12869 outer_width = TYPE_PRECISION (type);
12871 if (outer_width > HOST_BITS_PER_WIDE_INT)
12873 mask_hi = ((unsigned HOST_WIDE_INT) -1
12874 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
12880 mask_lo = ((unsigned HOST_WIDE_INT) -1
12881 >> (HOST_BITS_PER_WIDE_INT - outer_width));
12883 if (inner_width > HOST_BITS_PER_WIDE_INT)
12885 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
12886 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12890 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
12891 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12893 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
12894 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
12896 tem_type = signed_type_for (TREE_TYPE (tem));
12897 tem = fold_convert (tem_type, tem);
12899 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
12900 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
12902 tem_type = unsigned_type_for (TREE_TYPE (tem));
12903 tem = fold_convert (tem_type, tem);
12910 return fold_convert (type,
12911 fold_build2 (BIT_AND_EXPR,
12912 TREE_TYPE (tem), tem,
12913 fold_convert (TREE_TYPE (tem),
12917 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
12918 already handled above. */
12919 if (TREE_CODE (arg0) == BIT_AND_EXPR
12920 && integer_onep (TREE_OPERAND (arg0, 1))
12921 && integer_zerop (op2)
12922 && integer_pow2p (arg1))
12924 tree tem = TREE_OPERAND (arg0, 0);
12926 if (TREE_CODE (tem) == RSHIFT_EXPR
12927 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
12928 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
12929 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
12930 return fold_build2 (BIT_AND_EXPR, type,
12931 TREE_OPERAND (tem, 0), arg1);
12934 /* A & N ? N : 0 is simply A & N if N is a power of two. This
12935 is probably obsolete because the first operand should be a
12936 truth value (that's why we have the two cases above), but let's
12937 leave it in until we can confirm this for all front-ends. */
12938 if (integer_zerop (op2)
12939 && TREE_CODE (arg0) == NE_EXPR
12940 && integer_zerop (TREE_OPERAND (arg0, 1))
12941 && integer_pow2p (arg1)
12942 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12943 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12944 arg1, OEP_ONLY_CONST))
12945 return pedantic_non_lvalue (fold_convert (type,
12946 TREE_OPERAND (arg0, 0)));
12948 /* Convert A ? B : 0 into A && B if A and B are truth values. */
12949 if (integer_zerop (op2)
12950 && truth_value_p (TREE_CODE (arg0))
12951 && truth_value_p (TREE_CODE (arg1)))
12952 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12953 fold_convert (type, arg0),
12956 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
12957 if (integer_onep (op2)
12958 && truth_value_p (TREE_CODE (arg0))
12959 && truth_value_p (TREE_CODE (arg1)))
12961 /* Only perform transformation if ARG0 is easily inverted. */
12962 tem = fold_truth_not_expr (arg0);
12964 return fold_build2 (TRUTH_ORIF_EXPR, type,
12965 fold_convert (type, tem),
12969 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
12970 if (integer_zerop (arg1)
12971 && truth_value_p (TREE_CODE (arg0))
12972 && truth_value_p (TREE_CODE (op2)))
12974 /* Only perform transformation if ARG0 is easily inverted. */
12975 tem = fold_truth_not_expr (arg0);
12977 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12978 fold_convert (type, tem),
12982 /* Convert A ? 1 : B into A || B if A and B are truth values. */
12983 if (integer_onep (arg1)
12984 && truth_value_p (TREE_CODE (arg0))
12985 && truth_value_p (TREE_CODE (op2)))
12986 return fold_build2 (TRUTH_ORIF_EXPR, type,
12987 fold_convert (type, arg0),
12993 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
12994 of fold_ternary on them. */
12995 gcc_unreachable ();
12997 case BIT_FIELD_REF:
12998 if ((TREE_CODE (arg0) == VECTOR_CST
12999 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
13000 && type == TREE_TYPE (TREE_TYPE (arg0)))
13002 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
13003 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
13006 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
13007 && (idx % width) == 0
13008 && (idx = idx / width)
13009 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
13011 tree elements = NULL_TREE;
13013 if (TREE_CODE (arg0) == VECTOR_CST)
13014 elements = TREE_VECTOR_CST_ELTS (arg0);
13017 unsigned HOST_WIDE_INT idx;
13020 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
13021 elements = tree_cons (NULL_TREE, value, elements);
13023 while (idx-- > 0 && elements)
13024 elements = TREE_CHAIN (elements);
13026 return TREE_VALUE (elements);
13028 return fold_convert (type, integer_zero_node);
13035 } /* switch (code) */
13038 /* Perform constant folding and related simplification of EXPR.
13039 The related simplifications include x*1 => x, x*0 => 0, etc.,
13040 and application of the associative law.
13041 NOP_EXPR conversions may be removed freely (as long as we
13042 are careful not to change the type of the overall expression).
13043 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13044 but we can constant-fold them if they have constant operands. */
13046 #ifdef ENABLE_FOLD_CHECKING
13047 # define fold(x) fold_1 (x)
13048 static tree fold_1 (tree);
13054 const tree t = expr;
13055 enum tree_code code = TREE_CODE (t);
13056 enum tree_code_class kind = TREE_CODE_CLASS (code);
13059 /* Return right away if a constant. */
13060 if (kind == tcc_constant)
13063 /* CALL_EXPR-like objects with variable numbers of operands are
13064 treated specially. */
13065 if (kind == tcc_vl_exp)
13067 if (code == CALL_EXPR)
13069 tem = fold_call_expr (expr, false);
13070 return tem ? tem : expr;
13075 if (IS_EXPR_CODE_CLASS (kind)
13076 || IS_GIMPLE_STMT_CODE_CLASS (kind))
13078 tree type = TREE_TYPE (t);
13079 tree op0, op1, op2;
13081 switch (TREE_CODE_LENGTH (code))
13084 op0 = TREE_OPERAND (t, 0);
13085 tem = fold_unary (code, type, op0);
13086 return tem ? tem : expr;
13088 op0 = TREE_OPERAND (t, 0);
13089 op1 = TREE_OPERAND (t, 1);
13090 tem = fold_binary (code, type, op0, op1);
13091 return tem ? tem : expr;
13093 op0 = TREE_OPERAND (t, 0);
13094 op1 = TREE_OPERAND (t, 1);
13095 op2 = TREE_OPERAND (t, 2);
13096 tem = fold_ternary (code, type, op0, op1, op2);
13097 return tem ? tem : expr;
13107 tree op0 = TREE_OPERAND (t, 0);
13108 tree op1 = TREE_OPERAND (t, 1);
13110 if (TREE_CODE (op1) == INTEGER_CST
13111 && TREE_CODE (op0) == CONSTRUCTOR
13112 && ! type_contains_placeholder_p (TREE_TYPE (op0)))
13114 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (op0);
13115 unsigned HOST_WIDE_INT end = VEC_length (constructor_elt, elts);
13116 unsigned HOST_WIDE_INT begin = 0;
13118 /* Find a matching index by means of a binary search. */
13119 while (begin != end)
13121 unsigned HOST_WIDE_INT middle = (begin + end) / 2;
13122 tree index = VEC_index (constructor_elt, elts, middle)->index;
13124 if (TREE_CODE (index) == INTEGER_CST
13125 && tree_int_cst_lt (index, op1))
13126 begin = middle + 1;
13127 else if (TREE_CODE (index) == INTEGER_CST
13128 && tree_int_cst_lt (op1, index))
13130 else if (TREE_CODE (index) == RANGE_EXPR
13131 && tree_int_cst_lt (TREE_OPERAND (index, 1), op1))
13132 begin = middle + 1;
13133 else if (TREE_CODE (index) == RANGE_EXPR
13134 && tree_int_cst_lt (op1, TREE_OPERAND (index, 0)))
13137 return VEC_index (constructor_elt, elts, middle)->value;
13145 return fold (DECL_INITIAL (t));
13149 } /* switch (code) */
13152 #ifdef ENABLE_FOLD_CHECKING
13155 static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
13156 static void fold_check_failed (const_tree, const_tree);
13157 void print_fold_checksum (const_tree);
13159 /* When --enable-checking=fold, compute a digest of expr before
13160 and after actual fold call to see if fold did not accidentally
13161 change original expr. */
13167 struct md5_ctx ctx;
13168 unsigned char checksum_before[16], checksum_after[16];
13171 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13172 md5_init_ctx (&ctx);
13173 fold_checksum_tree (expr, &ctx, ht);
13174 md5_finish_ctx (&ctx, checksum_before);
13177 ret = fold_1 (expr);
13179 md5_init_ctx (&ctx);
13180 fold_checksum_tree (expr, &ctx, ht);
13181 md5_finish_ctx (&ctx, checksum_after);
13184 if (memcmp (checksum_before, checksum_after, 16))
13185 fold_check_failed (expr, ret);
13191 print_fold_checksum (const_tree expr)
13193 struct md5_ctx ctx;
13194 unsigned char checksum[16], cnt;
13197 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13198 md5_init_ctx (&ctx);
13199 fold_checksum_tree (expr, &ctx, ht);
13200 md5_finish_ctx (&ctx, checksum);
13202 for (cnt = 0; cnt < 16; ++cnt)
13203 fprintf (stderr, "%02x", checksum[cnt]);
13204 putc ('\n', stderr);
13208 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
13210 internal_error ("fold check: original tree changed by fold");
13214 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
13217 enum tree_code code;
13218 struct tree_function_decl buf;
13223 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
13224 <= sizeof (struct tree_function_decl))
13225 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
13228 slot = (const void **) htab_find_slot (ht, expr, INSERT);
13232 code = TREE_CODE (expr);
13233 if (TREE_CODE_CLASS (code) == tcc_declaration
13234 && DECL_ASSEMBLER_NAME_SET_P (expr))
13236 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13237 memcpy ((char *) &buf, expr, tree_size (expr));
13238 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
13239 expr = (tree) &buf;
13241 else if (TREE_CODE_CLASS (code) == tcc_type
13242 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
13243 || TYPE_CACHED_VALUES_P (expr)
13244 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
13246 /* Allow these fields to be modified. */
13248 memcpy ((char *) &buf, expr, tree_size (expr));
13249 expr = tmp = (tree) &buf;
13250 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
13251 TYPE_POINTER_TO (tmp) = NULL;
13252 TYPE_REFERENCE_TO (tmp) = NULL;
13253 if (TYPE_CACHED_VALUES_P (tmp))
13255 TYPE_CACHED_VALUES_P (tmp) = 0;
13256 TYPE_CACHED_VALUES (tmp) = NULL;
13259 md5_process_bytes (expr, tree_size (expr), ctx);
13260 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
13261 if (TREE_CODE_CLASS (code) != tcc_type
13262 && TREE_CODE_CLASS (code) != tcc_declaration
13263 && code != TREE_LIST
13264 && code != SSA_NAME)
13265 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
13266 switch (TREE_CODE_CLASS (code))
13272 md5_process_bytes (TREE_STRING_POINTER (expr),
13273 TREE_STRING_LENGTH (expr), ctx);
13276 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
13277 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
13280 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
13286 case tcc_exceptional:
13290 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
13291 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
13292 expr = TREE_CHAIN (expr);
13293 goto recursive_label;
13296 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
13297 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
13303 case tcc_expression:
13304 case tcc_reference:
13305 case tcc_comparison:
13308 case tcc_statement:
13310 len = TREE_OPERAND_LENGTH (expr);
13311 for (i = 0; i < len; ++i)
13312 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
13314 case tcc_declaration:
13315 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
13316 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
13317 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
13319 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
13320 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
13321 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
13322 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
13323 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
13325 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
13326 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
13328 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
13330 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
13331 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
13332 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
13336 if (TREE_CODE (expr) == ENUMERAL_TYPE)
13337 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
13338 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
13339 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
13340 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
13341 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
13342 if (INTEGRAL_TYPE_P (expr)
13343 || SCALAR_FLOAT_TYPE_P (expr))
13345 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
13346 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
13348 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
13349 if (TREE_CODE (expr) == RECORD_TYPE
13350 || TREE_CODE (expr) == UNION_TYPE
13351 || TREE_CODE (expr) == QUAL_UNION_TYPE)
13352 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
13353 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
13360 /* Helper function for outputting the checksum of a tree T. When
13361 debugging with gdb, you can "define mynext" to be "next" followed
13362 by "call debug_fold_checksum (op0)", then just trace down till the
13366 debug_fold_checksum (const_tree t)
13369 unsigned char checksum[16];
13370 struct md5_ctx ctx;
13371 htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13373 md5_init_ctx (&ctx);
13374 fold_checksum_tree (t, &ctx, ht);
13375 md5_finish_ctx (&ctx, checksum);
13378 for (i = 0; i < 16; i++)
13379 fprintf (stderr, "%d ", checksum[i]);
13381 fprintf (stderr, "\n");
13386 /* Fold a unary tree expression with code CODE of type TYPE with an
13387 operand OP0. Return a folded expression if successful. Otherwise,
13388 return a tree expression with code CODE of type TYPE with an
13392 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
13395 #ifdef ENABLE_FOLD_CHECKING
13396 unsigned char checksum_before[16], checksum_after[16];
13397 struct md5_ctx ctx;
13400 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13401 md5_init_ctx (&ctx);
13402 fold_checksum_tree (op0, &ctx, ht);
13403 md5_finish_ctx (&ctx, checksum_before);
13407 tem = fold_unary (code, type, op0);
13409 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
13411 #ifdef ENABLE_FOLD_CHECKING
13412 md5_init_ctx (&ctx);
13413 fold_checksum_tree (op0, &ctx, ht);
13414 md5_finish_ctx (&ctx, checksum_after);
13417 if (memcmp (checksum_before, checksum_after, 16))
13418 fold_check_failed (op0, tem);
13423 /* Fold a binary tree expression with code CODE of type TYPE with
13424 operands OP0 and OP1. Return a folded expression if successful.
13425 Otherwise, return a tree expression with code CODE of type TYPE
13426 with operands OP0 and OP1. */
13429 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
13433 #ifdef ENABLE_FOLD_CHECKING
13434 unsigned char checksum_before_op0[16],
13435 checksum_before_op1[16],
13436 checksum_after_op0[16],
13437 checksum_after_op1[16];
13438 struct md5_ctx ctx;
13441 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13442 md5_init_ctx (&ctx);
13443 fold_checksum_tree (op0, &ctx, ht);
13444 md5_finish_ctx (&ctx, checksum_before_op0);
13447 md5_init_ctx (&ctx);
13448 fold_checksum_tree (op1, &ctx, ht);
13449 md5_finish_ctx (&ctx, checksum_before_op1);
13453 tem = fold_binary (code, type, op0, op1);
13455 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
13457 #ifdef ENABLE_FOLD_CHECKING
13458 md5_init_ctx (&ctx);
13459 fold_checksum_tree (op0, &ctx, ht);
13460 md5_finish_ctx (&ctx, checksum_after_op0);
13463 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13464 fold_check_failed (op0, tem);
13466 md5_init_ctx (&ctx);
13467 fold_checksum_tree (op1, &ctx, ht);
13468 md5_finish_ctx (&ctx, checksum_after_op1);
13471 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13472 fold_check_failed (op1, tem);
13477 /* Fold a ternary tree expression with code CODE of type TYPE with
13478 operands OP0, OP1, and OP2. Return a folded expression if
13479 successful. Otherwise, return a tree expression with code CODE of
13480 type TYPE with operands OP0, OP1, and OP2. */
13483 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
13487 #ifdef ENABLE_FOLD_CHECKING
13488 unsigned char checksum_before_op0[16],
13489 checksum_before_op1[16],
13490 checksum_before_op2[16],
13491 checksum_after_op0[16],
13492 checksum_after_op1[16],
13493 checksum_after_op2[16];
13494 struct md5_ctx ctx;
13497 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13498 md5_init_ctx (&ctx);
13499 fold_checksum_tree (op0, &ctx, ht);
13500 md5_finish_ctx (&ctx, checksum_before_op0);
13503 md5_init_ctx (&ctx);
13504 fold_checksum_tree (op1, &ctx, ht);
13505 md5_finish_ctx (&ctx, checksum_before_op1);
13508 md5_init_ctx (&ctx);
13509 fold_checksum_tree (op2, &ctx, ht);
13510 md5_finish_ctx (&ctx, checksum_before_op2);
13514 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
13515 tem = fold_ternary (code, type, op0, op1, op2);
13517 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
13519 #ifdef ENABLE_FOLD_CHECKING
13520 md5_init_ctx (&ctx);
13521 fold_checksum_tree (op0, &ctx, ht);
13522 md5_finish_ctx (&ctx, checksum_after_op0);
13525 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13526 fold_check_failed (op0, tem);
13528 md5_init_ctx (&ctx);
13529 fold_checksum_tree (op1, &ctx, ht);
13530 md5_finish_ctx (&ctx, checksum_after_op1);
13533 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13534 fold_check_failed (op1, tem);
13536 md5_init_ctx (&ctx);
13537 fold_checksum_tree (op2, &ctx, ht);
13538 md5_finish_ctx (&ctx, checksum_after_op2);
13541 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
13542 fold_check_failed (op2, tem);
13547 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
13548 arguments in ARGARRAY, and a null static chain.
13549 Return a folded expression if successful. Otherwise, return a CALL_EXPR
13550 of type TYPE from the given operands as constructed by build_call_array. */
13553 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
13556 #ifdef ENABLE_FOLD_CHECKING
13557 unsigned char checksum_before_fn[16],
13558 checksum_before_arglist[16],
13559 checksum_after_fn[16],
13560 checksum_after_arglist[16];
13561 struct md5_ctx ctx;
13565 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13566 md5_init_ctx (&ctx);
13567 fold_checksum_tree (fn, &ctx, ht);
13568 md5_finish_ctx (&ctx, checksum_before_fn);
13571 md5_init_ctx (&ctx);
13572 for (i = 0; i < nargs; i++)
13573 fold_checksum_tree (argarray[i], &ctx, ht);
13574 md5_finish_ctx (&ctx, checksum_before_arglist);
13578 tem = fold_builtin_call_array (type, fn, nargs, argarray);
13580 #ifdef ENABLE_FOLD_CHECKING
13581 md5_init_ctx (&ctx);
13582 fold_checksum_tree (fn, &ctx, ht);
13583 md5_finish_ctx (&ctx, checksum_after_fn);
13586 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
13587 fold_check_failed (fn, tem);
13589 md5_init_ctx (&ctx);
13590 for (i = 0; i < nargs; i++)
13591 fold_checksum_tree (argarray[i], &ctx, ht);
13592 md5_finish_ctx (&ctx, checksum_after_arglist);
13595 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
13596 fold_check_failed (NULL_TREE, tem);
13601 /* Perform constant folding and related simplification of initializer
13602 expression EXPR. These behave identically to "fold_buildN" but ignore
13603 potential run-time traps and exceptions that fold must preserve. */
13605 #define START_FOLD_INIT \
13606 int saved_signaling_nans = flag_signaling_nans;\
13607 int saved_trapping_math = flag_trapping_math;\
13608 int saved_rounding_math = flag_rounding_math;\
13609 int saved_trapv = flag_trapv;\
13610 int saved_folding_initializer = folding_initializer;\
13611 flag_signaling_nans = 0;\
13612 flag_trapping_math = 0;\
13613 flag_rounding_math = 0;\
13615 folding_initializer = 1;
13617 #define END_FOLD_INIT \
13618 flag_signaling_nans = saved_signaling_nans;\
13619 flag_trapping_math = saved_trapping_math;\
13620 flag_rounding_math = saved_rounding_math;\
13621 flag_trapv = saved_trapv;\
13622 folding_initializer = saved_folding_initializer;
13625 fold_build1_initializer (enum tree_code code, tree type, tree op)
13630 result = fold_build1 (code, type, op);
13637 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
13642 result = fold_build2 (code, type, op0, op1);
13649 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
13655 result = fold_build3 (code, type, op0, op1, op2);
13662 fold_build_call_array_initializer (tree type, tree fn,
13663 int nargs, tree *argarray)
13668 result = fold_build_call_array (type, fn, nargs, argarray);
13674 #undef START_FOLD_INIT
13675 #undef END_FOLD_INIT
13677 /* Determine if first argument is a multiple of second argument. Return 0 if
13678 it is not, or we cannot easily determined it to be.
13680 An example of the sort of thing we care about (at this point; this routine
13681 could surely be made more general, and expanded to do what the *_DIV_EXPR's
13682 fold cases do now) is discovering that
13684 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13690 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
13692 This code also handles discovering that
13694 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13696 is a multiple of 8 so we don't have to worry about dealing with a
13697 possible remainder.
13699 Note that we *look* inside a SAVE_EXPR only to determine how it was
13700 calculated; it is not safe for fold to do much of anything else with the
13701 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
13702 at run time. For example, the latter example above *cannot* be implemented
13703 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
13704 evaluation time of the original SAVE_EXPR is not necessarily the same at
13705 the time the new expression is evaluated. The only optimization of this
13706 sort that would be valid is changing
13708 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
13712 SAVE_EXPR (I) * SAVE_EXPR (J)
13714 (where the same SAVE_EXPR (J) is used in the original and the
13715 transformed version). */
13718 multiple_of_p (tree type, const_tree top, const_tree bottom)
13720 if (operand_equal_p (top, bottom, 0))
13723 if (TREE_CODE (type) != INTEGER_TYPE)
13726 switch (TREE_CODE (top))
13729 /* Bitwise and provides a power of two multiple. If the mask is
13730 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
13731 if (!integer_pow2p (bottom))
13736 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13737 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13741 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13742 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13745 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
13749 op1 = TREE_OPERAND (top, 1);
13750 /* const_binop may not detect overflow correctly,
13751 so check for it explicitly here. */
13752 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
13753 > TREE_INT_CST_LOW (op1)
13754 && TREE_INT_CST_HIGH (op1) == 0
13755 && 0 != (t1 = fold_convert (type,
13756 const_binop (LSHIFT_EXPR,
13759 && !TREE_OVERFLOW (t1))
13760 return multiple_of_p (type, t1, bottom);
13765 /* Can't handle conversions from non-integral or wider integral type. */
13766 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
13767 || (TYPE_PRECISION (type)
13768 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
13771 /* .. fall through ... */
13774 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
13777 if (TREE_CODE (bottom) != INTEGER_CST
13778 || integer_zerop (bottom)
13779 || (TYPE_UNSIGNED (type)
13780 && (tree_int_cst_sgn (top) < 0
13781 || tree_int_cst_sgn (bottom) < 0)))
13783 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
13791 /* Return true if CODE or TYPE is known to be non-negative. */
13794 tree_simple_nonnegative_warnv_p (enum tree_code code, tree type)
13796 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
13797 && truth_value_p (code))
13798 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
13799 have a signed:1 type (where the value is -1 and 0). */
13804 /* Return true if (CODE OP0) is known to be non-negative. If the return
13805 value is based on the assumption that signed overflow is undefined,
13806 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13807 *STRICT_OVERFLOW_P. */
13810 tree_unary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
13811 bool *strict_overflow_p)
13813 if (TYPE_UNSIGNED (type))
13819 /* We can't return 1 if flag_wrapv is set because
13820 ABS_EXPR<INT_MIN> = INT_MIN. */
13821 if (!INTEGRAL_TYPE_P (type))
13823 if (TYPE_OVERFLOW_UNDEFINED (type))
13825 *strict_overflow_p = true;
13830 case NON_LVALUE_EXPR:
13832 case FIX_TRUNC_EXPR:
13833 return tree_expr_nonnegative_warnv_p (op0,
13834 strict_overflow_p);
13838 tree inner_type = TREE_TYPE (op0);
13839 tree outer_type = type;
13841 if (TREE_CODE (outer_type) == REAL_TYPE)
13843 if (TREE_CODE (inner_type) == REAL_TYPE)
13844 return tree_expr_nonnegative_warnv_p (op0,
13845 strict_overflow_p);
13846 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13848 if (TYPE_UNSIGNED (inner_type))
13850 return tree_expr_nonnegative_warnv_p (op0,
13851 strict_overflow_p);
13854 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
13856 if (TREE_CODE (inner_type) == REAL_TYPE)
13857 return tree_expr_nonnegative_warnv_p (op0,
13858 strict_overflow_p);
13859 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13860 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
13861 && TYPE_UNSIGNED (inner_type);
13867 return tree_simple_nonnegative_warnv_p (code, type);
13870 /* We don't know sign of `t', so be conservative and return false. */
13874 /* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
13875 value is based on the assumption that signed overflow is undefined,
13876 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13877 *STRICT_OVERFLOW_P. */
13880 tree_binary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
13881 tree op1, bool *strict_overflow_p)
13883 if (TYPE_UNSIGNED (type))
13888 case POINTER_PLUS_EXPR:
13890 if (FLOAT_TYPE_P (type))
13891 return (tree_expr_nonnegative_warnv_p (op0,
13893 && tree_expr_nonnegative_warnv_p (op1,
13894 strict_overflow_p));
13896 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
13897 both unsigned and at least 2 bits shorter than the result. */
13898 if (TREE_CODE (type) == INTEGER_TYPE
13899 && TREE_CODE (op0) == NOP_EXPR
13900 && TREE_CODE (op1) == NOP_EXPR)
13902 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
13903 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
13904 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13905 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13907 unsigned int prec = MAX (TYPE_PRECISION (inner1),
13908 TYPE_PRECISION (inner2)) + 1;
13909 return prec < TYPE_PRECISION (type);
13915 if (FLOAT_TYPE_P (type))
13917 /* x * x for floating point x is always non-negative. */
13918 if (operand_equal_p (op0, op1, 0))
13920 return (tree_expr_nonnegative_warnv_p (op0,
13922 && tree_expr_nonnegative_warnv_p (op1,
13923 strict_overflow_p));
13926 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
13927 both unsigned and their total bits is shorter than the result. */
13928 if (TREE_CODE (type) == INTEGER_TYPE
13929 && TREE_CODE (op0) == NOP_EXPR
13930 && TREE_CODE (op1) == NOP_EXPR)
13932 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
13933 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
13934 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13935 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13936 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
13937 < TYPE_PRECISION (type);
13943 return (tree_expr_nonnegative_warnv_p (op0,
13945 || tree_expr_nonnegative_warnv_p (op1,
13946 strict_overflow_p));
13952 case TRUNC_DIV_EXPR:
13953 case CEIL_DIV_EXPR:
13954 case FLOOR_DIV_EXPR:
13955 case ROUND_DIV_EXPR:
13956 return (tree_expr_nonnegative_warnv_p (op0,
13958 && tree_expr_nonnegative_warnv_p (op1,
13959 strict_overflow_p));
13961 case TRUNC_MOD_EXPR:
13962 case CEIL_MOD_EXPR:
13963 case FLOOR_MOD_EXPR:
13964 case ROUND_MOD_EXPR:
13965 return tree_expr_nonnegative_warnv_p (op0,
13966 strict_overflow_p);
13968 return tree_simple_nonnegative_warnv_p (code, type);
13971 /* We don't know sign of `t', so be conservative and return false. */
13975 /* Return true if T is known to be non-negative. If the return
13976 value is based on the assumption that signed overflow is undefined,
13977 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13978 *STRICT_OVERFLOW_P. */
13981 tree_single_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
13983 if (TYPE_UNSIGNED (TREE_TYPE (t)))
13986 switch (TREE_CODE (t))
13989 /* Query VRP to see if it has recorded any information about
13990 the range of this object. */
13991 return ssa_name_nonnegative_p (t);
13994 return tree_int_cst_sgn (t) >= 0;
13997 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
14000 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
14003 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14005 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
14006 strict_overflow_p));
14008 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14011 /* We don't know sign of `t', so be conservative and return false. */
14015 /* Return true if T is known to be non-negative. If the return
14016 value is based on the assumption that signed overflow is undefined,
14017 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14018 *STRICT_OVERFLOW_P. */
14021 tree_call_nonnegative_warnv_p (enum tree_code code, tree type, tree fndecl,
14022 tree arg0, tree arg1, bool *strict_overflow_p)
14024 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
14025 switch (DECL_FUNCTION_CODE (fndecl))
14027 CASE_FLT_FN (BUILT_IN_ACOS):
14028 CASE_FLT_FN (BUILT_IN_ACOSH):
14029 CASE_FLT_FN (BUILT_IN_CABS):
14030 CASE_FLT_FN (BUILT_IN_COSH):
14031 CASE_FLT_FN (BUILT_IN_ERFC):
14032 CASE_FLT_FN (BUILT_IN_EXP):
14033 CASE_FLT_FN (BUILT_IN_EXP10):
14034 CASE_FLT_FN (BUILT_IN_EXP2):
14035 CASE_FLT_FN (BUILT_IN_FABS):
14036 CASE_FLT_FN (BUILT_IN_FDIM):
14037 CASE_FLT_FN (BUILT_IN_HYPOT):
14038 CASE_FLT_FN (BUILT_IN_POW10):
14039 CASE_INT_FN (BUILT_IN_FFS):
14040 CASE_INT_FN (BUILT_IN_PARITY):
14041 CASE_INT_FN (BUILT_IN_POPCOUNT):
14042 case BUILT_IN_BSWAP32:
14043 case BUILT_IN_BSWAP64:
14047 CASE_FLT_FN (BUILT_IN_SQRT):
14048 /* sqrt(-0.0) is -0.0. */
14049 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
14051 return tree_expr_nonnegative_warnv_p (arg0,
14052 strict_overflow_p);
14054 CASE_FLT_FN (BUILT_IN_ASINH):
14055 CASE_FLT_FN (BUILT_IN_ATAN):
14056 CASE_FLT_FN (BUILT_IN_ATANH):
14057 CASE_FLT_FN (BUILT_IN_CBRT):
14058 CASE_FLT_FN (BUILT_IN_CEIL):
14059 CASE_FLT_FN (BUILT_IN_ERF):
14060 CASE_FLT_FN (BUILT_IN_EXPM1):
14061 CASE_FLT_FN (BUILT_IN_FLOOR):
14062 CASE_FLT_FN (BUILT_IN_FMOD):
14063 CASE_FLT_FN (BUILT_IN_FREXP):
14064 CASE_FLT_FN (BUILT_IN_LCEIL):
14065 CASE_FLT_FN (BUILT_IN_LDEXP):
14066 CASE_FLT_FN (BUILT_IN_LFLOOR):
14067 CASE_FLT_FN (BUILT_IN_LLCEIL):
14068 CASE_FLT_FN (BUILT_IN_LLFLOOR):
14069 CASE_FLT_FN (BUILT_IN_LLRINT):
14070 CASE_FLT_FN (BUILT_IN_LLROUND):
14071 CASE_FLT_FN (BUILT_IN_LRINT):
14072 CASE_FLT_FN (BUILT_IN_LROUND):
14073 CASE_FLT_FN (BUILT_IN_MODF):
14074 CASE_FLT_FN (BUILT_IN_NEARBYINT):
14075 CASE_FLT_FN (BUILT_IN_RINT):
14076 CASE_FLT_FN (BUILT_IN_ROUND):
14077 CASE_FLT_FN (BUILT_IN_SCALB):
14078 CASE_FLT_FN (BUILT_IN_SCALBLN):
14079 CASE_FLT_FN (BUILT_IN_SCALBN):
14080 CASE_FLT_FN (BUILT_IN_SIGNBIT):
14081 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
14082 CASE_FLT_FN (BUILT_IN_SINH):
14083 CASE_FLT_FN (BUILT_IN_TANH):
14084 CASE_FLT_FN (BUILT_IN_TRUNC):
14085 /* True if the 1st argument is nonnegative. */
14086 return tree_expr_nonnegative_warnv_p (arg0,
14087 strict_overflow_p);
14089 CASE_FLT_FN (BUILT_IN_FMAX):
14090 /* True if the 1st OR 2nd arguments are nonnegative. */
14091 return (tree_expr_nonnegative_warnv_p (arg0,
14093 || (tree_expr_nonnegative_warnv_p (arg1,
14094 strict_overflow_p)));
14096 CASE_FLT_FN (BUILT_IN_FMIN):
14097 /* True if the 1st AND 2nd arguments are nonnegative. */
14098 return (tree_expr_nonnegative_warnv_p (arg0,
14100 && (tree_expr_nonnegative_warnv_p (arg1,
14101 strict_overflow_p)));
14103 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14104 /* True if the 2nd argument is nonnegative. */
14105 return tree_expr_nonnegative_warnv_p (arg1,
14106 strict_overflow_p);
14108 CASE_FLT_FN (BUILT_IN_POWI):
14109 /* True if the 1st argument is nonnegative or the second
14110 argument is an even integer. */
14111 if (TREE_CODE (arg1) == INTEGER_CST
14112 && (TREE_INT_CST_LOW (arg1) & 1) == 0)
14114 return tree_expr_nonnegative_warnv_p (arg0,
14115 strict_overflow_p);
14117 CASE_FLT_FN (BUILT_IN_POW):
14118 /* True if the 1st argument is nonnegative or the second
14119 argument is an even integer valued real. */
14120 if (TREE_CODE (arg1) == REAL_CST)
14125 c = TREE_REAL_CST (arg1);
14126 n = real_to_integer (&c);
14129 REAL_VALUE_TYPE cint;
14130 real_from_integer (&cint, VOIDmode, n,
14131 n < 0 ? -1 : 0, 0);
14132 if (real_identical (&c, &cint))
14136 return tree_expr_nonnegative_warnv_p (arg0,
14137 strict_overflow_p);
14142 return tree_simple_nonnegative_warnv_p (code,
14146 /* Return true if T is known to be non-negative. If the return
14147 value is based on the assumption that signed overflow is undefined,
14148 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14149 *STRICT_OVERFLOW_P. */
14152 tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14154 enum tree_code code = TREE_CODE (t);
14155 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14162 tree temp = TARGET_EXPR_SLOT (t);
14163 t = TARGET_EXPR_INITIAL (t);
14165 /* If the initializer is non-void, then it's a normal expression
14166 that will be assigned to the slot. */
14167 if (!VOID_TYPE_P (t))
14168 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
14170 /* Otherwise, the initializer sets the slot in some way. One common
14171 way is an assignment statement at the end of the initializer. */
14174 if (TREE_CODE (t) == BIND_EXPR)
14175 t = expr_last (BIND_EXPR_BODY (t));
14176 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
14177 || TREE_CODE (t) == TRY_CATCH_EXPR)
14178 t = expr_last (TREE_OPERAND (t, 0));
14179 else if (TREE_CODE (t) == STATEMENT_LIST)
14184 if ((TREE_CODE (t) == MODIFY_EXPR
14185 || TREE_CODE (t) == GIMPLE_MODIFY_STMT)
14186 && GENERIC_TREE_OPERAND (t, 0) == temp)
14187 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14188 strict_overflow_p);
14195 tree arg0 = call_expr_nargs (t) > 0 ? CALL_EXPR_ARG (t, 0) : NULL_TREE;
14196 tree arg1 = call_expr_nargs (t) > 1 ? CALL_EXPR_ARG (t, 1) : NULL_TREE;
14198 return tree_call_nonnegative_warnv_p (TREE_CODE (t),
14200 get_callee_fndecl (t),
14203 strict_overflow_p);
14205 case COMPOUND_EXPR:
14207 case GIMPLE_MODIFY_STMT:
14208 return tree_expr_nonnegative_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14209 strict_overflow_p);
14211 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
14212 strict_overflow_p);
14214 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14215 strict_overflow_p);
14218 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14222 /* We don't know sign of `t', so be conservative and return false. */
14226 /* Return true if T is known to be non-negative. If the return
14227 value is based on the assumption that signed overflow is undefined,
14228 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14229 *STRICT_OVERFLOW_P. */
14232 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14234 enum tree_code code;
14235 if (t == error_mark_node)
14238 code = TREE_CODE (t);
14239 switch (TREE_CODE_CLASS (code))
14242 case tcc_comparison:
14243 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14245 TREE_OPERAND (t, 0),
14246 TREE_OPERAND (t, 1),
14247 strict_overflow_p);
14250 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14252 TREE_OPERAND (t, 0),
14253 strict_overflow_p);
14256 case tcc_declaration:
14257 case tcc_reference:
14258 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14266 case TRUTH_AND_EXPR:
14267 case TRUTH_OR_EXPR:
14268 case TRUTH_XOR_EXPR:
14269 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14271 TREE_OPERAND (t, 0),
14272 TREE_OPERAND (t, 1),
14273 strict_overflow_p);
14274 case TRUTH_NOT_EXPR:
14275 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14277 TREE_OPERAND (t, 0),
14278 strict_overflow_p);
14285 case WITH_SIZE_EXPR:
14289 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14292 return tree_invalid_nonnegative_warnv_p (t, strict_overflow_p);
14296 /* Return true if `t' is known to be non-negative. Handle warnings
14297 about undefined signed overflow. */
14300 tree_expr_nonnegative_p (tree t)
14302 bool ret, strict_overflow_p;
14304 strict_overflow_p = false;
14305 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
14306 if (strict_overflow_p)
14307 fold_overflow_warning (("assuming signed overflow does not occur when "
14308 "determining that expression is always "
14310 WARN_STRICT_OVERFLOW_MISC);
14315 /* Return true when (CODE OP0) is an address and is known to be nonzero.
14316 For floating point we further ensure that T is not denormal.
14317 Similar logic is present in nonzero_address in rtlanal.h.
14319 If the return value is based on the assumption that signed overflow
14320 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14321 change *STRICT_OVERFLOW_P. */
14324 tree_unary_nonzero_warnv_p (enum tree_code code, tree type, tree op0,
14325 bool *strict_overflow_p)
14330 return tree_expr_nonzero_warnv_p (op0,
14331 strict_overflow_p);
14335 tree inner_type = TREE_TYPE (op0);
14336 tree outer_type = type;
14338 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
14339 && tree_expr_nonzero_warnv_p (op0,
14340 strict_overflow_p));
14344 case NON_LVALUE_EXPR:
14345 return tree_expr_nonzero_warnv_p (op0,
14346 strict_overflow_p);
14355 /* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
14356 For floating point we further ensure that T is not denormal.
14357 Similar logic is present in nonzero_address in rtlanal.h.
14359 If the return value is based on the assumption that signed overflow
14360 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14361 change *STRICT_OVERFLOW_P. */
14364 tree_binary_nonzero_warnv_p (enum tree_code code,
14367 tree op1, bool *strict_overflow_p)
14369 bool sub_strict_overflow_p;
14372 case POINTER_PLUS_EXPR:
14374 if (TYPE_OVERFLOW_UNDEFINED (type))
14376 /* With the presence of negative values it is hard
14377 to say something. */
14378 sub_strict_overflow_p = false;
14379 if (!tree_expr_nonnegative_warnv_p (op0,
14380 &sub_strict_overflow_p)
14381 || !tree_expr_nonnegative_warnv_p (op1,
14382 &sub_strict_overflow_p))
14384 /* One of operands must be positive and the other non-negative. */
14385 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14386 overflows, on a twos-complement machine the sum of two
14387 nonnegative numbers can never be zero. */
14388 return (tree_expr_nonzero_warnv_p (op0,
14390 || tree_expr_nonzero_warnv_p (op1,
14391 strict_overflow_p));
14396 if (TYPE_OVERFLOW_UNDEFINED (type))
14398 if (tree_expr_nonzero_warnv_p (op0,
14400 && tree_expr_nonzero_warnv_p (op1,
14401 strict_overflow_p))
14403 *strict_overflow_p = true;
14410 sub_strict_overflow_p = false;
14411 if (tree_expr_nonzero_warnv_p (op0,
14412 &sub_strict_overflow_p)
14413 && tree_expr_nonzero_warnv_p (op1,
14414 &sub_strict_overflow_p))
14416 if (sub_strict_overflow_p)
14417 *strict_overflow_p = true;
14422 sub_strict_overflow_p = false;
14423 if (tree_expr_nonzero_warnv_p (op0,
14424 &sub_strict_overflow_p))
14426 if (sub_strict_overflow_p)
14427 *strict_overflow_p = true;
14429 /* When both operands are nonzero, then MAX must be too. */
14430 if (tree_expr_nonzero_warnv_p (op1,
14431 strict_overflow_p))
14434 /* MAX where operand 0 is positive is positive. */
14435 return tree_expr_nonnegative_warnv_p (op0,
14436 strict_overflow_p);
14438 /* MAX where operand 1 is positive is positive. */
14439 else if (tree_expr_nonzero_warnv_p (op1,
14440 &sub_strict_overflow_p)
14441 && tree_expr_nonnegative_warnv_p (op1,
14442 &sub_strict_overflow_p))
14444 if (sub_strict_overflow_p)
14445 *strict_overflow_p = true;
14451 return (tree_expr_nonzero_warnv_p (op1,
14453 || tree_expr_nonzero_warnv_p (op0,
14454 strict_overflow_p));
14463 /* Return true when T is an address and is known to be nonzero.
14464 For floating point we further ensure that T is not denormal.
14465 Similar logic is present in nonzero_address in rtlanal.h.
14467 If the return value is based on the assumption that signed overflow
14468 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14469 change *STRICT_OVERFLOW_P. */
14472 tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14474 bool sub_strict_overflow_p;
14475 switch (TREE_CODE (t))
14478 /* Query VRP to see if it has recorded any information about
14479 the range of this object. */
14480 return ssa_name_nonzero_p (t);
14483 return !integer_zerop (t);
14487 tree base = get_base_address (TREE_OPERAND (t, 0));
14492 /* Weak declarations may link to NULL. */
14493 if (VAR_OR_FUNCTION_DECL_P (base))
14494 return !DECL_WEAK (base);
14496 /* Constants are never weak. */
14497 if (CONSTANT_CLASS_P (base))
14504 sub_strict_overflow_p = false;
14505 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14506 &sub_strict_overflow_p)
14507 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
14508 &sub_strict_overflow_p))
14510 if (sub_strict_overflow_p)
14511 *strict_overflow_p = true;
14522 /* Return true when T is an address and is known to be nonzero.
14523 For floating point we further ensure that T is not denormal.
14524 Similar logic is present in nonzero_address in rtlanal.h.
14526 If the return value is based on the assumption that signed overflow
14527 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14528 change *STRICT_OVERFLOW_P. */
14531 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14533 tree type = TREE_TYPE (t);
14534 enum tree_code code;
14536 /* Doing something useful for floating point would need more work. */
14537 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
14540 code = TREE_CODE (t);
14541 switch (TREE_CODE_CLASS (code))
14544 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
14545 strict_overflow_p);
14547 case tcc_comparison:
14548 return tree_binary_nonzero_warnv_p (code, type,
14549 TREE_OPERAND (t, 0),
14550 TREE_OPERAND (t, 1),
14551 strict_overflow_p);
14553 case tcc_declaration:
14554 case tcc_reference:
14555 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
14563 case TRUTH_NOT_EXPR:
14564 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
14565 strict_overflow_p);
14567 case TRUTH_AND_EXPR:
14568 case TRUTH_OR_EXPR:
14569 case TRUTH_XOR_EXPR:
14570 return tree_binary_nonzero_warnv_p (code, type,
14571 TREE_OPERAND (t, 0),
14572 TREE_OPERAND (t, 1),
14573 strict_overflow_p);
14580 case WITH_SIZE_EXPR:
14584 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
14586 case COMPOUND_EXPR:
14588 case GIMPLE_MODIFY_STMT:
14590 return tree_expr_nonzero_warnv_p (GENERIC_TREE_OPERAND (t, 1),
14591 strict_overflow_p);
14594 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14595 strict_overflow_p);
14598 return alloca_call_p (t);
14606 /* Return true when T is an address and is known to be nonzero.
14607 Handle warnings about undefined signed overflow. */
14610 tree_expr_nonzero_p (tree t)
14612 bool ret, strict_overflow_p;
14614 strict_overflow_p = false;
14615 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
14616 if (strict_overflow_p)
14617 fold_overflow_warning (("assuming signed overflow does not occur when "
14618 "determining that expression is always "
14620 WARN_STRICT_OVERFLOW_MISC);
14624 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
14625 attempt to fold the expression to a constant without modifying TYPE,
14628 If the expression could be simplified to a constant, then return
14629 the constant. If the expression would not be simplified to a
14630 constant, then return NULL_TREE. */
14633 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
14635 tree tem = fold_binary (code, type, op0, op1);
14636 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14639 /* Given the components of a unary expression CODE, TYPE and OP0,
14640 attempt to fold the expression to a constant without modifying
14643 If the expression could be simplified to a constant, then return
14644 the constant. If the expression would not be simplified to a
14645 constant, then return NULL_TREE. */
14648 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
14650 tree tem = fold_unary (code, type, op0);
14651 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14654 /* If EXP represents referencing an element in a constant string
14655 (either via pointer arithmetic or array indexing), return the
14656 tree representing the value accessed, otherwise return NULL. */
14659 fold_read_from_constant_string (tree exp)
14661 if ((TREE_CODE (exp) == INDIRECT_REF
14662 || TREE_CODE (exp) == ARRAY_REF)
14663 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
14665 tree exp1 = TREE_OPERAND (exp, 0);
14669 if (TREE_CODE (exp) == INDIRECT_REF)
14670 string = string_constant (exp1, &index);
14673 tree low_bound = array_ref_low_bound (exp);
14674 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
14676 /* Optimize the special-case of a zero lower bound.
14678 We convert the low_bound to sizetype to avoid some problems
14679 with constant folding. (E.g. suppose the lower bound is 1,
14680 and its mode is QI. Without the conversion,l (ARRAY
14681 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
14682 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
14683 if (! integer_zerop (low_bound))
14684 index = size_diffop (index, fold_convert (sizetype, low_bound));
14690 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
14691 && TREE_CODE (string) == STRING_CST
14692 && TREE_CODE (index) == INTEGER_CST
14693 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
14694 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
14696 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
14697 return build_int_cst_type (TREE_TYPE (exp),
14698 (TREE_STRING_POINTER (string)
14699 [TREE_INT_CST_LOW (index)]));
14704 /* Return the tree for neg (ARG0) when ARG0 is known to be either
14705 an integer constant, real, or fixed-point constant.
14707 TYPE is the type of the result. */
14710 fold_negate_const (tree arg0, tree type)
14712 tree t = NULL_TREE;
14714 switch (TREE_CODE (arg0))
14718 unsigned HOST_WIDE_INT low;
14719 HOST_WIDE_INT high;
14720 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14721 TREE_INT_CST_HIGH (arg0),
14723 t = force_fit_type_double (type, low, high, 1,
14724 (overflow | TREE_OVERFLOW (arg0))
14725 && !TYPE_UNSIGNED (type));
14730 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14735 FIXED_VALUE_TYPE f;
14736 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
14737 &(TREE_FIXED_CST (arg0)), NULL,
14738 TYPE_SATURATING (type));
14739 t = build_fixed (type, f);
14740 /* Propagate overflow flags. */
14741 if (overflow_p | TREE_OVERFLOW (arg0))
14743 TREE_OVERFLOW (t) = 1;
14744 TREE_CONSTANT_OVERFLOW (t) = 1;
14746 else if (TREE_CONSTANT_OVERFLOW (arg0))
14747 TREE_CONSTANT_OVERFLOW (t) = 1;
14752 gcc_unreachable ();
14758 /* Return the tree for abs (ARG0) when ARG0 is known to be either
14759 an integer constant or real constant.
14761 TYPE is the type of the result. */
14764 fold_abs_const (tree arg0, tree type)
14766 tree t = NULL_TREE;
14768 switch (TREE_CODE (arg0))
14771 /* If the value is unsigned, then the absolute value is
14772 the same as the ordinary value. */
14773 if (TYPE_UNSIGNED (type))
14775 /* Similarly, if the value is non-negative. */
14776 else if (INT_CST_LT (integer_minus_one_node, arg0))
14778 /* If the value is negative, then the absolute value is
14782 unsigned HOST_WIDE_INT low;
14783 HOST_WIDE_INT high;
14784 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14785 TREE_INT_CST_HIGH (arg0),
14787 t = force_fit_type_double (type, low, high, -1,
14788 overflow | TREE_OVERFLOW (arg0));
14793 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
14794 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14800 gcc_unreachable ();
14806 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
14807 constant. TYPE is the type of the result. */
14810 fold_not_const (tree arg0, tree type)
14812 tree t = NULL_TREE;
14814 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
14816 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
14817 ~TREE_INT_CST_HIGH (arg0), 0,
14818 TREE_OVERFLOW (arg0));
14823 /* Given CODE, a relational operator, the target type, TYPE and two
14824 constant operands OP0 and OP1, return the result of the
14825 relational operation. If the result is not a compile time
14826 constant, then return NULL_TREE. */
14829 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
14831 int result, invert;
14833 /* From here on, the only cases we handle are when the result is
14834 known to be a constant. */
14836 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
14838 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
14839 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
14841 /* Handle the cases where either operand is a NaN. */
14842 if (real_isnan (c0) || real_isnan (c1))
14852 case UNORDERED_EXPR:
14866 if (flag_trapping_math)
14872 gcc_unreachable ();
14875 return constant_boolean_node (result, type);
14878 return constant_boolean_node (real_compare (code, c0, c1), type);
14881 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
14883 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
14884 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
14885 return constant_boolean_node (fixed_compare (code, c0, c1), type);
14888 /* Handle equality/inequality of complex constants. */
14889 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
14891 tree rcond = fold_relational_const (code, type,
14892 TREE_REALPART (op0),
14893 TREE_REALPART (op1));
14894 tree icond = fold_relational_const (code, type,
14895 TREE_IMAGPART (op0),
14896 TREE_IMAGPART (op1));
14897 if (code == EQ_EXPR)
14898 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
14899 else if (code == NE_EXPR)
14900 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
14905 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14907 To compute GT, swap the arguments and do LT.
14908 To compute GE, do LT and invert the result.
14909 To compute LE, swap the arguments, do LT and invert the result.
14910 To compute NE, do EQ and invert the result.
14912 Therefore, the code below must handle only EQ and LT. */
14914 if (code == LE_EXPR || code == GT_EXPR)
14919 code = swap_tree_comparison (code);
14922 /* Note that it is safe to invert for real values here because we
14923 have already handled the one case that it matters. */
14926 if (code == NE_EXPR || code == GE_EXPR)
14929 code = invert_tree_comparison (code, false);
14932 /* Compute a result for LT or EQ if args permit;
14933 Otherwise return T. */
14934 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
14936 if (code == EQ_EXPR)
14937 result = tree_int_cst_equal (op0, op1);
14938 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
14939 result = INT_CST_LT_UNSIGNED (op0, op1);
14941 result = INT_CST_LT (op0, op1);
14948 return constant_boolean_node (result, type);
14951 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
14952 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
14956 fold_build_cleanup_point_expr (tree type, tree expr)
14958 /* If the expression does not have side effects then we don't have to wrap
14959 it with a cleanup point expression. */
14960 if (!TREE_SIDE_EFFECTS (expr))
14963 /* If the expression is a return, check to see if the expression inside the
14964 return has no side effects or the right hand side of the modify expression
14965 inside the return. If either don't have side effects set we don't need to
14966 wrap the expression in a cleanup point expression. Note we don't check the
14967 left hand side of the modify because it should always be a return decl. */
14968 if (TREE_CODE (expr) == RETURN_EXPR)
14970 tree op = TREE_OPERAND (expr, 0);
14971 if (!op || !TREE_SIDE_EFFECTS (op))
14973 op = TREE_OPERAND (op, 1);
14974 if (!TREE_SIDE_EFFECTS (op))
14978 return build1 (CLEANUP_POINT_EXPR, type, expr);
14981 /* Given a pointer value OP0 and a type TYPE, return a simplified version
14982 of an indirection through OP0, or NULL_TREE if no simplification is
14986 fold_indirect_ref_1 (tree type, tree op0)
14992 subtype = TREE_TYPE (sub);
14993 if (!POINTER_TYPE_P (subtype))
14996 if (TREE_CODE (sub) == ADDR_EXPR)
14998 tree op = TREE_OPERAND (sub, 0);
14999 tree optype = TREE_TYPE (op);
15000 /* *&CONST_DECL -> to the value of the const decl. */
15001 if (TREE_CODE (op) == CONST_DECL)
15002 return DECL_INITIAL (op);
15003 /* *&p => p; make sure to handle *&"str"[cst] here. */
15004 if (type == optype)
15006 tree fop = fold_read_from_constant_string (op);
15012 /* *(foo *)&fooarray => fooarray[0] */
15013 else if (TREE_CODE (optype) == ARRAY_TYPE
15014 && type == TREE_TYPE (optype))
15016 tree type_domain = TYPE_DOMAIN (optype);
15017 tree min_val = size_zero_node;
15018 if (type_domain && TYPE_MIN_VALUE (type_domain))
15019 min_val = TYPE_MIN_VALUE (type_domain);
15020 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
15022 /* *(foo *)&complexfoo => __real__ complexfoo */
15023 else if (TREE_CODE (optype) == COMPLEX_TYPE
15024 && type == TREE_TYPE (optype))
15025 return fold_build1 (REALPART_EXPR, type, op);
15026 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
15027 else if (TREE_CODE (optype) == VECTOR_TYPE
15028 && type == TREE_TYPE (optype))
15030 tree part_width = TYPE_SIZE (type);
15031 tree index = bitsize_int (0);
15032 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
15036 /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
15037 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15038 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15040 tree op00 = TREE_OPERAND (sub, 0);
15041 tree op01 = TREE_OPERAND (sub, 1);
15045 op00type = TREE_TYPE (op00);
15046 if (TREE_CODE (op00) == ADDR_EXPR
15047 && TREE_CODE (TREE_TYPE (op00type)) == VECTOR_TYPE
15048 && type == TREE_TYPE (TREE_TYPE (op00type)))
15050 HOST_WIDE_INT offset = tree_low_cst (op01, 0);
15051 tree part_width = TYPE_SIZE (type);
15052 unsigned HOST_WIDE_INT part_widthi = tree_low_cst (part_width, 0)/BITS_PER_UNIT;
15053 unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
15054 tree index = bitsize_int (indexi);
15056 if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (op00type)))
15057 return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (op00, 0),
15058 part_width, index);
15064 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
15065 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15066 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15068 tree op00 = TREE_OPERAND (sub, 0);
15069 tree op01 = TREE_OPERAND (sub, 1);
15073 op00type = TREE_TYPE (op00);
15074 if (TREE_CODE (op00) == ADDR_EXPR
15075 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
15076 && type == TREE_TYPE (TREE_TYPE (op00type)))
15078 tree size = TYPE_SIZE_UNIT (type);
15079 if (tree_int_cst_equal (size, op01))
15080 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
15084 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
15085 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
15086 && type == TREE_TYPE (TREE_TYPE (subtype)))
15089 tree min_val = size_zero_node;
15090 sub = build_fold_indirect_ref (sub);
15091 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
15092 if (type_domain && TYPE_MIN_VALUE (type_domain))
15093 min_val = TYPE_MIN_VALUE (type_domain);
15094 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
15100 /* Builds an expression for an indirection through T, simplifying some
15104 build_fold_indirect_ref (tree t)
15106 tree type = TREE_TYPE (TREE_TYPE (t));
15107 tree sub = fold_indirect_ref_1 (type, t);
15112 return build1 (INDIRECT_REF, type, t);
15115 /* Given an INDIRECT_REF T, return either T or a simplified version. */
15118 fold_indirect_ref (tree t)
15120 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
15128 /* Strip non-trapping, non-side-effecting tree nodes from an expression
15129 whose result is ignored. The type of the returned tree need not be
15130 the same as the original expression. */
15133 fold_ignored_result (tree t)
15135 if (!TREE_SIDE_EFFECTS (t))
15136 return integer_zero_node;
15139 switch (TREE_CODE_CLASS (TREE_CODE (t)))
15142 t = TREE_OPERAND (t, 0);
15146 case tcc_comparison:
15147 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15148 t = TREE_OPERAND (t, 0);
15149 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
15150 t = TREE_OPERAND (t, 1);
15155 case tcc_expression:
15156 switch (TREE_CODE (t))
15158 case COMPOUND_EXPR:
15159 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15161 t = TREE_OPERAND (t, 0);
15165 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
15166 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
15168 t = TREE_OPERAND (t, 0);
15181 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
15182 This can only be applied to objects of a sizetype. */
15185 round_up (tree value, int divisor)
15187 tree div = NULL_TREE;
15189 gcc_assert (divisor > 0);
15193 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15194 have to do anything. Only do this when we are not given a const,
15195 because in that case, this check is more expensive than just
15197 if (TREE_CODE (value) != INTEGER_CST)
15199 div = build_int_cst (TREE_TYPE (value), divisor);
15201 if (multiple_of_p (TREE_TYPE (value), value, div))
15205 /* If divisor is a power of two, simplify this to bit manipulation. */
15206 if (divisor == (divisor & -divisor))
15208 if (TREE_CODE (value) == INTEGER_CST)
15210 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
15211 unsigned HOST_WIDE_INT high;
15214 if ((low & (divisor - 1)) == 0)
15217 overflow_p = TREE_OVERFLOW (value);
15218 high = TREE_INT_CST_HIGH (value);
15219 low &= ~(divisor - 1);
15228 return force_fit_type_double (TREE_TYPE (value), low, high,
15235 t = build_int_cst (TREE_TYPE (value), divisor - 1);
15236 value = size_binop (PLUS_EXPR, value, t);
15237 t = build_int_cst (TREE_TYPE (value), -divisor);
15238 value = size_binop (BIT_AND_EXPR, value, t);
15244 div = build_int_cst (TREE_TYPE (value), divisor);
15245 value = size_binop (CEIL_DIV_EXPR, value, div);
15246 value = size_binop (MULT_EXPR, value, div);
15252 /* Likewise, but round down. */
15255 round_down (tree value, int divisor)
15257 tree div = NULL_TREE;
15259 gcc_assert (divisor > 0);
15263 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15264 have to do anything. Only do this when we are not given a const,
15265 because in that case, this check is more expensive than just
15267 if (TREE_CODE (value) != INTEGER_CST)
15269 div = build_int_cst (TREE_TYPE (value), divisor);
15271 if (multiple_of_p (TREE_TYPE (value), value, div))
15275 /* If divisor is a power of two, simplify this to bit manipulation. */
15276 if (divisor == (divisor & -divisor))
15280 t = build_int_cst (TREE_TYPE (value), -divisor);
15281 value = size_binop (BIT_AND_EXPR, value, t);
15286 div = build_int_cst (TREE_TYPE (value), divisor);
15287 value = size_binop (FLOOR_DIV_EXPR, value, div);
15288 value = size_binop (MULT_EXPR, value, div);
15294 /* Returns the pointer to the base of the object addressed by EXP and
15295 extracts the information about the offset of the access, storing it
15296 to PBITPOS and POFFSET. */
15299 split_address_to_core_and_offset (tree exp,
15300 HOST_WIDE_INT *pbitpos, tree *poffset)
15303 enum machine_mode mode;
15304 int unsignedp, volatilep;
15305 HOST_WIDE_INT bitsize;
15307 if (TREE_CODE (exp) == ADDR_EXPR)
15309 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
15310 poffset, &mode, &unsignedp, &volatilep,
15312 core = fold_addr_expr (core);
15318 *poffset = NULL_TREE;
15324 /* Returns true if addresses of E1 and E2 differ by a constant, false
15325 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15328 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
15331 HOST_WIDE_INT bitpos1, bitpos2;
15332 tree toffset1, toffset2, tdiff, type;
15334 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
15335 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
15337 if (bitpos1 % BITS_PER_UNIT != 0
15338 || bitpos2 % BITS_PER_UNIT != 0
15339 || !operand_equal_p (core1, core2, 0))
15342 if (toffset1 && toffset2)
15344 type = TREE_TYPE (toffset1);
15345 if (type != TREE_TYPE (toffset2))
15346 toffset2 = fold_convert (type, toffset2);
15348 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
15349 if (!cst_and_fits_in_hwi (tdiff))
15352 *diff = int_cst_value (tdiff);
15354 else if (toffset1 || toffset2)
15356 /* If only one of the offsets is non-constant, the difference cannot
15363 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
15367 /* Simplify the floating point expression EXP when the sign of the
15368 result is not significant. Return NULL_TREE if no simplification
15372 fold_strip_sign_ops (tree exp)
15376 switch (TREE_CODE (exp))
15380 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15381 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
15385 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
15387 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15388 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15389 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
15390 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
15391 arg0 ? arg0 : TREE_OPERAND (exp, 0),
15392 arg1 ? arg1 : TREE_OPERAND (exp, 1));
15395 case COMPOUND_EXPR:
15396 arg0 = TREE_OPERAND (exp, 0);
15397 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15399 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
15403 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15404 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
15406 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
15407 arg0 ? arg0 : TREE_OPERAND (exp, 1),
15408 arg1 ? arg1 : TREE_OPERAND (exp, 2));
15413 const enum built_in_function fcode = builtin_mathfn_code (exp);
15416 CASE_FLT_FN (BUILT_IN_COPYSIGN):
15417 /* Strip copysign function call, return the 1st argument. */
15418 arg0 = CALL_EXPR_ARG (exp, 0);
15419 arg1 = CALL_EXPR_ARG (exp, 1);
15420 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
15423 /* Strip sign ops from the argument of "odd" math functions. */
15424 if (negate_mathfn_p (fcode))
15426 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
15428 return build_call_expr (get_callee_fndecl (exp), 1, arg0);