1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
31 and force_fit_type_double.
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type_double takes a constant, an overflowable flag and a
43 prior overflow indicator. It forces the value to fit the type and
46 Note: Since the folders get called on non-gimple code as well as
47 gimple code, we need to handle GIMPLE tuples as well as their
48 corresponding tree equivalents. */
52 #include "coretypes.h"
57 #include "fixed-value.h"
66 #include "langhooks.h"
70 /* Nonzero if we are folding constants inside an initializer; zero
72 int folding_initializer = 0;
74 /* The following constants represent a bit based encoding of GCC's
75 comparison operators. This encoding simplifies transformations
76 on relational comparison operators, such as AND and OR. */
77 enum comparison_code {
96 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
97 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
98 static bool negate_mathfn_p (enum built_in_function);
99 static bool negate_expr_p (tree);
100 static tree negate_expr (tree);
101 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
102 static tree associate_trees (tree, tree, enum tree_code, tree);
103 static tree const_binop (enum tree_code, tree, tree, int);
104 static enum comparison_code comparison_to_compcode (enum tree_code);
105 static enum tree_code compcode_to_comparison (enum comparison_code);
106 static tree combine_comparisons (enum tree_code, enum tree_code,
107 enum tree_code, tree, tree, tree);
108 static int truth_value_p (enum tree_code);
109 static int operand_equal_for_comparison_p (tree, tree, tree);
110 static int twoval_comparison_p (tree, tree *, tree *, int *);
111 static tree eval_subst (tree, tree, tree, tree, tree);
112 static tree pedantic_omit_one_operand (tree, tree, tree);
113 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
114 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
115 enum machine_mode *, int *, int *,
117 static tree sign_bit_p (tree, const_tree);
118 static int simple_operand_p (const_tree);
119 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
120 static tree range_predecessor (tree);
121 static tree range_successor (tree);
122 static tree make_range (tree, int *, tree *, tree *, bool *);
123 static tree build_range_check (tree, tree, int, tree, tree);
124 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
126 static tree fold_range_test (enum tree_code, tree, tree, tree);
127 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
128 static tree unextend (tree, int, int, tree);
129 static tree fold_truthop (enum tree_code, tree, tree, tree);
130 static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
131 static tree extract_muldiv (tree, tree, enum tree_code, tree, bool *);
132 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree, bool *);
133 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
136 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
138 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
139 static tree fold_div_compare (enum tree_code, tree, tree, tree);
140 static bool reorder_operands_p (const_tree, const_tree);
141 static tree fold_negate_const (tree, tree);
142 static tree fold_not_const (tree, tree);
143 static tree fold_relational_const (enum tree_code, tree, tree, tree);
146 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
147 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
148 and SUM1. Then this yields nonzero if overflow occurred during the
151 Overflow occurs if A and B have the same sign, but A and SUM differ in
152 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
154 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
156 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
157 We do that by representing the two-word integer in 4 words, with only
158 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
159 number. The value of the word is LOWPART + HIGHPART * BASE. */
162 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
163 #define HIGHPART(x) \
164 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
165 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
167 /* Unpack a two-word integer into 4 words.
168 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
169 WORDS points to the array of HOST_WIDE_INTs. */
172 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
174 words[0] = LOWPART (low);
175 words[1] = HIGHPART (low);
176 words[2] = LOWPART (hi);
177 words[3] = HIGHPART (hi);
180 /* Pack an array of 4 words into a two-word integer.
181 WORDS points to the array of words.
182 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
185 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
188 *low = words[0] + words[1] * BASE;
189 *hi = words[2] + words[3] * BASE;
192 /* Force the double-word integer L1, H1 to be within the range of the
193 integer type TYPE. Stores the properly truncated and sign-extended
194 double-word integer in *LV, *HV. Returns true if the operation
195 overflows, that is, argument and result are different. */
198 fit_double_type (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
199 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, const_tree type)
201 unsigned HOST_WIDE_INT low0 = l1;
202 HOST_WIDE_INT high0 = h1;
204 int sign_extended_type;
206 if (POINTER_TYPE_P (type)
207 || TREE_CODE (type) == OFFSET_TYPE)
210 prec = TYPE_PRECISION (type);
212 /* Size types *are* sign extended. */
213 sign_extended_type = (!TYPE_UNSIGNED (type)
214 || (TREE_CODE (type) == INTEGER_TYPE
215 && TYPE_IS_SIZETYPE (type)));
217 /* First clear all bits that are beyond the type's precision. */
218 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
220 else if (prec > HOST_BITS_PER_WIDE_INT)
221 h1 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
225 if (prec < HOST_BITS_PER_WIDE_INT)
226 l1 &= ~((HOST_WIDE_INT) (-1) << prec);
229 /* Then do sign extension if necessary. */
230 if (!sign_extended_type)
231 /* No sign extension */;
232 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
233 /* Correct width already. */;
234 else if (prec > HOST_BITS_PER_WIDE_INT)
236 /* Sign extend top half? */
237 if (h1 & ((unsigned HOST_WIDE_INT)1
238 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
239 h1 |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
241 else if (prec == HOST_BITS_PER_WIDE_INT)
243 if ((HOST_WIDE_INT)l1 < 0)
248 /* Sign extend bottom half? */
249 if (l1 & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
252 l1 |= (HOST_WIDE_INT)(-1) << prec;
259 /* If the value didn't fit, signal overflow. */
260 return l1 != low0 || h1 != high0;
263 /* We force the double-int HIGH:LOW to the range of the type TYPE by
264 sign or zero extending it.
265 OVERFLOWABLE indicates if we are interested
266 in overflow of the value, when >0 we are only interested in signed
267 overflow, for <0 we are interested in any overflow. OVERFLOWED
268 indicates whether overflow has already occurred. CONST_OVERFLOWED
269 indicates whether constant overflow has already occurred. We force
270 T's value to be within range of T's type (by setting to 0 or 1 all
271 the bits outside the type's range). We set TREE_OVERFLOWED if,
272 OVERFLOWED is nonzero,
273 or OVERFLOWABLE is >0 and signed overflow occurs
274 or OVERFLOWABLE is <0 and any overflow occurs
275 We return a new tree node for the extended double-int. The node
276 is shared if no overflow flags are set. */
279 force_fit_type_double (tree type, unsigned HOST_WIDE_INT low,
280 HOST_WIDE_INT high, int overflowable,
283 int sign_extended_type;
286 /* Size types *are* sign extended. */
287 sign_extended_type = (!TYPE_UNSIGNED (type)
288 || (TREE_CODE (type) == INTEGER_TYPE
289 && TYPE_IS_SIZETYPE (type)));
291 overflow = fit_double_type (low, high, &low, &high, type);
293 /* If we need to set overflow flags, return a new unshared node. */
294 if (overflowed || overflow)
298 || (overflowable > 0 && sign_extended_type))
300 tree t = make_node (INTEGER_CST);
301 TREE_INT_CST_LOW (t) = low;
302 TREE_INT_CST_HIGH (t) = high;
303 TREE_TYPE (t) = type;
304 TREE_OVERFLOW (t) = 1;
309 /* Else build a shared node. */
310 return build_int_cst_wide (type, low, high);
313 /* Add two doubleword integers with doubleword result.
314 Return nonzero if the operation overflows according to UNSIGNED_P.
315 Each argument is given as two `HOST_WIDE_INT' pieces.
316 One argument is L1 and H1; the other, L2 and H2.
317 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
320 add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
321 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
322 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
325 unsigned HOST_WIDE_INT l;
329 h = h1 + h2 + (l < l1);
335 return (unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1;
337 return OVERFLOW_SUM_SIGN (h1, h2, h);
340 /* Negate a doubleword integer with doubleword result.
341 Return nonzero if the operation overflows, assuming it's signed.
342 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
343 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
346 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
347 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
353 return (*hv & h1) < 0;
363 /* Multiply two doubleword integers with doubleword result.
364 Return nonzero if the operation overflows according to UNSIGNED_P.
365 Each argument is given as two `HOST_WIDE_INT' pieces.
366 One argument is L1 and H1; the other, L2 and H2.
367 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
370 mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
371 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
372 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
375 HOST_WIDE_INT arg1[4];
376 HOST_WIDE_INT arg2[4];
377 HOST_WIDE_INT prod[4 * 2];
378 unsigned HOST_WIDE_INT carry;
380 unsigned HOST_WIDE_INT toplow, neglow;
381 HOST_WIDE_INT tophigh, neghigh;
383 encode (arg1, l1, h1);
384 encode (arg2, l2, h2);
386 memset (prod, 0, sizeof prod);
388 for (i = 0; i < 4; i++)
391 for (j = 0; j < 4; j++)
394 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
395 carry += arg1[i] * arg2[j];
396 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
398 prod[k] = LOWPART (carry);
399 carry = HIGHPART (carry);
404 decode (prod, lv, hv);
405 decode (prod + 4, &toplow, &tophigh);
407 /* Unsigned overflow is immediate. */
409 return (toplow | tophigh) != 0;
411 /* Check for signed overflow by calculating the signed representation of the
412 top half of the result; it should agree with the low half's sign bit. */
415 neg_double (l2, h2, &neglow, &neghigh);
416 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
420 neg_double (l1, h1, &neglow, &neghigh);
421 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
423 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
426 /* Shift the doubleword integer in L1, H1 left by COUNT places
427 keeping only PREC bits of result.
428 Shift right if COUNT is negative.
429 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
430 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
433 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
434 HOST_WIDE_INT count, unsigned int prec,
435 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
437 unsigned HOST_WIDE_INT signmask;
441 rshift_double (l1, h1, -count, prec, lv, hv, arith);
445 if (SHIFT_COUNT_TRUNCATED)
448 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
450 /* Shifting by the host word size is undefined according to the
451 ANSI standard, so we must handle this as a special case. */
455 else if (count >= HOST_BITS_PER_WIDE_INT)
457 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
462 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
463 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
467 /* Sign extend all bits that are beyond the precision. */
469 signmask = -((prec > HOST_BITS_PER_WIDE_INT
470 ? ((unsigned HOST_WIDE_INT) *hv
471 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
472 : (*lv >> (prec - 1))) & 1);
474 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
476 else if (prec >= HOST_BITS_PER_WIDE_INT)
478 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
479 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
484 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
485 *lv |= signmask << prec;
489 /* Shift the doubleword integer in L1, H1 right by COUNT places
490 keeping only PREC bits of result. COUNT must be positive.
491 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
492 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
495 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
496 HOST_WIDE_INT count, unsigned int prec,
497 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
500 unsigned HOST_WIDE_INT signmask;
503 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
506 if (SHIFT_COUNT_TRUNCATED)
509 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
511 /* Shifting by the host word size is undefined according to the
512 ANSI standard, so we must handle this as a special case. */
516 else if (count >= HOST_BITS_PER_WIDE_INT)
519 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
523 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
525 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
528 /* Zero / sign extend all bits that are beyond the precision. */
530 if (count >= (HOST_WIDE_INT)prec)
535 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
537 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
539 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
540 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
545 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
546 *lv |= signmask << (prec - count);
550 /* Rotate the doubleword integer in L1, H1 left by COUNT places
551 keeping only PREC bits of result.
552 Rotate right if COUNT is negative.
553 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
556 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
557 HOST_WIDE_INT count, unsigned int prec,
558 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
560 unsigned HOST_WIDE_INT s1l, s2l;
561 HOST_WIDE_INT s1h, s2h;
567 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
568 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
573 /* Rotate the doubleword integer in L1, H1 left by COUNT places
574 keeping only PREC bits of result. COUNT must be positive.
575 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
578 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
579 HOST_WIDE_INT count, unsigned int prec,
580 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
582 unsigned HOST_WIDE_INT s1l, s2l;
583 HOST_WIDE_INT s1h, s2h;
589 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
590 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
595 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
596 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
597 CODE is a tree code for a kind of division, one of
598 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
600 It controls how the quotient is rounded to an integer.
601 Return nonzero if the operation overflows.
602 UNS nonzero says do unsigned division. */
605 div_and_round_double (enum tree_code code, int uns,
606 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
607 HOST_WIDE_INT hnum_orig,
608 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
609 HOST_WIDE_INT hden_orig,
610 unsigned HOST_WIDE_INT *lquo,
611 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
615 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
616 HOST_WIDE_INT den[4], quo[4];
618 unsigned HOST_WIDE_INT work;
619 unsigned HOST_WIDE_INT carry = 0;
620 unsigned HOST_WIDE_INT lnum = lnum_orig;
621 HOST_WIDE_INT hnum = hnum_orig;
622 unsigned HOST_WIDE_INT lden = lden_orig;
623 HOST_WIDE_INT hden = hden_orig;
626 if (hden == 0 && lden == 0)
627 overflow = 1, lden = 1;
629 /* Calculate quotient sign and convert operands to unsigned. */
635 /* (minimum integer) / (-1) is the only overflow case. */
636 if (neg_double (lnum, hnum, &lnum, &hnum)
637 && ((HOST_WIDE_INT) lden & hden) == -1)
643 neg_double (lden, hden, &lden, &hden);
647 if (hnum == 0 && hden == 0)
648 { /* single precision */
650 /* This unsigned division rounds toward zero. */
656 { /* trivial case: dividend < divisor */
657 /* hden != 0 already checked. */
664 memset (quo, 0, sizeof quo);
666 memset (num, 0, sizeof num); /* to zero 9th element */
667 memset (den, 0, sizeof den);
669 encode (num, lnum, hnum);
670 encode (den, lden, hden);
672 /* Special code for when the divisor < BASE. */
673 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
675 /* hnum != 0 already checked. */
676 for (i = 4 - 1; i >= 0; i--)
678 work = num[i] + carry * BASE;
679 quo[i] = work / lden;
685 /* Full double precision division,
686 with thanks to Don Knuth's "Seminumerical Algorithms". */
687 int num_hi_sig, den_hi_sig;
688 unsigned HOST_WIDE_INT quo_est, scale;
690 /* Find the highest nonzero divisor digit. */
691 for (i = 4 - 1;; i--)
698 /* Insure that the first digit of the divisor is at least BASE/2.
699 This is required by the quotient digit estimation algorithm. */
701 scale = BASE / (den[den_hi_sig] + 1);
703 { /* scale divisor and dividend */
705 for (i = 0; i <= 4 - 1; i++)
707 work = (num[i] * scale) + carry;
708 num[i] = LOWPART (work);
709 carry = HIGHPART (work);
714 for (i = 0; i <= 4 - 1; i++)
716 work = (den[i] * scale) + carry;
717 den[i] = LOWPART (work);
718 carry = HIGHPART (work);
719 if (den[i] != 0) den_hi_sig = i;
726 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
728 /* Guess the next quotient digit, quo_est, by dividing the first
729 two remaining dividend digits by the high order quotient digit.
730 quo_est is never low and is at most 2 high. */
731 unsigned HOST_WIDE_INT tmp;
733 num_hi_sig = i + den_hi_sig + 1;
734 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
735 if (num[num_hi_sig] != den[den_hi_sig])
736 quo_est = work / den[den_hi_sig];
740 /* Refine quo_est so it's usually correct, and at most one high. */
741 tmp = work - quo_est * den[den_hi_sig];
743 && (den[den_hi_sig - 1] * quo_est
744 > (tmp * BASE + num[num_hi_sig - 2])))
747 /* Try QUO_EST as the quotient digit, by multiplying the
748 divisor by QUO_EST and subtracting from the remaining dividend.
749 Keep in mind that QUO_EST is the I - 1st digit. */
752 for (j = 0; j <= den_hi_sig; j++)
754 work = quo_est * den[j] + carry;
755 carry = HIGHPART (work);
756 work = num[i + j] - LOWPART (work);
757 num[i + j] = LOWPART (work);
758 carry += HIGHPART (work) != 0;
761 /* If quo_est was high by one, then num[i] went negative and
762 we need to correct things. */
763 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
766 carry = 0; /* add divisor back in */
767 for (j = 0; j <= den_hi_sig; j++)
769 work = num[i + j] + den[j] + carry;
770 carry = HIGHPART (work);
771 num[i + j] = LOWPART (work);
774 num [num_hi_sig] += carry;
777 /* Store the quotient digit. */
782 decode (quo, lquo, hquo);
785 /* If result is negative, make it so. */
787 neg_double (*lquo, *hquo, lquo, hquo);
789 /* Compute trial remainder: rem = num - (quo * den) */
790 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
791 neg_double (*lrem, *hrem, lrem, hrem);
792 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
797 case TRUNC_MOD_EXPR: /* round toward zero */
798 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
802 case FLOOR_MOD_EXPR: /* round toward negative infinity */
803 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
806 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
814 case CEIL_MOD_EXPR: /* round toward positive infinity */
815 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
817 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
825 case ROUND_MOD_EXPR: /* round to closest integer */
827 unsigned HOST_WIDE_INT labs_rem = *lrem;
828 HOST_WIDE_INT habs_rem = *hrem;
829 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
830 HOST_WIDE_INT habs_den = hden, htwice;
832 /* Get absolute values. */
834 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
836 neg_double (lden, hden, &labs_den, &habs_den);
838 /* If (2 * abs (lrem) >= abs (lden)) */
839 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
840 labs_rem, habs_rem, <wice, &htwice);
842 if (((unsigned HOST_WIDE_INT) habs_den
843 < (unsigned HOST_WIDE_INT) htwice)
844 || (((unsigned HOST_WIDE_INT) habs_den
845 == (unsigned HOST_WIDE_INT) htwice)
846 && (labs_den < ltwice)))
850 add_double (*lquo, *hquo,
851 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
854 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
866 /* Compute true remainder: rem = num - (quo * den) */
867 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
868 neg_double (*lrem, *hrem, lrem, hrem);
869 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
873 /* If ARG2 divides ARG1 with zero remainder, carries out the division
874 of type CODE and returns the quotient.
875 Otherwise returns NULL_TREE. */
878 div_if_zero_remainder (enum tree_code code, const_tree arg1, const_tree arg2)
880 unsigned HOST_WIDE_INT int1l, int2l;
881 HOST_WIDE_INT int1h, int2h;
882 unsigned HOST_WIDE_INT quol, reml;
883 HOST_WIDE_INT quoh, remh;
884 tree type = TREE_TYPE (arg1);
885 int uns = TYPE_UNSIGNED (type);
887 int1l = TREE_INT_CST_LOW (arg1);
888 int1h = TREE_INT_CST_HIGH (arg1);
889 /* &obj[0] + -128 really should be compiled as &obj[-8] rather than
890 &obj[some_exotic_number]. */
891 if (POINTER_TYPE_P (type))
894 type = signed_type_for (type);
895 fit_double_type (int1l, int1h, &int1l, &int1h,
899 fit_double_type (int1l, int1h, &int1l, &int1h, type);
900 int2l = TREE_INT_CST_LOW (arg2);
901 int2h = TREE_INT_CST_HIGH (arg2);
903 div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
904 &quol, &quoh, &reml, &remh);
905 if (remh != 0 || reml != 0)
908 return build_int_cst_wide (type, quol, quoh);
911 /* This is nonzero if we should defer warnings about undefined
912 overflow. This facility exists because these warnings are a
913 special case. The code to estimate loop iterations does not want
914 to issue any warnings, since it works with expressions which do not
915 occur in user code. Various bits of cleanup code call fold(), but
916 only use the result if it has certain characteristics (e.g., is a
917 constant); that code only wants to issue a warning if the result is
920 static int fold_deferring_overflow_warnings;
922 /* If a warning about undefined overflow is deferred, this is the
923 warning. Note that this may cause us to turn two warnings into
924 one, but that is fine since it is sufficient to only give one
925 warning per expression. */
927 static const char* fold_deferred_overflow_warning;
929 /* If a warning about undefined overflow is deferred, this is the
930 level at which the warning should be emitted. */
932 static enum warn_strict_overflow_code fold_deferred_overflow_code;
934 /* Start deferring overflow warnings. We could use a stack here to
935 permit nested calls, but at present it is not necessary. */
938 fold_defer_overflow_warnings (void)
940 ++fold_deferring_overflow_warnings;
943 /* Stop deferring overflow warnings. If there is a pending warning,
944 and ISSUE is true, then issue the warning if appropriate. STMT is
945 the statement with which the warning should be associated (used for
946 location information); STMT may be NULL. CODE is the level of the
947 warning--a warn_strict_overflow_code value. This function will use
948 the smaller of CODE and the deferred code when deciding whether to
949 issue the warning. CODE may be zero to mean to always use the
953 fold_undefer_overflow_warnings (bool issue, const_gimple stmt, int code)
958 gcc_assert (fold_deferring_overflow_warnings > 0);
959 --fold_deferring_overflow_warnings;
960 if (fold_deferring_overflow_warnings > 0)
962 if (fold_deferred_overflow_warning != NULL
964 && code < (int) fold_deferred_overflow_code)
965 fold_deferred_overflow_code = code;
969 warnmsg = fold_deferred_overflow_warning;
970 fold_deferred_overflow_warning = NULL;
972 if (!issue || warnmsg == NULL)
975 if (gimple_no_warning_p (stmt))
978 /* Use the smallest code level when deciding to issue the
980 if (code == 0 || code > (int) fold_deferred_overflow_code)
981 code = fold_deferred_overflow_code;
983 if (!issue_strict_overflow_warning (code))
987 locus = input_location;
989 locus = gimple_location (stmt);
990 warning (OPT_Wstrict_overflow, "%H%s", &locus, warnmsg);
993 /* Stop deferring overflow warnings, ignoring any deferred
997 fold_undefer_and_ignore_overflow_warnings (void)
999 fold_undefer_overflow_warnings (false, NULL, 0);
1002 /* Whether we are deferring overflow warnings. */
1005 fold_deferring_overflow_warnings_p (void)
1007 return fold_deferring_overflow_warnings > 0;
1010 /* This is called when we fold something based on the fact that signed
1011 overflow is undefined. */
1014 fold_overflow_warning (const char* gmsgid, enum warn_strict_overflow_code wc)
1016 if (fold_deferring_overflow_warnings > 0)
1018 if (fold_deferred_overflow_warning == NULL
1019 || wc < fold_deferred_overflow_code)
1021 fold_deferred_overflow_warning = gmsgid;
1022 fold_deferred_overflow_code = wc;
1025 else if (issue_strict_overflow_warning (wc))
1026 warning (OPT_Wstrict_overflow, gmsgid);
1029 /* Return true if the built-in mathematical function specified by CODE
1030 is odd, i.e. -f(x) == f(-x). */
1033 negate_mathfn_p (enum built_in_function code)
1037 CASE_FLT_FN (BUILT_IN_ASIN):
1038 CASE_FLT_FN (BUILT_IN_ASINH):
1039 CASE_FLT_FN (BUILT_IN_ATAN):
1040 CASE_FLT_FN (BUILT_IN_ATANH):
1041 CASE_FLT_FN (BUILT_IN_CASIN):
1042 CASE_FLT_FN (BUILT_IN_CASINH):
1043 CASE_FLT_FN (BUILT_IN_CATAN):
1044 CASE_FLT_FN (BUILT_IN_CATANH):
1045 CASE_FLT_FN (BUILT_IN_CBRT):
1046 CASE_FLT_FN (BUILT_IN_CPROJ):
1047 CASE_FLT_FN (BUILT_IN_CSIN):
1048 CASE_FLT_FN (BUILT_IN_CSINH):
1049 CASE_FLT_FN (BUILT_IN_CTAN):
1050 CASE_FLT_FN (BUILT_IN_CTANH):
1051 CASE_FLT_FN (BUILT_IN_ERF):
1052 CASE_FLT_FN (BUILT_IN_LLROUND):
1053 CASE_FLT_FN (BUILT_IN_LROUND):
1054 CASE_FLT_FN (BUILT_IN_ROUND):
1055 CASE_FLT_FN (BUILT_IN_SIN):
1056 CASE_FLT_FN (BUILT_IN_SINH):
1057 CASE_FLT_FN (BUILT_IN_TAN):
1058 CASE_FLT_FN (BUILT_IN_TANH):
1059 CASE_FLT_FN (BUILT_IN_TRUNC):
1062 CASE_FLT_FN (BUILT_IN_LLRINT):
1063 CASE_FLT_FN (BUILT_IN_LRINT):
1064 CASE_FLT_FN (BUILT_IN_NEARBYINT):
1065 CASE_FLT_FN (BUILT_IN_RINT):
1066 return !flag_rounding_math;
1074 /* Check whether we may negate an integer constant T without causing
1078 may_negate_without_overflow_p (const_tree t)
1080 unsigned HOST_WIDE_INT val;
1084 gcc_assert (TREE_CODE (t) == INTEGER_CST);
1086 type = TREE_TYPE (t);
1087 if (TYPE_UNSIGNED (type))
1090 prec = TYPE_PRECISION (type);
1091 if (prec > HOST_BITS_PER_WIDE_INT)
1093 if (TREE_INT_CST_LOW (t) != 0)
1095 prec -= HOST_BITS_PER_WIDE_INT;
1096 val = TREE_INT_CST_HIGH (t);
1099 val = TREE_INT_CST_LOW (t);
1100 if (prec < HOST_BITS_PER_WIDE_INT)
1101 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1102 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
1105 /* Determine whether an expression T can be cheaply negated using
1106 the function negate_expr without introducing undefined overflow. */
1109 negate_expr_p (tree t)
1116 type = TREE_TYPE (t);
1118 STRIP_SIGN_NOPS (t);
1119 switch (TREE_CODE (t))
1122 if (TYPE_OVERFLOW_WRAPS (type))
1125 /* Check that -CST will not overflow type. */
1126 return may_negate_without_overflow_p (t);
1128 return (INTEGRAL_TYPE_P (type)
1129 && TYPE_OVERFLOW_WRAPS (type));
1137 return negate_expr_p (TREE_REALPART (t))
1138 && negate_expr_p (TREE_IMAGPART (t));
1141 return negate_expr_p (TREE_OPERAND (t, 0))
1142 && negate_expr_p (TREE_OPERAND (t, 1));
1145 return negate_expr_p (TREE_OPERAND (t, 0));
1148 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1149 || HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1151 /* -(A + B) -> (-B) - A. */
1152 if (negate_expr_p (TREE_OPERAND (t, 1))
1153 && reorder_operands_p (TREE_OPERAND (t, 0),
1154 TREE_OPERAND (t, 1)))
1156 /* -(A + B) -> (-A) - B. */
1157 return negate_expr_p (TREE_OPERAND (t, 0));
1160 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
1161 return !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1162 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1163 && reorder_operands_p (TREE_OPERAND (t, 0),
1164 TREE_OPERAND (t, 1));
1167 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1173 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1174 return negate_expr_p (TREE_OPERAND (t, 1))
1175 || negate_expr_p (TREE_OPERAND (t, 0));
1178 case TRUNC_DIV_EXPR:
1179 case ROUND_DIV_EXPR:
1180 case FLOOR_DIV_EXPR:
1182 case EXACT_DIV_EXPR:
1183 /* In general we can't negate A / B, because if A is INT_MIN and
1184 B is 1, we may turn this into INT_MIN / -1 which is undefined
1185 and actually traps on some architectures. But if overflow is
1186 undefined, we can negate, because - (INT_MIN / 1) is an
1188 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
1189 && !TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (t)))
1191 return negate_expr_p (TREE_OPERAND (t, 1))
1192 || negate_expr_p (TREE_OPERAND (t, 0));
1195 /* Negate -((double)float) as (double)(-float). */
1196 if (TREE_CODE (type) == REAL_TYPE)
1198 tree tem = strip_float_extensions (t);
1200 return negate_expr_p (tem);
1205 /* Negate -f(x) as f(-x). */
1206 if (negate_mathfn_p (builtin_mathfn_code (t)))
1207 return negate_expr_p (CALL_EXPR_ARG (t, 0));
1211 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1212 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1214 tree op1 = TREE_OPERAND (t, 1);
1215 if (TREE_INT_CST_HIGH (op1) == 0
1216 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1217 == TREE_INT_CST_LOW (op1))
1228 /* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1229 simplification is possible.
1230 If negate_expr_p would return true for T, NULL_TREE will never be
1234 fold_negate_expr (tree t)
1236 tree type = TREE_TYPE (t);
1239 switch (TREE_CODE (t))
1241 /* Convert - (~A) to A + 1. */
1243 if (INTEGRAL_TYPE_P (type))
1244 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1245 build_int_cst (type, 1));
1249 tem = fold_negate_const (t, type);
1250 if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
1251 || !TYPE_OVERFLOW_TRAPS (type))
1256 tem = fold_negate_const (t, type);
1257 /* Two's complement FP formats, such as c4x, may overflow. */
1258 if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1263 tem = fold_negate_const (t, type);
1268 tree rpart = negate_expr (TREE_REALPART (t));
1269 tree ipart = negate_expr (TREE_IMAGPART (t));
1271 if ((TREE_CODE (rpart) == REAL_CST
1272 && TREE_CODE (ipart) == REAL_CST)
1273 || (TREE_CODE (rpart) == INTEGER_CST
1274 && TREE_CODE (ipart) == INTEGER_CST))
1275 return build_complex (type, rpart, ipart);
1280 if (negate_expr_p (t))
1281 return fold_build2 (COMPLEX_EXPR, type,
1282 fold_negate_expr (TREE_OPERAND (t, 0)),
1283 fold_negate_expr (TREE_OPERAND (t, 1)));
1287 if (negate_expr_p (t))
1288 return fold_build1 (CONJ_EXPR, type,
1289 fold_negate_expr (TREE_OPERAND (t, 0)));
1293 return TREE_OPERAND (t, 0);
1296 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1297 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
1299 /* -(A + B) -> (-B) - A. */
1300 if (negate_expr_p (TREE_OPERAND (t, 1))
1301 && reorder_operands_p (TREE_OPERAND (t, 0),
1302 TREE_OPERAND (t, 1)))
1304 tem = negate_expr (TREE_OPERAND (t, 1));
1305 return fold_build2 (MINUS_EXPR, type,
1306 tem, TREE_OPERAND (t, 0));
1309 /* -(A + B) -> (-A) - B. */
1310 if (negate_expr_p (TREE_OPERAND (t, 0)))
1312 tem = negate_expr (TREE_OPERAND (t, 0));
1313 return fold_build2 (MINUS_EXPR, type,
1314 tem, TREE_OPERAND (t, 1));
1320 /* - (A - B) -> B - A */
1321 if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
1322 && !HONOR_SIGNED_ZEROS (TYPE_MODE (type))
1323 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1324 return fold_build2 (MINUS_EXPR, type,
1325 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
1329 if (TYPE_UNSIGNED (type))
1335 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
1337 tem = TREE_OPERAND (t, 1);
1338 if (negate_expr_p (tem))
1339 return fold_build2 (TREE_CODE (t), type,
1340 TREE_OPERAND (t, 0), negate_expr (tem));
1341 tem = TREE_OPERAND (t, 0);
1342 if (negate_expr_p (tem))
1343 return fold_build2 (TREE_CODE (t), type,
1344 negate_expr (tem), TREE_OPERAND (t, 1));
1348 case TRUNC_DIV_EXPR:
1349 case ROUND_DIV_EXPR:
1350 case FLOOR_DIV_EXPR:
1352 case EXACT_DIV_EXPR:
1353 /* In general we can't negate A / B, because if A is INT_MIN and
1354 B is 1, we may turn this into INT_MIN / -1 which is undefined
1355 and actually traps on some architectures. But if overflow is
1356 undefined, we can negate, because - (INT_MIN / 1) is an
1358 if (!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
1360 const char * const warnmsg = G_("assuming signed overflow does not "
1361 "occur when negating a division");
1362 tem = TREE_OPERAND (t, 1);
1363 if (negate_expr_p (tem))
1365 if (INTEGRAL_TYPE_P (type)
1366 && (TREE_CODE (tem) != INTEGER_CST
1367 || integer_onep (tem)))
1368 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1369 return fold_build2 (TREE_CODE (t), type,
1370 TREE_OPERAND (t, 0), negate_expr (tem));
1372 tem = TREE_OPERAND (t, 0);
1373 if (negate_expr_p (tem))
1375 if (INTEGRAL_TYPE_P (type)
1376 && (TREE_CODE (tem) != INTEGER_CST
1377 || tree_int_cst_equal (tem, TYPE_MIN_VALUE (type))))
1378 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MISC);
1379 return fold_build2 (TREE_CODE (t), type,
1380 negate_expr (tem), TREE_OPERAND (t, 1));
1386 /* Convert -((double)float) into (double)(-float). */
1387 if (TREE_CODE (type) == REAL_TYPE)
1389 tem = strip_float_extensions (t);
1390 if (tem != t && negate_expr_p (tem))
1391 return fold_convert (type, negate_expr (tem));
1396 /* Negate -f(x) as f(-x). */
1397 if (negate_mathfn_p (builtin_mathfn_code (t))
1398 && negate_expr_p (CALL_EXPR_ARG (t, 0)))
1402 fndecl = get_callee_fndecl (t);
1403 arg = negate_expr (CALL_EXPR_ARG (t, 0));
1404 return build_call_expr (fndecl, 1, arg);
1409 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1410 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1412 tree op1 = TREE_OPERAND (t, 1);
1413 if (TREE_INT_CST_HIGH (op1) == 0
1414 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1415 == TREE_INT_CST_LOW (op1))
1417 tree ntype = TYPE_UNSIGNED (type)
1418 ? signed_type_for (type)
1419 : unsigned_type_for (type);
1420 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1421 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
1422 return fold_convert (type, temp);
1434 /* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1435 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1436 return NULL_TREE. */
1439 negate_expr (tree t)
1446 type = TREE_TYPE (t);
1447 STRIP_SIGN_NOPS (t);
1449 tem = fold_negate_expr (t);
1451 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
1452 return fold_convert (type, tem);
1455 /* Split a tree IN into a constant, literal and variable parts that could be
1456 combined with CODE to make IN. "constant" means an expression with
1457 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1458 commutative arithmetic operation. Store the constant part into *CONP,
1459 the literal in *LITP and return the variable part. If a part isn't
1460 present, set it to null. If the tree does not decompose in this way,
1461 return the entire tree as the variable part and the other parts as null.
1463 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1464 case, we negate an operand that was subtracted. Except if it is a
1465 literal for which we use *MINUS_LITP instead.
1467 If NEGATE_P is true, we are negating all of IN, again except a literal
1468 for which we use *MINUS_LITP instead.
1470 If IN is itself a literal or constant, return it as appropriate.
1472 Note that we do not guarantee that any of the three values will be the
1473 same type as IN, but they will have the same signedness and mode. */
1476 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1477 tree *minus_litp, int negate_p)
1485 /* Strip any conversions that don't change the machine mode or signedness. */
1486 STRIP_SIGN_NOPS (in);
1488 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST
1489 || TREE_CODE (in) == FIXED_CST)
1491 else if (TREE_CODE (in) == code
1492 || ((! FLOAT_TYPE_P (TREE_TYPE (in)) || flag_associative_math)
1493 && ! SAT_FIXED_POINT_TYPE_P (TREE_TYPE (in))
1494 /* We can associate addition and subtraction together (even
1495 though the C standard doesn't say so) for integers because
1496 the value is not affected. For reals, the value might be
1497 affected, so we can't. */
1498 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1499 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1501 tree op0 = TREE_OPERAND (in, 0);
1502 tree op1 = TREE_OPERAND (in, 1);
1503 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1504 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1506 /* First see if either of the operands is a literal, then a constant. */
1507 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST
1508 || TREE_CODE (op0) == FIXED_CST)
1509 *litp = op0, op0 = 0;
1510 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST
1511 || TREE_CODE (op1) == FIXED_CST)
1512 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1514 if (op0 != 0 && TREE_CONSTANT (op0))
1515 *conp = op0, op0 = 0;
1516 else if (op1 != 0 && TREE_CONSTANT (op1))
1517 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1519 /* If we haven't dealt with either operand, this is not a case we can
1520 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1521 if (op0 != 0 && op1 != 0)
1526 var = op1, neg_var_p = neg1_p;
1528 /* Now do any needed negations. */
1530 *minus_litp = *litp, *litp = 0;
1532 *conp = negate_expr (*conp);
1534 var = negate_expr (var);
1536 else if (TREE_CONSTANT (in))
1544 *minus_litp = *litp, *litp = 0;
1545 else if (*minus_litp)
1546 *litp = *minus_litp, *minus_litp = 0;
1547 *conp = negate_expr (*conp);
1548 var = negate_expr (var);
1554 /* Re-associate trees split by the above function. T1 and T2 are either
1555 expressions to associate or null. Return the new expression, if any. If
1556 we build an operation, do it in TYPE and with CODE. */
1559 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1566 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1567 try to fold this since we will have infinite recursion. But do
1568 deal with any NEGATE_EXPRs. */
1569 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1570 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1572 if (code == PLUS_EXPR)
1574 if (TREE_CODE (t1) == NEGATE_EXPR)
1575 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1576 fold_convert (type, TREE_OPERAND (t1, 0)));
1577 else if (TREE_CODE (t2) == NEGATE_EXPR)
1578 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1579 fold_convert (type, TREE_OPERAND (t2, 0)));
1580 else if (integer_zerop (t2))
1581 return fold_convert (type, t1);
1583 else if (code == MINUS_EXPR)
1585 if (integer_zerop (t2))
1586 return fold_convert (type, t1);
1589 return build2 (code, type, fold_convert (type, t1),
1590 fold_convert (type, t2));
1593 return fold_build2 (code, type, fold_convert (type, t1),
1594 fold_convert (type, t2));
1597 /* Check whether TYPE1 and TYPE2 are equivalent integer types, suitable
1598 for use in int_const_binop, size_binop and size_diffop. */
1601 int_binop_types_match_p (enum tree_code code, const_tree type1, const_tree type2)
1603 if (TREE_CODE (type1) != INTEGER_TYPE && !POINTER_TYPE_P (type1))
1605 if (TREE_CODE (type2) != INTEGER_TYPE && !POINTER_TYPE_P (type2))
1620 return TYPE_UNSIGNED (type1) == TYPE_UNSIGNED (type2)
1621 && TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
1622 && TYPE_MODE (type1) == TYPE_MODE (type2);
1626 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1627 to produce a new constant. Return NULL_TREE if we don't know how
1628 to evaluate CODE at compile-time.
1630 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1633 int_const_binop (enum tree_code code, const_tree arg1, const_tree arg2, int notrunc)
1635 unsigned HOST_WIDE_INT int1l, int2l;
1636 HOST_WIDE_INT int1h, int2h;
1637 unsigned HOST_WIDE_INT low;
1639 unsigned HOST_WIDE_INT garbagel;
1640 HOST_WIDE_INT garbageh;
1642 tree type = TREE_TYPE (arg1);
1643 int uns = TYPE_UNSIGNED (type);
1645 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1648 int1l = TREE_INT_CST_LOW (arg1);
1649 int1h = TREE_INT_CST_HIGH (arg1);
1650 int2l = TREE_INT_CST_LOW (arg2);
1651 int2h = TREE_INT_CST_HIGH (arg2);
1656 low = int1l | int2l, hi = int1h | int2h;
1660 low = int1l ^ int2l, hi = int1h ^ int2h;
1664 low = int1l & int2l, hi = int1h & int2h;
1670 /* It's unclear from the C standard whether shifts can overflow.
1671 The following code ignores overflow; perhaps a C standard
1672 interpretation ruling is needed. */
1673 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1680 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1685 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1689 neg_double (int2l, int2h, &low, &hi);
1690 add_double (int1l, int1h, low, hi, &low, &hi);
1691 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1695 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1698 case TRUNC_DIV_EXPR:
1699 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1700 case EXACT_DIV_EXPR:
1701 /* This is a shortcut for a common special case. */
1702 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1703 && !TREE_OVERFLOW (arg1)
1704 && !TREE_OVERFLOW (arg2)
1705 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1707 if (code == CEIL_DIV_EXPR)
1710 low = int1l / int2l, hi = 0;
1714 /* ... fall through ... */
1716 case ROUND_DIV_EXPR:
1717 if (int2h == 0 && int2l == 0)
1719 if (int2h == 0 && int2l == 1)
1721 low = int1l, hi = int1h;
1724 if (int1l == int2l && int1h == int2h
1725 && ! (int1l == 0 && int1h == 0))
1730 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1731 &low, &hi, &garbagel, &garbageh);
1734 case TRUNC_MOD_EXPR:
1735 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1736 /* This is a shortcut for a common special case. */
1737 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1738 && !TREE_OVERFLOW (arg1)
1739 && !TREE_OVERFLOW (arg2)
1740 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1742 if (code == CEIL_MOD_EXPR)
1744 low = int1l % int2l, hi = 0;
1748 /* ... fall through ... */
1750 case ROUND_MOD_EXPR:
1751 if (int2h == 0 && int2l == 0)
1753 overflow = div_and_round_double (code, uns,
1754 int1l, int1h, int2l, int2h,
1755 &garbagel, &garbageh, &low, &hi);
1761 low = (((unsigned HOST_WIDE_INT) int1h
1762 < (unsigned HOST_WIDE_INT) int2h)
1763 || (((unsigned HOST_WIDE_INT) int1h
1764 == (unsigned HOST_WIDE_INT) int2h)
1767 low = (int1h < int2h
1768 || (int1h == int2h && int1l < int2l));
1770 if (low == (code == MIN_EXPR))
1771 low = int1l, hi = int1h;
1773 low = int2l, hi = int2h;
1782 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1784 /* Propagate overflow flags ourselves. */
1785 if (((!uns || is_sizetype) && overflow)
1786 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1789 TREE_OVERFLOW (t) = 1;
1793 t = force_fit_type_double (TREE_TYPE (arg1), low, hi, 1,
1794 ((!uns || is_sizetype) && overflow)
1795 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1800 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1801 constant. We assume ARG1 and ARG2 have the same data type, or at least
1802 are the same kind of constant and the same machine mode. Return zero if
1803 combining the constants is not allowed in the current operating mode.
1805 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1808 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1810 /* Sanity check for the recursive cases. */
1817 if (TREE_CODE (arg1) == INTEGER_CST)
1818 return int_const_binop (code, arg1, arg2, notrunc);
1820 if (TREE_CODE (arg1) == REAL_CST)
1822 enum machine_mode mode;
1825 REAL_VALUE_TYPE value;
1826 REAL_VALUE_TYPE result;
1830 /* The following codes are handled by real_arithmetic. */
1845 d1 = TREE_REAL_CST (arg1);
1846 d2 = TREE_REAL_CST (arg2);
1848 type = TREE_TYPE (arg1);
1849 mode = TYPE_MODE (type);
1851 /* Don't perform operation if we honor signaling NaNs and
1852 either operand is a NaN. */
1853 if (HONOR_SNANS (mode)
1854 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1857 /* Don't perform operation if it would raise a division
1858 by zero exception. */
1859 if (code == RDIV_EXPR
1860 && REAL_VALUES_EQUAL (d2, dconst0)
1861 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1864 /* If either operand is a NaN, just return it. Otherwise, set up
1865 for floating-point trap; we return an overflow. */
1866 if (REAL_VALUE_ISNAN (d1))
1868 else if (REAL_VALUE_ISNAN (d2))
1871 inexact = real_arithmetic (&value, code, &d1, &d2);
1872 real_convert (&result, mode, &value);
1874 /* Don't constant fold this floating point operation if
1875 the result has overflowed and flag_trapping_math. */
1876 if (flag_trapping_math
1877 && MODE_HAS_INFINITIES (mode)
1878 && REAL_VALUE_ISINF (result)
1879 && !REAL_VALUE_ISINF (d1)
1880 && !REAL_VALUE_ISINF (d2))
1883 /* Don't constant fold this floating point operation if the
1884 result may dependent upon the run-time rounding mode and
1885 flag_rounding_math is set, or if GCC's software emulation
1886 is unable to accurately represent the result. */
1887 if ((flag_rounding_math
1888 || (MODE_COMPOSITE_P (mode) && !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)
2400 || TREE_CODE (type) == OFFSET_TYPE)
2402 if (TREE_CODE (arg1) == INTEGER_CST)
2403 return fold_convert_const_int_from_int (type, arg1);
2404 else if (TREE_CODE (arg1) == REAL_CST)
2405 return fold_convert_const_int_from_real (code, type, arg1);
2406 else if (TREE_CODE (arg1) == FIXED_CST)
2407 return fold_convert_const_int_from_fixed (type, arg1);
2409 else if (TREE_CODE (type) == REAL_TYPE)
2411 if (TREE_CODE (arg1) == INTEGER_CST)
2412 return build_real_from_int_cst (type, arg1);
2413 else if (TREE_CODE (arg1) == REAL_CST)
2414 return fold_convert_const_real_from_real (type, arg1);
2415 else if (TREE_CODE (arg1) == FIXED_CST)
2416 return fold_convert_const_real_from_fixed (type, arg1);
2418 else if (TREE_CODE (type) == FIXED_POINT_TYPE)
2420 if (TREE_CODE (arg1) == FIXED_CST)
2421 return fold_convert_const_fixed_from_fixed (type, arg1);
2422 else if (TREE_CODE (arg1) == INTEGER_CST)
2423 return fold_convert_const_fixed_from_int (type, arg1);
2424 else if (TREE_CODE (arg1) == REAL_CST)
2425 return fold_convert_const_fixed_from_real (type, arg1);
2430 /* Construct a vector of zero elements of vector type TYPE. */
2433 build_zero_vector (tree type)
2438 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
2439 units = TYPE_VECTOR_SUBPARTS (type);
2442 for (i = 0; i < units; i++)
2443 list = tree_cons (NULL_TREE, elem, list);
2444 return build_vector (type, list);
2447 /* Returns true, if ARG is convertible to TYPE using a NOP_EXPR. */
2450 fold_convertible_p (const_tree type, const_tree arg)
2452 tree orig = TREE_TYPE (arg);
2457 if (TREE_CODE (arg) == ERROR_MARK
2458 || TREE_CODE (type) == ERROR_MARK
2459 || TREE_CODE (orig) == ERROR_MARK)
2462 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2465 switch (TREE_CODE (type))
2467 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2468 case POINTER_TYPE: case REFERENCE_TYPE:
2470 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2471 || TREE_CODE (orig) == OFFSET_TYPE)
2473 return (TREE_CODE (orig) == VECTOR_TYPE
2474 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2477 case FIXED_POINT_TYPE:
2481 return TREE_CODE (type) == TREE_CODE (orig);
2488 /* Convert expression ARG to type TYPE. Used by the middle-end for
2489 simple conversions in preference to calling the front-end's convert. */
2492 fold_convert (tree type, tree arg)
2494 tree orig = TREE_TYPE (arg);
2500 if (TREE_CODE (arg) == ERROR_MARK
2501 || TREE_CODE (type) == ERROR_MARK
2502 || TREE_CODE (orig) == ERROR_MARK)
2503 return error_mark_node;
2505 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
2506 return fold_build1 (NOP_EXPR, type, arg);
2508 switch (TREE_CODE (type))
2510 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
2511 case POINTER_TYPE: case REFERENCE_TYPE:
2513 if (TREE_CODE (arg) == INTEGER_CST)
2515 tem = fold_convert_const (NOP_EXPR, type, arg);
2516 if (tem != NULL_TREE)
2519 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2520 || TREE_CODE (orig) == OFFSET_TYPE)
2521 return fold_build1 (NOP_EXPR, type, arg);
2522 if (TREE_CODE (orig) == COMPLEX_TYPE)
2524 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2525 return fold_convert (type, tem);
2527 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2528 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2529 return fold_build1 (NOP_EXPR, type, arg);
2532 if (TREE_CODE (arg) == INTEGER_CST)
2534 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2535 if (tem != NULL_TREE)
2538 else if (TREE_CODE (arg) == REAL_CST)
2540 tem = fold_convert_const (NOP_EXPR, type, arg);
2541 if (tem != NULL_TREE)
2544 else if (TREE_CODE (arg) == FIXED_CST)
2546 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2547 if (tem != NULL_TREE)
2551 switch (TREE_CODE (orig))
2554 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2555 case POINTER_TYPE: case REFERENCE_TYPE:
2556 return fold_build1 (FLOAT_EXPR, type, arg);
2559 return fold_build1 (NOP_EXPR, type, arg);
2561 case FIXED_POINT_TYPE:
2562 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2565 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2566 return fold_convert (type, tem);
2572 case FIXED_POINT_TYPE:
2573 if (TREE_CODE (arg) == FIXED_CST || TREE_CODE (arg) == INTEGER_CST
2574 || TREE_CODE (arg) == REAL_CST)
2576 tem = fold_convert_const (FIXED_CONVERT_EXPR, type, arg);
2577 if (tem != NULL_TREE)
2581 switch (TREE_CODE (orig))
2583 case FIXED_POINT_TYPE:
2588 return fold_build1 (FIXED_CONVERT_EXPR, type, arg);
2591 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2592 return fold_convert (type, tem);
2599 switch (TREE_CODE (orig))
2602 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2603 case POINTER_TYPE: case REFERENCE_TYPE:
2605 case FIXED_POINT_TYPE:
2606 return build2 (COMPLEX_EXPR, type,
2607 fold_convert (TREE_TYPE (type), arg),
2608 fold_convert (TREE_TYPE (type), integer_zero_node));
2613 if (TREE_CODE (arg) == COMPLEX_EXPR)
2615 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2616 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
2617 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2620 arg = save_expr (arg);
2621 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2622 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
2623 rpart = fold_convert (TREE_TYPE (type), rpart);
2624 ipart = fold_convert (TREE_TYPE (type), ipart);
2625 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
2633 if (integer_zerop (arg))
2634 return build_zero_vector (type);
2635 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2636 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2637 || TREE_CODE (orig) == VECTOR_TYPE);
2638 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
2641 tem = fold_ignored_result (arg);
2642 if (TREE_CODE (tem) == MODIFY_EXPR)
2644 return fold_build1 (NOP_EXPR, type, tem);
2651 /* Return false if expr can be assumed not to be an lvalue, true
2655 maybe_lvalue_p (const_tree x)
2657 /* We only need to wrap lvalue tree codes. */
2658 switch (TREE_CODE (x))
2669 case ALIGN_INDIRECT_REF:
2670 case MISALIGNED_INDIRECT_REF:
2672 case ARRAY_RANGE_REF:
2678 case PREINCREMENT_EXPR:
2679 case PREDECREMENT_EXPR:
2681 case TRY_CATCH_EXPR:
2682 case WITH_CLEANUP_EXPR:
2693 /* Assume the worst for front-end tree codes. */
2694 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2702 /* Return an expr equal to X but certainly not valid as an lvalue. */
2707 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2712 if (! maybe_lvalue_p (x))
2714 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2717 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2718 Zero means allow extended lvalues. */
2720 int pedantic_lvalues;
2722 /* When pedantic, return an expr equal to X but certainly not valid as a
2723 pedantic lvalue. Otherwise, return X. */
2726 pedantic_non_lvalue (tree x)
2728 if (pedantic_lvalues)
2729 return non_lvalue (x);
2734 /* Given a tree comparison code, return the code that is the logical inverse
2735 of the given code. It is not safe to do this for floating-point
2736 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2737 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2740 invert_tree_comparison (enum tree_code code, bool honor_nans)
2742 if (honor_nans && flag_trapping_math)
2752 return honor_nans ? UNLE_EXPR : LE_EXPR;
2754 return honor_nans ? UNLT_EXPR : LT_EXPR;
2756 return honor_nans ? UNGE_EXPR : GE_EXPR;
2758 return honor_nans ? UNGT_EXPR : GT_EXPR;
2772 return UNORDERED_EXPR;
2773 case UNORDERED_EXPR:
2774 return ORDERED_EXPR;
2780 /* Similar, but return the comparison that results if the operands are
2781 swapped. This is safe for floating-point. */
2784 swap_tree_comparison (enum tree_code code)
2791 case UNORDERED_EXPR:
2817 /* Convert a comparison tree code from an enum tree_code representation
2818 into a compcode bit-based encoding. This function is the inverse of
2819 compcode_to_comparison. */
2821 static enum comparison_code
2822 comparison_to_compcode (enum tree_code code)
2839 return COMPCODE_ORD;
2840 case UNORDERED_EXPR:
2841 return COMPCODE_UNORD;
2843 return COMPCODE_UNLT;
2845 return COMPCODE_UNEQ;
2847 return COMPCODE_UNLE;
2849 return COMPCODE_UNGT;
2851 return COMPCODE_LTGT;
2853 return COMPCODE_UNGE;
2859 /* Convert a compcode bit-based encoding of a comparison operator back
2860 to GCC's enum tree_code representation. This function is the
2861 inverse of comparison_to_compcode. */
2863 static enum tree_code
2864 compcode_to_comparison (enum comparison_code code)
2881 return ORDERED_EXPR;
2882 case COMPCODE_UNORD:
2883 return UNORDERED_EXPR;
2901 /* Return a tree for the comparison which is the combination of
2902 doing the AND or OR (depending on CODE) of the two operations LCODE
2903 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2904 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2905 if this makes the transformation invalid. */
2908 combine_comparisons (enum tree_code code, enum tree_code lcode,
2909 enum tree_code rcode, tree truth_type,
2910 tree ll_arg, tree lr_arg)
2912 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2913 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2914 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2915 enum comparison_code compcode;
2919 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2920 compcode = lcompcode & rcompcode;
2923 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2924 compcode = lcompcode | rcompcode;
2933 /* Eliminate unordered comparisons, as well as LTGT and ORD
2934 which are not used unless the mode has NaNs. */
2935 compcode &= ~COMPCODE_UNORD;
2936 if (compcode == COMPCODE_LTGT)
2937 compcode = COMPCODE_NE;
2938 else if (compcode == COMPCODE_ORD)
2939 compcode = COMPCODE_TRUE;
2941 else if (flag_trapping_math)
2943 /* Check that the original operation and the optimized ones will trap
2944 under the same condition. */
2945 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2946 && (lcompcode != COMPCODE_EQ)
2947 && (lcompcode != COMPCODE_ORD);
2948 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2949 && (rcompcode != COMPCODE_EQ)
2950 && (rcompcode != COMPCODE_ORD);
2951 bool trap = (compcode & COMPCODE_UNORD) == 0
2952 && (compcode != COMPCODE_EQ)
2953 && (compcode != COMPCODE_ORD);
2955 /* In a short-circuited boolean expression the LHS might be
2956 such that the RHS, if evaluated, will never trap. For
2957 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2958 if neither x nor y is NaN. (This is a mixed blessing: for
2959 example, the expression above will never trap, hence
2960 optimizing it to x < y would be invalid). */
2961 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2962 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2965 /* If the comparison was short-circuited, and only the RHS
2966 trapped, we may now generate a spurious trap. */
2968 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2971 /* If we changed the conditions that cause a trap, we lose. */
2972 if ((ltrap || rtrap) != trap)
2976 if (compcode == COMPCODE_TRUE)
2977 return constant_boolean_node (true, truth_type);
2978 else if (compcode == COMPCODE_FALSE)
2979 return constant_boolean_node (false, truth_type);
2981 return fold_build2 (compcode_to_comparison (compcode),
2982 truth_type, ll_arg, lr_arg);
2985 /* Return nonzero if CODE is a tree code that represents a truth value. */
2988 truth_value_p (enum tree_code code)
2990 return (TREE_CODE_CLASS (code) == tcc_comparison
2991 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2992 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2993 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2996 /* Return nonzero if two operands (typically of the same tree node)
2997 are necessarily equal. If either argument has side-effects this
2998 function returns zero. FLAGS modifies behavior as follows:
3000 If OEP_ONLY_CONST is set, only return nonzero for constants.
3001 This function tests whether the operands are indistinguishable;
3002 it does not test whether they are equal using C's == operation.
3003 The distinction is important for IEEE floating point, because
3004 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
3005 (2) two NaNs may be indistinguishable, but NaN!=NaN.
3007 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
3008 even though it may hold multiple values during a function.
3009 This is because a GCC tree node guarantees that nothing else is
3010 executed between the evaluation of its "operands" (which may often
3011 be evaluated in arbitrary order). Hence if the operands themselves
3012 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
3013 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
3014 unset means assuming isochronic (or instantaneous) tree equivalence.
3015 Unless comparing arbitrary expression trees, such as from different
3016 statements, this flag can usually be left unset.
3018 If OEP_PURE_SAME is set, then pure functions with identical arguments
3019 are considered the same. It is used when the caller has other ways
3020 to ensure that global memory is unchanged in between. */
3023 operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
3025 /* If either is ERROR_MARK, they aren't equal. */
3026 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
3029 /* Check equality of integer constants before bailing out due to
3030 precision differences. */
3031 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
3032 return tree_int_cst_equal (arg0, arg1);
3034 /* If both types don't have the same signedness, then we can't consider
3035 them equal. We must check this before the STRIP_NOPS calls
3036 because they may change the signedness of the arguments. As pointers
3037 strictly don't have a signedness, require either two pointers or
3038 two non-pointers as well. */
3039 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1))
3040 || POINTER_TYPE_P (TREE_TYPE (arg0)) != POINTER_TYPE_P (TREE_TYPE (arg1)))
3043 /* If both types don't have the same precision, then it is not safe
3045 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
3051 /* In case both args are comparisons but with different comparison
3052 code, try to swap the comparison operands of one arg to produce
3053 a match and compare that variant. */
3054 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3055 && COMPARISON_CLASS_P (arg0)
3056 && COMPARISON_CLASS_P (arg1))
3058 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
3060 if (TREE_CODE (arg0) == swap_code)
3061 return operand_equal_p (TREE_OPERAND (arg0, 0),
3062 TREE_OPERAND (arg1, 1), flags)
3063 && operand_equal_p (TREE_OPERAND (arg0, 1),
3064 TREE_OPERAND (arg1, 0), flags);
3067 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3068 /* This is needed for conversions and for COMPONENT_REF.
3069 Might as well play it safe and always test this. */
3070 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
3071 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
3072 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
3075 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
3076 We don't care about side effects in that case because the SAVE_EXPR
3077 takes care of that for us. In all other cases, two expressions are
3078 equal if they have no side effects. If we have two identical
3079 expressions with side effects that should be treated the same due
3080 to the only side effects being identical SAVE_EXPR's, that will
3081 be detected in the recursive calls below. */
3082 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
3083 && (TREE_CODE (arg0) == SAVE_EXPR
3084 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
3087 /* Next handle constant cases, those for which we can return 1 even
3088 if ONLY_CONST is set. */
3089 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
3090 switch (TREE_CODE (arg0))
3093 return tree_int_cst_equal (arg0, arg1);
3096 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (arg0),
3097 TREE_FIXED_CST (arg1));
3100 if (REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
3101 TREE_REAL_CST (arg1)))
3105 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0))))
3107 /* If we do not distinguish between signed and unsigned zero,
3108 consider them equal. */
3109 if (real_zerop (arg0) && real_zerop (arg1))
3118 v1 = TREE_VECTOR_CST_ELTS (arg0);
3119 v2 = TREE_VECTOR_CST_ELTS (arg1);
3122 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
3125 v1 = TREE_CHAIN (v1);
3126 v2 = TREE_CHAIN (v2);
3133 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
3135 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
3139 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
3140 && ! memcmp (TREE_STRING_POINTER (arg0),
3141 TREE_STRING_POINTER (arg1),
3142 TREE_STRING_LENGTH (arg0)));
3145 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
3151 if (flags & OEP_ONLY_CONST)
3154 /* Define macros to test an operand from arg0 and arg1 for equality and a
3155 variant that allows null and views null as being different from any
3156 non-null value. In the latter case, if either is null, the both
3157 must be; otherwise, do the normal comparison. */
3158 #define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
3159 TREE_OPERAND (arg1, N), flags)
3161 #define OP_SAME_WITH_NULL(N) \
3162 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
3163 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
3165 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
3168 /* Two conversions are equal only if signedness and modes match. */
3169 switch (TREE_CODE (arg0))
3172 case FIX_TRUNC_EXPR:
3173 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
3174 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
3184 case tcc_comparison:
3186 if (OP_SAME (0) && OP_SAME (1))
3189 /* For commutative ops, allow the other order. */
3190 return (commutative_tree_code (TREE_CODE (arg0))
3191 && operand_equal_p (TREE_OPERAND (arg0, 0),
3192 TREE_OPERAND (arg1, 1), flags)
3193 && operand_equal_p (TREE_OPERAND (arg0, 1),
3194 TREE_OPERAND (arg1, 0), flags));
3197 /* If either of the pointer (or reference) expressions we are
3198 dereferencing contain a side effect, these cannot be equal. */
3199 if (TREE_SIDE_EFFECTS (arg0)
3200 || TREE_SIDE_EFFECTS (arg1))
3203 switch (TREE_CODE (arg0))
3206 case ALIGN_INDIRECT_REF:
3207 case MISALIGNED_INDIRECT_REF:
3213 case ARRAY_RANGE_REF:
3214 /* Operands 2 and 3 may be null.
3215 Compare the array index by value if it is constant first as we
3216 may have different types but same value here. */
3218 && (tree_int_cst_equal (TREE_OPERAND (arg0, 1),
3219 TREE_OPERAND (arg1, 1))
3221 && OP_SAME_WITH_NULL (2)
3222 && OP_SAME_WITH_NULL (3));
3225 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
3226 may be NULL when we're called to compare MEM_EXPRs. */
3227 return OP_SAME_WITH_NULL (0)
3229 && OP_SAME_WITH_NULL (2);
3232 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3238 case tcc_expression:
3239 switch (TREE_CODE (arg0))
3242 case TRUTH_NOT_EXPR:
3245 case TRUTH_ANDIF_EXPR:
3246 case TRUTH_ORIF_EXPR:
3247 return OP_SAME (0) && OP_SAME (1);
3249 case TRUTH_AND_EXPR:
3251 case TRUTH_XOR_EXPR:
3252 if (OP_SAME (0) && OP_SAME (1))
3255 /* Otherwise take into account this is a commutative operation. */
3256 return (operand_equal_p (TREE_OPERAND (arg0, 0),
3257 TREE_OPERAND (arg1, 1), flags)
3258 && operand_equal_p (TREE_OPERAND (arg0, 1),
3259 TREE_OPERAND (arg1, 0), flags));
3262 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
3269 switch (TREE_CODE (arg0))
3272 /* If the CALL_EXPRs call different functions, then they
3273 clearly can not be equal. */
3274 if (! operand_equal_p (CALL_EXPR_FN (arg0), CALL_EXPR_FN (arg1),
3279 unsigned int cef = call_expr_flags (arg0);
3280 if (flags & OEP_PURE_SAME)
3281 cef &= ECF_CONST | ECF_PURE;
3288 /* Now see if all the arguments are the same. */
3290 const_call_expr_arg_iterator iter0, iter1;
3292 for (a0 = first_const_call_expr_arg (arg0, &iter0),
3293 a1 = first_const_call_expr_arg (arg1, &iter1);
3295 a0 = next_const_call_expr_arg (&iter0),
3296 a1 = next_const_call_expr_arg (&iter1))
3297 if (! operand_equal_p (a0, a1, flags))
3300 /* If we get here and both argument lists are exhausted
3301 then the CALL_EXPRs are equal. */
3302 return ! (a0 || a1);
3308 case tcc_declaration:
3309 /* Consider __builtin_sqrt equal to sqrt. */
3310 return (TREE_CODE (arg0) == FUNCTION_DECL
3311 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
3312 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
3313 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
3320 #undef OP_SAME_WITH_NULL
3323 /* Similar to operand_equal_p, but see if ARG0 might have been made by
3324 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
3326 When in doubt, return 0. */
3329 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
3331 int unsignedp1, unsignedpo;
3332 tree primarg0, primarg1, primother;
3333 unsigned int correct_width;
3335 if (operand_equal_p (arg0, arg1, 0))
3338 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
3339 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
3342 /* Discard any conversions that don't change the modes of ARG0 and ARG1
3343 and see if the inner values are the same. This removes any
3344 signedness comparison, which doesn't matter here. */
3345 primarg0 = arg0, primarg1 = arg1;
3346 STRIP_NOPS (primarg0);
3347 STRIP_NOPS (primarg1);
3348 if (operand_equal_p (primarg0, primarg1, 0))
3351 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
3352 actual comparison operand, ARG0.
3354 First throw away any conversions to wider types
3355 already present in the operands. */
3357 primarg1 = get_narrower (arg1, &unsignedp1);
3358 primother = get_narrower (other, &unsignedpo);
3360 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
3361 if (unsignedp1 == unsignedpo
3362 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
3363 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
3365 tree type = TREE_TYPE (arg0);
3367 /* Make sure shorter operand is extended the right way
3368 to match the longer operand. */
3369 primarg1 = fold_convert (signed_or_unsigned_type_for
3370 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
3372 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
3379 /* See if ARG is an expression that is either a comparison or is performing
3380 arithmetic on comparisons. The comparisons must only be comparing
3381 two different values, which will be stored in *CVAL1 and *CVAL2; if
3382 they are nonzero it means that some operands have already been found.
3383 No variables may be used anywhere else in the expression except in the
3384 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
3385 the expression and save_expr needs to be called with CVAL1 and CVAL2.
3387 If this is true, return 1. Otherwise, return zero. */
3390 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
3392 enum tree_code code = TREE_CODE (arg);
3393 enum tree_code_class tclass = TREE_CODE_CLASS (code);
3395 /* We can handle some of the tcc_expression cases here. */
3396 if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
3398 else if (tclass == tcc_expression
3399 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
3400 || code == COMPOUND_EXPR))
3401 tclass = tcc_binary;
3403 else if (tclass == tcc_expression && code == SAVE_EXPR
3404 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
3406 /* If we've already found a CVAL1 or CVAL2, this expression is
3407 two complex to handle. */
3408 if (*cval1 || *cval2)
3418 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
3421 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
3422 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3423 cval1, cval2, save_p));
3428 case tcc_expression:
3429 if (code == COND_EXPR)
3430 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
3431 cval1, cval2, save_p)
3432 && twoval_comparison_p (TREE_OPERAND (arg, 1),
3433 cval1, cval2, save_p)
3434 && twoval_comparison_p (TREE_OPERAND (arg, 2),
3435 cval1, cval2, save_p));
3438 case tcc_comparison:
3439 /* First see if we can handle the first operand, then the second. For
3440 the second operand, we know *CVAL1 can't be zero. It must be that
3441 one side of the comparison is each of the values; test for the
3442 case where this isn't true by failing if the two operands
3445 if (operand_equal_p (TREE_OPERAND (arg, 0),
3446 TREE_OPERAND (arg, 1), 0))
3450 *cval1 = TREE_OPERAND (arg, 0);
3451 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
3453 else if (*cval2 == 0)
3454 *cval2 = TREE_OPERAND (arg, 0);
3455 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
3460 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
3462 else if (*cval2 == 0)
3463 *cval2 = TREE_OPERAND (arg, 1);
3464 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
3476 /* ARG is a tree that is known to contain just arithmetic operations and
3477 comparisons. Evaluate the operations in the tree substituting NEW0 for
3478 any occurrence of OLD0 as an operand of a comparison and likewise for
3482 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
3484 tree type = TREE_TYPE (arg);
3485 enum tree_code code = TREE_CODE (arg);
3486 enum tree_code_class tclass = TREE_CODE_CLASS (code);
3488 /* We can handle some of the tcc_expression cases here. */
3489 if (tclass == tcc_expression && code == TRUTH_NOT_EXPR)
3491 else if (tclass == tcc_expression
3492 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
3493 tclass = tcc_binary;
3498 return fold_build1 (code, type,
3499 eval_subst (TREE_OPERAND (arg, 0),
3500 old0, new0, old1, new1));
3503 return fold_build2 (code, type,
3504 eval_subst (TREE_OPERAND (arg, 0),
3505 old0, new0, old1, new1),
3506 eval_subst (TREE_OPERAND (arg, 1),
3507 old0, new0, old1, new1));
3509 case tcc_expression:
3513 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
3516 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
3519 return fold_build3 (code, type,
3520 eval_subst (TREE_OPERAND (arg, 0),
3521 old0, new0, old1, new1),
3522 eval_subst (TREE_OPERAND (arg, 1),
3523 old0, new0, old1, new1),
3524 eval_subst (TREE_OPERAND (arg, 2),
3525 old0, new0, old1, new1));
3529 /* Fall through - ??? */
3531 case tcc_comparison:
3533 tree arg0 = TREE_OPERAND (arg, 0);
3534 tree arg1 = TREE_OPERAND (arg, 1);
3536 /* We need to check both for exact equality and tree equality. The
3537 former will be true if the operand has a side-effect. In that
3538 case, we know the operand occurred exactly once. */
3540 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
3542 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
3545 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
3547 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
3550 return fold_build2 (code, type, arg0, arg1);
3558 /* Return a tree for the case when the result of an expression is RESULT
3559 converted to TYPE and OMITTED was previously an operand of the expression
3560 but is now not needed (e.g., we folded OMITTED * 0).
3562 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3563 the conversion of RESULT to TYPE. */
3566 omit_one_operand (tree type, tree result, tree omitted)
3568 tree t = fold_convert (type, result);
3570 /* If the resulting operand is an empty statement, just return the omitted
3571 statement casted to void. */
3572 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3573 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3575 if (TREE_SIDE_EFFECTS (omitted))
3576 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3578 return non_lvalue (t);
3581 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3584 pedantic_omit_one_operand (tree type, tree result, tree omitted)
3586 tree t = fold_convert (type, result);
3588 /* If the resulting operand is an empty statement, just return the omitted
3589 statement casted to void. */
3590 if (IS_EMPTY_STMT (t) && TREE_SIDE_EFFECTS (omitted))
3591 return build1 (NOP_EXPR, void_type_node, fold_ignored_result (omitted));
3593 if (TREE_SIDE_EFFECTS (omitted))
3594 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
3596 return pedantic_non_lvalue (t);
3599 /* Return a tree for the case when the result of an expression is RESULT
3600 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3601 of the expression but are now not needed.
3603 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3604 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3605 evaluated before OMITTED2. Otherwise, if neither has side effects,
3606 just do the conversion of RESULT to TYPE. */
3609 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3611 tree t = fold_convert (type, result);
3613 if (TREE_SIDE_EFFECTS (omitted2))
3614 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3615 if (TREE_SIDE_EFFECTS (omitted1))
3616 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3618 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3622 /* Return a simplified tree node for the truth-negation of ARG. This
3623 never alters ARG itself. We assume that ARG is an operation that
3624 returns a truth value (0 or 1).
3626 FIXME: one would think we would fold the result, but it causes
3627 problems with the dominator optimizer. */
3630 fold_truth_not_expr (tree arg)
3632 tree type = TREE_TYPE (arg);
3633 enum tree_code code = TREE_CODE (arg);
3635 /* If this is a comparison, we can simply invert it, except for
3636 floating-point non-equality comparisons, in which case we just
3637 enclose a TRUTH_NOT_EXPR around what we have. */
3639 if (TREE_CODE_CLASS (code) == tcc_comparison)
3641 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3642 if (FLOAT_TYPE_P (op_type)
3643 && flag_trapping_math
3644 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3645 && code != NE_EXPR && code != EQ_EXPR)
3649 code = invert_tree_comparison (code,
3650 HONOR_NANS (TYPE_MODE (op_type)));
3651 if (code == ERROR_MARK)
3654 return build2 (code, type,
3655 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3662 return constant_boolean_node (integer_zerop (arg), type);
3664 case TRUTH_AND_EXPR:
3665 return build2 (TRUTH_OR_EXPR, type,
3666 invert_truthvalue (TREE_OPERAND (arg, 0)),
3667 invert_truthvalue (TREE_OPERAND (arg, 1)));
3670 return build2 (TRUTH_AND_EXPR, type,
3671 invert_truthvalue (TREE_OPERAND (arg, 0)),
3672 invert_truthvalue (TREE_OPERAND (arg, 1)));
3674 case TRUTH_XOR_EXPR:
3675 /* Here we can invert either operand. We invert the first operand
3676 unless the second operand is a TRUTH_NOT_EXPR in which case our
3677 result is the XOR of the first operand with the inside of the
3678 negation of the second operand. */
3680 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
3681 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3682 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
3684 return build2 (TRUTH_XOR_EXPR, type,
3685 invert_truthvalue (TREE_OPERAND (arg, 0)),
3686 TREE_OPERAND (arg, 1));
3688 case TRUTH_ANDIF_EXPR:
3689 return build2 (TRUTH_ORIF_EXPR, type,
3690 invert_truthvalue (TREE_OPERAND (arg, 0)),
3691 invert_truthvalue (TREE_OPERAND (arg, 1)));
3693 case TRUTH_ORIF_EXPR:
3694 return build2 (TRUTH_ANDIF_EXPR, type,
3695 invert_truthvalue (TREE_OPERAND (arg, 0)),
3696 invert_truthvalue (TREE_OPERAND (arg, 1)));
3698 case TRUTH_NOT_EXPR:
3699 return TREE_OPERAND (arg, 0);
3703 tree arg1 = TREE_OPERAND (arg, 1);
3704 tree arg2 = TREE_OPERAND (arg, 2);
3705 /* A COND_EXPR may have a throw as one operand, which
3706 then has void type. Just leave void operands
3708 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3709 VOID_TYPE_P (TREE_TYPE (arg1))
3710 ? arg1 : invert_truthvalue (arg1),
3711 VOID_TYPE_P (TREE_TYPE (arg2))
3712 ? arg2 : invert_truthvalue (arg2));
3716 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3717 invert_truthvalue (TREE_OPERAND (arg, 1)));
3719 case NON_LVALUE_EXPR:
3720 return invert_truthvalue (TREE_OPERAND (arg, 0));
3723 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3724 return build1 (TRUTH_NOT_EXPR, type, arg);
3728 return build1 (TREE_CODE (arg), type,
3729 invert_truthvalue (TREE_OPERAND (arg, 0)));
3732 if (!integer_onep (TREE_OPERAND (arg, 1)))
3734 return build2 (EQ_EXPR, type, arg,
3735 build_int_cst (type, 0));
3738 return build1 (TRUTH_NOT_EXPR, type, arg);
3740 case CLEANUP_POINT_EXPR:
3741 return build1 (CLEANUP_POINT_EXPR, type,
3742 invert_truthvalue (TREE_OPERAND (arg, 0)));
3751 /* Return a simplified tree node for the truth-negation of ARG. This
3752 never alters ARG itself. We assume that ARG is an operation that
3753 returns a truth value (0 or 1).
3755 FIXME: one would think we would fold the result, but it causes
3756 problems with the dominator optimizer. */
3759 invert_truthvalue (tree arg)
3763 if (TREE_CODE (arg) == ERROR_MARK)
3766 tem = fold_truth_not_expr (arg);
3768 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3773 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3774 operands are another bit-wise operation with a common input. If so,
3775 distribute the bit operations to save an operation and possibly two if
3776 constants are involved. For example, convert
3777 (A | B) & (A | C) into A | (B & C)
3778 Further simplification will occur if B and C are constants.
3780 If this optimization cannot be done, 0 will be returned. */
3783 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3788 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3789 || TREE_CODE (arg0) == code
3790 || (TREE_CODE (arg0) != BIT_AND_EXPR
3791 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3794 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3796 common = TREE_OPERAND (arg0, 0);
3797 left = TREE_OPERAND (arg0, 1);
3798 right = TREE_OPERAND (arg1, 1);
3800 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3802 common = TREE_OPERAND (arg0, 0);
3803 left = TREE_OPERAND (arg0, 1);
3804 right = TREE_OPERAND (arg1, 0);
3806 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3808 common = TREE_OPERAND (arg0, 1);
3809 left = TREE_OPERAND (arg0, 0);
3810 right = TREE_OPERAND (arg1, 1);
3812 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3814 common = TREE_OPERAND (arg0, 1);
3815 left = TREE_OPERAND (arg0, 0);
3816 right = TREE_OPERAND (arg1, 0);
3821 return fold_build2 (TREE_CODE (arg0), type, common,
3822 fold_build2 (code, type, left, right));
3825 /* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3826 with code CODE. This optimization is unsafe. */
3828 distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3830 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3831 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3833 /* (A / C) +- (B / C) -> (A +- B) / C. */
3835 && operand_equal_p (TREE_OPERAND (arg0, 1),
3836 TREE_OPERAND (arg1, 1), 0))
3837 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3838 fold_build2 (code, type,
3839 TREE_OPERAND (arg0, 0),
3840 TREE_OPERAND (arg1, 0)),
3841 TREE_OPERAND (arg0, 1));
3843 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3844 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3845 TREE_OPERAND (arg1, 0), 0)
3846 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3847 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3849 REAL_VALUE_TYPE r0, r1;
3850 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3851 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3853 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3855 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3856 real_arithmetic (&r0, code, &r0, &r1);
3857 return fold_build2 (MULT_EXPR, type,
3858 TREE_OPERAND (arg0, 0),
3859 build_real (type, r0));
3865 /* Subroutine for fold_truthop: decode a field reference.
3867 If EXP is a comparison reference, we return the innermost reference.
3869 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3870 set to the starting bit number.
3872 If the innermost field can be completely contained in a mode-sized
3873 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3875 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3876 otherwise it is not changed.
3878 *PUNSIGNEDP is set to the signedness of the field.
3880 *PMASK is set to the mask used. This is either contained in a
3881 BIT_AND_EXPR or derived from the width of the field.
3883 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3885 Return 0 if this is not a component reference or is one that we can't
3886 do anything with. */
3889 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3890 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3891 int *punsignedp, int *pvolatilep,
3892 tree *pmask, tree *pand_mask)
3894 tree outer_type = 0;
3896 tree mask, inner, offset;
3898 unsigned int precision;
3900 /* All the optimizations using this function assume integer fields.
3901 There are problems with FP fields since the type_for_size call
3902 below can fail for, e.g., XFmode. */
3903 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3906 /* We are interested in the bare arrangement of bits, so strip everything
3907 that doesn't affect the machine mode. However, record the type of the
3908 outermost expression if it may matter below. */
3909 if (CONVERT_EXPR_P (exp)
3910 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3911 outer_type = TREE_TYPE (exp);
3914 if (TREE_CODE (exp) == BIT_AND_EXPR)
3916 and_mask = TREE_OPERAND (exp, 1);
3917 exp = TREE_OPERAND (exp, 0);
3918 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3919 if (TREE_CODE (and_mask) != INTEGER_CST)
3923 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3924 punsignedp, pvolatilep, false);
3925 if ((inner == exp && and_mask == 0)
3926 || *pbitsize < 0 || offset != 0
3927 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3930 /* If the number of bits in the reference is the same as the bitsize of
3931 the outer type, then the outer type gives the signedness. Otherwise
3932 (in case of a small bitfield) the signedness is unchanged. */
3933 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3934 *punsignedp = TYPE_UNSIGNED (outer_type);
3936 /* Compute the mask to access the bitfield. */
3937 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3938 precision = TYPE_PRECISION (unsigned_type);
3940 mask = build_int_cst_type (unsigned_type, -1);
3942 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3943 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3945 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3947 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
3948 fold_convert (unsigned_type, and_mask), mask);
3951 *pand_mask = and_mask;
3955 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3956 represents the sign bit of EXP's type. If EXP represents a sign
3957 or zero extension, also test VAL against the unextended type.
3958 The return value is the (sub)expression whose sign bit is VAL,
3959 or NULL_TREE otherwise. */
3962 sign_bit_p (tree exp, const_tree val)
3964 unsigned HOST_WIDE_INT mask_lo, lo;
3965 HOST_WIDE_INT mask_hi, hi;
3969 /* Tree EXP must have an integral type. */
3970 t = TREE_TYPE (exp);
3971 if (! INTEGRAL_TYPE_P (t))
3974 /* Tree VAL must be an integer constant. */
3975 if (TREE_CODE (val) != INTEGER_CST
3976 || TREE_OVERFLOW (val))
3979 width = TYPE_PRECISION (t);
3980 if (width > HOST_BITS_PER_WIDE_INT)
3982 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3985 mask_hi = ((unsigned HOST_WIDE_INT) -1
3986 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3992 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3995 mask_lo = ((unsigned HOST_WIDE_INT) -1
3996 >> (HOST_BITS_PER_WIDE_INT - width));
3999 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
4000 treat VAL as if it were unsigned. */
4001 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
4002 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
4005 /* Handle extension from a narrower type. */
4006 if (TREE_CODE (exp) == NOP_EXPR
4007 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
4008 return sign_bit_p (TREE_OPERAND (exp, 0), val);
4013 /* Subroutine for fold_truthop: determine if an operand is simple enough
4014 to be evaluated unconditionally. */
4017 simple_operand_p (const_tree exp)
4019 /* Strip any conversions that don't change the machine mode. */
4022 return (CONSTANT_CLASS_P (exp)
4023 || TREE_CODE (exp) == SSA_NAME
4025 && ! TREE_ADDRESSABLE (exp)
4026 && ! TREE_THIS_VOLATILE (exp)
4027 && ! DECL_NONLOCAL (exp)
4028 /* Don't regard global variables as simple. They may be
4029 allocated in ways unknown to the compiler (shared memory,
4030 #pragma weak, etc). */
4031 && ! TREE_PUBLIC (exp)
4032 && ! DECL_EXTERNAL (exp)
4033 /* Loading a static variable is unduly expensive, but global
4034 registers aren't expensive. */
4035 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
4038 /* The following functions are subroutines to fold_range_test and allow it to
4039 try to change a logical combination of comparisons into a range test.
4042 X == 2 || X == 3 || X == 4 || X == 5
4046 (unsigned) (X - 2) <= 3
4048 We describe each set of comparisons as being either inside or outside
4049 a range, using a variable named like IN_P, and then describe the
4050 range with a lower and upper bound. If one of the bounds is omitted,
4051 it represents either the highest or lowest value of the type.
4053 In the comments below, we represent a range by two numbers in brackets
4054 preceded by a "+" to designate being inside that range, or a "-" to
4055 designate being outside that range, so the condition can be inverted by
4056 flipping the prefix. An omitted bound is represented by a "-". For
4057 example, "- [-, 10]" means being outside the range starting at the lowest
4058 possible value and ending at 10, in other words, being greater than 10.
4059 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
4062 We set up things so that the missing bounds are handled in a consistent
4063 manner so neither a missing bound nor "true" and "false" need to be
4064 handled using a special case. */
4066 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
4067 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
4068 and UPPER1_P are nonzero if the respective argument is an upper bound
4069 and zero for a lower. TYPE, if nonzero, is the type of the result; it
4070 must be specified for a comparison. ARG1 will be converted to ARG0's
4071 type if both are specified. */
4074 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
4075 tree arg1, int upper1_p)
4081 /* If neither arg represents infinity, do the normal operation.
4082 Else, if not a comparison, return infinity. Else handle the special
4083 comparison rules. Note that most of the cases below won't occur, but
4084 are handled for consistency. */
4086 if (arg0 != 0 && arg1 != 0)
4088 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
4089 arg0, fold_convert (TREE_TYPE (arg0), arg1));
4091 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
4094 if (TREE_CODE_CLASS (code) != tcc_comparison)
4097 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
4098 for neither. In real maths, we cannot assume open ended ranges are
4099 the same. But, this is computer arithmetic, where numbers are finite.
4100 We can therefore make the transformation of any unbounded range with
4101 the value Z, Z being greater than any representable number. This permits
4102 us to treat unbounded ranges as equal. */
4103 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
4104 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
4108 result = sgn0 == sgn1;
4111 result = sgn0 != sgn1;
4114 result = sgn0 < sgn1;
4117 result = sgn0 <= sgn1;
4120 result = sgn0 > sgn1;
4123 result = sgn0 >= sgn1;
4129 return constant_boolean_node (result, type);
4132 /* Given EXP, a logical expression, set the range it is testing into
4133 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
4134 actually being tested. *PLOW and *PHIGH will be made of the same
4135 type as the returned expression. If EXP is not a comparison, we
4136 will most likely not be returning a useful value and range. Set
4137 *STRICT_OVERFLOW_P to true if the return value is only valid
4138 because signed overflow is undefined; otherwise, do not change
4139 *STRICT_OVERFLOW_P. */
4142 make_range (tree exp, int *pin_p, tree *plow, tree *phigh,
4143 bool *strict_overflow_p)
4145 enum tree_code code;
4146 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4147 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
4149 tree low, high, n_low, n_high;
4151 /* Start with simply saying "EXP != 0" and then look at the code of EXP
4152 and see if we can refine the range. Some of the cases below may not
4153 happen, but it doesn't seem worth worrying about this. We "continue"
4154 the outer loop when we've changed something; otherwise we "break"
4155 the switch, which will "break" the while. */
4158 low = high = build_int_cst (TREE_TYPE (exp), 0);
4162 code = TREE_CODE (exp);
4163 exp_type = TREE_TYPE (exp);
4165 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
4167 if (TREE_OPERAND_LENGTH (exp) > 0)
4168 arg0 = TREE_OPERAND (exp, 0);
4169 if (TREE_CODE_CLASS (code) == tcc_comparison
4170 || TREE_CODE_CLASS (code) == tcc_unary
4171 || TREE_CODE_CLASS (code) == tcc_binary)
4172 arg0_type = TREE_TYPE (arg0);
4173 if (TREE_CODE_CLASS (code) == tcc_binary
4174 || TREE_CODE_CLASS (code) == tcc_comparison
4175 || (TREE_CODE_CLASS (code) == tcc_expression
4176 && TREE_OPERAND_LENGTH (exp) > 1))
4177 arg1 = TREE_OPERAND (exp, 1);
4182 case TRUTH_NOT_EXPR:
4183 in_p = ! in_p, exp = arg0;
4186 case EQ_EXPR: case NE_EXPR:
4187 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
4188 /* We can only do something if the range is testing for zero
4189 and if the second operand is an integer constant. Note that
4190 saying something is "in" the range we make is done by
4191 complementing IN_P since it will set in the initial case of
4192 being not equal to zero; "out" is leaving it alone. */
4193 if (low == 0 || high == 0
4194 || ! integer_zerop (low) || ! integer_zerop (high)
4195 || TREE_CODE (arg1) != INTEGER_CST)
4200 case NE_EXPR: /* - [c, c] */
4203 case EQ_EXPR: /* + [c, c] */
4204 in_p = ! in_p, low = high = arg1;
4206 case GT_EXPR: /* - [-, c] */
4207 low = 0, high = arg1;
4209 case GE_EXPR: /* + [c, -] */
4210 in_p = ! in_p, low = arg1, high = 0;
4212 case LT_EXPR: /* - [c, -] */
4213 low = arg1, high = 0;
4215 case LE_EXPR: /* + [-, c] */
4216 in_p = ! in_p, low = 0, high = arg1;
4222 /* If this is an unsigned comparison, we also know that EXP is
4223 greater than or equal to zero. We base the range tests we make
4224 on that fact, so we record it here so we can parse existing
4225 range tests. We test arg0_type since often the return type
4226 of, e.g. EQ_EXPR, is boolean. */
4227 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
4229 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4231 build_int_cst (arg0_type, 0),
4235 in_p = n_in_p, low = n_low, high = n_high;
4237 /* If the high bound is missing, but we have a nonzero low
4238 bound, reverse the range so it goes from zero to the low bound
4240 if (high == 0 && low && ! integer_zerop (low))
4243 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
4244 integer_one_node, 0);
4245 low = build_int_cst (arg0_type, 0);
4253 /* (-x) IN [a,b] -> x in [-b, -a] */
4254 n_low = range_binop (MINUS_EXPR, exp_type,
4255 build_int_cst (exp_type, 0),
4257 n_high = range_binop (MINUS_EXPR, exp_type,
4258 build_int_cst (exp_type, 0),
4260 low = n_low, high = n_high;
4266 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
4267 build_int_cst (exp_type, 1));
4270 case PLUS_EXPR: case MINUS_EXPR:
4271 if (TREE_CODE (arg1) != INTEGER_CST)
4274 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
4275 move a constant to the other side. */
4276 if (!TYPE_UNSIGNED (arg0_type)
4277 && !TYPE_OVERFLOW_UNDEFINED (arg0_type))
4280 /* If EXP is signed, any overflow in the computation is undefined,
4281 so we don't worry about it so long as our computations on
4282 the bounds don't overflow. For unsigned, overflow is defined
4283 and this is exactly the right thing. */
4284 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4285 arg0_type, low, 0, arg1, 0);
4286 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
4287 arg0_type, high, 1, arg1, 0);
4288 if ((n_low != 0 && TREE_OVERFLOW (n_low))
4289 || (n_high != 0 && TREE_OVERFLOW (n_high)))
4292 if (TYPE_OVERFLOW_UNDEFINED (arg0_type))
4293 *strict_overflow_p = true;
4295 /* Check for an unsigned range which has wrapped around the maximum
4296 value thus making n_high < n_low, and normalize it. */
4297 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
4299 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
4300 integer_one_node, 0);
4301 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
4302 integer_one_node, 0);
4304 /* If the range is of the form +/- [ x+1, x ], we won't
4305 be able to normalize it. But then, it represents the
4306 whole range or the empty set, so make it
4308 if (tree_int_cst_equal (n_low, low)
4309 && tree_int_cst_equal (n_high, high))
4315 low = n_low, high = n_high;
4320 CASE_CONVERT: case NON_LVALUE_EXPR:
4321 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
4324 if (! INTEGRAL_TYPE_P (arg0_type)
4325 || (low != 0 && ! int_fits_type_p (low, arg0_type))
4326 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
4329 n_low = low, n_high = high;
4332 n_low = fold_convert (arg0_type, n_low);
4335 n_high = fold_convert (arg0_type, n_high);
4338 /* If we're converting arg0 from an unsigned type, to exp,
4339 a signed type, we will be doing the comparison as unsigned.
4340 The tests above have already verified that LOW and HIGH
4343 So we have to ensure that we will handle large unsigned
4344 values the same way that the current signed bounds treat
4347 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4351 /* For fixed-point modes, we need to pass the saturating flag
4352 as the 2nd parameter. */
4353 if (ALL_FIXED_POINT_MODE_P (TYPE_MODE (arg0_type)))
4354 equiv_type = lang_hooks.types.type_for_mode
4355 (TYPE_MODE (arg0_type),
4356 TYPE_SATURATING (arg0_type));
4358 equiv_type = lang_hooks.types.type_for_mode
4359 (TYPE_MODE (arg0_type), 1);
4361 /* A range without an upper bound is, naturally, unbounded.
4362 Since convert would have cropped a very large value, use
4363 the max value for the destination type. */
4365 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
4366 : TYPE_MAX_VALUE (arg0_type);
4368 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
4369 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4370 fold_convert (arg0_type,
4372 build_int_cst (arg0_type, 1));
4374 /* If the low bound is specified, "and" the range with the
4375 range for which the original unsigned value will be
4379 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4380 1, n_low, n_high, 1,
4381 fold_convert (arg0_type,
4386 in_p = (n_in_p == in_p);
4390 /* Otherwise, "or" the range with the range of the input
4391 that will be interpreted as negative. */
4392 if (! merge_ranges (&n_in_p, &n_low, &n_high,
4393 0, n_low, n_high, 1,
4394 fold_convert (arg0_type,
4399 in_p = (in_p != n_in_p);
4404 low = n_low, high = n_high;
4414 /* If EXP is a constant, we can evaluate whether this is true or false. */
4415 if (TREE_CODE (exp) == INTEGER_CST)
4417 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4419 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4425 *pin_p = in_p, *plow = low, *phigh = high;
4429 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4430 type, TYPE, return an expression to test if EXP is in (or out of, depending
4431 on IN_P) the range. Return 0 if the test couldn't be created. */
4434 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
4436 tree etype = TREE_TYPE (exp);
4439 #ifdef HAVE_canonicalize_funcptr_for_compare
4440 /* Disable this optimization for function pointer expressions
4441 on targets that require function pointer canonicalization. */
4442 if (HAVE_canonicalize_funcptr_for_compare
4443 && TREE_CODE (etype) == POINTER_TYPE
4444 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4450 value = build_range_check (type, exp, 1, low, high);
4452 return invert_truthvalue (value);
4457 if (low == 0 && high == 0)
4458 return build_int_cst (type, 1);
4461 return fold_build2 (LE_EXPR, type, exp,
4462 fold_convert (etype, high));
4465 return fold_build2 (GE_EXPR, type, exp,
4466 fold_convert (etype, low));
4468 if (operand_equal_p (low, high, 0))
4469 return fold_build2 (EQ_EXPR, type, exp,
4470 fold_convert (etype, low));
4472 if (integer_zerop (low))
4474 if (! TYPE_UNSIGNED (etype))
4476 etype = unsigned_type_for (etype);
4477 high = fold_convert (etype, high);
4478 exp = fold_convert (etype, exp);
4480 return build_range_check (type, exp, 1, 0, high);
4483 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4484 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4486 unsigned HOST_WIDE_INT lo;
4490 prec = TYPE_PRECISION (etype);
4491 if (prec <= HOST_BITS_PER_WIDE_INT)
4494 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4498 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4499 lo = (unsigned HOST_WIDE_INT) -1;
4502 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
4504 if (TYPE_UNSIGNED (etype))
4506 etype = signed_type_for (etype);
4507 exp = fold_convert (etype, exp);
4509 return fold_build2 (GT_EXPR, type, exp,
4510 build_int_cst (etype, 0));
4514 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4515 This requires wrap-around arithmetics for the type of the expression. */
4516 switch (TREE_CODE (etype))
4519 /* There is no requirement that LOW be within the range of ETYPE
4520 if the latter is a subtype. It must, however, be within the base
4521 type of ETYPE. So be sure we do the subtraction in that type. */
4522 if (TREE_TYPE (etype))
4523 etype = TREE_TYPE (etype);
4528 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4529 TYPE_UNSIGNED (etype));
4536 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4537 if (TREE_CODE (etype) == INTEGER_TYPE
4538 && !TYPE_OVERFLOW_WRAPS (etype))
4540 tree utype, minv, maxv;
4542 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4543 for the type in question, as we rely on this here. */
4544 utype = unsigned_type_for (etype);
4545 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4546 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4547 integer_one_node, 1);
4548 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4550 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4557 high = fold_convert (etype, high);
4558 low = fold_convert (etype, low);
4559 exp = fold_convert (etype, exp);
4561 value = const_binop (MINUS_EXPR, high, low, 0);
4564 if (POINTER_TYPE_P (etype))
4566 if (value != 0 && !TREE_OVERFLOW (value))
4568 low = fold_convert (sizetype, low);
4569 low = fold_build1 (NEGATE_EXPR, sizetype, low);
4570 return build_range_check (type,
4571 fold_build2 (POINTER_PLUS_EXPR, etype, exp, low),
4572 1, build_int_cst (etype, 0), value);
4577 if (value != 0 && !TREE_OVERFLOW (value))
4578 return build_range_check (type,
4579 fold_build2 (MINUS_EXPR, etype, exp, low),
4580 1, build_int_cst (etype, 0), value);
4585 /* Return the predecessor of VAL in its type, handling the infinite case. */
4588 range_predecessor (tree val)
4590 tree type = TREE_TYPE (val);
4592 if (INTEGRAL_TYPE_P (type)
4593 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
4596 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4599 /* Return the successor of VAL in its type, handling the infinite case. */
4602 range_successor (tree val)
4604 tree type = TREE_TYPE (val);
4606 if (INTEGRAL_TYPE_P (type)
4607 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
4610 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4613 /* Given two ranges, see if we can merge them into one. Return 1 if we
4614 can, 0 if we can't. Set the output range into the specified parameters. */
4617 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4618 tree high0, int in1_p, tree low1, tree high1)
4626 int lowequal = ((low0 == 0 && low1 == 0)
4627 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4628 low0, 0, low1, 0)));
4629 int highequal = ((high0 == 0 && high1 == 0)
4630 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4631 high0, 1, high1, 1)));
4633 /* Make range 0 be the range that starts first, or ends last if they
4634 start at the same value. Swap them if it isn't. */
4635 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
4638 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4639 high1, 1, high0, 1))))
4641 temp = in0_p, in0_p = in1_p, in1_p = temp;
4642 tem = low0, low0 = low1, low1 = tem;
4643 tem = high0, high0 = high1, high1 = tem;
4646 /* Now flag two cases, whether the ranges are disjoint or whether the
4647 second range is totally subsumed in the first. Note that the tests
4648 below are simplified by the ones above. */
4649 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4650 high0, 1, low1, 0));
4651 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
4652 high1, 1, high0, 1));
4654 /* We now have four cases, depending on whether we are including or
4655 excluding the two ranges. */
4658 /* If they don't overlap, the result is false. If the second range
4659 is a subset it is the result. Otherwise, the range is from the start
4660 of the second to the end of the first. */
4662 in_p = 0, low = high = 0;
4664 in_p = 1, low = low1, high = high1;
4666 in_p = 1, low = low1, high = high0;
4669 else if (in0_p && ! in1_p)
4671 /* If they don't overlap, the result is the first range. If they are
4672 equal, the result is false. If the second range is a subset of the
4673 first, and the ranges begin at the same place, we go from just after
4674 the end of the second range to the end of the first. If the second
4675 range is not a subset of the first, or if it is a subset and both
4676 ranges end at the same place, the range starts at the start of the
4677 first range and ends just before the second range.
4678 Otherwise, we can't describe this as a single range. */
4680 in_p = 1, low = low0, high = high0;
4681 else if (lowequal && highequal)
4682 in_p = 0, low = high = 0;
4683 else if (subset && lowequal)
4685 low = range_successor (high1);
4690 /* We are in the weird situation where high0 > high1 but
4691 high1 has no successor. Punt. */
4695 else if (! subset || highequal)
4698 high = range_predecessor (low1);
4702 /* low0 < low1 but low1 has no predecessor. Punt. */
4710 else if (! in0_p && in1_p)
4712 /* If they don't overlap, the result is the second range. If the second
4713 is a subset of the first, the result is false. Otherwise,
4714 the range starts just after the first range and ends at the
4715 end of the second. */
4717 in_p = 1, low = low1, high = high1;
4718 else if (subset || highequal)
4719 in_p = 0, low = high = 0;
4722 low = range_successor (high0);
4727 /* high1 > high0 but high0 has no successor. Punt. */
4735 /* The case where we are excluding both ranges. Here the complex case
4736 is if they don't overlap. In that case, the only time we have a
4737 range is if they are adjacent. If the second is a subset of the
4738 first, the result is the first. Otherwise, the range to exclude
4739 starts at the beginning of the first range and ends at the end of the
4743 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4744 range_successor (high0),
4746 in_p = 0, low = low0, high = high1;
4749 /* Canonicalize - [min, x] into - [-, x]. */
4750 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4751 switch (TREE_CODE (TREE_TYPE (low0)))
4754 if (TYPE_PRECISION (TREE_TYPE (low0))
4755 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4759 if (tree_int_cst_equal (low0,
4760 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4764 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4765 && integer_zerop (low0))
4772 /* Canonicalize - [x, max] into - [x, -]. */
4773 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4774 switch (TREE_CODE (TREE_TYPE (high1)))
4777 if (TYPE_PRECISION (TREE_TYPE (high1))
4778 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4782 if (tree_int_cst_equal (high1,
4783 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4787 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4788 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4790 integer_one_node, 1)))
4797 /* The ranges might be also adjacent between the maximum and
4798 minimum values of the given type. For
4799 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4800 return + [x + 1, y - 1]. */
4801 if (low0 == 0 && high1 == 0)
4803 low = range_successor (high0);
4804 high = range_predecessor (low1);
4805 if (low == 0 || high == 0)
4815 in_p = 0, low = low0, high = high0;
4817 in_p = 0, low = low0, high = high1;
4820 *pin_p = in_p, *plow = low, *phigh = high;
4825 /* Subroutine of fold, looking inside expressions of the form
4826 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4827 of the COND_EXPR. This function is being used also to optimize
4828 A op B ? C : A, by reversing the comparison first.
4830 Return a folded expression whose code is not a COND_EXPR
4831 anymore, or NULL_TREE if no folding opportunity is found. */
4834 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4836 enum tree_code comp_code = TREE_CODE (arg0);
4837 tree arg00 = TREE_OPERAND (arg0, 0);
4838 tree arg01 = TREE_OPERAND (arg0, 1);
4839 tree arg1_type = TREE_TYPE (arg1);
4845 /* If we have A op 0 ? A : -A, consider applying the following
4848 A == 0? A : -A same as -A
4849 A != 0? A : -A same as A
4850 A >= 0? A : -A same as abs (A)
4851 A > 0? A : -A same as abs (A)
4852 A <= 0? A : -A same as -abs (A)
4853 A < 0? A : -A same as -abs (A)
4855 None of these transformations work for modes with signed
4856 zeros. If A is +/-0, the first two transformations will
4857 change the sign of the result (from +0 to -0, or vice
4858 versa). The last four will fix the sign of the result,
4859 even though the original expressions could be positive or
4860 negative, depending on the sign of A.
4862 Note that all these transformations are correct if A is
4863 NaN, since the two alternatives (A and -A) are also NaNs. */
4864 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4865 && (FLOAT_TYPE_P (TREE_TYPE (arg01))
4866 ? real_zerop (arg01)
4867 : integer_zerop (arg01))
4868 && ((TREE_CODE (arg2) == NEGATE_EXPR
4869 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4870 /* In the case that A is of the form X-Y, '-A' (arg2) may
4871 have already been folded to Y-X, check for that. */
4872 || (TREE_CODE (arg1) == MINUS_EXPR
4873 && TREE_CODE (arg2) == MINUS_EXPR
4874 && operand_equal_p (TREE_OPERAND (arg1, 0),
4875 TREE_OPERAND (arg2, 1), 0)
4876 && operand_equal_p (TREE_OPERAND (arg1, 1),
4877 TREE_OPERAND (arg2, 0), 0))))
4882 tem = fold_convert (arg1_type, arg1);
4883 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4886 return pedantic_non_lvalue (fold_convert (type, arg1));
4889 if (flag_trapping_math)
4894 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4895 arg1 = fold_convert (signed_type_for
4896 (TREE_TYPE (arg1)), arg1);
4897 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4898 return pedantic_non_lvalue (fold_convert (type, tem));
4901 if (flag_trapping_math)
4905 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4906 arg1 = fold_convert (signed_type_for
4907 (TREE_TYPE (arg1)), arg1);
4908 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
4909 return negate_expr (fold_convert (type, tem));
4911 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
4915 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4916 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4917 both transformations are correct when A is NaN: A != 0
4918 is then true, and A == 0 is false. */
4920 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4921 && integer_zerop (arg01) && integer_zerop (arg2))
4923 if (comp_code == NE_EXPR)
4924 return pedantic_non_lvalue (fold_convert (type, arg1));
4925 else if (comp_code == EQ_EXPR)
4926 return build_int_cst (type, 0);
4929 /* Try some transformations of A op B ? A : B.
4931 A == B? A : B same as B
4932 A != B? A : B same as A
4933 A >= B? A : B same as max (A, B)
4934 A > B? A : B same as max (B, A)
4935 A <= B? A : B same as min (A, B)
4936 A < B? A : B same as min (B, A)
4938 As above, these transformations don't work in the presence
4939 of signed zeros. For example, if A and B are zeros of
4940 opposite sign, the first two transformations will change
4941 the sign of the result. In the last four, the original
4942 expressions give different results for (A=+0, B=-0) and
4943 (A=-0, B=+0), but the transformed expressions do not.
4945 The first two transformations are correct if either A or B
4946 is a NaN. In the first transformation, the condition will
4947 be false, and B will indeed be chosen. In the case of the
4948 second transformation, the condition A != B will be true,
4949 and A will be chosen.
4951 The conversions to max() and min() are not correct if B is
4952 a number and A is not. The conditions in the original
4953 expressions will be false, so all four give B. The min()
4954 and max() versions would give a NaN instead. */
4955 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type))
4956 && operand_equal_for_comparison_p (arg01, arg2, arg00)
4957 /* Avoid these transformations if the COND_EXPR may be used
4958 as an lvalue in the C++ front-end. PR c++/19199. */
4960 || (strcmp (lang_hooks.name, "GNU C++") != 0
4961 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
4962 || ! maybe_lvalue_p (arg1)
4963 || ! maybe_lvalue_p (arg2)))
4965 tree comp_op0 = arg00;
4966 tree comp_op1 = arg01;
4967 tree comp_type = TREE_TYPE (comp_op0);
4969 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4970 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4980 return pedantic_non_lvalue (fold_convert (type, arg2));
4982 return pedantic_non_lvalue (fold_convert (type, arg1));
4987 /* In C++ a ?: expression can be an lvalue, so put the
4988 operand which will be used if they are equal first
4989 so that we can convert this back to the
4990 corresponding COND_EXPR. */
4991 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4993 comp_op0 = fold_convert (comp_type, comp_op0);
4994 comp_op1 = fold_convert (comp_type, comp_op1);
4995 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
4996 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
4997 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
4998 return pedantic_non_lvalue (fold_convert (type, tem));
5005 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5007 comp_op0 = fold_convert (comp_type, comp_op0);
5008 comp_op1 = fold_convert (comp_type, comp_op1);
5009 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
5010 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
5011 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
5012 return pedantic_non_lvalue (fold_convert (type, tem));
5016 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5017 return pedantic_non_lvalue (fold_convert (type, arg2));
5020 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5021 return pedantic_non_lvalue (fold_convert (type, arg1));
5024 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
5029 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
5030 we might still be able to simplify this. For example,
5031 if C1 is one less or one more than C2, this might have started
5032 out as a MIN or MAX and been transformed by this function.
5033 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
5035 if (INTEGRAL_TYPE_P (type)
5036 && TREE_CODE (arg01) == INTEGER_CST
5037 && TREE_CODE (arg2) == INTEGER_CST)
5041 /* We can replace A with C1 in this case. */
5042 arg1 = fold_convert (type, arg01);
5043 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
5046 /* If C1 is C2 + 1, this is min(A, C2). */
5047 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5049 && operand_equal_p (arg01,
5050 const_binop (PLUS_EXPR, arg2,
5051 build_int_cst (type, 1), 0),
5053 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5055 fold_convert (type, arg1),
5060 /* If C1 is C2 - 1, this is min(A, C2). */
5061 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5063 && operand_equal_p (arg01,
5064 const_binop (MINUS_EXPR, arg2,
5065 build_int_cst (type, 1), 0),
5067 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
5069 fold_convert (type, arg1),
5074 /* If C1 is C2 - 1, this is max(A, C2). */
5075 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
5077 && operand_equal_p (arg01,
5078 const_binop (MINUS_EXPR, arg2,
5079 build_int_cst (type, 1), 0),
5081 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5083 fold_convert (type, arg1),
5088 /* If C1 is C2 + 1, this is max(A, C2). */
5089 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
5091 && operand_equal_p (arg01,
5092 const_binop (PLUS_EXPR, arg2,
5093 build_int_cst (type, 1), 0),
5095 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
5097 fold_convert (type, arg1),
5111 #ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
5112 #define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
5115 /* EXP is some logical combination of boolean tests. See if we can
5116 merge it into some range test. Return the new tree if so. */
5119 fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
5121 int or_op = (code == TRUTH_ORIF_EXPR
5122 || code == TRUTH_OR_EXPR);
5123 int in0_p, in1_p, in_p;
5124 tree low0, low1, low, high0, high1, high;
5125 bool strict_overflow_p = false;
5126 tree lhs = make_range (op0, &in0_p, &low0, &high0, &strict_overflow_p);
5127 tree rhs = make_range (op1, &in1_p, &low1, &high1, &strict_overflow_p);
5129 const char * const warnmsg = G_("assuming signed overflow does not occur "
5130 "when simplifying range test");
5132 /* If this is an OR operation, invert both sides; we will invert
5133 again at the end. */
5135 in0_p = ! in0_p, in1_p = ! in1_p;
5137 /* If both expressions are the same, if we can merge the ranges, and we
5138 can build the range test, return it or it inverted. If one of the
5139 ranges is always true or always false, consider it to be the same
5140 expression as the other. */
5141 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
5142 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
5144 && 0 != (tem = (build_range_check (type,
5146 : rhs != 0 ? rhs : integer_zero_node,
5149 if (strict_overflow_p)
5150 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
5151 return or_op ? invert_truthvalue (tem) : tem;
5154 /* On machines where the branch cost is expensive, if this is a
5155 short-circuited branch and the underlying object on both sides
5156 is the same, make a non-short-circuit operation. */
5157 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
5158 && lhs != 0 && rhs != 0
5159 && (code == TRUTH_ANDIF_EXPR
5160 || code == TRUTH_ORIF_EXPR)
5161 && operand_equal_p (lhs, rhs, 0))
5163 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
5164 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
5165 which cases we can't do this. */
5166 if (simple_operand_p (lhs))
5167 return build2 (code == TRUTH_ANDIF_EXPR
5168 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5171 else if (lang_hooks.decls.global_bindings_p () == 0
5172 && ! CONTAINS_PLACEHOLDER_P (lhs))
5174 tree common = save_expr (lhs);
5176 if (0 != (lhs = build_range_check (type, common,
5177 or_op ? ! in0_p : in0_p,
5179 && (0 != (rhs = build_range_check (type, common,
5180 or_op ? ! in1_p : in1_p,
5183 if (strict_overflow_p)
5184 fold_overflow_warning (warnmsg,
5185 WARN_STRICT_OVERFLOW_COMPARISON);
5186 return build2 (code == TRUTH_ANDIF_EXPR
5187 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
5196 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
5197 bit value. Arrange things so the extra bits will be set to zero if and
5198 only if C is signed-extended to its full width. If MASK is nonzero,
5199 it is an INTEGER_CST that should be AND'ed with the extra bits. */
5202 unextend (tree c, int p, int unsignedp, tree mask)
5204 tree type = TREE_TYPE (c);
5205 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
5208 if (p == modesize || unsignedp)
5211 /* We work by getting just the sign bit into the low-order bit, then
5212 into the high-order bit, then sign-extend. We then XOR that value
5214 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
5215 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
5217 /* We must use a signed type in order to get an arithmetic right shift.
5218 However, we must also avoid introducing accidental overflows, so that
5219 a subsequent call to integer_zerop will work. Hence we must
5220 do the type conversion here. At this point, the constant is either
5221 zero or one, and the conversion to a signed type can never overflow.
5222 We could get an overflow if this conversion is done anywhere else. */
5223 if (TYPE_UNSIGNED (type))
5224 temp = fold_convert (signed_type_for (type), temp);
5226 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
5227 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
5229 temp = const_binop (BIT_AND_EXPR, temp,
5230 fold_convert (TREE_TYPE (c), mask), 0);
5231 /* If necessary, convert the type back to match the type of C. */
5232 if (TYPE_UNSIGNED (type))
5233 temp = fold_convert (type, temp);
5235 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
5238 /* Find ways of folding logical expressions of LHS and RHS:
5239 Try to merge two comparisons to the same innermost item.
5240 Look for range tests like "ch >= '0' && ch <= '9'".
5241 Look for combinations of simple terms on machines with expensive branches
5242 and evaluate the RHS unconditionally.
5244 For example, if we have p->a == 2 && p->b == 4 and we can make an
5245 object large enough to span both A and B, we can do this with a comparison
5246 against the object ANDed with the a mask.
5248 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
5249 operations to do this with one comparison.
5251 We check for both normal comparisons and the BIT_AND_EXPRs made this by
5252 function and the one above.
5254 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
5255 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
5257 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
5260 We return the simplified tree or 0 if no optimization is possible. */
5263 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
5265 /* If this is the "or" of two comparisons, we can do something if
5266 the comparisons are NE_EXPR. If this is the "and", we can do something
5267 if the comparisons are EQ_EXPR. I.e.,
5268 (a->b == 2 && a->c == 4) can become (a->new == NEW).
5270 WANTED_CODE is this operation code. For single bit fields, we can
5271 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
5272 comparison for one-bit fields. */
5274 enum tree_code wanted_code;
5275 enum tree_code lcode, rcode;
5276 tree ll_arg, lr_arg, rl_arg, rr_arg;
5277 tree ll_inner, lr_inner, rl_inner, rr_inner;
5278 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
5279 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
5280 HOST_WIDE_INT xll_bitpos, xrl_bitpos;
5281 HOST_WIDE_INT lnbitsize, lnbitpos;
5282 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
5283 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
5284 enum machine_mode lnmode;
5285 tree ll_mask, lr_mask, rl_mask, rr_mask;
5286 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
5287 tree l_const, r_const;
5288 tree lntype, result;
5289 int first_bit, end_bit;
5291 tree orig_lhs = lhs, orig_rhs = rhs;
5292 enum tree_code orig_code = code;
5294 /* Start by getting the comparison codes. Fail if anything is volatile.
5295 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
5296 it were surrounded with a NE_EXPR. */
5298 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
5301 lcode = TREE_CODE (lhs);
5302 rcode = TREE_CODE (rhs);
5304 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
5306 lhs = build2 (NE_EXPR, truth_type, lhs,
5307 build_int_cst (TREE_TYPE (lhs), 0));
5311 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
5313 rhs = build2 (NE_EXPR, truth_type, rhs,
5314 build_int_cst (TREE_TYPE (rhs), 0));
5318 if (TREE_CODE_CLASS (lcode) != tcc_comparison
5319 || TREE_CODE_CLASS (rcode) != tcc_comparison)
5322 ll_arg = TREE_OPERAND (lhs, 0);
5323 lr_arg = TREE_OPERAND (lhs, 1);
5324 rl_arg = TREE_OPERAND (rhs, 0);
5325 rr_arg = TREE_OPERAND (rhs, 1);
5327 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
5328 if (simple_operand_p (ll_arg)
5329 && simple_operand_p (lr_arg))
5332 if (operand_equal_p (ll_arg, rl_arg, 0)
5333 && operand_equal_p (lr_arg, rr_arg, 0))
5335 result = combine_comparisons (code, lcode, rcode,
5336 truth_type, ll_arg, lr_arg);
5340 else if (operand_equal_p (ll_arg, rr_arg, 0)
5341 && operand_equal_p (lr_arg, rl_arg, 0))
5343 result = combine_comparisons (code, lcode,
5344 swap_tree_comparison (rcode),
5345 truth_type, ll_arg, lr_arg);
5351 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
5352 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
5354 /* If the RHS can be evaluated unconditionally and its operands are
5355 simple, it wins to evaluate the RHS unconditionally on machines
5356 with expensive branches. In this case, this isn't a comparison
5357 that can be merged. Avoid doing this if the RHS is a floating-point
5358 comparison since those can trap. */
5360 if (BRANCH_COST >= 2
5361 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
5362 && simple_operand_p (rl_arg)
5363 && simple_operand_p (rr_arg))
5365 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
5366 if (code == TRUTH_OR_EXPR
5367 && lcode == NE_EXPR && integer_zerop (lr_arg)
5368 && rcode == NE_EXPR && integer_zerop (rr_arg)
5369 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5370 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5371 return build2 (NE_EXPR, truth_type,
5372 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5374 build_int_cst (TREE_TYPE (ll_arg), 0));
5376 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
5377 if (code == TRUTH_AND_EXPR
5378 && lcode == EQ_EXPR && integer_zerop (lr_arg)
5379 && rcode == EQ_EXPR && integer_zerop (rr_arg)
5380 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg)
5381 && INTEGRAL_TYPE_P (TREE_TYPE (ll_arg)))
5382 return build2 (EQ_EXPR, truth_type,
5383 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
5385 build_int_cst (TREE_TYPE (ll_arg), 0));
5387 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
5389 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
5390 return build2 (code, truth_type, lhs, rhs);
5395 /* See if the comparisons can be merged. Then get all the parameters for
5398 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
5399 || (rcode != EQ_EXPR && rcode != NE_EXPR))
5403 ll_inner = decode_field_reference (ll_arg,
5404 &ll_bitsize, &ll_bitpos, &ll_mode,
5405 &ll_unsignedp, &volatilep, &ll_mask,
5407 lr_inner = decode_field_reference (lr_arg,
5408 &lr_bitsize, &lr_bitpos, &lr_mode,
5409 &lr_unsignedp, &volatilep, &lr_mask,
5411 rl_inner = decode_field_reference (rl_arg,
5412 &rl_bitsize, &rl_bitpos, &rl_mode,
5413 &rl_unsignedp, &volatilep, &rl_mask,
5415 rr_inner = decode_field_reference (rr_arg,
5416 &rr_bitsize, &rr_bitpos, &rr_mode,
5417 &rr_unsignedp, &volatilep, &rr_mask,
5420 /* It must be true that the inner operation on the lhs of each
5421 comparison must be the same if we are to be able to do anything.
5422 Then see if we have constants. If not, the same must be true for
5424 if (volatilep || ll_inner == 0 || rl_inner == 0
5425 || ! operand_equal_p (ll_inner, rl_inner, 0))
5428 if (TREE_CODE (lr_arg) == INTEGER_CST
5429 && TREE_CODE (rr_arg) == INTEGER_CST)
5430 l_const = lr_arg, r_const = rr_arg;
5431 else if (lr_inner == 0 || rr_inner == 0
5432 || ! operand_equal_p (lr_inner, rr_inner, 0))
5435 l_const = r_const = 0;
5437 /* If either comparison code is not correct for our logical operation,
5438 fail. However, we can convert a one-bit comparison against zero into
5439 the opposite comparison against that bit being set in the field. */
5441 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
5442 if (lcode != wanted_code)
5444 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
5446 /* Make the left operand unsigned, since we are only interested
5447 in the value of one bit. Otherwise we are doing the wrong
5456 /* This is analogous to the code for l_const above. */
5457 if (rcode != wanted_code)
5459 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
5468 /* See if we can find a mode that contains both fields being compared on
5469 the left. If we can't, fail. Otherwise, update all constants and masks
5470 to be relative to a field of that size. */
5471 first_bit = MIN (ll_bitpos, rl_bitpos);
5472 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5473 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5474 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5476 if (lnmode == VOIDmode)
5479 lnbitsize = GET_MODE_BITSIZE (lnmode);
5480 lnbitpos = first_bit & ~ (lnbitsize - 1);
5481 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
5482 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5484 if (BYTES_BIG_ENDIAN)
5486 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5487 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5490 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5491 size_int (xll_bitpos), 0);
5492 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5493 size_int (xrl_bitpos), 0);
5497 l_const = fold_convert (lntype, l_const);
5498 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
5499 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5500 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
5501 fold_build1 (BIT_NOT_EXPR,
5505 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5507 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5512 r_const = fold_convert (lntype, r_const);
5513 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
5514 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5515 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
5516 fold_build1 (BIT_NOT_EXPR,
5520 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
5522 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
5526 /* Handle the case of comparisons with constants. If there is something in
5527 common between the masks, those bits of the constants must be the same.
5528 If not, the condition is always false. Test for this to avoid generating
5529 incorrect code below. */
5530 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
5531 if (! integer_zerop (result)
5532 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5533 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
5535 if (wanted_code == NE_EXPR)
5537 warning (0, "%<or%> of unmatched not-equal tests is always 1");
5538 return constant_boolean_node (true, truth_type);
5542 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
5543 return constant_boolean_node (false, truth_type);
5550 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
5554 optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
5557 enum tree_code op_code;
5560 int consts_equal, consts_lt;
5563 STRIP_SIGN_NOPS (arg0);
5565 op_code = TREE_CODE (arg0);
5566 minmax_const = TREE_OPERAND (arg0, 1);
5567 comp_const = fold_convert (TREE_TYPE (arg0), op1);
5568 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5569 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5570 inner = TREE_OPERAND (arg0, 0);
5572 /* If something does not permit us to optimize, return the original tree. */
5573 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5574 || TREE_CODE (comp_const) != INTEGER_CST
5575 || TREE_OVERFLOW (comp_const)
5576 || TREE_CODE (minmax_const) != INTEGER_CST
5577 || TREE_OVERFLOW (minmax_const))
5580 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5581 and GT_EXPR, doing the rest with recursive calls using logical
5585 case NE_EXPR: case LT_EXPR: case LE_EXPR:
5587 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5590 return invert_truthvalue (tem);
5596 fold_build2 (TRUTH_ORIF_EXPR, type,
5597 optimize_minmax_comparison
5598 (EQ_EXPR, type, arg0, comp_const),
5599 optimize_minmax_comparison
5600 (GT_EXPR, type, arg0, comp_const));
5603 if (op_code == MAX_EXPR && consts_equal)
5604 /* MAX (X, 0) == 0 -> X <= 0 */
5605 return fold_build2 (LE_EXPR, type, inner, comp_const);
5607 else if (op_code == MAX_EXPR && consts_lt)
5608 /* MAX (X, 0) == 5 -> X == 5 */
5609 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5611 else if (op_code == MAX_EXPR)
5612 /* MAX (X, 0) == -1 -> false */
5613 return omit_one_operand (type, integer_zero_node, inner);
5615 else if (consts_equal)
5616 /* MIN (X, 0) == 0 -> X >= 0 */
5617 return fold_build2 (GE_EXPR, type, inner, comp_const);
5620 /* MIN (X, 0) == 5 -> false */
5621 return omit_one_operand (type, integer_zero_node, inner);
5624 /* MIN (X, 0) == -1 -> X == -1 */
5625 return fold_build2 (EQ_EXPR, type, inner, comp_const);
5628 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5629 /* MAX (X, 0) > 0 -> X > 0
5630 MAX (X, 0) > 5 -> X > 5 */
5631 return fold_build2 (GT_EXPR, type, inner, comp_const);
5633 else if (op_code == MAX_EXPR)
5634 /* MAX (X, 0) > -1 -> true */
5635 return omit_one_operand (type, integer_one_node, inner);
5637 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5638 /* MIN (X, 0) > 0 -> false
5639 MIN (X, 0) > 5 -> false */
5640 return omit_one_operand (type, integer_zero_node, inner);
5643 /* MIN (X, 0) > -1 -> X > -1 */
5644 return fold_build2 (GT_EXPR, type, inner, comp_const);
5651 /* T is an integer expression that is being multiplied, divided, or taken a
5652 modulus (CODE says which and what kind of divide or modulus) by a
5653 constant C. See if we can eliminate that operation by folding it with
5654 other operations already in T. WIDE_TYPE, if non-null, is a type that
5655 should be used for the computation if wider than our type.
5657 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5658 (X * 2) + (Y * 4). We must, however, be assured that either the original
5659 expression would not overflow or that overflow is undefined for the type
5660 in the language in question.
5662 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5663 the machine has a multiply-accumulate insn or that this is part of an
5664 addressing calculation.
5666 If we return a non-null expression, it is an equivalent form of the
5667 original computation, but need not be in the original type.
5669 We set *STRICT_OVERFLOW_P to true if the return values depends on
5670 signed overflow being undefined. Otherwise we do not change
5671 *STRICT_OVERFLOW_P. */
5674 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type,
5675 bool *strict_overflow_p)
5677 /* To avoid exponential search depth, refuse to allow recursion past
5678 three levels. Beyond that (1) it's highly unlikely that we'll find
5679 something interesting and (2) we've probably processed it before
5680 when we built the inner expression. */
5689 ret = extract_muldiv_1 (t, c, code, wide_type, strict_overflow_p);
5696 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
5697 bool *strict_overflow_p)
5699 tree type = TREE_TYPE (t);
5700 enum tree_code tcode = TREE_CODE (t);
5701 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5702 > GET_MODE_SIZE (TYPE_MODE (type)))
5703 ? wide_type : type);
5705 int same_p = tcode == code;
5706 tree op0 = NULL_TREE, op1 = NULL_TREE;
5707 bool sub_strict_overflow_p;
5709 /* Don't deal with constants of zero here; they confuse the code below. */
5710 if (integer_zerop (c))
5713 if (TREE_CODE_CLASS (tcode) == tcc_unary)
5714 op0 = TREE_OPERAND (t, 0);
5716 if (TREE_CODE_CLASS (tcode) == tcc_binary)
5717 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5719 /* Note that we need not handle conditional operations here since fold
5720 already handles those cases. So just do arithmetic here. */
5724 /* For a constant, we can always simplify if we are a multiply
5725 or (for divide and modulus) if it is a multiple of our constant. */
5726 if (code == MULT_EXPR
5727 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5728 return const_binop (code, fold_convert (ctype, t),
5729 fold_convert (ctype, c), 0);
5732 CASE_CONVERT: case NON_LVALUE_EXPR:
5733 /* If op0 is an expression ... */
5734 if ((COMPARISON_CLASS_P (op0)
5735 || UNARY_CLASS_P (op0)
5736 || BINARY_CLASS_P (op0)
5737 || VL_EXP_CLASS_P (op0)
5738 || EXPRESSION_CLASS_P (op0))
5739 /* ... and has wrapping overflow, and its type is smaller
5740 than ctype, then we cannot pass through as widening. */
5741 && ((TYPE_OVERFLOW_WRAPS (TREE_TYPE (op0))
5742 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5743 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5744 && (TYPE_PRECISION (ctype)
5745 > TYPE_PRECISION (TREE_TYPE (op0))))
5746 /* ... or this is a truncation (t is narrower than op0),
5747 then we cannot pass through this narrowing. */
5748 || (TYPE_PRECISION (type)
5749 < TYPE_PRECISION (TREE_TYPE (op0)))
5750 /* ... or signedness changes for division or modulus,
5751 then we cannot pass through this conversion. */
5752 || (code != MULT_EXPR
5753 && (TYPE_UNSIGNED (ctype)
5754 != TYPE_UNSIGNED (TREE_TYPE (op0))))
5755 /* ... or has undefined overflow while the converted to
5756 type has not, we cannot do the operation in the inner type
5757 as that would introduce undefined overflow. */
5758 || (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0))
5759 && !TYPE_OVERFLOW_UNDEFINED (type))))
5762 /* Pass the constant down and see if we can make a simplification. If
5763 we can, replace this expression with the inner simplification for
5764 possible later conversion to our or some other type. */
5765 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5766 && TREE_CODE (t2) == INTEGER_CST
5767 && !TREE_OVERFLOW (t2)
5768 && (0 != (t1 = extract_muldiv (op0, t2, code,
5770 ? ctype : NULL_TREE,
5771 strict_overflow_p))))
5776 /* If widening the type changes it from signed to unsigned, then we
5777 must avoid building ABS_EXPR itself as unsigned. */
5778 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5780 tree cstype = (*signed_type_for) (ctype);
5781 if ((t1 = extract_muldiv (op0, c, code, cstype, strict_overflow_p))
5784 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
5785 return fold_convert (ctype, t1);
5789 /* If the constant is negative, we cannot simplify this. */
5790 if (tree_int_cst_sgn (c) == -1)
5794 if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
5796 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
5799 case MIN_EXPR: case MAX_EXPR:
5800 /* If widening the type changes the signedness, then we can't perform
5801 this optimization as that changes the result. */
5802 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5805 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5806 sub_strict_overflow_p = false;
5807 if ((t1 = extract_muldiv (op0, c, code, wide_type,
5808 &sub_strict_overflow_p)) != 0
5809 && (t2 = extract_muldiv (op1, c, code, wide_type,
5810 &sub_strict_overflow_p)) != 0)
5812 if (tree_int_cst_sgn (c) < 0)
5813 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5814 if (sub_strict_overflow_p)
5815 *strict_overflow_p = true;
5816 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5817 fold_convert (ctype, t2));
5821 case LSHIFT_EXPR: case RSHIFT_EXPR:
5822 /* If the second operand is constant, this is a multiplication
5823 or floor division, by a power of two, so we can treat it that
5824 way unless the multiplier or divisor overflows. Signed
5825 left-shift overflow is implementation-defined rather than
5826 undefined in C90, so do not convert signed left shift into
5828 if (TREE_CODE (op1) == INTEGER_CST
5829 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5830 /* const_binop may not detect overflow correctly,
5831 so check for it explicitly here. */
5832 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5833 && TREE_INT_CST_HIGH (op1) == 0
5834 && 0 != (t1 = fold_convert (ctype,
5835 const_binop (LSHIFT_EXPR,
5838 && !TREE_OVERFLOW (t1))
5839 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5840 ? MULT_EXPR : FLOOR_DIV_EXPR,
5841 ctype, fold_convert (ctype, op0), t1),
5842 c, code, wide_type, strict_overflow_p);
5845 case PLUS_EXPR: case MINUS_EXPR:
5846 /* See if we can eliminate the operation on both sides. If we can, we
5847 can return a new PLUS or MINUS. If we can't, the only remaining
5848 cases where we can do anything are if the second operand is a
5850 sub_strict_overflow_p = false;
5851 t1 = extract_muldiv (op0, c, code, wide_type, &sub_strict_overflow_p);
5852 t2 = extract_muldiv (op1, c, code, wide_type, &sub_strict_overflow_p);
5853 if (t1 != 0 && t2 != 0
5854 && (code == MULT_EXPR
5855 /* If not multiplication, we can only do this if both operands
5856 are divisible by c. */
5857 || (multiple_of_p (ctype, op0, c)
5858 && multiple_of_p (ctype, op1, c))))
5860 if (sub_strict_overflow_p)
5861 *strict_overflow_p = true;
5862 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5863 fold_convert (ctype, t2));
5866 /* If this was a subtraction, negate OP1 and set it to be an addition.
5867 This simplifies the logic below. */
5868 if (tcode == MINUS_EXPR)
5869 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5871 if (TREE_CODE (op1) != INTEGER_CST)
5874 /* If either OP1 or C are negative, this optimization is not safe for
5875 some of the division and remainder types while for others we need
5876 to change the code. */
5877 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5879 if (code == CEIL_DIV_EXPR)
5880 code = FLOOR_DIV_EXPR;
5881 else if (code == FLOOR_DIV_EXPR)
5882 code = CEIL_DIV_EXPR;
5883 else if (code != MULT_EXPR
5884 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5888 /* If it's a multiply or a division/modulus operation of a multiple
5889 of our constant, do the operation and verify it doesn't overflow. */
5890 if (code == MULT_EXPR
5891 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5893 op1 = const_binop (code, fold_convert (ctype, op1),
5894 fold_convert (ctype, c), 0);
5895 /* We allow the constant to overflow with wrapping semantics. */
5897 || (TREE_OVERFLOW (op1) && !TYPE_OVERFLOW_WRAPS (ctype)))
5903 /* If we have an unsigned type is not a sizetype, we cannot widen
5904 the operation since it will change the result if the original
5905 computation overflowed. */
5906 if (TYPE_UNSIGNED (ctype)
5907 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5911 /* If we were able to eliminate our operation from the first side,
5912 apply our operation to the second side and reform the PLUS. */
5913 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5914 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
5916 /* The last case is if we are a multiply. In that case, we can
5917 apply the distributive law to commute the multiply and addition
5918 if the multiplication of the constants doesn't overflow. */
5919 if (code == MULT_EXPR)
5920 return fold_build2 (tcode, ctype,
5921 fold_build2 (code, ctype,
5922 fold_convert (ctype, op0),
5923 fold_convert (ctype, c)),
5929 /* We have a special case here if we are doing something like
5930 (C * 8) % 4 since we know that's zero. */
5931 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5932 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5933 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5934 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5935 return omit_one_operand (type, integer_zero_node, op0);
5937 /* ... fall through ... */
5939 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5940 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5941 /* If we can extract our operation from the LHS, do so and return a
5942 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5943 do something only if the second operand is a constant. */
5945 && (t1 = extract_muldiv (op0, c, code, wide_type,
5946 strict_overflow_p)) != 0)
5947 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5948 fold_convert (ctype, op1));
5949 else if (tcode == MULT_EXPR && code == MULT_EXPR
5950 && (t1 = extract_muldiv (op1, c, code, wide_type,
5951 strict_overflow_p)) != 0)
5952 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5953 fold_convert (ctype, t1));
5954 else if (TREE_CODE (op1) != INTEGER_CST)
5957 /* If these are the same operation types, we can associate them
5958 assuming no overflow. */
5960 && 0 != (t1 = int_const_binop (MULT_EXPR, fold_convert (ctype, op1),
5961 fold_convert (ctype, c), 1))
5962 && 0 != (t1 = force_fit_type_double (ctype, TREE_INT_CST_LOW (t1),
5963 TREE_INT_CST_HIGH (t1),
5964 (TYPE_UNSIGNED (ctype)
5965 && tcode != MULT_EXPR) ? -1 : 1,
5966 TREE_OVERFLOW (t1)))
5967 && !TREE_OVERFLOW (t1))
5968 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
5970 /* If these operations "cancel" each other, we have the main
5971 optimizations of this pass, which occur when either constant is a
5972 multiple of the other, in which case we replace this with either an
5973 operation or CODE or TCODE.
5975 If we have an unsigned type that is not a sizetype, we cannot do
5976 this since it will change the result if the original computation
5978 if ((TYPE_OVERFLOW_UNDEFINED (ctype)
5979 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5980 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5981 || (tcode == MULT_EXPR
5982 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5983 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR
5984 && code != MULT_EXPR)))
5986 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5988 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5989 *strict_overflow_p = true;
5990 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5991 fold_convert (ctype,
5992 const_binop (TRUNC_DIV_EXPR,
5995 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5997 if (TYPE_OVERFLOW_UNDEFINED (ctype))
5998 *strict_overflow_p = true;
5999 return fold_build2 (code, ctype, fold_convert (ctype, op0),
6000 fold_convert (ctype,
6001 const_binop (TRUNC_DIV_EXPR,
6014 /* Return a node which has the indicated constant VALUE (either 0 or
6015 1), and is of the indicated TYPE. */
6018 constant_boolean_node (int value, tree type)
6020 if (type == integer_type_node)
6021 return value ? integer_one_node : integer_zero_node;
6022 else if (type == boolean_type_node)
6023 return value ? boolean_true_node : boolean_false_node;
6025 return build_int_cst (type, value);
6029 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
6030 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
6031 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6032 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
6033 COND is the first argument to CODE; otherwise (as in the example
6034 given here), it is the second argument. TYPE is the type of the
6035 original expression. Return NULL_TREE if no simplification is
6039 fold_binary_op_with_conditional_arg (enum tree_code code,
6040 tree type, tree op0, tree op1,
6041 tree cond, tree arg, int cond_first_p)
6043 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
6044 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
6045 tree test, true_value, false_value;
6046 tree lhs = NULL_TREE;
6047 tree rhs = NULL_TREE;
6049 /* This transformation is only worthwhile if we don't have to wrap
6050 arg in a SAVE_EXPR, and the operation can be simplified on at least
6051 one of the branches once its pushed inside the COND_EXPR. */
6052 if (!TREE_CONSTANT (arg))
6055 if (TREE_CODE (cond) == COND_EXPR)
6057 test = TREE_OPERAND (cond, 0);
6058 true_value = TREE_OPERAND (cond, 1);
6059 false_value = TREE_OPERAND (cond, 2);
6060 /* If this operand throws an expression, then it does not make
6061 sense to try to perform a logical or arithmetic operation
6063 if (VOID_TYPE_P (TREE_TYPE (true_value)))
6065 if (VOID_TYPE_P (TREE_TYPE (false_value)))
6070 tree testtype = TREE_TYPE (cond);
6072 true_value = constant_boolean_node (true, testtype);
6073 false_value = constant_boolean_node (false, testtype);
6076 arg = fold_convert (arg_type, arg);
6079 true_value = fold_convert (cond_type, true_value);
6081 lhs = fold_build2 (code, type, true_value, arg);
6083 lhs = fold_build2 (code, type, arg, true_value);
6087 false_value = fold_convert (cond_type, false_value);
6089 rhs = fold_build2 (code, type, false_value, arg);
6091 rhs = fold_build2 (code, type, arg, false_value);
6094 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
6095 return fold_convert (type, test);
6099 /* Subroutine of fold() that checks for the addition of +/- 0.0.
6101 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
6102 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
6103 ADDEND is the same as X.
6105 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
6106 and finite. The problematic cases are when X is zero, and its mode
6107 has signed zeros. In the case of rounding towards -infinity,
6108 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
6109 modes, X + 0 is not the same as X because -0 + 0 is 0. */
6112 fold_real_zero_addition_p (const_tree type, const_tree addend, int negate)
6114 if (!real_zerop (addend))
6117 /* Don't allow the fold with -fsignaling-nans. */
6118 if (HONOR_SNANS (TYPE_MODE (type)))
6121 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
6122 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
6125 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
6126 if (TREE_CODE (addend) == REAL_CST
6127 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
6130 /* The mode has signed zeros, and we have to honor their sign.
6131 In this situation, there is only one case we can return true for.
6132 X - 0 is the same as X unless rounding towards -infinity is
6134 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
6137 /* Subroutine of fold() that checks comparisons of built-in math
6138 functions against real constants.
6140 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
6141 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
6142 is the type of the result and ARG0 and ARG1 are the operands of the
6143 comparison. ARG1 must be a TREE_REAL_CST.
6145 The function returns the constant folded tree if a simplification
6146 can be made, and NULL_TREE otherwise. */
6149 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
6150 tree type, tree arg0, tree arg1)
6154 if (BUILTIN_SQRT_P (fcode))
6156 tree arg = CALL_EXPR_ARG (arg0, 0);
6157 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
6159 c = TREE_REAL_CST (arg1);
6160 if (REAL_VALUE_NEGATIVE (c))
6162 /* sqrt(x) < y is always false, if y is negative. */
6163 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
6164 return omit_one_operand (type, integer_zero_node, arg);
6166 /* sqrt(x) > y is always true, if y is negative and we
6167 don't care about NaNs, i.e. negative values of x. */
6168 if (code == NE_EXPR || !HONOR_NANS (mode))
6169 return omit_one_operand (type, integer_one_node, arg);
6171 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
6172 return fold_build2 (GE_EXPR, type, arg,
6173 build_real (TREE_TYPE (arg), dconst0));
6175 else if (code == GT_EXPR || code == GE_EXPR)
6179 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6180 real_convert (&c2, mode, &c2);
6182 if (REAL_VALUE_ISINF (c2))
6184 /* sqrt(x) > y is x == +Inf, when y is very large. */
6185 if (HONOR_INFINITIES (mode))
6186 return fold_build2 (EQ_EXPR, type, arg,
6187 build_real (TREE_TYPE (arg), c2));
6189 /* sqrt(x) > y is always false, when y is very large
6190 and we don't care about infinities. */
6191 return omit_one_operand (type, integer_zero_node, arg);
6194 /* sqrt(x) > c is the same as x > c*c. */
6195 return fold_build2 (code, type, arg,
6196 build_real (TREE_TYPE (arg), c2));
6198 else if (code == LT_EXPR || code == LE_EXPR)
6202 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
6203 real_convert (&c2, mode, &c2);
6205 if (REAL_VALUE_ISINF (c2))
6207 /* sqrt(x) < y is always true, when y is a very large
6208 value and we don't care about NaNs or Infinities. */
6209 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
6210 return omit_one_operand (type, integer_one_node, arg);
6212 /* sqrt(x) < y is x != +Inf when y is very large and we
6213 don't care about NaNs. */
6214 if (! HONOR_NANS (mode))
6215 return fold_build2 (NE_EXPR, type, arg,
6216 build_real (TREE_TYPE (arg), c2));
6218 /* sqrt(x) < y is x >= 0 when y is very large and we
6219 don't care about Infinities. */
6220 if (! HONOR_INFINITIES (mode))
6221 return fold_build2 (GE_EXPR, type, arg,
6222 build_real (TREE_TYPE (arg), dconst0));
6224 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
6225 if (lang_hooks.decls.global_bindings_p () != 0
6226 || CONTAINS_PLACEHOLDER_P (arg))
6229 arg = save_expr (arg);
6230 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6231 fold_build2 (GE_EXPR, type, arg,
6232 build_real (TREE_TYPE (arg),
6234 fold_build2 (NE_EXPR, type, arg,
6235 build_real (TREE_TYPE (arg),
6239 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
6240 if (! HONOR_NANS (mode))
6241 return fold_build2 (code, type, arg,
6242 build_real (TREE_TYPE (arg), c2));
6244 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
6245 if (lang_hooks.decls.global_bindings_p () == 0
6246 && ! CONTAINS_PLACEHOLDER_P (arg))
6248 arg = save_expr (arg);
6249 return fold_build2 (TRUTH_ANDIF_EXPR, type,
6250 fold_build2 (GE_EXPR, type, arg,
6251 build_real (TREE_TYPE (arg),
6253 fold_build2 (code, type, arg,
6254 build_real (TREE_TYPE (arg),
6263 /* Subroutine of fold() that optimizes comparisons against Infinities,
6264 either +Inf or -Inf.
6266 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6267 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6268 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6270 The function returns the constant folded tree if a simplification
6271 can be made, and NULL_TREE otherwise. */
6274 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6276 enum machine_mode mode;
6277 REAL_VALUE_TYPE max;
6281 mode = TYPE_MODE (TREE_TYPE (arg0));
6283 /* For negative infinity swap the sense of the comparison. */
6284 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6286 code = swap_tree_comparison (code);
6291 /* x > +Inf is always false, if with ignore sNANs. */
6292 if (HONOR_SNANS (mode))
6294 return omit_one_operand (type, integer_zero_node, arg0);
6297 /* x <= +Inf is always true, if we don't case about NaNs. */
6298 if (! HONOR_NANS (mode))
6299 return omit_one_operand (type, integer_one_node, arg0);
6301 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
6302 if (lang_hooks.decls.global_bindings_p () == 0
6303 && ! CONTAINS_PLACEHOLDER_P (arg0))
6305 arg0 = save_expr (arg0);
6306 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6312 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6313 real_maxval (&max, neg, mode);
6314 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6315 arg0, build_real (TREE_TYPE (arg0), max));
6318 /* x < +Inf is always equal to x <= DBL_MAX. */
6319 real_maxval (&max, neg, mode);
6320 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6321 arg0, build_real (TREE_TYPE (arg0), max));
6324 /* x != +Inf is always equal to !(x > DBL_MAX). */
6325 real_maxval (&max, neg, mode);
6326 if (! HONOR_NANS (mode))
6327 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6328 arg0, build_real (TREE_TYPE (arg0), max));
6330 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6331 arg0, build_real (TREE_TYPE (arg0), max));
6332 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6341 /* Subroutine of fold() that optimizes comparisons of a division by
6342 a nonzero integer constant against an integer constant, i.e.
6345 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6346 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6347 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6349 The function returns the constant folded tree if a simplification
6350 can be made, and NULL_TREE otherwise. */
6353 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6355 tree prod, tmp, hi, lo;
6356 tree arg00 = TREE_OPERAND (arg0, 0);
6357 tree arg01 = TREE_OPERAND (arg0, 1);
6358 unsigned HOST_WIDE_INT lpart;
6359 HOST_WIDE_INT hpart;
6360 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
6364 /* We have to do this the hard way to detect unsigned overflow.
6365 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
6366 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6367 TREE_INT_CST_HIGH (arg01),
6368 TREE_INT_CST_LOW (arg1),
6369 TREE_INT_CST_HIGH (arg1),
6370 &lpart, &hpart, unsigned_p);
6371 prod = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6373 neg_overflow = false;
6377 tmp = int_const_binop (MINUS_EXPR, arg01,
6378 build_int_cst (TREE_TYPE (arg01), 1), 0);
6381 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
6382 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6383 TREE_INT_CST_HIGH (prod),
6384 TREE_INT_CST_LOW (tmp),
6385 TREE_INT_CST_HIGH (tmp),
6386 &lpart, &hpart, unsigned_p);
6387 hi = force_fit_type_double (TREE_TYPE (arg00), lpart, hpart,
6388 -1, overflow | TREE_OVERFLOW (prod));
6390 else if (tree_int_cst_sgn (arg01) >= 0)
6392 tmp = int_const_binop (MINUS_EXPR, arg01,
6393 build_int_cst (TREE_TYPE (arg01), 1), 0);
6394 switch (tree_int_cst_sgn (arg1))
6397 neg_overflow = true;
6398 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6403 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6408 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6418 /* A negative divisor reverses the relational operators. */
6419 code = swap_tree_comparison (code);
6421 tmp = int_const_binop (PLUS_EXPR, arg01,
6422 build_int_cst (TREE_TYPE (arg01), 1), 0);
6423 switch (tree_int_cst_sgn (arg1))
6426 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6431 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6436 neg_overflow = true;
6437 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6449 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6450 return omit_one_operand (type, integer_zero_node, arg00);
6451 if (TREE_OVERFLOW (hi))
6452 return fold_build2 (GE_EXPR, type, arg00, lo);
6453 if (TREE_OVERFLOW (lo))
6454 return fold_build2 (LE_EXPR, type, arg00, hi);
6455 return build_range_check (type, arg00, 1, lo, hi);
6458 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6459 return omit_one_operand (type, integer_one_node, arg00);
6460 if (TREE_OVERFLOW (hi))
6461 return fold_build2 (LT_EXPR, type, arg00, lo);
6462 if (TREE_OVERFLOW (lo))
6463 return fold_build2 (GT_EXPR, type, arg00, hi);
6464 return build_range_check (type, arg00, 0, lo, hi);
6467 if (TREE_OVERFLOW (lo))
6469 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6470 return omit_one_operand (type, tmp, arg00);
6472 return fold_build2 (LT_EXPR, type, arg00, lo);
6475 if (TREE_OVERFLOW (hi))
6477 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6478 return omit_one_operand (type, tmp, arg00);
6480 return fold_build2 (LE_EXPR, type, arg00, hi);
6483 if (TREE_OVERFLOW (hi))
6485 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6486 return omit_one_operand (type, tmp, arg00);
6488 return fold_build2 (GT_EXPR, type, arg00, hi);
6491 if (TREE_OVERFLOW (lo))
6493 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6494 return omit_one_operand (type, tmp, arg00);
6496 return fold_build2 (GE_EXPR, type, arg00, lo);
6506 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6507 equality/inequality test, then return a simplified form of the test
6508 using a sign testing. Otherwise return NULL. TYPE is the desired
6512 fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6515 /* If this is testing a single bit, we can optimize the test. */
6516 if ((code == NE_EXPR || code == EQ_EXPR)
6517 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6518 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6520 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6521 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6522 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6524 if (arg00 != NULL_TREE
6525 /* This is only a win if casting to a signed type is cheap,
6526 i.e. when arg00's type is not a partial mode. */
6527 && TYPE_PRECISION (TREE_TYPE (arg00))
6528 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6530 tree stype = signed_type_for (TREE_TYPE (arg00));
6531 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6532 result_type, fold_convert (stype, arg00),
6533 build_int_cst (stype, 0));
6540 /* If CODE with arguments ARG0 and ARG1 represents a single bit
6541 equality/inequality test, then return a simplified form of
6542 the test using shifts and logical operations. Otherwise return
6543 NULL. TYPE is the desired result type. */
6546 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6549 /* If this is testing a single bit, we can optimize the test. */
6550 if ((code == NE_EXPR || code == EQ_EXPR)
6551 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6552 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6554 tree inner = TREE_OPERAND (arg0, 0);
6555 tree type = TREE_TYPE (arg0);
6556 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6557 enum machine_mode operand_mode = TYPE_MODE (type);
6559 tree signed_type, unsigned_type, intermediate_type;
6562 /* First, see if we can fold the single bit test into a sign-bit
6564 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6569 /* Otherwise we have (A & C) != 0 where C is a single bit,
6570 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6571 Similarly for (A & C) == 0. */
6573 /* If INNER is a right shift of a constant and it plus BITNUM does
6574 not overflow, adjust BITNUM and INNER. */
6575 if (TREE_CODE (inner) == RSHIFT_EXPR
6576 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6577 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6578 && bitnum < TYPE_PRECISION (type)
6579 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6580 bitnum - TYPE_PRECISION (type)))
6582 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6583 inner = TREE_OPERAND (inner, 0);
6586 /* If we are going to be able to omit the AND below, we must do our
6587 operations as unsigned. If we must use the AND, we have a choice.
6588 Normally unsigned is faster, but for some machines signed is. */
6589 #ifdef LOAD_EXTEND_OP
6590 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6591 && !flag_syntax_only) ? 0 : 1;
6596 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6597 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
6598 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
6599 inner = fold_convert (intermediate_type, inner);
6602 inner = build2 (RSHIFT_EXPR, intermediate_type,
6603 inner, size_int (bitnum));
6605 one = build_int_cst (intermediate_type, 1);
6607 if (code == EQ_EXPR)
6608 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type, inner, one);
6610 /* Put the AND last so it can combine with more things. */
6611 inner = build2 (BIT_AND_EXPR, intermediate_type, inner, one);
6613 /* Make sure to return the proper type. */
6614 inner = fold_convert (result_type, inner);
6621 /* Check whether we are allowed to reorder operands arg0 and arg1,
6622 such that the evaluation of arg1 occurs before arg0. */
6625 reorder_operands_p (const_tree arg0, const_tree arg1)
6627 if (! flag_evaluation_order)
6629 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6631 return ! TREE_SIDE_EFFECTS (arg0)
6632 && ! TREE_SIDE_EFFECTS (arg1);
6635 /* Test whether it is preferable two swap two operands, ARG0 and
6636 ARG1, for example because ARG0 is an integer constant and ARG1
6637 isn't. If REORDER is true, only recommend swapping if we can
6638 evaluate the operands in reverse order. */
6641 tree_swap_operands_p (const_tree arg0, const_tree arg1, bool reorder)
6643 STRIP_SIGN_NOPS (arg0);
6644 STRIP_SIGN_NOPS (arg1);
6646 if (TREE_CODE (arg1) == INTEGER_CST)
6648 if (TREE_CODE (arg0) == INTEGER_CST)
6651 if (TREE_CODE (arg1) == REAL_CST)
6653 if (TREE_CODE (arg0) == REAL_CST)
6656 if (TREE_CODE (arg1) == FIXED_CST)
6658 if (TREE_CODE (arg0) == FIXED_CST)
6661 if (TREE_CODE (arg1) == COMPLEX_CST)
6663 if (TREE_CODE (arg0) == COMPLEX_CST)
6666 if (TREE_CONSTANT (arg1))
6668 if (TREE_CONSTANT (arg0))
6674 if (reorder && flag_evaluation_order
6675 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6678 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6679 for commutative and comparison operators. Ensuring a canonical
6680 form allows the optimizers to find additional redundancies without
6681 having to explicitly check for both orderings. */
6682 if (TREE_CODE (arg0) == SSA_NAME
6683 && TREE_CODE (arg1) == SSA_NAME
6684 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6687 /* Put SSA_NAMEs last. */
6688 if (TREE_CODE (arg1) == SSA_NAME)
6690 if (TREE_CODE (arg0) == SSA_NAME)
6693 /* Put variables last. */
6702 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6703 ARG0 is extended to a wider type. */
6706 fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6708 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6710 tree shorter_type, outer_type;
6714 if (arg0_unw == arg0)
6716 shorter_type = TREE_TYPE (arg0_unw);
6718 #ifdef HAVE_canonicalize_funcptr_for_compare
6719 /* Disable this optimization if we're casting a function pointer
6720 type on targets that require function pointer canonicalization. */
6721 if (HAVE_canonicalize_funcptr_for_compare
6722 && TREE_CODE (shorter_type) == POINTER_TYPE
6723 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
6727 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6730 arg1_unw = get_unwidened (arg1, NULL_TREE);
6732 /* If possible, express the comparison in the shorter mode. */
6733 if ((code == EQ_EXPR || code == NE_EXPR
6734 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6735 && (TREE_TYPE (arg1_unw) == shorter_type
6736 || ((TYPE_PRECISION (shorter_type)
6737 >= TYPE_PRECISION (TREE_TYPE (arg1_unw)))
6738 && (TYPE_UNSIGNED (shorter_type)
6739 == TYPE_UNSIGNED (TREE_TYPE (arg1_unw))))
6740 || (TREE_CODE (arg1_unw) == INTEGER_CST
6741 && (TREE_CODE (shorter_type) == INTEGER_TYPE
6742 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
6743 && int_fits_type_p (arg1_unw, shorter_type))))
6744 return fold_build2 (code, type, arg0_unw,
6745 fold_convert (shorter_type, arg1_unw));
6747 if (TREE_CODE (arg1_unw) != INTEGER_CST
6748 || TREE_CODE (shorter_type) != INTEGER_TYPE
6749 || !int_fits_type_p (arg1_unw, shorter_type))
6752 /* If we are comparing with the integer that does not fit into the range
6753 of the shorter type, the result is known. */
6754 outer_type = TREE_TYPE (arg1_unw);
6755 min = lower_bound_in_type (outer_type, shorter_type);
6756 max = upper_bound_in_type (outer_type, shorter_type);
6758 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6760 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6767 return omit_one_operand (type, integer_zero_node, arg0);
6772 return omit_one_operand (type, integer_one_node, arg0);
6778 return omit_one_operand (type, integer_one_node, arg0);
6780 return omit_one_operand (type, integer_zero_node, arg0);
6785 return omit_one_operand (type, integer_zero_node, arg0);
6787 return omit_one_operand (type, integer_one_node, arg0);
6796 /* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6797 ARG0 just the signedness is changed. */
6800 fold_sign_changed_comparison (enum tree_code code, tree type,
6801 tree arg0, tree arg1)
6804 tree inner_type, outer_type;
6806 if (!CONVERT_EXPR_P (arg0))
6809 outer_type = TREE_TYPE (arg0);
6810 arg0_inner = TREE_OPERAND (arg0, 0);
6811 inner_type = TREE_TYPE (arg0_inner);
6813 #ifdef HAVE_canonicalize_funcptr_for_compare
6814 /* Disable this optimization if we're casting a function pointer
6815 type on targets that require function pointer canonicalization. */
6816 if (HAVE_canonicalize_funcptr_for_compare
6817 && TREE_CODE (inner_type) == POINTER_TYPE
6818 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
6822 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6825 /* If the conversion is from an integral subtype to its basetype
6827 if (TREE_TYPE (inner_type) == outer_type)
6830 if (TREE_CODE (arg1) != INTEGER_CST
6831 && !(CONVERT_EXPR_P (arg1)
6832 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6835 if ((TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6836 || POINTER_TYPE_P (inner_type) != POINTER_TYPE_P (outer_type))
6841 if (TREE_CODE (arg1) == INTEGER_CST)
6842 arg1 = force_fit_type_double (inner_type, TREE_INT_CST_LOW (arg1),
6843 TREE_INT_CST_HIGH (arg1), 0,
6844 TREE_OVERFLOW (arg1));
6846 arg1 = fold_convert (inner_type, arg1);
6848 return fold_build2 (code, type, arg0_inner, arg1);
6851 /* Tries to replace &a[idx] p+ s * delta with &a[idx + delta], if s is
6852 step of the array. Reconstructs s and delta in the case of s * delta
6853 being an integer constant (and thus already folded).
6854 ADDR is the address. MULT is the multiplicative expression.
6855 If the function succeeds, the new address expression is returned. Otherwise
6856 NULL_TREE is returned. */
6859 try_move_mult_to_index (tree addr, tree op1)
6861 tree s, delta, step;
6862 tree ref = TREE_OPERAND (addr, 0), pref;
6867 /* Strip the nops that might be added when converting op1 to sizetype. */
6870 /* Canonicalize op1 into a possibly non-constant delta
6871 and an INTEGER_CST s. */
6872 if (TREE_CODE (op1) == MULT_EXPR)
6874 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
6879 if (TREE_CODE (arg0) == INTEGER_CST)
6884 else if (TREE_CODE (arg1) == INTEGER_CST)
6892 else if (TREE_CODE (op1) == INTEGER_CST)
6899 /* Simulate we are delta * 1. */
6901 s = integer_one_node;
6904 for (;; ref = TREE_OPERAND (ref, 0))
6906 if (TREE_CODE (ref) == ARRAY_REF)
6908 /* Remember if this was a multi-dimensional array. */
6909 if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
6912 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
6916 step = array_ref_element_size (ref);
6917 if (TREE_CODE (step) != INTEGER_CST)
6922 if (! tree_int_cst_equal (step, s))
6927 /* Try if delta is a multiple of step. */
6928 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, op1, step);
6934 /* Only fold here if we can verify we do not overflow one
6935 dimension of a multi-dimensional array. */
6940 if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
6941 || !INTEGRAL_TYPE_P (itype)
6942 || !TYPE_MAX_VALUE (itype)
6943 || TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
6946 tmp = fold_binary (PLUS_EXPR, itype,
6947 fold_convert (itype,
6948 TREE_OPERAND (ref, 1)),
6949 fold_convert (itype, delta));
6951 || TREE_CODE (tmp) != INTEGER_CST
6952 || tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
6961 if (!handled_component_p (ref))
6965 /* We found the suitable array reference. So copy everything up to it,
6966 and replace the index. */
6968 pref = TREE_OPERAND (addr, 0);
6969 ret = copy_node (pref);
6974 pref = TREE_OPERAND (pref, 0);
6975 TREE_OPERAND (pos, 0) = copy_node (pref);
6976 pos = TREE_OPERAND (pos, 0);
6979 TREE_OPERAND (pos, 1) = fold_build2 (PLUS_EXPR, itype,
6980 fold_convert (itype,
6981 TREE_OPERAND (pos, 1)),
6982 fold_convert (itype, delta));
6984 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
6988 /* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6989 means A >= Y && A != MAX, but in this case we know that
6990 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6993 fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6995 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6997 if (TREE_CODE (bound) == LT_EXPR)
6998 a = TREE_OPERAND (bound, 0);
6999 else if (TREE_CODE (bound) == GT_EXPR)
7000 a = TREE_OPERAND (bound, 1);
7004 typea = TREE_TYPE (a);
7005 if (!INTEGRAL_TYPE_P (typea)
7006 && !POINTER_TYPE_P (typea))
7009 if (TREE_CODE (ineq) == LT_EXPR)
7011 a1 = TREE_OPERAND (ineq, 1);
7012 y = TREE_OPERAND (ineq, 0);
7014 else if (TREE_CODE (ineq) == GT_EXPR)
7016 a1 = TREE_OPERAND (ineq, 0);
7017 y = TREE_OPERAND (ineq, 1);
7022 if (TREE_TYPE (a1) != typea)
7025 if (POINTER_TYPE_P (typea))
7027 /* Convert the pointer types into integer before taking the difference. */
7028 tree ta = fold_convert (ssizetype, a);
7029 tree ta1 = fold_convert (ssizetype, a1);
7030 diff = fold_binary (MINUS_EXPR, ssizetype, ta1, ta);
7033 diff = fold_binary (MINUS_EXPR, typea, a1, a);
7035 if (!diff || !integer_onep (diff))
7038 return fold_build2 (GE_EXPR, type, a, y);
7041 /* Fold a sum or difference of at least one multiplication.
7042 Returns the folded tree or NULL if no simplification could be made. */
7045 fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
7047 tree arg00, arg01, arg10, arg11;
7048 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
7050 /* (A * C) +- (B * C) -> (A+-B) * C.
7051 (A * C) +- A -> A * (C+-1).
7052 We are most concerned about the case where C is a constant,
7053 but other combinations show up during loop reduction. Since
7054 it is not difficult, try all four possibilities. */
7056 if (TREE_CODE (arg0) == MULT_EXPR)
7058 arg00 = TREE_OPERAND (arg0, 0);
7059 arg01 = TREE_OPERAND (arg0, 1);
7061 else if (TREE_CODE (arg0) == INTEGER_CST)
7063 arg00 = build_one_cst (type);
7068 /* We cannot generate constant 1 for fract. */
7069 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7072 arg01 = build_one_cst (type);
7074 if (TREE_CODE (arg1) == MULT_EXPR)
7076 arg10 = TREE_OPERAND (arg1, 0);
7077 arg11 = TREE_OPERAND (arg1, 1);
7079 else if (TREE_CODE (arg1) == INTEGER_CST)
7081 arg10 = build_one_cst (type);
7086 /* We cannot generate constant 1 for fract. */
7087 if (ALL_FRACT_MODE_P (TYPE_MODE (type)))
7090 arg11 = build_one_cst (type);
7094 if (operand_equal_p (arg01, arg11, 0))
7095 same = arg01, alt0 = arg00, alt1 = arg10;
7096 else if (operand_equal_p (arg00, arg10, 0))
7097 same = arg00, alt0 = arg01, alt1 = arg11;
7098 else if (operand_equal_p (arg00, arg11, 0))
7099 same = arg00, alt0 = arg01, alt1 = arg10;
7100 else if (operand_equal_p (arg01, arg10, 0))
7101 same = arg01, alt0 = arg00, alt1 = arg11;
7103 /* No identical multiplicands; see if we can find a common
7104 power-of-two factor in non-power-of-two multiplies. This
7105 can help in multi-dimensional array access. */
7106 else if (host_integerp (arg01, 0)
7107 && host_integerp (arg11, 0))
7109 HOST_WIDE_INT int01, int11, tmp;
7112 int01 = TREE_INT_CST_LOW (arg01);
7113 int11 = TREE_INT_CST_LOW (arg11);
7115 /* Move min of absolute values to int11. */
7116 if ((int01 >= 0 ? int01 : -int01)
7117 < (int11 >= 0 ? int11 : -int11))
7119 tmp = int01, int01 = int11, int11 = tmp;
7120 alt0 = arg00, arg00 = arg10, arg10 = alt0;
7127 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
7129 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
7130 build_int_cst (TREE_TYPE (arg00),
7135 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
7140 return fold_build2 (MULT_EXPR, type,
7141 fold_build2 (code, type,
7142 fold_convert (type, alt0),
7143 fold_convert (type, alt1)),
7144 fold_convert (type, same));
7149 /* Subroutine of native_encode_expr. Encode the INTEGER_CST
7150 specified by EXPR into the buffer PTR of length LEN bytes.
7151 Return the number of bytes placed in the buffer, or zero
7155 native_encode_int (const_tree expr, unsigned char *ptr, int len)
7157 tree type = TREE_TYPE (expr);
7158 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7159 int byte, offset, word, words;
7160 unsigned char value;
7162 if (total_bytes > len)
7164 words = total_bytes / UNITS_PER_WORD;
7166 for (byte = 0; byte < total_bytes; byte++)
7168 int bitpos = byte * BITS_PER_UNIT;
7169 if (bitpos < HOST_BITS_PER_WIDE_INT)
7170 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
7172 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
7173 >> (bitpos - HOST_BITS_PER_WIDE_INT));
7175 if (total_bytes > UNITS_PER_WORD)
7177 word = byte / UNITS_PER_WORD;
7178 if (WORDS_BIG_ENDIAN)
7179 word = (words - 1) - word;
7180 offset = word * UNITS_PER_WORD;
7181 if (BYTES_BIG_ENDIAN)
7182 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7184 offset += byte % UNITS_PER_WORD;
7187 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7188 ptr[offset] = value;
7194 /* Subroutine of native_encode_expr. Encode the REAL_CST
7195 specified by EXPR into the buffer PTR of length LEN bytes.
7196 Return the number of bytes placed in the buffer, or zero
7200 native_encode_real (const_tree expr, unsigned char *ptr, int len)
7202 tree type = TREE_TYPE (expr);
7203 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7204 int byte, offset, word, words, bitpos;
7205 unsigned char value;
7207 /* There are always 32 bits in each long, no matter the size of
7208 the hosts long. We handle floating point representations with
7212 if (total_bytes > len)
7214 words = 32 / UNITS_PER_WORD;
7216 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
7218 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7219 bitpos += BITS_PER_UNIT)
7221 byte = (bitpos / BITS_PER_UNIT) & 3;
7222 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
7224 if (UNITS_PER_WORD < 4)
7226 word = byte / UNITS_PER_WORD;
7227 if (WORDS_BIG_ENDIAN)
7228 word = (words - 1) - word;
7229 offset = word * UNITS_PER_WORD;
7230 if (BYTES_BIG_ENDIAN)
7231 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7233 offset += byte % UNITS_PER_WORD;
7236 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7237 ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)] = value;
7242 /* Subroutine of native_encode_expr. Encode the COMPLEX_CST
7243 specified by EXPR into the buffer PTR of length LEN bytes.
7244 Return the number of bytes placed in the buffer, or zero
7248 native_encode_complex (const_tree expr, unsigned char *ptr, int len)
7253 part = TREE_REALPART (expr);
7254 rsize = native_encode_expr (part, ptr, len);
7257 part = TREE_IMAGPART (expr);
7258 isize = native_encode_expr (part, ptr+rsize, len-rsize);
7261 return rsize + isize;
7265 /* Subroutine of native_encode_expr. Encode the VECTOR_CST
7266 specified by EXPR into the buffer PTR of length LEN bytes.
7267 Return the number of bytes placed in the buffer, or zero
7271 native_encode_vector (const_tree expr, unsigned char *ptr, int len)
7273 int i, size, offset, count;
7274 tree itype, elem, elements;
7277 elements = TREE_VECTOR_CST_ELTS (expr);
7278 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
7279 itype = TREE_TYPE (TREE_TYPE (expr));
7280 size = GET_MODE_SIZE (TYPE_MODE (itype));
7281 for (i = 0; i < count; i++)
7285 elem = TREE_VALUE (elements);
7286 elements = TREE_CHAIN (elements);
7293 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
7298 if (offset + size > len)
7300 memset (ptr+offset, 0, size);
7308 /* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
7309 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
7310 buffer PTR of length LEN bytes. Return the number of bytes
7311 placed in the buffer, or zero upon failure. */
7314 native_encode_expr (const_tree expr, unsigned char *ptr, int len)
7316 switch (TREE_CODE (expr))
7319 return native_encode_int (expr, ptr, len);
7322 return native_encode_real (expr, ptr, len);
7325 return native_encode_complex (expr, ptr, len);
7328 return native_encode_vector (expr, ptr, len);
7336 /* Subroutine of native_interpret_expr. Interpret the contents of
7337 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7338 If the buffer cannot be interpreted, return NULL_TREE. */
7341 native_interpret_int (tree type, const unsigned char *ptr, int len)
7343 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7344 int byte, offset, word, words;
7345 unsigned char value;
7346 unsigned int HOST_WIDE_INT lo = 0;
7347 HOST_WIDE_INT hi = 0;
7349 if (total_bytes > len)
7351 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7353 words = total_bytes / UNITS_PER_WORD;
7355 for (byte = 0; byte < total_bytes; byte++)
7357 int bitpos = byte * BITS_PER_UNIT;
7358 if (total_bytes > UNITS_PER_WORD)
7360 word = byte / UNITS_PER_WORD;
7361 if (WORDS_BIG_ENDIAN)
7362 word = (words - 1) - word;
7363 offset = word * UNITS_PER_WORD;
7364 if (BYTES_BIG_ENDIAN)
7365 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7367 offset += byte % UNITS_PER_WORD;
7370 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7371 value = ptr[offset];
7373 if (bitpos < HOST_BITS_PER_WIDE_INT)
7374 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7376 hi |= (unsigned HOST_WIDE_INT) value
7377 << (bitpos - HOST_BITS_PER_WIDE_INT);
7380 return build_int_cst_wide_type (type, lo, hi);
7384 /* Subroutine of native_interpret_expr. Interpret the contents of
7385 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7386 If the buffer cannot be interpreted, return NULL_TREE. */
7389 native_interpret_real (tree type, const unsigned char *ptr, int len)
7391 enum machine_mode mode = TYPE_MODE (type);
7392 int total_bytes = GET_MODE_SIZE (mode);
7393 int byte, offset, word, words, bitpos;
7394 unsigned char value;
7395 /* There are always 32 bits in each long, no matter the size of
7396 the hosts long. We handle floating point representations with
7401 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7402 if (total_bytes > len || total_bytes > 24)
7404 words = 32 / UNITS_PER_WORD;
7406 memset (tmp, 0, sizeof (tmp));
7407 for (bitpos = 0; bitpos < total_bytes * BITS_PER_UNIT;
7408 bitpos += BITS_PER_UNIT)
7410 byte = (bitpos / BITS_PER_UNIT) & 3;
7411 if (UNITS_PER_WORD < 4)
7413 word = byte / UNITS_PER_WORD;
7414 if (WORDS_BIG_ENDIAN)
7415 word = (words - 1) - word;
7416 offset = word * UNITS_PER_WORD;
7417 if (BYTES_BIG_ENDIAN)
7418 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7420 offset += byte % UNITS_PER_WORD;
7423 offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
7424 value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
7426 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7429 real_from_target (&r, tmp, mode);
7430 return build_real (type, r);
7434 /* Subroutine of native_interpret_expr. Interpret the contents of
7435 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7436 If the buffer cannot be interpreted, return NULL_TREE. */
7439 native_interpret_complex (tree type, const unsigned char *ptr, int len)
7441 tree etype, rpart, ipart;
7444 etype = TREE_TYPE (type);
7445 size = GET_MODE_SIZE (TYPE_MODE (etype));
7448 rpart = native_interpret_expr (etype, ptr, size);
7451 ipart = native_interpret_expr (etype, ptr+size, size);
7454 return build_complex (type, rpart, ipart);
7458 /* Subroutine of native_interpret_expr. Interpret the contents of
7459 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7460 If the buffer cannot be interpreted, return NULL_TREE. */
7463 native_interpret_vector (tree type, const unsigned char *ptr, int len)
7465 tree etype, elem, elements;
7468 etype = TREE_TYPE (type);
7469 size = GET_MODE_SIZE (TYPE_MODE (etype));
7470 count = TYPE_VECTOR_SUBPARTS (type);
7471 if (size * count > len)
7474 elements = NULL_TREE;
7475 for (i = count - 1; i >= 0; i--)
7477 elem = native_interpret_expr (etype, ptr+(i*size), size);
7480 elements = tree_cons (NULL_TREE, elem, elements);
7482 return build_vector (type, elements);
7486 /* Subroutine of fold_view_convert_expr. Interpret the contents of
7487 the buffer PTR of length LEN as a constant of type TYPE. For
7488 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7489 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7490 return NULL_TREE. */
7493 native_interpret_expr (tree type, const unsigned char *ptr, int len)
7495 switch (TREE_CODE (type))
7500 return native_interpret_int (type, ptr, len);
7503 return native_interpret_real (type, ptr, len);
7506 return native_interpret_complex (type, ptr, len);
7509 return native_interpret_vector (type, ptr, len);
7517 /* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7518 TYPE at compile-time. If we're unable to perform the conversion
7519 return NULL_TREE. */
7522 fold_view_convert_expr (tree type, tree expr)
7524 /* We support up to 512-bit values (for V8DFmode). */
7525 unsigned char buffer[64];
7528 /* Check that the host and target are sane. */
7529 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7532 len = native_encode_expr (expr, buffer, sizeof (buffer));
7536 return native_interpret_expr (type, buffer, len);
7539 /* Build an expression for the address of T. Folds away INDIRECT_REF
7540 to avoid confusing the gimplify process. When IN_FOLD is true
7541 avoid modifications of T. */
7544 build_fold_addr_expr_with_type_1 (tree t, tree ptrtype, bool in_fold)
7546 /* The size of the object is not relevant when talking about its address. */
7547 if (TREE_CODE (t) == WITH_SIZE_EXPR)
7548 t = TREE_OPERAND (t, 0);
7550 /* Note: doesn't apply to ALIGN_INDIRECT_REF */
7551 if (TREE_CODE (t) == INDIRECT_REF
7552 || TREE_CODE (t) == MISALIGNED_INDIRECT_REF)
7554 t = TREE_OPERAND (t, 0);
7556 if (TREE_TYPE (t) != ptrtype)
7557 t = build1 (NOP_EXPR, ptrtype, t);
7563 while (handled_component_p (base))
7564 base = TREE_OPERAND (base, 0);
7567 TREE_ADDRESSABLE (base) = 1;
7569 t = build1 (ADDR_EXPR, ptrtype, t);
7572 t = build1 (ADDR_EXPR, ptrtype, t);
7577 /* Build an expression for the address of T with type PTRTYPE. This
7578 function modifies the input parameter 'T' by sometimes setting the
7579 TREE_ADDRESSABLE flag. */
7582 build_fold_addr_expr_with_type (tree t, tree ptrtype)
7584 return build_fold_addr_expr_with_type_1 (t, ptrtype, false);
7587 /* Build an expression for the address of T. This function modifies
7588 the input parameter 'T' by sometimes setting the TREE_ADDRESSABLE
7589 flag. When called from fold functions, use fold_addr_expr instead. */
7592 build_fold_addr_expr (tree t)
7594 return build_fold_addr_expr_with_type_1 (t,
7595 build_pointer_type (TREE_TYPE (t)),
7599 /* Same as build_fold_addr_expr, builds an expression for the address
7600 of T, but avoids touching the input node 't'. Fold functions
7601 should use this version. */
7604 fold_addr_expr (tree t)
7606 tree ptrtype = build_pointer_type (TREE_TYPE (t));
7608 return build_fold_addr_expr_with_type_1 (t, ptrtype, true);
7611 /* Fold a unary expression of code CODE and type TYPE with operand
7612 OP0. Return the folded expression if folding is successful.
7613 Otherwise, return NULL_TREE. */
7616 fold_unary (enum tree_code code, tree type, tree op0)
7620 enum tree_code_class kind = TREE_CODE_CLASS (code);
7622 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7623 && TREE_CODE_LENGTH (code) == 1);
7628 if (code == NOP_EXPR || code == CONVERT_EXPR
7629 || code == FLOAT_EXPR || code == ABS_EXPR)
7631 /* Don't use STRIP_NOPS, because signedness of argument type
7633 STRIP_SIGN_NOPS (arg0);
7637 /* Strip any conversions that don't change the mode. This
7638 is safe for every expression, except for a comparison
7639 expression because its signedness is derived from its
7642 Note that this is done as an internal manipulation within
7643 the constant folder, in order to find the simplest
7644 representation of the arguments so that their form can be
7645 studied. In any cases, the appropriate type conversions
7646 should be put back in the tree that will get out of the
7652 if (TREE_CODE_CLASS (code) == tcc_unary)
7654 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7655 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7656 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
7657 else if (TREE_CODE (arg0) == COND_EXPR)
7659 tree arg01 = TREE_OPERAND (arg0, 1);
7660 tree arg02 = TREE_OPERAND (arg0, 2);
7661 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7662 arg01 = fold_build1 (code, type, arg01);
7663 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7664 arg02 = fold_build1 (code, type, arg02);
7665 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
7668 /* If this was a conversion, and all we did was to move into
7669 inside the COND_EXPR, bring it back out. But leave it if
7670 it is a conversion from integer to integer and the
7671 result precision is no wider than a word since such a
7672 conversion is cheap and may be optimized away by combine,
7673 while it couldn't if it were outside the COND_EXPR. Then return
7674 so we don't get into an infinite recursion loop taking the
7675 conversion out and then back in. */
7677 if ((code == NOP_EXPR || code == CONVERT_EXPR
7678 || code == NON_LVALUE_EXPR)
7679 && TREE_CODE (tem) == COND_EXPR
7680 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7681 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7682 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7683 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7684 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7685 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7686 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7688 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7689 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7690 || flag_syntax_only))
7691 tem = build1 (code, type,
7693 TREE_TYPE (TREE_OPERAND
7694 (TREE_OPERAND (tem, 1), 0)),
7695 TREE_OPERAND (tem, 0),
7696 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7697 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
7700 else if (COMPARISON_CLASS_P (arg0))
7702 if (TREE_CODE (type) == BOOLEAN_TYPE)
7704 arg0 = copy_node (arg0);
7705 TREE_TYPE (arg0) = type;
7708 else if (TREE_CODE (type) != INTEGER_TYPE)
7709 return fold_build3 (COND_EXPR, type, arg0,
7710 fold_build1 (code, type,
7712 fold_build1 (code, type,
7713 integer_zero_node));
7720 /* Re-association barriers around constants and other re-association
7721 barriers can be removed. */
7722 if (CONSTANT_CLASS_P (op0)
7723 || TREE_CODE (op0) == PAREN_EXPR)
7724 return fold_convert (type, op0);
7729 case FIX_TRUNC_EXPR:
7730 if (TREE_TYPE (op0) == type)
7733 /* If we have (type) (a CMP b) and type is an integral type, return
7734 new expression involving the new type. */
7735 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
7736 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
7737 TREE_OPERAND (op0, 1));
7739 /* Handle cases of two conversions in a row. */
7740 if (CONVERT_EXPR_P (op0))
7742 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
7743 tree inter_type = TREE_TYPE (op0);
7744 int inside_int = INTEGRAL_TYPE_P (inside_type);
7745 int inside_ptr = POINTER_TYPE_P (inside_type);
7746 int inside_float = FLOAT_TYPE_P (inside_type);
7747 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
7748 unsigned int inside_prec = TYPE_PRECISION (inside_type);
7749 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
7750 int inter_int = INTEGRAL_TYPE_P (inter_type);
7751 int inter_ptr = POINTER_TYPE_P (inter_type);
7752 int inter_float = FLOAT_TYPE_P (inter_type);
7753 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
7754 unsigned int inter_prec = TYPE_PRECISION (inter_type);
7755 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
7756 int final_int = INTEGRAL_TYPE_P (type);
7757 int final_ptr = POINTER_TYPE_P (type);
7758 int final_float = FLOAT_TYPE_P (type);
7759 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
7760 unsigned int final_prec = TYPE_PRECISION (type);
7761 int final_unsignedp = TYPE_UNSIGNED (type);
7763 /* In addition to the cases of two conversions in a row
7764 handled below, if we are converting something to its own
7765 type via an object of identical or wider precision, neither
7766 conversion is needed. */
7767 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
7768 && (((inter_int || inter_ptr) && final_int)
7769 || (inter_float && final_float))
7770 && inter_prec >= final_prec)
7771 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7773 /* Likewise, if the intermediate and final types are either both
7774 float or both integer, we don't need the middle conversion if
7775 it is wider than the final type and doesn't change the signedness
7776 (for integers). Avoid this if the final type is a pointer
7777 since then we sometimes need the inner conversion. Likewise if
7778 the outer has a precision not equal to the size of its mode. */
7779 if (((inter_int && inside_int)
7780 || (inter_float && inside_float)
7781 || (inter_vec && inside_vec))
7782 && inter_prec >= inside_prec
7783 && (inter_float || inter_vec
7784 || inter_unsignedp == inside_unsignedp)
7785 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7786 && TYPE_MODE (type) == TYPE_MODE (inter_type))
7788 && (! final_vec || inter_prec == inside_prec))
7789 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7791 /* If we have a sign-extension of a zero-extended value, we can
7792 replace that by a single zero-extension. */
7793 if (inside_int && inter_int && final_int
7794 && inside_prec < inter_prec && inter_prec < final_prec
7795 && inside_unsignedp && !inter_unsignedp)
7796 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7798 /* Two conversions in a row are not needed unless:
7799 - some conversion is floating-point (overstrict for now), or
7800 - some conversion is a vector (overstrict for now), or
7801 - the intermediate type is narrower than both initial and
7803 - the intermediate type and innermost type differ in signedness,
7804 and the outermost type is wider than the intermediate, or
7805 - the initial type is a pointer type and the precisions of the
7806 intermediate and final types differ, or
7807 - the final type is a pointer type and the precisions of the
7808 initial and intermediate types differ. */
7809 if (! inside_float && ! inter_float && ! final_float
7810 && ! inside_vec && ! inter_vec && ! final_vec
7811 && (inter_prec >= inside_prec || inter_prec >= final_prec)
7812 && ! (inside_int && inter_int
7813 && inter_unsignedp != inside_unsignedp
7814 && inter_prec < final_prec)
7815 && ((inter_unsignedp && inter_prec > inside_prec)
7816 == (final_unsignedp && final_prec > inter_prec))
7817 && ! (inside_ptr && inter_prec != final_prec)
7818 && ! (final_ptr && inside_prec != inter_prec)
7819 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7820 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
7821 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
7824 /* Handle (T *)&A.B.C for A being of type T and B and C
7825 living at offset zero. This occurs frequently in
7826 C++ upcasting and then accessing the base. */
7827 if (TREE_CODE (op0) == ADDR_EXPR
7828 && POINTER_TYPE_P (type)
7829 && handled_component_p (TREE_OPERAND (op0, 0)))
7831 HOST_WIDE_INT bitsize, bitpos;
7833 enum machine_mode mode;
7834 int unsignedp, volatilep;
7835 tree base = TREE_OPERAND (op0, 0);
7836 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
7837 &mode, &unsignedp, &volatilep, false);
7838 /* If the reference was to a (constant) zero offset, we can use
7839 the address of the base if it has the same base type
7840 as the result type. */
7841 if (! offset && bitpos == 0
7842 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
7843 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
7844 return fold_convert (type, fold_addr_expr (base));
7847 if (TREE_CODE (op0) == MODIFY_EXPR
7848 && TREE_CONSTANT (TREE_OPERAND (op0, 1))
7849 /* Detect assigning a bitfield. */
7850 && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
7852 (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
7854 /* Don't leave an assignment inside a conversion
7855 unless assigning a bitfield. */
7856 tem = fold_build1 (code, type, TREE_OPERAND (op0, 1));
7857 /* First do the assignment, then return converted constant. */
7858 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
7859 TREE_NO_WARNING (tem) = 1;
7860 TREE_USED (tem) = 1;
7864 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7865 constants (if x has signed type, the sign bit cannot be set
7866 in c). This folds extension into the BIT_AND_EXPR.
7867 ??? We don't do it for BOOLEAN_TYPE or ENUMERAL_TYPE because they
7868 very likely don't have maximal range for their precision and this
7869 transformation effectively doesn't preserve non-maximal ranges. */
7870 if (TREE_CODE (type) == INTEGER_TYPE
7871 && TREE_CODE (op0) == BIT_AND_EXPR
7872 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
7875 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
7878 if (TYPE_UNSIGNED (TREE_TYPE (and))
7879 || (TYPE_PRECISION (type)
7880 <= TYPE_PRECISION (TREE_TYPE (and))))
7882 else if (TYPE_PRECISION (TREE_TYPE (and1))
7883 <= HOST_BITS_PER_WIDE_INT
7884 && host_integerp (and1, 1))
7886 unsigned HOST_WIDE_INT cst;
7888 cst = tree_low_cst (and1, 1);
7889 cst &= (HOST_WIDE_INT) -1
7890 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
7891 change = (cst == 0);
7892 #ifdef LOAD_EXTEND_OP
7894 && !flag_syntax_only
7895 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
7898 tree uns = unsigned_type_for (TREE_TYPE (and0));
7899 and0 = fold_convert (uns, and0);
7900 and1 = fold_convert (uns, and1);
7906 tem = force_fit_type_double (type, TREE_INT_CST_LOW (and1),
7907 TREE_INT_CST_HIGH (and1), 0,
7908 TREE_OVERFLOW (and1));
7909 return fold_build2 (BIT_AND_EXPR, type,
7910 fold_convert (type, and0), tem);
7914 /* Convert (T1)(X p+ Y) into ((T1)X p+ Y), for pointer type,
7915 when one of the new casts will fold away. Conservatively we assume
7916 that this happens when X or Y is NOP_EXPR or Y is INTEGER_CST. */
7917 if (POINTER_TYPE_P (type)
7918 && TREE_CODE (arg0) == POINTER_PLUS_EXPR
7919 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7920 || TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
7921 || TREE_CODE (TREE_OPERAND (arg0, 1)) == NOP_EXPR))
7923 tree arg00 = TREE_OPERAND (arg0, 0);
7924 tree arg01 = TREE_OPERAND (arg0, 1);
7926 return fold_build2 (TREE_CODE (arg0), type, fold_convert (type, arg00),
7927 fold_convert (sizetype, arg01));
7930 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
7931 of the same precision, and X is an integer type not narrower than
7932 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
7933 if (INTEGRAL_TYPE_P (type)
7934 && TREE_CODE (op0) == BIT_NOT_EXPR
7935 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7936 && CONVERT_EXPR_P (TREE_OPERAND (op0, 0))
7937 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
7939 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
7940 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7941 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
7942 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
7945 /* Convert (T1)(X * Y) into (T1)X * (T1)Y if T1 is narrower than the
7946 type of X and Y (integer types only). */
7947 if (INTEGRAL_TYPE_P (type)
7948 && TREE_CODE (op0) == MULT_EXPR
7949 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7950 && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (op0)))
7952 /* Be careful not to introduce new overflows. */
7954 if (TYPE_OVERFLOW_WRAPS (type))
7957 mult_type = unsigned_type_for (type);
7959 tem = fold_build2 (MULT_EXPR, mult_type,
7960 fold_convert (mult_type, TREE_OPERAND (op0, 0)),
7961 fold_convert (mult_type, TREE_OPERAND (op0, 1)));
7962 return fold_convert (type, tem);
7965 tem = fold_convert_const (code, type, op0);
7966 return tem ? tem : NULL_TREE;
7968 case FIXED_CONVERT_EXPR:
7969 tem = fold_convert_const (code, type, arg0);
7970 return tem ? tem : NULL_TREE;
7972 case VIEW_CONVERT_EXPR:
7973 if (TREE_TYPE (op0) == type)
7975 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
7976 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7978 /* For integral conversions with the same precision or pointer
7979 conversions use a NOP_EXPR instead. */
7980 if ((INTEGRAL_TYPE_P (type)
7981 || POINTER_TYPE_P (type))
7982 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
7983 || POINTER_TYPE_P (TREE_TYPE (op0)))
7984 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0))
7985 /* Do not muck with VIEW_CONVERT_EXPRs that convert from
7986 a sub-type to its base type as generated by the Ada FE. */
7987 && !(INTEGRAL_TYPE_P (TREE_TYPE (op0))
7988 && TREE_TYPE (TREE_TYPE (op0))))
7989 return fold_convert (type, op0);
7991 /* Strip inner integral conversions that do not change the precision. */
7992 if (CONVERT_EXPR_P (op0)
7993 && (INTEGRAL_TYPE_P (TREE_TYPE (op0))
7994 || POINTER_TYPE_P (TREE_TYPE (op0)))
7995 && (INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
7996 || POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0))))
7997 && (TYPE_PRECISION (TREE_TYPE (op0))
7998 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
7999 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
8001 return fold_view_convert_expr (type, op0);
8004 tem = fold_negate_expr (arg0);
8006 return fold_convert (type, tem);
8010 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
8011 return fold_abs_const (arg0, type);
8012 else if (TREE_CODE (arg0) == NEGATE_EXPR)
8013 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
8014 /* Convert fabs((double)float) into (double)fabsf(float). */
8015 else if (TREE_CODE (arg0) == NOP_EXPR
8016 && TREE_CODE (type) == REAL_TYPE)
8018 tree targ0 = strip_float_extensions (arg0);
8020 return fold_convert (type, fold_build1 (ABS_EXPR,
8024 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
8025 else if (TREE_CODE (arg0) == ABS_EXPR)
8027 else if (tree_expr_nonnegative_p (arg0))
8030 /* Strip sign ops from argument. */
8031 if (TREE_CODE (type) == REAL_TYPE)
8033 tem = fold_strip_sign_ops (arg0);
8035 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
8040 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8041 return fold_convert (type, arg0);
8042 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8044 tree itype = TREE_TYPE (type);
8045 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
8046 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
8047 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
8049 if (TREE_CODE (arg0) == COMPLEX_CST)
8051 tree itype = TREE_TYPE (type);
8052 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
8053 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
8054 return build_complex (type, rpart, negate_expr (ipart));
8056 if (TREE_CODE (arg0) == CONJ_EXPR)
8057 return fold_convert (type, TREE_OPERAND (arg0, 0));
8061 if (TREE_CODE (arg0) == INTEGER_CST)
8062 return fold_not_const (arg0, type);
8063 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
8064 return fold_convert (type, TREE_OPERAND (arg0, 0));
8065 /* Convert ~ (-A) to A - 1. */
8066 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
8067 return fold_build2 (MINUS_EXPR, type,
8068 fold_convert (type, TREE_OPERAND (arg0, 0)),
8069 build_int_cst (type, 1));
8070 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
8071 else if (INTEGRAL_TYPE_P (type)
8072 && ((TREE_CODE (arg0) == MINUS_EXPR
8073 && integer_onep (TREE_OPERAND (arg0, 1)))
8074 || (TREE_CODE (arg0) == PLUS_EXPR
8075 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
8076 return fold_build1 (NEGATE_EXPR, type,
8077 fold_convert (type, TREE_OPERAND (arg0, 0)));
8078 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
8079 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8080 && (tem = fold_unary (BIT_NOT_EXPR, type,
8082 TREE_OPERAND (arg0, 0)))))
8083 return fold_build2 (BIT_XOR_EXPR, type, tem,
8084 fold_convert (type, TREE_OPERAND (arg0, 1)));
8085 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
8086 && (tem = fold_unary (BIT_NOT_EXPR, type,
8088 TREE_OPERAND (arg0, 1)))))
8089 return fold_build2 (BIT_XOR_EXPR, type,
8090 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
8091 /* Perform BIT_NOT_EXPR on each element individually. */
8092 else if (TREE_CODE (arg0) == VECTOR_CST)
8094 tree elements = TREE_VECTOR_CST_ELTS (arg0), elem, list = NULL_TREE;
8095 int count = TYPE_VECTOR_SUBPARTS (type), i;
8097 for (i = 0; i < count; i++)
8101 elem = TREE_VALUE (elements);
8102 elem = fold_unary (BIT_NOT_EXPR, TREE_TYPE (type), elem);
8103 if (elem == NULL_TREE)
8105 elements = TREE_CHAIN (elements);
8108 elem = build_int_cst (TREE_TYPE (type), -1);
8109 list = tree_cons (NULL_TREE, elem, list);
8112 return build_vector (type, nreverse (list));
8117 case TRUTH_NOT_EXPR:
8118 /* The argument to invert_truthvalue must have Boolean type. */
8119 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
8120 arg0 = fold_convert (boolean_type_node, arg0);
8122 /* Note that the operand of this must be an int
8123 and its values must be 0 or 1.
8124 ("true" is a fixed value perhaps depending on the language,
8125 but we don't handle values other than 1 correctly yet.) */
8126 tem = fold_truth_not_expr (arg0);
8129 return fold_convert (type, tem);
8132 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8133 return fold_convert (type, arg0);
8134 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8135 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8136 TREE_OPERAND (arg0, 1));
8137 if (TREE_CODE (arg0) == COMPLEX_CST)
8138 return fold_convert (type, TREE_REALPART (arg0));
8139 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8141 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8142 tem = fold_build2 (TREE_CODE (arg0), itype,
8143 fold_build1 (REALPART_EXPR, itype,
8144 TREE_OPERAND (arg0, 0)),
8145 fold_build1 (REALPART_EXPR, itype,
8146 TREE_OPERAND (arg0, 1)));
8147 return fold_convert (type, tem);
8149 if (TREE_CODE (arg0) == CONJ_EXPR)
8151 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8152 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8153 return fold_convert (type, tem);
8155 if (TREE_CODE (arg0) == CALL_EXPR)
8157 tree fn = get_callee_fndecl (arg0);
8158 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8159 switch (DECL_FUNCTION_CODE (fn))
8161 CASE_FLT_FN (BUILT_IN_CEXPI):
8162 fn = mathfn_built_in (type, BUILT_IN_COS);
8164 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8174 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8175 return fold_convert (type, integer_zero_node);
8176 if (TREE_CODE (arg0) == COMPLEX_EXPR)
8177 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8178 TREE_OPERAND (arg0, 0));
8179 if (TREE_CODE (arg0) == COMPLEX_CST)
8180 return fold_convert (type, TREE_IMAGPART (arg0));
8181 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8183 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8184 tem = fold_build2 (TREE_CODE (arg0), itype,
8185 fold_build1 (IMAGPART_EXPR, itype,
8186 TREE_OPERAND (arg0, 0)),
8187 fold_build1 (IMAGPART_EXPR, itype,
8188 TREE_OPERAND (arg0, 1)));
8189 return fold_convert (type, tem);
8191 if (TREE_CODE (arg0) == CONJ_EXPR)
8193 tree itype = TREE_TYPE (TREE_TYPE (arg0));
8194 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
8195 return fold_convert (type, negate_expr (tem));
8197 if (TREE_CODE (arg0) == CALL_EXPR)
8199 tree fn = get_callee_fndecl (arg0);
8200 if (fn && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8201 switch (DECL_FUNCTION_CODE (fn))
8203 CASE_FLT_FN (BUILT_IN_CEXPI):
8204 fn = mathfn_built_in (type, BUILT_IN_SIN);
8206 return build_call_expr (fn, 1, CALL_EXPR_ARG (arg0, 0));
8217 } /* switch (code) */
8220 /* Fold a binary expression of code CODE and type TYPE with operands
8221 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
8222 Return the folded expression if folding is successful. Otherwise,
8223 return NULL_TREE. */
8226 fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
8228 enum tree_code compl_code;
8230 if (code == MIN_EXPR)
8231 compl_code = MAX_EXPR;
8232 else if (code == MAX_EXPR)
8233 compl_code = MIN_EXPR;
8237 /* MIN (MAX (a, b), b) == b. */
8238 if (TREE_CODE (op0) == compl_code
8239 && operand_equal_p (TREE_OPERAND (op0, 1), op1, 0))
8240 return omit_one_operand (type, op1, TREE_OPERAND (op0, 0));
8242 /* MIN (MAX (b, a), b) == b. */
8243 if (TREE_CODE (op0) == compl_code
8244 && operand_equal_p (TREE_OPERAND (op0, 0), op1, 0)
8245 && reorder_operands_p (TREE_OPERAND (op0, 1), op1))
8246 return omit_one_operand (type, op1, TREE_OPERAND (op0, 1));
8248 /* MIN (a, MAX (a, b)) == a. */
8249 if (TREE_CODE (op1) == compl_code
8250 && operand_equal_p (op0, TREE_OPERAND (op1, 0), 0)
8251 && reorder_operands_p (op0, TREE_OPERAND (op1, 1)))
8252 return omit_one_operand (type, op0, TREE_OPERAND (op1, 1));
8254 /* MIN (a, MAX (b, a)) == a. */
8255 if (TREE_CODE (op1) == compl_code
8256 && operand_equal_p (op0, TREE_OPERAND (op1, 1), 0)
8257 && reorder_operands_p (op0, TREE_OPERAND (op1, 0)))
8258 return omit_one_operand (type, op0, TREE_OPERAND (op1, 0));
8263 /* Helper that tries to canonicalize the comparison ARG0 CODE ARG1
8264 by changing CODE to reduce the magnitude of constants involved in
8265 ARG0 of the comparison.
8266 Returns a canonicalized comparison tree if a simplification was
8267 possible, otherwise returns NULL_TREE.
8268 Set *STRICT_OVERFLOW_P to true if the canonicalization is only
8269 valid if signed overflow is undefined. */
8272 maybe_canonicalize_comparison_1 (enum tree_code code, tree type,
8273 tree arg0, tree arg1,
8274 bool *strict_overflow_p)
8276 enum tree_code code0 = TREE_CODE (arg0);
8277 tree t, cst0 = NULL_TREE;
8281 /* Match A +- CST code arg1 and CST code arg1. */
8282 if (!(((code0 == MINUS_EXPR
8283 || code0 == PLUS_EXPR)
8284 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8285 || code0 == INTEGER_CST))
8288 /* Identify the constant in arg0 and its sign. */
8289 if (code0 == INTEGER_CST)
8292 cst0 = TREE_OPERAND (arg0, 1);
8293 sgn0 = tree_int_cst_sgn (cst0);
8295 /* Overflowed constants and zero will cause problems. */
8296 if (integer_zerop (cst0)
8297 || TREE_OVERFLOW (cst0))
8300 /* See if we can reduce the magnitude of the constant in
8301 arg0 by changing the comparison code. */
8302 if (code0 == INTEGER_CST)
8304 /* CST <= arg1 -> CST-1 < arg1. */
8305 if (code == LE_EXPR && sgn0 == 1)
8307 /* -CST < arg1 -> -CST-1 <= arg1. */
8308 else if (code == LT_EXPR && sgn0 == -1)
8310 /* CST > arg1 -> CST-1 >= arg1. */
8311 else if (code == GT_EXPR && sgn0 == 1)
8313 /* -CST >= arg1 -> -CST-1 > arg1. */
8314 else if (code == GE_EXPR && sgn0 == -1)
8318 /* arg1 code' CST' might be more canonical. */
8323 /* A - CST < arg1 -> A - CST-1 <= arg1. */
8325 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8327 /* A + CST > arg1 -> A + CST-1 >= arg1. */
8328 else if (code == GT_EXPR
8329 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8331 /* A + CST <= arg1 -> A + CST-1 < arg1. */
8332 else if (code == LE_EXPR
8333 && code0 == ((sgn0 == -1) ? MINUS_EXPR : PLUS_EXPR))
8335 /* A - CST >= arg1 -> A - CST-1 > arg1. */
8336 else if (code == GE_EXPR
8337 && code0 == ((sgn0 == -1) ? PLUS_EXPR : MINUS_EXPR))
8341 *strict_overflow_p = true;
8344 /* Now build the constant reduced in magnitude. */
8345 t = int_const_binop (sgn0 == -1 ? PLUS_EXPR : MINUS_EXPR,
8346 cst0, build_int_cst (TREE_TYPE (cst0), 1), 0);
8347 if (code0 != INTEGER_CST)
8348 t = fold_build2 (code0, TREE_TYPE (arg0), TREE_OPERAND (arg0, 0), t);
8350 /* If swapping might yield to a more canonical form, do so. */
8352 return fold_build2 (swap_tree_comparison (code), type, arg1, t);
8354 return fold_build2 (code, type, t, arg1);
8357 /* Canonicalize the comparison ARG0 CODE ARG1 with type TYPE with undefined
8358 overflow further. Try to decrease the magnitude of constants involved
8359 by changing LE_EXPR and GE_EXPR to LT_EXPR and GT_EXPR or vice versa
8360 and put sole constants at the second argument position.
8361 Returns the canonicalized tree if changed, otherwise NULL_TREE. */
8364 maybe_canonicalize_comparison (enum tree_code code, tree type,
8365 tree arg0, tree arg1)
8368 bool strict_overflow_p;
8369 const char * const warnmsg = G_("assuming signed overflow does not occur "
8370 "when reducing constant in comparison");
8372 /* In principle pointers also have undefined overflow behavior,
8373 but that causes problems elsewhere. */
8374 if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8375 || POINTER_TYPE_P (TREE_TYPE (arg0)))
8378 /* Try canonicalization by simplifying arg0. */
8379 strict_overflow_p = false;
8380 t = maybe_canonicalize_comparison_1 (code, type, arg0, arg1,
8381 &strict_overflow_p);
8384 if (strict_overflow_p)
8385 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8389 /* Try canonicalization by simplifying arg1 using the swapped
8391 code = swap_tree_comparison (code);
8392 strict_overflow_p = false;
8393 t = maybe_canonicalize_comparison_1 (code, type, arg1, arg0,
8394 &strict_overflow_p);
8395 if (t && strict_overflow_p)
8396 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_MAGNITUDE);
8400 /* Return whether BASE + OFFSET + BITPOS may wrap around the address
8401 space. This is used to avoid issuing overflow warnings for
8402 expressions like &p->x which can not wrap. */
8405 pointer_may_wrap_p (tree base, tree offset, HOST_WIDE_INT bitpos)
8407 unsigned HOST_WIDE_INT offset_low, total_low;
8408 HOST_WIDE_INT size, offset_high, total_high;
8410 if (!POINTER_TYPE_P (TREE_TYPE (base)))
8416 if (offset == NULL_TREE)
8421 else if (TREE_CODE (offset) != INTEGER_CST || TREE_OVERFLOW (offset))
8425 offset_low = TREE_INT_CST_LOW (offset);
8426 offset_high = TREE_INT_CST_HIGH (offset);
8429 if (add_double_with_sign (offset_low, offset_high,
8430 bitpos / BITS_PER_UNIT, 0,
8431 &total_low, &total_high,
8435 if (total_high != 0)
8438 size = int_size_in_bytes (TREE_TYPE (TREE_TYPE (base)));
8442 /* We can do slightly better for SIZE if we have an ADDR_EXPR of an
8444 if (TREE_CODE (base) == ADDR_EXPR)
8446 HOST_WIDE_INT base_size;
8448 base_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (base, 0)));
8449 if (base_size > 0 && size < base_size)
8453 return total_low > (unsigned HOST_WIDE_INT) size;
8456 /* Subroutine of fold_binary. This routine performs all of the
8457 transformations that are common to the equality/inequality
8458 operators (EQ_EXPR and NE_EXPR) and the ordering operators
8459 (LT_EXPR, LE_EXPR, GE_EXPR and GT_EXPR). Callers other than
8460 fold_binary should call fold_binary. Fold a comparison with
8461 tree code CODE and type TYPE with operands OP0 and OP1. Return
8462 the folded comparison or NULL_TREE. */
8465 fold_comparison (enum tree_code code, tree type, tree op0, tree op1)
8467 tree arg0, arg1, tem;
8472 STRIP_SIGN_NOPS (arg0);
8473 STRIP_SIGN_NOPS (arg1);
8475 tem = fold_relational_const (code, type, arg0, arg1);
8476 if (tem != NULL_TREE)
8479 /* If one arg is a real or integer constant, put it last. */
8480 if (tree_swap_operands_p (arg0, arg1, true))
8481 return fold_build2 (swap_tree_comparison (code), type, op1, op0);
8483 /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
8484 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8485 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8486 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8487 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
8488 && (TREE_CODE (arg1) == INTEGER_CST
8489 && !TREE_OVERFLOW (arg1)))
8491 tree const1 = TREE_OPERAND (arg0, 1);
8493 tree variable = TREE_OPERAND (arg0, 0);
8496 lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
8498 lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
8499 TREE_TYPE (arg1), const2, const1);
8501 /* If the constant operation overflowed this can be
8502 simplified as a comparison against INT_MAX/INT_MIN. */
8503 if (TREE_CODE (lhs) == INTEGER_CST
8504 && TREE_OVERFLOW (lhs))
8506 int const1_sgn = tree_int_cst_sgn (const1);
8507 enum tree_code code2 = code;
8509 /* Get the sign of the constant on the lhs if the
8510 operation were VARIABLE + CONST1. */
8511 if (TREE_CODE (arg0) == MINUS_EXPR)
8512 const1_sgn = -const1_sgn;
8514 /* The sign of the constant determines if we overflowed
8515 INT_MAX (const1_sgn == -1) or INT_MIN (const1_sgn == 1).
8516 Canonicalize to the INT_MIN overflow by swapping the comparison
8518 if (const1_sgn == -1)
8519 code2 = swap_tree_comparison (code);
8521 /* We now can look at the canonicalized case
8522 VARIABLE + 1 CODE2 INT_MIN
8523 and decide on the result. */
8524 if (code2 == LT_EXPR
8526 || code2 == EQ_EXPR)
8527 return omit_one_operand (type, boolean_false_node, variable);
8528 else if (code2 == NE_EXPR
8530 || code2 == GT_EXPR)
8531 return omit_one_operand (type, boolean_true_node, variable);
8534 if (TREE_CODE (lhs) == TREE_CODE (arg1)
8535 && (TREE_CODE (lhs) != INTEGER_CST
8536 || !TREE_OVERFLOW (lhs)))
8538 fold_overflow_warning (("assuming signed overflow does not occur "
8539 "when changing X +- C1 cmp C2 to "
8541 WARN_STRICT_OVERFLOW_COMPARISON);
8542 return fold_build2 (code, type, variable, lhs);
8546 /* For comparisons of pointers we can decompose it to a compile time
8547 comparison of the base objects and the offsets into the object.
8548 This requires at least one operand being an ADDR_EXPR or a
8549 POINTER_PLUS_EXPR to do more than the operand_equal_p test below. */
8550 if (POINTER_TYPE_P (TREE_TYPE (arg0))
8551 && (TREE_CODE (arg0) == ADDR_EXPR
8552 || TREE_CODE (arg1) == ADDR_EXPR
8553 || TREE_CODE (arg0) == POINTER_PLUS_EXPR
8554 || TREE_CODE (arg1) == POINTER_PLUS_EXPR))
8556 tree base0, base1, offset0 = NULL_TREE, offset1 = NULL_TREE;
8557 HOST_WIDE_INT bitsize, bitpos0 = 0, bitpos1 = 0;
8558 enum machine_mode mode;
8559 int volatilep, unsignedp;
8560 bool indirect_base0 = false, indirect_base1 = false;
8562 /* Get base and offset for the access. Strip ADDR_EXPR for
8563 get_inner_reference, but put it back by stripping INDIRECT_REF
8564 off the base object if possible. indirect_baseN will be true
8565 if baseN is not an address but refers to the object itself. */
8567 if (TREE_CODE (arg0) == ADDR_EXPR)
8569 base0 = get_inner_reference (TREE_OPERAND (arg0, 0),
8570 &bitsize, &bitpos0, &offset0, &mode,
8571 &unsignedp, &volatilep, false);
8572 if (TREE_CODE (base0) == INDIRECT_REF)
8573 base0 = TREE_OPERAND (base0, 0);
8575 indirect_base0 = true;
8577 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
8579 base0 = TREE_OPERAND (arg0, 0);
8580 offset0 = TREE_OPERAND (arg0, 1);
8584 if (TREE_CODE (arg1) == ADDR_EXPR)
8586 base1 = get_inner_reference (TREE_OPERAND (arg1, 0),
8587 &bitsize, &bitpos1, &offset1, &mode,
8588 &unsignedp, &volatilep, false);
8589 if (TREE_CODE (base1) == INDIRECT_REF)
8590 base1 = TREE_OPERAND (base1, 0);
8592 indirect_base1 = true;
8594 else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR)
8596 base1 = TREE_OPERAND (arg1, 0);
8597 offset1 = TREE_OPERAND (arg1, 1);
8600 /* If we have equivalent bases we might be able to simplify. */
8601 if (indirect_base0 == indirect_base1
8602 && operand_equal_p (base0, base1, 0))
8604 /* We can fold this expression to a constant if the non-constant
8605 offset parts are equal. */
8606 if ((offset0 == offset1
8607 || (offset0 && offset1
8608 && operand_equal_p (offset0, offset1, 0)))
8611 || POINTER_TYPE_OVERFLOW_UNDEFINED))
8616 && bitpos0 != bitpos1
8617 && (pointer_may_wrap_p (base0, offset0, bitpos0)
8618 || pointer_may_wrap_p (base1, offset1, bitpos1)))
8619 fold_overflow_warning (("assuming pointer wraparound does not "
8620 "occur when comparing P +- C1 with "
8622 WARN_STRICT_OVERFLOW_CONDITIONAL);
8627 return build_int_cst (boolean_type_node, bitpos0 == bitpos1);
8629 return build_int_cst (boolean_type_node, bitpos0 != bitpos1);
8631 return build_int_cst (boolean_type_node, bitpos0 < bitpos1);
8633 return build_int_cst (boolean_type_node, bitpos0 <= bitpos1);
8635 return build_int_cst (boolean_type_node, bitpos0 >= bitpos1);
8637 return build_int_cst (boolean_type_node, bitpos0 > bitpos1);
8641 /* We can simplify the comparison to a comparison of the variable
8642 offset parts if the constant offset parts are equal.
8643 Be careful to use signed size type here because otherwise we
8644 mess with array offsets in the wrong way. This is possible
8645 because pointer arithmetic is restricted to retain within an
8646 object and overflow on pointer differences is undefined as of
8647 6.5.6/8 and /9 with respect to the signed ptrdiff_t. */
8648 else if (bitpos0 == bitpos1
8649 && ((code == EQ_EXPR || code == NE_EXPR)
8650 || POINTER_TYPE_OVERFLOW_UNDEFINED))
8652 tree signed_size_type_node;
8653 signed_size_type_node = signed_type_for (size_type_node);
8655 /* By converting to signed size type we cover middle-end pointer
8656 arithmetic which operates on unsigned pointer types of size
8657 type size and ARRAY_REF offsets which are properly sign or
8658 zero extended from their type in case it is narrower than
8660 if (offset0 == NULL_TREE)
8661 offset0 = build_int_cst (signed_size_type_node, 0);
8663 offset0 = fold_convert (signed_size_type_node, offset0);
8664 if (offset1 == NULL_TREE)
8665 offset1 = build_int_cst (signed_size_type_node, 0);
8667 offset1 = fold_convert (signed_size_type_node, offset1);
8671 && (pointer_may_wrap_p (base0, offset0, bitpos0)
8672 || pointer_may_wrap_p (base1, offset1, bitpos1)))
8673 fold_overflow_warning (("assuming pointer wraparound does not "
8674 "occur when comparing P +- C1 with "
8676 WARN_STRICT_OVERFLOW_COMPARISON);
8678 return fold_build2 (code, type, offset0, offset1);
8681 /* For non-equal bases we can simplify if they are addresses
8682 of local binding decls or constants. */
8683 else if (indirect_base0 && indirect_base1
8684 /* We know that !operand_equal_p (base0, base1, 0)
8685 because the if condition was false. But make
8686 sure two decls are not the same. */
8688 && TREE_CODE (arg0) == ADDR_EXPR
8689 && TREE_CODE (arg1) == ADDR_EXPR
8690 && (((TREE_CODE (base0) == VAR_DECL
8691 || TREE_CODE (base0) == PARM_DECL)
8692 && (targetm.binds_local_p (base0)
8693 || CONSTANT_CLASS_P (base1)))
8694 || CONSTANT_CLASS_P (base0))
8695 && (((TREE_CODE (base1) == VAR_DECL
8696 || TREE_CODE (base1) == PARM_DECL)
8697 && (targetm.binds_local_p (base1)
8698 || CONSTANT_CLASS_P (base0)))
8699 || CONSTANT_CLASS_P (base1)))
8701 if (code == EQ_EXPR)
8702 return omit_two_operands (type, boolean_false_node, arg0, arg1);
8703 else if (code == NE_EXPR)
8704 return omit_two_operands (type, boolean_true_node, arg0, arg1);
8706 /* For equal offsets we can simplify to a comparison of the
8708 else if (bitpos0 == bitpos1
8710 ? base0 != TREE_OPERAND (arg0, 0) : base0 != arg0)
8712 ? base1 != TREE_OPERAND (arg1, 0) : base1 != arg1)
8713 && ((offset0 == offset1)
8714 || (offset0 && offset1
8715 && operand_equal_p (offset0, offset1, 0))))
8718 base0 = fold_addr_expr (base0);
8720 base1 = fold_addr_expr (base1);
8721 return fold_build2 (code, type, base0, base1);
8725 /* Transform comparisons of the form X +- C1 CMP Y +- C2 to
8726 X CMP Y +- C2 +- C1 for signed X, Y. This is valid if
8727 the resulting offset is smaller in absolute value than the
8729 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8730 && (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8731 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8732 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8733 && (TREE_CODE (arg1) == PLUS_EXPR || TREE_CODE (arg1) == MINUS_EXPR)
8734 && (TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
8735 && !TREE_OVERFLOW (TREE_OPERAND (arg1, 1))))
8737 tree const1 = TREE_OPERAND (arg0, 1);
8738 tree const2 = TREE_OPERAND (arg1, 1);
8739 tree variable1 = TREE_OPERAND (arg0, 0);
8740 tree variable2 = TREE_OPERAND (arg1, 0);
8742 const char * const warnmsg = G_("assuming signed overflow does not "
8743 "occur when combining constants around "
8746 /* Put the constant on the side where it doesn't overflow and is
8747 of lower absolute value than before. */
8748 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8749 ? MINUS_EXPR : PLUS_EXPR,
8751 if (!TREE_OVERFLOW (cst)
8752 && tree_int_cst_compare (const2, cst) == tree_int_cst_sgn (const2))
8754 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8755 return fold_build2 (code, type,
8757 fold_build2 (TREE_CODE (arg1), TREE_TYPE (arg1),
8761 cst = int_const_binop (TREE_CODE (arg0) == TREE_CODE (arg1)
8762 ? MINUS_EXPR : PLUS_EXPR,
8764 if (!TREE_OVERFLOW (cst)
8765 && tree_int_cst_compare (const1, cst) == tree_int_cst_sgn (const1))
8767 fold_overflow_warning (warnmsg, WARN_STRICT_OVERFLOW_COMPARISON);
8768 return fold_build2 (code, type,
8769 fold_build2 (TREE_CODE (arg0), TREE_TYPE (arg0),
8775 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
8776 signed arithmetic case. That form is created by the compiler
8777 often enough for folding it to be of value. One example is in
8778 computing loop trip counts after Operator Strength Reduction. */
8779 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg0))
8780 && TREE_CODE (arg0) == MULT_EXPR
8781 && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8782 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)))
8783 && integer_zerop (arg1))
8785 tree const1 = TREE_OPERAND (arg0, 1);
8786 tree const2 = arg1; /* zero */
8787 tree variable1 = TREE_OPERAND (arg0, 0);
8788 enum tree_code cmp_code = code;
8790 gcc_assert (!integer_zerop (const1));
8792 fold_overflow_warning (("assuming signed overflow does not occur when "
8793 "eliminating multiplication in comparison "
8795 WARN_STRICT_OVERFLOW_COMPARISON);
8797 /* If const1 is negative we swap the sense of the comparison. */
8798 if (tree_int_cst_sgn (const1) < 0)
8799 cmp_code = swap_tree_comparison (cmp_code);
8801 return fold_build2 (cmp_code, type, variable1, const2);
8804 tem = maybe_canonicalize_comparison (code, type, op0, op1);
8808 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
8810 tree targ0 = strip_float_extensions (arg0);
8811 tree targ1 = strip_float_extensions (arg1);
8812 tree newtype = TREE_TYPE (targ0);
8814 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8815 newtype = TREE_TYPE (targ1);
8817 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8818 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8819 return fold_build2 (code, type, fold_convert (newtype, targ0),
8820 fold_convert (newtype, targ1));
8822 /* (-a) CMP (-b) -> b CMP a */
8823 if (TREE_CODE (arg0) == NEGATE_EXPR
8824 && TREE_CODE (arg1) == NEGATE_EXPR)
8825 return fold_build2 (code, type, TREE_OPERAND (arg1, 0),
8826 TREE_OPERAND (arg0, 0));
8828 if (TREE_CODE (arg1) == REAL_CST)
8830 REAL_VALUE_TYPE cst;
8831 cst = TREE_REAL_CST (arg1);
8833 /* (-a) CMP CST -> a swap(CMP) (-CST) */
8834 if (TREE_CODE (arg0) == NEGATE_EXPR)
8835 return fold_build2 (swap_tree_comparison (code), type,
8836 TREE_OPERAND (arg0, 0),
8837 build_real (TREE_TYPE (arg1),
8838 REAL_VALUE_NEGATE (cst)));
8840 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
8841 /* a CMP (-0) -> a CMP 0 */
8842 if (REAL_VALUE_MINUS_ZERO (cst))
8843 return fold_build2 (code, type, arg0,
8844 build_real (TREE_TYPE (arg1), dconst0));
8846 /* x != NaN is always true, other ops are always false. */
8847 if (REAL_VALUE_ISNAN (cst)
8848 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
8850 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
8851 return omit_one_operand (type, tem, arg0);
8854 /* Fold comparisons against infinity. */
8855 if (REAL_VALUE_ISINF (cst))
8857 tem = fold_inf_compare (code, type, arg0, arg1);
8858 if (tem != NULL_TREE)
8863 /* If this is a comparison of a real constant with a PLUS_EXPR
8864 or a MINUS_EXPR of a real constant, we can convert it into a
8865 comparison with a revised real constant as long as no overflow
8866 occurs when unsafe_math_optimizations are enabled. */
8867 if (flag_unsafe_math_optimizations
8868 && TREE_CODE (arg1) == REAL_CST
8869 && (TREE_CODE (arg0) == PLUS_EXPR
8870 || TREE_CODE (arg0) == MINUS_EXPR)
8871 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
8872 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8873 ? MINUS_EXPR : PLUS_EXPR,
8874 arg1, TREE_OPERAND (arg0, 1), 0))
8875 && !TREE_OVERFLOW (tem))
8876 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
8878 /* Likewise, we can simplify a comparison of a real constant with
8879 a MINUS_EXPR whose first operand is also a real constant, i.e.
8880 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
8881 floating-point types only if -fassociative-math is set. */
8882 if (flag_associative_math
8883 && TREE_CODE (arg1) == REAL_CST
8884 && TREE_CODE (arg0) == MINUS_EXPR
8885 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
8886 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
8888 && !TREE_OVERFLOW (tem))
8889 return fold_build2 (swap_tree_comparison (code), type,
8890 TREE_OPERAND (arg0, 1), tem);
8892 /* Fold comparisons against built-in math functions. */
8893 if (TREE_CODE (arg1) == REAL_CST
8894 && flag_unsafe_math_optimizations
8895 && ! flag_errno_math)
8897 enum built_in_function fcode = builtin_mathfn_code (arg0);
8899 if (fcode != END_BUILTINS)
8901 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8902 if (tem != NULL_TREE)
8908 if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8909 && CONVERT_EXPR_P (arg0))
8911 /* If we are widening one operand of an integer comparison,
8912 see if the other operand is similarly being widened. Perhaps we
8913 can do the comparison in the narrower type. */
8914 tem = fold_widened_comparison (code, type, arg0, arg1);
8918 /* Or if we are changing signedness. */
8919 tem = fold_sign_changed_comparison (code, type, arg0, arg1);
8924 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8925 constant, we can simplify it. */
8926 if (TREE_CODE (arg1) == INTEGER_CST
8927 && (TREE_CODE (arg0) == MIN_EXPR
8928 || TREE_CODE (arg0) == MAX_EXPR)
8929 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8931 tem = optimize_minmax_comparison (code, type, op0, op1);
8936 /* Simplify comparison of something with itself. (For IEEE
8937 floating-point, we can only do some of these simplifications.) */
8938 if (operand_equal_p (arg0, arg1, 0))
8943 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8944 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8945 return constant_boolean_node (1, type);
8950 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8951 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8952 return constant_boolean_node (1, type);
8953 return fold_build2 (EQ_EXPR, type, arg0, arg1);
8956 /* For NE, we can only do this simplification if integer
8957 or we don't honor IEEE floating point NaNs. */
8958 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8959 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8961 /* ... fall through ... */
8964 return constant_boolean_node (0, type);
8970 /* If we are comparing an expression that just has comparisons
8971 of two integer values, arithmetic expressions of those comparisons,
8972 and constants, we can simplify it. There are only three cases
8973 to check: the two values can either be equal, the first can be
8974 greater, or the second can be greater. Fold the expression for
8975 those three values. Since each value must be 0 or 1, we have
8976 eight possibilities, each of which corresponds to the constant 0
8977 or 1 or one of the six possible comparisons.
8979 This handles common cases like (a > b) == 0 but also handles
8980 expressions like ((x > y) - (y > x)) > 0, which supposedly
8981 occur in macroized code. */
8983 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8985 tree cval1 = 0, cval2 = 0;
8988 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8989 /* Don't handle degenerate cases here; they should already
8990 have been handled anyway. */
8991 && cval1 != 0 && cval2 != 0
8992 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8993 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8994 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8995 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8996 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8997 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8998 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
9000 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
9001 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
9003 /* We can't just pass T to eval_subst in case cval1 or cval2
9004 was the same as ARG1. */
9007 = fold_build2 (code, type,
9008 eval_subst (arg0, cval1, maxval,
9012 = fold_build2 (code, type,
9013 eval_subst (arg0, cval1, maxval,
9017 = fold_build2 (code, type,
9018 eval_subst (arg0, cval1, minval,
9022 /* All three of these results should be 0 or 1. Confirm they are.
9023 Then use those values to select the proper code to use. */
9025 if (TREE_CODE (high_result) == INTEGER_CST
9026 && TREE_CODE (equal_result) == INTEGER_CST
9027 && TREE_CODE (low_result) == INTEGER_CST)
9029 /* Make a 3-bit mask with the high-order bit being the
9030 value for `>', the next for '=', and the low for '<'. */
9031 switch ((integer_onep (high_result) * 4)
9032 + (integer_onep (equal_result) * 2)
9033 + integer_onep (low_result))
9037 return omit_one_operand (type, integer_zero_node, arg0);
9058 return omit_one_operand (type, integer_one_node, arg0);
9062 return save_expr (build2 (code, type, cval1, cval2));
9063 return fold_build2 (code, type, cval1, cval2);
9068 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
9069 into a single range test. */
9070 if ((TREE_CODE (arg0) == TRUNC_DIV_EXPR
9071 || TREE_CODE (arg0) == EXACT_DIV_EXPR)
9072 && TREE_CODE (arg1) == INTEGER_CST
9073 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9074 && !integer_zerop (TREE_OPERAND (arg0, 1))
9075 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
9076 && !TREE_OVERFLOW (arg1))
9078 tem = fold_div_compare (code, type, arg0, arg1);
9079 if (tem != NULL_TREE)
9083 /* Fold ~X op ~Y as Y op X. */
9084 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9085 && TREE_CODE (arg1) == BIT_NOT_EXPR)
9087 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9088 return fold_build2 (code, type,
9089 fold_convert (cmp_type, TREE_OPERAND (arg1, 0)),
9090 TREE_OPERAND (arg0, 0));
9093 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
9094 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9095 && TREE_CODE (arg1) == INTEGER_CST)
9097 tree cmp_type = TREE_TYPE (TREE_OPERAND (arg0, 0));
9098 return fold_build2 (swap_tree_comparison (code), type,
9099 TREE_OPERAND (arg0, 0),
9100 fold_build1 (BIT_NOT_EXPR, cmp_type,
9101 fold_convert (cmp_type, arg1)));
9108 /* Subroutine of fold_binary. Optimize complex multiplications of the
9109 form z * conj(z), as pow(realpart(z),2) + pow(imagpart(z),2). The
9110 argument EXPR represents the expression "z" of type TYPE. */
9113 fold_mult_zconjz (tree type, tree expr)
9115 tree itype = TREE_TYPE (type);
9116 tree rpart, ipart, tem;
9118 if (TREE_CODE (expr) == COMPLEX_EXPR)
9120 rpart = TREE_OPERAND (expr, 0);
9121 ipart = TREE_OPERAND (expr, 1);
9123 else if (TREE_CODE (expr) == COMPLEX_CST)
9125 rpart = TREE_REALPART (expr);
9126 ipart = TREE_IMAGPART (expr);
9130 expr = save_expr (expr);
9131 rpart = fold_build1 (REALPART_EXPR, itype, expr);
9132 ipart = fold_build1 (IMAGPART_EXPR, itype, expr);
9135 rpart = save_expr (rpart);
9136 ipart = save_expr (ipart);
9137 tem = fold_build2 (PLUS_EXPR, itype,
9138 fold_build2 (MULT_EXPR, itype, rpart, rpart),
9139 fold_build2 (MULT_EXPR, itype, ipart, ipart));
9140 return fold_build2 (COMPLEX_EXPR, type, tem,
9141 fold_convert (itype, integer_zero_node));
9145 /* Subroutine of fold_binary. If P is the value of EXPR, computes
9146 power-of-two M and (arbitrary) N such that M divides (P-N). This condition
9147 guarantees that P and N have the same least significant log2(M) bits.
9148 N is not otherwise constrained. In particular, N is not normalized to
9149 0 <= N < M as is common. In general, the precise value of P is unknown.
9150 M is chosen as large as possible such that constant N can be determined.
9152 Returns M and sets *RESIDUE to N. */
9154 static unsigned HOST_WIDE_INT
9155 get_pointer_modulus_and_residue (tree expr, unsigned HOST_WIDE_INT *residue)
9157 enum tree_code code;
9161 code = TREE_CODE (expr);
9162 if (code == ADDR_EXPR)
9164 expr = TREE_OPERAND (expr, 0);
9165 if (handled_component_p (expr))
9167 HOST_WIDE_INT bitsize, bitpos;
9169 enum machine_mode mode;
9170 int unsignedp, volatilep;
9172 expr = get_inner_reference (expr, &bitsize, &bitpos, &offset,
9173 &mode, &unsignedp, &volatilep, false);
9174 *residue = bitpos / BITS_PER_UNIT;
9177 if (TREE_CODE (offset) == INTEGER_CST)
9178 *residue += TREE_INT_CST_LOW (offset);
9180 /* We don't handle more complicated offset expressions. */
9185 if (DECL_P (expr) && TREE_CODE (expr) != FUNCTION_DECL)
9186 return DECL_ALIGN_UNIT (expr);
9188 else if (code == POINTER_PLUS_EXPR)
9191 unsigned HOST_WIDE_INT modulus;
9192 enum tree_code inner_code;
9194 op0 = TREE_OPERAND (expr, 0);
9196 modulus = get_pointer_modulus_and_residue (op0, residue);
9198 op1 = TREE_OPERAND (expr, 1);
9200 inner_code = TREE_CODE (op1);
9201 if (inner_code == INTEGER_CST)
9203 *residue += TREE_INT_CST_LOW (op1);
9206 else if (inner_code == MULT_EXPR)
9208 op1 = TREE_OPERAND (op1, 1);
9209 if (TREE_CODE (op1) == INTEGER_CST)
9211 unsigned HOST_WIDE_INT align;
9213 /* Compute the greatest power-of-2 divisor of op1. */
9214 align = TREE_INT_CST_LOW (op1);
9217 /* If align is non-zero and less than *modulus, replace
9218 *modulus with align., If align is 0, then either op1 is 0
9219 or the greatest power-of-2 divisor of op1 doesn't fit in an
9220 unsigned HOST_WIDE_INT. In either case, no additional
9221 constraint is imposed. */
9223 modulus = MIN (modulus, align);
9230 /* If we get here, we were unable to determine anything useful about the
9236 /* Fold a binary expression of code CODE and type TYPE with operands
9237 OP0 and OP1. Return the folded expression if folding is
9238 successful. Otherwise, return NULL_TREE. */
9241 fold_binary (enum tree_code code, tree type, tree op0, tree op1)
9243 enum tree_code_class kind = TREE_CODE_CLASS (code);
9244 tree arg0, arg1, tem;
9245 tree t1 = NULL_TREE;
9246 bool strict_overflow_p;
9248 gcc_assert (IS_EXPR_CODE_CLASS (kind)
9249 && TREE_CODE_LENGTH (code) == 2
9251 && op1 != NULL_TREE);
9256 /* Strip any conversions that don't change the mode. This is
9257 safe for every expression, except for a comparison expression
9258 because its signedness is derived from its operands. So, in
9259 the latter case, only strip conversions that don't change the
9260 signedness. MIN_EXPR/MAX_EXPR also need signedness of arguments
9263 Note that this is done as an internal manipulation within the
9264 constant folder, in order to find the simplest representation
9265 of the arguments so that their form can be studied. In any
9266 cases, the appropriate type conversions should be put back in
9267 the tree that will get out of the constant folder. */
9269 if (kind == tcc_comparison || code == MIN_EXPR || code == MAX_EXPR)
9271 STRIP_SIGN_NOPS (arg0);
9272 STRIP_SIGN_NOPS (arg1);
9280 /* Note that TREE_CONSTANT isn't enough: static var addresses are
9281 constant but we can't do arithmetic on them. */
9282 if ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9283 || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
9284 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == FIXED_CST)
9285 || (TREE_CODE (arg0) == FIXED_CST && TREE_CODE (arg1) == INTEGER_CST)
9286 || (TREE_CODE (arg0) == COMPLEX_CST && TREE_CODE (arg1) == COMPLEX_CST)
9287 || (TREE_CODE (arg0) == VECTOR_CST && TREE_CODE (arg1) == VECTOR_CST))
9289 if (kind == tcc_binary)
9291 /* Make sure type and arg0 have the same saturating flag. */
9292 gcc_assert (TYPE_SATURATING (type)
9293 == TYPE_SATURATING (TREE_TYPE (arg0)));
9294 tem = const_binop (code, arg0, arg1, 0);
9296 else if (kind == tcc_comparison)
9297 tem = fold_relational_const (code, type, arg0, arg1);
9301 if (tem != NULL_TREE)
9303 if (TREE_TYPE (tem) != type)
9304 tem = fold_convert (type, tem);
9309 /* If this is a commutative operation, and ARG0 is a constant, move it
9310 to ARG1 to reduce the number of tests below. */
9311 if (commutative_tree_code (code)
9312 && tree_swap_operands_p (arg0, arg1, true))
9313 return fold_build2 (code, type, op1, op0);
9315 /* ARG0 is the first operand of EXPR, and ARG1 is the second operand.
9317 First check for cases where an arithmetic operation is applied to a
9318 compound, conditional, or comparison operation. Push the arithmetic
9319 operation inside the compound or conditional to see if any folding
9320 can then be done. Convert comparison to conditional for this purpose.
9321 The also optimizes non-constant cases that used to be done in
9324 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
9325 one of the operands is a comparison and the other is a comparison, a
9326 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
9327 code below would make the expression more complex. Change it to a
9328 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
9329 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
9331 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
9332 || code == EQ_EXPR || code == NE_EXPR)
9333 && ((truth_value_p (TREE_CODE (arg0))
9334 && (truth_value_p (TREE_CODE (arg1))
9335 || (TREE_CODE (arg1) == BIT_AND_EXPR
9336 && integer_onep (TREE_OPERAND (arg1, 1)))))
9337 || (truth_value_p (TREE_CODE (arg1))
9338 && (truth_value_p (TREE_CODE (arg0))
9339 || (TREE_CODE (arg0) == BIT_AND_EXPR
9340 && integer_onep (TREE_OPERAND (arg0, 1)))))))
9342 tem = fold_build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
9343 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
9346 fold_convert (boolean_type_node, arg0),
9347 fold_convert (boolean_type_node, arg1));
9349 if (code == EQ_EXPR)
9350 tem = invert_truthvalue (tem);
9352 return fold_convert (type, tem);
9355 if (TREE_CODE_CLASS (code) == tcc_binary
9356 || TREE_CODE_CLASS (code) == tcc_comparison)
9358 if (TREE_CODE (arg0) == COMPOUND_EXPR)
9359 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
9360 fold_build2 (code, type,
9361 fold_convert (TREE_TYPE (op0),
9362 TREE_OPERAND (arg0, 1)),
9364 if (TREE_CODE (arg1) == COMPOUND_EXPR
9365 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
9366 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
9367 fold_build2 (code, type, op0,
9368 fold_convert (TREE_TYPE (op1),
9369 TREE_OPERAND (arg1, 1))));
9371 if (TREE_CODE (arg0) == COND_EXPR || COMPARISON_CLASS_P (arg0))
9373 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9375 /*cond_first_p=*/1);
9376 if (tem != NULL_TREE)
9380 if (TREE_CODE (arg1) == COND_EXPR || COMPARISON_CLASS_P (arg1))
9382 tem = fold_binary_op_with_conditional_arg (code, type, op0, op1,
9384 /*cond_first_p=*/0);
9385 if (tem != NULL_TREE)
9392 case POINTER_PLUS_EXPR:
9393 /* 0 +p index -> (type)index */
9394 if (integer_zerop (arg0))
9395 return non_lvalue (fold_convert (type, arg1));
9397 /* PTR +p 0 -> PTR */
9398 if (integer_zerop (arg1))
9399 return non_lvalue (fold_convert (type, arg0));
9401 /* INT +p INT -> (PTR)(INT + INT). Stripping types allows for this. */
9402 if (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
9403 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9404 return fold_convert (type, fold_build2 (PLUS_EXPR, sizetype,
9405 fold_convert (sizetype, arg1),
9406 fold_convert (sizetype, arg0)));
9408 /* index +p PTR -> PTR +p index */
9409 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9410 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9411 return fold_build2 (POINTER_PLUS_EXPR, type,
9412 fold_convert (type, arg1),
9413 fold_convert (sizetype, arg0));
9415 /* (PTR +p B) +p A -> PTR +p (B + A) */
9416 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9419 tree arg01 = fold_convert (sizetype, TREE_OPERAND (arg0, 1));
9420 tree arg00 = TREE_OPERAND (arg0, 0);
9421 inner = fold_build2 (PLUS_EXPR, sizetype,
9422 arg01, fold_convert (sizetype, arg1));
9423 return fold_convert (type,
9424 fold_build2 (POINTER_PLUS_EXPR,
9425 TREE_TYPE (arg00), arg00, inner));
9428 /* PTR_CST +p CST -> CST1 */
9429 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
9430 return fold_build2 (PLUS_EXPR, type, arg0, fold_convert (type, arg1));
9432 /* Try replacing &a[i1] +p c * i2 with &a[i1 + i2], if c is step
9433 of the array. Loop optimizer sometimes produce this type of
9435 if (TREE_CODE (arg0) == ADDR_EXPR)
9437 tem = try_move_mult_to_index (arg0, fold_convert (sizetype, arg1));
9439 return fold_convert (type, tem);
9445 /* PTR + INT -> (INT)(PTR p+ INT) */
9446 if (POINTER_TYPE_P (TREE_TYPE (arg0))
9447 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
9448 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9451 fold_convert (sizetype, arg1)));
9452 /* INT + PTR -> (INT)(PTR p+ INT) */
9453 if (POINTER_TYPE_P (TREE_TYPE (arg1))
9454 && INTEGRAL_TYPE_P (TREE_TYPE (arg0)))
9455 return fold_convert (type, fold_build2 (POINTER_PLUS_EXPR,
9458 fold_convert (sizetype, arg0)));
9459 /* A + (-B) -> A - B */
9460 if (TREE_CODE (arg1) == NEGATE_EXPR)
9461 return fold_build2 (MINUS_EXPR, type,
9462 fold_convert (type, arg0),
9463 fold_convert (type, TREE_OPERAND (arg1, 0)));
9464 /* (-A) + B -> B - A */
9465 if (TREE_CODE (arg0) == NEGATE_EXPR
9466 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
9467 return fold_build2 (MINUS_EXPR, type,
9468 fold_convert (type, arg1),
9469 fold_convert (type, TREE_OPERAND (arg0, 0)));
9471 if (INTEGRAL_TYPE_P (type))
9473 /* Convert ~A + 1 to -A. */
9474 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9475 && integer_onep (arg1))
9476 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
9479 if (TREE_CODE (arg0) == BIT_NOT_EXPR
9480 && !TYPE_OVERFLOW_TRAPS (type))
9482 tree tem = TREE_OPERAND (arg0, 0);
9485 if (operand_equal_p (tem, arg1, 0))
9487 t1 = build_int_cst_type (type, -1);
9488 return omit_one_operand (type, t1, arg1);
9493 if (TREE_CODE (arg1) == BIT_NOT_EXPR
9494 && !TYPE_OVERFLOW_TRAPS (type))
9496 tree tem = TREE_OPERAND (arg1, 0);
9499 if (operand_equal_p (arg0, tem, 0))
9501 t1 = build_int_cst_type (type, -1);
9502 return omit_one_operand (type, t1, arg0);
9506 /* X + (X / CST) * -CST is X % CST. */
9507 if (TREE_CODE (arg1) == MULT_EXPR
9508 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9509 && operand_equal_p (arg0,
9510 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
9512 tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
9513 tree cst1 = TREE_OPERAND (arg1, 1);
9514 tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
9515 if (sum && integer_zerop (sum))
9516 return fold_convert (type,
9517 fold_build2 (TRUNC_MOD_EXPR,
9518 TREE_TYPE (arg0), arg0, cst0));
9522 /* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
9523 same or one. Make sure type is not saturating.
9524 fold_plusminus_mult_expr will re-associate. */
9525 if ((TREE_CODE (arg0) == MULT_EXPR
9526 || TREE_CODE (arg1) == MULT_EXPR)
9527 && !TYPE_SATURATING (type)
9528 && (!FLOAT_TYPE_P (type) || flag_associative_math))
9530 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
9535 if (! FLOAT_TYPE_P (type))
9537 if (integer_zerop (arg1))
9538 return non_lvalue (fold_convert (type, arg0));
9540 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
9541 with a constant, and the two constants have no bits in common,
9542 we should treat this as a BIT_IOR_EXPR since this may produce more
9544 if (TREE_CODE (arg0) == BIT_AND_EXPR
9545 && TREE_CODE (arg1) == BIT_AND_EXPR
9546 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
9547 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
9548 && integer_zerop (const_binop (BIT_AND_EXPR,
9549 TREE_OPERAND (arg0, 1),
9550 TREE_OPERAND (arg1, 1), 0)))
9552 code = BIT_IOR_EXPR;
9556 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
9557 (plus (plus (mult) (mult)) (foo)) so that we can
9558 take advantage of the factoring cases below. */
9559 if (((TREE_CODE (arg0) == PLUS_EXPR
9560 || TREE_CODE (arg0) == MINUS_EXPR)
9561 && TREE_CODE (arg1) == MULT_EXPR)
9562 || ((TREE_CODE (arg1) == PLUS_EXPR
9563 || TREE_CODE (arg1) == MINUS_EXPR)
9564 && TREE_CODE (arg0) == MULT_EXPR))
9566 tree parg0, parg1, parg, marg;
9567 enum tree_code pcode;
9569 if (TREE_CODE (arg1) == MULT_EXPR)
9570 parg = arg0, marg = arg1;
9572 parg = arg1, marg = arg0;
9573 pcode = TREE_CODE (parg);
9574 parg0 = TREE_OPERAND (parg, 0);
9575 parg1 = TREE_OPERAND (parg, 1);
9579 if (TREE_CODE (parg0) == MULT_EXPR
9580 && TREE_CODE (parg1) != MULT_EXPR)
9581 return fold_build2 (pcode, type,
9582 fold_build2 (PLUS_EXPR, type,
9583 fold_convert (type, parg0),
9584 fold_convert (type, marg)),
9585 fold_convert (type, parg1));
9586 if (TREE_CODE (parg0) != MULT_EXPR
9587 && TREE_CODE (parg1) == MULT_EXPR)
9588 return fold_build2 (PLUS_EXPR, type,
9589 fold_convert (type, parg0),
9590 fold_build2 (pcode, type,
9591 fold_convert (type, marg),
9598 /* See if ARG1 is zero and X + ARG1 reduces to X. */
9599 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
9600 return non_lvalue (fold_convert (type, arg0));
9602 /* Likewise if the operands are reversed. */
9603 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
9604 return non_lvalue (fold_convert (type, arg1));
9606 /* Convert X + -C into X - C. */
9607 if (TREE_CODE (arg1) == REAL_CST
9608 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
9610 tem = fold_negate_const (arg1, type);
9611 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
9612 return fold_build2 (MINUS_EXPR, type,
9613 fold_convert (type, arg0),
9614 fold_convert (type, tem));
9617 /* Fold __complex__ ( x, 0 ) + __complex__ ( 0, y )
9618 to __complex__ ( x, y ). This is not the same for SNaNs or
9619 if signed zeros are involved. */
9620 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
9621 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
9622 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
9624 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
9625 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
9626 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
9627 bool arg0rz = false, arg0iz = false;
9628 if ((arg0r && (arg0rz = real_zerop (arg0r)))
9629 || (arg0i && (arg0iz = real_zerop (arg0i))))
9631 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
9632 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
9633 if (arg0rz && arg1i && real_zerop (arg1i))
9635 tree rp = arg1r ? arg1r
9636 : build1 (REALPART_EXPR, rtype, arg1);
9637 tree ip = arg0i ? arg0i
9638 : build1 (IMAGPART_EXPR, rtype, arg0);
9639 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9641 else if (arg0iz && arg1r && real_zerop (arg1r))
9643 tree rp = arg0r ? arg0r
9644 : build1 (REALPART_EXPR, rtype, arg0);
9645 tree ip = arg1i ? arg1i
9646 : build1 (IMAGPART_EXPR, rtype, arg1);
9647 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
9652 if (flag_unsafe_math_optimizations
9653 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
9654 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
9655 && (tem = distribute_real_division (code, type, arg0, arg1)))
9658 /* Convert x+x into x*2.0. */
9659 if (operand_equal_p (arg0, arg1, 0)
9660 && SCALAR_FLOAT_TYPE_P (type))
9661 return fold_build2 (MULT_EXPR, type, arg0,
9662 build_real (type, dconst2));
9664 /* Convert a + (b*c + d*e) into (a + b*c) + d*e.
9665 We associate floats only if the user has specified
9666 -fassociative-math. */
9667 if (flag_associative_math
9668 && TREE_CODE (arg1) == PLUS_EXPR
9669 && TREE_CODE (arg0) != MULT_EXPR)
9671 tree tree10 = TREE_OPERAND (arg1, 0);
9672 tree tree11 = TREE_OPERAND (arg1, 1);
9673 if (TREE_CODE (tree11) == MULT_EXPR
9674 && TREE_CODE (tree10) == MULT_EXPR)
9677 tree0 = fold_build2 (PLUS_EXPR, type, arg0, tree10);
9678 return fold_build2 (PLUS_EXPR, type, tree0, tree11);
9681 /* Convert (b*c + d*e) + a into b*c + (d*e +a).
9682 We associate floats only if the user has specified
9683 -fassociative-math. */
9684 if (flag_associative_math
9685 && TREE_CODE (arg0) == PLUS_EXPR
9686 && TREE_CODE (arg1) != MULT_EXPR)
9688 tree tree00 = TREE_OPERAND (arg0, 0);
9689 tree tree01 = TREE_OPERAND (arg0, 1);
9690 if (TREE_CODE (tree01) == MULT_EXPR
9691 && TREE_CODE (tree00) == MULT_EXPR)
9694 tree0 = fold_build2 (PLUS_EXPR, type, tree01, arg1);
9695 return fold_build2 (PLUS_EXPR, type, tree00, tree0);
9701 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
9702 is a rotate of A by C1 bits. */
9703 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
9704 is a rotate of A by B bits. */
9706 enum tree_code code0, code1;
9708 code0 = TREE_CODE (arg0);
9709 code1 = TREE_CODE (arg1);
9710 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
9711 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
9712 && operand_equal_p (TREE_OPERAND (arg0, 0),
9713 TREE_OPERAND (arg1, 0), 0)
9714 && (rtype = TREE_TYPE (TREE_OPERAND (arg0, 0)),
9715 TYPE_UNSIGNED (rtype))
9716 /* Only create rotates in complete modes. Other cases are not
9717 expanded properly. */
9718 && TYPE_PRECISION (rtype) == GET_MODE_PRECISION (TYPE_MODE (rtype)))
9720 tree tree01, tree11;
9721 enum tree_code code01, code11;
9723 tree01 = TREE_OPERAND (arg0, 1);
9724 tree11 = TREE_OPERAND (arg1, 1);
9725 STRIP_NOPS (tree01);
9726 STRIP_NOPS (tree11);
9727 code01 = TREE_CODE (tree01);
9728 code11 = TREE_CODE (tree11);
9729 if (code01 == INTEGER_CST
9730 && code11 == INTEGER_CST
9731 && TREE_INT_CST_HIGH (tree01) == 0
9732 && TREE_INT_CST_HIGH (tree11) == 0
9733 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
9734 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
9735 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
9736 code0 == LSHIFT_EXPR ? tree01 : tree11);
9737 else if (code11 == MINUS_EXPR)
9739 tree tree110, tree111;
9740 tree110 = TREE_OPERAND (tree11, 0);
9741 tree111 = TREE_OPERAND (tree11, 1);
9742 STRIP_NOPS (tree110);
9743 STRIP_NOPS (tree111);
9744 if (TREE_CODE (tree110) == INTEGER_CST
9745 && 0 == compare_tree_int (tree110,
9747 (TREE_TYPE (TREE_OPERAND
9749 && operand_equal_p (tree01, tree111, 0))
9750 return build2 ((code0 == LSHIFT_EXPR
9753 type, TREE_OPERAND (arg0, 0), tree01);
9755 else if (code01 == MINUS_EXPR)
9757 tree tree010, tree011;
9758 tree010 = TREE_OPERAND (tree01, 0);
9759 tree011 = TREE_OPERAND (tree01, 1);
9760 STRIP_NOPS (tree010);
9761 STRIP_NOPS (tree011);
9762 if (TREE_CODE (tree010) == INTEGER_CST
9763 && 0 == compare_tree_int (tree010,
9765 (TREE_TYPE (TREE_OPERAND
9767 && operand_equal_p (tree11, tree011, 0))
9768 return build2 ((code0 != LSHIFT_EXPR
9771 type, TREE_OPERAND (arg0, 0), tree11);
9777 /* In most languages, can't associate operations on floats through
9778 parentheses. Rather than remember where the parentheses were, we
9779 don't associate floats at all, unless the user has specified
9781 And, we need to make sure type is not saturating. */
9783 if ((! FLOAT_TYPE_P (type) || flag_associative_math)
9784 && !TYPE_SATURATING (type))
9786 tree var0, con0, lit0, minus_lit0;
9787 tree var1, con1, lit1, minus_lit1;
9790 /* Split both trees into variables, constants, and literals. Then
9791 associate each group together, the constants with literals,
9792 then the result with variables. This increases the chances of
9793 literals being recombined later and of generating relocatable
9794 expressions for the sum of a constant and literal. */
9795 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
9796 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
9797 code == MINUS_EXPR);
9799 /* With undefined overflow we can only associate constants
9800 with one variable. */
9801 if (((POINTER_TYPE_P (type) && POINTER_TYPE_OVERFLOW_UNDEFINED)
9802 || (INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type)))
9808 if (TREE_CODE (tmp0) == NEGATE_EXPR)
9809 tmp0 = TREE_OPERAND (tmp0, 0);
9810 if (TREE_CODE (tmp1) == NEGATE_EXPR)
9811 tmp1 = TREE_OPERAND (tmp1, 0);
9812 /* The only case we can still associate with two variables
9813 is if they are the same, modulo negation. */
9814 if (!operand_equal_p (tmp0, tmp1, 0))
9818 /* Only do something if we found more than two objects. Otherwise,
9819 nothing has changed and we risk infinite recursion. */
9821 && (2 < ((var0 != 0) + (var1 != 0)
9822 + (con0 != 0) + (con1 != 0)
9823 + (lit0 != 0) + (lit1 != 0)
9824 + (minus_lit0 != 0) + (minus_lit1 != 0))))
9826 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
9827 if (code == MINUS_EXPR)
9830 var0 = associate_trees (var0, var1, code, type);
9831 con0 = associate_trees (con0, con1, code, type);
9832 lit0 = associate_trees (lit0, lit1, code, type);
9833 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
9835 /* Preserve the MINUS_EXPR if the negative part of the literal is
9836 greater than the positive part. Otherwise, the multiplicative
9837 folding code (i.e extract_muldiv) may be fooled in case
9838 unsigned constants are subtracted, like in the following
9839 example: ((X*2 + 4) - 8U)/2. */
9840 if (minus_lit0 && lit0)
9842 if (TREE_CODE (lit0) == INTEGER_CST
9843 && TREE_CODE (minus_lit0) == INTEGER_CST
9844 && tree_int_cst_lt (lit0, minus_lit0))
9846 minus_lit0 = associate_trees (minus_lit0, lit0,
9852 lit0 = associate_trees (lit0, minus_lit0,
9860 return fold_convert (type,
9861 associate_trees (var0, minus_lit0,
9865 con0 = associate_trees (con0, minus_lit0,
9867 return fold_convert (type,
9868 associate_trees (var0, con0,
9873 con0 = associate_trees (con0, lit0, code, type);
9874 return fold_convert (type, associate_trees (var0, con0,
9882 /* Pointer simplifications for subtraction, simple reassociations. */
9883 if (POINTER_TYPE_P (TREE_TYPE (arg1)) && POINTER_TYPE_P (TREE_TYPE (arg0)))
9885 /* (PTR0 p+ A) - (PTR1 p+ B) -> (PTR0 - PTR1) + (A - B) */
9886 if (TREE_CODE (arg0) == POINTER_PLUS_EXPR
9887 && TREE_CODE (arg1) == POINTER_PLUS_EXPR)
9889 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
9890 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
9891 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
9892 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
9893 return fold_build2 (PLUS_EXPR, type,
9894 fold_build2 (MINUS_EXPR, type, arg00, arg10),
9895 fold_build2 (MINUS_EXPR, type, arg01, arg11));
9897 /* (PTR0 p+ A) - PTR1 -> (PTR0 - PTR1) + A, assuming PTR0 - PTR1 simplifies. */
9898 else if (TREE_CODE (arg0) == POINTER_PLUS_EXPR)
9900 tree arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
9901 tree arg01 = fold_convert (type, TREE_OPERAND (arg0, 1));
9902 tree tmp = fold_binary (MINUS_EXPR, type, arg00, fold_convert (type, arg1));
9904 return fold_build2 (PLUS_EXPR, type, tmp, arg01);
9907 /* A - (-B) -> A + B */
9908 if (TREE_CODE (arg1) == NEGATE_EXPR)
9909 return fold_build2 (PLUS_EXPR, type, op0,
9910 fold_convert (type, TREE_OPERAND (arg1, 0)));
9911 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
9912 if (TREE_CODE (arg0) == NEGATE_EXPR
9913 && (FLOAT_TYPE_P (type)
9914 || INTEGRAL_TYPE_P (type))
9915 && negate_expr_p (arg1)
9916 && reorder_operands_p (arg0, arg1))
9917 return fold_build2 (MINUS_EXPR, type,
9918 fold_convert (type, negate_expr (arg1)),
9919 fold_convert (type, TREE_OPERAND (arg0, 0)));
9920 /* Convert -A - 1 to ~A. */
9921 if (INTEGRAL_TYPE_P (type)
9922 && TREE_CODE (arg0) == NEGATE_EXPR
9923 && integer_onep (arg1)
9924 && !TYPE_OVERFLOW_TRAPS (type))
9925 return fold_build1 (BIT_NOT_EXPR, type,
9926 fold_convert (type, TREE_OPERAND (arg0, 0)));
9928 /* Convert -1 - A to ~A. */
9929 if (INTEGRAL_TYPE_P (type)
9930 && integer_all_onesp (arg0))
9931 return fold_build1 (BIT_NOT_EXPR, type, op1);
9934 /* X - (X / CST) * CST is X % CST. */
9935 if (INTEGRAL_TYPE_P (type)
9936 && TREE_CODE (arg1) == MULT_EXPR
9937 && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
9938 && operand_equal_p (arg0,
9939 TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
9940 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
9941 TREE_OPERAND (arg1, 1), 0))
9942 return fold_convert (type,
9943 fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
9944 arg0, TREE_OPERAND (arg1, 1)));
9946 if (! FLOAT_TYPE_P (type))
9948 if (integer_zerop (arg0))
9949 return negate_expr (fold_convert (type, arg1));
9950 if (integer_zerop (arg1))
9951 return non_lvalue (fold_convert (type, arg0));
9953 /* Fold A - (A & B) into ~B & A. */
9954 if (!TREE_SIDE_EFFECTS (arg0)
9955 && TREE_CODE (arg1) == BIT_AND_EXPR)
9957 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
9959 tree arg10 = fold_convert (type, TREE_OPERAND (arg1, 0));
9960 return fold_build2 (BIT_AND_EXPR, type,
9961 fold_build1 (BIT_NOT_EXPR, type, arg10),
9962 fold_convert (type, arg0));
9964 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
9966 tree arg11 = fold_convert (type, TREE_OPERAND (arg1, 1));
9967 return fold_build2 (BIT_AND_EXPR, type,
9968 fold_build1 (BIT_NOT_EXPR, type, arg11),
9969 fold_convert (type, arg0));
9973 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
9974 any power of 2 minus 1. */
9975 if (TREE_CODE (arg0) == BIT_AND_EXPR
9976 && TREE_CODE (arg1) == BIT_AND_EXPR
9977 && operand_equal_p (TREE_OPERAND (arg0, 0),
9978 TREE_OPERAND (arg1, 0), 0))
9980 tree mask0 = TREE_OPERAND (arg0, 1);
9981 tree mask1 = TREE_OPERAND (arg1, 1);
9982 tree tem = fold_build1 (BIT_NOT_EXPR, type, mask0);
9984 if (operand_equal_p (tem, mask1, 0))
9986 tem = fold_build2 (BIT_XOR_EXPR, type,
9987 TREE_OPERAND (arg0, 0), mask1);
9988 return fold_build2 (MINUS_EXPR, type, tem, mask1);
9993 /* See if ARG1 is zero and X - ARG1 reduces to X. */
9994 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
9995 return non_lvalue (fold_convert (type, arg0));
9997 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
9998 ARG0 is zero and X + ARG0 reduces to X, since that would mean
9999 (-ARG1 + ARG0) reduces to -ARG1. */
10000 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
10001 return negate_expr (fold_convert (type, arg1));
10003 /* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
10004 __complex__ ( x, -y ). This is not the same for SNaNs or if
10005 signed zeros are involved. */
10006 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10007 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10008 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0)))
10010 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10011 tree arg0r = fold_unary (REALPART_EXPR, rtype, arg0);
10012 tree arg0i = fold_unary (IMAGPART_EXPR, rtype, arg0);
10013 bool arg0rz = false, arg0iz = false;
10014 if ((arg0r && (arg0rz = real_zerop (arg0r)))
10015 || (arg0i && (arg0iz = real_zerop (arg0i))))
10017 tree arg1r = fold_unary (REALPART_EXPR, rtype, arg1);
10018 tree arg1i = fold_unary (IMAGPART_EXPR, rtype, arg1);
10019 if (arg0rz && arg1i && real_zerop (arg1i))
10021 tree rp = fold_build1 (NEGATE_EXPR, rtype,
10023 : build1 (REALPART_EXPR, rtype, arg1));
10024 tree ip = arg0i ? arg0i
10025 : build1 (IMAGPART_EXPR, rtype, arg0);
10026 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10028 else if (arg0iz && arg1r && real_zerop (arg1r))
10030 tree rp = arg0r ? arg0r
10031 : build1 (REALPART_EXPR, rtype, arg0);
10032 tree ip = fold_build1 (NEGATE_EXPR, rtype,
10034 : build1 (IMAGPART_EXPR, rtype, arg1));
10035 return fold_build2 (COMPLEX_EXPR, type, rp, ip);
10040 /* Fold &x - &x. This can happen from &x.foo - &x.
10041 This is unsafe for certain floats even in non-IEEE formats.
10042 In IEEE, it is unsafe because it does wrong for NaNs.
10043 Also note that operand_equal_p is always false if an operand
10046 if ((!FLOAT_TYPE_P (type) || !HONOR_NANS (TYPE_MODE (type)))
10047 && operand_equal_p (arg0, arg1, 0))
10048 return fold_convert (type, integer_zero_node);
10050 /* A - B -> A + (-B) if B is easily negatable. */
10051 if (negate_expr_p (arg1)
10052 && ((FLOAT_TYPE_P (type)
10053 /* Avoid this transformation if B is a positive REAL_CST. */
10054 && (TREE_CODE (arg1) != REAL_CST
10055 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
10056 || INTEGRAL_TYPE_P (type)))
10057 return fold_build2 (PLUS_EXPR, type,
10058 fold_convert (type, arg0),
10059 fold_convert (type, negate_expr (arg1)));
10061 /* Try folding difference of addresses. */
10063 HOST_WIDE_INT diff;
10065 if ((TREE_CODE (arg0) == ADDR_EXPR
10066 || TREE_CODE (arg1) == ADDR_EXPR)
10067 && ptr_difference_const (arg0, arg1, &diff))
10068 return build_int_cst_type (type, diff);
10071 /* Fold &a[i] - &a[j] to i-j. */
10072 if (TREE_CODE (arg0) == ADDR_EXPR
10073 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ARRAY_REF
10074 && TREE_CODE (arg1) == ADDR_EXPR
10075 && TREE_CODE (TREE_OPERAND (arg1, 0)) == ARRAY_REF)
10077 tree aref0 = TREE_OPERAND (arg0, 0);
10078 tree aref1 = TREE_OPERAND (arg1, 0);
10079 if (operand_equal_p (TREE_OPERAND (aref0, 0),
10080 TREE_OPERAND (aref1, 0), 0))
10082 tree op0 = fold_convert (type, TREE_OPERAND (aref0, 1));
10083 tree op1 = fold_convert (type, TREE_OPERAND (aref1, 1));
10084 tree esz = array_ref_element_size (aref0);
10085 tree diff = build2 (MINUS_EXPR, type, op0, op1);
10086 return fold_build2 (MULT_EXPR, type, diff,
10087 fold_convert (type, esz));
10092 if (flag_unsafe_math_optimizations
10093 && (TREE_CODE (arg0) == RDIV_EXPR || TREE_CODE (arg0) == MULT_EXPR)
10094 && (TREE_CODE (arg1) == RDIV_EXPR || TREE_CODE (arg1) == MULT_EXPR)
10095 && (tem = distribute_real_division (code, type, arg0, arg1)))
10098 /* Handle (A1 * C1) - (A2 * C2) with A1, A2 or C1, C2 being the
10099 same or one. Make sure type is not saturating.
10100 fold_plusminus_mult_expr will re-associate. */
10101 if ((TREE_CODE (arg0) == MULT_EXPR
10102 || TREE_CODE (arg1) == MULT_EXPR)
10103 && !TYPE_SATURATING (type)
10104 && (!FLOAT_TYPE_P (type) || flag_associative_math))
10106 tree tem = fold_plusminus_mult_expr (code, type, arg0, arg1);
10114 /* (-A) * (-B) -> A * B */
10115 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10116 return fold_build2 (MULT_EXPR, type,
10117 fold_convert (type, TREE_OPERAND (arg0, 0)),
10118 fold_convert (type, negate_expr (arg1)));
10119 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10120 return fold_build2 (MULT_EXPR, type,
10121 fold_convert (type, negate_expr (arg0)),
10122 fold_convert (type, TREE_OPERAND (arg1, 0)));
10124 if (! FLOAT_TYPE_P (type))
10126 if (integer_zerop (arg1))
10127 return omit_one_operand (type, arg1, arg0);
10128 if (integer_onep (arg1))
10129 return non_lvalue (fold_convert (type, arg0));
10130 /* Transform x * -1 into -x. Make sure to do the negation
10131 on the original operand with conversions not stripped
10132 because we can only strip non-sign-changing conversions. */
10133 if (integer_all_onesp (arg1))
10134 return fold_convert (type, negate_expr (op0));
10135 /* Transform x * -C into -x * C if x is easily negatable. */
10136 if (TREE_CODE (arg1) == INTEGER_CST
10137 && tree_int_cst_sgn (arg1) == -1
10138 && negate_expr_p (arg0)
10139 && (tem = negate_expr (arg1)) != arg1
10140 && !TREE_OVERFLOW (tem))
10141 return fold_build2 (MULT_EXPR, type,
10142 fold_convert (type, negate_expr (arg0)), tem);
10144 /* (a * (1 << b)) is (a << b) */
10145 if (TREE_CODE (arg1) == LSHIFT_EXPR
10146 && integer_onep (TREE_OPERAND (arg1, 0)))
10147 return fold_build2 (LSHIFT_EXPR, type, op0,
10148 TREE_OPERAND (arg1, 1));
10149 if (TREE_CODE (arg0) == LSHIFT_EXPR
10150 && integer_onep (TREE_OPERAND (arg0, 0)))
10151 return fold_build2 (LSHIFT_EXPR, type, op1,
10152 TREE_OPERAND (arg0, 1));
10154 /* (A + A) * C -> A * 2 * C */
10155 if (TREE_CODE (arg0) == PLUS_EXPR
10156 && TREE_CODE (arg1) == INTEGER_CST
10157 && operand_equal_p (TREE_OPERAND (arg0, 0),
10158 TREE_OPERAND (arg0, 1), 0))
10159 return fold_build2 (MULT_EXPR, type,
10160 omit_one_operand (type, TREE_OPERAND (arg0, 0),
10161 TREE_OPERAND (arg0, 1)),
10162 fold_build2 (MULT_EXPR, type,
10163 build_int_cst (type, 2) , arg1));
10165 strict_overflow_p = false;
10166 if (TREE_CODE (arg1) == INTEGER_CST
10167 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
10168 &strict_overflow_p)))
10170 if (strict_overflow_p)
10171 fold_overflow_warning (("assuming signed overflow does not "
10172 "occur when simplifying "
10174 WARN_STRICT_OVERFLOW_MISC);
10175 return fold_convert (type, tem);
10178 /* Optimize z * conj(z) for integer complex numbers. */
10179 if (TREE_CODE (arg0) == CONJ_EXPR
10180 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10181 return fold_mult_zconjz (type, arg1);
10182 if (TREE_CODE (arg1) == CONJ_EXPR
10183 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10184 return fold_mult_zconjz (type, arg0);
10188 /* Maybe fold x * 0 to 0. The expressions aren't the same
10189 when x is NaN, since x * 0 is also NaN. Nor are they the
10190 same in modes with signed zeros, since multiplying a
10191 negative value by 0 gives -0, not +0. */
10192 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10193 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10194 && real_zerop (arg1))
10195 return omit_one_operand (type, arg1, arg0);
10196 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
10197 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10198 && real_onep (arg1))
10199 return non_lvalue (fold_convert (type, arg0));
10201 /* Transform x * -1.0 into -x. */
10202 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
10203 && real_minus_onep (arg1))
10204 return fold_convert (type, negate_expr (arg0));
10206 /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
10207 the result for floating point types due to rounding so it is applied
10208 only if -fassociative-math was specify. */
10209 if (flag_associative_math
10210 && TREE_CODE (arg0) == RDIV_EXPR
10211 && TREE_CODE (arg1) == REAL_CST
10212 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
10214 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
10217 return fold_build2 (RDIV_EXPR, type, tem,
10218 TREE_OPERAND (arg0, 1));
10221 /* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
10222 if (operand_equal_p (arg0, arg1, 0))
10224 tree tem = fold_strip_sign_ops (arg0);
10225 if (tem != NULL_TREE)
10227 tem = fold_convert (type, tem);
10228 return fold_build2 (MULT_EXPR, type, tem, tem);
10232 /* Fold z * +-I to __complex__ (-+__imag z, +-__real z).
10233 This is not the same for NaNs or if signed zeros are
10235 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10236 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
10237 && COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10238 && TREE_CODE (arg1) == COMPLEX_CST
10239 && real_zerop (TREE_REALPART (arg1)))
10241 tree rtype = TREE_TYPE (TREE_TYPE (arg0));
10242 if (real_onep (TREE_IMAGPART (arg1)))
10243 return fold_build2 (COMPLEX_EXPR, type,
10244 negate_expr (fold_build1 (IMAGPART_EXPR,
10246 fold_build1 (REALPART_EXPR, rtype, arg0));
10247 else if (real_minus_onep (TREE_IMAGPART (arg1)))
10248 return fold_build2 (COMPLEX_EXPR, type,
10249 fold_build1 (IMAGPART_EXPR, rtype, arg0),
10250 negate_expr (fold_build1 (REALPART_EXPR,
10254 /* Optimize z * conj(z) for floating point complex numbers.
10255 Guarded by flag_unsafe_math_optimizations as non-finite
10256 imaginary components don't produce scalar results. */
10257 if (flag_unsafe_math_optimizations
10258 && TREE_CODE (arg0) == CONJ_EXPR
10259 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10260 return fold_mult_zconjz (type, arg1);
10261 if (flag_unsafe_math_optimizations
10262 && TREE_CODE (arg1) == CONJ_EXPR
10263 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10264 return fold_mult_zconjz (type, arg0);
10266 if (flag_unsafe_math_optimizations)
10268 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
10269 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
10271 /* Optimizations of root(...)*root(...). */
10272 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
10275 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10276 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10278 /* Optimize sqrt(x)*sqrt(x) as x. */
10279 if (BUILTIN_SQRT_P (fcode0)
10280 && operand_equal_p (arg00, arg10, 0)
10281 && ! HONOR_SNANS (TYPE_MODE (type)))
10284 /* Optimize root(x)*root(y) as root(x*y). */
10285 rootfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10286 arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10287 return build_call_expr (rootfn, 1, arg);
10290 /* Optimize expN(x)*expN(y) as expN(x+y). */
10291 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
10293 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10294 tree arg = fold_build2 (PLUS_EXPR, type,
10295 CALL_EXPR_ARG (arg0, 0),
10296 CALL_EXPR_ARG (arg1, 0));
10297 return build_call_expr (expfn, 1, arg);
10300 /* Optimizations of pow(...)*pow(...). */
10301 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
10302 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
10303 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
10305 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10306 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10307 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10308 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10310 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
10311 if (operand_equal_p (arg01, arg11, 0))
10313 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10314 tree arg = fold_build2 (MULT_EXPR, type, arg00, arg10);
10315 return build_call_expr (powfn, 2, arg, arg01);
10318 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
10319 if (operand_equal_p (arg00, arg10, 0))
10321 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10322 tree arg = fold_build2 (PLUS_EXPR, type, arg01, arg11);
10323 return build_call_expr (powfn, 2, arg00, arg);
10327 /* Optimize tan(x)*cos(x) as sin(x). */
10328 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
10329 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
10330 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
10331 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
10332 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
10333 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
10334 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
10335 CALL_EXPR_ARG (arg1, 0), 0))
10337 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
10339 if (sinfn != NULL_TREE)
10340 return build_call_expr (sinfn, 1, CALL_EXPR_ARG (arg0, 0));
10343 /* Optimize x*pow(x,c) as pow(x,c+1). */
10344 if (fcode1 == BUILT_IN_POW
10345 || fcode1 == BUILT_IN_POWF
10346 || fcode1 == BUILT_IN_POWL)
10348 tree arg10 = CALL_EXPR_ARG (arg1, 0);
10349 tree arg11 = CALL_EXPR_ARG (arg1, 1);
10350 if (TREE_CODE (arg11) == REAL_CST
10351 && !TREE_OVERFLOW (arg11)
10352 && operand_equal_p (arg0, arg10, 0))
10354 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
10358 c = TREE_REAL_CST (arg11);
10359 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10360 arg = build_real (type, c);
10361 return build_call_expr (powfn, 2, arg0, arg);
10365 /* Optimize pow(x,c)*x as pow(x,c+1). */
10366 if (fcode0 == BUILT_IN_POW
10367 || fcode0 == BUILT_IN_POWF
10368 || fcode0 == BUILT_IN_POWL)
10370 tree arg00 = CALL_EXPR_ARG (arg0, 0);
10371 tree arg01 = CALL_EXPR_ARG (arg0, 1);
10372 if (TREE_CODE (arg01) == REAL_CST
10373 && !TREE_OVERFLOW (arg01)
10374 && operand_equal_p (arg1, arg00, 0))
10376 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
10380 c = TREE_REAL_CST (arg01);
10381 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
10382 arg = build_real (type, c);
10383 return build_call_expr (powfn, 2, arg1, arg);
10387 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
10388 if (! optimize_size
10389 && operand_equal_p (arg0, arg1, 0))
10391 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
10395 tree arg = build_real (type, dconst2);
10396 return build_call_expr (powfn, 2, arg0, arg);
10405 if (integer_all_onesp (arg1))
10406 return omit_one_operand (type, arg1, arg0);
10407 if (integer_zerop (arg1))
10408 return non_lvalue (fold_convert (type, arg0));
10409 if (operand_equal_p (arg0, arg1, 0))
10410 return non_lvalue (fold_convert (type, arg0));
10412 /* ~X | X is -1. */
10413 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10414 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10416 t1 = fold_convert (type, integer_zero_node);
10417 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10418 return omit_one_operand (type, t1, arg1);
10421 /* X | ~X is -1. */
10422 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10423 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10425 t1 = fold_convert (type, integer_zero_node);
10426 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10427 return omit_one_operand (type, t1, arg0);
10430 /* Canonicalize (X & C1) | C2. */
10431 if (TREE_CODE (arg0) == BIT_AND_EXPR
10432 && TREE_CODE (arg1) == INTEGER_CST
10433 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10435 unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, hi3, lo3, mlo, mhi;
10436 int width = TYPE_PRECISION (type), w;
10437 hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
10438 lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
10439 hi2 = TREE_INT_CST_HIGH (arg1);
10440 lo2 = TREE_INT_CST_LOW (arg1);
10442 /* If (C1&C2) == C1, then (X&C1)|C2 becomes (X,C2). */
10443 if ((hi1 & hi2) == hi1 && (lo1 & lo2) == lo1)
10444 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10446 if (width > HOST_BITS_PER_WIDE_INT)
10448 mhi = (unsigned HOST_WIDE_INT) -1
10449 >> (2 * HOST_BITS_PER_WIDE_INT - width);
10455 mlo = (unsigned HOST_WIDE_INT) -1
10456 >> (HOST_BITS_PER_WIDE_INT - width);
10459 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
10460 if ((~(hi1 | hi2) & mhi) == 0 && (~(lo1 | lo2) & mlo) == 0)
10461 return fold_build2 (BIT_IOR_EXPR, type,
10462 TREE_OPERAND (arg0, 0), arg1);
10464 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
10465 unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
10466 mode which allows further optimizations. */
10473 for (w = BITS_PER_UNIT;
10474 w <= width && w <= HOST_BITS_PER_WIDE_INT;
10477 unsigned HOST_WIDE_INT mask
10478 = (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
10479 if (((lo1 | lo2) & mask) == mask
10480 && (lo1 & ~mask) == 0 && hi1 == 0)
10487 if (hi3 != hi1 || lo3 != lo1)
10488 return fold_build2 (BIT_IOR_EXPR, type,
10489 fold_build2 (BIT_AND_EXPR, type,
10490 TREE_OPERAND (arg0, 0),
10491 build_int_cst_wide (type,
10496 /* (X & Y) | Y is (X, Y). */
10497 if (TREE_CODE (arg0) == BIT_AND_EXPR
10498 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10499 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10500 /* (X & Y) | X is (Y, X). */
10501 if (TREE_CODE (arg0) == BIT_AND_EXPR
10502 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10503 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10504 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10505 /* X | (X & Y) is (Y, X). */
10506 if (TREE_CODE (arg1) == BIT_AND_EXPR
10507 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10508 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10509 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10510 /* X | (Y & X) is (Y, X). */
10511 if (TREE_CODE (arg1) == BIT_AND_EXPR
10512 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10513 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10514 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10516 t1 = distribute_bit_expr (code, type, arg0, arg1);
10517 if (t1 != NULL_TREE)
10520 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
10522 This results in more efficient code for machines without a NAND
10523 instruction. Combine will canonicalize to the first form
10524 which will allow use of NAND instructions provided by the
10525 backend if they exist. */
10526 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10527 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10529 return fold_build1 (BIT_NOT_EXPR, type,
10530 build2 (BIT_AND_EXPR, type,
10531 fold_convert (type,
10532 TREE_OPERAND (arg0, 0)),
10533 fold_convert (type,
10534 TREE_OPERAND (arg1, 0))));
10537 /* See if this can be simplified into a rotate first. If that
10538 is unsuccessful continue in the association code. */
10542 if (integer_zerop (arg1))
10543 return non_lvalue (fold_convert (type, arg0));
10544 if (integer_all_onesp (arg1))
10545 return fold_build1 (BIT_NOT_EXPR, type, op0);
10546 if (operand_equal_p (arg0, arg1, 0))
10547 return omit_one_operand (type, integer_zero_node, arg0);
10549 /* ~X ^ X is -1. */
10550 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10551 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10553 t1 = fold_convert (type, integer_zero_node);
10554 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10555 return omit_one_operand (type, t1, arg1);
10558 /* X ^ ~X is -1. */
10559 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10560 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10562 t1 = fold_convert (type, integer_zero_node);
10563 t1 = fold_unary (BIT_NOT_EXPR, type, t1);
10564 return omit_one_operand (type, t1, arg0);
10567 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
10568 with a constant, and the two constants have no bits in common,
10569 we should treat this as a BIT_IOR_EXPR since this may produce more
10570 simplifications. */
10571 if (TREE_CODE (arg0) == BIT_AND_EXPR
10572 && TREE_CODE (arg1) == BIT_AND_EXPR
10573 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
10574 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
10575 && integer_zerop (const_binop (BIT_AND_EXPR,
10576 TREE_OPERAND (arg0, 1),
10577 TREE_OPERAND (arg1, 1), 0)))
10579 code = BIT_IOR_EXPR;
10583 /* (X | Y) ^ X -> Y & ~ X*/
10584 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10585 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10587 tree t2 = TREE_OPERAND (arg0, 1);
10588 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10590 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10591 fold_convert (type, t1));
10595 /* (Y | X) ^ X -> Y & ~ X*/
10596 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10597 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10599 tree t2 = TREE_OPERAND (arg0, 0);
10600 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
10602 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10603 fold_convert (type, t1));
10607 /* X ^ (X | Y) -> Y & ~ X*/
10608 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10609 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
10611 tree t2 = TREE_OPERAND (arg1, 1);
10612 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10614 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10615 fold_convert (type, t1));
10619 /* X ^ (Y | X) -> Y & ~ X*/
10620 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10621 && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
10623 tree t2 = TREE_OPERAND (arg1, 0);
10624 t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
10626 t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
10627 fold_convert (type, t1));
10631 /* Convert ~X ^ ~Y to X ^ Y. */
10632 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10633 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10634 return fold_build2 (code, type,
10635 fold_convert (type, TREE_OPERAND (arg0, 0)),
10636 fold_convert (type, TREE_OPERAND (arg1, 0)));
10638 /* Convert ~X ^ C to X ^ ~C. */
10639 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10640 && TREE_CODE (arg1) == INTEGER_CST)
10641 return fold_build2 (code, type,
10642 fold_convert (type, TREE_OPERAND (arg0, 0)),
10643 fold_build1 (BIT_NOT_EXPR, type, arg1));
10645 /* Fold (X & 1) ^ 1 as (X & 1) == 0. */
10646 if (TREE_CODE (arg0) == BIT_AND_EXPR
10647 && integer_onep (TREE_OPERAND (arg0, 1))
10648 && integer_onep (arg1))
10649 return fold_build2 (EQ_EXPR, type, arg0,
10650 build_int_cst (TREE_TYPE (arg0), 0));
10652 /* Fold (X & Y) ^ Y as ~X & Y. */
10653 if (TREE_CODE (arg0) == BIT_AND_EXPR
10654 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10656 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10657 return fold_build2 (BIT_AND_EXPR, type,
10658 fold_build1 (BIT_NOT_EXPR, type, tem),
10659 fold_convert (type, arg1));
10661 /* Fold (X & Y) ^ X as ~Y & X. */
10662 if (TREE_CODE (arg0) == BIT_AND_EXPR
10663 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10664 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10666 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10667 return fold_build2 (BIT_AND_EXPR, type,
10668 fold_build1 (BIT_NOT_EXPR, type, tem),
10669 fold_convert (type, arg1));
10671 /* Fold X ^ (X & Y) as X & ~Y. */
10672 if (TREE_CODE (arg1) == BIT_AND_EXPR
10673 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10675 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10676 return fold_build2 (BIT_AND_EXPR, type,
10677 fold_convert (type, arg0),
10678 fold_build1 (BIT_NOT_EXPR, type, tem));
10680 /* Fold X ^ (Y & X) as ~Y & X. */
10681 if (TREE_CODE (arg1) == BIT_AND_EXPR
10682 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10683 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10685 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10686 return fold_build2 (BIT_AND_EXPR, type,
10687 fold_build1 (BIT_NOT_EXPR, type, tem),
10688 fold_convert (type, arg0));
10691 /* See if this can be simplified into a rotate first. If that
10692 is unsuccessful continue in the association code. */
10696 if (integer_all_onesp (arg1))
10697 return non_lvalue (fold_convert (type, arg0));
10698 if (integer_zerop (arg1))
10699 return omit_one_operand (type, arg1, arg0);
10700 if (operand_equal_p (arg0, arg1, 0))
10701 return non_lvalue (fold_convert (type, arg0));
10703 /* ~X & X is always zero. */
10704 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10705 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
10706 return omit_one_operand (type, integer_zero_node, arg1);
10708 /* X & ~X is always zero. */
10709 if (TREE_CODE (arg1) == BIT_NOT_EXPR
10710 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10711 return omit_one_operand (type, integer_zero_node, arg0);
10713 /* Canonicalize (X | C1) & C2 as (X & C2) | (C1 & C2). */
10714 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10715 && TREE_CODE (arg1) == INTEGER_CST
10716 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
10718 tree tmp1 = fold_convert (TREE_TYPE (arg0), arg1);
10719 tree tmp2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10720 TREE_OPERAND (arg0, 0), tmp1);
10721 tree tmp3 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
10722 TREE_OPERAND (arg0, 1), tmp1);
10723 return fold_convert (type,
10724 fold_build2 (BIT_IOR_EXPR, TREE_TYPE (arg0),
10728 /* (X | Y) & Y is (X, Y). */
10729 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10730 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10731 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
10732 /* (X | Y) & X is (Y, X). */
10733 if (TREE_CODE (arg0) == BIT_IOR_EXPR
10734 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10735 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10736 return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
10737 /* X & (X | Y) is (Y, X). */
10738 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10739 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
10740 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
10741 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
10742 /* X & (Y | X) is (Y, X). */
10743 if (TREE_CODE (arg1) == BIT_IOR_EXPR
10744 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10745 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10746 return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
10748 /* Fold (X ^ 1) & 1 as (X & 1) == 0. */
10749 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10750 && integer_onep (TREE_OPERAND (arg0, 1))
10751 && integer_onep (arg1))
10753 tem = TREE_OPERAND (arg0, 0);
10754 return fold_build2 (EQ_EXPR, type,
10755 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10756 build_int_cst (TREE_TYPE (tem), 1)),
10757 build_int_cst (TREE_TYPE (tem), 0));
10759 /* Fold ~X & 1 as (X & 1) == 0. */
10760 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10761 && integer_onep (arg1))
10763 tem = TREE_OPERAND (arg0, 0);
10764 return fold_build2 (EQ_EXPR, type,
10765 fold_build2 (BIT_AND_EXPR, TREE_TYPE (tem), tem,
10766 build_int_cst (TREE_TYPE (tem), 1)),
10767 build_int_cst (TREE_TYPE (tem), 0));
10770 /* Fold (X ^ Y) & Y as ~X & Y. */
10771 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10772 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
10774 tem = fold_convert (type, TREE_OPERAND (arg0, 0));
10775 return fold_build2 (BIT_AND_EXPR, type,
10776 fold_build1 (BIT_NOT_EXPR, type, tem),
10777 fold_convert (type, arg1));
10779 /* Fold (X ^ Y) & X as ~Y & X. */
10780 if (TREE_CODE (arg0) == BIT_XOR_EXPR
10781 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
10782 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
10784 tem = fold_convert (type, TREE_OPERAND (arg0, 1));
10785 return fold_build2 (BIT_AND_EXPR, type,
10786 fold_build1 (BIT_NOT_EXPR, type, tem),
10787 fold_convert (type, arg1));
10789 /* Fold X & (X ^ Y) as X & ~Y. */
10790 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10791 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
10793 tem = fold_convert (type, TREE_OPERAND (arg1, 1));
10794 return fold_build2 (BIT_AND_EXPR, type,
10795 fold_convert (type, arg0),
10796 fold_build1 (BIT_NOT_EXPR, type, tem));
10798 /* Fold X & (Y ^ X) as ~Y & X. */
10799 if (TREE_CODE (arg1) == BIT_XOR_EXPR
10800 && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
10801 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
10803 tem = fold_convert (type, TREE_OPERAND (arg1, 0));
10804 return fold_build2 (BIT_AND_EXPR, type,
10805 fold_build1 (BIT_NOT_EXPR, type, tem),
10806 fold_convert (type, arg0));
10809 t1 = distribute_bit_expr (code, type, arg0, arg1);
10810 if (t1 != NULL_TREE)
10812 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
10813 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
10814 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
10817 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
10819 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
10820 && (~TREE_INT_CST_LOW (arg1)
10821 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
10822 return fold_convert (type, TREE_OPERAND (arg0, 0));
10825 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
10827 This results in more efficient code for machines without a NOR
10828 instruction. Combine will canonicalize to the first form
10829 which will allow use of NOR instructions provided by the
10830 backend if they exist. */
10831 if (TREE_CODE (arg0) == BIT_NOT_EXPR
10832 && TREE_CODE (arg1) == BIT_NOT_EXPR)
10834 return fold_build1 (BIT_NOT_EXPR, type,
10835 build2 (BIT_IOR_EXPR, type,
10836 fold_convert (type,
10837 TREE_OPERAND (arg0, 0)),
10838 fold_convert (type,
10839 TREE_OPERAND (arg1, 0))));
10842 /* If arg0 is derived from the address of an object or function, we may
10843 be able to fold this expression using the object or function's
10845 if (POINTER_TYPE_P (TREE_TYPE (arg0)) && host_integerp (arg1, 1))
10847 unsigned HOST_WIDE_INT modulus, residue;
10848 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (arg1);
10850 modulus = get_pointer_modulus_and_residue (arg0, &residue);
10852 /* This works because modulus is a power of 2. If this weren't the
10853 case, we'd have to replace it by its greatest power-of-2
10854 divisor: modulus & -modulus. */
10856 return build_int_cst (type, residue & low);
10859 /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
10860 (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
10861 if the new mask might be further optimized. */
10862 if ((TREE_CODE (arg0) == LSHIFT_EXPR
10863 || TREE_CODE (arg0) == RSHIFT_EXPR)
10864 && host_integerp (TREE_OPERAND (arg0, 1), 1)
10865 && host_integerp (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)))
10866 && tree_low_cst (TREE_OPERAND (arg0, 1), 1)
10867 < TYPE_PRECISION (TREE_TYPE (arg0))
10868 && TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
10869 && tree_low_cst (TREE_OPERAND (arg0, 1), 1) > 0)
10871 unsigned int shiftc = tree_low_cst (TREE_OPERAND (arg0, 1), 1);
10872 unsigned HOST_WIDE_INT mask
10873 = tree_low_cst (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)));
10874 unsigned HOST_WIDE_INT newmask, zerobits = 0;
10875 tree shift_type = TREE_TYPE (arg0);
10877 if (TREE_CODE (arg0) == LSHIFT_EXPR)
10878 zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
10879 else if (TREE_CODE (arg0) == RSHIFT_EXPR
10880 && TYPE_PRECISION (TREE_TYPE (arg0))
10881 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg0))))
10883 unsigned int prec = TYPE_PRECISION (TREE_TYPE (arg0));
10884 tree arg00 = TREE_OPERAND (arg0, 0);
10885 /* See if more bits can be proven as zero because of
10887 if (TREE_CODE (arg00) == NOP_EXPR
10888 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
10890 tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
10891 if (TYPE_PRECISION (inner_type)
10892 == GET_MODE_BITSIZE (TYPE_MODE (inner_type))
10893 && TYPE_PRECISION (inner_type) < prec)
10895 prec = TYPE_PRECISION (inner_type);
10896 /* See if we can shorten the right shift. */
10898 shift_type = inner_type;
10901 zerobits = ~(unsigned HOST_WIDE_INT) 0;
10902 zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
10903 zerobits <<= prec - shiftc;
10904 /* For arithmetic shift if sign bit could be set, zerobits
10905 can contain actually sign bits, so no transformation is
10906 possible, unless MASK masks them all away. In that
10907 case the shift needs to be converted into logical shift. */
10908 if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
10909 && prec == TYPE_PRECISION (TREE_TYPE (arg0)))
10911 if ((mask & zerobits) == 0)
10912 shift_type = unsigned_type_for (TREE_TYPE (arg0));
10918 /* ((X << 16) & 0xff00) is (X, 0). */
10919 if ((mask & zerobits) == mask)
10920 return omit_one_operand (type, build_int_cst (type, 0), arg0);
10922 newmask = mask | zerobits;
10923 if (newmask != mask && (newmask & (newmask + 1)) == 0)
10927 /* Only do the transformation if NEWMASK is some integer
10929 for (prec = BITS_PER_UNIT;
10930 prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
10931 if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
10933 if (prec < HOST_BITS_PER_WIDE_INT
10934 || newmask == ~(unsigned HOST_WIDE_INT) 0)
10936 if (shift_type != TREE_TYPE (arg0))
10938 tem = fold_build2 (TREE_CODE (arg0), shift_type,
10939 fold_convert (shift_type,
10940 TREE_OPERAND (arg0, 0)),
10941 TREE_OPERAND (arg0, 1));
10942 tem = fold_convert (type, tem);
10946 return fold_build2 (BIT_AND_EXPR, type, tem,
10947 build_int_cst_type (TREE_TYPE (op1),
10956 /* Don't touch a floating-point divide by zero unless the mode
10957 of the constant can represent infinity. */
10958 if (TREE_CODE (arg1) == REAL_CST
10959 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
10960 && real_zerop (arg1))
10963 /* Optimize A / A to 1.0 if we don't care about
10964 NaNs or Infinities. Skip the transformation
10965 for non-real operands. */
10966 if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg0))
10967 && ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
10968 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg0)))
10969 && operand_equal_p (arg0, arg1, 0))
10971 tree r = build_real (TREE_TYPE (arg0), dconst1);
10973 return omit_two_operands (type, r, arg0, arg1);
10976 /* The complex version of the above A / A optimization. */
10977 if (COMPLEX_FLOAT_TYPE_P (TREE_TYPE (arg0))
10978 && operand_equal_p (arg0, arg1, 0))
10980 tree elem_type = TREE_TYPE (TREE_TYPE (arg0));
10981 if (! HONOR_NANS (TYPE_MODE (elem_type))
10982 && ! HONOR_INFINITIES (TYPE_MODE (elem_type)))
10984 tree r = build_real (elem_type, dconst1);
10985 /* omit_two_operands will call fold_convert for us. */
10986 return omit_two_operands (type, r, arg0, arg1);
10990 /* (-A) / (-B) -> A / B */
10991 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
10992 return fold_build2 (RDIV_EXPR, type,
10993 TREE_OPERAND (arg0, 0),
10994 negate_expr (arg1));
10995 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
10996 return fold_build2 (RDIV_EXPR, type,
10997 negate_expr (arg0),
10998 TREE_OPERAND (arg1, 0));
11000 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
11001 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11002 && real_onep (arg1))
11003 return non_lvalue (fold_convert (type, arg0));
11005 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
11006 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
11007 && real_minus_onep (arg1))
11008 return non_lvalue (fold_convert (type, negate_expr (arg0)));
11010 /* If ARG1 is a constant, we can convert this to a multiply by the
11011 reciprocal. This does not have the same rounding properties,
11012 so only do this if -freciprocal-math. We can actually
11013 always safely do it if ARG1 is a power of two, but it's hard to
11014 tell if it is or not in a portable manner. */
11015 if (TREE_CODE (arg1) == REAL_CST)
11017 if (flag_reciprocal_math
11018 && 0 != (tem = const_binop (code, build_real (type, dconst1),
11020 return fold_build2 (MULT_EXPR, type, arg0, tem);
11021 /* Find the reciprocal if optimizing and the result is exact. */
11025 r = TREE_REAL_CST (arg1);
11026 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
11028 tem = build_real (type, r);
11029 return fold_build2 (MULT_EXPR, type,
11030 fold_convert (type, arg0), tem);
11034 /* Convert A/B/C to A/(B*C). */
11035 if (flag_reciprocal_math
11036 && TREE_CODE (arg0) == RDIV_EXPR)
11037 return fold_build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
11038 fold_build2 (MULT_EXPR, type,
11039 TREE_OPERAND (arg0, 1), arg1));
11041 /* Convert A/(B/C) to (A/B)*C. */
11042 if (flag_reciprocal_math
11043 && TREE_CODE (arg1) == RDIV_EXPR)
11044 return fold_build2 (MULT_EXPR, type,
11045 fold_build2 (RDIV_EXPR, type, arg0,
11046 TREE_OPERAND (arg1, 0)),
11047 TREE_OPERAND (arg1, 1));
11049 /* Convert C1/(X*C2) into (C1/C2)/X. */
11050 if (flag_reciprocal_math
11051 && TREE_CODE (arg1) == MULT_EXPR
11052 && TREE_CODE (arg0) == REAL_CST
11053 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
11055 tree tem = const_binop (RDIV_EXPR, arg0,
11056 TREE_OPERAND (arg1, 1), 0);
11058 return fold_build2 (RDIV_EXPR, type, tem,
11059 TREE_OPERAND (arg1, 0));
11062 if (flag_unsafe_math_optimizations)
11064 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
11065 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
11067 /* Optimize sin(x)/cos(x) as tan(x). */
11068 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
11069 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
11070 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
11071 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11072 CALL_EXPR_ARG (arg1, 0), 0))
11074 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11076 if (tanfn != NULL_TREE)
11077 return build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11080 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
11081 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
11082 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
11083 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
11084 && operand_equal_p (CALL_EXPR_ARG (arg0, 0),
11085 CALL_EXPR_ARG (arg1, 0), 0))
11087 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
11089 if (tanfn != NULL_TREE)
11091 tree tmp = build_call_expr (tanfn, 1, CALL_EXPR_ARG (arg0, 0));
11092 return fold_build2 (RDIV_EXPR, type,
11093 build_real (type, dconst1), tmp);
11097 /* Optimize sin(x)/tan(x) as cos(x) if we don't care about
11098 NaNs or Infinities. */
11099 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_TAN)
11100 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_TANF)
11101 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_TANL)))
11103 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11104 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11106 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11107 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11108 && operand_equal_p (arg00, arg01, 0))
11110 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11112 if (cosfn != NULL_TREE)
11113 return build_call_expr (cosfn, 1, arg00);
11117 /* Optimize tan(x)/sin(x) as 1.0/cos(x) if we don't care about
11118 NaNs or Infinities. */
11119 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_SIN)
11120 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_SINF)
11121 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_SINL)))
11123 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11124 tree arg01 = CALL_EXPR_ARG (arg1, 0);
11126 if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg00)))
11127 && ! HONOR_INFINITIES (TYPE_MODE (TREE_TYPE (arg00)))
11128 && operand_equal_p (arg00, arg01, 0))
11130 tree cosfn = mathfn_built_in (type, BUILT_IN_COS);
11132 if (cosfn != NULL_TREE)
11134 tree tmp = build_call_expr (cosfn, 1, arg00);
11135 return fold_build2 (RDIV_EXPR, type,
11136 build_real (type, dconst1),
11142 /* Optimize pow(x,c)/x as pow(x,c-1). */
11143 if (fcode0 == BUILT_IN_POW
11144 || fcode0 == BUILT_IN_POWF
11145 || fcode0 == BUILT_IN_POWL)
11147 tree arg00 = CALL_EXPR_ARG (arg0, 0);
11148 tree arg01 = CALL_EXPR_ARG (arg0, 1);
11149 if (TREE_CODE (arg01) == REAL_CST
11150 && !TREE_OVERFLOW (arg01)
11151 && operand_equal_p (arg1, arg00, 0))
11153 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg0), 0);
11157 c = TREE_REAL_CST (arg01);
11158 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
11159 arg = build_real (type, c);
11160 return build_call_expr (powfn, 2, arg1, arg);
11164 /* Optimize a/root(b/c) into a*root(c/b). */
11165 if (BUILTIN_ROOT_P (fcode1))
11167 tree rootarg = CALL_EXPR_ARG (arg1, 0);
11169 if (TREE_CODE (rootarg) == RDIV_EXPR)
11171 tree rootfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11172 tree b = TREE_OPERAND (rootarg, 0);
11173 tree c = TREE_OPERAND (rootarg, 1);
11175 tree tmp = fold_build2 (RDIV_EXPR, type, c, b);
11177 tmp = build_call_expr (rootfn, 1, tmp);
11178 return fold_build2 (MULT_EXPR, type, arg0, tmp);
11182 /* Optimize x/expN(y) into x*expN(-y). */
11183 if (BUILTIN_EXPONENT_P (fcode1))
11185 tree expfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11186 tree arg = negate_expr (CALL_EXPR_ARG (arg1, 0));
11187 arg1 = build_call_expr (expfn, 1, fold_convert (type, arg));
11188 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11191 /* Optimize x/pow(y,z) into x*pow(y,-z). */
11192 if (fcode1 == BUILT_IN_POW
11193 || fcode1 == BUILT_IN_POWF
11194 || fcode1 == BUILT_IN_POWL)
11196 tree powfn = TREE_OPERAND (CALL_EXPR_FN (arg1), 0);
11197 tree arg10 = CALL_EXPR_ARG (arg1, 0);
11198 tree arg11 = CALL_EXPR_ARG (arg1, 1);
11199 tree neg11 = fold_convert (type, negate_expr (arg11));
11200 arg1 = build_call_expr (powfn, 2, arg10, neg11);
11201 return fold_build2 (MULT_EXPR, type, arg0, arg1);
11206 case TRUNC_DIV_EXPR:
11207 case FLOOR_DIV_EXPR:
11208 /* Simplify A / (B << N) where A and B are positive and B is
11209 a power of 2, to A >> (N + log2(B)). */
11210 strict_overflow_p = false;
11211 if (TREE_CODE (arg1) == LSHIFT_EXPR
11212 && (TYPE_UNSIGNED (type)
11213 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11215 tree sval = TREE_OPERAND (arg1, 0);
11216 if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
11218 tree sh_cnt = TREE_OPERAND (arg1, 1);
11219 unsigned long pow2 = exact_log2 (TREE_INT_CST_LOW (sval));
11221 if (strict_overflow_p)
11222 fold_overflow_warning (("assuming signed overflow does not "
11223 "occur when simplifying A / (B << N)"),
11224 WARN_STRICT_OVERFLOW_MISC);
11226 sh_cnt = fold_build2 (PLUS_EXPR, TREE_TYPE (sh_cnt),
11227 sh_cnt, build_int_cst (NULL_TREE, pow2));
11228 return fold_build2 (RSHIFT_EXPR, type,
11229 fold_convert (type, arg0), sh_cnt);
11233 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
11234 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
11235 if (INTEGRAL_TYPE_P (type)
11236 && TYPE_UNSIGNED (type)
11237 && code == FLOOR_DIV_EXPR)
11238 return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
11242 case ROUND_DIV_EXPR:
11243 case CEIL_DIV_EXPR:
11244 case EXACT_DIV_EXPR:
11245 if (integer_onep (arg1))
11246 return non_lvalue (fold_convert (type, arg0));
11247 if (integer_zerop (arg1))
11249 /* X / -1 is -X. */
11250 if (!TYPE_UNSIGNED (type)
11251 && TREE_CODE (arg1) == INTEGER_CST
11252 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11253 && TREE_INT_CST_HIGH (arg1) == -1)
11254 return fold_convert (type, negate_expr (arg0));
11256 /* Convert -A / -B to A / B when the type is signed and overflow is
11258 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11259 && TREE_CODE (arg0) == NEGATE_EXPR
11260 && negate_expr_p (arg1))
11262 if (INTEGRAL_TYPE_P (type))
11263 fold_overflow_warning (("assuming signed overflow does not occur "
11264 "when distributing negation across "
11266 WARN_STRICT_OVERFLOW_MISC);
11267 return fold_build2 (code, type,
11268 fold_convert (type, TREE_OPERAND (arg0, 0)),
11269 negate_expr (arg1));
11271 if ((!INTEGRAL_TYPE_P (type) || TYPE_OVERFLOW_UNDEFINED (type))
11272 && TREE_CODE (arg1) == NEGATE_EXPR
11273 && negate_expr_p (arg0))
11275 if (INTEGRAL_TYPE_P (type))
11276 fold_overflow_warning (("assuming signed overflow does not occur "
11277 "when distributing negation across "
11279 WARN_STRICT_OVERFLOW_MISC);
11280 return fold_build2 (code, type, negate_expr (arg0),
11281 TREE_OPERAND (arg1, 0));
11284 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
11285 operation, EXACT_DIV_EXPR.
11287 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
11288 At one time others generated faster code, it's not clear if they do
11289 after the last round to changes to the DIV code in expmed.c. */
11290 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
11291 && multiple_of_p (type, arg0, arg1))
11292 return fold_build2 (EXACT_DIV_EXPR, type, arg0, arg1);
11294 strict_overflow_p = false;
11295 if (TREE_CODE (arg1) == INTEGER_CST
11296 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11297 &strict_overflow_p)))
11299 if (strict_overflow_p)
11300 fold_overflow_warning (("assuming signed overflow does not occur "
11301 "when simplifying division"),
11302 WARN_STRICT_OVERFLOW_MISC);
11303 return fold_convert (type, tem);
11308 case CEIL_MOD_EXPR:
11309 case FLOOR_MOD_EXPR:
11310 case ROUND_MOD_EXPR:
11311 case TRUNC_MOD_EXPR:
11312 /* X % 1 is always zero, but be sure to preserve any side
11314 if (integer_onep (arg1))
11315 return omit_one_operand (type, integer_zero_node, arg0);
11317 /* X % 0, return X % 0 unchanged so that we can get the
11318 proper warnings and errors. */
11319 if (integer_zerop (arg1))
11322 /* 0 % X is always zero, but be sure to preserve any side
11323 effects in X. Place this after checking for X == 0. */
11324 if (integer_zerop (arg0))
11325 return omit_one_operand (type, integer_zero_node, arg1);
11327 /* X % -1 is zero. */
11328 if (!TYPE_UNSIGNED (type)
11329 && TREE_CODE (arg1) == INTEGER_CST
11330 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
11331 && TREE_INT_CST_HIGH (arg1) == -1)
11332 return omit_one_operand (type, integer_zero_node, arg0);
11334 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
11335 i.e. "X % C" into "X & (C - 1)", if X and C are positive. */
11336 strict_overflow_p = false;
11337 if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
11338 && (TYPE_UNSIGNED (type)
11339 || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
11342 /* Also optimize A % (C << N) where C is a power of 2,
11343 to A & ((C << N) - 1). */
11344 if (TREE_CODE (arg1) == LSHIFT_EXPR)
11345 c = TREE_OPERAND (arg1, 0);
11347 if (integer_pow2p (c) && tree_int_cst_sgn (c) > 0)
11349 tree mask = fold_build2 (MINUS_EXPR, TREE_TYPE (arg1), arg1,
11350 build_int_cst (TREE_TYPE (arg1), 1));
11351 if (strict_overflow_p)
11352 fold_overflow_warning (("assuming signed overflow does not "
11353 "occur when simplifying "
11354 "X % (power of two)"),
11355 WARN_STRICT_OVERFLOW_MISC);
11356 return fold_build2 (BIT_AND_EXPR, type,
11357 fold_convert (type, arg0),
11358 fold_convert (type, mask));
11362 /* X % -C is the same as X % C. */
11363 if (code == TRUNC_MOD_EXPR
11364 && !TYPE_UNSIGNED (type)
11365 && TREE_CODE (arg1) == INTEGER_CST
11366 && !TREE_OVERFLOW (arg1)
11367 && TREE_INT_CST_HIGH (arg1) < 0
11368 && !TYPE_OVERFLOW_TRAPS (type)
11369 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
11370 && !sign_bit_p (arg1, arg1))
11371 return fold_build2 (code, type, fold_convert (type, arg0),
11372 fold_convert (type, negate_expr (arg1)));
11374 /* X % -Y is the same as X % Y. */
11375 if (code == TRUNC_MOD_EXPR
11376 && !TYPE_UNSIGNED (type)
11377 && TREE_CODE (arg1) == NEGATE_EXPR
11378 && !TYPE_OVERFLOW_TRAPS (type))
11379 return fold_build2 (code, type, fold_convert (type, arg0),
11380 fold_convert (type, TREE_OPERAND (arg1, 0)));
11382 if (TREE_CODE (arg1) == INTEGER_CST
11383 && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,
11384 &strict_overflow_p)))
11386 if (strict_overflow_p)
11387 fold_overflow_warning (("assuming signed overflow does not occur "
11388 "when simplifying modulus"),
11389 WARN_STRICT_OVERFLOW_MISC);
11390 return fold_convert (type, tem);
11397 if (integer_all_onesp (arg0))
11398 return omit_one_operand (type, arg0, arg1);
11402 /* Optimize -1 >> x for arithmetic right shifts. */
11403 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
11404 return omit_one_operand (type, arg0, arg1);
11405 /* ... fall through ... */
11409 if (integer_zerop (arg1))
11410 return non_lvalue (fold_convert (type, arg0));
11411 if (integer_zerop (arg0))
11412 return omit_one_operand (type, arg0, arg1);
11414 /* Since negative shift count is not well-defined,
11415 don't try to compute it in the compiler. */
11416 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
11419 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
11420 if (TREE_CODE (op0) == code && host_integerp (arg1, false)
11421 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11422 && host_integerp (TREE_OPERAND (arg0, 1), false)
11423 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11425 HOST_WIDE_INT low = (TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1))
11426 + TREE_INT_CST_LOW (arg1));
11428 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
11429 being well defined. */
11430 if (low >= TYPE_PRECISION (type))
11432 if (code == LROTATE_EXPR || code == RROTATE_EXPR)
11433 low = low % TYPE_PRECISION (type);
11434 else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR)
11435 return build_int_cst (type, 0);
11437 low = TYPE_PRECISION (type) - 1;
11440 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11441 build_int_cst (type, low));
11444 /* Transform (x >> c) << c into x & (-1<<c), or transform (x << c) >> c
11445 into x & ((unsigned)-1 >> c) for unsigned types. */
11446 if (((code == LSHIFT_EXPR && TREE_CODE (arg0) == RSHIFT_EXPR)
11447 || (TYPE_UNSIGNED (type)
11448 && code == RSHIFT_EXPR && TREE_CODE (arg0) == LSHIFT_EXPR))
11449 && host_integerp (arg1, false)
11450 && TREE_INT_CST_LOW (arg1) < TYPE_PRECISION (type)
11451 && host_integerp (TREE_OPERAND (arg0, 1), false)
11452 && TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)) < TYPE_PRECISION (type))
11454 HOST_WIDE_INT low0 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
11455 HOST_WIDE_INT low1 = TREE_INT_CST_LOW (arg1);
11461 arg00 = fold_convert (type, TREE_OPERAND (arg0, 0));
11463 lshift = build_int_cst (type, -1);
11464 lshift = int_const_binop (code, lshift, arg1, 0);
11466 return fold_build2 (BIT_AND_EXPR, type, arg00, lshift);
11470 /* Rewrite an LROTATE_EXPR by a constant into an
11471 RROTATE_EXPR by a new constant. */
11472 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
11474 tree tem = build_int_cst (TREE_TYPE (arg1),
11475 TYPE_PRECISION (type));
11476 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
11477 return fold_build2 (RROTATE_EXPR, type, op0, tem);
11480 /* If we have a rotate of a bit operation with the rotate count and
11481 the second operand of the bit operation both constant,
11482 permute the two operations. */
11483 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11484 && (TREE_CODE (arg0) == BIT_AND_EXPR
11485 || TREE_CODE (arg0) == BIT_IOR_EXPR
11486 || TREE_CODE (arg0) == BIT_XOR_EXPR)
11487 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11488 return fold_build2 (TREE_CODE (arg0), type,
11489 fold_build2 (code, type,
11490 TREE_OPERAND (arg0, 0), arg1),
11491 fold_build2 (code, type,
11492 TREE_OPERAND (arg0, 1), arg1));
11494 /* Two consecutive rotates adding up to the precision of the
11495 type can be ignored. */
11496 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
11497 && TREE_CODE (arg0) == RROTATE_EXPR
11498 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11499 && TREE_INT_CST_HIGH (arg1) == 0
11500 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
11501 && ((TREE_INT_CST_LOW (arg1)
11502 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
11503 == (unsigned int) TYPE_PRECISION (type)))
11504 return TREE_OPERAND (arg0, 0);
11506 /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
11507 (X & C2) >> C1 into (X >> C1) & (C2 >> C1)
11508 if the latter can be further optimized. */
11509 if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
11510 && TREE_CODE (arg0) == BIT_AND_EXPR
11511 && TREE_CODE (arg1) == INTEGER_CST
11512 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11514 tree mask = fold_build2 (code, type,
11515 fold_convert (type, TREE_OPERAND (arg0, 1)),
11517 tree shift = fold_build2 (code, type,
11518 fold_convert (type, TREE_OPERAND (arg0, 0)),
11520 tem = fold_binary (BIT_AND_EXPR, type, shift, mask);
11528 if (operand_equal_p (arg0, arg1, 0))
11529 return omit_one_operand (type, arg0, arg1);
11530 if (INTEGRAL_TYPE_P (type)
11531 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
11532 return omit_one_operand (type, arg1, arg0);
11533 tem = fold_minmax (MIN_EXPR, type, arg0, arg1);
11539 if (operand_equal_p (arg0, arg1, 0))
11540 return omit_one_operand (type, arg0, arg1);
11541 if (INTEGRAL_TYPE_P (type)
11542 && TYPE_MAX_VALUE (type)
11543 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
11544 return omit_one_operand (type, arg1, arg0);
11545 tem = fold_minmax (MAX_EXPR, type, arg0, arg1);
11550 case TRUTH_ANDIF_EXPR:
11551 /* Note that the operands of this must be ints
11552 and their values must be 0 or 1.
11553 ("true" is a fixed value perhaps depending on the language.) */
11554 /* If first arg is constant zero, return it. */
11555 if (integer_zerop (arg0))
11556 return fold_convert (type, arg0);
11557 case TRUTH_AND_EXPR:
11558 /* If either arg is constant true, drop it. */
11559 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11560 return non_lvalue (fold_convert (type, arg1));
11561 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
11562 /* Preserve sequence points. */
11563 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11564 return non_lvalue (fold_convert (type, arg0));
11565 /* If second arg is constant zero, result is zero, but first arg
11566 must be evaluated. */
11567 if (integer_zerop (arg1))
11568 return omit_one_operand (type, arg1, arg0);
11569 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
11570 case will be handled here. */
11571 if (integer_zerop (arg0))
11572 return omit_one_operand (type, arg0, arg1);
11574 /* !X && X is always false. */
11575 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11576 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11577 return omit_one_operand (type, integer_zero_node, arg1);
11578 /* X && !X is always false. */
11579 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11580 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11581 return omit_one_operand (type, integer_zero_node, arg0);
11583 /* A < X && A + 1 > Y ==> A < X && A >= Y. Normally A + 1 > Y
11584 means A >= Y && A != MAX, but in this case we know that
11587 if (!TREE_SIDE_EFFECTS (arg0)
11588 && !TREE_SIDE_EFFECTS (arg1))
11590 tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
11591 if (tem && !operand_equal_p (tem, arg0, 0))
11592 return fold_build2 (code, type, tem, arg1);
11594 tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
11595 if (tem && !operand_equal_p (tem, arg1, 0))
11596 return fold_build2 (code, type, arg0, tem);
11600 /* We only do these simplifications if we are optimizing. */
11604 /* Check for things like (A || B) && (A || C). We can convert this
11605 to A || (B && C). Note that either operator can be any of the four
11606 truth and/or operations and the transformation will still be
11607 valid. Also note that we only care about order for the
11608 ANDIF and ORIF operators. If B contains side effects, this
11609 might change the truth-value of A. */
11610 if (TREE_CODE (arg0) == TREE_CODE (arg1)
11611 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
11612 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
11613 || TREE_CODE (arg0) == TRUTH_AND_EXPR
11614 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
11615 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
11617 tree a00 = TREE_OPERAND (arg0, 0);
11618 tree a01 = TREE_OPERAND (arg0, 1);
11619 tree a10 = TREE_OPERAND (arg1, 0);
11620 tree a11 = TREE_OPERAND (arg1, 1);
11621 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
11622 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
11623 && (code == TRUTH_AND_EXPR
11624 || code == TRUTH_OR_EXPR));
11626 if (operand_equal_p (a00, a10, 0))
11627 return fold_build2 (TREE_CODE (arg0), type, a00,
11628 fold_build2 (code, type, a01, a11));
11629 else if (commutative && operand_equal_p (a00, a11, 0))
11630 return fold_build2 (TREE_CODE (arg0), type, a00,
11631 fold_build2 (code, type, a01, a10));
11632 else if (commutative && operand_equal_p (a01, a10, 0))
11633 return fold_build2 (TREE_CODE (arg0), type, a01,
11634 fold_build2 (code, type, a00, a11));
11636 /* This case if tricky because we must either have commutative
11637 operators or else A10 must not have side-effects. */
11639 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
11640 && operand_equal_p (a01, a11, 0))
11641 return fold_build2 (TREE_CODE (arg0), type,
11642 fold_build2 (code, type, a00, a10),
11646 /* See if we can build a range comparison. */
11647 if (0 != (tem = fold_range_test (code, type, op0, op1)))
11650 /* Check for the possibility of merging component references. If our
11651 lhs is another similar operation, try to merge its rhs with our
11652 rhs. Then try to merge our lhs and rhs. */
11653 if (TREE_CODE (arg0) == code
11654 && 0 != (tem = fold_truthop (code, type,
11655 TREE_OPERAND (arg0, 1), arg1)))
11656 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11658 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
11663 case TRUTH_ORIF_EXPR:
11664 /* Note that the operands of this must be ints
11665 and their values must be 0 or true.
11666 ("true" is a fixed value perhaps depending on the language.) */
11667 /* If first arg is constant true, return it. */
11668 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11669 return fold_convert (type, arg0);
11670 case TRUTH_OR_EXPR:
11671 /* If either arg is constant zero, drop it. */
11672 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
11673 return non_lvalue (fold_convert (type, arg1));
11674 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
11675 /* Preserve sequence points. */
11676 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
11677 return non_lvalue (fold_convert (type, arg0));
11678 /* If second arg is constant true, result is true, but we must
11679 evaluate first arg. */
11680 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
11681 return omit_one_operand (type, arg1, arg0);
11682 /* Likewise for first arg, but note this only occurs here for
11684 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
11685 return omit_one_operand (type, arg0, arg1);
11687 /* !X || X is always true. */
11688 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11689 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11690 return omit_one_operand (type, integer_one_node, arg1);
11691 /* X || !X is always true. */
11692 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11693 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11694 return omit_one_operand (type, integer_one_node, arg0);
11698 case TRUTH_XOR_EXPR:
11699 /* If the second arg is constant zero, drop it. */
11700 if (integer_zerop (arg1))
11701 return non_lvalue (fold_convert (type, arg0));
11702 /* If the second arg is constant true, this is a logical inversion. */
11703 if (integer_onep (arg1))
11705 /* Only call invert_truthvalue if operand is a truth value. */
11706 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
11707 tem = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg0), arg0);
11709 tem = invert_truthvalue (arg0);
11710 return non_lvalue (fold_convert (type, tem));
11712 /* Identical arguments cancel to zero. */
11713 if (operand_equal_p (arg0, arg1, 0))
11714 return omit_one_operand (type, integer_zero_node, arg0);
11716 /* !X ^ X is always true. */
11717 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
11718 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
11719 return omit_one_operand (type, integer_one_node, arg1);
11721 /* X ^ !X is always true. */
11722 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
11723 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
11724 return omit_one_operand (type, integer_one_node, arg0);
11730 tem = fold_comparison (code, type, op0, op1);
11731 if (tem != NULL_TREE)
11734 /* bool_var != 0 becomes bool_var. */
11735 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11736 && code == NE_EXPR)
11737 return non_lvalue (fold_convert (type, arg0));
11739 /* bool_var == 1 becomes bool_var. */
11740 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11741 && code == EQ_EXPR)
11742 return non_lvalue (fold_convert (type, arg0));
11744 /* bool_var != 1 becomes !bool_var. */
11745 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
11746 && code == NE_EXPR)
11747 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11749 /* bool_var == 0 becomes !bool_var. */
11750 if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
11751 && code == EQ_EXPR)
11752 return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
11754 /* If this is an equality comparison of the address of two non-weak,
11755 unaliased symbols neither of which are extern (since we do not
11756 have access to attributes for externs), then we know the result. */
11757 if (TREE_CODE (arg0) == ADDR_EXPR
11758 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg0, 0))
11759 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
11760 && ! lookup_attribute ("alias",
11761 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
11762 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
11763 && TREE_CODE (arg1) == ADDR_EXPR
11764 && VAR_OR_FUNCTION_DECL_P (TREE_OPERAND (arg1, 0))
11765 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
11766 && ! lookup_attribute ("alias",
11767 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
11768 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
11770 /* We know that we're looking at the address of two
11771 non-weak, unaliased, static _DECL nodes.
11773 It is both wasteful and incorrect to call operand_equal_p
11774 to compare the two ADDR_EXPR nodes. It is wasteful in that
11775 all we need to do is test pointer equality for the arguments
11776 to the two ADDR_EXPR nodes. It is incorrect to use
11777 operand_equal_p as that function is NOT equivalent to a
11778 C equality test. It can in fact return false for two
11779 objects which would test as equal using the C equality
11781 bool equal = TREE_OPERAND (arg0, 0) == TREE_OPERAND (arg1, 0);
11782 return constant_boolean_node (equal
11783 ? code == EQ_EXPR : code != EQ_EXPR,
11787 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
11788 a MINUS_EXPR of a constant, we can convert it into a comparison with
11789 a revised constant as long as no overflow occurs. */
11790 if (TREE_CODE (arg1) == INTEGER_CST
11791 && (TREE_CODE (arg0) == PLUS_EXPR
11792 || TREE_CODE (arg0) == MINUS_EXPR)
11793 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11794 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
11795 ? MINUS_EXPR : PLUS_EXPR,
11796 fold_convert (TREE_TYPE (arg0), arg1),
11797 TREE_OPERAND (arg0, 1), 0))
11798 && !TREE_OVERFLOW (tem))
11799 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11801 /* Similarly for a NEGATE_EXPR. */
11802 if (TREE_CODE (arg0) == NEGATE_EXPR
11803 && TREE_CODE (arg1) == INTEGER_CST
11804 && 0 != (tem = negate_expr (arg1))
11805 && TREE_CODE (tem) == INTEGER_CST
11806 && !TREE_OVERFLOW (tem))
11807 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), tem);
11809 /* Similarly for a BIT_XOR_EXPR; X ^ C1 == C2 is X == (C1 ^ C2). */
11810 if (TREE_CODE (arg0) == BIT_XOR_EXPR
11811 && TREE_CODE (arg1) == INTEGER_CST
11812 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11813 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
11814 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg0),
11815 fold_convert (TREE_TYPE (arg0), arg1),
11816 TREE_OPERAND (arg0, 1)));
11818 /* Transform comparisons of the form X +- C CMP X. */
11819 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
11820 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
11821 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
11822 && (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
11823 || POINTER_TYPE_P (TREE_TYPE (arg0))))
11825 tree cst = TREE_OPERAND (arg0, 1);
11827 if (code == EQ_EXPR
11828 && !integer_zerop (cst))
11829 return omit_two_operands (type, boolean_false_node,
11830 TREE_OPERAND (arg0, 0), arg1);
11832 return omit_two_operands (type, boolean_true_node,
11833 TREE_OPERAND (arg0, 0), arg1);
11836 /* If we have X - Y == 0, we can convert that to X == Y and similarly
11837 for !=. Don't do this for ordered comparisons due to overflow. */
11838 if (TREE_CODE (arg0) == MINUS_EXPR
11839 && integer_zerop (arg1))
11840 return fold_build2 (code, type,
11841 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
11843 /* Convert ABS_EXPR<x> == 0 or ABS_EXPR<x> != 0 to x == 0 or x != 0. */
11844 if (TREE_CODE (arg0) == ABS_EXPR
11845 && (integer_zerop (arg1) || real_zerop (arg1)))
11846 return fold_build2 (code, type, TREE_OPERAND (arg0, 0), arg1);
11848 /* If this is an EQ or NE comparison with zero and ARG0 is
11849 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
11850 two operations, but the latter can be done in one less insn
11851 on machines that have only two-operand insns or on which a
11852 constant cannot be the first operand. */
11853 if (TREE_CODE (arg0) == BIT_AND_EXPR
11854 && integer_zerop (arg1))
11856 tree arg00 = TREE_OPERAND (arg0, 0);
11857 tree arg01 = TREE_OPERAND (arg0, 1);
11858 if (TREE_CODE (arg00) == LSHIFT_EXPR
11859 && integer_onep (TREE_OPERAND (arg00, 0)))
11861 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
11862 arg01, TREE_OPERAND (arg00, 1));
11863 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11864 build_int_cst (TREE_TYPE (arg0), 1));
11865 return fold_build2 (code, type,
11866 fold_convert (TREE_TYPE (arg1), tem), arg1);
11868 else if (TREE_CODE (arg01) == LSHIFT_EXPR
11869 && integer_onep (TREE_OPERAND (arg01, 0)))
11871 tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
11872 arg00, TREE_OPERAND (arg01, 1));
11873 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
11874 build_int_cst (TREE_TYPE (arg0), 1));
11875 return fold_build2 (code, type,
11876 fold_convert (TREE_TYPE (arg1), tem), arg1);
11880 /* If this is an NE or EQ comparison of zero against the result of a
11881 signed MOD operation whose second operand is a power of 2, make
11882 the MOD operation unsigned since it is simpler and equivalent. */
11883 if (integer_zerop (arg1)
11884 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
11885 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
11886 || TREE_CODE (arg0) == CEIL_MOD_EXPR
11887 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
11888 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
11889 && integer_pow2p (TREE_OPERAND (arg0, 1)))
11891 tree newtype = unsigned_type_for (TREE_TYPE (arg0));
11892 tree newmod = fold_build2 (TREE_CODE (arg0), newtype,
11893 fold_convert (newtype,
11894 TREE_OPERAND (arg0, 0)),
11895 fold_convert (newtype,
11896 TREE_OPERAND (arg0, 1)));
11898 return fold_build2 (code, type, newmod,
11899 fold_convert (newtype, arg1));
11902 /* Fold ((X >> C1) & C2) == 0 and ((X >> C1) & C2) != 0 where
11903 C1 is a valid shift constant, and C2 is a power of two, i.e.
11905 if (TREE_CODE (arg0) == BIT_AND_EXPR
11906 && TREE_CODE (TREE_OPERAND (arg0, 0)) == RSHIFT_EXPR
11907 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1))
11909 && integer_pow2p (TREE_OPERAND (arg0, 1))
11910 && integer_zerop (arg1))
11912 tree itype = TREE_TYPE (arg0);
11913 unsigned HOST_WIDE_INT prec = TYPE_PRECISION (itype);
11914 tree arg001 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 1);
11916 /* Check for a valid shift count. */
11917 if (TREE_INT_CST_HIGH (arg001) == 0
11918 && TREE_INT_CST_LOW (arg001) < prec)
11920 tree arg01 = TREE_OPERAND (arg0, 1);
11921 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
11922 unsigned HOST_WIDE_INT log2 = tree_log2 (arg01);
11923 /* If (C2 << C1) doesn't overflow, then ((X >> C1) & C2) != 0
11924 can be rewritten as (X & (C2 << C1)) != 0. */
11925 if ((log2 + TREE_INT_CST_LOW (arg001)) < prec)
11927 tem = fold_build2 (LSHIFT_EXPR, itype, arg01, arg001);
11928 tem = fold_build2 (BIT_AND_EXPR, itype, arg000, tem);
11929 return fold_build2 (code, type, tem, arg1);
11931 /* Otherwise, for signed (arithmetic) shifts,
11932 ((X >> C1) & C2) != 0 is rewritten as X < 0, and
11933 ((X >> C1) & C2) == 0 is rewritten as X >= 0. */
11934 else if (!TYPE_UNSIGNED (itype))
11935 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
11936 arg000, build_int_cst (itype, 0));
11937 /* Otherwise, of unsigned (logical) shifts,
11938 ((X >> C1) & C2) != 0 is rewritten as (X,false), and
11939 ((X >> C1) & C2) == 0 is rewritten as (X,true). */
11941 return omit_one_operand (type,
11942 code == EQ_EXPR ? integer_one_node
11943 : integer_zero_node,
11948 /* If this is an NE comparison of zero with an AND of one, remove the
11949 comparison since the AND will give the correct value. */
11950 if (code == NE_EXPR
11951 && integer_zerop (arg1)
11952 && TREE_CODE (arg0) == BIT_AND_EXPR
11953 && integer_onep (TREE_OPERAND (arg0, 1)))
11954 return fold_convert (type, arg0);
11956 /* If we have (A & C) == C where C is a power of 2, convert this into
11957 (A & C) != 0. Similarly for NE_EXPR. */
11958 if (TREE_CODE (arg0) == BIT_AND_EXPR
11959 && integer_pow2p (TREE_OPERAND (arg0, 1))
11960 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
11961 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
11962 arg0, fold_convert (TREE_TYPE (arg0),
11963 integer_zero_node));
11965 /* If we have (A & C) != 0 or (A & C) == 0 and C is the sign
11966 bit, then fold the expression into A < 0 or A >= 0. */
11967 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1, type);
11971 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
11972 Similarly for NE_EXPR. */
11973 if (TREE_CODE (arg0) == BIT_AND_EXPR
11974 && TREE_CODE (arg1) == INTEGER_CST
11975 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11977 tree notc = fold_build1 (BIT_NOT_EXPR,
11978 TREE_TYPE (TREE_OPERAND (arg0, 1)),
11979 TREE_OPERAND (arg0, 1));
11980 tree dandnotc = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11982 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11983 if (integer_nonzerop (dandnotc))
11984 return omit_one_operand (type, rslt, arg0);
11987 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
11988 Similarly for NE_EXPR. */
11989 if (TREE_CODE (arg0) == BIT_IOR_EXPR
11990 && TREE_CODE (arg1) == INTEGER_CST
11991 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
11993 tree notd = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1);
11994 tree candnotd = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
11995 TREE_OPERAND (arg0, 1), notd);
11996 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
11997 if (integer_nonzerop (candnotd))
11998 return omit_one_operand (type, rslt, arg0);
12001 /* Optimize comparisons of strlen vs zero to a compare of the
12002 first character of the string vs zero. To wit,
12003 strlen(ptr) == 0 => *ptr == 0
12004 strlen(ptr) != 0 => *ptr != 0
12005 Other cases should reduce to one of these two (or a constant)
12006 due to the return value of strlen being unsigned. */
12007 if (TREE_CODE (arg0) == CALL_EXPR
12008 && integer_zerop (arg1))
12010 tree fndecl = get_callee_fndecl (arg0);
12013 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
12014 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
12015 && call_expr_nargs (arg0) == 1
12016 && TREE_CODE (TREE_TYPE (CALL_EXPR_ARG (arg0, 0))) == POINTER_TYPE)
12018 tree iref = build_fold_indirect_ref (CALL_EXPR_ARG (arg0, 0));
12019 return fold_build2 (code, type, iref,
12020 build_int_cst (TREE_TYPE (iref), 0));
12024 /* Fold (X >> C) != 0 into X < 0 if C is one less than the width
12025 of X. Similarly fold (X >> C) == 0 into X >= 0. */
12026 if (TREE_CODE (arg0) == RSHIFT_EXPR
12027 && integer_zerop (arg1)
12028 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12030 tree arg00 = TREE_OPERAND (arg0, 0);
12031 tree arg01 = TREE_OPERAND (arg0, 1);
12032 tree itype = TREE_TYPE (arg00);
12033 if (TREE_INT_CST_HIGH (arg01) == 0
12034 && TREE_INT_CST_LOW (arg01)
12035 == (unsigned HOST_WIDE_INT) (TYPE_PRECISION (itype) - 1))
12037 if (TYPE_UNSIGNED (itype))
12039 itype = signed_type_for (itype);
12040 arg00 = fold_convert (itype, arg00);
12042 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
12043 type, arg00, build_int_cst (itype, 0));
12047 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
12048 if (integer_zerop (arg1)
12049 && TREE_CODE (arg0) == BIT_XOR_EXPR)
12050 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12051 TREE_OPERAND (arg0, 1));
12053 /* (X ^ Y) == Y becomes X == 0. We know that Y has no side-effects. */
12054 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12055 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
12056 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12057 build_int_cst (TREE_TYPE (arg1), 0));
12058 /* Likewise (X ^ Y) == X becomes Y == 0. X has no side-effects. */
12059 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12060 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12061 && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
12062 return fold_build2 (code, type, TREE_OPERAND (arg0, 1),
12063 build_int_cst (TREE_TYPE (arg1), 0));
12065 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
12066 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12067 && TREE_CODE (arg1) == INTEGER_CST
12068 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
12069 return fold_build2 (code, type, TREE_OPERAND (arg0, 0),
12070 fold_build2 (BIT_XOR_EXPR, TREE_TYPE (arg1),
12071 TREE_OPERAND (arg0, 1), arg1));
12073 /* Fold (~X & C) == 0 into (X & C) != 0 and (~X & C) != 0 into
12074 (X & C) == 0 when C is a single bit. */
12075 if (TREE_CODE (arg0) == BIT_AND_EXPR
12076 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_NOT_EXPR
12077 && integer_zerop (arg1)
12078 && integer_pow2p (TREE_OPERAND (arg0, 1)))
12080 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
12081 TREE_OPERAND (TREE_OPERAND (arg0, 0), 0),
12082 TREE_OPERAND (arg0, 1));
12083 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR,
12087 /* Fold ((X & C) ^ C) eq/ne 0 into (X & C) ne/eq 0, when the
12088 constant C is a power of two, i.e. a single bit. */
12089 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12090 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
12091 && integer_zerop (arg1)
12092 && integer_pow2p (TREE_OPERAND (arg0, 1))
12093 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12094 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12096 tree arg00 = TREE_OPERAND (arg0, 0);
12097 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12098 arg00, build_int_cst (TREE_TYPE (arg00), 0));
12101 /* Likewise, fold ((X ^ C) & C) eq/ne 0 into (X & C) ne/eq 0,
12102 when is C is a power of two, i.e. a single bit. */
12103 if (TREE_CODE (arg0) == BIT_AND_EXPR
12104 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_XOR_EXPR
12105 && integer_zerop (arg1)
12106 && integer_pow2p (TREE_OPERAND (arg0, 1))
12107 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
12108 TREE_OPERAND (arg0, 1), OEP_ONLY_CONST))
12110 tree arg000 = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
12111 tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg000),
12112 arg000, TREE_OPERAND (arg0, 1));
12113 return fold_build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
12114 tem, build_int_cst (TREE_TYPE (tem), 0));
12117 if (integer_zerop (arg1)
12118 && tree_expr_nonzero_p (arg0))
12120 tree res = constant_boolean_node (code==NE_EXPR, type);
12121 return omit_one_operand (type, res, arg0);
12124 /* Fold -X op -Y as X op Y, where op is eq/ne. */
12125 if (TREE_CODE (arg0) == NEGATE_EXPR
12126 && TREE_CODE (arg1) == NEGATE_EXPR)
12127 return fold_build2 (code, type,
12128 TREE_OPERAND (arg0, 0),
12129 TREE_OPERAND (arg1, 0));
12131 /* Fold (X & C) op (Y & C) as (X ^ Y) & C op 0", and symmetries. */
12132 if (TREE_CODE (arg0) == BIT_AND_EXPR
12133 && TREE_CODE (arg1) == BIT_AND_EXPR)
12135 tree arg00 = TREE_OPERAND (arg0, 0);
12136 tree arg01 = TREE_OPERAND (arg0, 1);
12137 tree arg10 = TREE_OPERAND (arg1, 0);
12138 tree arg11 = TREE_OPERAND (arg1, 1);
12139 tree itype = TREE_TYPE (arg0);
12141 if (operand_equal_p (arg01, arg11, 0))
12142 return fold_build2 (code, type,
12143 fold_build2 (BIT_AND_EXPR, itype,
12144 fold_build2 (BIT_XOR_EXPR, itype,
12147 build_int_cst (itype, 0));
12149 if (operand_equal_p (arg01, arg10, 0))
12150 return fold_build2 (code, type,
12151 fold_build2 (BIT_AND_EXPR, itype,
12152 fold_build2 (BIT_XOR_EXPR, itype,
12155 build_int_cst (itype, 0));
12157 if (operand_equal_p (arg00, arg11, 0))
12158 return fold_build2 (code, type,
12159 fold_build2 (BIT_AND_EXPR, itype,
12160 fold_build2 (BIT_XOR_EXPR, itype,
12163 build_int_cst (itype, 0));
12165 if (operand_equal_p (arg00, arg10, 0))
12166 return fold_build2 (code, type,
12167 fold_build2 (BIT_AND_EXPR, itype,
12168 fold_build2 (BIT_XOR_EXPR, itype,
12171 build_int_cst (itype, 0));
12174 if (TREE_CODE (arg0) == BIT_XOR_EXPR
12175 && TREE_CODE (arg1) == BIT_XOR_EXPR)
12177 tree arg00 = TREE_OPERAND (arg0, 0);
12178 tree arg01 = TREE_OPERAND (arg0, 1);
12179 tree arg10 = TREE_OPERAND (arg1, 0);
12180 tree arg11 = TREE_OPERAND (arg1, 1);
12181 tree itype = TREE_TYPE (arg0);
12183 /* Optimize (X ^ Z) op (Y ^ Z) as X op Y, and symmetries.
12184 operand_equal_p guarantees no side-effects so we don't need
12185 to use omit_one_operand on Z. */
12186 if (operand_equal_p (arg01, arg11, 0))
12187 return fold_build2 (code, type, arg00, arg10);
12188 if (operand_equal_p (arg01, arg10, 0))
12189 return fold_build2 (code, type, arg00, arg11);
12190 if (operand_equal_p (arg00, arg11, 0))
12191 return fold_build2 (code, type, arg01, arg10);
12192 if (operand_equal_p (arg00, arg10, 0))
12193 return fold_build2 (code, type, arg01, arg11);
12195 /* Optimize (X ^ C1) op (Y ^ C2) as (X ^ (C1 ^ C2)) op Y. */
12196 if (TREE_CODE (arg01) == INTEGER_CST
12197 && TREE_CODE (arg11) == INTEGER_CST)
12198 return fold_build2 (code, type,
12199 fold_build2 (BIT_XOR_EXPR, itype, arg00,
12200 fold_build2 (BIT_XOR_EXPR, itype,
12205 /* Attempt to simplify equality/inequality comparisons of complex
12206 values. Only lower the comparison if the result is known or
12207 can be simplified to a single scalar comparison. */
12208 if ((TREE_CODE (arg0) == COMPLEX_EXPR
12209 || TREE_CODE (arg0) == COMPLEX_CST)
12210 && (TREE_CODE (arg1) == COMPLEX_EXPR
12211 || TREE_CODE (arg1) == COMPLEX_CST))
12213 tree real0, imag0, real1, imag1;
12216 if (TREE_CODE (arg0) == COMPLEX_EXPR)
12218 real0 = TREE_OPERAND (arg0, 0);
12219 imag0 = TREE_OPERAND (arg0, 1);
12223 real0 = TREE_REALPART (arg0);
12224 imag0 = TREE_IMAGPART (arg0);
12227 if (TREE_CODE (arg1) == COMPLEX_EXPR)
12229 real1 = TREE_OPERAND (arg1, 0);
12230 imag1 = TREE_OPERAND (arg1, 1);
12234 real1 = TREE_REALPART (arg1);
12235 imag1 = TREE_IMAGPART (arg1);
12238 rcond = fold_binary (code, type, real0, real1);
12239 if (rcond && TREE_CODE (rcond) == INTEGER_CST)
12241 if (integer_zerop (rcond))
12243 if (code == EQ_EXPR)
12244 return omit_two_operands (type, boolean_false_node,
12246 return fold_build2 (NE_EXPR, type, imag0, imag1);
12250 if (code == NE_EXPR)
12251 return omit_two_operands (type, boolean_true_node,
12253 return fold_build2 (EQ_EXPR, type, imag0, imag1);
12257 icond = fold_binary (code, type, imag0, imag1);
12258 if (icond && TREE_CODE (icond) == INTEGER_CST)
12260 if (integer_zerop (icond))
12262 if (code == EQ_EXPR)
12263 return omit_two_operands (type, boolean_false_node,
12265 return fold_build2 (NE_EXPR, type, real0, real1);
12269 if (code == NE_EXPR)
12270 return omit_two_operands (type, boolean_true_node,
12272 return fold_build2 (EQ_EXPR, type, real0, real1);
12283 tem = fold_comparison (code, type, op0, op1);
12284 if (tem != NULL_TREE)
12287 /* Transform comparisons of the form X +- C CMP X. */
12288 if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
12289 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
12290 && ((TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
12291 && !HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0))))
12292 || (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
12293 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))))
12295 tree arg01 = TREE_OPERAND (arg0, 1);
12296 enum tree_code code0 = TREE_CODE (arg0);
12299 if (TREE_CODE (arg01) == REAL_CST)
12300 is_positive = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg01)) ? -1 : 1;
12302 is_positive = tree_int_cst_sgn (arg01);
12304 /* (X - c) > X becomes false. */
12305 if (code == GT_EXPR
12306 && ((code0 == MINUS_EXPR && is_positive >= 0)
12307 || (code0 == PLUS_EXPR && is_positive <= 0)))
12309 if (TREE_CODE (arg01) == INTEGER_CST
12310 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12311 fold_overflow_warning (("assuming signed overflow does not "
12312 "occur when assuming that (X - c) > X "
12313 "is always false"),
12314 WARN_STRICT_OVERFLOW_ALL);
12315 return constant_boolean_node (0, type);
12318 /* Likewise (X + c) < X becomes false. */
12319 if (code == LT_EXPR
12320 && ((code0 == PLUS_EXPR && is_positive >= 0)
12321 || (code0 == MINUS_EXPR && is_positive <= 0)))
12323 if (TREE_CODE (arg01) == INTEGER_CST
12324 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12325 fold_overflow_warning (("assuming signed overflow does not "
12326 "occur when assuming that "
12327 "(X + c) < X is always false"),
12328 WARN_STRICT_OVERFLOW_ALL);
12329 return constant_boolean_node (0, type);
12332 /* Convert (X - c) <= X to true. */
12333 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12335 && ((code0 == MINUS_EXPR && is_positive >= 0)
12336 || (code0 == PLUS_EXPR && is_positive <= 0)))
12338 if (TREE_CODE (arg01) == INTEGER_CST
12339 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12340 fold_overflow_warning (("assuming signed overflow does not "
12341 "occur when assuming that "
12342 "(X - c) <= X is always true"),
12343 WARN_STRICT_OVERFLOW_ALL);
12344 return constant_boolean_node (1, type);
12347 /* Convert (X + c) >= X to true. */
12348 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1)))
12350 && ((code0 == PLUS_EXPR && is_positive >= 0)
12351 || (code0 == MINUS_EXPR && is_positive <= 0)))
12353 if (TREE_CODE (arg01) == INTEGER_CST
12354 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12355 fold_overflow_warning (("assuming signed overflow does not "
12356 "occur when assuming that "
12357 "(X + c) >= X is always true"),
12358 WARN_STRICT_OVERFLOW_ALL);
12359 return constant_boolean_node (1, type);
12362 if (TREE_CODE (arg01) == INTEGER_CST)
12364 /* Convert X + c > X and X - c < X to true for integers. */
12365 if (code == GT_EXPR
12366 && ((code0 == PLUS_EXPR && is_positive > 0)
12367 || (code0 == MINUS_EXPR && is_positive < 0)))
12369 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12370 fold_overflow_warning (("assuming signed overflow does "
12371 "not occur when assuming that "
12372 "(X + c) > X is always true"),
12373 WARN_STRICT_OVERFLOW_ALL);
12374 return constant_boolean_node (1, type);
12377 if (code == LT_EXPR
12378 && ((code0 == MINUS_EXPR && is_positive > 0)
12379 || (code0 == PLUS_EXPR && is_positive < 0)))
12381 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12382 fold_overflow_warning (("assuming signed overflow does "
12383 "not occur when assuming that "
12384 "(X - c) < X is always true"),
12385 WARN_STRICT_OVERFLOW_ALL);
12386 return constant_boolean_node (1, type);
12389 /* Convert X + c <= X and X - c >= X to false for integers. */
12390 if (code == LE_EXPR
12391 && ((code0 == PLUS_EXPR && is_positive > 0)
12392 || (code0 == MINUS_EXPR && is_positive < 0)))
12394 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12395 fold_overflow_warning (("assuming signed overflow does "
12396 "not occur when assuming that "
12397 "(X + c) <= X is always false"),
12398 WARN_STRICT_OVERFLOW_ALL);
12399 return constant_boolean_node (0, type);
12402 if (code == GE_EXPR
12403 && ((code0 == MINUS_EXPR && is_positive > 0)
12404 || (code0 == PLUS_EXPR && is_positive < 0)))
12406 if (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (arg1)))
12407 fold_overflow_warning (("assuming signed overflow does "
12408 "not occur when assuming that "
12409 "(X - c) >= X is always false"),
12410 WARN_STRICT_OVERFLOW_ALL);
12411 return constant_boolean_node (0, type);
12416 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
12417 This transformation affects the cases which are handled in later
12418 optimizations involving comparisons with non-negative constants. */
12419 if (TREE_CODE (arg1) == INTEGER_CST
12420 && TREE_CODE (arg0) != INTEGER_CST
12421 && tree_int_cst_sgn (arg1) > 0)
12423 if (code == GE_EXPR)
12425 arg1 = const_binop (MINUS_EXPR, arg1,
12426 build_int_cst (TREE_TYPE (arg1), 1), 0);
12427 return fold_build2 (GT_EXPR, type, arg0,
12428 fold_convert (TREE_TYPE (arg0), arg1));
12430 if (code == LT_EXPR)
12432 arg1 = const_binop (MINUS_EXPR, arg1,
12433 build_int_cst (TREE_TYPE (arg1), 1), 0);
12434 return fold_build2 (LE_EXPR, type, arg0,
12435 fold_convert (TREE_TYPE (arg0), arg1));
12439 /* Comparisons with the highest or lowest possible integer of
12440 the specified precision will have known values. */
12442 tree arg1_type = TREE_TYPE (arg1);
12443 unsigned int width = TYPE_PRECISION (arg1_type);
12445 if (TREE_CODE (arg1) == INTEGER_CST
12446 && !TREE_OVERFLOW (arg1)
12447 && width <= 2 * HOST_BITS_PER_WIDE_INT
12448 && (INTEGRAL_TYPE_P (arg1_type) || POINTER_TYPE_P (arg1_type)))
12450 HOST_WIDE_INT signed_max_hi;
12451 unsigned HOST_WIDE_INT signed_max_lo;
12452 unsigned HOST_WIDE_INT max_hi, max_lo, min_hi, min_lo;
12454 if (width <= HOST_BITS_PER_WIDE_INT)
12456 signed_max_lo = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12461 if (TYPE_UNSIGNED (arg1_type))
12463 max_lo = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12469 max_lo = signed_max_lo;
12470 min_lo = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12476 width -= HOST_BITS_PER_WIDE_INT;
12477 signed_max_lo = -1;
12478 signed_max_hi = ((unsigned HOST_WIDE_INT) 1 << (width - 1))
12483 if (TYPE_UNSIGNED (arg1_type))
12485 max_hi = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
12490 max_hi = signed_max_hi;
12491 min_hi = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
12495 if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1) == max_hi
12496 && TREE_INT_CST_LOW (arg1) == max_lo)
12500 return omit_one_operand (type, integer_zero_node, arg0);
12503 return fold_build2 (EQ_EXPR, type, op0, op1);
12506 return omit_one_operand (type, integer_one_node, arg0);
12509 return fold_build2 (NE_EXPR, type, op0, op1);
12511 /* The GE_EXPR and LT_EXPR cases above are not normally
12512 reached because of previous transformations. */
12517 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12519 && TREE_INT_CST_LOW (arg1) == max_lo - 1)
12523 arg1 = const_binop (PLUS_EXPR, arg1,
12524 build_int_cst (TREE_TYPE (arg1), 1), 0);
12525 return fold_build2 (EQ_EXPR, type,
12526 fold_convert (TREE_TYPE (arg1), arg0),
12529 arg1 = const_binop (PLUS_EXPR, arg1,
12530 build_int_cst (TREE_TYPE (arg1), 1), 0);
12531 return fold_build2 (NE_EXPR, type,
12532 fold_convert (TREE_TYPE (arg1), arg0),
12537 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12539 && TREE_INT_CST_LOW (arg1) == min_lo)
12543 return omit_one_operand (type, integer_zero_node, arg0);
12546 return fold_build2 (EQ_EXPR, type, op0, op1);
12549 return omit_one_operand (type, integer_one_node, arg0);
12552 return fold_build2 (NE_EXPR, type, op0, op1);
12557 else if ((unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (arg1)
12559 && TREE_INT_CST_LOW (arg1) == min_lo + 1)
12563 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12564 return fold_build2 (NE_EXPR, type,
12565 fold_convert (TREE_TYPE (arg1), arg0),
12568 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
12569 return fold_build2 (EQ_EXPR, type,
12570 fold_convert (TREE_TYPE (arg1), arg0),
12576 else if (TREE_INT_CST_HIGH (arg1) == signed_max_hi
12577 && TREE_INT_CST_LOW (arg1) == signed_max_lo
12578 && TYPE_UNSIGNED (arg1_type)
12579 /* We will flip the signedness of the comparison operator
12580 associated with the mode of arg1, so the sign bit is
12581 specified by this mode. Check that arg1 is the signed
12582 max associated with this sign bit. */
12583 && width == GET_MODE_BITSIZE (TYPE_MODE (arg1_type))
12584 /* signed_type does not work on pointer types. */
12585 && INTEGRAL_TYPE_P (arg1_type))
12587 /* The following case also applies to X < signed_max+1
12588 and X >= signed_max+1 because previous transformations. */
12589 if (code == LE_EXPR || code == GT_EXPR)
12592 st = signed_type_for (TREE_TYPE (arg1));
12593 return fold_build2 (code == LE_EXPR ? GE_EXPR : LT_EXPR,
12594 type, fold_convert (st, arg0),
12595 build_int_cst (st, 0));
12601 /* If we are comparing an ABS_EXPR with a constant, we can
12602 convert all the cases into explicit comparisons, but they may
12603 well not be faster than doing the ABS and one comparison.
12604 But ABS (X) <= C is a range comparison, which becomes a subtraction
12605 and a comparison, and is probably faster. */
12606 if (code == LE_EXPR
12607 && TREE_CODE (arg1) == INTEGER_CST
12608 && TREE_CODE (arg0) == ABS_EXPR
12609 && ! TREE_SIDE_EFFECTS (arg0)
12610 && (0 != (tem = negate_expr (arg1)))
12611 && TREE_CODE (tem) == INTEGER_CST
12612 && !TREE_OVERFLOW (tem))
12613 return fold_build2 (TRUTH_ANDIF_EXPR, type,
12614 build2 (GE_EXPR, type,
12615 TREE_OPERAND (arg0, 0), tem),
12616 build2 (LE_EXPR, type,
12617 TREE_OPERAND (arg0, 0), arg1));
12619 /* Convert ABS_EXPR<x> >= 0 to true. */
12620 strict_overflow_p = false;
12621 if (code == GE_EXPR
12622 && (integer_zerop (arg1)
12623 || (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
12624 && real_zerop (arg1)))
12625 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12627 if (strict_overflow_p)
12628 fold_overflow_warning (("assuming signed overflow does not occur "
12629 "when simplifying comparison of "
12630 "absolute value and zero"),
12631 WARN_STRICT_OVERFLOW_CONDITIONAL);
12632 return omit_one_operand (type, integer_one_node, arg0);
12635 /* Convert ABS_EXPR<x> < 0 to false. */
12636 strict_overflow_p = false;
12637 if (code == LT_EXPR
12638 && (integer_zerop (arg1) || real_zerop (arg1))
12639 && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
12641 if (strict_overflow_p)
12642 fold_overflow_warning (("assuming signed overflow does not occur "
12643 "when simplifying comparison of "
12644 "absolute value and zero"),
12645 WARN_STRICT_OVERFLOW_CONDITIONAL);
12646 return omit_one_operand (type, integer_zero_node, arg0);
12649 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
12650 and similarly for >= into !=. */
12651 if ((code == LT_EXPR || code == GE_EXPR)
12652 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12653 && TREE_CODE (arg1) == LSHIFT_EXPR
12654 && integer_onep (TREE_OPERAND (arg1, 0)))
12655 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12656 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12657 TREE_OPERAND (arg1, 1)),
12658 build_int_cst (TREE_TYPE (arg0), 0));
12660 if ((code == LT_EXPR || code == GE_EXPR)
12661 && TYPE_UNSIGNED (TREE_TYPE (arg0))
12662 && CONVERT_EXPR_P (arg1)
12663 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
12664 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
12666 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
12667 fold_convert (TREE_TYPE (arg0),
12668 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
12669 TREE_OPERAND (TREE_OPERAND (arg1, 0),
12671 build_int_cst (TREE_TYPE (arg0), 0));
12675 case UNORDERED_EXPR:
12683 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
12685 t1 = fold_relational_const (code, type, arg0, arg1);
12686 if (t1 != NULL_TREE)
12690 /* If the first operand is NaN, the result is constant. */
12691 if (TREE_CODE (arg0) == REAL_CST
12692 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
12693 && (code != LTGT_EXPR || ! flag_trapping_math))
12695 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12696 ? integer_zero_node
12697 : integer_one_node;
12698 return omit_one_operand (type, t1, arg1);
12701 /* If the second operand is NaN, the result is constant. */
12702 if (TREE_CODE (arg1) == REAL_CST
12703 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
12704 && (code != LTGT_EXPR || ! flag_trapping_math))
12706 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
12707 ? integer_zero_node
12708 : integer_one_node;
12709 return omit_one_operand (type, t1, arg0);
12712 /* Simplify unordered comparison of something with itself. */
12713 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
12714 && operand_equal_p (arg0, arg1, 0))
12715 return constant_boolean_node (1, type);
12717 if (code == LTGT_EXPR
12718 && !flag_trapping_math
12719 && operand_equal_p (arg0, arg1, 0))
12720 return constant_boolean_node (0, type);
12722 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
12724 tree targ0 = strip_float_extensions (arg0);
12725 tree targ1 = strip_float_extensions (arg1);
12726 tree newtype = TREE_TYPE (targ0);
12728 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
12729 newtype = TREE_TYPE (targ1);
12731 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
12732 return fold_build2 (code, type, fold_convert (newtype, targ0),
12733 fold_convert (newtype, targ1));
12738 case COMPOUND_EXPR:
12739 /* When pedantic, a compound expression can be neither an lvalue
12740 nor an integer constant expression. */
12741 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
12743 /* Don't let (0, 0) be null pointer constant. */
12744 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
12745 : fold_convert (type, arg1);
12746 return pedantic_non_lvalue (tem);
12749 if ((TREE_CODE (arg0) == REAL_CST
12750 && TREE_CODE (arg1) == REAL_CST)
12751 || (TREE_CODE (arg0) == INTEGER_CST
12752 && TREE_CODE (arg1) == INTEGER_CST))
12753 return build_complex (type, arg0, arg1);
12757 /* An ASSERT_EXPR should never be passed to fold_binary. */
12758 gcc_unreachable ();
12762 } /* switch (code) */
12765 /* Callback for walk_tree, looking for LABEL_EXPR.
12766 Returns tree TP if it is LABEL_EXPR. Otherwise it returns NULL_TREE.
12767 Do not check the sub-tree of GOTO_EXPR. */
12770 contains_label_1 (tree *tp,
12771 int *walk_subtrees,
12772 void *data ATTRIBUTE_UNUSED)
12774 switch (TREE_CODE (*tp))
12779 *walk_subtrees = 0;
12786 /* Checks whether the sub-tree ST contains a label LABEL_EXPR which is
12787 accessible from outside the sub-tree. Returns NULL_TREE if no
12788 addressable label is found. */
12791 contains_label_p (tree st)
12793 return (walk_tree (&st, contains_label_1 , NULL, NULL) != NULL_TREE);
12796 /* Fold a ternary expression of code CODE and type TYPE with operands
12797 OP0, OP1, and OP2. Return the folded expression if folding is
12798 successful. Otherwise, return NULL_TREE. */
12801 fold_ternary (enum tree_code code, tree type, tree op0, tree op1, tree op2)
12804 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
12805 enum tree_code_class kind = TREE_CODE_CLASS (code);
12807 gcc_assert (IS_EXPR_CODE_CLASS (kind)
12808 && TREE_CODE_LENGTH (code) == 3);
12810 /* Strip any conversions that don't change the mode. This is safe
12811 for every expression, except for a comparison expression because
12812 its signedness is derived from its operands. So, in the latter
12813 case, only strip conversions that don't change the signedness.
12815 Note that this is done as an internal manipulation within the
12816 constant folder, in order to find the simplest representation of
12817 the arguments so that their form can be studied. In any cases,
12818 the appropriate type conversions should be put back in the tree
12819 that will get out of the constant folder. */
12834 case COMPONENT_REF:
12835 if (TREE_CODE (arg0) == CONSTRUCTOR
12836 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
12838 unsigned HOST_WIDE_INT idx;
12840 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg0), idx, field, value)
12847 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
12848 so all simple results must be passed through pedantic_non_lvalue. */
12849 if (TREE_CODE (arg0) == INTEGER_CST)
12851 tree unused_op = integer_zerop (arg0) ? op1 : op2;
12852 tem = integer_zerop (arg0) ? op2 : op1;
12853 /* Only optimize constant conditions when the selected branch
12854 has the same type as the COND_EXPR. This avoids optimizing
12855 away "c ? x : throw", where the throw has a void type.
12856 Avoid throwing away that operand which contains label. */
12857 if ((!TREE_SIDE_EFFECTS (unused_op)
12858 || !contains_label_p (unused_op))
12859 && (! VOID_TYPE_P (TREE_TYPE (tem))
12860 || VOID_TYPE_P (type)))
12861 return pedantic_non_lvalue (tem);
12864 if (operand_equal_p (arg1, op2, 0))
12865 return pedantic_omit_one_operand (type, arg1, arg0);
12867 /* If we have A op B ? A : C, we may be able to convert this to a
12868 simpler expression, depending on the operation and the values
12869 of B and C. Signed zeros prevent all of these transformations,
12870 for reasons given above each one.
12872 Also try swapping the arguments and inverting the conditional. */
12873 if (COMPARISON_CLASS_P (arg0)
12874 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12875 arg1, TREE_OPERAND (arg0, 1))
12876 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
12878 tem = fold_cond_expr_with_comparison (type, arg0, op1, op2);
12883 if (COMPARISON_CLASS_P (arg0)
12884 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
12886 TREE_OPERAND (arg0, 1))
12887 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op2))))
12889 tem = fold_truth_not_expr (arg0);
12890 if (tem && COMPARISON_CLASS_P (tem))
12892 tem = fold_cond_expr_with_comparison (type, tem, op2, op1);
12898 /* If the second operand is simpler than the third, swap them
12899 since that produces better jump optimization results. */
12900 if (truth_value_p (TREE_CODE (arg0))
12901 && tree_swap_operands_p (op1, op2, false))
12903 /* See if this can be inverted. If it can't, possibly because
12904 it was a floating-point inequality comparison, don't do
12906 tem = fold_truth_not_expr (arg0);
12908 return fold_build3 (code, type, tem, op2, op1);
12911 /* Convert A ? 1 : 0 to simply A. */
12912 if (integer_onep (op1)
12913 && integer_zerop (op2)
12914 /* If we try to convert OP0 to our type, the
12915 call to fold will try to move the conversion inside
12916 a COND, which will recurse. In that case, the COND_EXPR
12917 is probably the best choice, so leave it alone. */
12918 && type == TREE_TYPE (arg0))
12919 return pedantic_non_lvalue (arg0);
12921 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
12922 over COND_EXPR in cases such as floating point comparisons. */
12923 if (integer_zerop (op1)
12924 && integer_onep (op2)
12925 && truth_value_p (TREE_CODE (arg0)))
12926 return pedantic_non_lvalue (fold_convert (type,
12927 invert_truthvalue (arg0)));
12929 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
12930 if (TREE_CODE (arg0) == LT_EXPR
12931 && integer_zerop (TREE_OPERAND (arg0, 1))
12932 && integer_zerop (op2)
12933 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
12935 /* sign_bit_p only checks ARG1 bits within A's precision.
12936 If <sign bit of A> has wider type than A, bits outside
12937 of A's precision in <sign bit of A> need to be checked.
12938 If they are all 0, this optimization needs to be done
12939 in unsigned A's type, if they are all 1 in signed A's type,
12940 otherwise this can't be done. */
12941 if (TYPE_PRECISION (TREE_TYPE (tem))
12942 < TYPE_PRECISION (TREE_TYPE (arg1))
12943 && TYPE_PRECISION (TREE_TYPE (tem))
12944 < TYPE_PRECISION (type))
12946 unsigned HOST_WIDE_INT mask_lo;
12947 HOST_WIDE_INT mask_hi;
12948 int inner_width, outer_width;
12951 inner_width = TYPE_PRECISION (TREE_TYPE (tem));
12952 outer_width = TYPE_PRECISION (TREE_TYPE (arg1));
12953 if (outer_width > TYPE_PRECISION (type))
12954 outer_width = TYPE_PRECISION (type);
12956 if (outer_width > HOST_BITS_PER_WIDE_INT)
12958 mask_hi = ((unsigned HOST_WIDE_INT) -1
12959 >> (2 * HOST_BITS_PER_WIDE_INT - outer_width));
12965 mask_lo = ((unsigned HOST_WIDE_INT) -1
12966 >> (HOST_BITS_PER_WIDE_INT - outer_width));
12968 if (inner_width > HOST_BITS_PER_WIDE_INT)
12970 mask_hi &= ~((unsigned HOST_WIDE_INT) -1
12971 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12975 mask_lo &= ~((unsigned HOST_WIDE_INT) -1
12976 >> (HOST_BITS_PER_WIDE_INT - inner_width));
12978 if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == mask_hi
12979 && (TREE_INT_CST_LOW (arg1) & mask_lo) == mask_lo)
12981 tem_type = signed_type_for (TREE_TYPE (tem));
12982 tem = fold_convert (tem_type, tem);
12984 else if ((TREE_INT_CST_HIGH (arg1) & mask_hi) == 0
12985 && (TREE_INT_CST_LOW (arg1) & mask_lo) == 0)
12987 tem_type = unsigned_type_for (TREE_TYPE (tem));
12988 tem = fold_convert (tem_type, tem);
12995 return fold_convert (type,
12996 fold_build2 (BIT_AND_EXPR,
12997 TREE_TYPE (tem), tem,
12998 fold_convert (TREE_TYPE (tem),
13002 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
13003 already handled above. */
13004 if (TREE_CODE (arg0) == BIT_AND_EXPR
13005 && integer_onep (TREE_OPERAND (arg0, 1))
13006 && integer_zerop (op2)
13007 && integer_pow2p (arg1))
13009 tree tem = TREE_OPERAND (arg0, 0);
13011 if (TREE_CODE (tem) == RSHIFT_EXPR
13012 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
13013 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
13014 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
13015 return fold_build2 (BIT_AND_EXPR, type,
13016 TREE_OPERAND (tem, 0), arg1);
13019 /* A & N ? N : 0 is simply A & N if N is a power of two. This
13020 is probably obsolete because the first operand should be a
13021 truth value (that's why we have the two cases above), but let's
13022 leave it in until we can confirm this for all front-ends. */
13023 if (integer_zerop (op2)
13024 && TREE_CODE (arg0) == NE_EXPR
13025 && integer_zerop (TREE_OPERAND (arg0, 1))
13026 && integer_pow2p (arg1)
13027 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
13028 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
13029 arg1, OEP_ONLY_CONST))
13030 return pedantic_non_lvalue (fold_convert (type,
13031 TREE_OPERAND (arg0, 0)));
13033 /* Convert A ? B : 0 into A && B if A and B are truth values. */
13034 if (integer_zerop (op2)
13035 && truth_value_p (TREE_CODE (arg0))
13036 && truth_value_p (TREE_CODE (arg1)))
13037 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13038 fold_convert (type, arg0),
13041 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
13042 if (integer_onep (op2)
13043 && truth_value_p (TREE_CODE (arg0))
13044 && truth_value_p (TREE_CODE (arg1)))
13046 /* Only perform transformation if ARG0 is easily inverted. */
13047 tem = fold_truth_not_expr (arg0);
13049 return fold_build2 (TRUTH_ORIF_EXPR, type,
13050 fold_convert (type, tem),
13054 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
13055 if (integer_zerop (arg1)
13056 && truth_value_p (TREE_CODE (arg0))
13057 && truth_value_p (TREE_CODE (op2)))
13059 /* Only perform transformation if ARG0 is easily inverted. */
13060 tem = fold_truth_not_expr (arg0);
13062 return fold_build2 (TRUTH_ANDIF_EXPR, type,
13063 fold_convert (type, tem),
13067 /* Convert A ? 1 : B into A || B if A and B are truth values. */
13068 if (integer_onep (arg1)
13069 && truth_value_p (TREE_CODE (arg0))
13070 && truth_value_p (TREE_CODE (op2)))
13071 return fold_build2 (TRUTH_ORIF_EXPR, type,
13072 fold_convert (type, arg0),
13078 /* CALL_EXPRs used to be ternary exprs. Catch any mistaken uses
13079 of fold_ternary on them. */
13080 gcc_unreachable ();
13082 case BIT_FIELD_REF:
13083 if ((TREE_CODE (arg0) == VECTOR_CST
13084 || (TREE_CODE (arg0) == CONSTRUCTOR && TREE_CONSTANT (arg0)))
13085 && type == TREE_TYPE (TREE_TYPE (arg0)))
13087 unsigned HOST_WIDE_INT width = tree_low_cst (arg1, 1);
13088 unsigned HOST_WIDE_INT idx = tree_low_cst (op2, 1);
13091 && simple_cst_equal (arg1, TYPE_SIZE (type)) == 1
13092 && (idx % width) == 0
13093 && (idx = idx / width)
13094 < TYPE_VECTOR_SUBPARTS (TREE_TYPE (arg0)))
13096 tree elements = NULL_TREE;
13098 if (TREE_CODE (arg0) == VECTOR_CST)
13099 elements = TREE_VECTOR_CST_ELTS (arg0);
13102 unsigned HOST_WIDE_INT idx;
13105 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg0), idx, value)
13106 elements = tree_cons (NULL_TREE, value, elements);
13108 while (idx-- > 0 && elements)
13109 elements = TREE_CHAIN (elements);
13111 return TREE_VALUE (elements);
13113 return fold_convert (type, integer_zero_node);
13117 /* A bit-field-ref that referenced the full argument can be stripped. */
13118 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
13119 && TYPE_PRECISION (TREE_TYPE (arg0)) == tree_low_cst (arg1, 1)
13120 && integer_zerop (op2))
13121 return fold_convert (type, arg0);
13127 } /* switch (code) */
13130 /* Perform constant folding and related simplification of EXPR.
13131 The related simplifications include x*1 => x, x*0 => 0, etc.,
13132 and application of the associative law.
13133 NOP_EXPR conversions may be removed freely (as long as we
13134 are careful not to change the type of the overall expression).
13135 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
13136 but we can constant-fold them if they have constant operands. */
13138 #ifdef ENABLE_FOLD_CHECKING
13139 # define fold(x) fold_1 (x)
13140 static tree fold_1 (tree);
13146 const tree t = expr;
13147 enum tree_code code = TREE_CODE (t);
13148 enum tree_code_class kind = TREE_CODE_CLASS (code);
13151 /* Return right away if a constant. */
13152 if (kind == tcc_constant)
13155 /* CALL_EXPR-like objects with variable numbers of operands are
13156 treated specially. */
13157 if (kind == tcc_vl_exp)
13159 if (code == CALL_EXPR)
13161 tem = fold_call_expr (expr, false);
13162 return tem ? tem : expr;
13167 if (IS_EXPR_CODE_CLASS (kind))
13169 tree type = TREE_TYPE (t);
13170 tree op0, op1, op2;
13172 switch (TREE_CODE_LENGTH (code))
13175 op0 = TREE_OPERAND (t, 0);
13176 tem = fold_unary (code, type, op0);
13177 return tem ? tem : expr;
13179 op0 = TREE_OPERAND (t, 0);
13180 op1 = TREE_OPERAND (t, 1);
13181 tem = fold_binary (code, type, op0, op1);
13182 return tem ? tem : expr;
13184 op0 = TREE_OPERAND (t, 0);
13185 op1 = TREE_OPERAND (t, 1);
13186 op2 = TREE_OPERAND (t, 2);
13187 tem = fold_ternary (code, type, op0, op1, op2);
13188 return tem ? tem : expr;
13198 tree op0 = TREE_OPERAND (t, 0);
13199 tree op1 = TREE_OPERAND (t, 1);
13201 if (TREE_CODE (op1) == INTEGER_CST
13202 && TREE_CODE (op0) == CONSTRUCTOR
13203 && ! type_contains_placeholder_p (TREE_TYPE (op0)))
13205 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (op0);
13206 unsigned HOST_WIDE_INT end = VEC_length (constructor_elt, elts);
13207 unsigned HOST_WIDE_INT begin = 0;
13209 /* Find a matching index by means of a binary search. */
13210 while (begin != end)
13212 unsigned HOST_WIDE_INT middle = (begin + end) / 2;
13213 tree index = VEC_index (constructor_elt, elts, middle)->index;
13215 if (TREE_CODE (index) == INTEGER_CST
13216 && tree_int_cst_lt (index, op1))
13217 begin = middle + 1;
13218 else if (TREE_CODE (index) == INTEGER_CST
13219 && tree_int_cst_lt (op1, index))
13221 else if (TREE_CODE (index) == RANGE_EXPR
13222 && tree_int_cst_lt (TREE_OPERAND (index, 1), op1))
13223 begin = middle + 1;
13224 else if (TREE_CODE (index) == RANGE_EXPR
13225 && tree_int_cst_lt (op1, TREE_OPERAND (index, 0)))
13228 return VEC_index (constructor_elt, elts, middle)->value;
13236 return fold (DECL_INITIAL (t));
13240 } /* switch (code) */
13243 #ifdef ENABLE_FOLD_CHECKING
13246 static void fold_checksum_tree (const_tree, struct md5_ctx *, htab_t);
13247 static void fold_check_failed (const_tree, const_tree);
13248 void print_fold_checksum (const_tree);
13250 /* When --enable-checking=fold, compute a digest of expr before
13251 and after actual fold call to see if fold did not accidentally
13252 change original expr. */
13258 struct md5_ctx ctx;
13259 unsigned char checksum_before[16], checksum_after[16];
13262 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13263 md5_init_ctx (&ctx);
13264 fold_checksum_tree (expr, &ctx, ht);
13265 md5_finish_ctx (&ctx, checksum_before);
13268 ret = fold_1 (expr);
13270 md5_init_ctx (&ctx);
13271 fold_checksum_tree (expr, &ctx, ht);
13272 md5_finish_ctx (&ctx, checksum_after);
13275 if (memcmp (checksum_before, checksum_after, 16))
13276 fold_check_failed (expr, ret);
13282 print_fold_checksum (const_tree expr)
13284 struct md5_ctx ctx;
13285 unsigned char checksum[16], cnt;
13288 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13289 md5_init_ctx (&ctx);
13290 fold_checksum_tree (expr, &ctx, ht);
13291 md5_finish_ctx (&ctx, checksum);
13293 for (cnt = 0; cnt < 16; ++cnt)
13294 fprintf (stderr, "%02x", checksum[cnt]);
13295 putc ('\n', stderr);
13299 fold_check_failed (const_tree expr ATTRIBUTE_UNUSED, const_tree ret ATTRIBUTE_UNUSED)
13301 internal_error ("fold check: original tree changed by fold");
13305 fold_checksum_tree (const_tree expr, struct md5_ctx *ctx, htab_t ht)
13308 enum tree_code code;
13309 struct tree_function_decl buf;
13314 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
13315 <= sizeof (struct tree_function_decl))
13316 && sizeof (struct tree_type) <= sizeof (struct tree_function_decl));
13319 slot = (const void **) htab_find_slot (ht, expr, INSERT);
13323 code = TREE_CODE (expr);
13324 if (TREE_CODE_CLASS (code) == tcc_declaration
13325 && DECL_ASSEMBLER_NAME_SET_P (expr))
13327 /* Allow DECL_ASSEMBLER_NAME to be modified. */
13328 memcpy ((char *) &buf, expr, tree_size (expr));
13329 SET_DECL_ASSEMBLER_NAME ((tree)&buf, NULL);
13330 expr = (tree) &buf;
13332 else if (TREE_CODE_CLASS (code) == tcc_type
13333 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)
13334 || TYPE_CACHED_VALUES_P (expr)
13335 || TYPE_CONTAINS_PLACEHOLDER_INTERNAL (expr)))
13337 /* Allow these fields to be modified. */
13339 memcpy ((char *) &buf, expr, tree_size (expr));
13340 expr = tmp = (tree) &buf;
13341 TYPE_CONTAINS_PLACEHOLDER_INTERNAL (tmp) = 0;
13342 TYPE_POINTER_TO (tmp) = NULL;
13343 TYPE_REFERENCE_TO (tmp) = NULL;
13344 if (TYPE_CACHED_VALUES_P (tmp))
13346 TYPE_CACHED_VALUES_P (tmp) = 0;
13347 TYPE_CACHED_VALUES (tmp) = NULL;
13350 md5_process_bytes (expr, tree_size (expr), ctx);
13351 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
13352 if (TREE_CODE_CLASS (code) != tcc_type
13353 && TREE_CODE_CLASS (code) != tcc_declaration
13354 && code != TREE_LIST
13355 && code != SSA_NAME)
13356 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
13357 switch (TREE_CODE_CLASS (code))
13363 md5_process_bytes (TREE_STRING_POINTER (expr),
13364 TREE_STRING_LENGTH (expr), ctx);
13367 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
13368 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
13371 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
13377 case tcc_exceptional:
13381 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
13382 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
13383 expr = TREE_CHAIN (expr);
13384 goto recursive_label;
13387 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
13388 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
13394 case tcc_expression:
13395 case tcc_reference:
13396 case tcc_comparison:
13399 case tcc_statement:
13401 len = TREE_OPERAND_LENGTH (expr);
13402 for (i = 0; i < len; ++i)
13403 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
13405 case tcc_declaration:
13406 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
13407 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
13408 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_COMMON))
13410 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
13411 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
13412 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
13413 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
13414 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
13416 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_WITH_VIS))
13417 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
13419 if (CODE_CONTAINS_STRUCT (TREE_CODE (expr), TS_DECL_NON_COMMON))
13421 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
13422 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
13423 fold_checksum_tree (DECL_ARGUMENT_FLD (expr), ctx, ht);
13427 if (TREE_CODE (expr) == ENUMERAL_TYPE)
13428 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
13429 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
13430 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
13431 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
13432 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
13433 if (INTEGRAL_TYPE_P (expr)
13434 || SCALAR_FLOAT_TYPE_P (expr))
13436 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
13437 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
13439 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
13440 if (TREE_CODE (expr) == RECORD_TYPE
13441 || TREE_CODE (expr) == UNION_TYPE
13442 || TREE_CODE (expr) == QUAL_UNION_TYPE)
13443 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
13444 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
13451 /* Helper function for outputting the checksum of a tree T. When
13452 debugging with gdb, you can "define mynext" to be "next" followed
13453 by "call debug_fold_checksum (op0)", then just trace down till the
13457 debug_fold_checksum (const_tree t)
13460 unsigned char checksum[16];
13461 struct md5_ctx ctx;
13462 htab_t ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13464 md5_init_ctx (&ctx);
13465 fold_checksum_tree (t, &ctx, ht);
13466 md5_finish_ctx (&ctx, checksum);
13469 for (i = 0; i < 16; i++)
13470 fprintf (stderr, "%d ", checksum[i]);
13472 fprintf (stderr, "\n");
13477 /* Fold a unary tree expression with code CODE of type TYPE with an
13478 operand OP0. Return a folded expression if successful. Otherwise,
13479 return a tree expression with code CODE of type TYPE with an
13483 fold_build1_stat (enum tree_code code, tree type, tree op0 MEM_STAT_DECL)
13486 #ifdef ENABLE_FOLD_CHECKING
13487 unsigned char checksum_before[16], checksum_after[16];
13488 struct md5_ctx ctx;
13491 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13492 md5_init_ctx (&ctx);
13493 fold_checksum_tree (op0, &ctx, ht);
13494 md5_finish_ctx (&ctx, checksum_before);
13498 tem = fold_unary (code, type, op0);
13500 tem = build1_stat (code, type, op0 PASS_MEM_STAT);
13502 #ifdef ENABLE_FOLD_CHECKING
13503 md5_init_ctx (&ctx);
13504 fold_checksum_tree (op0, &ctx, ht);
13505 md5_finish_ctx (&ctx, checksum_after);
13508 if (memcmp (checksum_before, checksum_after, 16))
13509 fold_check_failed (op0, tem);
13514 /* Fold a binary tree expression with code CODE of type TYPE with
13515 operands OP0 and OP1. Return a folded expression if successful.
13516 Otherwise, return a tree expression with code CODE of type TYPE
13517 with operands OP0 and OP1. */
13520 fold_build2_stat (enum tree_code code, tree type, tree op0, tree op1
13524 #ifdef ENABLE_FOLD_CHECKING
13525 unsigned char checksum_before_op0[16],
13526 checksum_before_op1[16],
13527 checksum_after_op0[16],
13528 checksum_after_op1[16];
13529 struct md5_ctx ctx;
13532 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13533 md5_init_ctx (&ctx);
13534 fold_checksum_tree (op0, &ctx, ht);
13535 md5_finish_ctx (&ctx, checksum_before_op0);
13538 md5_init_ctx (&ctx);
13539 fold_checksum_tree (op1, &ctx, ht);
13540 md5_finish_ctx (&ctx, checksum_before_op1);
13544 tem = fold_binary (code, type, op0, op1);
13546 tem = build2_stat (code, type, op0, op1 PASS_MEM_STAT);
13548 #ifdef ENABLE_FOLD_CHECKING
13549 md5_init_ctx (&ctx);
13550 fold_checksum_tree (op0, &ctx, ht);
13551 md5_finish_ctx (&ctx, checksum_after_op0);
13554 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13555 fold_check_failed (op0, tem);
13557 md5_init_ctx (&ctx);
13558 fold_checksum_tree (op1, &ctx, ht);
13559 md5_finish_ctx (&ctx, checksum_after_op1);
13562 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13563 fold_check_failed (op1, tem);
13568 /* Fold a ternary tree expression with code CODE of type TYPE with
13569 operands OP0, OP1, and OP2. Return a folded expression if
13570 successful. Otherwise, return a tree expression with code CODE of
13571 type TYPE with operands OP0, OP1, and OP2. */
13574 fold_build3_stat (enum tree_code code, tree type, tree op0, tree op1, tree op2
13578 #ifdef ENABLE_FOLD_CHECKING
13579 unsigned char checksum_before_op0[16],
13580 checksum_before_op1[16],
13581 checksum_before_op2[16],
13582 checksum_after_op0[16],
13583 checksum_after_op1[16],
13584 checksum_after_op2[16];
13585 struct md5_ctx ctx;
13588 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13589 md5_init_ctx (&ctx);
13590 fold_checksum_tree (op0, &ctx, ht);
13591 md5_finish_ctx (&ctx, checksum_before_op0);
13594 md5_init_ctx (&ctx);
13595 fold_checksum_tree (op1, &ctx, ht);
13596 md5_finish_ctx (&ctx, checksum_before_op1);
13599 md5_init_ctx (&ctx);
13600 fold_checksum_tree (op2, &ctx, ht);
13601 md5_finish_ctx (&ctx, checksum_before_op2);
13605 gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
13606 tem = fold_ternary (code, type, op0, op1, op2);
13608 tem = build3_stat (code, type, op0, op1, op2 PASS_MEM_STAT);
13610 #ifdef ENABLE_FOLD_CHECKING
13611 md5_init_ctx (&ctx);
13612 fold_checksum_tree (op0, &ctx, ht);
13613 md5_finish_ctx (&ctx, checksum_after_op0);
13616 if (memcmp (checksum_before_op0, checksum_after_op0, 16))
13617 fold_check_failed (op0, tem);
13619 md5_init_ctx (&ctx);
13620 fold_checksum_tree (op1, &ctx, ht);
13621 md5_finish_ctx (&ctx, checksum_after_op1);
13624 if (memcmp (checksum_before_op1, checksum_after_op1, 16))
13625 fold_check_failed (op1, tem);
13627 md5_init_ctx (&ctx);
13628 fold_checksum_tree (op2, &ctx, ht);
13629 md5_finish_ctx (&ctx, checksum_after_op2);
13632 if (memcmp (checksum_before_op2, checksum_after_op2, 16))
13633 fold_check_failed (op2, tem);
13638 /* Fold a CALL_EXPR expression of type TYPE with operands FN and NARGS
13639 arguments in ARGARRAY, and a null static chain.
13640 Return a folded expression if successful. Otherwise, return a CALL_EXPR
13641 of type TYPE from the given operands as constructed by build_call_array. */
13644 fold_build_call_array (tree type, tree fn, int nargs, tree *argarray)
13647 #ifdef ENABLE_FOLD_CHECKING
13648 unsigned char checksum_before_fn[16],
13649 checksum_before_arglist[16],
13650 checksum_after_fn[16],
13651 checksum_after_arglist[16];
13652 struct md5_ctx ctx;
13656 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
13657 md5_init_ctx (&ctx);
13658 fold_checksum_tree (fn, &ctx, ht);
13659 md5_finish_ctx (&ctx, checksum_before_fn);
13662 md5_init_ctx (&ctx);
13663 for (i = 0; i < nargs; i++)
13664 fold_checksum_tree (argarray[i], &ctx, ht);
13665 md5_finish_ctx (&ctx, checksum_before_arglist);
13669 tem = fold_builtin_call_array (type, fn, nargs, argarray);
13671 #ifdef ENABLE_FOLD_CHECKING
13672 md5_init_ctx (&ctx);
13673 fold_checksum_tree (fn, &ctx, ht);
13674 md5_finish_ctx (&ctx, checksum_after_fn);
13677 if (memcmp (checksum_before_fn, checksum_after_fn, 16))
13678 fold_check_failed (fn, tem);
13680 md5_init_ctx (&ctx);
13681 for (i = 0; i < nargs; i++)
13682 fold_checksum_tree (argarray[i], &ctx, ht);
13683 md5_finish_ctx (&ctx, checksum_after_arglist);
13686 if (memcmp (checksum_before_arglist, checksum_after_arglist, 16))
13687 fold_check_failed (NULL_TREE, tem);
13692 /* Perform constant folding and related simplification of initializer
13693 expression EXPR. These behave identically to "fold_buildN" but ignore
13694 potential run-time traps and exceptions that fold must preserve. */
13696 #define START_FOLD_INIT \
13697 int saved_signaling_nans = flag_signaling_nans;\
13698 int saved_trapping_math = flag_trapping_math;\
13699 int saved_rounding_math = flag_rounding_math;\
13700 int saved_trapv = flag_trapv;\
13701 int saved_folding_initializer = folding_initializer;\
13702 flag_signaling_nans = 0;\
13703 flag_trapping_math = 0;\
13704 flag_rounding_math = 0;\
13706 folding_initializer = 1;
13708 #define END_FOLD_INIT \
13709 flag_signaling_nans = saved_signaling_nans;\
13710 flag_trapping_math = saved_trapping_math;\
13711 flag_rounding_math = saved_rounding_math;\
13712 flag_trapv = saved_trapv;\
13713 folding_initializer = saved_folding_initializer;
13716 fold_build1_initializer (enum tree_code code, tree type, tree op)
13721 result = fold_build1 (code, type, op);
13728 fold_build2_initializer (enum tree_code code, tree type, tree op0, tree op1)
13733 result = fold_build2 (code, type, op0, op1);
13740 fold_build3_initializer (enum tree_code code, tree type, tree op0, tree op1,
13746 result = fold_build3 (code, type, op0, op1, op2);
13753 fold_build_call_array_initializer (tree type, tree fn,
13754 int nargs, tree *argarray)
13759 result = fold_build_call_array (type, fn, nargs, argarray);
13765 #undef START_FOLD_INIT
13766 #undef END_FOLD_INIT
13768 /* Determine if first argument is a multiple of second argument. Return 0 if
13769 it is not, or we cannot easily determined it to be.
13771 An example of the sort of thing we care about (at this point; this routine
13772 could surely be made more general, and expanded to do what the *_DIV_EXPR's
13773 fold cases do now) is discovering that
13775 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13781 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
13783 This code also handles discovering that
13785 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
13787 is a multiple of 8 so we don't have to worry about dealing with a
13788 possible remainder.
13790 Note that we *look* inside a SAVE_EXPR only to determine how it was
13791 calculated; it is not safe for fold to do much of anything else with the
13792 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
13793 at run time. For example, the latter example above *cannot* be implemented
13794 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
13795 evaluation time of the original SAVE_EXPR is not necessarily the same at
13796 the time the new expression is evaluated. The only optimization of this
13797 sort that would be valid is changing
13799 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
13803 SAVE_EXPR (I) * SAVE_EXPR (J)
13805 (where the same SAVE_EXPR (J) is used in the original and the
13806 transformed version). */
13809 multiple_of_p (tree type, const_tree top, const_tree bottom)
13811 if (operand_equal_p (top, bottom, 0))
13814 if (TREE_CODE (type) != INTEGER_TYPE)
13817 switch (TREE_CODE (top))
13820 /* Bitwise and provides a power of two multiple. If the mask is
13821 a multiple of BOTTOM then TOP is a multiple of BOTTOM. */
13822 if (!integer_pow2p (bottom))
13827 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13828 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13832 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
13833 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
13836 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
13840 op1 = TREE_OPERAND (top, 1);
13841 /* const_binop may not detect overflow correctly,
13842 so check for it explicitly here. */
13843 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
13844 > TREE_INT_CST_LOW (op1)
13845 && TREE_INT_CST_HIGH (op1) == 0
13846 && 0 != (t1 = fold_convert (type,
13847 const_binop (LSHIFT_EXPR,
13850 && !TREE_OVERFLOW (t1))
13851 return multiple_of_p (type, t1, bottom);
13856 /* Can't handle conversions from non-integral or wider integral type. */
13857 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
13858 || (TYPE_PRECISION (type)
13859 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
13862 /* .. fall through ... */
13865 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
13868 if (TREE_CODE (bottom) != INTEGER_CST
13869 || integer_zerop (bottom)
13870 || (TYPE_UNSIGNED (type)
13871 && (tree_int_cst_sgn (top) < 0
13872 || tree_int_cst_sgn (bottom) < 0)))
13874 return integer_zerop (int_const_binop (TRUNC_MOD_EXPR,
13882 /* Return true if CODE or TYPE is known to be non-negative. */
13885 tree_simple_nonnegative_warnv_p (enum tree_code code, tree type)
13887 if ((TYPE_PRECISION (type) != 1 || TYPE_UNSIGNED (type))
13888 && truth_value_p (code))
13889 /* Truth values evaluate to 0 or 1, which is nonnegative unless we
13890 have a signed:1 type (where the value is -1 and 0). */
13895 /* Return true if (CODE OP0) is known to be non-negative. If the return
13896 value is based on the assumption that signed overflow is undefined,
13897 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13898 *STRICT_OVERFLOW_P. */
13901 tree_unary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
13902 bool *strict_overflow_p)
13904 if (TYPE_UNSIGNED (type))
13910 /* We can't return 1 if flag_wrapv is set because
13911 ABS_EXPR<INT_MIN> = INT_MIN. */
13912 if (!INTEGRAL_TYPE_P (type))
13914 if (TYPE_OVERFLOW_UNDEFINED (type))
13916 *strict_overflow_p = true;
13921 case NON_LVALUE_EXPR:
13923 case FIX_TRUNC_EXPR:
13924 return tree_expr_nonnegative_warnv_p (op0,
13925 strict_overflow_p);
13929 tree inner_type = TREE_TYPE (op0);
13930 tree outer_type = type;
13932 if (TREE_CODE (outer_type) == REAL_TYPE)
13934 if (TREE_CODE (inner_type) == REAL_TYPE)
13935 return tree_expr_nonnegative_warnv_p (op0,
13936 strict_overflow_p);
13937 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13939 if (TYPE_UNSIGNED (inner_type))
13941 return tree_expr_nonnegative_warnv_p (op0,
13942 strict_overflow_p);
13945 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
13947 if (TREE_CODE (inner_type) == REAL_TYPE)
13948 return tree_expr_nonnegative_warnv_p (op0,
13949 strict_overflow_p);
13950 if (TREE_CODE (inner_type) == INTEGER_TYPE)
13951 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
13952 && TYPE_UNSIGNED (inner_type);
13958 return tree_simple_nonnegative_warnv_p (code, type);
13961 /* We don't know sign of `t', so be conservative and return false. */
13965 /* Return true if (CODE OP0 OP1) is known to be non-negative. If the return
13966 value is based on the assumption that signed overflow is undefined,
13967 set *STRICT_OVERFLOW_P to true; otherwise, don't change
13968 *STRICT_OVERFLOW_P. */
13971 tree_binary_nonnegative_warnv_p (enum tree_code code, tree type, tree op0,
13972 tree op1, bool *strict_overflow_p)
13974 if (TYPE_UNSIGNED (type))
13979 case POINTER_PLUS_EXPR:
13981 if (FLOAT_TYPE_P (type))
13982 return (tree_expr_nonnegative_warnv_p (op0,
13984 && tree_expr_nonnegative_warnv_p (op1,
13985 strict_overflow_p));
13987 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
13988 both unsigned and at least 2 bits shorter than the result. */
13989 if (TREE_CODE (type) == INTEGER_TYPE
13990 && TREE_CODE (op0) == NOP_EXPR
13991 && TREE_CODE (op1) == NOP_EXPR)
13993 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
13994 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
13995 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
13996 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
13998 unsigned int prec = MAX (TYPE_PRECISION (inner1),
13999 TYPE_PRECISION (inner2)) + 1;
14000 return prec < TYPE_PRECISION (type);
14006 if (FLOAT_TYPE_P (type))
14008 /* x * x for floating point x is always non-negative. */
14009 if (operand_equal_p (op0, op1, 0))
14011 return (tree_expr_nonnegative_warnv_p (op0,
14013 && tree_expr_nonnegative_warnv_p (op1,
14014 strict_overflow_p));
14017 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
14018 both unsigned and their total bits is shorter than the result. */
14019 if (TREE_CODE (type) == INTEGER_TYPE
14020 && TREE_CODE (op0) == NOP_EXPR
14021 && TREE_CODE (op1) == NOP_EXPR)
14023 tree inner1 = TREE_TYPE (TREE_OPERAND (op0, 0));
14024 tree inner2 = TREE_TYPE (TREE_OPERAND (op1, 0));
14025 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
14026 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
14027 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
14028 < TYPE_PRECISION (type);
14034 return (tree_expr_nonnegative_warnv_p (op0,
14036 || tree_expr_nonnegative_warnv_p (op1,
14037 strict_overflow_p));
14043 case TRUNC_DIV_EXPR:
14044 case CEIL_DIV_EXPR:
14045 case FLOOR_DIV_EXPR:
14046 case ROUND_DIV_EXPR:
14047 return (tree_expr_nonnegative_warnv_p (op0,
14049 && tree_expr_nonnegative_warnv_p (op1,
14050 strict_overflow_p));
14052 case TRUNC_MOD_EXPR:
14053 case CEIL_MOD_EXPR:
14054 case FLOOR_MOD_EXPR:
14055 case ROUND_MOD_EXPR:
14056 return tree_expr_nonnegative_warnv_p (op0,
14057 strict_overflow_p);
14059 return tree_simple_nonnegative_warnv_p (code, type);
14062 /* We don't know sign of `t', so be conservative and return false. */
14066 /* Return true if T is known to be non-negative. If the return
14067 value is based on the assumption that signed overflow is undefined,
14068 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14069 *STRICT_OVERFLOW_P. */
14072 tree_single_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14074 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14077 switch (TREE_CODE (t))
14080 return tree_int_cst_sgn (t) >= 0;
14083 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
14086 return ! FIXED_VALUE_NEGATIVE (TREE_FIXED_CST (t));
14089 return (tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14091 && tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 2),
14092 strict_overflow_p));
14094 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14097 /* We don't know sign of `t', so be conservative and return false. */
14101 /* Return true if T is known to be non-negative. If the return
14102 value is based on the assumption that signed overflow is undefined,
14103 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14104 *STRICT_OVERFLOW_P. */
14107 tree_call_nonnegative_warnv_p (tree type, tree fndecl,
14108 tree arg0, tree arg1, bool *strict_overflow_p)
14110 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
14111 switch (DECL_FUNCTION_CODE (fndecl))
14113 CASE_FLT_FN (BUILT_IN_ACOS):
14114 CASE_FLT_FN (BUILT_IN_ACOSH):
14115 CASE_FLT_FN (BUILT_IN_CABS):
14116 CASE_FLT_FN (BUILT_IN_COSH):
14117 CASE_FLT_FN (BUILT_IN_ERFC):
14118 CASE_FLT_FN (BUILT_IN_EXP):
14119 CASE_FLT_FN (BUILT_IN_EXP10):
14120 CASE_FLT_FN (BUILT_IN_EXP2):
14121 CASE_FLT_FN (BUILT_IN_FABS):
14122 CASE_FLT_FN (BUILT_IN_FDIM):
14123 CASE_FLT_FN (BUILT_IN_HYPOT):
14124 CASE_FLT_FN (BUILT_IN_POW10):
14125 CASE_INT_FN (BUILT_IN_FFS):
14126 CASE_INT_FN (BUILT_IN_PARITY):
14127 CASE_INT_FN (BUILT_IN_POPCOUNT):
14128 case BUILT_IN_BSWAP32:
14129 case BUILT_IN_BSWAP64:
14133 CASE_FLT_FN (BUILT_IN_SQRT):
14134 /* sqrt(-0.0) is -0.0. */
14135 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
14137 return tree_expr_nonnegative_warnv_p (arg0,
14138 strict_overflow_p);
14140 CASE_FLT_FN (BUILT_IN_ASINH):
14141 CASE_FLT_FN (BUILT_IN_ATAN):
14142 CASE_FLT_FN (BUILT_IN_ATANH):
14143 CASE_FLT_FN (BUILT_IN_CBRT):
14144 CASE_FLT_FN (BUILT_IN_CEIL):
14145 CASE_FLT_FN (BUILT_IN_ERF):
14146 CASE_FLT_FN (BUILT_IN_EXPM1):
14147 CASE_FLT_FN (BUILT_IN_FLOOR):
14148 CASE_FLT_FN (BUILT_IN_FMOD):
14149 CASE_FLT_FN (BUILT_IN_FREXP):
14150 CASE_FLT_FN (BUILT_IN_LCEIL):
14151 CASE_FLT_FN (BUILT_IN_LDEXP):
14152 CASE_FLT_FN (BUILT_IN_LFLOOR):
14153 CASE_FLT_FN (BUILT_IN_LLCEIL):
14154 CASE_FLT_FN (BUILT_IN_LLFLOOR):
14155 CASE_FLT_FN (BUILT_IN_LLRINT):
14156 CASE_FLT_FN (BUILT_IN_LLROUND):
14157 CASE_FLT_FN (BUILT_IN_LRINT):
14158 CASE_FLT_FN (BUILT_IN_LROUND):
14159 CASE_FLT_FN (BUILT_IN_MODF):
14160 CASE_FLT_FN (BUILT_IN_NEARBYINT):
14161 CASE_FLT_FN (BUILT_IN_RINT):
14162 CASE_FLT_FN (BUILT_IN_ROUND):
14163 CASE_FLT_FN (BUILT_IN_SCALB):
14164 CASE_FLT_FN (BUILT_IN_SCALBLN):
14165 CASE_FLT_FN (BUILT_IN_SCALBN):
14166 CASE_FLT_FN (BUILT_IN_SIGNBIT):
14167 CASE_FLT_FN (BUILT_IN_SIGNIFICAND):
14168 CASE_FLT_FN (BUILT_IN_SINH):
14169 CASE_FLT_FN (BUILT_IN_TANH):
14170 CASE_FLT_FN (BUILT_IN_TRUNC):
14171 /* True if the 1st argument is nonnegative. */
14172 return tree_expr_nonnegative_warnv_p (arg0,
14173 strict_overflow_p);
14175 CASE_FLT_FN (BUILT_IN_FMAX):
14176 /* True if the 1st OR 2nd arguments are nonnegative. */
14177 return (tree_expr_nonnegative_warnv_p (arg0,
14179 || (tree_expr_nonnegative_warnv_p (arg1,
14180 strict_overflow_p)));
14182 CASE_FLT_FN (BUILT_IN_FMIN):
14183 /* True if the 1st AND 2nd arguments are nonnegative. */
14184 return (tree_expr_nonnegative_warnv_p (arg0,
14186 && (tree_expr_nonnegative_warnv_p (arg1,
14187 strict_overflow_p)));
14189 CASE_FLT_FN (BUILT_IN_COPYSIGN):
14190 /* True if the 2nd argument is nonnegative. */
14191 return tree_expr_nonnegative_warnv_p (arg1,
14192 strict_overflow_p);
14194 CASE_FLT_FN (BUILT_IN_POWI):
14195 /* True if the 1st argument is nonnegative or the second
14196 argument is an even integer. */
14197 if (TREE_CODE (arg1) == INTEGER_CST
14198 && (TREE_INT_CST_LOW (arg1) & 1) == 0)
14200 return tree_expr_nonnegative_warnv_p (arg0,
14201 strict_overflow_p);
14203 CASE_FLT_FN (BUILT_IN_POW):
14204 /* True if the 1st argument is nonnegative or the second
14205 argument is an even integer valued real. */
14206 if (TREE_CODE (arg1) == REAL_CST)
14211 c = TREE_REAL_CST (arg1);
14212 n = real_to_integer (&c);
14215 REAL_VALUE_TYPE cint;
14216 real_from_integer (&cint, VOIDmode, n,
14217 n < 0 ? -1 : 0, 0);
14218 if (real_identical (&c, &cint))
14222 return tree_expr_nonnegative_warnv_p (arg0,
14223 strict_overflow_p);
14228 return tree_simple_nonnegative_warnv_p (CALL_EXPR,
14232 /* Return true if T is known to be non-negative. If the return
14233 value is based on the assumption that signed overflow is undefined,
14234 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14235 *STRICT_OVERFLOW_P. */
14238 tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14240 enum tree_code code = TREE_CODE (t);
14241 if (TYPE_UNSIGNED (TREE_TYPE (t)))
14248 tree temp = TARGET_EXPR_SLOT (t);
14249 t = TARGET_EXPR_INITIAL (t);
14251 /* If the initializer is non-void, then it's a normal expression
14252 that will be assigned to the slot. */
14253 if (!VOID_TYPE_P (t))
14254 return tree_expr_nonnegative_warnv_p (t, strict_overflow_p);
14256 /* Otherwise, the initializer sets the slot in some way. One common
14257 way is an assignment statement at the end of the initializer. */
14260 if (TREE_CODE (t) == BIND_EXPR)
14261 t = expr_last (BIND_EXPR_BODY (t));
14262 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
14263 || TREE_CODE (t) == TRY_CATCH_EXPR)
14264 t = expr_last (TREE_OPERAND (t, 0));
14265 else if (TREE_CODE (t) == STATEMENT_LIST)
14270 if (TREE_CODE (t) == MODIFY_EXPR
14271 && TREE_OPERAND (t, 0) == temp)
14272 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14273 strict_overflow_p);
14280 tree arg0 = call_expr_nargs (t) > 0 ? CALL_EXPR_ARG (t, 0) : NULL_TREE;
14281 tree arg1 = call_expr_nargs (t) > 1 ? CALL_EXPR_ARG (t, 1) : NULL_TREE;
14283 return tree_call_nonnegative_warnv_p (TREE_TYPE (t),
14284 get_callee_fndecl (t),
14287 strict_overflow_p);
14289 case COMPOUND_EXPR:
14291 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 1),
14292 strict_overflow_p);
14294 return tree_expr_nonnegative_warnv_p (expr_last (TREE_OPERAND (t, 1)),
14295 strict_overflow_p);
14297 return tree_expr_nonnegative_warnv_p (TREE_OPERAND (t, 0),
14298 strict_overflow_p);
14301 return tree_simple_nonnegative_warnv_p (TREE_CODE (t),
14305 /* We don't know sign of `t', so be conservative and return false. */
14309 /* Return true if T is known to be non-negative. If the return
14310 value is based on the assumption that signed overflow is undefined,
14311 set *STRICT_OVERFLOW_P to true; otherwise, don't change
14312 *STRICT_OVERFLOW_P. */
14315 tree_expr_nonnegative_warnv_p (tree t, bool *strict_overflow_p)
14317 enum tree_code code;
14318 if (t == error_mark_node)
14321 code = TREE_CODE (t);
14322 switch (TREE_CODE_CLASS (code))
14325 case tcc_comparison:
14326 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14328 TREE_OPERAND (t, 0),
14329 TREE_OPERAND (t, 1),
14330 strict_overflow_p);
14333 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14335 TREE_OPERAND (t, 0),
14336 strict_overflow_p);
14339 case tcc_declaration:
14340 case tcc_reference:
14341 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14349 case TRUTH_AND_EXPR:
14350 case TRUTH_OR_EXPR:
14351 case TRUTH_XOR_EXPR:
14352 return tree_binary_nonnegative_warnv_p (TREE_CODE (t),
14354 TREE_OPERAND (t, 0),
14355 TREE_OPERAND (t, 1),
14356 strict_overflow_p);
14357 case TRUTH_NOT_EXPR:
14358 return tree_unary_nonnegative_warnv_p (TREE_CODE (t),
14360 TREE_OPERAND (t, 0),
14361 strict_overflow_p);
14368 case WITH_SIZE_EXPR:
14372 return tree_single_nonnegative_warnv_p (t, strict_overflow_p);
14375 return tree_invalid_nonnegative_warnv_p (t, strict_overflow_p);
14379 /* Return true if `t' is known to be non-negative. Handle warnings
14380 about undefined signed overflow. */
14383 tree_expr_nonnegative_p (tree t)
14385 bool ret, strict_overflow_p;
14387 strict_overflow_p = false;
14388 ret = tree_expr_nonnegative_warnv_p (t, &strict_overflow_p);
14389 if (strict_overflow_p)
14390 fold_overflow_warning (("assuming signed overflow does not occur when "
14391 "determining that expression is always "
14393 WARN_STRICT_OVERFLOW_MISC);
14398 /* Return true when (CODE OP0) is an address and is known to be nonzero.
14399 For floating point we further ensure that T is not denormal.
14400 Similar logic is present in nonzero_address in rtlanal.h.
14402 If the return value is based on the assumption that signed overflow
14403 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14404 change *STRICT_OVERFLOW_P. */
14407 tree_unary_nonzero_warnv_p (enum tree_code code, tree type, tree op0,
14408 bool *strict_overflow_p)
14413 return tree_expr_nonzero_warnv_p (op0,
14414 strict_overflow_p);
14418 tree inner_type = TREE_TYPE (op0);
14419 tree outer_type = type;
14421 return (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
14422 && tree_expr_nonzero_warnv_p (op0,
14423 strict_overflow_p));
14427 case NON_LVALUE_EXPR:
14428 return tree_expr_nonzero_warnv_p (op0,
14429 strict_overflow_p);
14438 /* Return true when (CODE OP0 OP1) is an address and is known to be nonzero.
14439 For floating point we further ensure that T is not denormal.
14440 Similar logic is present in nonzero_address in rtlanal.h.
14442 If the return value is based on the assumption that signed overflow
14443 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14444 change *STRICT_OVERFLOW_P. */
14447 tree_binary_nonzero_warnv_p (enum tree_code code,
14450 tree op1, bool *strict_overflow_p)
14452 bool sub_strict_overflow_p;
14455 case POINTER_PLUS_EXPR:
14457 if (TYPE_OVERFLOW_UNDEFINED (type))
14459 /* With the presence of negative values it is hard
14460 to say something. */
14461 sub_strict_overflow_p = false;
14462 if (!tree_expr_nonnegative_warnv_p (op0,
14463 &sub_strict_overflow_p)
14464 || !tree_expr_nonnegative_warnv_p (op1,
14465 &sub_strict_overflow_p))
14467 /* One of operands must be positive and the other non-negative. */
14468 /* We don't set *STRICT_OVERFLOW_P here: even if this value
14469 overflows, on a twos-complement machine the sum of two
14470 nonnegative numbers can never be zero. */
14471 return (tree_expr_nonzero_warnv_p (op0,
14473 || tree_expr_nonzero_warnv_p (op1,
14474 strict_overflow_p));
14479 if (TYPE_OVERFLOW_UNDEFINED (type))
14481 if (tree_expr_nonzero_warnv_p (op0,
14483 && tree_expr_nonzero_warnv_p (op1,
14484 strict_overflow_p))
14486 *strict_overflow_p = true;
14493 sub_strict_overflow_p = false;
14494 if (tree_expr_nonzero_warnv_p (op0,
14495 &sub_strict_overflow_p)
14496 && tree_expr_nonzero_warnv_p (op1,
14497 &sub_strict_overflow_p))
14499 if (sub_strict_overflow_p)
14500 *strict_overflow_p = true;
14505 sub_strict_overflow_p = false;
14506 if (tree_expr_nonzero_warnv_p (op0,
14507 &sub_strict_overflow_p))
14509 if (sub_strict_overflow_p)
14510 *strict_overflow_p = true;
14512 /* When both operands are nonzero, then MAX must be too. */
14513 if (tree_expr_nonzero_warnv_p (op1,
14514 strict_overflow_p))
14517 /* MAX where operand 0 is positive is positive. */
14518 return tree_expr_nonnegative_warnv_p (op0,
14519 strict_overflow_p);
14521 /* MAX where operand 1 is positive is positive. */
14522 else if (tree_expr_nonzero_warnv_p (op1,
14523 &sub_strict_overflow_p)
14524 && tree_expr_nonnegative_warnv_p (op1,
14525 &sub_strict_overflow_p))
14527 if (sub_strict_overflow_p)
14528 *strict_overflow_p = true;
14534 return (tree_expr_nonzero_warnv_p (op1,
14536 || tree_expr_nonzero_warnv_p (op0,
14537 strict_overflow_p));
14546 /* Return true when T is an address and is known to be nonzero.
14547 For floating point we further ensure that T is not denormal.
14548 Similar logic is present in nonzero_address in rtlanal.h.
14550 If the return value is based on the assumption that signed overflow
14551 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14552 change *STRICT_OVERFLOW_P. */
14555 tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14557 bool sub_strict_overflow_p;
14558 switch (TREE_CODE (t))
14561 return !integer_zerop (t);
14565 tree base = get_base_address (TREE_OPERAND (t, 0));
14570 /* Weak declarations may link to NULL. */
14571 if (VAR_OR_FUNCTION_DECL_P (base))
14572 return !DECL_WEAK (base);
14574 /* Constants are never weak. */
14575 if (CONSTANT_CLASS_P (base))
14582 sub_strict_overflow_p = false;
14583 if (tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14584 &sub_strict_overflow_p)
14585 && tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 2),
14586 &sub_strict_overflow_p))
14588 if (sub_strict_overflow_p)
14589 *strict_overflow_p = true;
14600 /* Return true when T is an address and is known to be nonzero.
14601 For floating point we further ensure that T is not denormal.
14602 Similar logic is present in nonzero_address in rtlanal.h.
14604 If the return value is based on the assumption that signed overflow
14605 is undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't
14606 change *STRICT_OVERFLOW_P. */
14609 tree_expr_nonzero_warnv_p (tree t, bool *strict_overflow_p)
14611 tree type = TREE_TYPE (t);
14612 enum tree_code code;
14614 /* Doing something useful for floating point would need more work. */
14615 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
14618 code = TREE_CODE (t);
14619 switch (TREE_CODE_CLASS (code))
14622 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
14623 strict_overflow_p);
14625 case tcc_comparison:
14626 return tree_binary_nonzero_warnv_p (code, type,
14627 TREE_OPERAND (t, 0),
14628 TREE_OPERAND (t, 1),
14629 strict_overflow_p);
14631 case tcc_declaration:
14632 case tcc_reference:
14633 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
14641 case TRUTH_NOT_EXPR:
14642 return tree_unary_nonzero_warnv_p (code, type, TREE_OPERAND (t, 0),
14643 strict_overflow_p);
14645 case TRUTH_AND_EXPR:
14646 case TRUTH_OR_EXPR:
14647 case TRUTH_XOR_EXPR:
14648 return tree_binary_nonzero_warnv_p (code, type,
14649 TREE_OPERAND (t, 0),
14650 TREE_OPERAND (t, 1),
14651 strict_overflow_p);
14658 case WITH_SIZE_EXPR:
14662 return tree_single_nonzero_warnv_p (t, strict_overflow_p);
14664 case COMPOUND_EXPR:
14667 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 1),
14668 strict_overflow_p);
14671 return tree_expr_nonzero_warnv_p (TREE_OPERAND (t, 0),
14672 strict_overflow_p);
14675 return alloca_call_p (t);
14683 /* Return true when T is an address and is known to be nonzero.
14684 Handle warnings about undefined signed overflow. */
14687 tree_expr_nonzero_p (tree t)
14689 bool ret, strict_overflow_p;
14691 strict_overflow_p = false;
14692 ret = tree_expr_nonzero_warnv_p (t, &strict_overflow_p);
14693 if (strict_overflow_p)
14694 fold_overflow_warning (("assuming signed overflow does not occur when "
14695 "determining that expression is always "
14697 WARN_STRICT_OVERFLOW_MISC);
14701 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
14702 attempt to fold the expression to a constant without modifying TYPE,
14705 If the expression could be simplified to a constant, then return
14706 the constant. If the expression would not be simplified to a
14707 constant, then return NULL_TREE. */
14710 fold_binary_to_constant (enum tree_code code, tree type, tree op0, tree op1)
14712 tree tem = fold_binary (code, type, op0, op1);
14713 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14716 /* Given the components of a unary expression CODE, TYPE and OP0,
14717 attempt to fold the expression to a constant without modifying
14720 If the expression could be simplified to a constant, then return
14721 the constant. If the expression would not be simplified to a
14722 constant, then return NULL_TREE. */
14725 fold_unary_to_constant (enum tree_code code, tree type, tree op0)
14727 tree tem = fold_unary (code, type, op0);
14728 return (tem && TREE_CONSTANT (tem)) ? tem : NULL_TREE;
14731 /* If EXP represents referencing an element in a constant string
14732 (either via pointer arithmetic or array indexing), return the
14733 tree representing the value accessed, otherwise return NULL. */
14736 fold_read_from_constant_string (tree exp)
14738 if ((TREE_CODE (exp) == INDIRECT_REF
14739 || TREE_CODE (exp) == ARRAY_REF)
14740 && TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE)
14742 tree exp1 = TREE_OPERAND (exp, 0);
14746 if (TREE_CODE (exp) == INDIRECT_REF)
14747 string = string_constant (exp1, &index);
14750 tree low_bound = array_ref_low_bound (exp);
14751 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
14753 /* Optimize the special-case of a zero lower bound.
14755 We convert the low_bound to sizetype to avoid some problems
14756 with constant folding. (E.g. suppose the lower bound is 1,
14757 and its mode is QI. Without the conversion,l (ARRAY
14758 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
14759 +INDEX), which becomes (ARRAY+255+INDEX). Oops!) */
14760 if (! integer_zerop (low_bound))
14761 index = size_diffop (index, fold_convert (sizetype, low_bound));
14767 && TYPE_MODE (TREE_TYPE (exp)) == TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))
14768 && TREE_CODE (string) == STRING_CST
14769 && TREE_CODE (index) == INTEGER_CST
14770 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
14771 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
14773 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
14774 return build_int_cst_type (TREE_TYPE (exp),
14775 (TREE_STRING_POINTER (string)
14776 [TREE_INT_CST_LOW (index)]));
14781 /* Return the tree for neg (ARG0) when ARG0 is known to be either
14782 an integer constant, real, or fixed-point constant.
14784 TYPE is the type of the result. */
14787 fold_negate_const (tree arg0, tree type)
14789 tree t = NULL_TREE;
14791 switch (TREE_CODE (arg0))
14795 unsigned HOST_WIDE_INT low;
14796 HOST_WIDE_INT high;
14797 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14798 TREE_INT_CST_HIGH (arg0),
14800 t = force_fit_type_double (type, low, high, 1,
14801 (overflow | TREE_OVERFLOW (arg0))
14802 && !TYPE_UNSIGNED (type));
14807 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14812 FIXED_VALUE_TYPE f;
14813 bool overflow_p = fixed_arithmetic (&f, NEGATE_EXPR,
14814 &(TREE_FIXED_CST (arg0)), NULL,
14815 TYPE_SATURATING (type));
14816 t = build_fixed (type, f);
14817 /* Propagate overflow flags. */
14818 if (overflow_p | TREE_OVERFLOW (arg0))
14820 TREE_OVERFLOW (t) = 1;
14821 TREE_CONSTANT_OVERFLOW (t) = 1;
14823 else if (TREE_CONSTANT_OVERFLOW (arg0))
14824 TREE_CONSTANT_OVERFLOW (t) = 1;
14829 gcc_unreachable ();
14835 /* Return the tree for abs (ARG0) when ARG0 is known to be either
14836 an integer constant or real constant.
14838 TYPE is the type of the result. */
14841 fold_abs_const (tree arg0, tree type)
14843 tree t = NULL_TREE;
14845 switch (TREE_CODE (arg0))
14848 /* If the value is unsigned, then the absolute value is
14849 the same as the ordinary value. */
14850 if (TYPE_UNSIGNED (type))
14852 /* Similarly, if the value is non-negative. */
14853 else if (INT_CST_LT (integer_minus_one_node, arg0))
14855 /* If the value is negative, then the absolute value is
14859 unsigned HOST_WIDE_INT low;
14860 HOST_WIDE_INT high;
14861 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
14862 TREE_INT_CST_HIGH (arg0),
14864 t = force_fit_type_double (type, low, high, -1,
14865 overflow | TREE_OVERFLOW (arg0));
14870 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
14871 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
14877 gcc_unreachable ();
14883 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
14884 constant. TYPE is the type of the result. */
14887 fold_not_const (tree arg0, tree type)
14889 tree t = NULL_TREE;
14891 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
14893 t = force_fit_type_double (type, ~TREE_INT_CST_LOW (arg0),
14894 ~TREE_INT_CST_HIGH (arg0), 0,
14895 TREE_OVERFLOW (arg0));
14900 /* Given CODE, a relational operator, the target type, TYPE and two
14901 constant operands OP0 and OP1, return the result of the
14902 relational operation. If the result is not a compile time
14903 constant, then return NULL_TREE. */
14906 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
14908 int result, invert;
14910 /* From here on, the only cases we handle are when the result is
14911 known to be a constant. */
14913 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
14915 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
14916 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
14918 /* Handle the cases where either operand is a NaN. */
14919 if (real_isnan (c0) || real_isnan (c1))
14929 case UNORDERED_EXPR:
14943 if (flag_trapping_math)
14949 gcc_unreachable ();
14952 return constant_boolean_node (result, type);
14955 return constant_boolean_node (real_compare (code, c0, c1), type);
14958 if (TREE_CODE (op0) == FIXED_CST && TREE_CODE (op1) == FIXED_CST)
14960 const FIXED_VALUE_TYPE *c0 = TREE_FIXED_CST_PTR (op0);
14961 const FIXED_VALUE_TYPE *c1 = TREE_FIXED_CST_PTR (op1);
14962 return constant_boolean_node (fixed_compare (code, c0, c1), type);
14965 /* Handle equality/inequality of complex constants. */
14966 if (TREE_CODE (op0) == COMPLEX_CST && TREE_CODE (op1) == COMPLEX_CST)
14968 tree rcond = fold_relational_const (code, type,
14969 TREE_REALPART (op0),
14970 TREE_REALPART (op1));
14971 tree icond = fold_relational_const (code, type,
14972 TREE_IMAGPART (op0),
14973 TREE_IMAGPART (op1));
14974 if (code == EQ_EXPR)
14975 return fold_build2 (TRUTH_ANDIF_EXPR, type, rcond, icond);
14976 else if (code == NE_EXPR)
14977 return fold_build2 (TRUTH_ORIF_EXPR, type, rcond, icond);
14982 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
14984 To compute GT, swap the arguments and do LT.
14985 To compute GE, do LT and invert the result.
14986 To compute LE, swap the arguments, do LT and invert the result.
14987 To compute NE, do EQ and invert the result.
14989 Therefore, the code below must handle only EQ and LT. */
14991 if (code == LE_EXPR || code == GT_EXPR)
14996 code = swap_tree_comparison (code);
14999 /* Note that it is safe to invert for real values here because we
15000 have already handled the one case that it matters. */
15003 if (code == NE_EXPR || code == GE_EXPR)
15006 code = invert_tree_comparison (code, false);
15009 /* Compute a result for LT or EQ if args permit;
15010 Otherwise return T. */
15011 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
15013 if (code == EQ_EXPR)
15014 result = tree_int_cst_equal (op0, op1);
15015 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
15016 result = INT_CST_LT_UNSIGNED (op0, op1);
15018 result = INT_CST_LT (op0, op1);
15025 return constant_boolean_node (result, type);
15028 /* If necessary, return a CLEANUP_POINT_EXPR for EXPR with the
15029 indicated TYPE. If no CLEANUP_POINT_EXPR is necessary, return EXPR
15033 fold_build_cleanup_point_expr (tree type, tree expr)
15035 /* If the expression does not have side effects then we don't have to wrap
15036 it with a cleanup point expression. */
15037 if (!TREE_SIDE_EFFECTS (expr))
15040 /* If the expression is a return, check to see if the expression inside the
15041 return has no side effects or the right hand side of the modify expression
15042 inside the return. If either don't have side effects set we don't need to
15043 wrap the expression in a cleanup point expression. Note we don't check the
15044 left hand side of the modify because it should always be a return decl. */
15045 if (TREE_CODE (expr) == RETURN_EXPR)
15047 tree op = TREE_OPERAND (expr, 0);
15048 if (!op || !TREE_SIDE_EFFECTS (op))
15050 op = TREE_OPERAND (op, 1);
15051 if (!TREE_SIDE_EFFECTS (op))
15055 return build1 (CLEANUP_POINT_EXPR, type, expr);
15058 /* Given a pointer value OP0 and a type TYPE, return a simplified version
15059 of an indirection through OP0, or NULL_TREE if no simplification is
15063 fold_indirect_ref_1 (tree type, tree op0)
15069 subtype = TREE_TYPE (sub);
15070 if (!POINTER_TYPE_P (subtype))
15073 if (TREE_CODE (sub) == ADDR_EXPR)
15075 tree op = TREE_OPERAND (sub, 0);
15076 tree optype = TREE_TYPE (op);
15077 /* *&CONST_DECL -> to the value of the const decl. */
15078 if (TREE_CODE (op) == CONST_DECL)
15079 return DECL_INITIAL (op);
15080 /* *&p => p; make sure to handle *&"str"[cst] here. */
15081 if (type == optype)
15083 tree fop = fold_read_from_constant_string (op);
15089 /* *(foo *)&fooarray => fooarray[0] */
15090 else if (TREE_CODE (optype) == ARRAY_TYPE
15091 && type == TREE_TYPE (optype))
15093 tree type_domain = TYPE_DOMAIN (optype);
15094 tree min_val = size_zero_node;
15095 if (type_domain && TYPE_MIN_VALUE (type_domain))
15096 min_val = TYPE_MIN_VALUE (type_domain);
15097 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
15099 /* *(foo *)&complexfoo => __real__ complexfoo */
15100 else if (TREE_CODE (optype) == COMPLEX_TYPE
15101 && type == TREE_TYPE (optype))
15102 return fold_build1 (REALPART_EXPR, type, op);
15103 /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */
15104 else if (TREE_CODE (optype) == VECTOR_TYPE
15105 && type == TREE_TYPE (optype))
15107 tree part_width = TYPE_SIZE (type);
15108 tree index = bitsize_int (0);
15109 return fold_build3 (BIT_FIELD_REF, type, op, part_width, index);
15113 /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */
15114 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15115 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15117 tree op00 = TREE_OPERAND (sub, 0);
15118 tree op01 = TREE_OPERAND (sub, 1);
15122 op00type = TREE_TYPE (op00);
15123 if (TREE_CODE (op00) == ADDR_EXPR
15124 && TREE_CODE (TREE_TYPE (op00type)) == VECTOR_TYPE
15125 && type == TREE_TYPE (TREE_TYPE (op00type)))
15127 HOST_WIDE_INT offset = tree_low_cst (op01, 0);
15128 tree part_width = TYPE_SIZE (type);
15129 unsigned HOST_WIDE_INT part_widthi = tree_low_cst (part_width, 0)/BITS_PER_UNIT;
15130 unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT;
15131 tree index = bitsize_int (indexi);
15133 if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (op00type)))
15134 return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (op00, 0),
15135 part_width, index);
15141 /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
15142 if (TREE_CODE (sub) == POINTER_PLUS_EXPR
15143 && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST)
15145 tree op00 = TREE_OPERAND (sub, 0);
15146 tree op01 = TREE_OPERAND (sub, 1);
15150 op00type = TREE_TYPE (op00);
15151 if (TREE_CODE (op00) == ADDR_EXPR
15152 && TREE_CODE (TREE_TYPE (op00type)) == COMPLEX_TYPE
15153 && type == TREE_TYPE (TREE_TYPE (op00type)))
15155 tree size = TYPE_SIZE_UNIT (type);
15156 if (tree_int_cst_equal (size, op01))
15157 return fold_build1 (IMAGPART_EXPR, type, TREE_OPERAND (op00, 0));
15161 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
15162 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
15163 && type == TREE_TYPE (TREE_TYPE (subtype)))
15166 tree min_val = size_zero_node;
15167 sub = build_fold_indirect_ref (sub);
15168 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
15169 if (type_domain && TYPE_MIN_VALUE (type_domain))
15170 min_val = TYPE_MIN_VALUE (type_domain);
15171 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
15177 /* Builds an expression for an indirection through T, simplifying some
15181 build_fold_indirect_ref (tree t)
15183 tree type = TREE_TYPE (TREE_TYPE (t));
15184 tree sub = fold_indirect_ref_1 (type, t);
15189 return build1 (INDIRECT_REF, type, t);
15192 /* Given an INDIRECT_REF T, return either T or a simplified version. */
15195 fold_indirect_ref (tree t)
15197 tree sub = fold_indirect_ref_1 (TREE_TYPE (t), TREE_OPERAND (t, 0));
15205 /* Strip non-trapping, non-side-effecting tree nodes from an expression
15206 whose result is ignored. The type of the returned tree need not be
15207 the same as the original expression. */
15210 fold_ignored_result (tree t)
15212 if (!TREE_SIDE_EFFECTS (t))
15213 return integer_zero_node;
15216 switch (TREE_CODE_CLASS (TREE_CODE (t)))
15219 t = TREE_OPERAND (t, 0);
15223 case tcc_comparison:
15224 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15225 t = TREE_OPERAND (t, 0);
15226 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
15227 t = TREE_OPERAND (t, 1);
15232 case tcc_expression:
15233 switch (TREE_CODE (t))
15235 case COMPOUND_EXPR:
15236 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
15238 t = TREE_OPERAND (t, 0);
15242 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
15243 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
15245 t = TREE_OPERAND (t, 0);
15258 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
15259 This can only be applied to objects of a sizetype. */
15262 round_up (tree value, int divisor)
15264 tree div = NULL_TREE;
15266 gcc_assert (divisor > 0);
15270 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15271 have to do anything. Only do this when we are not given a const,
15272 because in that case, this check is more expensive than just
15274 if (TREE_CODE (value) != INTEGER_CST)
15276 div = build_int_cst (TREE_TYPE (value), divisor);
15278 if (multiple_of_p (TREE_TYPE (value), value, div))
15282 /* If divisor is a power of two, simplify this to bit manipulation. */
15283 if (divisor == (divisor & -divisor))
15285 if (TREE_CODE (value) == INTEGER_CST)
15287 unsigned HOST_WIDE_INT low = TREE_INT_CST_LOW (value);
15288 unsigned HOST_WIDE_INT high;
15291 if ((low & (divisor - 1)) == 0)
15294 overflow_p = TREE_OVERFLOW (value);
15295 high = TREE_INT_CST_HIGH (value);
15296 low &= ~(divisor - 1);
15305 return force_fit_type_double (TREE_TYPE (value), low, high,
15312 t = build_int_cst (TREE_TYPE (value), divisor - 1);
15313 value = size_binop (PLUS_EXPR, value, t);
15314 t = build_int_cst (TREE_TYPE (value), -divisor);
15315 value = size_binop (BIT_AND_EXPR, value, t);
15321 div = build_int_cst (TREE_TYPE (value), divisor);
15322 value = size_binop (CEIL_DIV_EXPR, value, div);
15323 value = size_binop (MULT_EXPR, value, div);
15329 /* Likewise, but round down. */
15332 round_down (tree value, int divisor)
15334 tree div = NULL_TREE;
15336 gcc_assert (divisor > 0);
15340 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
15341 have to do anything. Only do this when we are not given a const,
15342 because in that case, this check is more expensive than just
15344 if (TREE_CODE (value) != INTEGER_CST)
15346 div = build_int_cst (TREE_TYPE (value), divisor);
15348 if (multiple_of_p (TREE_TYPE (value), value, div))
15352 /* If divisor is a power of two, simplify this to bit manipulation. */
15353 if (divisor == (divisor & -divisor))
15357 t = build_int_cst (TREE_TYPE (value), -divisor);
15358 value = size_binop (BIT_AND_EXPR, value, t);
15363 div = build_int_cst (TREE_TYPE (value), divisor);
15364 value = size_binop (FLOOR_DIV_EXPR, value, div);
15365 value = size_binop (MULT_EXPR, value, div);
15371 /* Returns the pointer to the base of the object addressed by EXP and
15372 extracts the information about the offset of the access, storing it
15373 to PBITPOS and POFFSET. */
15376 split_address_to_core_and_offset (tree exp,
15377 HOST_WIDE_INT *pbitpos, tree *poffset)
15380 enum machine_mode mode;
15381 int unsignedp, volatilep;
15382 HOST_WIDE_INT bitsize;
15384 if (TREE_CODE (exp) == ADDR_EXPR)
15386 core = get_inner_reference (TREE_OPERAND (exp, 0), &bitsize, pbitpos,
15387 poffset, &mode, &unsignedp, &volatilep,
15389 core = fold_addr_expr (core);
15395 *poffset = NULL_TREE;
15401 /* Returns true if addresses of E1 and E2 differ by a constant, false
15402 otherwise. If they do, E1 - E2 is stored in *DIFF. */
15405 ptr_difference_const (tree e1, tree e2, HOST_WIDE_INT *diff)
15408 HOST_WIDE_INT bitpos1, bitpos2;
15409 tree toffset1, toffset2, tdiff, type;
15411 core1 = split_address_to_core_and_offset (e1, &bitpos1, &toffset1);
15412 core2 = split_address_to_core_and_offset (e2, &bitpos2, &toffset2);
15414 if (bitpos1 % BITS_PER_UNIT != 0
15415 || bitpos2 % BITS_PER_UNIT != 0
15416 || !operand_equal_p (core1, core2, 0))
15419 if (toffset1 && toffset2)
15421 type = TREE_TYPE (toffset1);
15422 if (type != TREE_TYPE (toffset2))
15423 toffset2 = fold_convert (type, toffset2);
15425 tdiff = fold_build2 (MINUS_EXPR, type, toffset1, toffset2);
15426 if (!cst_and_fits_in_hwi (tdiff))
15429 *diff = int_cst_value (tdiff);
15431 else if (toffset1 || toffset2)
15433 /* If only one of the offsets is non-constant, the difference cannot
15440 *diff += (bitpos1 - bitpos2) / BITS_PER_UNIT;
15444 /* Simplify the floating point expression EXP when the sign of the
15445 result is not significant. Return NULL_TREE if no simplification
15449 fold_strip_sign_ops (tree exp)
15453 switch (TREE_CODE (exp))
15457 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15458 return arg0 ? arg0 : TREE_OPERAND (exp, 0);
15462 if (HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (exp))))
15464 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 0));
15465 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15466 if (arg0 != NULL_TREE || arg1 != NULL_TREE)
15467 return fold_build2 (TREE_CODE (exp), TREE_TYPE (exp),
15468 arg0 ? arg0 : TREE_OPERAND (exp, 0),
15469 arg1 ? arg1 : TREE_OPERAND (exp, 1));
15472 case COMPOUND_EXPR:
15473 arg0 = TREE_OPERAND (exp, 0);
15474 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15476 return fold_build2 (COMPOUND_EXPR, TREE_TYPE (exp), arg0, arg1);
15480 arg0 = fold_strip_sign_ops (TREE_OPERAND (exp, 1));
15481 arg1 = fold_strip_sign_ops (TREE_OPERAND (exp, 2));
15483 return fold_build3 (COND_EXPR, TREE_TYPE (exp), TREE_OPERAND (exp, 0),
15484 arg0 ? arg0 : TREE_OPERAND (exp, 1),
15485 arg1 ? arg1 : TREE_OPERAND (exp, 2));
15490 const enum built_in_function fcode = builtin_mathfn_code (exp);
15493 CASE_FLT_FN (BUILT_IN_COPYSIGN):
15494 /* Strip copysign function call, return the 1st argument. */
15495 arg0 = CALL_EXPR_ARG (exp, 0);
15496 arg1 = CALL_EXPR_ARG (exp, 1);
15497 return omit_one_operand (TREE_TYPE (exp), arg0, arg1);
15500 /* Strip sign ops from the argument of "odd" math functions. */
15501 if (negate_mathfn_p (fcode))
15503 arg0 = fold_strip_sign_ops (CALL_EXPR_ARG (exp, 0));
15505 return build_call_expr (get_callee_fndecl (exp), 1, arg0);