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 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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
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 takes a constant, an overflowable flag and prior
43 overflow indicators. It forces the value to fit the type and sets
44 TREE_OVERFLOW and TREE_CONSTANT_OVERFLOW as appropriate. */
48 #include "coretypes.h"
59 #include "langhooks.h"
62 /* The following constants represent a bit based encoding of GCC's
63 comparison operators. This encoding simplifies transformations
64 on relational comparison operators, such as AND and OR. */
65 enum comparison_code {
84 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
85 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
86 static bool negate_mathfn_p (enum built_in_function);
87 static bool negate_expr_p (tree);
88 static tree negate_expr (tree);
89 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
90 static tree associate_trees (tree, tree, enum tree_code, tree);
91 static tree const_binop (enum tree_code, tree, tree, int);
92 static tree build_zero_vector (tree);
93 static tree fold_convert_const (enum tree_code, tree, tree);
94 static enum tree_code invert_tree_comparison (enum tree_code, bool);
95 static enum comparison_code comparison_to_compcode (enum tree_code);
96 static enum tree_code compcode_to_comparison (enum comparison_code);
97 static tree combine_comparisons (enum tree_code, enum tree_code,
98 enum tree_code, tree, tree, tree);
99 static int truth_value_p (enum tree_code);
100 static int operand_equal_for_comparison_p (tree, tree, tree);
101 static int twoval_comparison_p (tree, tree *, tree *, int *);
102 static tree eval_subst (tree, tree, tree, tree, tree);
103 static tree pedantic_omit_one_operand (tree, tree, tree);
104 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
105 static tree make_bit_field_ref (tree, tree, int, int, int);
106 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
107 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
108 enum machine_mode *, int *, int *,
110 static int all_ones_mask_p (tree, int);
111 static tree sign_bit_p (tree, tree);
112 static int simple_operand_p (tree);
113 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
114 static tree make_range (tree, int *, tree *, tree *);
115 static tree build_range_check (tree, tree, int, tree, tree);
116 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
118 static tree fold_range_test (tree);
119 static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
120 static tree unextend (tree, int, int, tree);
121 static tree fold_truthop (enum tree_code, tree, tree, tree);
122 static tree optimize_minmax_comparison (tree);
123 static tree extract_muldiv (tree, tree, enum tree_code, tree);
124 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
125 static int multiple_of_p (tree, tree, tree);
126 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
128 static bool fold_real_zero_addition_p (tree, tree, int);
129 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
131 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
132 static tree fold_div_compare (enum tree_code, tree, tree, tree);
133 static bool reorder_operands_p (tree, tree);
134 static tree fold_negate_const (tree, tree);
135 static tree fold_not_const (tree, tree);
136 static tree fold_relational_const (enum tree_code, tree, tree, tree);
137 static tree fold_relational_hi_lo (enum tree_code *, const tree,
139 static bool tree_expr_nonzero_p (tree);
141 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
142 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
143 and SUM1. Then this yields nonzero if overflow occurred during the
146 Overflow occurs if A and B have the same sign, but A and SUM differ in
147 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
149 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
151 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
152 We do that by representing the two-word integer in 4 words, with only
153 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
154 number. The value of the word is LOWPART + HIGHPART * BASE. */
157 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
158 #define HIGHPART(x) \
159 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
160 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
162 /* Unpack a two-word integer into 4 words.
163 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
164 WORDS points to the array of HOST_WIDE_INTs. */
167 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
169 words[0] = LOWPART (low);
170 words[1] = HIGHPART (low);
171 words[2] = LOWPART (hi);
172 words[3] = HIGHPART (hi);
175 /* Pack an array of 4 words into a two-word integer.
176 WORDS points to the array of words.
177 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
180 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
183 *low = words[0] + words[1] * BASE;
184 *hi = words[2] + words[3] * BASE;
187 /* T is an INT_CST node. OVERFLOWABLE indicates if we are interested
188 in overflow of the value, when >0 we are only interested in signed
189 overflow, for <0 we are interested in any overflow. OVERFLOWED
190 indicates whether overflow has already occurred. CONST_OVERFLOWED
191 indicates whether constant overflow has already occurred. We force
192 T's value to be within range of T's type (by setting to 0 or 1 all
193 the bits outside the type's range). We set TREE_OVERFLOWED if,
194 OVERFLOWED is non-zero,
195 or OVERFLOWABLE is >0 and signed overflow occurs
196 or OVERFLOWABLE is <0 and any overflow occurs
197 We set TREE_CONSTANT_OVERFLOWED if,
198 CONST_OVERFLOWED is non-zero
199 or we set TREE_OVERFLOWED.
200 We return either the original T, or a copy. */
203 force_fit_type (tree t, int overflowable,
204 bool overflowed, bool overflowed_const)
206 unsigned HOST_WIDE_INT low;
209 int sign_extended_type;
211 gcc_assert (TREE_CODE (t) == INTEGER_CST);
213 low = TREE_INT_CST_LOW (t);
214 high = TREE_INT_CST_HIGH (t);
216 if (POINTER_TYPE_P (TREE_TYPE (t))
217 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
220 prec = TYPE_PRECISION (TREE_TYPE (t));
221 /* Size types *are* sign extended. */
222 sign_extended_type = (!TYPE_UNSIGNED (TREE_TYPE (t))
223 || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
224 && TYPE_IS_SIZETYPE (TREE_TYPE (t))));
226 /* First clear all bits that are beyond the type's precision. */
228 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
230 else if (prec > HOST_BITS_PER_WIDE_INT)
231 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
235 if (prec < HOST_BITS_PER_WIDE_INT)
236 low &= ~((HOST_WIDE_INT) (-1) << prec);
239 if (!sign_extended_type)
240 /* No sign extension */;
241 else if (prec == 2 * HOST_BITS_PER_WIDE_INT)
242 /* Correct width already. */;
243 else if (prec > HOST_BITS_PER_WIDE_INT)
245 /* Sign extend top half? */
246 if (high & ((unsigned HOST_WIDE_INT)1
247 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
248 high |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
250 else if (prec == HOST_BITS_PER_WIDE_INT)
252 if ((HOST_WIDE_INT)low < 0)
257 /* Sign extend bottom half? */
258 if (low & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
261 low |= (HOST_WIDE_INT)(-1) << prec;
265 /* If the value changed, return a new node. */
266 if (overflowed || overflowed_const
267 || low != TREE_INT_CST_LOW (t) || high != TREE_INT_CST_HIGH (t))
269 t = build_int_cst_wide (TREE_TYPE (t), low, high);
273 || (overflowable > 0 && sign_extended_type))
276 TREE_OVERFLOW (t) = 1;
277 TREE_CONSTANT_OVERFLOW (t) = 1;
279 else if (overflowed_const)
282 TREE_CONSTANT_OVERFLOW (t) = 1;
289 /* Add two doubleword integers with doubleword result.
290 Each argument is given as two `HOST_WIDE_INT' pieces.
291 One argument is L1 and H1; the other, L2 and H2.
292 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
295 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
296 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
297 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
299 unsigned HOST_WIDE_INT l;
303 h = h1 + h2 + (l < l1);
307 return OVERFLOW_SUM_SIGN (h1, h2, h);
310 /* Negate a doubleword integer with doubleword result.
311 Return nonzero if the operation overflows, assuming it's signed.
312 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
313 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
316 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
317 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
323 return (*hv & h1) < 0;
333 /* Multiply two doubleword integers with doubleword result.
334 Return nonzero if the operation overflows, assuming it's signed.
335 Each argument is given as two `HOST_WIDE_INT' pieces.
336 One argument is L1 and H1; the other, L2 and H2.
337 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
340 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
341 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
342 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
344 HOST_WIDE_INT arg1[4];
345 HOST_WIDE_INT arg2[4];
346 HOST_WIDE_INT prod[4 * 2];
347 unsigned HOST_WIDE_INT carry;
349 unsigned HOST_WIDE_INT toplow, neglow;
350 HOST_WIDE_INT tophigh, neghigh;
352 encode (arg1, l1, h1);
353 encode (arg2, l2, h2);
355 memset (prod, 0, sizeof prod);
357 for (i = 0; i < 4; i++)
360 for (j = 0; j < 4; j++)
363 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
364 carry += arg1[i] * arg2[j];
365 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
367 prod[k] = LOWPART (carry);
368 carry = HIGHPART (carry);
373 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
375 /* Check for overflow by calculating the top half of the answer in full;
376 it should agree with the low half's sign bit. */
377 decode (prod + 4, &toplow, &tophigh);
380 neg_double (l2, h2, &neglow, &neghigh);
381 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
385 neg_double (l1, h1, &neglow, &neghigh);
386 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
388 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
391 /* Shift the doubleword integer in L1, H1 left by COUNT places
392 keeping only PREC bits of result.
393 Shift right if COUNT is negative.
394 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
395 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
398 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
399 HOST_WIDE_INT count, unsigned int prec,
400 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
402 unsigned HOST_WIDE_INT signmask;
406 rshift_double (l1, h1, -count, prec, lv, hv, arith);
410 if (SHIFT_COUNT_TRUNCATED)
413 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
415 /* Shifting by the host word size is undefined according to the
416 ANSI standard, so we must handle this as a special case. */
420 else if (count >= HOST_BITS_PER_WIDE_INT)
422 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
427 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
428 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
432 /* Sign extend all bits that are beyond the precision. */
434 signmask = -((prec > HOST_BITS_PER_WIDE_INT
435 ? ((unsigned HOST_WIDE_INT) *hv
436 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
437 : (*lv >> (prec - 1))) & 1);
439 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
441 else if (prec >= HOST_BITS_PER_WIDE_INT)
443 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
444 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
449 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
450 *lv |= signmask << prec;
454 /* Shift the doubleword integer in L1, H1 right by COUNT places
455 keeping only PREC bits of result. COUNT must be positive.
456 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
457 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
460 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
461 HOST_WIDE_INT count, unsigned int prec,
462 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
465 unsigned HOST_WIDE_INT signmask;
468 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
471 if (SHIFT_COUNT_TRUNCATED)
474 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
476 /* Shifting by the host word size is undefined according to the
477 ANSI standard, so we must handle this as a special case. */
481 else if (count >= HOST_BITS_PER_WIDE_INT)
484 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
488 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
490 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
493 /* Zero / sign extend all bits that are beyond the precision. */
495 if (count >= (HOST_WIDE_INT)prec)
500 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
502 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
504 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
505 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
510 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
511 *lv |= signmask << (prec - count);
515 /* Rotate the doubleword integer in L1, H1 left by COUNT places
516 keeping only PREC bits of result.
517 Rotate right if COUNT is negative.
518 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
521 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
522 HOST_WIDE_INT count, unsigned int prec,
523 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
525 unsigned HOST_WIDE_INT s1l, s2l;
526 HOST_WIDE_INT s1h, s2h;
532 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
533 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
538 /* Rotate the doubleword integer in L1, H1 left by COUNT places
539 keeping only PREC bits of result. COUNT must be positive.
540 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
543 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
544 HOST_WIDE_INT count, unsigned int prec,
545 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
547 unsigned HOST_WIDE_INT s1l, s2l;
548 HOST_WIDE_INT s1h, s2h;
554 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
555 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
560 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
561 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
562 CODE is a tree code for a kind of division, one of
563 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
565 It controls how the quotient is rounded to an integer.
566 Return nonzero if the operation overflows.
567 UNS nonzero says do unsigned division. */
570 div_and_round_double (enum tree_code code, int uns,
571 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
572 HOST_WIDE_INT hnum_orig,
573 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
574 HOST_WIDE_INT hden_orig,
575 unsigned HOST_WIDE_INT *lquo,
576 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
580 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
581 HOST_WIDE_INT den[4], quo[4];
583 unsigned HOST_WIDE_INT work;
584 unsigned HOST_WIDE_INT carry = 0;
585 unsigned HOST_WIDE_INT lnum = lnum_orig;
586 HOST_WIDE_INT hnum = hnum_orig;
587 unsigned HOST_WIDE_INT lden = lden_orig;
588 HOST_WIDE_INT hden = hden_orig;
591 if (hden == 0 && lden == 0)
592 overflow = 1, lden = 1;
594 /* Calculate quotient sign and convert operands to unsigned. */
600 /* (minimum integer) / (-1) is the only overflow case. */
601 if (neg_double (lnum, hnum, &lnum, &hnum)
602 && ((HOST_WIDE_INT) lden & hden) == -1)
608 neg_double (lden, hden, &lden, &hden);
612 if (hnum == 0 && hden == 0)
613 { /* single precision */
615 /* This unsigned division rounds toward zero. */
621 { /* trivial case: dividend < divisor */
622 /* hden != 0 already checked. */
629 memset (quo, 0, sizeof quo);
631 memset (num, 0, sizeof num); /* to zero 9th element */
632 memset (den, 0, sizeof den);
634 encode (num, lnum, hnum);
635 encode (den, lden, hden);
637 /* Special code for when the divisor < BASE. */
638 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
640 /* hnum != 0 already checked. */
641 for (i = 4 - 1; i >= 0; i--)
643 work = num[i] + carry * BASE;
644 quo[i] = work / lden;
650 /* Full double precision division,
651 with thanks to Don Knuth's "Seminumerical Algorithms". */
652 int num_hi_sig, den_hi_sig;
653 unsigned HOST_WIDE_INT quo_est, scale;
655 /* Find the highest nonzero divisor digit. */
656 for (i = 4 - 1;; i--)
663 /* Insure that the first digit of the divisor is at least BASE/2.
664 This is required by the quotient digit estimation algorithm. */
666 scale = BASE / (den[den_hi_sig] + 1);
668 { /* scale divisor and dividend */
670 for (i = 0; i <= 4 - 1; i++)
672 work = (num[i] * scale) + carry;
673 num[i] = LOWPART (work);
674 carry = HIGHPART (work);
679 for (i = 0; i <= 4 - 1; i++)
681 work = (den[i] * scale) + carry;
682 den[i] = LOWPART (work);
683 carry = HIGHPART (work);
684 if (den[i] != 0) den_hi_sig = i;
691 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
693 /* Guess the next quotient digit, quo_est, by dividing the first
694 two remaining dividend digits by the high order quotient digit.
695 quo_est is never low and is at most 2 high. */
696 unsigned HOST_WIDE_INT tmp;
698 num_hi_sig = i + den_hi_sig + 1;
699 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
700 if (num[num_hi_sig] != den[den_hi_sig])
701 quo_est = work / den[den_hi_sig];
705 /* Refine quo_est so it's usually correct, and at most one high. */
706 tmp = work - quo_est * den[den_hi_sig];
708 && (den[den_hi_sig - 1] * quo_est
709 > (tmp * BASE + num[num_hi_sig - 2])))
712 /* Try QUO_EST as the quotient digit, by multiplying the
713 divisor by QUO_EST and subtracting from the remaining dividend.
714 Keep in mind that QUO_EST is the I - 1st digit. */
717 for (j = 0; j <= den_hi_sig; j++)
719 work = quo_est * den[j] + carry;
720 carry = HIGHPART (work);
721 work = num[i + j] - LOWPART (work);
722 num[i + j] = LOWPART (work);
723 carry += HIGHPART (work) != 0;
726 /* If quo_est was high by one, then num[i] went negative and
727 we need to correct things. */
728 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
731 carry = 0; /* add divisor back in */
732 for (j = 0; j <= den_hi_sig; j++)
734 work = num[i + j] + den[j] + carry;
735 carry = HIGHPART (work);
736 num[i + j] = LOWPART (work);
739 num [num_hi_sig] += carry;
742 /* Store the quotient digit. */
747 decode (quo, lquo, hquo);
750 /* If result is negative, make it so. */
752 neg_double (*lquo, *hquo, lquo, hquo);
754 /* Compute trial remainder: rem = num - (quo * den) */
755 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
756 neg_double (*lrem, *hrem, lrem, hrem);
757 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
762 case TRUNC_MOD_EXPR: /* round toward zero */
763 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
767 case FLOOR_MOD_EXPR: /* round toward negative infinity */
768 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
771 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
779 case CEIL_MOD_EXPR: /* round toward positive infinity */
780 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
782 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
790 case ROUND_MOD_EXPR: /* round to closest integer */
792 unsigned HOST_WIDE_INT labs_rem = *lrem;
793 HOST_WIDE_INT habs_rem = *hrem;
794 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
795 HOST_WIDE_INT habs_den = hden, htwice;
797 /* Get absolute values. */
799 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
801 neg_double (lden, hden, &labs_den, &habs_den);
803 /* If (2 * abs (lrem) >= abs (lden)) */
804 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
805 labs_rem, habs_rem, <wice, &htwice);
807 if (((unsigned HOST_WIDE_INT) habs_den
808 < (unsigned HOST_WIDE_INT) htwice)
809 || (((unsigned HOST_WIDE_INT) habs_den
810 == (unsigned HOST_WIDE_INT) htwice)
811 && (labs_den < ltwice)))
815 add_double (*lquo, *hquo,
816 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
819 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
831 /* Compute true remainder: rem = num - (quo * den) */
832 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
833 neg_double (*lrem, *hrem, lrem, hrem);
834 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
838 /* Return true if built-in mathematical function specified by CODE
839 preserves the sign of it argument, i.e. -f(x) == f(-x). */
842 negate_mathfn_p (enum built_in_function code)
866 /* Check whether we may negate an integer constant T without causing
870 may_negate_without_overflow_p (tree t)
872 unsigned HOST_WIDE_INT val;
876 gcc_assert (TREE_CODE (t) == INTEGER_CST);
878 type = TREE_TYPE (t);
879 if (TYPE_UNSIGNED (type))
882 prec = TYPE_PRECISION (type);
883 if (prec > HOST_BITS_PER_WIDE_INT)
885 if (TREE_INT_CST_LOW (t) != 0)
887 prec -= HOST_BITS_PER_WIDE_INT;
888 val = TREE_INT_CST_HIGH (t);
891 val = TREE_INT_CST_LOW (t);
892 if (prec < HOST_BITS_PER_WIDE_INT)
893 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
894 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
897 /* Determine whether an expression T can be cheaply negated using
898 the function negate_expr. */
901 negate_expr_p (tree t)
908 type = TREE_TYPE (t);
911 switch (TREE_CODE (t))
914 if (TYPE_UNSIGNED (type) || ! flag_trapv)
917 /* Check that -CST will not overflow type. */
918 return may_negate_without_overflow_p (t);
925 return negate_expr_p (TREE_REALPART (t))
926 && negate_expr_p (TREE_IMAGPART (t));
929 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
931 /* -(A + B) -> (-B) - A. */
932 if (negate_expr_p (TREE_OPERAND (t, 1))
933 && reorder_operands_p (TREE_OPERAND (t, 0),
934 TREE_OPERAND (t, 1)))
936 /* -(A + B) -> (-A) - B. */
937 return negate_expr_p (TREE_OPERAND (t, 0));
940 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
941 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
942 && reorder_operands_p (TREE_OPERAND (t, 0),
943 TREE_OPERAND (t, 1));
946 if (TYPE_UNSIGNED (TREE_TYPE (t)))
952 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
953 return negate_expr_p (TREE_OPERAND (t, 1))
954 || negate_expr_p (TREE_OPERAND (t, 0));
958 /* Negate -((double)float) as (double)(-float). */
959 if (TREE_CODE (type) == REAL_TYPE)
961 tree tem = strip_float_extensions (t);
963 return negate_expr_p (tem);
968 /* Negate -f(x) as f(-x). */
969 if (negate_mathfn_p (builtin_mathfn_code (t)))
970 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
974 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
975 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
977 tree op1 = TREE_OPERAND (t, 1);
978 if (TREE_INT_CST_HIGH (op1) == 0
979 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
980 == TREE_INT_CST_LOW (op1))
991 /* Given T, an expression, return the negation of T. Allow for T to be
992 null, in which case return null. */
1003 type = TREE_TYPE (t);
1004 STRIP_SIGN_NOPS (t);
1006 switch (TREE_CODE (t))
1009 tem = fold_negate_const (t, type);
1010 if (! TREE_OVERFLOW (tem)
1011 || TYPE_UNSIGNED (type)
1017 tem = fold_negate_const (t, type);
1018 /* Two's complement FP formats, such as c4x, may overflow. */
1019 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
1020 return fold_convert (type, tem);
1025 tree rpart = negate_expr (TREE_REALPART (t));
1026 tree ipart = negate_expr (TREE_IMAGPART (t));
1028 if ((TREE_CODE (rpart) == REAL_CST
1029 && TREE_CODE (ipart) == REAL_CST)
1030 || (TREE_CODE (rpart) == INTEGER_CST
1031 && TREE_CODE (ipart) == INTEGER_CST))
1032 return build_complex (type, rpart, ipart);
1037 return fold_convert (type, TREE_OPERAND (t, 0));
1040 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1042 /* -(A + B) -> (-B) - A. */
1043 if (negate_expr_p (TREE_OPERAND (t, 1))
1044 && reorder_operands_p (TREE_OPERAND (t, 0),
1045 TREE_OPERAND (t, 1)))
1047 tem = negate_expr (TREE_OPERAND (t, 1));
1048 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1049 tem, TREE_OPERAND (t, 0)));
1050 return fold_convert (type, tem);
1053 /* -(A + B) -> (-A) - B. */
1054 if (negate_expr_p (TREE_OPERAND (t, 0)))
1056 tem = negate_expr (TREE_OPERAND (t, 0));
1057 tem = fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1058 tem, TREE_OPERAND (t, 1)));
1059 return fold_convert (type, tem);
1065 /* - (A - B) -> B - A */
1066 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1067 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1068 return fold_convert (type,
1069 fold (build2 (MINUS_EXPR, TREE_TYPE (t),
1070 TREE_OPERAND (t, 1),
1071 TREE_OPERAND (t, 0))));
1075 if (TYPE_UNSIGNED (TREE_TYPE (t)))
1081 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1083 tem = TREE_OPERAND (t, 1);
1084 if (negate_expr_p (tem))
1085 return fold_convert (type,
1086 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1087 TREE_OPERAND (t, 0),
1088 negate_expr (tem))));
1089 tem = TREE_OPERAND (t, 0);
1090 if (negate_expr_p (tem))
1091 return fold_convert (type,
1092 fold (build2 (TREE_CODE (t), TREE_TYPE (t),
1094 TREE_OPERAND (t, 1))));
1099 /* Convert -((double)float) into (double)(-float). */
1100 if (TREE_CODE (type) == REAL_TYPE)
1102 tem = strip_float_extensions (t);
1103 if (tem != t && negate_expr_p (tem))
1104 return fold_convert (type, negate_expr (tem));
1109 /* Negate -f(x) as f(-x). */
1110 if (negate_mathfn_p (builtin_mathfn_code (t))
1111 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1113 tree fndecl, arg, arglist;
1115 fndecl = get_callee_fndecl (t);
1116 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1117 arglist = build_tree_list (NULL_TREE, arg);
1118 return build_function_call_expr (fndecl, arglist);
1123 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1124 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1126 tree op1 = TREE_OPERAND (t, 1);
1127 if (TREE_INT_CST_HIGH (op1) == 0
1128 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1129 == TREE_INT_CST_LOW (op1))
1131 tree ntype = TYPE_UNSIGNED (type)
1132 ? lang_hooks.types.signed_type (type)
1133 : lang_hooks.types.unsigned_type (type);
1134 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
1135 temp = fold (build2 (RSHIFT_EXPR, ntype, temp, op1));
1136 return fold_convert (type, temp);
1145 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1146 return fold_convert (type, tem);
1149 /* Split a tree IN into a constant, literal and variable parts that could be
1150 combined with CODE to make IN. "constant" means an expression with
1151 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1152 commutative arithmetic operation. Store the constant part into *CONP,
1153 the literal in *LITP and return the variable part. If a part isn't
1154 present, set it to null. If the tree does not decompose in this way,
1155 return the entire tree as the variable part and the other parts as null.
1157 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1158 case, we negate an operand that was subtracted. Except if it is a
1159 literal for which we use *MINUS_LITP instead.
1161 If NEGATE_P is true, we are negating all of IN, again except a literal
1162 for which we use *MINUS_LITP instead.
1164 If IN is itself a literal or constant, return it as appropriate.
1166 Note that we do not guarantee that any of the three values will be the
1167 same type as IN, but they will have the same signedness and mode. */
1170 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1171 tree *minus_litp, int negate_p)
1179 /* Strip any conversions that don't change the machine mode or signedness. */
1180 STRIP_SIGN_NOPS (in);
1182 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1184 else if (TREE_CODE (in) == code
1185 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1186 /* We can associate addition and subtraction together (even
1187 though the C standard doesn't say so) for integers because
1188 the value is not affected. For reals, the value might be
1189 affected, so we can't. */
1190 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1191 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1193 tree op0 = TREE_OPERAND (in, 0);
1194 tree op1 = TREE_OPERAND (in, 1);
1195 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1196 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1198 /* First see if either of the operands is a literal, then a constant. */
1199 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1200 *litp = op0, op0 = 0;
1201 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1202 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1204 if (op0 != 0 && TREE_CONSTANT (op0))
1205 *conp = op0, op0 = 0;
1206 else if (op1 != 0 && TREE_CONSTANT (op1))
1207 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1209 /* If we haven't dealt with either operand, this is not a case we can
1210 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1211 if (op0 != 0 && op1 != 0)
1216 var = op1, neg_var_p = neg1_p;
1218 /* Now do any needed negations. */
1220 *minus_litp = *litp, *litp = 0;
1222 *conp = negate_expr (*conp);
1224 var = negate_expr (var);
1226 else if (TREE_CONSTANT (in))
1234 *minus_litp = *litp, *litp = 0;
1235 else if (*minus_litp)
1236 *litp = *minus_litp, *minus_litp = 0;
1237 *conp = negate_expr (*conp);
1238 var = negate_expr (var);
1244 /* Re-associate trees split by the above function. T1 and T2 are either
1245 expressions to associate or null. Return the new expression, if any. If
1246 we build an operation, do it in TYPE and with CODE. */
1249 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1256 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1257 try to fold this since we will have infinite recursion. But do
1258 deal with any NEGATE_EXPRs. */
1259 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1260 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1262 if (code == PLUS_EXPR)
1264 if (TREE_CODE (t1) == NEGATE_EXPR)
1265 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1266 fold_convert (type, TREE_OPERAND (t1, 0)));
1267 else if (TREE_CODE (t2) == NEGATE_EXPR)
1268 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1269 fold_convert (type, TREE_OPERAND (t2, 0)));
1271 return build2 (code, type, fold_convert (type, t1),
1272 fold_convert (type, t2));
1275 return fold (build2 (code, type, fold_convert (type, t1),
1276 fold_convert (type, t2)));
1279 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1280 to produce a new constant.
1282 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1285 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1287 unsigned HOST_WIDE_INT int1l, int2l;
1288 HOST_WIDE_INT int1h, int2h;
1289 unsigned HOST_WIDE_INT low;
1291 unsigned HOST_WIDE_INT garbagel;
1292 HOST_WIDE_INT garbageh;
1294 tree type = TREE_TYPE (arg1);
1295 int uns = TYPE_UNSIGNED (type);
1297 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1299 int no_overflow = 0;
1301 int1l = TREE_INT_CST_LOW (arg1);
1302 int1h = TREE_INT_CST_HIGH (arg1);
1303 int2l = TREE_INT_CST_LOW (arg2);
1304 int2h = TREE_INT_CST_HIGH (arg2);
1309 low = int1l | int2l, hi = int1h | int2h;
1313 low = int1l ^ int2l, hi = int1h ^ int2h;
1317 low = int1l & int2l, hi = int1h & int2h;
1323 /* It's unclear from the C standard whether shifts can overflow.
1324 The following code ignores overflow; perhaps a C standard
1325 interpretation ruling is needed. */
1326 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1334 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1339 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1343 neg_double (int2l, int2h, &low, &hi);
1344 add_double (int1l, int1h, low, hi, &low, &hi);
1345 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1349 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1352 case TRUNC_DIV_EXPR:
1353 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1354 case EXACT_DIV_EXPR:
1355 /* This is a shortcut for a common special case. */
1356 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1357 && ! TREE_CONSTANT_OVERFLOW (arg1)
1358 && ! TREE_CONSTANT_OVERFLOW (arg2)
1359 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1361 if (code == CEIL_DIV_EXPR)
1364 low = int1l / int2l, hi = 0;
1368 /* ... fall through ... */
1370 case ROUND_DIV_EXPR:
1371 if (int2h == 0 && int2l == 1)
1373 low = int1l, hi = int1h;
1376 if (int1l == int2l && int1h == int2h
1377 && ! (int1l == 0 && int1h == 0))
1382 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1383 &low, &hi, &garbagel, &garbageh);
1386 case TRUNC_MOD_EXPR:
1387 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1388 /* This is a shortcut for a common special case. */
1389 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1390 && ! TREE_CONSTANT_OVERFLOW (arg1)
1391 && ! TREE_CONSTANT_OVERFLOW (arg2)
1392 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1394 if (code == CEIL_MOD_EXPR)
1396 low = int1l % int2l, hi = 0;
1400 /* ... fall through ... */
1402 case ROUND_MOD_EXPR:
1403 overflow = div_and_round_double (code, uns,
1404 int1l, int1h, int2l, int2h,
1405 &garbagel, &garbageh, &low, &hi);
1411 low = (((unsigned HOST_WIDE_INT) int1h
1412 < (unsigned HOST_WIDE_INT) int2h)
1413 || (((unsigned HOST_WIDE_INT) int1h
1414 == (unsigned HOST_WIDE_INT) int2h)
1417 low = (int1h < int2h
1418 || (int1h == int2h && int1l < int2l));
1420 if (low == (code == MIN_EXPR))
1421 low = int1l, hi = int1h;
1423 low = int2l, hi = int2h;
1430 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
1434 /* Propagate overflow flags ourselves. */
1435 if (((!uns || is_sizetype) && overflow)
1436 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
1439 TREE_OVERFLOW (t) = 1;
1440 TREE_CONSTANT_OVERFLOW (t) = 1;
1442 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1445 TREE_CONSTANT_OVERFLOW (t) = 1;
1449 t = force_fit_type (t, 1,
1450 ((!uns || is_sizetype) && overflow)
1451 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2),
1452 TREE_CONSTANT_OVERFLOW (arg1)
1453 | TREE_CONSTANT_OVERFLOW (arg2));
1458 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1459 constant. We assume ARG1 and ARG2 have the same data type, or at least
1460 are the same kind of constant and the same machine mode.
1462 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1465 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1470 if (TREE_CODE (arg1) == INTEGER_CST)
1471 return int_const_binop (code, arg1, arg2, notrunc);
1473 if (TREE_CODE (arg1) == REAL_CST)
1475 enum machine_mode mode;
1478 REAL_VALUE_TYPE value;
1481 d1 = TREE_REAL_CST (arg1);
1482 d2 = TREE_REAL_CST (arg2);
1484 type = TREE_TYPE (arg1);
1485 mode = TYPE_MODE (type);
1487 /* Don't perform operation if we honor signaling NaNs and
1488 either operand is a NaN. */
1489 if (HONOR_SNANS (mode)
1490 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1493 /* Don't perform operation if it would raise a division
1494 by zero exception. */
1495 if (code == RDIV_EXPR
1496 && REAL_VALUES_EQUAL (d2, dconst0)
1497 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1500 /* If either operand is a NaN, just return it. Otherwise, set up
1501 for floating-point trap; we return an overflow. */
1502 if (REAL_VALUE_ISNAN (d1))
1504 else if (REAL_VALUE_ISNAN (d2))
1507 REAL_ARITHMETIC (value, code, d1, d2);
1509 t = build_real (type, real_value_truncate (mode, value));
1511 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
1512 TREE_CONSTANT_OVERFLOW (t)
1514 | TREE_CONSTANT_OVERFLOW (arg1)
1515 | TREE_CONSTANT_OVERFLOW (arg2);
1518 if (TREE_CODE (arg1) == COMPLEX_CST)
1520 tree type = TREE_TYPE (arg1);
1521 tree r1 = TREE_REALPART (arg1);
1522 tree i1 = TREE_IMAGPART (arg1);
1523 tree r2 = TREE_REALPART (arg2);
1524 tree i2 = TREE_IMAGPART (arg2);
1530 t = build_complex (type,
1531 const_binop (PLUS_EXPR, r1, r2, notrunc),
1532 const_binop (PLUS_EXPR, i1, i2, notrunc));
1536 t = build_complex (type,
1537 const_binop (MINUS_EXPR, r1, r2, notrunc),
1538 const_binop (MINUS_EXPR, i1, i2, notrunc));
1542 t = build_complex (type,
1543 const_binop (MINUS_EXPR,
1544 const_binop (MULT_EXPR,
1546 const_binop (MULT_EXPR,
1549 const_binop (PLUS_EXPR,
1550 const_binop (MULT_EXPR,
1552 const_binop (MULT_EXPR,
1560 = const_binop (PLUS_EXPR,
1561 const_binop (MULT_EXPR, r2, r2, notrunc),
1562 const_binop (MULT_EXPR, i2, i2, notrunc),
1565 t = build_complex (type,
1567 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1568 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1569 const_binop (PLUS_EXPR,
1570 const_binop (MULT_EXPR, r1, r2,
1572 const_binop (MULT_EXPR, i1, i2,
1575 magsquared, notrunc),
1577 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1578 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1579 const_binop (MINUS_EXPR,
1580 const_binop (MULT_EXPR, i1, r2,
1582 const_binop (MULT_EXPR, r1, i2,
1585 magsquared, notrunc));
1597 /* Create a size type INT_CST node with NUMBER sign extended. KIND
1598 indicates which particular sizetype to create. */
1601 size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
1603 return build_int_cst (sizetype_tab[(int) kind], number);
1606 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1607 is a tree code. The type of the result is taken from the operands.
1608 Both must be the same type integer type and it must be a size type.
1609 If the operands are constant, so is the result. */
1612 size_binop (enum tree_code code, tree arg0, tree arg1)
1614 tree type = TREE_TYPE (arg0);
1616 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1617 && type == TREE_TYPE (arg1));
1619 /* Handle the special case of two integer constants faster. */
1620 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1622 /* And some specific cases even faster than that. */
1623 if (code == PLUS_EXPR && integer_zerop (arg0))
1625 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1626 && integer_zerop (arg1))
1628 else if (code == MULT_EXPR && integer_onep (arg0))
1631 /* Handle general case of two integer constants. */
1632 return int_const_binop (code, arg0, arg1, 0);
1635 if (arg0 == error_mark_node || arg1 == error_mark_node)
1636 return error_mark_node;
1638 return fold (build2 (code, type, arg0, arg1));
1641 /* Given two values, either both of sizetype or both of bitsizetype,
1642 compute the difference between the two values. Return the value
1643 in signed type corresponding to the type of the operands. */
1646 size_diffop (tree arg0, tree arg1)
1648 tree type = TREE_TYPE (arg0);
1651 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1652 && type == TREE_TYPE (arg1));
1654 /* If the type is already signed, just do the simple thing. */
1655 if (!TYPE_UNSIGNED (type))
1656 return size_binop (MINUS_EXPR, arg0, arg1);
1658 ctype = type == bitsizetype ? sbitsizetype : ssizetype;
1660 /* If either operand is not a constant, do the conversions to the signed
1661 type and subtract. The hardware will do the right thing with any
1662 overflow in the subtraction. */
1663 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1664 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1665 fold_convert (ctype, arg1));
1667 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1668 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1669 overflow) and negate (which can't either). Special-case a result
1670 of zero while we're here. */
1671 if (tree_int_cst_equal (arg0, arg1))
1672 return fold_convert (ctype, integer_zero_node);
1673 else if (tree_int_cst_lt (arg1, arg0))
1674 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1676 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1677 fold_convert (ctype, size_binop (MINUS_EXPR,
1681 /* Construct a vector of zero elements of vector type TYPE. */
1684 build_zero_vector (tree type)
1689 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
1690 units = TYPE_VECTOR_SUBPARTS (type);
1693 for (i = 0; i < units; i++)
1694 list = tree_cons (NULL_TREE, elem, list);
1695 return build_vector (type, list);
1699 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1700 type TYPE. If no simplification can be done return NULL_TREE. */
1703 fold_convert_const (enum tree_code code, tree type, tree arg1)
1708 if (TREE_TYPE (arg1) == type)
1711 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1713 if (TREE_CODE (arg1) == INTEGER_CST)
1715 /* If we would build a constant wider than GCC supports,
1716 leave the conversion unfolded. */
1717 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1720 /* Given an integer constant, make new constant with new type,
1721 appropriately sign-extended or truncated. */
1722 t = build_int_cst_wide (type, TREE_INT_CST_LOW (arg1),
1723 TREE_INT_CST_HIGH (arg1));
1725 t = force_fit_type (t,
1726 /* Don't set the overflow when
1727 converting a pointer */
1728 !POINTER_TYPE_P (TREE_TYPE (arg1)),
1729 (TREE_INT_CST_HIGH (arg1) < 0
1730 && (TYPE_UNSIGNED (type)
1731 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
1732 | TREE_OVERFLOW (arg1),
1733 TREE_CONSTANT_OVERFLOW (arg1));
1736 else if (TREE_CODE (arg1) == REAL_CST)
1738 /* The following code implements the floating point to integer
1739 conversion rules required by the Java Language Specification,
1740 that IEEE NaNs are mapped to zero and values that overflow
1741 the target precision saturate, i.e. values greater than
1742 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1743 are mapped to INT_MIN. These semantics are allowed by the
1744 C and C++ standards that simply state that the behavior of
1745 FP-to-integer conversion is unspecified upon overflow. */
1747 HOST_WIDE_INT high, low;
1749 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1753 case FIX_TRUNC_EXPR:
1754 real_trunc (&r, VOIDmode, &x);
1758 real_ceil (&r, VOIDmode, &x);
1761 case FIX_FLOOR_EXPR:
1762 real_floor (&r, VOIDmode, &x);
1765 case FIX_ROUND_EXPR:
1766 real_round (&r, VOIDmode, &x);
1773 /* If R is NaN, return zero and show we have an overflow. */
1774 if (REAL_VALUE_ISNAN (r))
1781 /* See if R is less than the lower bound or greater than the
1786 tree lt = TYPE_MIN_VALUE (type);
1787 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1788 if (REAL_VALUES_LESS (r, l))
1791 high = TREE_INT_CST_HIGH (lt);
1792 low = TREE_INT_CST_LOW (lt);
1798 tree ut = TYPE_MAX_VALUE (type);
1801 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1802 if (REAL_VALUES_LESS (u, r))
1805 high = TREE_INT_CST_HIGH (ut);
1806 low = TREE_INT_CST_LOW (ut);
1812 REAL_VALUE_TO_INT (&low, &high, r);
1814 t = build_int_cst_wide (type, low, high);
1816 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg1),
1817 TREE_CONSTANT_OVERFLOW (arg1));
1821 else if (TREE_CODE (type) == REAL_TYPE)
1823 if (TREE_CODE (arg1) == INTEGER_CST)
1824 return build_real_from_int_cst (type, arg1);
1825 if (TREE_CODE (arg1) == REAL_CST)
1827 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1829 /* We make a copy of ARG1 so that we don't modify an
1830 existing constant tree. */
1831 t = copy_node (arg1);
1832 TREE_TYPE (t) = type;
1836 t = build_real (type,
1837 real_value_truncate (TYPE_MODE (type),
1838 TREE_REAL_CST (arg1)));
1840 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
1841 TREE_CONSTANT_OVERFLOW (t)
1842 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1849 /* Convert expression ARG to type TYPE. Used by the middle-end for
1850 simple conversions in preference to calling the front-end's convert. */
1853 fold_convert (tree type, tree arg)
1855 tree orig = TREE_TYPE (arg);
1861 if (TREE_CODE (arg) == ERROR_MARK
1862 || TREE_CODE (type) == ERROR_MARK
1863 || TREE_CODE (orig) == ERROR_MARK)
1864 return error_mark_node;
1866 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
1867 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
1868 TYPE_MAIN_VARIANT (orig)))
1869 return fold (build1 (NOP_EXPR, type, arg));
1871 switch (TREE_CODE (type))
1873 case INTEGER_TYPE: case CHAR_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1874 case POINTER_TYPE: case REFERENCE_TYPE:
1876 if (TREE_CODE (arg) == INTEGER_CST)
1878 tem = fold_convert_const (NOP_EXPR, type, arg);
1879 if (tem != NULL_TREE)
1882 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1883 || TREE_CODE (orig) == OFFSET_TYPE)
1884 return fold (build1 (NOP_EXPR, type, arg));
1885 if (TREE_CODE (orig) == COMPLEX_TYPE)
1887 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1888 return fold_convert (type, tem);
1890 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
1891 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1892 return fold (build1 (NOP_EXPR, type, arg));
1895 if (TREE_CODE (arg) == INTEGER_CST)
1897 tem = fold_convert_const (FLOAT_EXPR, type, arg);
1898 if (tem != NULL_TREE)
1901 else if (TREE_CODE (arg) == REAL_CST)
1903 tem = fold_convert_const (NOP_EXPR, type, arg);
1904 if (tem != NULL_TREE)
1908 switch (TREE_CODE (orig))
1910 case INTEGER_TYPE: case CHAR_TYPE:
1911 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1912 case POINTER_TYPE: case REFERENCE_TYPE:
1913 return fold (build1 (FLOAT_EXPR, type, arg));
1916 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1920 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1921 return fold_convert (type, tem);
1928 switch (TREE_CODE (orig))
1930 case INTEGER_TYPE: case CHAR_TYPE:
1931 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
1932 case POINTER_TYPE: case REFERENCE_TYPE:
1934 return build2 (COMPLEX_EXPR, type,
1935 fold_convert (TREE_TYPE (type), arg),
1936 fold_convert (TREE_TYPE (type), integer_zero_node));
1941 if (TREE_CODE (arg) == COMPLEX_EXPR)
1943 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1944 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1945 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1948 arg = save_expr (arg);
1949 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1950 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1951 rpart = fold_convert (TREE_TYPE (type), rpart);
1952 ipart = fold_convert (TREE_TYPE (type), ipart);
1953 return fold (build2 (COMPLEX_EXPR, type, rpart, ipart));
1961 if (integer_zerop (arg))
1962 return build_zero_vector (type);
1963 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
1964 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
1965 || TREE_CODE (orig) == VECTOR_TYPE);
1966 return fold (build1 (NOP_EXPR, type, arg));
1969 return fold (build1 (CONVERT_EXPR, type, fold_ignored_result (arg)));
1976 /* Return an expr equal to X but certainly not valid as an lvalue. */
1981 /* We only need to wrap lvalue tree codes. */
1982 switch (TREE_CODE (x))
1994 case ARRAY_RANGE_REF:
2000 case PREINCREMENT_EXPR:
2001 case PREDECREMENT_EXPR:
2003 case TRY_CATCH_EXPR:
2004 case WITH_CLEANUP_EXPR:
2015 /* Assume the worst for front-end tree codes. */
2016 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2020 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2023 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2024 Zero means allow extended lvalues. */
2026 int pedantic_lvalues;
2028 /* When pedantic, return an expr equal to X but certainly not valid as a
2029 pedantic lvalue. Otherwise, return X. */
2032 pedantic_non_lvalue (tree x)
2034 if (pedantic_lvalues)
2035 return non_lvalue (x);
2040 /* Given a tree comparison code, return the code that is the logical inverse
2041 of the given code. It is not safe to do this for floating-point
2042 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2043 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2045 static enum tree_code
2046 invert_tree_comparison (enum tree_code code, bool honor_nans)
2048 if (honor_nans && flag_trapping_math)
2058 return honor_nans ? UNLE_EXPR : LE_EXPR;
2060 return honor_nans ? UNLT_EXPR : LT_EXPR;
2062 return honor_nans ? UNGE_EXPR : GE_EXPR;
2064 return honor_nans ? UNGT_EXPR : GT_EXPR;
2078 return UNORDERED_EXPR;
2079 case UNORDERED_EXPR:
2080 return ORDERED_EXPR;
2086 /* Similar, but return the comparison that results if the operands are
2087 swapped. This is safe for floating-point. */
2090 swap_tree_comparison (enum tree_code code)
2111 /* Convert a comparison tree code from an enum tree_code representation
2112 into a compcode bit-based encoding. This function is the inverse of
2113 compcode_to_comparison. */
2115 static enum comparison_code
2116 comparison_to_compcode (enum tree_code code)
2133 return COMPCODE_ORD;
2134 case UNORDERED_EXPR:
2135 return COMPCODE_UNORD;
2137 return COMPCODE_UNLT;
2139 return COMPCODE_UNEQ;
2141 return COMPCODE_UNLE;
2143 return COMPCODE_UNGT;
2145 return COMPCODE_LTGT;
2147 return COMPCODE_UNGE;
2153 /* Convert a compcode bit-based encoding of a comparison operator back
2154 to GCC's enum tree_code representation. This function is the
2155 inverse of comparison_to_compcode. */
2157 static enum tree_code
2158 compcode_to_comparison (enum comparison_code code)
2175 return ORDERED_EXPR;
2176 case COMPCODE_UNORD:
2177 return UNORDERED_EXPR;
2195 /* Return a tree for the comparison which is the combination of
2196 doing the AND or OR (depending on CODE) of the two operations LCODE
2197 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2198 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2199 if this makes the transformation invalid. */
2202 combine_comparisons (enum tree_code code, enum tree_code lcode,
2203 enum tree_code rcode, tree truth_type,
2204 tree ll_arg, tree lr_arg)
2206 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2207 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2208 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2209 enum comparison_code compcode;
2213 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2214 compcode = lcompcode & rcompcode;
2217 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2218 compcode = lcompcode | rcompcode;
2227 /* Eliminate unordered comparisons, as well as LTGT and ORD
2228 which are not used unless the mode has NaNs. */
2229 compcode &= ~COMPCODE_UNORD;
2230 if (compcode == COMPCODE_LTGT)
2231 compcode = COMPCODE_NE;
2232 else if (compcode == COMPCODE_ORD)
2233 compcode = COMPCODE_TRUE;
2235 else if (flag_trapping_math)
2237 /* Check that the original operation and the optimized ones will trap
2238 under the same condition. */
2239 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2240 && (lcompcode != COMPCODE_EQ)
2241 && (lcompcode != COMPCODE_ORD);
2242 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2243 && (rcompcode != COMPCODE_EQ)
2244 && (rcompcode != COMPCODE_ORD);
2245 bool trap = (compcode & COMPCODE_UNORD) == 0
2246 && (compcode != COMPCODE_EQ)
2247 && (compcode != COMPCODE_ORD);
2249 /* In a short-circuited boolean expression the LHS might be
2250 such that the RHS, if evaluated, will never trap. For
2251 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2252 if neither x nor y is NaN. (This is a mixed blessing: for
2253 example, the expression above will never trap, hence
2254 optimizing it to x < y would be invalid). */
2255 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2256 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2259 /* If the comparison was short-circuited, and only the RHS
2260 trapped, we may now generate a spurious trap. */
2262 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2265 /* If we changed the conditions that cause a trap, we lose. */
2266 if ((ltrap || rtrap) != trap)
2270 if (compcode == COMPCODE_TRUE)
2271 return constant_boolean_node (true, truth_type);
2272 else if (compcode == COMPCODE_FALSE)
2273 return constant_boolean_node (false, truth_type);
2275 return fold (build2 (compcode_to_comparison (compcode),
2276 truth_type, ll_arg, lr_arg));
2279 /* Return nonzero if CODE is a tree code that represents a truth value. */
2282 truth_value_p (enum tree_code code)
2284 return (TREE_CODE_CLASS (code) == '<'
2285 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2286 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2287 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2290 /* Return nonzero if two operands (typically of the same tree node)
2291 are necessarily equal. If either argument has side-effects this
2292 function returns zero. FLAGS modifies behavior as follows:
2294 If OEP_ONLY_CONST is set, only return nonzero for constants.
2295 This function tests whether the operands are indistinguishable;
2296 it does not test whether they are equal using C's == operation.
2297 The distinction is important for IEEE floating point, because
2298 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2299 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2301 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
2302 even though it may hold multiple values during a function.
2303 This is because a GCC tree node guarantees that nothing else is
2304 executed between the evaluation of its "operands" (which may often
2305 be evaluated in arbitrary order). Hence if the operands themselves
2306 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2307 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2308 unset means assuming isochronic (or instantaneous) tree equivalence.
2309 Unless comparing arbitrary expression trees, such as from different
2310 statements, this flag can usually be left unset.
2312 If OEP_PURE_SAME is set, then pure functions with identical arguments
2313 are considered the same. It is used when the caller has other ways
2314 to ensure that global memory is unchanged in between. */
2317 operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2319 /* If one is specified and the other isn't, they aren't equal and if
2320 neither is specified, they are.
2322 ??? This is temporary and is meant only to handle the cases of the
2323 optional operands for COMPONENT_REF and ARRAY_REF. */
2324 if ((arg0 && !arg1) || (!arg0 && arg1))
2326 else if (!arg0 && !arg1)
2328 /* If either is ERROR_MARK, they aren't equal. */
2329 else if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
2332 /* If both types don't have the same signedness, then we can't consider
2333 them equal. We must check this before the STRIP_NOPS calls
2334 because they may change the signedness of the arguments. */
2335 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2341 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2342 /* This is needed for conversions and for COMPONENT_REF.
2343 Might as well play it safe and always test this. */
2344 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2345 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2346 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2349 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2350 We don't care about side effects in that case because the SAVE_EXPR
2351 takes care of that for us. In all other cases, two expressions are
2352 equal if they have no side effects. If we have two identical
2353 expressions with side effects that should be treated the same due
2354 to the only side effects being identical SAVE_EXPR's, that will
2355 be detected in the recursive calls below. */
2356 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
2357 && (TREE_CODE (arg0) == SAVE_EXPR
2358 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2361 /* Next handle constant cases, those for which we can return 1 even
2362 if ONLY_CONST is set. */
2363 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2364 switch (TREE_CODE (arg0))
2367 return (! TREE_CONSTANT_OVERFLOW (arg0)
2368 && ! TREE_CONSTANT_OVERFLOW (arg1)
2369 && tree_int_cst_equal (arg0, arg1));
2372 return (! TREE_CONSTANT_OVERFLOW (arg0)
2373 && ! TREE_CONSTANT_OVERFLOW (arg1)
2374 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2375 TREE_REAL_CST (arg1)));
2381 if (TREE_CONSTANT_OVERFLOW (arg0)
2382 || TREE_CONSTANT_OVERFLOW (arg1))
2385 v1 = TREE_VECTOR_CST_ELTS (arg0);
2386 v2 = TREE_VECTOR_CST_ELTS (arg1);
2389 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2392 v1 = TREE_CHAIN (v1);
2393 v2 = TREE_CHAIN (v2);
2400 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2402 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2406 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2407 && ! memcmp (TREE_STRING_POINTER (arg0),
2408 TREE_STRING_POINTER (arg1),
2409 TREE_STRING_LENGTH (arg0)));
2412 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2418 if (flags & OEP_ONLY_CONST)
2421 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2424 /* Two conversions are equal only if signedness and modes match. */
2425 switch (TREE_CODE (arg0))
2430 case FIX_TRUNC_EXPR:
2431 case FIX_FLOOR_EXPR:
2432 case FIX_ROUND_EXPR:
2433 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
2434 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2441 return operand_equal_p (TREE_OPERAND (arg0, 0),
2442 TREE_OPERAND (arg1, 0), flags);
2446 if (operand_equal_p (TREE_OPERAND (arg0, 0),
2447 TREE_OPERAND (arg1, 0), flags)
2448 && operand_equal_p (TREE_OPERAND (arg0, 1),
2449 TREE_OPERAND (arg1, 1), flags))
2452 /* For commutative ops, allow the other order. */
2453 return (commutative_tree_code (TREE_CODE (arg0))
2454 && operand_equal_p (TREE_OPERAND (arg0, 0),
2455 TREE_OPERAND (arg1, 1), flags)
2456 && operand_equal_p (TREE_OPERAND (arg0, 1),
2457 TREE_OPERAND (arg1, 0), flags));
2460 /* If either of the pointer (or reference) expressions we are
2461 dereferencing contain a side effect, these cannot be equal. */
2462 if (TREE_SIDE_EFFECTS (arg0)
2463 || TREE_SIDE_EFFECTS (arg1))
2466 switch (TREE_CODE (arg0))
2471 return operand_equal_p (TREE_OPERAND (arg0, 0),
2472 TREE_OPERAND (arg1, 0), flags);
2475 case ARRAY_RANGE_REF:
2476 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2477 TREE_OPERAND (arg1, 0), flags)
2478 && operand_equal_p (TREE_OPERAND (arg0, 1),
2479 TREE_OPERAND (arg1, 1), flags)
2480 && operand_equal_p (TREE_OPERAND (arg0, 2),
2481 TREE_OPERAND (arg1, 2), flags)
2482 && operand_equal_p (TREE_OPERAND (arg0, 3),
2483 TREE_OPERAND (arg1, 3), flags));
2487 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2488 TREE_OPERAND (arg1, 0), flags)
2489 && operand_equal_p (TREE_OPERAND (arg0, 1),
2490 TREE_OPERAND (arg1, 1), flags)
2491 && operand_equal_p (TREE_OPERAND (arg0, 2),
2492 TREE_OPERAND (arg1, 2), flags));
2496 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2497 TREE_OPERAND (arg1, 0), flags)
2498 && operand_equal_p (TREE_OPERAND (arg0, 1),
2499 TREE_OPERAND (arg1, 1), flags)
2500 && operand_equal_p (TREE_OPERAND (arg0, 2),
2501 TREE_OPERAND (arg1, 2), flags));
2507 switch (TREE_CODE (arg0))
2510 case TRUTH_NOT_EXPR:
2511 return operand_equal_p (TREE_OPERAND (arg0, 0),
2512 TREE_OPERAND (arg1, 0), flags);
2514 case TRUTH_ANDIF_EXPR:
2515 case TRUTH_ORIF_EXPR:
2516 return operand_equal_p (TREE_OPERAND (arg0, 0),
2517 TREE_OPERAND (arg1, 0), flags)
2518 && operand_equal_p (TREE_OPERAND (arg0, 1),
2519 TREE_OPERAND (arg1, 1), flags);
2521 case TRUTH_AND_EXPR:
2523 case TRUTH_XOR_EXPR:
2524 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2525 TREE_OPERAND (arg1, 0), flags)
2526 && operand_equal_p (TREE_OPERAND (arg0, 1),
2527 TREE_OPERAND (arg1, 1), flags))
2528 || (operand_equal_p (TREE_OPERAND (arg0, 0),
2529 TREE_OPERAND (arg1, 1), flags)
2530 && operand_equal_p (TREE_OPERAND (arg0, 1),
2531 TREE_OPERAND (arg1, 0), flags));
2534 /* If the CALL_EXPRs call different functions, then they
2535 clearly can not be equal. */
2536 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2537 TREE_OPERAND (arg1, 0), flags))
2541 unsigned int cef = call_expr_flags (arg0);
2542 if (flags & OEP_PURE_SAME)
2543 cef &= ECF_CONST | ECF_PURE;
2550 /* Now see if all the arguments are the same. operand_equal_p
2551 does not handle TREE_LIST, so we walk the operands here
2552 feeding them to operand_equal_p. */
2553 arg0 = TREE_OPERAND (arg0, 1);
2554 arg1 = TREE_OPERAND (arg1, 1);
2555 while (arg0 && arg1)
2557 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2561 arg0 = TREE_CHAIN (arg0);
2562 arg1 = TREE_CHAIN (arg1);
2565 /* If we get here and both argument lists are exhausted
2566 then the CALL_EXPRs are equal. */
2567 return ! (arg0 || arg1);
2574 /* Consider __builtin_sqrt equal to sqrt. */
2575 return (TREE_CODE (arg0) == FUNCTION_DECL
2576 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2577 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2578 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
2585 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2586 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2588 When in doubt, return 0. */
2591 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2593 int unsignedp1, unsignedpo;
2594 tree primarg0, primarg1, primother;
2595 unsigned int correct_width;
2597 if (operand_equal_p (arg0, arg1, 0))
2600 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2601 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2604 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2605 and see if the inner values are the same. This removes any
2606 signedness comparison, which doesn't matter here. */
2607 primarg0 = arg0, primarg1 = arg1;
2608 STRIP_NOPS (primarg0);
2609 STRIP_NOPS (primarg1);
2610 if (operand_equal_p (primarg0, primarg1, 0))
2613 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2614 actual comparison operand, ARG0.
2616 First throw away any conversions to wider types
2617 already present in the operands. */
2619 primarg1 = get_narrower (arg1, &unsignedp1);
2620 primother = get_narrower (other, &unsignedpo);
2622 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2623 if (unsignedp1 == unsignedpo
2624 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2625 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2627 tree type = TREE_TYPE (arg0);
2629 /* Make sure shorter operand is extended the right way
2630 to match the longer operand. */
2631 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
2632 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2634 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2641 /* See if ARG is an expression that is either a comparison or is performing
2642 arithmetic on comparisons. The comparisons must only be comparing
2643 two different values, which will be stored in *CVAL1 and *CVAL2; if
2644 they are nonzero it means that some operands have already been found.
2645 No variables may be used anywhere else in the expression except in the
2646 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2647 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2649 If this is true, return 1. Otherwise, return zero. */
2652 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2654 enum tree_code code = TREE_CODE (arg);
2655 char class = TREE_CODE_CLASS (code);
2657 /* We can handle some of the 'e' cases here. */
2658 if (class == 'e' && code == TRUTH_NOT_EXPR)
2660 else if (class == 'e'
2661 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2662 || code == COMPOUND_EXPR))
2665 else if (class == 'e' && code == SAVE_EXPR
2666 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2668 /* If we've already found a CVAL1 or CVAL2, this expression is
2669 two complex to handle. */
2670 if (*cval1 || *cval2)
2680 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2683 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2684 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2685 cval1, cval2, save_p));
2691 if (code == COND_EXPR)
2692 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2693 cval1, cval2, save_p)
2694 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2695 cval1, cval2, save_p)
2696 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2697 cval1, cval2, save_p));
2701 /* First see if we can handle the first operand, then the second. For
2702 the second operand, we know *CVAL1 can't be zero. It must be that
2703 one side of the comparison is each of the values; test for the
2704 case where this isn't true by failing if the two operands
2707 if (operand_equal_p (TREE_OPERAND (arg, 0),
2708 TREE_OPERAND (arg, 1), 0))
2712 *cval1 = TREE_OPERAND (arg, 0);
2713 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2715 else if (*cval2 == 0)
2716 *cval2 = TREE_OPERAND (arg, 0);
2717 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2722 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2724 else if (*cval2 == 0)
2725 *cval2 = TREE_OPERAND (arg, 1);
2726 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2738 /* ARG is a tree that is known to contain just arithmetic operations and
2739 comparisons. Evaluate the operations in the tree substituting NEW0 for
2740 any occurrence of OLD0 as an operand of a comparison and likewise for
2744 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2746 tree type = TREE_TYPE (arg);
2747 enum tree_code code = TREE_CODE (arg);
2748 char class = TREE_CODE_CLASS (code);
2750 /* We can handle some of the 'e' cases here. */
2751 if (class == 'e' && code == TRUTH_NOT_EXPR)
2753 else if (class == 'e'
2754 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2760 return fold (build1 (code, type,
2761 eval_subst (TREE_OPERAND (arg, 0),
2762 old0, new0, old1, new1)));
2765 return fold (build2 (code, type,
2766 eval_subst (TREE_OPERAND (arg, 0),
2767 old0, new0, old1, new1),
2768 eval_subst (TREE_OPERAND (arg, 1),
2769 old0, new0, old1, new1)));
2775 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2778 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2781 return fold (build3 (code, type,
2782 eval_subst (TREE_OPERAND (arg, 0),
2783 old0, new0, old1, new1),
2784 eval_subst (TREE_OPERAND (arg, 1),
2785 old0, new0, old1, new1),
2786 eval_subst (TREE_OPERAND (arg, 2),
2787 old0, new0, old1, new1)));
2791 /* Fall through - ??? */
2795 tree arg0 = TREE_OPERAND (arg, 0);
2796 tree arg1 = TREE_OPERAND (arg, 1);
2798 /* We need to check both for exact equality and tree equality. The
2799 former will be true if the operand has a side-effect. In that
2800 case, we know the operand occurred exactly once. */
2802 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2804 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2807 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2809 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2812 return fold (build2 (code, type, arg0, arg1));
2820 /* Return a tree for the case when the result of an expression is RESULT
2821 converted to TYPE and OMITTED was previously an operand of the expression
2822 but is now not needed (e.g., we folded OMITTED * 0).
2824 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2825 the conversion of RESULT to TYPE. */
2828 omit_one_operand (tree type, tree result, tree omitted)
2830 tree t = fold_convert (type, result);
2832 if (TREE_SIDE_EFFECTS (omitted))
2833 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2835 return non_lvalue (t);
2838 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2841 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2843 tree t = fold_convert (type, result);
2845 if (TREE_SIDE_EFFECTS (omitted))
2846 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2848 return pedantic_non_lvalue (t);
2851 /* Return a tree for the case when the result of an expression is RESULT
2852 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
2853 of the expression but are now not needed.
2855 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
2856 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
2857 evaluated before OMITTED2. Otherwise, if neither has side effects,
2858 just do the conversion of RESULT to TYPE. */
2861 omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
2863 tree t = fold_convert (type, result);
2865 if (TREE_SIDE_EFFECTS (omitted2))
2866 t = build2 (COMPOUND_EXPR, type, omitted2, t);
2867 if (TREE_SIDE_EFFECTS (omitted1))
2868 t = build2 (COMPOUND_EXPR, type, omitted1, t);
2870 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
2874 /* Return a simplified tree node for the truth-negation of ARG. This
2875 never alters ARG itself. We assume that ARG is an operation that
2876 returns a truth value (0 or 1).
2878 FIXME: one would think we would fold the result, but it causes
2879 problems with the dominator optimizer. */
2881 invert_truthvalue (tree arg)
2883 tree type = TREE_TYPE (arg);
2884 enum tree_code code = TREE_CODE (arg);
2886 if (code == ERROR_MARK)
2889 /* If this is a comparison, we can simply invert it, except for
2890 floating-point non-equality comparisons, in which case we just
2891 enclose a TRUTH_NOT_EXPR around what we have. */
2893 if (TREE_CODE_CLASS (code) == '<')
2895 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
2896 if (FLOAT_TYPE_P (op_type)
2897 && flag_trapping_math
2898 && code != ORDERED_EXPR && code != UNORDERED_EXPR
2899 && code != NE_EXPR && code != EQ_EXPR)
2900 return build1 (TRUTH_NOT_EXPR, type, arg);
2903 code = invert_tree_comparison (code,
2904 HONOR_NANS (TYPE_MODE (op_type)));
2905 if (code == ERROR_MARK)
2906 return build1 (TRUTH_NOT_EXPR, type, arg);
2908 return build2 (code, type,
2909 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2916 return fold_convert (type,
2917 build_int_cst (NULL_TREE, integer_zerop (arg)));
2919 case TRUTH_AND_EXPR:
2920 return build2 (TRUTH_OR_EXPR, type,
2921 invert_truthvalue (TREE_OPERAND (arg, 0)),
2922 invert_truthvalue (TREE_OPERAND (arg, 1)));
2925 return build2 (TRUTH_AND_EXPR, type,
2926 invert_truthvalue (TREE_OPERAND (arg, 0)),
2927 invert_truthvalue (TREE_OPERAND (arg, 1)));
2929 case TRUTH_XOR_EXPR:
2930 /* Here we can invert either operand. We invert the first operand
2931 unless the second operand is a TRUTH_NOT_EXPR in which case our
2932 result is the XOR of the first operand with the inside of the
2933 negation of the second operand. */
2935 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2936 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2937 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2939 return build2 (TRUTH_XOR_EXPR, type,
2940 invert_truthvalue (TREE_OPERAND (arg, 0)),
2941 TREE_OPERAND (arg, 1));
2943 case TRUTH_ANDIF_EXPR:
2944 return build2 (TRUTH_ORIF_EXPR, type,
2945 invert_truthvalue (TREE_OPERAND (arg, 0)),
2946 invert_truthvalue (TREE_OPERAND (arg, 1)));
2948 case TRUTH_ORIF_EXPR:
2949 return build2 (TRUTH_ANDIF_EXPR, type,
2950 invert_truthvalue (TREE_OPERAND (arg, 0)),
2951 invert_truthvalue (TREE_OPERAND (arg, 1)));
2953 case TRUTH_NOT_EXPR:
2954 return TREE_OPERAND (arg, 0);
2957 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
2958 invert_truthvalue (TREE_OPERAND (arg, 1)),
2959 invert_truthvalue (TREE_OPERAND (arg, 2)));
2962 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2963 invert_truthvalue (TREE_OPERAND (arg, 1)));
2965 case NON_LVALUE_EXPR:
2966 return invert_truthvalue (TREE_OPERAND (arg, 0));
2969 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2974 return build1 (TREE_CODE (arg), type,
2975 invert_truthvalue (TREE_OPERAND (arg, 0)));
2978 if (!integer_onep (TREE_OPERAND (arg, 1)))
2980 return build2 (EQ_EXPR, type, arg,
2981 fold_convert (type, integer_zero_node));
2984 return build1 (TRUTH_NOT_EXPR, type, arg);
2986 case CLEANUP_POINT_EXPR:
2987 return build1 (CLEANUP_POINT_EXPR, type,
2988 invert_truthvalue (TREE_OPERAND (arg, 0)));
2993 gcc_assert (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE);
2994 return build1 (TRUTH_NOT_EXPR, type, arg);
2997 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2998 operands are another bit-wise operation with a common input. If so,
2999 distribute the bit operations to save an operation and possibly two if
3000 constants are involved. For example, convert
3001 (A | B) & (A | C) into A | (B & C)
3002 Further simplification will occur if B and C are constants.
3004 If this optimization cannot be done, 0 will be returned. */
3007 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
3012 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3013 || TREE_CODE (arg0) == code
3014 || (TREE_CODE (arg0) != BIT_AND_EXPR
3015 && TREE_CODE (arg0) != BIT_IOR_EXPR))
3018 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3020 common = TREE_OPERAND (arg0, 0);
3021 left = TREE_OPERAND (arg0, 1);
3022 right = TREE_OPERAND (arg1, 1);
3024 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3026 common = TREE_OPERAND (arg0, 0);
3027 left = TREE_OPERAND (arg0, 1);
3028 right = TREE_OPERAND (arg1, 0);
3030 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3032 common = TREE_OPERAND (arg0, 1);
3033 left = TREE_OPERAND (arg0, 0);
3034 right = TREE_OPERAND (arg1, 1);
3036 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3038 common = TREE_OPERAND (arg0, 1);
3039 left = TREE_OPERAND (arg0, 0);
3040 right = TREE_OPERAND (arg1, 0);
3045 return fold (build2 (TREE_CODE (arg0), type, common,
3046 fold (build2 (code, type, left, right))));
3049 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
3050 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
3053 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3056 tree result = build3 (BIT_FIELD_REF, type, inner,
3057 size_int (bitsize), bitsize_int (bitpos));
3059 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
3064 /* Optimize a bit-field compare.
3066 There are two cases: First is a compare against a constant and the
3067 second is a comparison of two items where the fields are at the same
3068 bit position relative to the start of a chunk (byte, halfword, word)
3069 large enough to contain it. In these cases we can avoid the shift
3070 implicit in bitfield extractions.
3072 For constants, we emit a compare of the shifted constant with the
3073 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3074 compared. For two fields at the same position, we do the ANDs with the
3075 similar mask and compare the result of the ANDs.
3077 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3078 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3079 are the left and right operands of the comparison, respectively.
3081 If the optimization described above can be done, we return the resulting
3082 tree. Otherwise we return zero. */
3085 optimize_bit_field_compare (enum tree_code code, tree compare_type,
3088 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
3089 tree type = TREE_TYPE (lhs);
3090 tree signed_type, unsigned_type;
3091 int const_p = TREE_CODE (rhs) == INTEGER_CST;
3092 enum machine_mode lmode, rmode, nmode;
3093 int lunsignedp, runsignedp;
3094 int lvolatilep = 0, rvolatilep = 0;
3095 tree linner, rinner = NULL_TREE;
3099 /* Get all the information about the extractions being done. If the bit size
3100 if the same as the size of the underlying object, we aren't doing an
3101 extraction at all and so can do nothing. We also don't want to
3102 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3103 then will no longer be able to replace it. */
3104 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
3105 &lunsignedp, &lvolatilep);
3106 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
3107 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
3112 /* If this is not a constant, we can only do something if bit positions,
3113 sizes, and signedness are the same. */
3114 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
3115 &runsignedp, &rvolatilep);
3117 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
3118 || lunsignedp != runsignedp || offset != 0
3119 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
3123 /* See if we can find a mode to refer to this field. We should be able to,
3124 but fail if we can't. */
3125 nmode = get_best_mode (lbitsize, lbitpos,
3126 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3127 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3128 TYPE_ALIGN (TREE_TYPE (rinner))),
3129 word_mode, lvolatilep || rvolatilep);
3130 if (nmode == VOIDmode)
3133 /* Set signed and unsigned types of the precision of this mode for the
3135 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3136 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
3138 /* Compute the bit position and size for the new reference and our offset
3139 within it. If the new reference is the same size as the original, we
3140 won't optimize anything, so return zero. */
3141 nbitsize = GET_MODE_BITSIZE (nmode);
3142 nbitpos = lbitpos & ~ (nbitsize - 1);
3144 if (nbitsize == lbitsize)
3147 if (BYTES_BIG_ENDIAN)
3148 lbitpos = nbitsize - lbitsize - lbitpos;
3150 /* Make the mask to be used against the extracted field. */
3151 mask = build_int_cst (unsigned_type, -1);
3152 mask = force_fit_type (mask, 0, false, false);
3153 mask = fold_convert (unsigned_type, mask);
3154 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
3155 mask = const_binop (RSHIFT_EXPR, mask,
3156 size_int (nbitsize - lbitsize - lbitpos), 0);
3159 /* If not comparing with constant, just rework the comparison
3161 return build2 (code, compare_type,
3162 build2 (BIT_AND_EXPR, unsigned_type,
3163 make_bit_field_ref (linner, unsigned_type,
3164 nbitsize, nbitpos, 1),
3166 build2 (BIT_AND_EXPR, unsigned_type,
3167 make_bit_field_ref (rinner, unsigned_type,
3168 nbitsize, nbitpos, 1),
3171 /* Otherwise, we are handling the constant case. See if the constant is too
3172 big for the field. Warn and return a tree of for 0 (false) if so. We do
3173 this not only for its own sake, but to avoid having to test for this
3174 error case below. If we didn't, we might generate wrong code.
3176 For unsigned fields, the constant shifted right by the field length should
3177 be all zero. For signed fields, the high-order bits should agree with
3182 if (! integer_zerop (const_binop (RSHIFT_EXPR,
3183 fold_convert (unsigned_type, rhs),
3184 size_int (lbitsize), 0)))
3186 warning ("comparison is always %d due to width of bit-field",
3188 return constant_boolean_node (code == NE_EXPR, compare_type);
3193 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
3194 size_int (lbitsize - 1), 0);
3195 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3197 warning ("comparison is always %d due to width of bit-field",
3199 return constant_boolean_node (code == NE_EXPR, compare_type);
3203 /* Single-bit compares should always be against zero. */
3204 if (lbitsize == 1 && ! integer_zerop (rhs))
3206 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3207 rhs = fold_convert (type, integer_zero_node);
3210 /* Make a new bitfield reference, shift the constant over the
3211 appropriate number of bits and mask it with the computed mask
3212 (in case this was a signed field). If we changed it, make a new one. */
3213 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
3216 TREE_SIDE_EFFECTS (lhs) = 1;
3217 TREE_THIS_VOLATILE (lhs) = 1;
3220 rhs = fold (const_binop (BIT_AND_EXPR,
3221 const_binop (LSHIFT_EXPR,
3222 fold_convert (unsigned_type, rhs),
3223 size_int (lbitpos), 0),
3226 return build2 (code, compare_type,
3227 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3231 /* Subroutine for fold_truthop: decode a field reference.
3233 If EXP is a comparison reference, we return the innermost reference.
3235 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3236 set to the starting bit number.
3238 If the innermost field can be completely contained in a mode-sized
3239 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3241 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3242 otherwise it is not changed.
3244 *PUNSIGNEDP is set to the signedness of the field.
3246 *PMASK is set to the mask used. This is either contained in a
3247 BIT_AND_EXPR or derived from the width of the field.
3249 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3251 Return 0 if this is not a component reference or is one that we can't
3252 do anything with. */
3255 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3256 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3257 int *punsignedp, int *pvolatilep,
3258 tree *pmask, tree *pand_mask)
3260 tree outer_type = 0;
3262 tree mask, inner, offset;
3264 unsigned int precision;
3266 /* All the optimizations using this function assume integer fields.
3267 There are problems with FP fields since the type_for_size call
3268 below can fail for, e.g., XFmode. */
3269 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3272 /* We are interested in the bare arrangement of bits, so strip everything
3273 that doesn't affect the machine mode. However, record the type of the
3274 outermost expression if it may matter below. */
3275 if (TREE_CODE (exp) == NOP_EXPR
3276 || TREE_CODE (exp) == CONVERT_EXPR
3277 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3278 outer_type = TREE_TYPE (exp);
3281 if (TREE_CODE (exp) == BIT_AND_EXPR)
3283 and_mask = TREE_OPERAND (exp, 1);
3284 exp = TREE_OPERAND (exp, 0);
3285 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3286 if (TREE_CODE (and_mask) != INTEGER_CST)
3290 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3291 punsignedp, pvolatilep);
3292 if ((inner == exp && and_mask == 0)
3293 || *pbitsize < 0 || offset != 0
3294 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3297 /* If the number of bits in the reference is the same as the bitsize of
3298 the outer type, then the outer type gives the signedness. Otherwise
3299 (in case of a small bitfield) the signedness is unchanged. */
3300 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
3301 *punsignedp = TYPE_UNSIGNED (outer_type);
3303 /* Compute the mask to access the bitfield. */
3304 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
3305 precision = TYPE_PRECISION (unsigned_type);
3307 mask = build_int_cst (unsigned_type, -1);
3308 mask = force_fit_type (mask, 0, false, false);
3310 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3311 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3313 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3315 mask = fold (build2 (BIT_AND_EXPR, unsigned_type,
3316 fold_convert (unsigned_type, and_mask), mask));
3319 *pand_mask = and_mask;
3323 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3327 all_ones_mask_p (tree mask, int size)
3329 tree type = TREE_TYPE (mask);
3330 unsigned int precision = TYPE_PRECISION (type);
3333 tmask = build_int_cst (lang_hooks.types.signed_type (type), -1);
3334 tmask = force_fit_type (tmask, 0, false, false);
3337 tree_int_cst_equal (mask,
3338 const_binop (RSHIFT_EXPR,
3339 const_binop (LSHIFT_EXPR, tmask,
3340 size_int (precision - size),
3342 size_int (precision - size), 0));
3345 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3346 represents the sign bit of EXP's type. If EXP represents a sign
3347 or zero extension, also test VAL against the unextended type.
3348 The return value is the (sub)expression whose sign bit is VAL,
3349 or NULL_TREE otherwise. */
3352 sign_bit_p (tree exp, tree val)
3354 unsigned HOST_WIDE_INT mask_lo, lo;
3355 HOST_WIDE_INT mask_hi, hi;
3359 /* Tree EXP must have an integral type. */
3360 t = TREE_TYPE (exp);
3361 if (! INTEGRAL_TYPE_P (t))
3364 /* Tree VAL must be an integer constant. */
3365 if (TREE_CODE (val) != INTEGER_CST
3366 || TREE_CONSTANT_OVERFLOW (val))
3369 width = TYPE_PRECISION (t);
3370 if (width > HOST_BITS_PER_WIDE_INT)
3372 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3375 mask_hi = ((unsigned HOST_WIDE_INT) -1
3376 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3382 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3385 mask_lo = ((unsigned HOST_WIDE_INT) -1
3386 >> (HOST_BITS_PER_WIDE_INT - width));
3389 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3390 treat VAL as if it were unsigned. */
3391 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3392 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3395 /* Handle extension from a narrower type. */
3396 if (TREE_CODE (exp) == NOP_EXPR
3397 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3398 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3403 /* Subroutine for fold_truthop: determine if an operand is simple enough
3404 to be evaluated unconditionally. */
3407 simple_operand_p (tree exp)
3409 /* Strip any conversions that don't change the machine mode. */
3410 while ((TREE_CODE (exp) == NOP_EXPR
3411 || TREE_CODE (exp) == CONVERT_EXPR)
3412 && (TYPE_MODE (TREE_TYPE (exp))
3413 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3414 exp = TREE_OPERAND (exp, 0);
3416 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3418 && ! TREE_ADDRESSABLE (exp)
3419 && ! TREE_THIS_VOLATILE (exp)
3420 && ! DECL_NONLOCAL (exp)
3421 /* Don't regard global variables as simple. They may be
3422 allocated in ways unknown to the compiler (shared memory,
3423 #pragma weak, etc). */
3424 && ! TREE_PUBLIC (exp)
3425 && ! DECL_EXTERNAL (exp)
3426 /* Loading a static variable is unduly expensive, but global
3427 registers aren't expensive. */
3428 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3431 /* The following functions are subroutines to fold_range_test and allow it to
3432 try to change a logical combination of comparisons into a range test.
3435 X == 2 || X == 3 || X == 4 || X == 5
3439 (unsigned) (X - 2) <= 3
3441 We describe each set of comparisons as being either inside or outside
3442 a range, using a variable named like IN_P, and then describe the
3443 range with a lower and upper bound. If one of the bounds is omitted,
3444 it represents either the highest or lowest value of the type.
3446 In the comments below, we represent a range by two numbers in brackets
3447 preceded by a "+" to designate being inside that range, or a "-" to
3448 designate being outside that range, so the condition can be inverted by
3449 flipping the prefix. An omitted bound is represented by a "-". For
3450 example, "- [-, 10]" means being outside the range starting at the lowest
3451 possible value and ending at 10, in other words, being greater than 10.
3452 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3455 We set up things so that the missing bounds are handled in a consistent
3456 manner so neither a missing bound nor "true" and "false" need to be
3457 handled using a special case. */
3459 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3460 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3461 and UPPER1_P are nonzero if the respective argument is an upper bound
3462 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3463 must be specified for a comparison. ARG1 will be converted to ARG0's
3464 type if both are specified. */
3467 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3468 tree arg1, int upper1_p)
3474 /* If neither arg represents infinity, do the normal operation.
3475 Else, if not a comparison, return infinity. Else handle the special
3476 comparison rules. Note that most of the cases below won't occur, but
3477 are handled for consistency. */
3479 if (arg0 != 0 && arg1 != 0)
3481 tem = fold (build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3482 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3484 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3487 if (TREE_CODE_CLASS (code) != '<')
3490 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3491 for neither. In real maths, we cannot assume open ended ranges are
3492 the same. But, this is computer arithmetic, where numbers are finite.
3493 We can therefore make the transformation of any unbounded range with
3494 the value Z, Z being greater than any representable number. This permits
3495 us to treat unbounded ranges as equal. */
3496 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3497 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3501 result = sgn0 == sgn1;
3504 result = sgn0 != sgn1;
3507 result = sgn0 < sgn1;
3510 result = sgn0 <= sgn1;
3513 result = sgn0 > sgn1;
3516 result = sgn0 >= sgn1;
3522 return constant_boolean_node (result, type);
3525 /* Given EXP, a logical expression, set the range it is testing into
3526 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3527 actually being tested. *PLOW and *PHIGH will be made of the same type
3528 as the returned expression. If EXP is not a comparison, we will most
3529 likely not be returning a useful value and range. */
3532 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3534 enum tree_code code;
3535 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
3536 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
3538 tree low, high, n_low, n_high;
3540 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3541 and see if we can refine the range. Some of the cases below may not
3542 happen, but it doesn't seem worth worrying about this. We "continue"
3543 the outer loop when we've changed something; otherwise we "break"
3544 the switch, which will "break" the while. */
3547 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3551 code = TREE_CODE (exp);
3552 exp_type = TREE_TYPE (exp);
3554 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3556 if (first_rtl_op (code) > 0)
3557 arg0 = TREE_OPERAND (exp, 0);
3558 if (TREE_CODE_CLASS (code) == '<'
3559 || TREE_CODE_CLASS (code) == '1'
3560 || TREE_CODE_CLASS (code) == '2')
3561 arg0_type = TREE_TYPE (arg0);
3562 if (TREE_CODE_CLASS (code) == '2'
3563 || TREE_CODE_CLASS (code) == '<'
3564 || (TREE_CODE_CLASS (code) == 'e'
3565 && TREE_CODE_LENGTH (code) > 1))
3566 arg1 = TREE_OPERAND (exp, 1);
3571 case TRUTH_NOT_EXPR:
3572 in_p = ! in_p, exp = arg0;
3575 case EQ_EXPR: case NE_EXPR:
3576 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3577 /* We can only do something if the range is testing for zero
3578 and if the second operand is an integer constant. Note that
3579 saying something is "in" the range we make is done by
3580 complementing IN_P since it will set in the initial case of
3581 being not equal to zero; "out" is leaving it alone. */
3582 if (low == 0 || high == 0
3583 || ! integer_zerop (low) || ! integer_zerop (high)
3584 || TREE_CODE (arg1) != INTEGER_CST)
3589 case NE_EXPR: /* - [c, c] */
3592 case EQ_EXPR: /* + [c, c] */
3593 in_p = ! in_p, low = high = arg1;
3595 case GT_EXPR: /* - [-, c] */
3596 low = 0, high = arg1;
3598 case GE_EXPR: /* + [c, -] */
3599 in_p = ! in_p, low = arg1, high = 0;
3601 case LT_EXPR: /* - [c, -] */
3602 low = arg1, high = 0;
3604 case LE_EXPR: /* + [-, c] */
3605 in_p = ! in_p, low = 0, high = arg1;
3611 /* If this is an unsigned comparison, we also know that EXP is
3612 greater than or equal to zero. We base the range tests we make
3613 on that fact, so we record it here so we can parse existing
3614 range tests. We test arg0_type since often the return type
3615 of, e.g. EQ_EXPR, is boolean. */
3616 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
3618 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3620 fold_convert (arg0_type, integer_zero_node),
3624 in_p = n_in_p, low = n_low, high = n_high;
3626 /* If the high bound is missing, but we have a nonzero low
3627 bound, reverse the range so it goes from zero to the low bound
3629 if (high == 0 && low && ! integer_zerop (low))
3632 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3633 integer_one_node, 0);
3634 low = fold_convert (arg0_type, integer_zero_node);
3642 /* (-x) IN [a,b] -> x in [-b, -a] */
3643 n_low = range_binop (MINUS_EXPR, exp_type,
3644 fold_convert (exp_type, integer_zero_node),
3646 n_high = range_binop (MINUS_EXPR, exp_type,
3647 fold_convert (exp_type, integer_zero_node),
3649 low = n_low, high = n_high;
3655 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
3656 fold_convert (exp_type, integer_one_node));
3659 case PLUS_EXPR: case MINUS_EXPR:
3660 if (TREE_CODE (arg1) != INTEGER_CST)
3663 /* If EXP is signed, any overflow in the computation is undefined,
3664 so we don't worry about it so long as our computations on
3665 the bounds don't overflow. For unsigned, overflow is defined
3666 and this is exactly the right thing. */
3667 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3668 arg0_type, low, 0, arg1, 0);
3669 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3670 arg0_type, high, 1, arg1, 0);
3671 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3672 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3675 /* Check for an unsigned range which has wrapped around the maximum
3676 value thus making n_high < n_low, and normalize it. */
3677 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3679 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
3680 integer_one_node, 0);
3681 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
3682 integer_one_node, 0);
3684 /* If the range is of the form +/- [ x+1, x ], we won't
3685 be able to normalize it. But then, it represents the
3686 whole range or the empty set, so make it
3688 if (tree_int_cst_equal (n_low, low)
3689 && tree_int_cst_equal (n_high, high))
3695 low = n_low, high = n_high;
3700 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3701 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
3704 if (! INTEGRAL_TYPE_P (arg0_type)
3705 || (low != 0 && ! int_fits_type_p (low, arg0_type))
3706 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
3709 n_low = low, n_high = high;
3712 n_low = fold_convert (arg0_type, n_low);
3715 n_high = fold_convert (arg0_type, n_high);
3718 /* If we're converting arg0 from an unsigned type, to exp,
3719 a signed type, we will be doing the comparison as unsigned.
3720 The tests above have already verified that LOW and HIGH
3723 So we have to ensure that we will handle large unsigned
3724 values the same way that the current signed bounds treat
3727 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
3730 tree equiv_type = lang_hooks.types.type_for_mode
3731 (TYPE_MODE (arg0_type), 1);
3733 /* A range without an upper bound is, naturally, unbounded.
3734 Since convert would have cropped a very large value, use
3735 the max value for the destination type. */
3737 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3738 : TYPE_MAX_VALUE (arg0_type);
3740 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
3741 high_positive = fold (build2 (RSHIFT_EXPR, arg0_type,
3742 fold_convert (arg0_type,
3744 fold_convert (arg0_type,
3745 integer_one_node)));
3747 /* If the low bound is specified, "and" the range with the
3748 range for which the original unsigned value will be
3752 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3753 1, n_low, n_high, 1,
3754 fold_convert (arg0_type,
3759 in_p = (n_in_p == in_p);
3763 /* Otherwise, "or" the range with the range of the input
3764 that will be interpreted as negative. */
3765 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3766 0, n_low, n_high, 1,
3767 fold_convert (arg0_type,
3772 in_p = (in_p != n_in_p);
3777 low = n_low, high = n_high;
3787 /* If EXP is a constant, we can evaluate whether this is true or false. */
3788 if (TREE_CODE (exp) == INTEGER_CST)
3790 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3792 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3798 *pin_p = in_p, *plow = low, *phigh = high;
3802 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3803 type, TYPE, return an expression to test if EXP is in (or out of, depending
3804 on IN_P) the range. Return 0 if the test couldn't be created. */
3807 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3809 tree etype = TREE_TYPE (exp);
3814 value = build_range_check (type, exp, 1, low, high);
3816 return invert_truthvalue (value);
3821 if (low == 0 && high == 0)
3822 return fold_convert (type, integer_one_node);
3825 return fold (build2 (LE_EXPR, type, exp, high));
3828 return fold (build2 (GE_EXPR, type, exp, low));
3830 if (operand_equal_p (low, high, 0))
3831 return fold (build2 (EQ_EXPR, type, exp, low));
3833 if (integer_zerop (low))
3835 if (! TYPE_UNSIGNED (etype))
3837 etype = lang_hooks.types.unsigned_type (etype);
3838 high = fold_convert (etype, high);
3839 exp = fold_convert (etype, exp);
3841 return build_range_check (type, exp, 1, 0, high);
3844 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3845 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3847 unsigned HOST_WIDE_INT lo;
3851 prec = TYPE_PRECISION (etype);
3852 if (prec <= HOST_BITS_PER_WIDE_INT)
3855 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3859 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3860 lo = (unsigned HOST_WIDE_INT) -1;
3863 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3865 if (TYPE_UNSIGNED (etype))
3867 etype = lang_hooks.types.signed_type (etype);
3868 exp = fold_convert (etype, exp);
3870 return fold (build2 (GT_EXPR, type, exp,
3871 fold_convert (etype, integer_zero_node)));
3875 value = const_binop (MINUS_EXPR, high, low, 0);
3876 if (value != 0 && TREE_OVERFLOW (value) && ! TYPE_UNSIGNED (etype))
3878 tree utype, minv, maxv;
3880 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
3881 for the type in question, as we rely on this here. */
3882 switch (TREE_CODE (etype))
3887 utype = lang_hooks.types.unsigned_type (etype);
3888 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
3889 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
3890 integer_one_node, 1);
3891 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
3892 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
3896 high = fold_convert (etype, high);
3897 low = fold_convert (etype, low);
3898 exp = fold_convert (etype, exp);
3899 value = const_binop (MINUS_EXPR, high, low, 0);
3907 if (value != 0 && ! TREE_OVERFLOW (value))
3908 return build_range_check (type,
3909 fold (build2 (MINUS_EXPR, etype, exp, low)),
3910 1, fold_convert (etype, integer_zero_node),
3916 /* Given two ranges, see if we can merge them into one. Return 1 if we
3917 can, 0 if we can't. Set the output range into the specified parameters. */
3920 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3921 tree high0, int in1_p, tree low1, tree high1)
3929 int lowequal = ((low0 == 0 && low1 == 0)
3930 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3931 low0, 0, low1, 0)));
3932 int highequal = ((high0 == 0 && high1 == 0)
3933 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3934 high0, 1, high1, 1)));
3936 /* Make range 0 be the range that starts first, or ends last if they
3937 start at the same value. Swap them if it isn't. */
3938 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3941 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3942 high1, 1, high0, 1))))
3944 temp = in0_p, in0_p = in1_p, in1_p = temp;
3945 tem = low0, low0 = low1, low1 = tem;
3946 tem = high0, high0 = high1, high1 = tem;
3949 /* Now flag two cases, whether the ranges are disjoint or whether the
3950 second range is totally subsumed in the first. Note that the tests
3951 below are simplified by the ones above. */
3952 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3953 high0, 1, low1, 0));
3954 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3955 high1, 1, high0, 1));
3957 /* We now have four cases, depending on whether we are including or
3958 excluding the two ranges. */
3961 /* If they don't overlap, the result is false. If the second range
3962 is a subset it is the result. Otherwise, the range is from the start
3963 of the second to the end of the first. */
3965 in_p = 0, low = high = 0;
3967 in_p = 1, low = low1, high = high1;
3969 in_p = 1, low = low1, high = high0;
3972 else if (in0_p && ! in1_p)
3974 /* If they don't overlap, the result is the first range. If they are
3975 equal, the result is false. If the second range is a subset of the
3976 first, and the ranges begin at the same place, we go from just after
3977 the end of the first range to the end of the second. If the second
3978 range is not a subset of the first, or if it is a subset and both
3979 ranges end at the same place, the range starts at the start of the
3980 first range and ends just before the second range.
3981 Otherwise, we can't describe this as a single range. */
3983 in_p = 1, low = low0, high = high0;
3984 else if (lowequal && highequal)
3985 in_p = 0, low = high = 0;
3986 else if (subset && lowequal)
3988 in_p = 1, high = high0;
3989 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3990 integer_one_node, 0);
3992 else if (! subset || highequal)
3994 in_p = 1, low = low0;
3995 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3996 integer_one_node, 0);
4002 else if (! in0_p && in1_p)
4004 /* If they don't overlap, the result is the second range. If the second
4005 is a subset of the first, the result is false. Otherwise,
4006 the range starts just after the first range and ends at the
4007 end of the second. */
4009 in_p = 1, low = low1, high = high1;
4010 else if (subset || highequal)
4011 in_p = 0, low = high = 0;
4014 in_p = 1, high = high1;
4015 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4016 integer_one_node, 0);
4022 /* The case where we are excluding both ranges. Here the complex case
4023 is if they don't overlap. In that case, the only time we have a
4024 range is if they are adjacent. If the second is a subset of the
4025 first, the result is the first. Otherwise, the range to exclude
4026 starts at the beginning of the first range and ends at the end of the
4030 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
4031 range_binop (PLUS_EXPR, NULL_TREE,
4033 integer_one_node, 1),
4035 in_p = 0, low = low0, high = high1;
4038 /* Canonicalize - [min, x] into - [-, x]. */
4039 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4040 switch (TREE_CODE (TREE_TYPE (low0)))
4043 if (TYPE_PRECISION (TREE_TYPE (low0))
4044 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4049 if (tree_int_cst_equal (low0,
4050 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4054 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4055 && integer_zerop (low0))
4062 /* Canonicalize - [x, max] into - [x, -]. */
4063 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4064 switch (TREE_CODE (TREE_TYPE (high1)))
4067 if (TYPE_PRECISION (TREE_TYPE (high1))
4068 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4073 if (tree_int_cst_equal (high1,
4074 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4078 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4079 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4081 integer_one_node, 1)))
4088 /* The ranges might be also adjacent between the maximum and
4089 minimum values of the given type. For
4090 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4091 return + [x + 1, y - 1]. */
4092 if (low0 == 0 && high1 == 0)
4094 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
4095 integer_one_node, 1);
4096 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
4097 integer_one_node, 0);
4098 if (low == 0 || high == 0)
4108 in_p = 0, low = low0, high = high0;
4110 in_p = 0, low = low0, high = high1;
4113 *pin_p = in_p, *plow = low, *phigh = high;
4118 /* Subroutine of fold, looking inside expressions of the form
4119 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4120 of the COND_EXPR. This function is being used also to optimize
4121 A op B ? C : A, by reversing the comparison first.
4123 Return a folded expression whose code is not a COND_EXPR
4124 anymore, or NULL_TREE if no folding opportunity is found. */
4127 fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
4129 enum tree_code comp_code = TREE_CODE (arg0);
4130 tree arg00 = TREE_OPERAND (arg0, 0);
4131 tree arg01 = TREE_OPERAND (arg0, 1);
4132 tree arg1_type = TREE_TYPE (arg1);
4138 /* If we have A op 0 ? A : -A, consider applying the following
4141 A == 0? A : -A same as -A
4142 A != 0? A : -A same as A
4143 A >= 0? A : -A same as abs (A)
4144 A > 0? A : -A same as abs (A)
4145 A <= 0? A : -A same as -abs (A)
4146 A < 0? A : -A same as -abs (A)
4148 None of these transformations work for modes with signed
4149 zeros. If A is +/-0, the first two transformations will
4150 change the sign of the result (from +0 to -0, or vice
4151 versa). The last four will fix the sign of the result,
4152 even though the original expressions could be positive or
4153 negative, depending on the sign of A.
4155 Note that all these transformations are correct if A is
4156 NaN, since the two alternatives (A and -A) are also NaNs. */
4157 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4158 ? real_zerop (arg01)
4159 : integer_zerop (arg01))
4160 && TREE_CODE (arg2) == NEGATE_EXPR
4161 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4165 tem = fold_convert (arg1_type, arg1);
4166 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
4168 return pedantic_non_lvalue (fold_convert (type, arg1));
4171 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4172 arg1 = fold_convert (lang_hooks.types.signed_type
4173 (TREE_TYPE (arg1)), arg1);
4174 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4175 return pedantic_non_lvalue (fold_convert (type, tem));
4178 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4179 arg1 = fold_convert (lang_hooks.types.signed_type
4180 (TREE_TYPE (arg1)), arg1);
4181 tem = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
4182 return negate_expr (fold_convert (type, tem));
4187 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4188 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4189 both transformations are correct when A is NaN: A != 0
4190 is then true, and A == 0 is false. */
4192 if (integer_zerop (arg01) && integer_zerop (arg2))
4194 if (comp_code == NE_EXPR)
4195 return pedantic_non_lvalue (fold_convert (type, arg1));
4196 else if (comp_code == EQ_EXPR)
4197 return fold_convert (type, integer_zero_node);
4200 /* Try some transformations of A op B ? A : B.
4202 A == B? A : B same as B
4203 A != B? A : B same as A
4204 A >= B? A : B same as max (A, B)
4205 A > B? A : B same as max (B, A)
4206 A <= B? A : B same as min (A, B)
4207 A < B? A : B same as min (B, A)
4209 As above, these transformations don't work in the presence
4210 of signed zeros. For example, if A and B are zeros of
4211 opposite sign, the first two transformations will change
4212 the sign of the result. In the last four, the original
4213 expressions give different results for (A=+0, B=-0) and
4214 (A=-0, B=+0), but the transformed expressions do not.
4216 The first two transformations are correct if either A or B
4217 is a NaN. In the first transformation, the condition will
4218 be false, and B will indeed be chosen. In the case of the
4219 second transformation, the condition A != B will be true,
4220 and A will be chosen.
4222 The conversions to max() and min() are not correct if B is
4223 a number and A is not. The conditions in the original
4224 expressions will be false, so all four give B. The min()
4225 and max() versions would give a NaN instead. */
4226 if (operand_equal_for_comparison_p (arg01, arg2, arg00))
4228 tree comp_op0 = arg00;
4229 tree comp_op1 = arg01;
4230 tree comp_type = TREE_TYPE (comp_op0);
4232 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4233 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4243 return pedantic_non_lvalue (fold_convert (type, arg2));
4245 return pedantic_non_lvalue (fold_convert (type, arg1));
4248 /* In C++ a ?: expression can be an lvalue, so put the
4249 operand which will be used if they are equal first
4250 so that we can convert this back to the
4251 corresponding COND_EXPR. */
4252 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4254 comp_op0 = fold_convert (comp_type, comp_op0);
4255 comp_op1 = fold_convert (comp_type, comp_op1);
4256 tem = fold (build2 (MIN_EXPR, comp_type,
4257 (comp_code == LE_EXPR
4258 ? comp_op0 : comp_op1),
4259 (comp_code == LE_EXPR
4260 ? comp_op1 : comp_op0)));
4261 return pedantic_non_lvalue (fold_convert (type, tem));
4266 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4268 comp_op0 = fold_convert (comp_type, comp_op0);
4269 comp_op1 = fold_convert (comp_type, comp_op1);
4270 tem = fold (build2 (MAX_EXPR, comp_type,
4271 (comp_code == GE_EXPR
4272 ? comp_op0 : comp_op1),
4273 (comp_code == GE_EXPR
4274 ? comp_op1 : comp_op0)));
4275 tem = fold (build2 (MAX_EXPR, comp_type, comp_op0, comp_op1));
4276 return pedantic_non_lvalue (fold_convert (type, tem));
4284 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4285 we might still be able to simplify this. For example,
4286 if C1 is one less or one more than C2, this might have started
4287 out as a MIN or MAX and been transformed by this function.
4288 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4290 if (INTEGRAL_TYPE_P (type)
4291 && TREE_CODE (arg01) == INTEGER_CST
4292 && TREE_CODE (arg2) == INTEGER_CST)
4296 /* We can replace A with C1 in this case. */
4297 arg1 = fold_convert (type, arg01);
4298 return fold (build3 (COND_EXPR, type, arg0, arg1, arg2));
4301 /* If C1 is C2 + 1, this is min(A, C2). */
4302 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4304 && operand_equal_p (arg01,
4305 const_binop (PLUS_EXPR, arg2,
4306 integer_one_node, 0),
4308 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4309 type, arg1, arg2)));
4313 /* If C1 is C2 - 1, this is min(A, C2). */
4314 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4316 && operand_equal_p (arg01,
4317 const_binop (MINUS_EXPR, arg2,
4318 integer_one_node, 0),
4320 return pedantic_non_lvalue (fold (build2 (MIN_EXPR,
4321 type, arg1, arg2)));
4325 /* If C1 is C2 - 1, this is max(A, C2). */
4326 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4328 && operand_equal_p (arg01,
4329 const_binop (MINUS_EXPR, arg2,
4330 integer_one_node, 0),
4332 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4333 type, arg1, arg2)));
4337 /* If C1 is C2 + 1, this is max(A, C2). */
4338 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4340 && operand_equal_p (arg01,
4341 const_binop (PLUS_EXPR, arg2,
4342 integer_one_node, 0),
4344 return pedantic_non_lvalue (fold (build2 (MAX_EXPR,
4345 type, arg1, arg2)));
4358 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
4359 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
4362 /* EXP is some logical combination of boolean tests. See if we can
4363 merge it into some range test. Return the new tree if so. */
4366 fold_range_test (tree exp)
4368 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
4369 || TREE_CODE (exp) == TRUTH_OR_EXPR);
4370 int in0_p, in1_p, in_p;
4371 tree low0, low1, low, high0, high1, high;
4372 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
4373 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
4376 /* If this is an OR operation, invert both sides; we will invert
4377 again at the end. */
4379 in0_p = ! in0_p, in1_p = ! in1_p;
4381 /* If both expressions are the same, if we can merge the ranges, and we
4382 can build the range test, return it or it inverted. If one of the
4383 ranges is always true or always false, consider it to be the same
4384 expression as the other. */
4385 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
4386 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4388 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
4390 : rhs != 0 ? rhs : integer_zero_node,
4392 return or_op ? invert_truthvalue (tem) : tem;
4394 /* On machines where the branch cost is expensive, if this is a
4395 short-circuited branch and the underlying object on both sides
4396 is the same, make a non-short-circuit operation. */
4397 else if (RANGE_TEST_NON_SHORT_CIRCUIT
4398 && lhs != 0 && rhs != 0
4399 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4400 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
4401 && operand_equal_p (lhs, rhs, 0))
4403 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
4404 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4405 which cases we can't do this. */
4406 if (simple_operand_p (lhs))
4407 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4408 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4409 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
4410 TREE_OPERAND (exp, 1));
4412 else if (lang_hooks.decls.global_bindings_p () == 0
4413 && ! CONTAINS_PLACEHOLDER_P (lhs))
4415 tree common = save_expr (lhs);
4417 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
4418 or_op ? ! in0_p : in0_p,
4420 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
4421 or_op ? ! in1_p : in1_p,
4423 return build2 (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
4424 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
4425 TREE_TYPE (exp), lhs, rhs);
4432 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
4433 bit value. Arrange things so the extra bits will be set to zero if and
4434 only if C is signed-extended to its full width. If MASK is nonzero,
4435 it is an INTEGER_CST that should be AND'ed with the extra bits. */
4438 unextend (tree c, int p, int unsignedp, tree mask)
4440 tree type = TREE_TYPE (c);
4441 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4444 if (p == modesize || unsignedp)
4447 /* We work by getting just the sign bit into the low-order bit, then
4448 into the high-order bit, then sign-extend. We then XOR that value
4450 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4451 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
4453 /* We must use a signed type in order to get an arithmetic right shift.
4454 However, we must also avoid introducing accidental overflows, so that
4455 a subsequent call to integer_zerop will work. Hence we must
4456 do the type conversion here. At this point, the constant is either
4457 zero or one, and the conversion to a signed type can never overflow.
4458 We could get an overflow if this conversion is done anywhere else. */
4459 if (TYPE_UNSIGNED (type))
4460 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
4462 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4463 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
4465 temp = const_binop (BIT_AND_EXPR, temp,
4466 fold_convert (TREE_TYPE (c), mask), 0);
4467 /* If necessary, convert the type back to match the type of C. */
4468 if (TYPE_UNSIGNED (type))
4469 temp = fold_convert (type, temp);
4471 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
4474 /* Find ways of folding logical expressions of LHS and RHS:
4475 Try to merge two comparisons to the same innermost item.
4476 Look for range tests like "ch >= '0' && ch <= '9'".
4477 Look for combinations of simple terms on machines with expensive branches
4478 and evaluate the RHS unconditionally.
4480 For example, if we have p->a == 2 && p->b == 4 and we can make an
4481 object large enough to span both A and B, we can do this with a comparison
4482 against the object ANDed with the a mask.
4484 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4485 operations to do this with one comparison.
4487 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4488 function and the one above.
4490 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4491 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4493 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4496 We return the simplified tree or 0 if no optimization is possible. */
4499 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
4501 /* If this is the "or" of two comparisons, we can do something if
4502 the comparisons are NE_EXPR. If this is the "and", we can do something
4503 if the comparisons are EQ_EXPR. I.e.,
4504 (a->b == 2 && a->c == 4) can become (a->new == NEW).
4506 WANTED_CODE is this operation code. For single bit fields, we can
4507 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4508 comparison for one-bit fields. */
4510 enum tree_code wanted_code;
4511 enum tree_code lcode, rcode;
4512 tree ll_arg, lr_arg, rl_arg, rr_arg;
4513 tree ll_inner, lr_inner, rl_inner, rr_inner;
4514 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
4515 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
4516 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
4517 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
4518 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
4519 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
4520 enum machine_mode lnmode, rnmode;
4521 tree ll_mask, lr_mask, rl_mask, rr_mask;
4522 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
4523 tree l_const, r_const;
4524 tree lntype, rntype, result;
4525 int first_bit, end_bit;
4528 /* Start by getting the comparison codes. Fail if anything is volatile.
4529 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4530 it were surrounded with a NE_EXPR. */
4532 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
4535 lcode = TREE_CODE (lhs);
4536 rcode = TREE_CODE (rhs);
4538 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
4540 lhs = build2 (NE_EXPR, truth_type, lhs,
4541 fold_convert (TREE_TYPE (lhs), integer_zero_node));
4545 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
4547 rhs = build2 (NE_EXPR, truth_type, rhs,
4548 fold_convert (TREE_TYPE (rhs), integer_zero_node));
4552 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
4555 ll_arg = TREE_OPERAND (lhs, 0);
4556 lr_arg = TREE_OPERAND (lhs, 1);
4557 rl_arg = TREE_OPERAND (rhs, 0);
4558 rr_arg = TREE_OPERAND (rhs, 1);
4560 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4561 if (simple_operand_p (ll_arg)
4562 && simple_operand_p (lr_arg))
4565 if (operand_equal_p (ll_arg, rl_arg, 0)
4566 && operand_equal_p (lr_arg, rr_arg, 0))
4568 result = combine_comparisons (code, lcode, rcode,
4569 truth_type, ll_arg, lr_arg);
4573 else if (operand_equal_p (ll_arg, rr_arg, 0)
4574 && operand_equal_p (lr_arg, rl_arg, 0))
4576 result = combine_comparisons (code, lcode,
4577 swap_tree_comparison (rcode),
4578 truth_type, ll_arg, lr_arg);
4584 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4585 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4587 /* If the RHS can be evaluated unconditionally and its operands are
4588 simple, it wins to evaluate the RHS unconditionally on machines
4589 with expensive branches. In this case, this isn't a comparison
4590 that can be merged. Avoid doing this if the RHS is a floating-point
4591 comparison since those can trap. */
4593 if (BRANCH_COST >= 2
4594 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
4595 && simple_operand_p (rl_arg)
4596 && simple_operand_p (rr_arg))
4598 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4599 if (code == TRUTH_OR_EXPR
4600 && lcode == NE_EXPR && integer_zerop (lr_arg)
4601 && rcode == NE_EXPR && integer_zerop (rr_arg)
4602 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4603 return build2 (NE_EXPR, truth_type,
4604 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4606 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4608 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4609 if (code == TRUTH_AND_EXPR
4610 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4611 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4612 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4613 return build2 (EQ_EXPR, truth_type,
4614 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4616 fold_convert (TREE_TYPE (ll_arg), integer_zero_node));
4618 return build2 (code, truth_type, lhs, rhs);
4621 /* See if the comparisons can be merged. Then get all the parameters for
4624 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4625 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4629 ll_inner = decode_field_reference (ll_arg,
4630 &ll_bitsize, &ll_bitpos, &ll_mode,
4631 &ll_unsignedp, &volatilep, &ll_mask,
4633 lr_inner = decode_field_reference (lr_arg,
4634 &lr_bitsize, &lr_bitpos, &lr_mode,
4635 &lr_unsignedp, &volatilep, &lr_mask,
4637 rl_inner = decode_field_reference (rl_arg,
4638 &rl_bitsize, &rl_bitpos, &rl_mode,
4639 &rl_unsignedp, &volatilep, &rl_mask,
4641 rr_inner = decode_field_reference (rr_arg,
4642 &rr_bitsize, &rr_bitpos, &rr_mode,
4643 &rr_unsignedp, &volatilep, &rr_mask,
4646 /* It must be true that the inner operation on the lhs of each
4647 comparison must be the same if we are to be able to do anything.
4648 Then see if we have constants. If not, the same must be true for
4650 if (volatilep || ll_inner == 0 || rl_inner == 0
4651 || ! operand_equal_p (ll_inner, rl_inner, 0))
4654 if (TREE_CODE (lr_arg) == INTEGER_CST
4655 && TREE_CODE (rr_arg) == INTEGER_CST)
4656 l_const = lr_arg, r_const = rr_arg;
4657 else if (lr_inner == 0 || rr_inner == 0
4658 || ! operand_equal_p (lr_inner, rr_inner, 0))
4661 l_const = r_const = 0;
4663 /* If either comparison code is not correct for our logical operation,
4664 fail. However, we can convert a one-bit comparison against zero into
4665 the opposite comparison against that bit being set in the field. */
4667 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4668 if (lcode != wanted_code)
4670 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4672 /* Make the left operand unsigned, since we are only interested
4673 in the value of one bit. Otherwise we are doing the wrong
4682 /* This is analogous to the code for l_const above. */
4683 if (rcode != wanted_code)
4685 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4694 /* After this point all optimizations will generate bit-field
4695 references, which we might not want. */
4696 if (! lang_hooks.can_use_bit_fields_p ())
4699 /* See if we can find a mode that contains both fields being compared on
4700 the left. If we can't, fail. Otherwise, update all constants and masks
4701 to be relative to a field of that size. */
4702 first_bit = MIN (ll_bitpos, rl_bitpos);
4703 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4704 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4705 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4707 if (lnmode == VOIDmode)
4710 lnbitsize = GET_MODE_BITSIZE (lnmode);
4711 lnbitpos = first_bit & ~ (lnbitsize - 1);
4712 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
4713 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4715 if (BYTES_BIG_ENDIAN)
4717 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4718 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4721 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4722 size_int (xll_bitpos), 0);
4723 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4724 size_int (xrl_bitpos), 0);
4728 l_const = fold_convert (lntype, l_const);
4729 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4730 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4731 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4732 fold (build1 (BIT_NOT_EXPR,
4736 warning ("comparison is always %d", wanted_code == NE_EXPR);
4738 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4743 r_const = fold_convert (lntype, r_const);
4744 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4745 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4746 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4747 fold (build1 (BIT_NOT_EXPR,
4751 warning ("comparison is always %d", wanted_code == NE_EXPR);
4753 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
4757 /* If the right sides are not constant, do the same for it. Also,
4758 disallow this optimization if a size or signedness mismatch occurs
4759 between the left and right sides. */
4762 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4763 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4764 /* Make sure the two fields on the right
4765 correspond to the left without being swapped. */
4766 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4769 first_bit = MIN (lr_bitpos, rr_bitpos);
4770 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4771 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4772 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4774 if (rnmode == VOIDmode)
4777 rnbitsize = GET_MODE_BITSIZE (rnmode);
4778 rnbitpos = first_bit & ~ (rnbitsize - 1);
4779 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
4780 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4782 if (BYTES_BIG_ENDIAN)
4784 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4785 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4788 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4789 size_int (xlr_bitpos), 0);
4790 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4791 size_int (xrr_bitpos), 0);
4793 /* Make a mask that corresponds to both fields being compared.
4794 Do this for both items being compared. If the operands are the
4795 same size and the bits being compared are in the same position
4796 then we can do this by masking both and comparing the masked
4798 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4799 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4800 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4802 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4803 ll_unsignedp || rl_unsignedp);
4804 if (! all_ones_mask_p (ll_mask, lnbitsize))
4805 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
4807 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4808 lr_unsignedp || rr_unsignedp);
4809 if (! all_ones_mask_p (lr_mask, rnbitsize))
4810 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
4812 return build2 (wanted_code, truth_type, lhs, rhs);
4815 /* There is still another way we can do something: If both pairs of
4816 fields being compared are adjacent, we may be able to make a wider
4817 field containing them both.
4819 Note that we still must mask the lhs/rhs expressions. Furthermore,
4820 the mask must be shifted to account for the shift done by
4821 make_bit_field_ref. */
4822 if ((ll_bitsize + ll_bitpos == rl_bitpos
4823 && lr_bitsize + lr_bitpos == rr_bitpos)
4824 || (ll_bitpos == rl_bitpos + rl_bitsize
4825 && lr_bitpos == rr_bitpos + rr_bitsize))
4829 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4830 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4831 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4832 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4834 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4835 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4836 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4837 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4839 /* Convert to the smaller type before masking out unwanted bits. */
4841 if (lntype != rntype)
4843 if (lnbitsize > rnbitsize)
4845 lhs = fold_convert (rntype, lhs);
4846 ll_mask = fold_convert (rntype, ll_mask);
4849 else if (lnbitsize < rnbitsize)
4851 rhs = fold_convert (lntype, rhs);
4852 lr_mask = fold_convert (lntype, lr_mask);
4857 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4858 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
4860 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4861 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
4863 return build2 (wanted_code, truth_type, lhs, rhs);
4869 /* Handle the case of comparisons with constants. If there is something in
4870 common between the masks, those bits of the constants must be the same.
4871 If not, the condition is always false. Test for this to avoid generating
4872 incorrect code below. */
4873 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4874 if (! integer_zerop (result)
4875 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4876 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4878 if (wanted_code == NE_EXPR)
4880 warning ("`or' of unmatched not-equal tests is always 1");
4881 return constant_boolean_node (true, truth_type);
4885 warning ("`and' of mutually exclusive equal-tests is always 0");
4886 return constant_boolean_node (false, truth_type);
4890 /* Construct the expression we will return. First get the component
4891 reference we will make. Unless the mask is all ones the width of
4892 that field, perform the mask operation. Then compare with the
4894 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4895 ll_unsignedp || rl_unsignedp);
4897 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4898 if (! all_ones_mask_p (ll_mask, lnbitsize))
4899 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
4901 return build2 (wanted_code, truth_type, result,
4902 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4905 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4909 optimize_minmax_comparison (tree t)
4911 tree type = TREE_TYPE (t);
4912 tree arg0 = TREE_OPERAND (t, 0);
4913 enum tree_code op_code;
4914 tree comp_const = TREE_OPERAND (t, 1);
4916 int consts_equal, consts_lt;
4919 STRIP_SIGN_NOPS (arg0);
4921 op_code = TREE_CODE (arg0);
4922 minmax_const = TREE_OPERAND (arg0, 1);
4923 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4924 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4925 inner = TREE_OPERAND (arg0, 0);
4927 /* If something does not permit us to optimize, return the original tree. */
4928 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4929 || TREE_CODE (comp_const) != INTEGER_CST
4930 || TREE_CONSTANT_OVERFLOW (comp_const)
4931 || TREE_CODE (minmax_const) != INTEGER_CST
4932 || TREE_CONSTANT_OVERFLOW (minmax_const))
4935 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4936 and GT_EXPR, doing the rest with recursive calls using logical
4938 switch (TREE_CODE (t))
4940 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4942 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4946 fold (build2 (TRUTH_ORIF_EXPR, type,
4947 optimize_minmax_comparison
4948 (build2 (EQ_EXPR, type, arg0, comp_const)),
4949 optimize_minmax_comparison
4950 (build2 (GT_EXPR, type, arg0, comp_const))));
4953 if (op_code == MAX_EXPR && consts_equal)
4954 /* MAX (X, 0) == 0 -> X <= 0 */
4955 return fold (build2 (LE_EXPR, type, inner, comp_const));
4957 else if (op_code == MAX_EXPR && consts_lt)
4958 /* MAX (X, 0) == 5 -> X == 5 */
4959 return fold (build2 (EQ_EXPR, type, inner, comp_const));
4961 else if (op_code == MAX_EXPR)
4962 /* MAX (X, 0) == -1 -> false */
4963 return omit_one_operand (type, integer_zero_node, inner);
4965 else if (consts_equal)
4966 /* MIN (X, 0) == 0 -> X >= 0 */
4967 return fold (build2 (GE_EXPR, type, inner, comp_const));
4970 /* MIN (X, 0) == 5 -> false */
4971 return omit_one_operand (type, integer_zero_node, inner);
4974 /* MIN (X, 0) == -1 -> X == -1 */
4975 return fold (build2 (EQ_EXPR, type, inner, comp_const));
4978 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4979 /* MAX (X, 0) > 0 -> X > 0
4980 MAX (X, 0) > 5 -> X > 5 */
4981 return fold (build2 (GT_EXPR, type, inner, comp_const));
4983 else if (op_code == MAX_EXPR)
4984 /* MAX (X, 0) > -1 -> true */
4985 return omit_one_operand (type, integer_one_node, inner);
4987 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4988 /* MIN (X, 0) > 0 -> false
4989 MIN (X, 0) > 5 -> false */
4990 return omit_one_operand (type, integer_zero_node, inner);
4993 /* MIN (X, 0) > -1 -> X > -1 */
4994 return fold (build2 (GT_EXPR, type, inner, comp_const));
5001 /* T is an integer expression that is being multiplied, divided, or taken a
5002 modulus (CODE says which and what kind of divide or modulus) by a
5003 constant C. See if we can eliminate that operation by folding it with
5004 other operations already in T. WIDE_TYPE, if non-null, is a type that
5005 should be used for the computation if wider than our type.
5007 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5008 (X * 2) + (Y * 4). We must, however, be assured that either the original
5009 expression would not overflow or that overflow is undefined for the type
5010 in the language in question.
5012 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5013 the machine has a multiply-accumulate insn or that this is part of an
5014 addressing calculation.
5016 If we return a non-null expression, it is an equivalent form of the
5017 original computation, but need not be in the original type. */
5020 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
5022 /* To avoid exponential search depth, refuse to allow recursion past
5023 three levels. Beyond that (1) it's highly unlikely that we'll find
5024 something interesting and (2) we've probably processed it before
5025 when we built the inner expression. */
5034 ret = extract_muldiv_1 (t, c, code, wide_type);
5041 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
5043 tree type = TREE_TYPE (t);
5044 enum tree_code tcode = TREE_CODE (t);
5045 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
5046 > GET_MODE_SIZE (TYPE_MODE (type)))
5047 ? wide_type : type);
5049 int same_p = tcode == code;
5050 tree op0 = NULL_TREE, op1 = NULL_TREE;
5052 /* Don't deal with constants of zero here; they confuse the code below. */
5053 if (integer_zerop (c))
5056 if (TREE_CODE_CLASS (tcode) == '1')
5057 op0 = TREE_OPERAND (t, 0);
5059 if (TREE_CODE_CLASS (tcode) == '2')
5060 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5062 /* Note that we need not handle conditional operations here since fold
5063 already handles those cases. So just do arithmetic here. */
5067 /* For a constant, we can always simplify if we are a multiply
5068 or (for divide and modulus) if it is a multiple of our constant. */
5069 if (code == MULT_EXPR
5070 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
5071 return const_binop (code, fold_convert (ctype, t),
5072 fold_convert (ctype, c), 0);
5075 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
5076 /* If op0 is an expression ... */
5077 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
5078 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
5079 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
5080 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
5081 /* ... and is unsigned, and its type is smaller than ctype,
5082 then we cannot pass through as widening. */
5083 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
5084 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5085 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5086 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5087 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
5088 /* ... or this is a truncation (t is narrower than op0),
5089 then we cannot pass through this narrowing. */
5090 || (GET_MODE_SIZE (TYPE_MODE (type))
5091 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5092 /* ... or signedness changes for division or modulus,
5093 then we cannot pass through this conversion. */
5094 || (code != MULT_EXPR
5095 && (TYPE_UNSIGNED (ctype)
5096 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
5099 /* Pass the constant down and see if we can make a simplification. If
5100 we can, replace this expression with the inner simplification for
5101 possible later conversion to our or some other type. */
5102 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
5103 && TREE_CODE (t2) == INTEGER_CST
5104 && ! TREE_CONSTANT_OVERFLOW (t2)
5105 && (0 != (t1 = extract_muldiv (op0, t2, code,
5107 ? ctype : NULL_TREE))))
5111 case NEGATE_EXPR: case ABS_EXPR:
5112 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5113 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
5116 case MIN_EXPR: case MAX_EXPR:
5117 /* If widening the type changes the signedness, then we can't perform
5118 this optimization as that changes the result. */
5119 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
5122 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5123 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
5124 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
5126 if (tree_int_cst_sgn (c) < 0)
5127 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5129 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5130 fold_convert (ctype, t2)));
5134 case LSHIFT_EXPR: case RSHIFT_EXPR:
5135 /* If the second operand is constant, this is a multiplication
5136 or floor division, by a power of two, so we can treat it that
5137 way unless the multiplier or divisor overflows. Signed
5138 left-shift overflow is implementation-defined rather than
5139 undefined in C90, so do not convert signed left shift into
5141 if (TREE_CODE (op1) == INTEGER_CST
5142 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
5143 /* const_binop may not detect overflow correctly,
5144 so check for it explicitly here. */
5145 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5146 && TREE_INT_CST_HIGH (op1) == 0
5147 && 0 != (t1 = fold_convert (ctype,
5148 const_binop (LSHIFT_EXPR,
5151 && ! TREE_OVERFLOW (t1))
5152 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5153 ? MULT_EXPR : FLOOR_DIV_EXPR,
5154 ctype, fold_convert (ctype, op0), t1),
5155 c, code, wide_type);
5158 case PLUS_EXPR: case MINUS_EXPR:
5159 /* See if we can eliminate the operation on both sides. If we can, we
5160 can return a new PLUS or MINUS. If we can't, the only remaining
5161 cases where we can do anything are if the second operand is a
5163 t1 = extract_muldiv (op0, c, code, wide_type);
5164 t2 = extract_muldiv (op1, c, code, wide_type);
5165 if (t1 != 0 && t2 != 0
5166 && (code == MULT_EXPR
5167 /* If not multiplication, we can only do this if both operands
5168 are divisible by c. */
5169 || (multiple_of_p (ctype, op0, c)
5170 && multiple_of_p (ctype, op1, c))))
5171 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5172 fold_convert (ctype, t2)));
5174 /* If this was a subtraction, negate OP1 and set it to be an addition.
5175 This simplifies the logic below. */
5176 if (tcode == MINUS_EXPR)
5177 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5179 if (TREE_CODE (op1) != INTEGER_CST)
5182 /* If either OP1 or C are negative, this optimization is not safe for
5183 some of the division and remainder types while for others we need
5184 to change the code. */
5185 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5187 if (code == CEIL_DIV_EXPR)
5188 code = FLOOR_DIV_EXPR;
5189 else if (code == FLOOR_DIV_EXPR)
5190 code = CEIL_DIV_EXPR;
5191 else if (code != MULT_EXPR
5192 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5196 /* If it's a multiply or a division/modulus operation of a multiple
5197 of our constant, do the operation and verify it doesn't overflow. */
5198 if (code == MULT_EXPR
5199 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5201 op1 = const_binop (code, fold_convert (ctype, op1),
5202 fold_convert (ctype, c), 0);
5203 /* We allow the constant to overflow with wrapping semantics. */
5205 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
5211 /* If we have an unsigned type is not a sizetype, we cannot widen
5212 the operation since it will change the result if the original
5213 computation overflowed. */
5214 if (TYPE_UNSIGNED (ctype)
5215 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
5219 /* If we were able to eliminate our operation from the first side,
5220 apply our operation to the second side and reform the PLUS. */
5221 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
5222 return fold (build2 (tcode, ctype, fold_convert (ctype, t1), op1));
5224 /* The last case is if we are a multiply. In that case, we can
5225 apply the distributive law to commute the multiply and addition
5226 if the multiplication of the constants doesn't overflow. */
5227 if (code == MULT_EXPR)
5228 return fold (build2 (tcode, ctype,
5229 fold (build2 (code, ctype,
5230 fold_convert (ctype, op0),
5231 fold_convert (ctype, c))),
5237 /* We have a special case here if we are doing something like
5238 (C * 8) % 4 since we know that's zero. */
5239 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5240 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5241 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5242 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5243 return omit_one_operand (type, integer_zero_node, op0);
5245 /* ... fall through ... */
5247 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5248 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5249 /* If we can extract our operation from the LHS, do so and return a
5250 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5251 do something only if the second operand is a constant. */
5253 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
5254 return fold (build2 (tcode, ctype, fold_convert (ctype, t1),
5255 fold_convert (ctype, op1)));
5256 else if (tcode == MULT_EXPR && code == MULT_EXPR
5257 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
5258 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5259 fold_convert (ctype, t1)));
5260 else if (TREE_CODE (op1) != INTEGER_CST)
5263 /* If these are the same operation types, we can associate them
5264 assuming no overflow. */
5266 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5267 fold_convert (ctype, c), 0))
5268 && ! TREE_OVERFLOW (t1))
5269 return fold (build2 (tcode, ctype, fold_convert (ctype, op0), t1));
5271 /* If these operations "cancel" each other, we have the main
5272 optimizations of this pass, which occur when either constant is a
5273 multiple of the other, in which case we replace this with either an
5274 operation or CODE or TCODE.
5276 If we have an unsigned type that is not a sizetype, we cannot do
5277 this since it will change the result if the original computation
5279 if ((! TYPE_UNSIGNED (ctype)
5280 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
5282 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5283 || (tcode == MULT_EXPR
5284 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5285 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
5287 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5288 return fold (build2 (tcode, ctype, fold_convert (ctype, op0),
5289 fold_convert (ctype,
5290 const_binop (TRUNC_DIV_EXPR,
5292 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
5293 return fold (build2 (code, ctype, fold_convert (ctype, op0),
5294 fold_convert (ctype,
5295 const_binop (TRUNC_DIV_EXPR,
5307 /* Return a node which has the indicated constant VALUE (either 0 or
5308 1), and is of the indicated TYPE. */
5311 constant_boolean_node (int value, tree type)
5313 if (type == integer_type_node)
5314 return value ? integer_one_node : integer_zero_node;
5315 else if (type == boolean_type_node)
5316 return value ? boolean_true_node : boolean_false_node;
5317 else if (TREE_CODE (type) == BOOLEAN_TYPE)
5318 return lang_hooks.truthvalue_conversion (value ? integer_one_node
5319 : integer_zero_node);
5321 return build_int_cst (type, value);
5324 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
5325 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5326 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
5327 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
5328 COND is the first argument to CODE; otherwise (as in the example
5329 given here), it is the second argument. TYPE is the type of the
5330 original expression. Return NULL_TREE if no simplification is
5334 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
5335 tree cond, tree arg, int cond_first_p)
5337 tree test, true_value, false_value;
5338 tree lhs = NULL_TREE;
5339 tree rhs = NULL_TREE;
5341 /* This transformation is only worthwhile if we don't have to wrap
5342 arg in a SAVE_EXPR, and the operation can be simplified on atleast
5343 one of the branches once its pushed inside the COND_EXPR. */
5344 if (!TREE_CONSTANT (arg))
5347 if (TREE_CODE (cond) == COND_EXPR)
5349 test = TREE_OPERAND (cond, 0);
5350 true_value = TREE_OPERAND (cond, 1);
5351 false_value = TREE_OPERAND (cond, 2);
5352 /* If this operand throws an expression, then it does not make
5353 sense to try to perform a logical or arithmetic operation
5355 if (VOID_TYPE_P (TREE_TYPE (true_value)))
5357 if (VOID_TYPE_P (TREE_TYPE (false_value)))
5362 tree testtype = TREE_TYPE (cond);
5364 true_value = constant_boolean_node (true, testtype);
5365 false_value = constant_boolean_node (false, testtype);
5369 lhs = fold (cond_first_p ? build2 (code, type, true_value, arg)
5370 : build2 (code, type, arg, true_value));
5372 rhs = fold (cond_first_p ? build2 (code, type, false_value, arg)
5373 : build2 (code, type, arg, false_value));
5375 test = fold (build3 (COND_EXPR, type, test, lhs, rhs));
5376 return fold_convert (type, test);
5380 /* Subroutine of fold() that checks for the addition of +/- 0.0.
5382 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5383 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5384 ADDEND is the same as X.
5386 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
5387 and finite. The problematic cases are when X is zero, and its mode
5388 has signed zeros. In the case of rounding towards -infinity,
5389 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5390 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5393 fold_real_zero_addition_p (tree type, tree addend, int negate)
5395 if (!real_zerop (addend))
5398 /* Don't allow the fold with -fsignaling-nans. */
5399 if (HONOR_SNANS (TYPE_MODE (type)))
5402 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5403 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5406 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5407 if (TREE_CODE (addend) == REAL_CST
5408 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5411 /* The mode has signed zeros, and we have to honor their sign.
5412 In this situation, there is only one case we can return true for.
5413 X - 0 is the same as X unless rounding towards -infinity is
5415 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5418 /* Subroutine of fold() that checks comparisons of built-in math
5419 functions against real constants.
5421 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5422 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5423 is the type of the result and ARG0 and ARG1 are the operands of the
5424 comparison. ARG1 must be a TREE_REAL_CST.
5426 The function returns the constant folded tree if a simplification
5427 can be made, and NULL_TREE otherwise. */
5430 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5431 tree type, tree arg0, tree arg1)
5435 if (BUILTIN_SQRT_P (fcode))
5437 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5438 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5440 c = TREE_REAL_CST (arg1);
5441 if (REAL_VALUE_NEGATIVE (c))
5443 /* sqrt(x) < y is always false, if y is negative. */
5444 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5445 return omit_one_operand (type, integer_zero_node, arg);
5447 /* sqrt(x) > y is always true, if y is negative and we
5448 don't care about NaNs, i.e. negative values of x. */
5449 if (code == NE_EXPR || !HONOR_NANS (mode))
5450 return omit_one_operand (type, integer_one_node, arg);
5452 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5453 return fold (build2 (GE_EXPR, type, arg,
5454 build_real (TREE_TYPE (arg), dconst0)));
5456 else if (code == GT_EXPR || code == GE_EXPR)
5460 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5461 real_convert (&c2, mode, &c2);
5463 if (REAL_VALUE_ISINF (c2))
5465 /* sqrt(x) > y is x == +Inf, when y is very large. */
5466 if (HONOR_INFINITIES (mode))
5467 return fold (build2 (EQ_EXPR, type, arg,
5468 build_real (TREE_TYPE (arg), c2)));
5470 /* sqrt(x) > y is always false, when y is very large
5471 and we don't care about infinities. */
5472 return omit_one_operand (type, integer_zero_node, arg);
5475 /* sqrt(x) > c is the same as x > c*c. */
5476 return fold (build2 (code, type, arg,
5477 build_real (TREE_TYPE (arg), c2)));
5479 else if (code == LT_EXPR || code == LE_EXPR)
5483 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5484 real_convert (&c2, mode, &c2);
5486 if (REAL_VALUE_ISINF (c2))
5488 /* sqrt(x) < y is always true, when y is a very large
5489 value and we don't care about NaNs or Infinities. */
5490 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5491 return omit_one_operand (type, integer_one_node, arg);
5493 /* sqrt(x) < y is x != +Inf when y is very large and we
5494 don't care about NaNs. */
5495 if (! HONOR_NANS (mode))
5496 return fold (build2 (NE_EXPR, type, arg,
5497 build_real (TREE_TYPE (arg), c2)));
5499 /* sqrt(x) < y is x >= 0 when y is very large and we
5500 don't care about Infinities. */
5501 if (! HONOR_INFINITIES (mode))
5502 return fold (build2 (GE_EXPR, type, arg,
5503 build_real (TREE_TYPE (arg), dconst0)));
5505 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5506 if (lang_hooks.decls.global_bindings_p () != 0
5507 || CONTAINS_PLACEHOLDER_P (arg))
5510 arg = save_expr (arg);
5511 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5512 fold (build2 (GE_EXPR, type, arg,
5513 build_real (TREE_TYPE (arg),
5515 fold (build2 (NE_EXPR, type, arg,
5516 build_real (TREE_TYPE (arg),
5520 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5521 if (! HONOR_NANS (mode))
5522 return fold (build2 (code, type, arg,
5523 build_real (TREE_TYPE (arg), c2)));
5525 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5526 if (lang_hooks.decls.global_bindings_p () == 0
5527 && ! CONTAINS_PLACEHOLDER_P (arg))
5529 arg = save_expr (arg);
5530 return fold (build2 (TRUTH_ANDIF_EXPR, type,
5531 fold (build2 (GE_EXPR, type, arg,
5532 build_real (TREE_TYPE (arg),
5534 fold (build2 (code, type, arg,
5535 build_real (TREE_TYPE (arg),
5544 /* Subroutine of fold() that optimizes comparisons against Infinities,
5545 either +Inf or -Inf.
5547 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5548 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5549 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5551 The function returns the constant folded tree if a simplification
5552 can be made, and NULL_TREE otherwise. */
5555 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5557 enum machine_mode mode;
5558 REAL_VALUE_TYPE max;
5562 mode = TYPE_MODE (TREE_TYPE (arg0));
5564 /* For negative infinity swap the sense of the comparison. */
5565 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5567 code = swap_tree_comparison (code);
5572 /* x > +Inf is always false, if with ignore sNANs. */
5573 if (HONOR_SNANS (mode))
5575 return omit_one_operand (type, integer_zero_node, arg0);
5578 /* x <= +Inf is always true, if we don't case about NaNs. */
5579 if (! HONOR_NANS (mode))
5580 return omit_one_operand (type, integer_one_node, arg0);
5582 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5583 if (lang_hooks.decls.global_bindings_p () == 0
5584 && ! CONTAINS_PLACEHOLDER_P (arg0))
5586 arg0 = save_expr (arg0);
5587 return fold (build2 (EQ_EXPR, type, arg0, arg0));
5593 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5594 real_maxval (&max, neg, mode);
5595 return fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5596 arg0, build_real (TREE_TYPE (arg0), max)));
5599 /* x < +Inf is always equal to x <= DBL_MAX. */
5600 real_maxval (&max, neg, mode);
5601 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5602 arg0, build_real (TREE_TYPE (arg0), max)));
5605 /* x != +Inf is always equal to !(x > DBL_MAX). */
5606 real_maxval (&max, neg, mode);
5607 if (! HONOR_NANS (mode))
5608 return fold (build2 (neg ? GE_EXPR : LE_EXPR, type,
5609 arg0, build_real (TREE_TYPE (arg0), max)));
5611 /* The transformation below creates non-gimple code and thus is
5612 not appropriate if we are in gimple form. */
5616 temp = fold (build2 (neg ? LT_EXPR : GT_EXPR, type,
5617 arg0, build_real (TREE_TYPE (arg0), max)));
5618 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5627 /* Subroutine of fold() that optimizes comparisons of a division by
5628 a nonzero integer constant against an integer constant, i.e.
5631 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5632 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5633 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5635 The function returns the constant folded tree if a simplification
5636 can be made, and NULL_TREE otherwise. */
5639 fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5641 tree prod, tmp, hi, lo;
5642 tree arg00 = TREE_OPERAND (arg0, 0);
5643 tree arg01 = TREE_OPERAND (arg0, 1);
5644 unsigned HOST_WIDE_INT lpart;
5645 HOST_WIDE_INT hpart;
5648 /* We have to do this the hard way to detect unsigned overflow.
5649 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
5650 overflow = mul_double (TREE_INT_CST_LOW (arg01),
5651 TREE_INT_CST_HIGH (arg01),
5652 TREE_INT_CST_LOW (arg1),
5653 TREE_INT_CST_HIGH (arg1), &lpart, &hpart);
5654 prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5655 prod = force_fit_type (prod, -1, overflow, false);
5657 if (TYPE_UNSIGNED (TREE_TYPE (arg0)))
5659 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5662 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
5663 overflow = add_double (TREE_INT_CST_LOW (prod),
5664 TREE_INT_CST_HIGH (prod),
5665 TREE_INT_CST_LOW (tmp),
5666 TREE_INT_CST_HIGH (tmp),
5668 hi = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
5669 hi = force_fit_type (hi, -1, overflow | TREE_OVERFLOW (prod),
5670 TREE_CONSTANT_OVERFLOW (prod));
5672 else if (tree_int_cst_sgn (arg01) >= 0)
5674 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
5675 switch (tree_int_cst_sgn (arg1))
5678 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5683 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
5688 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5698 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
5699 switch (tree_int_cst_sgn (arg1))
5702 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
5707 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
5712 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
5724 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5725 return omit_one_operand (type, integer_zero_node, arg00);
5726 if (TREE_OVERFLOW (hi))
5727 return fold (build2 (GE_EXPR, type, arg00, lo));
5728 if (TREE_OVERFLOW (lo))
5729 return fold (build2 (LE_EXPR, type, arg00, hi));
5730 return build_range_check (type, arg00, 1, lo, hi);
5733 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
5734 return omit_one_operand (type, integer_one_node, arg00);
5735 if (TREE_OVERFLOW (hi))
5736 return fold (build2 (LT_EXPR, type, arg00, lo));
5737 if (TREE_OVERFLOW (lo))
5738 return fold (build2 (GT_EXPR, type, arg00, hi));
5739 return build_range_check (type, arg00, 0, lo, hi);
5742 if (TREE_OVERFLOW (lo))
5743 return omit_one_operand (type, integer_zero_node, arg00);
5744 return fold (build2 (LT_EXPR, type, arg00, lo));
5747 if (TREE_OVERFLOW (hi))
5748 return omit_one_operand (type, integer_one_node, arg00);
5749 return fold (build2 (LE_EXPR, type, arg00, hi));
5752 if (TREE_OVERFLOW (hi))
5753 return omit_one_operand (type, integer_zero_node, arg00);
5754 return fold (build2 (GT_EXPR, type, arg00, hi));
5757 if (TREE_OVERFLOW (lo))
5758 return omit_one_operand (type, integer_one_node, arg00);
5759 return fold (build2 (GE_EXPR, type, arg00, lo));
5769 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5770 equality/inequality test, then return a simplified form of
5771 the test using shifts and logical operations. Otherwise return
5772 NULL. TYPE is the desired result type. */
5775 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5778 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5780 if (code == TRUTH_NOT_EXPR)
5782 code = TREE_CODE (arg0);
5783 if (code != NE_EXPR && code != EQ_EXPR)
5786 /* Extract the arguments of the EQ/NE. */
5787 arg1 = TREE_OPERAND (arg0, 1);
5788 arg0 = TREE_OPERAND (arg0, 0);
5790 /* This requires us to invert the code. */
5791 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
5794 /* If this is testing a single bit, we can optimize the test. */
5795 if ((code == NE_EXPR || code == EQ_EXPR)
5796 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5797 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5799 tree inner = TREE_OPERAND (arg0, 0);
5800 tree type = TREE_TYPE (arg0);
5801 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5802 enum machine_mode operand_mode = TYPE_MODE (type);
5804 tree signed_type, unsigned_type, intermediate_type;
5807 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5808 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5809 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5810 if (arg00 != NULL_TREE
5811 /* This is only a win if casting to a signed type is cheap,
5812 i.e. when arg00's type is not a partial mode. */
5813 && TYPE_PRECISION (TREE_TYPE (arg00))
5814 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
5816 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
5817 return fold (build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
5818 result_type, fold_convert (stype, arg00),
5819 fold_convert (stype, integer_zero_node)));
5822 /* Otherwise we have (A & C) != 0 where C is a single bit,
5823 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5824 Similarly for (A & C) == 0. */
5826 /* If INNER is a right shift of a constant and it plus BITNUM does
5827 not overflow, adjust BITNUM and INNER. */
5828 if (TREE_CODE (inner) == RSHIFT_EXPR
5829 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5830 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5831 && bitnum < TYPE_PRECISION (type)
5832 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5833 bitnum - TYPE_PRECISION (type)))
5835 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5836 inner = TREE_OPERAND (inner, 0);
5839 /* If we are going to be able to omit the AND below, we must do our
5840 operations as unsigned. If we must use the AND, we have a choice.
5841 Normally unsigned is faster, but for some machines signed is. */
5842 #ifdef LOAD_EXTEND_OP
5843 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
5848 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
5849 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
5850 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5851 inner = fold_convert (intermediate_type, inner);
5854 inner = build2 (RSHIFT_EXPR, intermediate_type,
5855 inner, size_int (bitnum));
5857 if (code == EQ_EXPR)
5858 inner = fold (build2 (BIT_XOR_EXPR, intermediate_type,
5859 inner, integer_one_node));
5861 /* Put the AND last so it can combine with more things. */
5862 inner = build2 (BIT_AND_EXPR, intermediate_type,
5863 inner, integer_one_node);
5865 /* Make sure to return the proper type. */
5866 inner = fold_convert (result_type, inner);
5873 /* Check whether we are allowed to reorder operands arg0 and arg1,
5874 such that the evaluation of arg1 occurs before arg0. */
5877 reorder_operands_p (tree arg0, tree arg1)
5879 if (! flag_evaluation_order)
5881 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5883 return ! TREE_SIDE_EFFECTS (arg0)
5884 && ! TREE_SIDE_EFFECTS (arg1);
5887 /* Test whether it is preferable two swap two operands, ARG0 and
5888 ARG1, for example because ARG0 is an integer constant and ARG1
5889 isn't. If REORDER is true, only recommend swapping if we can
5890 evaluate the operands in reverse order. */
5893 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
5895 STRIP_SIGN_NOPS (arg0);
5896 STRIP_SIGN_NOPS (arg1);
5898 if (TREE_CODE (arg1) == INTEGER_CST)
5900 if (TREE_CODE (arg0) == INTEGER_CST)
5903 if (TREE_CODE (arg1) == REAL_CST)
5905 if (TREE_CODE (arg0) == REAL_CST)
5908 if (TREE_CODE (arg1) == COMPLEX_CST)
5910 if (TREE_CODE (arg0) == COMPLEX_CST)
5913 if (TREE_CONSTANT (arg1))
5915 if (TREE_CONSTANT (arg0))
5921 if (reorder && flag_evaluation_order
5922 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5930 if (reorder && flag_evaluation_order
5931 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5939 /* It is preferable to swap two SSA_NAME to ensure a canonical form
5940 for commutative and comparison operators. Ensuring a canonical
5941 form allows the optimizers to find additional redundancies without
5942 having to explicitly check for both orderings. */
5943 if (TREE_CODE (arg0) == SSA_NAME
5944 && TREE_CODE (arg1) == SSA_NAME
5945 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
5951 /* Perform constant folding and related simplification of EXPR.
5952 The related simplifications include x*1 => x, x*0 => 0, etc.,
5953 and application of the associative law.
5954 NOP_EXPR conversions may be removed freely (as long as we
5955 are careful not to change the type of the overall expression).
5956 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
5957 but we can constant-fold them if they have constant operands. */
5959 #ifdef ENABLE_FOLD_CHECKING
5960 # define fold(x) fold_1 (x)
5961 static tree fold_1 (tree);
5967 const tree t = expr;
5968 const tree type = TREE_TYPE (expr);
5969 tree t1 = NULL_TREE;
5971 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
5972 enum tree_code code = TREE_CODE (t);
5973 int kind = TREE_CODE_CLASS (code);
5975 /* WINS will be nonzero when the switch is done
5976 if all operands are constant. */
5979 /* Return right away if a constant. */
5983 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
5987 /* Special case for conversion ops that can have fixed point args. */
5988 arg0 = TREE_OPERAND (t, 0);
5990 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
5992 STRIP_SIGN_NOPS (arg0);
5994 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
5995 subop = TREE_REALPART (arg0);
5999 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
6000 && TREE_CODE (subop) != REAL_CST)
6001 /* Note that TREE_CONSTANT isn't enough:
6002 static var addresses are constant but we can't
6003 do arithmetic on them. */
6006 else if (IS_EXPR_CODE_CLASS (kind))
6008 int len = first_rtl_op (code);
6010 for (i = 0; i < len; i++)
6012 tree op = TREE_OPERAND (t, i);
6016 continue; /* Valid for CALL_EXPR, at least. */
6018 /* Strip any conversions that don't change the mode. This is
6019 safe for every expression, except for a comparison expression
6020 because its signedness is derived from its operands. So, in
6021 the latter case, only strip conversions that don't change the
6024 Note that this is done as an internal manipulation within the
6025 constant folder, in order to find the simplest representation
6026 of the arguments so that their form can be studied. In any
6027 cases, the appropriate type conversions should be put back in
6028 the tree that will get out of the constant folder. */
6030 STRIP_SIGN_NOPS (op);
6034 if (TREE_CODE (op) == COMPLEX_CST)
6035 subop = TREE_REALPART (op);
6039 if (TREE_CODE (subop) != INTEGER_CST
6040 && TREE_CODE (subop) != REAL_CST)
6041 /* Note that TREE_CONSTANT isn't enough:
6042 static var addresses are constant but we can't
6043 do arithmetic on them. */
6053 /* If this is a commutative operation, and ARG0 is a constant, move it
6054 to ARG1 to reduce the number of tests below. */
6055 if (commutative_tree_code (code)
6056 && tree_swap_operands_p (arg0, arg1, true))
6057 return fold (build2 (code, type, TREE_OPERAND (t, 1),
6058 TREE_OPERAND (t, 0)));
6060 /* Now WINS is set as described above,
6061 ARG0 is the first operand of EXPR,
6062 and ARG1 is the second operand (if it has more than one operand).
6064 First check for cases where an arithmetic operation is applied to a
6065 compound, conditional, or comparison operation. Push the arithmetic
6066 operation inside the compound or conditional to see if any folding
6067 can then be done. Convert comparison to conditional for this purpose.
6068 The also optimizes non-constant cases that used to be done in
6071 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
6072 one of the operands is a comparison and the other is a comparison, a
6073 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
6074 code below would make the expression more complex. Change it to a
6075 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
6076 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
6078 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
6079 || code == EQ_EXPR || code == NE_EXPR)
6080 && ((truth_value_p (TREE_CODE (arg0))
6081 && (truth_value_p (TREE_CODE (arg1))
6082 || (TREE_CODE (arg1) == BIT_AND_EXPR
6083 && integer_onep (TREE_OPERAND (arg1, 1)))))
6084 || (truth_value_p (TREE_CODE (arg1))
6085 && (truth_value_p (TREE_CODE (arg0))
6086 || (TREE_CODE (arg0) == BIT_AND_EXPR
6087 && integer_onep (TREE_OPERAND (arg0, 1)))))))
6089 tem = fold (build2 (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
6090 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
6092 type, fold_convert (boolean_type_node, arg0),
6093 fold_convert (boolean_type_node, arg1)));
6095 if (code == EQ_EXPR)
6096 tem = invert_truthvalue (tem);
6101 if (TREE_CODE_CLASS (code) == '1')
6103 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6104 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6105 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
6106 else if (TREE_CODE (arg0) == COND_EXPR)
6108 tree arg01 = TREE_OPERAND (arg0, 1);
6109 tree arg02 = TREE_OPERAND (arg0, 2);
6110 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
6111 arg01 = fold (build1 (code, type, arg01));
6112 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
6113 arg02 = fold (build1 (code, type, arg02));
6114 tem = fold (build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
6117 /* If this was a conversion, and all we did was to move into
6118 inside the COND_EXPR, bring it back out. But leave it if
6119 it is a conversion from integer to integer and the
6120 result precision is no wider than a word since such a
6121 conversion is cheap and may be optimized away by combine,
6122 while it couldn't if it were outside the COND_EXPR. Then return
6123 so we don't get into an infinite recursion loop taking the
6124 conversion out and then back in. */
6126 if ((code == NOP_EXPR || code == CONVERT_EXPR
6127 || code == NON_LVALUE_EXPR)
6128 && TREE_CODE (tem) == COND_EXPR
6129 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
6130 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
6131 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
6132 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
6133 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
6134 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
6135 && ! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
6137 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
6138 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD))
6139 tem = build1 (code, type,
6141 TREE_TYPE (TREE_OPERAND
6142 (TREE_OPERAND (tem, 1), 0)),
6143 TREE_OPERAND (tem, 0),
6144 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
6145 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
6148 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
6150 if (TREE_CODE (type) == BOOLEAN_TYPE)
6152 arg0 = copy_node (arg0);
6153 TREE_TYPE (arg0) = type;
6156 else if (TREE_CODE (type) != INTEGER_TYPE)
6157 return fold (build3 (COND_EXPR, type, arg0,
6158 fold (build1 (code, type,
6160 fold (build1 (code, type,
6161 integer_zero_node))));
6164 else if (TREE_CODE_CLASS (code) == '<'
6165 && TREE_CODE (arg0) == COMPOUND_EXPR)
6166 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6167 fold (build2 (code, type, TREE_OPERAND (arg0, 1), arg1)));
6168 else if (TREE_CODE_CLASS (code) == '<'
6169 && TREE_CODE (arg1) == COMPOUND_EXPR)
6170 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6171 fold (build2 (code, type, arg0, TREE_OPERAND (arg1, 1))));
6172 else if (TREE_CODE_CLASS (code) == '2'
6173 || TREE_CODE_CLASS (code) == '<')
6175 if (TREE_CODE (arg0) == COMPOUND_EXPR)
6176 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
6177 fold (build2 (code, type, TREE_OPERAND (arg0, 1),
6179 if (TREE_CODE (arg1) == COMPOUND_EXPR
6180 && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
6181 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
6182 fold (build2 (code, type,
6183 arg0, TREE_OPERAND (arg1, 1))));
6185 if (TREE_CODE (arg0) == COND_EXPR
6186 || TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
6188 tem = fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
6189 /*cond_first_p=*/1);
6190 if (tem != NULL_TREE)
6194 if (TREE_CODE (arg1) == COND_EXPR
6195 || TREE_CODE_CLASS (TREE_CODE (arg1)) == '<')
6197 tem = fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
6198 /*cond_first_p=*/0);
6199 if (tem != NULL_TREE)
6207 return fold (DECL_INITIAL (t));
6212 case FIX_TRUNC_EXPR:
6214 case FIX_FLOOR_EXPR:
6215 case FIX_ROUND_EXPR:
6216 if (TREE_TYPE (TREE_OPERAND (t, 0)) == type)
6217 return TREE_OPERAND (t, 0);
6219 /* Handle cases of two conversions in a row. */
6220 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
6221 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
6223 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6224 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
6225 int inside_int = INTEGRAL_TYPE_P (inside_type);
6226 int inside_ptr = POINTER_TYPE_P (inside_type);
6227 int inside_float = FLOAT_TYPE_P (inside_type);
6228 unsigned int inside_prec = TYPE_PRECISION (inside_type);
6229 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
6230 int inter_int = INTEGRAL_TYPE_P (inter_type);
6231 int inter_ptr = POINTER_TYPE_P (inter_type);
6232 int inter_float = FLOAT_TYPE_P (inter_type);
6233 unsigned int inter_prec = TYPE_PRECISION (inter_type);
6234 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
6235 int final_int = INTEGRAL_TYPE_P (type);
6236 int final_ptr = POINTER_TYPE_P (type);
6237 int final_float = FLOAT_TYPE_P (type);
6238 unsigned int final_prec = TYPE_PRECISION (type);
6239 int final_unsignedp = TYPE_UNSIGNED (type);
6241 /* In addition to the cases of two conversions in a row
6242 handled below, if we are converting something to its own
6243 type via an object of identical or wider precision, neither
6244 conversion is needed. */
6245 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
6246 && ((inter_int && final_int) || (inter_float && final_float))
6247 && inter_prec >= final_prec)
6248 return fold (build1 (code, type,
6249 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6251 /* Likewise, if the intermediate and final types are either both
6252 float or both integer, we don't need the middle conversion if
6253 it is wider than the final type and doesn't change the signedness
6254 (for integers). Avoid this if the final type is a pointer
6255 since then we sometimes need the inner conversion. Likewise if
6256 the outer has a precision not equal to the size of its mode. */
6257 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6258 || (inter_float && inside_float))
6259 && inter_prec >= inside_prec
6260 && (inter_float || inter_unsignedp == inside_unsignedp)
6261 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6262 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6264 return fold (build1 (code, type,
6265 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6267 /* If we have a sign-extension of a zero-extended value, we can
6268 replace that by a single zero-extension. */
6269 if (inside_int && inter_int && final_int
6270 && inside_prec < inter_prec && inter_prec < final_prec
6271 && inside_unsignedp && !inter_unsignedp)
6272 return fold (build1 (code, type,
6273 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6275 /* Two conversions in a row are not needed unless:
6276 - some conversion is floating-point (overstrict for now), or
6277 - the intermediate type is narrower than both initial and
6279 - the intermediate type and innermost type differ in signedness,
6280 and the outermost type is wider than the intermediate, or
6281 - the initial type is a pointer type and the precisions of the
6282 intermediate and final types differ, or
6283 - the final type is a pointer type and the precisions of the
6284 initial and intermediate types differ. */
6285 if (! inside_float && ! inter_float && ! final_float
6286 && (inter_prec > inside_prec || inter_prec > final_prec)
6287 && ! (inside_int && inter_int
6288 && inter_unsignedp != inside_unsignedp
6289 && inter_prec < final_prec)
6290 && ((inter_unsignedp && inter_prec > inside_prec)
6291 == (final_unsignedp && final_prec > inter_prec))
6292 && ! (inside_ptr && inter_prec != final_prec)
6293 && ! (final_ptr && inside_prec != inter_prec)
6294 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
6295 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6297 return fold (build1 (code, type,
6298 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
6301 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
6302 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
6303 /* Detect assigning a bitfield. */
6304 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
6305 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
6307 /* Don't leave an assignment inside a conversion
6308 unless assigning a bitfield. */
6309 tree prev = TREE_OPERAND (t, 0);
6310 tem = copy_node (t);
6311 TREE_OPERAND (tem, 0) = TREE_OPERAND (prev, 1);
6312 /* First do the assignment, then return converted constant. */
6313 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), prev, fold (tem));
6314 TREE_NO_WARNING (tem) = 1;
6315 TREE_USED (tem) = 1;
6319 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
6320 constants (if x has signed type, the sign bit cannot be set
6321 in c). This folds extension into the BIT_AND_EXPR. */
6322 if (INTEGRAL_TYPE_P (type)
6323 && TREE_CODE (type) != BOOLEAN_TYPE
6324 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
6325 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
6327 tree and = TREE_OPERAND (t, 0);
6328 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
6331 if (TYPE_UNSIGNED (TREE_TYPE (and))
6332 || (TYPE_PRECISION (type)
6333 <= TYPE_PRECISION (TREE_TYPE (and))))
6335 else if (TYPE_PRECISION (TREE_TYPE (and1))
6336 <= HOST_BITS_PER_WIDE_INT
6337 && host_integerp (and1, 1))
6339 unsigned HOST_WIDE_INT cst;
6341 cst = tree_low_cst (and1, 1);
6342 cst &= (HOST_WIDE_INT) -1
6343 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
6344 change = (cst == 0);
6345 #ifdef LOAD_EXTEND_OP
6347 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
6350 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
6351 and0 = fold_convert (uns, and0);
6352 and1 = fold_convert (uns, and1);
6357 return fold (build2 (BIT_AND_EXPR, type,
6358 fold_convert (type, and0),
6359 fold_convert (type, and1)));
6362 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
6363 T2 being pointers to types of the same size. */
6364 if (POINTER_TYPE_P (TREE_TYPE (t))
6365 && TREE_CODE_CLASS (TREE_CODE (arg0)) == '2'
6366 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
6367 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6369 tree arg00 = TREE_OPERAND (arg0, 0);
6370 tree t0 = TREE_TYPE (t);
6371 tree t1 = TREE_TYPE (arg00);
6372 tree tt0 = TREE_TYPE (t0);
6373 tree tt1 = TREE_TYPE (t1);
6374 tree s0 = TYPE_SIZE (tt0);
6375 tree s1 = TYPE_SIZE (tt1);
6377 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
6378 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
6379 TREE_OPERAND (arg0, 1));
6382 tem = fold_convert_const (code, type, arg0);
6383 return tem ? tem : t;
6385 case VIEW_CONVERT_EXPR:
6386 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
6387 return build1 (VIEW_CONVERT_EXPR, type,
6388 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
6392 if (TREE_CODE (arg0) == CONSTRUCTOR
6393 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
6395 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
6397 return TREE_VALUE (m);
6402 if (TREE_CONSTANT (t) != wins)
6404 tem = copy_node (t);
6405 TREE_CONSTANT (tem) = wins;
6406 TREE_INVARIANT (tem) = wins;
6412 if (negate_expr_p (arg0))
6413 return fold_convert (type, negate_expr (arg0));
6417 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
6418 return fold_abs_const (arg0, type);
6419 else if (TREE_CODE (arg0) == NEGATE_EXPR)
6420 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
6421 /* Convert fabs((double)float) into (double)fabsf(float). */
6422 else if (TREE_CODE (arg0) == NOP_EXPR
6423 && TREE_CODE (type) == REAL_TYPE)
6425 tree targ0 = strip_float_extensions (arg0);
6427 return fold_convert (type, fold (build1 (ABS_EXPR,
6431 else if (tree_expr_nonnegative_p (arg0))
6436 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
6437 return fold_convert (type, arg0);
6438 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
6439 return build2 (COMPLEX_EXPR, type,
6440 TREE_OPERAND (arg0, 0),
6441 negate_expr (TREE_OPERAND (arg0, 1)));
6442 else if (TREE_CODE (arg0) == COMPLEX_CST)
6443 return build_complex (type, TREE_REALPART (arg0),
6444 negate_expr (TREE_IMAGPART (arg0)));
6445 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
6446 return fold (build2 (TREE_CODE (arg0), type,
6447 fold (build1 (CONJ_EXPR, type,
6448 TREE_OPERAND (arg0, 0))),
6449 fold (build1 (CONJ_EXPR, type,
6450 TREE_OPERAND (arg0, 1)))));
6451 else if (TREE_CODE (arg0) == CONJ_EXPR)
6452 return TREE_OPERAND (arg0, 0);
6456 if (TREE_CODE (arg0) == INTEGER_CST)
6457 return fold_not_const (arg0, type);
6458 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
6459 return TREE_OPERAND (arg0, 0);
6463 /* A + (-B) -> A - B */
6464 if (TREE_CODE (arg1) == NEGATE_EXPR)
6465 return fold (build2 (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6466 /* (-A) + B -> B - A */
6467 if (TREE_CODE (arg0) == NEGATE_EXPR
6468 && reorder_operands_p (TREE_OPERAND (arg0, 0), arg1))
6469 return fold (build2 (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
6470 if (! FLOAT_TYPE_P (type))
6472 if (integer_zerop (arg1))
6473 return non_lvalue (fold_convert (type, arg0));
6475 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
6476 with a constant, and the two constants have no bits in common,
6477 we should treat this as a BIT_IOR_EXPR since this may produce more
6479 if (TREE_CODE (arg0) == BIT_AND_EXPR
6480 && TREE_CODE (arg1) == BIT_AND_EXPR
6481 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6482 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6483 && integer_zerop (const_binop (BIT_AND_EXPR,
6484 TREE_OPERAND (arg0, 1),
6485 TREE_OPERAND (arg1, 1), 0)))
6487 code = BIT_IOR_EXPR;
6491 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
6492 (plus (plus (mult) (mult)) (foo)) so that we can
6493 take advantage of the factoring cases below. */
6494 if ((TREE_CODE (arg0) == PLUS_EXPR
6495 && TREE_CODE (arg1) == MULT_EXPR)
6496 || (TREE_CODE (arg1) == PLUS_EXPR
6497 && TREE_CODE (arg0) == MULT_EXPR))
6499 tree parg0, parg1, parg, marg;
6501 if (TREE_CODE (arg0) == PLUS_EXPR)
6502 parg = arg0, marg = arg1;
6504 parg = arg1, marg = arg0;
6505 parg0 = TREE_OPERAND (parg, 0);
6506 parg1 = TREE_OPERAND (parg, 1);
6510 if (TREE_CODE (parg0) == MULT_EXPR
6511 && TREE_CODE (parg1) != MULT_EXPR)
6512 return fold (build2 (PLUS_EXPR, type,
6513 fold (build2 (PLUS_EXPR, type,
6514 fold_convert (type, parg0),
6515 fold_convert (type, marg))),
6516 fold_convert (type, parg1)));
6517 if (TREE_CODE (parg0) != MULT_EXPR
6518 && TREE_CODE (parg1) == MULT_EXPR)
6519 return fold (build2 (PLUS_EXPR, type,
6520 fold (build2 (PLUS_EXPR, type,
6521 fold_convert (type, parg1),
6522 fold_convert (type, marg))),
6523 fold_convert (type, parg0)));
6526 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
6528 tree arg00, arg01, arg10, arg11;
6529 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
6531 /* (A * C) + (B * C) -> (A+B) * C.
6532 We are most concerned about the case where C is a constant,
6533 but other combinations show up during loop reduction. Since
6534 it is not difficult, try all four possibilities. */
6536 arg00 = TREE_OPERAND (arg0, 0);
6537 arg01 = TREE_OPERAND (arg0, 1);
6538 arg10 = TREE_OPERAND (arg1, 0);
6539 arg11 = TREE_OPERAND (arg1, 1);
6542 if (operand_equal_p (arg01, arg11, 0))
6543 same = arg01, alt0 = arg00, alt1 = arg10;
6544 else if (operand_equal_p (arg00, arg10, 0))
6545 same = arg00, alt0 = arg01, alt1 = arg11;
6546 else if (operand_equal_p (arg00, arg11, 0))
6547 same = arg00, alt0 = arg01, alt1 = arg10;
6548 else if (operand_equal_p (arg01, arg10, 0))
6549 same = arg01, alt0 = arg00, alt1 = arg11;
6551 /* No identical multiplicands; see if we can find a common
6552 power-of-two factor in non-power-of-two multiplies. This
6553 can help in multi-dimensional array access. */
6554 else if (TREE_CODE (arg01) == INTEGER_CST
6555 && TREE_CODE (arg11) == INTEGER_CST
6556 && TREE_INT_CST_HIGH (arg01) == 0
6557 && TREE_INT_CST_HIGH (arg11) == 0)
6559 HOST_WIDE_INT int01, int11, tmp;
6560 int01 = TREE_INT_CST_LOW (arg01);
6561 int11 = TREE_INT_CST_LOW (arg11);
6563 /* Move min of absolute values to int11. */
6564 if ((int01 >= 0 ? int01 : -int01)
6565 < (int11 >= 0 ? int11 : -int11))
6567 tmp = int01, int01 = int11, int11 = tmp;
6568 alt0 = arg00, arg00 = arg10, arg10 = alt0;
6569 alt0 = arg01, arg01 = arg11, arg11 = alt0;
6572 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
6574 alt0 = fold (build2 (MULT_EXPR, type, arg00,
6575 build_int_cst (NULL_TREE,
6583 return fold (build2 (MULT_EXPR, type,
6584 fold (build2 (PLUS_EXPR, type,
6591 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6592 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
6593 return non_lvalue (fold_convert (type, arg0));
6595 /* Likewise if the operands are reversed. */
6596 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6597 return non_lvalue (fold_convert (type, arg1));
6599 /* Convert X + -C into X - C. */
6600 if (TREE_CODE (arg1) == REAL_CST
6601 && REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)))
6603 tem = fold_negate_const (arg1, type);
6604 if (!TREE_OVERFLOW (arg1) || !flag_trapping_math)
6605 return fold (build2 (MINUS_EXPR, type,
6606 fold_convert (type, arg0),
6607 fold_convert (type, tem)));
6610 /* Convert x+x into x*2.0. */
6611 if (operand_equal_p (arg0, arg1, 0)
6612 && SCALAR_FLOAT_TYPE_P (type))
6613 return fold (build2 (MULT_EXPR, type, arg0,
6614 build_real (type, dconst2)));
6616 /* Convert x*c+x into x*(c+1). */
6617 if (flag_unsafe_math_optimizations
6618 && TREE_CODE (arg0) == MULT_EXPR
6619 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6620 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6621 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
6625 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6626 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6627 return fold (build2 (MULT_EXPR, type, arg1,
6628 build_real (type, c)));
6631 /* Convert x+x*c into x*(c+1). */
6632 if (flag_unsafe_math_optimizations
6633 && TREE_CODE (arg1) == MULT_EXPR
6634 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6635 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6636 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
6640 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6641 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6642 return fold (build2 (MULT_EXPR, type, arg0,
6643 build_real (type, c)));
6646 /* Convert x*c1+x*c2 into x*(c1+c2). */
6647 if (flag_unsafe_math_optimizations
6648 && TREE_CODE (arg0) == MULT_EXPR
6649 && TREE_CODE (arg1) == MULT_EXPR
6650 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6651 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6652 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6653 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6654 && operand_equal_p (TREE_OPERAND (arg0, 0),
6655 TREE_OPERAND (arg1, 0), 0))
6657 REAL_VALUE_TYPE c1, c2;
6659 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6660 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6661 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
6662 return fold (build2 (MULT_EXPR, type,
6663 TREE_OPERAND (arg0, 0),
6664 build_real (type, c1)));
6666 /* Convert a + (b*c + d*e) into (a + b*c) + d*e */
6667 if (flag_unsafe_math_optimizations
6668 && TREE_CODE (arg1) == PLUS_EXPR
6669 && TREE_CODE (arg0) != MULT_EXPR)
6671 tree tree10 = TREE_OPERAND (arg1, 0);
6672 tree tree11 = TREE_OPERAND (arg1, 1);
6673 if (TREE_CODE (tree11) == MULT_EXPR
6674 && TREE_CODE (tree10) == MULT_EXPR)
6677 tree0 = fold (build2 (PLUS_EXPR, type, arg0, tree10));
6678 return fold (build2 (PLUS_EXPR, type, tree0, tree11));
6681 /* Convert (b*c + d*e) + a into b*c + (d*e +a) */
6682 if (flag_unsafe_math_optimizations
6683 && TREE_CODE (arg0) == PLUS_EXPR
6684 && TREE_CODE (arg1) != MULT_EXPR)
6686 tree tree00 = TREE_OPERAND (arg0, 0);
6687 tree tree01 = TREE_OPERAND (arg0, 1);
6688 if (TREE_CODE (tree01) == MULT_EXPR
6689 && TREE_CODE (tree00) == MULT_EXPR)
6692 tree0 = fold (build2 (PLUS_EXPR, type, tree01, arg1));
6693 return fold (build2 (PLUS_EXPR, type, tree00, tree0));
6699 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6700 is a rotate of A by C1 bits. */
6701 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6702 is a rotate of A by B bits. */
6704 enum tree_code code0, code1;
6705 code0 = TREE_CODE (arg0);
6706 code1 = TREE_CODE (arg1);
6707 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
6708 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
6709 && operand_equal_p (TREE_OPERAND (arg0, 0),
6710 TREE_OPERAND (arg1, 0), 0)
6711 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6713 tree tree01, tree11;
6714 enum tree_code code01, code11;
6716 tree01 = TREE_OPERAND (arg0, 1);
6717 tree11 = TREE_OPERAND (arg1, 1);
6718 STRIP_NOPS (tree01);
6719 STRIP_NOPS (tree11);
6720 code01 = TREE_CODE (tree01);
6721 code11 = TREE_CODE (tree11);
6722 if (code01 == INTEGER_CST
6723 && code11 == INTEGER_CST
6724 && TREE_INT_CST_HIGH (tree01) == 0
6725 && TREE_INT_CST_HIGH (tree11) == 0
6726 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
6727 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
6728 return build2 (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
6729 code0 == LSHIFT_EXPR ? tree01 : tree11);
6730 else if (code11 == MINUS_EXPR)
6732 tree tree110, tree111;
6733 tree110 = TREE_OPERAND (tree11, 0);
6734 tree111 = TREE_OPERAND (tree11, 1);
6735 STRIP_NOPS (tree110);
6736 STRIP_NOPS (tree111);
6737 if (TREE_CODE (tree110) == INTEGER_CST
6738 && 0 == compare_tree_int (tree110,
6740 (TREE_TYPE (TREE_OPERAND
6742 && operand_equal_p (tree01, tree111, 0))
6743 return build2 ((code0 == LSHIFT_EXPR
6746 type, TREE_OPERAND (arg0, 0), tree01);
6748 else if (code01 == MINUS_EXPR)
6750 tree tree010, tree011;
6751 tree010 = TREE_OPERAND (tree01, 0);
6752 tree011 = TREE_OPERAND (tree01, 1);
6753 STRIP_NOPS (tree010);
6754 STRIP_NOPS (tree011);
6755 if (TREE_CODE (tree010) == INTEGER_CST
6756 && 0 == compare_tree_int (tree010,
6758 (TREE_TYPE (TREE_OPERAND
6760 && operand_equal_p (tree11, tree011, 0))
6761 return build2 ((code0 != LSHIFT_EXPR
6764 type, TREE_OPERAND (arg0, 0), tree11);
6770 /* In most languages, can't associate operations on floats through
6771 parentheses. Rather than remember where the parentheses were, we
6772 don't associate floats at all, unless the user has specified
6773 -funsafe-math-optimizations. */
6776 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
6778 tree var0, con0, lit0, minus_lit0;
6779 tree var1, con1, lit1, minus_lit1;
6781 /* Split both trees into variables, constants, and literals. Then
6782 associate each group together, the constants with literals,
6783 then the result with variables. This increases the chances of
6784 literals being recombined later and of generating relocatable
6785 expressions for the sum of a constant and literal. */
6786 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
6787 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
6788 code == MINUS_EXPR);
6790 /* Only do something if we found more than two objects. Otherwise,
6791 nothing has changed and we risk infinite recursion. */
6792 if (2 < ((var0 != 0) + (var1 != 0)
6793 + (con0 != 0) + (con1 != 0)
6794 + (lit0 != 0) + (lit1 != 0)
6795 + (minus_lit0 != 0) + (minus_lit1 != 0)))
6797 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
6798 if (code == MINUS_EXPR)
6801 var0 = associate_trees (var0, var1, code, type);
6802 con0 = associate_trees (con0, con1, code, type);
6803 lit0 = associate_trees (lit0, lit1, code, type);
6804 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
6806 /* Preserve the MINUS_EXPR if the negative part of the literal is
6807 greater than the positive part. Otherwise, the multiplicative
6808 folding code (i.e extract_muldiv) may be fooled in case
6809 unsigned constants are subtracted, like in the following
6810 example: ((X*2 + 4) - 8U)/2. */
6811 if (minus_lit0 && lit0)
6813 if (TREE_CODE (lit0) == INTEGER_CST
6814 && TREE_CODE (minus_lit0) == INTEGER_CST
6815 && tree_int_cst_lt (lit0, minus_lit0))
6817 minus_lit0 = associate_trees (minus_lit0, lit0,
6823 lit0 = associate_trees (lit0, minus_lit0,
6831 return fold_convert (type,
6832 associate_trees (var0, minus_lit0,
6836 con0 = associate_trees (con0, minus_lit0,
6838 return fold_convert (type,
6839 associate_trees (var0, con0,
6844 con0 = associate_trees (con0, lit0, code, type);
6845 return fold_convert (type, associate_trees (var0, con0,
6852 t1 = const_binop (code, arg0, arg1, 0);
6853 if (t1 != NULL_TREE)
6855 /* The return value should always have
6856 the same type as the original expression. */
6857 if (TREE_TYPE (t1) != type)
6858 t1 = fold_convert (type, t1);
6865 /* A - (-B) -> A + B */
6866 if (TREE_CODE (arg1) == NEGATE_EXPR)
6867 return fold (build2 (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6868 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
6869 if (TREE_CODE (arg0) == NEGATE_EXPR
6870 && (FLOAT_TYPE_P (type)
6871 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
6872 && negate_expr_p (arg1)
6873 && reorder_operands_p (arg0, arg1))
6874 return fold (build2 (MINUS_EXPR, type, negate_expr (arg1),
6875 TREE_OPERAND (arg0, 0)));
6877 if (! FLOAT_TYPE_P (type))
6879 if (! wins && integer_zerop (arg0))
6880 return negate_expr (fold_convert (type, arg1));
6881 if (integer_zerop (arg1))
6882 return non_lvalue (fold_convert (type, arg0));
6884 /* Fold A - (A & B) into ~B & A. */
6885 if (!TREE_SIDE_EFFECTS (arg0)
6886 && TREE_CODE (arg1) == BIT_AND_EXPR)
6888 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
6889 return fold (build2 (BIT_AND_EXPR, type,
6890 fold (build1 (BIT_NOT_EXPR, type,
6891 TREE_OPERAND (arg1, 0))),
6893 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
6894 return fold (build2 (BIT_AND_EXPR, type,
6895 fold (build1 (BIT_NOT_EXPR, type,
6896 TREE_OPERAND (arg1, 1))),
6900 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
6901 any power of 2 minus 1. */
6902 if (TREE_CODE (arg0) == BIT_AND_EXPR
6903 && TREE_CODE (arg1) == BIT_AND_EXPR
6904 && operand_equal_p (TREE_OPERAND (arg0, 0),
6905 TREE_OPERAND (arg1, 0), 0))
6907 tree mask0 = TREE_OPERAND (arg0, 1);
6908 tree mask1 = TREE_OPERAND (arg1, 1);
6909 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
6911 if (operand_equal_p (tem, mask1, 0))
6913 tem = fold (build2 (BIT_XOR_EXPR, type,
6914 TREE_OPERAND (arg0, 0), mask1));
6915 return fold (build2 (MINUS_EXPR, type, tem, mask1));
6920 /* See if ARG1 is zero and X - ARG1 reduces to X. */
6921 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
6922 return non_lvalue (fold_convert (type, arg0));
6924 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
6925 ARG0 is zero and X + ARG0 reduces to X, since that would mean
6926 (-ARG1 + ARG0) reduces to -ARG1. */
6927 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6928 return negate_expr (fold_convert (type, arg1));
6930 /* Fold &x - &x. This can happen from &x.foo - &x.
6931 This is unsafe for certain floats even in non-IEEE formats.
6932 In IEEE, it is unsafe because it does wrong for NaNs.
6933 Also note that operand_equal_p is always false if an operand
6936 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
6937 && operand_equal_p (arg0, arg1, 0))
6938 return fold_convert (type, integer_zero_node);
6940 /* A - B -> A + (-B) if B is easily negatable. */
6941 if (!wins && negate_expr_p (arg1)
6942 && ((FLOAT_TYPE_P (type)
6943 /* Avoid this transformation if B is a positive REAL_CST. */
6944 && (TREE_CODE (arg1) != REAL_CST
6945 || REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))))
6946 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
6947 return fold (build2 (PLUS_EXPR, type, arg0, negate_expr (arg1)));
6949 if (TREE_CODE (arg0) == MULT_EXPR
6950 && TREE_CODE (arg1) == MULT_EXPR
6951 && (INTEGRAL_TYPE_P (type) || flag_unsafe_math_optimizations))
6953 /* (A * C) - (B * C) -> (A-B) * C. */
6954 if (operand_equal_p (TREE_OPERAND (arg0, 1),
6955 TREE_OPERAND (arg1, 1), 0))
6956 return fold (build2 (MULT_EXPR, type,
6957 fold (build2 (MINUS_EXPR, type,
6958 TREE_OPERAND (arg0, 0),
6959 TREE_OPERAND (arg1, 0))),
6960 TREE_OPERAND (arg0, 1)));
6961 /* (A * C1) - (A * C2) -> A * (C1-C2). */
6962 if (operand_equal_p (TREE_OPERAND (arg0, 0),
6963 TREE_OPERAND (arg1, 0), 0))
6964 return fold (build2 (MULT_EXPR, type,
6965 TREE_OPERAND (arg0, 0),
6966 fold (build2 (MINUS_EXPR, type,
6967 TREE_OPERAND (arg0, 1),
6968 TREE_OPERAND (arg1, 1)))));
6974 /* (-A) * (-B) -> A * B */
6975 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6976 return fold (build2 (MULT_EXPR, type,
6977 TREE_OPERAND (arg0, 0),
6978 negate_expr (arg1)));
6979 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6980 return fold (build2 (MULT_EXPR, type,
6982 TREE_OPERAND (arg1, 0)));
6984 if (! FLOAT_TYPE_P (type))
6986 if (integer_zerop (arg1))
6987 return omit_one_operand (type, arg1, arg0);
6988 if (integer_onep (arg1))
6989 return non_lvalue (fold_convert (type, arg0));
6991 /* (a * (1 << b)) is (a << b) */
6992 if (TREE_CODE (arg1) == LSHIFT_EXPR
6993 && integer_onep (TREE_OPERAND (arg1, 0)))
6994 return fold (build2 (LSHIFT_EXPR, type, arg0,
6995 TREE_OPERAND (arg1, 1)));
6996 if (TREE_CODE (arg0) == LSHIFT_EXPR
6997 && integer_onep (TREE_OPERAND (arg0, 0)))
6998 return fold (build2 (LSHIFT_EXPR, type, arg1,
6999 TREE_OPERAND (arg0, 1)));
7001 if (TREE_CODE (arg1) == INTEGER_CST
7002 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
7003 fold_convert (type, arg1),
7005 return fold_convert (type, tem);
7010 /* Maybe fold x * 0 to 0. The expressions aren't the same
7011 when x is NaN, since x * 0 is also NaN. Nor are they the
7012 same in modes with signed zeros, since multiplying a
7013 negative value by 0 gives -0, not +0. */
7014 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
7015 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
7016 && real_zerop (arg1))
7017 return omit_one_operand (type, arg1, arg0);
7018 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
7019 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7020 && real_onep (arg1))
7021 return non_lvalue (fold_convert (type, arg0));
7023 /* Transform x * -1.0 into -x. */
7024 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7025 && real_minus_onep (arg1))
7026 return fold_convert (type, negate_expr (arg0));
7028 /* Convert (C1/X)*C2 into (C1*C2)/X. */
7029 if (flag_unsafe_math_optimizations
7030 && TREE_CODE (arg0) == RDIV_EXPR
7031 && TREE_CODE (arg1) == REAL_CST
7032 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
7034 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
7037 return fold (build2 (RDIV_EXPR, type, tem,
7038 TREE_OPERAND (arg0, 1)));
7041 if (flag_unsafe_math_optimizations)
7043 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7044 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7046 /* Optimizations of root(...)*root(...). */
7047 if (fcode0 == fcode1 && BUILTIN_ROOT_P (fcode0))
7049 tree rootfn, arg, arglist;
7050 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7051 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7053 /* Optimize sqrt(x)*sqrt(x) as x. */
7054 if (BUILTIN_SQRT_P (fcode0)
7055 && operand_equal_p (arg00, arg10, 0)
7056 && ! HONOR_SNANS (TYPE_MODE (type)))
7059 /* Optimize root(x)*root(y) as root(x*y). */
7060 rootfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7061 arg = fold (build2 (MULT_EXPR, type, arg00, arg10));
7062 arglist = build_tree_list (NULL_TREE, arg);
7063 return build_function_call_expr (rootfn, arglist);
7066 /* Optimize expN(x)*expN(y) as expN(x+y). */
7067 if (fcode0 == fcode1 && BUILTIN_EXPONENT_P (fcode0))
7069 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7070 tree arg = build2 (PLUS_EXPR, type,
7071 TREE_VALUE (TREE_OPERAND (arg0, 1)),
7072 TREE_VALUE (TREE_OPERAND (arg1, 1)));
7073 tree arglist = build_tree_list (NULL_TREE, fold (arg));
7074 return build_function_call_expr (expfn, arglist);
7077 /* Optimizations of pow(...)*pow(...). */
7078 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
7079 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
7080 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
7082 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7083 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7085 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7086 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7089 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
7090 if (operand_equal_p (arg01, arg11, 0))
7092 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7093 tree arg = build2 (MULT_EXPR, type, arg00, arg10);
7094 tree arglist = tree_cons (NULL_TREE, fold (arg),
7095 build_tree_list (NULL_TREE,
7097 return build_function_call_expr (powfn, arglist);
7100 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
7101 if (operand_equal_p (arg00, arg10, 0))
7103 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7104 tree arg = fold (build2 (PLUS_EXPR, type, arg01, arg11));
7105 tree arglist = tree_cons (NULL_TREE, arg00,
7106 build_tree_list (NULL_TREE,
7108 return build_function_call_expr (powfn, arglist);
7112 /* Optimize tan(x)*cos(x) as sin(x). */
7113 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
7114 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
7115 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
7116 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
7117 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
7118 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
7119 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7120 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7122 tree sinfn = mathfn_built_in (type, BUILT_IN_SIN);
7124 if (sinfn != NULL_TREE)
7125 return build_function_call_expr (sinfn,
7126 TREE_OPERAND (arg0, 1));
7129 /* Optimize x*pow(x,c) as pow(x,c+1). */
7130 if (fcode1 == BUILT_IN_POW
7131 || fcode1 == BUILT_IN_POWF
7132 || fcode1 == BUILT_IN_POWL)
7134 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7135 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
7137 if (TREE_CODE (arg11) == REAL_CST
7138 && ! TREE_CONSTANT_OVERFLOW (arg11)
7139 && operand_equal_p (arg0, arg10, 0))
7141 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7145 c = TREE_REAL_CST (arg11);
7146 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7147 arg = build_real (type, c);
7148 arglist = build_tree_list (NULL_TREE, arg);
7149 arglist = tree_cons (NULL_TREE, arg0, arglist);
7150 return build_function_call_expr (powfn, arglist);
7154 /* Optimize pow(x,c)*x as pow(x,c+1). */
7155 if (fcode0 == BUILT_IN_POW
7156 || fcode0 == BUILT_IN_POWF
7157 || fcode0 == BUILT_IN_POWL)
7159 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7160 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
7162 if (TREE_CODE (arg01) == REAL_CST
7163 && ! TREE_CONSTANT_OVERFLOW (arg01)
7164 && operand_equal_p (arg1, arg00, 0))
7166 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7170 c = TREE_REAL_CST (arg01);
7171 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
7172 arg = build_real (type, c);
7173 arglist = build_tree_list (NULL_TREE, arg);
7174 arglist = tree_cons (NULL_TREE, arg1, arglist);
7175 return build_function_call_expr (powfn, arglist);
7179 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
7181 && operand_equal_p (arg0, arg1, 0))
7183 tree powfn = mathfn_built_in (type, BUILT_IN_POW);
7187 tree arg = build_real (type, dconst2);
7188 tree arglist = build_tree_list (NULL_TREE, arg);
7189 arglist = tree_cons (NULL_TREE, arg0, arglist);
7190 return build_function_call_expr (powfn, arglist);
7199 if (integer_all_onesp (arg1))
7200 return omit_one_operand (type, arg1, arg0);
7201 if (integer_zerop (arg1))
7202 return non_lvalue (fold_convert (type, arg0));
7203 if (operand_equal_p (arg0, arg1, 0))
7204 return non_lvalue (fold_convert (type, arg0));
7207 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7208 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7210 t1 = build_int_cst (type, -1);
7211 t1 = force_fit_type (t1, 0, false, false);
7212 return omit_one_operand (type, t1, arg1);
7216 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7217 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7219 t1 = build_int_cst (type, -1);
7220 t1 = force_fit_type (t1, 0, false, false);
7221 return omit_one_operand (type, t1, arg0);
7224 t1 = distribute_bit_expr (code, type, arg0, arg1);
7225 if (t1 != NULL_TREE)
7228 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
7230 This results in more efficient code for machines without a NAND
7231 instruction. Combine will canonicalize to the first form
7232 which will allow use of NAND instructions provided by the
7233 backend if they exist. */
7234 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7235 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7237 return fold (build1 (BIT_NOT_EXPR, type,
7238 build2 (BIT_AND_EXPR, type,
7239 TREE_OPERAND (arg0, 0),
7240 TREE_OPERAND (arg1, 0))));
7243 /* See if this can be simplified into a rotate first. If that
7244 is unsuccessful continue in the association code. */
7248 if (integer_zerop (arg1))
7249 return non_lvalue (fold_convert (type, arg0));
7250 if (integer_all_onesp (arg1))
7251 return fold (build1 (BIT_NOT_EXPR, type, arg0));
7252 if (operand_equal_p (arg0, arg1, 0))
7253 return omit_one_operand (type, integer_zero_node, arg0);
7256 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7257 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7259 t1 = build_int_cst (type, -1);
7260 t1 = force_fit_type (t1, 0, false, false);
7261 return omit_one_operand (type, t1, arg1);
7265 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7266 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7268 t1 = build_int_cst (type, -1);
7269 t1 = force_fit_type (t1, 0, false, false);
7270 return omit_one_operand (type, t1, arg0);
7273 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
7274 with a constant, and the two constants have no bits in common,
7275 we should treat this as a BIT_IOR_EXPR since this may produce more
7277 if (TREE_CODE (arg0) == BIT_AND_EXPR
7278 && TREE_CODE (arg1) == BIT_AND_EXPR
7279 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7280 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
7281 && integer_zerop (const_binop (BIT_AND_EXPR,
7282 TREE_OPERAND (arg0, 1),
7283 TREE_OPERAND (arg1, 1), 0)))
7285 code = BIT_IOR_EXPR;
7289 /* See if this can be simplified into a rotate first. If that
7290 is unsuccessful continue in the association code. */
7294 if (integer_all_onesp (arg1))
7295 return non_lvalue (fold_convert (type, arg0));
7296 if (integer_zerop (arg1))
7297 return omit_one_operand (type, arg1, arg0);
7298 if (operand_equal_p (arg0, arg1, 0))
7299 return non_lvalue (fold_convert (type, arg0));
7301 /* ~X & X is always zero. */
7302 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7303 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7304 return omit_one_operand (type, integer_zero_node, arg1);
7306 /* X & ~X is always zero. */
7307 if (TREE_CODE (arg1) == BIT_NOT_EXPR
7308 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7309 return omit_one_operand (type, integer_zero_node, arg0);
7311 t1 = distribute_bit_expr (code, type, arg0, arg1);
7312 if (t1 != NULL_TREE)
7314 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
7315 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
7316 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7319 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
7321 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
7322 && (~TREE_INT_CST_LOW (arg1)
7323 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
7324 return fold_convert (type, TREE_OPERAND (arg0, 0));
7327 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
7329 This results in more efficient code for machines without a NOR
7330 instruction. Combine will canonicalize to the first form
7331 which will allow use of NOR instructions provided by the
7332 backend if they exist. */
7333 if (TREE_CODE (arg0) == BIT_NOT_EXPR
7334 && TREE_CODE (arg1) == BIT_NOT_EXPR)
7336 return fold (build1 (BIT_NOT_EXPR, type,
7337 build2 (BIT_IOR_EXPR, type,
7338 TREE_OPERAND (arg0, 0),
7339 TREE_OPERAND (arg1, 0))));
7345 /* Don't touch a floating-point divide by zero unless the mode
7346 of the constant can represent infinity. */
7347 if (TREE_CODE (arg1) == REAL_CST
7348 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
7349 && real_zerop (arg1))
7352 /* (-A) / (-B) -> A / B */
7353 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
7354 return fold (build2 (RDIV_EXPR, type,
7355 TREE_OPERAND (arg0, 0),
7356 negate_expr (arg1)));
7357 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
7358 return fold (build2 (RDIV_EXPR, type,
7360 TREE_OPERAND (arg1, 0)));
7362 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
7363 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7364 && real_onep (arg1))
7365 return non_lvalue (fold_convert (type, arg0));
7367 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
7368 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
7369 && real_minus_onep (arg1))
7370 return non_lvalue (fold_convert (type, negate_expr (arg0)));
7372 /* If ARG1 is a constant, we can convert this to a multiply by the
7373 reciprocal. This does not have the same rounding properties,
7374 so only do this if -funsafe-math-optimizations. We can actually
7375 always safely do it if ARG1 is a power of two, but it's hard to
7376 tell if it is or not in a portable manner. */
7377 if (TREE_CODE (arg1) == REAL_CST)
7379 if (flag_unsafe_math_optimizations
7380 && 0 != (tem = const_binop (code, build_real (type, dconst1),
7382 return fold (build2 (MULT_EXPR, type, arg0, tem));
7383 /* Find the reciprocal if optimizing and the result is exact. */
7387 r = TREE_REAL_CST (arg1);
7388 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
7390 tem = build_real (type, r);
7391 return fold (build2 (MULT_EXPR, type, arg0, tem));
7395 /* Convert A/B/C to A/(B*C). */
7396 if (flag_unsafe_math_optimizations
7397 && TREE_CODE (arg0) == RDIV_EXPR)
7398 return fold (build2 (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
7399 fold (build2 (MULT_EXPR, type,
7400 TREE_OPERAND (arg0, 1), arg1))));
7402 /* Convert A/(B/C) to (A/B)*C. */
7403 if (flag_unsafe_math_optimizations
7404 && TREE_CODE (arg1) == RDIV_EXPR)
7405 return fold (build2 (MULT_EXPR, type,
7406 fold (build2 (RDIV_EXPR, type, arg0,
7407 TREE_OPERAND (arg1, 0))),
7408 TREE_OPERAND (arg1, 1)));
7410 /* Convert C1/(X*C2) into (C1/C2)/X. */
7411 if (flag_unsafe_math_optimizations
7412 && TREE_CODE (arg1) == MULT_EXPR
7413 && TREE_CODE (arg0) == REAL_CST
7414 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
7416 tree tem = const_binop (RDIV_EXPR, arg0,
7417 TREE_OPERAND (arg1, 1), 0);
7419 return fold (build2 (RDIV_EXPR, type, tem,
7420 TREE_OPERAND (arg1, 0)));
7423 if (flag_unsafe_math_optimizations)
7425 enum built_in_function fcode = builtin_mathfn_code (arg1);
7426 /* Optimize x/expN(y) into x*expN(-y). */
7427 if (BUILTIN_EXPONENT_P (fcode))
7429 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7430 tree arg = negate_expr (TREE_VALUE (TREE_OPERAND (arg1, 1)));
7431 tree arglist = build_tree_list (NULL_TREE,
7432 fold_convert (type, arg));
7433 arg1 = build_function_call_expr (expfn, arglist);
7434 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7437 /* Optimize x/pow(y,z) into x*pow(y,-z). */
7438 if (fcode == BUILT_IN_POW
7439 || fcode == BUILT_IN_POWF
7440 || fcode == BUILT_IN_POWL)
7442 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
7443 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
7444 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
7445 tree neg11 = fold_convert (type, negate_expr (arg11));
7446 tree arglist = tree_cons(NULL_TREE, arg10,
7447 build_tree_list (NULL_TREE, neg11));
7448 arg1 = build_function_call_expr (powfn, arglist);
7449 return fold (build2 (MULT_EXPR, type, arg0, arg1));
7453 if (flag_unsafe_math_optimizations)
7455 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
7456 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
7458 /* Optimize sin(x)/cos(x) as tan(x). */
7459 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
7460 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
7461 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
7462 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7463 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7465 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7467 if (tanfn != NULL_TREE)
7468 return build_function_call_expr (tanfn,
7469 TREE_OPERAND (arg0, 1));
7472 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
7473 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
7474 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
7475 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
7476 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
7477 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
7479 tree tanfn = mathfn_built_in (type, BUILT_IN_TAN);
7481 if (tanfn != NULL_TREE)
7483 tree tmp = TREE_OPERAND (arg0, 1);
7484 tmp = build_function_call_expr (tanfn, tmp);
7485 return fold (build2 (RDIV_EXPR, type,
7486 build_real (type, dconst1), tmp));
7490 /* Optimize pow(x,c)/x as pow(x,c-1). */
7491 if (fcode0 == BUILT_IN_POW
7492 || fcode0 == BUILT_IN_POWF
7493 || fcode0 == BUILT_IN_POWL)
7495 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
7496 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
7497 if (TREE_CODE (arg01) == REAL_CST
7498 && ! TREE_CONSTANT_OVERFLOW (arg01)
7499 && operand_equal_p (arg1, arg00, 0))
7501 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7505 c = TREE_REAL_CST (arg01);
7506 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
7507 arg = build_real (type, c);
7508 arglist = build_tree_list (NULL_TREE, arg);
7509 arglist = tree_cons (NULL_TREE, arg1, arglist);
7510 return build_function_call_expr (powfn, arglist);
7516 case TRUNC_DIV_EXPR:
7517 case ROUND_DIV_EXPR:
7518 case FLOOR_DIV_EXPR:
7520 case EXACT_DIV_EXPR:
7521 if (integer_onep (arg1))
7522 return non_lvalue (fold_convert (type, arg0));
7523 if (integer_zerop (arg1))
7526 if (!TYPE_UNSIGNED (type)
7527 && TREE_CODE (arg1) == INTEGER_CST
7528 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7529 && TREE_INT_CST_HIGH (arg1) == -1)
7530 return fold_convert (type, negate_expr (arg0));
7532 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
7533 operation, EXACT_DIV_EXPR.
7535 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
7536 At one time others generated faster code, it's not clear if they do
7537 after the last round to changes to the DIV code in expmed.c. */
7538 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
7539 && multiple_of_p (type, arg0, arg1))
7540 return fold (build2 (EXACT_DIV_EXPR, type, arg0, arg1));
7542 if (TREE_CODE (arg1) == INTEGER_CST
7543 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7545 return fold_convert (type, tem);
7550 case FLOOR_MOD_EXPR:
7551 case ROUND_MOD_EXPR:
7552 case TRUNC_MOD_EXPR:
7553 if (integer_onep (arg1))
7554 return omit_one_operand (type, integer_zero_node, arg0);
7555 if (integer_zerop (arg1))
7558 /* X % -1 is zero. */
7559 if (!TYPE_UNSIGNED (type)
7560 && TREE_CODE (arg1) == INTEGER_CST
7561 && TREE_INT_CST_LOW (arg1) == (unsigned HOST_WIDE_INT) -1
7562 && TREE_INT_CST_HIGH (arg1) == -1)
7563 return omit_one_operand (type, integer_zero_node, arg0);
7565 /* Optimize unsigned TRUNC_MOD_EXPR by a power of two into a
7566 BIT_AND_EXPR, i.e. "X % C" into "X & C2". */
7567 if (code == TRUNC_MOD_EXPR
7568 && TYPE_UNSIGNED (type)
7569 && integer_pow2p (arg1))
7571 unsigned HOST_WIDE_INT high, low;
7575 l = tree_log2 (arg1);
7576 if (l >= HOST_BITS_PER_WIDE_INT)
7578 high = ((unsigned HOST_WIDE_INT) 1
7579 << (l - HOST_BITS_PER_WIDE_INT)) - 1;
7585 low = ((unsigned HOST_WIDE_INT) 1 << l) - 1;
7588 mask = build_int_cst_wide (type, low, high);
7589 return fold (build2 (BIT_AND_EXPR, type,
7590 fold_convert (type, arg0), mask));
7593 /* X % -C is the same as X % C. */
7594 if (code == TRUNC_MOD_EXPR
7595 && !TYPE_UNSIGNED (type)
7596 && TREE_CODE (arg1) == INTEGER_CST
7597 && TREE_INT_CST_HIGH (arg1) < 0
7599 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
7600 && !sign_bit_p (arg1, arg1))
7601 return fold (build2 (code, type, fold_convert (type, arg0),
7602 fold_convert (type, negate_expr (arg1))));
7604 /* X % -Y is the same as X % Y. */
7605 if (code == TRUNC_MOD_EXPR
7606 && !TYPE_UNSIGNED (type)
7607 && TREE_CODE (arg1) == NEGATE_EXPR
7609 return fold (build2 (code, type, fold_convert (type, arg0),
7610 fold_convert (type, TREE_OPERAND (arg1, 0))));
7612 if (TREE_CODE (arg1) == INTEGER_CST
7613 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
7615 return fold_convert (type, tem);
7621 if (integer_all_onesp (arg0))
7622 return omit_one_operand (type, arg0, arg1);
7626 /* Optimize -1 >> x for arithmetic right shifts. */
7627 if (integer_all_onesp (arg0) && !TYPE_UNSIGNED (type))
7628 return omit_one_operand (type, arg0, arg1);
7629 /* ... fall through ... */
7633 if (integer_zerop (arg1))
7634 return non_lvalue (fold_convert (type, arg0));
7635 if (integer_zerop (arg0))
7636 return omit_one_operand (type, arg0, arg1);
7638 /* Since negative shift count is not well-defined,
7639 don't try to compute it in the compiler. */
7640 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
7642 /* Rewrite an LROTATE_EXPR by a constant into an
7643 RROTATE_EXPR by a new constant. */
7644 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
7646 tree tem = build_int_cst (NULL_TREE,
7647 GET_MODE_BITSIZE (TYPE_MODE (type)));
7648 tem = fold_convert (TREE_TYPE (arg1), tem);
7649 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
7650 return fold (build2 (RROTATE_EXPR, type, arg0, tem));
7653 /* If we have a rotate of a bit operation with the rotate count and
7654 the second operand of the bit operation both constant,
7655 permute the two operations. */
7656 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7657 && (TREE_CODE (arg0) == BIT_AND_EXPR
7658 || TREE_CODE (arg0) == BIT_IOR_EXPR
7659 || TREE_CODE (arg0) == BIT_XOR_EXPR)
7660 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7661 return fold (build2 (TREE_CODE (arg0), type,
7662 fold (build2 (code, type,
7663 TREE_OPERAND (arg0, 0), arg1)),
7664 fold (build2 (code, type,
7665 TREE_OPERAND (arg0, 1), arg1))));
7667 /* Two consecutive rotates adding up to the width of the mode can
7669 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7670 && TREE_CODE (arg0) == RROTATE_EXPR
7671 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7672 && TREE_INT_CST_HIGH (arg1) == 0
7673 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
7674 && ((TREE_INT_CST_LOW (arg1)
7675 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
7676 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
7677 return TREE_OPERAND (arg0, 0);
7682 if (operand_equal_p (arg0, arg1, 0))
7683 return omit_one_operand (type, arg0, arg1);
7684 if (INTEGRAL_TYPE_P (type)
7685 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
7686 return omit_one_operand (type, arg1, arg0);
7690 if (operand_equal_p (arg0, arg1, 0))
7691 return omit_one_operand (type, arg0, arg1);
7692 if (INTEGRAL_TYPE_P (type)
7693 && TYPE_MAX_VALUE (type)
7694 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
7695 return omit_one_operand (type, arg1, arg0);
7698 case TRUTH_NOT_EXPR:
7699 /* The argument to invert_truthvalue must have Boolean type. */
7700 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7701 arg0 = fold_convert (boolean_type_node, arg0);
7703 /* Note that the operand of this must be an int
7704 and its values must be 0 or 1.
7705 ("true" is a fixed value perhaps depending on the language,
7706 but we don't handle values other than 1 correctly yet.) */
7707 tem = invert_truthvalue (arg0);
7708 /* Avoid infinite recursion. */
7709 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7711 tem = fold_single_bit_test (code, arg0, arg1, type);
7716 return fold_convert (type, tem);
7718 case TRUTH_ANDIF_EXPR:
7719 /* Note that the operands of this must be ints
7720 and their values must be 0 or 1.
7721 ("true" is a fixed value perhaps depending on the language.) */
7722 /* If first arg is constant zero, return it. */
7723 if (integer_zerop (arg0))
7724 return fold_convert (type, arg0);
7725 case TRUTH_AND_EXPR:
7726 /* If either arg is constant true, drop it. */
7727 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7728 return non_lvalue (fold_convert (type, arg1));
7729 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
7730 /* Preserve sequence points. */
7731 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7732 return non_lvalue (fold_convert (type, arg0));
7733 /* If second arg is constant zero, result is zero, but first arg
7734 must be evaluated. */
7735 if (integer_zerop (arg1))
7736 return omit_one_operand (type, arg1, arg0);
7737 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
7738 case will be handled here. */
7739 if (integer_zerop (arg0))
7740 return omit_one_operand (type, arg0, arg1);
7742 /* !X && X is always false. */
7743 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
7744 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7745 return omit_one_operand (type, integer_zero_node, arg1);
7746 /* X && !X is always false. */
7747 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
7748 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7749 return omit_one_operand (type, integer_zero_node, arg0);
7752 /* We only do these simplifications if we are optimizing. */
7756 /* Check for things like (A || B) && (A || C). We can convert this
7757 to A || (B && C). Note that either operator can be any of the four
7758 truth and/or operations and the transformation will still be
7759 valid. Also note that we only care about order for the
7760 ANDIF and ORIF operators. If B contains side effects, this
7761 might change the truth-value of A. */
7762 if (TREE_CODE (arg0) == TREE_CODE (arg1)
7763 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
7764 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
7765 || TREE_CODE (arg0) == TRUTH_AND_EXPR
7766 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
7767 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
7769 tree a00 = TREE_OPERAND (arg0, 0);
7770 tree a01 = TREE_OPERAND (arg0, 1);
7771 tree a10 = TREE_OPERAND (arg1, 0);
7772 tree a11 = TREE_OPERAND (arg1, 1);
7773 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
7774 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
7775 && (code == TRUTH_AND_EXPR
7776 || code == TRUTH_OR_EXPR));
7778 if (operand_equal_p (a00, a10, 0))
7779 return fold (build2 (TREE_CODE (arg0), type, a00,
7780 fold (build2 (code, type, a01, a11))));
7781 else if (commutative && operand_equal_p (a00, a11, 0))
7782 return fold (build2 (TREE_CODE (arg0), type, a00,
7783 fold (build2 (code, type, a01, a10))));
7784 else if (commutative && operand_equal_p (a01, a10, 0))
7785 return fold (build2 (TREE_CODE (arg0), type, a01,
7786 fold (build2 (code, type, a00, a11))));
7788 /* This case if tricky because we must either have commutative
7789 operators or else A10 must not have side-effects. */
7791 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
7792 && operand_equal_p (a01, a11, 0))
7793 return fold (build2 (TREE_CODE (arg0), type,
7794 fold (build2 (code, type, a00, a10)),
7798 /* See if we can build a range comparison. */
7799 if (0 != (tem = fold_range_test (t)))
7802 /* Check for the possibility of merging component references. If our
7803 lhs is another similar operation, try to merge its rhs with our
7804 rhs. Then try to merge our lhs and rhs. */
7805 if (TREE_CODE (arg0) == code
7806 && 0 != (tem = fold_truthop (code, type,
7807 TREE_OPERAND (arg0, 1), arg1)))
7808 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
7810 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
7815 case TRUTH_ORIF_EXPR:
7816 /* Note that the operands of this must be ints
7817 and their values must be 0 or true.
7818 ("true" is a fixed value perhaps depending on the language.) */
7819 /* If first arg is constant true, return it. */
7820 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7821 return fold_convert (type, arg0);
7823 /* If either arg is constant zero, drop it. */
7824 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
7825 return non_lvalue (fold_convert (type, arg1));
7826 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
7827 /* Preserve sequence points. */
7828 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7829 return non_lvalue (fold_convert (type, arg0));
7830 /* If second arg is constant true, result is true, but we must
7831 evaluate first arg. */
7832 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
7833 return omit_one_operand (type, arg1, arg0);
7834 /* Likewise for first arg, but note this only occurs here for
7836 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7837 return omit_one_operand (type, arg0, arg1);
7839 /* !X || X is always true. */
7840 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
7841 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7842 return omit_one_operand (type, integer_one_node, arg1);
7843 /* X || !X is always true. */
7844 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
7845 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7846 return omit_one_operand (type, integer_one_node, arg0);
7850 case TRUTH_XOR_EXPR:
7851 /* If the second arg is constant zero, drop it. */
7852 if (integer_zerop (arg1))
7853 return non_lvalue (fold_convert (type, arg0));
7854 /* If the second arg is constant true, this is a logical inversion. */
7855 if (integer_onep (arg1))
7856 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
7857 /* Identical arguments cancel to zero. */
7858 if (operand_equal_p (arg0, arg1, 0))
7859 return omit_one_operand (type, integer_zero_node, arg0);
7861 /* !X ^ X is always true. */
7862 if (TREE_CODE (arg0) == TRUTH_NOT_EXPR
7863 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
7864 return omit_one_operand (type, integer_one_node, arg1);
7866 /* X ^ !X is always true. */
7867 if (TREE_CODE (arg1) == TRUTH_NOT_EXPR
7868 && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
7869 return omit_one_operand (type, integer_one_node, arg0);
7879 /* If one arg is a real or integer constant, put it last. */
7880 if (tree_swap_operands_p (arg0, arg1, true))
7881 return fold (build2 (swap_tree_comparison (code), type, arg1, arg0));
7883 /* If this is an equality comparison of the address of a non-weak
7884 object against zero, then we know the result. */
7885 if ((code == EQ_EXPR || code == NE_EXPR)
7886 && TREE_CODE (arg0) == ADDR_EXPR
7887 && DECL_P (TREE_OPERAND (arg0, 0))
7888 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7889 && integer_zerop (arg1))
7890 return constant_boolean_node (code != EQ_EXPR, type);
7892 /* If this is an equality comparison of the address of two non-weak,
7893 unaliased symbols neither of which are extern (since we do not
7894 have access to attributes for externs), then we know the result. */
7895 if ((code == EQ_EXPR || code == NE_EXPR)
7896 && TREE_CODE (arg0) == ADDR_EXPR
7897 && DECL_P (TREE_OPERAND (arg0, 0))
7898 && ! DECL_WEAK (TREE_OPERAND (arg0, 0))
7899 && ! lookup_attribute ("alias",
7900 DECL_ATTRIBUTES (TREE_OPERAND (arg0, 0)))
7901 && ! DECL_EXTERNAL (TREE_OPERAND (arg0, 0))
7902 && TREE_CODE (arg1) == ADDR_EXPR
7903 && DECL_P (TREE_OPERAND (arg1, 0))
7904 && ! DECL_WEAK (TREE_OPERAND (arg1, 0))
7905 && ! lookup_attribute ("alias",
7906 DECL_ATTRIBUTES (TREE_OPERAND (arg1, 0)))
7907 && ! DECL_EXTERNAL (TREE_OPERAND (arg1, 0)))
7908 return constant_boolean_node (operand_equal_p (arg0, arg1, 0)
7909 ? code == EQ_EXPR : code != EQ_EXPR,
7912 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
7914 tree targ0 = strip_float_extensions (arg0);
7915 tree targ1 = strip_float_extensions (arg1);
7916 tree newtype = TREE_TYPE (targ0);
7918 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
7919 newtype = TREE_TYPE (targ1);
7921 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
7922 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
7923 return fold (build2 (code, type, fold_convert (newtype, targ0),
7924 fold_convert (newtype, targ1)));
7926 /* (-a) CMP (-b) -> b CMP a */
7927 if (TREE_CODE (arg0) == NEGATE_EXPR
7928 && TREE_CODE (arg1) == NEGATE_EXPR)
7929 return fold (build2 (code, type, TREE_OPERAND (arg1, 0),
7930 TREE_OPERAND (arg0, 0)));
7932 if (TREE_CODE (arg1) == REAL_CST)
7934 REAL_VALUE_TYPE cst;
7935 cst = TREE_REAL_CST (arg1);
7937 /* (-a) CMP CST -> a swap(CMP) (-CST) */
7938 if (TREE_CODE (arg0) == NEGATE_EXPR)
7940 fold (build2 (swap_tree_comparison (code), type,
7941 TREE_OPERAND (arg0, 0),
7942 build_real (TREE_TYPE (arg1),
7943 REAL_VALUE_NEGATE (cst))));
7945 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
7946 /* a CMP (-0) -> a CMP 0 */
7947 if (REAL_VALUE_MINUS_ZERO (cst))
7948 return fold (build2 (code, type, arg0,
7949 build_real (TREE_TYPE (arg1), dconst0)));
7951 /* x != NaN is always true, other ops are always false. */
7952 if (REAL_VALUE_ISNAN (cst)
7953 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
7955 tem = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
7956 return omit_one_operand (type, tem, arg0);
7959 /* Fold comparisons against infinity. */
7960 if (REAL_VALUE_ISINF (cst))
7962 tem = fold_inf_compare (code, type, arg0, arg1);
7963 if (tem != NULL_TREE)
7968 /* If this is a comparison of a real constant with a PLUS_EXPR
7969 or a MINUS_EXPR of a real constant, we can convert it into a
7970 comparison with a revised real constant as long as no overflow
7971 occurs when unsafe_math_optimizations are enabled. */
7972 if (flag_unsafe_math_optimizations
7973 && TREE_CODE (arg1) == REAL_CST
7974 && (TREE_CODE (arg0) == PLUS_EXPR
7975 || TREE_CODE (arg0) == MINUS_EXPR)
7976 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7977 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7978 ? MINUS_EXPR : PLUS_EXPR,
7979 arg1, TREE_OPERAND (arg0, 1), 0))
7980 && ! TREE_CONSTANT_OVERFLOW (tem))
7981 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
7983 /* Likewise, we can simplify a comparison of a real constant with
7984 a MINUS_EXPR whose first operand is also a real constant, i.e.
7985 (c1 - x) < c2 becomes x > c1-c2. */
7986 if (flag_unsafe_math_optimizations
7987 && TREE_CODE (arg1) == REAL_CST
7988 && TREE_CODE (arg0) == MINUS_EXPR
7989 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
7990 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
7992 && ! TREE_CONSTANT_OVERFLOW (tem))
7993 return fold (build2 (swap_tree_comparison (code), type,
7994 TREE_OPERAND (arg0, 1), tem));
7996 /* Fold comparisons against built-in math functions. */
7997 if (TREE_CODE (arg1) == REAL_CST
7998 && flag_unsafe_math_optimizations
7999 && ! flag_errno_math)
8001 enum built_in_function fcode = builtin_mathfn_code (arg0);
8003 if (fcode != END_BUILTINS)
8005 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
8006 if (tem != NULL_TREE)
8012 /* Convert foo++ == CONST into ++foo == CONST + INCR. */
8013 if (TREE_CONSTANT (arg1)
8014 && (TREE_CODE (arg0) == POSTINCREMENT_EXPR
8015 || TREE_CODE (arg0) == POSTDECREMENT_EXPR)
8016 /* This optimization is invalid for ordered comparisons
8017 if CONST+INCR overflows or if foo+incr might overflow.
8018 This optimization is invalid for floating point due to rounding.
8019 For pointer types we assume overflow doesn't happen. */
8020 && (POINTER_TYPE_P (TREE_TYPE (arg0))
8021 || (INTEGRAL_TYPE_P (TREE_TYPE (arg0))
8022 && (code == EQ_EXPR || code == NE_EXPR))))
8024 tree varop, newconst;
8026 if (TREE_CODE (arg0) == POSTINCREMENT_EXPR)
8028 newconst = fold (build2 (PLUS_EXPR, TREE_TYPE (arg0),
8029 arg1, TREE_OPERAND (arg0, 1)));
8030 varop = build2 (PREINCREMENT_EXPR, TREE_TYPE (arg0),
8031 TREE_OPERAND (arg0, 0),
8032 TREE_OPERAND (arg0, 1));
8036 newconst = fold (build2 (MINUS_EXPR, TREE_TYPE (arg0),
8037 arg1, TREE_OPERAND (arg0, 1)));
8038 varop = build2 (PREDECREMENT_EXPR, TREE_TYPE (arg0),
8039 TREE_OPERAND (arg0, 0),
8040 TREE_OPERAND (arg0, 1));
8044 /* If VAROP is a reference to a bitfield, we must mask
8045 the constant by the width of the field. */
8046 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
8047 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (varop, 0), 1))
8048 && host_integerp (DECL_SIZE (TREE_OPERAND
8049 (TREE_OPERAND (varop, 0), 1)), 1))
8051 tree fielddecl = TREE_OPERAND (TREE_OPERAND (varop, 0), 1);
8052 HOST_WIDE_INT size = tree_low_cst (DECL_SIZE (fielddecl), 1);
8053 tree folded_compare, shift;
8055 /* First check whether the comparison would come out
8056 always the same. If we don't do that we would
8057 change the meaning with the masking. */
8058 folded_compare = fold (build2 (code, type,
8059 TREE_OPERAND (varop, 0), arg1));
8060 if (integer_zerop (folded_compare)
8061 || integer_onep (folded_compare))
8062 return omit_one_operand (type, folded_compare, varop);
8064 shift = build_int_cst (NULL_TREE,
8065 TYPE_PRECISION (TREE_TYPE (varop)) - size);
8066 shift = fold_convert (TREE_TYPE (varop), shift);
8067 newconst = fold (build2 (LSHIFT_EXPR, TREE_TYPE (varop),
8069 newconst = fold (build2 (RSHIFT_EXPR, TREE_TYPE (varop),
8073 return fold (build2 (code, type, varop, newconst));
8076 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
8077 This transformation affects the cases which are handled in later
8078 optimizations involving comparisons with non-negative constants. */
8079 if (TREE_CODE (arg1) == INTEGER_CST
8080 && TREE_CODE (arg0) != INTEGER_CST
8081 && tree_int_cst_sgn (arg1) > 0)
8086 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8087 return fold (build2 (GT_EXPR, type, arg0, arg1));
8090 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8091 return fold (build2 (LE_EXPR, type, arg0, arg1));
8098 /* Comparisons with the highest or lowest possible integer of
8099 the specified size will have known values.
8101 This is quite similar to fold_relational_hi_lo; however, my
8102 attempts to share the code have been nothing but trouble.
8103 I give up for now. */
8105 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
8107 if (TREE_CODE (arg1) == INTEGER_CST
8108 && ! TREE_CONSTANT_OVERFLOW (arg1)
8109 && width <= HOST_BITS_PER_WIDE_INT
8110 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
8111 || POINTER_TYPE_P (TREE_TYPE (arg1))))
8113 unsigned HOST_WIDE_INT signed_max;
8114 unsigned HOST_WIDE_INT max, min;
8116 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
8118 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
8120 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
8126 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
8129 if (TREE_INT_CST_HIGH (arg1) == 0
8130 && TREE_INT_CST_LOW (arg1) == max)
8134 return omit_one_operand (type, integer_zero_node, arg0);
8137 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8140 return omit_one_operand (type, integer_one_node, arg0);
8143 return fold (build2 (NE_EXPR, type, arg0, arg1));
8145 /* The GE_EXPR and LT_EXPR cases above are not normally
8146 reached because of previous transformations. */
8151 else if (TREE_INT_CST_HIGH (arg1) == 0
8152 && TREE_INT_CST_LOW (arg1) == max - 1)
8156 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8157 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8159 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
8160 return fold (build2 (NE_EXPR, type, arg0, arg1));
8164 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8165 && TREE_INT_CST_LOW (arg1) == min)
8169 return omit_one_operand (type, integer_zero_node, arg0);
8172 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8175 return omit_one_operand (type, integer_one_node, arg0);
8178 return fold (build2 (NE_EXPR, type, arg0, arg1));
8183 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
8184 && TREE_INT_CST_LOW (arg1) == min + 1)
8188 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8189 return fold (build2 (NE_EXPR, type, arg0, arg1));
8191 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
8192 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8197 else if (!in_gimple_form
8198 && TREE_INT_CST_HIGH (arg1) == 0
8199 && TREE_INT_CST_LOW (arg1) == signed_max
8200 && TYPE_UNSIGNED (TREE_TYPE (arg1))
8201 /* signed_type does not work on pointer types. */
8202 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
8204 /* The following case also applies to X < signed_max+1
8205 and X >= signed_max+1 because previous transformations. */
8206 if (code == LE_EXPR || code == GT_EXPR)
8209 st0 = lang_hooks.types.signed_type (TREE_TYPE (arg0));
8210 st1 = lang_hooks.types.signed_type (TREE_TYPE (arg1));
8212 (build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
8213 type, fold_convert (st0, arg0),
8214 fold_convert (st1, integer_zero_node)));
8220 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
8221 a MINUS_EXPR of a constant, we can convert it into a comparison with
8222 a revised constant as long as no overflow occurs. */
8223 if ((code == EQ_EXPR || code == NE_EXPR)
8224 && TREE_CODE (arg1) == INTEGER_CST
8225 && (TREE_CODE (arg0) == PLUS_EXPR
8226 || TREE_CODE (arg0) == MINUS_EXPR)
8227 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8228 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
8229 ? MINUS_EXPR : PLUS_EXPR,
8230 arg1, TREE_OPERAND (arg0, 1), 0))
8231 && ! TREE_CONSTANT_OVERFLOW (tem))
8232 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8234 /* Similarly for a NEGATE_EXPR. */
8235 else if ((code == EQ_EXPR || code == NE_EXPR)
8236 && TREE_CODE (arg0) == NEGATE_EXPR
8237 && TREE_CODE (arg1) == INTEGER_CST
8238 && 0 != (tem = negate_expr (arg1))
8239 && TREE_CODE (tem) == INTEGER_CST
8240 && ! TREE_CONSTANT_OVERFLOW (tem))
8241 return fold (build2 (code, type, TREE_OPERAND (arg0, 0), tem));
8243 /* If we have X - Y == 0, we can convert that to X == Y and similarly
8244 for !=. Don't do this for ordered comparisons due to overflow. */
8245 else if ((code == NE_EXPR || code == EQ_EXPR)
8246 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
8247 return fold (build2 (code, type,
8248 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
8250 /* If we are widening one operand of an integer comparison,
8251 see if the other operand is similarly being widened. Perhaps we
8252 can do the comparison in the narrower type. */
8253 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
8254 && TREE_CODE (arg0) == NOP_EXPR
8255 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
8256 && (code == EQ_EXPR || code == NE_EXPR
8257 || TYPE_UNSIGNED (TREE_TYPE (arg0))
8258 == TYPE_UNSIGNED (TREE_TYPE (tem)))
8259 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
8260 && (TREE_TYPE (t1) == TREE_TYPE (tem)
8261 || (TREE_CODE (t1) == INTEGER_CST
8262 && int_fits_type_p (t1, TREE_TYPE (tem)))))
8263 return fold (build2 (code, type, tem,
8264 fold_convert (TREE_TYPE (tem), t1)));
8266 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
8267 constant, we can simplify it. */
8268 else if (TREE_CODE (arg1) == INTEGER_CST
8269 && (TREE_CODE (arg0) == MIN_EXPR
8270 || TREE_CODE (arg0) == MAX_EXPR)
8271 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8272 return optimize_minmax_comparison (t);
8274 /* If we are comparing an ABS_EXPR with a constant, we can
8275 convert all the cases into explicit comparisons, but they may
8276 well not be faster than doing the ABS and one comparison.
8277 But ABS (X) <= C is a range comparison, which becomes a subtraction
8278 and a comparison, and is probably faster. */
8279 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
8280 && TREE_CODE (arg0) == ABS_EXPR
8281 && ! TREE_SIDE_EFFECTS (arg0)
8282 && (0 != (tem = negate_expr (arg1)))
8283 && TREE_CODE (tem) == INTEGER_CST
8284 && ! TREE_CONSTANT_OVERFLOW (tem))
8285 return fold (build2 (TRUTH_ANDIF_EXPR, type,
8286 build2 (GE_EXPR, type,
8287 TREE_OPERAND (arg0, 0), tem),
8288 build2 (LE_EXPR, type,
8289 TREE_OPERAND (arg0, 0), arg1)));
8291 /* If this is an EQ or NE comparison with zero and ARG0 is
8292 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
8293 two operations, but the latter can be done in one less insn
8294 on machines that have only two-operand insns or on which a
8295 constant cannot be the first operand. */
8296 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
8297 && TREE_CODE (arg0) == BIT_AND_EXPR)
8299 tree arg00 = TREE_OPERAND (arg0, 0);
8300 tree arg01 = TREE_OPERAND (arg0, 1);
8301 if (TREE_CODE (arg00) == LSHIFT_EXPR
8302 && integer_onep (TREE_OPERAND (arg00, 0)))
8304 fold (build2 (code, type,
8305 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8306 build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
8307 arg01, TREE_OPERAND (arg00, 1)),
8308 fold_convert (TREE_TYPE (arg0),
8311 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
8312 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
8314 fold (build2 (code, type,
8315 build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8316 build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
8317 arg00, TREE_OPERAND (arg01, 1)),
8318 fold_convert (TREE_TYPE (arg0),
8323 /* If this is an NE or EQ comparison of zero against the result of a
8324 signed MOD operation whose second operand is a power of 2, make
8325 the MOD operation unsigned since it is simpler and equivalent. */
8326 if ((code == NE_EXPR || code == EQ_EXPR)
8327 && integer_zerop (arg1)
8328 && !TYPE_UNSIGNED (TREE_TYPE (arg0))
8329 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
8330 || TREE_CODE (arg0) == CEIL_MOD_EXPR
8331 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
8332 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
8333 && integer_pow2p (TREE_OPERAND (arg0, 1)))
8335 tree newtype = lang_hooks.types.unsigned_type (TREE_TYPE (arg0));
8336 tree newmod = fold (build2 (TREE_CODE (arg0), newtype,
8337 fold_convert (newtype,
8338 TREE_OPERAND (arg0, 0)),
8339 fold_convert (newtype,
8340 TREE_OPERAND (arg0, 1))));
8342 return fold (build2 (code, type, newmod,
8343 fold_convert (newtype, arg1)));
8346 /* If this is an NE comparison of zero with an AND of one, remove the
8347 comparison since the AND will give the correct value. */
8348 if (code == NE_EXPR && integer_zerop (arg1)
8349 && TREE_CODE (arg0) == BIT_AND_EXPR
8350 && integer_onep (TREE_OPERAND (arg0, 1)))
8351 return fold_convert (type, arg0);
8353 /* If we have (A & C) == C where C is a power of 2, convert this into
8354 (A & C) != 0. Similarly for NE_EXPR. */
8355 if ((code == EQ_EXPR || code == NE_EXPR)
8356 && TREE_CODE (arg0) == BIT_AND_EXPR
8357 && integer_pow2p (TREE_OPERAND (arg0, 1))
8358 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
8359 return fold (build2 (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
8360 arg0, fold_convert (TREE_TYPE (arg0),
8361 integer_zero_node)));
8363 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
8364 2, then fold the expression into shifts and logical operations. */
8365 tem = fold_single_bit_test (code, arg0, arg1, type);
8369 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
8370 Similarly for NE_EXPR. */
8371 if ((code == EQ_EXPR || code == NE_EXPR)
8372 && TREE_CODE (arg0) == BIT_AND_EXPR
8373 && TREE_CODE (arg1) == INTEGER_CST
8374 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8377 = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8378 arg1, build1 (BIT_NOT_EXPR,
8379 TREE_TYPE (TREE_OPERAND (arg0, 1)),
8380 TREE_OPERAND (arg0, 1))));
8381 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8382 if (integer_nonzerop (dandnotc))
8383 return omit_one_operand (type, rslt, arg0);
8386 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
8387 Similarly for NE_EXPR. */
8388 if ((code == EQ_EXPR || code == NE_EXPR)
8389 && TREE_CODE (arg0) == BIT_IOR_EXPR
8390 && TREE_CODE (arg1) == INTEGER_CST
8391 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
8394 = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
8395 TREE_OPERAND (arg0, 1),
8396 build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1)));
8397 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
8398 if (integer_nonzerop (candnotd))
8399 return omit_one_operand (type, rslt, arg0);
8402 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
8403 and similarly for >= into !=. */
8404 if ((code == LT_EXPR || code == GE_EXPR)
8405 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8406 && TREE_CODE (arg1) == LSHIFT_EXPR
8407 && integer_onep (TREE_OPERAND (arg1, 0)))
8408 return build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8409 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8410 TREE_OPERAND (arg1, 1)),
8411 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8413 else if ((code == LT_EXPR || code == GE_EXPR)
8414 && TYPE_UNSIGNED (TREE_TYPE (arg0))
8415 && (TREE_CODE (arg1) == NOP_EXPR
8416 || TREE_CODE (arg1) == CONVERT_EXPR)
8417 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
8418 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
8420 build2 (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
8421 fold_convert (TREE_TYPE (arg0),
8422 build2 (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
8423 TREE_OPERAND (TREE_OPERAND (arg1, 0),
8425 fold_convert (TREE_TYPE (arg0), integer_zero_node));
8427 /* Simplify comparison of something with itself. (For IEEE
8428 floating-point, we can only do some of these simplifications.) */
8429 if (operand_equal_p (arg0, arg1, 0))
8434 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8435 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8436 return constant_boolean_node (1, type);
8441 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
8442 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8443 return constant_boolean_node (1, type);
8444 return fold (build2 (EQ_EXPR, type, arg0, arg1));
8447 /* For NE, we can only do this simplification if integer
8448 or we don't honor IEEE floating point NaNs. */
8449 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
8450 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
8452 /* ... fall through ... */
8455 return constant_boolean_node (0, type);
8461 /* If we are comparing an expression that just has comparisons
8462 of two integer values, arithmetic expressions of those comparisons,
8463 and constants, we can simplify it. There are only three cases
8464 to check: the two values can either be equal, the first can be
8465 greater, or the second can be greater. Fold the expression for
8466 those three values. Since each value must be 0 or 1, we have
8467 eight possibilities, each of which corresponds to the constant 0
8468 or 1 or one of the six possible comparisons.
8470 This handles common cases like (a > b) == 0 but also handles
8471 expressions like ((x > y) - (y > x)) > 0, which supposedly
8472 occur in macroized code. */
8474 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
8476 tree cval1 = 0, cval2 = 0;
8479 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
8480 /* Don't handle degenerate cases here; they should already
8481 have been handled anyway. */
8482 && cval1 != 0 && cval2 != 0
8483 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
8484 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
8485 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
8486 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
8487 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
8488 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
8489 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
8491 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
8492 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
8494 /* We can't just pass T to eval_subst in case cval1 or cval2
8495 was the same as ARG1. */
8498 = fold (build2 (code, type,
8499 eval_subst (arg0, cval1, maxval,
8503 = fold (build2 (code, type,
8504 eval_subst (arg0, cval1, maxval,
8508 = fold (build2 (code, type,
8509 eval_subst (arg0, cval1, minval,
8513 /* All three of these results should be 0 or 1. Confirm they
8514 are. Then use those values to select the proper code
8517 if ((integer_zerop (high_result)
8518 || integer_onep (high_result))
8519 && (integer_zerop (equal_result)
8520 || integer_onep (equal_result))
8521 && (integer_zerop (low_result)
8522 || integer_onep (low_result)))
8524 /* Make a 3-bit mask with the high-order bit being the
8525 value for `>', the next for '=', and the low for '<'. */
8526 switch ((integer_onep (high_result) * 4)
8527 + (integer_onep (equal_result) * 2)
8528 + integer_onep (low_result))
8532 return omit_one_operand (type, integer_zero_node, arg0);
8553 return omit_one_operand (type, integer_one_node, arg0);
8556 tem = build2 (code, type, cval1, cval2);
8558 return save_expr (tem);
8565 /* If this is a comparison of a field, we may be able to simplify it. */
8566 if (((TREE_CODE (arg0) == COMPONENT_REF
8567 && lang_hooks.can_use_bit_fields_p ())
8568 || TREE_CODE (arg0) == BIT_FIELD_REF)
8569 && (code == EQ_EXPR || code == NE_EXPR)
8570 /* Handle the constant case even without -O
8571 to make sure the warnings are given. */
8572 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
8574 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
8579 /* If this is a comparison of complex values and either or both sides
8580 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
8581 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
8582 This may prevent needless evaluations. */
8583 if ((code == EQ_EXPR || code == NE_EXPR)
8584 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
8585 && (TREE_CODE (arg0) == COMPLEX_EXPR
8586 || TREE_CODE (arg1) == COMPLEX_EXPR
8587 || TREE_CODE (arg0) == COMPLEX_CST
8588 || TREE_CODE (arg1) == COMPLEX_CST))
8590 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
8591 tree real0, imag0, real1, imag1;
8593 arg0 = save_expr (arg0);
8594 arg1 = save_expr (arg1);
8595 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
8596 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
8597 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
8598 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
8600 return fold (build2 ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
8603 fold (build2 (code, type, real0, real1)),
8604 fold (build2 (code, type, imag0, imag1))));
8607 /* Optimize comparisons of strlen vs zero to a compare of the
8608 first character of the string vs zero. To wit,
8609 strlen(ptr) == 0 => *ptr == 0
8610 strlen(ptr) != 0 => *ptr != 0
8611 Other cases should reduce to one of these two (or a constant)
8612 due to the return value of strlen being unsigned. */
8613 if ((code == EQ_EXPR || code == NE_EXPR)
8614 && integer_zerop (arg1)
8615 && TREE_CODE (arg0) == CALL_EXPR)
8617 tree fndecl = get_callee_fndecl (arg0);
8621 && DECL_BUILT_IN (fndecl)
8622 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
8623 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
8624 && (arglist = TREE_OPERAND (arg0, 1))
8625 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
8626 && ! TREE_CHAIN (arglist))
8627 return fold (build2 (code, type,
8628 build1 (INDIRECT_REF, char_type_node,
8629 TREE_VALUE (arglist)),
8630 fold_convert (char_type_node,
8631 integer_zero_node)));
8634 /* We can fold X/C1 op C2 where C1 and C2 are integer constants
8635 into a single range test. */
8636 if (TREE_CODE (arg0) == TRUNC_DIV_EXPR
8637 && TREE_CODE (arg1) == INTEGER_CST
8638 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8639 && !integer_zerop (TREE_OPERAND (arg0, 1))
8640 && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
8641 && !TREE_OVERFLOW (arg1))
8643 t1 = fold_div_compare (code, type, arg0, arg1);
8644 if (t1 != NULL_TREE)
8648 if ((code == EQ_EXPR || code == NE_EXPR)
8649 && !TREE_SIDE_EFFECTS (arg0)
8650 && integer_zerop (arg1)
8651 && tree_expr_nonzero_p (arg0))
8652 return constant_boolean_node (code==NE_EXPR, type);
8654 t1 = fold_relational_const (code, type, arg0, arg1);
8655 return t1 == NULL_TREE ? t : t1;
8657 case UNORDERED_EXPR:
8665 if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
8667 t1 = fold_relational_const (code, type, arg0, arg1);
8668 if (t1 != NULL_TREE)
8672 /* If the first operand is NaN, the result is constant. */
8673 if (TREE_CODE (arg0) == REAL_CST
8674 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
8675 && (code != LTGT_EXPR || ! flag_trapping_math))
8677 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8680 return omit_one_operand (type, t1, arg1);
8683 /* If the second operand is NaN, the result is constant. */
8684 if (TREE_CODE (arg1) == REAL_CST
8685 && REAL_VALUE_ISNAN (TREE_REAL_CST (arg1))
8686 && (code != LTGT_EXPR || ! flag_trapping_math))
8688 t1 = (code == ORDERED_EXPR || code == LTGT_EXPR)
8691 return omit_one_operand (type, t1, arg0);
8694 /* Simplify unordered comparison of something with itself. */
8695 if ((code == UNLE_EXPR || code == UNGE_EXPR || code == UNEQ_EXPR)
8696 && operand_equal_p (arg0, arg1, 0))
8697 return constant_boolean_node (1, type);
8699 if (code == LTGT_EXPR
8700 && !flag_trapping_math
8701 && operand_equal_p (arg0, arg1, 0))
8702 return constant_boolean_node (0, type);
8704 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
8706 tree targ0 = strip_float_extensions (arg0);
8707 tree targ1 = strip_float_extensions (arg1);
8708 tree newtype = TREE_TYPE (targ0);
8710 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
8711 newtype = TREE_TYPE (targ1);
8713 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
8714 return fold (build2 (code, type, fold_convert (newtype, targ0),
8715 fold_convert (newtype, targ1)));
8721 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
8722 so all simple results must be passed through pedantic_non_lvalue. */
8723 if (TREE_CODE (arg0) == INTEGER_CST)
8725 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
8726 /* Only optimize constant conditions when the selected branch
8727 has the same type as the COND_EXPR. This avoids optimizing
8728 away "c ? x : throw", where the throw has a void type. */
8729 if (! VOID_TYPE_P (TREE_TYPE (tem))
8730 || VOID_TYPE_P (type))
8731 return pedantic_non_lvalue (tem);
8734 if (operand_equal_p (arg1, TREE_OPERAND (t, 2), 0))
8735 return pedantic_omit_one_operand (type, arg1, arg0);
8737 /* If we have A op B ? A : C, we may be able to convert this to a
8738 simpler expression, depending on the operation and the values
8739 of B and C. Signed zeros prevent all of these transformations,
8740 for reasons given above each one.
8742 Also try swapping the arguments and inverting the conditional. */
8743 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8744 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8745 arg1, TREE_OPERAND (arg0, 1))
8746 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
8748 tem = fold_cond_expr_with_comparison (type, arg0,
8749 TREE_OPERAND (t, 1),
8750 TREE_OPERAND (t, 2));
8755 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8756 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8757 TREE_OPERAND (t, 2),
8758 TREE_OPERAND (arg0, 1))
8759 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 2)))))
8761 tem = invert_truthvalue (arg0);
8762 if (TREE_CODE_CLASS (TREE_CODE (tem)) == '<')
8764 tem = fold_cond_expr_with_comparison (type, tem,
8765 TREE_OPERAND (t, 2),
8766 TREE_OPERAND (t, 1));
8772 /* If the second operand is simpler than the third, swap them
8773 since that produces better jump optimization results. */
8774 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
8775 TREE_OPERAND (t, 2), false))
8777 /* See if this can be inverted. If it can't, possibly because
8778 it was a floating-point inequality comparison, don't do
8780 tem = invert_truthvalue (arg0);
8782 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8783 return fold (build3 (code, type, tem,
8784 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
8787 /* Convert A ? 1 : 0 to simply A. */
8788 if (integer_onep (TREE_OPERAND (t, 1))
8789 && integer_zerop (TREE_OPERAND (t, 2))
8790 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8791 call to fold will try to move the conversion inside
8792 a COND, which will recurse. In that case, the COND_EXPR
8793 is probably the best choice, so leave it alone. */
8794 && type == TREE_TYPE (arg0))
8795 return pedantic_non_lvalue (arg0);
8797 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8798 over COND_EXPR in cases such as floating point comparisons. */
8799 if (integer_zerop (TREE_OPERAND (t, 1))
8800 && integer_onep (TREE_OPERAND (t, 2))
8801 && truth_value_p (TREE_CODE (arg0)))
8802 return pedantic_non_lvalue (fold_convert (type,
8803 invert_truthvalue (arg0)));
8805 /* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>). */
8806 if (TREE_CODE (arg0) == LT_EXPR
8807 && integer_zerop (TREE_OPERAND (arg0, 1))
8808 && integer_zerop (TREE_OPERAND (t, 2))
8809 && (tem = sign_bit_p (TREE_OPERAND (arg0, 0), arg1)))
8810 return fold_convert (type, fold (build2 (BIT_AND_EXPR,
8811 TREE_TYPE (tem), tem, arg1)));
8813 /* (A >> N) & 1 ? (1 << N) : 0 is simply A & (1 << N). A & 1 was
8814 already handled above. */
8815 if (TREE_CODE (arg0) == BIT_AND_EXPR
8816 && integer_onep (TREE_OPERAND (arg0, 1))
8817 && integer_zerop (TREE_OPERAND (t, 2))
8818 && integer_pow2p (arg1))
8820 tree tem = TREE_OPERAND (arg0, 0);
8822 if (TREE_CODE (tem) == RSHIFT_EXPR
8823 && TREE_CODE (TREE_OPERAND (tem, 1)) == INTEGER_CST
8824 && (unsigned HOST_WIDE_INT) tree_log2 (arg1) ==
8825 TREE_INT_CST_LOW (TREE_OPERAND (tem, 1)))
8826 return fold (build2 (BIT_AND_EXPR, type,
8827 TREE_OPERAND (tem, 0), arg1));
8830 /* A & N ? N : 0 is simply A & N if N is a power of two. This
8831 is probably obsolete because the first operand should be a
8832 truth value (that's why we have the two cases above), but let's
8833 leave it in until we can confirm this for all front-ends. */
8834 if (integer_zerop (TREE_OPERAND (t, 2))
8835 && TREE_CODE (arg0) == NE_EXPR
8836 && integer_zerop (TREE_OPERAND (arg0, 1))
8837 && integer_pow2p (arg1)
8838 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
8839 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
8840 arg1, OEP_ONLY_CONST))
8841 return pedantic_non_lvalue (fold_convert (type,
8842 TREE_OPERAND (arg0, 0)));
8844 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8845 if (integer_zerop (TREE_OPERAND (t, 2))
8846 && truth_value_p (TREE_CODE (arg0))
8847 && truth_value_p (TREE_CODE (arg1)))
8848 return fold (build2 (TRUTH_ANDIF_EXPR, type, arg0, arg1));
8850 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8851 if (integer_onep (TREE_OPERAND (t, 2))
8852 && truth_value_p (TREE_CODE (arg0))
8853 && truth_value_p (TREE_CODE (arg1)))
8855 /* Only perform transformation if ARG0 is easily inverted. */
8856 tem = invert_truthvalue (arg0);
8857 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8858 return fold (build2 (TRUTH_ORIF_EXPR, type, tem, arg1));
8861 /* Convert A ? 0 : B into !A && B if A and B are truth values. */
8862 if (integer_zerop (arg1)
8863 && truth_value_p (TREE_CODE (arg0))
8864 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
8866 /* Only perform transformation if ARG0 is easily inverted. */
8867 tem = invert_truthvalue (arg0);
8868 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8869 return fold (build2 (TRUTH_ANDIF_EXPR, type, tem,
8870 TREE_OPERAND (t, 2)));
8873 /* Convert A ? 1 : B into A || B if A and B are truth values. */
8874 if (integer_onep (arg1)
8875 && truth_value_p (TREE_CODE (arg0))
8876 && truth_value_p (TREE_CODE (TREE_OPERAND (t, 2))))
8877 return fold (build2 (TRUTH_ORIF_EXPR, type, arg0,
8878 TREE_OPERAND (t, 2)));
8883 /* When pedantic, a compound expression can be neither an lvalue
8884 nor an integer constant expression. */
8885 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
8887 /* Don't let (0, 0) be null pointer constant. */
8888 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
8889 : fold_convert (type, arg1);
8890 return pedantic_non_lvalue (tem);
8894 return build_complex (type, arg0, arg1);
8898 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8900 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8901 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8902 TREE_OPERAND (arg0, 1));
8903 else if (TREE_CODE (arg0) == COMPLEX_CST)
8904 return TREE_REALPART (arg0);
8905 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8906 return fold (build2 (TREE_CODE (arg0), type,
8907 fold (build1 (REALPART_EXPR, type,
8908 TREE_OPERAND (arg0, 0))),
8909 fold (build1 (REALPART_EXPR, type,
8910 TREE_OPERAND (arg0, 1)))));
8914 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8915 return fold_convert (type, integer_zero_node);
8916 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8917 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8918 TREE_OPERAND (arg0, 0));
8919 else if (TREE_CODE (arg0) == COMPLEX_CST)
8920 return TREE_IMAGPART (arg0);
8921 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8922 return fold (build2 (TREE_CODE (arg0), type,
8923 fold (build1 (IMAGPART_EXPR, type,
8924 TREE_OPERAND (arg0, 0))),
8925 fold (build1 (IMAGPART_EXPR, type,
8926 TREE_OPERAND (arg0, 1)))));
8929 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8931 case CLEANUP_POINT_EXPR:
8932 if (! has_cleanups (arg0))
8933 return TREE_OPERAND (t, 0);
8936 enum tree_code code0 = TREE_CODE (arg0);
8937 int kind0 = TREE_CODE_CLASS (code0);
8938 tree arg00 = TREE_OPERAND (arg0, 0);
8941 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
8942 return fold (build1 (code0, type,
8943 fold (build1 (CLEANUP_POINT_EXPR,
8944 TREE_TYPE (arg00), arg00))));
8946 if (kind0 == '<' || kind0 == '2'
8947 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
8948 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
8949 || code0 == TRUTH_XOR_EXPR)
8951 arg01 = TREE_OPERAND (arg0, 1);
8953 if (TREE_CONSTANT (arg00)
8954 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
8955 && ! has_cleanups (arg00)))
8956 return fold (build2 (code0, type, arg00,
8957 fold (build1 (CLEANUP_POINT_EXPR,
8958 TREE_TYPE (arg01), arg01))));
8960 if (TREE_CONSTANT (arg01))
8961 return fold (build2 (code0, type,
8962 fold (build1 (CLEANUP_POINT_EXPR,
8963 TREE_TYPE (arg00), arg00)),
8971 /* Check for a built-in function. */
8972 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
8973 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0))
8975 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (t, 0), 0)))
8977 tree tmp = fold_builtin (t, false);
8985 } /* switch (code) */
8988 #ifdef ENABLE_FOLD_CHECKING
8991 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
8992 static void fold_check_failed (tree, tree);
8993 void print_fold_checksum (tree);
8995 /* When --enable-checking=fold, compute a digest of expr before
8996 and after actual fold call to see if fold did not accidentally
8997 change original expr. */
9004 unsigned char checksum_before[16], checksum_after[16];
9007 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9008 md5_init_ctx (&ctx);
9009 fold_checksum_tree (expr, &ctx, ht);
9010 md5_finish_ctx (&ctx, checksum_before);
9013 ret = fold_1 (expr);
9015 md5_init_ctx (&ctx);
9016 fold_checksum_tree (expr, &ctx, ht);
9017 md5_finish_ctx (&ctx, checksum_after);
9020 if (memcmp (checksum_before, checksum_after, 16))
9021 fold_check_failed (expr, ret);
9027 print_fold_checksum (tree expr)
9030 unsigned char checksum[16], cnt;
9033 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
9034 md5_init_ctx (&ctx);
9035 fold_checksum_tree (expr, &ctx, ht);
9036 md5_finish_ctx (&ctx, checksum);
9038 for (cnt = 0; cnt < 16; ++cnt)
9039 fprintf (stderr, "%02x", checksum[cnt]);
9040 putc ('\n', stderr);
9044 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
9046 internal_error ("fold check: original tree changed by fold");
9050 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
9053 enum tree_code code;
9054 char buf[sizeof (struct tree_decl)];
9057 gcc_assert ((sizeof (struct tree_exp) + 5 * sizeof (tree)
9058 <= sizeof (struct tree_decl))
9059 && sizeof (struct tree_type) <= sizeof (struct tree_decl));
9062 slot = htab_find_slot (ht, expr, INSERT);
9066 code = TREE_CODE (expr);
9067 if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
9069 /* Allow DECL_ASSEMBLER_NAME to be modified. */
9070 memcpy (buf, expr, tree_size (expr));
9072 SET_DECL_ASSEMBLER_NAME (expr, NULL);
9074 else if (TREE_CODE_CLASS (code) == 't'
9075 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
9077 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
9078 memcpy (buf, expr, tree_size (expr));
9080 TYPE_POINTER_TO (expr) = NULL;
9081 TYPE_REFERENCE_TO (expr) = NULL;
9083 md5_process_bytes (expr, tree_size (expr), ctx);
9084 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
9085 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
9086 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
9087 switch (TREE_CODE_CLASS (code))
9093 md5_process_bytes (TREE_STRING_POINTER (expr),
9094 TREE_STRING_LENGTH (expr), ctx);
9097 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
9098 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
9101 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
9111 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
9112 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
9115 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
9116 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
9128 len = first_rtl_op (code);
9129 for (i = 0; i < len; ++i)
9130 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
9133 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
9134 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
9135 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
9136 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
9137 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
9138 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
9139 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
9140 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
9141 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
9142 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
9143 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
9146 if (TREE_CODE (expr) == ENUMERAL_TYPE)
9147 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
9148 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
9149 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
9150 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
9151 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
9152 if (INTEGRAL_TYPE_P (expr)
9153 || SCALAR_FLOAT_TYPE_P (expr))
9155 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
9156 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
9158 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
9159 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
9160 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
9169 /* Perform constant folding and related simplification of initializer
9170 expression EXPR. This behaves identically to "fold" but ignores
9171 potential run-time traps and exceptions that fold must preserve. */
9174 fold_initializer (tree expr)
9176 int saved_signaling_nans = flag_signaling_nans;
9177 int saved_trapping_math = flag_trapping_math;
9178 int saved_trapv = flag_trapv;
9181 flag_signaling_nans = 0;
9182 flag_trapping_math = 0;
9185 result = fold (expr);
9187 flag_signaling_nans = saved_signaling_nans;
9188 flag_trapping_math = saved_trapping_math;
9189 flag_trapv = saved_trapv;
9194 /* Determine if first argument is a multiple of second argument. Return 0 if
9195 it is not, or we cannot easily determined it to be.
9197 An example of the sort of thing we care about (at this point; this routine
9198 could surely be made more general, and expanded to do what the *_DIV_EXPR's
9199 fold cases do now) is discovering that
9201 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9207 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
9209 This code also handles discovering that
9211 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
9213 is a multiple of 8 so we don't have to worry about dealing with a
9216 Note that we *look* inside a SAVE_EXPR only to determine how it was
9217 calculated; it is not safe for fold to do much of anything else with the
9218 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
9219 at run time. For example, the latter example above *cannot* be implemented
9220 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
9221 evaluation time of the original SAVE_EXPR is not necessarily the same at
9222 the time the new expression is evaluated. The only optimization of this
9223 sort that would be valid is changing
9225 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
9229 SAVE_EXPR (I) * SAVE_EXPR (J)
9231 (where the same SAVE_EXPR (J) is used in the original and the
9232 transformed version). */
9235 multiple_of_p (tree type, tree top, tree bottom)
9237 if (operand_equal_p (top, bottom, 0))
9240 if (TREE_CODE (type) != INTEGER_TYPE)
9243 switch (TREE_CODE (top))
9246 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9247 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9251 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
9252 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
9255 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
9259 op1 = TREE_OPERAND (top, 1);
9260 /* const_binop may not detect overflow correctly,
9261 so check for it explicitly here. */
9262 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
9263 > TREE_INT_CST_LOW (op1)
9264 && TREE_INT_CST_HIGH (op1) == 0
9265 && 0 != (t1 = fold_convert (type,
9266 const_binop (LSHIFT_EXPR,
9269 && ! TREE_OVERFLOW (t1))
9270 return multiple_of_p (type, t1, bottom);
9275 /* Can't handle conversions from non-integral or wider integral type. */
9276 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
9277 || (TYPE_PRECISION (type)
9278 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
9281 /* .. fall through ... */
9284 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
9287 if (TREE_CODE (bottom) != INTEGER_CST
9288 || (TYPE_UNSIGNED (type)
9289 && (tree_int_cst_sgn (top) < 0
9290 || tree_int_cst_sgn (bottom) < 0)))
9292 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
9300 /* Return true if `t' is known to be non-negative. */
9303 tree_expr_nonnegative_p (tree t)
9305 switch (TREE_CODE (t))
9311 return tree_int_cst_sgn (t) >= 0;
9314 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
9317 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9318 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9319 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9321 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
9322 both unsigned and at least 2 bits shorter than the result. */
9323 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9324 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9325 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9327 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9328 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9329 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9330 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9332 unsigned int prec = MAX (TYPE_PRECISION (inner1),
9333 TYPE_PRECISION (inner2)) + 1;
9334 return prec < TYPE_PRECISION (TREE_TYPE (t));
9340 if (FLOAT_TYPE_P (TREE_TYPE (t)))
9342 /* x * x for floating point x is always non-negative. */
9343 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
9345 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9346 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9349 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
9350 both unsigned and their total bits is shorter than the result. */
9351 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
9352 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
9353 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
9355 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
9356 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
9357 if (TREE_CODE (inner1) == INTEGER_TYPE && TYPE_UNSIGNED (inner1)
9358 && TREE_CODE (inner2) == INTEGER_TYPE && TYPE_UNSIGNED (inner2))
9359 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
9360 < TYPE_PRECISION (TREE_TYPE (t));
9364 case TRUNC_DIV_EXPR:
9366 case FLOOR_DIV_EXPR:
9367 case ROUND_DIV_EXPR:
9368 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9369 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9371 case TRUNC_MOD_EXPR:
9373 case FLOOR_MOD_EXPR:
9374 case ROUND_MOD_EXPR:
9375 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9378 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9379 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9382 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9383 || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9386 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9387 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9391 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9392 tree outer_type = TREE_TYPE (t);
9394 if (TREE_CODE (outer_type) == REAL_TYPE)
9396 if (TREE_CODE (inner_type) == REAL_TYPE)
9397 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9398 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9400 if (TYPE_UNSIGNED (inner_type))
9402 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9405 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
9407 if (TREE_CODE (inner_type) == REAL_TYPE)
9408 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
9409 if (TREE_CODE (inner_type) == INTEGER_TYPE)
9410 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
9411 && TYPE_UNSIGNED (inner_type);
9417 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
9418 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
9420 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9422 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9423 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9425 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9426 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9428 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9430 return tree_expr_nonnegative_p (expr_last (TREE_OPERAND (t, 1)));
9432 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9433 case NON_LVALUE_EXPR:
9434 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9436 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9440 tree temp = TARGET_EXPR_SLOT (t);
9441 t = TARGET_EXPR_INITIAL (t);
9443 /* If the initializer is non-void, then it's a normal expression
9444 that will be assigned to the slot. */
9445 if (!VOID_TYPE_P (t))
9446 return tree_expr_nonnegative_p (t);
9448 /* Otherwise, the initializer sets the slot in some way. One common
9449 way is an assignment statement at the end of the initializer. */
9452 if (TREE_CODE (t) == BIND_EXPR)
9453 t = expr_last (BIND_EXPR_BODY (t));
9454 else if (TREE_CODE (t) == TRY_FINALLY_EXPR
9455 || TREE_CODE (t) == TRY_CATCH_EXPR)
9456 t = expr_last (TREE_OPERAND (t, 0));
9457 else if (TREE_CODE (t) == STATEMENT_LIST)
9462 if (TREE_CODE (t) == MODIFY_EXPR
9463 && TREE_OPERAND (t, 0) == temp)
9464 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
9471 tree fndecl = get_callee_fndecl (t);
9472 tree arglist = TREE_OPERAND (t, 1);
9474 && DECL_BUILT_IN (fndecl)
9475 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
9476 switch (DECL_FUNCTION_CODE (fndecl))
9478 #define CASE_BUILTIN_F(BUILT_IN_FN) \
9479 case BUILT_IN_FN: case BUILT_IN_FN##F: case BUILT_IN_FN##L:
9480 #define CASE_BUILTIN_I(BUILT_IN_FN) \
9481 case BUILT_IN_FN: case BUILT_IN_FN##L: case BUILT_IN_FN##LL:
9483 CASE_BUILTIN_F (BUILT_IN_ACOS)
9484 CASE_BUILTIN_F (BUILT_IN_ACOSH)
9485 CASE_BUILTIN_F (BUILT_IN_CABS)
9486 CASE_BUILTIN_F (BUILT_IN_COSH)
9487 CASE_BUILTIN_F (BUILT_IN_ERFC)
9488 CASE_BUILTIN_F (BUILT_IN_EXP)
9489 CASE_BUILTIN_F (BUILT_IN_EXP10)
9490 CASE_BUILTIN_F (BUILT_IN_EXP2)
9491 CASE_BUILTIN_F (BUILT_IN_FABS)
9492 CASE_BUILTIN_F (BUILT_IN_FDIM)
9493 CASE_BUILTIN_F (BUILT_IN_FREXP)
9494 CASE_BUILTIN_F (BUILT_IN_HYPOT)
9495 CASE_BUILTIN_F (BUILT_IN_POW10)
9496 CASE_BUILTIN_I (BUILT_IN_FFS)
9497 CASE_BUILTIN_I (BUILT_IN_PARITY)
9498 CASE_BUILTIN_I (BUILT_IN_POPCOUNT)
9502 CASE_BUILTIN_F (BUILT_IN_SQRT)
9503 /* sqrt(-0.0) is -0.0. */
9504 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (t))))
9506 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9508 CASE_BUILTIN_F (BUILT_IN_ASINH)
9509 CASE_BUILTIN_F (BUILT_IN_ATAN)
9510 CASE_BUILTIN_F (BUILT_IN_ATANH)
9511 CASE_BUILTIN_F (BUILT_IN_CBRT)
9512 CASE_BUILTIN_F (BUILT_IN_CEIL)
9513 CASE_BUILTIN_F (BUILT_IN_ERF)
9514 CASE_BUILTIN_F (BUILT_IN_EXPM1)
9515 CASE_BUILTIN_F (BUILT_IN_FLOOR)
9516 CASE_BUILTIN_F (BUILT_IN_FMOD)
9517 CASE_BUILTIN_F (BUILT_IN_LDEXP)
9518 CASE_BUILTIN_F (BUILT_IN_LLRINT)
9519 CASE_BUILTIN_F (BUILT_IN_LLROUND)
9520 CASE_BUILTIN_F (BUILT_IN_LRINT)
9521 CASE_BUILTIN_F (BUILT_IN_LROUND)
9522 CASE_BUILTIN_F (BUILT_IN_MODF)
9523 CASE_BUILTIN_F (BUILT_IN_NEARBYINT)
9524 CASE_BUILTIN_F (BUILT_IN_POW)
9525 CASE_BUILTIN_F (BUILT_IN_RINT)
9526 CASE_BUILTIN_F (BUILT_IN_ROUND)
9527 CASE_BUILTIN_F (BUILT_IN_SIGNBIT)
9528 CASE_BUILTIN_F (BUILT_IN_SINH)
9529 CASE_BUILTIN_F (BUILT_IN_TANH)
9530 CASE_BUILTIN_F (BUILT_IN_TRUNC)
9531 /* True if the 1st argument is nonnegative. */
9532 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9534 CASE_BUILTIN_F (BUILT_IN_FMAX)
9535 /* True if the 1st OR 2nd arguments are nonnegative. */
9536 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9537 || tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9539 CASE_BUILTIN_F (BUILT_IN_FMIN)
9540 /* True if the 1st AND 2nd arguments are nonnegative. */
9541 return tree_expr_nonnegative_p (TREE_VALUE (arglist))
9542 && tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9544 CASE_BUILTIN_F (BUILT_IN_COPYSIGN)
9545 /* True if the 2nd argument is nonnegative. */
9546 return tree_expr_nonnegative_p (TREE_VALUE (TREE_CHAIN (arglist)));
9550 #undef CASE_BUILTIN_F
9551 #undef CASE_BUILTIN_I
9555 /* ... fall through ... */
9558 if (truth_value_p (TREE_CODE (t)))
9559 /* Truth values evaluate to 0 or 1, which is nonnegative. */
9563 /* We don't know sign of `t', so be conservative and return false. */
9567 /* Return true when T is an address and is known to be nonzero.
9568 For floating point we further ensure that T is not denormal.
9569 Similar logic is present in nonzero_address in rtlanal.h */
9572 tree_expr_nonzero_p (tree t)
9574 tree type = TREE_TYPE (t);
9576 /* Doing something useful for floating point would need more work. */
9577 if (!INTEGRAL_TYPE_P (type) && !POINTER_TYPE_P (type))
9580 switch (TREE_CODE (t))
9583 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9584 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9587 /* We used to test for !integer_zerop here. This does not work correctly
9588 if TREE_CONSTANT_OVERFLOW (t). */
9589 return (TREE_INT_CST_LOW (t) != 0
9590 || TREE_INT_CST_HIGH (t) != 0);
9593 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9595 /* With the presence of negative values it is hard
9596 to say something. */
9597 if (!tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
9598 || !tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9600 /* One of operands must be positive and the other non-negative. */
9601 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9602 || tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9607 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
9609 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9610 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9616 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
9617 tree outer_type = TREE_TYPE (t);
9619 return (TYPE_PRECISION (inner_type) >= TYPE_PRECISION (outer_type)
9620 && tree_expr_nonzero_p (TREE_OPERAND (t, 0)));
9626 tree base = get_base_address (TREE_OPERAND (t, 0));
9631 /* Weak declarations may link to NULL. */
9633 return !DECL_WEAK (base);
9635 /* Constants are never weak. */
9636 if (TREE_CODE_CLASS (TREE_CODE (base)) == 'c')
9643 return (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9644 && tree_expr_nonzero_p (TREE_OPERAND (t, 2)));
9647 return (tree_expr_nonzero_p (TREE_OPERAND (t, 0))
9648 && tree_expr_nonzero_p (TREE_OPERAND (t, 1)));
9651 if (tree_expr_nonzero_p (TREE_OPERAND (t, 0)))
9653 /* When both operands are nonzero, then MAX must be too. */
9654 if (tree_expr_nonzero_p (TREE_OPERAND (t, 1)))
9657 /* MAX where operand 0 is positive is positive. */
9658 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
9660 /* MAX where operand 1 is positive is positive. */
9661 else if (tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9662 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1)))
9669 return tree_expr_nonzero_p (TREE_OPERAND (t, 1));
9672 case NON_LVALUE_EXPR:
9673 return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9676 return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
9677 || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
9685 /* See if we are applying CODE, a relational to the highest or lowest
9686 possible integer of TYPE. If so, then the result is a compile
9690 fold_relational_hi_lo (enum tree_code *code_p, const tree type, tree *op0_p,
9695 enum tree_code code = *code_p;
9696 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (op1)));
9698 if (TREE_CODE (op1) == INTEGER_CST
9699 && ! TREE_CONSTANT_OVERFLOW (op1)
9700 && width <= HOST_BITS_PER_WIDE_INT
9701 && (INTEGRAL_TYPE_P (TREE_TYPE (op1))
9702 || POINTER_TYPE_P (TREE_TYPE (op1))))
9704 unsigned HOST_WIDE_INT signed_max;
9705 unsigned HOST_WIDE_INT max, min;
9707 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
9709 if (TYPE_UNSIGNED (TREE_TYPE (op1)))
9711 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
9717 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
9720 if (TREE_INT_CST_HIGH (op1) == 0
9721 && TREE_INT_CST_LOW (op1) == max)
9725 return omit_one_operand (type, integer_zero_node, op0);
9731 return omit_one_operand (type, integer_one_node, op0);
9737 /* The GE_EXPR and LT_EXPR cases above are not normally
9738 reached because of previous transformations. */
9743 else if (TREE_INT_CST_HIGH (op1) == 0
9744 && TREE_INT_CST_LOW (op1) == max - 1)
9749 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9753 *op1_p = const_binop (PLUS_EXPR, op1, integer_one_node, 0);
9758 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9759 && TREE_INT_CST_LOW (op1) == min)
9763 return omit_one_operand (type, integer_zero_node, op0);
9770 return omit_one_operand (type, integer_one_node, op0);
9779 else if (TREE_INT_CST_HIGH (op1) == (min ? -1 : 0)
9780 && TREE_INT_CST_LOW (op1) == min + 1)
9785 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9789 *op1_p = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
9795 else if (TREE_INT_CST_HIGH (op1) == 0
9796 && TREE_INT_CST_LOW (op1) == signed_max
9797 && TYPE_UNSIGNED (TREE_TYPE (op1))
9798 /* signed_type does not work on pointer types. */
9799 && INTEGRAL_TYPE_P (TREE_TYPE (op1)))
9801 /* The following case also applies to X < signed_max+1
9802 and X >= signed_max+1 because previous transformations. */
9803 if (code == LE_EXPR || code == GT_EXPR)
9805 tree st0, st1, exp, retval;
9806 st0 = lang_hooks.types.signed_type (TREE_TYPE (op0));
9807 st1 = lang_hooks.types.signed_type (TREE_TYPE (op1));
9809 exp = build2 (code == LE_EXPR ? GE_EXPR: LT_EXPR,
9811 fold_convert (st0, op0),
9812 fold_convert (st1, integer_zero_node));
9815 = nondestructive_fold_binary_to_constant (TREE_CODE (exp),
9817 TREE_OPERAND (exp, 0),
9818 TREE_OPERAND (exp, 1));
9820 /* If we are in gimple form, then returning EXP would create
9821 non-gimple expressions. Clearing it is safe and insures
9822 we do not allow a non-gimple expression to escape. */
9826 return (retval ? retval : exp);
9835 /* Given the components of a binary expression CODE, TYPE, OP0 and OP1,
9836 attempt to fold the expression to a constant without modifying TYPE,
9839 If the expression could be simplified to a constant, then return
9840 the constant. If the expression would not be simplified to a
9841 constant, then return NULL_TREE.
9843 Note this is primarily designed to be called after gimplification
9844 of the tree structures and when at least one operand is a constant.
9845 As a result of those simplifying assumptions this routine is far
9846 simpler than the generic fold routine. */
9849 nondestructive_fold_binary_to_constant (enum tree_code code, tree type,
9857 /* If this is a commutative operation, and ARG0 is a constant, move it
9858 to ARG1 to reduce the number of tests below. */
9859 if (commutative_tree_code (code)
9860 && (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST))
9867 /* If either operand is a complex type, extract its real component. */
9868 if (TREE_CODE (op0) == COMPLEX_CST)
9869 subop0 = TREE_REALPART (op0);
9873 if (TREE_CODE (op1) == COMPLEX_CST)
9874 subop1 = TREE_REALPART (op1);
9878 /* Note if either argument is not a real or integer constant.
9879 With a few exceptions, simplification is limited to cases
9880 where both arguments are constants. */
9881 if ((TREE_CODE (subop0) != INTEGER_CST
9882 && TREE_CODE (subop0) != REAL_CST)
9883 || (TREE_CODE (subop1) != INTEGER_CST
9884 && TREE_CODE (subop1) != REAL_CST))
9890 /* (plus (address) (const_int)) is a constant. */
9891 if (TREE_CODE (op0) == PLUS_EXPR
9892 && TREE_CODE (op1) == INTEGER_CST
9893 && (TREE_CODE (TREE_OPERAND (op0, 0)) == ADDR_EXPR
9894 || (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
9895 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (op0, 0), 0))
9897 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
9899 return build2 (PLUS_EXPR, type, TREE_OPERAND (op0, 0),
9900 const_binop (PLUS_EXPR, op1,
9901 TREE_OPERAND (op0, 1), 0));
9909 /* Both arguments are constants. Simplify. */
9910 tem = const_binop (code, op0, op1, 0);
9911 if (tem != NULL_TREE)
9913 /* The return value should always have the same type as
9914 the original expression. */
9915 if (TREE_TYPE (tem) != type)
9916 tem = fold_convert (type, tem);
9923 /* Fold &x - &x. This can happen from &x.foo - &x.
9924 This is unsafe for certain floats even in non-IEEE formats.
9925 In IEEE, it is unsafe because it does wrong for NaNs.
9926 Also note that operand_equal_p is always false if an
9927 operand is volatile. */
9928 if (! FLOAT_TYPE_P (type) && operand_equal_p (op0, op1, 0))
9929 return fold_convert (type, integer_zero_node);
9935 /* Special case multiplication or bitwise AND where one argument
9937 if (! FLOAT_TYPE_P (type) && integer_zerop (op1))
9938 return omit_one_operand (type, op1, op0);
9940 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (op0)))
9941 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (op0)))
9942 && real_zerop (op1))
9943 return omit_one_operand (type, op1, op0);
9948 /* Special case when we know the result will be all ones. */
9949 if (integer_all_onesp (op1))
9950 return omit_one_operand (type, op1, op0);
9954 case TRUNC_DIV_EXPR:
9955 case ROUND_DIV_EXPR:
9956 case FLOOR_DIV_EXPR:
9958 case EXACT_DIV_EXPR:
9959 case TRUNC_MOD_EXPR:
9960 case ROUND_MOD_EXPR:
9961 case FLOOR_MOD_EXPR:
9964 /* Division by zero is undefined. */
9965 if (integer_zerop (op1))
9968 if (TREE_CODE (op1) == REAL_CST
9969 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (op1)))
9970 && real_zerop (op1))
9976 if (INTEGRAL_TYPE_P (type)
9977 && operand_equal_p (op1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
9978 return omit_one_operand (type, op1, op0);
9983 if (INTEGRAL_TYPE_P (type)
9984 && TYPE_MAX_VALUE (type)
9985 && operand_equal_p (op1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
9986 return omit_one_operand (type, op1, op0);
9991 /* Optimize -1 >> x for arithmetic right shifts. */
9992 if (integer_all_onesp (op0) && ! TYPE_UNSIGNED (type))
9993 return omit_one_operand (type, op0, op1);
9994 /* ... fall through ... */
9997 if (integer_zerop (op0))
9998 return omit_one_operand (type, op0, op1);
10000 /* Since negative shift count is not well-defined, don't
10001 try to compute it in the compiler. */
10002 if (TREE_CODE (op1) == INTEGER_CST && tree_int_cst_sgn (op1) < 0)
10009 /* -1 rotated either direction by any amount is still -1. */
10010 if (integer_all_onesp (op0))
10011 return omit_one_operand (type, op0, op1);
10013 /* 0 rotated either direction by any amount is still zero. */
10014 if (integer_zerop (op0))
10015 return omit_one_operand (type, op0, op1);
10021 return build_complex (type, op0, op1);
10030 /* If one arg is a real or integer constant, put it last. */
10031 if ((TREE_CODE (op0) == INTEGER_CST
10032 && TREE_CODE (op1) != INTEGER_CST)
10033 || (TREE_CODE (op0) == REAL_CST
10034 && TREE_CODE (op0) != REAL_CST))
10041 code = swap_tree_comparison (code);
10044 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
10045 This transformation affects the cases which are handled in later
10046 optimizations involving comparisons with non-negative constants. */
10047 if (TREE_CODE (op1) == INTEGER_CST
10048 && TREE_CODE (op0) != INTEGER_CST
10049 && tree_int_cst_sgn (op1) > 0)
10055 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10060 op1 = const_binop (MINUS_EXPR, op1, integer_one_node, 0);
10068 tem = fold_relational_hi_lo (&code, type, &op0, &op1);
10072 /* Fall through. */
10075 case UNORDERED_EXPR:
10085 return fold_relational_const (code, type, op0, op1);
10088 /* This could probably be handled. */
10091 case TRUTH_AND_EXPR:
10092 /* If second arg is constant zero, result is zero, but first arg
10093 must be evaluated. */
10094 if (integer_zerop (op1))
10095 return omit_one_operand (type, op1, op0);
10096 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
10097 case will be handled here. */
10098 if (integer_zerop (op0))
10099 return omit_one_operand (type, op0, op1);
10100 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10101 return constant_boolean_node (true, type);
10104 case TRUTH_OR_EXPR:
10105 /* If second arg is constant true, result is true, but we must
10106 evaluate first arg. */
10107 if (TREE_CODE (op1) == INTEGER_CST && ! integer_zerop (op1))
10108 return omit_one_operand (type, op1, op0);
10109 /* Likewise for first arg, but note this only occurs here for
10111 if (TREE_CODE (op0) == INTEGER_CST && ! integer_zerop (op0))
10112 return omit_one_operand (type, op0, op1);
10113 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10114 return constant_boolean_node (false, type);
10117 case TRUTH_XOR_EXPR:
10118 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10120 int x = ! integer_zerop (op0) ^ ! integer_zerop (op1);
10121 return constant_boolean_node (x, type);
10130 /* Given the components of a unary expression CODE, TYPE and OP0,
10131 attempt to fold the expression to a constant without modifying
10134 If the expression could be simplified to a constant, then return
10135 the constant. If the expression would not be simplified to a
10136 constant, then return NULL_TREE.
10138 Note this is primarily designed to be called after gimplification
10139 of the tree structures and when op0 is a constant. As a result
10140 of those simplifying assumptions this routine is far simpler than
10141 the generic fold routine. */
10144 nondestructive_fold_unary_to_constant (enum tree_code code, tree type,
10147 /* Make sure we have a suitable constant argument. */
10148 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
10152 if (TREE_CODE (op0) == COMPLEX_CST)
10153 subop = TREE_REALPART (op0);
10157 if (TREE_CODE (subop) != INTEGER_CST && TREE_CODE (subop) != REAL_CST)
10166 case FIX_TRUNC_EXPR:
10167 case FIX_FLOOR_EXPR:
10168 case FIX_CEIL_EXPR:
10169 return fold_convert_const (code, type, op0);
10172 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10173 return fold_negate_const (op0, type);
10178 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
10179 return fold_abs_const (op0, type);
10184 if (TREE_CODE (op0) == INTEGER_CST)
10185 return fold_not_const (op0, type);
10189 case REALPART_EXPR:
10190 if (TREE_CODE (op0) == COMPLEX_CST)
10191 return TREE_REALPART (op0);
10195 case IMAGPART_EXPR:
10196 if (TREE_CODE (op0) == COMPLEX_CST)
10197 return TREE_IMAGPART (op0);
10202 if (TREE_CODE (op0) == COMPLEX_CST
10203 && TREE_CODE (TREE_TYPE (op0)) == COMPLEX_TYPE)
10204 return build_complex (type, TREE_REALPART (op0),
10205 negate_expr (TREE_IMAGPART (op0)));
10213 /* If EXP represents referencing an element in a constant string
10214 (either via pointer arithmetic or array indexing), return the
10215 tree representing the value accessed, otherwise return NULL. */
10218 fold_read_from_constant_string (tree exp)
10220 if (TREE_CODE (exp) == INDIRECT_REF || TREE_CODE (exp) == ARRAY_REF)
10222 tree exp1 = TREE_OPERAND (exp, 0);
10226 if (TREE_CODE (exp) == INDIRECT_REF)
10227 string = string_constant (exp1, &index);
10230 tree low_bound = array_ref_low_bound (exp);
10231 index = fold_convert (sizetype, TREE_OPERAND (exp, 1));
10233 /* Optimize the special-case of a zero lower bound.
10235 We convert the low_bound to sizetype to avoid some problems
10236 with constant folding. (E.g. suppose the lower bound is 1,
10237 and its mode is QI. Without the conversion,l (ARRAY
10238 +(INDEX-(unsigned char)1)) becomes ((ARRAY+(-(unsigned char)1))
10239 +INDEX), which becomes (ARRAY+255+INDEX). Opps!) */
10240 if (! integer_zerop (low_bound))
10241 index = size_diffop (index, fold_convert (sizetype, low_bound));
10247 && TREE_TYPE (exp) == TREE_TYPE (TREE_TYPE (string))
10248 && TREE_CODE (string) == STRING_CST
10249 && TREE_CODE (index) == INTEGER_CST
10250 && compare_tree_int (index, TREE_STRING_LENGTH (string)) < 0
10251 && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (string))))
10253 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (string)))) == 1))
10254 return fold_convert (TREE_TYPE (exp),
10255 build_int_cst (NULL_TREE,
10256 (TREE_STRING_POINTER (string)
10257 [TREE_INT_CST_LOW (index)])));
10262 /* Return the tree for neg (ARG0) when ARG0 is known to be either
10263 an integer constant or real constant.
10265 TYPE is the type of the result. */
10268 fold_negate_const (tree arg0, tree type)
10270 tree t = NULL_TREE;
10272 switch (TREE_CODE (arg0))
10276 unsigned HOST_WIDE_INT low;
10277 HOST_WIDE_INT high;
10278 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10279 TREE_INT_CST_HIGH (arg0),
10281 t = build_int_cst_wide (type, low, high);
10282 t = force_fit_type (t, 1,
10283 (overflow | TREE_OVERFLOW (arg0))
10284 && !TYPE_UNSIGNED (type),
10285 TREE_CONSTANT_OVERFLOW (arg0));
10290 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10294 gcc_unreachable ();
10300 /* Return the tree for abs (ARG0) when ARG0 is known to be either
10301 an integer constant or real constant.
10303 TYPE is the type of the result. */
10306 fold_abs_const (tree arg0, tree type)
10308 tree t = NULL_TREE;
10310 switch (TREE_CODE (arg0))
10313 /* If the value is unsigned, then the absolute value is
10314 the same as the ordinary value. */
10315 if (TYPE_UNSIGNED (type))
10317 /* Similarly, if the value is non-negative. */
10318 else if (INT_CST_LT (integer_minus_one_node, arg0))
10320 /* If the value is negative, then the absolute value is
10324 unsigned HOST_WIDE_INT low;
10325 HOST_WIDE_INT high;
10326 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
10327 TREE_INT_CST_HIGH (arg0),
10329 t = build_int_cst_wide (type, low, high);
10330 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg0),
10331 TREE_CONSTANT_OVERFLOW (arg0));
10336 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
10337 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
10343 gcc_unreachable ();
10349 /* Return the tree for not (ARG0) when ARG0 is known to be an integer
10350 constant. TYPE is the type of the result. */
10353 fold_not_const (tree arg0, tree type)
10355 tree t = NULL_TREE;
10357 gcc_assert (TREE_CODE (arg0) == INTEGER_CST);
10359 t = build_int_cst_wide (type,
10360 ~ TREE_INT_CST_LOW (arg0),
10361 ~ TREE_INT_CST_HIGH (arg0));
10362 t = force_fit_type (t, 0, TREE_OVERFLOW (arg0),
10363 TREE_CONSTANT_OVERFLOW (arg0));
10368 /* Given CODE, a relational operator, the target type, TYPE and two
10369 constant operands OP0 and OP1, return the result of the
10370 relational operation. If the result is not a compile time
10371 constant, then return NULL_TREE. */
10374 fold_relational_const (enum tree_code code, tree type, tree op0, tree op1)
10376 int result, invert;
10378 /* From here on, the only cases we handle are when the result is
10379 known to be a constant. */
10381 if (TREE_CODE (op0) == REAL_CST && TREE_CODE (op1) == REAL_CST)
10383 const REAL_VALUE_TYPE *c0 = TREE_REAL_CST_PTR (op0);
10384 const REAL_VALUE_TYPE *c1 = TREE_REAL_CST_PTR (op1);
10386 /* Handle the cases where either operand is a NaN. */
10387 if (real_isnan (c0) || real_isnan (c1))
10397 case UNORDERED_EXPR:
10411 if (flag_trapping_math)
10417 gcc_unreachable ();
10420 return constant_boolean_node (result, type);
10423 return constant_boolean_node (real_compare (code, c0, c1), type);
10426 /* From here on we only handle LT, LE, GT, GE, EQ and NE.
10428 To compute GT, swap the arguments and do LT.
10429 To compute GE, do LT and invert the result.
10430 To compute LE, swap the arguments, do LT and invert the result.
10431 To compute NE, do EQ and invert the result.
10433 Therefore, the code below must handle only EQ and LT. */
10435 if (code == LE_EXPR || code == GT_EXPR)
10440 code = swap_tree_comparison (code);
10443 /* Note that it is safe to invert for real values here because we
10444 have already handled the one case that it matters. */
10447 if (code == NE_EXPR || code == GE_EXPR)
10450 code = invert_tree_comparison (code, false);
10453 /* Compute a result for LT or EQ if args permit;
10454 Otherwise return T. */
10455 if (TREE_CODE (op0) == INTEGER_CST && TREE_CODE (op1) == INTEGER_CST)
10457 if (code == EQ_EXPR)
10458 result = tree_int_cst_equal (op0, op1);
10459 else if (TYPE_UNSIGNED (TREE_TYPE (op0)))
10460 result = INT_CST_LT_UNSIGNED (op0, op1);
10462 result = INT_CST_LT (op0, op1);
10469 return constant_boolean_node (result, type);
10472 /* Build an expression for the address of T. Folds away INDIRECT_REF to
10473 avoid confusing the gimplify process. */
10476 build_fold_addr_expr_with_type (tree t, tree ptrtype)
10478 /* The size of the object is not relevant when talking about its address. */
10479 if (TREE_CODE (t) == WITH_SIZE_EXPR)
10480 t = TREE_OPERAND (t, 0);
10482 if (TREE_CODE (t) == INDIRECT_REF)
10484 t = TREE_OPERAND (t, 0);
10485 if (TREE_TYPE (t) != ptrtype)
10486 t = build1 (NOP_EXPR, ptrtype, t);
10492 while (handled_component_p (base)
10493 || TREE_CODE (base) == REALPART_EXPR
10494 || TREE_CODE (base) == IMAGPART_EXPR)
10495 base = TREE_OPERAND (base, 0);
10497 TREE_ADDRESSABLE (base) = 1;
10499 t = build1 (ADDR_EXPR, ptrtype, t);
10506 build_fold_addr_expr (tree t)
10508 return build_fold_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
10511 /* Builds an expression for an indirection through T, simplifying some
10515 build_fold_indirect_ref (tree t)
10517 tree type = TREE_TYPE (TREE_TYPE (t));
10522 if (TREE_CODE (sub) == ADDR_EXPR)
10524 tree op = TREE_OPERAND (sub, 0);
10525 tree optype = TREE_TYPE (op);
10527 if (lang_hooks.types_compatible_p (type, optype))
10529 /* *(foo *)&fooarray => fooarray[0] */
10530 else if (TREE_CODE (optype) == ARRAY_TYPE
10531 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
10532 return build4 (ARRAY_REF, type, op, size_zero_node, NULL_TREE, NULL_TREE);
10535 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
10536 subtype = TREE_TYPE (sub);
10537 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
10538 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
10540 sub = build_fold_indirect_ref (sub);
10541 return build4 (ARRAY_REF, type, sub, size_zero_node, NULL_TREE, NULL_TREE);
10544 return build1 (INDIRECT_REF, type, t);
10547 /* Strip non-trapping, non-side-effecting tree nodes from an expression
10548 whose result is ignored. The type of the returned tree need not be
10549 the same as the original expression. */
10552 fold_ignored_result (tree t)
10554 if (!TREE_SIDE_EFFECTS (t))
10555 return integer_zero_node;
10558 switch (TREE_CODE_CLASS (TREE_CODE (t)))
10561 t = TREE_OPERAND (t, 0);
10566 if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
10567 t = TREE_OPERAND (t, 0);
10568 else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0)))
10569 t = TREE_OPERAND (t, 1);
10575 switch (TREE_CODE (t))
10577 case COMPOUND_EXPR:
10578 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)))
10580 t = TREE_OPERAND (t, 0);
10584 if (TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1))
10585 || TREE_SIDE_EFFECTS (TREE_OPERAND (t, 2)))
10587 t = TREE_OPERAND (t, 0);
10600 /* Return the value of VALUE, rounded up to a multiple of DIVISOR.
10601 This can only be applied to objects of a sizetype. */
10604 round_up (tree value, int divisor)
10606 tree div = NULL_TREE;
10608 gcc_assert (divisor > 0);
10612 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
10613 have to do anything. Only do this when we are not given a const,
10614 because in that case, this check is more expensive than just
10616 if (TREE_CODE (value) != INTEGER_CST)
10618 div = build_int_cst (TREE_TYPE (value), divisor);
10620 if (multiple_of_p (TREE_TYPE (value), value, div))
10624 /* If divisor is a power of two, simplify this to bit manipulation. */
10625 if (divisor == (divisor & -divisor))
10629 t = build_int_cst (TREE_TYPE (value), divisor - 1);
10630 value = size_binop (PLUS_EXPR, value, t);
10631 t = build_int_cst (TREE_TYPE (value), -divisor);
10632 value = size_binop (BIT_AND_EXPR, value, t);
10637 div = build_int_cst (TREE_TYPE (value), divisor);
10638 value = size_binop (CEIL_DIV_EXPR, value, div);
10639 value = size_binop (MULT_EXPR, value, div);
10645 /* Likewise, but round down. */
10648 round_down (tree value, int divisor)
10650 tree div = NULL_TREE;
10652 gcc_assert (divisor > 0);
10656 /* See if VALUE is already a multiple of DIVISOR. If so, we don't
10657 have to do anything. Only do this when we are not given a const,
10658 because in that case, this check is more expensive than just
10660 if (TREE_CODE (value) != INTEGER_CST)
10662 div = build_int_cst (TREE_TYPE (value), divisor);
10664 if (multiple_of_p (TREE_TYPE (value), value, div))
10668 /* If divisor is a power of two, simplify this to bit manipulation. */
10669 if (divisor == (divisor & -divisor))
10673 t = build_int_cst (TREE_TYPE (value), -divisor);
10674 value = size_binop (BIT_AND_EXPR, value, t);
10679 div = build_int_cst (TREE_TYPE (value), divisor);
10680 value = size_binop (FLOOR_DIV_EXPR, value, div);
10681 value = size_binop (MULT_EXPR, value, div);