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 and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
61 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
62 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
63 static bool negate_mathfn_p (enum built_in_function);
64 static bool negate_expr_p (tree);
65 static tree negate_expr (tree);
66 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
67 static tree associate_trees (tree, tree, enum tree_code, tree);
68 static tree int_const_binop (enum tree_code, tree, tree, int);
69 static tree const_binop (enum tree_code, tree, tree, int);
70 static hashval_t size_htab_hash (const void *);
71 static int size_htab_eq (const void *, const void *);
72 static tree fold_convert_const (enum tree_code, tree, tree);
73 static tree fold_convert (tree, tree);
74 static enum tree_code invert_tree_comparison (enum tree_code);
75 static enum tree_code swap_tree_comparison (enum tree_code);
76 static int comparison_to_compcode (enum tree_code);
77 static enum tree_code compcode_to_comparison (int);
78 static int truth_value_p (enum tree_code);
79 static int operand_equal_for_comparison_p (tree, tree, tree);
80 static int twoval_comparison_p (tree, tree *, tree *, int *);
81 static tree eval_subst (tree, tree, tree, tree, tree);
82 static tree pedantic_omit_one_operand (tree, tree, tree);
83 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
84 static tree make_bit_field_ref (tree, tree, int, int, int);
85 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
86 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
87 enum machine_mode *, int *, int *,
89 static int all_ones_mask_p (tree, int);
90 static tree sign_bit_p (tree, tree);
91 static int simple_operand_p (tree);
92 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
93 static tree make_range (tree, int *, tree *, tree *);
94 static tree build_range_check (tree, tree, int, tree, tree);
95 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
97 static tree fold_range_test (tree);
98 static tree unextend (tree, int, int, tree);
99 static tree fold_truthop (enum tree_code, tree, tree, tree);
100 static tree optimize_minmax_comparison (tree);
101 static tree extract_muldiv (tree, tree, enum tree_code, tree);
102 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
103 static tree strip_compound_expr (tree, tree);
104 static int multiple_of_p (tree, tree, tree);
105 static tree constant_boolean_node (int, tree);
106 static int count_cond (tree, int);
107 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
109 static bool fold_real_zero_addition_p (tree, tree, int);
110 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
112 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
113 static bool reorder_operands_p (tree, tree);
114 static bool tree_swap_operands_p (tree, tree, bool);
116 /* The following constants represent a bit based encoding of GCC's
117 comparison operators. This encoding simplifies transformations
118 on relational comparison operators, such as AND and OR. */
119 #define COMPCODE_FALSE 0
120 #define COMPCODE_LT 1
121 #define COMPCODE_EQ 2
122 #define COMPCODE_LE 3
123 #define COMPCODE_GT 4
124 #define COMPCODE_NE 5
125 #define COMPCODE_GE 6
126 #define COMPCODE_TRUE 7
128 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
129 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
130 and SUM1. Then this yields nonzero if overflow occurred during the
133 Overflow occurs if A and B have the same sign, but A and SUM differ in
134 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
136 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
138 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
139 We do that by representing the two-word integer in 4 words, with only
140 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
141 number. The value of the word is LOWPART + HIGHPART * BASE. */
144 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
145 #define HIGHPART(x) \
146 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
147 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
149 /* Unpack a two-word integer into 4 words.
150 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
151 WORDS points to the array of HOST_WIDE_INTs. */
154 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
156 words[0] = LOWPART (low);
157 words[1] = HIGHPART (low);
158 words[2] = LOWPART (hi);
159 words[3] = HIGHPART (hi);
162 /* Pack an array of 4 words into a two-word integer.
163 WORDS points to the array of words.
164 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
167 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
170 *low = words[0] + words[1] * BASE;
171 *hi = words[2] + words[3] * BASE;
174 /* Make the integer constant T valid for its type by setting to 0 or 1 all
175 the bits in the constant that don't belong in the type.
177 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
178 nonzero, a signed overflow has already occurred in calculating T, so
182 force_fit_type (tree t, int overflow)
184 unsigned HOST_WIDE_INT low;
188 if (TREE_CODE (t) == REAL_CST)
190 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
191 Consider doing it via real_convert now. */
195 else if (TREE_CODE (t) != INTEGER_CST)
198 low = TREE_INT_CST_LOW (t);
199 high = TREE_INT_CST_HIGH (t);
201 if (POINTER_TYPE_P (TREE_TYPE (t))
202 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
205 prec = TYPE_PRECISION (TREE_TYPE (t));
207 /* First clear all bits that are beyond the type's precision. */
209 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
211 else if (prec > HOST_BITS_PER_WIDE_INT)
212 TREE_INT_CST_HIGH (t)
213 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
216 TREE_INT_CST_HIGH (t) = 0;
217 if (prec < HOST_BITS_PER_WIDE_INT)
218 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
221 /* Unsigned types do not suffer sign extension or overflow unless they
223 if (TREE_UNSIGNED (TREE_TYPE (t))
224 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
225 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
228 /* If the value's sign bit is set, extend the sign. */
229 if (prec != 2 * HOST_BITS_PER_WIDE_INT
230 && (prec > HOST_BITS_PER_WIDE_INT
231 ? 0 != (TREE_INT_CST_HIGH (t)
233 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
234 : 0 != (TREE_INT_CST_LOW (t)
235 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
237 /* Value is negative:
238 set to 1 all the bits that are outside this type's precision. */
239 if (prec > HOST_BITS_PER_WIDE_INT)
240 TREE_INT_CST_HIGH (t)
241 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
244 TREE_INT_CST_HIGH (t) = -1;
245 if (prec < HOST_BITS_PER_WIDE_INT)
246 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
250 /* Return nonzero if signed overflow occurred. */
252 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
256 /* Add two doubleword integers with doubleword result.
257 Each argument is given as two `HOST_WIDE_INT' pieces.
258 One argument is L1 and H1; the other, L2 and H2.
259 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
262 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
263 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
264 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
266 unsigned HOST_WIDE_INT l;
270 h = h1 + h2 + (l < l1);
274 return OVERFLOW_SUM_SIGN (h1, h2, h);
277 /* Negate a doubleword integer with doubleword result.
278 Return nonzero if the operation overflows, assuming it's signed.
279 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
280 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
283 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
284 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
290 return (*hv & h1) < 0;
300 /* Multiply two doubleword integers with doubleword result.
301 Return nonzero if the operation overflows, assuming it's signed.
302 Each argument is given as two `HOST_WIDE_INT' pieces.
303 One argument is L1 and H1; the other, L2 and H2.
304 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
307 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
308 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
309 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
311 HOST_WIDE_INT arg1[4];
312 HOST_WIDE_INT arg2[4];
313 HOST_WIDE_INT prod[4 * 2];
314 unsigned HOST_WIDE_INT carry;
316 unsigned HOST_WIDE_INT toplow, neglow;
317 HOST_WIDE_INT tophigh, neghigh;
319 encode (arg1, l1, h1);
320 encode (arg2, l2, h2);
322 memset (prod, 0, sizeof prod);
324 for (i = 0; i < 4; i++)
327 for (j = 0; j < 4; j++)
330 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
331 carry += arg1[i] * arg2[j];
332 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
334 prod[k] = LOWPART (carry);
335 carry = HIGHPART (carry);
340 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
342 /* Check for overflow by calculating the top half of the answer in full;
343 it should agree with the low half's sign bit. */
344 decode (prod + 4, &toplow, &tophigh);
347 neg_double (l2, h2, &neglow, &neghigh);
348 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
352 neg_double (l1, h1, &neglow, &neghigh);
353 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
355 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
358 /* Shift the doubleword integer in L1, H1 left by COUNT places
359 keeping only PREC bits of result.
360 Shift right if COUNT is negative.
361 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
362 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
365 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
366 HOST_WIDE_INT count, unsigned int prec,
367 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
369 unsigned HOST_WIDE_INT signmask;
373 rshift_double (l1, h1, -count, prec, lv, hv, arith);
377 if (SHIFT_COUNT_TRUNCATED)
380 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
382 /* Shifting by the host word size is undefined according to the
383 ANSI standard, so we must handle this as a special case. */
387 else if (count >= HOST_BITS_PER_WIDE_INT)
389 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
394 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
395 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
399 /* Sign extend all bits that are beyond the precision. */
401 signmask = -((prec > HOST_BITS_PER_WIDE_INT
402 ? ((unsigned HOST_WIDE_INT) *hv
403 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
404 : (*lv >> (prec - 1))) & 1);
406 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
408 else if (prec >= HOST_BITS_PER_WIDE_INT)
410 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
411 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
416 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
417 *lv |= signmask << prec;
421 /* Shift the doubleword integer in L1, H1 right by COUNT places
422 keeping only PREC bits of result. COUNT must be positive.
423 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
424 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
427 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
428 HOST_WIDE_INT count, unsigned int prec,
429 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
432 unsigned HOST_WIDE_INT signmask;
435 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
438 if (SHIFT_COUNT_TRUNCATED)
441 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
443 /* Shifting by the host word size is undefined according to the
444 ANSI standard, so we must handle this as a special case. */
448 else if (count >= HOST_BITS_PER_WIDE_INT)
451 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
455 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
457 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
460 /* Zero / sign extend all bits that are beyond the precision. */
462 if (count >= (HOST_WIDE_INT)prec)
467 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
469 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
471 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
472 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
477 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
478 *lv |= signmask << (prec - count);
482 /* Rotate the doubleword integer in L1, H1 left by COUNT places
483 keeping only PREC bits of result.
484 Rotate right if COUNT is negative.
485 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
488 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
489 HOST_WIDE_INT count, unsigned int prec,
490 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
492 unsigned HOST_WIDE_INT s1l, s2l;
493 HOST_WIDE_INT s1h, s2h;
499 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
500 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
505 /* Rotate the doubleword integer in L1, H1 left by COUNT places
506 keeping only PREC bits of result. COUNT must be positive.
507 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
510 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
511 HOST_WIDE_INT count, unsigned int prec,
512 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
514 unsigned HOST_WIDE_INT s1l, s2l;
515 HOST_WIDE_INT s1h, s2h;
521 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
522 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
527 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
528 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
529 CODE is a tree code for a kind of division, one of
530 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
532 It controls how the quotient is rounded to an integer.
533 Return nonzero if the operation overflows.
534 UNS nonzero says do unsigned division. */
537 div_and_round_double (enum tree_code code, int uns,
538 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
539 HOST_WIDE_INT hnum_orig,
540 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
541 HOST_WIDE_INT hden_orig,
542 unsigned HOST_WIDE_INT *lquo,
543 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
547 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
548 HOST_WIDE_INT den[4], quo[4];
550 unsigned HOST_WIDE_INT work;
551 unsigned HOST_WIDE_INT carry = 0;
552 unsigned HOST_WIDE_INT lnum = lnum_orig;
553 HOST_WIDE_INT hnum = hnum_orig;
554 unsigned HOST_WIDE_INT lden = lden_orig;
555 HOST_WIDE_INT hden = hden_orig;
558 if (hden == 0 && lden == 0)
559 overflow = 1, lden = 1;
561 /* Calculate quotient sign and convert operands to unsigned. */
567 /* (minimum integer) / (-1) is the only overflow case. */
568 if (neg_double (lnum, hnum, &lnum, &hnum)
569 && ((HOST_WIDE_INT) lden & hden) == -1)
575 neg_double (lden, hden, &lden, &hden);
579 if (hnum == 0 && hden == 0)
580 { /* single precision */
582 /* This unsigned division rounds toward zero. */
588 { /* trivial case: dividend < divisor */
589 /* hden != 0 already checked. */
596 memset (quo, 0, sizeof quo);
598 memset (num, 0, sizeof num); /* to zero 9th element */
599 memset (den, 0, sizeof den);
601 encode (num, lnum, hnum);
602 encode (den, lden, hden);
604 /* Special code for when the divisor < BASE. */
605 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
607 /* hnum != 0 already checked. */
608 for (i = 4 - 1; i >= 0; i--)
610 work = num[i] + carry * BASE;
611 quo[i] = work / lden;
617 /* Full double precision division,
618 with thanks to Don Knuth's "Seminumerical Algorithms". */
619 int num_hi_sig, den_hi_sig;
620 unsigned HOST_WIDE_INT quo_est, scale;
622 /* Find the highest nonzero divisor digit. */
623 for (i = 4 - 1;; i--)
630 /* Insure that the first digit of the divisor is at least BASE/2.
631 This is required by the quotient digit estimation algorithm. */
633 scale = BASE / (den[den_hi_sig] + 1);
635 { /* scale divisor and dividend */
637 for (i = 0; i <= 4 - 1; i++)
639 work = (num[i] * scale) + carry;
640 num[i] = LOWPART (work);
641 carry = HIGHPART (work);
646 for (i = 0; i <= 4 - 1; i++)
648 work = (den[i] * scale) + carry;
649 den[i] = LOWPART (work);
650 carry = HIGHPART (work);
651 if (den[i] != 0) den_hi_sig = i;
658 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
660 /* Guess the next quotient digit, quo_est, by dividing the first
661 two remaining dividend digits by the high order quotient digit.
662 quo_est is never low and is at most 2 high. */
663 unsigned HOST_WIDE_INT tmp;
665 num_hi_sig = i + den_hi_sig + 1;
666 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
667 if (num[num_hi_sig] != den[den_hi_sig])
668 quo_est = work / den[den_hi_sig];
672 /* Refine quo_est so it's usually correct, and at most one high. */
673 tmp = work - quo_est * den[den_hi_sig];
675 && (den[den_hi_sig - 1] * quo_est
676 > (tmp * BASE + num[num_hi_sig - 2])))
679 /* Try QUO_EST as the quotient digit, by multiplying the
680 divisor by QUO_EST and subtracting from the remaining dividend.
681 Keep in mind that QUO_EST is the I - 1st digit. */
684 for (j = 0; j <= den_hi_sig; j++)
686 work = quo_est * den[j] + carry;
687 carry = HIGHPART (work);
688 work = num[i + j] - LOWPART (work);
689 num[i + j] = LOWPART (work);
690 carry += HIGHPART (work) != 0;
693 /* If quo_est was high by one, then num[i] went negative and
694 we need to correct things. */
695 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
698 carry = 0; /* add divisor back in */
699 for (j = 0; j <= den_hi_sig; j++)
701 work = num[i + j] + den[j] + carry;
702 carry = HIGHPART (work);
703 num[i + j] = LOWPART (work);
706 num [num_hi_sig] += carry;
709 /* Store the quotient digit. */
714 decode (quo, lquo, hquo);
717 /* If result is negative, make it so. */
719 neg_double (*lquo, *hquo, lquo, hquo);
721 /* compute trial remainder: rem = num - (quo * den) */
722 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
723 neg_double (*lrem, *hrem, lrem, hrem);
724 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
729 case TRUNC_MOD_EXPR: /* round toward zero */
730 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
734 case FLOOR_MOD_EXPR: /* round toward negative infinity */
735 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
738 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
746 case CEIL_MOD_EXPR: /* round toward positive infinity */
747 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
749 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
757 case ROUND_MOD_EXPR: /* round to closest integer */
759 unsigned HOST_WIDE_INT labs_rem = *lrem;
760 HOST_WIDE_INT habs_rem = *hrem;
761 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
762 HOST_WIDE_INT habs_den = hden, htwice;
764 /* Get absolute values. */
766 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
768 neg_double (lden, hden, &labs_den, &habs_den);
770 /* If (2 * abs (lrem) >= abs (lden)) */
771 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
772 labs_rem, habs_rem, <wice, &htwice);
774 if (((unsigned HOST_WIDE_INT) habs_den
775 < (unsigned HOST_WIDE_INT) htwice)
776 || (((unsigned HOST_WIDE_INT) habs_den
777 == (unsigned HOST_WIDE_INT) htwice)
778 && (labs_den < ltwice)))
782 add_double (*lquo, *hquo,
783 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
786 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
798 /* Compute true remainder: rem = num - (quo * den) */
799 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
800 neg_double (*lrem, *hrem, lrem, hrem);
801 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
805 /* Return true if built-in mathematical function specified by CODE
806 preserves the sign of it argument, i.e. -f(x) == f(-x). */
809 negate_mathfn_p (enum built_in_function code)
833 /* Determine whether an expression T can be cheaply negated using
834 the function negate_expr. */
837 negate_expr_p (tree t)
839 unsigned HOST_WIDE_INT val;
846 type = TREE_TYPE (t);
849 switch (TREE_CODE (t))
852 if (TREE_UNSIGNED (type) || ! flag_trapv)
855 /* Check that -CST will not overflow type. */
856 prec = TYPE_PRECISION (type);
857 if (prec > HOST_BITS_PER_WIDE_INT)
859 if (TREE_INT_CST_LOW (t) != 0)
861 prec -= HOST_BITS_PER_WIDE_INT;
862 val = TREE_INT_CST_HIGH (t);
865 val = TREE_INT_CST_LOW (t);
866 if (prec < HOST_BITS_PER_WIDE_INT)
867 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
868 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
875 return negate_expr_p (TREE_REALPART (t))
876 && negate_expr_p (TREE_IMAGPART (t));
879 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
881 /* -(A + B) -> (-B) - A. */
882 if (negate_expr_p (TREE_OPERAND (t, 1))
883 && reorder_operands_p (TREE_OPERAND (t, 0),
884 TREE_OPERAND (t, 1)))
886 /* -(A + B) -> (-A) - B. */
887 return negate_expr_p (TREE_OPERAND (t, 0));
890 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
891 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
892 && reorder_operands_p (TREE_OPERAND (t, 0),
893 TREE_OPERAND (t, 1));
896 if (TREE_UNSIGNED (TREE_TYPE (t)))
902 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
903 return negate_expr_p (TREE_OPERAND (t, 1))
904 || negate_expr_p (TREE_OPERAND (t, 0));
908 /* Negate -((double)float) as (double)(-float). */
909 if (TREE_CODE (type) == REAL_TYPE)
911 tree tem = strip_float_extensions (t);
913 return negate_expr_p (tem);
918 /* Negate -f(x) as f(-x). */
919 if (negate_mathfn_p (builtin_mathfn_code (t)))
920 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
929 /* Given T, an expression, return the negation of T. Allow for T to be
930 null, in which case return null. */
941 type = TREE_TYPE (t);
944 switch (TREE_CODE (t))
948 unsigned HOST_WIDE_INT low;
950 int overflow = neg_double (TREE_INT_CST_LOW (t),
951 TREE_INT_CST_HIGH (t),
953 tem = build_int_2 (low, high);
954 TREE_TYPE (tem) = type;
957 | force_fit_type (tem, overflow && !TREE_UNSIGNED (type)));
958 TREE_CONSTANT_OVERFLOW (tem)
959 = TREE_OVERFLOW (tem) | TREE_CONSTANT_OVERFLOW (t);
961 if (! TREE_OVERFLOW (tem)
962 || TREE_UNSIGNED (type)
968 tem = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (t)));
969 /* Two's complement FP formats, such as c4x, may overflow. */
970 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
971 return fold_convert (type, tem);
976 tree rpart = negate_expr (TREE_REALPART (t));
977 tree ipart = negate_expr (TREE_IMAGPART (t));
979 if ((TREE_CODE (rpart) == REAL_CST
980 && TREE_CODE (ipart) == REAL_CST)
981 || (TREE_CODE (rpart) == INTEGER_CST
982 && TREE_CODE (ipart) == INTEGER_CST))
983 return build_complex (type, rpart, ipart);
988 return fold_convert (type, TREE_OPERAND (t, 0));
991 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
993 /* -(A + B) -> (-B) - A. */
994 if (negate_expr_p (TREE_OPERAND (t, 1))
995 && reorder_operands_p (TREE_OPERAND (t, 0),
996 TREE_OPERAND (t, 1)))
997 return fold_convert (type,
998 fold (build (MINUS_EXPR, TREE_TYPE (t),
999 negate_expr (TREE_OPERAND (t, 1)),
1000 TREE_OPERAND (t, 0))));
1001 /* -(A + B) -> (-A) - B. */
1002 if (negate_expr_p (TREE_OPERAND (t, 0)))
1003 return fold_convert (type,
1004 fold (build (MINUS_EXPR, TREE_TYPE (t),
1005 negate_expr (TREE_OPERAND (t, 0)),
1006 TREE_OPERAND (t, 1))));
1011 /* - (A - B) -> B - A */
1012 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1013 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
1014 return fold_convert (type,
1015 fold (build (MINUS_EXPR, TREE_TYPE (t),
1016 TREE_OPERAND (t, 1),
1017 TREE_OPERAND (t, 0))));
1021 if (TREE_UNSIGNED (TREE_TYPE (t)))
1027 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
1029 tem = TREE_OPERAND (t, 1);
1030 if (negate_expr_p (tem))
1031 return fold_convert (type,
1032 fold (build (TREE_CODE (t), TREE_TYPE (t),
1033 TREE_OPERAND (t, 0),
1034 negate_expr (tem))));
1035 tem = TREE_OPERAND (t, 0);
1036 if (negate_expr_p (tem))
1037 return fold_convert (type,
1038 fold (build (TREE_CODE (t), TREE_TYPE (t),
1040 TREE_OPERAND (t, 1))));
1045 /* Convert -((double)float) into (double)(-float). */
1046 if (TREE_CODE (type) == REAL_TYPE)
1048 tem = strip_float_extensions (t);
1049 if (tem != t && negate_expr_p (tem))
1050 return fold_convert (type, negate_expr (tem));
1055 /* Negate -f(x) as f(-x). */
1056 if (negate_mathfn_p (builtin_mathfn_code (t))
1057 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1059 tree fndecl, arg, arglist;
1061 fndecl = get_callee_fndecl (t);
1062 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1063 arglist = build_tree_list (NULL_TREE, arg);
1064 return build_function_call_expr (fndecl, arglist);
1072 tem = fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t));
1073 return fold_convert (type, tem);
1076 /* Split a tree IN into a constant, literal and variable parts that could be
1077 combined with CODE to make IN. "constant" means an expression with
1078 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1079 commutative arithmetic operation. Store the constant part into *CONP,
1080 the literal in *LITP and return the variable part. If a part isn't
1081 present, set it to null. If the tree does not decompose in this way,
1082 return the entire tree as the variable part and the other parts as null.
1084 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1085 case, we negate an operand that was subtracted. Except if it is a
1086 literal for which we use *MINUS_LITP instead.
1088 If NEGATE_P is true, we are negating all of IN, again except a literal
1089 for which we use *MINUS_LITP instead.
1091 If IN is itself a literal or constant, return it as appropriate.
1093 Note that we do not guarantee that any of the three values will be the
1094 same type as IN, but they will have the same signedness and mode. */
1097 split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1098 tree *minus_litp, int negate_p)
1106 /* Strip any conversions that don't change the machine mode or signedness. */
1107 STRIP_SIGN_NOPS (in);
1109 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1111 else if (TREE_CODE (in) == code
1112 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1113 /* We can associate addition and subtraction together (even
1114 though the C standard doesn't say so) for integers because
1115 the value is not affected. For reals, the value might be
1116 affected, so we can't. */
1117 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1118 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1120 tree op0 = TREE_OPERAND (in, 0);
1121 tree op1 = TREE_OPERAND (in, 1);
1122 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1123 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1125 /* First see if either of the operands is a literal, then a constant. */
1126 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1127 *litp = op0, op0 = 0;
1128 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1129 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1131 if (op0 != 0 && TREE_CONSTANT (op0))
1132 *conp = op0, op0 = 0;
1133 else if (op1 != 0 && TREE_CONSTANT (op1))
1134 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1136 /* If we haven't dealt with either operand, this is not a case we can
1137 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1138 if (op0 != 0 && op1 != 0)
1143 var = op1, neg_var_p = neg1_p;
1145 /* Now do any needed negations. */
1147 *minus_litp = *litp, *litp = 0;
1149 *conp = negate_expr (*conp);
1151 var = negate_expr (var);
1153 else if (TREE_CONSTANT (in))
1161 *minus_litp = *litp, *litp = 0;
1162 else if (*minus_litp)
1163 *litp = *minus_litp, *minus_litp = 0;
1164 *conp = negate_expr (*conp);
1165 var = negate_expr (var);
1171 /* Re-associate trees split by the above function. T1 and T2 are either
1172 expressions to associate or null. Return the new expression, if any. If
1173 we build an operation, do it in TYPE and with CODE. */
1176 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
1183 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1184 try to fold this since we will have infinite recursion. But do
1185 deal with any NEGATE_EXPRs. */
1186 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1187 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1189 if (code == PLUS_EXPR)
1191 if (TREE_CODE (t1) == NEGATE_EXPR)
1192 return build (MINUS_EXPR, type, fold_convert (type, t2),
1193 fold_convert (type, TREE_OPERAND (t1, 0)));
1194 else if (TREE_CODE (t2) == NEGATE_EXPR)
1195 return build (MINUS_EXPR, type, fold_convert (type, t1),
1196 fold_convert (type, TREE_OPERAND (t2, 0)));
1198 return build (code, type, fold_convert (type, t1),
1199 fold_convert (type, t2));
1202 return fold (build (code, type, fold_convert (type, t1),
1203 fold_convert (type, t2)));
1206 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1207 to produce a new constant.
1209 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1212 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1214 unsigned HOST_WIDE_INT int1l, int2l;
1215 HOST_WIDE_INT int1h, int2h;
1216 unsigned HOST_WIDE_INT low;
1218 unsigned HOST_WIDE_INT garbagel;
1219 HOST_WIDE_INT garbageh;
1221 tree type = TREE_TYPE (arg1);
1222 int uns = TREE_UNSIGNED (type);
1224 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1226 int no_overflow = 0;
1228 int1l = TREE_INT_CST_LOW (arg1);
1229 int1h = TREE_INT_CST_HIGH (arg1);
1230 int2l = TREE_INT_CST_LOW (arg2);
1231 int2h = TREE_INT_CST_HIGH (arg2);
1236 low = int1l | int2l, hi = int1h | int2h;
1240 low = int1l ^ int2l, hi = int1h ^ int2h;
1244 low = int1l & int2l, hi = int1h & int2h;
1250 /* It's unclear from the C standard whether shifts can overflow.
1251 The following code ignores overflow; perhaps a C standard
1252 interpretation ruling is needed. */
1253 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1261 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1266 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1270 neg_double (int2l, int2h, &low, &hi);
1271 add_double (int1l, int1h, low, hi, &low, &hi);
1272 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1276 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1279 case TRUNC_DIV_EXPR:
1280 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1281 case EXACT_DIV_EXPR:
1282 /* This is a shortcut for a common special case. */
1283 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1284 && ! TREE_CONSTANT_OVERFLOW (arg1)
1285 && ! TREE_CONSTANT_OVERFLOW (arg2)
1286 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1288 if (code == CEIL_DIV_EXPR)
1291 low = int1l / int2l, hi = 0;
1295 /* ... fall through ... */
1297 case ROUND_DIV_EXPR:
1298 if (int2h == 0 && int2l == 1)
1300 low = int1l, hi = int1h;
1303 if (int1l == int2l && int1h == int2h
1304 && ! (int1l == 0 && int1h == 0))
1309 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1310 &low, &hi, &garbagel, &garbageh);
1313 case TRUNC_MOD_EXPR:
1314 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1315 /* This is a shortcut for a common special case. */
1316 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1317 && ! TREE_CONSTANT_OVERFLOW (arg1)
1318 && ! TREE_CONSTANT_OVERFLOW (arg2)
1319 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1321 if (code == CEIL_MOD_EXPR)
1323 low = int1l % int2l, hi = 0;
1327 /* ... fall through ... */
1329 case ROUND_MOD_EXPR:
1330 overflow = div_and_round_double (code, uns,
1331 int1l, int1h, int2l, int2h,
1332 &garbagel, &garbageh, &low, &hi);
1338 low = (((unsigned HOST_WIDE_INT) int1h
1339 < (unsigned HOST_WIDE_INT) int2h)
1340 || (((unsigned HOST_WIDE_INT) int1h
1341 == (unsigned HOST_WIDE_INT) int2h)
1344 low = (int1h < int2h
1345 || (int1h == int2h && int1l < int2l));
1347 if (low == (code == MIN_EXPR))
1348 low = int1l, hi = int1h;
1350 low = int2l, hi = int2h;
1357 /* If this is for a sizetype, can be represented as one (signed)
1358 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1361 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1362 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1363 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1364 return size_int_type_wide (low, type);
1367 t = build_int_2 (low, hi);
1368 TREE_TYPE (t) = TREE_TYPE (arg1);
1373 ? (!uns || is_sizetype) && overflow
1374 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1376 | TREE_OVERFLOW (arg1)
1377 | TREE_OVERFLOW (arg2));
1379 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1380 So check if force_fit_type truncated the value. */
1382 && ! TREE_OVERFLOW (t)
1383 && (TREE_INT_CST_HIGH (t) != hi
1384 || TREE_INT_CST_LOW (t) != low))
1385 TREE_OVERFLOW (t) = 1;
1387 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1388 | TREE_CONSTANT_OVERFLOW (arg1)
1389 | TREE_CONSTANT_OVERFLOW (arg2));
1393 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1394 constant. We assume ARG1 and ARG2 have the same data type, or at least
1395 are the same kind of constant and the same machine mode.
1397 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1400 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1405 if (TREE_CODE (arg1) == INTEGER_CST)
1406 return int_const_binop (code, arg1, arg2, notrunc);
1408 if (TREE_CODE (arg1) == REAL_CST)
1410 enum machine_mode mode;
1413 REAL_VALUE_TYPE value;
1416 d1 = TREE_REAL_CST (arg1);
1417 d2 = TREE_REAL_CST (arg2);
1419 type = TREE_TYPE (arg1);
1420 mode = TYPE_MODE (type);
1422 /* Don't perform operation if we honor signaling NaNs and
1423 either operand is a NaN. */
1424 if (HONOR_SNANS (mode)
1425 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1428 /* Don't perform operation if it would raise a division
1429 by zero exception. */
1430 if (code == RDIV_EXPR
1431 && REAL_VALUES_EQUAL (d2, dconst0)
1432 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1435 /* If either operand is a NaN, just return it. Otherwise, set up
1436 for floating-point trap; we return an overflow. */
1437 if (REAL_VALUE_ISNAN (d1))
1439 else if (REAL_VALUE_ISNAN (d2))
1442 REAL_ARITHMETIC (value, code, d1, d2);
1444 t = build_real (type, real_value_truncate (mode, value));
1447 = (force_fit_type (t, 0)
1448 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1449 TREE_CONSTANT_OVERFLOW (t)
1451 | TREE_CONSTANT_OVERFLOW (arg1)
1452 | TREE_CONSTANT_OVERFLOW (arg2);
1455 if (TREE_CODE (arg1) == COMPLEX_CST)
1457 tree type = TREE_TYPE (arg1);
1458 tree r1 = TREE_REALPART (arg1);
1459 tree i1 = TREE_IMAGPART (arg1);
1460 tree r2 = TREE_REALPART (arg2);
1461 tree i2 = TREE_IMAGPART (arg2);
1467 t = build_complex (type,
1468 const_binop (PLUS_EXPR, r1, r2, notrunc),
1469 const_binop (PLUS_EXPR, i1, i2, notrunc));
1473 t = build_complex (type,
1474 const_binop (MINUS_EXPR, r1, r2, notrunc),
1475 const_binop (MINUS_EXPR, i1, i2, notrunc));
1479 t = build_complex (type,
1480 const_binop (MINUS_EXPR,
1481 const_binop (MULT_EXPR,
1483 const_binop (MULT_EXPR,
1486 const_binop (PLUS_EXPR,
1487 const_binop (MULT_EXPR,
1489 const_binop (MULT_EXPR,
1497 = const_binop (PLUS_EXPR,
1498 const_binop (MULT_EXPR, r2, r2, notrunc),
1499 const_binop (MULT_EXPR, i2, i2, notrunc),
1502 t = build_complex (type,
1504 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1505 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1506 const_binop (PLUS_EXPR,
1507 const_binop (MULT_EXPR, r1, r2,
1509 const_binop (MULT_EXPR, i1, i2,
1512 magsquared, notrunc),
1514 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1515 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1516 const_binop (MINUS_EXPR,
1517 const_binop (MULT_EXPR, i1, r2,
1519 const_binop (MULT_EXPR, r1, i2,
1522 magsquared, notrunc));
1534 /* These are the hash table functions for the hash table of INTEGER_CST
1535 nodes of a sizetype. */
1537 /* Return the hash code code X, an INTEGER_CST. */
1540 size_htab_hash (const void *x)
1544 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1545 ^ htab_hash_pointer (TREE_TYPE (t))
1546 ^ (TREE_OVERFLOW (t) << 20));
1549 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1550 is the same as that given by *Y, which is the same. */
1553 size_htab_eq (const void *x, const void *y)
1558 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1559 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1560 && TREE_TYPE (xt) == TREE_TYPE (yt)
1561 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1564 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1565 bits are given by NUMBER and of the sizetype represented by KIND. */
1568 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1570 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1573 /* Likewise, but the desired type is specified explicitly. */
1575 static GTY (()) tree new_const;
1576 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1580 size_int_type_wide (HOST_WIDE_INT number, tree type)
1586 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1587 new_const = make_node (INTEGER_CST);
1590 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1591 hash table, we return the value from the hash table. Otherwise, we
1592 place that in the hash table and make a new node for the next time. */
1593 TREE_INT_CST_LOW (new_const) = number;
1594 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1595 TREE_TYPE (new_const) = type;
1596 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1597 = force_fit_type (new_const, 0);
1599 slot = htab_find_slot (size_htab, new_const, INSERT);
1605 new_const = make_node (INTEGER_CST);
1609 return (tree) *slot;
1612 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1613 is a tree code. The type of the result is taken from the operands.
1614 Both must be the same type integer type and it must be a size type.
1615 If the operands are constant, so is the result. */
1618 size_binop (enum tree_code code, tree arg0, tree arg1)
1620 tree type = TREE_TYPE (arg0);
1622 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1623 || type != TREE_TYPE (arg1))
1626 /* Handle the special case of two integer constants faster. */
1627 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1629 /* And some specific cases even faster than that. */
1630 if (code == PLUS_EXPR && integer_zerop (arg0))
1632 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1633 && integer_zerop (arg1))
1635 else if (code == MULT_EXPR && integer_onep (arg0))
1638 /* Handle general case of two integer constants. */
1639 return int_const_binop (code, arg0, arg1, 0);
1642 if (arg0 == error_mark_node || arg1 == error_mark_node)
1643 return error_mark_node;
1645 return fold (build (code, type, arg0, arg1));
1648 /* Given two values, either both of sizetype or both of bitsizetype,
1649 compute the difference between the two values. Return the value
1650 in signed type corresponding to the type of the operands. */
1653 size_diffop (tree arg0, tree arg1)
1655 tree type = TREE_TYPE (arg0);
1658 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1659 || type != TREE_TYPE (arg1))
1662 /* If the type is already signed, just do the simple thing. */
1663 if (! TREE_UNSIGNED (type))
1664 return size_binop (MINUS_EXPR, arg0, arg1);
1666 ctype = (type == bitsizetype || type == ubitsizetype
1667 ? sbitsizetype : ssizetype);
1669 /* If either operand is not a constant, do the conversions to the signed
1670 type and subtract. The hardware will do the right thing with any
1671 overflow in the subtraction. */
1672 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1673 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1674 fold_convert (ctype, arg1));
1676 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1677 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1678 overflow) and negate (which can't either). Special-case a result
1679 of zero while we're here. */
1680 if (tree_int_cst_equal (arg0, arg1))
1681 return fold_convert (ctype, integer_zero_node);
1682 else if (tree_int_cst_lt (arg1, arg0))
1683 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1685 return size_binop (MINUS_EXPR, fold_convert (ctype, integer_zero_node),
1686 fold_convert (ctype, size_binop (MINUS_EXPR,
1691 /* Attempt to fold type conversion operation CODE of expression ARG1 to
1692 type TYPE. If no simplification can be done return NULL_TREE. */
1695 fold_convert_const (enum tree_code code, tree type, tree arg1)
1700 if (TREE_TYPE (arg1) == type)
1703 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1705 if (TREE_CODE (arg1) == INTEGER_CST)
1707 /* If we would build a constant wider than GCC supports,
1708 leave the conversion unfolded. */
1709 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1712 /* If we are trying to make a sizetype for a small integer, use
1713 size_int to pick up cached types to reduce duplicate nodes. */
1714 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1715 && !TREE_CONSTANT_OVERFLOW (arg1)
1716 && compare_tree_int (arg1, 10000) < 0)
1717 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1719 /* Given an integer constant, make new constant with new type,
1720 appropriately sign-extended or truncated. */
1721 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1722 TREE_INT_CST_HIGH (arg1));
1723 TREE_TYPE (t) = type;
1724 /* Indicate an overflow if (1) ARG1 already overflowed,
1725 or (2) force_fit_type indicates an overflow.
1726 Tell force_fit_type that an overflow has already occurred
1727 if ARG1 is a too-large unsigned value and T is signed.
1728 But don't indicate an overflow if converting a pointer. */
1730 = ((force_fit_type (t,
1731 (TREE_INT_CST_HIGH (arg1) < 0
1732 && (TREE_UNSIGNED (type)
1733 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1734 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1735 || TREE_OVERFLOW (arg1));
1736 TREE_CONSTANT_OVERFLOW (t)
1737 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1740 else if (TREE_CODE (arg1) == REAL_CST)
1742 /* The following code implements the floating point to integer
1743 conversion rules required by the Java Language Specification,
1744 that IEEE NaNs are mapped to zero and values that overflow
1745 the target precision saturate, i.e. values greater than
1746 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1747 are mapped to INT_MIN. These semantics are allowed by the
1748 C and C++ standards that simply state that the behavior of
1749 FP-to-integer conversion is unspecified upon overflow. */
1751 HOST_WIDE_INT high, low;
1754 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1758 case FIX_TRUNC_EXPR:
1759 real_trunc (&r, VOIDmode, &x);
1763 real_ceil (&r, VOIDmode, &x);
1766 case FIX_FLOOR_EXPR:
1767 real_floor (&r, VOIDmode, &x);
1774 /* If R is NaN, return zero and show we have an overflow. */
1775 if (REAL_VALUE_ISNAN (r))
1782 /* See if R is less than the lower bound or greater than the
1787 tree lt = TYPE_MIN_VALUE (type);
1788 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1789 if (REAL_VALUES_LESS (r, l))
1792 high = TREE_INT_CST_HIGH (lt);
1793 low = TREE_INT_CST_LOW (lt);
1799 tree ut = TYPE_MAX_VALUE (type);
1802 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1803 if (REAL_VALUES_LESS (u, r))
1806 high = TREE_INT_CST_HIGH (ut);
1807 low = TREE_INT_CST_LOW (ut);
1813 REAL_VALUE_TO_INT (&low, &high, r);
1815 t = build_int_2 (low, high);
1816 TREE_TYPE (t) = type;
1818 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1819 TREE_CONSTANT_OVERFLOW (t)
1820 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1824 else if (TREE_CODE (type) == REAL_TYPE)
1826 if (TREE_CODE (arg1) == INTEGER_CST)
1827 return build_real_from_int_cst (type, arg1);
1828 if (TREE_CODE (arg1) == REAL_CST)
1830 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1832 /* We make a copy of ARG1 so that we don't modify an
1833 existing constant tree. */
1834 t = copy_node (arg1);
1835 TREE_TYPE (t) = type;
1839 t = build_real (type,
1840 real_value_truncate (TYPE_MODE (type),
1841 TREE_REAL_CST (arg1)));
1844 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1845 TREE_CONSTANT_OVERFLOW (t)
1846 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1853 /* Convert expression ARG to type TYPE. Used by the middle-end for
1854 simple conversions in preference to calling the front-end's convert. */
1857 fold_convert (tree type, tree arg)
1859 tree orig = TREE_TYPE (arg);
1865 if (TREE_CODE (arg) == ERROR_MARK
1866 || TREE_CODE (type) == ERROR_MARK
1867 || TREE_CODE (orig) == ERROR_MARK)
1868 return error_mark_node;
1870 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig))
1871 return fold (build1 (NOP_EXPR, type, arg));
1873 if (INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type))
1875 if (TREE_CODE (arg) == INTEGER_CST)
1877 tem = fold_convert_const (NOP_EXPR, type, arg);
1878 if (tem != NULL_TREE)
1881 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1882 return fold (build1 (NOP_EXPR, type, arg));
1883 if (TREE_CODE (orig) == COMPLEX_TYPE)
1885 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1886 return fold_convert (type, tem);
1888 if (TREE_CODE (orig) == VECTOR_TYPE
1889 && GET_MODE_SIZE (TYPE_MODE (type))
1890 == GET_MODE_SIZE (TYPE_MODE (orig)))
1891 return fold (build1 (NOP_EXPR, type, arg));
1893 else if (TREE_CODE (type) == REAL_TYPE)
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 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1909 return fold (build1 (FLOAT_EXPR, type, arg));
1910 if (TREE_CODE (orig) == REAL_TYPE)
1911 return fold (build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
1913 if (TREE_CODE (orig) == COMPLEX_TYPE)
1915 tem = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1916 return fold_convert (type, tem);
1919 else if (TREE_CODE (type) == COMPLEX_TYPE)
1921 if (INTEGRAL_TYPE_P (orig)
1922 || POINTER_TYPE_P (orig)
1923 || TREE_CODE (orig) == REAL_TYPE)
1924 return build (COMPLEX_EXPR, type,
1925 fold_convert (TREE_TYPE (type), arg),
1926 fold_convert (TREE_TYPE (type), integer_zero_node));
1927 if (TREE_CODE (orig) == COMPLEX_TYPE)
1931 if (TREE_CODE (arg) == COMPLEX_EXPR)
1933 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
1934 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
1935 return fold (build (COMPLEX_EXPR, type, rpart, ipart));
1938 arg = save_expr (arg);
1939 rpart = fold (build1 (REALPART_EXPR, TREE_TYPE (orig), arg));
1940 ipart = fold (build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg));
1941 rpart = fold_convert (TREE_TYPE (type), rpart);
1942 ipart = fold_convert (TREE_TYPE (type), ipart);
1943 return fold (build (COMPLEX_EXPR, type, rpart, ipart));
1946 else if (TREE_CODE (type) == VECTOR_TYPE)
1948 if ((INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig))
1949 && GET_MODE_SIZE (TYPE_MODE (type))
1950 == GET_MODE_SIZE (TYPE_MODE (orig)))
1951 return fold (build1 (NOP_EXPR, type, arg));
1952 if (TREE_CODE (orig) == VECTOR_TYPE
1953 && GET_MODE_SIZE (TYPE_MODE (type))
1954 == GET_MODE_SIZE (TYPE_MODE (orig)))
1955 return fold (build1 (NOP_EXPR, type, arg));
1957 else if (VOID_TYPE_P (type))
1958 return fold (build1 (CONVERT_EXPR, type, arg));
1962 /* Return an expr equal to X but certainly not valid as an lvalue. */
1969 /* These things are certainly not lvalues. */
1970 if (TREE_CODE (x) == NON_LVALUE_EXPR
1971 || TREE_CODE (x) == INTEGER_CST
1972 || TREE_CODE (x) == REAL_CST
1973 || TREE_CODE (x) == STRING_CST
1974 || TREE_CODE (x) == ADDR_EXPR)
1977 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1978 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1982 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1983 Zero means allow extended lvalues. */
1985 int pedantic_lvalues;
1987 /* When pedantic, return an expr equal to X but certainly not valid as a
1988 pedantic lvalue. Otherwise, return X. */
1991 pedantic_non_lvalue (tree x)
1993 if (pedantic_lvalues)
1994 return non_lvalue (x);
1999 /* Given a tree comparison code, return the code that is the logical inverse
2000 of the given code. It is not safe to do this for floating-point
2001 comparisons, except for NE_EXPR and EQ_EXPR. */
2003 static enum tree_code
2004 invert_tree_comparison (enum tree_code code)
2025 /* Similar, but return the comparison that results if the operands are
2026 swapped. This is safe for floating-point. */
2028 static enum tree_code
2029 swap_tree_comparison (enum tree_code code)
2050 /* Convert a comparison tree code from an enum tree_code representation
2051 into a compcode bit-based encoding. This function is the inverse of
2052 compcode_to_comparison. */
2055 comparison_to_compcode (enum tree_code code)
2076 /* Convert a compcode bit-based encoding of a comparison operator back
2077 to GCC's enum tree_code representation. This function is the
2078 inverse of comparison_to_compcode. */
2080 static enum tree_code
2081 compcode_to_comparison (int code)
2102 /* Return nonzero if CODE is a tree code that represents a truth value. */
2105 truth_value_p (enum tree_code code)
2107 return (TREE_CODE_CLASS (code) == '<'
2108 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2109 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2110 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2113 /* Return nonzero if two operands (typically of the same tree node)
2114 are necessarily equal. If either argument has side-effects this
2115 function returns zero.
2117 If ONLY_CONST is nonzero, only return nonzero for constants.
2118 This function tests whether the operands are indistinguishable;
2119 it does not test whether they are equal using C's == operation.
2120 The distinction is important for IEEE floating point, because
2121 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2122 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2124 If ONLY_CONST is zero, a VAR_DECL is considered equal to itself
2125 even though it may hold multiple values during a function.
2126 This is because a GCC tree node guarantees that nothing else is
2127 executed between the evaluation of its "operands" (which may often
2128 be evaluated in arbitrary order). Hence if the operands themselves
2129 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
2130 same value in each operand/subexpression. Hence a zero value for
2131 ONLY_CONST assumes isochronic (or instantaneous) tree equivalence.
2132 If comparing arbitrary expression trees, such as from different
2133 statements, ONLY_CONST must usually be nonzero. */
2136 operand_equal_p (tree arg0, tree arg1, int only_const)
2140 /* If both types don't have the same signedness, then we can't consider
2141 them equal. We must check this before the STRIP_NOPS calls
2142 because they may change the signedness of the arguments. */
2143 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
2149 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2150 /* This is needed for conversions and for COMPONENT_REF.
2151 Might as well play it safe and always test this. */
2152 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2153 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
2154 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2157 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2158 We don't care about side effects in that case because the SAVE_EXPR
2159 takes care of that for us. In all other cases, two expressions are
2160 equal if they have no side effects. If we have two identical
2161 expressions with side effects that should be treated the same due
2162 to the only side effects being identical SAVE_EXPR's, that will
2163 be detected in the recursive calls below. */
2164 if (arg0 == arg1 && ! only_const
2165 && (TREE_CODE (arg0) == SAVE_EXPR
2166 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2169 /* Next handle constant cases, those for which we can return 1 even
2170 if ONLY_CONST is set. */
2171 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2172 switch (TREE_CODE (arg0))
2175 return (! TREE_CONSTANT_OVERFLOW (arg0)
2176 && ! TREE_CONSTANT_OVERFLOW (arg1)
2177 && tree_int_cst_equal (arg0, arg1));
2180 return (! TREE_CONSTANT_OVERFLOW (arg0)
2181 && ! TREE_CONSTANT_OVERFLOW (arg1)
2182 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2183 TREE_REAL_CST (arg1)));
2189 if (TREE_CONSTANT_OVERFLOW (arg0)
2190 || TREE_CONSTANT_OVERFLOW (arg1))
2193 v1 = TREE_VECTOR_CST_ELTS (arg0);
2194 v2 = TREE_VECTOR_CST_ELTS (arg1);
2197 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
2200 v1 = TREE_CHAIN (v1);
2201 v2 = TREE_CHAIN (v2);
2208 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
2210 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
2214 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
2215 && ! memcmp (TREE_STRING_POINTER (arg0),
2216 TREE_STRING_POINTER (arg1),
2217 TREE_STRING_LENGTH (arg0)));
2220 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2229 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2232 /* Two conversions are equal only if signedness and modes match. */
2233 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
2234 && (TREE_UNSIGNED (TREE_TYPE (arg0))
2235 != TREE_UNSIGNED (TREE_TYPE (arg1))))
2238 return operand_equal_p (TREE_OPERAND (arg0, 0),
2239 TREE_OPERAND (arg1, 0), 0);
2243 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
2244 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
2248 /* For commutative ops, allow the other order. */
2249 return (commutative_tree_code (TREE_CODE (arg0))
2250 && operand_equal_p (TREE_OPERAND (arg0, 0),
2251 TREE_OPERAND (arg1, 1), 0)
2252 && operand_equal_p (TREE_OPERAND (arg0, 1),
2253 TREE_OPERAND (arg1, 0), 0));
2256 /* If either of the pointer (or reference) expressions we are
2257 dereferencing contain a side effect, these cannot be equal. */
2258 if (TREE_SIDE_EFFECTS (arg0)
2259 || TREE_SIDE_EFFECTS (arg1))
2262 switch (TREE_CODE (arg0))
2265 return operand_equal_p (TREE_OPERAND (arg0, 0),
2266 TREE_OPERAND (arg1, 0), 0);
2270 case ARRAY_RANGE_REF:
2271 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2272 TREE_OPERAND (arg1, 0), 0)
2273 && operand_equal_p (TREE_OPERAND (arg0, 1),
2274 TREE_OPERAND (arg1, 1), 0));
2277 return (operand_equal_p (TREE_OPERAND (arg0, 0),
2278 TREE_OPERAND (arg1, 0), 0)
2279 && operand_equal_p (TREE_OPERAND (arg0, 1),
2280 TREE_OPERAND (arg1, 1), 0)
2281 && operand_equal_p (TREE_OPERAND (arg0, 2),
2282 TREE_OPERAND (arg1, 2), 0));
2288 switch (TREE_CODE (arg0))
2291 case TRUTH_NOT_EXPR:
2292 return operand_equal_p (TREE_OPERAND (arg0, 0),
2293 TREE_OPERAND (arg1, 0), 0);
2296 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
2299 /* If the CALL_EXPRs call different functions, then they
2300 clearly can not be equal. */
2301 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
2302 TREE_OPERAND (arg1, 0), 0))
2305 /* Only consider const functions equivalent. */
2306 fndecl = get_callee_fndecl (arg0);
2307 if (fndecl == NULL_TREE
2308 || ! (flags_from_decl_or_type (fndecl) & ECF_CONST))
2311 /* Now see if all the arguments are the same. operand_equal_p
2312 does not handle TREE_LIST, so we walk the operands here
2313 feeding them to operand_equal_p. */
2314 arg0 = TREE_OPERAND (arg0, 1);
2315 arg1 = TREE_OPERAND (arg1, 1);
2316 while (arg0 && arg1)
2318 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1), 0))
2321 arg0 = TREE_CHAIN (arg0);
2322 arg1 = TREE_CHAIN (arg1);
2325 /* If we get here and both argument lists are exhausted
2326 then the CALL_EXPRs are equal. */
2327 return ! (arg0 || arg1);
2334 /* Consider __builtin_sqrt equal to sqrt. */
2335 return TREE_CODE (arg0) == FUNCTION_DECL
2336 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2337 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2338 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1);
2345 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2346 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2348 When in doubt, return 0. */
2351 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2353 int unsignedp1, unsignedpo;
2354 tree primarg0, primarg1, primother;
2355 unsigned int correct_width;
2357 if (operand_equal_p (arg0, arg1, 0))
2360 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2361 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2364 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2365 and see if the inner values are the same. This removes any
2366 signedness comparison, which doesn't matter here. */
2367 primarg0 = arg0, primarg1 = arg1;
2368 STRIP_NOPS (primarg0);
2369 STRIP_NOPS (primarg1);
2370 if (operand_equal_p (primarg0, primarg1, 0))
2373 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2374 actual comparison operand, ARG0.
2376 First throw away any conversions to wider types
2377 already present in the operands. */
2379 primarg1 = get_narrower (arg1, &unsignedp1);
2380 primother = get_narrower (other, &unsignedpo);
2382 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2383 if (unsignedp1 == unsignedpo
2384 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2385 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2387 tree type = TREE_TYPE (arg0);
2389 /* Make sure shorter operand is extended the right way
2390 to match the longer operand. */
2391 primarg1 = fold_convert ((*lang_hooks.types.signed_or_unsigned_type)
2392 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2394 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2401 /* See if ARG is an expression that is either a comparison or is performing
2402 arithmetic on comparisons. The comparisons must only be comparing
2403 two different values, which will be stored in *CVAL1 and *CVAL2; if
2404 they are nonzero it means that some operands have already been found.
2405 No variables may be used anywhere else in the expression except in the
2406 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2407 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2409 If this is true, return 1. Otherwise, return zero. */
2412 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2414 enum tree_code code = TREE_CODE (arg);
2415 char class = TREE_CODE_CLASS (code);
2417 /* We can handle some of the 'e' cases here. */
2418 if (class == 'e' && code == TRUTH_NOT_EXPR)
2420 else if (class == 'e'
2421 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2422 || code == COMPOUND_EXPR))
2425 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2426 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2428 /* If we've already found a CVAL1 or CVAL2, this expression is
2429 two complex to handle. */
2430 if (*cval1 || *cval2)
2440 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2443 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2444 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2445 cval1, cval2, save_p));
2451 if (code == COND_EXPR)
2452 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2453 cval1, cval2, save_p)
2454 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2455 cval1, cval2, save_p)
2456 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2457 cval1, cval2, save_p));
2461 /* First see if we can handle the first operand, then the second. For
2462 the second operand, we know *CVAL1 can't be zero. It must be that
2463 one side of the comparison is each of the values; test for the
2464 case where this isn't true by failing if the two operands
2467 if (operand_equal_p (TREE_OPERAND (arg, 0),
2468 TREE_OPERAND (arg, 1), 0))
2472 *cval1 = TREE_OPERAND (arg, 0);
2473 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2475 else if (*cval2 == 0)
2476 *cval2 = TREE_OPERAND (arg, 0);
2477 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2482 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2484 else if (*cval2 == 0)
2485 *cval2 = TREE_OPERAND (arg, 1);
2486 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2498 /* ARG is a tree that is known to contain just arithmetic operations and
2499 comparisons. Evaluate the operations in the tree substituting NEW0 for
2500 any occurrence of OLD0 as an operand of a comparison and likewise for
2504 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2506 tree type = TREE_TYPE (arg);
2507 enum tree_code code = TREE_CODE (arg);
2508 char class = TREE_CODE_CLASS (code);
2510 /* We can handle some of the 'e' cases here. */
2511 if (class == 'e' && code == TRUTH_NOT_EXPR)
2513 else if (class == 'e'
2514 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2520 return fold (build1 (code, type,
2521 eval_subst (TREE_OPERAND (arg, 0),
2522 old0, new0, old1, new1)));
2525 return fold (build (code, type,
2526 eval_subst (TREE_OPERAND (arg, 0),
2527 old0, new0, old1, new1),
2528 eval_subst (TREE_OPERAND (arg, 1),
2529 old0, new0, old1, new1)));
2535 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2538 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2541 return fold (build (code, type,
2542 eval_subst (TREE_OPERAND (arg, 0),
2543 old0, new0, old1, new1),
2544 eval_subst (TREE_OPERAND (arg, 1),
2545 old0, new0, old1, new1),
2546 eval_subst (TREE_OPERAND (arg, 2),
2547 old0, new0, old1, new1)));
2551 /* Fall through - ??? */
2555 tree arg0 = TREE_OPERAND (arg, 0);
2556 tree arg1 = TREE_OPERAND (arg, 1);
2558 /* We need to check both for exact equality and tree equality. The
2559 former will be true if the operand has a side-effect. In that
2560 case, we know the operand occurred exactly once. */
2562 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2564 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2567 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2569 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2572 return fold (build (code, type, arg0, arg1));
2580 /* Return a tree for the case when the result of an expression is RESULT
2581 converted to TYPE and OMITTED was previously an operand of the expression
2582 but is now not needed (e.g., we folded OMITTED * 0).
2584 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2585 the conversion of RESULT to TYPE. */
2588 omit_one_operand (tree type, tree result, tree omitted)
2590 tree t = fold_convert (type, result);
2592 if (TREE_SIDE_EFFECTS (omitted))
2593 return build (COMPOUND_EXPR, type, omitted, t);
2595 return non_lvalue (t);
2598 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2601 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2603 tree t = fold_convert (type, result);
2605 if (TREE_SIDE_EFFECTS (omitted))
2606 return build (COMPOUND_EXPR, type, omitted, t);
2608 return pedantic_non_lvalue (t);
2611 /* Return a simplified tree node for the truth-negation of ARG. This
2612 never alters ARG itself. We assume that ARG is an operation that
2613 returns a truth value (0 or 1). */
2616 invert_truthvalue (tree arg)
2618 tree type = TREE_TYPE (arg);
2619 enum tree_code code = TREE_CODE (arg);
2621 if (code == ERROR_MARK)
2624 /* If this is a comparison, we can simply invert it, except for
2625 floating-point non-equality comparisons, in which case we just
2626 enclose a TRUTH_NOT_EXPR around what we have. */
2628 if (TREE_CODE_CLASS (code) == '<')
2630 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2631 && !flag_unsafe_math_optimizations
2634 return build1 (TRUTH_NOT_EXPR, type, arg);
2635 else if (code == UNORDERED_EXPR
2636 || code == ORDERED_EXPR
2637 || code == UNEQ_EXPR
2638 || code == UNLT_EXPR
2639 || code == UNLE_EXPR
2640 || code == UNGT_EXPR
2641 || code == UNGE_EXPR)
2642 return build1 (TRUTH_NOT_EXPR, type, arg);
2644 return build (invert_tree_comparison (code), type,
2645 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2651 return fold_convert (type, build_int_2 (integer_zerop (arg), 0));
2653 case TRUTH_AND_EXPR:
2654 return build (TRUTH_OR_EXPR, type,
2655 invert_truthvalue (TREE_OPERAND (arg, 0)),
2656 invert_truthvalue (TREE_OPERAND (arg, 1)));
2659 return build (TRUTH_AND_EXPR, type,
2660 invert_truthvalue (TREE_OPERAND (arg, 0)),
2661 invert_truthvalue (TREE_OPERAND (arg, 1)));
2663 case TRUTH_XOR_EXPR:
2664 /* Here we can invert either operand. We invert the first operand
2665 unless the second operand is a TRUTH_NOT_EXPR in which case our
2666 result is the XOR of the first operand with the inside of the
2667 negation of the second operand. */
2669 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2670 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2671 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2673 return build (TRUTH_XOR_EXPR, type,
2674 invert_truthvalue (TREE_OPERAND (arg, 0)),
2675 TREE_OPERAND (arg, 1));
2677 case TRUTH_ANDIF_EXPR:
2678 return build (TRUTH_ORIF_EXPR, type,
2679 invert_truthvalue (TREE_OPERAND (arg, 0)),
2680 invert_truthvalue (TREE_OPERAND (arg, 1)));
2682 case TRUTH_ORIF_EXPR:
2683 return build (TRUTH_ANDIF_EXPR, type,
2684 invert_truthvalue (TREE_OPERAND (arg, 0)),
2685 invert_truthvalue (TREE_OPERAND (arg, 1)));
2687 case TRUTH_NOT_EXPR:
2688 return TREE_OPERAND (arg, 0);
2691 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2692 invert_truthvalue (TREE_OPERAND (arg, 1)),
2693 invert_truthvalue (TREE_OPERAND (arg, 2)));
2696 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2697 invert_truthvalue (TREE_OPERAND (arg, 1)));
2699 case WITH_RECORD_EXPR:
2700 return build (WITH_RECORD_EXPR, type,
2701 invert_truthvalue (TREE_OPERAND (arg, 0)),
2702 TREE_OPERAND (arg, 1));
2704 case NON_LVALUE_EXPR:
2705 return invert_truthvalue (TREE_OPERAND (arg, 0));
2710 return build1 (TREE_CODE (arg), type,
2711 invert_truthvalue (TREE_OPERAND (arg, 0)));
2714 if (!integer_onep (TREE_OPERAND (arg, 1)))
2716 return build (EQ_EXPR, type, arg,
2717 fold_convert (type, integer_zero_node));
2720 return build1 (TRUTH_NOT_EXPR, type, arg);
2722 case CLEANUP_POINT_EXPR:
2723 return build1 (CLEANUP_POINT_EXPR, type,
2724 invert_truthvalue (TREE_OPERAND (arg, 0)));
2729 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2731 return build1 (TRUTH_NOT_EXPR, type, arg);
2734 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2735 operands are another bit-wise operation with a common input. If so,
2736 distribute the bit operations to save an operation and possibly two if
2737 constants are involved. For example, convert
2738 (A | B) & (A | C) into A | (B & C)
2739 Further simplification will occur if B and C are constants.
2741 If this optimization cannot be done, 0 will be returned. */
2744 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2749 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2750 || TREE_CODE (arg0) == code
2751 || (TREE_CODE (arg0) != BIT_AND_EXPR
2752 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2755 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2757 common = TREE_OPERAND (arg0, 0);
2758 left = TREE_OPERAND (arg0, 1);
2759 right = TREE_OPERAND (arg1, 1);
2761 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2763 common = TREE_OPERAND (arg0, 0);
2764 left = TREE_OPERAND (arg0, 1);
2765 right = TREE_OPERAND (arg1, 0);
2767 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2769 common = TREE_OPERAND (arg0, 1);
2770 left = TREE_OPERAND (arg0, 0);
2771 right = TREE_OPERAND (arg1, 1);
2773 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2775 common = TREE_OPERAND (arg0, 1);
2776 left = TREE_OPERAND (arg0, 0);
2777 right = TREE_OPERAND (arg1, 0);
2782 return fold (build (TREE_CODE (arg0), type, common,
2783 fold (build (code, type, left, right))));
2786 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2787 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2790 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
2793 tree result = build (BIT_FIELD_REF, type, inner,
2794 size_int (bitsize), bitsize_int (bitpos));
2796 TREE_UNSIGNED (result) = unsignedp;
2801 /* Optimize a bit-field compare.
2803 There are two cases: First is a compare against a constant and the
2804 second is a comparison of two items where the fields are at the same
2805 bit position relative to the start of a chunk (byte, halfword, word)
2806 large enough to contain it. In these cases we can avoid the shift
2807 implicit in bitfield extractions.
2809 For constants, we emit a compare of the shifted constant with the
2810 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2811 compared. For two fields at the same position, we do the ANDs with the
2812 similar mask and compare the result of the ANDs.
2814 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2815 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2816 are the left and right operands of the comparison, respectively.
2818 If the optimization described above can be done, we return the resulting
2819 tree. Otherwise we return zero. */
2822 optimize_bit_field_compare (enum tree_code code, tree compare_type,
2825 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2826 tree type = TREE_TYPE (lhs);
2827 tree signed_type, unsigned_type;
2828 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2829 enum machine_mode lmode, rmode, nmode;
2830 int lunsignedp, runsignedp;
2831 int lvolatilep = 0, rvolatilep = 0;
2832 tree linner, rinner = NULL_TREE;
2836 /* Get all the information about the extractions being done. If the bit size
2837 if the same as the size of the underlying object, we aren't doing an
2838 extraction at all and so can do nothing. We also don't want to
2839 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2840 then will no longer be able to replace it. */
2841 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2842 &lunsignedp, &lvolatilep);
2843 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2844 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2849 /* If this is not a constant, we can only do something if bit positions,
2850 sizes, and signedness are the same. */
2851 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2852 &runsignedp, &rvolatilep);
2854 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2855 || lunsignedp != runsignedp || offset != 0
2856 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2860 /* See if we can find a mode to refer to this field. We should be able to,
2861 but fail if we can't. */
2862 nmode = get_best_mode (lbitsize, lbitpos,
2863 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2864 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2865 TYPE_ALIGN (TREE_TYPE (rinner))),
2866 word_mode, lvolatilep || rvolatilep);
2867 if (nmode == VOIDmode)
2870 /* Set signed and unsigned types of the precision of this mode for the
2872 signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
2873 unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
2875 /* Compute the bit position and size for the new reference and our offset
2876 within it. If the new reference is the same size as the original, we
2877 won't optimize anything, so return zero. */
2878 nbitsize = GET_MODE_BITSIZE (nmode);
2879 nbitpos = lbitpos & ~ (nbitsize - 1);
2881 if (nbitsize == lbitsize)
2884 if (BYTES_BIG_ENDIAN)
2885 lbitpos = nbitsize - lbitsize - lbitpos;
2887 /* Make the mask to be used against the extracted field. */
2888 mask = build_int_2 (~0, ~0);
2889 TREE_TYPE (mask) = unsigned_type;
2890 force_fit_type (mask, 0);
2891 mask = fold_convert (unsigned_type, mask);
2892 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2893 mask = const_binop (RSHIFT_EXPR, mask,
2894 size_int (nbitsize - lbitsize - lbitpos), 0);
2897 /* If not comparing with constant, just rework the comparison
2899 return build (code, compare_type,
2900 build (BIT_AND_EXPR, unsigned_type,
2901 make_bit_field_ref (linner, unsigned_type,
2902 nbitsize, nbitpos, 1),
2904 build (BIT_AND_EXPR, unsigned_type,
2905 make_bit_field_ref (rinner, unsigned_type,
2906 nbitsize, nbitpos, 1),
2909 /* Otherwise, we are handling the constant case. See if the constant is too
2910 big for the field. Warn and return a tree of for 0 (false) if so. We do
2911 this not only for its own sake, but to avoid having to test for this
2912 error case below. If we didn't, we might generate wrong code.
2914 For unsigned fields, the constant shifted right by the field length should
2915 be all zero. For signed fields, the high-order bits should agree with
2920 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2921 fold_convert (unsigned_type, rhs),
2922 size_int (lbitsize), 0)))
2924 warning ("comparison is always %d due to width of bit-field",
2926 return fold_convert (compare_type,
2928 ? integer_one_node : integer_zero_node));
2933 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
2934 size_int (lbitsize - 1), 0);
2935 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2937 warning ("comparison is always %d due to width of bit-field",
2939 return fold_convert (compare_type,
2941 ? integer_one_node : integer_zero_node));
2945 /* Single-bit compares should always be against zero. */
2946 if (lbitsize == 1 && ! integer_zerop (rhs))
2948 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2949 rhs = fold_convert (type, integer_zero_node);
2952 /* Make a new bitfield reference, shift the constant over the
2953 appropriate number of bits and mask it with the computed mask
2954 (in case this was a signed field). If we changed it, make a new one. */
2955 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2958 TREE_SIDE_EFFECTS (lhs) = 1;
2959 TREE_THIS_VOLATILE (lhs) = 1;
2962 rhs = fold (const_binop (BIT_AND_EXPR,
2963 const_binop (LSHIFT_EXPR,
2964 fold_convert (unsigned_type, rhs),
2965 size_int (lbitpos), 0),
2968 return build (code, compare_type,
2969 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2973 /* Subroutine for fold_truthop: decode a field reference.
2975 If EXP is a comparison reference, we return the innermost reference.
2977 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2978 set to the starting bit number.
2980 If the innermost field can be completely contained in a mode-sized
2981 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2983 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2984 otherwise it is not changed.
2986 *PUNSIGNEDP is set to the signedness of the field.
2988 *PMASK is set to the mask used. This is either contained in a
2989 BIT_AND_EXPR or derived from the width of the field.
2991 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2993 Return 0 if this is not a component reference or is one that we can't
2994 do anything with. */
2997 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
2998 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
2999 int *punsignedp, int *pvolatilep,
3000 tree *pmask, tree *pand_mask)
3002 tree outer_type = 0;
3004 tree mask, inner, offset;
3006 unsigned int precision;
3008 /* All the optimizations using this function assume integer fields.
3009 There are problems with FP fields since the type_for_size call
3010 below can fail for, e.g., XFmode. */
3011 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3014 /* We are interested in the bare arrangement of bits, so strip everything
3015 that doesn't affect the machine mode. However, record the type of the
3016 outermost expression if it may matter below. */
3017 if (TREE_CODE (exp) == NOP_EXPR
3018 || TREE_CODE (exp) == CONVERT_EXPR
3019 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3020 outer_type = TREE_TYPE (exp);
3023 if (TREE_CODE (exp) == BIT_AND_EXPR)
3025 and_mask = TREE_OPERAND (exp, 1);
3026 exp = TREE_OPERAND (exp, 0);
3027 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3028 if (TREE_CODE (and_mask) != INTEGER_CST)
3032 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
3033 punsignedp, pvolatilep);
3034 if ((inner == exp && and_mask == 0)
3035 || *pbitsize < 0 || offset != 0
3036 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
3039 /* If the number of bits in the reference is the same as the bitsize of
3040 the outer type, then the outer type gives the signedness. Otherwise
3041 (in case of a small bitfield) the signedness is unchanged. */
3042 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
3043 *punsignedp = TREE_UNSIGNED (outer_type);
3045 /* Compute the mask to access the bitfield. */
3046 unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
3047 precision = TYPE_PRECISION (unsigned_type);
3049 mask = build_int_2 (~0, ~0);
3050 TREE_TYPE (mask) = unsigned_type;
3051 force_fit_type (mask, 0);
3052 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3053 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3055 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3057 mask = fold (build (BIT_AND_EXPR, unsigned_type,
3058 fold_convert (unsigned_type, and_mask), mask));
3061 *pand_mask = and_mask;
3065 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
3069 all_ones_mask_p (tree mask, int size)
3071 tree type = TREE_TYPE (mask);
3072 unsigned int precision = TYPE_PRECISION (type);
3075 tmask = build_int_2 (~0, ~0);
3076 TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
3077 force_fit_type (tmask, 0);
3079 tree_int_cst_equal (mask,
3080 const_binop (RSHIFT_EXPR,
3081 const_binop (LSHIFT_EXPR, tmask,
3082 size_int (precision - size),
3084 size_int (precision - size), 0));
3087 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3088 represents the sign bit of EXP's type. If EXP represents a sign
3089 or zero extension, also test VAL against the unextended type.
3090 The return value is the (sub)expression whose sign bit is VAL,
3091 or NULL_TREE otherwise. */
3094 sign_bit_p (tree exp, tree val)
3096 unsigned HOST_WIDE_INT mask_lo, lo;
3097 HOST_WIDE_INT mask_hi, hi;
3101 /* Tree EXP must have an integral type. */
3102 t = TREE_TYPE (exp);
3103 if (! INTEGRAL_TYPE_P (t))
3106 /* Tree VAL must be an integer constant. */
3107 if (TREE_CODE (val) != INTEGER_CST
3108 || TREE_CONSTANT_OVERFLOW (val))
3111 width = TYPE_PRECISION (t);
3112 if (width > HOST_BITS_PER_WIDE_INT)
3114 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3117 mask_hi = ((unsigned HOST_WIDE_INT) -1
3118 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3124 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
3127 mask_lo = ((unsigned HOST_WIDE_INT) -1
3128 >> (HOST_BITS_PER_WIDE_INT - width));
3131 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3132 treat VAL as if it were unsigned. */
3133 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3134 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
3137 /* Handle extension from a narrower type. */
3138 if (TREE_CODE (exp) == NOP_EXPR
3139 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3140 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3145 /* Subroutine for fold_truthop: determine if an operand is simple enough
3146 to be evaluated unconditionally. */
3149 simple_operand_p (tree exp)
3151 /* Strip any conversions that don't change the machine mode. */
3152 while ((TREE_CODE (exp) == NOP_EXPR
3153 || TREE_CODE (exp) == CONVERT_EXPR)
3154 && (TYPE_MODE (TREE_TYPE (exp))
3155 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
3156 exp = TREE_OPERAND (exp, 0);
3158 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
3160 && ! TREE_ADDRESSABLE (exp)
3161 && ! TREE_THIS_VOLATILE (exp)
3162 && ! DECL_NONLOCAL (exp)
3163 /* Don't regard global variables as simple. They may be
3164 allocated in ways unknown to the compiler (shared memory,
3165 #pragma weak, etc). */
3166 && ! TREE_PUBLIC (exp)
3167 && ! DECL_EXTERNAL (exp)
3168 /* Loading a static variable is unduly expensive, but global
3169 registers aren't expensive. */
3170 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
3173 /* The following functions are subroutines to fold_range_test and allow it to
3174 try to change a logical combination of comparisons into a range test.
3177 X == 2 || X == 3 || X == 4 || X == 5
3181 (unsigned) (X - 2) <= 3
3183 We describe each set of comparisons as being either inside or outside
3184 a range, using a variable named like IN_P, and then describe the
3185 range with a lower and upper bound. If one of the bounds is omitted,
3186 it represents either the highest or lowest value of the type.
3188 In the comments below, we represent a range by two numbers in brackets
3189 preceded by a "+" to designate being inside that range, or a "-" to
3190 designate being outside that range, so the condition can be inverted by
3191 flipping the prefix. An omitted bound is represented by a "-". For
3192 example, "- [-, 10]" means being outside the range starting at the lowest
3193 possible value and ending at 10, in other words, being greater than 10.
3194 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3197 We set up things so that the missing bounds are handled in a consistent
3198 manner so neither a missing bound nor "true" and "false" need to be
3199 handled using a special case. */
3201 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3202 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3203 and UPPER1_P are nonzero if the respective argument is an upper bound
3204 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3205 must be specified for a comparison. ARG1 will be converted to ARG0's
3206 type if both are specified. */
3209 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3210 tree arg1, int upper1_p)
3216 /* If neither arg represents infinity, do the normal operation.
3217 Else, if not a comparison, return infinity. Else handle the special
3218 comparison rules. Note that most of the cases below won't occur, but
3219 are handled for consistency. */
3221 if (arg0 != 0 && arg1 != 0)
3223 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
3224 arg0, fold_convert (TREE_TYPE (arg0), arg1)));
3226 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3229 if (TREE_CODE_CLASS (code) != '<')
3232 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3233 for neither. In real maths, we cannot assume open ended ranges are
3234 the same. But, this is computer arithmetic, where numbers are finite.
3235 We can therefore make the transformation of any unbounded range with
3236 the value Z, Z being greater than any representable number. This permits
3237 us to treat unbounded ranges as equal. */
3238 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
3239 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
3243 result = sgn0 == sgn1;
3246 result = sgn0 != sgn1;
3249 result = sgn0 < sgn1;
3252 result = sgn0 <= sgn1;
3255 result = sgn0 > sgn1;
3258 result = sgn0 >= sgn1;
3264 return fold_convert (type, result ? integer_one_node : integer_zero_node);
3267 /* Given EXP, a logical expression, set the range it is testing into
3268 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3269 actually being tested. *PLOW and *PHIGH will be made of the same type
3270 as the returned expression. If EXP is not a comparison, we will most
3271 likely not be returning a useful value and range. */
3274 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
3276 enum tree_code code;
3277 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
3278 tree orig_type = NULL_TREE;
3280 tree low, high, n_low, n_high;
3282 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3283 and see if we can refine the range. Some of the cases below may not
3284 happen, but it doesn't seem worth worrying about this. We "continue"
3285 the outer loop when we've changed something; otherwise we "break"
3286 the switch, which will "break" the while. */
3289 low = high = fold_convert (TREE_TYPE (exp), integer_zero_node);
3293 code = TREE_CODE (exp);
3295 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3297 if (first_rtl_op (code) > 0)
3298 arg0 = TREE_OPERAND (exp, 0);
3299 if (TREE_CODE_CLASS (code) == '<'
3300 || TREE_CODE_CLASS (code) == '1'
3301 || TREE_CODE_CLASS (code) == '2')
3302 type = TREE_TYPE (arg0);
3303 if (TREE_CODE_CLASS (code) == '2'
3304 || TREE_CODE_CLASS (code) == '<'
3305 || (TREE_CODE_CLASS (code) == 'e'
3306 && TREE_CODE_LENGTH (code) > 1))
3307 arg1 = TREE_OPERAND (exp, 1);
3310 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3311 lose a cast by accident. */
3312 if (type != NULL_TREE && orig_type == NULL_TREE)
3317 case TRUTH_NOT_EXPR:
3318 in_p = ! in_p, exp = arg0;
3321 case EQ_EXPR: case NE_EXPR:
3322 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3323 /* We can only do something if the range is testing for zero
3324 and if the second operand is an integer constant. Note that
3325 saying something is "in" the range we make is done by
3326 complementing IN_P since it will set in the initial case of
3327 being not equal to zero; "out" is leaving it alone. */
3328 if (low == 0 || high == 0
3329 || ! integer_zerop (low) || ! integer_zerop (high)
3330 || TREE_CODE (arg1) != INTEGER_CST)
3335 case NE_EXPR: /* - [c, c] */
3338 case EQ_EXPR: /* + [c, c] */
3339 in_p = ! in_p, low = high = arg1;
3341 case GT_EXPR: /* - [-, c] */
3342 low = 0, high = arg1;
3344 case GE_EXPR: /* + [c, -] */
3345 in_p = ! in_p, low = arg1, high = 0;
3347 case LT_EXPR: /* - [c, -] */
3348 low = arg1, high = 0;
3350 case LE_EXPR: /* + [-, c] */
3351 in_p = ! in_p, low = 0, high = arg1;
3359 /* If this is an unsigned comparison, we also know that EXP is
3360 greater than or equal to zero. We base the range tests we make
3361 on that fact, so we record it here so we can parse existing
3363 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
3365 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
3366 1, fold_convert (type, integer_zero_node),
3370 in_p = n_in_p, low = n_low, high = n_high;
3372 /* If the high bound is missing, but we have a nonzero low
3373 bound, reverse the range so it goes from zero to the low bound
3375 if (high == 0 && low && ! integer_zerop (low))
3378 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3379 integer_one_node, 0);
3380 low = fold_convert (type, integer_zero_node);
3386 /* (-x) IN [a,b] -> x in [-b, -a] */
3387 n_low = range_binop (MINUS_EXPR, type,
3388 fold_convert (type, integer_zero_node),
3390 n_high = range_binop (MINUS_EXPR, type,
3391 fold_convert (type, integer_zero_node),
3393 low = n_low, high = n_high;
3399 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3400 fold_convert (type, integer_one_node));
3403 case PLUS_EXPR: case MINUS_EXPR:
3404 if (TREE_CODE (arg1) != INTEGER_CST)
3407 /* If EXP is signed, any overflow in the computation is undefined,
3408 so we don't worry about it so long as our computations on
3409 the bounds don't overflow. For unsigned, overflow is defined
3410 and this is exactly the right thing. */
3411 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3412 type, low, 0, arg1, 0);
3413 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3414 type, high, 1, arg1, 0);
3415 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3416 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3419 /* Check for an unsigned range which has wrapped around the maximum
3420 value thus making n_high < n_low, and normalize it. */
3421 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3423 low = range_binop (PLUS_EXPR, type, n_high, 0,
3424 integer_one_node, 0);
3425 high = range_binop (MINUS_EXPR, type, n_low, 0,
3426 integer_one_node, 0);
3428 /* If the range is of the form +/- [ x+1, x ], we won't
3429 be able to normalize it. But then, it represents the
3430 whole range or the empty set, so make it
3432 if (tree_int_cst_equal (n_low, low)
3433 && tree_int_cst_equal (n_high, high))
3439 low = n_low, high = n_high;
3444 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3445 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3448 if (! INTEGRAL_TYPE_P (type)
3449 || (low != 0 && ! int_fits_type_p (low, type))
3450 || (high != 0 && ! int_fits_type_p (high, type)))
3453 n_low = low, n_high = high;
3456 n_low = fold_convert (type, n_low);
3459 n_high = fold_convert (type, n_high);
3461 /* If we're converting from an unsigned to a signed type,
3462 we will be doing the comparison as unsigned. The tests above
3463 have already verified that LOW and HIGH are both positive.
3465 So we have to make sure that the original unsigned value will
3466 be interpreted as positive. */
3467 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3469 tree equiv_type = (*lang_hooks.types.type_for_mode)
3470 (TYPE_MODE (type), 1);
3473 /* A range without an upper bound is, naturally, unbounded.
3474 Since convert would have cropped a very large value, use
3475 the max value for the destination type. */
3477 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3478 : TYPE_MAX_VALUE (type);
3480 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3481 high_positive = fold (build (RSHIFT_EXPR, type,
3485 integer_one_node)));
3487 /* If the low bound is specified, "and" the range with the
3488 range for which the original unsigned value will be
3492 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3493 1, n_low, n_high, 1,
3494 fold_convert (type, integer_zero_node),
3498 in_p = (n_in_p == in_p);
3502 /* Otherwise, "or" the range with the range of the input
3503 that will be interpreted as negative. */
3504 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3505 0, n_low, n_high, 1,
3506 fold_convert (type, integer_zero_node),
3510 in_p = (in_p != n_in_p);
3515 low = n_low, high = n_high;
3525 /* If EXP is a constant, we can evaluate whether this is true or false. */
3526 if (TREE_CODE (exp) == INTEGER_CST)
3528 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3530 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3536 *pin_p = in_p, *plow = low, *phigh = high;
3540 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3541 type, TYPE, return an expression to test if EXP is in (or out of, depending
3542 on IN_P) the range. */
3545 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3547 tree etype = TREE_TYPE (exp);
3551 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3552 return invert_truthvalue (value);
3554 if (low == 0 && high == 0)
3555 return fold_convert (type, integer_one_node);
3558 return fold (build (LE_EXPR, type, exp, high));
3561 return fold (build (GE_EXPR, type, exp, low));
3563 if (operand_equal_p (low, high, 0))
3564 return fold (build (EQ_EXPR, type, exp, low));
3566 if (integer_zerop (low))
3568 if (! TREE_UNSIGNED (etype))
3570 etype = (*lang_hooks.types.unsigned_type) (etype);
3571 high = fold_convert (etype, high);
3572 exp = fold_convert (etype, exp);
3574 return build_range_check (type, exp, 1, 0, high);
3577 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3578 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3580 unsigned HOST_WIDE_INT lo;
3584 prec = TYPE_PRECISION (etype);
3585 if (prec <= HOST_BITS_PER_WIDE_INT)
3588 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3592 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3593 lo = (unsigned HOST_WIDE_INT) -1;
3596 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3598 if (TREE_UNSIGNED (etype))
3600 etype = (*lang_hooks.types.signed_type) (etype);
3601 exp = fold_convert (etype, exp);
3603 return fold (build (GT_EXPR, type, exp,
3604 fold_convert (etype, integer_zero_node)));
3608 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3609 && ! TREE_OVERFLOW (value))
3610 return build_range_check (type,
3611 fold (build (MINUS_EXPR, etype, exp, low)),
3612 1, fold_convert (etype, integer_zero_node),
3618 /* Given two ranges, see if we can merge them into one. Return 1 if we
3619 can, 0 if we can't. Set the output range into the specified parameters. */
3622 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
3623 tree high0, int in1_p, tree low1, tree high1)
3631 int lowequal = ((low0 == 0 && low1 == 0)
3632 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3633 low0, 0, low1, 0)));
3634 int highequal = ((high0 == 0 && high1 == 0)
3635 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3636 high0, 1, high1, 1)));
3638 /* Make range 0 be the range that starts first, or ends last if they
3639 start at the same value. Swap them if it isn't. */
3640 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3643 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3644 high1, 1, high0, 1))))
3646 temp = in0_p, in0_p = in1_p, in1_p = temp;
3647 tem = low0, low0 = low1, low1 = tem;
3648 tem = high0, high0 = high1, high1 = tem;
3651 /* Now flag two cases, whether the ranges are disjoint or whether the
3652 second range is totally subsumed in the first. Note that the tests
3653 below are simplified by the ones above. */
3654 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3655 high0, 1, low1, 0));
3656 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3657 high1, 1, high0, 1));
3659 /* We now have four cases, depending on whether we are including or
3660 excluding the two ranges. */
3663 /* If they don't overlap, the result is false. If the second range
3664 is a subset it is the result. Otherwise, the range is from the start
3665 of the second to the end of the first. */
3667 in_p = 0, low = high = 0;
3669 in_p = 1, low = low1, high = high1;
3671 in_p = 1, low = low1, high = high0;
3674 else if (in0_p && ! in1_p)
3676 /* If they don't overlap, the result is the first range. If they are
3677 equal, the result is false. If the second range is a subset of the
3678 first, and the ranges begin at the same place, we go from just after
3679 the end of the first range to the end of the second. If the second
3680 range is not a subset of the first, or if it is a subset and both
3681 ranges end at the same place, the range starts at the start of the
3682 first range and ends just before the second range.
3683 Otherwise, we can't describe this as a single range. */
3685 in_p = 1, low = low0, high = high0;
3686 else if (lowequal && highequal)
3687 in_p = 0, low = high = 0;
3688 else if (subset && lowequal)
3690 in_p = 1, high = high0;
3691 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3692 integer_one_node, 0);
3694 else if (! subset || highequal)
3696 in_p = 1, low = low0;
3697 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3698 integer_one_node, 0);
3704 else if (! in0_p && in1_p)
3706 /* If they don't overlap, the result is the second range. If the second
3707 is a subset of the first, the result is false. Otherwise,
3708 the range starts just after the first range and ends at the
3709 end of the second. */
3711 in_p = 1, low = low1, high = high1;
3712 else if (subset || highequal)
3713 in_p = 0, low = high = 0;
3716 in_p = 1, high = high1;
3717 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3718 integer_one_node, 0);
3724 /* The case where we are excluding both ranges. Here the complex case
3725 is if they don't overlap. In that case, the only time we have a
3726 range is if they are adjacent. If the second is a subset of the
3727 first, the result is the first. Otherwise, the range to exclude
3728 starts at the beginning of the first range and ends at the end of the
3732 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3733 range_binop (PLUS_EXPR, NULL_TREE,
3735 integer_one_node, 1),
3737 in_p = 0, low = low0, high = high1;
3742 in_p = 0, low = low0, high = high0;
3744 in_p = 0, low = low0, high = high1;
3747 *pin_p = in_p, *plow = low, *phigh = high;
3751 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3752 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3755 /* EXP is some logical combination of boolean tests. See if we can
3756 merge it into some range test. Return the new tree if so. */
3759 fold_range_test (tree exp)
3761 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3762 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3763 int in0_p, in1_p, in_p;
3764 tree low0, low1, low, high0, high1, high;
3765 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3766 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3769 /* If this is an OR operation, invert both sides; we will invert
3770 again at the end. */
3772 in0_p = ! in0_p, in1_p = ! in1_p;
3774 /* If both expressions are the same, if we can merge the ranges, and we
3775 can build the range test, return it or it inverted. If one of the
3776 ranges is always true or always false, consider it to be the same
3777 expression as the other. */
3778 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3779 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3781 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3783 : rhs != 0 ? rhs : integer_zero_node,
3785 return or_op ? invert_truthvalue (tem) : tem;
3787 /* On machines where the branch cost is expensive, if this is a
3788 short-circuited branch and the underlying object on both sides
3789 is the same, make a non-short-circuit operation. */
3790 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3791 && lhs != 0 && rhs != 0
3792 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3793 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3794 && operand_equal_p (lhs, rhs, 0))
3796 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3797 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3798 which cases we can't do this. */
3799 if (simple_operand_p (lhs))
3800 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3801 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3802 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3803 TREE_OPERAND (exp, 1));
3805 else if ((*lang_hooks.decls.global_bindings_p) () == 0
3806 && ! CONTAINS_PLACEHOLDER_P (lhs))
3808 tree common = save_expr (lhs);
3810 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3811 or_op ? ! in0_p : in0_p,
3813 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3814 or_op ? ! in1_p : in1_p,
3816 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3817 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3818 TREE_TYPE (exp), lhs, rhs);
3825 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3826 bit value. Arrange things so the extra bits will be set to zero if and
3827 only if C is signed-extended to its full width. If MASK is nonzero,
3828 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3831 unextend (tree c, int p, int unsignedp, tree mask)
3833 tree type = TREE_TYPE (c);
3834 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3837 if (p == modesize || unsignedp)
3840 /* We work by getting just the sign bit into the low-order bit, then
3841 into the high-order bit, then sign-extend. We then XOR that value
3843 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3844 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3846 /* We must use a signed type in order to get an arithmetic right shift.
3847 However, we must also avoid introducing accidental overflows, so that
3848 a subsequent call to integer_zerop will work. Hence we must
3849 do the type conversion here. At this point, the constant is either
3850 zero or one, and the conversion to a signed type can never overflow.
3851 We could get an overflow if this conversion is done anywhere else. */
3852 if (TREE_UNSIGNED (type))
3853 temp = fold_convert ((*lang_hooks.types.signed_type) (type), temp);
3855 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3856 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3858 temp = const_binop (BIT_AND_EXPR, temp,
3859 fold_convert (TREE_TYPE (c), mask), 0);
3860 /* If necessary, convert the type back to match the type of C. */
3861 if (TREE_UNSIGNED (type))
3862 temp = fold_convert (type, temp);
3864 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3867 /* Find ways of folding logical expressions of LHS and RHS:
3868 Try to merge two comparisons to the same innermost item.
3869 Look for range tests like "ch >= '0' && ch <= '9'".
3870 Look for combinations of simple terms on machines with expensive branches
3871 and evaluate the RHS unconditionally.
3873 For example, if we have p->a == 2 && p->b == 4 and we can make an
3874 object large enough to span both A and B, we can do this with a comparison
3875 against the object ANDed with the a mask.
3877 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3878 operations to do this with one comparison.
3880 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3881 function and the one above.
3883 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3884 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3886 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3889 We return the simplified tree or 0 if no optimization is possible. */
3892 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
3894 /* If this is the "or" of two comparisons, we can do something if
3895 the comparisons are NE_EXPR. If this is the "and", we can do something
3896 if the comparisons are EQ_EXPR. I.e.,
3897 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3899 WANTED_CODE is this operation code. For single bit fields, we can
3900 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3901 comparison for one-bit fields. */
3903 enum tree_code wanted_code;
3904 enum tree_code lcode, rcode;
3905 tree ll_arg, lr_arg, rl_arg, rr_arg;
3906 tree ll_inner, lr_inner, rl_inner, rr_inner;
3907 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3908 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3909 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3910 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3911 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3912 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3913 enum machine_mode lnmode, rnmode;
3914 tree ll_mask, lr_mask, rl_mask, rr_mask;
3915 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3916 tree l_const, r_const;
3917 tree lntype, rntype, result;
3918 int first_bit, end_bit;
3921 /* Start by getting the comparison codes. Fail if anything is volatile.
3922 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3923 it were surrounded with a NE_EXPR. */
3925 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3928 lcode = TREE_CODE (lhs);
3929 rcode = TREE_CODE (rhs);
3931 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3932 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3934 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3935 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3937 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3940 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3941 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3943 ll_arg = TREE_OPERAND (lhs, 0);
3944 lr_arg = TREE_OPERAND (lhs, 1);
3945 rl_arg = TREE_OPERAND (rhs, 0);
3946 rr_arg = TREE_OPERAND (rhs, 1);
3948 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3949 if (simple_operand_p (ll_arg)
3950 && simple_operand_p (lr_arg)
3951 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3955 if (operand_equal_p (ll_arg, rl_arg, 0)
3956 && operand_equal_p (lr_arg, rr_arg, 0))
3958 int lcompcode, rcompcode;
3960 lcompcode = comparison_to_compcode (lcode);
3961 rcompcode = comparison_to_compcode (rcode);
3962 compcode = (code == TRUTH_AND_EXPR)
3963 ? lcompcode & rcompcode
3964 : lcompcode | rcompcode;
3966 else if (operand_equal_p (ll_arg, rr_arg, 0)
3967 && operand_equal_p (lr_arg, rl_arg, 0))
3969 int lcompcode, rcompcode;
3971 rcode = swap_tree_comparison (rcode);
3972 lcompcode = comparison_to_compcode (lcode);
3973 rcompcode = comparison_to_compcode (rcode);
3974 compcode = (code == TRUTH_AND_EXPR)
3975 ? lcompcode & rcompcode
3976 : lcompcode | rcompcode;
3981 if (compcode == COMPCODE_TRUE)
3982 return fold_convert (truth_type, integer_one_node);
3983 else if (compcode == COMPCODE_FALSE)
3984 return fold_convert (truth_type, integer_zero_node);
3985 else if (compcode != -1)
3986 return build (compcode_to_comparison (compcode),
3987 truth_type, ll_arg, lr_arg);
3990 /* If the RHS can be evaluated unconditionally and its operands are
3991 simple, it wins to evaluate the RHS unconditionally on machines
3992 with expensive branches. In this case, this isn't a comparison
3993 that can be merged. Avoid doing this if the RHS is a floating-point
3994 comparison since those can trap. */
3996 if (BRANCH_COST >= 2
3997 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3998 && simple_operand_p (rl_arg)
3999 && simple_operand_p (rr_arg))
4001 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4002 if (code == TRUTH_OR_EXPR
4003 && lcode == NE_EXPR && integer_zerop (lr_arg)
4004 && rcode == NE_EXPR && integer_zerop (rr_arg)
4005 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4006 return build (NE_EXPR, truth_type,
4007 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4011 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4012 if (code == TRUTH_AND_EXPR
4013 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4014 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4015 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
4016 return build (EQ_EXPR, truth_type,
4017 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4021 return build (code, truth_type, lhs, rhs);
4024 /* See if the comparisons can be merged. Then get all the parameters for
4027 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
4028 || (rcode != EQ_EXPR && rcode != NE_EXPR))
4032 ll_inner = decode_field_reference (ll_arg,
4033 &ll_bitsize, &ll_bitpos, &ll_mode,
4034 &ll_unsignedp, &volatilep, &ll_mask,
4036 lr_inner = decode_field_reference (lr_arg,
4037 &lr_bitsize, &lr_bitpos, &lr_mode,
4038 &lr_unsignedp, &volatilep, &lr_mask,
4040 rl_inner = decode_field_reference (rl_arg,
4041 &rl_bitsize, &rl_bitpos, &rl_mode,
4042 &rl_unsignedp, &volatilep, &rl_mask,
4044 rr_inner = decode_field_reference (rr_arg,
4045 &rr_bitsize, &rr_bitpos, &rr_mode,
4046 &rr_unsignedp, &volatilep, &rr_mask,
4049 /* It must be true that the inner operation on the lhs of each
4050 comparison must be the same if we are to be able to do anything.
4051 Then see if we have constants. If not, the same must be true for
4053 if (volatilep || ll_inner == 0 || rl_inner == 0
4054 || ! operand_equal_p (ll_inner, rl_inner, 0))
4057 if (TREE_CODE (lr_arg) == INTEGER_CST
4058 && TREE_CODE (rr_arg) == INTEGER_CST)
4059 l_const = lr_arg, r_const = rr_arg;
4060 else if (lr_inner == 0 || rr_inner == 0
4061 || ! operand_equal_p (lr_inner, rr_inner, 0))
4064 l_const = r_const = 0;
4066 /* If either comparison code is not correct for our logical operation,
4067 fail. However, we can convert a one-bit comparison against zero into
4068 the opposite comparison against that bit being set in the field. */
4070 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
4071 if (lcode != wanted_code)
4073 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
4075 /* Make the left operand unsigned, since we are only interested
4076 in the value of one bit. Otherwise we are doing the wrong
4085 /* This is analogous to the code for l_const above. */
4086 if (rcode != wanted_code)
4088 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
4097 /* After this point all optimizations will generate bit-field
4098 references, which we might not want. */
4099 if (! (*lang_hooks.can_use_bit_fields_p) ())
4102 /* See if we can find a mode that contains both fields being compared on
4103 the left. If we can't, fail. Otherwise, update all constants and masks
4104 to be relative to a field of that size. */
4105 first_bit = MIN (ll_bitpos, rl_bitpos);
4106 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
4107 lnmode = get_best_mode (end_bit - first_bit, first_bit,
4108 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
4110 if (lnmode == VOIDmode)
4113 lnbitsize = GET_MODE_BITSIZE (lnmode);
4114 lnbitpos = first_bit & ~ (lnbitsize - 1);
4115 lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
4116 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
4118 if (BYTES_BIG_ENDIAN)
4120 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
4121 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
4124 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
4125 size_int (xll_bitpos), 0);
4126 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
4127 size_int (xrl_bitpos), 0);
4131 l_const = fold_convert (lntype, l_const);
4132 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
4133 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
4134 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
4135 fold (build1 (BIT_NOT_EXPR,
4139 warning ("comparison is always %d", wanted_code == NE_EXPR);
4141 return fold_convert (truth_type,
4142 wanted_code == NE_EXPR
4143 ? integer_one_node : integer_zero_node);
4148 r_const = fold_convert (lntype, r_const);
4149 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
4150 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
4151 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
4152 fold (build1 (BIT_NOT_EXPR,
4156 warning ("comparison is always %d", wanted_code == NE_EXPR);
4158 return fold_convert (truth_type,
4159 wanted_code == NE_EXPR
4160 ? integer_one_node : integer_zero_node);
4164 /* If the right sides are not constant, do the same for it. Also,
4165 disallow this optimization if a size or signedness mismatch occurs
4166 between the left and right sides. */
4169 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
4170 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
4171 /* Make sure the two fields on the right
4172 correspond to the left without being swapped. */
4173 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
4176 first_bit = MIN (lr_bitpos, rr_bitpos);
4177 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
4178 rnmode = get_best_mode (end_bit - first_bit, first_bit,
4179 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
4181 if (rnmode == VOIDmode)
4184 rnbitsize = GET_MODE_BITSIZE (rnmode);
4185 rnbitpos = first_bit & ~ (rnbitsize - 1);
4186 rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
4187 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
4189 if (BYTES_BIG_ENDIAN)
4191 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
4192 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
4195 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
4196 size_int (xlr_bitpos), 0);
4197 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
4198 size_int (xrr_bitpos), 0);
4200 /* Make a mask that corresponds to both fields being compared.
4201 Do this for both items being compared. If the operands are the
4202 same size and the bits being compared are in the same position
4203 then we can do this by masking both and comparing the masked
4205 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4206 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
4207 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
4209 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4210 ll_unsignedp || rl_unsignedp);
4211 if (! all_ones_mask_p (ll_mask, lnbitsize))
4212 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
4214 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
4215 lr_unsignedp || rr_unsignedp);
4216 if (! all_ones_mask_p (lr_mask, rnbitsize))
4217 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
4219 return build (wanted_code, truth_type, lhs, rhs);
4222 /* There is still another way we can do something: If both pairs of
4223 fields being compared are adjacent, we may be able to make a wider
4224 field containing them both.
4226 Note that we still must mask the lhs/rhs expressions. Furthermore,
4227 the mask must be shifted to account for the shift done by
4228 make_bit_field_ref. */
4229 if ((ll_bitsize + ll_bitpos == rl_bitpos
4230 && lr_bitsize + lr_bitpos == rr_bitpos)
4231 || (ll_bitpos == rl_bitpos + rl_bitsize
4232 && lr_bitpos == rr_bitpos + rr_bitsize))
4236 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4237 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
4238 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
4239 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
4241 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
4242 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
4243 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
4244 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
4246 /* Convert to the smaller type before masking out unwanted bits. */
4248 if (lntype != rntype)
4250 if (lnbitsize > rnbitsize)
4252 lhs = fold_convert (rntype, lhs);
4253 ll_mask = fold_convert (rntype, ll_mask);
4256 else if (lnbitsize < rnbitsize)
4258 rhs = fold_convert (lntype, rhs);
4259 lr_mask = fold_convert (lntype, lr_mask);
4264 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
4265 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
4267 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
4268 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
4270 return build (wanted_code, truth_type, lhs, rhs);
4276 /* Handle the case of comparisons with constants. If there is something in
4277 common between the masks, those bits of the constants must be the same.
4278 If not, the condition is always false. Test for this to avoid generating
4279 incorrect code below. */
4280 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
4281 if (! integer_zerop (result)
4282 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
4283 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
4285 if (wanted_code == NE_EXPR)
4287 warning ("`or' of unmatched not-equal tests is always 1");
4288 return fold_convert (truth_type, integer_one_node);
4292 warning ("`and' of mutually exclusive equal-tests is always 0");
4293 return fold_convert (truth_type, integer_zero_node);
4297 /* Construct the expression we will return. First get the component
4298 reference we will make. Unless the mask is all ones the width of
4299 that field, perform the mask operation. Then compare with the
4301 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
4302 ll_unsignedp || rl_unsignedp);
4304 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
4305 if (! all_ones_mask_p (ll_mask, lnbitsize))
4306 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
4308 return build (wanted_code, truth_type, result,
4309 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
4312 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4316 optimize_minmax_comparison (tree t)
4318 tree type = TREE_TYPE (t);
4319 tree arg0 = TREE_OPERAND (t, 0);
4320 enum tree_code op_code;
4321 tree comp_const = TREE_OPERAND (t, 1);
4323 int consts_equal, consts_lt;
4326 STRIP_SIGN_NOPS (arg0);
4328 op_code = TREE_CODE (arg0);
4329 minmax_const = TREE_OPERAND (arg0, 1);
4330 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
4331 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
4332 inner = TREE_OPERAND (arg0, 0);
4334 /* If something does not permit us to optimize, return the original tree. */
4335 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
4336 || TREE_CODE (comp_const) != INTEGER_CST
4337 || TREE_CONSTANT_OVERFLOW (comp_const)
4338 || TREE_CODE (minmax_const) != INTEGER_CST
4339 || TREE_CONSTANT_OVERFLOW (minmax_const))
4342 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4343 and GT_EXPR, doing the rest with recursive calls using logical
4345 switch (TREE_CODE (t))
4347 case NE_EXPR: case LT_EXPR: case LE_EXPR:
4349 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
4353 fold (build (TRUTH_ORIF_EXPR, type,
4354 optimize_minmax_comparison
4355 (build (EQ_EXPR, type, arg0, comp_const)),
4356 optimize_minmax_comparison
4357 (build (GT_EXPR, type, arg0, comp_const))));
4360 if (op_code == MAX_EXPR && consts_equal)
4361 /* MAX (X, 0) == 0 -> X <= 0 */
4362 return fold (build (LE_EXPR, type, inner, comp_const));
4364 else if (op_code == MAX_EXPR && consts_lt)
4365 /* MAX (X, 0) == 5 -> X == 5 */
4366 return fold (build (EQ_EXPR, type, inner, comp_const));
4368 else if (op_code == MAX_EXPR)
4369 /* MAX (X, 0) == -1 -> false */
4370 return omit_one_operand (type, integer_zero_node, inner);
4372 else if (consts_equal)
4373 /* MIN (X, 0) == 0 -> X >= 0 */
4374 return fold (build (GE_EXPR, type, inner, comp_const));
4377 /* MIN (X, 0) == 5 -> false */
4378 return omit_one_operand (type, integer_zero_node, inner);
4381 /* MIN (X, 0) == -1 -> X == -1 */
4382 return fold (build (EQ_EXPR, type, inner, comp_const));
4385 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
4386 /* MAX (X, 0) > 0 -> X > 0
4387 MAX (X, 0) > 5 -> X > 5 */
4388 return fold (build (GT_EXPR, type, inner, comp_const));
4390 else if (op_code == MAX_EXPR)
4391 /* MAX (X, 0) > -1 -> true */
4392 return omit_one_operand (type, integer_one_node, inner);
4394 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4395 /* MIN (X, 0) > 0 -> false
4396 MIN (X, 0) > 5 -> false */
4397 return omit_one_operand (type, integer_zero_node, inner);
4400 /* MIN (X, 0) > -1 -> X > -1 */
4401 return fold (build (GT_EXPR, type, inner, comp_const));
4408 /* T is an integer expression that is being multiplied, divided, or taken a
4409 modulus (CODE says which and what kind of divide or modulus) by a
4410 constant C. See if we can eliminate that operation by folding it with
4411 other operations already in T. WIDE_TYPE, if non-null, is a type that
4412 should be used for the computation if wider than our type.
4414 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4415 (X * 2) + (Y * 4). We must, however, be assured that either the original
4416 expression would not overflow or that overflow is undefined for the type
4417 in the language in question.
4419 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4420 the machine has a multiply-accumulate insn or that this is part of an
4421 addressing calculation.
4423 If we return a non-null expression, it is an equivalent form of the
4424 original computation, but need not be in the original type. */
4427 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
4429 /* To avoid exponential search depth, refuse to allow recursion past
4430 three levels. Beyond that (1) it's highly unlikely that we'll find
4431 something interesting and (2) we've probably processed it before
4432 when we built the inner expression. */
4441 ret = extract_muldiv_1 (t, c, code, wide_type);
4448 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
4450 tree type = TREE_TYPE (t);
4451 enum tree_code tcode = TREE_CODE (t);
4452 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4453 > GET_MODE_SIZE (TYPE_MODE (type)))
4454 ? wide_type : type);
4456 int same_p = tcode == code;
4457 tree op0 = NULL_TREE, op1 = NULL_TREE;
4459 /* Don't deal with constants of zero here; they confuse the code below. */
4460 if (integer_zerop (c))
4463 if (TREE_CODE_CLASS (tcode) == '1')
4464 op0 = TREE_OPERAND (t, 0);
4466 if (TREE_CODE_CLASS (tcode) == '2')
4467 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4469 /* Note that we need not handle conditional operations here since fold
4470 already handles those cases. So just do arithmetic here. */
4474 /* For a constant, we can always simplify if we are a multiply
4475 or (for divide and modulus) if it is a multiple of our constant. */
4476 if (code == MULT_EXPR
4477 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4478 return const_binop (code, fold_convert (ctype, t),
4479 fold_convert (ctype, c), 0);
4482 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4483 /* If op0 is an expression ... */
4484 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4485 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4486 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4487 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4488 /* ... and is unsigned, and its type is smaller than ctype,
4489 then we cannot pass through as widening. */
4490 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4491 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4492 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4493 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4494 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4495 /* ... or its type is larger than ctype,
4496 then we cannot pass through this truncation. */
4497 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4498 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4499 /* ... or signedness changes for division or modulus,
4500 then we cannot pass through this conversion. */
4501 || (code != MULT_EXPR
4502 && (TREE_UNSIGNED (ctype)
4503 != TREE_UNSIGNED (TREE_TYPE (op0))))))
4506 /* Pass the constant down and see if we can make a simplification. If
4507 we can, replace this expression with the inner simplification for
4508 possible later conversion to our or some other type. */
4509 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
4510 && TREE_CODE (t2) == INTEGER_CST
4511 && ! TREE_CONSTANT_OVERFLOW (t2)
4512 && (0 != (t1 = extract_muldiv (op0, t2, code,
4514 ? ctype : NULL_TREE))))
4518 case NEGATE_EXPR: case ABS_EXPR:
4519 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4520 return fold (build1 (tcode, ctype, fold_convert (ctype, t1)));
4523 case MIN_EXPR: case MAX_EXPR:
4524 /* If widening the type changes the signedness, then we can't perform
4525 this optimization as that changes the result. */
4526 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4529 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4530 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4531 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4533 if (tree_int_cst_sgn (c) < 0)
4534 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4536 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4537 fold_convert (ctype, t2)));
4541 case WITH_RECORD_EXPR:
4542 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4543 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4544 TREE_OPERAND (t, 1));
4547 case LSHIFT_EXPR: case RSHIFT_EXPR:
4548 /* If the second operand is constant, this is a multiplication
4549 or floor division, by a power of two, so we can treat it that
4550 way unless the multiplier or divisor overflows. */
4551 if (TREE_CODE (op1) == INTEGER_CST
4552 /* const_binop may not detect overflow correctly,
4553 so check for it explicitly here. */
4554 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4555 && TREE_INT_CST_HIGH (op1) == 0
4556 && 0 != (t1 = fold_convert (ctype,
4557 const_binop (LSHIFT_EXPR,
4560 && ! TREE_OVERFLOW (t1))
4561 return extract_muldiv (build (tcode == LSHIFT_EXPR
4562 ? MULT_EXPR : FLOOR_DIV_EXPR,
4563 ctype, fold_convert (ctype, op0), t1),
4564 c, code, wide_type);
4567 case PLUS_EXPR: case MINUS_EXPR:
4568 /* See if we can eliminate the operation on both sides. If we can, we
4569 can return a new PLUS or MINUS. If we can't, the only remaining
4570 cases where we can do anything are if the second operand is a
4572 t1 = extract_muldiv (op0, c, code, wide_type);
4573 t2 = extract_muldiv (op1, c, code, wide_type);
4574 if (t1 != 0 && t2 != 0
4575 && (code == MULT_EXPR
4576 /* If not multiplication, we can only do this if both operands
4577 are divisible by c. */
4578 || (multiple_of_p (ctype, op0, c)
4579 && multiple_of_p (ctype, op1, c))))
4580 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4581 fold_convert (ctype, t2)));
4583 /* If this was a subtraction, negate OP1 and set it to be an addition.
4584 This simplifies the logic below. */
4585 if (tcode == MINUS_EXPR)
4586 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4588 if (TREE_CODE (op1) != INTEGER_CST)
4591 /* If either OP1 or C are negative, this optimization is not safe for
4592 some of the division and remainder types while for others we need
4593 to change the code. */
4594 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4596 if (code == CEIL_DIV_EXPR)
4597 code = FLOOR_DIV_EXPR;
4598 else if (code == FLOOR_DIV_EXPR)
4599 code = CEIL_DIV_EXPR;
4600 else if (code != MULT_EXPR
4601 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4605 /* If it's a multiply or a division/modulus operation of a multiple
4606 of our constant, do the operation and verify it doesn't overflow. */
4607 if (code == MULT_EXPR
4608 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4610 op1 = const_binop (code, fold_convert (ctype, op1),
4611 fold_convert (ctype, c), 0);
4612 /* We allow the constant to overflow with wrapping semantics. */
4614 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
4620 /* If we have an unsigned type is not a sizetype, we cannot widen
4621 the operation since it will change the result if the original
4622 computation overflowed. */
4623 if (TREE_UNSIGNED (ctype)
4624 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4628 /* If we were able to eliminate our operation from the first side,
4629 apply our operation to the second side and reform the PLUS. */
4630 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4631 return fold (build (tcode, ctype, fold_convert (ctype, t1), op1));
4633 /* The last case is if we are a multiply. In that case, we can
4634 apply the distributive law to commute the multiply and addition
4635 if the multiplication of the constants doesn't overflow. */
4636 if (code == MULT_EXPR)
4637 return fold (build (tcode, ctype,
4638 fold (build (code, ctype,
4639 fold_convert (ctype, op0),
4640 fold_convert (ctype, c))),
4646 /* We have a special case here if we are doing something like
4647 (C * 8) % 4 since we know that's zero. */
4648 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4649 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4650 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4651 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4652 return omit_one_operand (type, integer_zero_node, op0);
4654 /* ... fall through ... */
4656 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4657 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4658 /* If we can extract our operation from the LHS, do so and return a
4659 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4660 do something only if the second operand is a constant. */
4662 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4663 return fold (build (tcode, ctype, fold_convert (ctype, t1),
4664 fold_convert (ctype, op1)));
4665 else if (tcode == MULT_EXPR && code == MULT_EXPR
4666 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4667 return fold (build (tcode, ctype, fold_convert (ctype, op0),
4668 fold_convert (ctype, t1)));
4669 else if (TREE_CODE (op1) != INTEGER_CST)
4672 /* If these are the same operation types, we can associate them
4673 assuming no overflow. */
4675 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
4676 fold_convert (ctype, c), 0))
4677 && ! TREE_OVERFLOW (t1))
4678 return fold (build (tcode, ctype, fold_convert (ctype, op0), t1));
4680 /* If these operations "cancel" each other, we have the main
4681 optimizations of this pass, which occur when either constant is a
4682 multiple of the other, in which case we replace this with either an
4683 operation or CODE or TCODE.
4685 If we have an unsigned type that is not a sizetype, we cannot do
4686 this since it will change the result if the original computation
4688 if ((! TREE_UNSIGNED (ctype)
4689 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4691 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4692 || (tcode == MULT_EXPR
4693 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4694 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4696 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4697 return fold (build (tcode, ctype, fold_convert (ctype, op0),
4698 fold_convert (ctype,
4699 const_binop (TRUNC_DIV_EXPR,
4701 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4702 return fold (build (code, ctype, fold_convert (ctype, op0),
4703 fold_convert (ctype,
4704 const_binop (TRUNC_DIV_EXPR,
4716 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4717 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4718 that we may sometimes modify the tree. */
4721 strip_compound_expr (tree t, tree s)
4723 enum tree_code code = TREE_CODE (t);
4725 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4726 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4727 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4728 return TREE_OPERAND (t, 1);
4730 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4731 don't bother handling any other types. */
4732 else if (code == COND_EXPR)
4734 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4735 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4736 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4738 else if (TREE_CODE_CLASS (code) == '1')
4739 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4740 else if (TREE_CODE_CLASS (code) == '<'
4741 || TREE_CODE_CLASS (code) == '2')
4743 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4744 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4750 /* Return a node which has the indicated constant VALUE (either 0 or
4751 1), and is of the indicated TYPE. */
4754 constant_boolean_node (int value, tree type)
4756 if (type == integer_type_node)
4757 return value ? integer_one_node : integer_zero_node;
4758 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4759 return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
4763 tree t = build_int_2 (value, 0);
4765 TREE_TYPE (t) = type;
4770 /* Utility function for the following routine, to see how complex a nesting of
4771 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4772 we don't care (to avoid spending too much time on complex expressions.). */
4775 count_cond (tree expr, int lim)
4779 if (TREE_CODE (expr) != COND_EXPR)
4784 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4785 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4786 return MIN (lim, 1 + ctrue + cfalse);
4789 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4790 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4791 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4792 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4793 COND is the first argument to CODE; otherwise (as in the example
4794 given here), it is the second argument. TYPE is the type of the
4795 original expression. */
4798 fold_binary_op_with_conditional_arg (enum tree_code code, tree type,
4799 tree cond, tree arg, int cond_first_p)
4801 tree test, true_value, false_value;
4802 tree lhs = NULL_TREE;
4803 tree rhs = NULL_TREE;
4804 /* In the end, we'll produce a COND_EXPR. Both arms of the
4805 conditional expression will be binary operations. The left-hand
4806 side of the expression to be executed if the condition is true
4807 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4808 of the expression to be executed if the condition is true will be
4809 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4810 but apply to the expression to be executed if the conditional is
4816 /* These are the codes to use for the left-hand side and right-hand
4817 side of the COND_EXPR. Normally, they are the same as CODE. */
4818 enum tree_code lhs_code = code;
4819 enum tree_code rhs_code = code;
4820 /* And these are the types of the expressions. */
4821 tree lhs_type = type;
4822 tree rhs_type = type;
4827 true_rhs = false_rhs = &arg;
4828 true_lhs = &true_value;
4829 false_lhs = &false_value;
4833 true_lhs = false_lhs = &arg;
4834 true_rhs = &true_value;
4835 false_rhs = &false_value;
4838 if (TREE_CODE (cond) == COND_EXPR)
4840 test = TREE_OPERAND (cond, 0);
4841 true_value = TREE_OPERAND (cond, 1);
4842 false_value = TREE_OPERAND (cond, 2);
4843 /* If this operand throws an expression, then it does not make
4844 sense to try to perform a logical or arithmetic operation
4845 involving it. Instead of building `a + throw 3' for example,
4846 we simply build `a, throw 3'. */
4847 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4851 lhs_code = COMPOUND_EXPR;
4852 lhs_type = void_type_node;
4857 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4861 rhs_code = COMPOUND_EXPR;
4862 rhs_type = void_type_node;
4870 tree testtype = TREE_TYPE (cond);
4872 true_value = fold_convert (testtype, integer_one_node);
4873 false_value = fold_convert (testtype, integer_zero_node);
4876 /* If ARG is complex we want to make sure we only evaluate it once. Though
4877 this is only required if it is volatile, it might be more efficient even
4878 if it is not. However, if we succeed in folding one part to a constant,
4879 we do not need to make this SAVE_EXPR. Since we do this optimization
4880 primarily to see if we do end up with constant and this SAVE_EXPR
4881 interferes with later optimizations, suppressing it when we can is
4884 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4885 do so. Don't try to see if the result is a constant if an arm is a
4886 COND_EXPR since we get exponential behavior in that case. */
4888 if (saved_expr_p (arg))
4890 else if (lhs == 0 && rhs == 0
4891 && !TREE_CONSTANT (arg)
4892 && (*lang_hooks.decls.global_bindings_p) () == 0
4893 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4894 || TREE_SIDE_EFFECTS (arg)))
4896 if (TREE_CODE (true_value) != COND_EXPR)
4897 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4899 if (TREE_CODE (false_value) != COND_EXPR)
4900 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4902 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4903 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4905 arg = save_expr (arg);
4907 save = saved_expr_p (arg);
4912 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4914 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4916 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4918 /* If ARG involves a SAVE_EXPR, we need to ensure it is evaluated
4919 ahead of the COND_EXPR we made. Otherwise we would have it only
4920 evaluated in one branch, with the other branch using the result
4921 but missing the evaluation code. Beware that the save_expr call
4922 above might not return a SAVE_EXPR, so testing the TREE_CODE
4923 of ARG is not enough to decide here. Â */
4925 return build (COMPOUND_EXPR, type,
4926 fold_convert (void_type_node, arg),
4927 strip_compound_expr (test, arg));
4929 return fold_convert (type, test);
4933 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4935 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4936 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4937 ADDEND is the same as X.
4939 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4940 and finite. The problematic cases are when X is zero, and its mode
4941 has signed zeros. In the case of rounding towards -infinity,
4942 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4943 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4946 fold_real_zero_addition_p (tree type, tree addend, int negate)
4948 if (!real_zerop (addend))
4951 /* Don't allow the fold with -fsignaling-nans. */
4952 if (HONOR_SNANS (TYPE_MODE (type)))
4955 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4956 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4959 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4960 if (TREE_CODE (addend) == REAL_CST
4961 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4964 /* The mode has signed zeros, and we have to honor their sign.
4965 In this situation, there is only one case we can return true for.
4966 X - 0 is the same as X unless rounding towards -infinity is
4968 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4971 /* Subroutine of fold() that checks comparisons of built-in math
4972 functions against real constants.
4974 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4975 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4976 is the type of the result and ARG0 and ARG1 are the operands of the
4977 comparison. ARG1 must be a TREE_REAL_CST.
4979 The function returns the constant folded tree if a simplification
4980 can be made, and NULL_TREE otherwise. */
4983 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
4984 tree type, tree arg0, tree arg1)
4988 if (fcode == BUILT_IN_SQRT
4989 || fcode == BUILT_IN_SQRTF
4990 || fcode == BUILT_IN_SQRTL)
4992 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
4993 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
4995 c = TREE_REAL_CST (arg1);
4996 if (REAL_VALUE_NEGATIVE (c))
4998 /* sqrt(x) < y is always false, if y is negative. */
4999 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
5000 return omit_one_operand (type,
5001 fold_convert (type, integer_zero_node),
5004 /* sqrt(x) > y is always true, if y is negative and we
5005 don't care about NaNs, i.e. negative values of x. */
5006 if (code == NE_EXPR || !HONOR_NANS (mode))
5007 return omit_one_operand (type,
5008 fold_convert (type, integer_one_node),
5011 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
5012 return fold (build (GE_EXPR, type, arg,
5013 build_real (TREE_TYPE (arg), dconst0)));
5015 else if (code == GT_EXPR || code == GE_EXPR)
5019 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5020 real_convert (&c2, mode, &c2);
5022 if (REAL_VALUE_ISINF (c2))
5024 /* sqrt(x) > y is x == +Inf, when y is very large. */
5025 if (HONOR_INFINITIES (mode))
5026 return fold (build (EQ_EXPR, type, arg,
5027 build_real (TREE_TYPE (arg), c2)));
5029 /* sqrt(x) > y is always false, when y is very large
5030 and we don't care about infinities. */
5031 return omit_one_operand (type,
5032 fold_convert (type, integer_zero_node),
5036 /* sqrt(x) > c is the same as x > c*c. */
5037 return fold (build (code, type, arg,
5038 build_real (TREE_TYPE (arg), c2)));
5040 else if (code == LT_EXPR || code == LE_EXPR)
5044 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5045 real_convert (&c2, mode, &c2);
5047 if (REAL_VALUE_ISINF (c2))
5049 /* sqrt(x) < y is always true, when y is a very large
5050 value and we don't care about NaNs or Infinities. */
5051 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
5052 return omit_one_operand (type,
5053 fold_convert (type, integer_one_node),
5056 /* sqrt(x) < y is x != +Inf when y is very large and we
5057 don't care about NaNs. */
5058 if (! HONOR_NANS (mode))
5059 return fold (build (NE_EXPR, type, arg,
5060 build_real (TREE_TYPE (arg), c2)));
5062 /* sqrt(x) < y is x >= 0 when y is very large and we
5063 don't care about Infinities. */
5064 if (! HONOR_INFINITIES (mode))
5065 return fold (build (GE_EXPR, type, arg,
5066 build_real (TREE_TYPE (arg), dconst0)));
5068 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
5069 if ((*lang_hooks.decls.global_bindings_p) () != 0
5070 || CONTAINS_PLACEHOLDER_P (arg))
5073 arg = save_expr (arg);
5074 return fold (build (TRUTH_ANDIF_EXPR, type,
5075 fold (build (GE_EXPR, type, arg,
5076 build_real (TREE_TYPE (arg),
5078 fold (build (NE_EXPR, type, arg,
5079 build_real (TREE_TYPE (arg),
5083 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5084 if (! HONOR_NANS (mode))
5085 return fold (build (code, type, arg,
5086 build_real (TREE_TYPE (arg), c2)));
5088 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
5089 if ((*lang_hooks.decls.global_bindings_p) () == 0
5090 && ! CONTAINS_PLACEHOLDER_P (arg))
5092 arg = save_expr (arg);
5093 return fold (build (TRUTH_ANDIF_EXPR, type,
5094 fold (build (GE_EXPR, type, arg,
5095 build_real (TREE_TYPE (arg),
5097 fold (build (code, type, arg,
5098 build_real (TREE_TYPE (arg),
5107 /* Subroutine of fold() that optimizes comparisons against Infinities,
5108 either +Inf or -Inf.
5110 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5111 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
5112 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
5114 The function returns the constant folded tree if a simplification
5115 can be made, and NULL_TREE otherwise. */
5118 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
5120 enum machine_mode mode;
5121 REAL_VALUE_TYPE max;
5125 mode = TYPE_MODE (TREE_TYPE (arg0));
5127 /* For negative infinity swap the sense of the comparison. */
5128 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
5130 code = swap_tree_comparison (code);
5135 /* x > +Inf is always false, if with ignore sNANs. */
5136 if (HONOR_SNANS (mode))
5138 return omit_one_operand (type,
5139 fold_convert (type, integer_zero_node),
5143 /* x <= +Inf is always true, if we don't case about NaNs. */
5144 if (! HONOR_NANS (mode))
5145 return omit_one_operand (type,
5146 fold_convert (type, integer_one_node),
5149 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
5150 if ((*lang_hooks.decls.global_bindings_p) () == 0
5151 && ! CONTAINS_PLACEHOLDER_P (arg0))
5153 arg0 = save_expr (arg0);
5154 return fold (build (EQ_EXPR, type, arg0, arg0));
5160 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
5161 real_maxval (&max, neg, mode);
5162 return fold (build (neg ? LT_EXPR : GT_EXPR, type,
5163 arg0, build_real (TREE_TYPE (arg0), max)));
5166 /* x < +Inf is always equal to x <= DBL_MAX. */
5167 real_maxval (&max, neg, mode);
5168 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
5169 arg0, build_real (TREE_TYPE (arg0), max)));
5172 /* x != +Inf is always equal to !(x > DBL_MAX). */
5173 real_maxval (&max, neg, mode);
5174 if (! HONOR_NANS (mode))
5175 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
5176 arg0, build_real (TREE_TYPE (arg0), max)));
5177 temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
5178 arg0, build_real (TREE_TYPE (arg0), max)));
5179 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
5188 /* If CODE with arguments ARG0 and ARG1 represents a single bit
5189 equality/inequality test, then return a simplified form of
5190 the test using shifts and logical operations. Otherwise return
5191 NULL. TYPE is the desired result type. */
5194 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
5197 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
5199 if (code == TRUTH_NOT_EXPR)
5201 code = TREE_CODE (arg0);
5202 if (code != NE_EXPR && code != EQ_EXPR)
5205 /* Extract the arguments of the EQ/NE. */
5206 arg1 = TREE_OPERAND (arg0, 1);
5207 arg0 = TREE_OPERAND (arg0, 0);
5209 /* This requires us to invert the code. */
5210 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
5213 /* If this is testing a single bit, we can optimize the test. */
5214 if ((code == NE_EXPR || code == EQ_EXPR)
5215 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
5216 && integer_pow2p (TREE_OPERAND (arg0, 1)))
5218 tree inner = TREE_OPERAND (arg0, 0);
5219 tree type = TREE_TYPE (arg0);
5220 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
5221 enum machine_mode operand_mode = TYPE_MODE (type);
5223 tree signed_type, unsigned_type, intermediate_type;
5226 /* If we have (A & C) != 0 where C is the sign bit of A, convert
5227 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
5228 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
5229 if (arg00 != NULL_TREE)
5231 tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
5232 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, result_type,
5233 fold_convert (stype, arg00),
5234 fold_convert (stype, integer_zero_node)));
5237 /* At this point, we know that arg0 is not testing the sign bit. */
5238 if (TYPE_PRECISION (type) - 1 == bitnum)
5241 /* Otherwise we have (A & C) != 0 where C is a single bit,
5242 convert that into ((A >> C2) & 1). Where C2 = log2(C).
5243 Similarly for (A & C) == 0. */
5245 /* If INNER is a right shift of a constant and it plus BITNUM does
5246 not overflow, adjust BITNUM and INNER. */
5247 if (TREE_CODE (inner) == RSHIFT_EXPR
5248 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
5249 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
5250 && bitnum < TYPE_PRECISION (type)
5251 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
5252 bitnum - TYPE_PRECISION (type)))
5254 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
5255 inner = TREE_OPERAND (inner, 0);
5258 /* If we are going to be able to omit the AND below, we must do our
5259 operations as unsigned. If we must use the AND, we have a choice.
5260 Normally unsigned is faster, but for some machines signed is. */
5261 #ifdef LOAD_EXTEND_OP
5262 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1);
5267 signed_type = (*lang_hooks.types.type_for_mode) (operand_mode, 0);
5268 unsigned_type = (*lang_hooks.types.type_for_mode) (operand_mode, 1);
5269 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
5270 inner = fold_convert (intermediate_type, inner);
5273 inner = build (RSHIFT_EXPR, intermediate_type,
5274 inner, size_int (bitnum));
5276 if (code == EQ_EXPR)
5277 inner = build (BIT_XOR_EXPR, intermediate_type,
5278 inner, integer_one_node);
5280 /* Put the AND last so it can combine with more things. */
5281 inner = build (BIT_AND_EXPR, intermediate_type,
5282 inner, integer_one_node);
5284 /* Make sure to return the proper type. */
5285 inner = fold_convert (result_type, inner);
5292 /* Check whether we are allowed to reorder operands arg0 and arg1,
5293 such that the evaluation of arg1 occurs before arg0. */
5296 reorder_operands_p (tree arg0, tree arg1)
5298 if (! flag_evaluation_order)
5300 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
5302 return ! TREE_SIDE_EFFECTS (arg0)
5303 && ! TREE_SIDE_EFFECTS (arg1);
5306 /* Test whether it is preferable two swap two operands, ARG0 and
5307 ARG1, for example because ARG0 is an integer constant and ARG1
5308 isn't. If REORDER is true, only recommend swapping if we can
5309 evaluate the operands in reverse order. */
5312 tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
5314 STRIP_SIGN_NOPS (arg0);
5315 STRIP_SIGN_NOPS (arg1);
5317 if (TREE_CODE (arg1) == INTEGER_CST)
5319 if (TREE_CODE (arg0) == INTEGER_CST)
5322 if (TREE_CODE (arg1) == REAL_CST)
5324 if (TREE_CODE (arg0) == REAL_CST)
5327 if (TREE_CODE (arg1) == COMPLEX_CST)
5329 if (TREE_CODE (arg0) == COMPLEX_CST)
5332 if (TREE_CONSTANT (arg1))
5334 if (TREE_CONSTANT (arg0))
5340 if (reorder && flag_evaluation_order
5341 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
5352 /* Perform constant folding and related simplification of EXPR.
5353 The related simplifications include x*1 => x, x*0 => 0, etc.,
5354 and application of the associative law.
5355 NOP_EXPR conversions may be removed freely (as long as we
5356 are careful not to change the C type of the overall expression)
5357 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
5358 but we can constant-fold them if they have constant operands. */
5360 #ifdef ENABLE_FOLD_CHECKING
5361 # define fold(x) fold_1 (x)
5362 static tree fold_1 (tree);
5368 tree t = expr, orig_t;
5369 tree t1 = NULL_TREE;
5371 tree type = TREE_TYPE (expr);
5372 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
5373 enum tree_code code = TREE_CODE (t);
5374 int kind = TREE_CODE_CLASS (code);
5376 /* WINS will be nonzero when the switch is done
5377 if all operands are constant. */
5380 /* Don't try to process an RTL_EXPR since its operands aren't trees.
5381 Likewise for a SAVE_EXPR that's already been evaluated. */
5382 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
5385 /* Return right away if a constant. */
5391 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
5395 /* Special case for conversion ops that can have fixed point args. */
5396 arg0 = TREE_OPERAND (t, 0);
5398 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
5400 STRIP_SIGN_NOPS (arg0);
5402 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
5403 subop = TREE_REALPART (arg0);
5407 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
5408 && TREE_CODE (subop) != REAL_CST)
5409 /* Note that TREE_CONSTANT isn't enough:
5410 static var addresses are constant but we can't
5411 do arithmetic on them. */
5414 else if (IS_EXPR_CODE_CLASS (kind))
5416 int len = first_rtl_op (code);
5418 for (i = 0; i < len; i++)
5420 tree op = TREE_OPERAND (t, i);
5424 continue; /* Valid for CALL_EXPR, at least. */
5429 || code == RSHIFT_EXPR)
5431 /* Signedness matters here. Perhaps we can refine this
5433 STRIP_SIGN_NOPS (op);
5436 /* Strip any conversions that don't change the mode. */
5439 if (TREE_CODE (op) == COMPLEX_CST)
5440 subop = TREE_REALPART (op);
5444 if (TREE_CODE (subop) != INTEGER_CST
5445 && TREE_CODE (subop) != REAL_CST)
5446 /* Note that TREE_CONSTANT isn't enough:
5447 static var addresses are constant but we can't
5448 do arithmetic on them. */
5458 /* If this is a commutative operation, and ARG0 is a constant, move it
5459 to ARG1 to reduce the number of tests below. */
5460 if (commutative_tree_code (code)
5461 && tree_swap_operands_p (arg0, arg1, true))
5462 return fold (build (code, type, arg1, arg0));
5464 /* Now WINS is set as described above,
5465 ARG0 is the first operand of EXPR,
5466 and ARG1 is the second operand (if it has more than one operand).
5468 First check for cases where an arithmetic operation is applied to a
5469 compound, conditional, or comparison operation. Push the arithmetic
5470 operation inside the compound or conditional to see if any folding
5471 can then be done. Convert comparison to conditional for this purpose.
5472 The also optimizes non-constant cases that used to be done in
5475 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5476 one of the operands is a comparison and the other is a comparison, a
5477 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5478 code below would make the expression more complex. Change it to a
5479 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5480 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5482 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5483 || code == EQ_EXPR || code == NE_EXPR)
5484 && ((truth_value_p (TREE_CODE (arg0))
5485 && (truth_value_p (TREE_CODE (arg1))
5486 || (TREE_CODE (arg1) == BIT_AND_EXPR
5487 && integer_onep (TREE_OPERAND (arg1, 1)))))
5488 || (truth_value_p (TREE_CODE (arg1))
5489 && (truth_value_p (TREE_CODE (arg0))
5490 || (TREE_CODE (arg0) == BIT_AND_EXPR
5491 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5493 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5494 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5498 if (code == EQ_EXPR)
5499 t = invert_truthvalue (t);
5504 if (TREE_CODE_CLASS (code) == '1')
5506 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5507 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5508 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5509 else if (TREE_CODE (arg0) == COND_EXPR)
5511 tree arg01 = TREE_OPERAND (arg0, 1);
5512 tree arg02 = TREE_OPERAND (arg0, 2);
5513 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5514 arg01 = fold (build1 (code, type, arg01));
5515 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5516 arg02 = fold (build1 (code, type, arg02));
5517 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5520 /* If this was a conversion, and all we did was to move into
5521 inside the COND_EXPR, bring it back out. But leave it if
5522 it is a conversion from integer to integer and the
5523 result precision is no wider than a word since such a
5524 conversion is cheap and may be optimized away by combine,
5525 while it couldn't if it were outside the COND_EXPR. Then return
5526 so we don't get into an infinite recursion loop taking the
5527 conversion out and then back in. */
5529 if ((code == NOP_EXPR || code == CONVERT_EXPR
5530 || code == NON_LVALUE_EXPR)
5531 && TREE_CODE (t) == COND_EXPR
5532 && TREE_CODE (TREE_OPERAND (t, 1)) == code
5533 && TREE_CODE (TREE_OPERAND (t, 2)) == code
5534 && ! VOID_TYPE_P (TREE_OPERAND (t, 1))
5535 && ! VOID_TYPE_P (TREE_OPERAND (t, 2))
5536 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
5537 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
5538 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
5540 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
5541 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
5542 t = build1 (code, type,
5544 TREE_TYPE (TREE_OPERAND
5545 (TREE_OPERAND (t, 1), 0)),
5546 TREE_OPERAND (t, 0),
5547 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
5548 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
5551 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5552 return fold (build (COND_EXPR, type, arg0,
5553 fold (build1 (code, type, integer_one_node)),
5554 fold (build1 (code, type, integer_zero_node))));
5556 else if (TREE_CODE_CLASS (code) == '<'
5557 && TREE_CODE (arg0) == COMPOUND_EXPR)
5558 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5559 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5560 else if (TREE_CODE_CLASS (code) == '<'
5561 && TREE_CODE (arg1) == COMPOUND_EXPR)
5562 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5563 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5564 else if (TREE_CODE_CLASS (code) == '2'
5565 || TREE_CODE_CLASS (code) == '<')
5567 if (TREE_CODE (arg1) == COMPOUND_EXPR
5568 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5569 && ! TREE_SIDE_EFFECTS (arg0))
5570 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5571 fold (build (code, type,
5572 arg0, TREE_OPERAND (arg1, 1))));
5573 else if ((TREE_CODE (arg1) == COND_EXPR
5574 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5575 && TREE_CODE_CLASS (code) != '<'))
5576 && (TREE_CODE (arg0) != COND_EXPR
5577 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5578 && (! TREE_SIDE_EFFECTS (arg0)
5579 || ((*lang_hooks.decls.global_bindings_p) () == 0
5580 && ! CONTAINS_PLACEHOLDER_P (arg0))))
5582 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5583 /*cond_first_p=*/0);
5584 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5585 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5586 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5587 else if ((TREE_CODE (arg0) == COND_EXPR
5588 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5589 && TREE_CODE_CLASS (code) != '<'))
5590 && (TREE_CODE (arg1) != COND_EXPR
5591 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5592 && (! TREE_SIDE_EFFECTS (arg1)
5593 || ((*lang_hooks.decls.global_bindings_p) () == 0
5594 && ! CONTAINS_PLACEHOLDER_P (arg1))))
5596 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5597 /*cond_first_p=*/1);
5611 return fold (DECL_INITIAL (t));
5616 case FIX_TRUNC_EXPR:
5618 case FIX_FLOOR_EXPR:
5619 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5620 return TREE_OPERAND (t, 0);
5622 /* Handle cases of two conversions in a row. */
5623 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5624 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5626 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5627 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5628 tree final_type = TREE_TYPE (t);
5629 int inside_int = INTEGRAL_TYPE_P (inside_type);
5630 int inside_ptr = POINTER_TYPE_P (inside_type);
5631 int inside_float = FLOAT_TYPE_P (inside_type);
5632 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5633 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5634 int inter_int = INTEGRAL_TYPE_P (inter_type);
5635 int inter_ptr = POINTER_TYPE_P (inter_type);
5636 int inter_float = FLOAT_TYPE_P (inter_type);
5637 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5638 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5639 int final_int = INTEGRAL_TYPE_P (final_type);
5640 int final_ptr = POINTER_TYPE_P (final_type);
5641 int final_float = FLOAT_TYPE_P (final_type);
5642 unsigned int final_prec = TYPE_PRECISION (final_type);
5643 int final_unsignedp = TREE_UNSIGNED (final_type);
5645 /* In addition to the cases of two conversions in a row
5646 handled below, if we are converting something to its own
5647 type via an object of identical or wider precision, neither
5648 conversion is needed. */
5649 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
5650 && ((inter_int && final_int) || (inter_float && final_float))
5651 && inter_prec >= final_prec)
5652 return fold (build1 (code, final_type,
5653 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5655 /* Likewise, if the intermediate and final types are either both
5656 float or both integer, we don't need the middle conversion if
5657 it is wider than the final type and doesn't change the signedness
5658 (for integers). Avoid this if the final type is a pointer
5659 since then we sometimes need the inner conversion. Likewise if
5660 the outer has a precision not equal to the size of its mode. */
5661 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5662 || (inter_float && inside_float))
5663 && inter_prec >= inside_prec
5664 && (inter_float || inter_unsignedp == inside_unsignedp)
5665 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5666 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5668 return fold (build1 (code, final_type,
5669 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5671 /* If we have a sign-extension of a zero-extended value, we can
5672 replace that by a single zero-extension. */
5673 if (inside_int && inter_int && final_int
5674 && inside_prec < inter_prec && inter_prec < final_prec
5675 && inside_unsignedp && !inter_unsignedp)
5676 return fold (build1 (code, final_type,
5677 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5679 /* Two conversions in a row are not needed unless:
5680 - some conversion is floating-point (overstrict for now), or
5681 - the intermediate type is narrower than both initial and
5683 - the intermediate type and innermost type differ in signedness,
5684 and the outermost type is wider than the intermediate, or
5685 - the initial type is a pointer type and the precisions of the
5686 intermediate and final types differ, or
5687 - the final type is a pointer type and the precisions of the
5688 initial and intermediate types differ. */
5689 if (! inside_float && ! inter_float && ! final_float
5690 && (inter_prec > inside_prec || inter_prec > final_prec)
5691 && ! (inside_int && inter_int
5692 && inter_unsignedp != inside_unsignedp
5693 && inter_prec < final_prec)
5694 && ((inter_unsignedp && inter_prec > inside_prec)
5695 == (final_unsignedp && final_prec > inter_prec))
5696 && ! (inside_ptr && inter_prec != final_prec)
5697 && ! (final_ptr && inside_prec != inter_prec)
5698 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5699 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5701 return fold (build1 (code, final_type,
5702 TREE_OPERAND (TREE_OPERAND (t, 0), 0)));
5705 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5706 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5707 /* Detect assigning a bitfield. */
5708 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5709 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5711 /* Don't leave an assignment inside a conversion
5712 unless assigning a bitfield. */
5713 tree prev = TREE_OPERAND (t, 0);
5716 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5717 /* First do the assignment, then return converted constant. */
5718 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5723 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5724 constants (if x has signed type, the sign bit cannot be set
5725 in c). This folds extension into the BIT_AND_EXPR. */
5726 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
5727 && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
5728 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5729 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5731 tree and = TREE_OPERAND (t, 0);
5732 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5735 if (TREE_UNSIGNED (TREE_TYPE (and))
5736 || (TYPE_PRECISION (TREE_TYPE (t))
5737 <= TYPE_PRECISION (TREE_TYPE (and))))
5739 else if (TYPE_PRECISION (TREE_TYPE (and1))
5740 <= HOST_BITS_PER_WIDE_INT
5741 && host_integerp (and1, 1))
5743 unsigned HOST_WIDE_INT cst;
5745 cst = tree_low_cst (and1, 1);
5746 cst &= (HOST_WIDE_INT) -1
5747 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5748 change = (cst == 0);
5749 #ifdef LOAD_EXTEND_OP
5751 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5754 tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
5755 and0 = fold_convert (uns, and0);
5756 and1 = fold_convert (uns, and1);
5761 return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
5762 fold_convert (TREE_TYPE (t), and0),
5763 fold_convert (TREE_TYPE (t), and1)));
5766 tem = fold_convert_const (code, TREE_TYPE (t), arg0);
5767 return tem ? tem : t;
5769 case VIEW_CONVERT_EXPR:
5770 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5771 return build1 (VIEW_CONVERT_EXPR, type,
5772 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5776 if (TREE_CODE (arg0) == CONSTRUCTOR
5777 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
5779 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5786 if (TREE_CONSTANT (t) != wins)
5790 TREE_CONSTANT (t) = wins;
5795 if (negate_expr_p (arg0))
5796 return fold_convert (type, negate_expr (arg0));
5802 if (TREE_CODE (arg0) == INTEGER_CST)
5804 /* If the value is unsigned, then the absolute value is
5805 the same as the ordinary value. */
5806 if (TREE_UNSIGNED (type))
5808 /* Similarly, if the value is non-negative. */
5809 else if (INT_CST_LT (integer_minus_one_node, arg0))
5811 /* If the value is negative, then the absolute value is
5815 unsigned HOST_WIDE_INT low;
5817 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5818 TREE_INT_CST_HIGH (arg0),
5820 t = build_int_2 (low, high);
5821 TREE_TYPE (t) = type;
5823 = (TREE_OVERFLOW (arg0)
5824 | force_fit_type (t, overflow));
5825 TREE_CONSTANT_OVERFLOW (t)
5826 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5829 else if (TREE_CODE (arg0) == REAL_CST)
5831 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5832 t = build_real (type,
5833 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5836 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5837 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
5838 /* Convert fabs((double)float) into (double)fabsf(float). */
5839 else if (TREE_CODE (arg0) == NOP_EXPR
5840 && TREE_CODE (type) == REAL_TYPE)
5842 tree targ0 = strip_float_extensions (arg0);
5844 return fold_convert (type, fold (build1 (ABS_EXPR,
5848 else if (tree_expr_nonnegative_p (arg0))
5853 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5854 return fold_convert (type, arg0);
5855 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5856 return build (COMPLEX_EXPR, type,
5857 TREE_OPERAND (arg0, 0),
5858 negate_expr (TREE_OPERAND (arg0, 1)));
5859 else if (TREE_CODE (arg0) == COMPLEX_CST)
5860 return build_complex (type, TREE_REALPART (arg0),
5861 negate_expr (TREE_IMAGPART (arg0)));
5862 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5863 return fold (build (TREE_CODE (arg0), type,
5864 fold (build1 (CONJ_EXPR, type,
5865 TREE_OPERAND (arg0, 0))),
5866 fold (build1 (CONJ_EXPR,
5867 type, TREE_OPERAND (arg0, 1)))));
5868 else if (TREE_CODE (arg0) == CONJ_EXPR)
5869 return TREE_OPERAND (arg0, 0);
5875 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5876 ~ TREE_INT_CST_HIGH (arg0));
5877 TREE_TYPE (t) = type;
5878 force_fit_type (t, 0);
5879 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5880 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5882 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5883 return TREE_OPERAND (arg0, 0);
5887 /* A + (-B) -> A - B */
5888 if (TREE_CODE (arg1) == NEGATE_EXPR)
5889 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5890 /* (-A) + B -> B - A */
5891 if (TREE_CODE (arg0) == NEGATE_EXPR)
5892 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5893 else if (! FLOAT_TYPE_P (type))
5895 if (integer_zerop (arg1))
5896 return non_lvalue (fold_convert (type, arg0));
5898 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5899 with a constant, and the two constants have no bits in common,
5900 we should treat this as a BIT_IOR_EXPR since this may produce more
5902 if (TREE_CODE (arg0) == BIT_AND_EXPR
5903 && TREE_CODE (arg1) == BIT_AND_EXPR
5904 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5905 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5906 && integer_zerop (const_binop (BIT_AND_EXPR,
5907 TREE_OPERAND (arg0, 1),
5908 TREE_OPERAND (arg1, 1), 0)))
5910 code = BIT_IOR_EXPR;
5914 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5915 (plus (plus (mult) (mult)) (foo)) so that we can
5916 take advantage of the factoring cases below. */
5917 if ((TREE_CODE (arg0) == PLUS_EXPR
5918 && TREE_CODE (arg1) == MULT_EXPR)
5919 || (TREE_CODE (arg1) == PLUS_EXPR
5920 && TREE_CODE (arg0) == MULT_EXPR))
5922 tree parg0, parg1, parg, marg;
5924 if (TREE_CODE (arg0) == PLUS_EXPR)
5925 parg = arg0, marg = arg1;
5927 parg = arg1, marg = arg0;
5928 parg0 = TREE_OPERAND (parg, 0);
5929 parg1 = TREE_OPERAND (parg, 1);
5933 if (TREE_CODE (parg0) == MULT_EXPR
5934 && TREE_CODE (parg1) != MULT_EXPR)
5935 return fold (build (PLUS_EXPR, type,
5936 fold (build (PLUS_EXPR, type,
5937 fold_convert (type, parg0),
5938 fold_convert (type, marg))),
5939 fold_convert (type, parg1)));
5940 if (TREE_CODE (parg0) != MULT_EXPR
5941 && TREE_CODE (parg1) == MULT_EXPR)
5942 return fold (build (PLUS_EXPR, type,
5943 fold (build (PLUS_EXPR, type,
5944 fold_convert (type, parg1),
5945 fold_convert (type, marg))),
5946 fold_convert (type, parg0)));
5949 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5951 tree arg00, arg01, arg10, arg11;
5952 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5954 /* (A * C) + (B * C) -> (A+B) * C.
5955 We are most concerned about the case where C is a constant,
5956 but other combinations show up during loop reduction. Since
5957 it is not difficult, try all four possibilities. */
5959 arg00 = TREE_OPERAND (arg0, 0);
5960 arg01 = TREE_OPERAND (arg0, 1);
5961 arg10 = TREE_OPERAND (arg1, 0);
5962 arg11 = TREE_OPERAND (arg1, 1);
5965 if (operand_equal_p (arg01, arg11, 0))
5966 same = arg01, alt0 = arg00, alt1 = arg10;
5967 else if (operand_equal_p (arg00, arg10, 0))
5968 same = arg00, alt0 = arg01, alt1 = arg11;
5969 else if (operand_equal_p (arg00, arg11, 0))
5970 same = arg00, alt0 = arg01, alt1 = arg10;
5971 else if (operand_equal_p (arg01, arg10, 0))
5972 same = arg01, alt0 = arg00, alt1 = arg11;
5974 /* No identical multiplicands; see if we can find a common
5975 power-of-two factor in non-power-of-two multiplies. This
5976 can help in multi-dimensional array access. */
5977 else if (TREE_CODE (arg01) == INTEGER_CST
5978 && TREE_CODE (arg11) == INTEGER_CST
5979 && TREE_INT_CST_HIGH (arg01) == 0
5980 && TREE_INT_CST_HIGH (arg11) == 0)
5982 HOST_WIDE_INT int01, int11, tmp;
5983 int01 = TREE_INT_CST_LOW (arg01);
5984 int11 = TREE_INT_CST_LOW (arg11);
5986 /* Move min of absolute values to int11. */
5987 if ((int01 >= 0 ? int01 : -int01)
5988 < (int11 >= 0 ? int11 : -int11))
5990 tmp = int01, int01 = int11, int11 = tmp;
5991 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5992 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5995 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5997 alt0 = fold (build (MULT_EXPR, type, arg00,
5998 build_int_2 (int01 / int11, 0)));
6005 return fold (build (MULT_EXPR, type,
6006 fold (build (PLUS_EXPR, type, alt0, alt1)),
6012 /* See if ARG1 is zero and X + ARG1 reduces to X. */
6013 if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
6014 return non_lvalue (fold_convert (type, arg0));
6016 /* Likewise if the operands are reversed. */
6017 if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6018 return non_lvalue (fold_convert (type, arg1));
6020 /* Convert x+x into x*2.0. */
6021 if (operand_equal_p (arg0, arg1, 0)
6022 && SCALAR_FLOAT_TYPE_P (type))
6023 return fold (build (MULT_EXPR, type, arg0,
6024 build_real (type, dconst2)));
6026 /* Convert x*c+x into x*(c+1). */
6027 if (flag_unsafe_math_optimizations
6028 && TREE_CODE (arg0) == MULT_EXPR
6029 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6030 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6031 && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
6035 c = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6036 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6037 return fold (build (MULT_EXPR, type, arg1,
6038 build_real (type, c)));
6041 /* Convert x+x*c into x*(c+1). */
6042 if (flag_unsafe_math_optimizations
6043 && TREE_CODE (arg1) == MULT_EXPR
6044 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6045 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6046 && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
6050 c = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6051 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6052 return fold (build (MULT_EXPR, type, arg0,
6053 build_real (type, c)));
6056 /* Convert x*c1+x*c2 into x*(c1+c2). */
6057 if (flag_unsafe_math_optimizations
6058 && TREE_CODE (arg0) == MULT_EXPR
6059 && TREE_CODE (arg1) == MULT_EXPR
6060 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6061 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0, 1))
6062 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST
6063 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1, 1))
6064 && operand_equal_p (TREE_OPERAND (arg0, 0),
6065 TREE_OPERAND (arg1, 0), 0))
6067 REAL_VALUE_TYPE c1, c2;
6069 c1 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
6070 c2 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
6071 real_arithmetic (&c1, PLUS_EXPR, &c1, &c2);
6072 return fold (build (MULT_EXPR, type,
6073 TREE_OPERAND (arg0, 0),
6074 build_real (type, c1)));
6079 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
6080 is a rotate of A by C1 bits. */
6081 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
6082 is a rotate of A by B bits. */
6084 enum tree_code code0, code1;
6085 code0 = TREE_CODE (arg0);
6086 code1 = TREE_CODE (arg1);
6087 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
6088 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
6089 && operand_equal_p (TREE_OPERAND (arg0, 0),
6090 TREE_OPERAND (arg1, 0), 0)
6091 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6093 tree tree01, tree11;
6094 enum tree_code code01, code11;
6096 tree01 = TREE_OPERAND (arg0, 1);
6097 tree11 = TREE_OPERAND (arg1, 1);
6098 STRIP_NOPS (tree01);
6099 STRIP_NOPS (tree11);
6100 code01 = TREE_CODE (tree01);
6101 code11 = TREE_CODE (tree11);
6102 if (code01 == INTEGER_CST
6103 && code11 == INTEGER_CST
6104 && TREE_INT_CST_HIGH (tree01) == 0
6105 && TREE_INT_CST_HIGH (tree11) == 0
6106 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
6107 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
6108 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
6109 code0 == LSHIFT_EXPR ? tree01 : tree11);
6110 else if (code11 == MINUS_EXPR)
6112 tree tree110, tree111;
6113 tree110 = TREE_OPERAND (tree11, 0);
6114 tree111 = TREE_OPERAND (tree11, 1);
6115 STRIP_NOPS (tree110);
6116 STRIP_NOPS (tree111);
6117 if (TREE_CODE (tree110) == INTEGER_CST
6118 && 0 == compare_tree_int (tree110,
6120 (TREE_TYPE (TREE_OPERAND
6122 && operand_equal_p (tree01, tree111, 0))
6123 return build ((code0 == LSHIFT_EXPR
6126 type, TREE_OPERAND (arg0, 0), tree01);
6128 else if (code01 == MINUS_EXPR)
6130 tree tree010, tree011;
6131 tree010 = TREE_OPERAND (tree01, 0);
6132 tree011 = TREE_OPERAND (tree01, 1);
6133 STRIP_NOPS (tree010);
6134 STRIP_NOPS (tree011);
6135 if (TREE_CODE (tree010) == INTEGER_CST
6136 && 0 == compare_tree_int (tree010,
6138 (TREE_TYPE (TREE_OPERAND
6140 && operand_equal_p (tree11, tree011, 0))
6141 return build ((code0 != LSHIFT_EXPR
6144 type, TREE_OPERAND (arg0, 0), tree11);
6150 /* In most languages, can't associate operations on floats through
6151 parentheses. Rather than remember where the parentheses were, we
6152 don't associate floats at all, unless the user has specified
6153 -funsafe-math-optimizations. */
6156 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
6158 tree var0, con0, lit0, minus_lit0;
6159 tree var1, con1, lit1, minus_lit1;
6161 /* Split both trees into variables, constants, and literals. Then
6162 associate each group together, the constants with literals,
6163 then the result with variables. This increases the chances of
6164 literals being recombined later and of generating relocatable
6165 expressions for the sum of a constant and literal. */
6166 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
6167 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
6168 code == MINUS_EXPR);
6170 /* Only do something if we found more than two objects. Otherwise,
6171 nothing has changed and we risk infinite recursion. */
6172 if (2 < ((var0 != 0) + (var1 != 0)
6173 + (con0 != 0) + (con1 != 0)
6174 + (lit0 != 0) + (lit1 != 0)
6175 + (minus_lit0 != 0) + (minus_lit1 != 0)))
6177 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
6178 if (code == MINUS_EXPR)
6181 var0 = associate_trees (var0, var1, code, type);
6182 con0 = associate_trees (con0, con1, code, type);
6183 lit0 = associate_trees (lit0, lit1, code, type);
6184 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
6186 /* Preserve the MINUS_EXPR if the negative part of the literal is
6187 greater than the positive part. Otherwise, the multiplicative
6188 folding code (i.e extract_muldiv) may be fooled in case
6189 unsigned constants are subtracted, like in the following
6190 example: ((X*2 + 4) - 8U)/2. */
6191 if (minus_lit0 && lit0)
6193 if (TREE_CODE (lit0) == INTEGER_CST
6194 && TREE_CODE (minus_lit0) == INTEGER_CST
6195 && tree_int_cst_lt (lit0, minus_lit0))
6197 minus_lit0 = associate_trees (minus_lit0, lit0,
6203 lit0 = associate_trees (lit0, minus_lit0,
6211 return fold_convert (type,
6212 associate_trees (var0, minus_lit0,
6216 con0 = associate_trees (con0, minus_lit0,
6218 return fold_convert (type,
6219 associate_trees (var0, con0,
6224 con0 = associate_trees (con0, lit0, code, type);
6225 return fold_convert (type, associate_trees (var0, con0,
6232 t1 = const_binop (code, arg0, arg1, 0);
6233 if (t1 != NULL_TREE)
6235 /* The return value should always have
6236 the same type as the original expression. */
6237 if (TREE_TYPE (t1) != TREE_TYPE (t))
6238 t1 = fold_convert (TREE_TYPE (t), t1);
6245 /* A - (-B) -> A + B */
6246 if (TREE_CODE (arg1) == NEGATE_EXPR)
6247 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
6248 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
6249 if (TREE_CODE (arg0) == NEGATE_EXPR
6250 && (FLOAT_TYPE_P (type)
6251 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
6252 && negate_expr_p (arg1)
6253 && reorder_operands_p (arg0, arg1))
6254 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
6255 TREE_OPERAND (arg0, 0)));
6257 if (! FLOAT_TYPE_P (type))
6259 if (! wins && integer_zerop (arg0))
6260 return negate_expr (fold_convert (type, arg1));
6261 if (integer_zerop (arg1))
6262 return non_lvalue (fold_convert (type, arg0));
6264 /* Fold A - (A & B) into ~B & A. */
6265 if (!TREE_SIDE_EFFECTS (arg0)
6266 && TREE_CODE (arg1) == BIT_AND_EXPR)
6268 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
6269 return fold (build (BIT_AND_EXPR, type,
6270 fold (build1 (BIT_NOT_EXPR, type,
6271 TREE_OPERAND (arg1, 0))),
6273 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
6274 return fold (build (BIT_AND_EXPR, type,
6275 fold (build1 (BIT_NOT_EXPR, type,
6276 TREE_OPERAND (arg1, 1))),
6280 /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
6281 any power of 2 minus 1. */
6282 if (TREE_CODE (arg0) == BIT_AND_EXPR
6283 && TREE_CODE (arg1) == BIT_AND_EXPR
6284 && operand_equal_p (TREE_OPERAND (arg0, 0),
6285 TREE_OPERAND (arg1, 0), 0))
6287 tree mask0 = TREE_OPERAND (arg0, 1);
6288 tree mask1 = TREE_OPERAND (arg1, 1);
6289 tree tem = fold (build1 (BIT_NOT_EXPR, type, mask0));
6291 if (operand_equal_p (tem, mask1, 0))
6293 tem = fold (build (BIT_XOR_EXPR, type,
6294 TREE_OPERAND (arg0, 0), mask1));
6295 return fold (build (MINUS_EXPR, type, tem, mask1));
6300 /* See if ARG1 is zero and X - ARG1 reduces to X. */
6301 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
6302 return non_lvalue (fold_convert (type, arg0));
6304 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
6305 ARG0 is zero and X + ARG0 reduces to X, since that would mean
6306 (-ARG1 + ARG0) reduces to -ARG1. */
6307 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
6308 return negate_expr (fold_convert (type, arg1));
6310 /* Fold &x - &x. This can happen from &x.foo - &x.
6311 This is unsafe for certain floats even in non-IEEE formats.
6312 In IEEE, it is unsafe because it does wrong for NaNs.
6313 Also note that operand_equal_p is always false if an operand
6316 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
6317 && operand_equal_p (arg0, arg1, 0))
6318 return fold_convert (type, integer_zero_node);
6320 /* A - B -> A + (-B) if B is easily negatable. */
6321 if (!wins && negate_expr_p (arg1)
6322 && (FLOAT_TYPE_P (type)
6323 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv)))
6324 return fold (build (PLUS_EXPR, type, arg0, negate_expr (arg1)));
6326 if (TREE_CODE (arg0) == MULT_EXPR
6327 && TREE_CODE (arg1) == MULT_EXPR
6328 && (INTEGRAL_TYPE_P (type) || flag_unsafe_math_optimizations))
6330 /* (A * C) - (B * C) -> (A-B) * C. */
6331 if (operand_equal_p (TREE_OPERAND (arg0, 1),
6332 TREE_OPERAND (arg1, 1), 0))
6333 return fold (build (MULT_EXPR, type,
6334 fold (build (MINUS_EXPR, type,
6335 TREE_OPERAND (arg0, 0),
6336 TREE_OPERAND (arg1, 0))),
6337 TREE_OPERAND (arg0, 1)));
6338 /* (A * C1) - (A * C2) -> A * (C1-C2). */
6339 if (operand_equal_p (TREE_OPERAND (arg0, 0),
6340 TREE_OPERAND (arg1, 0), 0))
6341 return fold (build (MULT_EXPR, type,
6342 TREE_OPERAND (arg0, 0),
6343 fold (build (MINUS_EXPR, type,
6344 TREE_OPERAND (arg0, 1),
6345 TREE_OPERAND (arg1, 1)))));
6351 /* (-A) * (-B) -> A * B */
6352 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6353 return fold (build (MULT_EXPR, type,
6354 TREE_OPERAND (arg0, 0),
6355 negate_expr (arg1)));
6356 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6357 return fold (build (MULT_EXPR, type,
6359 TREE_OPERAND (arg1, 0)));
6361 if (! FLOAT_TYPE_P (type))
6363 if (integer_zerop (arg1))
6364 return omit_one_operand (type, arg1, arg0);
6365 if (integer_onep (arg1))
6366 return non_lvalue (fold_convert (type, arg0));
6368 /* (a * (1 << b)) is (a << b) */
6369 if (TREE_CODE (arg1) == LSHIFT_EXPR
6370 && integer_onep (TREE_OPERAND (arg1, 0)))
6371 return fold (build (LSHIFT_EXPR, type, arg0,
6372 TREE_OPERAND (arg1, 1)));
6373 if (TREE_CODE (arg0) == LSHIFT_EXPR
6374 && integer_onep (TREE_OPERAND (arg0, 0)))
6375 return fold (build (LSHIFT_EXPR, type, arg1,
6376 TREE_OPERAND (arg0, 1)));
6378 if (TREE_CODE (arg1) == INTEGER_CST
6379 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
6380 fold_convert (type, arg1),
6382 return fold_convert (type, tem);
6387 /* Maybe fold x * 0 to 0. The expressions aren't the same
6388 when x is NaN, since x * 0 is also NaN. Nor are they the
6389 same in modes with signed zeros, since multiplying a
6390 negative value by 0 gives -0, not +0. */
6391 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
6392 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
6393 && real_zerop (arg1))
6394 return omit_one_operand (type, arg1, arg0);
6395 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
6396 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6397 && real_onep (arg1))
6398 return non_lvalue (fold_convert (type, arg0));
6400 /* Transform x * -1.0 into -x. */
6401 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6402 && real_minus_onep (arg1))
6403 return fold (build1 (NEGATE_EXPR, type, arg0));
6405 /* Convert (C1/X)*C2 into (C1*C2)/X. */
6406 if (flag_unsafe_math_optimizations
6407 && TREE_CODE (arg0) == RDIV_EXPR
6408 && TREE_CODE (arg1) == REAL_CST
6409 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
6411 tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
6414 return fold (build (RDIV_EXPR, type, tem,
6415 TREE_OPERAND (arg0, 1)));
6418 if (flag_unsafe_math_optimizations)
6420 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6421 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6423 /* Optimizations of sqrt(...)*sqrt(...). */
6424 if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT)
6425 || (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF)
6426 || (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL))
6428 tree sqrtfn, arg, arglist;
6429 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6430 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6432 /* Optimize sqrt(x)*sqrt(x) as x. */
6433 if (operand_equal_p (arg00, arg10, 0)
6434 && ! HONOR_SNANS (TYPE_MODE (type)))
6437 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
6438 sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6439 arg = fold (build (MULT_EXPR, type, arg00, arg10));
6440 arglist = build_tree_list (NULL_TREE, arg);
6441 return build_function_call_expr (sqrtfn, arglist);
6444 /* Optimize expN(x)*expN(y) as expN(x+y). */
6445 if (fcode0 == fcode1
6446 && (fcode0 == BUILT_IN_EXP
6447 || fcode0 == BUILT_IN_EXPF
6448 || fcode0 == BUILT_IN_EXPL
6449 || fcode0 == BUILT_IN_EXP2
6450 || fcode0 == BUILT_IN_EXP2F
6451 || fcode0 == BUILT_IN_EXP2L
6452 || fcode0 == BUILT_IN_EXP10
6453 || fcode0 == BUILT_IN_EXP10F
6454 || fcode0 == BUILT_IN_EXP10L
6455 || fcode0 == BUILT_IN_POW10
6456 || fcode0 == BUILT_IN_POW10F
6457 || fcode0 == BUILT_IN_POW10L))
6459 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6460 tree arg = build (PLUS_EXPR, type,
6461 TREE_VALUE (TREE_OPERAND (arg0, 1)),
6462 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6463 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6464 return build_function_call_expr (expfn, arglist);
6467 /* Optimizations of pow(...)*pow(...). */
6468 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
6469 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
6470 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
6472 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6473 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6475 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6476 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6479 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
6480 if (operand_equal_p (arg01, arg11, 0))
6482 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6483 tree arg = build (MULT_EXPR, type, arg00, arg10);
6484 tree arglist = tree_cons (NULL_TREE, fold (arg),
6485 build_tree_list (NULL_TREE,
6487 return build_function_call_expr (powfn, arglist);
6490 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
6491 if (operand_equal_p (arg00, arg10, 0))
6493 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6494 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
6495 tree arglist = tree_cons (NULL_TREE, arg00,
6496 build_tree_list (NULL_TREE,
6498 return build_function_call_expr (powfn, arglist);
6502 /* Optimize tan(x)*cos(x) as sin(x). */
6503 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
6504 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
6505 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
6506 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
6507 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
6508 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
6509 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6510 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6518 sinfn = implicit_built_in_decls[BUILT_IN_SIN];
6522 sinfn = implicit_built_in_decls[BUILT_IN_SINF];
6526 sinfn = implicit_built_in_decls[BUILT_IN_SINL];
6532 if (sinfn != NULL_TREE)
6533 return build_function_call_expr (sinfn,
6534 TREE_OPERAND (arg0, 1));
6537 /* Optimize x*pow(x,c) as pow(x,c+1). */
6538 if (fcode1 == BUILT_IN_POW
6539 || fcode1 == BUILT_IN_POWF
6540 || fcode1 == BUILT_IN_POWL)
6542 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6543 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
6545 if (TREE_CODE (arg11) == REAL_CST
6546 && ! TREE_CONSTANT_OVERFLOW (arg11)
6547 && operand_equal_p (arg0, arg10, 0))
6549 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6553 c = TREE_REAL_CST (arg11);
6554 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6555 arg = build_real (type, c);
6556 arglist = build_tree_list (NULL_TREE, arg);
6557 arglist = tree_cons (NULL_TREE, arg0, arglist);
6558 return build_function_call_expr (powfn, arglist);
6562 /* Optimize pow(x,c)*x as pow(x,c+1). */
6563 if (fcode0 == BUILT_IN_POW
6564 || fcode0 == BUILT_IN_POWF
6565 || fcode0 == BUILT_IN_POWL)
6567 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6568 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
6570 if (TREE_CODE (arg01) == REAL_CST
6571 && ! TREE_CONSTANT_OVERFLOW (arg01)
6572 && operand_equal_p (arg1, arg00, 0))
6574 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6578 c = TREE_REAL_CST (arg01);
6579 real_arithmetic (&c, PLUS_EXPR, &c, &dconst1);
6580 arg = build_real (type, c);
6581 arglist = build_tree_list (NULL_TREE, arg);
6582 arglist = tree_cons (NULL_TREE, arg1, arglist);
6583 return build_function_call_expr (powfn, arglist);
6587 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
6589 && operand_equal_p (arg0, arg1, 0))
6593 if (type == double_type_node)
6594 powfn = implicit_built_in_decls[BUILT_IN_POW];
6595 else if (type == float_type_node)
6596 powfn = implicit_built_in_decls[BUILT_IN_POWF];
6597 else if (type == long_double_type_node)
6598 powfn = implicit_built_in_decls[BUILT_IN_POWL];
6604 tree arg = build_real (type, dconst2);
6605 tree arglist = build_tree_list (NULL_TREE, arg);
6606 arglist = tree_cons (NULL_TREE, arg0, arglist);
6607 return build_function_call_expr (powfn, arglist);
6616 if (integer_all_onesp (arg1))
6617 return omit_one_operand (type, arg1, arg0);
6618 if (integer_zerop (arg1))
6619 return non_lvalue (fold_convert (type, arg0));
6620 t1 = distribute_bit_expr (code, type, arg0, arg1);
6621 if (t1 != NULL_TREE)
6624 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6626 This results in more efficient code for machines without a NAND
6627 instruction. Combine will canonicalize to the first form
6628 which will allow use of NAND instructions provided by the
6629 backend if they exist. */
6630 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6631 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6633 return fold (build1 (BIT_NOT_EXPR, type,
6634 build (BIT_AND_EXPR, type,
6635 TREE_OPERAND (arg0, 0),
6636 TREE_OPERAND (arg1, 0))));
6639 /* See if this can be simplified into a rotate first. If that
6640 is unsuccessful continue in the association code. */
6644 if (integer_zerop (arg1))
6645 return non_lvalue (fold_convert (type, arg0));
6646 if (integer_all_onesp (arg1))
6647 return fold (build1 (BIT_NOT_EXPR, type, arg0));
6649 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6650 with a constant, and the two constants have no bits in common,
6651 we should treat this as a BIT_IOR_EXPR since this may produce more
6653 if (TREE_CODE (arg0) == BIT_AND_EXPR
6654 && TREE_CODE (arg1) == BIT_AND_EXPR
6655 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6656 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6657 && integer_zerop (const_binop (BIT_AND_EXPR,
6658 TREE_OPERAND (arg0, 1),
6659 TREE_OPERAND (arg1, 1), 0)))
6661 code = BIT_IOR_EXPR;
6665 /* See if this can be simplified into a rotate first. If that
6666 is unsuccessful continue in the association code. */
6670 if (integer_all_onesp (arg1))
6671 return non_lvalue (fold_convert (type, arg0));
6672 if (integer_zerop (arg1))
6673 return omit_one_operand (type, arg1, arg0);
6674 t1 = distribute_bit_expr (code, type, arg0, arg1);
6675 if (t1 != NULL_TREE)
6677 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6678 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
6679 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6682 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6684 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6685 && (~TREE_INT_CST_LOW (arg1)
6686 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6687 return fold_convert (type, TREE_OPERAND (arg0, 0));
6690 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6692 This results in more efficient code for machines without a NOR
6693 instruction. Combine will canonicalize to the first form
6694 which will allow use of NOR instructions provided by the
6695 backend if they exist. */
6696 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6697 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6699 return fold (build1 (BIT_NOT_EXPR, type,
6700 build (BIT_IOR_EXPR, type,
6701 TREE_OPERAND (arg0, 0),
6702 TREE_OPERAND (arg1, 0))));
6708 /* Don't touch a floating-point divide by zero unless the mode
6709 of the constant can represent infinity. */
6710 if (TREE_CODE (arg1) == REAL_CST
6711 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6712 && real_zerop (arg1))
6715 /* (-A) / (-B) -> A / B */
6716 if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
6717 return fold (build (RDIV_EXPR, type,
6718 TREE_OPERAND (arg0, 0),
6719 negate_expr (arg1)));
6720 if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
6721 return fold (build (RDIV_EXPR, type,
6723 TREE_OPERAND (arg1, 0)));
6725 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6726 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6727 && real_onep (arg1))
6728 return non_lvalue (fold_convert (type, arg0));
6730 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
6731 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6732 && real_minus_onep (arg1))
6733 return non_lvalue (fold_convert (type, negate_expr (arg0)));
6735 /* If ARG1 is a constant, we can convert this to a multiply by the
6736 reciprocal. This does not have the same rounding properties,
6737 so only do this if -funsafe-math-optimizations. We can actually
6738 always safely do it if ARG1 is a power of two, but it's hard to
6739 tell if it is or not in a portable manner. */
6740 if (TREE_CODE (arg1) == REAL_CST)
6742 if (flag_unsafe_math_optimizations
6743 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6745 return fold (build (MULT_EXPR, type, arg0, tem));
6746 /* Find the reciprocal if optimizing and the result is exact. */
6750 r = TREE_REAL_CST (arg1);
6751 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6753 tem = build_real (type, r);
6754 return fold (build (MULT_EXPR, type, arg0, tem));
6758 /* Convert A/B/C to A/(B*C). */
6759 if (flag_unsafe_math_optimizations
6760 && TREE_CODE (arg0) == RDIV_EXPR)
6761 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6762 fold (build (MULT_EXPR, type,
6763 TREE_OPERAND (arg0, 1), arg1))));
6765 /* Convert A/(B/C) to (A/B)*C. */
6766 if (flag_unsafe_math_optimizations
6767 && TREE_CODE (arg1) == RDIV_EXPR)
6768 return fold (build (MULT_EXPR, type,
6769 fold (build (RDIV_EXPR, type, arg0,
6770 TREE_OPERAND (arg1, 0))),
6771 TREE_OPERAND (arg1, 1)));
6773 /* Convert C1/(X*C2) into (C1/C2)/X. */
6774 if (flag_unsafe_math_optimizations
6775 && TREE_CODE (arg1) == MULT_EXPR
6776 && TREE_CODE (arg0) == REAL_CST
6777 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
6779 tree tem = const_binop (RDIV_EXPR, arg0,
6780 TREE_OPERAND (arg1, 1), 0);
6782 return fold (build (RDIV_EXPR, type, tem,
6783 TREE_OPERAND (arg1, 0)));
6786 if (flag_unsafe_math_optimizations)
6788 enum built_in_function fcode = builtin_mathfn_code (arg1);
6789 /* Optimize x/expN(y) into x*expN(-y). */
6790 if (fcode == BUILT_IN_EXP
6791 || fcode == BUILT_IN_EXPF
6792 || fcode == BUILT_IN_EXPL
6793 || fcode == BUILT_IN_EXP2
6794 || fcode == BUILT_IN_EXP2F
6795 || fcode == BUILT_IN_EXP2L
6796 || fcode == BUILT_IN_EXP10
6797 || fcode == BUILT_IN_EXP10F
6798 || fcode == BUILT_IN_EXP10L
6799 || fcode == BUILT_IN_POW10
6800 || fcode == BUILT_IN_POW10F
6801 || fcode == BUILT_IN_POW10L)
6803 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6804 tree arg = build1 (NEGATE_EXPR, type,
6805 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6806 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6807 arg1 = build_function_call_expr (expfn, arglist);
6808 return fold (build (MULT_EXPR, type, arg0, arg1));
6811 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6812 if (fcode == BUILT_IN_POW
6813 || fcode == BUILT_IN_POWF
6814 || fcode == BUILT_IN_POWL)
6816 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6817 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6818 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6819 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6820 tree arglist = tree_cons(NULL_TREE, arg10,
6821 build_tree_list (NULL_TREE, neg11));
6822 arg1 = build_function_call_expr (powfn, arglist);
6823 return fold (build (MULT_EXPR, type, arg0, arg1));
6827 if (flag_unsafe_math_optimizations)
6829 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6830 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6832 /* Optimize sin(x)/cos(x) as tan(x). */
6833 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
6834 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
6835 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
6836 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6837 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6841 if (fcode0 == BUILT_IN_SIN)
6842 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6843 else if (fcode0 == BUILT_IN_SINF)
6844 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6845 else if (fcode0 == BUILT_IN_SINL)
6846 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6850 if (tanfn != NULL_TREE)
6851 return build_function_call_expr (tanfn,
6852 TREE_OPERAND (arg0, 1));
6855 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6856 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
6857 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
6858 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
6859 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6860 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6864 if (fcode0 == BUILT_IN_COS)
6865 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6866 else if (fcode0 == BUILT_IN_COSF)
6867 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6868 else if (fcode0 == BUILT_IN_COSL)
6869 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6873 if (tanfn != NULL_TREE)
6875 tree tmp = TREE_OPERAND (arg0, 1);
6876 tmp = build_function_call_expr (tanfn, tmp);
6877 return fold (build (RDIV_EXPR, type,
6878 build_real (type, dconst1),
6883 /* Optimize pow(x,c)/x as pow(x,c-1). */
6884 if (fcode0 == BUILT_IN_POW
6885 || fcode0 == BUILT_IN_POWF
6886 || fcode0 == BUILT_IN_POWL)
6888 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
6889 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0, 1)));
6890 if (TREE_CODE (arg01) == REAL_CST
6891 && ! TREE_CONSTANT_OVERFLOW (arg01)
6892 && operand_equal_p (arg1, arg00, 0))
6894 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
6898 c = TREE_REAL_CST (arg01);
6899 real_arithmetic (&c, MINUS_EXPR, &c, &dconst1);
6900 arg = build_real (type, c);
6901 arglist = build_tree_list (NULL_TREE, arg);
6902 arglist = tree_cons (NULL_TREE, arg1, arglist);
6903 return build_function_call_expr (powfn, arglist);
6909 case TRUNC_DIV_EXPR:
6910 case ROUND_DIV_EXPR:
6911 case FLOOR_DIV_EXPR:
6913 case EXACT_DIV_EXPR:
6914 if (integer_onep (arg1))
6915 return non_lvalue (fold_convert (type, arg0));
6916 if (integer_zerop (arg1))
6919 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6920 operation, EXACT_DIV_EXPR.
6922 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6923 At one time others generated faster code, it's not clear if they do
6924 after the last round to changes to the DIV code in expmed.c. */
6925 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6926 && multiple_of_p (type, arg0, arg1))
6927 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6929 if (TREE_CODE (arg1) == INTEGER_CST
6930 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6932 return fold_convert (type, tem);
6937 case FLOOR_MOD_EXPR:
6938 case ROUND_MOD_EXPR:
6939 case TRUNC_MOD_EXPR:
6940 if (integer_onep (arg1))
6941 return omit_one_operand (type, integer_zero_node, arg0);
6942 if (integer_zerop (arg1))
6945 if (TREE_CODE (arg1) == INTEGER_CST
6946 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6948 return fold_convert (type, tem);
6954 if (integer_all_onesp (arg0))
6955 return omit_one_operand (type, arg0, arg1);
6959 /* Optimize -1 >> x for arithmetic right shifts. */
6960 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
6961 return omit_one_operand (type, arg0, arg1);
6962 /* ... fall through ... */
6966 if (integer_zerop (arg1))
6967 return non_lvalue (fold_convert (type, arg0));
6968 if (integer_zerop (arg0))
6969 return omit_one_operand (type, arg0, arg1);
6971 /* Since negative shift count is not well-defined,
6972 don't try to compute it in the compiler. */
6973 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6975 /* Rewrite an LROTATE_EXPR by a constant into an
6976 RROTATE_EXPR by a new constant. */
6977 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6979 tree tem = build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0);
6980 tem = fold_convert (TREE_TYPE (arg1), tem);
6981 tem = const_binop (MINUS_EXPR, tem, arg1, 0);
6982 return fold (build (RROTATE_EXPR, type, arg0, tem));
6985 /* If we have a rotate of a bit operation with the rotate count and
6986 the second operand of the bit operation both constant,
6987 permute the two operations. */
6988 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6989 && (TREE_CODE (arg0) == BIT_AND_EXPR
6990 || TREE_CODE (arg0) == BIT_IOR_EXPR
6991 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6992 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6993 return fold (build (TREE_CODE (arg0), type,
6994 fold (build (code, type,
6995 TREE_OPERAND (arg0, 0), arg1)),
6996 fold (build (code, type,
6997 TREE_OPERAND (arg0, 1), arg1))));
6999 /* Two consecutive rotates adding up to the width of the mode can
7001 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7002 && TREE_CODE (arg0) == RROTATE_EXPR
7003 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7004 && TREE_INT_CST_HIGH (arg1) == 0
7005 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
7006 && ((TREE_INT_CST_LOW (arg1)
7007 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
7008 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
7009 return TREE_OPERAND (arg0, 0);
7014 if (operand_equal_p (arg0, arg1, 0))
7015 return omit_one_operand (type, arg0, arg1);
7016 if (INTEGRAL_TYPE_P (type)
7017 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
7018 return omit_one_operand (type, arg1, arg0);
7022 if (operand_equal_p (arg0, arg1, 0))
7023 return omit_one_operand (type, arg0, arg1);
7024 if (INTEGRAL_TYPE_P (type)
7025 && TYPE_MAX_VALUE (type)
7026 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
7027 return omit_one_operand (type, arg1, arg0);
7030 case TRUTH_NOT_EXPR:
7031 /* Note that the operand of this must be an int
7032 and its values must be 0 or 1.
7033 ("true" is a fixed value perhaps depending on the language,
7034 but we don't handle values other than 1 correctly yet.) */
7035 tem = invert_truthvalue (arg0);
7036 /* Avoid infinite recursion. */
7037 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
7039 tem = fold_single_bit_test (code, arg0, arg1, type);
7044 return fold_convert (type, tem);
7046 case TRUTH_ANDIF_EXPR:
7047 /* Note that the operands of this must be ints
7048 and their values must be 0 or 1.
7049 ("true" is a fixed value perhaps depending on the language.) */
7050 /* If first arg is constant zero, return it. */
7051 if (integer_zerop (arg0))
7052 return fold_convert (type, arg0);
7053 case TRUTH_AND_EXPR:
7054 /* If either arg is constant true, drop it. */
7055 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7056 return non_lvalue (fold_convert (type, arg1));
7057 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
7058 /* Preserve sequence points. */
7059 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7060 return non_lvalue (fold_convert (type, arg0));
7061 /* If second arg is constant zero, result is zero, but first arg
7062 must be evaluated. */
7063 if (integer_zerop (arg1))
7064 return omit_one_operand (type, arg1, arg0);
7065 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
7066 case will be handled here. */
7067 if (integer_zerop (arg0))
7068 return omit_one_operand (type, arg0, arg1);
7071 /* We only do these simplifications if we are optimizing. */
7075 /* Check for things like (A || B) && (A || C). We can convert this
7076 to A || (B && C). Note that either operator can be any of the four
7077 truth and/or operations and the transformation will still be
7078 valid. Also note that we only care about order for the
7079 ANDIF and ORIF operators. If B contains side effects, this
7080 might change the truth-value of A. */
7081 if (TREE_CODE (arg0) == TREE_CODE (arg1)
7082 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
7083 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
7084 || TREE_CODE (arg0) == TRUTH_AND_EXPR
7085 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
7086 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
7088 tree a00 = TREE_OPERAND (arg0, 0);
7089 tree a01 = TREE_OPERAND (arg0, 1);
7090 tree a10 = TREE_OPERAND (arg1, 0);
7091 tree a11 = TREE_OPERAND (arg1, 1);
7092 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
7093 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
7094 && (code == TRUTH_AND_EXPR
7095 || code == TRUTH_OR_EXPR));
7097 if (operand_equal_p (a00, a10, 0))
7098 return fold (build (TREE_CODE (arg0), type, a00,
7099 fold (build (code, type, a01, a11))));
7100 else if (commutative && operand_equal_p (a00, a11, 0))
7101 return fold (build (TREE_CODE (arg0), type, a00,
7102 fold (build (code, type, a01, a10))));
7103 else if (commutative && operand_equal_p (a01, a10, 0))
7104 return fold (build (TREE_CODE (arg0), type, a01,
7105 fold (build (code, type, a00, a11))));
7107 /* This case if tricky because we must either have commutative
7108 operators or else A10 must not have side-effects. */
7110 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
7111 && operand_equal_p (a01, a11, 0))
7112 return fold (build (TREE_CODE (arg0), type,
7113 fold (build (code, type, a00, a10)),
7117 /* See if we can build a range comparison. */
7118 if (0 != (tem = fold_range_test (t)))
7121 /* Check for the possibility of merging component references. If our
7122 lhs is another similar operation, try to merge its rhs with our
7123 rhs. Then try to merge our lhs and rhs. */
7124 if (TREE_CODE (arg0) == code
7125 && 0 != (tem = fold_truthop (code, type,
7126 TREE_OPERAND (arg0, 1), arg1)))
7127 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7129 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
7134 case TRUTH_ORIF_EXPR:
7135 /* Note that the operands of this must be ints
7136 and their values must be 0 or true.
7137 ("true" is a fixed value perhaps depending on the language.) */
7138 /* If first arg is constant true, return it. */
7139 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7140 return fold_convert (type, arg0);
7142 /* If either arg is constant zero, drop it. */
7143 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
7144 return non_lvalue (fold_convert (type, arg1));
7145 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
7146 /* Preserve sequence points. */
7147 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
7148 return non_lvalue (fold_convert (type, arg0));
7149 /* If second arg is constant true, result is true, but we must
7150 evaluate first arg. */
7151 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
7152 return omit_one_operand (type, arg1, arg0);
7153 /* Likewise for first arg, but note this only occurs here for
7155 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
7156 return omit_one_operand (type, arg0, arg1);
7159 case TRUTH_XOR_EXPR:
7160 /* If either arg is constant zero, drop it. */
7161 if (integer_zerop (arg0))
7162 return non_lvalue (fold_convert (type, arg1));
7163 if (integer_zerop (arg1))
7164 return non_lvalue (fold_convert (type, arg0));
7165 /* If either arg is constant true, this is a logical inversion. */
7166 if (integer_onep (arg0))
7167 return non_lvalue (fold_convert (type, invert_truthvalue (arg1)));
7168 if (integer_onep (arg1))
7169 return non_lvalue (fold_convert (type, invert_truthvalue (arg0)));
7178 /* If one arg is a real or integer constant, put it last. */
7179 if (tree_swap_operands_p (arg0, arg1, true))
7180 return fold (build (swap_tree_comparison (code), type, arg1, arg0));
7182 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
7184 tree targ0 = strip_float_extensions (arg0);
7185 tree targ1 = strip_float_extensions (arg1);
7186 tree newtype = TREE_TYPE (targ0);
7188 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
7189 newtype = TREE_TYPE (targ1);
7191 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
7192 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
7193 return fold (build (code, type, fold_convert (newtype, targ0),
7194 fold_convert (newtype, targ1)));
7196 /* (-a) CMP (-b) -> b CMP a */
7197 if (TREE_CODE (arg0) == NEGATE_EXPR
7198 && TREE_CODE (arg1) == NEGATE_EXPR)
7199 return fold (build (code, type, TREE_OPERAND (arg1, 0),
7200 TREE_OPERAND (arg0, 0)));
7202 if (TREE_CODE (arg1) == REAL_CST)
7204 REAL_VALUE_TYPE cst;
7205 cst = TREE_REAL_CST (arg1);
7207 /* (-a) CMP CST -> a swap(CMP) (-CST) */
7208 if (TREE_CODE (arg0) == NEGATE_EXPR)
7210 fold (build (swap_tree_comparison (code), type,
7211 TREE_OPERAND (arg0, 0),
7212 build_real (TREE_TYPE (arg1),
7213 REAL_VALUE_NEGATE (cst))));
7215 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
7216 /* a CMP (-0) -> a CMP 0 */
7217 if (REAL_VALUE_MINUS_ZERO (cst))
7218 return fold (build (code, type, arg0,
7219 build_real (TREE_TYPE (arg1), dconst0)));
7221 /* x != NaN is always true, other ops are always false. */
7222 if (REAL_VALUE_ISNAN (cst)
7223 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
7225 t = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
7226 return omit_one_operand (type, fold_convert (type, t), arg0);
7229 /* Fold comparisons against infinity. */
7230 if (REAL_VALUE_ISINF (cst))
7232 tem = fold_inf_compare (code, type, arg0, arg1);
7233 if (tem != NULL_TREE)
7238 /* If this is a comparison of a real constant with a PLUS_EXPR
7239 or a MINUS_EXPR of a real constant, we can convert it into a
7240 comparison with a revised real constant as long as no overflow
7241 occurs when unsafe_math_optimizations are enabled. */
7242 if (flag_unsafe_math_optimizations
7243 && TREE_CODE (arg1) == REAL_CST
7244 && (TREE_CODE (arg0) == PLUS_EXPR
7245 || TREE_CODE (arg0) == MINUS_EXPR)
7246 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
7247 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7248 ? MINUS_EXPR : PLUS_EXPR,
7249 arg1, TREE_OPERAND (arg0, 1), 0))
7250 && ! TREE_CONSTANT_OVERFLOW (tem))
7251 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7253 /* Likewise, we can simplify a comparison of a real constant with
7254 a MINUS_EXPR whose first operand is also a real constant, i.e.
7255 (c1 - x) < c2 becomes x > c1-c2. */
7256 if (flag_unsafe_math_optimizations
7257 && TREE_CODE (arg1) == REAL_CST
7258 && TREE_CODE (arg0) == MINUS_EXPR
7259 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
7260 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
7262 && ! TREE_CONSTANT_OVERFLOW (tem))
7263 return fold (build (swap_tree_comparison (code), type,
7264 TREE_OPERAND (arg0, 1), tem));
7266 /* Fold comparisons against built-in math functions. */
7267 if (TREE_CODE (arg1) == REAL_CST
7268 && flag_unsafe_math_optimizations
7269 && ! flag_errno_math)
7271 enum built_in_function fcode = builtin_mathfn_code (arg0);
7273 if (fcode != END_BUILTINS)
7275 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
7276 if (tem != NULL_TREE)
7282 /* Convert foo++ == CONST into ++foo == CONST + INCR.
7283 First, see if one arg is constant; find the constant arg
7284 and the other one. */
7286 tree constop = 0, varop = NULL_TREE;
7287 int constopnum = -1;
7289 if (TREE_CONSTANT (arg1))
7290 constopnum = 1, constop = arg1, varop = arg0;
7291 if (TREE_CONSTANT (arg0))
7292 constopnum = 0, constop = arg0, varop = arg1;
7294 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
7296 /* This optimization is invalid for ordered comparisons
7297 if CONST+INCR overflows or if foo+incr might overflow.
7298 This optimization is invalid for floating point due to rounding.
7299 For pointer types we assume overflow doesn't happen. */
7300 if (POINTER_TYPE_P (TREE_TYPE (varop))
7301 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
7302 && (code == EQ_EXPR || code == NE_EXPR)))
7305 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
7306 constop, TREE_OPERAND (varop, 1)));
7308 /* Do not overwrite the current varop to be a preincrement,
7309 create a new node so that we won't confuse our caller who
7310 might create trees and throw them away, reusing the
7311 arguments that they passed to build. This shows up in
7312 the THEN or ELSE parts of ?: being postincrements. */
7313 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
7314 TREE_OPERAND (varop, 0),
7315 TREE_OPERAND (varop, 1));
7317 /* If VAROP is a reference to a bitfield, we must mask
7318 the constant by the width of the field. */
7319 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
7320 && DECL_BIT_FIELD(TREE_OPERAND
7321 (TREE_OPERAND (varop, 0), 1)))
7324 = TREE_INT_CST_LOW (DECL_SIZE
7326 (TREE_OPERAND (varop, 0), 1)));
7327 tree mask, unsigned_type;
7328 unsigned int precision;
7329 tree folded_compare;
7331 /* First check whether the comparison would come out
7332 always the same. If we don't do that we would
7333 change the meaning with the masking. */
7334 if (constopnum == 0)
7335 folded_compare = fold (build (code, type, constop,
7336 TREE_OPERAND (varop, 0)));
7338 folded_compare = fold (build (code, type,
7339 TREE_OPERAND (varop, 0),
7341 if (integer_zerop (folded_compare)
7342 || integer_onep (folded_compare))
7343 return omit_one_operand (type, folded_compare, varop);
7345 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
7346 precision = TYPE_PRECISION (unsigned_type);
7347 mask = build_int_2 (~0, ~0);
7348 TREE_TYPE (mask) = unsigned_type;
7349 force_fit_type (mask, 0);
7350 mask = const_binop (RSHIFT_EXPR, mask,
7351 size_int (precision - size), 0);
7352 newconst = fold (build (BIT_AND_EXPR,
7353 TREE_TYPE (varop), newconst,
7354 fold_convert (TREE_TYPE (varop),
7358 t = build (code, type,
7359 (constopnum == 0) ? newconst : varop,
7360 (constopnum == 1) ? newconst : varop);
7364 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
7366 if (POINTER_TYPE_P (TREE_TYPE (varop))
7367 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
7368 && (code == EQ_EXPR || code == NE_EXPR)))
7371 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
7372 constop, TREE_OPERAND (varop, 1)));
7374 /* Do not overwrite the current varop to be a predecrement,
7375 create a new node so that we won't confuse our caller who
7376 might create trees and throw them away, reusing the
7377 arguments that they passed to build. This shows up in
7378 the THEN or ELSE parts of ?: being postdecrements. */
7379 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
7380 TREE_OPERAND (varop, 0),
7381 TREE_OPERAND (varop, 1));
7383 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
7384 && DECL_BIT_FIELD(TREE_OPERAND
7385 (TREE_OPERAND (varop, 0), 1)))
7388 = TREE_INT_CST_LOW (DECL_SIZE
7390 (TREE_OPERAND (varop, 0), 1)));
7391 tree mask, unsigned_type;
7392 unsigned int precision;
7393 tree folded_compare;
7395 if (constopnum == 0)
7396 folded_compare = fold (build (code, type, constop,
7397 TREE_OPERAND (varop, 0)));
7399 folded_compare = fold (build (code, type,
7400 TREE_OPERAND (varop, 0),
7402 if (integer_zerop (folded_compare)
7403 || integer_onep (folded_compare))
7404 return omit_one_operand (type, folded_compare, varop);
7406 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
7407 precision = TYPE_PRECISION (unsigned_type);
7408 mask = build_int_2 (~0, ~0);
7409 TREE_TYPE (mask) = TREE_TYPE (varop);
7410 force_fit_type (mask, 0);
7411 mask = const_binop (RSHIFT_EXPR, mask,
7412 size_int (precision - size), 0);
7413 newconst = fold (build (BIT_AND_EXPR,
7414 TREE_TYPE (varop), newconst,
7415 fold_convert (TREE_TYPE (varop),
7419 t = build (code, type,
7420 (constopnum == 0) ? newconst : varop,
7421 (constopnum == 1) ? newconst : varop);
7427 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
7428 This transformation affects the cases which are handled in later
7429 optimizations involving comparisons with non-negative constants. */
7430 if (TREE_CODE (arg1) == INTEGER_CST
7431 && TREE_CODE (arg0) != INTEGER_CST
7432 && tree_int_cst_sgn (arg1) > 0)
7437 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7438 return fold (build (GT_EXPR, type, arg0, arg1));
7441 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7442 return fold (build (LE_EXPR, type, arg0, arg1));
7449 /* Comparisons with the highest or lowest possible integer of
7450 the specified size will have known values. */
7452 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
7454 if (TREE_CODE (arg1) == INTEGER_CST
7455 && ! TREE_CONSTANT_OVERFLOW (arg1)
7456 && width <= HOST_BITS_PER_WIDE_INT
7457 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
7458 || POINTER_TYPE_P (TREE_TYPE (arg1))))
7460 unsigned HOST_WIDE_INT signed_max;
7461 unsigned HOST_WIDE_INT max, min;
7463 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
7465 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7467 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
7473 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
7476 if (TREE_INT_CST_HIGH (arg1) == 0
7477 && TREE_INT_CST_LOW (arg1) == max)
7481 return omit_one_operand (type,
7486 return fold (build (EQ_EXPR, type, arg0, arg1));
7489 return omit_one_operand (type,
7494 return fold (build (NE_EXPR, type, arg0, arg1));
7496 /* The GE_EXPR and LT_EXPR cases above are not normally
7497 reached because of previous transformations. */
7502 else if (TREE_INT_CST_HIGH (arg1) == 0
7503 && TREE_INT_CST_LOW (arg1) == max - 1)
7507 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7508 return fold (build (EQ_EXPR, type, arg0, arg1));
7510 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
7511 return fold (build (NE_EXPR, type, arg0, arg1));
7515 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7516 && TREE_INT_CST_LOW (arg1) == min)
7520 return omit_one_operand (type,
7525 return fold (build (EQ_EXPR, type, arg0, arg1));
7528 return omit_one_operand (type,
7533 return fold (build (NE_EXPR, type, arg0, arg1));
7538 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
7539 && TREE_INT_CST_LOW (arg1) == min + 1)
7543 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7544 return fold (build (NE_EXPR, type, arg0, arg1));
7546 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
7547 return fold (build (EQ_EXPR, type, arg0, arg1));
7552 else if (TREE_INT_CST_HIGH (arg1) == 0
7553 && TREE_INT_CST_LOW (arg1) == signed_max
7554 && TREE_UNSIGNED (TREE_TYPE (arg1))
7555 /* signed_type does not work on pointer types. */
7556 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
7558 /* The following case also applies to X < signed_max+1
7559 and X >= signed_max+1 because previous transformations. */
7560 if (code == LE_EXPR || code == GT_EXPR)
7563 st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
7564 st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
7566 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
7567 type, fold_convert (st0, arg0),
7568 fold_convert (st1, integer_zero_node)));
7574 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
7575 a MINUS_EXPR of a constant, we can convert it into a comparison with
7576 a revised constant as long as no overflow occurs. */
7577 if ((code == EQ_EXPR || code == NE_EXPR)
7578 && TREE_CODE (arg1) == INTEGER_CST
7579 && (TREE_CODE (arg0) == PLUS_EXPR
7580 || TREE_CODE (arg0) == MINUS_EXPR)
7581 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7582 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
7583 ? MINUS_EXPR : PLUS_EXPR,
7584 arg1, TREE_OPERAND (arg0, 1), 0))
7585 && ! TREE_CONSTANT_OVERFLOW (tem))
7586 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7588 /* Similarly for a NEGATE_EXPR. */
7589 else if ((code == EQ_EXPR || code == NE_EXPR)
7590 && TREE_CODE (arg0) == NEGATE_EXPR
7591 && TREE_CODE (arg1) == INTEGER_CST
7592 && 0 != (tem = negate_expr (arg1))
7593 && TREE_CODE (tem) == INTEGER_CST
7594 && ! TREE_CONSTANT_OVERFLOW (tem))
7595 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
7597 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7598 for !=. Don't do this for ordered comparisons due to overflow. */
7599 else if ((code == NE_EXPR || code == EQ_EXPR)
7600 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
7601 return fold (build (code, type,
7602 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
7604 /* If we are widening one operand of an integer comparison,
7605 see if the other operand is similarly being widened. Perhaps we
7606 can do the comparison in the narrower type. */
7607 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
7608 && TREE_CODE (arg0) == NOP_EXPR
7609 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
7610 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
7611 && (TREE_TYPE (t1) == TREE_TYPE (tem)
7612 || (TREE_CODE (t1) == INTEGER_CST
7613 && int_fits_type_p (t1, TREE_TYPE (tem)))))
7614 return fold (build (code, type, tem,
7615 fold_convert (TREE_TYPE (tem), t1)));
7617 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7618 constant, we can simplify it. */
7619 else if (TREE_CODE (arg1) == INTEGER_CST
7620 && (TREE_CODE (arg0) == MIN_EXPR
7621 || TREE_CODE (arg0) == MAX_EXPR)
7622 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7623 return optimize_minmax_comparison (t);
7625 /* If we are comparing an ABS_EXPR with a constant, we can
7626 convert all the cases into explicit comparisons, but they may
7627 well not be faster than doing the ABS and one comparison.
7628 But ABS (X) <= C is a range comparison, which becomes a subtraction
7629 and a comparison, and is probably faster. */
7630 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7631 && TREE_CODE (arg0) == ABS_EXPR
7632 && ! TREE_SIDE_EFFECTS (arg0)
7633 && (0 != (tem = negate_expr (arg1)))
7634 && TREE_CODE (tem) == INTEGER_CST
7635 && ! TREE_CONSTANT_OVERFLOW (tem))
7636 return fold (build (TRUTH_ANDIF_EXPR, type,
7637 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
7638 build (LE_EXPR, type,
7639 TREE_OPERAND (arg0, 0), arg1)));
7641 /* If this is an EQ or NE comparison with zero and ARG0 is
7642 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7643 two operations, but the latter can be done in one less insn
7644 on machines that have only two-operand insns or on which a
7645 constant cannot be the first operand. */
7646 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
7647 && TREE_CODE (arg0) == BIT_AND_EXPR)
7649 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
7650 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
7652 fold (build (code, type,
7653 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7655 TREE_TYPE (TREE_OPERAND (arg0, 0)),
7656 TREE_OPERAND (arg0, 1),
7657 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
7658 fold_convert (TREE_TYPE (arg0),
7661 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
7662 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
7664 fold (build (code, type,
7665 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7667 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7668 TREE_OPERAND (arg0, 0),
7669 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
7670 fold_convert (TREE_TYPE (arg0),
7675 /* If this is an NE or EQ comparison of zero against the result of a
7676 signed MOD operation whose second operand is a power of 2, make
7677 the MOD operation unsigned since it is simpler and equivalent. */
7678 if ((code == NE_EXPR || code == EQ_EXPR)
7679 && integer_zerop (arg1)
7680 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
7681 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
7682 || TREE_CODE (arg0) == CEIL_MOD_EXPR
7683 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
7684 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
7685 && integer_pow2p (TREE_OPERAND (arg0, 1)))
7687 tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
7688 tree newmod = build (TREE_CODE (arg0), newtype,
7689 fold_convert (newtype,
7690 TREE_OPERAND (arg0, 0)),
7691 fold_convert (newtype,
7692 TREE_OPERAND (arg0, 1)));
7694 return build (code, type, newmod, fold_convert (newtype, arg1));
7697 /* If this is an NE comparison of zero with an AND of one, remove the
7698 comparison since the AND will give the correct value. */
7699 if (code == NE_EXPR && integer_zerop (arg1)
7700 && TREE_CODE (arg0) == BIT_AND_EXPR
7701 && integer_onep (TREE_OPERAND (arg0, 1)))
7702 return fold_convert (type, arg0);
7704 /* If we have (A & C) == C where C is a power of 2, convert this into
7705 (A & C) != 0. Similarly for NE_EXPR. */
7706 if ((code == EQ_EXPR || code == NE_EXPR)
7707 && TREE_CODE (arg0) == BIT_AND_EXPR
7708 && integer_pow2p (TREE_OPERAND (arg0, 1))
7709 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
7710 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
7711 arg0, integer_zero_node));
7713 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7714 2, then fold the expression into shifts and logical operations. */
7715 tem = fold_single_bit_test (code, arg0, arg1, type);
7719 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
7720 Similarly for NE_EXPR. */
7721 if ((code == EQ_EXPR || code == NE_EXPR)
7722 && TREE_CODE (arg0) == BIT_AND_EXPR
7723 && TREE_CODE (arg1) == INTEGER_CST
7724 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7727 = fold (build (BIT_AND_EXPR, TREE_TYPE (arg0),
7728 arg1, build1 (BIT_NOT_EXPR,
7729 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7730 TREE_OPERAND (arg0, 1))));
7731 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7732 if (integer_nonzerop (dandnotc))
7733 return omit_one_operand (type, rslt, arg0);
7736 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
7737 Similarly for NE_EXPR. */
7738 if ((code == EQ_EXPR || code == NE_EXPR)
7739 && TREE_CODE (arg0) == BIT_IOR_EXPR
7740 && TREE_CODE (arg1) == INTEGER_CST
7741 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7744 = fold (build (BIT_AND_EXPR, TREE_TYPE (arg0),
7745 TREE_OPERAND (arg0, 1),
7746 build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1)));
7747 tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
7748 if (integer_nonzerop (candnotd))
7749 return omit_one_operand (type, rslt, arg0);
7752 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7753 and similarly for >= into !=. */
7754 if ((code == LT_EXPR || code == GE_EXPR)
7755 && TREE_UNSIGNED (TREE_TYPE (arg0))
7756 && TREE_CODE (arg1) == LSHIFT_EXPR
7757 && integer_onep (TREE_OPERAND (arg1, 0)))
7758 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7759 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7760 TREE_OPERAND (arg1, 1)),
7761 fold_convert (TREE_TYPE (arg0), integer_zero_node));
7763 else if ((code == LT_EXPR || code == GE_EXPR)
7764 && TREE_UNSIGNED (TREE_TYPE (arg0))
7765 && (TREE_CODE (arg1) == NOP_EXPR
7766 || TREE_CODE (arg1) == CONVERT_EXPR)
7767 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
7768 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
7770 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7771 fold_convert (TREE_TYPE (arg0),
7772 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7773 TREE_OPERAND (TREE_OPERAND (arg1, 0),
7775 fold_convert (TREE_TYPE (arg0), integer_zero_node));
7777 /* Simplify comparison of something with itself. (For IEEE
7778 floating-point, we can only do some of these simplifications.) */
7779 if (operand_equal_p (arg0, arg1, 0))
7784 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7785 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7786 return constant_boolean_node (1, type);
7791 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7792 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7793 return constant_boolean_node (1, type);
7794 return fold (build (EQ_EXPR, type, arg0, arg1));
7797 /* For NE, we can only do this simplification if integer
7798 or we don't honor IEEE floating point NaNs. */
7799 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
7800 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7802 /* ... fall through ... */
7805 return constant_boolean_node (0, type);
7811 /* If we are comparing an expression that just has comparisons
7812 of two integer values, arithmetic expressions of those comparisons,
7813 and constants, we can simplify it. There are only three cases
7814 to check: the two values can either be equal, the first can be
7815 greater, or the second can be greater. Fold the expression for
7816 those three values. Since each value must be 0 or 1, we have
7817 eight possibilities, each of which corresponds to the constant 0
7818 or 1 or one of the six possible comparisons.
7820 This handles common cases like (a > b) == 0 but also handles
7821 expressions like ((x > y) - (y > x)) > 0, which supposedly
7822 occur in macroized code. */
7824 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7826 tree cval1 = 0, cval2 = 0;
7829 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7830 /* Don't handle degenerate cases here; they should already
7831 have been handled anyway. */
7832 && cval1 != 0 && cval2 != 0
7833 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7834 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7835 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7836 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7837 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7838 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7839 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7841 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7842 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7844 /* We can't just pass T to eval_subst in case cval1 or cval2
7845 was the same as ARG1. */
7848 = fold (build (code, type,
7849 eval_subst (arg0, cval1, maxval, cval2, minval),
7852 = fold (build (code, type,
7853 eval_subst (arg0, cval1, maxval, cval2, maxval),
7856 = fold (build (code, type,
7857 eval_subst (arg0, cval1, minval, cval2, maxval),
7860 /* All three of these results should be 0 or 1. Confirm they
7861 are. Then use those values to select the proper code
7864 if ((integer_zerop (high_result)
7865 || integer_onep (high_result))
7866 && (integer_zerop (equal_result)
7867 || integer_onep (equal_result))
7868 && (integer_zerop (low_result)
7869 || integer_onep (low_result)))
7871 /* Make a 3-bit mask with the high-order bit being the
7872 value for `>', the next for '=', and the low for '<'. */
7873 switch ((integer_onep (high_result) * 4)
7874 + (integer_onep (equal_result) * 2)
7875 + integer_onep (low_result))
7879 return omit_one_operand (type, integer_zero_node, arg0);
7900 return omit_one_operand (type, integer_one_node, arg0);
7903 t = build (code, type, cval1, cval2);
7905 return save_expr (t);
7912 /* If this is a comparison of a field, we may be able to simplify it. */
7913 if (((TREE_CODE (arg0) == COMPONENT_REF
7914 && (*lang_hooks.can_use_bit_fields_p) ())
7915 || TREE_CODE (arg0) == BIT_FIELD_REF)
7916 && (code == EQ_EXPR || code == NE_EXPR)
7917 /* Handle the constant case even without -O
7918 to make sure the warnings are given. */
7919 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7921 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7926 /* If this is a comparison of complex values and either or both sides
7927 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7928 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7929 This may prevent needless evaluations. */
7930 if ((code == EQ_EXPR || code == NE_EXPR)
7931 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7932 && (TREE_CODE (arg0) == COMPLEX_EXPR
7933 || TREE_CODE (arg1) == COMPLEX_EXPR
7934 || TREE_CODE (arg0) == COMPLEX_CST
7935 || TREE_CODE (arg1) == COMPLEX_CST))
7937 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7938 tree real0, imag0, real1, imag1;
7940 arg0 = save_expr (arg0);
7941 arg1 = save_expr (arg1);
7942 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7943 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7944 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7945 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7947 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7950 fold (build (code, type, real0, real1)),
7951 fold (build (code, type, imag0, imag1))));
7954 /* Optimize comparisons of strlen vs zero to a compare of the
7955 first character of the string vs zero. To wit,
7956 strlen(ptr) == 0 => *ptr == 0
7957 strlen(ptr) != 0 => *ptr != 0
7958 Other cases should reduce to one of these two (or a constant)
7959 due to the return value of strlen being unsigned. */
7960 if ((code == EQ_EXPR || code == NE_EXPR)
7961 && integer_zerop (arg1)
7962 && TREE_CODE (arg0) == CALL_EXPR)
7964 tree fndecl = get_callee_fndecl (arg0);
7968 && DECL_BUILT_IN (fndecl)
7969 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7970 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7971 && (arglist = TREE_OPERAND (arg0, 1))
7972 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7973 && ! TREE_CHAIN (arglist))
7974 return fold (build (code, type,
7975 build1 (INDIRECT_REF, char_type_node,
7976 TREE_VALUE(arglist)),
7977 integer_zero_node));
7980 /* From here on, the only cases we handle are when the result is
7981 known to be a constant.
7983 To compute GT, swap the arguments and do LT.
7984 To compute GE, do LT and invert the result.
7985 To compute LE, swap the arguments, do LT and invert the result.
7986 To compute NE, do EQ and invert the result.
7988 Therefore, the code below must handle only EQ and LT. */
7990 if (code == LE_EXPR || code == GT_EXPR)
7992 tem = arg0, arg0 = arg1, arg1 = tem;
7993 code = swap_tree_comparison (code);
7996 /* Note that it is safe to invert for real values here because we
7997 will check below in the one case that it matters. */
8001 if (code == NE_EXPR || code == GE_EXPR)
8004 code = invert_tree_comparison (code);
8007 /* Compute a result for LT or EQ if args permit;
8008 otherwise return T. */
8009 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
8011 if (code == EQ_EXPR)
8012 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
8014 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
8015 ? INT_CST_LT_UNSIGNED (arg0, arg1)
8016 : INT_CST_LT (arg0, arg1)),
8020 #if 0 /* This is no longer useful, but breaks some real code. */
8021 /* Assume a nonexplicit constant cannot equal an explicit one,
8022 since such code would be undefined anyway.
8023 Exception: on sysvr4, using #pragma weak,
8024 a label can come out as 0. */
8025 else if (TREE_CODE (arg1) == INTEGER_CST
8026 && !integer_zerop (arg1)
8027 && TREE_CONSTANT (arg0)
8028 && TREE_CODE (arg0) == ADDR_EXPR
8030 t1 = build_int_2 (0, 0);
8032 /* Two real constants can be compared explicitly. */
8033 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
8035 /* If either operand is a NaN, the result is false with two
8036 exceptions: First, an NE_EXPR is true on NaNs, but that case
8037 is already handled correctly since we will be inverting the
8038 result for NE_EXPR. Second, if we had inverted a LE_EXPR
8039 or a GE_EXPR into a LT_EXPR, we must return true so that it
8040 will be inverted into false. */
8042 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
8043 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
8044 t1 = build_int_2 (invert && code == LT_EXPR, 0);
8046 else if (code == EQ_EXPR)
8047 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
8048 TREE_REAL_CST (arg1)),
8051 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
8052 TREE_REAL_CST (arg1)),
8056 if (t1 == NULL_TREE)
8060 TREE_INT_CST_LOW (t1) ^= 1;
8062 TREE_TYPE (t1) = type;
8063 if (TREE_CODE (type) == BOOLEAN_TYPE)
8064 return (*lang_hooks.truthvalue_conversion) (t1);
8068 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
8069 so all simple results must be passed through pedantic_non_lvalue. */
8070 if (TREE_CODE (arg0) == INTEGER_CST)
8072 tem = TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1));
8073 /* Only optimize constant conditions when the selected branch
8074 has the same type as the COND_EXPR. This avoids optimizing
8075 away "c ? x : throw", where the throw has a void type. */
8076 if (! VOID_TYPE_P (TREE_TYPE (tem))
8077 || VOID_TYPE_P (TREE_TYPE (t)))
8078 return pedantic_non_lvalue (tem);
8081 if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
8082 return pedantic_omit_one_operand (type, arg1, arg0);
8084 /* If we have A op B ? A : C, we may be able to convert this to a
8085 simpler expression, depending on the operation and the values
8086 of B and C. Signed zeros prevent all of these transformations,
8087 for reasons given above each one. */
8089 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
8090 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
8091 arg1, TREE_OPERAND (arg0, 1))
8092 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
8094 tree arg2 = TREE_OPERAND (t, 2);
8095 enum tree_code comp_code = TREE_CODE (arg0);
8099 /* If we have A op 0 ? A : -A, consider applying the following
8102 A == 0? A : -A same as -A
8103 A != 0? A : -A same as A
8104 A >= 0? A : -A same as abs (A)
8105 A > 0? A : -A same as abs (A)
8106 A <= 0? A : -A same as -abs (A)
8107 A < 0? A : -A same as -abs (A)
8109 None of these transformations work for modes with signed
8110 zeros. If A is +/-0, the first two transformations will
8111 change the sign of the result (from +0 to -0, or vice
8112 versa). The last four will fix the sign of the result,
8113 even though the original expressions could be positive or
8114 negative, depending on the sign of A.
8116 Note that all these transformations are correct if A is
8117 NaN, since the two alternatives (A and -A) are also NaNs. */
8118 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
8119 ? real_zerop (TREE_OPERAND (arg0, 1))
8120 : integer_zerop (TREE_OPERAND (arg0, 1)))
8121 && TREE_CODE (arg2) == NEGATE_EXPR
8122 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
8126 tem = fold_convert (TREE_TYPE (TREE_OPERAND (t, 1)), arg1);
8127 tem = fold_convert (type, negate_expr (tem));
8128 return pedantic_non_lvalue (tem);
8130 return pedantic_non_lvalue (fold_convert (type, arg1));
8133 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
8134 arg1 = fold_convert ((*lang_hooks.types.signed_type)
8135 (TREE_TYPE (arg1)), arg1);
8136 arg1 = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
8137 return pedantic_non_lvalue (fold_convert (type, arg1));
8140 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
8141 arg1 = fold_convert ((lang_hooks.types.signed_type)
8142 (TREE_TYPE (arg1)), arg1);
8143 arg1 = fold (build1 (ABS_EXPR, TREE_TYPE (arg1), arg1));
8144 arg1 = negate_expr (fold_convert (type, arg1));
8145 return pedantic_non_lvalue (arg1);
8150 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
8151 A == 0 ? A : 0 is always 0 unless A is -0. Note that
8152 both transformations are correct when A is NaN: A != 0
8153 is then true, and A == 0 is false. */
8155 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
8157 if (comp_code == NE_EXPR)
8158 return pedantic_non_lvalue (fold_convert (type, arg1));
8159 else if (comp_code == EQ_EXPR)
8160 return pedantic_non_lvalue (fold_convert (type, integer_zero_node));
8163 /* Try some transformations of A op B ? A : B.
8165 A == B? A : B same as B
8166 A != B? A : B same as A
8167 A >= B? A : B same as max (A, B)
8168 A > B? A : B same as max (B, A)
8169 A <= B? A : B same as min (A, B)
8170 A < B? A : B same as min (B, A)
8172 As above, these transformations don't work in the presence
8173 of signed zeros. For example, if A and B are zeros of
8174 opposite sign, the first two transformations will change
8175 the sign of the result. In the last four, the original
8176 expressions give different results for (A=+0, B=-0) and
8177 (A=-0, B=+0), but the transformed expressions do not.
8179 The first two transformations are correct if either A or B
8180 is a NaN. In the first transformation, the condition will
8181 be false, and B will indeed be chosen. In the case of the
8182 second transformation, the condition A != B will be true,
8183 and A will be chosen.
8185 The conversions to max() and min() are not correct if B is
8186 a number and A is not. The conditions in the original
8187 expressions will be false, so all four give B. The min()
8188 and max() versions would give a NaN instead. */
8189 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
8190 arg2, TREE_OPERAND (arg0, 0)))
8192 tree comp_op0 = TREE_OPERAND (arg0, 0);
8193 tree comp_op1 = TREE_OPERAND (arg0, 1);
8194 tree comp_type = TREE_TYPE (comp_op0);
8196 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
8197 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
8207 return pedantic_non_lvalue (fold_convert (type, arg2));
8209 return pedantic_non_lvalue (fold_convert (type, arg1));
8212 /* In C++ a ?: expression can be an lvalue, so put the
8213 operand which will be used if they are equal first
8214 so that we can convert this back to the
8215 corresponding COND_EXPR. */
8216 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
8217 return pedantic_non_lvalue (fold_convert
8218 (type, fold (build (MIN_EXPR, comp_type,
8219 (comp_code == LE_EXPR
8220 ? comp_op0 : comp_op1),
8221 (comp_code == LE_EXPR
8222 ? comp_op1 : comp_op0)))));
8226 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
8227 return pedantic_non_lvalue (fold_convert
8228 (type, fold (build (MAX_EXPR, comp_type,
8229 (comp_code == GE_EXPR
8230 ? comp_op0 : comp_op1),
8231 (comp_code == GE_EXPR
8232 ? comp_op1 : comp_op0)))));
8239 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
8240 we might still be able to simplify this. For example,
8241 if C1 is one less or one more than C2, this might have started
8242 out as a MIN or MAX and been transformed by this function.
8243 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
8245 if (INTEGRAL_TYPE_P (type)
8246 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
8247 && TREE_CODE (arg2) == INTEGER_CST)
8251 /* We can replace A with C1 in this case. */
8252 arg1 = fold_convert (type, TREE_OPERAND (arg0, 1));
8253 return fold (build (code, type, TREE_OPERAND (t, 0), arg1,
8254 TREE_OPERAND (t, 2)));
8257 /* If C1 is C2 + 1, this is min(A, C2). */
8258 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
8259 && operand_equal_p (TREE_OPERAND (arg0, 1),
8260 const_binop (PLUS_EXPR, arg2,
8261 integer_one_node, 0), 1))
8262 return pedantic_non_lvalue
8263 (fold (build (MIN_EXPR, type, arg1, arg2)));
8267 /* If C1 is C2 - 1, this is min(A, C2). */
8268 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
8269 && operand_equal_p (TREE_OPERAND (arg0, 1),
8270 const_binop (MINUS_EXPR, arg2,
8271 integer_one_node, 0), 1))
8272 return pedantic_non_lvalue
8273 (fold (build (MIN_EXPR, type, arg1, arg2)));
8277 /* If C1 is C2 - 1, this is max(A, C2). */
8278 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
8279 && operand_equal_p (TREE_OPERAND (arg0, 1),
8280 const_binop (MINUS_EXPR, arg2,
8281 integer_one_node, 0), 1))
8282 return pedantic_non_lvalue
8283 (fold (build (MAX_EXPR, type, arg1, arg2)));
8287 /* If C1 is C2 + 1, this is max(A, C2). */
8288 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
8289 && operand_equal_p (TREE_OPERAND (arg0, 1),
8290 const_binop (PLUS_EXPR, arg2,
8291 integer_one_node, 0), 1))
8292 return pedantic_non_lvalue
8293 (fold (build (MAX_EXPR, type, arg1, arg2)));
8302 /* If the second operand is simpler than the third, swap them
8303 since that produces better jump optimization results. */
8304 if (tree_swap_operands_p (TREE_OPERAND (t, 1),
8305 TREE_OPERAND (t, 2), false))
8307 /* See if this can be inverted. If it can't, possibly because
8308 it was a floating-point inequality comparison, don't do
8310 tem = invert_truthvalue (arg0);
8312 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8313 return fold (build (code, type, tem,
8314 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1)));
8317 /* Convert A ? 1 : 0 to simply A. */
8318 if (integer_onep (TREE_OPERAND (t, 1))
8319 && integer_zerop (TREE_OPERAND (t, 2))
8320 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8321 call to fold will try to move the conversion inside
8322 a COND, which will recurse. In that case, the COND_EXPR
8323 is probably the best choice, so leave it alone. */
8324 && type == TREE_TYPE (arg0))
8325 return pedantic_non_lvalue (arg0);
8327 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8328 over COND_EXPR in cases such as floating point comparisons. */
8329 if (integer_zerop (TREE_OPERAND (t, 1))
8330 && integer_onep (TREE_OPERAND (t, 2))
8331 && truth_value_p (TREE_CODE (arg0)))
8332 return pedantic_non_lvalue (fold_convert (type,
8333 invert_truthvalue (arg0)));
8335 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
8336 operation is simply A & 2. */
8338 if (integer_zerop (TREE_OPERAND (t, 2))
8339 && TREE_CODE (arg0) == NE_EXPR
8340 && integer_zerop (TREE_OPERAND (arg0, 1))
8341 && integer_pow2p (arg1)
8342 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
8343 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
8345 return pedantic_non_lvalue (fold_convert (type,
8346 TREE_OPERAND (arg0, 0)));
8348 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8349 if (integer_zerop (TREE_OPERAND (t, 2))
8350 && truth_value_p (TREE_CODE (arg0))
8351 && truth_value_p (TREE_CODE (arg1)))
8352 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
8355 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8356 if (integer_onep (TREE_OPERAND (t, 2))
8357 && truth_value_p (TREE_CODE (arg0))
8358 && truth_value_p (TREE_CODE (arg1)))
8360 /* Only perform transformation if ARG0 is easily inverted. */
8361 tem = invert_truthvalue (arg0);
8362 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
8363 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
8370 /* When pedantic, a compound expression can be neither an lvalue
8371 nor an integer constant expression. */
8372 if (TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
8374 /* Don't let (0, 0) be null pointer constant. */
8375 tem = integer_zerop (arg1) ? build1 (NOP_EXPR, type, arg1)
8376 : fold_convert (type, arg1);
8377 return pedantic_non_lvalue (tem);
8381 return build_complex (type, arg0, arg1);
8385 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8387 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8388 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
8389 TREE_OPERAND (arg0, 1));
8390 else if (TREE_CODE (arg0) == COMPLEX_CST)
8391 return TREE_REALPART (arg0);
8392 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8393 return fold (build (TREE_CODE (arg0), type,
8394 fold (build1 (REALPART_EXPR, type,
8395 TREE_OPERAND (arg0, 0))),
8396 fold (build1 (REALPART_EXPR,
8397 type, TREE_OPERAND (arg0, 1)))));
8401 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
8402 return fold_convert (type, integer_zero_node);
8403 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
8404 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
8405 TREE_OPERAND (arg0, 0));
8406 else if (TREE_CODE (arg0) == COMPLEX_CST)
8407 return TREE_IMAGPART (arg0);
8408 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
8409 return fold (build (TREE_CODE (arg0), type,
8410 fold (build1 (IMAGPART_EXPR, type,
8411 TREE_OPERAND (arg0, 0))),
8412 fold (build1 (IMAGPART_EXPR, type,
8413 TREE_OPERAND (arg0, 1)))));
8416 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8418 case CLEANUP_POINT_EXPR:
8419 if (! has_cleanups (arg0))
8420 return TREE_OPERAND (t, 0);
8423 enum tree_code code0 = TREE_CODE (arg0);
8424 int kind0 = TREE_CODE_CLASS (code0);
8425 tree arg00 = TREE_OPERAND (arg0, 0);
8428 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
8429 return fold (build1 (code0, type,
8430 fold (build1 (CLEANUP_POINT_EXPR,
8431 TREE_TYPE (arg00), arg00))));
8433 if (kind0 == '<' || kind0 == '2'
8434 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
8435 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
8436 || code0 == TRUTH_XOR_EXPR)
8438 arg01 = TREE_OPERAND (arg0, 1);
8440 if (TREE_CONSTANT (arg00)
8441 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
8442 && ! has_cleanups (arg00)))
8443 return fold (build (code0, type, arg00,
8444 fold (build1 (CLEANUP_POINT_EXPR,
8445 TREE_TYPE (arg01), arg01))));
8447 if (TREE_CONSTANT (arg01))
8448 return fold (build (code0, type,
8449 fold (build1 (CLEANUP_POINT_EXPR,
8450 TREE_TYPE (arg00), arg00)),
8458 /* Check for a built-in function. */
8459 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
8460 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
8462 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
8464 tree tmp = fold_builtin (expr);
8472 } /* switch (code) */
8475 #ifdef ENABLE_FOLD_CHECKING
8478 static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
8479 static void fold_check_failed (tree, tree);
8480 void print_fold_checksum (tree);
8482 /* When --enable-checking=fold, compute a digest of expr before
8483 and after actual fold call to see if fold did not accidentally
8484 change original expr. */
8491 unsigned char checksum_before[16], checksum_after[16];
8494 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8495 md5_init_ctx (&ctx);
8496 fold_checksum_tree (expr, &ctx, ht);
8497 md5_finish_ctx (&ctx, checksum_before);
8500 ret = fold_1 (expr);
8502 md5_init_ctx (&ctx);
8503 fold_checksum_tree (expr, &ctx, ht);
8504 md5_finish_ctx (&ctx, checksum_after);
8507 if (memcmp (checksum_before, checksum_after, 16))
8508 fold_check_failed (expr, ret);
8514 print_fold_checksum (tree expr)
8517 unsigned char checksum[16], cnt;
8520 ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
8521 md5_init_ctx (&ctx);
8522 fold_checksum_tree (expr, &ctx, ht);
8523 md5_finish_ctx (&ctx, checksum);
8525 for (cnt = 0; cnt < 16; ++cnt)
8526 fprintf (stderr, "%02x", checksum[cnt]);
8527 putc ('\n', stderr);
8531 fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
8533 internal_error ("fold check: original tree changed by fold");
8537 fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
8540 enum tree_code code;
8541 char buf[sizeof (struct tree_decl)];
8544 if (sizeof (struct tree_exp) + 5 * sizeof (tree)
8545 > sizeof (struct tree_decl)
8546 || sizeof (struct tree_type) > sizeof (struct tree_decl))
8550 slot = htab_find_slot (ht, expr, INSERT);
8554 code = TREE_CODE (expr);
8555 if (code == SAVE_EXPR && SAVE_EXPR_NOPLACEHOLDER (expr))
8557 /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
8558 memcpy (buf, expr, tree_size (expr));
8560 SAVE_EXPR_NOPLACEHOLDER (expr) = 0;
8562 else if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
8564 /* Allow DECL_ASSEMBLER_NAME to be modified. */
8565 memcpy (buf, expr, tree_size (expr));
8567 SET_DECL_ASSEMBLER_NAME (expr, NULL);
8569 else if (TREE_CODE_CLASS (code) == 't'
8570 && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
8572 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
8573 memcpy (buf, expr, tree_size (expr));
8575 TYPE_POINTER_TO (expr) = NULL;
8576 TYPE_REFERENCE_TO (expr) = NULL;
8578 md5_process_bytes (expr, tree_size (expr), ctx);
8579 fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
8580 if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
8581 fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
8582 len = TREE_CODE_LENGTH (code);
8583 switch (TREE_CODE_CLASS (code))
8589 md5_process_bytes (TREE_STRING_POINTER (expr),
8590 TREE_STRING_LENGTH (expr), ctx);
8593 fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
8594 fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
8597 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
8607 fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
8608 fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
8611 for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
8612 fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
8621 case SAVE_EXPR: len = 2; break;
8622 case GOTO_SUBROUTINE_EXPR: len = 0; break;
8623 case RTL_EXPR: len = 0; break;
8624 case WITH_CLEANUP_EXPR: len = 2; break;
8633 for (i = 0; i < len; ++i)
8634 fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
8637 fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
8638 fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
8639 fold_checksum_tree (DECL_NAME (expr), ctx, ht);
8640 fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
8641 fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
8642 fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
8643 fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
8644 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
8645 fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
8646 fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
8647 fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
8650 fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
8651 fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
8652 fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
8653 fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
8654 fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
8655 fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
8656 fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
8657 fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
8658 fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
8659 fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
8668 /* Perform constant folding and related simplification of initializer
8669 expression EXPR. This behaves identically to "fold" but ignores
8670 potential run-time traps and exceptions that fold must preserve. */
8673 fold_initializer (tree expr)
8675 int saved_signaling_nans = flag_signaling_nans;
8676 int saved_trapping_math = flag_trapping_math;
8677 int saved_trapv = flag_trapv;
8680 flag_signaling_nans = 0;
8681 flag_trapping_math = 0;
8684 result = fold (expr);
8686 flag_signaling_nans = saved_signaling_nans;
8687 flag_trapping_math = saved_trapping_math;
8688 flag_trapv = saved_trapv;
8693 /* Determine if first argument is a multiple of second argument. Return 0 if
8694 it is not, or we cannot easily determined it to be.
8696 An example of the sort of thing we care about (at this point; this routine
8697 could surely be made more general, and expanded to do what the *_DIV_EXPR's
8698 fold cases do now) is discovering that
8700 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8706 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
8708 This code also handles discovering that
8710 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8712 is a multiple of 8 so we don't have to worry about dealing with a
8715 Note that we *look* inside a SAVE_EXPR only to determine how it was
8716 calculated; it is not safe for fold to do much of anything else with the
8717 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
8718 at run time. For example, the latter example above *cannot* be implemented
8719 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
8720 evaluation time of the original SAVE_EXPR is not necessarily the same at
8721 the time the new expression is evaluated. The only optimization of this
8722 sort that would be valid is changing
8724 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
8728 SAVE_EXPR (I) * SAVE_EXPR (J)
8730 (where the same SAVE_EXPR (J) is used in the original and the
8731 transformed version). */
8734 multiple_of_p (tree type, tree top, tree bottom)
8736 if (operand_equal_p (top, bottom, 0))
8739 if (TREE_CODE (type) != INTEGER_TYPE)
8742 switch (TREE_CODE (top))
8745 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8746 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8750 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
8751 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
8754 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
8758 op1 = TREE_OPERAND (top, 1);
8759 /* const_binop may not detect overflow correctly,
8760 so check for it explicitly here. */
8761 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
8762 > TREE_INT_CST_LOW (op1)
8763 && TREE_INT_CST_HIGH (op1) == 0
8764 && 0 != (t1 = fold_convert (type,
8765 const_binop (LSHIFT_EXPR,
8768 && ! TREE_OVERFLOW (t1))
8769 return multiple_of_p (type, t1, bottom);
8774 /* Can't handle conversions from non-integral or wider integral type. */
8775 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
8776 || (TYPE_PRECISION (type)
8777 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
8780 /* .. fall through ... */
8783 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
8786 if (TREE_CODE (bottom) != INTEGER_CST
8787 || (TREE_UNSIGNED (type)
8788 && (tree_int_cst_sgn (top) < 0
8789 || tree_int_cst_sgn (bottom) < 0)))
8791 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
8799 /* Return true if `t' is known to be non-negative. */
8802 tree_expr_nonnegative_p (tree t)
8804 switch (TREE_CODE (t))
8810 return tree_int_cst_sgn (t) >= 0;
8813 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
8816 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8817 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8818 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8820 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8821 both unsigned and at least 2 bits shorter than the result. */
8822 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8823 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8824 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8826 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8827 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8828 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8829 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8831 unsigned int prec = MAX (TYPE_PRECISION (inner1),
8832 TYPE_PRECISION (inner2)) + 1;
8833 return prec < TYPE_PRECISION (TREE_TYPE (t));
8839 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8841 /* x * x for floating point x is always non-negative. */
8842 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
8844 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8845 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8848 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8849 both unsigned and their total bits is shorter than the result. */
8850 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8851 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8852 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8854 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8855 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8856 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8857 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8858 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
8859 < TYPE_PRECISION (TREE_TYPE (t));
8863 case TRUNC_DIV_EXPR:
8865 case FLOOR_DIV_EXPR:
8866 case ROUND_DIV_EXPR:
8867 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8868 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8870 case TRUNC_MOD_EXPR:
8872 case FLOOR_MOD_EXPR:
8873 case ROUND_MOD_EXPR:
8874 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8877 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8878 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8882 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8883 tree outer_type = TREE_TYPE (t);
8885 if (TREE_CODE (outer_type) == REAL_TYPE)
8887 if (TREE_CODE (inner_type) == REAL_TYPE)
8888 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8889 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8891 if (TREE_UNSIGNED (inner_type))
8893 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8896 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
8898 if (TREE_CODE (inner_type) == REAL_TYPE)
8899 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
8900 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8901 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
8902 && TREE_UNSIGNED (inner_type);
8908 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8909 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
8911 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8913 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8914 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8916 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8917 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8919 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8921 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8923 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8924 case NON_LVALUE_EXPR:
8925 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8927 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8929 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
8933 tree fndecl = get_callee_fndecl (t);
8934 tree arglist = TREE_OPERAND (t, 1);
8936 && DECL_BUILT_IN (fndecl)
8937 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
8938 switch (DECL_FUNCTION_CODE (fndecl))
8941 case BUILT_IN_CABSL:
8942 case BUILT_IN_CABSF:
8947 case BUILT_IN_EXP2F:
8948 case BUILT_IN_EXP2L:
8949 case BUILT_IN_EXP10:
8950 case BUILT_IN_EXP10F:
8951 case BUILT_IN_EXP10L:
8953 case BUILT_IN_FABSF:
8954 case BUILT_IN_FABSL:
8957 case BUILT_IN_FFSLL:
8958 case BUILT_IN_PARITY:
8959 case BUILT_IN_PARITYL:
8960 case BUILT_IN_PARITYLL:
8961 case BUILT_IN_POPCOUNT:
8962 case BUILT_IN_POPCOUNTL:
8963 case BUILT_IN_POPCOUNTLL:
8964 case BUILT_IN_POW10:
8965 case BUILT_IN_POW10F:
8966 case BUILT_IN_POW10L:
8968 case BUILT_IN_SQRTF:
8969 case BUILT_IN_SQRTL:
8973 case BUILT_IN_ATANF:
8974 case BUILT_IN_ATANL:
8976 case BUILT_IN_CEILF:
8977 case BUILT_IN_CEILL:
8978 case BUILT_IN_FLOOR:
8979 case BUILT_IN_FLOORF:
8980 case BUILT_IN_FLOORL:
8981 case BUILT_IN_NEARBYINT:
8982 case BUILT_IN_NEARBYINTF:
8983 case BUILT_IN_NEARBYINTL:
8984 case BUILT_IN_ROUND:
8985 case BUILT_IN_ROUNDF:
8986 case BUILT_IN_ROUNDL:
8987 case BUILT_IN_TRUNC:
8988 case BUILT_IN_TRUNCF:
8989 case BUILT_IN_TRUNCL:
8990 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8995 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
9002 /* ... fall through ... */
9005 if (truth_value_p (TREE_CODE (t)))
9006 /* Truth values evaluate to 0 or 1, which is nonnegative. */
9010 /* We don't know sign of `t', so be conservative and return false. */
9014 /* Return true if `r' is known to be non-negative.
9015 Only handles constants at the moment. */
9018 rtl_expr_nonnegative_p (rtx r)
9020 switch (GET_CODE (r))
9023 return INTVAL (r) >= 0;
9026 if (GET_MODE (r) == VOIDmode)
9027 return CONST_DOUBLE_HIGH (r) >= 0;
9035 units = CONST_VECTOR_NUNITS (r);
9037 for (i = 0; i < units; ++i)
9039 elt = CONST_VECTOR_ELT (r, i);
9040 if (!rtl_expr_nonnegative_p (elt))
9049 /* These are always nonnegative. */
9057 #include "gt-fold-const.h"