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 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"
60 static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
61 static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
62 static bool negate_expr_p (tree);
63 static tree negate_expr (tree);
64 static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
65 static tree associate_trees (tree, tree, enum tree_code, tree);
66 static tree int_const_binop (enum tree_code, tree, tree, int);
67 static tree const_binop (enum tree_code, tree, tree, int);
68 static hashval_t size_htab_hash (const void *);
69 static int size_htab_eq (const void *, const void *);
70 static tree fold_convert (tree, tree);
71 static enum tree_code invert_tree_comparison (enum tree_code);
72 static enum tree_code swap_tree_comparison (enum tree_code);
73 static int comparison_to_compcode (enum tree_code);
74 static enum tree_code compcode_to_comparison (int);
75 static int truth_value_p (enum tree_code);
76 static int operand_equal_for_comparison_p (tree, tree, tree);
77 static int twoval_comparison_p (tree, tree *, tree *, int *);
78 static tree eval_subst (tree, tree, tree, tree, tree);
79 static tree pedantic_omit_one_operand (tree, tree, tree);
80 static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
81 static tree make_bit_field_ref (tree, tree, int, int, int);
82 static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
83 static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
84 enum machine_mode *, int *, int *,
86 static int all_ones_mask_p (tree, int);
87 static tree sign_bit_p (tree, tree);
88 static int simple_operand_p (tree);
89 static tree range_binop (enum tree_code, tree, tree, int, tree, int);
90 static tree make_range (tree, int *, tree *, tree *);
91 static tree build_range_check (tree, tree, int, tree, tree);
92 static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
94 static tree fold_range_test (tree);
95 static tree unextend (tree, int, int, tree);
96 static tree fold_truthop (enum tree_code, tree, tree, tree);
97 static tree optimize_minmax_comparison (tree);
98 static tree extract_muldiv (tree, tree, enum tree_code, tree);
99 static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
100 static tree strip_compound_expr (tree, tree);
101 static int multiple_of_p (tree, tree, tree);
102 static tree constant_boolean_node (int, tree);
103 static int count_cond (tree, int);
104 static tree fold_binary_op_with_conditional_arg (enum tree_code, tree, tree,
106 static bool fold_real_zero_addition_p (tree, tree, int);
107 static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
109 static tree fold_inf_compare (enum tree_code, tree, tree, tree);
111 /* The following constants represent a bit based encoding of GCC's
112 comparison operators. This encoding simplifies transformations
113 on relational comparison operators, such as AND and OR. */
114 #define COMPCODE_FALSE 0
115 #define COMPCODE_LT 1
116 #define COMPCODE_EQ 2
117 #define COMPCODE_LE 3
118 #define COMPCODE_GT 4
119 #define COMPCODE_NE 5
120 #define COMPCODE_GE 6
121 #define COMPCODE_TRUE 7
123 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
124 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
125 and SUM1. Then this yields nonzero if overflow occurred during the
128 Overflow occurs if A and B have the same sign, but A and SUM differ in
129 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
131 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
133 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
134 We do that by representing the two-word integer in 4 words, with only
135 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
136 number. The value of the word is LOWPART + HIGHPART * BASE. */
139 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
140 #define HIGHPART(x) \
141 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
142 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
144 /* Unpack a two-word integer into 4 words.
145 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
146 WORDS points to the array of HOST_WIDE_INTs. */
149 encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
151 words[0] = LOWPART (low);
152 words[1] = HIGHPART (low);
153 words[2] = LOWPART (hi);
154 words[3] = HIGHPART (hi);
157 /* Pack an array of 4 words into a two-word integer.
158 WORDS points to the array of words.
159 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
162 decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low, HOST_WIDE_INT *hi)
164 *low = words[0] + words[1] * BASE;
165 *hi = words[2] + words[3] * BASE;
168 /* Make the integer constant T valid for its type by setting to 0 or 1 all
169 the bits in the constant that don't belong in the type.
171 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
172 nonzero, a signed overflow has already occurred in calculating T, so
176 force_fit_type (tree t, int overflow)
178 unsigned HOST_WIDE_INT low;
182 if (TREE_CODE (t) == REAL_CST)
184 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
185 Consider doing it via real_convert now. */
189 else if (TREE_CODE (t) != INTEGER_CST)
192 low = TREE_INT_CST_LOW (t);
193 high = TREE_INT_CST_HIGH (t);
195 if (POINTER_TYPE_P (TREE_TYPE (t)))
198 prec = TYPE_PRECISION (TREE_TYPE (t));
200 /* First clear all bits that are beyond the type's precision. */
202 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
204 else if (prec > HOST_BITS_PER_WIDE_INT)
205 TREE_INT_CST_HIGH (t)
206 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
209 TREE_INT_CST_HIGH (t) = 0;
210 if (prec < HOST_BITS_PER_WIDE_INT)
211 TREE_INT_CST_LOW (t) &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
214 /* Unsigned types do not suffer sign extension or overflow unless they
216 if (TREE_UNSIGNED (TREE_TYPE (t))
217 && ! (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
218 && TYPE_IS_SIZETYPE (TREE_TYPE (t))))
221 /* If the value's sign bit is set, extend the sign. */
222 if (prec != 2 * HOST_BITS_PER_WIDE_INT
223 && (prec > HOST_BITS_PER_WIDE_INT
224 ? 0 != (TREE_INT_CST_HIGH (t)
226 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
227 : 0 != (TREE_INT_CST_LOW (t)
228 & ((unsigned HOST_WIDE_INT) 1 << (prec - 1)))))
230 /* Value is negative:
231 set to 1 all the bits that are outside this type's precision. */
232 if (prec > HOST_BITS_PER_WIDE_INT)
233 TREE_INT_CST_HIGH (t)
234 |= ((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
237 TREE_INT_CST_HIGH (t) = -1;
238 if (prec < HOST_BITS_PER_WIDE_INT)
239 TREE_INT_CST_LOW (t) |= ((unsigned HOST_WIDE_INT) (-1) << prec);
243 /* Return nonzero if signed overflow occurred. */
245 ((overflow | (low ^ TREE_INT_CST_LOW (t)) | (high ^ TREE_INT_CST_HIGH (t)))
249 /* Add two doubleword integers with doubleword result.
250 Each argument is given as two `HOST_WIDE_INT' pieces.
251 One argument is L1 and H1; the other, L2 and H2.
252 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
255 add_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1, unsigned HOST_WIDE_INT l2,
256 HOST_WIDE_INT h2, unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
258 unsigned HOST_WIDE_INT l;
262 h = h1 + h2 + (l < l1);
266 return OVERFLOW_SUM_SIGN (h1, h2, h);
269 /* Negate a doubleword integer with doubleword result.
270 Return nonzero if the operation overflows, assuming it's signed.
271 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
272 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
275 neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1, unsigned HOST_WIDE_INT *lv,
282 return (*hv & h1) < 0;
292 /* Multiply two doubleword integers with doubleword result.
293 Return nonzero if the operation overflows, assuming it's signed.
294 Each argument is given as two `HOST_WIDE_INT' pieces.
295 One argument is L1 and H1; the other, L2 and H2.
296 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
299 mul_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1, unsigned HOST_WIDE_INT l2,
300 HOST_WIDE_INT h2, unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
302 HOST_WIDE_INT arg1[4];
303 HOST_WIDE_INT arg2[4];
304 HOST_WIDE_INT prod[4 * 2];
305 unsigned HOST_WIDE_INT carry;
307 unsigned HOST_WIDE_INT toplow, neglow;
308 HOST_WIDE_INT tophigh, neghigh;
310 encode (arg1, l1, h1);
311 encode (arg2, l2, h2);
313 memset ((char *) prod, 0, sizeof prod);
315 for (i = 0; i < 4; i++)
318 for (j = 0; j < 4; j++)
321 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
322 carry += arg1[i] * arg2[j];
323 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
325 prod[k] = LOWPART (carry);
326 carry = HIGHPART (carry);
331 decode (prod, lv, hv); /* This ignores prod[4] through prod[4*2-1] */
333 /* Check for overflow by calculating the top half of the answer in full;
334 it should agree with the low half's sign bit. */
335 decode (prod + 4, &toplow, &tophigh);
338 neg_double (l2, h2, &neglow, &neghigh);
339 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
343 neg_double (l1, h1, &neglow, &neghigh);
344 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
346 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
349 /* Shift the doubleword integer in L1, H1 left by COUNT places
350 keeping only PREC bits of result.
351 Shift right if COUNT is negative.
352 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
353 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
356 lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1, HOST_WIDE_INT count,
357 unsigned int prec, unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
360 unsigned HOST_WIDE_INT signmask;
364 rshift_double (l1, h1, -count, prec, lv, hv, arith);
368 #ifdef SHIFT_COUNT_TRUNCATED
369 if (SHIFT_COUNT_TRUNCATED)
373 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
375 /* Shifting by the host word size is undefined according to the
376 ANSI standard, so we must handle this as a special case. */
380 else if (count >= HOST_BITS_PER_WIDE_INT)
382 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
387 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
388 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
392 /* Sign extend all bits that are beyond the precision. */
394 signmask = -((prec > HOST_BITS_PER_WIDE_INT
395 ? ((unsigned HOST_WIDE_INT) *hv
396 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
397 : (*lv >> (prec - 1))) & 1);
399 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
401 else if (prec >= HOST_BITS_PER_WIDE_INT)
403 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
404 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
409 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
410 *lv |= signmask << prec;
414 /* Shift the doubleword integer in L1, H1 right by COUNT places
415 keeping only PREC bits of result. COUNT must be positive.
416 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
417 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
420 rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1, HOST_WIDE_INT count,
421 unsigned int prec, unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
424 unsigned HOST_WIDE_INT signmask;
427 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
430 #ifdef SHIFT_COUNT_TRUNCATED
431 if (SHIFT_COUNT_TRUNCATED)
435 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
437 /* Shifting by the host word size is undefined according to the
438 ANSI standard, so we must handle this as a special case. */
442 else if (count >= HOST_BITS_PER_WIDE_INT)
445 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
449 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
451 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
454 /* Zero / sign extend all bits that are beyond the precision. */
456 if (count >= (HOST_WIDE_INT)prec)
461 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
463 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
465 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
466 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
471 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
472 *lv |= signmask << (prec - count);
476 /* Rotate the doubleword integer in L1, H1 left by COUNT places
477 keeping only PREC bits of result.
478 Rotate right if COUNT is negative.
479 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
482 lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1, HOST_WIDE_INT count,
483 unsigned int prec, unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
485 unsigned HOST_WIDE_INT s1l, s2l;
486 HOST_WIDE_INT s1h, s2h;
492 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
493 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
498 /* Rotate the doubleword integer in L1, H1 left by COUNT places
499 keeping only PREC bits of result. COUNT must be positive.
500 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
503 rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1, HOST_WIDE_INT count,
504 unsigned int prec, unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
506 unsigned HOST_WIDE_INT s1l, s2l;
507 HOST_WIDE_INT s1h, s2h;
513 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
514 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
519 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
520 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
521 CODE is a tree code for a kind of division, one of
522 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
524 It controls how the quotient is rounded to an integer.
525 Return nonzero if the operation overflows.
526 UNS nonzero says do unsigned division. */
529 div_and_round_double (enum tree_code code, int uns,
530 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
531 HOST_WIDE_INT hnum_orig,
532 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
533 HOST_WIDE_INT hden_orig, unsigned HOST_WIDE_INT *lquo,
534 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
538 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
539 HOST_WIDE_INT den[4], quo[4];
541 unsigned HOST_WIDE_INT work;
542 unsigned HOST_WIDE_INT carry = 0;
543 unsigned HOST_WIDE_INT lnum = lnum_orig;
544 HOST_WIDE_INT hnum = hnum_orig;
545 unsigned HOST_WIDE_INT lden = lden_orig;
546 HOST_WIDE_INT hden = hden_orig;
549 if (hden == 0 && lden == 0)
550 overflow = 1, lden = 1;
552 /* calculate quotient sign and convert operands to unsigned. */
558 /* (minimum integer) / (-1) is the only overflow case. */
559 if (neg_double (lnum, hnum, &lnum, &hnum)
560 && ((HOST_WIDE_INT) lden & hden) == -1)
566 neg_double (lden, hden, &lden, &hden);
570 if (hnum == 0 && hden == 0)
571 { /* single precision */
573 /* This unsigned division rounds toward zero. */
579 { /* trivial case: dividend < divisor */
580 /* hden != 0 already checked. */
587 memset ((char *) quo, 0, sizeof quo);
589 memset ((char *) num, 0, sizeof num); /* to zero 9th element */
590 memset ((char *) den, 0, sizeof den);
592 encode (num, lnum, hnum);
593 encode (den, lden, hden);
595 /* Special code for when the divisor < BASE. */
596 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
598 /* hnum != 0 already checked. */
599 for (i = 4 - 1; i >= 0; i--)
601 work = num[i] + carry * BASE;
602 quo[i] = work / lden;
608 /* Full double precision division,
609 with thanks to Don Knuth's "Seminumerical Algorithms". */
610 int num_hi_sig, den_hi_sig;
611 unsigned HOST_WIDE_INT quo_est, scale;
613 /* Find the highest nonzero divisor digit. */
614 for (i = 4 - 1;; i--)
621 /* Insure that the first digit of the divisor is at least BASE/2.
622 This is required by the quotient digit estimation algorithm. */
624 scale = BASE / (den[den_hi_sig] + 1);
626 { /* scale divisor and dividend */
628 for (i = 0; i <= 4 - 1; i++)
630 work = (num[i] * scale) + carry;
631 num[i] = LOWPART (work);
632 carry = HIGHPART (work);
637 for (i = 0; i <= 4 - 1; i++)
639 work = (den[i] * scale) + carry;
640 den[i] = LOWPART (work);
641 carry = HIGHPART (work);
642 if (den[i] != 0) den_hi_sig = i;
649 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
651 /* Guess the next quotient digit, quo_est, by dividing the first
652 two remaining dividend digits by the high order quotient digit.
653 quo_est is never low and is at most 2 high. */
654 unsigned HOST_WIDE_INT tmp;
656 num_hi_sig = i + den_hi_sig + 1;
657 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
658 if (num[num_hi_sig] != den[den_hi_sig])
659 quo_est = work / den[den_hi_sig];
663 /* Refine quo_est so it's usually correct, and at most one high. */
664 tmp = work - quo_est * den[den_hi_sig];
666 && (den[den_hi_sig - 1] * quo_est
667 > (tmp * BASE + num[num_hi_sig - 2])))
670 /* Try QUO_EST as the quotient digit, by multiplying the
671 divisor by QUO_EST and subtracting from the remaining dividend.
672 Keep in mind that QUO_EST is the I - 1st digit. */
675 for (j = 0; j <= den_hi_sig; j++)
677 work = quo_est * den[j] + carry;
678 carry = HIGHPART (work);
679 work = num[i + j] - LOWPART (work);
680 num[i + j] = LOWPART (work);
681 carry += HIGHPART (work) != 0;
684 /* If quo_est was high by one, then num[i] went negative and
685 we need to correct things. */
686 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
689 carry = 0; /* add divisor back in */
690 for (j = 0; j <= den_hi_sig; j++)
692 work = num[i + j] + den[j] + carry;
693 carry = HIGHPART (work);
694 num[i + j] = LOWPART (work);
697 num [num_hi_sig] += carry;
700 /* Store the quotient digit. */
705 decode (quo, lquo, hquo);
708 /* if result is negative, make it so. */
710 neg_double (*lquo, *hquo, lquo, hquo);
712 /* compute trial remainder: rem = num - (quo * den) */
713 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
714 neg_double (*lrem, *hrem, lrem, hrem);
715 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
720 case TRUNC_MOD_EXPR: /* round toward zero */
721 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
725 case FLOOR_MOD_EXPR: /* round toward negative infinity */
726 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
729 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
737 case CEIL_MOD_EXPR: /* round toward positive infinity */
738 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
740 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
748 case ROUND_MOD_EXPR: /* round to closest integer */
750 unsigned HOST_WIDE_INT labs_rem = *lrem;
751 HOST_WIDE_INT habs_rem = *hrem;
752 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
753 HOST_WIDE_INT habs_den = hden, htwice;
755 /* Get absolute values. */
757 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
759 neg_double (lden, hden, &labs_den, &habs_den);
761 /* If (2 * abs (lrem) >= abs (lden)) */
762 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
763 labs_rem, habs_rem, <wice, &htwice);
765 if (((unsigned HOST_WIDE_INT) habs_den
766 < (unsigned HOST_WIDE_INT) htwice)
767 || (((unsigned HOST_WIDE_INT) habs_den
768 == (unsigned HOST_WIDE_INT) htwice)
769 && (labs_den < ltwice)))
773 add_double (*lquo, *hquo,
774 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
777 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
789 /* compute true remainder: rem = num - (quo * den) */
790 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
791 neg_double (*lrem, *hrem, lrem, hrem);
792 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
796 /* Determine whether an expression T can be cheaply negated using
797 the function negate_expr. */
800 negate_expr_p (tree t)
802 unsigned HOST_WIDE_INT val;
809 type = TREE_TYPE (t);
812 switch (TREE_CODE (t))
815 if (TREE_UNSIGNED (type))
818 /* Check that -CST will not overflow type. */
819 prec = TYPE_PRECISION (type);
820 if (prec > HOST_BITS_PER_WIDE_INT)
822 if (TREE_INT_CST_LOW (t) != 0)
824 prec -= HOST_BITS_PER_WIDE_INT;
825 val = TREE_INT_CST_HIGH (t);
828 val = TREE_INT_CST_LOW (t);
829 if (prec < HOST_BITS_PER_WIDE_INT)
830 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
831 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
844 /* Given T, an expression, return the negation of T. Allow for T to be
845 null, in which case return null. */
856 type = TREE_TYPE (t);
859 switch (TREE_CODE (t))
863 if (! TREE_UNSIGNED (type)
864 && 0 != (tem = fold (build1 (NEGATE_EXPR, type, t)))
865 && ! TREE_OVERFLOW (tem))
870 return convert (type, TREE_OPERAND (t, 0));
873 /* - (A - B) -> B - A */
874 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
875 return convert (type,
876 fold (build (MINUS_EXPR, TREE_TYPE (t),
878 TREE_OPERAND (t, 0))));
885 return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t)));
888 /* Split a tree IN into a constant, literal and variable parts that could be
889 combined with CODE to make IN. "constant" means an expression with
890 TREE_CONSTANT but that isn't an actual constant. CODE must be a
891 commutative arithmetic operation. Store the constant part into *CONP,
892 the literal in *LITP and return the variable part. If a part isn't
893 present, set it to null. If the tree does not decompose in this way,
894 return the entire tree as the variable part and the other parts as null.
896 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
897 case, we negate an operand that was subtracted. Except if it is a
898 literal for which we use *MINUS_LITP instead.
900 If NEGATE_P is true, we are negating all of IN, again except a literal
901 for which we use *MINUS_LITP instead.
903 If IN is itself a literal or constant, return it as appropriate.
905 Note that we do not guarantee that any of the three values will be the
906 same type as IN, but they will have the same signedness and mode. */
909 split_tree (tree in, enum tree_code code, tree *conp, tree *litp, tree *minus_litp, int negate_p)
917 /* Strip any conversions that don't change the machine mode or signedness. */
918 STRIP_SIGN_NOPS (in);
920 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
922 else if (TREE_CODE (in) == code
923 || (! FLOAT_TYPE_P (TREE_TYPE (in))
924 /* We can associate addition and subtraction together (even
925 though the C standard doesn't say so) for integers because
926 the value is not affected. For reals, the value might be
927 affected, so we can't. */
928 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
929 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
931 tree op0 = TREE_OPERAND (in, 0);
932 tree op1 = TREE_OPERAND (in, 1);
933 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
934 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
936 /* First see if either of the operands is a literal, then a constant. */
937 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
938 *litp = op0, op0 = 0;
939 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
940 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
942 if (op0 != 0 && TREE_CONSTANT (op0))
943 *conp = op0, op0 = 0;
944 else if (op1 != 0 && TREE_CONSTANT (op1))
945 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
947 /* If we haven't dealt with either operand, this is not a case we can
948 decompose. Otherwise, VAR is either of the ones remaining, if any. */
949 if (op0 != 0 && op1 != 0)
954 var = op1, neg_var_p = neg1_p;
956 /* Now do any needed negations. */
958 *minus_litp = *litp, *litp = 0;
960 *conp = negate_expr (*conp);
962 var = negate_expr (var);
964 else if (TREE_CONSTANT (in))
972 *minus_litp = *litp, *litp = 0;
973 else if (*minus_litp)
974 *litp = *minus_litp, *minus_litp = 0;
975 *conp = negate_expr (*conp);
976 var = negate_expr (var);
982 /* Re-associate trees split by the above function. T1 and T2 are either
983 expressions to associate or null. Return the new expression, if any. If
984 we build an operation, do it in TYPE and with CODE. */
987 associate_trees (tree t1, tree t2, enum tree_code code, tree type)
994 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
995 try to fold this since we will have infinite recursion. But do
996 deal with any NEGATE_EXPRs. */
997 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
998 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1000 if (code == PLUS_EXPR)
1002 if (TREE_CODE (t1) == NEGATE_EXPR)
1003 return build (MINUS_EXPR, type, convert (type, t2),
1004 convert (type, TREE_OPERAND (t1, 0)));
1005 else if (TREE_CODE (t2) == NEGATE_EXPR)
1006 return build (MINUS_EXPR, type, convert (type, t1),
1007 convert (type, TREE_OPERAND (t2, 0)));
1009 return build (code, type, convert (type, t1), convert (type, t2));
1012 return fold (build (code, type, convert (type, t1), convert (type, t2)));
1015 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1016 to produce a new constant.
1018 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1021 int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1023 unsigned HOST_WIDE_INT int1l, int2l;
1024 HOST_WIDE_INT int1h, int2h;
1025 unsigned HOST_WIDE_INT low;
1027 unsigned HOST_WIDE_INT garbagel;
1028 HOST_WIDE_INT garbageh;
1030 tree type = TREE_TYPE (arg1);
1031 int uns = TREE_UNSIGNED (type);
1033 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
1035 int no_overflow = 0;
1037 int1l = TREE_INT_CST_LOW (arg1);
1038 int1h = TREE_INT_CST_HIGH (arg1);
1039 int2l = TREE_INT_CST_LOW (arg2);
1040 int2h = TREE_INT_CST_HIGH (arg2);
1045 low = int1l | int2l, hi = int1h | int2h;
1049 low = int1l ^ int2l, hi = int1h ^ int2h;
1053 low = int1l & int2l, hi = int1h & int2h;
1056 case BIT_ANDTC_EXPR:
1057 low = int1l & ~int2l, hi = int1h & ~int2h;
1063 /* It's unclear from the C standard whether shifts can overflow.
1064 The following code ignores overflow; perhaps a C standard
1065 interpretation ruling is needed. */
1066 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1074 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
1079 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1083 neg_double (int2l, int2h, &low, &hi);
1084 add_double (int1l, int1h, low, hi, &low, &hi);
1085 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
1089 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1092 case TRUNC_DIV_EXPR:
1093 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1094 case EXACT_DIV_EXPR:
1095 /* This is a shortcut for a common special case. */
1096 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1097 && ! TREE_CONSTANT_OVERFLOW (arg1)
1098 && ! TREE_CONSTANT_OVERFLOW (arg2)
1099 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1101 if (code == CEIL_DIV_EXPR)
1104 low = int1l / int2l, hi = 0;
1108 /* ... fall through ... */
1110 case ROUND_DIV_EXPR:
1111 if (int2h == 0 && int2l == 1)
1113 low = int1l, hi = int1h;
1116 if (int1l == int2l && int1h == int2h
1117 && ! (int1l == 0 && int1h == 0))
1122 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
1123 &low, &hi, &garbagel, &garbageh);
1126 case TRUNC_MOD_EXPR:
1127 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1128 /* This is a shortcut for a common special case. */
1129 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
1130 && ! TREE_CONSTANT_OVERFLOW (arg1)
1131 && ! TREE_CONSTANT_OVERFLOW (arg2)
1132 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
1134 if (code == CEIL_MOD_EXPR)
1136 low = int1l % int2l, hi = 0;
1140 /* ... fall through ... */
1142 case ROUND_MOD_EXPR:
1143 overflow = div_and_round_double (code, uns,
1144 int1l, int1h, int2l, int2h,
1145 &garbagel, &garbageh, &low, &hi);
1151 low = (((unsigned HOST_WIDE_INT) int1h
1152 < (unsigned HOST_WIDE_INT) int2h)
1153 || (((unsigned HOST_WIDE_INT) int1h
1154 == (unsigned HOST_WIDE_INT) int2h)
1157 low = (int1h < int2h
1158 || (int1h == int2h && int1l < int2l));
1160 if (low == (code == MIN_EXPR))
1161 low = int1l, hi = int1h;
1163 low = int2l, hi = int2h;
1170 /* If this is for a sizetype, can be represented as one (signed)
1171 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1174 && ((hi == 0 && (HOST_WIDE_INT) low >= 0)
1175 || (hi == -1 && (HOST_WIDE_INT) low < 0))
1176 && overflow == 0 && ! TREE_OVERFLOW (arg1) && ! TREE_OVERFLOW (arg2))
1177 return size_int_type_wide (low, type);
1180 t = build_int_2 (low, hi);
1181 TREE_TYPE (t) = TREE_TYPE (arg1);
1186 ? (!uns || is_sizetype) && overflow
1187 : (force_fit_type (t, (!uns || is_sizetype) && overflow)
1189 | TREE_OVERFLOW (arg1)
1190 | TREE_OVERFLOW (arg2));
1192 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1193 So check if force_fit_type truncated the value. */
1195 && ! TREE_OVERFLOW (t)
1196 && (TREE_INT_CST_HIGH (t) != hi
1197 || TREE_INT_CST_LOW (t) != low))
1198 TREE_OVERFLOW (t) = 1;
1200 TREE_CONSTANT_OVERFLOW (t) = (TREE_OVERFLOW (t)
1201 | TREE_CONSTANT_OVERFLOW (arg1)
1202 | TREE_CONSTANT_OVERFLOW (arg2));
1206 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1207 constant. We assume ARG1 and ARG2 have the same data type, or at least
1208 are the same kind of constant and the same machine mode.
1210 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1213 const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
1218 if (TREE_CODE (arg1) == INTEGER_CST)
1219 return int_const_binop (code, arg1, arg2, notrunc);
1221 if (TREE_CODE (arg1) == REAL_CST)
1225 REAL_VALUE_TYPE value;
1228 d1 = TREE_REAL_CST (arg1);
1229 d2 = TREE_REAL_CST (arg2);
1231 /* If either operand is a NaN, just return it. Otherwise, set up
1232 for floating-point trap; we return an overflow. */
1233 if (REAL_VALUE_ISNAN (d1))
1235 else if (REAL_VALUE_ISNAN (d2))
1238 REAL_ARITHMETIC (value, code, d1, d2);
1240 t = build_real (TREE_TYPE (arg1),
1241 real_value_truncate (TYPE_MODE (TREE_TYPE (arg1)),
1245 = (force_fit_type (t, 0)
1246 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
1247 TREE_CONSTANT_OVERFLOW (t)
1249 | TREE_CONSTANT_OVERFLOW (arg1)
1250 | TREE_CONSTANT_OVERFLOW (arg2);
1253 if (TREE_CODE (arg1) == COMPLEX_CST)
1255 tree type = TREE_TYPE (arg1);
1256 tree r1 = TREE_REALPART (arg1);
1257 tree i1 = TREE_IMAGPART (arg1);
1258 tree r2 = TREE_REALPART (arg2);
1259 tree i2 = TREE_IMAGPART (arg2);
1265 t = build_complex (type,
1266 const_binop (PLUS_EXPR, r1, r2, notrunc),
1267 const_binop (PLUS_EXPR, i1, i2, notrunc));
1271 t = build_complex (type,
1272 const_binop (MINUS_EXPR, r1, r2, notrunc),
1273 const_binop (MINUS_EXPR, i1, i2, notrunc));
1277 t = build_complex (type,
1278 const_binop (MINUS_EXPR,
1279 const_binop (MULT_EXPR,
1281 const_binop (MULT_EXPR,
1284 const_binop (PLUS_EXPR,
1285 const_binop (MULT_EXPR,
1287 const_binop (MULT_EXPR,
1295 = const_binop (PLUS_EXPR,
1296 const_binop (MULT_EXPR, r2, r2, notrunc),
1297 const_binop (MULT_EXPR, i2, i2, notrunc),
1300 t = build_complex (type,
1302 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1303 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1304 const_binop (PLUS_EXPR,
1305 const_binop (MULT_EXPR, r1, r2,
1307 const_binop (MULT_EXPR, i1, i2,
1310 magsquared, notrunc),
1312 (INTEGRAL_TYPE_P (TREE_TYPE (r1))
1313 ? TRUNC_DIV_EXPR : RDIV_EXPR,
1314 const_binop (MINUS_EXPR,
1315 const_binop (MULT_EXPR, i1, r2,
1317 const_binop (MULT_EXPR, r1, i2,
1320 magsquared, notrunc));
1332 /* These are the hash table functions for the hash table of INTEGER_CST
1333 nodes of a sizetype. */
1335 /* Return the hash code code X, an INTEGER_CST. */
1338 size_htab_hash (const void *x)
1342 return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1343 ^ htab_hash_pointer (TREE_TYPE (t))
1344 ^ (TREE_OVERFLOW (t) << 20));
1347 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1348 is the same as that given by *Y, which is the same. */
1351 size_htab_eq (const void *x, const void *y)
1356 return (TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1357 && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt)
1358 && TREE_TYPE (xt) == TREE_TYPE (yt)
1359 && TREE_OVERFLOW (xt) == TREE_OVERFLOW (yt));
1362 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1363 bits are given by NUMBER and of the sizetype represented by KIND. */
1366 size_int_wide (HOST_WIDE_INT number, enum size_type_kind kind)
1368 return size_int_type_wide (number, sizetype_tab[(int) kind]);
1371 /* Likewise, but the desired type is specified explicitly. */
1373 static GTY (()) tree new_const;
1374 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
1378 size_int_type_wide (HOST_WIDE_INT number, tree type)
1384 size_htab = htab_create_ggc (1024, size_htab_hash, size_htab_eq, NULL);
1385 new_const = make_node (INTEGER_CST);
1388 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1389 hash table, we return the value from the hash table. Otherwise, we
1390 place that in the hash table and make a new node for the next time. */
1391 TREE_INT_CST_LOW (new_const) = number;
1392 TREE_INT_CST_HIGH (new_const) = number < 0 ? -1 : 0;
1393 TREE_TYPE (new_const) = type;
1394 TREE_OVERFLOW (new_const) = TREE_CONSTANT_OVERFLOW (new_const)
1395 = force_fit_type (new_const, 0);
1397 slot = htab_find_slot (size_htab, new_const, INSERT);
1403 new_const = make_node (INTEGER_CST);
1407 return (tree) *slot;
1410 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1411 is a tree code. The type of the result is taken from the operands.
1412 Both must be the same type integer type and it must be a size type.
1413 If the operands are constant, so is the result. */
1416 size_binop (enum tree_code code, tree arg0, tree arg1)
1418 tree type = TREE_TYPE (arg0);
1420 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1421 || type != TREE_TYPE (arg1))
1424 /* Handle the special case of two integer constants faster. */
1425 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1427 /* And some specific cases even faster than that. */
1428 if (code == PLUS_EXPR && integer_zerop (arg0))
1430 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1431 && integer_zerop (arg1))
1433 else if (code == MULT_EXPR && integer_onep (arg0))
1436 /* Handle general case of two integer constants. */
1437 return int_const_binop (code, arg0, arg1, 0);
1440 if (arg0 == error_mark_node || arg1 == error_mark_node)
1441 return error_mark_node;
1443 return fold (build (code, type, arg0, arg1));
1446 /* Given two values, either both of sizetype or both of bitsizetype,
1447 compute the difference between the two values. Return the value
1448 in signed type corresponding to the type of the operands. */
1451 size_diffop (tree arg0, tree arg1)
1453 tree type = TREE_TYPE (arg0);
1456 if (TREE_CODE (type) != INTEGER_TYPE || ! TYPE_IS_SIZETYPE (type)
1457 || type != TREE_TYPE (arg1))
1460 /* If the type is already signed, just do the simple thing. */
1461 if (! TREE_UNSIGNED (type))
1462 return size_binop (MINUS_EXPR, arg0, arg1);
1464 ctype = (type == bitsizetype || type == ubitsizetype
1465 ? sbitsizetype : ssizetype);
1467 /* If either operand is not a constant, do the conversions to the signed
1468 type and subtract. The hardware will do the right thing with any
1469 overflow in the subtraction. */
1470 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
1471 return size_binop (MINUS_EXPR, convert (ctype, arg0),
1472 convert (ctype, arg1));
1474 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1475 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1476 overflow) and negate (which can't either). Special-case a result
1477 of zero while we're here. */
1478 if (tree_int_cst_equal (arg0, arg1))
1479 return convert (ctype, integer_zero_node);
1480 else if (tree_int_cst_lt (arg1, arg0))
1481 return convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
1483 return size_binop (MINUS_EXPR, convert (ctype, integer_zero_node),
1484 convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
1488 /* Given T, a tree representing type conversion of ARG1, a constant,
1489 return a constant tree representing the result of conversion. */
1492 fold_convert (tree t, tree arg1)
1494 tree type = TREE_TYPE (t);
1497 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1499 if (TREE_CODE (arg1) == INTEGER_CST)
1501 /* If we would build a constant wider than GCC supports,
1502 leave the conversion unfolded. */
1503 if (TYPE_PRECISION (type) > 2 * HOST_BITS_PER_WIDE_INT)
1506 /* If we are trying to make a sizetype for a small integer, use
1507 size_int to pick up cached types to reduce duplicate nodes. */
1508 if (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1509 && !TREE_CONSTANT_OVERFLOW (arg1)
1510 && compare_tree_int (arg1, 10000) < 0)
1511 return size_int_type_wide (TREE_INT_CST_LOW (arg1), type);
1513 /* Given an integer constant, make new constant with new type,
1514 appropriately sign-extended or truncated. */
1515 t = build_int_2 (TREE_INT_CST_LOW (arg1),
1516 TREE_INT_CST_HIGH (arg1));
1517 TREE_TYPE (t) = type;
1518 /* Indicate an overflow if (1) ARG1 already overflowed,
1519 or (2) force_fit_type indicates an overflow.
1520 Tell force_fit_type that an overflow has already occurred
1521 if ARG1 is a too-large unsigned value and T is signed.
1522 But don't indicate an overflow if converting a pointer. */
1524 = ((force_fit_type (t,
1525 (TREE_INT_CST_HIGH (arg1) < 0
1526 && (TREE_UNSIGNED (type)
1527 < TREE_UNSIGNED (TREE_TYPE (arg1)))))
1528 && ! POINTER_TYPE_P (TREE_TYPE (arg1)))
1529 || TREE_OVERFLOW (arg1));
1530 TREE_CONSTANT_OVERFLOW (t)
1531 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1533 else if (TREE_CODE (arg1) == REAL_CST)
1535 /* Don't initialize these, use assignments.
1536 Initialized local aggregates don't work on old compilers. */
1540 tree type1 = TREE_TYPE (arg1);
1543 x = TREE_REAL_CST (arg1);
1544 l = real_value_from_int_cst (type1, TYPE_MIN_VALUE (type));
1546 no_upper_bound = (TYPE_MAX_VALUE (type) == NULL);
1547 if (!no_upper_bound)
1548 u = real_value_from_int_cst (type1, TYPE_MAX_VALUE (type));
1550 /* See if X will be in range after truncation towards 0.
1551 To compensate for truncation, move the bounds away from 0,
1552 but reject if X exactly equals the adjusted bounds. */
1553 REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
1554 if (!no_upper_bound)
1555 REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
1556 /* If X is a NaN, use zero instead and show we have an overflow.
1557 Otherwise, range check. */
1558 if (REAL_VALUE_ISNAN (x))
1559 overflow = 1, x = dconst0;
1560 else if (! (REAL_VALUES_LESS (l, x)
1562 && REAL_VALUES_LESS (x, u)))
1566 HOST_WIDE_INT low, high;
1567 REAL_VALUE_TO_INT (&low, &high, x);
1568 t = build_int_2 (low, high);
1570 TREE_TYPE (t) = type;
1572 = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
1573 TREE_CONSTANT_OVERFLOW (t)
1574 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1576 TREE_TYPE (t) = type;
1578 else if (TREE_CODE (type) == REAL_TYPE)
1580 if (TREE_CODE (arg1) == INTEGER_CST)
1581 return build_real_from_int_cst (type, arg1);
1582 if (TREE_CODE (arg1) == REAL_CST)
1584 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
1586 /* We make a copy of ARG1 so that we don't modify an
1587 existing constant tree. */
1588 t = copy_node (arg1);
1589 TREE_TYPE (t) = type;
1593 t = build_real (type,
1594 real_value_truncate (TYPE_MODE (type),
1595 TREE_REAL_CST (arg1)));
1598 = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
1599 TREE_CONSTANT_OVERFLOW (t)
1600 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1604 TREE_CONSTANT (t) = 1;
1608 /* Return an expr equal to X but certainly not valid as an lvalue. */
1615 /* These things are certainly not lvalues. */
1616 if (TREE_CODE (x) == NON_LVALUE_EXPR
1617 || TREE_CODE (x) == INTEGER_CST
1618 || TREE_CODE (x) == REAL_CST
1619 || TREE_CODE (x) == STRING_CST
1620 || TREE_CODE (x) == ADDR_EXPR)
1623 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
1624 TREE_CONSTANT (result) = TREE_CONSTANT (x);
1628 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1629 Zero means allow extended lvalues. */
1631 int pedantic_lvalues;
1633 /* When pedantic, return an expr equal to X but certainly not valid as a
1634 pedantic lvalue. Otherwise, return X. */
1637 pedantic_non_lvalue (tree x)
1639 if (pedantic_lvalues)
1640 return non_lvalue (x);
1645 /* Given a tree comparison code, return the code that is the logical inverse
1646 of the given code. It is not safe to do this for floating-point
1647 comparisons, except for NE_EXPR and EQ_EXPR. */
1649 static enum tree_code
1650 invert_tree_comparison (enum tree_code code)
1671 /* Similar, but return the comparison that results if the operands are
1672 swapped. This is safe for floating-point. */
1674 static enum tree_code
1675 swap_tree_comparison (enum tree_code code)
1696 /* Convert a comparison tree code from an enum tree_code representation
1697 into a compcode bit-based encoding. This function is the inverse of
1698 compcode_to_comparison. */
1701 comparison_to_compcode (enum tree_code code)
1722 /* Convert a compcode bit-based encoding of a comparison operator back
1723 to GCC's enum tree_code representation. This function is the
1724 inverse of comparison_to_compcode. */
1726 static enum tree_code
1727 compcode_to_comparison (int code)
1748 /* Return nonzero if CODE is a tree code that represents a truth value. */
1751 truth_value_p (enum tree_code code)
1753 return (TREE_CODE_CLASS (code) == '<'
1754 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
1755 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
1756 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
1759 /* Return nonzero if two operands are necessarily equal.
1760 If ONLY_CONST is nonzero, only return nonzero for constants.
1761 This function tests whether the operands are indistinguishable;
1762 it does not test whether they are equal using C's == operation.
1763 The distinction is important for IEEE floating point, because
1764 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1765 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1768 operand_equal_p (tree arg0, tree arg1, int only_const)
1770 /* If both types don't have the same signedness, then we can't consider
1771 them equal. We must check this before the STRIP_NOPS calls
1772 because they may change the signedness of the arguments. */
1773 if (TREE_UNSIGNED (TREE_TYPE (arg0)) != TREE_UNSIGNED (TREE_TYPE (arg1)))
1779 if (TREE_CODE (arg0) != TREE_CODE (arg1)
1780 /* This is needed for conversions and for COMPONENT_REF.
1781 Might as well play it safe and always test this. */
1782 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
1783 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
1784 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
1787 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1788 We don't care about side effects in that case because the SAVE_EXPR
1789 takes care of that for us. In all other cases, two expressions are
1790 equal if they have no side effects. If we have two identical
1791 expressions with side effects that should be treated the same due
1792 to the only side effects being identical SAVE_EXPR's, that will
1793 be detected in the recursive calls below. */
1794 if (arg0 == arg1 && ! only_const
1795 && (TREE_CODE (arg0) == SAVE_EXPR
1796 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
1799 /* Next handle constant cases, those for which we can return 1 even
1800 if ONLY_CONST is set. */
1801 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
1802 switch (TREE_CODE (arg0))
1805 return (! TREE_CONSTANT_OVERFLOW (arg0)
1806 && ! TREE_CONSTANT_OVERFLOW (arg1)
1807 && tree_int_cst_equal (arg0, arg1));
1810 return (! TREE_CONSTANT_OVERFLOW (arg0)
1811 && ! TREE_CONSTANT_OVERFLOW (arg1)
1812 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
1813 TREE_REAL_CST (arg1)));
1819 if (TREE_CONSTANT_OVERFLOW (arg0)
1820 || TREE_CONSTANT_OVERFLOW (arg1))
1823 v1 = TREE_VECTOR_CST_ELTS (arg0);
1824 v2 = TREE_VECTOR_CST_ELTS (arg1);
1827 if (!operand_equal_p (v1, v2, only_const))
1829 v1 = TREE_CHAIN (v1);
1830 v2 = TREE_CHAIN (v2);
1837 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
1839 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
1843 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
1844 && ! memcmp (TREE_STRING_POINTER (arg0),
1845 TREE_STRING_POINTER (arg1),
1846 TREE_STRING_LENGTH (arg0)));
1849 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
1858 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
1861 /* Two conversions are equal only if signedness and modes match. */
1862 if ((TREE_CODE (arg0) == NOP_EXPR || TREE_CODE (arg0) == CONVERT_EXPR)
1863 && (TREE_UNSIGNED (TREE_TYPE (arg0))
1864 != TREE_UNSIGNED (TREE_TYPE (arg1))))
1867 return operand_equal_p (TREE_OPERAND (arg0, 0),
1868 TREE_OPERAND (arg1, 0), 0);
1872 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0)
1873 && operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1),
1877 /* For commutative ops, allow the other order. */
1878 return ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MULT_EXPR
1879 || TREE_CODE (arg0) == MIN_EXPR || TREE_CODE (arg0) == MAX_EXPR
1880 || TREE_CODE (arg0) == BIT_IOR_EXPR
1881 || TREE_CODE (arg0) == BIT_XOR_EXPR
1882 || TREE_CODE (arg0) == BIT_AND_EXPR
1883 || TREE_CODE (arg0) == NE_EXPR || TREE_CODE (arg0) == EQ_EXPR)
1884 && operand_equal_p (TREE_OPERAND (arg0, 0),
1885 TREE_OPERAND (arg1, 1), 0)
1886 && operand_equal_p (TREE_OPERAND (arg0, 1),
1887 TREE_OPERAND (arg1, 0), 0));
1890 /* If either of the pointer (or reference) expressions we are
1891 dereferencing contain a side effect, these cannot be equal. */
1892 if (TREE_SIDE_EFFECTS (arg0)
1893 || TREE_SIDE_EFFECTS (arg1))
1896 switch (TREE_CODE (arg0))
1899 return operand_equal_p (TREE_OPERAND (arg0, 0),
1900 TREE_OPERAND (arg1, 0), 0);
1904 case ARRAY_RANGE_REF:
1905 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1906 TREE_OPERAND (arg1, 0), 0)
1907 && operand_equal_p (TREE_OPERAND (arg0, 1),
1908 TREE_OPERAND (arg1, 1), 0));
1911 return (operand_equal_p (TREE_OPERAND (arg0, 0),
1912 TREE_OPERAND (arg1, 0), 0)
1913 && operand_equal_p (TREE_OPERAND (arg0, 1),
1914 TREE_OPERAND (arg1, 1), 0)
1915 && operand_equal_p (TREE_OPERAND (arg0, 2),
1916 TREE_OPERAND (arg1, 2), 0));
1922 switch (TREE_CODE (arg0))
1925 case TRUTH_NOT_EXPR:
1926 return operand_equal_p (TREE_OPERAND (arg0, 0),
1927 TREE_OPERAND (arg1, 0), 0);
1930 return rtx_equal_p (RTL_EXPR_RTL (arg0), RTL_EXPR_RTL (arg1));
1933 /* If the CALL_EXPRs call different functions, then they
1934 clearly can not be equal. */
1935 if (! operand_equal_p (TREE_OPERAND (arg0, 0),
1936 TREE_OPERAND (arg1, 0), 0))
1939 /* Only consider const functions equivalent. */
1940 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
1942 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
1943 if (! (flags_from_decl_or_type (fndecl) & ECF_CONST))
1949 /* Now see if all the arguments are the same. operand_equal_p
1950 does not handle TREE_LIST, so we walk the operands here
1951 feeding them to operand_equal_p. */
1952 arg0 = TREE_OPERAND (arg0, 1);
1953 arg1 = TREE_OPERAND (arg1, 1);
1954 while (arg0 && arg1)
1956 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1), 0))
1959 arg0 = TREE_CHAIN (arg0);
1960 arg1 = TREE_CHAIN (arg1);
1963 /* If we get here and both argument lists are exhausted
1964 then the CALL_EXPRs are equal. */
1965 return ! (arg0 || arg1);
1972 /* Consider __builtin_sqrt equal to sqrt. */
1973 return TREE_CODE (arg0) == FUNCTION_DECL
1974 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
1975 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
1976 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1);
1983 /* Similar to operand_equal_p, but see if ARG0 might have been made by
1984 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
1986 When in doubt, return 0. */
1989 operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
1991 int unsignedp1, unsignedpo;
1992 tree primarg0, primarg1, primother;
1993 unsigned int correct_width;
1995 if (operand_equal_p (arg0, arg1, 0))
1998 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
1999 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2002 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2003 and see if the inner values are the same. This removes any
2004 signedness comparison, which doesn't matter here. */
2005 primarg0 = arg0, primarg1 = arg1;
2006 STRIP_NOPS (primarg0);
2007 STRIP_NOPS (primarg1);
2008 if (operand_equal_p (primarg0, primarg1, 0))
2011 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2012 actual comparison operand, ARG0.
2014 First throw away any conversions to wider types
2015 already present in the operands. */
2017 primarg1 = get_narrower (arg1, &unsignedp1);
2018 primother = get_narrower (other, &unsignedpo);
2020 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2021 if (unsignedp1 == unsignedpo
2022 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2023 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2025 tree type = TREE_TYPE (arg0);
2027 /* Make sure shorter operand is extended the right way
2028 to match the longer operand. */
2029 primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type)
2030 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2032 if (operand_equal_p (arg0, convert (type, primarg1), 0))
2039 /* See if ARG is an expression that is either a comparison or is performing
2040 arithmetic on comparisons. The comparisons must only be comparing
2041 two different values, which will be stored in *CVAL1 and *CVAL2; if
2042 they are nonzero it means that some operands have already been found.
2043 No variables may be used anywhere else in the expression except in the
2044 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2045 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2047 If this is true, return 1. Otherwise, return zero. */
2050 twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
2052 enum tree_code code = TREE_CODE (arg);
2053 char class = TREE_CODE_CLASS (code);
2055 /* We can handle some of the 'e' cases here. */
2056 if (class == 'e' && code == TRUTH_NOT_EXPR)
2058 else if (class == 'e'
2059 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2060 || code == COMPOUND_EXPR))
2063 else if (class == 'e' && code == SAVE_EXPR && SAVE_EXPR_RTL (arg) == 0
2064 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
2066 /* If we've already found a CVAL1 or CVAL2, this expression is
2067 two complex to handle. */
2068 if (*cval1 || *cval2)
2078 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
2081 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2082 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2083 cval1, cval2, save_p));
2089 if (code == COND_EXPR)
2090 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2091 cval1, cval2, save_p)
2092 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2093 cval1, cval2, save_p)
2094 && twoval_comparison_p (TREE_OPERAND (arg, 2),
2095 cval1, cval2, save_p));
2099 /* First see if we can handle the first operand, then the second. For
2100 the second operand, we know *CVAL1 can't be zero. It must be that
2101 one side of the comparison is each of the values; test for the
2102 case where this isn't true by failing if the two operands
2105 if (operand_equal_p (TREE_OPERAND (arg, 0),
2106 TREE_OPERAND (arg, 1), 0))
2110 *cval1 = TREE_OPERAND (arg, 0);
2111 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2113 else if (*cval2 == 0)
2114 *cval2 = TREE_OPERAND (arg, 0);
2115 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2120 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2122 else if (*cval2 == 0)
2123 *cval2 = TREE_OPERAND (arg, 1);
2124 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2136 /* ARG is a tree that is known to contain just arithmetic operations and
2137 comparisons. Evaluate the operations in the tree substituting NEW0 for
2138 any occurrence of OLD0 as an operand of a comparison and likewise for
2142 eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
2144 tree type = TREE_TYPE (arg);
2145 enum tree_code code = TREE_CODE (arg);
2146 char class = TREE_CODE_CLASS (code);
2148 /* We can handle some of the 'e' cases here. */
2149 if (class == 'e' && code == TRUTH_NOT_EXPR)
2151 else if (class == 'e'
2152 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2158 return fold (build1 (code, type,
2159 eval_subst (TREE_OPERAND (arg, 0),
2160 old0, new0, old1, new1)));
2163 return fold (build (code, type,
2164 eval_subst (TREE_OPERAND (arg, 0),
2165 old0, new0, old1, new1),
2166 eval_subst (TREE_OPERAND (arg, 1),
2167 old0, new0, old1, new1)));
2173 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2176 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2179 return fold (build (code, type,
2180 eval_subst (TREE_OPERAND (arg, 0),
2181 old0, new0, old1, new1),
2182 eval_subst (TREE_OPERAND (arg, 1),
2183 old0, new0, old1, new1),
2184 eval_subst (TREE_OPERAND (arg, 2),
2185 old0, new0, old1, new1)));
2189 /* fall through - ??? */
2193 tree arg0 = TREE_OPERAND (arg, 0);
2194 tree arg1 = TREE_OPERAND (arg, 1);
2196 /* We need to check both for exact equality and tree equality. The
2197 former will be true if the operand has a side-effect. In that
2198 case, we know the operand occurred exactly once. */
2200 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2202 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2205 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2207 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2210 return fold (build (code, type, arg0, arg1));
2218 /* Return a tree for the case when the result of an expression is RESULT
2219 converted to TYPE and OMITTED was previously an operand of the expression
2220 but is now not needed (e.g., we folded OMITTED * 0).
2222 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2223 the conversion of RESULT to TYPE. */
2226 omit_one_operand (tree type, tree result, tree omitted)
2228 tree t = convert (type, result);
2230 if (TREE_SIDE_EFFECTS (omitted))
2231 return build (COMPOUND_EXPR, type, omitted, t);
2233 return non_lvalue (t);
2236 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2239 pedantic_omit_one_operand (tree type, tree result, tree omitted)
2241 tree t = convert (type, result);
2243 if (TREE_SIDE_EFFECTS (omitted))
2244 return build (COMPOUND_EXPR, type, omitted, t);
2246 return pedantic_non_lvalue (t);
2249 /* Return a simplified tree node for the truth-negation of ARG. This
2250 never alters ARG itself. We assume that ARG is an operation that
2251 returns a truth value (0 or 1). */
2254 invert_truthvalue (tree arg)
2256 tree type = TREE_TYPE (arg);
2257 enum tree_code code = TREE_CODE (arg);
2259 if (code == ERROR_MARK)
2262 /* If this is a comparison, we can simply invert it, except for
2263 floating-point non-equality comparisons, in which case we just
2264 enclose a TRUTH_NOT_EXPR around what we have. */
2266 if (TREE_CODE_CLASS (code) == '<')
2268 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
2269 && !flag_unsafe_math_optimizations
2272 return build1 (TRUTH_NOT_EXPR, type, arg);
2274 return build (invert_tree_comparison (code), type,
2275 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
2281 return convert (type, build_int_2 (integer_zerop (arg), 0));
2283 case TRUTH_AND_EXPR:
2284 return build (TRUTH_OR_EXPR, type,
2285 invert_truthvalue (TREE_OPERAND (arg, 0)),
2286 invert_truthvalue (TREE_OPERAND (arg, 1)));
2289 return build (TRUTH_AND_EXPR, type,
2290 invert_truthvalue (TREE_OPERAND (arg, 0)),
2291 invert_truthvalue (TREE_OPERAND (arg, 1)));
2293 case TRUTH_XOR_EXPR:
2294 /* Here we can invert either operand. We invert the first operand
2295 unless the second operand is a TRUTH_NOT_EXPR in which case our
2296 result is the XOR of the first operand with the inside of the
2297 negation of the second operand. */
2299 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
2300 return build (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
2301 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
2303 return build (TRUTH_XOR_EXPR, type,
2304 invert_truthvalue (TREE_OPERAND (arg, 0)),
2305 TREE_OPERAND (arg, 1));
2307 case TRUTH_ANDIF_EXPR:
2308 return build (TRUTH_ORIF_EXPR, type,
2309 invert_truthvalue (TREE_OPERAND (arg, 0)),
2310 invert_truthvalue (TREE_OPERAND (arg, 1)));
2312 case TRUTH_ORIF_EXPR:
2313 return build (TRUTH_ANDIF_EXPR, type,
2314 invert_truthvalue (TREE_OPERAND (arg, 0)),
2315 invert_truthvalue (TREE_OPERAND (arg, 1)));
2317 case TRUTH_NOT_EXPR:
2318 return TREE_OPERAND (arg, 0);
2321 return build (COND_EXPR, type, TREE_OPERAND (arg, 0),
2322 invert_truthvalue (TREE_OPERAND (arg, 1)),
2323 invert_truthvalue (TREE_OPERAND (arg, 2)));
2326 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
2327 invert_truthvalue (TREE_OPERAND (arg, 1)));
2329 case WITH_RECORD_EXPR:
2330 return build (WITH_RECORD_EXPR, type,
2331 invert_truthvalue (TREE_OPERAND (arg, 0)),
2332 TREE_OPERAND (arg, 1));
2334 case NON_LVALUE_EXPR:
2335 return invert_truthvalue (TREE_OPERAND (arg, 0));
2340 return build1 (TREE_CODE (arg), type,
2341 invert_truthvalue (TREE_OPERAND (arg, 0)));
2344 if (!integer_onep (TREE_OPERAND (arg, 1)))
2346 return build (EQ_EXPR, type, arg, convert (type, integer_zero_node));
2349 return build1 (TRUTH_NOT_EXPR, type, arg);
2351 case CLEANUP_POINT_EXPR:
2352 return build1 (CLEANUP_POINT_EXPR, type,
2353 invert_truthvalue (TREE_OPERAND (arg, 0)));
2358 if (TREE_CODE (TREE_TYPE (arg)) != BOOLEAN_TYPE)
2360 return build1 (TRUTH_NOT_EXPR, type, arg);
2363 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2364 operands are another bit-wise operation with a common input. If so,
2365 distribute the bit operations to save an operation and possibly two if
2366 constants are involved. For example, convert
2367 (A | B) & (A | C) into A | (B & C)
2368 Further simplification will occur if B and C are constants.
2370 If this optimization cannot be done, 0 will be returned. */
2373 distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2378 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2379 || TREE_CODE (arg0) == code
2380 || (TREE_CODE (arg0) != BIT_AND_EXPR
2381 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2384 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
2386 common = TREE_OPERAND (arg0, 0);
2387 left = TREE_OPERAND (arg0, 1);
2388 right = TREE_OPERAND (arg1, 1);
2390 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
2392 common = TREE_OPERAND (arg0, 0);
2393 left = TREE_OPERAND (arg0, 1);
2394 right = TREE_OPERAND (arg1, 0);
2396 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
2398 common = TREE_OPERAND (arg0, 1);
2399 left = TREE_OPERAND (arg0, 0);
2400 right = TREE_OPERAND (arg1, 1);
2402 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
2404 common = TREE_OPERAND (arg0, 1);
2405 left = TREE_OPERAND (arg0, 0);
2406 right = TREE_OPERAND (arg1, 0);
2411 return fold (build (TREE_CODE (arg0), type, common,
2412 fold (build (code, type, left, right))));
2415 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2416 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2419 make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos, int unsignedp)
2421 tree result = build (BIT_FIELD_REF, type, inner,
2422 size_int (bitsize), bitsize_int (bitpos));
2424 TREE_UNSIGNED (result) = unsignedp;
2429 /* Optimize a bit-field compare.
2431 There are two cases: First is a compare against a constant and the
2432 second is a comparison of two items where the fields are at the same
2433 bit position relative to the start of a chunk (byte, halfword, word)
2434 large enough to contain it. In these cases we can avoid the shift
2435 implicit in bitfield extractions.
2437 For constants, we emit a compare of the shifted constant with the
2438 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2439 compared. For two fields at the same position, we do the ANDs with the
2440 similar mask and compare the result of the ANDs.
2442 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2443 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2444 are the left and right operands of the comparison, respectively.
2446 If the optimization described above can be done, we return the resulting
2447 tree. Otherwise we return zero. */
2450 optimize_bit_field_compare (enum tree_code code, tree compare_type, tree lhs, tree rhs)
2452 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2453 tree type = TREE_TYPE (lhs);
2454 tree signed_type, unsigned_type;
2455 int const_p = TREE_CODE (rhs) == INTEGER_CST;
2456 enum machine_mode lmode, rmode, nmode;
2457 int lunsignedp, runsignedp;
2458 int lvolatilep = 0, rvolatilep = 0;
2459 tree linner, rinner = NULL_TREE;
2463 /* Get all the information about the extractions being done. If the bit size
2464 if the same as the size of the underlying object, we aren't doing an
2465 extraction at all and so can do nothing. We also don't want to
2466 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2467 then will no longer be able to replace it. */
2468 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
2469 &lunsignedp, &lvolatilep);
2470 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
2471 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2476 /* If this is not a constant, we can only do something if bit positions,
2477 sizes, and signedness are the same. */
2478 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
2479 &runsignedp, &rvolatilep);
2481 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
2482 || lunsignedp != runsignedp || offset != 0
2483 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2487 /* See if we can find a mode to refer to this field. We should be able to,
2488 but fail if we can't. */
2489 nmode = get_best_mode (lbitsize, lbitpos,
2490 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
2491 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
2492 TYPE_ALIGN (TREE_TYPE (rinner))),
2493 word_mode, lvolatilep || rvolatilep);
2494 if (nmode == VOIDmode)
2497 /* Set signed and unsigned types of the precision of this mode for the
2499 signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
2500 unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
2502 /* Compute the bit position and size for the new reference and our offset
2503 within it. If the new reference is the same size as the original, we
2504 won't optimize anything, so return zero. */
2505 nbitsize = GET_MODE_BITSIZE (nmode);
2506 nbitpos = lbitpos & ~ (nbitsize - 1);
2508 if (nbitsize == lbitsize)
2511 if (BYTES_BIG_ENDIAN)
2512 lbitpos = nbitsize - lbitsize - lbitpos;
2514 /* Make the mask to be used against the extracted field. */
2515 mask = build_int_2 (~0, ~0);
2516 TREE_TYPE (mask) = unsigned_type;
2517 force_fit_type (mask, 0);
2518 mask = convert (unsigned_type, mask);
2519 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2520 mask = const_binop (RSHIFT_EXPR, mask,
2521 size_int (nbitsize - lbitsize - lbitpos), 0);
2524 /* If not comparing with constant, just rework the comparison
2526 return build (code, compare_type,
2527 build (BIT_AND_EXPR, unsigned_type,
2528 make_bit_field_ref (linner, unsigned_type,
2529 nbitsize, nbitpos, 1),
2531 build (BIT_AND_EXPR, unsigned_type,
2532 make_bit_field_ref (rinner, unsigned_type,
2533 nbitsize, nbitpos, 1),
2536 /* Otherwise, we are handling the constant case. See if the constant is too
2537 big for the field. Warn and return a tree of for 0 (false) if so. We do
2538 this not only for its own sake, but to avoid having to test for this
2539 error case below. If we didn't, we might generate wrong code.
2541 For unsigned fields, the constant shifted right by the field length should
2542 be all zero. For signed fields, the high-order bits should agree with
2547 if (! integer_zerop (const_binop (RSHIFT_EXPR,
2548 convert (unsigned_type, rhs),
2549 size_int (lbitsize), 0)))
2551 warning ("comparison is always %d due to width of bit-field",
2553 return convert (compare_type,
2555 ? integer_one_node : integer_zero_node));
2560 tree tem = const_binop (RSHIFT_EXPR, convert (signed_type, rhs),
2561 size_int (lbitsize - 1), 0);
2562 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
2564 warning ("comparison is always %d due to width of bit-field",
2566 return convert (compare_type,
2568 ? integer_one_node : integer_zero_node));
2572 /* Single-bit compares should always be against zero. */
2573 if (lbitsize == 1 && ! integer_zerop (rhs))
2575 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
2576 rhs = convert (type, integer_zero_node);
2579 /* Make a new bitfield reference, shift the constant over the
2580 appropriate number of bits and mask it with the computed mask
2581 (in case this was a signed field). If we changed it, make a new one. */
2582 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
2585 TREE_SIDE_EFFECTS (lhs) = 1;
2586 TREE_THIS_VOLATILE (lhs) = 1;
2589 rhs = fold (const_binop (BIT_AND_EXPR,
2590 const_binop (LSHIFT_EXPR,
2591 convert (unsigned_type, rhs),
2592 size_int (lbitpos), 0),
2595 return build (code, compare_type,
2596 build (BIT_AND_EXPR, unsigned_type, lhs, mask),
2600 /* Subroutine for fold_truthop: decode a field reference.
2602 If EXP is a comparison reference, we return the innermost reference.
2604 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2605 set to the starting bit number.
2607 If the innermost field can be completely contained in a mode-sized
2608 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2610 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2611 otherwise it is not changed.
2613 *PUNSIGNEDP is set to the signedness of the field.
2615 *PMASK is set to the mask used. This is either contained in a
2616 BIT_AND_EXPR or derived from the width of the field.
2618 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2620 Return 0 if this is not a component reference or is one that we can't
2621 do anything with. */
2624 decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize, HOST_WIDE_INT *pbitpos,
2625 enum machine_mode *pmode, int *punsignedp, int *pvolatilep,
2626 tree *pmask, tree *pand_mask)
2628 tree outer_type = 0;
2630 tree mask, inner, offset;
2632 unsigned int precision;
2634 /* All the optimizations using this function assume integer fields.
2635 There are problems with FP fields since the type_for_size call
2636 below can fail for, e.g., XFmode. */
2637 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
2640 /* We are interested in the bare arrangement of bits, so strip everything
2641 that doesn't affect the machine mode. However, record the type of the
2642 outermost expression if it may matter below. */
2643 if (TREE_CODE (exp) == NOP_EXPR
2644 || TREE_CODE (exp) == CONVERT_EXPR
2645 || TREE_CODE (exp) == NON_LVALUE_EXPR)
2646 outer_type = TREE_TYPE (exp);
2649 if (TREE_CODE (exp) == BIT_AND_EXPR)
2651 and_mask = TREE_OPERAND (exp, 1);
2652 exp = TREE_OPERAND (exp, 0);
2653 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
2654 if (TREE_CODE (and_mask) != INTEGER_CST)
2658 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
2659 punsignedp, pvolatilep);
2660 if ((inner == exp && and_mask == 0)
2661 || *pbitsize < 0 || offset != 0
2662 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
2665 /* If the number of bits in the reference is the same as the bitsize of
2666 the outer type, then the outer type gives the signedness. Otherwise
2667 (in case of a small bitfield) the signedness is unchanged. */
2668 if (outer_type && *pbitsize == tree_low_cst (TYPE_SIZE (outer_type), 1))
2669 *punsignedp = TREE_UNSIGNED (outer_type);
2671 /* Compute the mask to access the bitfield. */
2672 unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
2673 precision = TYPE_PRECISION (unsigned_type);
2675 mask = build_int_2 (~0, ~0);
2676 TREE_TYPE (mask) = unsigned_type;
2677 force_fit_type (mask, 0);
2678 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2679 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
2681 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2683 mask = fold (build (BIT_AND_EXPR, unsigned_type,
2684 convert (unsigned_type, and_mask), mask));
2687 *pand_mask = and_mask;
2691 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2695 all_ones_mask_p (tree mask, int size)
2697 tree type = TREE_TYPE (mask);
2698 unsigned int precision = TYPE_PRECISION (type);
2701 tmask = build_int_2 (~0, ~0);
2702 TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
2703 force_fit_type (tmask, 0);
2705 tree_int_cst_equal (mask,
2706 const_binop (RSHIFT_EXPR,
2707 const_binop (LSHIFT_EXPR, tmask,
2708 size_int (precision - size),
2710 size_int (precision - size), 0));
2713 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2714 represents the sign bit of EXP's type. If EXP represents a sign
2715 or zero extension, also test VAL against the unextended type.
2716 The return value is the (sub)expression whose sign bit is VAL,
2717 or NULL_TREE otherwise. */
2720 sign_bit_p (tree exp, tree val)
2722 unsigned HOST_WIDE_INT lo;
2727 /* Tree EXP must have an integral type. */
2728 t = TREE_TYPE (exp);
2729 if (! INTEGRAL_TYPE_P (t))
2732 /* Tree VAL must be an integer constant. */
2733 if (TREE_CODE (val) != INTEGER_CST
2734 || TREE_CONSTANT_OVERFLOW (val))
2737 width = TYPE_PRECISION (t);
2738 if (width > HOST_BITS_PER_WIDE_INT)
2740 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
2746 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
2749 if (TREE_INT_CST_HIGH (val) == hi && TREE_INT_CST_LOW (val) == lo)
2752 /* Handle extension from a narrower type. */
2753 if (TREE_CODE (exp) == NOP_EXPR
2754 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
2755 return sign_bit_p (TREE_OPERAND (exp, 0), val);
2760 /* Subroutine for fold_truthop: determine if an operand is simple enough
2761 to be evaluated unconditionally. */
2764 simple_operand_p (tree exp)
2766 /* Strip any conversions that don't change the machine mode. */
2767 while ((TREE_CODE (exp) == NOP_EXPR
2768 || TREE_CODE (exp) == CONVERT_EXPR)
2769 && (TYPE_MODE (TREE_TYPE (exp))
2770 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)))))
2771 exp = TREE_OPERAND (exp, 0);
2773 return (TREE_CODE_CLASS (TREE_CODE (exp)) == 'c'
2775 && ! TREE_ADDRESSABLE (exp)
2776 && ! TREE_THIS_VOLATILE (exp)
2777 && ! DECL_NONLOCAL (exp)
2778 /* Don't regard global variables as simple. They may be
2779 allocated in ways unknown to the compiler (shared memory,
2780 #pragma weak, etc). */
2781 && ! TREE_PUBLIC (exp)
2782 && ! DECL_EXTERNAL (exp)
2783 /* Loading a static variable is unduly expensive, but global
2784 registers aren't expensive. */
2785 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
2788 /* The following functions are subroutines to fold_range_test and allow it to
2789 try to change a logical combination of comparisons into a range test.
2792 X == 2 || X == 3 || X == 4 || X == 5
2796 (unsigned) (X - 2) <= 3
2798 We describe each set of comparisons as being either inside or outside
2799 a range, using a variable named like IN_P, and then describe the
2800 range with a lower and upper bound. If one of the bounds is omitted,
2801 it represents either the highest or lowest value of the type.
2803 In the comments below, we represent a range by two numbers in brackets
2804 preceded by a "+" to designate being inside that range, or a "-" to
2805 designate being outside that range, so the condition can be inverted by
2806 flipping the prefix. An omitted bound is represented by a "-". For
2807 example, "- [-, 10]" means being outside the range starting at the lowest
2808 possible value and ending at 10, in other words, being greater than 10.
2809 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2812 We set up things so that the missing bounds are handled in a consistent
2813 manner so neither a missing bound nor "true" and "false" need to be
2814 handled using a special case. */
2816 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2817 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2818 and UPPER1_P are nonzero if the respective argument is an upper bound
2819 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2820 must be specified for a comparison. ARG1 will be converted to ARG0's
2821 type if both are specified. */
2824 range_binop (enum tree_code code, tree type, tree arg0, int upper0_p, tree arg1,
2831 /* If neither arg represents infinity, do the normal operation.
2832 Else, if not a comparison, return infinity. Else handle the special
2833 comparison rules. Note that most of the cases below won't occur, but
2834 are handled for consistency. */
2836 if (arg0 != 0 && arg1 != 0)
2838 tem = fold (build (code, type != 0 ? type : TREE_TYPE (arg0),
2839 arg0, convert (TREE_TYPE (arg0), arg1)));
2841 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
2844 if (TREE_CODE_CLASS (code) != '<')
2847 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2848 for neither. In real maths, we cannot assume open ended ranges are
2849 the same. But, this is computer arithmetic, where numbers are finite.
2850 We can therefore make the transformation of any unbounded range with
2851 the value Z, Z being greater than any representable number. This permits
2852 us to treat unbounded ranges as equal. */
2853 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
2854 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
2858 result = sgn0 == sgn1;
2861 result = sgn0 != sgn1;
2864 result = sgn0 < sgn1;
2867 result = sgn0 <= sgn1;
2870 result = sgn0 > sgn1;
2873 result = sgn0 >= sgn1;
2879 return convert (type, result ? integer_one_node : integer_zero_node);
2882 /* Given EXP, a logical expression, set the range it is testing into
2883 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2884 actually being tested. *PLOW and *PHIGH will be made of the same type
2885 as the returned expression. If EXP is not a comparison, we will most
2886 likely not be returning a useful value and range. */
2889 make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
2891 enum tree_code code;
2892 tree arg0 = NULL_TREE, arg1 = NULL_TREE, type = NULL_TREE;
2893 tree orig_type = NULL_TREE;
2895 tree low, high, n_low, n_high;
2897 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2898 and see if we can refine the range. Some of the cases below may not
2899 happen, but it doesn't seem worth worrying about this. We "continue"
2900 the outer loop when we've changed something; otherwise we "break"
2901 the switch, which will "break" the while. */
2903 in_p = 0, low = high = convert (TREE_TYPE (exp), integer_zero_node);
2907 code = TREE_CODE (exp);
2909 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
2911 arg0 = TREE_OPERAND (exp, 0);
2912 if (TREE_CODE_CLASS (code) == '<'
2913 || TREE_CODE_CLASS (code) == '1'
2914 || TREE_CODE_CLASS (code) == '2')
2915 type = TREE_TYPE (arg0);
2916 if (TREE_CODE_CLASS (code) == '2'
2917 || TREE_CODE_CLASS (code) == '<'
2918 || (TREE_CODE_CLASS (code) == 'e'
2919 && TREE_CODE_LENGTH (code) > 1))
2920 arg1 = TREE_OPERAND (exp, 1);
2923 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
2924 lose a cast by accident. */
2925 if (type != NULL_TREE && orig_type == NULL_TREE)
2930 case TRUTH_NOT_EXPR:
2931 in_p = ! in_p, exp = arg0;
2934 case EQ_EXPR: case NE_EXPR:
2935 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
2936 /* We can only do something if the range is testing for zero
2937 and if the second operand is an integer constant. Note that
2938 saying something is "in" the range we make is done by
2939 complementing IN_P since it will set in the initial case of
2940 being not equal to zero; "out" is leaving it alone. */
2941 if (low == 0 || high == 0
2942 || ! integer_zerop (low) || ! integer_zerop (high)
2943 || TREE_CODE (arg1) != INTEGER_CST)
2948 case NE_EXPR: /* - [c, c] */
2951 case EQ_EXPR: /* + [c, c] */
2952 in_p = ! in_p, low = high = arg1;
2954 case GT_EXPR: /* - [-, c] */
2955 low = 0, high = arg1;
2957 case GE_EXPR: /* + [c, -] */
2958 in_p = ! in_p, low = arg1, high = 0;
2960 case LT_EXPR: /* - [c, -] */
2961 low = arg1, high = 0;
2963 case LE_EXPR: /* + [-, c] */
2964 in_p = ! in_p, low = 0, high = arg1;
2972 /* If this is an unsigned comparison, we also know that EXP is
2973 greater than or equal to zero. We base the range tests we make
2974 on that fact, so we record it here so we can parse existing
2976 if (TREE_UNSIGNED (type) && (low == 0 || high == 0))
2978 if (! merge_ranges (&n_in_p, &n_low, &n_high, in_p, low, high,
2979 1, convert (type, integer_zero_node),
2983 in_p = n_in_p, low = n_low, high = n_high;
2985 /* If the high bound is missing, but we
2986 have a low bound, reverse the range so
2987 it goes from zero to the low bound minus 1. */
2988 if (high == 0 && low)
2991 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
2992 integer_one_node, 0);
2993 low = convert (type, integer_zero_node);
2999 /* (-x) IN [a,b] -> x in [-b, -a] */
3000 n_low = range_binop (MINUS_EXPR, type,
3001 convert (type, integer_zero_node), 0, high, 1);
3002 n_high = range_binop (MINUS_EXPR, type,
3003 convert (type, integer_zero_node), 0, low, 0);
3004 low = n_low, high = n_high;
3010 exp = build (MINUS_EXPR, type, negate_expr (arg0),
3011 convert (type, integer_one_node));
3014 case PLUS_EXPR: case MINUS_EXPR:
3015 if (TREE_CODE (arg1) != INTEGER_CST)
3018 /* If EXP is signed, any overflow in the computation is undefined,
3019 so we don't worry about it so long as our computations on
3020 the bounds don't overflow. For unsigned, overflow is defined
3021 and this is exactly the right thing. */
3022 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3023 type, low, 0, arg1, 0);
3024 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
3025 type, high, 1, arg1, 0);
3026 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3027 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3030 /* Check for an unsigned range which has wrapped around the maximum
3031 value thus making n_high < n_low, and normalize it. */
3032 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
3034 low = range_binop (PLUS_EXPR, type, n_high, 0,
3035 integer_one_node, 0);
3036 high = range_binop (MINUS_EXPR, type, n_low, 0,
3037 integer_one_node, 0);
3039 /* If the range is of the form +/- [ x+1, x ], we won't
3040 be able to normalize it. But then, it represents the
3041 whole range or the empty set, so make it
3043 if (tree_int_cst_equal (n_low, low)
3044 && tree_int_cst_equal (n_high, high))
3050 low = n_low, high = n_high;
3055 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
3056 if (TYPE_PRECISION (type) > TYPE_PRECISION (orig_type))
3059 if (! INTEGRAL_TYPE_P (type)
3060 || (low != 0 && ! int_fits_type_p (low, type))
3061 || (high != 0 && ! int_fits_type_p (high, type)))
3064 n_low = low, n_high = high;
3067 n_low = convert (type, n_low);
3070 n_high = convert (type, n_high);
3072 /* If we're converting from an unsigned to a signed type,
3073 we will be doing the comparison as unsigned. The tests above
3074 have already verified that LOW and HIGH are both positive.
3076 So we have to make sure that the original unsigned value will
3077 be interpreted as positive. */
3078 if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
3080 tree equiv_type = (*lang_hooks.types.type_for_mode)
3081 (TYPE_MODE (type), 1);
3084 /* A range without an upper bound is, naturally, unbounded.
3085 Since convert would have cropped a very large value, use
3086 the max value for the destination type. */
3088 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
3089 : TYPE_MAX_VALUE (type);
3091 if (TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (exp)))
3092 high_positive = fold (build (RSHIFT_EXPR, type,
3093 convert (type, high_positive),
3094 convert (type, integer_one_node)));
3096 /* If the low bound is specified, "and" the range with the
3097 range for which the original unsigned value will be
3101 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3103 1, convert (type, integer_zero_node),
3107 in_p = (n_in_p == in_p);
3111 /* Otherwise, "or" the range with the range of the input
3112 that will be interpreted as negative. */
3113 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3115 1, convert (type, integer_zero_node),
3119 in_p = (in_p != n_in_p);
3124 low = n_low, high = n_high;
3134 /* If EXP is a constant, we can evaluate whether this is true or false. */
3135 if (TREE_CODE (exp) == INTEGER_CST)
3137 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
3139 && integer_onep (range_binop (LE_EXPR, integer_type_node,
3145 *pin_p = in_p, *plow = low, *phigh = high;
3149 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3150 type, TYPE, return an expression to test if EXP is in (or out of, depending
3151 on IN_P) the range. */
3154 build_range_check (tree type, tree exp, int in_p, tree low, tree high)
3156 tree etype = TREE_TYPE (exp);
3160 && (0 != (value = build_range_check (type, exp, 1, low, high))))
3161 return invert_truthvalue (value);
3163 if (low == 0 && high == 0)
3164 return convert (type, integer_one_node);
3167 return fold (build (LE_EXPR, type, exp, high));
3170 return fold (build (GE_EXPR, type, exp, low));
3172 if (operand_equal_p (low, high, 0))
3173 return fold (build (EQ_EXPR, type, exp, low));
3175 if (integer_zerop (low))
3177 if (! TREE_UNSIGNED (etype))
3179 etype = (*lang_hooks.types.unsigned_type) (etype);
3180 high = convert (etype, high);
3181 exp = convert (etype, exp);
3183 return build_range_check (type, exp, 1, 0, high);
3186 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3187 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
3189 unsigned HOST_WIDE_INT lo;
3193 prec = TYPE_PRECISION (etype);
3194 if (prec <= HOST_BITS_PER_WIDE_INT)
3197 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
3201 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
3202 lo = (unsigned HOST_WIDE_INT) -1;
3205 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
3207 if (TREE_UNSIGNED (etype))
3209 etype = (*lang_hooks.types.signed_type) (etype);
3210 exp = convert (etype, exp);
3212 return fold (build (GT_EXPR, type, exp,
3213 convert (etype, integer_zero_node)));
3217 if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
3218 && ! TREE_OVERFLOW (value))
3219 return build_range_check (type,
3220 fold (build (MINUS_EXPR, etype, exp, low)),
3221 1, convert (etype, integer_zero_node), value);
3226 /* Given two ranges, see if we can merge them into one. Return 1 if we
3227 can, 0 if we can't. Set the output range into the specified parameters. */
3230 merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0, tree high0,
3231 int in1_p, tree low1, tree high1)
3239 int lowequal = ((low0 == 0 && low1 == 0)
3240 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3241 low0, 0, low1, 0)));
3242 int highequal = ((high0 == 0 && high1 == 0)
3243 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
3244 high0, 1, high1, 1)));
3246 /* Make range 0 be the range that starts first, or ends last if they
3247 start at the same value. Swap them if it isn't. */
3248 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
3251 && integer_onep (range_binop (GT_EXPR, integer_type_node,
3252 high1, 1, high0, 1))))
3254 temp = in0_p, in0_p = in1_p, in1_p = temp;
3255 tem = low0, low0 = low1, low1 = tem;
3256 tem = high0, high0 = high1, high1 = tem;
3259 /* Now flag two cases, whether the ranges are disjoint or whether the
3260 second range is totally subsumed in the first. Note that the tests
3261 below are simplified by the ones above. */
3262 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
3263 high0, 1, low1, 0));
3264 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
3265 high1, 1, high0, 1));
3267 /* We now have four cases, depending on whether we are including or
3268 excluding the two ranges. */
3271 /* If they don't overlap, the result is false. If the second range
3272 is a subset it is the result. Otherwise, the range is from the start
3273 of the second to the end of the first. */
3275 in_p = 0, low = high = 0;
3277 in_p = 1, low = low1, high = high1;
3279 in_p = 1, low = low1, high = high0;
3282 else if (in0_p && ! in1_p)
3284 /* If they don't overlap, the result is the first range. If they are
3285 equal, the result is false. If the second range is a subset of the
3286 first, and the ranges begin at the same place, we go from just after
3287 the end of the first range to the end of the second. If the second
3288 range is not a subset of the first, or if it is a subset and both
3289 ranges end at the same place, the range starts at the start of the
3290 first range and ends just before the second range.
3291 Otherwise, we can't describe this as a single range. */
3293 in_p = 1, low = low0, high = high0;
3294 else if (lowequal && highequal)
3295 in_p = 0, low = high = 0;
3296 else if (subset && lowequal)
3298 in_p = 1, high = high0;
3299 low = range_binop (PLUS_EXPR, NULL_TREE, high1, 0,
3300 integer_one_node, 0);
3302 else if (! subset || highequal)
3304 in_p = 1, low = low0;
3305 high = range_binop (MINUS_EXPR, NULL_TREE, low1, 0,
3306 integer_one_node, 0);
3312 else if (! in0_p && in1_p)
3314 /* If they don't overlap, the result is the second range. If the second
3315 is a subset of the first, the result is false. Otherwise,
3316 the range starts just after the first range and ends at the
3317 end of the second. */
3319 in_p = 1, low = low1, high = high1;
3320 else if (subset || highequal)
3321 in_p = 0, low = high = 0;
3324 in_p = 1, high = high1;
3325 low = range_binop (PLUS_EXPR, NULL_TREE, high0, 1,
3326 integer_one_node, 0);
3332 /* The case where we are excluding both ranges. Here the complex case
3333 is if they don't overlap. In that case, the only time we have a
3334 range is if they are adjacent. If the second is a subset of the
3335 first, the result is the first. Otherwise, the range to exclude
3336 starts at the beginning of the first range and ends at the end of the
3340 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
3341 range_binop (PLUS_EXPR, NULL_TREE,
3343 integer_one_node, 1),
3345 in_p = 0, low = low0, high = high1;
3350 in_p = 0, low = low0, high = high0;
3352 in_p = 0, low = low0, high = high1;
3355 *pin_p = in_p, *plow = low, *phigh = high;
3359 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3360 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3363 /* EXP is some logical combination of boolean tests. See if we can
3364 merge it into some range test. Return the new tree if so. */
3367 fold_range_test (tree exp)
3369 int or_op = (TREE_CODE (exp) == TRUTH_ORIF_EXPR
3370 || TREE_CODE (exp) == TRUTH_OR_EXPR);
3371 int in0_p, in1_p, in_p;
3372 tree low0, low1, low, high0, high1, high;
3373 tree lhs = make_range (TREE_OPERAND (exp, 0), &in0_p, &low0, &high0);
3374 tree rhs = make_range (TREE_OPERAND (exp, 1), &in1_p, &low1, &high1);
3377 /* If this is an OR operation, invert both sides; we will invert
3378 again at the end. */
3380 in0_p = ! in0_p, in1_p = ! in1_p;
3382 /* If both expressions are the same, if we can merge the ranges, and we
3383 can build the range test, return it or it inverted. If one of the
3384 ranges is always true or always false, consider it to be the same
3385 expression as the other. */
3386 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
3387 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
3389 && 0 != (tem = (build_range_check (TREE_TYPE (exp),
3391 : rhs != 0 ? rhs : integer_zero_node,
3393 return or_op ? invert_truthvalue (tem) : tem;
3395 /* On machines where the branch cost is expensive, if this is a
3396 short-circuited branch and the underlying object on both sides
3397 is the same, make a non-short-circuit operation. */
3398 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3399 && lhs != 0 && rhs != 0
3400 && (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3401 || TREE_CODE (exp) == TRUTH_ORIF_EXPR)
3402 && operand_equal_p (lhs, rhs, 0))
3404 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3405 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3406 which cases we can't do this. */
3407 if (simple_operand_p (lhs))
3408 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3409 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3410 TREE_TYPE (exp), TREE_OPERAND (exp, 0),
3411 TREE_OPERAND (exp, 1));
3413 else if ((*lang_hooks.decls.global_bindings_p) () == 0
3414 && ! CONTAINS_PLACEHOLDER_P (lhs))
3416 tree common = save_expr (lhs);
3418 if (0 != (lhs = build_range_check (TREE_TYPE (exp), common,
3419 or_op ? ! in0_p : in0_p,
3421 && (0 != (rhs = build_range_check (TREE_TYPE (exp), common,
3422 or_op ? ! in1_p : in1_p,
3424 return build (TREE_CODE (exp) == TRUTH_ANDIF_EXPR
3425 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
3426 TREE_TYPE (exp), lhs, rhs);
3433 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3434 bit value. Arrange things so the extra bits will be set to zero if and
3435 only if C is signed-extended to its full width. If MASK is nonzero,
3436 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3439 unextend (tree c, int p, int unsignedp, tree mask)
3441 tree type = TREE_TYPE (c);
3442 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
3445 if (p == modesize || unsignedp)
3448 /* We work by getting just the sign bit into the low-order bit, then
3449 into the high-order bit, then sign-extend. We then XOR that value
3451 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
3452 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
3454 /* We must use a signed type in order to get an arithmetic right shift.
3455 However, we must also avoid introducing accidental overflows, so that
3456 a subsequent call to integer_zerop will work. Hence we must
3457 do the type conversion here. At this point, the constant is either
3458 zero or one, and the conversion to a signed type can never overflow.
3459 We could get an overflow if this conversion is done anywhere else. */
3460 if (TREE_UNSIGNED (type))
3461 temp = convert ((*lang_hooks.types.signed_type) (type), temp);
3463 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
3464 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
3466 temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0);
3467 /* If necessary, convert the type back to match the type of C. */
3468 if (TREE_UNSIGNED (type))
3469 temp = convert (type, temp);
3471 return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
3474 /* Find ways of folding logical expressions of LHS and RHS:
3475 Try to merge two comparisons to the same innermost item.
3476 Look for range tests like "ch >= '0' && ch <= '9'".
3477 Look for combinations of simple terms on machines with expensive branches
3478 and evaluate the RHS unconditionally.
3480 For example, if we have p->a == 2 && p->b == 4 and we can make an
3481 object large enough to span both A and B, we can do this with a comparison
3482 against the object ANDed with the a mask.
3484 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3485 operations to do this with one comparison.
3487 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3488 function and the one above.
3490 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3491 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3493 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3496 We return the simplified tree or 0 if no optimization is possible. */
3499 fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
3501 /* If this is the "or" of two comparisons, we can do something if
3502 the comparisons are NE_EXPR. If this is the "and", we can do something
3503 if the comparisons are EQ_EXPR. I.e.,
3504 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3506 WANTED_CODE is this operation code. For single bit fields, we can
3507 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3508 comparison for one-bit fields. */
3510 enum tree_code wanted_code;
3511 enum tree_code lcode, rcode;
3512 tree ll_arg, lr_arg, rl_arg, rr_arg;
3513 tree ll_inner, lr_inner, rl_inner, rr_inner;
3514 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
3515 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
3516 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
3517 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
3518 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
3519 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
3520 enum machine_mode lnmode, rnmode;
3521 tree ll_mask, lr_mask, rl_mask, rr_mask;
3522 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
3523 tree l_const, r_const;
3524 tree lntype, rntype, result;
3525 int first_bit, end_bit;
3528 /* Start by getting the comparison codes. Fail if anything is volatile.
3529 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3530 it were surrounded with a NE_EXPR. */
3532 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
3535 lcode = TREE_CODE (lhs);
3536 rcode = TREE_CODE (rhs);
3538 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
3539 lcode = NE_EXPR, lhs = build (NE_EXPR, truth_type, lhs, integer_zero_node);
3541 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
3542 rcode = NE_EXPR, rhs = build (NE_EXPR, truth_type, rhs, integer_zero_node);
3544 if (TREE_CODE_CLASS (lcode) != '<' || TREE_CODE_CLASS (rcode) != '<')
3547 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
3548 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
3550 ll_arg = TREE_OPERAND (lhs, 0);
3551 lr_arg = TREE_OPERAND (lhs, 1);
3552 rl_arg = TREE_OPERAND (rhs, 0);
3553 rr_arg = TREE_OPERAND (rhs, 1);
3555 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3556 if (simple_operand_p (ll_arg)
3557 && simple_operand_p (lr_arg)
3558 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg)))
3562 if (operand_equal_p (ll_arg, rl_arg, 0)
3563 && operand_equal_p (lr_arg, rr_arg, 0))
3565 int lcompcode, rcompcode;
3567 lcompcode = comparison_to_compcode (lcode);
3568 rcompcode = comparison_to_compcode (rcode);
3569 compcode = (code == TRUTH_AND_EXPR)
3570 ? lcompcode & rcompcode
3571 : lcompcode | rcompcode;
3573 else if (operand_equal_p (ll_arg, rr_arg, 0)
3574 && operand_equal_p (lr_arg, rl_arg, 0))
3576 int lcompcode, rcompcode;
3578 rcode = swap_tree_comparison (rcode);
3579 lcompcode = comparison_to_compcode (lcode);
3580 rcompcode = comparison_to_compcode (rcode);
3581 compcode = (code == TRUTH_AND_EXPR)
3582 ? lcompcode & rcompcode
3583 : lcompcode | rcompcode;
3588 if (compcode == COMPCODE_TRUE)
3589 return convert (truth_type, integer_one_node);
3590 else if (compcode == COMPCODE_FALSE)
3591 return convert (truth_type, integer_zero_node);
3592 else if (compcode != -1)
3593 return build (compcode_to_comparison (compcode),
3594 truth_type, ll_arg, lr_arg);
3597 /* If the RHS can be evaluated unconditionally and its operands are
3598 simple, it wins to evaluate the RHS unconditionally on machines
3599 with expensive branches. In this case, this isn't a comparison
3600 that can be merged. Avoid doing this if the RHS is a floating-point
3601 comparison since those can trap. */
3603 if (BRANCH_COST >= 2
3604 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
3605 && simple_operand_p (rl_arg)
3606 && simple_operand_p (rr_arg))
3608 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3609 if (code == TRUTH_OR_EXPR
3610 && lcode == NE_EXPR && integer_zerop (lr_arg)
3611 && rcode == NE_EXPR && integer_zerop (rr_arg)
3612 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3613 return build (NE_EXPR, truth_type,
3614 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3618 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3619 if (code == TRUTH_AND_EXPR
3620 && lcode == EQ_EXPR && integer_zerop (lr_arg)
3621 && rcode == EQ_EXPR && integer_zerop (rr_arg)
3622 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
3623 return build (EQ_EXPR, truth_type,
3624 build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
3628 return build (code, truth_type, lhs, rhs);
3631 /* See if the comparisons can be merged. Then get all the parameters for
3634 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
3635 || (rcode != EQ_EXPR && rcode != NE_EXPR))
3639 ll_inner = decode_field_reference (ll_arg,
3640 &ll_bitsize, &ll_bitpos, &ll_mode,
3641 &ll_unsignedp, &volatilep, &ll_mask,
3643 lr_inner = decode_field_reference (lr_arg,
3644 &lr_bitsize, &lr_bitpos, &lr_mode,
3645 &lr_unsignedp, &volatilep, &lr_mask,
3647 rl_inner = decode_field_reference (rl_arg,
3648 &rl_bitsize, &rl_bitpos, &rl_mode,
3649 &rl_unsignedp, &volatilep, &rl_mask,
3651 rr_inner = decode_field_reference (rr_arg,
3652 &rr_bitsize, &rr_bitpos, &rr_mode,
3653 &rr_unsignedp, &volatilep, &rr_mask,
3656 /* It must be true that the inner operation on the lhs of each
3657 comparison must be the same if we are to be able to do anything.
3658 Then see if we have constants. If not, the same must be true for
3660 if (volatilep || ll_inner == 0 || rl_inner == 0
3661 || ! operand_equal_p (ll_inner, rl_inner, 0))
3664 if (TREE_CODE (lr_arg) == INTEGER_CST
3665 && TREE_CODE (rr_arg) == INTEGER_CST)
3666 l_const = lr_arg, r_const = rr_arg;
3667 else if (lr_inner == 0 || rr_inner == 0
3668 || ! operand_equal_p (lr_inner, rr_inner, 0))
3671 l_const = r_const = 0;
3673 /* If either comparison code is not correct for our logical operation,
3674 fail. However, we can convert a one-bit comparison against zero into
3675 the opposite comparison against that bit being set in the field. */
3677 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
3678 if (lcode != wanted_code)
3680 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
3682 /* Make the left operand unsigned, since we are only interested
3683 in the value of one bit. Otherwise we are doing the wrong
3692 /* This is analogous to the code for l_const above. */
3693 if (rcode != wanted_code)
3695 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
3704 /* After this point all optimizations will generate bit-field
3705 references, which we might not want. */
3706 if (! (*lang_hooks.can_use_bit_fields_p) ())
3709 /* See if we can find a mode that contains both fields being compared on
3710 the left. If we can't, fail. Otherwise, update all constants and masks
3711 to be relative to a field of that size. */
3712 first_bit = MIN (ll_bitpos, rl_bitpos);
3713 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
3714 lnmode = get_best_mode (end_bit - first_bit, first_bit,
3715 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
3717 if (lnmode == VOIDmode)
3720 lnbitsize = GET_MODE_BITSIZE (lnmode);
3721 lnbitpos = first_bit & ~ (lnbitsize - 1);
3722 lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
3723 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
3725 if (BYTES_BIG_ENDIAN)
3727 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
3728 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
3731 ll_mask = const_binop (LSHIFT_EXPR, convert (lntype, ll_mask),
3732 size_int (xll_bitpos), 0);
3733 rl_mask = const_binop (LSHIFT_EXPR, convert (lntype, rl_mask),
3734 size_int (xrl_bitpos), 0);
3738 l_const = convert (lntype, l_const);
3739 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
3740 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
3741 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
3742 fold (build1 (BIT_NOT_EXPR,
3746 warning ("comparison is always %d", wanted_code == NE_EXPR);
3748 return convert (truth_type,
3749 wanted_code == NE_EXPR
3750 ? integer_one_node : integer_zero_node);
3755 r_const = convert (lntype, r_const);
3756 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
3757 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
3758 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
3759 fold (build1 (BIT_NOT_EXPR,
3763 warning ("comparison is always %d", wanted_code == NE_EXPR);
3765 return convert (truth_type,
3766 wanted_code == NE_EXPR
3767 ? integer_one_node : integer_zero_node);
3771 /* If the right sides are not constant, do the same for it. Also,
3772 disallow this optimization if a size or signedness mismatch occurs
3773 between the left and right sides. */
3776 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
3777 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
3778 /* Make sure the two fields on the right
3779 correspond to the left without being swapped. */
3780 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
3783 first_bit = MIN (lr_bitpos, rr_bitpos);
3784 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
3785 rnmode = get_best_mode (end_bit - first_bit, first_bit,
3786 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
3788 if (rnmode == VOIDmode)
3791 rnbitsize = GET_MODE_BITSIZE (rnmode);
3792 rnbitpos = first_bit & ~ (rnbitsize - 1);
3793 rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
3794 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
3796 if (BYTES_BIG_ENDIAN)
3798 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
3799 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
3802 lr_mask = const_binop (LSHIFT_EXPR, convert (rntype, lr_mask),
3803 size_int (xlr_bitpos), 0);
3804 rr_mask = const_binop (LSHIFT_EXPR, convert (rntype, rr_mask),
3805 size_int (xrr_bitpos), 0);
3807 /* Make a mask that corresponds to both fields being compared.
3808 Do this for both items being compared. If the operands are the
3809 same size and the bits being compared are in the same position
3810 then we can do this by masking both and comparing the masked
3812 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3813 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
3814 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
3816 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3817 ll_unsignedp || rl_unsignedp);
3818 if (! all_ones_mask_p (ll_mask, lnbitsize))
3819 lhs = build (BIT_AND_EXPR, lntype, lhs, ll_mask);
3821 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
3822 lr_unsignedp || rr_unsignedp);
3823 if (! all_ones_mask_p (lr_mask, rnbitsize))
3824 rhs = build (BIT_AND_EXPR, rntype, rhs, lr_mask);
3826 return build (wanted_code, truth_type, lhs, rhs);
3829 /* There is still another way we can do something: If both pairs of
3830 fields being compared are adjacent, we may be able to make a wider
3831 field containing them both.
3833 Note that we still must mask the lhs/rhs expressions. Furthermore,
3834 the mask must be shifted to account for the shift done by
3835 make_bit_field_ref. */
3836 if ((ll_bitsize + ll_bitpos == rl_bitpos
3837 && lr_bitsize + lr_bitpos == rr_bitpos)
3838 || (ll_bitpos == rl_bitpos + rl_bitsize
3839 && lr_bitpos == rr_bitpos + rr_bitsize))
3843 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
3844 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
3845 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
3846 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
3848 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
3849 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
3850 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
3851 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
3853 /* Convert to the smaller type before masking out unwanted bits. */
3855 if (lntype != rntype)
3857 if (lnbitsize > rnbitsize)
3859 lhs = convert (rntype, lhs);
3860 ll_mask = convert (rntype, ll_mask);
3863 else if (lnbitsize < rnbitsize)
3865 rhs = convert (lntype, rhs);
3866 lr_mask = convert (lntype, lr_mask);
3871 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
3872 lhs = build (BIT_AND_EXPR, type, lhs, ll_mask);
3874 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
3875 rhs = build (BIT_AND_EXPR, type, rhs, lr_mask);
3877 return build (wanted_code, truth_type, lhs, rhs);
3883 /* Handle the case of comparisons with constants. If there is something in
3884 common between the masks, those bits of the constants must be the same.
3885 If not, the condition is always false. Test for this to avoid generating
3886 incorrect code below. */
3887 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
3888 if (! integer_zerop (result)
3889 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
3890 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
3892 if (wanted_code == NE_EXPR)
3894 warning ("`or' of unmatched not-equal tests is always 1");
3895 return convert (truth_type, integer_one_node);
3899 warning ("`and' of mutually exclusive equal-tests is always 0");
3900 return convert (truth_type, integer_zero_node);
3904 /* Construct the expression we will return. First get the component
3905 reference we will make. Unless the mask is all ones the width of
3906 that field, perform the mask operation. Then compare with the
3908 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
3909 ll_unsignedp || rl_unsignedp);
3911 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
3912 if (! all_ones_mask_p (ll_mask, lnbitsize))
3913 result = build (BIT_AND_EXPR, lntype, result, ll_mask);
3915 return build (wanted_code, truth_type, result,
3916 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
3919 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
3923 optimize_minmax_comparison (tree t)
3925 tree type = TREE_TYPE (t);
3926 tree arg0 = TREE_OPERAND (t, 0);
3927 enum tree_code op_code;
3928 tree comp_const = TREE_OPERAND (t, 1);
3930 int consts_equal, consts_lt;
3933 STRIP_SIGN_NOPS (arg0);
3935 op_code = TREE_CODE (arg0);
3936 minmax_const = TREE_OPERAND (arg0, 1);
3937 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
3938 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
3939 inner = TREE_OPERAND (arg0, 0);
3941 /* If something does not permit us to optimize, return the original tree. */
3942 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
3943 || TREE_CODE (comp_const) != INTEGER_CST
3944 || TREE_CONSTANT_OVERFLOW (comp_const)
3945 || TREE_CODE (minmax_const) != INTEGER_CST
3946 || TREE_CONSTANT_OVERFLOW (minmax_const))
3949 /* Now handle all the various comparison codes. We only handle EQ_EXPR
3950 and GT_EXPR, doing the rest with recursive calls using logical
3952 switch (TREE_CODE (t))
3954 case NE_EXPR: case LT_EXPR: case LE_EXPR:
3956 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t)));
3960 fold (build (TRUTH_ORIF_EXPR, type,
3961 optimize_minmax_comparison
3962 (build (EQ_EXPR, type, arg0, comp_const)),
3963 optimize_minmax_comparison
3964 (build (GT_EXPR, type, arg0, comp_const))));
3967 if (op_code == MAX_EXPR && consts_equal)
3968 /* MAX (X, 0) == 0 -> X <= 0 */
3969 return fold (build (LE_EXPR, type, inner, comp_const));
3971 else if (op_code == MAX_EXPR && consts_lt)
3972 /* MAX (X, 0) == 5 -> X == 5 */
3973 return fold (build (EQ_EXPR, type, inner, comp_const));
3975 else if (op_code == MAX_EXPR)
3976 /* MAX (X, 0) == -1 -> false */
3977 return omit_one_operand (type, integer_zero_node, inner);
3979 else if (consts_equal)
3980 /* MIN (X, 0) == 0 -> X >= 0 */
3981 return fold (build (GE_EXPR, type, inner, comp_const));
3984 /* MIN (X, 0) == 5 -> false */
3985 return omit_one_operand (type, integer_zero_node, inner);
3988 /* MIN (X, 0) == -1 -> X == -1 */
3989 return fold (build (EQ_EXPR, type, inner, comp_const));
3992 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
3993 /* MAX (X, 0) > 0 -> X > 0
3994 MAX (X, 0) > 5 -> X > 5 */
3995 return fold (build (GT_EXPR, type, inner, comp_const));
3997 else if (op_code == MAX_EXPR)
3998 /* MAX (X, 0) > -1 -> true */
3999 return omit_one_operand (type, integer_one_node, inner);
4001 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
4002 /* MIN (X, 0) > 0 -> false
4003 MIN (X, 0) > 5 -> false */
4004 return omit_one_operand (type, integer_zero_node, inner);
4007 /* MIN (X, 0) > -1 -> X > -1 */
4008 return fold (build (GT_EXPR, type, inner, comp_const));
4015 /* T is an integer expression that is being multiplied, divided, or taken a
4016 modulus (CODE says which and what kind of divide or modulus) by a
4017 constant C. See if we can eliminate that operation by folding it with
4018 other operations already in T. WIDE_TYPE, if non-null, is a type that
4019 should be used for the computation if wider than our type.
4021 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4022 (X * 2) + (Y * 4). We must, however, be assured that either the original
4023 expression would not overflow or that overflow is undefined for the type
4024 in the language in question.
4026 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4027 the machine has a multiply-accumulate insn or that this is part of an
4028 addressing calculation.
4030 If we return a non-null expression, it is an equivalent form of the
4031 original computation, but need not be in the original type. */
4034 extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
4036 /* To avoid exponential search depth, refuse to allow recursion past
4037 three levels. Beyond that (1) it's highly unlikely that we'll find
4038 something interesting and (2) we've probably processed it before
4039 when we built the inner expression. */
4048 ret = extract_muldiv_1 (t, c, code, wide_type);
4055 extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
4057 tree type = TREE_TYPE (t);
4058 enum tree_code tcode = TREE_CODE (t);
4059 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
4060 > GET_MODE_SIZE (TYPE_MODE (type)))
4061 ? wide_type : type);
4063 int same_p = tcode == code;
4064 tree op0 = NULL_TREE, op1 = NULL_TREE;
4066 /* Don't deal with constants of zero here; they confuse the code below. */
4067 if (integer_zerop (c))
4070 if (TREE_CODE_CLASS (tcode) == '1')
4071 op0 = TREE_OPERAND (t, 0);
4073 if (TREE_CODE_CLASS (tcode) == '2')
4074 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
4076 /* Note that we need not handle conditional operations here since fold
4077 already handles those cases. So just do arithmetic here. */
4081 /* For a constant, we can always simplify if we are a multiply
4082 or (for divide and modulus) if it is a multiple of our constant. */
4083 if (code == MULT_EXPR
4084 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
4085 return const_binop (code, convert (ctype, t), convert (ctype, c), 0);
4088 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
4089 /* If op0 is an expression ... */
4090 if ((TREE_CODE_CLASS (TREE_CODE (op0)) == '<'
4091 || TREE_CODE_CLASS (TREE_CODE (op0)) == '1'
4092 || TREE_CODE_CLASS (TREE_CODE (op0)) == '2'
4093 || TREE_CODE_CLASS (TREE_CODE (op0)) == 'e')
4094 /* ... and is unsigned, and its type is smaller than ctype,
4095 then we cannot pass through as widening. */
4096 && ((TREE_UNSIGNED (TREE_TYPE (op0))
4097 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
4098 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
4099 && (GET_MODE_SIZE (TYPE_MODE (ctype))
4100 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
4101 /* ... or its type is larger than ctype,
4102 then we cannot pass through this truncation. */
4103 || (GET_MODE_SIZE (TYPE_MODE (ctype))
4104 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
4105 /* ... or signedness changes for division or modulus,
4106 then we cannot pass through this conversion. */
4107 || (code != MULT_EXPR
4108 && (TREE_UNSIGNED (ctype)
4109 != TREE_UNSIGNED (TREE_TYPE (op0))))))
4112 /* Pass the constant down and see if we can make a simplification. If
4113 we can, replace this expression with the inner simplification for
4114 possible later conversion to our or some other type. */
4115 if ((t2 = convert (TREE_TYPE (op0), c)) != 0
4116 && TREE_CODE (t2) == INTEGER_CST
4117 && ! TREE_CONSTANT_OVERFLOW (t2)
4118 && (0 != (t1 = extract_muldiv (op0, t2, code,
4120 ? ctype : NULL_TREE))))
4124 case NEGATE_EXPR: case ABS_EXPR:
4125 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4126 return fold (build1 (tcode, ctype, convert (ctype, t1)));
4129 case MIN_EXPR: case MAX_EXPR:
4130 /* If widening the type changes the signedness, then we can't perform
4131 this optimization as that changes the result. */
4132 if (TREE_UNSIGNED (ctype) != TREE_UNSIGNED (type))
4135 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4136 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
4137 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
4139 if (tree_int_cst_sgn (c) < 0)
4140 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
4142 return fold (build (tcode, ctype, convert (ctype, t1),
4143 convert (ctype, t2)));
4147 case WITH_RECORD_EXPR:
4148 if ((t1 = extract_muldiv (TREE_OPERAND (t, 0), c, code, wide_type)) != 0)
4149 return build (WITH_RECORD_EXPR, TREE_TYPE (t1), t1,
4150 TREE_OPERAND (t, 1));
4153 case LSHIFT_EXPR: case RSHIFT_EXPR:
4154 /* If the second operand is constant, this is a multiplication
4155 or floor division, by a power of two, so we can treat it that
4156 way unless the multiplier or divisor overflows. */
4157 if (TREE_CODE (op1) == INTEGER_CST
4158 /* const_binop may not detect overflow correctly,
4159 so check for it explicitly here. */
4160 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
4161 && TREE_INT_CST_HIGH (op1) == 0
4162 && 0 != (t1 = convert (ctype,
4163 const_binop (LSHIFT_EXPR, size_one_node,
4165 && ! TREE_OVERFLOW (t1))
4166 return extract_muldiv (build (tcode == LSHIFT_EXPR
4167 ? MULT_EXPR : FLOOR_DIV_EXPR,
4168 ctype, convert (ctype, op0), t1),
4169 c, code, wide_type);
4172 case PLUS_EXPR: case MINUS_EXPR:
4173 /* See if we can eliminate the operation on both sides. If we can, we
4174 can return a new PLUS or MINUS. If we can't, the only remaining
4175 cases where we can do anything are if the second operand is a
4177 t1 = extract_muldiv (op0, c, code, wide_type);
4178 t2 = extract_muldiv (op1, c, code, wide_type);
4179 if (t1 != 0 && t2 != 0
4180 && (code == MULT_EXPR
4181 /* If not multiplication, we can only do this if both operands
4182 are divisible by c. */
4183 || (multiple_of_p (ctype, op0, c)
4184 && multiple_of_p (ctype, op1, c))))
4185 return fold (build (tcode, ctype, convert (ctype, t1),
4186 convert (ctype, t2)));
4188 /* If this was a subtraction, negate OP1 and set it to be an addition.
4189 This simplifies the logic below. */
4190 if (tcode == MINUS_EXPR)
4191 tcode = PLUS_EXPR, op1 = negate_expr (op1);
4193 if (TREE_CODE (op1) != INTEGER_CST)
4196 /* If either OP1 or C are negative, this optimization is not safe for
4197 some of the division and remainder types while for others we need
4198 to change the code. */
4199 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
4201 if (code == CEIL_DIV_EXPR)
4202 code = FLOOR_DIV_EXPR;
4203 else if (code == FLOOR_DIV_EXPR)
4204 code = CEIL_DIV_EXPR;
4205 else if (code != MULT_EXPR
4206 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
4210 /* If it's a multiply or a division/modulus operation of a multiple
4211 of our constant, do the operation and verify it doesn't overflow. */
4212 if (code == MULT_EXPR
4213 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4215 op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
4216 if (op1 == 0 || TREE_OVERFLOW (op1))
4222 /* If we have an unsigned type is not a sizetype, we cannot widen
4223 the operation since it will change the result if the original
4224 computation overflowed. */
4225 if (TREE_UNSIGNED (ctype)
4226 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
4230 /* If we were able to eliminate our operation from the first side,
4231 apply our operation to the second side and reform the PLUS. */
4232 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
4233 return fold (build (tcode, ctype, convert (ctype, t1), op1));
4235 /* The last case is if we are a multiply. In that case, we can
4236 apply the distributive law to commute the multiply and addition
4237 if the multiplication of the constants doesn't overflow. */
4238 if (code == MULT_EXPR)
4239 return fold (build (tcode, ctype, fold (build (code, ctype,
4240 convert (ctype, op0),
4241 convert (ctype, c))),
4247 /* We have a special case here if we are doing something like
4248 (C * 8) % 4 since we know that's zero. */
4249 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
4250 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
4251 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
4252 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4253 return omit_one_operand (type, integer_zero_node, op0);
4255 /* ... fall through ... */
4257 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
4258 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
4259 /* If we can extract our operation from the LHS, do so and return a
4260 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4261 do something only if the second operand is a constant. */
4263 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
4264 return fold (build (tcode, ctype, convert (ctype, t1),
4265 convert (ctype, op1)));
4266 else if (tcode == MULT_EXPR && code == MULT_EXPR
4267 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
4268 return fold (build (tcode, ctype, convert (ctype, op0),
4269 convert (ctype, t1)));
4270 else if (TREE_CODE (op1) != INTEGER_CST)
4273 /* If these are the same operation types, we can associate them
4274 assuming no overflow. */
4276 && 0 != (t1 = const_binop (MULT_EXPR, convert (ctype, op1),
4277 convert (ctype, c), 0))
4278 && ! TREE_OVERFLOW (t1))
4279 return fold (build (tcode, ctype, convert (ctype, op0), t1));
4281 /* If these operations "cancel" each other, we have the main
4282 optimizations of this pass, which occur when either constant is a
4283 multiple of the other, in which case we replace this with either an
4284 operation or CODE or TCODE.
4286 If we have an unsigned type that is not a sizetype, we cannot do
4287 this since it will change the result if the original computation
4289 if ((! TREE_UNSIGNED (ctype)
4290 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
4292 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
4293 || (tcode == MULT_EXPR
4294 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
4295 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
4297 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
4298 return fold (build (tcode, ctype, convert (ctype, op0),
4300 const_binop (TRUNC_DIV_EXPR,
4302 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
4303 return fold (build (code, ctype, convert (ctype, op0),
4305 const_binop (TRUNC_DIV_EXPR,
4317 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4318 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4319 that we may sometimes modify the tree. */
4322 strip_compound_expr (tree t, tree s)
4324 enum tree_code code = TREE_CODE (t);
4326 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4327 if (code == COMPOUND_EXPR && TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR
4328 && TREE_OPERAND (TREE_OPERAND (t, 0), 0) == s)
4329 return TREE_OPERAND (t, 1);
4331 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4332 don't bother handling any other types. */
4333 else if (code == COND_EXPR)
4335 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4336 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4337 TREE_OPERAND (t, 2) = strip_compound_expr (TREE_OPERAND (t, 2), s);
4339 else if (TREE_CODE_CLASS (code) == '1')
4340 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4341 else if (TREE_CODE_CLASS (code) == '<'
4342 || TREE_CODE_CLASS (code) == '2')
4344 TREE_OPERAND (t, 0) = strip_compound_expr (TREE_OPERAND (t, 0), s);
4345 TREE_OPERAND (t, 1) = strip_compound_expr (TREE_OPERAND (t, 1), s);
4351 /* Return a node which has the indicated constant VALUE (either 0 or
4352 1), and is of the indicated TYPE. */
4355 constant_boolean_node (int value, tree type)
4357 if (type == integer_type_node)
4358 return value ? integer_one_node : integer_zero_node;
4359 else if (TREE_CODE (type) == BOOLEAN_TYPE)
4360 return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
4364 tree t = build_int_2 (value, 0);
4366 TREE_TYPE (t) = type;
4371 /* Utility function for the following routine, to see how complex a nesting of
4372 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4373 we don't care (to avoid spending too much time on complex expressions.). */
4376 count_cond (tree expr, int lim)
4380 if (TREE_CODE (expr) != COND_EXPR)
4385 ctrue = count_cond (TREE_OPERAND (expr, 1), lim - 1);
4386 cfalse = count_cond (TREE_OPERAND (expr, 2), lim - 1 - ctrue);
4387 return MIN (lim, 1 + ctrue + cfalse);
4390 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4391 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4392 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4393 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4394 COND is the first argument to CODE; otherwise (as in the example
4395 given here), it is the second argument. TYPE is the type of the
4396 original expression. */
4399 fold_binary_op_with_conditional_arg (enum tree_code code, tree type, tree cond, tree arg, int cond_first_p)
4401 tree test, true_value, false_value;
4402 tree lhs = NULL_TREE;
4403 tree rhs = NULL_TREE;
4404 /* In the end, we'll produce a COND_EXPR. Both arms of the
4405 conditional expression will be binary operations. The left-hand
4406 side of the expression to be executed if the condition is true
4407 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4408 of the expression to be executed if the condition is true will be
4409 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4410 but apply to the expression to be executed if the conditional is
4416 /* These are the codes to use for the left-hand side and right-hand
4417 side of the COND_EXPR. Normally, they are the same as CODE. */
4418 enum tree_code lhs_code = code;
4419 enum tree_code rhs_code = code;
4420 /* And these are the types of the expressions. */
4421 tree lhs_type = type;
4422 tree rhs_type = type;
4427 true_rhs = false_rhs = &arg;
4428 true_lhs = &true_value;
4429 false_lhs = &false_value;
4433 true_lhs = false_lhs = &arg;
4434 true_rhs = &true_value;
4435 false_rhs = &false_value;
4438 if (TREE_CODE (cond) == COND_EXPR)
4440 test = TREE_OPERAND (cond, 0);
4441 true_value = TREE_OPERAND (cond, 1);
4442 false_value = TREE_OPERAND (cond, 2);
4443 /* If this operand throws an expression, then it does not make
4444 sense to try to perform a logical or arithmetic operation
4445 involving it. Instead of building `a + throw 3' for example,
4446 we simply build `a, throw 3'. */
4447 if (VOID_TYPE_P (TREE_TYPE (true_value)))
4451 lhs_code = COMPOUND_EXPR;
4452 lhs_type = void_type_node;
4457 if (VOID_TYPE_P (TREE_TYPE (false_value)))
4461 rhs_code = COMPOUND_EXPR;
4462 rhs_type = void_type_node;
4470 tree testtype = TREE_TYPE (cond);
4472 true_value = convert (testtype, integer_one_node);
4473 false_value = convert (testtype, integer_zero_node);
4476 /* If ARG is complex we want to make sure we only evaluate it once. Though
4477 this is only required if it is volatile, it might be more efficient even
4478 if it is not. However, if we succeed in folding one part to a constant,
4479 we do not need to make this SAVE_EXPR. Since we do this optimization
4480 primarily to see if we do end up with constant and this SAVE_EXPR
4481 interferes with later optimizations, suppressing it when we can is
4484 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4485 do so. Don't try to see if the result is a constant if an arm is a
4486 COND_EXPR since we get exponential behavior in that case. */
4488 if (saved_expr_p (arg))
4490 else if (lhs == 0 && rhs == 0
4491 && !TREE_CONSTANT (arg)
4492 && (*lang_hooks.decls.global_bindings_p) () == 0
4493 && ((TREE_CODE (arg) != VAR_DECL && TREE_CODE (arg) != PARM_DECL)
4494 || TREE_SIDE_EFFECTS (arg)))
4496 if (TREE_CODE (true_value) != COND_EXPR)
4497 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4499 if (TREE_CODE (false_value) != COND_EXPR)
4500 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4502 if ((lhs == 0 || ! TREE_CONSTANT (lhs))
4503 && (rhs == 0 || !TREE_CONSTANT (rhs)))
4505 arg = save_expr (arg);
4512 lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
4514 rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
4516 test = fold (build (COND_EXPR, type, test, lhs, rhs));
4519 return build (COMPOUND_EXPR, type,
4520 convert (void_type_node, arg),
4521 strip_compound_expr (test, arg));
4523 return convert (type, test);
4527 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4529 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4530 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4531 ADDEND is the same as X.
4533 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4534 and finite. The problematic cases are when X is zero, and its mode
4535 has signed zeros. In the case of rounding towards -infinity,
4536 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4537 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4540 fold_real_zero_addition_p (tree type, tree addend, int negate)
4542 if (!real_zerop (addend))
4545 /* Don't allow the fold with -fsignaling-nans. */
4546 if (HONOR_SNANS (TYPE_MODE (type)))
4549 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4550 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
4553 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4554 if (TREE_CODE (addend) == REAL_CST
4555 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
4558 /* The mode has signed zeros, and we have to honor their sign.
4559 In this situation, there is only one case we can return true for.
4560 X - 0 is the same as X unless rounding towards -infinity is
4562 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
4565 /* Subroutine of fold() that checks comparisons of built-in math
4566 functions against real constants.
4568 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4569 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4570 is the type of the result and ARG0 and ARG1 are the operands of the
4571 comparison. ARG1 must be a TREE_REAL_CST.
4573 The function returns the constant folded tree if a simplification
4574 can be made, and NULL_TREE otherwise. */
4577 fold_mathfn_compare (enum built_in_function fcode, enum tree_code code, tree type, tree arg0, tree arg1)
4581 if (fcode == BUILT_IN_SQRT
4582 || fcode == BUILT_IN_SQRTF
4583 || fcode == BUILT_IN_SQRTL)
4585 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
4586 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
4588 c = TREE_REAL_CST (arg1);
4589 if (REAL_VALUE_NEGATIVE (c))
4591 /* sqrt(x) < y is always false, if y is negative. */
4592 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
4593 return omit_one_operand (type,
4594 convert (type, integer_zero_node),
4597 /* sqrt(x) > y is always true, if y is negative and we
4598 don't care about NaNs, i.e. negative values of x. */
4599 if (code == NE_EXPR || !HONOR_NANS (mode))
4600 return omit_one_operand (type,
4601 convert (type, integer_one_node),
4604 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4605 return fold (build (GE_EXPR, type, arg,
4606 build_real (TREE_TYPE (arg), dconst0)));
4608 else if (code == GT_EXPR || code == GE_EXPR)
4612 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4613 real_convert (&c2, mode, &c2);
4615 if (REAL_VALUE_ISINF (c2))
4617 /* sqrt(x) > y is x == +Inf, when y is very large. */
4618 if (HONOR_INFINITIES (mode))
4619 return fold (build (EQ_EXPR, type, arg,
4620 build_real (TREE_TYPE (arg), c2)));
4622 /* sqrt(x) > y is always false, when y is very large
4623 and we don't care about infinities. */
4624 return omit_one_operand (type,
4625 convert (type, integer_zero_node),
4629 /* sqrt(x) > c is the same as x > c*c. */
4630 return fold (build (code, type, arg,
4631 build_real (TREE_TYPE (arg), c2)));
4633 else if (code == LT_EXPR || code == LE_EXPR)
4637 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
4638 real_convert (&c2, mode, &c2);
4640 if (REAL_VALUE_ISINF (c2))
4642 /* sqrt(x) < y is always true, when y is a very large
4643 value and we don't care about NaNs or Infinities. */
4644 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
4645 return omit_one_operand (type,
4646 convert (type, integer_one_node),
4649 /* sqrt(x) < y is x != +Inf when y is very large and we
4650 don't care about NaNs. */
4651 if (! HONOR_NANS (mode))
4652 return fold (build (NE_EXPR, type, arg,
4653 build_real (TREE_TYPE (arg), c2)));
4655 /* sqrt(x) < y is x >= 0 when y is very large and we
4656 don't care about Infinities. */
4657 if (! HONOR_INFINITIES (mode))
4658 return fold (build (GE_EXPR, type, arg,
4659 build_real (TREE_TYPE (arg), dconst0)));
4661 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4662 if ((*lang_hooks.decls.global_bindings_p) () != 0
4663 || CONTAINS_PLACEHOLDER_P (arg))
4666 arg = save_expr (arg);
4667 return fold (build (TRUTH_ANDIF_EXPR, type,
4668 fold (build (GE_EXPR, type, arg,
4669 build_real (TREE_TYPE (arg),
4671 fold (build (NE_EXPR, type, arg,
4672 build_real (TREE_TYPE (arg),
4676 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4677 if (! HONOR_NANS (mode))
4678 return fold (build (code, type, arg,
4679 build_real (TREE_TYPE (arg), c2)));
4681 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4682 if ((*lang_hooks.decls.global_bindings_p) () == 0
4683 && ! CONTAINS_PLACEHOLDER_P (arg))
4685 arg = save_expr (arg);
4686 return fold (build (TRUTH_ANDIF_EXPR, type,
4687 fold (build (GE_EXPR, type, arg,
4688 build_real (TREE_TYPE (arg),
4690 fold (build (code, type, arg,
4691 build_real (TREE_TYPE (arg),
4700 /* Subroutine of fold() that optimizes comparisons against Infinities,
4701 either +Inf or -Inf.
4703 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4704 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4705 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4707 The function returns the constant folded tree if a simplification
4708 can be made, and NULL_TREE otherwise. */
4711 fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
4713 enum machine_mode mode;
4714 REAL_VALUE_TYPE max;
4718 mode = TYPE_MODE (TREE_TYPE (arg0));
4720 /* For negative infinity swap the sense of the comparison. */
4721 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
4723 code = swap_tree_comparison (code);
4728 /* x > +Inf is always false, if with ignore sNANs. */
4729 if (HONOR_SNANS (mode))
4731 return omit_one_operand (type,
4732 convert (type, integer_zero_node),
4736 /* x <= +Inf is always true, if we don't case about NaNs. */
4737 if (! HONOR_NANS (mode))
4738 return omit_one_operand (type,
4739 convert (type, integer_one_node),
4742 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4743 if ((*lang_hooks.decls.global_bindings_p) () == 0
4744 && ! CONTAINS_PLACEHOLDER_P (arg0))
4746 arg0 = save_expr (arg0);
4747 return fold (build (EQ_EXPR, type, arg0, arg0));
4753 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
4754 real_maxval (&max, neg, mode);
4755 return fold (build (neg ? LT_EXPR : GT_EXPR, type,
4756 arg0, build_real (TREE_TYPE (arg0), max)));
4759 /* x < +Inf is always equal to x <= DBL_MAX. */
4760 real_maxval (&max, neg, mode);
4761 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4762 arg0, build_real (TREE_TYPE (arg0), max)));
4765 /* x != +Inf is always equal to !(x > DBL_MAX). */
4766 real_maxval (&max, neg, mode);
4767 if (! HONOR_NANS (mode))
4768 return fold (build (neg ? GE_EXPR : LE_EXPR, type,
4769 arg0, build_real (TREE_TYPE (arg0), max)));
4770 temp = fold (build (neg ? LT_EXPR : GT_EXPR, type,
4771 arg0, build_real (TREE_TYPE (arg0), max)));
4772 return fold (build1 (TRUTH_NOT_EXPR, type, temp));
4781 /* If CODE with arguments ARG0 and ARG1 represents a single bit
4782 equality/inequality test, then return a simplified form of
4783 the test using shifts and logical operations. Otherwise return
4784 NULL. TYPE is the desired result type. */
4787 fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
4790 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
4792 if (code == TRUTH_NOT_EXPR)
4794 code = TREE_CODE (arg0);
4795 if (code != NE_EXPR && code != EQ_EXPR)
4798 /* Extract the arguments of the EQ/NE. */
4799 arg1 = TREE_OPERAND (arg0, 1);
4800 arg0 = TREE_OPERAND (arg0, 0);
4802 /* This requires us to invert the code. */
4803 code = (code == EQ_EXPR ? NE_EXPR : EQ_EXPR);
4806 /* If this is testing a single bit, we can optimize the test. */
4807 if ((code == NE_EXPR || code == EQ_EXPR)
4808 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
4809 && integer_pow2p (TREE_OPERAND (arg0, 1)))
4811 tree inner = TREE_OPERAND (arg0, 0);
4812 tree type = TREE_TYPE (arg0);
4813 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
4814 enum machine_mode operand_mode = TYPE_MODE (type);
4816 tree signed_type, unsigned_type;
4819 /* If we have (A & C) != 0 where C is the sign bit of A, convert
4820 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
4821 arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
4822 if (arg00 != NULL_TREE)
4824 tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
4825 return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, result_type,
4826 convert (stype, arg00),
4827 convert (stype, integer_zero_node)));
4830 /* Otherwise we have (A & C) != 0 where C is a single bit,
4831 convert that into ((A >> C2) & 1). Where C2 = log2(C).
4832 Similarly for (A & C) == 0. */
4834 /* If INNER is a right shift of a constant and it plus BITNUM does
4835 not overflow, adjust BITNUM and INNER. */
4836 if (TREE_CODE (inner) == RSHIFT_EXPR
4837 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
4838 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
4839 && bitnum < TYPE_PRECISION (type)
4840 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
4841 bitnum - TYPE_PRECISION (type)))
4843 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
4844 inner = TREE_OPERAND (inner, 0);
4847 /* If we are going to be able to omit the AND below, we must do our
4848 operations as unsigned. If we must use the AND, we have a choice.
4849 Normally unsigned is faster, but for some machines signed is. */
4850 ops_unsigned = (bitnum == TYPE_PRECISION (type) - 1 ? 1
4851 #ifdef LOAD_EXTEND_OP
4852 : (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND ? 0 : 1)
4858 signed_type = (*lang_hooks.types.type_for_mode) (operand_mode, 0);
4859 unsigned_type = (*lang_hooks.types.type_for_mode) (operand_mode, 1);
4862 inner = build (RSHIFT_EXPR, ops_unsigned ? unsigned_type : signed_type,
4863 inner, size_int (bitnum));
4865 if (code == EQ_EXPR)
4866 inner = build (BIT_XOR_EXPR, ops_unsigned ? unsigned_type : signed_type,
4867 inner, integer_one_node);
4869 /* Put the AND last so it can combine with more things. */
4870 if (bitnum != TYPE_PRECISION (type) - 1)
4871 inner = build (BIT_AND_EXPR, ops_unsigned ? unsigned_type : signed_type,
4872 inner, integer_one_node);
4874 /* Make sure to return the proper type. */
4875 if (TREE_TYPE (inner) != result_type)
4876 inner = convert (result_type, inner);
4883 /* Perform constant folding and related simplification of EXPR.
4884 The related simplifications include x*1 => x, x*0 => 0, etc.,
4885 and application of the associative law.
4886 NOP_EXPR conversions may be removed freely (as long as we
4887 are careful not to change the C type of the overall expression)
4888 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4889 but we can constant-fold them if they have constant operands. */
4895 tree t1 = NULL_TREE;
4897 tree type = TREE_TYPE (expr);
4898 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
4899 enum tree_code code = TREE_CODE (t);
4900 int kind = TREE_CODE_CLASS (code);
4902 /* WINS will be nonzero when the switch is done
4903 if all operands are constant. */
4906 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4907 Likewise for a SAVE_EXPR that's already been evaluated. */
4908 if (code == RTL_EXPR || (code == SAVE_EXPR && SAVE_EXPR_RTL (t) != 0))
4911 /* Return right away if a constant. */
4915 #ifdef MAX_INTEGER_COMPUTATION_MODE
4916 check_max_integer_computation_mode (expr);
4919 if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
4923 /* Special case for conversion ops that can have fixed point args. */
4924 arg0 = TREE_OPERAND (t, 0);
4926 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4928 STRIP_SIGN_NOPS (arg0);
4930 if (arg0 != 0 && TREE_CODE (arg0) == COMPLEX_CST)
4931 subop = TREE_REALPART (arg0);
4935 if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
4936 && TREE_CODE (subop) != REAL_CST
4938 /* Note that TREE_CONSTANT isn't enough:
4939 static var addresses are constant but we can't
4940 do arithmetic on them. */
4943 else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
4945 int len = first_rtl_op (code);
4947 for (i = 0; i < len; i++)
4949 tree op = TREE_OPERAND (t, i);
4953 continue; /* Valid for CALL_EXPR, at least. */
4955 if (kind == '<' || code == RSHIFT_EXPR)
4957 /* Signedness matters here. Perhaps we can refine this
4959 STRIP_SIGN_NOPS (op);
4962 /* Strip any conversions that don't change the mode. */
4965 if (TREE_CODE (op) == COMPLEX_CST)
4966 subop = TREE_REALPART (op);
4970 if (TREE_CODE (subop) != INTEGER_CST
4971 && TREE_CODE (subop) != REAL_CST)
4972 /* Note that TREE_CONSTANT isn't enough:
4973 static var addresses are constant but we can't
4974 do arithmetic on them. */
4984 /* If this is a commutative operation, and ARG0 is a constant, move it
4985 to ARG1 to reduce the number of tests below. */
4986 if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
4987 || code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
4988 || code == BIT_AND_EXPR)
4989 && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
4991 tem = arg0; arg0 = arg1; arg1 = tem;
4993 tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
4994 TREE_OPERAND (t, 1) = tem;
4997 /* Now WINS is set as described above,
4998 ARG0 is the first operand of EXPR,
4999 and ARG1 is the second operand (if it has more than one operand).
5001 First check for cases where an arithmetic operation is applied to a
5002 compound, conditional, or comparison operation. Push the arithmetic
5003 operation inside the compound or conditional to see if any folding
5004 can then be done. Convert comparison to conditional for this purpose.
5005 The also optimizes non-constant cases that used to be done in
5008 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5009 one of the operands is a comparison and the other is a comparison, a
5010 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5011 code below would make the expression more complex. Change it to a
5012 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5013 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5015 if ((code == BIT_AND_EXPR || code == BIT_IOR_EXPR
5016 || code == EQ_EXPR || code == NE_EXPR)
5017 && ((truth_value_p (TREE_CODE (arg0))
5018 && (truth_value_p (TREE_CODE (arg1))
5019 || (TREE_CODE (arg1) == BIT_AND_EXPR
5020 && integer_onep (TREE_OPERAND (arg1, 1)))))
5021 || (truth_value_p (TREE_CODE (arg1))
5022 && (truth_value_p (TREE_CODE (arg0))
5023 || (TREE_CODE (arg0) == BIT_AND_EXPR
5024 && integer_onep (TREE_OPERAND (arg0, 1)))))))
5026 t = fold (build (code == BIT_AND_EXPR ? TRUTH_AND_EXPR
5027 : code == BIT_IOR_EXPR ? TRUTH_OR_EXPR
5031 if (code == EQ_EXPR)
5032 t = invert_truthvalue (t);
5037 if (TREE_CODE_CLASS (code) == '1')
5039 if (TREE_CODE (arg0) == COMPOUND_EXPR)
5040 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5041 fold (build1 (code, type, TREE_OPERAND (arg0, 1))));
5042 else if (TREE_CODE (arg0) == COND_EXPR)
5044 tree arg01 = TREE_OPERAND (arg0, 1);
5045 tree arg02 = TREE_OPERAND (arg0, 2);
5046 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
5047 arg01 = fold (build1 (code, type, arg01));
5048 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
5049 arg02 = fold (build1 (code, type, arg02));
5050 t = fold (build (COND_EXPR, type, TREE_OPERAND (arg0, 0),
5053 /* If this was a conversion, and all we did was to move into
5054 inside the COND_EXPR, bring it back out. But leave it if
5055 it is a conversion from integer to integer and the
5056 result precision is no wider than a word since such a
5057 conversion is cheap and may be optimized away by combine,
5058 while it couldn't if it were outside the COND_EXPR. Then return
5059 so we don't get into an infinite recursion loop taking the
5060 conversion out and then back in. */
5062 if ((code == NOP_EXPR || code == CONVERT_EXPR
5063 || code == NON_LVALUE_EXPR)
5064 && TREE_CODE (t) == COND_EXPR
5065 && TREE_CODE (TREE_OPERAND (t, 1)) == code
5066 && TREE_CODE (TREE_OPERAND (t, 2)) == code
5067 && ! VOID_TYPE_P (TREE_OPERAND (t, 1))
5068 && ! VOID_TYPE_P (TREE_OPERAND (t, 2))
5069 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))
5070 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 2), 0)))
5071 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t))
5073 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0))))
5074 && TYPE_PRECISION (TREE_TYPE (t)) <= BITS_PER_WORD))
5075 t = build1 (code, type,
5077 TREE_TYPE (TREE_OPERAND
5078 (TREE_OPERAND (t, 1), 0)),
5079 TREE_OPERAND (t, 0),
5080 TREE_OPERAND (TREE_OPERAND (t, 1), 0),
5081 TREE_OPERAND (TREE_OPERAND (t, 2), 0)));
5084 else if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<')
5085 return fold (build (COND_EXPR, type, arg0,
5086 fold (build1 (code, type, integer_one_node)),
5087 fold (build1 (code, type, integer_zero_node))));
5089 else if (TREE_CODE_CLASS (code) == '<'
5090 && TREE_CODE (arg0) == COMPOUND_EXPR)
5091 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5092 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5093 else if (TREE_CODE_CLASS (code) == '<'
5094 && TREE_CODE (arg1) == COMPOUND_EXPR)
5095 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5096 fold (build (code, type, arg0, TREE_OPERAND (arg1, 1))));
5097 else if (TREE_CODE_CLASS (code) == '2'
5098 || TREE_CODE_CLASS (code) == '<')
5100 if (TREE_CODE (arg1) == COMPOUND_EXPR
5101 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1, 0))
5102 && ! TREE_SIDE_EFFECTS (arg0))
5103 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg1, 0),
5104 fold (build (code, type,
5105 arg0, TREE_OPERAND (arg1, 1))));
5106 else if ((TREE_CODE (arg1) == COND_EXPR
5107 || (TREE_CODE_CLASS (TREE_CODE (arg1)) == '<'
5108 && TREE_CODE_CLASS (code) != '<'))
5109 && (TREE_CODE (arg0) != COND_EXPR
5110 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5111 && (! TREE_SIDE_EFFECTS (arg0)
5112 || ((*lang_hooks.decls.global_bindings_p) () == 0
5113 && ! CONTAINS_PLACEHOLDER_P (arg0))))
5115 fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
5116 /*cond_first_p=*/0);
5117 else if (TREE_CODE (arg0) == COMPOUND_EXPR)
5118 return build (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
5119 fold (build (code, type, TREE_OPERAND (arg0, 1), arg1)));
5120 else if ((TREE_CODE (arg0) == COND_EXPR
5121 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
5122 && TREE_CODE_CLASS (code) != '<'))
5123 && (TREE_CODE (arg1) != COND_EXPR
5124 || count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
5125 && (! TREE_SIDE_EFFECTS (arg1)
5126 || ((*lang_hooks.decls.global_bindings_p) () == 0
5127 && ! CONTAINS_PLACEHOLDER_P (arg1))))
5129 fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
5130 /*cond_first_p=*/1);
5144 return fold (DECL_INITIAL (t));
5149 case FIX_TRUNC_EXPR:
5150 /* Other kinds of FIX are not handled properly by fold_convert. */
5152 if (TREE_TYPE (TREE_OPERAND (t, 0)) == TREE_TYPE (t))
5153 return TREE_OPERAND (t, 0);
5155 /* Handle cases of two conversions in a row. */
5156 if (TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
5157 || TREE_CODE (TREE_OPERAND (t, 0)) == CONVERT_EXPR)
5159 tree inside_type = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5160 tree inter_type = TREE_TYPE (TREE_OPERAND (t, 0));
5161 tree final_type = TREE_TYPE (t);
5162 int inside_int = INTEGRAL_TYPE_P (inside_type);
5163 int inside_ptr = POINTER_TYPE_P (inside_type);
5164 int inside_float = FLOAT_TYPE_P (inside_type);
5165 unsigned int inside_prec = TYPE_PRECISION (inside_type);
5166 int inside_unsignedp = TREE_UNSIGNED (inside_type);
5167 int inter_int = INTEGRAL_TYPE_P (inter_type);
5168 int inter_ptr = POINTER_TYPE_P (inter_type);
5169 int inter_float = FLOAT_TYPE_P (inter_type);
5170 unsigned int inter_prec = TYPE_PRECISION (inter_type);
5171 int inter_unsignedp = TREE_UNSIGNED (inter_type);
5172 int final_int = INTEGRAL_TYPE_P (final_type);
5173 int final_ptr = POINTER_TYPE_P (final_type);
5174 int final_float = FLOAT_TYPE_P (final_type);
5175 unsigned int final_prec = TYPE_PRECISION (final_type);
5176 int final_unsignedp = TREE_UNSIGNED (final_type);
5178 /* In addition to the cases of two conversions in a row
5179 handled below, if we are converting something to its own
5180 type via an object of identical or wider precision, neither
5181 conversion is needed. */
5182 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (final_type)
5183 && ((inter_int && final_int) || (inter_float && final_float))
5184 && inter_prec >= final_prec)
5185 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5187 /* Likewise, if the intermediate and final types are either both
5188 float or both integer, we don't need the middle conversion if
5189 it is wider than the final type and doesn't change the signedness
5190 (for integers). Avoid this if the final type is a pointer
5191 since then we sometimes need the inner conversion. Likewise if
5192 the outer has a precision not equal to the size of its mode. */
5193 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
5194 || (inter_float && inside_float))
5195 && inter_prec >= inside_prec
5196 && (inter_float || inter_unsignedp == inside_unsignedp)
5197 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5198 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5200 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5202 /* If we have a sign-extension of a zero-extended value, we can
5203 replace that by a single zero-extension. */
5204 if (inside_int && inter_int && final_int
5205 && inside_prec < inter_prec && inter_prec < final_prec
5206 && inside_unsignedp && !inter_unsignedp)
5207 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5209 /* Two conversions in a row are not needed unless:
5210 - some conversion is floating-point (overstrict for now), or
5211 - the intermediate type is narrower than both initial and
5213 - the intermediate type and innermost type differ in signedness,
5214 and the outermost type is wider than the intermediate, or
5215 - the initial type is a pointer type and the precisions of the
5216 intermediate and final types differ, or
5217 - the final type is a pointer type and the precisions of the
5218 initial and intermediate types differ. */
5219 if (! inside_float && ! inter_float && ! final_float
5220 && (inter_prec > inside_prec || inter_prec > final_prec)
5221 && ! (inside_int && inter_int
5222 && inter_unsignedp != inside_unsignedp
5223 && inter_prec < final_prec)
5224 && ((inter_unsignedp && inter_prec > inside_prec)
5225 == (final_unsignedp && final_prec > inter_prec))
5226 && ! (inside_ptr && inter_prec != final_prec)
5227 && ! (final_ptr && inside_prec != inter_prec)
5228 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (final_type))
5229 && TYPE_MODE (final_type) == TYPE_MODE (inter_type))
5231 return convert (final_type, TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5234 if (TREE_CODE (TREE_OPERAND (t, 0)) == MODIFY_EXPR
5235 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t, 0), 1))
5236 /* Detect assigning a bitfield. */
5237 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 0)) == COMPONENT_REF
5238 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t, 0), 0), 1))))
5240 /* Don't leave an assignment inside a conversion
5241 unless assigning a bitfield. */
5242 tree prev = TREE_OPERAND (t, 0);
5243 TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
5244 /* First do the assignment, then return converted constant. */
5245 t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
5250 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5251 constants (if x has signed type, the sign bit cannot be set
5252 in c). This folds extension into the BIT_AND_EXPR. */
5253 if (INTEGRAL_TYPE_P (TREE_TYPE (t))
5254 && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
5255 && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
5256 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
5258 tree and = TREE_OPERAND (t, 0);
5259 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
5262 if (TREE_UNSIGNED (TREE_TYPE (and))
5263 || (TYPE_PRECISION (TREE_TYPE (t))
5264 <= TYPE_PRECISION (TREE_TYPE (and))))
5266 else if (TYPE_PRECISION (TREE_TYPE (and1))
5267 <= HOST_BITS_PER_WIDE_INT
5268 && host_integerp (and1, 1))
5270 unsigned HOST_WIDE_INT cst;
5272 cst = tree_low_cst (and1, 1);
5273 cst &= (HOST_WIDE_INT) -1
5274 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
5275 change = (cst == 0);
5276 #ifdef LOAD_EXTEND_OP
5278 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
5281 tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
5282 and0 = convert (uns, and0);
5283 and1 = convert (uns, and1);
5288 return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
5289 convert (TREE_TYPE (t), and0),
5290 convert (TREE_TYPE (t), and1)));
5295 TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
5298 return fold_convert (t, arg0);
5300 case VIEW_CONVERT_EXPR:
5301 if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
5302 return build1 (VIEW_CONVERT_EXPR, type,
5303 TREE_OPERAND (TREE_OPERAND (t, 0), 0));
5307 if (TREE_CODE (arg0) == CONSTRUCTOR
5308 && ! type_contains_placeholder_p (TREE_TYPE (arg0)))
5310 tree m = purpose_member (arg1, CONSTRUCTOR_ELTS (arg0));
5317 TREE_CONSTANT (t) = wins;
5323 if (TREE_CODE (arg0) == INTEGER_CST)
5325 unsigned HOST_WIDE_INT low;
5327 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5328 TREE_INT_CST_HIGH (arg0),
5330 t = build_int_2 (low, high);
5331 TREE_TYPE (t) = type;
5333 = (TREE_OVERFLOW (arg0)
5334 | force_fit_type (t, overflow && !TREE_UNSIGNED (type)));
5335 TREE_CONSTANT_OVERFLOW (t)
5336 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5338 else if (TREE_CODE (arg0) == REAL_CST)
5339 t = build_real (type, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5341 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5342 return TREE_OPERAND (arg0, 0);
5343 /* Convert -((double)float) into (double)(-float). */
5344 else if (TREE_CODE (arg0) == NOP_EXPR
5345 && TREE_CODE (type) == REAL_TYPE)
5347 tree targ0 = strip_float_extensions (arg0);
5349 return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (targ0), targ0));
5353 /* Convert - (a - b) to (b - a) for non-floating-point. */
5354 else if (TREE_CODE (arg0) == MINUS_EXPR
5355 && (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations))
5356 return build (MINUS_EXPR, type, TREE_OPERAND (arg0, 1),
5357 TREE_OPERAND (arg0, 0));
5359 /* Convert -f(x) into f(-x) where f is sin, tan or atan. */
5360 switch (builtin_mathfn_code (arg0))
5369 case BUILT_IN_ATANF:
5370 case BUILT_IN_ATANL:
5371 if (negate_expr_p (TREE_VALUE (TREE_OPERAND (arg0, 1))))
5373 tree fndecl, arg, arglist;
5375 fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5376 arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5377 arg = fold (build1 (NEGATE_EXPR, type, arg));
5378 arglist = build_tree_list (NULL_TREE, arg);
5379 return build_function_call_expr (fndecl, arglist);
5391 if (TREE_CODE (arg0) == INTEGER_CST)
5393 /* If the value is unsigned, then the absolute value is
5394 the same as the ordinary value. */
5395 if (TREE_UNSIGNED (type))
5397 /* Similarly, if the value is non-negative. */
5398 else if (INT_CST_LT (integer_minus_one_node, arg0))
5400 /* If the value is negative, then the absolute value is
5404 unsigned HOST_WIDE_INT low;
5406 int overflow = neg_double (TREE_INT_CST_LOW (arg0),
5407 TREE_INT_CST_HIGH (arg0),
5409 t = build_int_2 (low, high);
5410 TREE_TYPE (t) = type;
5412 = (TREE_OVERFLOW (arg0)
5413 | force_fit_type (t, overflow));
5414 TREE_CONSTANT_OVERFLOW (t)
5415 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg0);
5418 else if (TREE_CODE (arg0) == REAL_CST)
5420 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0)))
5421 t = build_real (type,
5422 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0)));
5425 else if (TREE_CODE (arg0) == NEGATE_EXPR)
5426 return fold (build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0)));
5427 /* Convert fabs((double)float) into (double)fabsf(float). */
5428 else if (TREE_CODE (arg0) == NOP_EXPR
5429 && TREE_CODE (type) == REAL_TYPE)
5431 tree targ0 = strip_float_extensions (arg0);
5433 return convert (type, fold (build1 (ABS_EXPR, TREE_TYPE (targ0),
5436 else if (tree_expr_nonnegative_p (arg0))
5441 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
5442 return convert (type, arg0);
5443 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
5444 return build (COMPLEX_EXPR, type,
5445 TREE_OPERAND (arg0, 0),
5446 negate_expr (TREE_OPERAND (arg0, 1)));
5447 else if (TREE_CODE (arg0) == COMPLEX_CST)
5448 return build_complex (type, TREE_REALPART (arg0),
5449 negate_expr (TREE_IMAGPART (arg0)));
5450 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
5451 return fold (build (TREE_CODE (arg0), type,
5452 fold (build1 (CONJ_EXPR, type,
5453 TREE_OPERAND (arg0, 0))),
5454 fold (build1 (CONJ_EXPR,
5455 type, TREE_OPERAND (arg0, 1)))));
5456 else if (TREE_CODE (arg0) == CONJ_EXPR)
5457 return TREE_OPERAND (arg0, 0);
5463 t = build_int_2 (~ TREE_INT_CST_LOW (arg0),
5464 ~ TREE_INT_CST_HIGH (arg0));
5465 TREE_TYPE (t) = type;
5466 force_fit_type (t, 0);
5467 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg0);
5468 TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (arg0);
5470 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
5471 return TREE_OPERAND (arg0, 0);
5475 /* A + (-B) -> A - B */
5476 if (TREE_CODE (arg1) == NEGATE_EXPR)
5477 return fold (build (MINUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5478 /* (-A) + B -> B - A */
5479 if (TREE_CODE (arg0) == NEGATE_EXPR)
5480 return fold (build (MINUS_EXPR, type, arg1, TREE_OPERAND (arg0, 0)));
5481 else if (! FLOAT_TYPE_P (type))
5483 if (integer_zerop (arg1))
5484 return non_lvalue (convert (type, arg0));
5486 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5487 with a constant, and the two constants have no bits in common,
5488 we should treat this as a BIT_IOR_EXPR since this may produce more
5490 if (TREE_CODE (arg0) == BIT_AND_EXPR
5491 && TREE_CODE (arg1) == BIT_AND_EXPR
5492 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
5493 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
5494 && integer_zerop (const_binop (BIT_AND_EXPR,
5495 TREE_OPERAND (arg0, 1),
5496 TREE_OPERAND (arg1, 1), 0)))
5498 code = BIT_IOR_EXPR;
5502 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5503 (plus (plus (mult) (mult)) (foo)) so that we can
5504 take advantage of the factoring cases below. */
5505 if ((TREE_CODE (arg0) == PLUS_EXPR
5506 && TREE_CODE (arg1) == MULT_EXPR)
5507 || (TREE_CODE (arg1) == PLUS_EXPR
5508 && TREE_CODE (arg0) == MULT_EXPR))
5510 tree parg0, parg1, parg, marg;
5512 if (TREE_CODE (arg0) == PLUS_EXPR)
5513 parg = arg0, marg = arg1;
5515 parg = arg1, marg = arg0;
5516 parg0 = TREE_OPERAND (parg, 0);
5517 parg1 = TREE_OPERAND (parg, 1);
5521 if (TREE_CODE (parg0) == MULT_EXPR
5522 && TREE_CODE (parg1) != MULT_EXPR)
5523 return fold (build (PLUS_EXPR, type,
5524 fold (build (PLUS_EXPR, type,
5525 convert (type, parg0),
5526 convert (type, marg))),
5527 convert (type, parg1)));
5528 if (TREE_CODE (parg0) != MULT_EXPR
5529 && TREE_CODE (parg1) == MULT_EXPR)
5530 return fold (build (PLUS_EXPR, type,
5531 fold (build (PLUS_EXPR, type,
5532 convert (type, parg1),
5533 convert (type, marg))),
5534 convert (type, parg0)));
5537 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR)
5539 tree arg00, arg01, arg10, arg11;
5540 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
5542 /* (A * C) + (B * C) -> (A+B) * C.
5543 We are most concerned about the case where C is a constant,
5544 but other combinations show up during loop reduction. Since
5545 it is not difficult, try all four possibilities. */
5547 arg00 = TREE_OPERAND (arg0, 0);
5548 arg01 = TREE_OPERAND (arg0, 1);
5549 arg10 = TREE_OPERAND (arg1, 0);
5550 arg11 = TREE_OPERAND (arg1, 1);
5553 if (operand_equal_p (arg01, arg11, 0))
5554 same = arg01, alt0 = arg00, alt1 = arg10;
5555 else if (operand_equal_p (arg00, arg10, 0))
5556 same = arg00, alt0 = arg01, alt1 = arg11;
5557 else if (operand_equal_p (arg00, arg11, 0))
5558 same = arg00, alt0 = arg01, alt1 = arg10;
5559 else if (operand_equal_p (arg01, arg10, 0))
5560 same = arg01, alt0 = arg00, alt1 = arg11;
5562 /* No identical multiplicands; see if we can find a common
5563 power-of-two factor in non-power-of-two multiplies. This
5564 can help in multi-dimensional array access. */
5565 else if (TREE_CODE (arg01) == INTEGER_CST
5566 && TREE_CODE (arg11) == INTEGER_CST
5567 && TREE_INT_CST_HIGH (arg01) == 0
5568 && TREE_INT_CST_HIGH (arg11) == 0)
5570 HOST_WIDE_INT int01, int11, tmp;
5571 int01 = TREE_INT_CST_LOW (arg01);
5572 int11 = TREE_INT_CST_LOW (arg11);
5574 /* Move min of absolute values to int11. */
5575 if ((int01 >= 0 ? int01 : -int01)
5576 < (int11 >= 0 ? int11 : -int11))
5578 tmp = int01, int01 = int11, int11 = tmp;
5579 alt0 = arg00, arg00 = arg10, arg10 = alt0;
5580 alt0 = arg01, arg01 = arg11, arg11 = alt0;
5583 if (exact_log2 (int11) > 0 && int01 % int11 == 0)
5585 alt0 = fold (build (MULT_EXPR, type, arg00,
5586 build_int_2 (int01 / int11, 0)));
5593 return fold (build (MULT_EXPR, type,
5594 fold (build (PLUS_EXPR, type, alt0, alt1)),
5599 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5600 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
5601 return non_lvalue (convert (type, arg0));
5603 /* Likewise if the operands are reversed. */
5604 else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5605 return non_lvalue (convert (type, arg1));
5608 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5609 is a rotate of A by C1 bits. */
5610 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5611 is a rotate of A by B bits. */
5613 enum tree_code code0, code1;
5614 code0 = TREE_CODE (arg0);
5615 code1 = TREE_CODE (arg1);
5616 if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
5617 || (code1 == RSHIFT_EXPR && code0 == LSHIFT_EXPR))
5618 && operand_equal_p (TREE_OPERAND (arg0, 0),
5619 TREE_OPERAND (arg1, 0), 0)
5620 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
5622 tree tree01, tree11;
5623 enum tree_code code01, code11;
5625 tree01 = TREE_OPERAND (arg0, 1);
5626 tree11 = TREE_OPERAND (arg1, 1);
5627 STRIP_NOPS (tree01);
5628 STRIP_NOPS (tree11);
5629 code01 = TREE_CODE (tree01);
5630 code11 = TREE_CODE (tree11);
5631 if (code01 == INTEGER_CST
5632 && code11 == INTEGER_CST
5633 && TREE_INT_CST_HIGH (tree01) == 0
5634 && TREE_INT_CST_HIGH (tree11) == 0
5635 && ((TREE_INT_CST_LOW (tree01) + TREE_INT_CST_LOW (tree11))
5636 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)))))
5637 return build (LROTATE_EXPR, type, TREE_OPERAND (arg0, 0),
5638 code0 == LSHIFT_EXPR ? tree01 : tree11);
5639 else if (code11 == MINUS_EXPR)
5641 tree tree110, tree111;
5642 tree110 = TREE_OPERAND (tree11, 0);
5643 tree111 = TREE_OPERAND (tree11, 1);
5644 STRIP_NOPS (tree110);
5645 STRIP_NOPS (tree111);
5646 if (TREE_CODE (tree110) == INTEGER_CST
5647 && 0 == compare_tree_int (tree110,
5649 (TREE_TYPE (TREE_OPERAND
5651 && operand_equal_p (tree01, tree111, 0))
5652 return build ((code0 == LSHIFT_EXPR
5655 type, TREE_OPERAND (arg0, 0), tree01);
5657 else if (code01 == MINUS_EXPR)
5659 tree tree010, tree011;
5660 tree010 = TREE_OPERAND (tree01, 0);
5661 tree011 = TREE_OPERAND (tree01, 1);
5662 STRIP_NOPS (tree010);
5663 STRIP_NOPS (tree011);
5664 if (TREE_CODE (tree010) == INTEGER_CST
5665 && 0 == compare_tree_int (tree010,
5667 (TREE_TYPE (TREE_OPERAND
5669 && operand_equal_p (tree11, tree011, 0))
5670 return build ((code0 != LSHIFT_EXPR
5673 type, TREE_OPERAND (arg0, 0), tree11);
5679 /* In most languages, can't associate operations on floats through
5680 parentheses. Rather than remember where the parentheses were, we
5681 don't associate floats at all. It shouldn't matter much. However,
5682 associating multiplications is only very slightly inaccurate, so do
5683 that if -funsafe-math-optimizations is specified. */
5686 && (! FLOAT_TYPE_P (type)
5687 || (flag_unsafe_math_optimizations && code == MULT_EXPR)))
5689 tree var0, con0, lit0, minus_lit0;
5690 tree var1, con1, lit1, minus_lit1;
5692 /* Split both trees into variables, constants, and literals. Then
5693 associate each group together, the constants with literals,
5694 then the result with variables. This increases the chances of
5695 literals being recombined later and of generating relocatable
5696 expressions for the sum of a constant and literal. */
5697 var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
5698 var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
5699 code == MINUS_EXPR);
5701 /* Only do something if we found more than two objects. Otherwise,
5702 nothing has changed and we risk infinite recursion. */
5703 if (2 < ((var0 != 0) + (var1 != 0)
5704 + (con0 != 0) + (con1 != 0)
5705 + (lit0 != 0) + (lit1 != 0)
5706 + (minus_lit0 != 0) + (minus_lit1 != 0)))
5708 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5709 if (code == MINUS_EXPR)
5712 var0 = associate_trees (var0, var1, code, type);
5713 con0 = associate_trees (con0, con1, code, type);
5714 lit0 = associate_trees (lit0, lit1, code, type);
5715 minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
5717 /* Preserve the MINUS_EXPR if the negative part of the literal is
5718 greater than the positive part. Otherwise, the multiplicative
5719 folding code (i.e extract_muldiv) may be fooled in case
5720 unsigned constants are subtracted, like in the following
5721 example: ((X*2 + 4) - 8U)/2. */
5722 if (minus_lit0 && lit0)
5724 if (tree_int_cst_lt (lit0, minus_lit0))
5726 minus_lit0 = associate_trees (minus_lit0, lit0,
5732 lit0 = associate_trees (lit0, minus_lit0,
5740 return convert (type, associate_trees (var0, minus_lit0,
5744 con0 = associate_trees (con0, minus_lit0,
5746 return convert (type, associate_trees (var0, con0,
5751 con0 = associate_trees (con0, lit0, code, type);
5752 return convert (type, associate_trees (var0, con0, code, type));
5758 t1 = const_binop (code, arg0, arg1, 0);
5759 if (t1 != NULL_TREE)
5761 /* The return value should always have
5762 the same type as the original expression. */
5763 if (TREE_TYPE (t1) != TREE_TYPE (t))
5764 t1 = convert (TREE_TYPE (t), t1);
5771 /* A - (-B) -> A + B */
5772 if (TREE_CODE (arg1) == NEGATE_EXPR)
5773 return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0)));
5774 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5775 if (TREE_CODE (arg0) == NEGATE_EXPR
5776 && (FLOAT_TYPE_P (type)
5777 || (INTEGRAL_TYPE_P (type) && flag_wrapv && !flag_trapv))
5778 && negate_expr_p (arg1)
5779 && (! TREE_SIDE_EFFECTS (arg0) || TREE_CONSTANT (arg1))
5780 && (! TREE_SIDE_EFFECTS (arg1) || TREE_CONSTANT (arg0)))
5781 return fold (build (MINUS_EXPR, type, negate_expr (arg1),
5782 TREE_OPERAND (arg0, 0)));
5784 if (! FLOAT_TYPE_P (type))
5786 if (! wins && integer_zerop (arg0))
5787 return negate_expr (convert (type, arg1));
5788 if (integer_zerop (arg1))
5789 return non_lvalue (convert (type, arg0));
5791 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5792 about the case where C is a constant, just try one of the
5793 four possibilities. */
5795 if (TREE_CODE (arg0) == MULT_EXPR && TREE_CODE (arg1) == MULT_EXPR
5796 && operand_equal_p (TREE_OPERAND (arg0, 1),
5797 TREE_OPERAND (arg1, 1), 0))
5798 return fold (build (MULT_EXPR, type,
5799 fold (build (MINUS_EXPR, type,
5800 TREE_OPERAND (arg0, 0),
5801 TREE_OPERAND (arg1, 0))),
5802 TREE_OPERAND (arg0, 1)));
5804 /* Fold A - (A & B) into ~B & A. */
5805 if (!TREE_SIDE_EFFECTS (arg0)
5806 && TREE_CODE (arg1) == BIT_AND_EXPR)
5808 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
5809 return fold (build (BIT_AND_EXPR, type,
5810 fold (build1 (BIT_NOT_EXPR, type,
5811 TREE_OPERAND (arg1, 0))),
5813 if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
5814 return fold (build (BIT_AND_EXPR, type,
5815 fold (build1 (BIT_NOT_EXPR, type,
5816 TREE_OPERAND (arg1, 1))),
5821 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5822 else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
5823 return non_lvalue (convert (type, arg0));
5825 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5826 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5827 (-ARG1 + ARG0) reduces to -ARG1. */
5828 else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
5829 return negate_expr (convert (type, arg1));
5831 /* Fold &x - &x. This can happen from &x.foo - &x.
5832 This is unsafe for certain floats even in non-IEEE formats.
5833 In IEEE, it is unsafe because it does wrong for NaNs.
5834 Also note that operand_equal_p is always false if an operand
5837 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
5838 && operand_equal_p (arg0, arg1, 0))
5839 return convert (type, integer_zero_node);
5844 /* (-A) * (-B) -> A * B */
5845 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
5846 return fold (build (MULT_EXPR, type, TREE_OPERAND (arg0, 0),
5847 TREE_OPERAND (arg1, 0)));
5849 if (! FLOAT_TYPE_P (type))
5851 if (integer_zerop (arg1))
5852 return omit_one_operand (type, arg1, arg0);
5853 if (integer_onep (arg1))
5854 return non_lvalue (convert (type, arg0));
5856 /* (a * (1 << b)) is (a << b) */
5857 if (TREE_CODE (arg1) == LSHIFT_EXPR
5858 && integer_onep (TREE_OPERAND (arg1, 0)))
5859 return fold (build (LSHIFT_EXPR, type, arg0,
5860 TREE_OPERAND (arg1, 1)));
5861 if (TREE_CODE (arg0) == LSHIFT_EXPR
5862 && integer_onep (TREE_OPERAND (arg0, 0)))
5863 return fold (build (LSHIFT_EXPR, type, arg1,
5864 TREE_OPERAND (arg0, 1)));
5866 if (TREE_CODE (arg1) == INTEGER_CST
5867 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0),
5868 convert (type, arg1),
5870 return convert (type, tem);
5875 /* Maybe fold x * 0 to 0. The expressions aren't the same
5876 when x is NaN, since x * 0 is also NaN. Nor are they the
5877 same in modes with signed zeros, since multiplying a
5878 negative value by 0 gives -0, not +0. */
5879 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
5880 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
5881 && real_zerop (arg1))
5882 return omit_one_operand (type, arg1, arg0);
5883 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
5884 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5885 && real_onep (arg1))
5886 return non_lvalue (convert (type, arg0));
5888 /* Transform x * -1.0 into -x. */
5889 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
5890 && real_minus_onep (arg1))
5891 return fold (build1 (NEGATE_EXPR, type, arg0));
5894 if (! wins && real_twop (arg1)
5895 && (*lang_hooks.decls.global_bindings_p) () == 0
5896 && ! CONTAINS_PLACEHOLDER_P (arg0))
5898 tree arg = save_expr (arg0);
5899 return fold (build (PLUS_EXPR, type, arg, arg));
5902 if (flag_unsafe_math_optimizations)
5904 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
5905 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
5907 /* Optimizations of sqrt(...)*sqrt(...). */
5908 if ((fcode0 == BUILT_IN_SQRT && fcode1 == BUILT_IN_SQRT)
5909 || (fcode0 == BUILT_IN_SQRTF && fcode1 == BUILT_IN_SQRTF)
5910 || (fcode0 == BUILT_IN_SQRTL && fcode1 == BUILT_IN_SQRTL))
5912 tree sqrtfn, arg, arglist;
5913 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
5914 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
5916 /* Optimize sqrt(x)*sqrt(x) as x. */
5917 if (operand_equal_p (arg00, arg10, 0)
5918 && ! HONOR_SNANS (TYPE_MODE (type)))
5921 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
5922 sqrtfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5923 arg = fold (build (MULT_EXPR, type, arg00, arg10));
5924 arglist = build_tree_list (NULL_TREE, arg);
5925 return build_function_call_expr (sqrtfn, arglist);
5928 /* Optimize exp(x)*exp(y) as exp(x+y). */
5929 if ((fcode0 == BUILT_IN_EXP && fcode1 == BUILT_IN_EXP)
5930 || (fcode0 == BUILT_IN_EXPF && fcode1 == BUILT_IN_EXPF)
5931 || (fcode0 == BUILT_IN_EXPL && fcode1 == BUILT_IN_EXPL))
5933 tree expfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5934 tree arg = build (PLUS_EXPR, type,
5935 TREE_VALUE (TREE_OPERAND (arg0, 1)),
5936 TREE_VALUE (TREE_OPERAND (arg1, 1)));
5937 tree arglist = build_tree_list (NULL_TREE, fold (arg));
5938 return build_function_call_expr (expfn, arglist);
5941 /* Optimizations of pow(...)*pow(...). */
5942 if ((fcode0 == BUILT_IN_POW && fcode1 == BUILT_IN_POW)
5943 || (fcode0 == BUILT_IN_POWF && fcode1 == BUILT_IN_POWF)
5944 || (fcode0 == BUILT_IN_POWL && fcode1 == BUILT_IN_POWL))
5946 tree arg00 = TREE_VALUE (TREE_OPERAND (arg0, 1));
5947 tree arg01 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0,
5949 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
5950 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1,
5953 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
5954 if (operand_equal_p (arg01, arg11, 0))
5956 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5957 tree arg = build (MULT_EXPR, type, arg00, arg10);
5958 tree arglist = tree_cons (NULL_TREE, fold (arg),
5959 build_tree_list (NULL_TREE,
5961 return build_function_call_expr (powfn, arglist);
5964 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
5965 if (operand_equal_p (arg00, arg10, 0))
5967 tree powfn = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
5968 tree arg = fold (build (PLUS_EXPR, type, arg01, arg11));
5969 tree arglist = tree_cons (NULL_TREE, arg00,
5970 build_tree_list (NULL_TREE,
5972 return build_function_call_expr (powfn, arglist);
5976 /* Optimize tan(x)*cos(x) as sin(x). */
5977 if (((fcode0 == BUILT_IN_TAN && fcode1 == BUILT_IN_COS)
5978 || (fcode0 == BUILT_IN_TANF && fcode1 == BUILT_IN_COSF)
5979 || (fcode0 == BUILT_IN_TANL && fcode1 == BUILT_IN_COSL)
5980 || (fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_TAN)
5981 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_TANF)
5982 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_TANL))
5983 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
5984 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
5992 sinfn = implicit_built_in_decls[BUILT_IN_SIN];
5996 sinfn = implicit_built_in_decls[BUILT_IN_SINF];
6000 sinfn = implicit_built_in_decls[BUILT_IN_SINL];
6006 if (sinfn != NULL_TREE)
6007 return build_function_call_expr (sinfn,
6008 TREE_OPERAND (arg0, 1));
6016 if (integer_all_onesp (arg1))
6017 return omit_one_operand (type, arg1, arg0);
6018 if (integer_zerop (arg1))
6019 return non_lvalue (convert (type, arg0));
6020 t1 = distribute_bit_expr (code, type, arg0, arg1);
6021 if (t1 != NULL_TREE)
6024 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6026 This results in more efficient code for machines without a NAND
6027 instruction. Combine will canonicalize to the first form
6028 which will allow use of NAND instructions provided by the
6029 backend if they exist. */
6030 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6031 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6033 return fold (build1 (BIT_NOT_EXPR, type,
6034 build (BIT_AND_EXPR, type,
6035 TREE_OPERAND (arg0, 0),
6036 TREE_OPERAND (arg1, 0))));
6039 /* See if this can be simplified into a rotate first. If that
6040 is unsuccessful continue in the association code. */
6044 if (integer_zerop (arg1))
6045 return non_lvalue (convert (type, arg0));
6046 if (integer_all_onesp (arg1))
6047 return fold (build1 (BIT_NOT_EXPR, type, arg0));
6049 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6050 with a constant, and the two constants have no bits in common,
6051 we should treat this as a BIT_IOR_EXPR since this may produce more
6053 if (TREE_CODE (arg0) == BIT_AND_EXPR
6054 && TREE_CODE (arg1) == BIT_AND_EXPR
6055 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6056 && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
6057 && integer_zerop (const_binop (BIT_AND_EXPR,
6058 TREE_OPERAND (arg0, 1),
6059 TREE_OPERAND (arg1, 1), 0)))
6061 code = BIT_IOR_EXPR;
6065 /* See if this can be simplified into a rotate first. If that
6066 is unsuccessful continue in the association code. */
6071 if (integer_all_onesp (arg1))
6072 return non_lvalue (convert (type, arg0));
6073 if (integer_zerop (arg1))
6074 return omit_one_operand (type, arg1, arg0);
6075 t1 = distribute_bit_expr (code, type, arg0, arg1);
6076 if (t1 != NULL_TREE)
6078 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6079 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
6080 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
6083 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0, 0)));
6085 if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
6086 && (~TREE_INT_CST_LOW (arg1)
6087 & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
6088 return build1 (NOP_EXPR, type, TREE_OPERAND (arg0, 0));
6091 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6093 This results in more efficient code for machines without a NOR
6094 instruction. Combine will canonicalize to the first form
6095 which will allow use of NOR instructions provided by the
6096 backend if they exist. */
6097 if (TREE_CODE (arg0) == BIT_NOT_EXPR
6098 && TREE_CODE (arg1) == BIT_NOT_EXPR)
6100 return fold (build1 (BIT_NOT_EXPR, type,
6101 build (BIT_IOR_EXPR, type,
6102 TREE_OPERAND (arg0, 0),
6103 TREE_OPERAND (arg1, 0))));
6108 case BIT_ANDTC_EXPR:
6109 if (integer_all_onesp (arg0))
6110 return non_lvalue (convert (type, arg1));
6111 if (integer_zerop (arg0))
6112 return omit_one_operand (type, arg0, arg1);
6113 if (TREE_CODE (arg1) == INTEGER_CST)
6115 arg1 = fold (build1 (BIT_NOT_EXPR, type, arg1));
6116 code = BIT_AND_EXPR;
6122 /* Don't touch a floating-point divide by zero unless the mode
6123 of the constant can represent infinity. */
6124 if (TREE_CODE (arg1) == REAL_CST
6125 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
6126 && real_zerop (arg1))
6129 /* (-A) / (-B) -> A / B */
6130 if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
6131 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6132 TREE_OPERAND (arg1, 0)));
6134 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6135 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))
6136 && real_onep (arg1))
6137 return non_lvalue (convert (type, arg0));
6139 /* If ARG1 is a constant, we can convert this to a multiply by the
6140 reciprocal. This does not have the same rounding properties,
6141 so only do this if -funsafe-math-optimizations. We can actually
6142 always safely do it if ARG1 is a power of two, but it's hard to
6143 tell if it is or not in a portable manner. */
6144 if (TREE_CODE (arg1) == REAL_CST)
6146 if (flag_unsafe_math_optimizations
6147 && 0 != (tem = const_binop (code, build_real (type, dconst1),
6149 return fold (build (MULT_EXPR, type, arg0, tem));
6150 /* Find the reciprocal if optimizing and the result is exact. */
6154 r = TREE_REAL_CST (arg1);
6155 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0)), &r))
6157 tem = build_real (type, r);
6158 return fold (build (MULT_EXPR, type, arg0, tem));
6162 /* Convert A/B/C to A/(B*C). */
6163 if (flag_unsafe_math_optimizations
6164 && TREE_CODE (arg0) == RDIV_EXPR)
6166 return fold (build (RDIV_EXPR, type, TREE_OPERAND (arg0, 0),
6167 build (MULT_EXPR, type, TREE_OPERAND (arg0, 1),
6170 /* Convert A/(B/C) to (A/B)*C. */
6171 if (flag_unsafe_math_optimizations
6172 && TREE_CODE (arg1) == RDIV_EXPR)
6174 return fold (build (MULT_EXPR, type,
6175 build (RDIV_EXPR, type, arg0,
6176 TREE_OPERAND (arg1, 0)),
6177 TREE_OPERAND (arg1, 1)));
6180 if (flag_unsafe_math_optimizations)
6182 enum built_in_function fcode = builtin_mathfn_code (arg1);
6183 /* Optimize x/exp(y) into x*exp(-y). */
6184 if (fcode == BUILT_IN_EXP
6185 || fcode == BUILT_IN_EXPF
6186 || fcode == BUILT_IN_EXPL)
6188 tree expfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6189 tree arg = build1 (NEGATE_EXPR, type,
6190 TREE_VALUE (TREE_OPERAND (arg1, 1)));
6191 tree arglist = build_tree_list (NULL_TREE, fold (arg));
6192 arg1 = build_function_call_expr (expfn, arglist);
6193 return fold (build (MULT_EXPR, type, arg0, arg1));
6196 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6197 if (fcode == BUILT_IN_POW
6198 || fcode == BUILT_IN_POWF
6199 || fcode == BUILT_IN_POWL)
6201 tree powfn = TREE_OPERAND (TREE_OPERAND (arg1, 0), 0);
6202 tree arg10 = TREE_VALUE (TREE_OPERAND (arg1, 1));
6203 tree arg11 = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1, 1)));
6204 tree neg11 = fold (build1 (NEGATE_EXPR, type, arg11));
6205 tree arglist = tree_cons(NULL_TREE, arg10,
6206 build_tree_list (NULL_TREE, neg11));
6207 arg1 = build_function_call_expr (powfn, arglist);
6208 return fold (build (MULT_EXPR, type, arg0, arg1));
6212 if (flag_unsafe_math_optimizations)
6214 enum built_in_function fcode0 = builtin_mathfn_code (arg0);
6215 enum built_in_function fcode1 = builtin_mathfn_code (arg1);
6217 /* Optimize sin(x)/cos(x) as tan(x). */
6218 if (((fcode0 == BUILT_IN_SIN && fcode1 == BUILT_IN_COS)
6219 || (fcode0 == BUILT_IN_SINF && fcode1 == BUILT_IN_COSF)
6220 || (fcode0 == BUILT_IN_SINL && fcode1 == BUILT_IN_COSL))
6221 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6222 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6226 if (fcode0 == BUILT_IN_SIN)
6227 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6228 else if (fcode0 == BUILT_IN_SINF)
6229 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6230 else if (fcode0 == BUILT_IN_SINL)
6231 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6235 if (tanfn != NULL_TREE)
6236 return build_function_call_expr (tanfn,
6237 TREE_OPERAND (arg0, 1));
6240 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6241 if (((fcode0 == BUILT_IN_COS && fcode1 == BUILT_IN_SIN)
6242 || (fcode0 == BUILT_IN_COSF && fcode1 == BUILT_IN_SINF)
6243 || (fcode0 == BUILT_IN_COSL && fcode1 == BUILT_IN_SINL))
6244 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0, 1)),
6245 TREE_VALUE (TREE_OPERAND (arg1, 1)), 0))
6249 if (fcode0 == BUILT_IN_COS)
6250 tanfn = implicit_built_in_decls[BUILT_IN_TAN];
6251 else if (fcode0 == BUILT_IN_COSF)
6252 tanfn = implicit_built_in_decls[BUILT_IN_TANF];
6253 else if (fcode0 == BUILT_IN_COSL)
6254 tanfn = implicit_built_in_decls[BUILT_IN_TANL];
6258 if (tanfn != NULL_TREE)
6260 tree tmp = TREE_OPERAND (arg0, 1);
6261 tmp = build_function_call_expr (tanfn, tmp);
6262 return fold (build (RDIV_EXPR, type,
6263 build_real (type, dconst1),
6270 case TRUNC_DIV_EXPR:
6271 case ROUND_DIV_EXPR:
6272 case FLOOR_DIV_EXPR:
6274 case EXACT_DIV_EXPR:
6275 if (integer_onep (arg1))
6276 return non_lvalue (convert (type, arg0));
6277 if (integer_zerop (arg1))
6280 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6281 operation, EXACT_DIV_EXPR.
6283 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6284 At one time others generated faster code, it's not clear if they do
6285 after the last round to changes to the DIV code in expmed.c. */
6286 if ((code == CEIL_DIV_EXPR || code == FLOOR_DIV_EXPR)
6287 && multiple_of_p (type, arg0, arg1))
6288 return fold (build (EXACT_DIV_EXPR, type, arg0, arg1));
6290 if (TREE_CODE (arg1) == INTEGER_CST
6291 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6293 return convert (type, tem);
6298 case FLOOR_MOD_EXPR:
6299 case ROUND_MOD_EXPR:
6300 case TRUNC_MOD_EXPR:
6301 if (integer_onep (arg1))
6302 return omit_one_operand (type, integer_zero_node, arg0);
6303 if (integer_zerop (arg1))
6306 if (TREE_CODE (arg1) == INTEGER_CST
6307 && 0 != (tem = extract_muldiv (TREE_OPERAND (t, 0), arg1,
6309 return convert (type, tem);
6315 if (integer_all_onesp (arg0))
6316 return omit_one_operand (type, arg0, arg1);
6320 /* Optimize -1 >> x for arithmetic right shifts. */
6321 if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type))
6322 return omit_one_operand (type, arg0, arg1);
6323 /* ... fall through ... */
6327 if (integer_zerop (arg1))
6328 return non_lvalue (convert (type, arg0));
6329 if (integer_zerop (arg0))
6330 return omit_one_operand (type, arg0, arg1);
6332 /* Since negative shift count is not well-defined,
6333 don't try to compute it in the compiler. */
6334 if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0)
6336 /* Rewrite an LROTATE_EXPR by a constant into an
6337 RROTATE_EXPR by a new constant. */
6338 if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
6340 TREE_SET_CODE (t, RROTATE_EXPR);
6341 code = RROTATE_EXPR;
6342 TREE_OPERAND (t, 1) = arg1
6345 convert (TREE_TYPE (arg1),
6346 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type)), 0)),
6348 if (tree_int_cst_sgn (arg1) < 0)
6352 /* If we have a rotate of a bit operation with the rotate count and
6353 the second operand of the bit operation both constant,
6354 permute the two operations. */
6355 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6356 && (TREE_CODE (arg0) == BIT_AND_EXPR
6357 || TREE_CODE (arg0) == BIT_ANDTC_EXPR
6358 || TREE_CODE (arg0) == BIT_IOR_EXPR
6359 || TREE_CODE (arg0) == BIT_XOR_EXPR)
6360 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
6361 return fold (build (TREE_CODE (arg0), type,
6362 fold (build (code, type,
6363 TREE_OPERAND (arg0, 0), arg1)),
6364 fold (build (code, type,
6365 TREE_OPERAND (arg0, 1), arg1))));
6367 /* Two consecutive rotates adding up to the width of the mode can
6369 if (code == RROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST
6370 && TREE_CODE (arg0) == RROTATE_EXPR
6371 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6372 && TREE_INT_CST_HIGH (arg1) == 0
6373 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1)) == 0
6374 && ((TREE_INT_CST_LOW (arg1)
6375 + TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1)))
6376 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
6377 return TREE_OPERAND (arg0, 0);
6382 if (operand_equal_p (arg0, arg1, 0))
6383 return omit_one_operand (type, arg0, arg1);
6384 if (INTEGRAL_TYPE_P (type)
6385 && operand_equal_p (arg1, TYPE_MIN_VALUE (type), 1))
6386 return omit_one_operand (type, arg1, arg0);
6390 if (operand_equal_p (arg0, arg1, 0))
6391 return omit_one_operand (type, arg0, arg1);
6392 if (INTEGRAL_TYPE_P (type)
6393 && TYPE_MAX_VALUE (type)
6394 && operand_equal_p (arg1, TYPE_MAX_VALUE (type), 1))
6395 return omit_one_operand (type, arg1, arg0);
6398 case TRUTH_NOT_EXPR:
6399 /* Note that the operand of this must be an int
6400 and its values must be 0 or 1.
6401 ("true" is a fixed value perhaps depending on the language,
6402 but we don't handle values other than 1 correctly yet.) */
6403 tem = invert_truthvalue (arg0);
6404 /* Avoid infinite recursion. */
6405 if (TREE_CODE (tem) == TRUTH_NOT_EXPR)
6407 tem = fold_single_bit_test (code, arg0, arg1, type);
6412 return convert (type, tem);
6414 case TRUTH_ANDIF_EXPR:
6415 /* Note that the operands of this must be ints
6416 and their values must be 0 or 1.
6417 ("true" is a fixed value perhaps depending on the language.) */
6418 /* If first arg is constant zero, return it. */
6419 if (integer_zerop (arg0))
6420 return convert (type, arg0);
6421 case TRUTH_AND_EXPR:
6422 /* If either arg is constant true, drop it. */
6423 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6424 return non_lvalue (convert (type, arg1));
6425 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1)
6426 /* Preserve sequence points. */
6427 && (code != TRUTH_ANDIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6428 return non_lvalue (convert (type, arg0));
6429 /* If second arg is constant zero, result is zero, but first arg
6430 must be evaluated. */
6431 if (integer_zerop (arg1))
6432 return omit_one_operand (type, arg1, arg0);
6433 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6434 case will be handled here. */
6435 if (integer_zerop (arg0))
6436 return omit_one_operand (type, arg0, arg1);
6439 /* We only do these simplifications if we are optimizing. */
6443 /* Check for things like (A || B) && (A || C). We can convert this
6444 to A || (B && C). Note that either operator can be any of the four
6445 truth and/or operations and the transformation will still be
6446 valid. Also note that we only care about order for the
6447 ANDIF and ORIF operators. If B contains side effects, this
6448 might change the truth-value of A. */
6449 if (TREE_CODE (arg0) == TREE_CODE (arg1)
6450 && (TREE_CODE (arg0) == TRUTH_ANDIF_EXPR
6451 || TREE_CODE (arg0) == TRUTH_ORIF_EXPR
6452 || TREE_CODE (arg0) == TRUTH_AND_EXPR
6453 || TREE_CODE (arg0) == TRUTH_OR_EXPR)
6454 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0, 1)))
6456 tree a00 = TREE_OPERAND (arg0, 0);
6457 tree a01 = TREE_OPERAND (arg0, 1);
6458 tree a10 = TREE_OPERAND (arg1, 0);
6459 tree a11 = TREE_OPERAND (arg1, 1);
6460 int commutative = ((TREE_CODE (arg0) == TRUTH_OR_EXPR
6461 || TREE_CODE (arg0) == TRUTH_AND_EXPR)
6462 && (code == TRUTH_AND_EXPR
6463 || code == TRUTH_OR_EXPR));
6465 if (operand_equal_p (a00, a10, 0))
6466 return fold (build (TREE_CODE (arg0), type, a00,
6467 fold (build (code, type, a01, a11))));
6468 else if (commutative && operand_equal_p (a00, a11, 0))
6469 return fold (build (TREE_CODE (arg0), type, a00,
6470 fold (build (code, type, a01, a10))));
6471 else if (commutative && operand_equal_p (a01, a10, 0))
6472 return fold (build (TREE_CODE (arg0), type, a01,
6473 fold (build (code, type, a00, a11))));
6475 /* This case if tricky because we must either have commutative
6476 operators or else A10 must not have side-effects. */
6478 else if ((commutative || ! TREE_SIDE_EFFECTS (a10))
6479 && operand_equal_p (a01, a11, 0))
6480 return fold (build (TREE_CODE (arg0), type,
6481 fold (build (code, type, a00, a10)),
6485 /* See if we can build a range comparison. */
6486 if (0 != (tem = fold_range_test (t)))
6489 /* Check for the possibility of merging component references. If our
6490 lhs is another similar operation, try to merge its rhs with our
6491 rhs. Then try to merge our lhs and rhs. */
6492 if (TREE_CODE (arg0) == code
6493 && 0 != (tem = fold_truthop (code, type,
6494 TREE_OPERAND (arg0, 1), arg1)))
6495 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6497 if ((tem = fold_truthop (code, type, arg0, arg1)) != 0)
6502 case TRUTH_ORIF_EXPR:
6503 /* Note that the operands of this must be ints
6504 and their values must be 0 or true.
6505 ("true" is a fixed value perhaps depending on the language.) */
6506 /* If first arg is constant true, return it. */
6507 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6508 return convert (type, arg0);
6510 /* If either arg is constant zero, drop it. */
6511 if (TREE_CODE (arg0) == INTEGER_CST && integer_zerop (arg0))
6512 return non_lvalue (convert (type, arg1));
6513 if (TREE_CODE (arg1) == INTEGER_CST && integer_zerop (arg1)
6514 /* Preserve sequence points. */
6515 && (code != TRUTH_ORIF_EXPR || ! TREE_SIDE_EFFECTS (arg0)))
6516 return non_lvalue (convert (type, arg0));
6517 /* If second arg is constant true, result is true, but we must
6518 evaluate first arg. */
6519 if (TREE_CODE (arg1) == INTEGER_CST && ! integer_zerop (arg1))
6520 return omit_one_operand (type, arg1, arg0);
6521 /* Likewise for first arg, but note this only occurs here for
6523 if (TREE_CODE (arg0) == INTEGER_CST && ! integer_zerop (arg0))
6524 return omit_one_operand (type, arg0, arg1);
6527 case TRUTH_XOR_EXPR:
6528 /* If either arg is constant zero, drop it. */
6529 if (integer_zerop (arg0))
6530 return non_lvalue (convert (type, arg1));
6531 if (integer_zerop (arg1))
6532 return non_lvalue (convert (type, arg0));
6533 /* If either arg is constant true, this is a logical inversion. */
6534 if (integer_onep (arg0))
6535 return non_lvalue (convert (type, invert_truthvalue (arg1)));
6536 if (integer_onep (arg1))
6537 return non_lvalue (convert (type, invert_truthvalue (arg0)));
6546 /* If one arg is a real or integer constant, put it last. */
6547 if ((TREE_CODE (arg0) == INTEGER_CST
6548 && TREE_CODE (arg1) != INTEGER_CST)
6549 || (TREE_CODE (arg0) == REAL_CST
6550 && TREE_CODE (arg0) != REAL_CST))
6552 TREE_OPERAND (t, 0) = arg1;
6553 TREE_OPERAND (t, 1) = arg0;
6554 arg0 = TREE_OPERAND (t, 0);
6555 arg1 = TREE_OPERAND (t, 1);
6556 code = swap_tree_comparison (code);
6557 TREE_SET_CODE (t, code);
6560 if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
6562 tree targ0 = strip_float_extensions (arg0);
6563 tree targ1 = strip_float_extensions (arg1);
6564 tree newtype = TREE_TYPE (targ0);
6566 if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
6567 newtype = TREE_TYPE (targ1);
6569 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6570 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
6571 return fold (build (code, type, convert (newtype, targ0),
6572 convert (newtype, targ1)));
6574 /* (-a) CMP (-b) -> b CMP a */
6575 if (TREE_CODE (arg0) == NEGATE_EXPR
6576 && TREE_CODE (arg1) == NEGATE_EXPR)
6577 return fold (build (code, type, TREE_OPERAND (arg1, 0),
6578 TREE_OPERAND (arg0, 0)));
6580 if (TREE_CODE (arg1) == REAL_CST)
6582 REAL_VALUE_TYPE cst;
6583 cst = TREE_REAL_CST (arg1);
6585 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6586 if (TREE_CODE (arg0) == NEGATE_EXPR)
6588 fold (build (swap_tree_comparison (code), type,
6589 TREE_OPERAND (arg0, 0),
6590 build_real (TREE_TYPE (arg1),
6591 REAL_VALUE_NEGATE (cst))));
6593 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6594 /* a CMP (-0) -> a CMP 0 */
6595 if (REAL_VALUE_MINUS_ZERO (cst))
6596 return fold (build (code, type, arg0,
6597 build_real (TREE_TYPE (arg1), dconst0)));
6599 /* x != NaN is always true, other ops are always false. */
6600 if (REAL_VALUE_ISNAN (cst)
6601 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1))))
6603 t = (code == NE_EXPR) ? integer_one_node : integer_zero_node;
6604 return omit_one_operand (type, convert (type, t), arg0);
6607 /* Fold comparisons against infinity. */
6608 if (REAL_VALUE_ISINF (cst))
6610 tem = fold_inf_compare (code, type, arg0, arg1);
6611 if (tem != NULL_TREE)
6616 /* If this is a comparison of a real constant with a PLUS_EXPR
6617 or a MINUS_EXPR of a real constant, we can convert it into a
6618 comparison with a revised real constant as long as no overflow
6619 occurs when unsafe_math_optimizations are enabled. */
6620 if (flag_unsafe_math_optimizations
6621 && TREE_CODE (arg1) == REAL_CST
6622 && (TREE_CODE (arg0) == PLUS_EXPR
6623 || TREE_CODE (arg0) == MINUS_EXPR)
6624 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
6625 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6626 ? MINUS_EXPR : PLUS_EXPR,
6627 arg1, TREE_OPERAND (arg0, 1), 0))
6628 && ! TREE_CONSTANT_OVERFLOW (tem))
6629 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6631 /* Likewise, we can simplify a comparison of a real constant with
6632 a MINUS_EXPR whose first operand is also a real constant, i.e.
6633 (c1 - x) < c2 becomes x > c1-c2. */
6634 if (flag_unsafe_math_optimizations
6635 && TREE_CODE (arg1) == REAL_CST
6636 && TREE_CODE (arg0) == MINUS_EXPR
6637 && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST
6638 && 0 != (tem = const_binop (MINUS_EXPR, TREE_OPERAND (arg0, 0),
6640 && ! TREE_CONSTANT_OVERFLOW (tem))
6641 return fold (build (swap_tree_comparison (code), type,
6642 TREE_OPERAND (arg0, 1), tem));
6644 /* Fold comparisons against built-in math functions. */
6645 if (TREE_CODE (arg1) == REAL_CST
6646 && flag_unsafe_math_optimizations
6647 && ! flag_errno_math)
6649 enum built_in_function fcode = builtin_mathfn_code (arg0);
6651 if (fcode != END_BUILTINS)
6653 tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
6654 if (tem != NULL_TREE)
6660 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6661 First, see if one arg is constant; find the constant arg
6662 and the other one. */
6664 tree constop = 0, varop = NULL_TREE;
6665 int constopnum = -1;
6667 if (TREE_CONSTANT (arg1))
6668 constopnum = 1, constop = arg1, varop = arg0;
6669 if (TREE_CONSTANT (arg0))
6670 constopnum = 0, constop = arg0, varop = arg1;
6672 if (constop && TREE_CODE (varop) == POSTINCREMENT_EXPR)
6674 /* This optimization is invalid for ordered comparisons
6675 if CONST+INCR overflows or if foo+incr might overflow.
6676 This optimization is invalid for floating point due to rounding.
6677 For pointer types we assume overflow doesn't happen. */
6678 if (POINTER_TYPE_P (TREE_TYPE (varop))
6679 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6680 && (code == EQ_EXPR || code == NE_EXPR)))
6683 = fold (build (PLUS_EXPR, TREE_TYPE (varop),
6684 constop, TREE_OPERAND (varop, 1)));
6686 /* Do not overwrite the current varop to be a preincrement,
6687 create a new node so that we won't confuse our caller who
6688 might create trees and throw them away, reusing the
6689 arguments that they passed to build. This shows up in
6690 the THEN or ELSE parts of ?: being postincrements. */
6691 varop = build (PREINCREMENT_EXPR, TREE_TYPE (varop),
6692 TREE_OPERAND (varop, 0),
6693 TREE_OPERAND (varop, 1));
6695 /* If VAROP is a reference to a bitfield, we must mask
6696 the constant by the width of the field. */
6697 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6698 && DECL_BIT_FIELD(TREE_OPERAND
6699 (TREE_OPERAND (varop, 0), 1)))
6702 = TREE_INT_CST_LOW (DECL_SIZE
6704 (TREE_OPERAND (varop, 0), 1)));
6705 tree mask, unsigned_type;
6706 unsigned int precision;
6707 tree folded_compare;
6709 /* First check whether the comparison would come out
6710 always the same. If we don't do that we would
6711 change the meaning with the masking. */
6712 if (constopnum == 0)
6713 folded_compare = fold (build (code, type, constop,
6714 TREE_OPERAND (varop, 0)));
6716 folded_compare = fold (build (code, type,
6717 TREE_OPERAND (varop, 0),
6719 if (integer_zerop (folded_compare)
6720 || integer_onep (folded_compare))
6721 return omit_one_operand (type, folded_compare, varop);
6723 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6724 precision = TYPE_PRECISION (unsigned_type);
6725 mask = build_int_2 (~0, ~0);
6726 TREE_TYPE (mask) = unsigned_type;
6727 force_fit_type (mask, 0);
6728 mask = const_binop (RSHIFT_EXPR, mask,
6729 size_int (precision - size), 0);
6730 newconst = fold (build (BIT_AND_EXPR,
6731 TREE_TYPE (varop), newconst,
6732 convert (TREE_TYPE (varop),
6736 t = build (code, type,
6737 (constopnum == 0) ? newconst : varop,
6738 (constopnum == 1) ? newconst : varop);
6742 else if (constop && TREE_CODE (varop) == POSTDECREMENT_EXPR)
6744 if (POINTER_TYPE_P (TREE_TYPE (varop))
6745 || (! FLOAT_TYPE_P (TREE_TYPE (varop))
6746 && (code == EQ_EXPR || code == NE_EXPR)))
6749 = fold (build (MINUS_EXPR, TREE_TYPE (varop),
6750 constop, TREE_OPERAND (varop, 1)));
6752 /* Do not overwrite the current varop to be a predecrement,
6753 create a new node so that we won't confuse our caller who
6754 might create trees and throw them away, reusing the
6755 arguments that they passed to build. This shows up in
6756 the THEN or ELSE parts of ?: being postdecrements. */
6757 varop = build (PREDECREMENT_EXPR, TREE_TYPE (varop),
6758 TREE_OPERAND (varop, 0),
6759 TREE_OPERAND (varop, 1));
6761 if (TREE_CODE (TREE_OPERAND (varop, 0)) == COMPONENT_REF
6762 && DECL_BIT_FIELD(TREE_OPERAND
6763 (TREE_OPERAND (varop, 0), 1)))
6766 = TREE_INT_CST_LOW (DECL_SIZE
6768 (TREE_OPERAND (varop, 0), 1)));
6769 tree mask, unsigned_type;
6770 unsigned int precision;
6771 tree folded_compare;
6773 if (constopnum == 0)
6774 folded_compare = fold (build (code, type, constop,
6775 TREE_OPERAND (varop, 0)));
6777 folded_compare = fold (build (code, type,
6778 TREE_OPERAND (varop, 0),
6780 if (integer_zerop (folded_compare)
6781 || integer_onep (folded_compare))
6782 return omit_one_operand (type, folded_compare, varop);
6784 unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
6785 precision = TYPE_PRECISION (unsigned_type);
6786 mask = build_int_2 (~0, ~0);
6787 TREE_TYPE (mask) = TREE_TYPE (varop);
6788 force_fit_type (mask, 0);
6789 mask = const_binop (RSHIFT_EXPR, mask,
6790 size_int (precision - size), 0);
6791 newconst = fold (build (BIT_AND_EXPR,
6792 TREE_TYPE (varop), newconst,
6793 convert (TREE_TYPE (varop),
6797 t = build (code, type,
6798 (constopnum == 0) ? newconst : varop,
6799 (constopnum == 1) ? newconst : varop);
6805 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
6806 This transformation affects the cases which are handled in later
6807 optimizations involving comparisons with non-negative constants. */
6808 if (TREE_CODE (arg1) == INTEGER_CST
6809 && TREE_CODE (arg0) != INTEGER_CST
6810 && tree_int_cst_sgn (arg1) > 0)
6816 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6817 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6822 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6823 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6831 /* Comparisons with the highest or lowest possible integer of
6832 the specified size will have known values. */
6834 int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
6836 if (TREE_CODE (arg1) == INTEGER_CST
6837 && ! TREE_CONSTANT_OVERFLOW (arg1)
6838 && width <= HOST_BITS_PER_WIDE_INT
6839 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
6840 || POINTER_TYPE_P (TREE_TYPE (arg1))))
6842 unsigned HOST_WIDE_INT signed_max;
6843 unsigned HOST_WIDE_INT max, min;
6845 signed_max = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
6847 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
6849 max = ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1;
6855 min = ((unsigned HOST_WIDE_INT) -1 << (width - 1));
6858 if (TREE_INT_CST_HIGH (arg1) == 0
6859 && TREE_INT_CST_LOW (arg1) == max)
6863 return omit_one_operand (type,
6864 convert (type, integer_zero_node),
6868 TREE_SET_CODE (t, EQ_EXPR);
6871 return omit_one_operand (type,
6872 convert (type, integer_one_node),
6876 TREE_SET_CODE (t, NE_EXPR);
6879 /* The GE_EXPR and LT_EXPR cases above are not normally
6880 reached because of previous transformations. */
6885 else if (TREE_INT_CST_HIGH (arg1) == 0
6886 && TREE_INT_CST_LOW (arg1) == max - 1)
6891 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6892 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6896 arg1 = const_binop (PLUS_EXPR, arg1, integer_one_node, 0);
6897 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6902 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6903 && TREE_INT_CST_LOW (arg1) == min)
6907 return omit_one_operand (type,
6908 convert (type, integer_zero_node),
6912 TREE_SET_CODE (t, EQ_EXPR);
6916 return omit_one_operand (type,
6917 convert (type, integer_one_node),
6921 TREE_SET_CODE (t, NE_EXPR);
6927 else if (TREE_INT_CST_HIGH (arg1) == (min ? -1 : 0)
6928 && TREE_INT_CST_LOW (arg1) == min + 1)
6933 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6934 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6938 arg1 = const_binop (MINUS_EXPR, arg1, integer_one_node, 0);
6939 t = build (code, type, TREE_OPERAND (t, 0), arg1);
6945 else if (TREE_INT_CST_HIGH (arg1) == 0
6946 && TREE_INT_CST_LOW (arg1) == signed_max
6947 && TREE_UNSIGNED (TREE_TYPE (arg1))
6948 /* signed_type does not work on pointer types. */
6949 && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
6951 /* The following case also applies to X < signed_max+1
6952 and X >= signed_max+1 because previous transformations. */
6953 if (code == LE_EXPR || code == GT_EXPR)
6956 st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
6957 st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
6959 (build (code == LE_EXPR ? GE_EXPR: LT_EXPR,
6960 type, convert (st0, arg0),
6961 convert (st1, integer_zero_node)));
6967 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6968 a MINUS_EXPR of a constant, we can convert it into a comparison with
6969 a revised constant as long as no overflow occurs. */
6970 if ((code == EQ_EXPR || code == NE_EXPR)
6971 && TREE_CODE (arg1) == INTEGER_CST
6972 && (TREE_CODE (arg0) == PLUS_EXPR
6973 || TREE_CODE (arg0) == MINUS_EXPR)
6974 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
6975 && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
6976 ? MINUS_EXPR : PLUS_EXPR,
6977 arg1, TREE_OPERAND (arg0, 1), 0))
6978 && ! TREE_CONSTANT_OVERFLOW (tem))
6979 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6981 /* Similarly for a NEGATE_EXPR. */
6982 else if ((code == EQ_EXPR || code == NE_EXPR)
6983 && TREE_CODE (arg0) == NEGATE_EXPR
6984 && TREE_CODE (arg1) == INTEGER_CST
6985 && 0 != (tem = negate_expr (arg1))
6986 && TREE_CODE (tem) == INTEGER_CST
6987 && ! TREE_CONSTANT_OVERFLOW (tem))
6988 return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
6990 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6991 for !=. Don't do this for ordered comparisons due to overflow. */
6992 else if ((code == NE_EXPR || code == EQ_EXPR)
6993 && integer_zerop (arg1) && TREE_CODE (arg0) == MINUS_EXPR)
6994 return fold (build (code, type,
6995 TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1)));
6997 /* If we are widening one operand of an integer comparison,
6998 see if the other operand is similarly being widened. Perhaps we
6999 can do the comparison in the narrower type. */
7000 else if (TREE_CODE (TREE_TYPE (arg0)) == INTEGER_TYPE
7001 && TREE_CODE (arg0) == NOP_EXPR
7002 && (tem = get_unwidened (arg0, NULL_TREE)) != arg0
7003 && (t1 = get_unwidened (arg1, TREE_TYPE (tem))) != 0
7004 && (TREE_TYPE (t1) == TREE_TYPE (tem)
7005 || (TREE_CODE (t1) == INTEGER_CST
7006 && int_fits_type_p (t1, TREE_TYPE (tem)))))
7007 return fold (build (code, type, tem, convert (TREE_TYPE (tem), t1)));
7009 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7010 constant, we can simplify it. */
7011 else if (TREE_CODE (arg1) == INTEGER_CST
7012 && (TREE_CODE (arg0) == MIN_EXPR
7013 || TREE_CODE (arg0) == MAX_EXPR)
7014 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
7015 return optimize_minmax_comparison (t);
7017 /* If we are comparing an ABS_EXPR with a constant, we can
7018 convert all the cases into explicit comparisons, but they may
7019 well not be faster than doing the ABS and one comparison.
7020 But ABS (X) <= C is a range comparison, which becomes a subtraction
7021 and a comparison, and is probably faster. */
7022 else if (code == LE_EXPR && TREE_CODE (arg1) == INTEGER_CST
7023 && TREE_CODE (arg0) == ABS_EXPR
7024 && ! TREE_SIDE_EFFECTS (arg0)
7025 && (0 != (tem = negate_expr (arg1)))
7026 && TREE_CODE (tem) == INTEGER_CST
7027 && ! TREE_CONSTANT_OVERFLOW (tem))
7028 return fold (build (TRUTH_ANDIF_EXPR, type,
7029 build (GE_EXPR, type, TREE_OPERAND (arg0, 0), tem),
7030 build (LE_EXPR, type,
7031 TREE_OPERAND (arg0, 0), arg1)));
7033 /* If this is an EQ or NE comparison with zero and ARG0 is
7034 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7035 two operations, but the latter can be done in one less insn
7036 on machines that have only two-operand insns or on which a
7037 constant cannot be the first operand. */
7038 if (integer_zerop (arg1) && (code == EQ_EXPR || code == NE_EXPR)
7039 && TREE_CODE (arg0) == BIT_AND_EXPR)
7041 if (TREE_CODE (TREE_OPERAND (arg0, 0)) == LSHIFT_EXPR
7042 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 0), 0)))
7044 fold (build (code, type,
7045 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7047 TREE_TYPE (TREE_OPERAND (arg0, 0)),
7048 TREE_OPERAND (arg0, 1),
7049 TREE_OPERAND (TREE_OPERAND (arg0, 0), 1)),
7050 convert (TREE_TYPE (arg0),
7053 else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
7054 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
7056 fold (build (code, type,
7057 build (BIT_AND_EXPR, TREE_TYPE (arg0),
7059 TREE_TYPE (TREE_OPERAND (arg0, 1)),
7060 TREE_OPERAND (arg0, 0),
7061 TREE_OPERAND (TREE_OPERAND (arg0, 1), 1)),
7062 convert (TREE_TYPE (arg0),
7067 /* If this is an NE or EQ comparison of zero against the result of a
7068 signed MOD operation whose second operand is a power of 2, make
7069 the MOD operation unsigned since it is simpler and equivalent. */
7070 if ((code == NE_EXPR || code == EQ_EXPR)
7071 && integer_zerop (arg1)
7072 && ! TREE_UNSIGNED (TREE_TYPE (arg0))
7073 && (TREE_CODE (arg0) == TRUNC_MOD_EXPR
7074 || TREE_CODE (arg0) == CEIL_MOD_EXPR
7075 || TREE_CODE (arg0) == FLOOR_MOD_EXPR
7076 || TREE_CODE (arg0) == ROUND_MOD_EXPR)
7077 && integer_pow2p (TREE_OPERAND (arg0, 1)))
7079 tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
7080 tree newmod = build (TREE_CODE (arg0), newtype,
7081 convert (newtype, TREE_OPERAND (arg0, 0)),
7082 convert (newtype, TREE_OPERAND (arg0, 1)));
7084 return build (code, type, newmod, convert (newtype, arg1));
7087 /* If this is an NE comparison of zero with an AND of one, remove the
7088 comparison since the AND will give the correct value. */
7089 if (code == NE_EXPR && integer_zerop (arg1)
7090 && TREE_CODE (arg0) == BIT_AND_EXPR
7091 && integer_onep (TREE_OPERAND (arg0, 1)))
7092 return convert (type, arg0);
7094 /* If we have (A & C) == C where C is a power of 2, convert this into
7095 (A & C) != 0. Similarly for NE_EXPR. */
7096 if ((code == EQ_EXPR || code == NE_EXPR)
7097 && TREE_CODE (arg0) == BIT_AND_EXPR
7098 && integer_pow2p (TREE_OPERAND (arg0, 1))
7099 && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
7100 return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
7101 arg0, integer_zero_node));
7103 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7104 2, then fold the expression into shifts and logical operations. */
7105 tem = fold_single_bit_test (code, arg0, arg1, type);
7109 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7110 and similarly for >= into !=. */
7111 if ((code == LT_EXPR || code == GE_EXPR)
7112 && TREE_UNSIGNED (TREE_TYPE (arg0))
7113 && TREE_CODE (arg1) == LSHIFT_EXPR
7114 && integer_onep (TREE_OPERAND (arg1, 0)))
7115 return build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7116 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7117 TREE_OPERAND (arg1, 1)),
7118 convert (TREE_TYPE (arg0), integer_zero_node));
7120 else if ((code == LT_EXPR || code == GE_EXPR)
7121 && TREE_UNSIGNED (TREE_TYPE (arg0))
7122 && (TREE_CODE (arg1) == NOP_EXPR
7123 || TREE_CODE (arg1) == CONVERT_EXPR)
7124 && TREE_CODE (TREE_OPERAND (arg1, 0)) == LSHIFT_EXPR
7125 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1, 0), 0)))
7127 build (code == LT_EXPR ? EQ_EXPR : NE_EXPR, type,
7128 convert (TREE_TYPE (arg0),
7129 build (RSHIFT_EXPR, TREE_TYPE (arg0), arg0,
7130 TREE_OPERAND (TREE_OPERAND (arg1, 0), 1))),
7131 convert (TREE_TYPE (arg0), integer_zero_node));
7133 /* Simplify comparison of something with itself. (For IEEE
7134 floating-point, we can only do some of these simplifications.) */
7135 if (operand_equal_p (arg0, arg1, 0))
7142 if (! FLOAT_TYPE_P (TREE_TYPE (arg0))
7143 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7144 return constant_boolean_node (1, type);
7146 TREE_SET_CODE (t, code);
7150 /* For NE, we can only do this simplification if integer
7151 or we don't honor IEEE floating point NaNs. */
7152 if (FLOAT_TYPE_P (TREE_TYPE (arg0))
7153 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
7155 /* ... fall through ... */
7158 return constant_boolean_node (0, type);
7164 /* If we are comparing an expression that just has comparisons
7165 of two integer values, arithmetic expressions of those comparisons,
7166 and constants, we can simplify it. There are only three cases
7167 to check: the two values can either be equal, the first can be
7168 greater, or the second can be greater. Fold the expression for
7169 those three values. Since each value must be 0 or 1, we have
7170 eight possibilities, each of which corresponds to the constant 0
7171 or 1 or one of the six possible comparisons.
7173 This handles common cases like (a > b) == 0 but also handles
7174 expressions like ((x > y) - (y > x)) > 0, which supposedly
7175 occur in macroized code. */
7177 if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) != INTEGER_CST)
7179 tree cval1 = 0, cval2 = 0;
7182 if (twoval_comparison_p (arg0, &cval1, &cval2, &save_p)
7183 /* Don't handle degenerate cases here; they should already
7184 have been handled anyway. */
7185 && cval1 != 0 && cval2 != 0
7186 && ! (TREE_CONSTANT (cval1) && TREE_CONSTANT (cval2))
7187 && TREE_TYPE (cval1) == TREE_TYPE (cval2)
7188 && INTEGRAL_TYPE_P (TREE_TYPE (cval1))
7189 && TYPE_MAX_VALUE (TREE_TYPE (cval1))
7190 && TYPE_MAX_VALUE (TREE_TYPE (cval2))
7191 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1)),
7192 TYPE_MAX_VALUE (TREE_TYPE (cval2)), 0))
7194 tree maxval = TYPE_MAX_VALUE (TREE_TYPE (cval1));
7195 tree minval = TYPE_MIN_VALUE (TREE_TYPE (cval1));
7197 /* We can't just pass T to eval_subst in case cval1 or cval2
7198 was the same as ARG1. */
7201 = fold (build (code, type,
7202 eval_subst (arg0, cval1, maxval, cval2, minval),
7205 = fold (build (code, type,
7206 eval_subst (arg0, cval1, maxval, cval2, maxval),
7209 = fold (build (code, type,
7210 eval_subst (arg0, cval1, minval, cval2, maxval),
7213 /* All three of these results should be 0 or 1. Confirm they
7214 are. Then use those values to select the proper code
7217 if ((integer_zerop (high_result)
7218 || integer_onep (high_result))
7219 && (integer_zerop (equal_result)
7220 || integer_onep (equal_result))
7221 && (integer_zerop (low_result)
7222 || integer_onep (low_result)))
7224 /* Make a 3-bit mask with the high-order bit being the
7225 value for `>', the next for '=', and the low for '<'. */
7226 switch ((integer_onep (high_result) * 4)
7227 + (integer_onep (equal_result) * 2)
7228 + integer_onep (low_result))
7232 return omit_one_operand (type, integer_zero_node, arg0);
7253 return omit_one_operand (type, integer_one_node, arg0);
7256 t = build (code, type, cval1, cval2);
7258 return save_expr (t);
7265 /* If this is a comparison of a field, we may be able to simplify it. */
7266 if (((TREE_CODE (arg0) == COMPONENT_REF
7267 && (*lang_hooks.can_use_bit_fields_p) ())
7268 || TREE_CODE (arg0) == BIT_FIELD_REF)
7269 && (code == EQ_EXPR || code == NE_EXPR)
7270 /* Handle the constant case even without -O
7271 to make sure the warnings are given. */
7272 && (optimize || TREE_CODE (arg1) == INTEGER_CST))
7274 t1 = optimize_bit_field_compare (code, type, arg0, arg1);
7278 /* If this is a comparison of complex values and either or both sides
7279 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7280 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7281 This may prevent needless evaluations. */
7282 if ((code == EQ_EXPR || code == NE_EXPR)
7283 && TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
7284 && (TREE_CODE (arg0) == COMPLEX_EXPR
7285 || TREE_CODE (arg1) == COMPLEX_EXPR
7286 || TREE_CODE (arg0) == COMPLEX_CST
7287 || TREE_CODE (arg1) == COMPLEX_CST))
7289 tree subtype = TREE_TYPE (TREE_TYPE (arg0));
7290 tree real0, imag0, real1, imag1;
7292 arg0 = save_expr (arg0);
7293 arg1 = save_expr (arg1);
7294 real0 = fold (build1 (REALPART_EXPR, subtype, arg0));
7295 imag0 = fold (build1 (IMAGPART_EXPR, subtype, arg0));
7296 real1 = fold (build1 (REALPART_EXPR, subtype, arg1));
7297 imag1 = fold (build1 (IMAGPART_EXPR, subtype, arg1));
7299 return fold (build ((code == EQ_EXPR ? TRUTH_ANDIF_EXPR
7302 fold (build (code, type, real0, real1)),
7303 fold (build (code, type, imag0, imag1))));
7306 /* Optimize comparisons of strlen vs zero to a compare of the
7307 first character of the string vs zero. To wit,
7308 strlen(ptr) == 0 => *ptr == 0
7309 strlen(ptr) != 0 => *ptr != 0
7310 Other cases should reduce to one of these two (or a constant)
7311 due to the return value of strlen being unsigned. */
7312 if ((code == EQ_EXPR || code == NE_EXPR)
7313 && integer_zerop (arg1)
7314 && TREE_CODE (arg0) == CALL_EXPR
7315 && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
7317 tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
7320 if (TREE_CODE (fndecl) == FUNCTION_DECL
7321 && DECL_BUILT_IN (fndecl)
7322 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
7323 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
7324 && (arglist = TREE_OPERAND (arg0, 1))
7325 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
7326 && ! TREE_CHAIN (arglist))
7327 return fold (build (code, type,
7328 build1 (INDIRECT_REF, char_type_node,
7329 TREE_VALUE(arglist)),
7330 integer_zero_node));
7333 /* From here on, the only cases we handle are when the result is
7334 known to be a constant.
7336 To compute GT, swap the arguments and do LT.
7337 To compute GE, do LT and invert the result.
7338 To compute LE, swap the arguments, do LT and invert the result.
7339 To compute NE, do EQ and invert the result.
7341 Therefore, the code below must handle only EQ and LT. */
7343 if (code == LE_EXPR || code == GT_EXPR)
7345 tem = arg0, arg0 = arg1, arg1 = tem;
7346 code = swap_tree_comparison (code);
7349 /* Note that it is safe to invert for real values here because we
7350 will check below in the one case that it matters. */
7354 if (code == NE_EXPR || code == GE_EXPR)
7357 code = invert_tree_comparison (code);
7360 /* Compute a result for LT or EQ if args permit;
7361 otherwise return T. */
7362 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
7364 if (code == EQ_EXPR)
7365 t1 = build_int_2 (tree_int_cst_equal (arg0, arg1), 0);
7367 t1 = build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0))
7368 ? INT_CST_LT_UNSIGNED (arg0, arg1)
7369 : INT_CST_LT (arg0, arg1)),
7373 #if 0 /* This is no longer useful, but breaks some real code. */
7374 /* Assume a nonexplicit constant cannot equal an explicit one,
7375 since such code would be undefined anyway.
7376 Exception: on sysvr4, using #pragma weak,
7377 a label can come out as 0. */
7378 else if (TREE_CODE (arg1) == INTEGER_CST
7379 && !integer_zerop (arg1)
7380 && TREE_CONSTANT (arg0)
7381 && TREE_CODE (arg0) == ADDR_EXPR
7383 t1 = build_int_2 (0, 0);
7385 /* Two real constants can be compared explicitly. */
7386 else if (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) == REAL_CST)
7388 /* If either operand is a NaN, the result is false with two
7389 exceptions: First, an NE_EXPR is true on NaNs, but that case
7390 is already handled correctly since we will be inverting the
7391 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7392 or a GE_EXPR into a LT_EXPR, we must return true so that it
7393 will be inverted into false. */
7395 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0))
7396 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
7397 t1 = build_int_2 (invert && code == LT_EXPR, 0);
7399 else if (code == EQ_EXPR)
7400 t1 = build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0),
7401 TREE_REAL_CST (arg1)),
7404 t1 = build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0),
7405 TREE_REAL_CST (arg1)),
7409 if (t1 == NULL_TREE)
7413 TREE_INT_CST_LOW (t1) ^= 1;
7415 TREE_TYPE (t1) = type;
7416 if (TREE_CODE (type) == BOOLEAN_TYPE)
7417 return (*lang_hooks.truthvalue_conversion) (t1);
7421 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7422 so all simple results must be passed through pedantic_non_lvalue. */
7423 if (TREE_CODE (arg0) == INTEGER_CST)
7424 return pedantic_non_lvalue
7425 (TREE_OPERAND (t, (integer_zerop (arg0) ? 2 : 1)));
7426 else if (operand_equal_p (arg1, TREE_OPERAND (expr, 2), 0))
7427 return pedantic_omit_one_operand (type, arg1, arg0);
7429 /* If the second operand is zero, invert the comparison and swap
7430 the second and third operands. Likewise if the second operand
7431 is constant and the third is not or if the third operand is
7432 equivalent to the first operand of the comparison. */
7434 if (integer_zerop (arg1)
7435 || (TREE_CONSTANT (arg1) && ! TREE_CONSTANT (TREE_OPERAND (t, 2)))
7436 || (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7437 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7438 TREE_OPERAND (t, 2),
7439 TREE_OPERAND (arg0, 1))))
7441 /* See if this can be inverted. If it can't, possibly because
7442 it was a floating-point inequality comparison, don't do
7444 tem = invert_truthvalue (arg0);
7446 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7448 t = build (code, type, tem,
7449 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7451 /* arg1 should be the first argument of the new T. */
7452 arg1 = TREE_OPERAND (t, 1);
7457 /* If we have A op B ? A : C, we may be able to convert this to a
7458 simpler expression, depending on the operation and the values
7459 of B and C. Signed zeros prevent all of these transformations,
7460 for reasons given above each one. */
7462 if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
7463 && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
7464 arg1, TREE_OPERAND (arg0, 1))
7465 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
7467 tree arg2 = TREE_OPERAND (t, 2);
7468 enum tree_code comp_code = TREE_CODE (arg0);
7472 /* If we have A op 0 ? A : -A, consider applying the following
7475 A == 0? A : -A same as -A
7476 A != 0? A : -A same as A
7477 A >= 0? A : -A same as abs (A)
7478 A > 0? A : -A same as abs (A)
7479 A <= 0? A : -A same as -abs (A)
7480 A < 0? A : -A same as -abs (A)
7482 None of these transformations work for modes with signed
7483 zeros. If A is +/-0, the first two transformations will
7484 change the sign of the result (from +0 to -0, or vice
7485 versa). The last four will fix the sign of the result,
7486 even though the original expressions could be positive or
7487 negative, depending on the sign of A.
7489 Note that all these transformations are correct if A is
7490 NaN, since the two alternatives (A and -A) are also NaNs. */
7491 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
7492 ? real_zerop (TREE_OPERAND (arg0, 1))
7493 : integer_zerop (TREE_OPERAND (arg0, 1)))
7494 && TREE_CODE (arg2) == NEGATE_EXPR
7495 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
7503 (convert (TREE_TYPE (TREE_OPERAND (t, 1)),
7506 return pedantic_non_lvalue (convert (type, arg1));
7509 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7510 arg1 = convert ((*lang_hooks.types.signed_type)
7511 (TREE_TYPE (arg1)), arg1);
7512 return pedantic_non_lvalue
7513 (convert (type, fold (build1 (ABS_EXPR,
7514 TREE_TYPE (arg1), arg1))));
7517 if (TREE_UNSIGNED (TREE_TYPE (arg1)))
7518 arg1 = convert ((lang_hooks.types.signed_type)
7519 (TREE_TYPE (arg1)), arg1);
7520 return pedantic_non_lvalue
7521 (negate_expr (convert (type,
7522 fold (build1 (ABS_EXPR,
7529 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7530 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7531 both transformations are correct when A is NaN: A != 0
7532 is then true, and A == 0 is false. */
7534 if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
7536 if (comp_code == NE_EXPR)
7537 return pedantic_non_lvalue (convert (type, arg1));
7538 else if (comp_code == EQ_EXPR)
7539 return pedantic_non_lvalue (convert (type, integer_zero_node));
7542 /* Try some transformations of A op B ? A : B.
7544 A == B? A : B same as B
7545 A != B? A : B same as A
7546 A >= B? A : B same as max (A, B)
7547 A > B? A : B same as max (B, A)
7548 A <= B? A : B same as min (A, B)
7549 A < B? A : B same as min (B, A)
7551 As above, these transformations don't work in the presence
7552 of signed zeros. For example, if A and B are zeros of
7553 opposite sign, the first two transformations will change
7554 the sign of the result. In the last four, the original
7555 expressions give different results for (A=+0, B=-0) and
7556 (A=-0, B=+0), but the transformed expressions do not.
7558 The first two transformations are correct if either A or B
7559 is a NaN. In the first transformation, the condition will
7560 be false, and B will indeed be chosen. In the case of the
7561 second transformation, the condition A != B will be true,
7562 and A will be chosen.
7564 The conversions to max() and min() are not correct if B is
7565 a number and A is not. The conditions in the original
7566 expressions will be false, so all four give B. The min()
7567 and max() versions would give a NaN instead. */
7568 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
7569 arg2, TREE_OPERAND (arg0, 0)))
7571 tree comp_op0 = TREE_OPERAND (arg0, 0);
7572 tree comp_op1 = TREE_OPERAND (arg0, 1);
7573 tree comp_type = TREE_TYPE (comp_op0);
7575 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7576 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
7586 return pedantic_non_lvalue (convert (type, arg2));
7588 return pedantic_non_lvalue (convert (type, arg1));
7591 /* In C++ a ?: expression can be an lvalue, so put the
7592 operand which will be used if they are equal first
7593 so that we can convert this back to the
7594 corresponding COND_EXPR. */
7595 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7596 return pedantic_non_lvalue
7597 (convert (type, fold (build (MIN_EXPR, comp_type,
7598 (comp_code == LE_EXPR
7599 ? comp_op0 : comp_op1),
7600 (comp_code == LE_EXPR
7601 ? comp_op1 : comp_op0)))));
7605 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
7606 return pedantic_non_lvalue
7607 (convert (type, fold (build (MAX_EXPR, comp_type,
7608 (comp_code == GE_EXPR
7609 ? comp_op0 : comp_op1),
7610 (comp_code == GE_EXPR
7611 ? comp_op1 : comp_op0)))));
7618 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7619 we might still be able to simplify this. For example,
7620 if C1 is one less or one more than C2, this might have started
7621 out as a MIN or MAX and been transformed by this function.
7622 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7624 if (INTEGRAL_TYPE_P (type)
7625 && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
7626 && TREE_CODE (arg2) == INTEGER_CST)
7630 /* We can replace A with C1 in this case. */
7631 arg1 = convert (type, TREE_OPERAND (arg0, 1));
7632 t = build (code, type, TREE_OPERAND (t, 0), arg1,
7633 TREE_OPERAND (t, 2));
7637 /* If C1 is C2 + 1, this is min(A, C2). */
7638 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7639 && operand_equal_p (TREE_OPERAND (arg0, 1),
7640 const_binop (PLUS_EXPR, arg2,
7641 integer_one_node, 0), 1))
7642 return pedantic_non_lvalue
7643 (fold (build (MIN_EXPR, type, arg1, arg2)));
7647 /* If C1 is C2 - 1, this is min(A, C2). */
7648 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7649 && operand_equal_p (TREE_OPERAND (arg0, 1),
7650 const_binop (MINUS_EXPR, arg2,
7651 integer_one_node, 0), 1))
7652 return pedantic_non_lvalue
7653 (fold (build (MIN_EXPR, type, arg1, arg2)));
7657 /* If C1 is C2 - 1, this is max(A, C2). */
7658 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type), 1)
7659 && operand_equal_p (TREE_OPERAND (arg0, 1),
7660 const_binop (MINUS_EXPR, arg2,
7661 integer_one_node, 0), 1))
7662 return pedantic_non_lvalue
7663 (fold (build (MAX_EXPR, type, arg1, arg2)));
7667 /* If C1 is C2 + 1, this is max(A, C2). */
7668 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type), 1)
7669 && operand_equal_p (TREE_OPERAND (arg0, 1),
7670 const_binop (PLUS_EXPR, arg2,
7671 integer_one_node, 0), 1))
7672 return pedantic_non_lvalue
7673 (fold (build (MAX_EXPR, type, arg1, arg2)));
7682 /* If the second operand is simpler than the third, swap them
7683 since that produces better jump optimization results. */
7684 if ((TREE_CONSTANT (arg1) || DECL_P (arg1)
7685 || TREE_CODE (arg1) == SAVE_EXPR)
7686 && ! (TREE_CONSTANT (TREE_OPERAND (t, 2))
7687 || DECL_P (TREE_OPERAND (t, 2))
7688 || TREE_CODE (TREE_OPERAND (t, 2)) == SAVE_EXPR))
7690 /* See if this can be inverted. If it can't, possibly because
7691 it was a floating-point inequality comparison, don't do
7693 tem = invert_truthvalue (arg0);
7695 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7697 t = build (code, type, tem,
7698 TREE_OPERAND (t, 2), TREE_OPERAND (t, 1));
7700 /* arg1 should be the first argument of the new T. */
7701 arg1 = TREE_OPERAND (t, 1);
7706 /* Convert A ? 1 : 0 to simply A. */
7707 if (integer_onep (TREE_OPERAND (t, 1))
7708 && integer_zerop (TREE_OPERAND (t, 2))
7709 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7710 call to fold will try to move the conversion inside
7711 a COND, which will recurse. In that case, the COND_EXPR
7712 is probably the best choice, so leave it alone. */
7713 && type == TREE_TYPE (arg0))
7714 return pedantic_non_lvalue (arg0);
7716 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7717 over COND_EXPR in cases such as floating point comparisons. */
7718 if (integer_zerop (TREE_OPERAND (t, 1))
7719 && integer_onep (TREE_OPERAND (t, 2))
7720 && truth_value_p (TREE_CODE (arg0)))
7721 return pedantic_non_lvalue (convert (type,
7722 invert_truthvalue (arg0)));
7724 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7725 operation is simply A & 2. */
7727 if (integer_zerop (TREE_OPERAND (t, 2))
7728 && TREE_CODE (arg0) == NE_EXPR
7729 && integer_zerop (TREE_OPERAND (arg0, 1))
7730 && integer_pow2p (arg1)
7731 && TREE_CODE (TREE_OPERAND (arg0, 0)) == BIT_AND_EXPR
7732 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0, 0), 1),
7734 return pedantic_non_lvalue (convert (type, TREE_OPERAND (arg0, 0)));
7736 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7737 if (integer_zerop (TREE_OPERAND (t, 2))
7738 && truth_value_p (TREE_CODE (arg0))
7739 && truth_value_p (TREE_CODE (arg1)))
7740 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR, type,
7743 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
7744 if (integer_onep (TREE_OPERAND (t, 2))
7745 && truth_value_p (TREE_CODE (arg0))
7746 && truth_value_p (TREE_CODE (arg1)))
7748 /* Only perform transformation if ARG0 is easily inverted. */
7749 tem = invert_truthvalue (arg0);
7750 if (TREE_CODE (tem) != TRUTH_NOT_EXPR)
7751 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR, type,
7758 /* When pedantic, a compound expression can be neither an lvalue
7759 nor an integer constant expression. */
7760 if (TREE_SIDE_EFFECTS (arg0) || pedantic)
7762 /* Don't let (0, 0) be null pointer constant. */
7763 if (integer_zerop (arg1))
7764 return build1 (NOP_EXPR, type, arg1);
7765 return convert (type, arg1);
7769 return build_complex (type, arg0, arg1);
7773 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7775 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7776 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7777 TREE_OPERAND (arg0, 1));
7778 else if (TREE_CODE (arg0) == COMPLEX_CST)
7779 return TREE_REALPART (arg0);
7780 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7781 return fold (build (TREE_CODE (arg0), type,
7782 fold (build1 (REALPART_EXPR, type,
7783 TREE_OPERAND (arg0, 0))),
7784 fold (build1 (REALPART_EXPR,
7785 type, TREE_OPERAND (arg0, 1)))));
7789 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7790 return convert (type, integer_zero_node);
7791 else if (TREE_CODE (arg0) == COMPLEX_EXPR)
7792 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7793 TREE_OPERAND (arg0, 0));
7794 else if (TREE_CODE (arg0) == COMPLEX_CST)
7795 return TREE_IMAGPART (arg0);
7796 else if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7797 return fold (build (TREE_CODE (arg0), type,
7798 fold (build1 (IMAGPART_EXPR, type,
7799 TREE_OPERAND (arg0, 0))),
7800 fold (build1 (IMAGPART_EXPR, type,
7801 TREE_OPERAND (arg0, 1)))));
7804 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7806 case CLEANUP_POINT_EXPR:
7807 if (! has_cleanups (arg0))
7808 return TREE_OPERAND (t, 0);
7811 enum tree_code code0 = TREE_CODE (arg0);
7812 int kind0 = TREE_CODE_CLASS (code0);
7813 tree arg00 = TREE_OPERAND (arg0, 0);
7816 if (kind0 == '1' || code0 == TRUTH_NOT_EXPR)
7817 return fold (build1 (code0, type,
7818 fold (build1 (CLEANUP_POINT_EXPR,
7819 TREE_TYPE (arg00), arg00))));
7821 if (kind0 == '<' || kind0 == '2'
7822 || code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR
7823 || code0 == TRUTH_AND_EXPR || code0 == TRUTH_OR_EXPR
7824 || code0 == TRUTH_XOR_EXPR)
7826 arg01 = TREE_OPERAND (arg0, 1);
7828 if (TREE_CONSTANT (arg00)
7829 || ((code0 == TRUTH_ANDIF_EXPR || code0 == TRUTH_ORIF_EXPR)
7830 && ! has_cleanups (arg00)))
7831 return fold (build (code0, type, arg00,
7832 fold (build1 (CLEANUP_POINT_EXPR,
7833 TREE_TYPE (arg01), arg01))));
7835 if (TREE_CONSTANT (arg01))
7836 return fold (build (code0, type,
7837 fold (build1 (CLEANUP_POINT_EXPR,
7838 TREE_TYPE (arg00), arg00)),
7846 /* Check for a built-in function. */
7847 if (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR
7848 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr, 0), 0))
7850 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr, 0), 0)))
7852 tree tmp = fold_builtin (expr);
7860 } /* switch (code) */
7863 /* Determine if first argument is a multiple of second argument. Return 0 if
7864 it is not, or we cannot easily determined it to be.
7866 An example of the sort of thing we care about (at this point; this routine
7867 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7868 fold cases do now) is discovering that
7870 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7876 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7878 This code also handles discovering that
7880 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7882 is a multiple of 8 so we don't have to worry about dealing with a
7885 Note that we *look* inside a SAVE_EXPR only to determine how it was
7886 calculated; it is not safe for fold to do much of anything else with the
7887 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7888 at run time. For example, the latter example above *cannot* be implemented
7889 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7890 evaluation time of the original SAVE_EXPR is not necessarily the same at
7891 the time the new expression is evaluated. The only optimization of this
7892 sort that would be valid is changing
7894 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7898 SAVE_EXPR (I) * SAVE_EXPR (J)
7900 (where the same SAVE_EXPR (J) is used in the original and the
7901 transformed version). */
7904 multiple_of_p (tree type, tree top, tree bottom)
7906 if (operand_equal_p (top, bottom, 0))
7909 if (TREE_CODE (type) != INTEGER_TYPE)
7912 switch (TREE_CODE (top))
7915 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7916 || multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7920 return (multiple_of_p (type, TREE_OPERAND (top, 0), bottom)
7921 && multiple_of_p (type, TREE_OPERAND (top, 1), bottom));
7924 if (TREE_CODE (TREE_OPERAND (top, 1)) == INTEGER_CST)
7928 op1 = TREE_OPERAND (top, 1);
7929 /* const_binop may not detect overflow correctly,
7930 so check for it explicitly here. */
7931 if (TYPE_PRECISION (TREE_TYPE (size_one_node))
7932 > TREE_INT_CST_LOW (op1)
7933 && TREE_INT_CST_HIGH (op1) == 0
7934 && 0 != (t1 = convert (type,
7935 const_binop (LSHIFT_EXPR, size_one_node,
7937 && ! TREE_OVERFLOW (t1))
7938 return multiple_of_p (type, t1, bottom);
7943 /* Can't handle conversions from non-integral or wider integral type. */
7944 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top, 0))) != INTEGER_TYPE)
7945 || (TYPE_PRECISION (type)
7946 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top, 0)))))
7949 /* .. fall through ... */
7952 return multiple_of_p (type, TREE_OPERAND (top, 0), bottom);
7955 if (TREE_CODE (bottom) != INTEGER_CST
7956 || (TREE_UNSIGNED (type)
7957 && (tree_int_cst_sgn (top) < 0
7958 || tree_int_cst_sgn (bottom) < 0)))
7960 return integer_zerop (const_binop (TRUNC_MOD_EXPR,
7968 /* Return true if `t' is known to be non-negative. */
7971 tree_expr_nonnegative_p (tree t)
7973 switch (TREE_CODE (t))
7983 /* These are undefined at zero. This is true even if
7984 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
7985 computing here is a user-visible property. */
7989 return tree_int_cst_sgn (t) >= 0;
7992 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t));
7995 if (FLOAT_TYPE_P (TREE_TYPE (t)))
7996 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
7997 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
7999 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8000 both unsigned and at least 2 bits shorter than the result. */
8001 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8002 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8003 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8005 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8006 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8007 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8008 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8010 unsigned int prec = MAX (TYPE_PRECISION (inner1),
8011 TYPE_PRECISION (inner2)) + 1;
8012 return prec < TYPE_PRECISION (TREE_TYPE (t));
8018 if (FLOAT_TYPE_P (TREE_TYPE (t)))
8020 /* x * x for floating point x is always non-negative. */
8021 if (operand_equal_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1), 0))
8023 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8024 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8027 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8028 both unsigned and their total bits is shorter than the result. */
8029 if (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
8030 && TREE_CODE (TREE_OPERAND (t, 0)) == NOP_EXPR
8031 && TREE_CODE (TREE_OPERAND (t, 1)) == NOP_EXPR)
8033 tree inner1 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 0), 0));
8034 tree inner2 = TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t, 1), 0));
8035 if (TREE_CODE (inner1) == INTEGER_TYPE && TREE_UNSIGNED (inner1)
8036 && TREE_CODE (inner2) == INTEGER_TYPE && TREE_UNSIGNED (inner2))
8037 return TYPE_PRECISION (inner1) + TYPE_PRECISION (inner2)
8038 < TYPE_PRECISION (TREE_TYPE (t));
8042 case TRUNC_DIV_EXPR:
8044 case FLOOR_DIV_EXPR:
8045 case ROUND_DIV_EXPR:
8046 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8047 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8049 case TRUNC_MOD_EXPR:
8051 case FLOOR_MOD_EXPR:
8052 case ROUND_MOD_EXPR:
8053 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8056 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8057 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8061 tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
8062 tree outer_type = TREE_TYPE (t);
8064 if (TREE_CODE (outer_type) == REAL_TYPE)
8066 if (TREE_CODE (inner_type) == REAL_TYPE)
8067 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8068 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8070 if (TREE_UNSIGNED (inner_type))
8072 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8075 else if (TREE_CODE (outer_type) == INTEGER_TYPE)
8077 if (TREE_CODE (inner_type) == REAL_TYPE)
8078 return tree_expr_nonnegative_p (TREE_OPERAND (t,0));
8079 if (TREE_CODE (inner_type) == INTEGER_TYPE)
8080 return TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)
8081 && TREE_UNSIGNED (inner_type);
8087 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
8088 && tree_expr_nonnegative_p (TREE_OPERAND (t, 2));
8090 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8092 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8093 && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8095 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
8096 || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8098 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8100 return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
8102 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8103 case NON_LVALUE_EXPR:
8104 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8106 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
8108 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
8111 if (TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR)
8113 tree fndecl = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
8114 tree arglist = TREE_OPERAND (t, 1);
8115 if (TREE_CODE (fndecl) == FUNCTION_DECL
8116 && DECL_BUILT_IN (fndecl)
8117 && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD)
8118 switch (DECL_FUNCTION_CODE (fndecl))
8121 case BUILT_IN_CABSL:
8122 case BUILT_IN_CABSF:
8127 case BUILT_IN_FABSF:
8128 case BUILT_IN_FABSL:
8130 case BUILT_IN_SQRTF:
8131 case BUILT_IN_SQRTL:
8135 case BUILT_IN_ATANF:
8136 case BUILT_IN_ATANL:
8138 case BUILT_IN_CEILF:
8139 case BUILT_IN_CEILL:
8140 case BUILT_IN_FLOOR:
8141 case BUILT_IN_FLOORF:
8142 case BUILT_IN_FLOORL:
8143 case BUILT_IN_NEARBYINT:
8144 case BUILT_IN_NEARBYINTF:
8145 case BUILT_IN_NEARBYINTL:
8146 case BUILT_IN_ROUND:
8147 case BUILT_IN_ROUNDF:
8148 case BUILT_IN_ROUNDL:
8149 case BUILT_IN_TRUNC:
8150 case BUILT_IN_TRUNCF:
8151 case BUILT_IN_TRUNCL:
8152 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8157 return tree_expr_nonnegative_p (TREE_VALUE (arglist));
8164 /* ... fall through ... */
8167 if (truth_value_p (TREE_CODE (t)))
8168 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8172 /* We don't know sign of `t', so be conservative and return false. */
8176 /* Return true if `r' is known to be non-negative.
8177 Only handles constants at the moment. */
8180 rtl_expr_nonnegative_p (rtx r)
8182 switch (GET_CODE (r))
8185 return INTVAL (r) >= 0;
8188 if (GET_MODE (r) == VOIDmode)
8189 return CONST_DOUBLE_HIGH (r) >= 0;
8197 units = CONST_VECTOR_NUNITS (r);
8199 for (i = 0; i < units; ++i)
8201 elt = CONST_VECTOR_ELT (r, i);
8202 if (!rtl_expr_nonnegative_p (elt))
8211 /* These are always nonnegative. */
8219 #include "gt-fold-const.h"